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Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[thirdparty/kernel/linux.git] / fs / btrfs / inode.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/bio.h>
8 #include <linux/buffer_head.h>
9 #include <linux/file.h>
10 #include <linux/fs.h>
11 #include <linux/pagemap.h>
12 #include <linux/highmem.h>
13 #include <linux/time.h>
14 #include <linux/init.h>
15 #include <linux/string.h>
16 #include <linux/backing-dev.h>
17 #include <linux/writeback.h>
18 #include <linux/compat.h>
19 #include <linux/xattr.h>
20 #include <linux/posix_acl.h>
21 #include <linux/falloc.h>
22 #include <linux/slab.h>
23 #include <linux/ratelimit.h>
24 #include <linux/btrfs.h>
25 #include <linux/blkdev.h>
26 #include <linux/posix_acl_xattr.h>
27 #include <linux/uio.h>
28 #include <linux/magic.h>
29 #include <linux/iversion.h>
30 #include <linux/swap.h>
31 #include <asm/unaligned.h>
32 #include "ctree.h"
33 #include "disk-io.h"
34 #include "transaction.h"
35 #include "btrfs_inode.h"
36 #include "print-tree.h"
37 #include "ordered-data.h"
38 #include "xattr.h"
39 #include "tree-log.h"
40 #include "volumes.h"
41 #include "compression.h"
42 #include "locking.h"
43 #include "free-space-cache.h"
44 #include "inode-map.h"
45 #include "backref.h"
46 #include "props.h"
47 #include "qgroup.h"
48 #include "dedupe.h"
49
50 struct btrfs_iget_args {
51 struct btrfs_key *location;
52 struct btrfs_root *root;
53 };
54
55 struct btrfs_dio_data {
56 u64 reserve;
57 u64 unsubmitted_oe_range_start;
58 u64 unsubmitted_oe_range_end;
59 int overwrite;
60 };
61
62 static const struct inode_operations btrfs_dir_inode_operations;
63 static const struct inode_operations btrfs_symlink_inode_operations;
64 static const struct inode_operations btrfs_dir_ro_inode_operations;
65 static const struct inode_operations btrfs_special_inode_operations;
66 static const struct inode_operations btrfs_file_inode_operations;
67 static const struct address_space_operations btrfs_aops;
68 static const struct file_operations btrfs_dir_file_operations;
69 static const struct extent_io_ops btrfs_extent_io_ops;
70
71 static struct kmem_cache *btrfs_inode_cachep;
72 struct kmem_cache *btrfs_trans_handle_cachep;
73 struct kmem_cache *btrfs_path_cachep;
74 struct kmem_cache *btrfs_free_space_cachep;
75
76 #define S_SHIFT 12
77 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
78 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
79 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
80 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
81 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
82 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
83 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
84 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
85 };
86
87 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
88 static int btrfs_truncate(struct inode *inode, bool skip_writeback);
89 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
90 static noinline int cow_file_range(struct inode *inode,
91 struct page *locked_page,
92 u64 start, u64 end, u64 delalloc_end,
93 int *page_started, unsigned long *nr_written,
94 int unlock, struct btrfs_dedupe_hash *hash);
95 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
96 u64 orig_start, u64 block_start,
97 u64 block_len, u64 orig_block_len,
98 u64 ram_bytes, int compress_type,
99 int type);
100
101 static void __endio_write_update_ordered(struct inode *inode,
102 const u64 offset, const u64 bytes,
103 const bool uptodate);
104
105 /*
106 * Cleanup all submitted ordered extents in specified range to handle errors
107 * from the btrfs_run_delalloc_range() callback.
108 *
109 * NOTE: caller must ensure that when an error happens, it can not call
110 * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
111 * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
112 * to be released, which we want to happen only when finishing the ordered
113 * extent (btrfs_finish_ordered_io()).
114 */
115 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
116 struct page *locked_page,
117 u64 offset, u64 bytes)
118 {
119 unsigned long index = offset >> PAGE_SHIFT;
120 unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
121 u64 page_start = page_offset(locked_page);
122 u64 page_end = page_start + PAGE_SIZE - 1;
123
124 struct page *page;
125
126 while (index <= end_index) {
127 page = find_get_page(inode->i_mapping, index);
128 index++;
129 if (!page)
130 continue;
131 ClearPagePrivate2(page);
132 put_page(page);
133 }
134
135 /*
136 * In case this page belongs to the delalloc range being instantiated
137 * then skip it, since the first page of a range is going to be
138 * properly cleaned up by the caller of run_delalloc_range
139 */
140 if (page_start >= offset && page_end <= (offset + bytes - 1)) {
141 offset += PAGE_SIZE;
142 bytes -= PAGE_SIZE;
143 }
144
145 return __endio_write_update_ordered(inode, offset, bytes, false);
146 }
147
148 static int btrfs_dirty_inode(struct inode *inode);
149
150 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
151 void btrfs_test_inode_set_ops(struct inode *inode)
152 {
153 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
154 }
155 #endif
156
157 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
158 struct inode *inode, struct inode *dir,
159 const struct qstr *qstr)
160 {
161 int err;
162
163 err = btrfs_init_acl(trans, inode, dir);
164 if (!err)
165 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
166 return err;
167 }
168
169 /*
170 * this does all the hard work for inserting an inline extent into
171 * the btree. The caller should have done a btrfs_drop_extents so that
172 * no overlapping inline items exist in the btree
173 */
174 static int insert_inline_extent(struct btrfs_trans_handle *trans,
175 struct btrfs_path *path, int extent_inserted,
176 struct btrfs_root *root, struct inode *inode,
177 u64 start, size_t size, size_t compressed_size,
178 int compress_type,
179 struct page **compressed_pages)
180 {
181 struct extent_buffer *leaf;
182 struct page *page = NULL;
183 char *kaddr;
184 unsigned long ptr;
185 struct btrfs_file_extent_item *ei;
186 int ret;
187 size_t cur_size = size;
188 unsigned long offset;
189
190 if (compressed_size && compressed_pages)
191 cur_size = compressed_size;
192
193 inode_add_bytes(inode, size);
194
195 if (!extent_inserted) {
196 struct btrfs_key key;
197 size_t datasize;
198
199 key.objectid = btrfs_ino(BTRFS_I(inode));
200 key.offset = start;
201 key.type = BTRFS_EXTENT_DATA_KEY;
202
203 datasize = btrfs_file_extent_calc_inline_size(cur_size);
204 path->leave_spinning = 1;
205 ret = btrfs_insert_empty_item(trans, root, path, &key,
206 datasize);
207 if (ret)
208 goto fail;
209 }
210 leaf = path->nodes[0];
211 ei = btrfs_item_ptr(leaf, path->slots[0],
212 struct btrfs_file_extent_item);
213 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
214 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
215 btrfs_set_file_extent_encryption(leaf, ei, 0);
216 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
217 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
218 ptr = btrfs_file_extent_inline_start(ei);
219
220 if (compress_type != BTRFS_COMPRESS_NONE) {
221 struct page *cpage;
222 int i = 0;
223 while (compressed_size > 0) {
224 cpage = compressed_pages[i];
225 cur_size = min_t(unsigned long, compressed_size,
226 PAGE_SIZE);
227
228 kaddr = kmap_atomic(cpage);
229 write_extent_buffer(leaf, kaddr, ptr, cur_size);
230 kunmap_atomic(kaddr);
231
232 i++;
233 ptr += cur_size;
234 compressed_size -= cur_size;
235 }
236 btrfs_set_file_extent_compression(leaf, ei,
237 compress_type);
238 } else {
239 page = find_get_page(inode->i_mapping,
240 start >> PAGE_SHIFT);
241 btrfs_set_file_extent_compression(leaf, ei, 0);
242 kaddr = kmap_atomic(page);
243 offset = offset_in_page(start);
244 write_extent_buffer(leaf, kaddr + offset, ptr, size);
245 kunmap_atomic(kaddr);
246 put_page(page);
247 }
248 btrfs_mark_buffer_dirty(leaf);
249 btrfs_release_path(path);
250
251 /*
252 * we're an inline extent, so nobody can
253 * extend the file past i_size without locking
254 * a page we already have locked.
255 *
256 * We must do any isize and inode updates
257 * before we unlock the pages. Otherwise we
258 * could end up racing with unlink.
259 */
260 BTRFS_I(inode)->disk_i_size = inode->i_size;
261 ret = btrfs_update_inode(trans, root, inode);
262
263 fail:
264 return ret;
265 }
266
267
268 /*
269 * conditionally insert an inline extent into the file. This
270 * does the checks required to make sure the data is small enough
271 * to fit as an inline extent.
272 */
273 static noinline int cow_file_range_inline(struct inode *inode, u64 start,
274 u64 end, size_t compressed_size,
275 int compress_type,
276 struct page **compressed_pages)
277 {
278 struct btrfs_root *root = BTRFS_I(inode)->root;
279 struct btrfs_fs_info *fs_info = root->fs_info;
280 struct btrfs_trans_handle *trans;
281 u64 isize = i_size_read(inode);
282 u64 actual_end = min(end + 1, isize);
283 u64 inline_len = actual_end - start;
284 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
285 u64 data_len = inline_len;
286 int ret;
287 struct btrfs_path *path;
288 int extent_inserted = 0;
289 u32 extent_item_size;
290
291 if (compressed_size)
292 data_len = compressed_size;
293
294 if (start > 0 ||
295 actual_end > fs_info->sectorsize ||
296 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
297 (!compressed_size &&
298 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
299 end + 1 < isize ||
300 data_len > fs_info->max_inline) {
301 return 1;
302 }
303
304 path = btrfs_alloc_path();
305 if (!path)
306 return -ENOMEM;
307
308 trans = btrfs_join_transaction(root);
309 if (IS_ERR(trans)) {
310 btrfs_free_path(path);
311 return PTR_ERR(trans);
312 }
313 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
314
315 if (compressed_size && compressed_pages)
316 extent_item_size = btrfs_file_extent_calc_inline_size(
317 compressed_size);
318 else
319 extent_item_size = btrfs_file_extent_calc_inline_size(
320 inline_len);
321
322 ret = __btrfs_drop_extents(trans, root, inode, path,
323 start, aligned_end, NULL,
324 1, 1, extent_item_size, &extent_inserted);
325 if (ret) {
326 btrfs_abort_transaction(trans, ret);
327 goto out;
328 }
329
330 if (isize > actual_end)
331 inline_len = min_t(u64, isize, actual_end);
332 ret = insert_inline_extent(trans, path, extent_inserted,
333 root, inode, start,
334 inline_len, compressed_size,
335 compress_type, compressed_pages);
336 if (ret && ret != -ENOSPC) {
337 btrfs_abort_transaction(trans, ret);
338 goto out;
339 } else if (ret == -ENOSPC) {
340 ret = 1;
341 goto out;
342 }
343
344 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
345 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
346 out:
347 /*
348 * Don't forget to free the reserved space, as for inlined extent
349 * it won't count as data extent, free them directly here.
350 * And at reserve time, it's always aligned to page size, so
351 * just free one page here.
352 */
353 btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
354 btrfs_free_path(path);
355 btrfs_end_transaction(trans);
356 return ret;
357 }
358
359 struct async_extent {
360 u64 start;
361 u64 ram_size;
362 u64 compressed_size;
363 struct page **pages;
364 unsigned long nr_pages;
365 int compress_type;
366 struct list_head list;
367 };
368
369 struct async_cow {
370 struct inode *inode;
371 struct btrfs_fs_info *fs_info;
372 struct page *locked_page;
373 u64 start;
374 u64 end;
375 unsigned int write_flags;
376 struct list_head extents;
377 struct btrfs_work work;
378 };
379
380 static noinline int add_async_extent(struct async_cow *cow,
381 u64 start, u64 ram_size,
382 u64 compressed_size,
383 struct page **pages,
384 unsigned long nr_pages,
385 int compress_type)
386 {
387 struct async_extent *async_extent;
388
389 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
390 BUG_ON(!async_extent); /* -ENOMEM */
391 async_extent->start = start;
392 async_extent->ram_size = ram_size;
393 async_extent->compressed_size = compressed_size;
394 async_extent->pages = pages;
395 async_extent->nr_pages = nr_pages;
396 async_extent->compress_type = compress_type;
397 list_add_tail(&async_extent->list, &cow->extents);
398 return 0;
399 }
400
401 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
402 {
403 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
404
405 /* force compress */
406 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
407 return 1;
408 /* defrag ioctl */
409 if (BTRFS_I(inode)->defrag_compress)
410 return 1;
411 /* bad compression ratios */
412 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
413 return 0;
414 if (btrfs_test_opt(fs_info, COMPRESS) ||
415 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
416 BTRFS_I(inode)->prop_compress)
417 return btrfs_compress_heuristic(inode, start, end);
418 return 0;
419 }
420
421 static inline void inode_should_defrag(struct btrfs_inode *inode,
422 u64 start, u64 end, u64 num_bytes, u64 small_write)
423 {
424 /* If this is a small write inside eof, kick off a defrag */
425 if (num_bytes < small_write &&
426 (start > 0 || end + 1 < inode->disk_i_size))
427 btrfs_add_inode_defrag(NULL, inode);
428 }
429
430 /*
431 * we create compressed extents in two phases. The first
432 * phase compresses a range of pages that have already been
433 * locked (both pages and state bits are locked).
434 *
435 * This is done inside an ordered work queue, and the compression
436 * is spread across many cpus. The actual IO submission is step
437 * two, and the ordered work queue takes care of making sure that
438 * happens in the same order things were put onto the queue by
439 * writepages and friends.
440 *
441 * If this code finds it can't get good compression, it puts an
442 * entry onto the work queue to write the uncompressed bytes. This
443 * makes sure that both compressed inodes and uncompressed inodes
444 * are written in the same order that the flusher thread sent them
445 * down.
446 */
447 static noinline void compress_file_range(struct inode *inode,
448 struct page *locked_page,
449 u64 start, u64 end,
450 struct async_cow *async_cow,
451 int *num_added)
452 {
453 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
454 u64 blocksize = fs_info->sectorsize;
455 u64 actual_end;
456 u64 isize = i_size_read(inode);
457 int ret = 0;
458 struct page **pages = NULL;
459 unsigned long nr_pages;
460 unsigned long total_compressed = 0;
461 unsigned long total_in = 0;
462 int i;
463 int will_compress;
464 int compress_type = fs_info->compress_type;
465 int redirty = 0;
466
467 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
468 SZ_16K);
469
470 actual_end = min_t(u64, isize, end + 1);
471 again:
472 will_compress = 0;
473 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
474 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
475 nr_pages = min_t(unsigned long, nr_pages,
476 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
477
478 /*
479 * we don't want to send crud past the end of i_size through
480 * compression, that's just a waste of CPU time. So, if the
481 * end of the file is before the start of our current
482 * requested range of bytes, we bail out to the uncompressed
483 * cleanup code that can deal with all of this.
484 *
485 * It isn't really the fastest way to fix things, but this is a
486 * very uncommon corner.
487 */
488 if (actual_end <= start)
489 goto cleanup_and_bail_uncompressed;
490
491 total_compressed = actual_end - start;
492
493 /*
494 * skip compression for a small file range(<=blocksize) that
495 * isn't an inline extent, since it doesn't save disk space at all.
496 */
497 if (total_compressed <= blocksize &&
498 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
499 goto cleanup_and_bail_uncompressed;
500
501 total_compressed = min_t(unsigned long, total_compressed,
502 BTRFS_MAX_UNCOMPRESSED);
503 total_in = 0;
504 ret = 0;
505
506 /*
507 * we do compression for mount -o compress and when the
508 * inode has not been flagged as nocompress. This flag can
509 * change at any time if we discover bad compression ratios.
510 */
511 if (inode_need_compress(inode, start, end)) {
512 WARN_ON(pages);
513 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
514 if (!pages) {
515 /* just bail out to the uncompressed code */
516 nr_pages = 0;
517 goto cont;
518 }
519
520 if (BTRFS_I(inode)->defrag_compress)
521 compress_type = BTRFS_I(inode)->defrag_compress;
522 else if (BTRFS_I(inode)->prop_compress)
523 compress_type = BTRFS_I(inode)->prop_compress;
524
525 /*
526 * we need to call clear_page_dirty_for_io on each
527 * page in the range. Otherwise applications with the file
528 * mmap'd can wander in and change the page contents while
529 * we are compressing them.
530 *
531 * If the compression fails for any reason, we set the pages
532 * dirty again later on.
533 *
534 * Note that the remaining part is redirtied, the start pointer
535 * has moved, the end is the original one.
536 */
537 if (!redirty) {
538 extent_range_clear_dirty_for_io(inode, start, end);
539 redirty = 1;
540 }
541
542 /* Compression level is applied here and only here */
543 ret = btrfs_compress_pages(
544 compress_type | (fs_info->compress_level << 4),
545 inode->i_mapping, start,
546 pages,
547 &nr_pages,
548 &total_in,
549 &total_compressed);
550
551 if (!ret) {
552 unsigned long offset = offset_in_page(total_compressed);
553 struct page *page = pages[nr_pages - 1];
554 char *kaddr;
555
556 /* zero the tail end of the last page, we might be
557 * sending it down to disk
558 */
559 if (offset) {
560 kaddr = kmap_atomic(page);
561 memset(kaddr + offset, 0,
562 PAGE_SIZE - offset);
563 kunmap_atomic(kaddr);
564 }
565 will_compress = 1;
566 }
567 }
568 cont:
569 if (start == 0) {
570 /* lets try to make an inline extent */
571 if (ret || total_in < actual_end) {
572 /* we didn't compress the entire range, try
573 * to make an uncompressed inline extent.
574 */
575 ret = cow_file_range_inline(inode, start, end, 0,
576 BTRFS_COMPRESS_NONE, NULL);
577 } else {
578 /* try making a compressed inline extent */
579 ret = cow_file_range_inline(inode, start, end,
580 total_compressed,
581 compress_type, pages);
582 }
583 if (ret <= 0) {
584 unsigned long clear_flags = EXTENT_DELALLOC |
585 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
586 EXTENT_DO_ACCOUNTING;
587 unsigned long page_error_op;
588
589 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
590
591 /*
592 * inline extent creation worked or returned error,
593 * we don't need to create any more async work items.
594 * Unlock and free up our temp pages.
595 *
596 * We use DO_ACCOUNTING here because we need the
597 * delalloc_release_metadata to be done _after_ we drop
598 * our outstanding extent for clearing delalloc for this
599 * range.
600 */
601 extent_clear_unlock_delalloc(inode, start, end, end,
602 NULL, clear_flags,
603 PAGE_UNLOCK |
604 PAGE_CLEAR_DIRTY |
605 PAGE_SET_WRITEBACK |
606 page_error_op |
607 PAGE_END_WRITEBACK);
608 goto free_pages_out;
609 }
610 }
611
612 if (will_compress) {
613 /*
614 * we aren't doing an inline extent round the compressed size
615 * up to a block size boundary so the allocator does sane
616 * things
617 */
618 total_compressed = ALIGN(total_compressed, blocksize);
619
620 /*
621 * one last check to make sure the compression is really a
622 * win, compare the page count read with the blocks on disk,
623 * compression must free at least one sector size
624 */
625 total_in = ALIGN(total_in, PAGE_SIZE);
626 if (total_compressed + blocksize <= total_in) {
627 *num_added += 1;
628
629 /*
630 * The async work queues will take care of doing actual
631 * allocation on disk for these compressed pages, and
632 * will submit them to the elevator.
633 */
634 add_async_extent(async_cow, start, total_in,
635 total_compressed, pages, nr_pages,
636 compress_type);
637
638 if (start + total_in < end) {
639 start += total_in;
640 pages = NULL;
641 cond_resched();
642 goto again;
643 }
644 return;
645 }
646 }
647 if (pages) {
648 /*
649 * the compression code ran but failed to make things smaller,
650 * free any pages it allocated and our page pointer array
651 */
652 for (i = 0; i < nr_pages; i++) {
653 WARN_ON(pages[i]->mapping);
654 put_page(pages[i]);
655 }
656 kfree(pages);
657 pages = NULL;
658 total_compressed = 0;
659 nr_pages = 0;
660
661 /* flag the file so we don't compress in the future */
662 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
663 !(BTRFS_I(inode)->prop_compress)) {
664 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
665 }
666 }
667 cleanup_and_bail_uncompressed:
668 /*
669 * No compression, but we still need to write the pages in the file
670 * we've been given so far. redirty the locked page if it corresponds
671 * to our extent and set things up for the async work queue to run
672 * cow_file_range to do the normal delalloc dance.
673 */
674 if (page_offset(locked_page) >= start &&
675 page_offset(locked_page) <= end)
676 __set_page_dirty_nobuffers(locked_page);
677 /* unlocked later on in the async handlers */
678
679 if (redirty)
680 extent_range_redirty_for_io(inode, start, end);
681 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
682 BTRFS_COMPRESS_NONE);
683 *num_added += 1;
684
685 return;
686
687 free_pages_out:
688 for (i = 0; i < nr_pages; i++) {
689 WARN_ON(pages[i]->mapping);
690 put_page(pages[i]);
691 }
692 kfree(pages);
693 }
694
695 static void free_async_extent_pages(struct async_extent *async_extent)
696 {
697 int i;
698
699 if (!async_extent->pages)
700 return;
701
702 for (i = 0; i < async_extent->nr_pages; i++) {
703 WARN_ON(async_extent->pages[i]->mapping);
704 put_page(async_extent->pages[i]);
705 }
706 kfree(async_extent->pages);
707 async_extent->nr_pages = 0;
708 async_extent->pages = NULL;
709 }
710
711 /*
712 * phase two of compressed writeback. This is the ordered portion
713 * of the code, which only gets called in the order the work was
714 * queued. We walk all the async extents created by compress_file_range
715 * and send them down to the disk.
716 */
717 static noinline void submit_compressed_extents(struct inode *inode,
718 struct async_cow *async_cow)
719 {
720 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
721 struct async_extent *async_extent;
722 u64 alloc_hint = 0;
723 struct btrfs_key ins;
724 struct extent_map *em;
725 struct btrfs_root *root = BTRFS_I(inode)->root;
726 struct extent_io_tree *io_tree;
727 int ret = 0;
728
729 again:
730 while (!list_empty(&async_cow->extents)) {
731 async_extent = list_entry(async_cow->extents.next,
732 struct async_extent, list);
733 list_del(&async_extent->list);
734
735 io_tree = &BTRFS_I(inode)->io_tree;
736
737 retry:
738 /* did the compression code fall back to uncompressed IO? */
739 if (!async_extent->pages) {
740 int page_started = 0;
741 unsigned long nr_written = 0;
742
743 lock_extent(io_tree, async_extent->start,
744 async_extent->start +
745 async_extent->ram_size - 1);
746
747 /* allocate blocks */
748 ret = cow_file_range(inode, async_cow->locked_page,
749 async_extent->start,
750 async_extent->start +
751 async_extent->ram_size - 1,
752 async_extent->start +
753 async_extent->ram_size - 1,
754 &page_started, &nr_written, 0,
755 NULL);
756
757 /* JDM XXX */
758
759 /*
760 * if page_started, cow_file_range inserted an
761 * inline extent and took care of all the unlocking
762 * and IO for us. Otherwise, we need to submit
763 * all those pages down to the drive.
764 */
765 if (!page_started && !ret)
766 extent_write_locked_range(inode,
767 async_extent->start,
768 async_extent->start +
769 async_extent->ram_size - 1,
770 WB_SYNC_ALL);
771 else if (ret)
772 unlock_page(async_cow->locked_page);
773 kfree(async_extent);
774 cond_resched();
775 continue;
776 }
777
778 lock_extent(io_tree, async_extent->start,
779 async_extent->start + async_extent->ram_size - 1);
780
781 ret = btrfs_reserve_extent(root, async_extent->ram_size,
782 async_extent->compressed_size,
783 async_extent->compressed_size,
784 0, alloc_hint, &ins, 1, 1);
785 if (ret) {
786 free_async_extent_pages(async_extent);
787
788 if (ret == -ENOSPC) {
789 unlock_extent(io_tree, async_extent->start,
790 async_extent->start +
791 async_extent->ram_size - 1);
792
793 /*
794 * we need to redirty the pages if we decide to
795 * fallback to uncompressed IO, otherwise we
796 * will not submit these pages down to lower
797 * layers.
798 */
799 extent_range_redirty_for_io(inode,
800 async_extent->start,
801 async_extent->start +
802 async_extent->ram_size - 1);
803
804 goto retry;
805 }
806 goto out_free;
807 }
808 /*
809 * here we're doing allocation and writeback of the
810 * compressed pages
811 */
812 em = create_io_em(inode, async_extent->start,
813 async_extent->ram_size, /* len */
814 async_extent->start, /* orig_start */
815 ins.objectid, /* block_start */
816 ins.offset, /* block_len */
817 ins.offset, /* orig_block_len */
818 async_extent->ram_size, /* ram_bytes */
819 async_extent->compress_type,
820 BTRFS_ORDERED_COMPRESSED);
821 if (IS_ERR(em))
822 /* ret value is not necessary due to void function */
823 goto out_free_reserve;
824 free_extent_map(em);
825
826 ret = btrfs_add_ordered_extent_compress(inode,
827 async_extent->start,
828 ins.objectid,
829 async_extent->ram_size,
830 ins.offset,
831 BTRFS_ORDERED_COMPRESSED,
832 async_extent->compress_type);
833 if (ret) {
834 btrfs_drop_extent_cache(BTRFS_I(inode),
835 async_extent->start,
836 async_extent->start +
837 async_extent->ram_size - 1, 0);
838 goto out_free_reserve;
839 }
840 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
841
842 /*
843 * clear dirty, set writeback and unlock the pages.
844 */
845 extent_clear_unlock_delalloc(inode, async_extent->start,
846 async_extent->start +
847 async_extent->ram_size - 1,
848 async_extent->start +
849 async_extent->ram_size - 1,
850 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
851 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
852 PAGE_SET_WRITEBACK);
853 if (btrfs_submit_compressed_write(inode,
854 async_extent->start,
855 async_extent->ram_size,
856 ins.objectid,
857 ins.offset, async_extent->pages,
858 async_extent->nr_pages,
859 async_cow->write_flags)) {
860 struct page *p = async_extent->pages[0];
861 const u64 start = async_extent->start;
862 const u64 end = start + async_extent->ram_size - 1;
863
864 p->mapping = inode->i_mapping;
865 btrfs_writepage_endio_finish_ordered(p, start, end, 0);
866
867 p->mapping = NULL;
868 extent_clear_unlock_delalloc(inode, start, end, end,
869 NULL, 0,
870 PAGE_END_WRITEBACK |
871 PAGE_SET_ERROR);
872 free_async_extent_pages(async_extent);
873 }
874 alloc_hint = ins.objectid + ins.offset;
875 kfree(async_extent);
876 cond_resched();
877 }
878 return;
879 out_free_reserve:
880 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
881 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
882 out_free:
883 extent_clear_unlock_delalloc(inode, async_extent->start,
884 async_extent->start +
885 async_extent->ram_size - 1,
886 async_extent->start +
887 async_extent->ram_size - 1,
888 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
889 EXTENT_DELALLOC_NEW |
890 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
891 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
892 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
893 PAGE_SET_ERROR);
894 free_async_extent_pages(async_extent);
895 kfree(async_extent);
896 goto again;
897 }
898
899 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
900 u64 num_bytes)
901 {
902 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
903 struct extent_map *em;
904 u64 alloc_hint = 0;
905
906 read_lock(&em_tree->lock);
907 em = search_extent_mapping(em_tree, start, num_bytes);
908 if (em) {
909 /*
910 * if block start isn't an actual block number then find the
911 * first block in this inode and use that as a hint. If that
912 * block is also bogus then just don't worry about it.
913 */
914 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
915 free_extent_map(em);
916 em = search_extent_mapping(em_tree, 0, 0);
917 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
918 alloc_hint = em->block_start;
919 if (em)
920 free_extent_map(em);
921 } else {
922 alloc_hint = em->block_start;
923 free_extent_map(em);
924 }
925 }
926 read_unlock(&em_tree->lock);
927
928 return alloc_hint;
929 }
930
931 /*
932 * when extent_io.c finds a delayed allocation range in the file,
933 * the call backs end up in this code. The basic idea is to
934 * allocate extents on disk for the range, and create ordered data structs
935 * in ram to track those extents.
936 *
937 * locked_page is the page that writepage had locked already. We use
938 * it to make sure we don't do extra locks or unlocks.
939 *
940 * *page_started is set to one if we unlock locked_page and do everything
941 * required to start IO on it. It may be clean and already done with
942 * IO when we return.
943 */
944 static noinline int cow_file_range(struct inode *inode,
945 struct page *locked_page,
946 u64 start, u64 end, u64 delalloc_end,
947 int *page_started, unsigned long *nr_written,
948 int unlock, struct btrfs_dedupe_hash *hash)
949 {
950 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
951 struct btrfs_root *root = BTRFS_I(inode)->root;
952 u64 alloc_hint = 0;
953 u64 num_bytes;
954 unsigned long ram_size;
955 u64 cur_alloc_size = 0;
956 u64 blocksize = fs_info->sectorsize;
957 struct btrfs_key ins;
958 struct extent_map *em;
959 unsigned clear_bits;
960 unsigned long page_ops;
961 bool extent_reserved = false;
962 int ret = 0;
963
964 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
965 WARN_ON_ONCE(1);
966 ret = -EINVAL;
967 goto out_unlock;
968 }
969
970 num_bytes = ALIGN(end - start + 1, blocksize);
971 num_bytes = max(blocksize, num_bytes);
972 ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
973
974 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
975
976 if (start == 0) {
977 /* lets try to make an inline extent */
978 ret = cow_file_range_inline(inode, start, end, 0,
979 BTRFS_COMPRESS_NONE, NULL);
980 if (ret == 0) {
981 /*
982 * We use DO_ACCOUNTING here because we need the
983 * delalloc_release_metadata to be run _after_ we drop
984 * our outstanding extent for clearing delalloc for this
985 * range.
986 */
987 extent_clear_unlock_delalloc(inode, start, end,
988 delalloc_end, NULL,
989 EXTENT_LOCKED | EXTENT_DELALLOC |
990 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
991 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
992 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
993 PAGE_END_WRITEBACK);
994 *nr_written = *nr_written +
995 (end - start + PAGE_SIZE) / PAGE_SIZE;
996 *page_started = 1;
997 goto out;
998 } else if (ret < 0) {
999 goto out_unlock;
1000 }
1001 }
1002
1003 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
1004 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1005 start + num_bytes - 1, 0);
1006
1007 while (num_bytes > 0) {
1008 cur_alloc_size = num_bytes;
1009 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1010 fs_info->sectorsize, 0, alloc_hint,
1011 &ins, 1, 1);
1012 if (ret < 0)
1013 goto out_unlock;
1014 cur_alloc_size = ins.offset;
1015 extent_reserved = true;
1016
1017 ram_size = ins.offset;
1018 em = create_io_em(inode, start, ins.offset, /* len */
1019 start, /* orig_start */
1020 ins.objectid, /* block_start */
1021 ins.offset, /* block_len */
1022 ins.offset, /* orig_block_len */
1023 ram_size, /* ram_bytes */
1024 BTRFS_COMPRESS_NONE, /* compress_type */
1025 BTRFS_ORDERED_REGULAR /* type */);
1026 if (IS_ERR(em)) {
1027 ret = PTR_ERR(em);
1028 goto out_reserve;
1029 }
1030 free_extent_map(em);
1031
1032 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1033 ram_size, cur_alloc_size, 0);
1034 if (ret)
1035 goto out_drop_extent_cache;
1036
1037 if (root->root_key.objectid ==
1038 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1039 ret = btrfs_reloc_clone_csums(inode, start,
1040 cur_alloc_size);
1041 /*
1042 * Only drop cache here, and process as normal.
1043 *
1044 * We must not allow extent_clear_unlock_delalloc()
1045 * at out_unlock label to free meta of this ordered
1046 * extent, as its meta should be freed by
1047 * btrfs_finish_ordered_io().
1048 *
1049 * So we must continue until @start is increased to
1050 * skip current ordered extent.
1051 */
1052 if (ret)
1053 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1054 start + ram_size - 1, 0);
1055 }
1056
1057 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1058
1059 /* we're not doing compressed IO, don't unlock the first
1060 * page (which the caller expects to stay locked), don't
1061 * clear any dirty bits and don't set any writeback bits
1062 *
1063 * Do set the Private2 bit so we know this page was properly
1064 * setup for writepage
1065 */
1066 page_ops = unlock ? PAGE_UNLOCK : 0;
1067 page_ops |= PAGE_SET_PRIVATE2;
1068
1069 extent_clear_unlock_delalloc(inode, start,
1070 start + ram_size - 1,
1071 delalloc_end, locked_page,
1072 EXTENT_LOCKED | EXTENT_DELALLOC,
1073 page_ops);
1074 if (num_bytes < cur_alloc_size)
1075 num_bytes = 0;
1076 else
1077 num_bytes -= cur_alloc_size;
1078 alloc_hint = ins.objectid + ins.offset;
1079 start += cur_alloc_size;
1080 extent_reserved = false;
1081
1082 /*
1083 * btrfs_reloc_clone_csums() error, since start is increased
1084 * extent_clear_unlock_delalloc() at out_unlock label won't
1085 * free metadata of current ordered extent, we're OK to exit.
1086 */
1087 if (ret)
1088 goto out_unlock;
1089 }
1090 out:
1091 return ret;
1092
1093 out_drop_extent_cache:
1094 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1095 out_reserve:
1096 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1097 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1098 out_unlock:
1099 clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1100 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1101 page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1102 PAGE_END_WRITEBACK;
1103 /*
1104 * If we reserved an extent for our delalloc range (or a subrange) and
1105 * failed to create the respective ordered extent, then it means that
1106 * when we reserved the extent we decremented the extent's size from
1107 * the data space_info's bytes_may_use counter and incremented the
1108 * space_info's bytes_reserved counter by the same amount. We must make
1109 * sure extent_clear_unlock_delalloc() does not try to decrement again
1110 * the data space_info's bytes_may_use counter, therefore we do not pass
1111 * it the flag EXTENT_CLEAR_DATA_RESV.
1112 */
1113 if (extent_reserved) {
1114 extent_clear_unlock_delalloc(inode, start,
1115 start + cur_alloc_size,
1116 start + cur_alloc_size,
1117 locked_page,
1118 clear_bits,
1119 page_ops);
1120 start += cur_alloc_size;
1121 if (start >= end)
1122 goto out;
1123 }
1124 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1125 locked_page,
1126 clear_bits | EXTENT_CLEAR_DATA_RESV,
1127 page_ops);
1128 goto out;
1129 }
1130
1131 /*
1132 * work queue call back to started compression on a file and pages
1133 */
1134 static noinline void async_cow_start(struct btrfs_work *work)
1135 {
1136 struct async_cow *async_cow;
1137 int num_added = 0;
1138 async_cow = container_of(work, struct async_cow, work);
1139
1140 compress_file_range(async_cow->inode, async_cow->locked_page,
1141 async_cow->start, async_cow->end, async_cow,
1142 &num_added);
1143 if (num_added == 0) {
1144 btrfs_add_delayed_iput(async_cow->inode);
1145 async_cow->inode = NULL;
1146 }
1147 }
1148
1149 /*
1150 * work queue call back to submit previously compressed pages
1151 */
1152 static noinline void async_cow_submit(struct btrfs_work *work)
1153 {
1154 struct btrfs_fs_info *fs_info;
1155 struct async_cow *async_cow;
1156 unsigned long nr_pages;
1157
1158 async_cow = container_of(work, struct async_cow, work);
1159
1160 fs_info = async_cow->fs_info;
1161 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1162 PAGE_SHIFT;
1163
1164 /* atomic_sub_return implies a barrier */
1165 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1166 5 * SZ_1M)
1167 cond_wake_up_nomb(&fs_info->async_submit_wait);
1168
1169 if (async_cow->inode)
1170 submit_compressed_extents(async_cow->inode, async_cow);
1171 }
1172
1173 static noinline void async_cow_free(struct btrfs_work *work)
1174 {
1175 struct async_cow *async_cow;
1176 async_cow = container_of(work, struct async_cow, work);
1177 if (async_cow->inode)
1178 btrfs_add_delayed_iput(async_cow->inode);
1179 kfree(async_cow);
1180 }
1181
1182 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1183 u64 start, u64 end, int *page_started,
1184 unsigned long *nr_written,
1185 unsigned int write_flags)
1186 {
1187 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1188 struct async_cow *async_cow;
1189 unsigned long nr_pages;
1190 u64 cur_end;
1191
1192 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1193 1, 0, NULL);
1194 while (start < end) {
1195 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1196 BUG_ON(!async_cow); /* -ENOMEM */
1197 async_cow->inode = igrab(inode);
1198 async_cow->fs_info = fs_info;
1199 async_cow->locked_page = locked_page;
1200 async_cow->start = start;
1201 async_cow->write_flags = write_flags;
1202
1203 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1204 !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1205 cur_end = end;
1206 else
1207 cur_end = min(end, start + SZ_512K - 1);
1208
1209 async_cow->end = cur_end;
1210 INIT_LIST_HEAD(&async_cow->extents);
1211
1212 btrfs_init_work(&async_cow->work,
1213 btrfs_delalloc_helper,
1214 async_cow_start, async_cow_submit,
1215 async_cow_free);
1216
1217 nr_pages = (cur_end - start + PAGE_SIZE) >>
1218 PAGE_SHIFT;
1219 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1220
1221 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1222
1223 *nr_written += nr_pages;
1224 start = cur_end + 1;
1225 }
1226 *page_started = 1;
1227 return 0;
1228 }
1229
1230 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1231 u64 bytenr, u64 num_bytes)
1232 {
1233 int ret;
1234 struct btrfs_ordered_sum *sums;
1235 LIST_HEAD(list);
1236
1237 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1238 bytenr + num_bytes - 1, &list, 0);
1239 if (ret == 0 && list_empty(&list))
1240 return 0;
1241
1242 while (!list_empty(&list)) {
1243 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1244 list_del(&sums->list);
1245 kfree(sums);
1246 }
1247 if (ret < 0)
1248 return ret;
1249 return 1;
1250 }
1251
1252 /*
1253 * when nowcow writeback call back. This checks for snapshots or COW copies
1254 * of the extents that exist in the file, and COWs the file as required.
1255 *
1256 * If no cow copies or snapshots exist, we write directly to the existing
1257 * blocks on disk
1258 */
1259 static noinline int run_delalloc_nocow(struct inode *inode,
1260 struct page *locked_page,
1261 u64 start, u64 end, int *page_started, int force,
1262 unsigned long *nr_written)
1263 {
1264 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1265 struct btrfs_root *root = BTRFS_I(inode)->root;
1266 struct extent_buffer *leaf;
1267 struct btrfs_path *path;
1268 struct btrfs_file_extent_item *fi;
1269 struct btrfs_key found_key;
1270 struct extent_map *em;
1271 u64 cow_start;
1272 u64 cur_offset;
1273 u64 extent_end;
1274 u64 extent_offset;
1275 u64 disk_bytenr;
1276 u64 num_bytes;
1277 u64 disk_num_bytes;
1278 u64 ram_bytes;
1279 int extent_type;
1280 int ret;
1281 int type;
1282 int nocow;
1283 int check_prev = 1;
1284 bool nolock;
1285 u64 ino = btrfs_ino(BTRFS_I(inode));
1286
1287 path = btrfs_alloc_path();
1288 if (!path) {
1289 extent_clear_unlock_delalloc(inode, start, end, end,
1290 locked_page,
1291 EXTENT_LOCKED | EXTENT_DELALLOC |
1292 EXTENT_DO_ACCOUNTING |
1293 EXTENT_DEFRAG, PAGE_UNLOCK |
1294 PAGE_CLEAR_DIRTY |
1295 PAGE_SET_WRITEBACK |
1296 PAGE_END_WRITEBACK);
1297 return -ENOMEM;
1298 }
1299
1300 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1301
1302 cow_start = (u64)-1;
1303 cur_offset = start;
1304 while (1) {
1305 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1306 cur_offset, 0);
1307 if (ret < 0)
1308 goto error;
1309 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1310 leaf = path->nodes[0];
1311 btrfs_item_key_to_cpu(leaf, &found_key,
1312 path->slots[0] - 1);
1313 if (found_key.objectid == ino &&
1314 found_key.type == BTRFS_EXTENT_DATA_KEY)
1315 path->slots[0]--;
1316 }
1317 check_prev = 0;
1318 next_slot:
1319 leaf = path->nodes[0];
1320 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1321 ret = btrfs_next_leaf(root, path);
1322 if (ret < 0) {
1323 if (cow_start != (u64)-1)
1324 cur_offset = cow_start;
1325 goto error;
1326 }
1327 if (ret > 0)
1328 break;
1329 leaf = path->nodes[0];
1330 }
1331
1332 nocow = 0;
1333 disk_bytenr = 0;
1334 num_bytes = 0;
1335 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1336
1337 if (found_key.objectid > ino)
1338 break;
1339 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1340 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1341 path->slots[0]++;
1342 goto next_slot;
1343 }
1344 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1345 found_key.offset > end)
1346 break;
1347
1348 if (found_key.offset > cur_offset) {
1349 extent_end = found_key.offset;
1350 extent_type = 0;
1351 goto out_check;
1352 }
1353
1354 fi = btrfs_item_ptr(leaf, path->slots[0],
1355 struct btrfs_file_extent_item);
1356 extent_type = btrfs_file_extent_type(leaf, fi);
1357
1358 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1359 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1360 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1361 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1362 extent_offset = btrfs_file_extent_offset(leaf, fi);
1363 extent_end = found_key.offset +
1364 btrfs_file_extent_num_bytes(leaf, fi);
1365 disk_num_bytes =
1366 btrfs_file_extent_disk_num_bytes(leaf, fi);
1367 if (extent_end <= start) {
1368 path->slots[0]++;
1369 goto next_slot;
1370 }
1371 if (disk_bytenr == 0)
1372 goto out_check;
1373 if (btrfs_file_extent_compression(leaf, fi) ||
1374 btrfs_file_extent_encryption(leaf, fi) ||
1375 btrfs_file_extent_other_encoding(leaf, fi))
1376 goto out_check;
1377 /*
1378 * Do the same check as in btrfs_cross_ref_exist but
1379 * without the unnecessary search.
1380 */
1381 if (!nolock &&
1382 btrfs_file_extent_generation(leaf, fi) <=
1383 btrfs_root_last_snapshot(&root->root_item))
1384 goto out_check;
1385 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1386 goto out_check;
1387 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1388 goto out_check;
1389 ret = btrfs_cross_ref_exist(root, ino,
1390 found_key.offset -
1391 extent_offset, disk_bytenr);
1392 if (ret) {
1393 /*
1394 * ret could be -EIO if the above fails to read
1395 * metadata.
1396 */
1397 if (ret < 0) {
1398 if (cow_start != (u64)-1)
1399 cur_offset = cow_start;
1400 goto error;
1401 }
1402
1403 WARN_ON_ONCE(nolock);
1404 goto out_check;
1405 }
1406 disk_bytenr += extent_offset;
1407 disk_bytenr += cur_offset - found_key.offset;
1408 num_bytes = min(end + 1, extent_end) - cur_offset;
1409 /*
1410 * if there are pending snapshots for this root,
1411 * we fall into common COW way.
1412 */
1413 if (!nolock && atomic_read(&root->snapshot_force_cow))
1414 goto out_check;
1415 /*
1416 * force cow if csum exists in the range.
1417 * this ensure that csum for a given extent are
1418 * either valid or do not exist.
1419 */
1420 ret = csum_exist_in_range(fs_info, disk_bytenr,
1421 num_bytes);
1422 if (ret) {
1423 /*
1424 * ret could be -EIO if the above fails to read
1425 * metadata.
1426 */
1427 if (ret < 0) {
1428 if (cow_start != (u64)-1)
1429 cur_offset = cow_start;
1430 goto error;
1431 }
1432 WARN_ON_ONCE(nolock);
1433 goto out_check;
1434 }
1435 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
1436 goto out_check;
1437 nocow = 1;
1438 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1439 extent_end = found_key.offset +
1440 btrfs_file_extent_ram_bytes(leaf, fi);
1441 extent_end = ALIGN(extent_end,
1442 fs_info->sectorsize);
1443 } else {
1444 BUG_ON(1);
1445 }
1446 out_check:
1447 if (extent_end <= start) {
1448 path->slots[0]++;
1449 if (nocow)
1450 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1451 goto next_slot;
1452 }
1453 if (!nocow) {
1454 if (cow_start == (u64)-1)
1455 cow_start = cur_offset;
1456 cur_offset = extent_end;
1457 if (cur_offset > end)
1458 break;
1459 path->slots[0]++;
1460 goto next_slot;
1461 }
1462
1463 btrfs_release_path(path);
1464 if (cow_start != (u64)-1) {
1465 ret = cow_file_range(inode, locked_page,
1466 cow_start, found_key.offset - 1,
1467 end, page_started, nr_written, 1,
1468 NULL);
1469 if (ret) {
1470 if (nocow)
1471 btrfs_dec_nocow_writers(fs_info,
1472 disk_bytenr);
1473 goto error;
1474 }
1475 cow_start = (u64)-1;
1476 }
1477
1478 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1479 u64 orig_start = found_key.offset - extent_offset;
1480
1481 em = create_io_em(inode, cur_offset, num_bytes,
1482 orig_start,
1483 disk_bytenr, /* block_start */
1484 num_bytes, /* block_len */
1485 disk_num_bytes, /* orig_block_len */
1486 ram_bytes, BTRFS_COMPRESS_NONE,
1487 BTRFS_ORDERED_PREALLOC);
1488 if (IS_ERR(em)) {
1489 if (nocow)
1490 btrfs_dec_nocow_writers(fs_info,
1491 disk_bytenr);
1492 ret = PTR_ERR(em);
1493 goto error;
1494 }
1495 free_extent_map(em);
1496 }
1497
1498 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1499 type = BTRFS_ORDERED_PREALLOC;
1500 } else {
1501 type = BTRFS_ORDERED_NOCOW;
1502 }
1503
1504 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1505 num_bytes, num_bytes, type);
1506 if (nocow)
1507 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1508 BUG_ON(ret); /* -ENOMEM */
1509
1510 if (root->root_key.objectid ==
1511 BTRFS_DATA_RELOC_TREE_OBJECTID)
1512 /*
1513 * Error handled later, as we must prevent
1514 * extent_clear_unlock_delalloc() in error handler
1515 * from freeing metadata of created ordered extent.
1516 */
1517 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1518 num_bytes);
1519
1520 extent_clear_unlock_delalloc(inode, cur_offset,
1521 cur_offset + num_bytes - 1, end,
1522 locked_page, EXTENT_LOCKED |
1523 EXTENT_DELALLOC |
1524 EXTENT_CLEAR_DATA_RESV,
1525 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1526
1527 cur_offset = extent_end;
1528
1529 /*
1530 * btrfs_reloc_clone_csums() error, now we're OK to call error
1531 * handler, as metadata for created ordered extent will only
1532 * be freed by btrfs_finish_ordered_io().
1533 */
1534 if (ret)
1535 goto error;
1536 if (cur_offset > end)
1537 break;
1538 }
1539 btrfs_release_path(path);
1540
1541 if (cur_offset <= end && cow_start == (u64)-1)
1542 cow_start = cur_offset;
1543
1544 if (cow_start != (u64)-1) {
1545 cur_offset = end;
1546 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1547 page_started, nr_written, 1, NULL);
1548 if (ret)
1549 goto error;
1550 }
1551
1552 error:
1553 if (ret && cur_offset < end)
1554 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1555 locked_page, EXTENT_LOCKED |
1556 EXTENT_DELALLOC | EXTENT_DEFRAG |
1557 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1558 PAGE_CLEAR_DIRTY |
1559 PAGE_SET_WRITEBACK |
1560 PAGE_END_WRITEBACK);
1561 btrfs_free_path(path);
1562 return ret;
1563 }
1564
1565 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1566 {
1567
1568 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1569 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1570 return 0;
1571
1572 /*
1573 * @defrag_bytes is a hint value, no spinlock held here,
1574 * if is not zero, it means the file is defragging.
1575 * Force cow if given extent needs to be defragged.
1576 */
1577 if (BTRFS_I(inode)->defrag_bytes &&
1578 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1579 EXTENT_DEFRAG, 0, NULL))
1580 return 1;
1581
1582 return 0;
1583 }
1584
1585 /*
1586 * Function to process delayed allocation (create CoW) for ranges which are
1587 * being touched for the first time.
1588 */
1589 int btrfs_run_delalloc_range(void *private_data, struct page *locked_page,
1590 u64 start, u64 end, int *page_started, unsigned long *nr_written,
1591 struct writeback_control *wbc)
1592 {
1593 struct inode *inode = private_data;
1594 int ret;
1595 int force_cow = need_force_cow(inode, start, end);
1596 unsigned int write_flags = wbc_to_write_flags(wbc);
1597
1598 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1599 ret = run_delalloc_nocow(inode, locked_page, start, end,
1600 page_started, 1, nr_written);
1601 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1602 ret = run_delalloc_nocow(inode, locked_page, start, end,
1603 page_started, 0, nr_written);
1604 } else if (!inode_need_compress(inode, start, end)) {
1605 ret = cow_file_range(inode, locked_page, start, end, end,
1606 page_started, nr_written, 1, NULL);
1607 } else {
1608 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1609 &BTRFS_I(inode)->runtime_flags);
1610 ret = cow_file_range_async(inode, locked_page, start, end,
1611 page_started, nr_written,
1612 write_flags);
1613 }
1614 if (ret)
1615 btrfs_cleanup_ordered_extents(inode, locked_page, start,
1616 end - start + 1);
1617 return ret;
1618 }
1619
1620 void btrfs_split_delalloc_extent(struct inode *inode,
1621 struct extent_state *orig, u64 split)
1622 {
1623 u64 size;
1624
1625 /* not delalloc, ignore it */
1626 if (!(orig->state & EXTENT_DELALLOC))
1627 return;
1628
1629 size = orig->end - orig->start + 1;
1630 if (size > BTRFS_MAX_EXTENT_SIZE) {
1631 u32 num_extents;
1632 u64 new_size;
1633
1634 /*
1635 * See the explanation in btrfs_merge_delalloc_extent, the same
1636 * applies here, just in reverse.
1637 */
1638 new_size = orig->end - split + 1;
1639 num_extents = count_max_extents(new_size);
1640 new_size = split - orig->start;
1641 num_extents += count_max_extents(new_size);
1642 if (count_max_extents(size) >= num_extents)
1643 return;
1644 }
1645
1646 spin_lock(&BTRFS_I(inode)->lock);
1647 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1648 spin_unlock(&BTRFS_I(inode)->lock);
1649 }
1650
1651 /*
1652 * Handle merged delayed allocation extents so we can keep track of new extents
1653 * that are just merged onto old extents, such as when we are doing sequential
1654 * writes, so we can properly account for the metadata space we'll need.
1655 */
1656 void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
1657 struct extent_state *other)
1658 {
1659 u64 new_size, old_size;
1660 u32 num_extents;
1661
1662 /* not delalloc, ignore it */
1663 if (!(other->state & EXTENT_DELALLOC))
1664 return;
1665
1666 if (new->start > other->start)
1667 new_size = new->end - other->start + 1;
1668 else
1669 new_size = other->end - new->start + 1;
1670
1671 /* we're not bigger than the max, unreserve the space and go */
1672 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1673 spin_lock(&BTRFS_I(inode)->lock);
1674 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1675 spin_unlock(&BTRFS_I(inode)->lock);
1676 return;
1677 }
1678
1679 /*
1680 * We have to add up either side to figure out how many extents were
1681 * accounted for before we merged into one big extent. If the number of
1682 * extents we accounted for is <= the amount we need for the new range
1683 * then we can return, otherwise drop. Think of it like this
1684 *
1685 * [ 4k][MAX_SIZE]
1686 *
1687 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1688 * need 2 outstanding extents, on one side we have 1 and the other side
1689 * we have 1 so they are == and we can return. But in this case
1690 *
1691 * [MAX_SIZE+4k][MAX_SIZE+4k]
1692 *
1693 * Each range on their own accounts for 2 extents, but merged together
1694 * they are only 3 extents worth of accounting, so we need to drop in
1695 * this case.
1696 */
1697 old_size = other->end - other->start + 1;
1698 num_extents = count_max_extents(old_size);
1699 old_size = new->end - new->start + 1;
1700 num_extents += count_max_extents(old_size);
1701 if (count_max_extents(new_size) >= num_extents)
1702 return;
1703
1704 spin_lock(&BTRFS_I(inode)->lock);
1705 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1706 spin_unlock(&BTRFS_I(inode)->lock);
1707 }
1708
1709 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1710 struct inode *inode)
1711 {
1712 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1713
1714 spin_lock(&root->delalloc_lock);
1715 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1716 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1717 &root->delalloc_inodes);
1718 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1719 &BTRFS_I(inode)->runtime_flags);
1720 root->nr_delalloc_inodes++;
1721 if (root->nr_delalloc_inodes == 1) {
1722 spin_lock(&fs_info->delalloc_root_lock);
1723 BUG_ON(!list_empty(&root->delalloc_root));
1724 list_add_tail(&root->delalloc_root,
1725 &fs_info->delalloc_roots);
1726 spin_unlock(&fs_info->delalloc_root_lock);
1727 }
1728 }
1729 spin_unlock(&root->delalloc_lock);
1730 }
1731
1732
1733 void __btrfs_del_delalloc_inode(struct btrfs_root *root,
1734 struct btrfs_inode *inode)
1735 {
1736 struct btrfs_fs_info *fs_info = root->fs_info;
1737
1738 if (!list_empty(&inode->delalloc_inodes)) {
1739 list_del_init(&inode->delalloc_inodes);
1740 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1741 &inode->runtime_flags);
1742 root->nr_delalloc_inodes--;
1743 if (!root->nr_delalloc_inodes) {
1744 ASSERT(list_empty(&root->delalloc_inodes));
1745 spin_lock(&fs_info->delalloc_root_lock);
1746 BUG_ON(list_empty(&root->delalloc_root));
1747 list_del_init(&root->delalloc_root);
1748 spin_unlock(&fs_info->delalloc_root_lock);
1749 }
1750 }
1751 }
1752
1753 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1754 struct btrfs_inode *inode)
1755 {
1756 spin_lock(&root->delalloc_lock);
1757 __btrfs_del_delalloc_inode(root, inode);
1758 spin_unlock(&root->delalloc_lock);
1759 }
1760
1761 /*
1762 * Properly track delayed allocation bytes in the inode and to maintain the
1763 * list of inodes that have pending delalloc work to be done.
1764 */
1765 void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
1766 unsigned *bits)
1767 {
1768 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1769
1770 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1771 WARN_ON(1);
1772 /*
1773 * set_bit and clear bit hooks normally require _irqsave/restore
1774 * but in this case, we are only testing for the DELALLOC
1775 * bit, which is only set or cleared with irqs on
1776 */
1777 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1778 struct btrfs_root *root = BTRFS_I(inode)->root;
1779 u64 len = state->end + 1 - state->start;
1780 u32 num_extents = count_max_extents(len);
1781 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1782
1783 spin_lock(&BTRFS_I(inode)->lock);
1784 btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
1785 spin_unlock(&BTRFS_I(inode)->lock);
1786
1787 /* For sanity tests */
1788 if (btrfs_is_testing(fs_info))
1789 return;
1790
1791 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1792 fs_info->delalloc_batch);
1793 spin_lock(&BTRFS_I(inode)->lock);
1794 BTRFS_I(inode)->delalloc_bytes += len;
1795 if (*bits & EXTENT_DEFRAG)
1796 BTRFS_I(inode)->defrag_bytes += len;
1797 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1798 &BTRFS_I(inode)->runtime_flags))
1799 btrfs_add_delalloc_inodes(root, inode);
1800 spin_unlock(&BTRFS_I(inode)->lock);
1801 }
1802
1803 if (!(state->state & EXTENT_DELALLOC_NEW) &&
1804 (*bits & EXTENT_DELALLOC_NEW)) {
1805 spin_lock(&BTRFS_I(inode)->lock);
1806 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1807 state->start;
1808 spin_unlock(&BTRFS_I(inode)->lock);
1809 }
1810 }
1811
1812 /*
1813 * Once a range is no longer delalloc this function ensures that proper
1814 * accounting happens.
1815 */
1816 void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
1817 struct extent_state *state, unsigned *bits)
1818 {
1819 struct btrfs_inode *inode = BTRFS_I(vfs_inode);
1820 struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb);
1821 u64 len = state->end + 1 - state->start;
1822 u32 num_extents = count_max_extents(len);
1823
1824 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1825 spin_lock(&inode->lock);
1826 inode->defrag_bytes -= len;
1827 spin_unlock(&inode->lock);
1828 }
1829
1830 /*
1831 * set_bit and clear bit hooks normally require _irqsave/restore
1832 * but in this case, we are only testing for the DELALLOC
1833 * bit, which is only set or cleared with irqs on
1834 */
1835 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1836 struct btrfs_root *root = inode->root;
1837 bool do_list = !btrfs_is_free_space_inode(inode);
1838
1839 spin_lock(&inode->lock);
1840 btrfs_mod_outstanding_extents(inode, -num_extents);
1841 spin_unlock(&inode->lock);
1842
1843 /*
1844 * We don't reserve metadata space for space cache inodes so we
1845 * don't need to call delalloc_release_metadata if there is an
1846 * error.
1847 */
1848 if (*bits & EXTENT_CLEAR_META_RESV &&
1849 root != fs_info->tree_root)
1850 btrfs_delalloc_release_metadata(inode, len, false);
1851
1852 /* For sanity tests. */
1853 if (btrfs_is_testing(fs_info))
1854 return;
1855
1856 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1857 do_list && !(state->state & EXTENT_NORESERVE) &&
1858 (*bits & EXTENT_CLEAR_DATA_RESV))
1859 btrfs_free_reserved_data_space_noquota(
1860 &inode->vfs_inode,
1861 state->start, len);
1862
1863 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1864 fs_info->delalloc_batch);
1865 spin_lock(&inode->lock);
1866 inode->delalloc_bytes -= len;
1867 if (do_list && inode->delalloc_bytes == 0 &&
1868 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1869 &inode->runtime_flags))
1870 btrfs_del_delalloc_inode(root, inode);
1871 spin_unlock(&inode->lock);
1872 }
1873
1874 if ((state->state & EXTENT_DELALLOC_NEW) &&
1875 (*bits & EXTENT_DELALLOC_NEW)) {
1876 spin_lock(&inode->lock);
1877 ASSERT(inode->new_delalloc_bytes >= len);
1878 inode->new_delalloc_bytes -= len;
1879 spin_unlock(&inode->lock);
1880 }
1881 }
1882
1883 /*
1884 * btrfs_bio_fits_in_stripe - Checks whether the size of the given bio will fit
1885 * in a chunk's stripe. This function ensures that bios do not span a
1886 * stripe/chunk
1887 *
1888 * @page - The page we are about to add to the bio
1889 * @size - size we want to add to the bio
1890 * @bio - bio we want to ensure is smaller than a stripe
1891 * @bio_flags - flags of the bio
1892 *
1893 * return 1 if page cannot be added to the bio
1894 * return 0 if page can be added to the bio
1895 * return error otherwise
1896 */
1897 int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
1898 unsigned long bio_flags)
1899 {
1900 struct inode *inode = page->mapping->host;
1901 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1902 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1903 u64 length = 0;
1904 u64 map_length;
1905 int ret;
1906
1907 if (bio_flags & EXTENT_BIO_COMPRESSED)
1908 return 0;
1909
1910 length = bio->bi_iter.bi_size;
1911 map_length = length;
1912 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1913 NULL, 0);
1914 if (ret < 0)
1915 return ret;
1916 if (map_length < length + size)
1917 return 1;
1918 return 0;
1919 }
1920
1921 /*
1922 * in order to insert checksums into the metadata in large chunks,
1923 * we wait until bio submission time. All the pages in the bio are
1924 * checksummed and sums are attached onto the ordered extent record.
1925 *
1926 * At IO completion time the cums attached on the ordered extent record
1927 * are inserted into the btree
1928 */
1929 static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
1930 u64 bio_offset)
1931 {
1932 struct inode *inode = private_data;
1933 blk_status_t ret = 0;
1934
1935 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1936 BUG_ON(ret); /* -ENOMEM */
1937 return 0;
1938 }
1939
1940 /*
1941 * extent_io.c submission hook. This does the right thing for csum calculation
1942 * on write, or reading the csums from the tree before a read.
1943 *
1944 * Rules about async/sync submit,
1945 * a) read: sync submit
1946 *
1947 * b) write without checksum: sync submit
1948 *
1949 * c) write with checksum:
1950 * c-1) if bio is issued by fsync: sync submit
1951 * (sync_writers != 0)
1952 *
1953 * c-2) if root is reloc root: sync submit
1954 * (only in case of buffered IO)
1955 *
1956 * c-3) otherwise: async submit
1957 */
1958 static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1959 int mirror_num, unsigned long bio_flags,
1960 u64 bio_offset)
1961 {
1962 struct inode *inode = private_data;
1963 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1964 struct btrfs_root *root = BTRFS_I(inode)->root;
1965 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1966 blk_status_t ret = 0;
1967 int skip_sum;
1968 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1969
1970 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1971
1972 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
1973 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1974
1975 if (bio_op(bio) != REQ_OP_WRITE) {
1976 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
1977 if (ret)
1978 goto out;
1979
1980 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1981 ret = btrfs_submit_compressed_read(inode, bio,
1982 mirror_num,
1983 bio_flags);
1984 goto out;
1985 } else if (!skip_sum) {
1986 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
1987 if (ret)
1988 goto out;
1989 }
1990 goto mapit;
1991 } else if (async && !skip_sum) {
1992 /* csum items have already been cloned */
1993 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1994 goto mapit;
1995 /* we're doing a write, do the async checksumming */
1996 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
1997 bio_offset, inode,
1998 btrfs_submit_bio_start);
1999 goto out;
2000 } else if (!skip_sum) {
2001 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2002 if (ret)
2003 goto out;
2004 }
2005
2006 mapit:
2007 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
2008
2009 out:
2010 if (ret) {
2011 bio->bi_status = ret;
2012 bio_endio(bio);
2013 }
2014 return ret;
2015 }
2016
2017 /*
2018 * given a list of ordered sums record them in the inode. This happens
2019 * at IO completion time based on sums calculated at bio submission time.
2020 */
2021 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2022 struct inode *inode, struct list_head *list)
2023 {
2024 struct btrfs_ordered_sum *sum;
2025 int ret;
2026
2027 list_for_each_entry(sum, list, list) {
2028 trans->adding_csums = true;
2029 ret = btrfs_csum_file_blocks(trans,
2030 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2031 trans->adding_csums = false;
2032 if (ret)
2033 return ret;
2034 }
2035 return 0;
2036 }
2037
2038 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2039 unsigned int extra_bits,
2040 struct extent_state **cached_state, int dedupe)
2041 {
2042 WARN_ON(PAGE_ALIGNED(end));
2043 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2044 extra_bits, cached_state);
2045 }
2046
2047 /* see btrfs_writepage_start_hook for details on why this is required */
2048 struct btrfs_writepage_fixup {
2049 struct page *page;
2050 struct btrfs_work work;
2051 };
2052
2053 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2054 {
2055 struct btrfs_writepage_fixup *fixup;
2056 struct btrfs_ordered_extent *ordered;
2057 struct extent_state *cached_state = NULL;
2058 struct extent_changeset *data_reserved = NULL;
2059 struct page *page;
2060 struct inode *inode;
2061 u64 page_start;
2062 u64 page_end;
2063 int ret;
2064
2065 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2066 page = fixup->page;
2067 again:
2068 lock_page(page);
2069 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2070 ClearPageChecked(page);
2071 goto out_page;
2072 }
2073
2074 inode = page->mapping->host;
2075 page_start = page_offset(page);
2076 page_end = page_offset(page) + PAGE_SIZE - 1;
2077
2078 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2079 &cached_state);
2080
2081 /* already ordered? We're done */
2082 if (PagePrivate2(page))
2083 goto out;
2084
2085 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2086 PAGE_SIZE);
2087 if (ordered) {
2088 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2089 page_end, &cached_state);
2090 unlock_page(page);
2091 btrfs_start_ordered_extent(inode, ordered, 1);
2092 btrfs_put_ordered_extent(ordered);
2093 goto again;
2094 }
2095
2096 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2097 PAGE_SIZE);
2098 if (ret) {
2099 mapping_set_error(page->mapping, ret);
2100 end_extent_writepage(page, ret, page_start, page_end);
2101 ClearPageChecked(page);
2102 goto out;
2103 }
2104
2105 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
2106 &cached_state, 0);
2107 if (ret) {
2108 mapping_set_error(page->mapping, ret);
2109 end_extent_writepage(page, ret, page_start, page_end);
2110 ClearPageChecked(page);
2111 goto out;
2112 }
2113
2114 ClearPageChecked(page);
2115 set_page_dirty(page);
2116 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, false);
2117 out:
2118 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2119 &cached_state);
2120 out_page:
2121 unlock_page(page);
2122 put_page(page);
2123 kfree(fixup);
2124 extent_changeset_free(data_reserved);
2125 }
2126
2127 /*
2128 * There are a few paths in the higher layers of the kernel that directly
2129 * set the page dirty bit without asking the filesystem if it is a
2130 * good idea. This causes problems because we want to make sure COW
2131 * properly happens and the data=ordered rules are followed.
2132 *
2133 * In our case any range that doesn't have the ORDERED bit set
2134 * hasn't been properly setup for IO. We kick off an async process
2135 * to fix it up. The async helper will wait for ordered extents, set
2136 * the delalloc bit and make it safe to write the page.
2137 */
2138 int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end)
2139 {
2140 struct inode *inode = page->mapping->host;
2141 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2142 struct btrfs_writepage_fixup *fixup;
2143
2144 /* this page is properly in the ordered list */
2145 if (TestClearPagePrivate2(page))
2146 return 0;
2147
2148 if (PageChecked(page))
2149 return -EAGAIN;
2150
2151 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2152 if (!fixup)
2153 return -EAGAIN;
2154
2155 SetPageChecked(page);
2156 get_page(page);
2157 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2158 btrfs_writepage_fixup_worker, NULL, NULL);
2159 fixup->page = page;
2160 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2161 return -EBUSY;
2162 }
2163
2164 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2165 struct inode *inode, u64 file_pos,
2166 u64 disk_bytenr, u64 disk_num_bytes,
2167 u64 num_bytes, u64 ram_bytes,
2168 u8 compression, u8 encryption,
2169 u16 other_encoding, int extent_type)
2170 {
2171 struct btrfs_root *root = BTRFS_I(inode)->root;
2172 struct btrfs_file_extent_item *fi;
2173 struct btrfs_path *path;
2174 struct extent_buffer *leaf;
2175 struct btrfs_key ins;
2176 u64 qg_released;
2177 int extent_inserted = 0;
2178 int ret;
2179
2180 path = btrfs_alloc_path();
2181 if (!path)
2182 return -ENOMEM;
2183
2184 /*
2185 * we may be replacing one extent in the tree with another.
2186 * The new extent is pinned in the extent map, and we don't want
2187 * to drop it from the cache until it is completely in the btree.
2188 *
2189 * So, tell btrfs_drop_extents to leave this extent in the cache.
2190 * the caller is expected to unpin it and allow it to be merged
2191 * with the others.
2192 */
2193 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2194 file_pos + num_bytes, NULL, 0,
2195 1, sizeof(*fi), &extent_inserted);
2196 if (ret)
2197 goto out;
2198
2199 if (!extent_inserted) {
2200 ins.objectid = btrfs_ino(BTRFS_I(inode));
2201 ins.offset = file_pos;
2202 ins.type = BTRFS_EXTENT_DATA_KEY;
2203
2204 path->leave_spinning = 1;
2205 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2206 sizeof(*fi));
2207 if (ret)
2208 goto out;
2209 }
2210 leaf = path->nodes[0];
2211 fi = btrfs_item_ptr(leaf, path->slots[0],
2212 struct btrfs_file_extent_item);
2213 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2214 btrfs_set_file_extent_type(leaf, fi, extent_type);
2215 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2216 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2217 btrfs_set_file_extent_offset(leaf, fi, 0);
2218 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2219 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2220 btrfs_set_file_extent_compression(leaf, fi, compression);
2221 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2222 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2223
2224 btrfs_mark_buffer_dirty(leaf);
2225 btrfs_release_path(path);
2226
2227 inode_add_bytes(inode, num_bytes);
2228
2229 ins.objectid = disk_bytenr;
2230 ins.offset = disk_num_bytes;
2231 ins.type = BTRFS_EXTENT_ITEM_KEY;
2232
2233 /*
2234 * Release the reserved range from inode dirty range map, as it is
2235 * already moved into delayed_ref_head
2236 */
2237 ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2238 if (ret < 0)
2239 goto out;
2240 qg_released = ret;
2241 ret = btrfs_alloc_reserved_file_extent(trans, root,
2242 btrfs_ino(BTRFS_I(inode)),
2243 file_pos, qg_released, &ins);
2244 out:
2245 btrfs_free_path(path);
2246
2247 return ret;
2248 }
2249
2250 /* snapshot-aware defrag */
2251 struct sa_defrag_extent_backref {
2252 struct rb_node node;
2253 struct old_sa_defrag_extent *old;
2254 u64 root_id;
2255 u64 inum;
2256 u64 file_pos;
2257 u64 extent_offset;
2258 u64 num_bytes;
2259 u64 generation;
2260 };
2261
2262 struct old_sa_defrag_extent {
2263 struct list_head list;
2264 struct new_sa_defrag_extent *new;
2265
2266 u64 extent_offset;
2267 u64 bytenr;
2268 u64 offset;
2269 u64 len;
2270 int count;
2271 };
2272
2273 struct new_sa_defrag_extent {
2274 struct rb_root root;
2275 struct list_head head;
2276 struct btrfs_path *path;
2277 struct inode *inode;
2278 u64 file_pos;
2279 u64 len;
2280 u64 bytenr;
2281 u64 disk_len;
2282 u8 compress_type;
2283 };
2284
2285 static int backref_comp(struct sa_defrag_extent_backref *b1,
2286 struct sa_defrag_extent_backref *b2)
2287 {
2288 if (b1->root_id < b2->root_id)
2289 return -1;
2290 else if (b1->root_id > b2->root_id)
2291 return 1;
2292
2293 if (b1->inum < b2->inum)
2294 return -1;
2295 else if (b1->inum > b2->inum)
2296 return 1;
2297
2298 if (b1->file_pos < b2->file_pos)
2299 return -1;
2300 else if (b1->file_pos > b2->file_pos)
2301 return 1;
2302
2303 /*
2304 * [------------------------------] ===> (a range of space)
2305 * |<--->| |<---->| =============> (fs/file tree A)
2306 * |<---------------------------->| ===> (fs/file tree B)
2307 *
2308 * A range of space can refer to two file extents in one tree while
2309 * refer to only one file extent in another tree.
2310 *
2311 * So we may process a disk offset more than one time(two extents in A)
2312 * and locate at the same extent(one extent in B), then insert two same
2313 * backrefs(both refer to the extent in B).
2314 */
2315 return 0;
2316 }
2317
2318 static void backref_insert(struct rb_root *root,
2319 struct sa_defrag_extent_backref *backref)
2320 {
2321 struct rb_node **p = &root->rb_node;
2322 struct rb_node *parent = NULL;
2323 struct sa_defrag_extent_backref *entry;
2324 int ret;
2325
2326 while (*p) {
2327 parent = *p;
2328 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2329
2330 ret = backref_comp(backref, entry);
2331 if (ret < 0)
2332 p = &(*p)->rb_left;
2333 else
2334 p = &(*p)->rb_right;
2335 }
2336
2337 rb_link_node(&backref->node, parent, p);
2338 rb_insert_color(&backref->node, root);
2339 }
2340
2341 /*
2342 * Note the backref might has changed, and in this case we just return 0.
2343 */
2344 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2345 void *ctx)
2346 {
2347 struct btrfs_file_extent_item *extent;
2348 struct old_sa_defrag_extent *old = ctx;
2349 struct new_sa_defrag_extent *new = old->new;
2350 struct btrfs_path *path = new->path;
2351 struct btrfs_key key;
2352 struct btrfs_root *root;
2353 struct sa_defrag_extent_backref *backref;
2354 struct extent_buffer *leaf;
2355 struct inode *inode = new->inode;
2356 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2357 int slot;
2358 int ret;
2359 u64 extent_offset;
2360 u64 num_bytes;
2361
2362 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2363 inum == btrfs_ino(BTRFS_I(inode)))
2364 return 0;
2365
2366 key.objectid = root_id;
2367 key.type = BTRFS_ROOT_ITEM_KEY;
2368 key.offset = (u64)-1;
2369
2370 root = btrfs_read_fs_root_no_name(fs_info, &key);
2371 if (IS_ERR(root)) {
2372 if (PTR_ERR(root) == -ENOENT)
2373 return 0;
2374 WARN_ON(1);
2375 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2376 inum, offset, root_id);
2377 return PTR_ERR(root);
2378 }
2379
2380 key.objectid = inum;
2381 key.type = BTRFS_EXTENT_DATA_KEY;
2382 if (offset > (u64)-1 << 32)
2383 key.offset = 0;
2384 else
2385 key.offset = offset;
2386
2387 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2388 if (WARN_ON(ret < 0))
2389 return ret;
2390 ret = 0;
2391
2392 while (1) {
2393 cond_resched();
2394
2395 leaf = path->nodes[0];
2396 slot = path->slots[0];
2397
2398 if (slot >= btrfs_header_nritems(leaf)) {
2399 ret = btrfs_next_leaf(root, path);
2400 if (ret < 0) {
2401 goto out;
2402 } else if (ret > 0) {
2403 ret = 0;
2404 goto out;
2405 }
2406 continue;
2407 }
2408
2409 path->slots[0]++;
2410
2411 btrfs_item_key_to_cpu(leaf, &key, slot);
2412
2413 if (key.objectid > inum)
2414 goto out;
2415
2416 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2417 continue;
2418
2419 extent = btrfs_item_ptr(leaf, slot,
2420 struct btrfs_file_extent_item);
2421
2422 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2423 continue;
2424
2425 /*
2426 * 'offset' refers to the exact key.offset,
2427 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2428 * (key.offset - extent_offset).
2429 */
2430 if (key.offset != offset)
2431 continue;
2432
2433 extent_offset = btrfs_file_extent_offset(leaf, extent);
2434 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2435
2436 if (extent_offset >= old->extent_offset + old->offset +
2437 old->len || extent_offset + num_bytes <=
2438 old->extent_offset + old->offset)
2439 continue;
2440 break;
2441 }
2442
2443 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2444 if (!backref) {
2445 ret = -ENOENT;
2446 goto out;
2447 }
2448
2449 backref->root_id = root_id;
2450 backref->inum = inum;
2451 backref->file_pos = offset;
2452 backref->num_bytes = num_bytes;
2453 backref->extent_offset = extent_offset;
2454 backref->generation = btrfs_file_extent_generation(leaf, extent);
2455 backref->old = old;
2456 backref_insert(&new->root, backref);
2457 old->count++;
2458 out:
2459 btrfs_release_path(path);
2460 WARN_ON(ret);
2461 return ret;
2462 }
2463
2464 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2465 struct new_sa_defrag_extent *new)
2466 {
2467 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2468 struct old_sa_defrag_extent *old, *tmp;
2469 int ret;
2470
2471 new->path = path;
2472
2473 list_for_each_entry_safe(old, tmp, &new->head, list) {
2474 ret = iterate_inodes_from_logical(old->bytenr +
2475 old->extent_offset, fs_info,
2476 path, record_one_backref,
2477 old, false);
2478 if (ret < 0 && ret != -ENOENT)
2479 return false;
2480
2481 /* no backref to be processed for this extent */
2482 if (!old->count) {
2483 list_del(&old->list);
2484 kfree(old);
2485 }
2486 }
2487
2488 if (list_empty(&new->head))
2489 return false;
2490
2491 return true;
2492 }
2493
2494 static int relink_is_mergable(struct extent_buffer *leaf,
2495 struct btrfs_file_extent_item *fi,
2496 struct new_sa_defrag_extent *new)
2497 {
2498 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2499 return 0;
2500
2501 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2502 return 0;
2503
2504 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2505 return 0;
2506
2507 if (btrfs_file_extent_encryption(leaf, fi) ||
2508 btrfs_file_extent_other_encoding(leaf, fi))
2509 return 0;
2510
2511 return 1;
2512 }
2513
2514 /*
2515 * Note the backref might has changed, and in this case we just return 0.
2516 */
2517 static noinline int relink_extent_backref(struct btrfs_path *path,
2518 struct sa_defrag_extent_backref *prev,
2519 struct sa_defrag_extent_backref *backref)
2520 {
2521 struct btrfs_file_extent_item *extent;
2522 struct btrfs_file_extent_item *item;
2523 struct btrfs_ordered_extent *ordered;
2524 struct btrfs_trans_handle *trans;
2525 struct btrfs_root *root;
2526 struct btrfs_key key;
2527 struct extent_buffer *leaf;
2528 struct old_sa_defrag_extent *old = backref->old;
2529 struct new_sa_defrag_extent *new = old->new;
2530 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2531 struct inode *inode;
2532 struct extent_state *cached = NULL;
2533 int ret = 0;
2534 u64 start;
2535 u64 len;
2536 u64 lock_start;
2537 u64 lock_end;
2538 bool merge = false;
2539 int index;
2540
2541 if (prev && prev->root_id == backref->root_id &&
2542 prev->inum == backref->inum &&
2543 prev->file_pos + prev->num_bytes == backref->file_pos)
2544 merge = true;
2545
2546 /* step 1: get root */
2547 key.objectid = backref->root_id;
2548 key.type = BTRFS_ROOT_ITEM_KEY;
2549 key.offset = (u64)-1;
2550
2551 index = srcu_read_lock(&fs_info->subvol_srcu);
2552
2553 root = btrfs_read_fs_root_no_name(fs_info, &key);
2554 if (IS_ERR(root)) {
2555 srcu_read_unlock(&fs_info->subvol_srcu, index);
2556 if (PTR_ERR(root) == -ENOENT)
2557 return 0;
2558 return PTR_ERR(root);
2559 }
2560
2561 if (btrfs_root_readonly(root)) {
2562 srcu_read_unlock(&fs_info->subvol_srcu, index);
2563 return 0;
2564 }
2565
2566 /* step 2: get inode */
2567 key.objectid = backref->inum;
2568 key.type = BTRFS_INODE_ITEM_KEY;
2569 key.offset = 0;
2570
2571 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2572 if (IS_ERR(inode)) {
2573 srcu_read_unlock(&fs_info->subvol_srcu, index);
2574 return 0;
2575 }
2576
2577 srcu_read_unlock(&fs_info->subvol_srcu, index);
2578
2579 /* step 3: relink backref */
2580 lock_start = backref->file_pos;
2581 lock_end = backref->file_pos + backref->num_bytes - 1;
2582 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2583 &cached);
2584
2585 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2586 if (ordered) {
2587 btrfs_put_ordered_extent(ordered);
2588 goto out_unlock;
2589 }
2590
2591 trans = btrfs_join_transaction(root);
2592 if (IS_ERR(trans)) {
2593 ret = PTR_ERR(trans);
2594 goto out_unlock;
2595 }
2596
2597 key.objectid = backref->inum;
2598 key.type = BTRFS_EXTENT_DATA_KEY;
2599 key.offset = backref->file_pos;
2600
2601 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2602 if (ret < 0) {
2603 goto out_free_path;
2604 } else if (ret > 0) {
2605 ret = 0;
2606 goto out_free_path;
2607 }
2608
2609 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2610 struct btrfs_file_extent_item);
2611
2612 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2613 backref->generation)
2614 goto out_free_path;
2615
2616 btrfs_release_path(path);
2617
2618 start = backref->file_pos;
2619 if (backref->extent_offset < old->extent_offset + old->offset)
2620 start += old->extent_offset + old->offset -
2621 backref->extent_offset;
2622
2623 len = min(backref->extent_offset + backref->num_bytes,
2624 old->extent_offset + old->offset + old->len);
2625 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2626
2627 ret = btrfs_drop_extents(trans, root, inode, start,
2628 start + len, 1);
2629 if (ret)
2630 goto out_free_path;
2631 again:
2632 key.objectid = btrfs_ino(BTRFS_I(inode));
2633 key.type = BTRFS_EXTENT_DATA_KEY;
2634 key.offset = start;
2635
2636 path->leave_spinning = 1;
2637 if (merge) {
2638 struct btrfs_file_extent_item *fi;
2639 u64 extent_len;
2640 struct btrfs_key found_key;
2641
2642 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2643 if (ret < 0)
2644 goto out_free_path;
2645
2646 path->slots[0]--;
2647 leaf = path->nodes[0];
2648 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2649
2650 fi = btrfs_item_ptr(leaf, path->slots[0],
2651 struct btrfs_file_extent_item);
2652 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2653
2654 if (extent_len + found_key.offset == start &&
2655 relink_is_mergable(leaf, fi, new)) {
2656 btrfs_set_file_extent_num_bytes(leaf, fi,
2657 extent_len + len);
2658 btrfs_mark_buffer_dirty(leaf);
2659 inode_add_bytes(inode, len);
2660
2661 ret = 1;
2662 goto out_free_path;
2663 } else {
2664 merge = false;
2665 btrfs_release_path(path);
2666 goto again;
2667 }
2668 }
2669
2670 ret = btrfs_insert_empty_item(trans, root, path, &key,
2671 sizeof(*extent));
2672 if (ret) {
2673 btrfs_abort_transaction(trans, ret);
2674 goto out_free_path;
2675 }
2676
2677 leaf = path->nodes[0];
2678 item = btrfs_item_ptr(leaf, path->slots[0],
2679 struct btrfs_file_extent_item);
2680 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2681 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2682 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2683 btrfs_set_file_extent_num_bytes(leaf, item, len);
2684 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2685 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2686 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2687 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2688 btrfs_set_file_extent_encryption(leaf, item, 0);
2689 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2690
2691 btrfs_mark_buffer_dirty(leaf);
2692 inode_add_bytes(inode, len);
2693 btrfs_release_path(path);
2694
2695 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2696 new->disk_len, 0,
2697 backref->root_id, backref->inum,
2698 new->file_pos); /* start - extent_offset */
2699 if (ret) {
2700 btrfs_abort_transaction(trans, ret);
2701 goto out_free_path;
2702 }
2703
2704 ret = 1;
2705 out_free_path:
2706 btrfs_release_path(path);
2707 path->leave_spinning = 0;
2708 btrfs_end_transaction(trans);
2709 out_unlock:
2710 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2711 &cached);
2712 iput(inode);
2713 return ret;
2714 }
2715
2716 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2717 {
2718 struct old_sa_defrag_extent *old, *tmp;
2719
2720 if (!new)
2721 return;
2722
2723 list_for_each_entry_safe(old, tmp, &new->head, list) {
2724 kfree(old);
2725 }
2726 kfree(new);
2727 }
2728
2729 static void relink_file_extents(struct new_sa_defrag_extent *new)
2730 {
2731 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2732 struct btrfs_path *path;
2733 struct sa_defrag_extent_backref *backref;
2734 struct sa_defrag_extent_backref *prev = NULL;
2735 struct rb_node *node;
2736 int ret;
2737
2738 path = btrfs_alloc_path();
2739 if (!path)
2740 return;
2741
2742 if (!record_extent_backrefs(path, new)) {
2743 btrfs_free_path(path);
2744 goto out;
2745 }
2746 btrfs_release_path(path);
2747
2748 while (1) {
2749 node = rb_first(&new->root);
2750 if (!node)
2751 break;
2752 rb_erase(node, &new->root);
2753
2754 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2755
2756 ret = relink_extent_backref(path, prev, backref);
2757 WARN_ON(ret < 0);
2758
2759 kfree(prev);
2760
2761 if (ret == 1)
2762 prev = backref;
2763 else
2764 prev = NULL;
2765 cond_resched();
2766 }
2767 kfree(prev);
2768
2769 btrfs_free_path(path);
2770 out:
2771 free_sa_defrag_extent(new);
2772
2773 atomic_dec(&fs_info->defrag_running);
2774 wake_up(&fs_info->transaction_wait);
2775 }
2776
2777 static struct new_sa_defrag_extent *
2778 record_old_file_extents(struct inode *inode,
2779 struct btrfs_ordered_extent *ordered)
2780 {
2781 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2782 struct btrfs_root *root = BTRFS_I(inode)->root;
2783 struct btrfs_path *path;
2784 struct btrfs_key key;
2785 struct old_sa_defrag_extent *old;
2786 struct new_sa_defrag_extent *new;
2787 int ret;
2788
2789 new = kmalloc(sizeof(*new), GFP_NOFS);
2790 if (!new)
2791 return NULL;
2792
2793 new->inode = inode;
2794 new->file_pos = ordered->file_offset;
2795 new->len = ordered->len;
2796 new->bytenr = ordered->start;
2797 new->disk_len = ordered->disk_len;
2798 new->compress_type = ordered->compress_type;
2799 new->root = RB_ROOT;
2800 INIT_LIST_HEAD(&new->head);
2801
2802 path = btrfs_alloc_path();
2803 if (!path)
2804 goto out_kfree;
2805
2806 key.objectid = btrfs_ino(BTRFS_I(inode));
2807 key.type = BTRFS_EXTENT_DATA_KEY;
2808 key.offset = new->file_pos;
2809
2810 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2811 if (ret < 0)
2812 goto out_free_path;
2813 if (ret > 0 && path->slots[0] > 0)
2814 path->slots[0]--;
2815
2816 /* find out all the old extents for the file range */
2817 while (1) {
2818 struct btrfs_file_extent_item *extent;
2819 struct extent_buffer *l;
2820 int slot;
2821 u64 num_bytes;
2822 u64 offset;
2823 u64 end;
2824 u64 disk_bytenr;
2825 u64 extent_offset;
2826
2827 l = path->nodes[0];
2828 slot = path->slots[0];
2829
2830 if (slot >= btrfs_header_nritems(l)) {
2831 ret = btrfs_next_leaf(root, path);
2832 if (ret < 0)
2833 goto out_free_path;
2834 else if (ret > 0)
2835 break;
2836 continue;
2837 }
2838
2839 btrfs_item_key_to_cpu(l, &key, slot);
2840
2841 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2842 break;
2843 if (key.type != BTRFS_EXTENT_DATA_KEY)
2844 break;
2845 if (key.offset >= new->file_pos + new->len)
2846 break;
2847
2848 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2849
2850 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2851 if (key.offset + num_bytes < new->file_pos)
2852 goto next;
2853
2854 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2855 if (!disk_bytenr)
2856 goto next;
2857
2858 extent_offset = btrfs_file_extent_offset(l, extent);
2859
2860 old = kmalloc(sizeof(*old), GFP_NOFS);
2861 if (!old)
2862 goto out_free_path;
2863
2864 offset = max(new->file_pos, key.offset);
2865 end = min(new->file_pos + new->len, key.offset + num_bytes);
2866
2867 old->bytenr = disk_bytenr;
2868 old->extent_offset = extent_offset;
2869 old->offset = offset - key.offset;
2870 old->len = end - offset;
2871 old->new = new;
2872 old->count = 0;
2873 list_add_tail(&old->list, &new->head);
2874 next:
2875 path->slots[0]++;
2876 cond_resched();
2877 }
2878
2879 btrfs_free_path(path);
2880 atomic_inc(&fs_info->defrag_running);
2881
2882 return new;
2883
2884 out_free_path:
2885 btrfs_free_path(path);
2886 out_kfree:
2887 free_sa_defrag_extent(new);
2888 return NULL;
2889 }
2890
2891 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2892 u64 start, u64 len)
2893 {
2894 struct btrfs_block_group_cache *cache;
2895
2896 cache = btrfs_lookup_block_group(fs_info, start);
2897 ASSERT(cache);
2898
2899 spin_lock(&cache->lock);
2900 cache->delalloc_bytes -= len;
2901 spin_unlock(&cache->lock);
2902
2903 btrfs_put_block_group(cache);
2904 }
2905
2906 /* as ordered data IO finishes, this gets called so we can finish
2907 * an ordered extent if the range of bytes in the file it covers are
2908 * fully written.
2909 */
2910 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2911 {
2912 struct inode *inode = ordered_extent->inode;
2913 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2914 struct btrfs_root *root = BTRFS_I(inode)->root;
2915 struct btrfs_trans_handle *trans = NULL;
2916 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2917 struct extent_state *cached_state = NULL;
2918 struct new_sa_defrag_extent *new = NULL;
2919 int compress_type = 0;
2920 int ret = 0;
2921 u64 logical_len = ordered_extent->len;
2922 bool nolock;
2923 bool truncated = false;
2924 bool range_locked = false;
2925 bool clear_new_delalloc_bytes = false;
2926 bool clear_reserved_extent = true;
2927
2928 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2929 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2930 !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2931 clear_new_delalloc_bytes = true;
2932
2933 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2934
2935 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2936 ret = -EIO;
2937 goto out;
2938 }
2939
2940 btrfs_free_io_failure_record(BTRFS_I(inode),
2941 ordered_extent->file_offset,
2942 ordered_extent->file_offset +
2943 ordered_extent->len - 1);
2944
2945 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2946 truncated = true;
2947 logical_len = ordered_extent->truncated_len;
2948 /* Truncated the entire extent, don't bother adding */
2949 if (!logical_len)
2950 goto out;
2951 }
2952
2953 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2954 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2955
2956 /*
2957 * For mwrite(mmap + memset to write) case, we still reserve
2958 * space for NOCOW range.
2959 * As NOCOW won't cause a new delayed ref, just free the space
2960 */
2961 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
2962 ordered_extent->len);
2963 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2964 if (nolock)
2965 trans = btrfs_join_transaction_nolock(root);
2966 else
2967 trans = btrfs_join_transaction(root);
2968 if (IS_ERR(trans)) {
2969 ret = PTR_ERR(trans);
2970 trans = NULL;
2971 goto out;
2972 }
2973 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
2974 ret = btrfs_update_inode_fallback(trans, root, inode);
2975 if (ret) /* -ENOMEM or corruption */
2976 btrfs_abort_transaction(trans, ret);
2977 goto out;
2978 }
2979
2980 range_locked = true;
2981 lock_extent_bits(io_tree, ordered_extent->file_offset,
2982 ordered_extent->file_offset + ordered_extent->len - 1,
2983 &cached_state);
2984
2985 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2986 ordered_extent->file_offset + ordered_extent->len - 1,
2987 EXTENT_DEFRAG, 0, cached_state);
2988 if (ret) {
2989 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2990 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2991 /* the inode is shared */
2992 new = record_old_file_extents(inode, ordered_extent);
2993
2994 clear_extent_bit(io_tree, ordered_extent->file_offset,
2995 ordered_extent->file_offset + ordered_extent->len - 1,
2996 EXTENT_DEFRAG, 0, 0, &cached_state);
2997 }
2998
2999 if (nolock)
3000 trans = btrfs_join_transaction_nolock(root);
3001 else
3002 trans = btrfs_join_transaction(root);
3003 if (IS_ERR(trans)) {
3004 ret = PTR_ERR(trans);
3005 trans = NULL;
3006 goto out;
3007 }
3008
3009 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3010
3011 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3012 compress_type = ordered_extent->compress_type;
3013 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3014 BUG_ON(compress_type);
3015 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3016 ordered_extent->len);
3017 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
3018 ordered_extent->file_offset,
3019 ordered_extent->file_offset +
3020 logical_len);
3021 } else {
3022 BUG_ON(root == fs_info->tree_root);
3023 ret = insert_reserved_file_extent(trans, inode,
3024 ordered_extent->file_offset,
3025 ordered_extent->start,
3026 ordered_extent->disk_len,
3027 logical_len, logical_len,
3028 compress_type, 0, 0,
3029 BTRFS_FILE_EXTENT_REG);
3030 if (!ret) {
3031 clear_reserved_extent = false;
3032 btrfs_release_delalloc_bytes(fs_info,
3033 ordered_extent->start,
3034 ordered_extent->disk_len);
3035 }
3036 }
3037 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3038 ordered_extent->file_offset, ordered_extent->len,
3039 trans->transid);
3040 if (ret < 0) {
3041 btrfs_abort_transaction(trans, ret);
3042 goto out;
3043 }
3044
3045 ret = add_pending_csums(trans, inode, &ordered_extent->list);
3046 if (ret) {
3047 btrfs_abort_transaction(trans, ret);
3048 goto out;
3049 }
3050
3051 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3052 ret = btrfs_update_inode_fallback(trans, root, inode);
3053 if (ret) { /* -ENOMEM or corruption */
3054 btrfs_abort_transaction(trans, ret);
3055 goto out;
3056 }
3057 ret = 0;
3058 out:
3059 if (range_locked || clear_new_delalloc_bytes) {
3060 unsigned int clear_bits = 0;
3061
3062 if (range_locked)
3063 clear_bits |= EXTENT_LOCKED;
3064 if (clear_new_delalloc_bytes)
3065 clear_bits |= EXTENT_DELALLOC_NEW;
3066 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3067 ordered_extent->file_offset,
3068 ordered_extent->file_offset +
3069 ordered_extent->len - 1,
3070 clear_bits,
3071 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3072 0, &cached_state);
3073 }
3074
3075 if (trans)
3076 btrfs_end_transaction(trans);
3077
3078 if (ret || truncated) {
3079 u64 start, end;
3080
3081 if (truncated)
3082 start = ordered_extent->file_offset + logical_len;
3083 else
3084 start = ordered_extent->file_offset;
3085 end = ordered_extent->file_offset + ordered_extent->len - 1;
3086 clear_extent_uptodate(io_tree, start, end, NULL);
3087
3088 /* Drop the cache for the part of the extent we didn't write. */
3089 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3090
3091 /*
3092 * If the ordered extent had an IOERR or something else went
3093 * wrong we need to return the space for this ordered extent
3094 * back to the allocator. We only free the extent in the
3095 * truncated case if we didn't write out the extent at all.
3096 *
3097 * If we made it past insert_reserved_file_extent before we
3098 * errored out then we don't need to do this as the accounting
3099 * has already been done.
3100 */
3101 if ((ret || !logical_len) &&
3102 clear_reserved_extent &&
3103 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3104 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3105 btrfs_free_reserved_extent(fs_info,
3106 ordered_extent->start,
3107 ordered_extent->disk_len, 1);
3108 }
3109
3110
3111 /*
3112 * This needs to be done to make sure anybody waiting knows we are done
3113 * updating everything for this ordered extent.
3114 */
3115 btrfs_remove_ordered_extent(inode, ordered_extent);
3116
3117 /* for snapshot-aware defrag */
3118 if (new) {
3119 if (ret) {
3120 free_sa_defrag_extent(new);
3121 atomic_dec(&fs_info->defrag_running);
3122 } else {
3123 relink_file_extents(new);
3124 }
3125 }
3126
3127 /* once for us */
3128 btrfs_put_ordered_extent(ordered_extent);
3129 /* once for the tree */
3130 btrfs_put_ordered_extent(ordered_extent);
3131
3132 return ret;
3133 }
3134
3135 static void finish_ordered_fn(struct btrfs_work *work)
3136 {
3137 struct btrfs_ordered_extent *ordered_extent;
3138 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3139 btrfs_finish_ordered_io(ordered_extent);
3140 }
3141
3142 void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
3143 u64 end, int uptodate)
3144 {
3145 struct inode *inode = page->mapping->host;
3146 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3147 struct btrfs_ordered_extent *ordered_extent = NULL;
3148 struct btrfs_workqueue *wq;
3149 btrfs_work_func_t func;
3150
3151 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3152
3153 ClearPagePrivate2(page);
3154 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3155 end - start + 1, uptodate))
3156 return;
3157
3158 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3159 wq = fs_info->endio_freespace_worker;
3160 func = btrfs_freespace_write_helper;
3161 } else {
3162 wq = fs_info->endio_write_workers;
3163 func = btrfs_endio_write_helper;
3164 }
3165
3166 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3167 NULL);
3168 btrfs_queue_work(wq, &ordered_extent->work);
3169 }
3170
3171 static int __readpage_endio_check(struct inode *inode,
3172 struct btrfs_io_bio *io_bio,
3173 int icsum, struct page *page,
3174 int pgoff, u64 start, size_t len)
3175 {
3176 char *kaddr;
3177 u32 csum_expected;
3178 u32 csum = ~(u32)0;
3179
3180 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3181
3182 kaddr = kmap_atomic(page);
3183 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3184 btrfs_csum_final(csum, (u8 *)&csum);
3185 if (csum != csum_expected)
3186 goto zeroit;
3187
3188 kunmap_atomic(kaddr);
3189 return 0;
3190 zeroit:
3191 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3192 io_bio->mirror_num);
3193 memset(kaddr + pgoff, 1, len);
3194 flush_dcache_page(page);
3195 kunmap_atomic(kaddr);
3196 return -EIO;
3197 }
3198
3199 /*
3200 * when reads are done, we need to check csums to verify the data is correct
3201 * if there's a match, we allow the bio to finish. If not, the code in
3202 * extent_io.c will try to find good copies for us.
3203 */
3204 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3205 u64 phy_offset, struct page *page,
3206 u64 start, u64 end, int mirror)
3207 {
3208 size_t offset = start - page_offset(page);
3209 struct inode *inode = page->mapping->host;
3210 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3211 struct btrfs_root *root = BTRFS_I(inode)->root;
3212
3213 if (PageChecked(page)) {
3214 ClearPageChecked(page);
3215 return 0;
3216 }
3217
3218 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3219 return 0;
3220
3221 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3222 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3223 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3224 return 0;
3225 }
3226
3227 phy_offset >>= inode->i_sb->s_blocksize_bits;
3228 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3229 start, (size_t)(end - start + 1));
3230 }
3231
3232 /*
3233 * btrfs_add_delayed_iput - perform a delayed iput on @inode
3234 *
3235 * @inode: The inode we want to perform iput on
3236 *
3237 * This function uses the generic vfs_inode::i_count to track whether we should
3238 * just decrement it (in case it's > 1) or if this is the last iput then link
3239 * the inode to the delayed iput machinery. Delayed iputs are processed at
3240 * transaction commit time/superblock commit/cleaner kthread.
3241 */
3242 void btrfs_add_delayed_iput(struct inode *inode)
3243 {
3244 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3245 struct btrfs_inode *binode = BTRFS_I(inode);
3246
3247 if (atomic_add_unless(&inode->i_count, -1, 1))
3248 return;
3249
3250 spin_lock(&fs_info->delayed_iput_lock);
3251 ASSERT(list_empty(&binode->delayed_iput));
3252 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3253 spin_unlock(&fs_info->delayed_iput_lock);
3254 if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
3255 wake_up_process(fs_info->cleaner_kthread);
3256 }
3257
3258 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3259 {
3260
3261 spin_lock(&fs_info->delayed_iput_lock);
3262 while (!list_empty(&fs_info->delayed_iputs)) {
3263 struct btrfs_inode *inode;
3264
3265 inode = list_first_entry(&fs_info->delayed_iputs,
3266 struct btrfs_inode, delayed_iput);
3267 list_del_init(&inode->delayed_iput);
3268 spin_unlock(&fs_info->delayed_iput_lock);
3269 iput(&inode->vfs_inode);
3270 spin_lock(&fs_info->delayed_iput_lock);
3271 }
3272 spin_unlock(&fs_info->delayed_iput_lock);
3273 }
3274
3275 /*
3276 * This creates an orphan entry for the given inode in case something goes wrong
3277 * in the middle of an unlink.
3278 */
3279 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3280 struct btrfs_inode *inode)
3281 {
3282 int ret;
3283
3284 ret = btrfs_insert_orphan_item(trans, inode->root, btrfs_ino(inode));
3285 if (ret && ret != -EEXIST) {
3286 btrfs_abort_transaction(trans, ret);
3287 return ret;
3288 }
3289
3290 return 0;
3291 }
3292
3293 /*
3294 * We have done the delete so we can go ahead and remove the orphan item for
3295 * this particular inode.
3296 */
3297 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3298 struct btrfs_inode *inode)
3299 {
3300 return btrfs_del_orphan_item(trans, inode->root, btrfs_ino(inode));
3301 }
3302
3303 /*
3304 * this cleans up any orphans that may be left on the list from the last use
3305 * of this root.
3306 */
3307 int btrfs_orphan_cleanup(struct btrfs_root *root)
3308 {
3309 struct btrfs_fs_info *fs_info = root->fs_info;
3310 struct btrfs_path *path;
3311 struct extent_buffer *leaf;
3312 struct btrfs_key key, found_key;
3313 struct btrfs_trans_handle *trans;
3314 struct inode *inode;
3315 u64 last_objectid = 0;
3316 int ret = 0, nr_unlink = 0;
3317
3318 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3319 return 0;
3320
3321 path = btrfs_alloc_path();
3322 if (!path) {
3323 ret = -ENOMEM;
3324 goto out;
3325 }
3326 path->reada = READA_BACK;
3327
3328 key.objectid = BTRFS_ORPHAN_OBJECTID;
3329 key.type = BTRFS_ORPHAN_ITEM_KEY;
3330 key.offset = (u64)-1;
3331
3332 while (1) {
3333 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3334 if (ret < 0)
3335 goto out;
3336
3337 /*
3338 * if ret == 0 means we found what we were searching for, which
3339 * is weird, but possible, so only screw with path if we didn't
3340 * find the key and see if we have stuff that matches
3341 */
3342 if (ret > 0) {
3343 ret = 0;
3344 if (path->slots[0] == 0)
3345 break;
3346 path->slots[0]--;
3347 }
3348
3349 /* pull out the item */
3350 leaf = path->nodes[0];
3351 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3352
3353 /* make sure the item matches what we want */
3354 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3355 break;
3356 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3357 break;
3358
3359 /* release the path since we're done with it */
3360 btrfs_release_path(path);
3361
3362 /*
3363 * this is where we are basically btrfs_lookup, without the
3364 * crossing root thing. we store the inode number in the
3365 * offset of the orphan item.
3366 */
3367
3368 if (found_key.offset == last_objectid) {
3369 btrfs_err(fs_info,
3370 "Error removing orphan entry, stopping orphan cleanup");
3371 ret = -EINVAL;
3372 goto out;
3373 }
3374
3375 last_objectid = found_key.offset;
3376
3377 found_key.objectid = found_key.offset;
3378 found_key.type = BTRFS_INODE_ITEM_KEY;
3379 found_key.offset = 0;
3380 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3381 ret = PTR_ERR_OR_ZERO(inode);
3382 if (ret && ret != -ENOENT)
3383 goto out;
3384
3385 if (ret == -ENOENT && root == fs_info->tree_root) {
3386 struct btrfs_root *dead_root;
3387 struct btrfs_fs_info *fs_info = root->fs_info;
3388 int is_dead_root = 0;
3389
3390 /*
3391 * this is an orphan in the tree root. Currently these
3392 * could come from 2 sources:
3393 * a) a snapshot deletion in progress
3394 * b) a free space cache inode
3395 * We need to distinguish those two, as the snapshot
3396 * orphan must not get deleted.
3397 * find_dead_roots already ran before us, so if this
3398 * is a snapshot deletion, we should find the root
3399 * in the dead_roots list
3400 */
3401 spin_lock(&fs_info->trans_lock);
3402 list_for_each_entry(dead_root, &fs_info->dead_roots,
3403 root_list) {
3404 if (dead_root->root_key.objectid ==
3405 found_key.objectid) {
3406 is_dead_root = 1;
3407 break;
3408 }
3409 }
3410 spin_unlock(&fs_info->trans_lock);
3411 if (is_dead_root) {
3412 /* prevent this orphan from being found again */
3413 key.offset = found_key.objectid - 1;
3414 continue;
3415 }
3416
3417 }
3418
3419 /*
3420 * If we have an inode with links, there are a couple of
3421 * possibilities. Old kernels (before v3.12) used to create an
3422 * orphan item for truncate indicating that there were possibly
3423 * extent items past i_size that needed to be deleted. In v3.12,
3424 * truncate was changed to update i_size in sync with the extent
3425 * items, but the (useless) orphan item was still created. Since
3426 * v4.18, we don't create the orphan item for truncate at all.
3427 *
3428 * So, this item could mean that we need to do a truncate, but
3429 * only if this filesystem was last used on a pre-v3.12 kernel
3430 * and was not cleanly unmounted. The odds of that are quite
3431 * slim, and it's a pain to do the truncate now, so just delete
3432 * the orphan item.
3433 *
3434 * It's also possible that this orphan item was supposed to be
3435 * deleted but wasn't. The inode number may have been reused,
3436 * but either way, we can delete the orphan item.
3437 */
3438 if (ret == -ENOENT || inode->i_nlink) {
3439 if (!ret)
3440 iput(inode);
3441 trans = btrfs_start_transaction(root, 1);
3442 if (IS_ERR(trans)) {
3443 ret = PTR_ERR(trans);
3444 goto out;
3445 }
3446 btrfs_debug(fs_info, "auto deleting %Lu",
3447 found_key.objectid);
3448 ret = btrfs_del_orphan_item(trans, root,
3449 found_key.objectid);
3450 btrfs_end_transaction(trans);
3451 if (ret)
3452 goto out;
3453 continue;
3454 }
3455
3456 nr_unlink++;
3457
3458 /* this will do delete_inode and everything for us */
3459 iput(inode);
3460 }
3461 /* release the path since we're done with it */
3462 btrfs_release_path(path);
3463
3464 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3465
3466 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3467 trans = btrfs_join_transaction(root);
3468 if (!IS_ERR(trans))
3469 btrfs_end_transaction(trans);
3470 }
3471
3472 if (nr_unlink)
3473 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3474
3475 out:
3476 if (ret)
3477 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3478 btrfs_free_path(path);
3479 return ret;
3480 }
3481
3482 /*
3483 * very simple check to peek ahead in the leaf looking for xattrs. If we
3484 * don't find any xattrs, we know there can't be any acls.
3485 *
3486 * slot is the slot the inode is in, objectid is the objectid of the inode
3487 */
3488 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3489 int slot, u64 objectid,
3490 int *first_xattr_slot)
3491 {
3492 u32 nritems = btrfs_header_nritems(leaf);
3493 struct btrfs_key found_key;
3494 static u64 xattr_access = 0;
3495 static u64 xattr_default = 0;
3496 int scanned = 0;
3497
3498 if (!xattr_access) {
3499 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3500 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3501 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3502 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3503 }
3504
3505 slot++;
3506 *first_xattr_slot = -1;
3507 while (slot < nritems) {
3508 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3509
3510 /* we found a different objectid, there must not be acls */
3511 if (found_key.objectid != objectid)
3512 return 0;
3513
3514 /* we found an xattr, assume we've got an acl */
3515 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3516 if (*first_xattr_slot == -1)
3517 *first_xattr_slot = slot;
3518 if (found_key.offset == xattr_access ||
3519 found_key.offset == xattr_default)
3520 return 1;
3521 }
3522
3523 /*
3524 * we found a key greater than an xattr key, there can't
3525 * be any acls later on
3526 */
3527 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3528 return 0;
3529
3530 slot++;
3531 scanned++;
3532
3533 /*
3534 * it goes inode, inode backrefs, xattrs, extents,
3535 * so if there are a ton of hard links to an inode there can
3536 * be a lot of backrefs. Don't waste time searching too hard,
3537 * this is just an optimization
3538 */
3539 if (scanned >= 8)
3540 break;
3541 }
3542 /* we hit the end of the leaf before we found an xattr or
3543 * something larger than an xattr. We have to assume the inode
3544 * has acls
3545 */
3546 if (*first_xattr_slot == -1)
3547 *first_xattr_slot = slot;
3548 return 1;
3549 }
3550
3551 /*
3552 * read an inode from the btree into the in-memory inode
3553 */
3554 static int btrfs_read_locked_inode(struct inode *inode,
3555 struct btrfs_path *in_path)
3556 {
3557 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3558 struct btrfs_path *path = in_path;
3559 struct extent_buffer *leaf;
3560 struct btrfs_inode_item *inode_item;
3561 struct btrfs_root *root = BTRFS_I(inode)->root;
3562 struct btrfs_key location;
3563 unsigned long ptr;
3564 int maybe_acls;
3565 u32 rdev;
3566 int ret;
3567 bool filled = false;
3568 int first_xattr_slot;
3569
3570 ret = btrfs_fill_inode(inode, &rdev);
3571 if (!ret)
3572 filled = true;
3573
3574 if (!path) {
3575 path = btrfs_alloc_path();
3576 if (!path)
3577 return -ENOMEM;
3578 }
3579
3580 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3581
3582 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3583 if (ret) {
3584 if (path != in_path)
3585 btrfs_free_path(path);
3586 return ret;
3587 }
3588
3589 leaf = path->nodes[0];
3590
3591 if (filled)
3592 goto cache_index;
3593
3594 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3595 struct btrfs_inode_item);
3596 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3597 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3598 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3599 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3600 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3601
3602 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3603 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3604
3605 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3606 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3607
3608 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3609 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3610
3611 BTRFS_I(inode)->i_otime.tv_sec =
3612 btrfs_timespec_sec(leaf, &inode_item->otime);
3613 BTRFS_I(inode)->i_otime.tv_nsec =
3614 btrfs_timespec_nsec(leaf, &inode_item->otime);
3615
3616 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3617 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3618 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3619
3620 inode_set_iversion_queried(inode,
3621 btrfs_inode_sequence(leaf, inode_item));
3622 inode->i_generation = BTRFS_I(inode)->generation;
3623 inode->i_rdev = 0;
3624 rdev = btrfs_inode_rdev(leaf, inode_item);
3625
3626 BTRFS_I(inode)->index_cnt = (u64)-1;
3627 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3628
3629 cache_index:
3630 /*
3631 * If we were modified in the current generation and evicted from memory
3632 * and then re-read we need to do a full sync since we don't have any
3633 * idea about which extents were modified before we were evicted from
3634 * cache.
3635 *
3636 * This is required for both inode re-read from disk and delayed inode
3637 * in delayed_nodes_tree.
3638 */
3639 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3640 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3641 &BTRFS_I(inode)->runtime_flags);
3642
3643 /*
3644 * We don't persist the id of the transaction where an unlink operation
3645 * against the inode was last made. So here we assume the inode might
3646 * have been evicted, and therefore the exact value of last_unlink_trans
3647 * lost, and set it to last_trans to avoid metadata inconsistencies
3648 * between the inode and its parent if the inode is fsync'ed and the log
3649 * replayed. For example, in the scenario:
3650 *
3651 * touch mydir/foo
3652 * ln mydir/foo mydir/bar
3653 * sync
3654 * unlink mydir/bar
3655 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3656 * xfs_io -c fsync mydir/foo
3657 * <power failure>
3658 * mount fs, triggers fsync log replay
3659 *
3660 * We must make sure that when we fsync our inode foo we also log its
3661 * parent inode, otherwise after log replay the parent still has the
3662 * dentry with the "bar" name but our inode foo has a link count of 1
3663 * and doesn't have an inode ref with the name "bar" anymore.
3664 *
3665 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3666 * but it guarantees correctness at the expense of occasional full
3667 * transaction commits on fsync if our inode is a directory, or if our
3668 * inode is not a directory, logging its parent unnecessarily.
3669 */
3670 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3671 /*
3672 * Similar reasoning for last_link_trans, needs to be set otherwise
3673 * for a case like the following:
3674 *
3675 * mkdir A
3676 * touch foo
3677 * ln foo A/bar
3678 * echo 2 > /proc/sys/vm/drop_caches
3679 * fsync foo
3680 * <power failure>
3681 *
3682 * Would result in link bar and directory A not existing after the power
3683 * failure.
3684 */
3685 BTRFS_I(inode)->last_link_trans = BTRFS_I(inode)->last_trans;
3686
3687 path->slots[0]++;
3688 if (inode->i_nlink != 1 ||
3689 path->slots[0] >= btrfs_header_nritems(leaf))
3690 goto cache_acl;
3691
3692 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3693 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3694 goto cache_acl;
3695
3696 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3697 if (location.type == BTRFS_INODE_REF_KEY) {
3698 struct btrfs_inode_ref *ref;
3699
3700 ref = (struct btrfs_inode_ref *)ptr;
3701 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3702 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3703 struct btrfs_inode_extref *extref;
3704
3705 extref = (struct btrfs_inode_extref *)ptr;
3706 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3707 extref);
3708 }
3709 cache_acl:
3710 /*
3711 * try to precache a NULL acl entry for files that don't have
3712 * any xattrs or acls
3713 */
3714 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3715 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3716 if (first_xattr_slot != -1) {
3717 path->slots[0] = first_xattr_slot;
3718 ret = btrfs_load_inode_props(inode, path);
3719 if (ret)
3720 btrfs_err(fs_info,
3721 "error loading props for ino %llu (root %llu): %d",
3722 btrfs_ino(BTRFS_I(inode)),
3723 root->root_key.objectid, ret);
3724 }
3725 if (path != in_path)
3726 btrfs_free_path(path);
3727
3728 if (!maybe_acls)
3729 cache_no_acl(inode);
3730
3731 switch (inode->i_mode & S_IFMT) {
3732 case S_IFREG:
3733 inode->i_mapping->a_ops = &btrfs_aops;
3734 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3735 inode->i_fop = &btrfs_file_operations;
3736 inode->i_op = &btrfs_file_inode_operations;
3737 break;
3738 case S_IFDIR:
3739 inode->i_fop = &btrfs_dir_file_operations;
3740 inode->i_op = &btrfs_dir_inode_operations;
3741 break;
3742 case S_IFLNK:
3743 inode->i_op = &btrfs_symlink_inode_operations;
3744 inode_nohighmem(inode);
3745 inode->i_mapping->a_ops = &btrfs_aops;
3746 break;
3747 default:
3748 inode->i_op = &btrfs_special_inode_operations;
3749 init_special_inode(inode, inode->i_mode, rdev);
3750 break;
3751 }
3752
3753 btrfs_sync_inode_flags_to_i_flags(inode);
3754 return 0;
3755 }
3756
3757 /*
3758 * given a leaf and an inode, copy the inode fields into the leaf
3759 */
3760 static void fill_inode_item(struct btrfs_trans_handle *trans,
3761 struct extent_buffer *leaf,
3762 struct btrfs_inode_item *item,
3763 struct inode *inode)
3764 {
3765 struct btrfs_map_token token;
3766
3767 btrfs_init_map_token(&token);
3768
3769 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3770 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3771 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3772 &token);
3773 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3774 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3775
3776 btrfs_set_token_timespec_sec(leaf, &item->atime,
3777 inode->i_atime.tv_sec, &token);
3778 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3779 inode->i_atime.tv_nsec, &token);
3780
3781 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3782 inode->i_mtime.tv_sec, &token);
3783 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3784 inode->i_mtime.tv_nsec, &token);
3785
3786 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3787 inode->i_ctime.tv_sec, &token);
3788 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3789 inode->i_ctime.tv_nsec, &token);
3790
3791 btrfs_set_token_timespec_sec(leaf, &item->otime,
3792 BTRFS_I(inode)->i_otime.tv_sec, &token);
3793 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3794 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3795
3796 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3797 &token);
3798 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3799 &token);
3800 btrfs_set_token_inode_sequence(leaf, item, inode_peek_iversion(inode),
3801 &token);
3802 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3803 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3804 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3805 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3806 }
3807
3808 /*
3809 * copy everything in the in-memory inode into the btree.
3810 */
3811 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3812 struct btrfs_root *root, struct inode *inode)
3813 {
3814 struct btrfs_inode_item *inode_item;
3815 struct btrfs_path *path;
3816 struct extent_buffer *leaf;
3817 int ret;
3818
3819 path = btrfs_alloc_path();
3820 if (!path)
3821 return -ENOMEM;
3822
3823 path->leave_spinning = 1;
3824 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3825 1);
3826 if (ret) {
3827 if (ret > 0)
3828 ret = -ENOENT;
3829 goto failed;
3830 }
3831
3832 leaf = path->nodes[0];
3833 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3834 struct btrfs_inode_item);
3835
3836 fill_inode_item(trans, leaf, inode_item, inode);
3837 btrfs_mark_buffer_dirty(leaf);
3838 btrfs_set_inode_last_trans(trans, inode);
3839 ret = 0;
3840 failed:
3841 btrfs_free_path(path);
3842 return ret;
3843 }
3844
3845 /*
3846 * copy everything in the in-memory inode into the btree.
3847 */
3848 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3849 struct btrfs_root *root, struct inode *inode)
3850 {
3851 struct btrfs_fs_info *fs_info = root->fs_info;
3852 int ret;
3853
3854 /*
3855 * If the inode is a free space inode, we can deadlock during commit
3856 * if we put it into the delayed code.
3857 *
3858 * The data relocation inode should also be directly updated
3859 * without delay
3860 */
3861 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
3862 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3863 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
3864 btrfs_update_root_times(trans, root);
3865
3866 ret = btrfs_delayed_update_inode(trans, root, inode);
3867 if (!ret)
3868 btrfs_set_inode_last_trans(trans, inode);
3869 return ret;
3870 }
3871
3872 return btrfs_update_inode_item(trans, root, inode);
3873 }
3874
3875 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3876 struct btrfs_root *root,
3877 struct inode *inode)
3878 {
3879 int ret;
3880
3881 ret = btrfs_update_inode(trans, root, inode);
3882 if (ret == -ENOSPC)
3883 return btrfs_update_inode_item(trans, root, inode);
3884 return ret;
3885 }
3886
3887 /*
3888 * unlink helper that gets used here in inode.c and in the tree logging
3889 * recovery code. It remove a link in a directory with a given name, and
3890 * also drops the back refs in the inode to the directory
3891 */
3892 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3893 struct btrfs_root *root,
3894 struct btrfs_inode *dir,
3895 struct btrfs_inode *inode,
3896 const char *name, int name_len)
3897 {
3898 struct btrfs_fs_info *fs_info = root->fs_info;
3899 struct btrfs_path *path;
3900 int ret = 0;
3901 struct extent_buffer *leaf;
3902 struct btrfs_dir_item *di;
3903 struct btrfs_key key;
3904 u64 index;
3905 u64 ino = btrfs_ino(inode);
3906 u64 dir_ino = btrfs_ino(dir);
3907
3908 path = btrfs_alloc_path();
3909 if (!path) {
3910 ret = -ENOMEM;
3911 goto out;
3912 }
3913
3914 path->leave_spinning = 1;
3915 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3916 name, name_len, -1);
3917 if (IS_ERR_OR_NULL(di)) {
3918 ret = di ? PTR_ERR(di) : -ENOENT;
3919 goto err;
3920 }
3921 leaf = path->nodes[0];
3922 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3923 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3924 if (ret)
3925 goto err;
3926 btrfs_release_path(path);
3927
3928 /*
3929 * If we don't have dir index, we have to get it by looking up
3930 * the inode ref, since we get the inode ref, remove it directly,
3931 * it is unnecessary to do delayed deletion.
3932 *
3933 * But if we have dir index, needn't search inode ref to get it.
3934 * Since the inode ref is close to the inode item, it is better
3935 * that we delay to delete it, and just do this deletion when
3936 * we update the inode item.
3937 */
3938 if (inode->dir_index) {
3939 ret = btrfs_delayed_delete_inode_ref(inode);
3940 if (!ret) {
3941 index = inode->dir_index;
3942 goto skip_backref;
3943 }
3944 }
3945
3946 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3947 dir_ino, &index);
3948 if (ret) {
3949 btrfs_info(fs_info,
3950 "failed to delete reference to %.*s, inode %llu parent %llu",
3951 name_len, name, ino, dir_ino);
3952 btrfs_abort_transaction(trans, ret);
3953 goto err;
3954 }
3955 skip_backref:
3956 ret = btrfs_delete_delayed_dir_index(trans, dir, index);
3957 if (ret) {
3958 btrfs_abort_transaction(trans, ret);
3959 goto err;
3960 }
3961
3962 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
3963 dir_ino);
3964 if (ret != 0 && ret != -ENOENT) {
3965 btrfs_abort_transaction(trans, ret);
3966 goto err;
3967 }
3968
3969 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
3970 index);
3971 if (ret == -ENOENT)
3972 ret = 0;
3973 else if (ret)
3974 btrfs_abort_transaction(trans, ret);
3975 err:
3976 btrfs_free_path(path);
3977 if (ret)
3978 goto out;
3979
3980 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
3981 inode_inc_iversion(&inode->vfs_inode);
3982 inode_inc_iversion(&dir->vfs_inode);
3983 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
3984 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
3985 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
3986 out:
3987 return ret;
3988 }
3989
3990 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3991 struct btrfs_root *root,
3992 struct btrfs_inode *dir, struct btrfs_inode *inode,
3993 const char *name, int name_len)
3994 {
3995 int ret;
3996 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3997 if (!ret) {
3998 drop_nlink(&inode->vfs_inode);
3999 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4000 }
4001 return ret;
4002 }
4003
4004 /*
4005 * helper to start transaction for unlink and rmdir.
4006 *
4007 * unlink and rmdir are special in btrfs, they do not always free space, so
4008 * if we cannot make our reservations the normal way try and see if there is
4009 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4010 * allow the unlink to occur.
4011 */
4012 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4013 {
4014 struct btrfs_root *root = BTRFS_I(dir)->root;
4015
4016 /*
4017 * 1 for the possible orphan item
4018 * 1 for the dir item
4019 * 1 for the dir index
4020 * 1 for the inode ref
4021 * 1 for the inode
4022 */
4023 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4024 }
4025
4026 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4027 {
4028 struct btrfs_root *root = BTRFS_I(dir)->root;
4029 struct btrfs_trans_handle *trans;
4030 struct inode *inode = d_inode(dentry);
4031 int ret;
4032
4033 trans = __unlink_start_trans(dir);
4034 if (IS_ERR(trans))
4035 return PTR_ERR(trans);
4036
4037 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4038 0);
4039
4040 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4041 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4042 dentry->d_name.len);
4043 if (ret)
4044 goto out;
4045
4046 if (inode->i_nlink == 0) {
4047 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4048 if (ret)
4049 goto out;
4050 }
4051
4052 out:
4053 btrfs_end_transaction(trans);
4054 btrfs_btree_balance_dirty(root->fs_info);
4055 return ret;
4056 }
4057
4058 static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4059 struct inode *dir, u64 objectid,
4060 const char *name, int name_len)
4061 {
4062 struct btrfs_root *root = BTRFS_I(dir)->root;
4063 struct btrfs_path *path;
4064 struct extent_buffer *leaf;
4065 struct btrfs_dir_item *di;
4066 struct btrfs_key key;
4067 u64 index;
4068 int ret;
4069 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4070
4071 path = btrfs_alloc_path();
4072 if (!path)
4073 return -ENOMEM;
4074
4075 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4076 name, name_len, -1);
4077 if (IS_ERR_OR_NULL(di)) {
4078 ret = di ? PTR_ERR(di) : -ENOENT;
4079 goto out;
4080 }
4081
4082 leaf = path->nodes[0];
4083 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4084 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4085 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4086 if (ret) {
4087 btrfs_abort_transaction(trans, ret);
4088 goto out;
4089 }
4090 btrfs_release_path(path);
4091
4092 ret = btrfs_del_root_ref(trans, objectid, root->root_key.objectid,
4093 dir_ino, &index, name, name_len);
4094 if (ret < 0) {
4095 if (ret != -ENOENT) {
4096 btrfs_abort_transaction(trans, ret);
4097 goto out;
4098 }
4099 di = btrfs_search_dir_index_item(root, path, dir_ino,
4100 name, name_len);
4101 if (IS_ERR_OR_NULL(di)) {
4102 if (!di)
4103 ret = -ENOENT;
4104 else
4105 ret = PTR_ERR(di);
4106 btrfs_abort_transaction(trans, ret);
4107 goto out;
4108 }
4109
4110 leaf = path->nodes[0];
4111 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4112 index = key.offset;
4113 }
4114 btrfs_release_path(path);
4115
4116 ret = btrfs_delete_delayed_dir_index(trans, BTRFS_I(dir), index);
4117 if (ret) {
4118 btrfs_abort_transaction(trans, ret);
4119 goto out;
4120 }
4121
4122 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4123 inode_inc_iversion(dir);
4124 dir->i_mtime = dir->i_ctime = current_time(dir);
4125 ret = btrfs_update_inode_fallback(trans, root, dir);
4126 if (ret)
4127 btrfs_abort_transaction(trans, ret);
4128 out:
4129 btrfs_free_path(path);
4130 return ret;
4131 }
4132
4133 /*
4134 * Helper to check if the subvolume references other subvolumes or if it's
4135 * default.
4136 */
4137 static noinline int may_destroy_subvol(struct btrfs_root *root)
4138 {
4139 struct btrfs_fs_info *fs_info = root->fs_info;
4140 struct btrfs_path *path;
4141 struct btrfs_dir_item *di;
4142 struct btrfs_key key;
4143 u64 dir_id;
4144 int ret;
4145
4146 path = btrfs_alloc_path();
4147 if (!path)
4148 return -ENOMEM;
4149
4150 /* Make sure this root isn't set as the default subvol */
4151 dir_id = btrfs_super_root_dir(fs_info->super_copy);
4152 di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
4153 dir_id, "default", 7, 0);
4154 if (di && !IS_ERR(di)) {
4155 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
4156 if (key.objectid == root->root_key.objectid) {
4157 ret = -EPERM;
4158 btrfs_err(fs_info,
4159 "deleting default subvolume %llu is not allowed",
4160 key.objectid);
4161 goto out;
4162 }
4163 btrfs_release_path(path);
4164 }
4165
4166 key.objectid = root->root_key.objectid;
4167 key.type = BTRFS_ROOT_REF_KEY;
4168 key.offset = (u64)-1;
4169
4170 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
4171 if (ret < 0)
4172 goto out;
4173 BUG_ON(ret == 0);
4174
4175 ret = 0;
4176 if (path->slots[0] > 0) {
4177 path->slots[0]--;
4178 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
4179 if (key.objectid == root->root_key.objectid &&
4180 key.type == BTRFS_ROOT_REF_KEY)
4181 ret = -ENOTEMPTY;
4182 }
4183 out:
4184 btrfs_free_path(path);
4185 return ret;
4186 }
4187
4188 /* Delete all dentries for inodes belonging to the root */
4189 static void btrfs_prune_dentries(struct btrfs_root *root)
4190 {
4191 struct btrfs_fs_info *fs_info = root->fs_info;
4192 struct rb_node *node;
4193 struct rb_node *prev;
4194 struct btrfs_inode *entry;
4195 struct inode *inode;
4196 u64 objectid = 0;
4197
4198 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
4199 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4200
4201 spin_lock(&root->inode_lock);
4202 again:
4203 node = root->inode_tree.rb_node;
4204 prev = NULL;
4205 while (node) {
4206 prev = node;
4207 entry = rb_entry(node, struct btrfs_inode, rb_node);
4208
4209 if (objectid < btrfs_ino(entry))
4210 node = node->rb_left;
4211 else if (objectid > btrfs_ino(entry))
4212 node = node->rb_right;
4213 else
4214 break;
4215 }
4216 if (!node) {
4217 while (prev) {
4218 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4219 if (objectid <= btrfs_ino(entry)) {
4220 node = prev;
4221 break;
4222 }
4223 prev = rb_next(prev);
4224 }
4225 }
4226 while (node) {
4227 entry = rb_entry(node, struct btrfs_inode, rb_node);
4228 objectid = btrfs_ino(entry) + 1;
4229 inode = igrab(&entry->vfs_inode);
4230 if (inode) {
4231 spin_unlock(&root->inode_lock);
4232 if (atomic_read(&inode->i_count) > 1)
4233 d_prune_aliases(inode);
4234 /*
4235 * btrfs_drop_inode will have it removed from the inode
4236 * cache when its usage count hits zero.
4237 */
4238 iput(inode);
4239 cond_resched();
4240 spin_lock(&root->inode_lock);
4241 goto again;
4242 }
4243
4244 if (cond_resched_lock(&root->inode_lock))
4245 goto again;
4246
4247 node = rb_next(node);
4248 }
4249 spin_unlock(&root->inode_lock);
4250 }
4251
4252 int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry)
4253 {
4254 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
4255 struct btrfs_root *root = BTRFS_I(dir)->root;
4256 struct inode *inode = d_inode(dentry);
4257 struct btrfs_root *dest = BTRFS_I(inode)->root;
4258 struct btrfs_trans_handle *trans;
4259 struct btrfs_block_rsv block_rsv;
4260 u64 root_flags;
4261 int ret;
4262 int err;
4263
4264 /*
4265 * Don't allow to delete a subvolume with send in progress. This is
4266 * inside the inode lock so the error handling that has to drop the bit
4267 * again is not run concurrently.
4268 */
4269 spin_lock(&dest->root_item_lock);
4270 if (dest->send_in_progress) {
4271 spin_unlock(&dest->root_item_lock);
4272 btrfs_warn(fs_info,
4273 "attempt to delete subvolume %llu during send",
4274 dest->root_key.objectid);
4275 return -EPERM;
4276 }
4277 root_flags = btrfs_root_flags(&dest->root_item);
4278 btrfs_set_root_flags(&dest->root_item,
4279 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
4280 spin_unlock(&dest->root_item_lock);
4281
4282 down_write(&fs_info->subvol_sem);
4283
4284 err = may_destroy_subvol(dest);
4285 if (err)
4286 goto out_up_write;
4287
4288 btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
4289 /*
4290 * One for dir inode,
4291 * two for dir entries,
4292 * two for root ref/backref.
4293 */
4294 err = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
4295 if (err)
4296 goto out_up_write;
4297
4298 trans = btrfs_start_transaction(root, 0);
4299 if (IS_ERR(trans)) {
4300 err = PTR_ERR(trans);
4301 goto out_release;
4302 }
4303 trans->block_rsv = &block_rsv;
4304 trans->bytes_reserved = block_rsv.size;
4305
4306 btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
4307
4308 ret = btrfs_unlink_subvol(trans, dir, dest->root_key.objectid,
4309 dentry->d_name.name, dentry->d_name.len);
4310 if (ret) {
4311 err = ret;
4312 btrfs_abort_transaction(trans, ret);
4313 goto out_end_trans;
4314 }
4315
4316 btrfs_record_root_in_trans(trans, dest);
4317
4318 memset(&dest->root_item.drop_progress, 0,
4319 sizeof(dest->root_item.drop_progress));
4320 dest->root_item.drop_level = 0;
4321 btrfs_set_root_refs(&dest->root_item, 0);
4322
4323 if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
4324 ret = btrfs_insert_orphan_item(trans,
4325 fs_info->tree_root,
4326 dest->root_key.objectid);
4327 if (ret) {
4328 btrfs_abort_transaction(trans, ret);
4329 err = ret;
4330 goto out_end_trans;
4331 }
4332 }
4333
4334 ret = btrfs_uuid_tree_remove(trans, dest->root_item.uuid,
4335 BTRFS_UUID_KEY_SUBVOL,
4336 dest->root_key.objectid);
4337 if (ret && ret != -ENOENT) {
4338 btrfs_abort_transaction(trans, ret);
4339 err = ret;
4340 goto out_end_trans;
4341 }
4342 if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
4343 ret = btrfs_uuid_tree_remove(trans,
4344 dest->root_item.received_uuid,
4345 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4346 dest->root_key.objectid);
4347 if (ret && ret != -ENOENT) {
4348 btrfs_abort_transaction(trans, ret);
4349 err = ret;
4350 goto out_end_trans;
4351 }
4352 }
4353
4354 out_end_trans:
4355 trans->block_rsv = NULL;
4356 trans->bytes_reserved = 0;
4357 ret = btrfs_end_transaction(trans);
4358 if (ret && !err)
4359 err = ret;
4360 inode->i_flags |= S_DEAD;
4361 out_release:
4362 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
4363 out_up_write:
4364 up_write(&fs_info->subvol_sem);
4365 if (err) {
4366 spin_lock(&dest->root_item_lock);
4367 root_flags = btrfs_root_flags(&dest->root_item);
4368 btrfs_set_root_flags(&dest->root_item,
4369 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
4370 spin_unlock(&dest->root_item_lock);
4371 } else {
4372 d_invalidate(dentry);
4373 btrfs_prune_dentries(dest);
4374 ASSERT(dest->send_in_progress == 0);
4375
4376 /* the last ref */
4377 if (dest->ino_cache_inode) {
4378 iput(dest->ino_cache_inode);
4379 dest->ino_cache_inode = NULL;
4380 }
4381 }
4382
4383 return err;
4384 }
4385
4386 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4387 {
4388 struct inode *inode = d_inode(dentry);
4389 int err = 0;
4390 struct btrfs_root *root = BTRFS_I(dir)->root;
4391 struct btrfs_trans_handle *trans;
4392 u64 last_unlink_trans;
4393
4394 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4395 return -ENOTEMPTY;
4396 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4397 return btrfs_delete_subvolume(dir, dentry);
4398
4399 trans = __unlink_start_trans(dir);
4400 if (IS_ERR(trans))
4401 return PTR_ERR(trans);
4402
4403 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4404 err = btrfs_unlink_subvol(trans, dir,
4405 BTRFS_I(inode)->location.objectid,
4406 dentry->d_name.name,
4407 dentry->d_name.len);
4408 goto out;
4409 }
4410
4411 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4412 if (err)
4413 goto out;
4414
4415 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4416
4417 /* now the directory is empty */
4418 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4419 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4420 dentry->d_name.len);
4421 if (!err) {
4422 btrfs_i_size_write(BTRFS_I(inode), 0);
4423 /*
4424 * Propagate the last_unlink_trans value of the deleted dir to
4425 * its parent directory. This is to prevent an unrecoverable
4426 * log tree in the case we do something like this:
4427 * 1) create dir foo
4428 * 2) create snapshot under dir foo
4429 * 3) delete the snapshot
4430 * 4) rmdir foo
4431 * 5) mkdir foo
4432 * 6) fsync foo or some file inside foo
4433 */
4434 if (last_unlink_trans >= trans->transid)
4435 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4436 }
4437 out:
4438 btrfs_end_transaction(trans);
4439 btrfs_btree_balance_dirty(root->fs_info);
4440
4441 return err;
4442 }
4443
4444 /*
4445 * Return this if we need to call truncate_block for the last bit of the
4446 * truncate.
4447 */
4448 #define NEED_TRUNCATE_BLOCK 1
4449
4450 /*
4451 * this can truncate away extent items, csum items and directory items.
4452 * It starts at a high offset and removes keys until it can't find
4453 * any higher than new_size
4454 *
4455 * csum items that cross the new i_size are truncated to the new size
4456 * as well.
4457 *
4458 * min_type is the minimum key type to truncate down to. If set to 0, this
4459 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4460 */
4461 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4462 struct btrfs_root *root,
4463 struct inode *inode,
4464 u64 new_size, u32 min_type)
4465 {
4466 struct btrfs_fs_info *fs_info = root->fs_info;
4467 struct btrfs_path *path;
4468 struct extent_buffer *leaf;
4469 struct btrfs_file_extent_item *fi;
4470 struct btrfs_key key;
4471 struct btrfs_key found_key;
4472 u64 extent_start = 0;
4473 u64 extent_num_bytes = 0;
4474 u64 extent_offset = 0;
4475 u64 item_end = 0;
4476 u64 last_size = new_size;
4477 u32 found_type = (u8)-1;
4478 int found_extent;
4479 int del_item;
4480 int pending_del_nr = 0;
4481 int pending_del_slot = 0;
4482 int extent_type = -1;
4483 int ret;
4484 u64 ino = btrfs_ino(BTRFS_I(inode));
4485 u64 bytes_deleted = 0;
4486 bool be_nice = false;
4487 bool should_throttle = false;
4488
4489 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4490
4491 /*
4492 * for non-free space inodes and ref cows, we want to back off from
4493 * time to time
4494 */
4495 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4496 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4497 be_nice = true;
4498
4499 path = btrfs_alloc_path();
4500 if (!path)
4501 return -ENOMEM;
4502 path->reada = READA_BACK;
4503
4504 /*
4505 * We want to drop from the next block forward in case this new size is
4506 * not block aligned since we will be keeping the last block of the
4507 * extent just the way it is.
4508 */
4509 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4510 root == fs_info->tree_root)
4511 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4512 fs_info->sectorsize),
4513 (u64)-1, 0);
4514
4515 /*
4516 * This function is also used to drop the items in the log tree before
4517 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4518 * it is used to drop the logged items. So we shouldn't kill the delayed
4519 * items.
4520 */
4521 if (min_type == 0 && root == BTRFS_I(inode)->root)
4522 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4523
4524 key.objectid = ino;
4525 key.offset = (u64)-1;
4526 key.type = (u8)-1;
4527
4528 search_again:
4529 /*
4530 * with a 16K leaf size and 128MB extents, you can actually queue
4531 * up a huge file in a single leaf. Most of the time that
4532 * bytes_deleted is > 0, it will be huge by the time we get here
4533 */
4534 if (be_nice && bytes_deleted > SZ_32M &&
4535 btrfs_should_end_transaction(trans)) {
4536 ret = -EAGAIN;
4537 goto out;
4538 }
4539
4540 path->leave_spinning = 1;
4541 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4542 if (ret < 0)
4543 goto out;
4544
4545 if (ret > 0) {
4546 ret = 0;
4547 /* there are no items in the tree for us to truncate, we're
4548 * done
4549 */
4550 if (path->slots[0] == 0)
4551 goto out;
4552 path->slots[0]--;
4553 }
4554
4555 while (1) {
4556 fi = NULL;
4557 leaf = path->nodes[0];
4558 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4559 found_type = found_key.type;
4560
4561 if (found_key.objectid != ino)
4562 break;
4563
4564 if (found_type < min_type)
4565 break;
4566
4567 item_end = found_key.offset;
4568 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4569 fi = btrfs_item_ptr(leaf, path->slots[0],
4570 struct btrfs_file_extent_item);
4571 extent_type = btrfs_file_extent_type(leaf, fi);
4572 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4573 item_end +=
4574 btrfs_file_extent_num_bytes(leaf, fi);
4575
4576 trace_btrfs_truncate_show_fi_regular(
4577 BTRFS_I(inode), leaf, fi,
4578 found_key.offset);
4579 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4580 item_end += btrfs_file_extent_ram_bytes(leaf,
4581 fi);
4582
4583 trace_btrfs_truncate_show_fi_inline(
4584 BTRFS_I(inode), leaf, fi, path->slots[0],
4585 found_key.offset);
4586 }
4587 item_end--;
4588 }
4589 if (found_type > min_type) {
4590 del_item = 1;
4591 } else {
4592 if (item_end < new_size)
4593 break;
4594 if (found_key.offset >= new_size)
4595 del_item = 1;
4596 else
4597 del_item = 0;
4598 }
4599 found_extent = 0;
4600 /* FIXME, shrink the extent if the ref count is only 1 */
4601 if (found_type != BTRFS_EXTENT_DATA_KEY)
4602 goto delete;
4603
4604 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4605 u64 num_dec;
4606 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4607 if (!del_item) {
4608 u64 orig_num_bytes =
4609 btrfs_file_extent_num_bytes(leaf, fi);
4610 extent_num_bytes = ALIGN(new_size -
4611 found_key.offset,
4612 fs_info->sectorsize);
4613 btrfs_set_file_extent_num_bytes(leaf, fi,
4614 extent_num_bytes);
4615 num_dec = (orig_num_bytes -
4616 extent_num_bytes);
4617 if (test_bit(BTRFS_ROOT_REF_COWS,
4618 &root->state) &&
4619 extent_start != 0)
4620 inode_sub_bytes(inode, num_dec);
4621 btrfs_mark_buffer_dirty(leaf);
4622 } else {
4623 extent_num_bytes =
4624 btrfs_file_extent_disk_num_bytes(leaf,
4625 fi);
4626 extent_offset = found_key.offset -
4627 btrfs_file_extent_offset(leaf, fi);
4628
4629 /* FIXME blocksize != 4096 */
4630 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4631 if (extent_start != 0) {
4632 found_extent = 1;
4633 if (test_bit(BTRFS_ROOT_REF_COWS,
4634 &root->state))
4635 inode_sub_bytes(inode, num_dec);
4636 }
4637 }
4638 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4639 /*
4640 * we can't truncate inline items that have had
4641 * special encodings
4642 */
4643 if (!del_item &&
4644 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4645 btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
4646 btrfs_file_extent_compression(leaf, fi) == 0) {
4647 u32 size = (u32)(new_size - found_key.offset);
4648
4649 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4650 size = btrfs_file_extent_calc_inline_size(size);
4651 btrfs_truncate_item(root->fs_info, path, size, 1);
4652 } else if (!del_item) {
4653 /*
4654 * We have to bail so the last_size is set to
4655 * just before this extent.
4656 */
4657 ret = NEED_TRUNCATE_BLOCK;
4658 break;
4659 }
4660
4661 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4662 inode_sub_bytes(inode, item_end + 1 - new_size);
4663 }
4664 delete:
4665 if (del_item)
4666 last_size = found_key.offset;
4667 else
4668 last_size = new_size;
4669 if (del_item) {
4670 if (!pending_del_nr) {
4671 /* no pending yet, add ourselves */
4672 pending_del_slot = path->slots[0];
4673 pending_del_nr = 1;
4674 } else if (pending_del_nr &&
4675 path->slots[0] + 1 == pending_del_slot) {
4676 /* hop on the pending chunk */
4677 pending_del_nr++;
4678 pending_del_slot = path->slots[0];
4679 } else {
4680 BUG();
4681 }
4682 } else {
4683 break;
4684 }
4685 should_throttle = false;
4686
4687 if (found_extent &&
4688 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4689 root == fs_info->tree_root)) {
4690 btrfs_set_path_blocking(path);
4691 bytes_deleted += extent_num_bytes;
4692 ret = btrfs_free_extent(trans, root, extent_start,
4693 extent_num_bytes, 0,
4694 btrfs_header_owner(leaf),
4695 ino, extent_offset);
4696 if (ret) {
4697 btrfs_abort_transaction(trans, ret);
4698 break;
4699 }
4700 if (be_nice) {
4701 if (btrfs_should_throttle_delayed_refs(trans))
4702 should_throttle = true;
4703 }
4704 }
4705
4706 if (found_type == BTRFS_INODE_ITEM_KEY)
4707 break;
4708
4709 if (path->slots[0] == 0 ||
4710 path->slots[0] != pending_del_slot ||
4711 should_throttle) {
4712 if (pending_del_nr) {
4713 ret = btrfs_del_items(trans, root, path,
4714 pending_del_slot,
4715 pending_del_nr);
4716 if (ret) {
4717 btrfs_abort_transaction(trans, ret);
4718 break;
4719 }
4720 pending_del_nr = 0;
4721 }
4722 btrfs_release_path(path);
4723
4724 /*
4725 * We can generate a lot of delayed refs, so we need to
4726 * throttle every once and a while and make sure we're
4727 * adding enough space to keep up with the work we are
4728 * generating. Since we hold a transaction here we
4729 * can't flush, and we don't want to FLUSH_LIMIT because
4730 * we could have generated too many delayed refs to
4731 * actually allocate, so just bail if we're short and
4732 * let the normal reservation dance happen higher up.
4733 */
4734 if (should_throttle) {
4735 ret = btrfs_delayed_refs_rsv_refill(fs_info,
4736 BTRFS_RESERVE_NO_FLUSH);
4737 if (ret) {
4738 ret = -EAGAIN;
4739 break;
4740 }
4741 }
4742 goto search_again;
4743 } else {
4744 path->slots[0]--;
4745 }
4746 }
4747 out:
4748 if (ret >= 0 && pending_del_nr) {
4749 int err;
4750
4751 err = btrfs_del_items(trans, root, path, pending_del_slot,
4752 pending_del_nr);
4753 if (err) {
4754 btrfs_abort_transaction(trans, err);
4755 ret = err;
4756 }
4757 }
4758 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4759 ASSERT(last_size >= new_size);
4760 if (!ret && last_size > new_size)
4761 last_size = new_size;
4762 btrfs_ordered_update_i_size(inode, last_size, NULL);
4763 }
4764
4765 btrfs_free_path(path);
4766 return ret;
4767 }
4768
4769 /*
4770 * btrfs_truncate_block - read, zero a chunk and write a block
4771 * @inode - inode that we're zeroing
4772 * @from - the offset to start zeroing
4773 * @len - the length to zero, 0 to zero the entire range respective to the
4774 * offset
4775 * @front - zero up to the offset instead of from the offset on
4776 *
4777 * This will find the block for the "from" offset and cow the block and zero the
4778 * part we want to zero. This is used with truncate and hole punching.
4779 */
4780 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4781 int front)
4782 {
4783 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4784 struct address_space *mapping = inode->i_mapping;
4785 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4786 struct btrfs_ordered_extent *ordered;
4787 struct extent_state *cached_state = NULL;
4788 struct extent_changeset *data_reserved = NULL;
4789 char *kaddr;
4790 u32 blocksize = fs_info->sectorsize;
4791 pgoff_t index = from >> PAGE_SHIFT;
4792 unsigned offset = from & (blocksize - 1);
4793 struct page *page;
4794 gfp_t mask = btrfs_alloc_write_mask(mapping);
4795 int ret = 0;
4796 u64 block_start;
4797 u64 block_end;
4798
4799 if (IS_ALIGNED(offset, blocksize) &&
4800 (!len || IS_ALIGNED(len, blocksize)))
4801 goto out;
4802
4803 block_start = round_down(from, blocksize);
4804 block_end = block_start + blocksize - 1;
4805
4806 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
4807 block_start, blocksize);
4808 if (ret)
4809 goto out;
4810
4811 again:
4812 page = find_or_create_page(mapping, index, mask);
4813 if (!page) {
4814 btrfs_delalloc_release_space(inode, data_reserved,
4815 block_start, blocksize, true);
4816 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, true);
4817 ret = -ENOMEM;
4818 goto out;
4819 }
4820
4821 if (!PageUptodate(page)) {
4822 ret = btrfs_readpage(NULL, page);
4823 lock_page(page);
4824 if (page->mapping != mapping) {
4825 unlock_page(page);
4826 put_page(page);
4827 goto again;
4828 }
4829 if (!PageUptodate(page)) {
4830 ret = -EIO;
4831 goto out_unlock;
4832 }
4833 }
4834 wait_on_page_writeback(page);
4835
4836 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4837 set_page_extent_mapped(page);
4838
4839 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4840 if (ordered) {
4841 unlock_extent_cached(io_tree, block_start, block_end,
4842 &cached_state);
4843 unlock_page(page);
4844 put_page(page);
4845 btrfs_start_ordered_extent(inode, ordered, 1);
4846 btrfs_put_ordered_extent(ordered);
4847 goto again;
4848 }
4849
4850 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4851 EXTENT_DIRTY | EXTENT_DELALLOC |
4852 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4853 0, 0, &cached_state);
4854
4855 ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
4856 &cached_state, 0);
4857 if (ret) {
4858 unlock_extent_cached(io_tree, block_start, block_end,
4859 &cached_state);
4860 goto out_unlock;
4861 }
4862
4863 if (offset != blocksize) {
4864 if (!len)
4865 len = blocksize - offset;
4866 kaddr = kmap(page);
4867 if (front)
4868 memset(kaddr + (block_start - page_offset(page)),
4869 0, offset);
4870 else
4871 memset(kaddr + (block_start - page_offset(page)) + offset,
4872 0, len);
4873 flush_dcache_page(page);
4874 kunmap(page);
4875 }
4876 ClearPageChecked(page);
4877 set_page_dirty(page);
4878 unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
4879
4880 out_unlock:
4881 if (ret)
4882 btrfs_delalloc_release_space(inode, data_reserved, block_start,
4883 blocksize, true);
4884 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, (ret != 0));
4885 unlock_page(page);
4886 put_page(page);
4887 out:
4888 extent_changeset_free(data_reserved);
4889 return ret;
4890 }
4891
4892 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4893 u64 offset, u64 len)
4894 {
4895 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4896 struct btrfs_trans_handle *trans;
4897 int ret;
4898
4899 /*
4900 * Still need to make sure the inode looks like it's been updated so
4901 * that any holes get logged if we fsync.
4902 */
4903 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4904 BTRFS_I(inode)->last_trans = fs_info->generation;
4905 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4906 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4907 return 0;
4908 }
4909
4910 /*
4911 * 1 - for the one we're dropping
4912 * 1 - for the one we're adding
4913 * 1 - for updating the inode.
4914 */
4915 trans = btrfs_start_transaction(root, 3);
4916 if (IS_ERR(trans))
4917 return PTR_ERR(trans);
4918
4919 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4920 if (ret) {
4921 btrfs_abort_transaction(trans, ret);
4922 btrfs_end_transaction(trans);
4923 return ret;
4924 }
4925
4926 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4927 offset, 0, 0, len, 0, len, 0, 0, 0);
4928 if (ret)
4929 btrfs_abort_transaction(trans, ret);
4930 else
4931 btrfs_update_inode(trans, root, inode);
4932 btrfs_end_transaction(trans);
4933 return ret;
4934 }
4935
4936 /*
4937 * This function puts in dummy file extents for the area we're creating a hole
4938 * for. So if we are truncating this file to a larger size we need to insert
4939 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4940 * the range between oldsize and size
4941 */
4942 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4943 {
4944 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4945 struct btrfs_root *root = BTRFS_I(inode)->root;
4946 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4947 struct extent_map *em = NULL;
4948 struct extent_state *cached_state = NULL;
4949 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4950 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4951 u64 block_end = ALIGN(size, fs_info->sectorsize);
4952 u64 last_byte;
4953 u64 cur_offset;
4954 u64 hole_size;
4955 int err = 0;
4956
4957 /*
4958 * If our size started in the middle of a block we need to zero out the
4959 * rest of the block before we expand the i_size, otherwise we could
4960 * expose stale data.
4961 */
4962 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4963 if (err)
4964 return err;
4965
4966 if (size <= hole_start)
4967 return 0;
4968
4969 while (1) {
4970 struct btrfs_ordered_extent *ordered;
4971
4972 lock_extent_bits(io_tree, hole_start, block_end - 1,
4973 &cached_state);
4974 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4975 block_end - hole_start);
4976 if (!ordered)
4977 break;
4978 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4979 &cached_state);
4980 btrfs_start_ordered_extent(inode, ordered, 1);
4981 btrfs_put_ordered_extent(ordered);
4982 }
4983
4984 cur_offset = hole_start;
4985 while (1) {
4986 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4987 block_end - cur_offset, 0);
4988 if (IS_ERR(em)) {
4989 err = PTR_ERR(em);
4990 em = NULL;
4991 break;
4992 }
4993 last_byte = min(extent_map_end(em), block_end);
4994 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4995 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4996 struct extent_map *hole_em;
4997 hole_size = last_byte - cur_offset;
4998
4999 err = maybe_insert_hole(root, inode, cur_offset,
5000 hole_size);
5001 if (err)
5002 break;
5003 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
5004 cur_offset + hole_size - 1, 0);
5005 hole_em = alloc_extent_map();
5006 if (!hole_em) {
5007 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
5008 &BTRFS_I(inode)->runtime_flags);
5009 goto next;
5010 }
5011 hole_em->start = cur_offset;
5012 hole_em->len = hole_size;
5013 hole_em->orig_start = cur_offset;
5014
5015 hole_em->block_start = EXTENT_MAP_HOLE;
5016 hole_em->block_len = 0;
5017 hole_em->orig_block_len = 0;
5018 hole_em->ram_bytes = hole_size;
5019 hole_em->bdev = fs_info->fs_devices->latest_bdev;
5020 hole_em->compress_type = BTRFS_COMPRESS_NONE;
5021 hole_em->generation = fs_info->generation;
5022
5023 while (1) {
5024 write_lock(&em_tree->lock);
5025 err = add_extent_mapping(em_tree, hole_em, 1);
5026 write_unlock(&em_tree->lock);
5027 if (err != -EEXIST)
5028 break;
5029 btrfs_drop_extent_cache(BTRFS_I(inode),
5030 cur_offset,
5031 cur_offset +
5032 hole_size - 1, 0);
5033 }
5034 free_extent_map(hole_em);
5035 }
5036 next:
5037 free_extent_map(em);
5038 em = NULL;
5039 cur_offset = last_byte;
5040 if (cur_offset >= block_end)
5041 break;
5042 }
5043 free_extent_map(em);
5044 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
5045 return err;
5046 }
5047
5048 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5049 {
5050 struct btrfs_root *root = BTRFS_I(inode)->root;
5051 struct btrfs_trans_handle *trans;
5052 loff_t oldsize = i_size_read(inode);
5053 loff_t newsize = attr->ia_size;
5054 int mask = attr->ia_valid;
5055 int ret;
5056
5057 /*
5058 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5059 * special case where we need to update the times despite not having
5060 * these flags set. For all other operations the VFS set these flags
5061 * explicitly if it wants a timestamp update.
5062 */
5063 if (newsize != oldsize) {
5064 inode_inc_iversion(inode);
5065 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5066 inode->i_ctime = inode->i_mtime =
5067 current_time(inode);
5068 }
5069
5070 if (newsize > oldsize) {
5071 /*
5072 * Don't do an expanding truncate while snapshotting is ongoing.
5073 * This is to ensure the snapshot captures a fully consistent
5074 * state of this file - if the snapshot captures this expanding
5075 * truncation, it must capture all writes that happened before
5076 * this truncation.
5077 */
5078 btrfs_wait_for_snapshot_creation(root);
5079 ret = btrfs_cont_expand(inode, oldsize, newsize);
5080 if (ret) {
5081 btrfs_end_write_no_snapshotting(root);
5082 return ret;
5083 }
5084
5085 trans = btrfs_start_transaction(root, 1);
5086 if (IS_ERR(trans)) {
5087 btrfs_end_write_no_snapshotting(root);
5088 return PTR_ERR(trans);
5089 }
5090
5091 i_size_write(inode, newsize);
5092 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5093 pagecache_isize_extended(inode, oldsize, newsize);
5094 ret = btrfs_update_inode(trans, root, inode);
5095 btrfs_end_write_no_snapshotting(root);
5096 btrfs_end_transaction(trans);
5097 } else {
5098
5099 /*
5100 * We're truncating a file that used to have good data down to
5101 * zero. Make sure it gets into the ordered flush list so that
5102 * any new writes get down to disk quickly.
5103 */
5104 if (newsize == 0)
5105 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5106 &BTRFS_I(inode)->runtime_flags);
5107
5108 truncate_setsize(inode, newsize);
5109
5110 /* Disable nonlocked read DIO to avoid the endless truncate */
5111 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5112 inode_dio_wait(inode);
5113 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5114
5115 ret = btrfs_truncate(inode, newsize == oldsize);
5116 if (ret && inode->i_nlink) {
5117 int err;
5118
5119 /*
5120 * Truncate failed, so fix up the in-memory size. We
5121 * adjusted disk_i_size down as we removed extents, so
5122 * wait for disk_i_size to be stable and then update the
5123 * in-memory size to match.
5124 */
5125 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5126 if (err)
5127 return err;
5128 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5129 }
5130 }
5131
5132 return ret;
5133 }
5134
5135 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5136 {
5137 struct inode *inode = d_inode(dentry);
5138 struct btrfs_root *root = BTRFS_I(inode)->root;
5139 int err;
5140
5141 if (btrfs_root_readonly(root))
5142 return -EROFS;
5143
5144 err = setattr_prepare(dentry, attr);
5145 if (err)
5146 return err;
5147
5148 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5149 err = btrfs_setsize(inode, attr);
5150 if (err)
5151 return err;
5152 }
5153
5154 if (attr->ia_valid) {
5155 setattr_copy(inode, attr);
5156 inode_inc_iversion(inode);
5157 err = btrfs_dirty_inode(inode);
5158
5159 if (!err && attr->ia_valid & ATTR_MODE)
5160 err = posix_acl_chmod(inode, inode->i_mode);
5161 }
5162
5163 return err;
5164 }
5165
5166 /*
5167 * While truncating the inode pages during eviction, we get the VFS calling
5168 * btrfs_invalidatepage() against each page of the inode. This is slow because
5169 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5170 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5171 * extent_state structures over and over, wasting lots of time.
5172 *
5173 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5174 * those expensive operations on a per page basis and do only the ordered io
5175 * finishing, while we release here the extent_map and extent_state structures,
5176 * without the excessive merging and splitting.
5177 */
5178 static void evict_inode_truncate_pages(struct inode *inode)
5179 {
5180 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5181 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5182 struct rb_node *node;
5183
5184 ASSERT(inode->i_state & I_FREEING);
5185 truncate_inode_pages_final(&inode->i_data);
5186
5187 write_lock(&map_tree->lock);
5188 while (!RB_EMPTY_ROOT(&map_tree->map.rb_root)) {
5189 struct extent_map *em;
5190
5191 node = rb_first_cached(&map_tree->map);
5192 em = rb_entry(node, struct extent_map, rb_node);
5193 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5194 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5195 remove_extent_mapping(map_tree, em);
5196 free_extent_map(em);
5197 if (need_resched()) {
5198 write_unlock(&map_tree->lock);
5199 cond_resched();
5200 write_lock(&map_tree->lock);
5201 }
5202 }
5203 write_unlock(&map_tree->lock);
5204
5205 /*
5206 * Keep looping until we have no more ranges in the io tree.
5207 * We can have ongoing bios started by readpages (called from readahead)
5208 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5209 * still in progress (unlocked the pages in the bio but did not yet
5210 * unlocked the ranges in the io tree). Therefore this means some
5211 * ranges can still be locked and eviction started because before
5212 * submitting those bios, which are executed by a separate task (work
5213 * queue kthread), inode references (inode->i_count) were not taken
5214 * (which would be dropped in the end io callback of each bio).
5215 * Therefore here we effectively end up waiting for those bios and
5216 * anyone else holding locked ranges without having bumped the inode's
5217 * reference count - if we don't do it, when they access the inode's
5218 * io_tree to unlock a range it may be too late, leading to an
5219 * use-after-free issue.
5220 */
5221 spin_lock(&io_tree->lock);
5222 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5223 struct extent_state *state;
5224 struct extent_state *cached_state = NULL;
5225 u64 start;
5226 u64 end;
5227 unsigned state_flags;
5228
5229 node = rb_first(&io_tree->state);
5230 state = rb_entry(node, struct extent_state, rb_node);
5231 start = state->start;
5232 end = state->end;
5233 state_flags = state->state;
5234 spin_unlock(&io_tree->lock);
5235
5236 lock_extent_bits(io_tree, start, end, &cached_state);
5237
5238 /*
5239 * If still has DELALLOC flag, the extent didn't reach disk,
5240 * and its reserved space won't be freed by delayed_ref.
5241 * So we need to free its reserved space here.
5242 * (Refer to comment in btrfs_invalidatepage, case 2)
5243 *
5244 * Note, end is the bytenr of last byte, so we need + 1 here.
5245 */
5246 if (state_flags & EXTENT_DELALLOC)
5247 btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5248
5249 clear_extent_bit(io_tree, start, end,
5250 EXTENT_LOCKED | EXTENT_DIRTY |
5251 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5252 EXTENT_DEFRAG, 1, 1, &cached_state);
5253
5254 cond_resched();
5255 spin_lock(&io_tree->lock);
5256 }
5257 spin_unlock(&io_tree->lock);
5258 }
5259
5260 static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
5261 struct btrfs_block_rsv *rsv)
5262 {
5263 struct btrfs_fs_info *fs_info = root->fs_info;
5264 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5265 int failures = 0;
5266
5267 for (;;) {
5268 struct btrfs_trans_handle *trans;
5269 int ret;
5270
5271 ret = btrfs_block_rsv_refill(root, rsv, rsv->size,
5272 BTRFS_RESERVE_FLUSH_LIMIT);
5273
5274 if (ret && ++failures > 2) {
5275 btrfs_warn(fs_info,
5276 "could not allocate space for a delete; will truncate on mount");
5277 return ERR_PTR(-ENOSPC);
5278 }
5279
5280 trans = btrfs_join_transaction(root);
5281 if (IS_ERR(trans) || !ret)
5282 return trans;
5283
5284 /*
5285 * Try to steal from the global reserve if there is space for
5286 * it.
5287 */
5288 if (!btrfs_check_space_for_delayed_refs(fs_info) &&
5289 !btrfs_block_rsv_migrate(global_rsv, rsv, rsv->size, 0))
5290 return trans;
5291
5292 /* If not, commit and try again. */
5293 ret = btrfs_commit_transaction(trans);
5294 if (ret)
5295 return ERR_PTR(ret);
5296 }
5297 }
5298
5299 void btrfs_evict_inode(struct inode *inode)
5300 {
5301 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5302 struct btrfs_trans_handle *trans;
5303 struct btrfs_root *root = BTRFS_I(inode)->root;
5304 struct btrfs_block_rsv *rsv;
5305 int ret;
5306
5307 trace_btrfs_inode_evict(inode);
5308
5309 if (!root) {
5310 clear_inode(inode);
5311 return;
5312 }
5313
5314 evict_inode_truncate_pages(inode);
5315
5316 if (inode->i_nlink &&
5317 ((btrfs_root_refs(&root->root_item) != 0 &&
5318 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5319 btrfs_is_free_space_inode(BTRFS_I(inode))))
5320 goto no_delete;
5321
5322 if (is_bad_inode(inode))
5323 goto no_delete;
5324
5325 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5326
5327 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
5328 goto no_delete;
5329
5330 if (inode->i_nlink > 0) {
5331 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5332 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5333 goto no_delete;
5334 }
5335
5336 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5337 if (ret)
5338 goto no_delete;
5339
5340 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5341 if (!rsv)
5342 goto no_delete;
5343 rsv->size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5344 rsv->failfast = 1;
5345
5346 btrfs_i_size_write(BTRFS_I(inode), 0);
5347
5348 while (1) {
5349 trans = evict_refill_and_join(root, rsv);
5350 if (IS_ERR(trans))
5351 goto free_rsv;
5352
5353 trans->block_rsv = rsv;
5354
5355 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5356 trans->block_rsv = &fs_info->trans_block_rsv;
5357 btrfs_end_transaction(trans);
5358 btrfs_btree_balance_dirty(fs_info);
5359 if (ret && ret != -ENOSPC && ret != -EAGAIN)
5360 goto free_rsv;
5361 else if (!ret)
5362 break;
5363 }
5364
5365 /*
5366 * Errors here aren't a big deal, it just means we leave orphan items in
5367 * the tree. They will be cleaned up on the next mount. If the inode
5368 * number gets reused, cleanup deletes the orphan item without doing
5369 * anything, and unlink reuses the existing orphan item.
5370 *
5371 * If it turns out that we are dropping too many of these, we might want
5372 * to add a mechanism for retrying these after a commit.
5373 */
5374 trans = evict_refill_and_join(root, rsv);
5375 if (!IS_ERR(trans)) {
5376 trans->block_rsv = rsv;
5377 btrfs_orphan_del(trans, BTRFS_I(inode));
5378 trans->block_rsv = &fs_info->trans_block_rsv;
5379 btrfs_end_transaction(trans);
5380 }
5381
5382 if (!(root == fs_info->tree_root ||
5383 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5384 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5385
5386 free_rsv:
5387 btrfs_free_block_rsv(fs_info, rsv);
5388 no_delete:
5389 /*
5390 * If we didn't successfully delete, the orphan item will still be in
5391 * the tree and we'll retry on the next mount. Again, we might also want
5392 * to retry these periodically in the future.
5393 */
5394 btrfs_remove_delayed_node(BTRFS_I(inode));
5395 clear_inode(inode);
5396 }
5397
5398 /*
5399 * this returns the key found in the dir entry in the location pointer.
5400 * If no dir entries were found, returns -ENOENT.
5401 * If found a corrupted location in dir entry, returns -EUCLEAN.
5402 */
5403 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5404 struct btrfs_key *location)
5405 {
5406 const char *name = dentry->d_name.name;
5407 int namelen = dentry->d_name.len;
5408 struct btrfs_dir_item *di;
5409 struct btrfs_path *path;
5410 struct btrfs_root *root = BTRFS_I(dir)->root;
5411 int ret = 0;
5412
5413 path = btrfs_alloc_path();
5414 if (!path)
5415 return -ENOMEM;
5416
5417 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5418 name, namelen, 0);
5419 if (IS_ERR_OR_NULL(di)) {
5420 ret = di ? PTR_ERR(di) : -ENOENT;
5421 goto out;
5422 }
5423
5424 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5425 if (location->type != BTRFS_INODE_ITEM_KEY &&
5426 location->type != BTRFS_ROOT_ITEM_KEY) {
5427 ret = -EUCLEAN;
5428 btrfs_warn(root->fs_info,
5429 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5430 __func__, name, btrfs_ino(BTRFS_I(dir)),
5431 location->objectid, location->type, location->offset);
5432 }
5433 out:
5434 btrfs_free_path(path);
5435 return ret;
5436 }
5437
5438 /*
5439 * when we hit a tree root in a directory, the btrfs part of the inode
5440 * needs to be changed to reflect the root directory of the tree root. This
5441 * is kind of like crossing a mount point.
5442 */
5443 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5444 struct inode *dir,
5445 struct dentry *dentry,
5446 struct btrfs_key *location,
5447 struct btrfs_root **sub_root)
5448 {
5449 struct btrfs_path *path;
5450 struct btrfs_root *new_root;
5451 struct btrfs_root_ref *ref;
5452 struct extent_buffer *leaf;
5453 struct btrfs_key key;
5454 int ret;
5455 int err = 0;
5456
5457 path = btrfs_alloc_path();
5458 if (!path) {
5459 err = -ENOMEM;
5460 goto out;
5461 }
5462
5463 err = -ENOENT;
5464 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5465 key.type = BTRFS_ROOT_REF_KEY;
5466 key.offset = location->objectid;
5467
5468 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5469 if (ret) {
5470 if (ret < 0)
5471 err = ret;
5472 goto out;
5473 }
5474
5475 leaf = path->nodes[0];
5476 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5477 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5478 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5479 goto out;
5480
5481 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5482 (unsigned long)(ref + 1),
5483 dentry->d_name.len);
5484 if (ret)
5485 goto out;
5486
5487 btrfs_release_path(path);
5488
5489 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5490 if (IS_ERR(new_root)) {
5491 err = PTR_ERR(new_root);
5492 goto out;
5493 }
5494
5495 *sub_root = new_root;
5496 location->objectid = btrfs_root_dirid(&new_root->root_item);
5497 location->type = BTRFS_INODE_ITEM_KEY;
5498 location->offset = 0;
5499 err = 0;
5500 out:
5501 btrfs_free_path(path);
5502 return err;
5503 }
5504
5505 static void inode_tree_add(struct inode *inode)
5506 {
5507 struct btrfs_root *root = BTRFS_I(inode)->root;
5508 struct btrfs_inode *entry;
5509 struct rb_node **p;
5510 struct rb_node *parent;
5511 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5512 u64 ino = btrfs_ino(BTRFS_I(inode));
5513
5514 if (inode_unhashed(inode))
5515 return;
5516 parent = NULL;
5517 spin_lock(&root->inode_lock);
5518 p = &root->inode_tree.rb_node;
5519 while (*p) {
5520 parent = *p;
5521 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5522
5523 if (ino < btrfs_ino(entry))
5524 p = &parent->rb_left;
5525 else if (ino > btrfs_ino(entry))
5526 p = &parent->rb_right;
5527 else {
5528 WARN_ON(!(entry->vfs_inode.i_state &
5529 (I_WILL_FREE | I_FREEING)));
5530 rb_replace_node(parent, new, &root->inode_tree);
5531 RB_CLEAR_NODE(parent);
5532 spin_unlock(&root->inode_lock);
5533 return;
5534 }
5535 }
5536 rb_link_node(new, parent, p);
5537 rb_insert_color(new, &root->inode_tree);
5538 spin_unlock(&root->inode_lock);
5539 }
5540
5541 static void inode_tree_del(struct inode *inode)
5542 {
5543 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5544 struct btrfs_root *root = BTRFS_I(inode)->root;
5545 int empty = 0;
5546
5547 spin_lock(&root->inode_lock);
5548 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5549 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5550 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5551 empty = RB_EMPTY_ROOT(&root->inode_tree);
5552 }
5553 spin_unlock(&root->inode_lock);
5554
5555 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5556 synchronize_srcu(&fs_info->subvol_srcu);
5557 spin_lock(&root->inode_lock);
5558 empty = RB_EMPTY_ROOT(&root->inode_tree);
5559 spin_unlock(&root->inode_lock);
5560 if (empty)
5561 btrfs_add_dead_root(root);
5562 }
5563 }
5564
5565
5566 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5567 {
5568 struct btrfs_iget_args *args = p;
5569 inode->i_ino = args->location->objectid;
5570 memcpy(&BTRFS_I(inode)->location, args->location,
5571 sizeof(*args->location));
5572 BTRFS_I(inode)->root = args->root;
5573 return 0;
5574 }
5575
5576 static int btrfs_find_actor(struct inode *inode, void *opaque)
5577 {
5578 struct btrfs_iget_args *args = opaque;
5579 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5580 args->root == BTRFS_I(inode)->root;
5581 }
5582
5583 static struct inode *btrfs_iget_locked(struct super_block *s,
5584 struct btrfs_key *location,
5585 struct btrfs_root *root)
5586 {
5587 struct inode *inode;
5588 struct btrfs_iget_args args;
5589 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5590
5591 args.location = location;
5592 args.root = root;
5593
5594 inode = iget5_locked(s, hashval, btrfs_find_actor,
5595 btrfs_init_locked_inode,
5596 (void *)&args);
5597 return inode;
5598 }
5599
5600 /* Get an inode object given its location and corresponding root.
5601 * Returns in *is_new if the inode was read from disk
5602 */
5603 struct inode *btrfs_iget_path(struct super_block *s, struct btrfs_key *location,
5604 struct btrfs_root *root, int *new,
5605 struct btrfs_path *path)
5606 {
5607 struct inode *inode;
5608
5609 inode = btrfs_iget_locked(s, location, root);
5610 if (!inode)
5611 return ERR_PTR(-ENOMEM);
5612
5613 if (inode->i_state & I_NEW) {
5614 int ret;
5615
5616 ret = btrfs_read_locked_inode(inode, path);
5617 if (!ret) {
5618 inode_tree_add(inode);
5619 unlock_new_inode(inode);
5620 if (new)
5621 *new = 1;
5622 } else {
5623 iget_failed(inode);
5624 /*
5625 * ret > 0 can come from btrfs_search_slot called by
5626 * btrfs_read_locked_inode, this means the inode item
5627 * was not found.
5628 */
5629 if (ret > 0)
5630 ret = -ENOENT;
5631 inode = ERR_PTR(ret);
5632 }
5633 }
5634
5635 return inode;
5636 }
5637
5638 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5639 struct btrfs_root *root, int *new)
5640 {
5641 return btrfs_iget_path(s, location, root, new, NULL);
5642 }
5643
5644 static struct inode *new_simple_dir(struct super_block *s,
5645 struct btrfs_key *key,
5646 struct btrfs_root *root)
5647 {
5648 struct inode *inode = new_inode(s);
5649
5650 if (!inode)
5651 return ERR_PTR(-ENOMEM);
5652
5653 BTRFS_I(inode)->root = root;
5654 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5655 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5656
5657 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5658 inode->i_op = &btrfs_dir_ro_inode_operations;
5659 inode->i_opflags &= ~IOP_XATTR;
5660 inode->i_fop = &simple_dir_operations;
5661 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5662 inode->i_mtime = current_time(inode);
5663 inode->i_atime = inode->i_mtime;
5664 inode->i_ctime = inode->i_mtime;
5665 BTRFS_I(inode)->i_otime = inode->i_mtime;
5666
5667 return inode;
5668 }
5669
5670 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5671 {
5672 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5673 struct inode *inode;
5674 struct btrfs_root *root = BTRFS_I(dir)->root;
5675 struct btrfs_root *sub_root = root;
5676 struct btrfs_key location;
5677 int index;
5678 int ret = 0;
5679
5680 if (dentry->d_name.len > BTRFS_NAME_LEN)
5681 return ERR_PTR(-ENAMETOOLONG);
5682
5683 ret = btrfs_inode_by_name(dir, dentry, &location);
5684 if (ret < 0)
5685 return ERR_PTR(ret);
5686
5687 if (location.type == BTRFS_INODE_ITEM_KEY) {
5688 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5689 return inode;
5690 }
5691
5692 index = srcu_read_lock(&fs_info->subvol_srcu);
5693 ret = fixup_tree_root_location(fs_info, dir, dentry,
5694 &location, &sub_root);
5695 if (ret < 0) {
5696 if (ret != -ENOENT)
5697 inode = ERR_PTR(ret);
5698 else
5699 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5700 } else {
5701 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5702 }
5703 srcu_read_unlock(&fs_info->subvol_srcu, index);
5704
5705 if (!IS_ERR(inode) && root != sub_root) {
5706 down_read(&fs_info->cleanup_work_sem);
5707 if (!sb_rdonly(inode->i_sb))
5708 ret = btrfs_orphan_cleanup(sub_root);
5709 up_read(&fs_info->cleanup_work_sem);
5710 if (ret) {
5711 iput(inode);
5712 inode = ERR_PTR(ret);
5713 }
5714 }
5715
5716 return inode;
5717 }
5718
5719 static int btrfs_dentry_delete(const struct dentry *dentry)
5720 {
5721 struct btrfs_root *root;
5722 struct inode *inode = d_inode(dentry);
5723
5724 if (!inode && !IS_ROOT(dentry))
5725 inode = d_inode(dentry->d_parent);
5726
5727 if (inode) {
5728 root = BTRFS_I(inode)->root;
5729 if (btrfs_root_refs(&root->root_item) == 0)
5730 return 1;
5731
5732 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5733 return 1;
5734 }
5735 return 0;
5736 }
5737
5738 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5739 unsigned int flags)
5740 {
5741 struct inode *inode = btrfs_lookup_dentry(dir, dentry);
5742
5743 if (inode == ERR_PTR(-ENOENT))
5744 inode = NULL;
5745 return d_splice_alias(inode, dentry);
5746 }
5747
5748 unsigned char btrfs_filetype_table[] = {
5749 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5750 };
5751
5752 /*
5753 * All this infrastructure exists because dir_emit can fault, and we are holding
5754 * the tree lock when doing readdir. For now just allocate a buffer and copy
5755 * our information into that, and then dir_emit from the buffer. This is
5756 * similar to what NFS does, only we don't keep the buffer around in pagecache
5757 * because I'm afraid I'll mess that up. Long term we need to make filldir do
5758 * copy_to_user_inatomic so we don't have to worry about page faulting under the
5759 * tree lock.
5760 */
5761 static int btrfs_opendir(struct inode *inode, struct file *file)
5762 {
5763 struct btrfs_file_private *private;
5764
5765 private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
5766 if (!private)
5767 return -ENOMEM;
5768 private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
5769 if (!private->filldir_buf) {
5770 kfree(private);
5771 return -ENOMEM;
5772 }
5773 file->private_data = private;
5774 return 0;
5775 }
5776
5777 struct dir_entry {
5778 u64 ino;
5779 u64 offset;
5780 unsigned type;
5781 int name_len;
5782 };
5783
5784 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
5785 {
5786 while (entries--) {
5787 struct dir_entry *entry = addr;
5788 char *name = (char *)(entry + 1);
5789
5790 ctx->pos = get_unaligned(&entry->offset);
5791 if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
5792 get_unaligned(&entry->ino),
5793 get_unaligned(&entry->type)))
5794 return 1;
5795 addr += sizeof(struct dir_entry) +
5796 get_unaligned(&entry->name_len);
5797 ctx->pos++;
5798 }
5799 return 0;
5800 }
5801
5802 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5803 {
5804 struct inode *inode = file_inode(file);
5805 struct btrfs_root *root = BTRFS_I(inode)->root;
5806 struct btrfs_file_private *private = file->private_data;
5807 struct btrfs_dir_item *di;
5808 struct btrfs_key key;
5809 struct btrfs_key found_key;
5810 struct btrfs_path *path;
5811 void *addr;
5812 struct list_head ins_list;
5813 struct list_head del_list;
5814 int ret;
5815 struct extent_buffer *leaf;
5816 int slot;
5817 char *name_ptr;
5818 int name_len;
5819 int entries = 0;
5820 int total_len = 0;
5821 bool put = false;
5822 struct btrfs_key location;
5823
5824 if (!dir_emit_dots(file, ctx))
5825 return 0;
5826
5827 path = btrfs_alloc_path();
5828 if (!path)
5829 return -ENOMEM;
5830
5831 addr = private->filldir_buf;
5832 path->reada = READA_FORWARD;
5833
5834 INIT_LIST_HEAD(&ins_list);
5835 INIT_LIST_HEAD(&del_list);
5836 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5837
5838 again:
5839 key.type = BTRFS_DIR_INDEX_KEY;
5840 key.offset = ctx->pos;
5841 key.objectid = btrfs_ino(BTRFS_I(inode));
5842
5843 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5844 if (ret < 0)
5845 goto err;
5846
5847 while (1) {
5848 struct dir_entry *entry;
5849
5850 leaf = path->nodes[0];
5851 slot = path->slots[0];
5852 if (slot >= btrfs_header_nritems(leaf)) {
5853 ret = btrfs_next_leaf(root, path);
5854 if (ret < 0)
5855 goto err;
5856 else if (ret > 0)
5857 break;
5858 continue;
5859 }
5860
5861 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5862
5863 if (found_key.objectid != key.objectid)
5864 break;
5865 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5866 break;
5867 if (found_key.offset < ctx->pos)
5868 goto next;
5869 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5870 goto next;
5871 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5872 name_len = btrfs_dir_name_len(leaf, di);
5873 if ((total_len + sizeof(struct dir_entry) + name_len) >=
5874 PAGE_SIZE) {
5875 btrfs_release_path(path);
5876 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
5877 if (ret)
5878 goto nopos;
5879 addr = private->filldir_buf;
5880 entries = 0;
5881 total_len = 0;
5882 goto again;
5883 }
5884
5885 entry = addr;
5886 put_unaligned(name_len, &entry->name_len);
5887 name_ptr = (char *)(entry + 1);
5888 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
5889 name_len);
5890 put_unaligned(btrfs_filetype_table[btrfs_dir_type(leaf, di)],
5891 &entry->type);
5892 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5893 put_unaligned(location.objectid, &entry->ino);
5894 put_unaligned(found_key.offset, &entry->offset);
5895 entries++;
5896 addr += sizeof(struct dir_entry) + name_len;
5897 total_len += sizeof(struct dir_entry) + name_len;
5898 next:
5899 path->slots[0]++;
5900 }
5901 btrfs_release_path(path);
5902
5903 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
5904 if (ret)
5905 goto nopos;
5906
5907 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5908 if (ret)
5909 goto nopos;
5910
5911 /*
5912 * Stop new entries from being returned after we return the last
5913 * entry.
5914 *
5915 * New directory entries are assigned a strictly increasing
5916 * offset. This means that new entries created during readdir
5917 * are *guaranteed* to be seen in the future by that readdir.
5918 * This has broken buggy programs which operate on names as
5919 * they're returned by readdir. Until we re-use freed offsets
5920 * we have this hack to stop new entries from being returned
5921 * under the assumption that they'll never reach this huge
5922 * offset.
5923 *
5924 * This is being careful not to overflow 32bit loff_t unless the
5925 * last entry requires it because doing so has broken 32bit apps
5926 * in the past.
5927 */
5928 if (ctx->pos >= INT_MAX)
5929 ctx->pos = LLONG_MAX;
5930 else
5931 ctx->pos = INT_MAX;
5932 nopos:
5933 ret = 0;
5934 err:
5935 if (put)
5936 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
5937 btrfs_free_path(path);
5938 return ret;
5939 }
5940
5941 /*
5942 * This is somewhat expensive, updating the tree every time the
5943 * inode changes. But, it is most likely to find the inode in cache.
5944 * FIXME, needs more benchmarking...there are no reasons other than performance
5945 * to keep or drop this code.
5946 */
5947 static int btrfs_dirty_inode(struct inode *inode)
5948 {
5949 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5950 struct btrfs_root *root = BTRFS_I(inode)->root;
5951 struct btrfs_trans_handle *trans;
5952 int ret;
5953
5954 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5955 return 0;
5956
5957 trans = btrfs_join_transaction(root);
5958 if (IS_ERR(trans))
5959 return PTR_ERR(trans);
5960
5961 ret = btrfs_update_inode(trans, root, inode);
5962 if (ret && ret == -ENOSPC) {
5963 /* whoops, lets try again with the full transaction */
5964 btrfs_end_transaction(trans);
5965 trans = btrfs_start_transaction(root, 1);
5966 if (IS_ERR(trans))
5967 return PTR_ERR(trans);
5968
5969 ret = btrfs_update_inode(trans, root, inode);
5970 }
5971 btrfs_end_transaction(trans);
5972 if (BTRFS_I(inode)->delayed_node)
5973 btrfs_balance_delayed_items(fs_info);
5974
5975 return ret;
5976 }
5977
5978 /*
5979 * This is a copy of file_update_time. We need this so we can return error on
5980 * ENOSPC for updating the inode in the case of file write and mmap writes.
5981 */
5982 static int btrfs_update_time(struct inode *inode, struct timespec64 *now,
5983 int flags)
5984 {
5985 struct btrfs_root *root = BTRFS_I(inode)->root;
5986 bool dirty = flags & ~S_VERSION;
5987
5988 if (btrfs_root_readonly(root))
5989 return -EROFS;
5990
5991 if (flags & S_VERSION)
5992 dirty |= inode_maybe_inc_iversion(inode, dirty);
5993 if (flags & S_CTIME)
5994 inode->i_ctime = *now;
5995 if (flags & S_MTIME)
5996 inode->i_mtime = *now;
5997 if (flags & S_ATIME)
5998 inode->i_atime = *now;
5999 return dirty ? btrfs_dirty_inode(inode) : 0;
6000 }
6001
6002 /*
6003 * find the highest existing sequence number in a directory
6004 * and then set the in-memory index_cnt variable to reflect
6005 * free sequence numbers
6006 */
6007 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6008 {
6009 struct btrfs_root *root = inode->root;
6010 struct btrfs_key key, found_key;
6011 struct btrfs_path *path;
6012 struct extent_buffer *leaf;
6013 int ret;
6014
6015 key.objectid = btrfs_ino(inode);
6016 key.type = BTRFS_DIR_INDEX_KEY;
6017 key.offset = (u64)-1;
6018
6019 path = btrfs_alloc_path();
6020 if (!path)
6021 return -ENOMEM;
6022
6023 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6024 if (ret < 0)
6025 goto out;
6026 /* FIXME: we should be able to handle this */
6027 if (ret == 0)
6028 goto out;
6029 ret = 0;
6030
6031 /*
6032 * MAGIC NUMBER EXPLANATION:
6033 * since we search a directory based on f_pos we have to start at 2
6034 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6035 * else has to start at 2
6036 */
6037 if (path->slots[0] == 0) {
6038 inode->index_cnt = 2;
6039 goto out;
6040 }
6041
6042 path->slots[0]--;
6043
6044 leaf = path->nodes[0];
6045 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6046
6047 if (found_key.objectid != btrfs_ino(inode) ||
6048 found_key.type != BTRFS_DIR_INDEX_KEY) {
6049 inode->index_cnt = 2;
6050 goto out;
6051 }
6052
6053 inode->index_cnt = found_key.offset + 1;
6054 out:
6055 btrfs_free_path(path);
6056 return ret;
6057 }
6058
6059 /*
6060 * helper to find a free sequence number in a given directory. This current
6061 * code is very simple, later versions will do smarter things in the btree
6062 */
6063 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6064 {
6065 int ret = 0;
6066
6067 if (dir->index_cnt == (u64)-1) {
6068 ret = btrfs_inode_delayed_dir_index_count(dir);
6069 if (ret) {
6070 ret = btrfs_set_inode_index_count(dir);
6071 if (ret)
6072 return ret;
6073 }
6074 }
6075
6076 *index = dir->index_cnt;
6077 dir->index_cnt++;
6078
6079 return ret;
6080 }
6081
6082 static int btrfs_insert_inode_locked(struct inode *inode)
6083 {
6084 struct btrfs_iget_args args;
6085 args.location = &BTRFS_I(inode)->location;
6086 args.root = BTRFS_I(inode)->root;
6087
6088 return insert_inode_locked4(inode,
6089 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6090 btrfs_find_actor, &args);
6091 }
6092
6093 /*
6094 * Inherit flags from the parent inode.
6095 *
6096 * Currently only the compression flags and the cow flags are inherited.
6097 */
6098 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6099 {
6100 unsigned int flags;
6101
6102 if (!dir)
6103 return;
6104
6105 flags = BTRFS_I(dir)->flags;
6106
6107 if (flags & BTRFS_INODE_NOCOMPRESS) {
6108 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6109 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6110 } else if (flags & BTRFS_INODE_COMPRESS) {
6111 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6112 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6113 }
6114
6115 if (flags & BTRFS_INODE_NODATACOW) {
6116 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6117 if (S_ISREG(inode->i_mode))
6118 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6119 }
6120
6121 btrfs_sync_inode_flags_to_i_flags(inode);
6122 }
6123
6124 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6125 struct btrfs_root *root,
6126 struct inode *dir,
6127 const char *name, int name_len,
6128 u64 ref_objectid, u64 objectid,
6129 umode_t mode, u64 *index)
6130 {
6131 struct btrfs_fs_info *fs_info = root->fs_info;
6132 struct inode *inode;
6133 struct btrfs_inode_item *inode_item;
6134 struct btrfs_key *location;
6135 struct btrfs_path *path;
6136 struct btrfs_inode_ref *ref;
6137 struct btrfs_key key[2];
6138 u32 sizes[2];
6139 int nitems = name ? 2 : 1;
6140 unsigned long ptr;
6141 int ret;
6142
6143 path = btrfs_alloc_path();
6144 if (!path)
6145 return ERR_PTR(-ENOMEM);
6146
6147 inode = new_inode(fs_info->sb);
6148 if (!inode) {
6149 btrfs_free_path(path);
6150 return ERR_PTR(-ENOMEM);
6151 }
6152
6153 /*
6154 * O_TMPFILE, set link count to 0, so that after this point,
6155 * we fill in an inode item with the correct link count.
6156 */
6157 if (!name)
6158 set_nlink(inode, 0);
6159
6160 /*
6161 * we have to initialize this early, so we can reclaim the inode
6162 * number if we fail afterwards in this function.
6163 */
6164 inode->i_ino = objectid;
6165
6166 if (dir && name) {
6167 trace_btrfs_inode_request(dir);
6168
6169 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6170 if (ret) {
6171 btrfs_free_path(path);
6172 iput(inode);
6173 return ERR_PTR(ret);
6174 }
6175 } else if (dir) {
6176 *index = 0;
6177 }
6178 /*
6179 * index_cnt is ignored for everything but a dir,
6180 * btrfs_set_inode_index_count has an explanation for the magic
6181 * number
6182 */
6183 BTRFS_I(inode)->index_cnt = 2;
6184 BTRFS_I(inode)->dir_index = *index;
6185 BTRFS_I(inode)->root = root;
6186 BTRFS_I(inode)->generation = trans->transid;
6187 inode->i_generation = BTRFS_I(inode)->generation;
6188
6189 /*
6190 * We could have gotten an inode number from somebody who was fsynced
6191 * and then removed in this same transaction, so let's just set full
6192 * sync since it will be a full sync anyway and this will blow away the
6193 * old info in the log.
6194 */
6195 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6196
6197 key[0].objectid = objectid;
6198 key[0].type = BTRFS_INODE_ITEM_KEY;
6199 key[0].offset = 0;
6200
6201 sizes[0] = sizeof(struct btrfs_inode_item);
6202
6203 if (name) {
6204 /*
6205 * Start new inodes with an inode_ref. This is slightly more
6206 * efficient for small numbers of hard links since they will
6207 * be packed into one item. Extended refs will kick in if we
6208 * add more hard links than can fit in the ref item.
6209 */
6210 key[1].objectid = objectid;
6211 key[1].type = BTRFS_INODE_REF_KEY;
6212 key[1].offset = ref_objectid;
6213
6214 sizes[1] = name_len + sizeof(*ref);
6215 }
6216
6217 location = &BTRFS_I(inode)->location;
6218 location->objectid = objectid;
6219 location->offset = 0;
6220 location->type = BTRFS_INODE_ITEM_KEY;
6221
6222 ret = btrfs_insert_inode_locked(inode);
6223 if (ret < 0) {
6224 iput(inode);
6225 goto fail;
6226 }
6227
6228 path->leave_spinning = 1;
6229 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6230 if (ret != 0)
6231 goto fail_unlock;
6232
6233 inode_init_owner(inode, dir, mode);
6234 inode_set_bytes(inode, 0);
6235
6236 inode->i_mtime = current_time(inode);
6237 inode->i_atime = inode->i_mtime;
6238 inode->i_ctime = inode->i_mtime;
6239 BTRFS_I(inode)->i_otime = inode->i_mtime;
6240
6241 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6242 struct btrfs_inode_item);
6243 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6244 sizeof(*inode_item));
6245 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6246
6247 if (name) {
6248 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6249 struct btrfs_inode_ref);
6250 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6251 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6252 ptr = (unsigned long)(ref + 1);
6253 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6254 }
6255
6256 btrfs_mark_buffer_dirty(path->nodes[0]);
6257 btrfs_free_path(path);
6258
6259 btrfs_inherit_iflags(inode, dir);
6260
6261 if (S_ISREG(mode)) {
6262 if (btrfs_test_opt(fs_info, NODATASUM))
6263 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6264 if (btrfs_test_opt(fs_info, NODATACOW))
6265 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6266 BTRFS_INODE_NODATASUM;
6267 }
6268
6269 inode_tree_add(inode);
6270
6271 trace_btrfs_inode_new(inode);
6272 btrfs_set_inode_last_trans(trans, inode);
6273
6274 btrfs_update_root_times(trans, root);
6275
6276 ret = btrfs_inode_inherit_props(trans, inode, dir);
6277 if (ret)
6278 btrfs_err(fs_info,
6279 "error inheriting props for ino %llu (root %llu): %d",
6280 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6281
6282 return inode;
6283
6284 fail_unlock:
6285 discard_new_inode(inode);
6286 fail:
6287 if (dir && name)
6288 BTRFS_I(dir)->index_cnt--;
6289 btrfs_free_path(path);
6290 return ERR_PTR(ret);
6291 }
6292
6293 static inline u8 btrfs_inode_type(struct inode *inode)
6294 {
6295 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6296 }
6297
6298 /*
6299 * utility function to add 'inode' into 'parent_inode' with
6300 * a give name and a given sequence number.
6301 * if 'add_backref' is true, also insert a backref from the
6302 * inode to the parent directory.
6303 */
6304 int btrfs_add_link(struct btrfs_trans_handle *trans,
6305 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6306 const char *name, int name_len, int add_backref, u64 index)
6307 {
6308 int ret = 0;
6309 struct btrfs_key key;
6310 struct btrfs_root *root = parent_inode->root;
6311 u64 ino = btrfs_ino(inode);
6312 u64 parent_ino = btrfs_ino(parent_inode);
6313
6314 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6315 memcpy(&key, &inode->root->root_key, sizeof(key));
6316 } else {
6317 key.objectid = ino;
6318 key.type = BTRFS_INODE_ITEM_KEY;
6319 key.offset = 0;
6320 }
6321
6322 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6323 ret = btrfs_add_root_ref(trans, key.objectid,
6324 root->root_key.objectid, parent_ino,
6325 index, name, name_len);
6326 } else if (add_backref) {
6327 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6328 parent_ino, index);
6329 }
6330
6331 /* Nothing to clean up yet */
6332 if (ret)
6333 return ret;
6334
6335 ret = btrfs_insert_dir_item(trans, name, name_len, parent_inode, &key,
6336 btrfs_inode_type(&inode->vfs_inode), index);
6337 if (ret == -EEXIST || ret == -EOVERFLOW)
6338 goto fail_dir_item;
6339 else if (ret) {
6340 btrfs_abort_transaction(trans, ret);
6341 return ret;
6342 }
6343
6344 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6345 name_len * 2);
6346 inode_inc_iversion(&parent_inode->vfs_inode);
6347 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6348 current_time(&parent_inode->vfs_inode);
6349 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6350 if (ret)
6351 btrfs_abort_transaction(trans, ret);
6352 return ret;
6353
6354 fail_dir_item:
6355 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6356 u64 local_index;
6357 int err;
6358 err = btrfs_del_root_ref(trans, key.objectid,
6359 root->root_key.objectid, parent_ino,
6360 &local_index, name, name_len);
6361 if (err)
6362 btrfs_abort_transaction(trans, err);
6363 } else if (add_backref) {
6364 u64 local_index;
6365 int err;
6366
6367 err = btrfs_del_inode_ref(trans, root, name, name_len,
6368 ino, parent_ino, &local_index);
6369 if (err)
6370 btrfs_abort_transaction(trans, err);
6371 }
6372
6373 /* Return the original error code */
6374 return ret;
6375 }
6376
6377 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6378 struct btrfs_inode *dir, struct dentry *dentry,
6379 struct btrfs_inode *inode, int backref, u64 index)
6380 {
6381 int err = btrfs_add_link(trans, dir, inode,
6382 dentry->d_name.name, dentry->d_name.len,
6383 backref, index);
6384 if (err > 0)
6385 err = -EEXIST;
6386 return err;
6387 }
6388
6389 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6390 umode_t mode, dev_t rdev)
6391 {
6392 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6393 struct btrfs_trans_handle *trans;
6394 struct btrfs_root *root = BTRFS_I(dir)->root;
6395 struct inode *inode = NULL;
6396 int err;
6397 u64 objectid;
6398 u64 index = 0;
6399
6400 /*
6401 * 2 for inode item and ref
6402 * 2 for dir items
6403 * 1 for xattr if selinux is on
6404 */
6405 trans = btrfs_start_transaction(root, 5);
6406 if (IS_ERR(trans))
6407 return PTR_ERR(trans);
6408
6409 err = btrfs_find_free_ino(root, &objectid);
6410 if (err)
6411 goto out_unlock;
6412
6413 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6414 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6415 mode, &index);
6416 if (IS_ERR(inode)) {
6417 err = PTR_ERR(inode);
6418 inode = NULL;
6419 goto out_unlock;
6420 }
6421
6422 /*
6423 * If the active LSM wants to access the inode during
6424 * d_instantiate it needs these. Smack checks to see
6425 * if the filesystem supports xattrs by looking at the
6426 * ops vector.
6427 */
6428 inode->i_op = &btrfs_special_inode_operations;
6429 init_special_inode(inode, inode->i_mode, rdev);
6430
6431 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6432 if (err)
6433 goto out_unlock;
6434
6435 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6436 0, index);
6437 if (err)
6438 goto out_unlock;
6439
6440 btrfs_update_inode(trans, root, inode);
6441 d_instantiate_new(dentry, inode);
6442
6443 out_unlock:
6444 btrfs_end_transaction(trans);
6445 btrfs_btree_balance_dirty(fs_info);
6446 if (err && inode) {
6447 inode_dec_link_count(inode);
6448 discard_new_inode(inode);
6449 }
6450 return err;
6451 }
6452
6453 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6454 umode_t mode, bool excl)
6455 {
6456 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6457 struct btrfs_trans_handle *trans;
6458 struct btrfs_root *root = BTRFS_I(dir)->root;
6459 struct inode *inode = NULL;
6460 int err;
6461 u64 objectid;
6462 u64 index = 0;
6463
6464 /*
6465 * 2 for inode item and ref
6466 * 2 for dir items
6467 * 1 for xattr if selinux is on
6468 */
6469 trans = btrfs_start_transaction(root, 5);
6470 if (IS_ERR(trans))
6471 return PTR_ERR(trans);
6472
6473 err = btrfs_find_free_ino(root, &objectid);
6474 if (err)
6475 goto out_unlock;
6476
6477 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6478 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6479 mode, &index);
6480 if (IS_ERR(inode)) {
6481 err = PTR_ERR(inode);
6482 inode = NULL;
6483 goto out_unlock;
6484 }
6485 /*
6486 * If the active LSM wants to access the inode during
6487 * d_instantiate it needs these. Smack checks to see
6488 * if the filesystem supports xattrs by looking at the
6489 * ops vector.
6490 */
6491 inode->i_fop = &btrfs_file_operations;
6492 inode->i_op = &btrfs_file_inode_operations;
6493 inode->i_mapping->a_ops = &btrfs_aops;
6494
6495 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6496 if (err)
6497 goto out_unlock;
6498
6499 err = btrfs_update_inode(trans, root, inode);
6500 if (err)
6501 goto out_unlock;
6502
6503 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6504 0, index);
6505 if (err)
6506 goto out_unlock;
6507
6508 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6509 d_instantiate_new(dentry, inode);
6510
6511 out_unlock:
6512 btrfs_end_transaction(trans);
6513 if (err && inode) {
6514 inode_dec_link_count(inode);
6515 discard_new_inode(inode);
6516 }
6517 btrfs_btree_balance_dirty(fs_info);
6518 return err;
6519 }
6520
6521 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6522 struct dentry *dentry)
6523 {
6524 struct btrfs_trans_handle *trans = NULL;
6525 struct btrfs_root *root = BTRFS_I(dir)->root;
6526 struct inode *inode = d_inode(old_dentry);
6527 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6528 u64 index;
6529 int err;
6530 int drop_inode = 0;
6531
6532 /* do not allow sys_link's with other subvols of the same device */
6533 if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
6534 return -EXDEV;
6535
6536 if (inode->i_nlink >= BTRFS_LINK_MAX)
6537 return -EMLINK;
6538
6539 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6540 if (err)
6541 goto fail;
6542
6543 /*
6544 * 2 items for inode and inode ref
6545 * 2 items for dir items
6546 * 1 item for parent inode
6547 * 1 item for orphan item deletion if O_TMPFILE
6548 */
6549 trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6);
6550 if (IS_ERR(trans)) {
6551 err = PTR_ERR(trans);
6552 trans = NULL;
6553 goto fail;
6554 }
6555
6556 /* There are several dir indexes for this inode, clear the cache. */
6557 BTRFS_I(inode)->dir_index = 0ULL;
6558 inc_nlink(inode);
6559 inode_inc_iversion(inode);
6560 inode->i_ctime = current_time(inode);
6561 ihold(inode);
6562 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6563
6564 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6565 1, index);
6566
6567 if (err) {
6568 drop_inode = 1;
6569 } else {
6570 struct dentry *parent = dentry->d_parent;
6571 int ret;
6572
6573 err = btrfs_update_inode(trans, root, inode);
6574 if (err)
6575 goto fail;
6576 if (inode->i_nlink == 1) {
6577 /*
6578 * If new hard link count is 1, it's a file created
6579 * with open(2) O_TMPFILE flag.
6580 */
6581 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6582 if (err)
6583 goto fail;
6584 }
6585 BTRFS_I(inode)->last_link_trans = trans->transid;
6586 d_instantiate(dentry, inode);
6587 ret = btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent,
6588 true, NULL);
6589 if (ret == BTRFS_NEED_TRANS_COMMIT) {
6590 err = btrfs_commit_transaction(trans);
6591 trans = NULL;
6592 }
6593 }
6594
6595 fail:
6596 if (trans)
6597 btrfs_end_transaction(trans);
6598 if (drop_inode) {
6599 inode_dec_link_count(inode);
6600 iput(inode);
6601 }
6602 btrfs_btree_balance_dirty(fs_info);
6603 return err;
6604 }
6605
6606 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6607 {
6608 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6609 struct inode *inode = NULL;
6610 struct btrfs_trans_handle *trans;
6611 struct btrfs_root *root = BTRFS_I(dir)->root;
6612 int err = 0;
6613 u64 objectid = 0;
6614 u64 index = 0;
6615
6616 /*
6617 * 2 items for inode and ref
6618 * 2 items for dir items
6619 * 1 for xattr if selinux is on
6620 */
6621 trans = btrfs_start_transaction(root, 5);
6622 if (IS_ERR(trans))
6623 return PTR_ERR(trans);
6624
6625 err = btrfs_find_free_ino(root, &objectid);
6626 if (err)
6627 goto out_fail;
6628
6629 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6630 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6631 S_IFDIR | mode, &index);
6632 if (IS_ERR(inode)) {
6633 err = PTR_ERR(inode);
6634 inode = NULL;
6635 goto out_fail;
6636 }
6637
6638 /* these must be set before we unlock the inode */
6639 inode->i_op = &btrfs_dir_inode_operations;
6640 inode->i_fop = &btrfs_dir_file_operations;
6641
6642 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6643 if (err)
6644 goto out_fail;
6645
6646 btrfs_i_size_write(BTRFS_I(inode), 0);
6647 err = btrfs_update_inode(trans, root, inode);
6648 if (err)
6649 goto out_fail;
6650
6651 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6652 dentry->d_name.name,
6653 dentry->d_name.len, 0, index);
6654 if (err)
6655 goto out_fail;
6656
6657 d_instantiate_new(dentry, inode);
6658
6659 out_fail:
6660 btrfs_end_transaction(trans);
6661 if (err && inode) {
6662 inode_dec_link_count(inode);
6663 discard_new_inode(inode);
6664 }
6665 btrfs_btree_balance_dirty(fs_info);
6666 return err;
6667 }
6668
6669 static noinline int uncompress_inline(struct btrfs_path *path,
6670 struct page *page,
6671 size_t pg_offset, u64 extent_offset,
6672 struct btrfs_file_extent_item *item)
6673 {
6674 int ret;
6675 struct extent_buffer *leaf = path->nodes[0];
6676 char *tmp;
6677 size_t max_size;
6678 unsigned long inline_size;
6679 unsigned long ptr;
6680 int compress_type;
6681
6682 WARN_ON(pg_offset != 0);
6683 compress_type = btrfs_file_extent_compression(leaf, item);
6684 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6685 inline_size = btrfs_file_extent_inline_item_len(leaf,
6686 btrfs_item_nr(path->slots[0]));
6687 tmp = kmalloc(inline_size, GFP_NOFS);
6688 if (!tmp)
6689 return -ENOMEM;
6690 ptr = btrfs_file_extent_inline_start(item);
6691
6692 read_extent_buffer(leaf, tmp, ptr, inline_size);
6693
6694 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6695 ret = btrfs_decompress(compress_type, tmp, page,
6696 extent_offset, inline_size, max_size);
6697
6698 /*
6699 * decompression code contains a memset to fill in any space between the end
6700 * of the uncompressed data and the end of max_size in case the decompressed
6701 * data ends up shorter than ram_bytes. That doesn't cover the hole between
6702 * the end of an inline extent and the beginning of the next block, so we
6703 * cover that region here.
6704 */
6705
6706 if (max_size + pg_offset < PAGE_SIZE) {
6707 char *map = kmap(page);
6708 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6709 kunmap(page);
6710 }
6711 kfree(tmp);
6712 return ret;
6713 }
6714
6715 /*
6716 * a bit scary, this does extent mapping from logical file offset to the disk.
6717 * the ugly parts come from merging extents from the disk with the in-ram
6718 * representation. This gets more complex because of the data=ordered code,
6719 * where the in-ram extents might be locked pending data=ordered completion.
6720 *
6721 * This also copies inline extents directly into the page.
6722 */
6723 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6724 struct page *page,
6725 size_t pg_offset, u64 start, u64 len,
6726 int create)
6727 {
6728 struct btrfs_fs_info *fs_info = inode->root->fs_info;
6729 int ret;
6730 int err = 0;
6731 u64 extent_start = 0;
6732 u64 extent_end = 0;
6733 u64 objectid = btrfs_ino(inode);
6734 u32 found_type;
6735 struct btrfs_path *path = NULL;
6736 struct btrfs_root *root = inode->root;
6737 struct btrfs_file_extent_item *item;
6738 struct extent_buffer *leaf;
6739 struct btrfs_key found_key;
6740 struct extent_map *em = NULL;
6741 struct extent_map_tree *em_tree = &inode->extent_tree;
6742 struct extent_io_tree *io_tree = &inode->io_tree;
6743 const bool new_inline = !page || create;
6744
6745 read_lock(&em_tree->lock);
6746 em = lookup_extent_mapping(em_tree, start, len);
6747 if (em)
6748 em->bdev = fs_info->fs_devices->latest_bdev;
6749 read_unlock(&em_tree->lock);
6750
6751 if (em) {
6752 if (em->start > start || em->start + em->len <= start)
6753 free_extent_map(em);
6754 else if (em->block_start == EXTENT_MAP_INLINE && page)
6755 free_extent_map(em);
6756 else
6757 goto out;
6758 }
6759 em = alloc_extent_map();
6760 if (!em) {
6761 err = -ENOMEM;
6762 goto out;
6763 }
6764 em->bdev = fs_info->fs_devices->latest_bdev;
6765 em->start = EXTENT_MAP_HOLE;
6766 em->orig_start = EXTENT_MAP_HOLE;
6767 em->len = (u64)-1;
6768 em->block_len = (u64)-1;
6769
6770 path = btrfs_alloc_path();
6771 if (!path) {
6772 err = -ENOMEM;
6773 goto out;
6774 }
6775
6776 /* Chances are we'll be called again, so go ahead and do readahead */
6777 path->reada = READA_FORWARD;
6778
6779 /*
6780 * Unless we're going to uncompress the inline extent, no sleep would
6781 * happen.
6782 */
6783 path->leave_spinning = 1;
6784
6785 ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
6786 if (ret < 0) {
6787 err = ret;
6788 goto out;
6789 }
6790
6791 if (ret != 0) {
6792 if (path->slots[0] == 0)
6793 goto not_found;
6794 path->slots[0]--;
6795 }
6796
6797 leaf = path->nodes[0];
6798 item = btrfs_item_ptr(leaf, path->slots[0],
6799 struct btrfs_file_extent_item);
6800 /* are we inside the extent that was found? */
6801 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6802 found_type = found_key.type;
6803 if (found_key.objectid != objectid ||
6804 found_type != BTRFS_EXTENT_DATA_KEY) {
6805 /*
6806 * If we backup past the first extent we want to move forward
6807 * and see if there is an extent in front of us, otherwise we'll
6808 * say there is a hole for our whole search range which can
6809 * cause problems.
6810 */
6811 extent_end = start;
6812 goto next;
6813 }
6814
6815 found_type = btrfs_file_extent_type(leaf, item);
6816 extent_start = found_key.offset;
6817 if (found_type == BTRFS_FILE_EXTENT_REG ||
6818 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6819 extent_end = extent_start +
6820 btrfs_file_extent_num_bytes(leaf, item);
6821
6822 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
6823 extent_start);
6824 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6825 size_t size;
6826
6827 size = btrfs_file_extent_ram_bytes(leaf, item);
6828 extent_end = ALIGN(extent_start + size,
6829 fs_info->sectorsize);
6830
6831 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
6832 path->slots[0],
6833 extent_start);
6834 }
6835 next:
6836 if (start >= extent_end) {
6837 path->slots[0]++;
6838 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6839 ret = btrfs_next_leaf(root, path);
6840 if (ret < 0) {
6841 err = ret;
6842 goto out;
6843 }
6844 if (ret > 0)
6845 goto not_found;
6846 leaf = path->nodes[0];
6847 }
6848 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6849 if (found_key.objectid != objectid ||
6850 found_key.type != BTRFS_EXTENT_DATA_KEY)
6851 goto not_found;
6852 if (start + len <= found_key.offset)
6853 goto not_found;
6854 if (start > found_key.offset)
6855 goto next;
6856 em->start = start;
6857 em->orig_start = start;
6858 em->len = found_key.offset - start;
6859 goto not_found_em;
6860 }
6861
6862 btrfs_extent_item_to_extent_map(inode, path, item,
6863 new_inline, em);
6864
6865 if (found_type == BTRFS_FILE_EXTENT_REG ||
6866 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6867 goto insert;
6868 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6869 unsigned long ptr;
6870 char *map;
6871 size_t size;
6872 size_t extent_offset;
6873 size_t copy_size;
6874
6875 if (new_inline)
6876 goto out;
6877
6878 size = btrfs_file_extent_ram_bytes(leaf, item);
6879 extent_offset = page_offset(page) + pg_offset - extent_start;
6880 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6881 size - extent_offset);
6882 em->start = extent_start + extent_offset;
6883 em->len = ALIGN(copy_size, fs_info->sectorsize);
6884 em->orig_block_len = em->len;
6885 em->orig_start = em->start;
6886 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6887
6888 btrfs_set_path_blocking(path);
6889 if (!PageUptodate(page)) {
6890 if (btrfs_file_extent_compression(leaf, item) !=
6891 BTRFS_COMPRESS_NONE) {
6892 ret = uncompress_inline(path, page, pg_offset,
6893 extent_offset, item);
6894 if (ret) {
6895 err = ret;
6896 goto out;
6897 }
6898 } else {
6899 map = kmap(page);
6900 read_extent_buffer(leaf, map + pg_offset, ptr,
6901 copy_size);
6902 if (pg_offset + copy_size < PAGE_SIZE) {
6903 memset(map + pg_offset + copy_size, 0,
6904 PAGE_SIZE - pg_offset -
6905 copy_size);
6906 }
6907 kunmap(page);
6908 }
6909 flush_dcache_page(page);
6910 }
6911 set_extent_uptodate(io_tree, em->start,
6912 extent_map_end(em) - 1, NULL, GFP_NOFS);
6913 goto insert;
6914 }
6915 not_found:
6916 em->start = start;
6917 em->orig_start = start;
6918 em->len = len;
6919 not_found_em:
6920 em->block_start = EXTENT_MAP_HOLE;
6921 insert:
6922 btrfs_release_path(path);
6923 if (em->start > start || extent_map_end(em) <= start) {
6924 btrfs_err(fs_info,
6925 "bad extent! em: [%llu %llu] passed [%llu %llu]",
6926 em->start, em->len, start, len);
6927 err = -EIO;
6928 goto out;
6929 }
6930
6931 err = 0;
6932 write_lock(&em_tree->lock);
6933 err = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
6934 write_unlock(&em_tree->lock);
6935 out:
6936 btrfs_free_path(path);
6937
6938 trace_btrfs_get_extent(root, inode, em);
6939
6940 if (err) {
6941 free_extent_map(em);
6942 return ERR_PTR(err);
6943 }
6944 BUG_ON(!em); /* Error is always set */
6945 return em;
6946 }
6947
6948 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
6949 struct page *page,
6950 size_t pg_offset, u64 start, u64 len,
6951 int create)
6952 {
6953 struct extent_map *em;
6954 struct extent_map *hole_em = NULL;
6955 u64 range_start = start;
6956 u64 end;
6957 u64 found;
6958 u64 found_end;
6959 int err = 0;
6960
6961 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6962 if (IS_ERR(em))
6963 return em;
6964 /*
6965 * If our em maps to:
6966 * - a hole or
6967 * - a pre-alloc extent,
6968 * there might actually be delalloc bytes behind it.
6969 */
6970 if (em->block_start != EXTENT_MAP_HOLE &&
6971 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6972 return em;
6973 else
6974 hole_em = em;
6975
6976 /* check to see if we've wrapped (len == -1 or similar) */
6977 end = start + len;
6978 if (end < start)
6979 end = (u64)-1;
6980 else
6981 end -= 1;
6982
6983 em = NULL;
6984
6985 /* ok, we didn't find anything, lets look for delalloc */
6986 found = count_range_bits(&inode->io_tree, &range_start,
6987 end, len, EXTENT_DELALLOC, 1);
6988 found_end = range_start + found;
6989 if (found_end < range_start)
6990 found_end = (u64)-1;
6991
6992 /*
6993 * we didn't find anything useful, return
6994 * the original results from get_extent()
6995 */
6996 if (range_start > end || found_end <= start) {
6997 em = hole_em;
6998 hole_em = NULL;
6999 goto out;
7000 }
7001
7002 /* adjust the range_start to make sure it doesn't
7003 * go backwards from the start they passed in
7004 */
7005 range_start = max(start, range_start);
7006 found = found_end - range_start;
7007
7008 if (found > 0) {
7009 u64 hole_start = start;
7010 u64 hole_len = len;
7011
7012 em = alloc_extent_map();
7013 if (!em) {
7014 err = -ENOMEM;
7015 goto out;
7016 }
7017 /*
7018 * when btrfs_get_extent can't find anything it
7019 * returns one huge hole
7020 *
7021 * make sure what it found really fits our range, and
7022 * adjust to make sure it is based on the start from
7023 * the caller
7024 */
7025 if (hole_em) {
7026 u64 calc_end = extent_map_end(hole_em);
7027
7028 if (calc_end <= start || (hole_em->start > end)) {
7029 free_extent_map(hole_em);
7030 hole_em = NULL;
7031 } else {
7032 hole_start = max(hole_em->start, start);
7033 hole_len = calc_end - hole_start;
7034 }
7035 }
7036 em->bdev = NULL;
7037 if (hole_em && range_start > hole_start) {
7038 /* our hole starts before our delalloc, so we
7039 * have to return just the parts of the hole
7040 * that go until the delalloc starts
7041 */
7042 em->len = min(hole_len,
7043 range_start - hole_start);
7044 em->start = hole_start;
7045 em->orig_start = hole_start;
7046 /*
7047 * don't adjust block start at all,
7048 * it is fixed at EXTENT_MAP_HOLE
7049 */
7050 em->block_start = hole_em->block_start;
7051 em->block_len = hole_len;
7052 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7053 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7054 } else {
7055 em->start = range_start;
7056 em->len = found;
7057 em->orig_start = range_start;
7058 em->block_start = EXTENT_MAP_DELALLOC;
7059 em->block_len = found;
7060 }
7061 } else {
7062 return hole_em;
7063 }
7064 out:
7065
7066 free_extent_map(hole_em);
7067 if (err) {
7068 free_extent_map(em);
7069 return ERR_PTR(err);
7070 }
7071 return em;
7072 }
7073
7074 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7075 const u64 start,
7076 const u64 len,
7077 const u64 orig_start,
7078 const u64 block_start,
7079 const u64 block_len,
7080 const u64 orig_block_len,
7081 const u64 ram_bytes,
7082 const int type)
7083 {
7084 struct extent_map *em = NULL;
7085 int ret;
7086
7087 if (type != BTRFS_ORDERED_NOCOW) {
7088 em = create_io_em(inode, start, len, orig_start,
7089 block_start, block_len, orig_block_len,
7090 ram_bytes,
7091 BTRFS_COMPRESS_NONE, /* compress_type */
7092 type);
7093 if (IS_ERR(em))
7094 goto out;
7095 }
7096 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7097 len, block_len, type);
7098 if (ret) {
7099 if (em) {
7100 free_extent_map(em);
7101 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7102 start + len - 1, 0);
7103 }
7104 em = ERR_PTR(ret);
7105 }
7106 out:
7107
7108 return em;
7109 }
7110
7111 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7112 u64 start, u64 len)
7113 {
7114 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7115 struct btrfs_root *root = BTRFS_I(inode)->root;
7116 struct extent_map *em;
7117 struct btrfs_key ins;
7118 u64 alloc_hint;
7119 int ret;
7120
7121 alloc_hint = get_extent_allocation_hint(inode, start, len);
7122 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7123 0, alloc_hint, &ins, 1, 1);
7124 if (ret)
7125 return ERR_PTR(ret);
7126
7127 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7128 ins.objectid, ins.offset, ins.offset,
7129 ins.offset, BTRFS_ORDERED_REGULAR);
7130 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7131 if (IS_ERR(em))
7132 btrfs_free_reserved_extent(fs_info, ins.objectid,
7133 ins.offset, 1);
7134
7135 return em;
7136 }
7137
7138 /*
7139 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7140 * block must be cow'd
7141 */
7142 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7143 u64 *orig_start, u64 *orig_block_len,
7144 u64 *ram_bytes)
7145 {
7146 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7147 struct btrfs_path *path;
7148 int ret;
7149 struct extent_buffer *leaf;
7150 struct btrfs_root *root = BTRFS_I(inode)->root;
7151 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7152 struct btrfs_file_extent_item *fi;
7153 struct btrfs_key key;
7154 u64 disk_bytenr;
7155 u64 backref_offset;
7156 u64 extent_end;
7157 u64 num_bytes;
7158 int slot;
7159 int found_type;
7160 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7161
7162 path = btrfs_alloc_path();
7163 if (!path)
7164 return -ENOMEM;
7165
7166 ret = btrfs_lookup_file_extent(NULL, root, path,
7167 btrfs_ino(BTRFS_I(inode)), offset, 0);
7168 if (ret < 0)
7169 goto out;
7170
7171 slot = path->slots[0];
7172 if (ret == 1) {
7173 if (slot == 0) {
7174 /* can't find the item, must cow */
7175 ret = 0;
7176 goto out;
7177 }
7178 slot--;
7179 }
7180 ret = 0;
7181 leaf = path->nodes[0];
7182 btrfs_item_key_to_cpu(leaf, &key, slot);
7183 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7184 key.type != BTRFS_EXTENT_DATA_KEY) {
7185 /* not our file or wrong item type, must cow */
7186 goto out;
7187 }
7188
7189 if (key.offset > offset) {
7190 /* Wrong offset, must cow */
7191 goto out;
7192 }
7193
7194 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7195 found_type = btrfs_file_extent_type(leaf, fi);
7196 if (found_type != BTRFS_FILE_EXTENT_REG &&
7197 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7198 /* not a regular extent, must cow */
7199 goto out;
7200 }
7201
7202 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7203 goto out;
7204
7205 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7206 if (extent_end <= offset)
7207 goto out;
7208
7209 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7210 if (disk_bytenr == 0)
7211 goto out;
7212
7213 if (btrfs_file_extent_compression(leaf, fi) ||
7214 btrfs_file_extent_encryption(leaf, fi) ||
7215 btrfs_file_extent_other_encoding(leaf, fi))
7216 goto out;
7217
7218 /*
7219 * Do the same check as in btrfs_cross_ref_exist but without the
7220 * unnecessary search.
7221 */
7222 if (btrfs_file_extent_generation(leaf, fi) <=
7223 btrfs_root_last_snapshot(&root->root_item))
7224 goto out;
7225
7226 backref_offset = btrfs_file_extent_offset(leaf, fi);
7227
7228 if (orig_start) {
7229 *orig_start = key.offset - backref_offset;
7230 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7231 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7232 }
7233
7234 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7235 goto out;
7236
7237 num_bytes = min(offset + *len, extent_end) - offset;
7238 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7239 u64 range_end;
7240
7241 range_end = round_up(offset + num_bytes,
7242 root->fs_info->sectorsize) - 1;
7243 ret = test_range_bit(io_tree, offset, range_end,
7244 EXTENT_DELALLOC, 0, NULL);
7245 if (ret) {
7246 ret = -EAGAIN;
7247 goto out;
7248 }
7249 }
7250
7251 btrfs_release_path(path);
7252
7253 /*
7254 * look for other files referencing this extent, if we
7255 * find any we must cow
7256 */
7257
7258 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7259 key.offset - backref_offset, disk_bytenr);
7260 if (ret) {
7261 ret = 0;
7262 goto out;
7263 }
7264
7265 /*
7266 * adjust disk_bytenr and num_bytes to cover just the bytes
7267 * in this extent we are about to write. If there
7268 * are any csums in that range we have to cow in order
7269 * to keep the csums correct
7270 */
7271 disk_bytenr += backref_offset;
7272 disk_bytenr += offset - key.offset;
7273 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7274 goto out;
7275 /*
7276 * all of the above have passed, it is safe to overwrite this extent
7277 * without cow
7278 */
7279 *len = num_bytes;
7280 ret = 1;
7281 out:
7282 btrfs_free_path(path);
7283 return ret;
7284 }
7285
7286 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7287 struct extent_state **cached_state, int writing)
7288 {
7289 struct btrfs_ordered_extent *ordered;
7290 int ret = 0;
7291
7292 while (1) {
7293 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7294 cached_state);
7295 /*
7296 * We're concerned with the entire range that we're going to be
7297 * doing DIO to, so we need to make sure there's no ordered
7298 * extents in this range.
7299 */
7300 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7301 lockend - lockstart + 1);
7302
7303 /*
7304 * We need to make sure there are no buffered pages in this
7305 * range either, we could have raced between the invalidate in
7306 * generic_file_direct_write and locking the extent. The
7307 * invalidate needs to happen so that reads after a write do not
7308 * get stale data.
7309 */
7310 if (!ordered &&
7311 (!writing || !filemap_range_has_page(inode->i_mapping,
7312 lockstart, lockend)))
7313 break;
7314
7315 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7316 cached_state);
7317
7318 if (ordered) {
7319 /*
7320 * If we are doing a DIO read and the ordered extent we
7321 * found is for a buffered write, we can not wait for it
7322 * to complete and retry, because if we do so we can
7323 * deadlock with concurrent buffered writes on page
7324 * locks. This happens only if our DIO read covers more
7325 * than one extent map, if at this point has already
7326 * created an ordered extent for a previous extent map
7327 * and locked its range in the inode's io tree, and a
7328 * concurrent write against that previous extent map's
7329 * range and this range started (we unlock the ranges
7330 * in the io tree only when the bios complete and
7331 * buffered writes always lock pages before attempting
7332 * to lock range in the io tree).
7333 */
7334 if (writing ||
7335 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7336 btrfs_start_ordered_extent(inode, ordered, 1);
7337 else
7338 ret = -ENOTBLK;
7339 btrfs_put_ordered_extent(ordered);
7340 } else {
7341 /*
7342 * We could trigger writeback for this range (and wait
7343 * for it to complete) and then invalidate the pages for
7344 * this range (through invalidate_inode_pages2_range()),
7345 * but that can lead us to a deadlock with a concurrent
7346 * call to readpages() (a buffered read or a defrag call
7347 * triggered a readahead) on a page lock due to an
7348 * ordered dio extent we created before but did not have
7349 * yet a corresponding bio submitted (whence it can not
7350 * complete), which makes readpages() wait for that
7351 * ordered extent to complete while holding a lock on
7352 * that page.
7353 */
7354 ret = -ENOTBLK;
7355 }
7356
7357 if (ret)
7358 break;
7359
7360 cond_resched();
7361 }
7362
7363 return ret;
7364 }
7365
7366 /* The callers of this must take lock_extent() */
7367 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7368 u64 orig_start, u64 block_start,
7369 u64 block_len, u64 orig_block_len,
7370 u64 ram_bytes, int compress_type,
7371 int type)
7372 {
7373 struct extent_map_tree *em_tree;
7374 struct extent_map *em;
7375 struct btrfs_root *root = BTRFS_I(inode)->root;
7376 int ret;
7377
7378 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7379 type == BTRFS_ORDERED_COMPRESSED ||
7380 type == BTRFS_ORDERED_NOCOW ||
7381 type == BTRFS_ORDERED_REGULAR);
7382
7383 em_tree = &BTRFS_I(inode)->extent_tree;
7384 em = alloc_extent_map();
7385 if (!em)
7386 return ERR_PTR(-ENOMEM);
7387
7388 em->start = start;
7389 em->orig_start = orig_start;
7390 em->len = len;
7391 em->block_len = block_len;
7392 em->block_start = block_start;
7393 em->bdev = root->fs_info->fs_devices->latest_bdev;
7394 em->orig_block_len = orig_block_len;
7395 em->ram_bytes = ram_bytes;
7396 em->generation = -1;
7397 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7398 if (type == BTRFS_ORDERED_PREALLOC) {
7399 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7400 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7401 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7402 em->compress_type = compress_type;
7403 }
7404
7405 do {
7406 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7407 em->start + em->len - 1, 0);
7408 write_lock(&em_tree->lock);
7409 ret = add_extent_mapping(em_tree, em, 1);
7410 write_unlock(&em_tree->lock);
7411 /*
7412 * The caller has taken lock_extent(), who could race with us
7413 * to add em?
7414 */
7415 } while (ret == -EEXIST);
7416
7417 if (ret) {
7418 free_extent_map(em);
7419 return ERR_PTR(ret);
7420 }
7421
7422 /* em got 2 refs now, callers needs to do free_extent_map once. */
7423 return em;
7424 }
7425
7426
7427 static int btrfs_get_blocks_direct_read(struct extent_map *em,
7428 struct buffer_head *bh_result,
7429 struct inode *inode,
7430 u64 start, u64 len)
7431 {
7432 if (em->block_start == EXTENT_MAP_HOLE ||
7433 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7434 return -ENOENT;
7435
7436 len = min(len, em->len - (start - em->start));
7437
7438 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7439 inode->i_blkbits;
7440 bh_result->b_size = len;
7441 bh_result->b_bdev = em->bdev;
7442 set_buffer_mapped(bh_result);
7443
7444 return 0;
7445 }
7446
7447 static int btrfs_get_blocks_direct_write(struct extent_map **map,
7448 struct buffer_head *bh_result,
7449 struct inode *inode,
7450 struct btrfs_dio_data *dio_data,
7451 u64 start, u64 len)
7452 {
7453 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7454 struct extent_map *em = *map;
7455 int ret = 0;
7456
7457 /*
7458 * We don't allocate a new extent in the following cases
7459 *
7460 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7461 * existing extent.
7462 * 2) The extent is marked as PREALLOC. We're good to go here and can
7463 * just use the extent.
7464 *
7465 */
7466 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7467 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7468 em->block_start != EXTENT_MAP_HOLE)) {
7469 int type;
7470 u64 block_start, orig_start, orig_block_len, ram_bytes;
7471
7472 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7473 type = BTRFS_ORDERED_PREALLOC;
7474 else
7475 type = BTRFS_ORDERED_NOCOW;
7476 len = min(len, em->len - (start - em->start));
7477 block_start = em->block_start + (start - em->start);
7478
7479 if (can_nocow_extent(inode, start, &len, &orig_start,
7480 &orig_block_len, &ram_bytes) == 1 &&
7481 btrfs_inc_nocow_writers(fs_info, block_start)) {
7482 struct extent_map *em2;
7483
7484 em2 = btrfs_create_dio_extent(inode, start, len,
7485 orig_start, block_start,
7486 len, orig_block_len,
7487 ram_bytes, type);
7488 btrfs_dec_nocow_writers(fs_info, block_start);
7489 if (type == BTRFS_ORDERED_PREALLOC) {
7490 free_extent_map(em);
7491 *map = em = em2;
7492 }
7493
7494 if (em2 && IS_ERR(em2)) {
7495 ret = PTR_ERR(em2);
7496 goto out;
7497 }
7498 /*
7499 * For inode marked NODATACOW or extent marked PREALLOC,
7500 * use the existing or preallocated extent, so does not
7501 * need to adjust btrfs_space_info's bytes_may_use.
7502 */
7503 btrfs_free_reserved_data_space_noquota(inode, start,
7504 len);
7505 goto skip_cow;
7506 }
7507 }
7508
7509 /* this will cow the extent */
7510 len = bh_result->b_size;
7511 free_extent_map(em);
7512 *map = em = btrfs_new_extent_direct(inode, start, len);
7513 if (IS_ERR(em)) {
7514 ret = PTR_ERR(em);
7515 goto out;
7516 }
7517
7518 len = min(len, em->len - (start - em->start));
7519
7520 skip_cow:
7521 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7522 inode->i_blkbits;
7523 bh_result->b_size = len;
7524 bh_result->b_bdev = em->bdev;
7525 set_buffer_mapped(bh_result);
7526
7527 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7528 set_buffer_new(bh_result);
7529
7530 /*
7531 * Need to update the i_size under the extent lock so buffered
7532 * readers will get the updated i_size when we unlock.
7533 */
7534 if (!dio_data->overwrite && start + len > i_size_read(inode))
7535 i_size_write(inode, start + len);
7536
7537 WARN_ON(dio_data->reserve < len);
7538 dio_data->reserve -= len;
7539 dio_data->unsubmitted_oe_range_end = start + len;
7540 current->journal_info = dio_data;
7541 out:
7542 return ret;
7543 }
7544
7545 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7546 struct buffer_head *bh_result, int create)
7547 {
7548 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7549 struct extent_map *em;
7550 struct extent_state *cached_state = NULL;
7551 struct btrfs_dio_data *dio_data = NULL;
7552 u64 start = iblock << inode->i_blkbits;
7553 u64 lockstart, lockend;
7554 u64 len = bh_result->b_size;
7555 int unlock_bits = EXTENT_LOCKED;
7556 int ret = 0;
7557
7558 if (create)
7559 unlock_bits |= EXTENT_DIRTY;
7560 else
7561 len = min_t(u64, len, fs_info->sectorsize);
7562
7563 lockstart = start;
7564 lockend = start + len - 1;
7565
7566 if (current->journal_info) {
7567 /*
7568 * Need to pull our outstanding extents and set journal_info to NULL so
7569 * that anything that needs to check if there's a transaction doesn't get
7570 * confused.
7571 */
7572 dio_data = current->journal_info;
7573 current->journal_info = NULL;
7574 }
7575
7576 /*
7577 * If this errors out it's because we couldn't invalidate pagecache for
7578 * this range and we need to fallback to buffered.
7579 */
7580 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7581 create)) {
7582 ret = -ENOTBLK;
7583 goto err;
7584 }
7585
7586 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7587 if (IS_ERR(em)) {
7588 ret = PTR_ERR(em);
7589 goto unlock_err;
7590 }
7591
7592 /*
7593 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7594 * io. INLINE is special, and we could probably kludge it in here, but
7595 * it's still buffered so for safety lets just fall back to the generic
7596 * buffered path.
7597 *
7598 * For COMPRESSED we _have_ to read the entire extent in so we can
7599 * decompress it, so there will be buffering required no matter what we
7600 * do, so go ahead and fallback to buffered.
7601 *
7602 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7603 * to buffered IO. Don't blame me, this is the price we pay for using
7604 * the generic code.
7605 */
7606 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7607 em->block_start == EXTENT_MAP_INLINE) {
7608 free_extent_map(em);
7609 ret = -ENOTBLK;
7610 goto unlock_err;
7611 }
7612
7613 if (create) {
7614 ret = btrfs_get_blocks_direct_write(&em, bh_result, inode,
7615 dio_data, start, len);
7616 if (ret < 0)
7617 goto unlock_err;
7618
7619 /* clear and unlock the entire range */
7620 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7621 unlock_bits, 1, 0, &cached_state);
7622 } else {
7623 ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
7624 start, len);
7625 /* Can be negative only if we read from a hole */
7626 if (ret < 0) {
7627 ret = 0;
7628 free_extent_map(em);
7629 goto unlock_err;
7630 }
7631 /*
7632 * We need to unlock only the end area that we aren't using.
7633 * The rest is going to be unlocked by the endio routine.
7634 */
7635 lockstart = start + bh_result->b_size;
7636 if (lockstart < lockend) {
7637 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7638 lockend, unlock_bits, 1, 0,
7639 &cached_state);
7640 } else {
7641 free_extent_state(cached_state);
7642 }
7643 }
7644
7645 free_extent_map(em);
7646
7647 return 0;
7648
7649 unlock_err:
7650 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7651 unlock_bits, 1, 0, &cached_state);
7652 err:
7653 if (dio_data)
7654 current->journal_info = dio_data;
7655 return ret;
7656 }
7657
7658 static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
7659 struct bio *bio,
7660 int mirror_num)
7661 {
7662 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7663 blk_status_t ret;
7664
7665 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7666
7667 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7668 if (ret)
7669 return ret;
7670
7671 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7672
7673 return ret;
7674 }
7675
7676 static int btrfs_check_dio_repairable(struct inode *inode,
7677 struct bio *failed_bio,
7678 struct io_failure_record *failrec,
7679 int failed_mirror)
7680 {
7681 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7682 int num_copies;
7683
7684 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7685 if (num_copies == 1) {
7686 /*
7687 * we only have a single copy of the data, so don't bother with
7688 * all the retry and error correction code that follows. no
7689 * matter what the error is, it is very likely to persist.
7690 */
7691 btrfs_debug(fs_info,
7692 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7693 num_copies, failrec->this_mirror, failed_mirror);
7694 return 0;
7695 }
7696
7697 failrec->failed_mirror = failed_mirror;
7698 failrec->this_mirror++;
7699 if (failrec->this_mirror == failed_mirror)
7700 failrec->this_mirror++;
7701
7702 if (failrec->this_mirror > num_copies) {
7703 btrfs_debug(fs_info,
7704 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7705 num_copies, failrec->this_mirror, failed_mirror);
7706 return 0;
7707 }
7708
7709 return 1;
7710 }
7711
7712 static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
7713 struct page *page, unsigned int pgoff,
7714 u64 start, u64 end, int failed_mirror,
7715 bio_end_io_t *repair_endio, void *repair_arg)
7716 {
7717 struct io_failure_record *failrec;
7718 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7719 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
7720 struct bio *bio;
7721 int isector;
7722 unsigned int read_mode = 0;
7723 int segs;
7724 int ret;
7725 blk_status_t status;
7726 struct bio_vec bvec;
7727
7728 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7729
7730 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7731 if (ret)
7732 return errno_to_blk_status(ret);
7733
7734 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7735 failed_mirror);
7736 if (!ret) {
7737 free_io_failure(failure_tree, io_tree, failrec);
7738 return BLK_STS_IOERR;
7739 }
7740
7741 segs = bio_segments(failed_bio);
7742 bio_get_first_bvec(failed_bio, &bvec);
7743 if (segs > 1 ||
7744 (bvec.bv_len > btrfs_inode_sectorsize(inode)))
7745 read_mode |= REQ_FAILFAST_DEV;
7746
7747 isector = start - btrfs_io_bio(failed_bio)->logical;
7748 isector >>= inode->i_sb->s_blocksize_bits;
7749 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7750 pgoff, isector, repair_endio, repair_arg);
7751 bio->bi_opf = REQ_OP_READ | read_mode;
7752
7753 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7754 "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
7755 read_mode, failrec->this_mirror, failrec->in_validation);
7756
7757 status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7758 if (status) {
7759 free_io_failure(failure_tree, io_tree, failrec);
7760 bio_put(bio);
7761 }
7762
7763 return status;
7764 }
7765
7766 struct btrfs_retry_complete {
7767 struct completion done;
7768 struct inode *inode;
7769 u64 start;
7770 int uptodate;
7771 };
7772
7773 static void btrfs_retry_endio_nocsum(struct bio *bio)
7774 {
7775 struct btrfs_retry_complete *done = bio->bi_private;
7776 struct inode *inode = done->inode;
7777 struct bio_vec *bvec;
7778 struct extent_io_tree *io_tree, *failure_tree;
7779 int i;
7780
7781 if (bio->bi_status)
7782 goto end;
7783
7784 ASSERT(bio->bi_vcnt == 1);
7785 io_tree = &BTRFS_I(inode)->io_tree;
7786 failure_tree = &BTRFS_I(inode)->io_failure_tree;
7787 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
7788
7789 done->uptodate = 1;
7790 ASSERT(!bio_flagged(bio, BIO_CLONED));
7791 bio_for_each_segment_all(bvec, bio, i)
7792 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
7793 io_tree, done->start, bvec->bv_page,
7794 btrfs_ino(BTRFS_I(inode)), 0);
7795 end:
7796 complete(&done->done);
7797 bio_put(bio);
7798 }
7799
7800 static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
7801 struct btrfs_io_bio *io_bio)
7802 {
7803 struct btrfs_fs_info *fs_info;
7804 struct bio_vec bvec;
7805 struct bvec_iter iter;
7806 struct btrfs_retry_complete done;
7807 u64 start;
7808 unsigned int pgoff;
7809 u32 sectorsize;
7810 int nr_sectors;
7811 blk_status_t ret;
7812 blk_status_t err = BLK_STS_OK;
7813
7814 fs_info = BTRFS_I(inode)->root->fs_info;
7815 sectorsize = fs_info->sectorsize;
7816
7817 start = io_bio->logical;
7818 done.inode = inode;
7819 io_bio->bio.bi_iter = io_bio->iter;
7820
7821 bio_for_each_segment(bvec, &io_bio->bio, iter) {
7822 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
7823 pgoff = bvec.bv_offset;
7824
7825 next_block_or_try_again:
7826 done.uptodate = 0;
7827 done.start = start;
7828 init_completion(&done.done);
7829
7830 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
7831 pgoff, start, start + sectorsize - 1,
7832 io_bio->mirror_num,
7833 btrfs_retry_endio_nocsum, &done);
7834 if (ret) {
7835 err = ret;
7836 goto next;
7837 }
7838
7839 wait_for_completion_io(&done.done);
7840
7841 if (!done.uptodate) {
7842 /* We might have another mirror, so try again */
7843 goto next_block_or_try_again;
7844 }
7845
7846 next:
7847 start += sectorsize;
7848
7849 nr_sectors--;
7850 if (nr_sectors) {
7851 pgoff += sectorsize;
7852 ASSERT(pgoff < PAGE_SIZE);
7853 goto next_block_or_try_again;
7854 }
7855 }
7856
7857 return err;
7858 }
7859
7860 static void btrfs_retry_endio(struct bio *bio)
7861 {
7862 struct btrfs_retry_complete *done = bio->bi_private;
7863 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7864 struct extent_io_tree *io_tree, *failure_tree;
7865 struct inode *inode = done->inode;
7866 struct bio_vec *bvec;
7867 int uptodate;
7868 int ret;
7869 int i;
7870
7871 if (bio->bi_status)
7872 goto end;
7873
7874 uptodate = 1;
7875
7876 ASSERT(bio->bi_vcnt == 1);
7877 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
7878
7879 io_tree = &BTRFS_I(inode)->io_tree;
7880 failure_tree = &BTRFS_I(inode)->io_failure_tree;
7881
7882 ASSERT(!bio_flagged(bio, BIO_CLONED));
7883 bio_for_each_segment_all(bvec, bio, i) {
7884 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7885 bvec->bv_offset, done->start,
7886 bvec->bv_len);
7887 if (!ret)
7888 clean_io_failure(BTRFS_I(inode)->root->fs_info,
7889 failure_tree, io_tree, done->start,
7890 bvec->bv_page,
7891 btrfs_ino(BTRFS_I(inode)),
7892 bvec->bv_offset);
7893 else
7894 uptodate = 0;
7895 }
7896
7897 done->uptodate = uptodate;
7898 end:
7899 complete(&done->done);
7900 bio_put(bio);
7901 }
7902
7903 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
7904 struct btrfs_io_bio *io_bio, blk_status_t err)
7905 {
7906 struct btrfs_fs_info *fs_info;
7907 struct bio_vec bvec;
7908 struct bvec_iter iter;
7909 struct btrfs_retry_complete done;
7910 u64 start;
7911 u64 offset = 0;
7912 u32 sectorsize;
7913 int nr_sectors;
7914 unsigned int pgoff;
7915 int csum_pos;
7916 bool uptodate = (err == 0);
7917 int ret;
7918 blk_status_t status;
7919
7920 fs_info = BTRFS_I(inode)->root->fs_info;
7921 sectorsize = fs_info->sectorsize;
7922
7923 err = BLK_STS_OK;
7924 start = io_bio->logical;
7925 done.inode = inode;
7926 io_bio->bio.bi_iter = io_bio->iter;
7927
7928 bio_for_each_segment(bvec, &io_bio->bio, iter) {
7929 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
7930
7931 pgoff = bvec.bv_offset;
7932 next_block:
7933 if (uptodate) {
7934 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
7935 ret = __readpage_endio_check(inode, io_bio, csum_pos,
7936 bvec.bv_page, pgoff, start, sectorsize);
7937 if (likely(!ret))
7938 goto next;
7939 }
7940 try_again:
7941 done.uptodate = 0;
7942 done.start = start;
7943 init_completion(&done.done);
7944
7945 status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
7946 pgoff, start, start + sectorsize - 1,
7947 io_bio->mirror_num, btrfs_retry_endio,
7948 &done);
7949 if (status) {
7950 err = status;
7951 goto next;
7952 }
7953
7954 wait_for_completion_io(&done.done);
7955
7956 if (!done.uptodate) {
7957 /* We might have another mirror, so try again */
7958 goto try_again;
7959 }
7960 next:
7961 offset += sectorsize;
7962 start += sectorsize;
7963
7964 ASSERT(nr_sectors);
7965
7966 nr_sectors--;
7967 if (nr_sectors) {
7968 pgoff += sectorsize;
7969 ASSERT(pgoff < PAGE_SIZE);
7970 goto next_block;
7971 }
7972 }
7973
7974 return err;
7975 }
7976
7977 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
7978 struct btrfs_io_bio *io_bio, blk_status_t err)
7979 {
7980 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7981
7982 if (skip_csum) {
7983 if (unlikely(err))
7984 return __btrfs_correct_data_nocsum(inode, io_bio);
7985 else
7986 return BLK_STS_OK;
7987 } else {
7988 return __btrfs_subio_endio_read(inode, io_bio, err);
7989 }
7990 }
7991
7992 static void btrfs_endio_direct_read(struct bio *bio)
7993 {
7994 struct btrfs_dio_private *dip = bio->bi_private;
7995 struct inode *inode = dip->inode;
7996 struct bio *dio_bio;
7997 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7998 blk_status_t err = bio->bi_status;
7999
8000 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8001 err = btrfs_subio_endio_read(inode, io_bio, err);
8002
8003 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8004 dip->logical_offset + dip->bytes - 1);
8005 dio_bio = dip->dio_bio;
8006
8007 kfree(dip);
8008
8009 dio_bio->bi_status = err;
8010 dio_end_io(dio_bio);
8011 btrfs_io_bio_free_csum(io_bio);
8012 bio_put(bio);
8013 }
8014
8015 static void __endio_write_update_ordered(struct inode *inode,
8016 const u64 offset, const u64 bytes,
8017 const bool uptodate)
8018 {
8019 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8020 struct btrfs_ordered_extent *ordered = NULL;
8021 struct btrfs_workqueue *wq;
8022 btrfs_work_func_t func;
8023 u64 ordered_offset = offset;
8024 u64 ordered_bytes = bytes;
8025 u64 last_offset;
8026
8027 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8028 wq = fs_info->endio_freespace_worker;
8029 func = btrfs_freespace_write_helper;
8030 } else {
8031 wq = fs_info->endio_write_workers;
8032 func = btrfs_endio_write_helper;
8033 }
8034
8035 while (ordered_offset < offset + bytes) {
8036 last_offset = ordered_offset;
8037 if (btrfs_dec_test_first_ordered_pending(inode, &ordered,
8038 &ordered_offset,
8039 ordered_bytes,
8040 uptodate)) {
8041 btrfs_init_work(&ordered->work, func,
8042 finish_ordered_fn,
8043 NULL, NULL);
8044 btrfs_queue_work(wq, &ordered->work);
8045 }
8046 /*
8047 * If btrfs_dec_test_ordered_pending does not find any ordered
8048 * extent in the range, we can exit.
8049 */
8050 if (ordered_offset == last_offset)
8051 return;
8052 /*
8053 * Our bio might span multiple ordered extents. In this case
8054 * we keep going until we have accounted the whole dio.
8055 */
8056 if (ordered_offset < offset + bytes) {
8057 ordered_bytes = offset + bytes - ordered_offset;
8058 ordered = NULL;
8059 }
8060 }
8061 }
8062
8063 static void btrfs_endio_direct_write(struct bio *bio)
8064 {
8065 struct btrfs_dio_private *dip = bio->bi_private;
8066 struct bio *dio_bio = dip->dio_bio;
8067
8068 __endio_write_update_ordered(dip->inode, dip->logical_offset,
8069 dip->bytes, !bio->bi_status);
8070
8071 kfree(dip);
8072
8073 dio_bio->bi_status = bio->bi_status;
8074 dio_end_io(dio_bio);
8075 bio_put(bio);
8076 }
8077
8078 static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
8079 struct bio *bio, u64 offset)
8080 {
8081 struct inode *inode = private_data;
8082 blk_status_t ret;
8083 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8084 BUG_ON(ret); /* -ENOMEM */
8085 return 0;
8086 }
8087
8088 static void btrfs_end_dio_bio(struct bio *bio)
8089 {
8090 struct btrfs_dio_private *dip = bio->bi_private;
8091 blk_status_t err = bio->bi_status;
8092
8093 if (err)
8094 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8095 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8096 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8097 bio->bi_opf,
8098 (unsigned long long)bio->bi_iter.bi_sector,
8099 bio->bi_iter.bi_size, err);
8100
8101 if (dip->subio_endio)
8102 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8103
8104 if (err) {
8105 /*
8106 * We want to perceive the errors flag being set before
8107 * decrementing the reference count. We don't need a barrier
8108 * since atomic operations with a return value are fully
8109 * ordered as per atomic_t.txt
8110 */
8111 dip->errors = 1;
8112 }
8113
8114 /* if there are more bios still pending for this dio, just exit */
8115 if (!atomic_dec_and_test(&dip->pending_bios))
8116 goto out;
8117
8118 if (dip->errors) {
8119 bio_io_error(dip->orig_bio);
8120 } else {
8121 dip->dio_bio->bi_status = BLK_STS_OK;
8122 bio_endio(dip->orig_bio);
8123 }
8124 out:
8125 bio_put(bio);
8126 }
8127
8128 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8129 struct btrfs_dio_private *dip,
8130 struct bio *bio,
8131 u64 file_offset)
8132 {
8133 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8134 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8135 blk_status_t ret;
8136
8137 /*
8138 * We load all the csum data we need when we submit
8139 * the first bio to reduce the csum tree search and
8140 * contention.
8141 */
8142 if (dip->logical_offset == file_offset) {
8143 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8144 file_offset);
8145 if (ret)
8146 return ret;
8147 }
8148
8149 if (bio == dip->orig_bio)
8150 return 0;
8151
8152 file_offset -= dip->logical_offset;
8153 file_offset >>= inode->i_sb->s_blocksize_bits;
8154 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8155
8156 return 0;
8157 }
8158
8159 static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
8160 struct inode *inode, u64 file_offset, int async_submit)
8161 {
8162 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8163 struct btrfs_dio_private *dip = bio->bi_private;
8164 bool write = bio_op(bio) == REQ_OP_WRITE;
8165 blk_status_t ret;
8166
8167 /* Check btrfs_submit_bio_hook() for rules about async submit. */
8168 if (async_submit)
8169 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8170
8171 if (!write) {
8172 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8173 if (ret)
8174 goto err;
8175 }
8176
8177 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8178 goto map;
8179
8180 if (write && async_submit) {
8181 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8182 file_offset, inode,
8183 btrfs_submit_bio_start_direct_io);
8184 goto err;
8185 } else if (write) {
8186 /*
8187 * If we aren't doing async submit, calculate the csum of the
8188 * bio now.
8189 */
8190 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8191 if (ret)
8192 goto err;
8193 } else {
8194 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8195 file_offset);
8196 if (ret)
8197 goto err;
8198 }
8199 map:
8200 ret = btrfs_map_bio(fs_info, bio, 0, 0);
8201 err:
8202 return ret;
8203 }
8204
8205 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8206 {
8207 struct inode *inode = dip->inode;
8208 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8209 struct bio *bio;
8210 struct bio *orig_bio = dip->orig_bio;
8211 u64 start_sector = orig_bio->bi_iter.bi_sector;
8212 u64 file_offset = dip->logical_offset;
8213 u64 map_length;
8214 int async_submit = 0;
8215 u64 submit_len;
8216 int clone_offset = 0;
8217 int clone_len;
8218 int ret;
8219 blk_status_t status;
8220
8221 map_length = orig_bio->bi_iter.bi_size;
8222 submit_len = map_length;
8223 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8224 &map_length, NULL, 0);
8225 if (ret)
8226 return -EIO;
8227
8228 if (map_length >= submit_len) {
8229 bio = orig_bio;
8230 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8231 goto submit;
8232 }
8233
8234 /* async crcs make it difficult to collect full stripe writes. */
8235 if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8236 async_submit = 0;
8237 else
8238 async_submit = 1;
8239
8240 /* bio split */
8241 ASSERT(map_length <= INT_MAX);
8242 atomic_inc(&dip->pending_bios);
8243 do {
8244 clone_len = min_t(int, submit_len, map_length);
8245
8246 /*
8247 * This will never fail as it's passing GPF_NOFS and
8248 * the allocation is backed by btrfs_bioset.
8249 */
8250 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8251 clone_len);
8252 bio->bi_private = dip;
8253 bio->bi_end_io = btrfs_end_dio_bio;
8254 btrfs_io_bio(bio)->logical = file_offset;
8255
8256 ASSERT(submit_len >= clone_len);
8257 submit_len -= clone_len;
8258 if (submit_len == 0)
8259 break;
8260
8261 /*
8262 * Increase the count before we submit the bio so we know
8263 * the end IO handler won't happen before we increase the
8264 * count. Otherwise, the dip might get freed before we're
8265 * done setting it up.
8266 */
8267 atomic_inc(&dip->pending_bios);
8268
8269 status = btrfs_submit_dio_bio(bio, inode, file_offset,
8270 async_submit);
8271 if (status) {
8272 bio_put(bio);
8273 atomic_dec(&dip->pending_bios);
8274 goto out_err;
8275 }
8276
8277 clone_offset += clone_len;
8278 start_sector += clone_len >> 9;
8279 file_offset += clone_len;
8280
8281 map_length = submit_len;
8282 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8283 start_sector << 9, &map_length, NULL, 0);
8284 if (ret)
8285 goto out_err;
8286 } while (submit_len > 0);
8287
8288 submit:
8289 status = btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8290 if (!status)
8291 return 0;
8292
8293 bio_put(bio);
8294 out_err:
8295 dip->errors = 1;
8296 /*
8297 * Before atomic variable goto zero, we must make sure dip->errors is
8298 * perceived to be set. This ordering is ensured by the fact that an
8299 * atomic operations with a return value are fully ordered as per
8300 * atomic_t.txt
8301 */
8302 if (atomic_dec_and_test(&dip->pending_bios))
8303 bio_io_error(dip->orig_bio);
8304
8305 /* bio_end_io() will handle error, so we needn't return it */
8306 return 0;
8307 }
8308
8309 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8310 loff_t file_offset)
8311 {
8312 struct btrfs_dio_private *dip = NULL;
8313 struct bio *bio = NULL;
8314 struct btrfs_io_bio *io_bio;
8315 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8316 int ret = 0;
8317
8318 bio = btrfs_bio_clone(dio_bio);
8319
8320 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8321 if (!dip) {
8322 ret = -ENOMEM;
8323 goto free_ordered;
8324 }
8325
8326 dip->private = dio_bio->bi_private;
8327 dip->inode = inode;
8328 dip->logical_offset = file_offset;
8329 dip->bytes = dio_bio->bi_iter.bi_size;
8330 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8331 bio->bi_private = dip;
8332 dip->orig_bio = bio;
8333 dip->dio_bio = dio_bio;
8334 atomic_set(&dip->pending_bios, 0);
8335 io_bio = btrfs_io_bio(bio);
8336 io_bio->logical = file_offset;
8337
8338 if (write) {
8339 bio->bi_end_io = btrfs_endio_direct_write;
8340 } else {
8341 bio->bi_end_io = btrfs_endio_direct_read;
8342 dip->subio_endio = btrfs_subio_endio_read;
8343 }
8344
8345 /*
8346 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8347 * even if we fail to submit a bio, because in such case we do the
8348 * corresponding error handling below and it must not be done a second
8349 * time by btrfs_direct_IO().
8350 */
8351 if (write) {
8352 struct btrfs_dio_data *dio_data = current->journal_info;
8353
8354 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8355 dip->bytes;
8356 dio_data->unsubmitted_oe_range_start =
8357 dio_data->unsubmitted_oe_range_end;
8358 }
8359
8360 ret = btrfs_submit_direct_hook(dip);
8361 if (!ret)
8362 return;
8363
8364 btrfs_io_bio_free_csum(io_bio);
8365
8366 free_ordered:
8367 /*
8368 * If we arrived here it means either we failed to submit the dip
8369 * or we either failed to clone the dio_bio or failed to allocate the
8370 * dip. If we cloned the dio_bio and allocated the dip, we can just
8371 * call bio_endio against our io_bio so that we get proper resource
8372 * cleanup if we fail to submit the dip, otherwise, we must do the
8373 * same as btrfs_endio_direct_[write|read] because we can't call these
8374 * callbacks - they require an allocated dip and a clone of dio_bio.
8375 */
8376 if (bio && dip) {
8377 bio_io_error(bio);
8378 /*
8379 * The end io callbacks free our dip, do the final put on bio
8380 * and all the cleanup and final put for dio_bio (through
8381 * dio_end_io()).
8382 */
8383 dip = NULL;
8384 bio = NULL;
8385 } else {
8386 if (write)
8387 __endio_write_update_ordered(inode,
8388 file_offset,
8389 dio_bio->bi_iter.bi_size,
8390 false);
8391 else
8392 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8393 file_offset + dio_bio->bi_iter.bi_size - 1);
8394
8395 dio_bio->bi_status = BLK_STS_IOERR;
8396 /*
8397 * Releases and cleans up our dio_bio, no need to bio_put()
8398 * nor bio_endio()/bio_io_error() against dio_bio.
8399 */
8400 dio_end_io(dio_bio);
8401 }
8402 if (bio)
8403 bio_put(bio);
8404 kfree(dip);
8405 }
8406
8407 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8408 const struct iov_iter *iter, loff_t offset)
8409 {
8410 int seg;
8411 int i;
8412 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8413 ssize_t retval = -EINVAL;
8414
8415 if (offset & blocksize_mask)
8416 goto out;
8417
8418 if (iov_iter_alignment(iter) & blocksize_mask)
8419 goto out;
8420
8421 /* If this is a write we don't need to check anymore */
8422 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8423 return 0;
8424 /*
8425 * Check to make sure we don't have duplicate iov_base's in this
8426 * iovec, if so return EINVAL, otherwise we'll get csum errors
8427 * when reading back.
8428 */
8429 for (seg = 0; seg < iter->nr_segs; seg++) {
8430 for (i = seg + 1; i < iter->nr_segs; i++) {
8431 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8432 goto out;
8433 }
8434 }
8435 retval = 0;
8436 out:
8437 return retval;
8438 }
8439
8440 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8441 {
8442 struct file *file = iocb->ki_filp;
8443 struct inode *inode = file->f_mapping->host;
8444 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8445 struct btrfs_dio_data dio_data = { 0 };
8446 struct extent_changeset *data_reserved = NULL;
8447 loff_t offset = iocb->ki_pos;
8448 size_t count = 0;
8449 int flags = 0;
8450 bool wakeup = true;
8451 bool relock = false;
8452 ssize_t ret;
8453
8454 if (check_direct_IO(fs_info, iter, offset))
8455 return 0;
8456
8457 inode_dio_begin(inode);
8458
8459 /*
8460 * The generic stuff only does filemap_write_and_wait_range, which
8461 * isn't enough if we've written compressed pages to this area, so
8462 * we need to flush the dirty pages again to make absolutely sure
8463 * that any outstanding dirty pages are on disk.
8464 */
8465 count = iov_iter_count(iter);
8466 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8467 &BTRFS_I(inode)->runtime_flags))
8468 filemap_fdatawrite_range(inode->i_mapping, offset,
8469 offset + count - 1);
8470
8471 if (iov_iter_rw(iter) == WRITE) {
8472 /*
8473 * If the write DIO is beyond the EOF, we need update
8474 * the isize, but it is protected by i_mutex. So we can
8475 * not unlock the i_mutex at this case.
8476 */
8477 if (offset + count <= inode->i_size) {
8478 dio_data.overwrite = 1;
8479 inode_unlock(inode);
8480 relock = true;
8481 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8482 ret = -EAGAIN;
8483 goto out;
8484 }
8485 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8486 offset, count);
8487 if (ret)
8488 goto out;
8489
8490 /*
8491 * We need to know how many extents we reserved so that we can
8492 * do the accounting properly if we go over the number we
8493 * originally calculated. Abuse current->journal_info for this.
8494 */
8495 dio_data.reserve = round_up(count,
8496 fs_info->sectorsize);
8497 dio_data.unsubmitted_oe_range_start = (u64)offset;
8498 dio_data.unsubmitted_oe_range_end = (u64)offset;
8499 current->journal_info = &dio_data;
8500 down_read(&BTRFS_I(inode)->dio_sem);
8501 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8502 &BTRFS_I(inode)->runtime_flags)) {
8503 inode_dio_end(inode);
8504 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8505 wakeup = false;
8506 }
8507
8508 ret = __blockdev_direct_IO(iocb, inode,
8509 fs_info->fs_devices->latest_bdev,
8510 iter, btrfs_get_blocks_direct, NULL,
8511 btrfs_submit_direct, flags);
8512 if (iov_iter_rw(iter) == WRITE) {
8513 up_read(&BTRFS_I(inode)->dio_sem);
8514 current->journal_info = NULL;
8515 if (ret < 0 && ret != -EIOCBQUEUED) {
8516 if (dio_data.reserve)
8517 btrfs_delalloc_release_space(inode, data_reserved,
8518 offset, dio_data.reserve, true);
8519 /*
8520 * On error we might have left some ordered extents
8521 * without submitting corresponding bios for them, so
8522 * cleanup them up to avoid other tasks getting them
8523 * and waiting for them to complete forever.
8524 */
8525 if (dio_data.unsubmitted_oe_range_start <
8526 dio_data.unsubmitted_oe_range_end)
8527 __endio_write_update_ordered(inode,
8528 dio_data.unsubmitted_oe_range_start,
8529 dio_data.unsubmitted_oe_range_end -
8530 dio_data.unsubmitted_oe_range_start,
8531 false);
8532 } else if (ret >= 0 && (size_t)ret < count)
8533 btrfs_delalloc_release_space(inode, data_reserved,
8534 offset, count - (size_t)ret, true);
8535 btrfs_delalloc_release_extents(BTRFS_I(inode), count, false);
8536 }
8537 out:
8538 if (wakeup)
8539 inode_dio_end(inode);
8540 if (relock)
8541 inode_lock(inode);
8542
8543 extent_changeset_free(data_reserved);
8544 return ret;
8545 }
8546
8547 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8548
8549 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8550 __u64 start, __u64 len)
8551 {
8552 int ret;
8553
8554 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8555 if (ret)
8556 return ret;
8557
8558 return extent_fiemap(inode, fieinfo, start, len);
8559 }
8560
8561 int btrfs_readpage(struct file *file, struct page *page)
8562 {
8563 struct extent_io_tree *tree;
8564 tree = &BTRFS_I(page->mapping->host)->io_tree;
8565 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8566 }
8567
8568 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8569 {
8570 struct inode *inode = page->mapping->host;
8571 int ret;
8572
8573 if (current->flags & PF_MEMALLOC) {
8574 redirty_page_for_writepage(wbc, page);
8575 unlock_page(page);
8576 return 0;
8577 }
8578
8579 /*
8580 * If we are under memory pressure we will call this directly from the
8581 * VM, we need to make sure we have the inode referenced for the ordered
8582 * extent. If not just return like we didn't do anything.
8583 */
8584 if (!igrab(inode)) {
8585 redirty_page_for_writepage(wbc, page);
8586 return AOP_WRITEPAGE_ACTIVATE;
8587 }
8588 ret = extent_write_full_page(page, wbc);
8589 btrfs_add_delayed_iput(inode);
8590 return ret;
8591 }
8592
8593 static int btrfs_writepages(struct address_space *mapping,
8594 struct writeback_control *wbc)
8595 {
8596 return extent_writepages(mapping, wbc);
8597 }
8598
8599 static int
8600 btrfs_readpages(struct file *file, struct address_space *mapping,
8601 struct list_head *pages, unsigned nr_pages)
8602 {
8603 return extent_readpages(mapping, pages, nr_pages);
8604 }
8605
8606 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8607 {
8608 int ret = try_release_extent_mapping(page, gfp_flags);
8609 if (ret == 1) {
8610 ClearPagePrivate(page);
8611 set_page_private(page, 0);
8612 put_page(page);
8613 }
8614 return ret;
8615 }
8616
8617 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8618 {
8619 if (PageWriteback(page) || PageDirty(page))
8620 return 0;
8621 return __btrfs_releasepage(page, gfp_flags);
8622 }
8623
8624 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8625 unsigned int length)
8626 {
8627 struct inode *inode = page->mapping->host;
8628 struct extent_io_tree *tree;
8629 struct btrfs_ordered_extent *ordered;
8630 struct extent_state *cached_state = NULL;
8631 u64 page_start = page_offset(page);
8632 u64 page_end = page_start + PAGE_SIZE - 1;
8633 u64 start;
8634 u64 end;
8635 int inode_evicting = inode->i_state & I_FREEING;
8636
8637 /*
8638 * we have the page locked, so new writeback can't start,
8639 * and the dirty bit won't be cleared while we are here.
8640 *
8641 * Wait for IO on this page so that we can safely clear
8642 * the PagePrivate2 bit and do ordered accounting
8643 */
8644 wait_on_page_writeback(page);
8645
8646 tree = &BTRFS_I(inode)->io_tree;
8647 if (offset) {
8648 btrfs_releasepage(page, GFP_NOFS);
8649 return;
8650 }
8651
8652 if (!inode_evicting)
8653 lock_extent_bits(tree, page_start, page_end, &cached_state);
8654 again:
8655 start = page_start;
8656 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8657 page_end - start + 1);
8658 if (ordered) {
8659 end = min(page_end, ordered->file_offset + ordered->len - 1);
8660 /*
8661 * IO on this page will never be started, so we need
8662 * to account for any ordered extents now
8663 */
8664 if (!inode_evicting)
8665 clear_extent_bit(tree, start, end,
8666 EXTENT_DIRTY | EXTENT_DELALLOC |
8667 EXTENT_DELALLOC_NEW |
8668 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8669 EXTENT_DEFRAG, 1, 0, &cached_state);
8670 /*
8671 * whoever cleared the private bit is responsible
8672 * for the finish_ordered_io
8673 */
8674 if (TestClearPagePrivate2(page)) {
8675 struct btrfs_ordered_inode_tree *tree;
8676 u64 new_len;
8677
8678 tree = &BTRFS_I(inode)->ordered_tree;
8679
8680 spin_lock_irq(&tree->lock);
8681 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8682 new_len = start - ordered->file_offset;
8683 if (new_len < ordered->truncated_len)
8684 ordered->truncated_len = new_len;
8685 spin_unlock_irq(&tree->lock);
8686
8687 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8688 start,
8689 end - start + 1, 1))
8690 btrfs_finish_ordered_io(ordered);
8691 }
8692 btrfs_put_ordered_extent(ordered);
8693 if (!inode_evicting) {
8694 cached_state = NULL;
8695 lock_extent_bits(tree, start, end,
8696 &cached_state);
8697 }
8698
8699 start = end + 1;
8700 if (start < page_end)
8701 goto again;
8702 }
8703
8704 /*
8705 * Qgroup reserved space handler
8706 * Page here will be either
8707 * 1) Already written to disk
8708 * In this case, its reserved space is released from data rsv map
8709 * and will be freed by delayed_ref handler finally.
8710 * So even we call qgroup_free_data(), it won't decrease reserved
8711 * space.
8712 * 2) Not written to disk
8713 * This means the reserved space should be freed here. However,
8714 * if a truncate invalidates the page (by clearing PageDirty)
8715 * and the page is accounted for while allocating extent
8716 * in btrfs_check_data_free_space() we let delayed_ref to
8717 * free the entire extent.
8718 */
8719 if (PageDirty(page))
8720 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
8721 if (!inode_evicting) {
8722 clear_extent_bit(tree, page_start, page_end,
8723 EXTENT_LOCKED | EXTENT_DIRTY |
8724 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
8725 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
8726 &cached_state);
8727
8728 __btrfs_releasepage(page, GFP_NOFS);
8729 }
8730
8731 ClearPageChecked(page);
8732 if (PagePrivate(page)) {
8733 ClearPagePrivate(page);
8734 set_page_private(page, 0);
8735 put_page(page);
8736 }
8737 }
8738
8739 /*
8740 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8741 * called from a page fault handler when a page is first dirtied. Hence we must
8742 * be careful to check for EOF conditions here. We set the page up correctly
8743 * for a written page which means we get ENOSPC checking when writing into
8744 * holes and correct delalloc and unwritten extent mapping on filesystems that
8745 * support these features.
8746 *
8747 * We are not allowed to take the i_mutex here so we have to play games to
8748 * protect against truncate races as the page could now be beyond EOF. Because
8749 * truncate_setsize() writes the inode size before removing pages, once we have
8750 * the page lock we can determine safely if the page is beyond EOF. If it is not
8751 * beyond EOF, then the page is guaranteed safe against truncation until we
8752 * unlock the page.
8753 */
8754 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
8755 {
8756 struct page *page = vmf->page;
8757 struct inode *inode = file_inode(vmf->vma->vm_file);
8758 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8759 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8760 struct btrfs_ordered_extent *ordered;
8761 struct extent_state *cached_state = NULL;
8762 struct extent_changeset *data_reserved = NULL;
8763 char *kaddr;
8764 unsigned long zero_start;
8765 loff_t size;
8766 vm_fault_t ret;
8767 int ret2;
8768 int reserved = 0;
8769 u64 reserved_space;
8770 u64 page_start;
8771 u64 page_end;
8772 u64 end;
8773
8774 reserved_space = PAGE_SIZE;
8775
8776 sb_start_pagefault(inode->i_sb);
8777 page_start = page_offset(page);
8778 page_end = page_start + PAGE_SIZE - 1;
8779 end = page_end;
8780
8781 /*
8782 * Reserving delalloc space after obtaining the page lock can lead to
8783 * deadlock. For example, if a dirty page is locked by this function
8784 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8785 * dirty page write out, then the btrfs_writepage() function could
8786 * end up waiting indefinitely to get a lock on the page currently
8787 * being processed by btrfs_page_mkwrite() function.
8788 */
8789 ret2 = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
8790 reserved_space);
8791 if (!ret2) {
8792 ret2 = file_update_time(vmf->vma->vm_file);
8793 reserved = 1;
8794 }
8795 if (ret2) {
8796 ret = vmf_error(ret2);
8797 if (reserved)
8798 goto out;
8799 goto out_noreserve;
8800 }
8801
8802 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8803 again:
8804 lock_page(page);
8805 size = i_size_read(inode);
8806
8807 if ((page->mapping != inode->i_mapping) ||
8808 (page_start >= size)) {
8809 /* page got truncated out from underneath us */
8810 goto out_unlock;
8811 }
8812 wait_on_page_writeback(page);
8813
8814 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8815 set_page_extent_mapped(page);
8816
8817 /*
8818 * we can't set the delalloc bits if there are pending ordered
8819 * extents. Drop our locks and wait for them to finish
8820 */
8821 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
8822 PAGE_SIZE);
8823 if (ordered) {
8824 unlock_extent_cached(io_tree, page_start, page_end,
8825 &cached_state);
8826 unlock_page(page);
8827 btrfs_start_ordered_extent(inode, ordered, 1);
8828 btrfs_put_ordered_extent(ordered);
8829 goto again;
8830 }
8831
8832 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8833 reserved_space = round_up(size - page_start,
8834 fs_info->sectorsize);
8835 if (reserved_space < PAGE_SIZE) {
8836 end = page_start + reserved_space - 1;
8837 btrfs_delalloc_release_space(inode, data_reserved,
8838 page_start, PAGE_SIZE - reserved_space,
8839 true);
8840 }
8841 }
8842
8843 /*
8844 * page_mkwrite gets called when the page is firstly dirtied after it's
8845 * faulted in, but write(2) could also dirty a page and set delalloc
8846 * bits, thus in this case for space account reason, we still need to
8847 * clear any delalloc bits within this page range since we have to
8848 * reserve data&meta space before lock_page() (see above comments).
8849 */
8850 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
8851 EXTENT_DIRTY | EXTENT_DELALLOC |
8852 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8853 0, 0, &cached_state);
8854
8855 ret2 = btrfs_set_extent_delalloc(inode, page_start, end, 0,
8856 &cached_state, 0);
8857 if (ret2) {
8858 unlock_extent_cached(io_tree, page_start, page_end,
8859 &cached_state);
8860 ret = VM_FAULT_SIGBUS;
8861 goto out_unlock;
8862 }
8863 ret2 = 0;
8864
8865 /* page is wholly or partially inside EOF */
8866 if (page_start + PAGE_SIZE > size)
8867 zero_start = offset_in_page(size);
8868 else
8869 zero_start = PAGE_SIZE;
8870
8871 if (zero_start != PAGE_SIZE) {
8872 kaddr = kmap(page);
8873 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
8874 flush_dcache_page(page);
8875 kunmap(page);
8876 }
8877 ClearPageChecked(page);
8878 set_page_dirty(page);
8879 SetPageUptodate(page);
8880
8881 BTRFS_I(inode)->last_trans = fs_info->generation;
8882 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
8883 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
8884
8885 unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
8886
8887 if (!ret2) {
8888 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true);
8889 sb_end_pagefault(inode->i_sb);
8890 extent_changeset_free(data_reserved);
8891 return VM_FAULT_LOCKED;
8892 }
8893
8894 out_unlock:
8895 unlock_page(page);
8896 out:
8897 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, (ret != 0));
8898 btrfs_delalloc_release_space(inode, data_reserved, page_start,
8899 reserved_space, (ret != 0));
8900 out_noreserve:
8901 sb_end_pagefault(inode->i_sb);
8902 extent_changeset_free(data_reserved);
8903 return ret;
8904 }
8905
8906 static int btrfs_truncate(struct inode *inode, bool skip_writeback)
8907 {
8908 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8909 struct btrfs_root *root = BTRFS_I(inode)->root;
8910 struct btrfs_block_rsv *rsv;
8911 int ret;
8912 struct btrfs_trans_handle *trans;
8913 u64 mask = fs_info->sectorsize - 1;
8914 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
8915
8916 if (!skip_writeback) {
8917 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8918 (u64)-1);
8919 if (ret)
8920 return ret;
8921 }
8922
8923 /*
8924 * Yes ladies and gentlemen, this is indeed ugly. We have a couple of
8925 * things going on here:
8926 *
8927 * 1) We need to reserve space to update our inode.
8928 *
8929 * 2) We need to have something to cache all the space that is going to
8930 * be free'd up by the truncate operation, but also have some slack
8931 * space reserved in case it uses space during the truncate (thank you
8932 * very much snapshotting).
8933 *
8934 * And we need these to be separate. The fact is we can use a lot of
8935 * space doing the truncate, and we have no earthly idea how much space
8936 * we will use, so we need the truncate reservation to be separate so it
8937 * doesn't end up using space reserved for updating the inode. We also
8938 * need to be able to stop the transaction and start a new one, which
8939 * means we need to be able to update the inode several times, and we
8940 * have no idea of knowing how many times that will be, so we can't just
8941 * reserve 1 item for the entirety of the operation, so that has to be
8942 * done separately as well.
8943 *
8944 * So that leaves us with
8945 *
8946 * 1) rsv - for the truncate reservation, which we will steal from the
8947 * transaction reservation.
8948 * 2) fs_info->trans_block_rsv - this will have 1 items worth left for
8949 * updating the inode.
8950 */
8951 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
8952 if (!rsv)
8953 return -ENOMEM;
8954 rsv->size = min_size;
8955 rsv->failfast = 1;
8956
8957 /*
8958 * 1 for the truncate slack space
8959 * 1 for updating the inode.
8960 */
8961 trans = btrfs_start_transaction(root, 2);
8962 if (IS_ERR(trans)) {
8963 ret = PTR_ERR(trans);
8964 goto out;
8965 }
8966
8967 /* Migrate the slack space for the truncate to our reserve */
8968 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
8969 min_size, false);
8970 BUG_ON(ret);
8971
8972 /*
8973 * So if we truncate and then write and fsync we normally would just
8974 * write the extents that changed, which is a problem if we need to
8975 * first truncate that entire inode. So set this flag so we write out
8976 * all of the extents in the inode to the sync log so we're completely
8977 * safe.
8978 */
8979 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
8980 trans->block_rsv = rsv;
8981
8982 while (1) {
8983 ret = btrfs_truncate_inode_items(trans, root, inode,
8984 inode->i_size,
8985 BTRFS_EXTENT_DATA_KEY);
8986 trans->block_rsv = &fs_info->trans_block_rsv;
8987 if (ret != -ENOSPC && ret != -EAGAIN)
8988 break;
8989
8990 ret = btrfs_update_inode(trans, root, inode);
8991 if (ret)
8992 break;
8993
8994 btrfs_end_transaction(trans);
8995 btrfs_btree_balance_dirty(fs_info);
8996
8997 trans = btrfs_start_transaction(root, 2);
8998 if (IS_ERR(trans)) {
8999 ret = PTR_ERR(trans);
9000 trans = NULL;
9001 break;
9002 }
9003
9004 btrfs_block_rsv_release(fs_info, rsv, -1);
9005 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9006 rsv, min_size, false);
9007 BUG_ON(ret); /* shouldn't happen */
9008 trans->block_rsv = rsv;
9009 }
9010
9011 /*
9012 * We can't call btrfs_truncate_block inside a trans handle as we could
9013 * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
9014 * we've truncated everything except the last little bit, and can do
9015 * btrfs_truncate_block and then update the disk_i_size.
9016 */
9017 if (ret == NEED_TRUNCATE_BLOCK) {
9018 btrfs_end_transaction(trans);
9019 btrfs_btree_balance_dirty(fs_info);
9020
9021 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
9022 if (ret)
9023 goto out;
9024 trans = btrfs_start_transaction(root, 1);
9025 if (IS_ERR(trans)) {
9026 ret = PTR_ERR(trans);
9027 goto out;
9028 }
9029 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
9030 }
9031
9032 if (trans) {
9033 int ret2;
9034
9035 trans->block_rsv = &fs_info->trans_block_rsv;
9036 ret2 = btrfs_update_inode(trans, root, inode);
9037 if (ret2 && !ret)
9038 ret = ret2;
9039
9040 ret2 = btrfs_end_transaction(trans);
9041 if (ret2 && !ret)
9042 ret = ret2;
9043 btrfs_btree_balance_dirty(fs_info);
9044 }
9045 out:
9046 btrfs_free_block_rsv(fs_info, rsv);
9047
9048 return ret;
9049 }
9050
9051 /*
9052 * create a new subvolume directory/inode (helper for the ioctl).
9053 */
9054 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9055 struct btrfs_root *new_root,
9056 struct btrfs_root *parent_root,
9057 u64 new_dirid)
9058 {
9059 struct inode *inode;
9060 int err;
9061 u64 index = 0;
9062
9063 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9064 new_dirid, new_dirid,
9065 S_IFDIR | (~current_umask() & S_IRWXUGO),
9066 &index);
9067 if (IS_ERR(inode))
9068 return PTR_ERR(inode);
9069 inode->i_op = &btrfs_dir_inode_operations;
9070 inode->i_fop = &btrfs_dir_file_operations;
9071
9072 set_nlink(inode, 1);
9073 btrfs_i_size_write(BTRFS_I(inode), 0);
9074 unlock_new_inode(inode);
9075
9076 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9077 if (err)
9078 btrfs_err(new_root->fs_info,
9079 "error inheriting subvolume %llu properties: %d",
9080 new_root->root_key.objectid, err);
9081
9082 err = btrfs_update_inode(trans, new_root, inode);
9083
9084 iput(inode);
9085 return err;
9086 }
9087
9088 struct inode *btrfs_alloc_inode(struct super_block *sb)
9089 {
9090 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
9091 struct btrfs_inode *ei;
9092 struct inode *inode;
9093
9094 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
9095 if (!ei)
9096 return NULL;
9097
9098 ei->root = NULL;
9099 ei->generation = 0;
9100 ei->last_trans = 0;
9101 ei->last_sub_trans = 0;
9102 ei->logged_trans = 0;
9103 ei->delalloc_bytes = 0;
9104 ei->new_delalloc_bytes = 0;
9105 ei->defrag_bytes = 0;
9106 ei->disk_i_size = 0;
9107 ei->flags = 0;
9108 ei->csum_bytes = 0;
9109 ei->index_cnt = (u64)-1;
9110 ei->dir_index = 0;
9111 ei->last_unlink_trans = 0;
9112 ei->last_link_trans = 0;
9113 ei->last_log_commit = 0;
9114
9115 spin_lock_init(&ei->lock);
9116 ei->outstanding_extents = 0;
9117 if (sb->s_magic != BTRFS_TEST_MAGIC)
9118 btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
9119 BTRFS_BLOCK_RSV_DELALLOC);
9120 ei->runtime_flags = 0;
9121 ei->prop_compress = BTRFS_COMPRESS_NONE;
9122 ei->defrag_compress = BTRFS_COMPRESS_NONE;
9123
9124 ei->delayed_node = NULL;
9125
9126 ei->i_otime.tv_sec = 0;
9127 ei->i_otime.tv_nsec = 0;
9128
9129 inode = &ei->vfs_inode;
9130 extent_map_tree_init(&ei->extent_tree);
9131 extent_io_tree_init(&ei->io_tree, inode);
9132 extent_io_tree_init(&ei->io_failure_tree, inode);
9133 ei->io_tree.track_uptodate = 1;
9134 ei->io_failure_tree.track_uptodate = 1;
9135 atomic_set(&ei->sync_writers, 0);
9136 mutex_init(&ei->log_mutex);
9137 mutex_init(&ei->delalloc_mutex);
9138 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9139 INIT_LIST_HEAD(&ei->delalloc_inodes);
9140 INIT_LIST_HEAD(&ei->delayed_iput);
9141 RB_CLEAR_NODE(&ei->rb_node);
9142 init_rwsem(&ei->dio_sem);
9143
9144 return inode;
9145 }
9146
9147 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9148 void btrfs_test_destroy_inode(struct inode *inode)
9149 {
9150 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9151 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9152 }
9153 #endif
9154
9155 static void btrfs_i_callback(struct rcu_head *head)
9156 {
9157 struct inode *inode = container_of(head, struct inode, i_rcu);
9158 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9159 }
9160
9161 void btrfs_destroy_inode(struct inode *inode)
9162 {
9163 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9164 struct btrfs_ordered_extent *ordered;
9165 struct btrfs_root *root = BTRFS_I(inode)->root;
9166
9167 WARN_ON(!hlist_empty(&inode->i_dentry));
9168 WARN_ON(inode->i_data.nrpages);
9169 WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
9170 WARN_ON(BTRFS_I(inode)->block_rsv.size);
9171 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9172 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9173 WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9174 WARN_ON(BTRFS_I(inode)->csum_bytes);
9175 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9176
9177 /*
9178 * This can happen where we create an inode, but somebody else also
9179 * created the same inode and we need to destroy the one we already
9180 * created.
9181 */
9182 if (!root)
9183 goto free;
9184
9185 while (1) {
9186 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9187 if (!ordered)
9188 break;
9189 else {
9190 btrfs_err(fs_info,
9191 "found ordered extent %llu %llu on inode cleanup",
9192 ordered->file_offset, ordered->len);
9193 btrfs_remove_ordered_extent(inode, ordered);
9194 btrfs_put_ordered_extent(ordered);
9195 btrfs_put_ordered_extent(ordered);
9196 }
9197 }
9198 btrfs_qgroup_check_reserved_leak(inode);
9199 inode_tree_del(inode);
9200 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9201 free:
9202 call_rcu(&inode->i_rcu, btrfs_i_callback);
9203 }
9204
9205 int btrfs_drop_inode(struct inode *inode)
9206 {
9207 struct btrfs_root *root = BTRFS_I(inode)->root;
9208
9209 if (root == NULL)
9210 return 1;
9211
9212 /* the snap/subvol tree is on deleting */
9213 if (btrfs_root_refs(&root->root_item) == 0)
9214 return 1;
9215 else
9216 return generic_drop_inode(inode);
9217 }
9218
9219 static void init_once(void *foo)
9220 {
9221 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9222
9223 inode_init_once(&ei->vfs_inode);
9224 }
9225
9226 void __cold btrfs_destroy_cachep(void)
9227 {
9228 /*
9229 * Make sure all delayed rcu free inodes are flushed before we
9230 * destroy cache.
9231 */
9232 rcu_barrier();
9233 kmem_cache_destroy(btrfs_inode_cachep);
9234 kmem_cache_destroy(btrfs_trans_handle_cachep);
9235 kmem_cache_destroy(btrfs_path_cachep);
9236 kmem_cache_destroy(btrfs_free_space_cachep);
9237 }
9238
9239 int __init btrfs_init_cachep(void)
9240 {
9241 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9242 sizeof(struct btrfs_inode), 0,
9243 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9244 init_once);
9245 if (!btrfs_inode_cachep)
9246 goto fail;
9247
9248 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9249 sizeof(struct btrfs_trans_handle), 0,
9250 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9251 if (!btrfs_trans_handle_cachep)
9252 goto fail;
9253
9254 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9255 sizeof(struct btrfs_path), 0,
9256 SLAB_MEM_SPREAD, NULL);
9257 if (!btrfs_path_cachep)
9258 goto fail;
9259
9260 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9261 sizeof(struct btrfs_free_space), 0,
9262 SLAB_MEM_SPREAD, NULL);
9263 if (!btrfs_free_space_cachep)
9264 goto fail;
9265
9266 return 0;
9267 fail:
9268 btrfs_destroy_cachep();
9269 return -ENOMEM;
9270 }
9271
9272 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9273 u32 request_mask, unsigned int flags)
9274 {
9275 u64 delalloc_bytes;
9276 struct inode *inode = d_inode(path->dentry);
9277 u32 blocksize = inode->i_sb->s_blocksize;
9278 u32 bi_flags = BTRFS_I(inode)->flags;
9279
9280 stat->result_mask |= STATX_BTIME;
9281 stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9282 stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9283 if (bi_flags & BTRFS_INODE_APPEND)
9284 stat->attributes |= STATX_ATTR_APPEND;
9285 if (bi_flags & BTRFS_INODE_COMPRESS)
9286 stat->attributes |= STATX_ATTR_COMPRESSED;
9287 if (bi_flags & BTRFS_INODE_IMMUTABLE)
9288 stat->attributes |= STATX_ATTR_IMMUTABLE;
9289 if (bi_flags & BTRFS_INODE_NODUMP)
9290 stat->attributes |= STATX_ATTR_NODUMP;
9291
9292 stat->attributes_mask |= (STATX_ATTR_APPEND |
9293 STATX_ATTR_COMPRESSED |
9294 STATX_ATTR_IMMUTABLE |
9295 STATX_ATTR_NODUMP);
9296
9297 generic_fillattr(inode, stat);
9298 stat->dev = BTRFS_I(inode)->root->anon_dev;
9299
9300 spin_lock(&BTRFS_I(inode)->lock);
9301 delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9302 spin_unlock(&BTRFS_I(inode)->lock);
9303 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9304 ALIGN(delalloc_bytes, blocksize)) >> 9;
9305 return 0;
9306 }
9307
9308 static int btrfs_rename_exchange(struct inode *old_dir,
9309 struct dentry *old_dentry,
9310 struct inode *new_dir,
9311 struct dentry *new_dentry)
9312 {
9313 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9314 struct btrfs_trans_handle *trans;
9315 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9316 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9317 struct inode *new_inode = new_dentry->d_inode;
9318 struct inode *old_inode = old_dentry->d_inode;
9319 struct timespec64 ctime = current_time(old_inode);
9320 struct dentry *parent;
9321 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9322 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9323 u64 old_idx = 0;
9324 u64 new_idx = 0;
9325 u64 root_objectid;
9326 int ret;
9327 bool root_log_pinned = false;
9328 bool dest_log_pinned = false;
9329 struct btrfs_log_ctx ctx_root;
9330 struct btrfs_log_ctx ctx_dest;
9331 bool sync_log_root = false;
9332 bool sync_log_dest = false;
9333 bool commit_transaction = false;
9334
9335 /* we only allow rename subvolume link between subvolumes */
9336 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9337 return -EXDEV;
9338
9339 btrfs_init_log_ctx(&ctx_root, old_inode);
9340 btrfs_init_log_ctx(&ctx_dest, new_inode);
9341
9342 /* close the race window with snapshot create/destroy ioctl */
9343 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9344 down_read(&fs_info->subvol_sem);
9345 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9346 down_read(&fs_info->subvol_sem);
9347
9348 /*
9349 * We want to reserve the absolute worst case amount of items. So if
9350 * both inodes are subvols and we need to unlink them then that would
9351 * require 4 item modifications, but if they are both normal inodes it
9352 * would require 5 item modifications, so we'll assume their normal
9353 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9354 * should cover the worst case number of items we'll modify.
9355 */
9356 trans = btrfs_start_transaction(root, 12);
9357 if (IS_ERR(trans)) {
9358 ret = PTR_ERR(trans);
9359 goto out_notrans;
9360 }
9361
9362 /*
9363 * We need to find a free sequence number both in the source and
9364 * in the destination directory for the exchange.
9365 */
9366 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9367 if (ret)
9368 goto out_fail;
9369 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9370 if (ret)
9371 goto out_fail;
9372
9373 BTRFS_I(old_inode)->dir_index = 0ULL;
9374 BTRFS_I(new_inode)->dir_index = 0ULL;
9375
9376 /* Reference for the source. */
9377 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9378 /* force full log commit if subvolume involved. */
9379 btrfs_set_log_full_commit(fs_info, trans);
9380 } else {
9381 btrfs_pin_log_trans(root);
9382 root_log_pinned = true;
9383 ret = btrfs_insert_inode_ref(trans, dest,
9384 new_dentry->d_name.name,
9385 new_dentry->d_name.len,
9386 old_ino,
9387 btrfs_ino(BTRFS_I(new_dir)),
9388 old_idx);
9389 if (ret)
9390 goto out_fail;
9391 }
9392
9393 /* And now for the dest. */
9394 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9395 /* force full log commit if subvolume involved. */
9396 btrfs_set_log_full_commit(fs_info, trans);
9397 } else {
9398 btrfs_pin_log_trans(dest);
9399 dest_log_pinned = true;
9400 ret = btrfs_insert_inode_ref(trans, root,
9401 old_dentry->d_name.name,
9402 old_dentry->d_name.len,
9403 new_ino,
9404 btrfs_ino(BTRFS_I(old_dir)),
9405 new_idx);
9406 if (ret)
9407 goto out_fail;
9408 }
9409
9410 /* Update inode version and ctime/mtime. */
9411 inode_inc_iversion(old_dir);
9412 inode_inc_iversion(new_dir);
9413 inode_inc_iversion(old_inode);
9414 inode_inc_iversion(new_inode);
9415 old_dir->i_ctime = old_dir->i_mtime = ctime;
9416 new_dir->i_ctime = new_dir->i_mtime = ctime;
9417 old_inode->i_ctime = ctime;
9418 new_inode->i_ctime = ctime;
9419
9420 if (old_dentry->d_parent != new_dentry->d_parent) {
9421 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9422 BTRFS_I(old_inode), 1);
9423 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9424 BTRFS_I(new_inode), 1);
9425 }
9426
9427 /* src is a subvolume */
9428 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9429 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9430 ret = btrfs_unlink_subvol(trans, old_dir, root_objectid,
9431 old_dentry->d_name.name,
9432 old_dentry->d_name.len);
9433 } else { /* src is an inode */
9434 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9435 BTRFS_I(old_dentry->d_inode),
9436 old_dentry->d_name.name,
9437 old_dentry->d_name.len);
9438 if (!ret)
9439 ret = btrfs_update_inode(trans, root, old_inode);
9440 }
9441 if (ret) {
9442 btrfs_abort_transaction(trans, ret);
9443 goto out_fail;
9444 }
9445
9446 /* dest is a subvolume */
9447 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9448 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9449 ret = btrfs_unlink_subvol(trans, new_dir, root_objectid,
9450 new_dentry->d_name.name,
9451 new_dentry->d_name.len);
9452 } else { /* dest is an inode */
9453 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9454 BTRFS_I(new_dentry->d_inode),
9455 new_dentry->d_name.name,
9456 new_dentry->d_name.len);
9457 if (!ret)
9458 ret = btrfs_update_inode(trans, dest, new_inode);
9459 }
9460 if (ret) {
9461 btrfs_abort_transaction(trans, ret);
9462 goto out_fail;
9463 }
9464
9465 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9466 new_dentry->d_name.name,
9467 new_dentry->d_name.len, 0, old_idx);
9468 if (ret) {
9469 btrfs_abort_transaction(trans, ret);
9470 goto out_fail;
9471 }
9472
9473 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9474 old_dentry->d_name.name,
9475 old_dentry->d_name.len, 0, new_idx);
9476 if (ret) {
9477 btrfs_abort_transaction(trans, ret);
9478 goto out_fail;
9479 }
9480
9481 if (old_inode->i_nlink == 1)
9482 BTRFS_I(old_inode)->dir_index = old_idx;
9483 if (new_inode->i_nlink == 1)
9484 BTRFS_I(new_inode)->dir_index = new_idx;
9485
9486 if (root_log_pinned) {
9487 parent = new_dentry->d_parent;
9488 ret = btrfs_log_new_name(trans, BTRFS_I(old_inode),
9489 BTRFS_I(old_dir), parent,
9490 false, &ctx_root);
9491 if (ret == BTRFS_NEED_LOG_SYNC)
9492 sync_log_root = true;
9493 else if (ret == BTRFS_NEED_TRANS_COMMIT)
9494 commit_transaction = true;
9495 ret = 0;
9496 btrfs_end_log_trans(root);
9497 root_log_pinned = false;
9498 }
9499 if (dest_log_pinned) {
9500 if (!commit_transaction) {
9501 parent = old_dentry->d_parent;
9502 ret = btrfs_log_new_name(trans, BTRFS_I(new_inode),
9503 BTRFS_I(new_dir), parent,
9504 false, &ctx_dest);
9505 if (ret == BTRFS_NEED_LOG_SYNC)
9506 sync_log_dest = true;
9507 else if (ret == BTRFS_NEED_TRANS_COMMIT)
9508 commit_transaction = true;
9509 ret = 0;
9510 }
9511 btrfs_end_log_trans(dest);
9512 dest_log_pinned = false;
9513 }
9514 out_fail:
9515 /*
9516 * If we have pinned a log and an error happened, we unpin tasks
9517 * trying to sync the log and force them to fallback to a transaction
9518 * commit if the log currently contains any of the inodes involved in
9519 * this rename operation (to ensure we do not persist a log with an
9520 * inconsistent state for any of these inodes or leading to any
9521 * inconsistencies when replayed). If the transaction was aborted, the
9522 * abortion reason is propagated to userspace when attempting to commit
9523 * the transaction. If the log does not contain any of these inodes, we
9524 * allow the tasks to sync it.
9525 */
9526 if (ret && (root_log_pinned || dest_log_pinned)) {
9527 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9528 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9529 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9530 (new_inode &&
9531 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9532 btrfs_set_log_full_commit(fs_info, trans);
9533
9534 if (root_log_pinned) {
9535 btrfs_end_log_trans(root);
9536 root_log_pinned = false;
9537 }
9538 if (dest_log_pinned) {
9539 btrfs_end_log_trans(dest);
9540 dest_log_pinned = false;
9541 }
9542 }
9543 if (!ret && sync_log_root && !commit_transaction) {
9544 ret = btrfs_sync_log(trans, BTRFS_I(old_inode)->root,
9545 &ctx_root);
9546 if (ret)
9547 commit_transaction = true;
9548 }
9549 if (!ret && sync_log_dest && !commit_transaction) {
9550 ret = btrfs_sync_log(trans, BTRFS_I(new_inode)->root,
9551 &ctx_dest);
9552 if (ret)
9553 commit_transaction = true;
9554 }
9555 if (commit_transaction) {
9556 ret = btrfs_commit_transaction(trans);
9557 } else {
9558 int ret2;
9559
9560 ret2 = btrfs_end_transaction(trans);
9561 ret = ret ? ret : ret2;
9562 }
9563 out_notrans:
9564 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9565 up_read(&fs_info->subvol_sem);
9566 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9567 up_read(&fs_info->subvol_sem);
9568
9569 return ret;
9570 }
9571
9572 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9573 struct btrfs_root *root,
9574 struct inode *dir,
9575 struct dentry *dentry)
9576 {
9577 int ret;
9578 struct inode *inode;
9579 u64 objectid;
9580 u64 index;
9581
9582 ret = btrfs_find_free_ino(root, &objectid);
9583 if (ret)
9584 return ret;
9585
9586 inode = btrfs_new_inode(trans, root, dir,
9587 dentry->d_name.name,
9588 dentry->d_name.len,
9589 btrfs_ino(BTRFS_I(dir)),
9590 objectid,
9591 S_IFCHR | WHITEOUT_MODE,
9592 &index);
9593
9594 if (IS_ERR(inode)) {
9595 ret = PTR_ERR(inode);
9596 return ret;
9597 }
9598
9599 inode->i_op = &btrfs_special_inode_operations;
9600 init_special_inode(inode, inode->i_mode,
9601 WHITEOUT_DEV);
9602
9603 ret = btrfs_init_inode_security(trans, inode, dir,
9604 &dentry->d_name);
9605 if (ret)
9606 goto out;
9607
9608 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9609 BTRFS_I(inode), 0, index);
9610 if (ret)
9611 goto out;
9612
9613 ret = btrfs_update_inode(trans, root, inode);
9614 out:
9615 unlock_new_inode(inode);
9616 if (ret)
9617 inode_dec_link_count(inode);
9618 iput(inode);
9619
9620 return ret;
9621 }
9622
9623 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9624 struct inode *new_dir, struct dentry *new_dentry,
9625 unsigned int flags)
9626 {
9627 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9628 struct btrfs_trans_handle *trans;
9629 unsigned int trans_num_items;
9630 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9631 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9632 struct inode *new_inode = d_inode(new_dentry);
9633 struct inode *old_inode = d_inode(old_dentry);
9634 u64 index = 0;
9635 u64 root_objectid;
9636 int ret;
9637 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9638 bool log_pinned = false;
9639 struct btrfs_log_ctx ctx;
9640 bool sync_log = false;
9641 bool commit_transaction = false;
9642
9643 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9644 return -EPERM;
9645
9646 /* we only allow rename subvolume link between subvolumes */
9647 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9648 return -EXDEV;
9649
9650 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9651 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9652 return -ENOTEMPTY;
9653
9654 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9655 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9656 return -ENOTEMPTY;
9657
9658
9659 /* check for collisions, even if the name isn't there */
9660 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9661 new_dentry->d_name.name,
9662 new_dentry->d_name.len);
9663
9664 if (ret) {
9665 if (ret == -EEXIST) {
9666 /* we shouldn't get
9667 * eexist without a new_inode */
9668 if (WARN_ON(!new_inode)) {
9669 return ret;
9670 }
9671 } else {
9672 /* maybe -EOVERFLOW */
9673 return ret;
9674 }
9675 }
9676 ret = 0;
9677
9678 /*
9679 * we're using rename to replace one file with another. Start IO on it
9680 * now so we don't add too much work to the end of the transaction
9681 */
9682 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9683 filemap_flush(old_inode->i_mapping);
9684
9685 /* close the racy window with snapshot create/destroy ioctl */
9686 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9687 down_read(&fs_info->subvol_sem);
9688 /*
9689 * We want to reserve the absolute worst case amount of items. So if
9690 * both inodes are subvols and we need to unlink them then that would
9691 * require 4 item modifications, but if they are both normal inodes it
9692 * would require 5 item modifications, so we'll assume they are normal
9693 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9694 * should cover the worst case number of items we'll modify.
9695 * If our rename has the whiteout flag, we need more 5 units for the
9696 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9697 * when selinux is enabled).
9698 */
9699 trans_num_items = 11;
9700 if (flags & RENAME_WHITEOUT)
9701 trans_num_items += 5;
9702 trans = btrfs_start_transaction(root, trans_num_items);
9703 if (IS_ERR(trans)) {
9704 ret = PTR_ERR(trans);
9705 goto out_notrans;
9706 }
9707
9708 if (dest != root)
9709 btrfs_record_root_in_trans(trans, dest);
9710
9711 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9712 if (ret)
9713 goto out_fail;
9714
9715 BTRFS_I(old_inode)->dir_index = 0ULL;
9716 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9717 /* force full log commit if subvolume involved. */
9718 btrfs_set_log_full_commit(fs_info, trans);
9719 } else {
9720 btrfs_pin_log_trans(root);
9721 log_pinned = true;
9722 ret = btrfs_insert_inode_ref(trans, dest,
9723 new_dentry->d_name.name,
9724 new_dentry->d_name.len,
9725 old_ino,
9726 btrfs_ino(BTRFS_I(new_dir)), index);
9727 if (ret)
9728 goto out_fail;
9729 }
9730
9731 inode_inc_iversion(old_dir);
9732 inode_inc_iversion(new_dir);
9733 inode_inc_iversion(old_inode);
9734 old_dir->i_ctime = old_dir->i_mtime =
9735 new_dir->i_ctime = new_dir->i_mtime =
9736 old_inode->i_ctime = current_time(old_dir);
9737
9738 if (old_dentry->d_parent != new_dentry->d_parent)
9739 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9740 BTRFS_I(old_inode), 1);
9741
9742 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9743 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9744 ret = btrfs_unlink_subvol(trans, old_dir, root_objectid,
9745 old_dentry->d_name.name,
9746 old_dentry->d_name.len);
9747 } else {
9748 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9749 BTRFS_I(d_inode(old_dentry)),
9750 old_dentry->d_name.name,
9751 old_dentry->d_name.len);
9752 if (!ret)
9753 ret = btrfs_update_inode(trans, root, old_inode);
9754 }
9755 if (ret) {
9756 btrfs_abort_transaction(trans, ret);
9757 goto out_fail;
9758 }
9759
9760 if (new_inode) {
9761 inode_inc_iversion(new_inode);
9762 new_inode->i_ctime = current_time(new_inode);
9763 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
9764 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9765 root_objectid = BTRFS_I(new_inode)->location.objectid;
9766 ret = btrfs_unlink_subvol(trans, new_dir, root_objectid,
9767 new_dentry->d_name.name,
9768 new_dentry->d_name.len);
9769 BUG_ON(new_inode->i_nlink == 0);
9770 } else {
9771 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9772 BTRFS_I(d_inode(new_dentry)),
9773 new_dentry->d_name.name,
9774 new_dentry->d_name.len);
9775 }
9776 if (!ret && new_inode->i_nlink == 0)
9777 ret = btrfs_orphan_add(trans,
9778 BTRFS_I(d_inode(new_dentry)));
9779 if (ret) {
9780 btrfs_abort_transaction(trans, ret);
9781 goto out_fail;
9782 }
9783 }
9784
9785 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9786 new_dentry->d_name.name,
9787 new_dentry->d_name.len, 0, index);
9788 if (ret) {
9789 btrfs_abort_transaction(trans, ret);
9790 goto out_fail;
9791 }
9792
9793 if (old_inode->i_nlink == 1)
9794 BTRFS_I(old_inode)->dir_index = index;
9795
9796 if (log_pinned) {
9797 struct dentry *parent = new_dentry->d_parent;
9798
9799 btrfs_init_log_ctx(&ctx, old_inode);
9800 ret = btrfs_log_new_name(trans, BTRFS_I(old_inode),
9801 BTRFS_I(old_dir), parent,
9802 false, &ctx);
9803 if (ret == BTRFS_NEED_LOG_SYNC)
9804 sync_log = true;
9805 else if (ret == BTRFS_NEED_TRANS_COMMIT)
9806 commit_transaction = true;
9807 ret = 0;
9808 btrfs_end_log_trans(root);
9809 log_pinned = false;
9810 }
9811
9812 if (flags & RENAME_WHITEOUT) {
9813 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9814 old_dentry);
9815
9816 if (ret) {
9817 btrfs_abort_transaction(trans, ret);
9818 goto out_fail;
9819 }
9820 }
9821 out_fail:
9822 /*
9823 * If we have pinned the log and an error happened, we unpin tasks
9824 * trying to sync the log and force them to fallback to a transaction
9825 * commit if the log currently contains any of the inodes involved in
9826 * this rename operation (to ensure we do not persist a log with an
9827 * inconsistent state for any of these inodes or leading to any
9828 * inconsistencies when replayed). If the transaction was aborted, the
9829 * abortion reason is propagated to userspace when attempting to commit
9830 * the transaction. If the log does not contain any of these inodes, we
9831 * allow the tasks to sync it.
9832 */
9833 if (ret && log_pinned) {
9834 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9835 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9836 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9837 (new_inode &&
9838 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9839 btrfs_set_log_full_commit(fs_info, trans);
9840
9841 btrfs_end_log_trans(root);
9842 log_pinned = false;
9843 }
9844 if (!ret && sync_log) {
9845 ret = btrfs_sync_log(trans, BTRFS_I(old_inode)->root, &ctx);
9846 if (ret)
9847 commit_transaction = true;
9848 }
9849 if (commit_transaction) {
9850 ret = btrfs_commit_transaction(trans);
9851 } else {
9852 int ret2;
9853
9854 ret2 = btrfs_end_transaction(trans);
9855 ret = ret ? ret : ret2;
9856 }
9857 out_notrans:
9858 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9859 up_read(&fs_info->subvol_sem);
9860
9861 return ret;
9862 }
9863
9864 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9865 struct inode *new_dir, struct dentry *new_dentry,
9866 unsigned int flags)
9867 {
9868 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9869 return -EINVAL;
9870
9871 if (flags & RENAME_EXCHANGE)
9872 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9873 new_dentry);
9874
9875 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9876 }
9877
9878 struct btrfs_delalloc_work {
9879 struct inode *inode;
9880 struct completion completion;
9881 struct list_head list;
9882 struct btrfs_work work;
9883 };
9884
9885 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9886 {
9887 struct btrfs_delalloc_work *delalloc_work;
9888 struct inode *inode;
9889
9890 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9891 work);
9892 inode = delalloc_work->inode;
9893 filemap_flush(inode->i_mapping);
9894 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9895 &BTRFS_I(inode)->runtime_flags))
9896 filemap_flush(inode->i_mapping);
9897
9898 iput(inode);
9899 complete(&delalloc_work->completion);
9900 }
9901
9902 static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode)
9903 {
9904 struct btrfs_delalloc_work *work;
9905
9906 work = kmalloc(sizeof(*work), GFP_NOFS);
9907 if (!work)
9908 return NULL;
9909
9910 init_completion(&work->completion);
9911 INIT_LIST_HEAD(&work->list);
9912 work->inode = inode;
9913 WARN_ON_ONCE(!inode);
9914 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9915 btrfs_run_delalloc_work, NULL, NULL);
9916
9917 return work;
9918 }
9919
9920 /*
9921 * some fairly slow code that needs optimization. This walks the list
9922 * of all the inodes with pending delalloc and forces them to disk.
9923 */
9924 static int start_delalloc_inodes(struct btrfs_root *root, int nr, bool snapshot)
9925 {
9926 struct btrfs_inode *binode;
9927 struct inode *inode;
9928 struct btrfs_delalloc_work *work, *next;
9929 struct list_head works;
9930 struct list_head splice;
9931 int ret = 0;
9932
9933 INIT_LIST_HEAD(&works);
9934 INIT_LIST_HEAD(&splice);
9935
9936 mutex_lock(&root->delalloc_mutex);
9937 spin_lock(&root->delalloc_lock);
9938 list_splice_init(&root->delalloc_inodes, &splice);
9939 while (!list_empty(&splice)) {
9940 binode = list_entry(splice.next, struct btrfs_inode,
9941 delalloc_inodes);
9942
9943 list_move_tail(&binode->delalloc_inodes,
9944 &root->delalloc_inodes);
9945 inode = igrab(&binode->vfs_inode);
9946 if (!inode) {
9947 cond_resched_lock(&root->delalloc_lock);
9948 continue;
9949 }
9950 spin_unlock(&root->delalloc_lock);
9951
9952 if (snapshot)
9953 set_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
9954 &binode->runtime_flags);
9955 work = btrfs_alloc_delalloc_work(inode);
9956 if (!work) {
9957 iput(inode);
9958 ret = -ENOMEM;
9959 goto out;
9960 }
9961 list_add_tail(&work->list, &works);
9962 btrfs_queue_work(root->fs_info->flush_workers,
9963 &work->work);
9964 ret++;
9965 if (nr != -1 && ret >= nr)
9966 goto out;
9967 cond_resched();
9968 spin_lock(&root->delalloc_lock);
9969 }
9970 spin_unlock(&root->delalloc_lock);
9971
9972 out:
9973 list_for_each_entry_safe(work, next, &works, list) {
9974 list_del_init(&work->list);
9975 wait_for_completion(&work->completion);
9976 kfree(work);
9977 }
9978
9979 if (!list_empty(&splice)) {
9980 spin_lock(&root->delalloc_lock);
9981 list_splice_tail(&splice, &root->delalloc_inodes);
9982 spin_unlock(&root->delalloc_lock);
9983 }
9984 mutex_unlock(&root->delalloc_mutex);
9985 return ret;
9986 }
9987
9988 int btrfs_start_delalloc_snapshot(struct btrfs_root *root)
9989 {
9990 struct btrfs_fs_info *fs_info = root->fs_info;
9991 int ret;
9992
9993 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
9994 return -EROFS;
9995
9996 ret = start_delalloc_inodes(root, -1, true);
9997 if (ret > 0)
9998 ret = 0;
9999 return ret;
10000 }
10001
10002 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int nr)
10003 {
10004 struct btrfs_root *root;
10005 struct list_head splice;
10006 int ret;
10007
10008 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10009 return -EROFS;
10010
10011 INIT_LIST_HEAD(&splice);
10012
10013 mutex_lock(&fs_info->delalloc_root_mutex);
10014 spin_lock(&fs_info->delalloc_root_lock);
10015 list_splice_init(&fs_info->delalloc_roots, &splice);
10016 while (!list_empty(&splice) && nr) {
10017 root = list_first_entry(&splice, struct btrfs_root,
10018 delalloc_root);
10019 root = btrfs_grab_fs_root(root);
10020 BUG_ON(!root);
10021 list_move_tail(&root->delalloc_root,
10022 &fs_info->delalloc_roots);
10023 spin_unlock(&fs_info->delalloc_root_lock);
10024
10025 ret = start_delalloc_inodes(root, nr, false);
10026 btrfs_put_fs_root(root);
10027 if (ret < 0)
10028 goto out;
10029
10030 if (nr != -1) {
10031 nr -= ret;
10032 WARN_ON(nr < 0);
10033 }
10034 spin_lock(&fs_info->delalloc_root_lock);
10035 }
10036 spin_unlock(&fs_info->delalloc_root_lock);
10037
10038 ret = 0;
10039 out:
10040 if (!list_empty(&splice)) {
10041 spin_lock(&fs_info->delalloc_root_lock);
10042 list_splice_tail(&splice, &fs_info->delalloc_roots);
10043 spin_unlock(&fs_info->delalloc_root_lock);
10044 }
10045 mutex_unlock(&fs_info->delalloc_root_mutex);
10046 return ret;
10047 }
10048
10049 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10050 const char *symname)
10051 {
10052 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10053 struct btrfs_trans_handle *trans;
10054 struct btrfs_root *root = BTRFS_I(dir)->root;
10055 struct btrfs_path *path;
10056 struct btrfs_key key;
10057 struct inode *inode = NULL;
10058 int err;
10059 u64 objectid;
10060 u64 index = 0;
10061 int name_len;
10062 int datasize;
10063 unsigned long ptr;
10064 struct btrfs_file_extent_item *ei;
10065 struct extent_buffer *leaf;
10066
10067 name_len = strlen(symname);
10068 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10069 return -ENAMETOOLONG;
10070
10071 /*
10072 * 2 items for inode item and ref
10073 * 2 items for dir items
10074 * 1 item for updating parent inode item
10075 * 1 item for the inline extent item
10076 * 1 item for xattr if selinux is on
10077 */
10078 trans = btrfs_start_transaction(root, 7);
10079 if (IS_ERR(trans))
10080 return PTR_ERR(trans);
10081
10082 err = btrfs_find_free_ino(root, &objectid);
10083 if (err)
10084 goto out_unlock;
10085
10086 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10087 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10088 objectid, S_IFLNK|S_IRWXUGO, &index);
10089 if (IS_ERR(inode)) {
10090 err = PTR_ERR(inode);
10091 inode = NULL;
10092 goto out_unlock;
10093 }
10094
10095 /*
10096 * If the active LSM wants to access the inode during
10097 * d_instantiate it needs these. Smack checks to see
10098 * if the filesystem supports xattrs by looking at the
10099 * ops vector.
10100 */
10101 inode->i_fop = &btrfs_file_operations;
10102 inode->i_op = &btrfs_file_inode_operations;
10103 inode->i_mapping->a_ops = &btrfs_aops;
10104 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10105
10106 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10107 if (err)
10108 goto out_unlock;
10109
10110 path = btrfs_alloc_path();
10111 if (!path) {
10112 err = -ENOMEM;
10113 goto out_unlock;
10114 }
10115 key.objectid = btrfs_ino(BTRFS_I(inode));
10116 key.offset = 0;
10117 key.type = BTRFS_EXTENT_DATA_KEY;
10118 datasize = btrfs_file_extent_calc_inline_size(name_len);
10119 err = btrfs_insert_empty_item(trans, root, path, &key,
10120 datasize);
10121 if (err) {
10122 btrfs_free_path(path);
10123 goto out_unlock;
10124 }
10125 leaf = path->nodes[0];
10126 ei = btrfs_item_ptr(leaf, path->slots[0],
10127 struct btrfs_file_extent_item);
10128 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10129 btrfs_set_file_extent_type(leaf, ei,
10130 BTRFS_FILE_EXTENT_INLINE);
10131 btrfs_set_file_extent_encryption(leaf, ei, 0);
10132 btrfs_set_file_extent_compression(leaf, ei, 0);
10133 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10134 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10135
10136 ptr = btrfs_file_extent_inline_start(ei);
10137 write_extent_buffer(leaf, symname, ptr, name_len);
10138 btrfs_mark_buffer_dirty(leaf);
10139 btrfs_free_path(path);
10140
10141 inode->i_op = &btrfs_symlink_inode_operations;
10142 inode_nohighmem(inode);
10143 inode->i_mapping->a_ops = &btrfs_aops;
10144 inode_set_bytes(inode, name_len);
10145 btrfs_i_size_write(BTRFS_I(inode), name_len);
10146 err = btrfs_update_inode(trans, root, inode);
10147 /*
10148 * Last step, add directory indexes for our symlink inode. This is the
10149 * last step to avoid extra cleanup of these indexes if an error happens
10150 * elsewhere above.
10151 */
10152 if (!err)
10153 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10154 BTRFS_I(inode), 0, index);
10155 if (err)
10156 goto out_unlock;
10157
10158 d_instantiate_new(dentry, inode);
10159
10160 out_unlock:
10161 btrfs_end_transaction(trans);
10162 if (err && inode) {
10163 inode_dec_link_count(inode);
10164 discard_new_inode(inode);
10165 }
10166 btrfs_btree_balance_dirty(fs_info);
10167 return err;
10168 }
10169
10170 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10171 u64 start, u64 num_bytes, u64 min_size,
10172 loff_t actual_len, u64 *alloc_hint,
10173 struct btrfs_trans_handle *trans)
10174 {
10175 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10176 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10177 struct extent_map *em;
10178 struct btrfs_root *root = BTRFS_I(inode)->root;
10179 struct btrfs_key ins;
10180 u64 cur_offset = start;
10181 u64 i_size;
10182 u64 cur_bytes;
10183 u64 last_alloc = (u64)-1;
10184 int ret = 0;
10185 bool own_trans = true;
10186 u64 end = start + num_bytes - 1;
10187
10188 if (trans)
10189 own_trans = false;
10190 while (num_bytes > 0) {
10191 if (own_trans) {
10192 trans = btrfs_start_transaction(root, 3);
10193 if (IS_ERR(trans)) {
10194 ret = PTR_ERR(trans);
10195 break;
10196 }
10197 }
10198
10199 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10200 cur_bytes = max(cur_bytes, min_size);
10201 /*
10202 * If we are severely fragmented we could end up with really
10203 * small allocations, so if the allocator is returning small
10204 * chunks lets make its job easier by only searching for those
10205 * sized chunks.
10206 */
10207 cur_bytes = min(cur_bytes, last_alloc);
10208 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10209 min_size, 0, *alloc_hint, &ins, 1, 0);
10210 if (ret) {
10211 if (own_trans)
10212 btrfs_end_transaction(trans);
10213 break;
10214 }
10215 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10216
10217 last_alloc = ins.offset;
10218 ret = insert_reserved_file_extent(trans, inode,
10219 cur_offset, ins.objectid,
10220 ins.offset, ins.offset,
10221 ins.offset, 0, 0, 0,
10222 BTRFS_FILE_EXTENT_PREALLOC);
10223 if (ret) {
10224 btrfs_free_reserved_extent(fs_info, ins.objectid,
10225 ins.offset, 0);
10226 btrfs_abort_transaction(trans, ret);
10227 if (own_trans)
10228 btrfs_end_transaction(trans);
10229 break;
10230 }
10231
10232 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10233 cur_offset + ins.offset -1, 0);
10234
10235 em = alloc_extent_map();
10236 if (!em) {
10237 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10238 &BTRFS_I(inode)->runtime_flags);
10239 goto next;
10240 }
10241
10242 em->start = cur_offset;
10243 em->orig_start = cur_offset;
10244 em->len = ins.offset;
10245 em->block_start = ins.objectid;
10246 em->block_len = ins.offset;
10247 em->orig_block_len = ins.offset;
10248 em->ram_bytes = ins.offset;
10249 em->bdev = fs_info->fs_devices->latest_bdev;
10250 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10251 em->generation = trans->transid;
10252
10253 while (1) {
10254 write_lock(&em_tree->lock);
10255 ret = add_extent_mapping(em_tree, em, 1);
10256 write_unlock(&em_tree->lock);
10257 if (ret != -EEXIST)
10258 break;
10259 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10260 cur_offset + ins.offset - 1,
10261 0);
10262 }
10263 free_extent_map(em);
10264 next:
10265 num_bytes -= ins.offset;
10266 cur_offset += ins.offset;
10267 *alloc_hint = ins.objectid + ins.offset;
10268
10269 inode_inc_iversion(inode);
10270 inode->i_ctime = current_time(inode);
10271 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10272 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10273 (actual_len > inode->i_size) &&
10274 (cur_offset > inode->i_size)) {
10275 if (cur_offset > actual_len)
10276 i_size = actual_len;
10277 else
10278 i_size = cur_offset;
10279 i_size_write(inode, i_size);
10280 btrfs_ordered_update_i_size(inode, i_size, NULL);
10281 }
10282
10283 ret = btrfs_update_inode(trans, root, inode);
10284
10285 if (ret) {
10286 btrfs_abort_transaction(trans, ret);
10287 if (own_trans)
10288 btrfs_end_transaction(trans);
10289 break;
10290 }
10291
10292 if (own_trans)
10293 btrfs_end_transaction(trans);
10294 }
10295 if (cur_offset < end)
10296 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10297 end - cur_offset + 1);
10298 return ret;
10299 }
10300
10301 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10302 u64 start, u64 num_bytes, u64 min_size,
10303 loff_t actual_len, u64 *alloc_hint)
10304 {
10305 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10306 min_size, actual_len, alloc_hint,
10307 NULL);
10308 }
10309
10310 int btrfs_prealloc_file_range_trans(struct inode *inode,
10311 struct btrfs_trans_handle *trans, int mode,
10312 u64 start, u64 num_bytes, u64 min_size,
10313 loff_t actual_len, u64 *alloc_hint)
10314 {
10315 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10316 min_size, actual_len, alloc_hint, trans);
10317 }
10318
10319 static int btrfs_set_page_dirty(struct page *page)
10320 {
10321 return __set_page_dirty_nobuffers(page);
10322 }
10323
10324 static int btrfs_permission(struct inode *inode, int mask)
10325 {
10326 struct btrfs_root *root = BTRFS_I(inode)->root;
10327 umode_t mode = inode->i_mode;
10328
10329 if (mask & MAY_WRITE &&
10330 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10331 if (btrfs_root_readonly(root))
10332 return -EROFS;
10333 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10334 return -EACCES;
10335 }
10336 return generic_permission(inode, mask);
10337 }
10338
10339 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10340 {
10341 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10342 struct btrfs_trans_handle *trans;
10343 struct btrfs_root *root = BTRFS_I(dir)->root;
10344 struct inode *inode = NULL;
10345 u64 objectid;
10346 u64 index;
10347 int ret = 0;
10348
10349 /*
10350 * 5 units required for adding orphan entry
10351 */
10352 trans = btrfs_start_transaction(root, 5);
10353 if (IS_ERR(trans))
10354 return PTR_ERR(trans);
10355
10356 ret = btrfs_find_free_ino(root, &objectid);
10357 if (ret)
10358 goto out;
10359
10360 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10361 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10362 if (IS_ERR(inode)) {
10363 ret = PTR_ERR(inode);
10364 inode = NULL;
10365 goto out;
10366 }
10367
10368 inode->i_fop = &btrfs_file_operations;
10369 inode->i_op = &btrfs_file_inode_operations;
10370
10371 inode->i_mapping->a_ops = &btrfs_aops;
10372 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10373
10374 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10375 if (ret)
10376 goto out;
10377
10378 ret = btrfs_update_inode(trans, root, inode);
10379 if (ret)
10380 goto out;
10381 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10382 if (ret)
10383 goto out;
10384
10385 /*
10386 * We set number of links to 0 in btrfs_new_inode(), and here we set
10387 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10388 * through:
10389 *
10390 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10391 */
10392 set_nlink(inode, 1);
10393 d_tmpfile(dentry, inode);
10394 unlock_new_inode(inode);
10395 mark_inode_dirty(inode);
10396 out:
10397 btrfs_end_transaction(trans);
10398 if (ret && inode)
10399 discard_new_inode(inode);
10400 btrfs_btree_balance_dirty(fs_info);
10401 return ret;
10402 }
10403
10404 void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
10405 {
10406 struct inode *inode = tree->private_data;
10407 unsigned long index = start >> PAGE_SHIFT;
10408 unsigned long end_index = end >> PAGE_SHIFT;
10409 struct page *page;
10410
10411 while (index <= end_index) {
10412 page = find_get_page(inode->i_mapping, index);
10413 ASSERT(page); /* Pages should be in the extent_io_tree */
10414 set_page_writeback(page);
10415 put_page(page);
10416 index++;
10417 }
10418 }
10419
10420 #ifdef CONFIG_SWAP
10421 /*
10422 * Add an entry indicating a block group or device which is pinned by a
10423 * swapfile. Returns 0 on success, 1 if there is already an entry for it, or a
10424 * negative errno on failure.
10425 */
10426 static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr,
10427 bool is_block_group)
10428 {
10429 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
10430 struct btrfs_swapfile_pin *sp, *entry;
10431 struct rb_node **p;
10432 struct rb_node *parent = NULL;
10433
10434 sp = kmalloc(sizeof(*sp), GFP_NOFS);
10435 if (!sp)
10436 return -ENOMEM;
10437 sp->ptr = ptr;
10438 sp->inode = inode;
10439 sp->is_block_group = is_block_group;
10440
10441 spin_lock(&fs_info->swapfile_pins_lock);
10442 p = &fs_info->swapfile_pins.rb_node;
10443 while (*p) {
10444 parent = *p;
10445 entry = rb_entry(parent, struct btrfs_swapfile_pin, node);
10446 if (sp->ptr < entry->ptr ||
10447 (sp->ptr == entry->ptr && sp->inode < entry->inode)) {
10448 p = &(*p)->rb_left;
10449 } else if (sp->ptr > entry->ptr ||
10450 (sp->ptr == entry->ptr && sp->inode > entry->inode)) {
10451 p = &(*p)->rb_right;
10452 } else {
10453 spin_unlock(&fs_info->swapfile_pins_lock);
10454 kfree(sp);
10455 return 1;
10456 }
10457 }
10458 rb_link_node(&sp->node, parent, p);
10459 rb_insert_color(&sp->node, &fs_info->swapfile_pins);
10460 spin_unlock(&fs_info->swapfile_pins_lock);
10461 return 0;
10462 }
10463
10464 /* Free all of the entries pinned by this swapfile. */
10465 static void btrfs_free_swapfile_pins(struct inode *inode)
10466 {
10467 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
10468 struct btrfs_swapfile_pin *sp;
10469 struct rb_node *node, *next;
10470
10471 spin_lock(&fs_info->swapfile_pins_lock);
10472 node = rb_first(&fs_info->swapfile_pins);
10473 while (node) {
10474 next = rb_next(node);
10475 sp = rb_entry(node, struct btrfs_swapfile_pin, node);
10476 if (sp->inode == inode) {
10477 rb_erase(&sp->node, &fs_info->swapfile_pins);
10478 if (sp->is_block_group)
10479 btrfs_put_block_group(sp->ptr);
10480 kfree(sp);
10481 }
10482 node = next;
10483 }
10484 spin_unlock(&fs_info->swapfile_pins_lock);
10485 }
10486
10487 struct btrfs_swap_info {
10488 u64 start;
10489 u64 block_start;
10490 u64 block_len;
10491 u64 lowest_ppage;
10492 u64 highest_ppage;
10493 unsigned long nr_pages;
10494 int nr_extents;
10495 };
10496
10497 static int btrfs_add_swap_extent(struct swap_info_struct *sis,
10498 struct btrfs_swap_info *bsi)
10499 {
10500 unsigned long nr_pages;
10501 u64 first_ppage, first_ppage_reported, next_ppage;
10502 int ret;
10503
10504 first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT;
10505 next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len,
10506 PAGE_SIZE) >> PAGE_SHIFT;
10507
10508 if (first_ppage >= next_ppage)
10509 return 0;
10510 nr_pages = next_ppage - first_ppage;
10511
10512 first_ppage_reported = first_ppage;
10513 if (bsi->start == 0)
10514 first_ppage_reported++;
10515 if (bsi->lowest_ppage > first_ppage_reported)
10516 bsi->lowest_ppage = first_ppage_reported;
10517 if (bsi->highest_ppage < (next_ppage - 1))
10518 bsi->highest_ppage = next_ppage - 1;
10519
10520 ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage);
10521 if (ret < 0)
10522 return ret;
10523 bsi->nr_extents += ret;
10524 bsi->nr_pages += nr_pages;
10525 return 0;
10526 }
10527
10528 static void btrfs_swap_deactivate(struct file *file)
10529 {
10530 struct inode *inode = file_inode(file);
10531
10532 btrfs_free_swapfile_pins(inode);
10533 atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles);
10534 }
10535
10536 static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
10537 sector_t *span)
10538 {
10539 struct inode *inode = file_inode(file);
10540 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
10541 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
10542 struct extent_state *cached_state = NULL;
10543 struct extent_map *em = NULL;
10544 struct btrfs_device *device = NULL;
10545 struct btrfs_swap_info bsi = {
10546 .lowest_ppage = (sector_t)-1ULL,
10547 };
10548 int ret = 0;
10549 u64 isize;
10550 u64 start;
10551
10552 /*
10553 * If the swap file was just created, make sure delalloc is done. If the
10554 * file changes again after this, the user is doing something stupid and
10555 * we don't really care.
10556 */
10557 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
10558 if (ret)
10559 return ret;
10560
10561 /*
10562 * The inode is locked, so these flags won't change after we check them.
10563 */
10564 if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) {
10565 btrfs_warn(fs_info, "swapfile must not be compressed");
10566 return -EINVAL;
10567 }
10568 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) {
10569 btrfs_warn(fs_info, "swapfile must not be copy-on-write");
10570 return -EINVAL;
10571 }
10572 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
10573 btrfs_warn(fs_info, "swapfile must not be checksummed");
10574 return -EINVAL;
10575 }
10576
10577 /*
10578 * Balance or device remove/replace/resize can move stuff around from
10579 * under us. The EXCL_OP flag makes sure they aren't running/won't run
10580 * concurrently while we are mapping the swap extents, and
10581 * fs_info->swapfile_pins prevents them from running while the swap file
10582 * is active and moving the extents. Note that this also prevents a
10583 * concurrent device add which isn't actually necessary, but it's not
10584 * really worth the trouble to allow it.
10585 */
10586 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
10587 btrfs_warn(fs_info,
10588 "cannot activate swapfile while exclusive operation is running");
10589 return -EBUSY;
10590 }
10591 /*
10592 * Snapshots can create extents which require COW even if NODATACOW is
10593 * set. We use this counter to prevent snapshots. We must increment it
10594 * before walking the extents because we don't want a concurrent
10595 * snapshot to run after we've already checked the extents.
10596 */
10597 atomic_inc(&BTRFS_I(inode)->root->nr_swapfiles);
10598
10599 isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize);
10600
10601 lock_extent_bits(io_tree, 0, isize - 1, &cached_state);
10602 start = 0;
10603 while (start < isize) {
10604 u64 logical_block_start, physical_block_start;
10605 struct btrfs_block_group_cache *bg;
10606 u64 len = isize - start;
10607
10608 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
10609 if (IS_ERR(em)) {
10610 ret = PTR_ERR(em);
10611 goto out;
10612 }
10613
10614 if (em->block_start == EXTENT_MAP_HOLE) {
10615 btrfs_warn(fs_info, "swapfile must not have holes");
10616 ret = -EINVAL;
10617 goto out;
10618 }
10619 if (em->block_start == EXTENT_MAP_INLINE) {
10620 /*
10621 * It's unlikely we'll ever actually find ourselves
10622 * here, as a file small enough to fit inline won't be
10623 * big enough to store more than the swap header, but in
10624 * case something changes in the future, let's catch it
10625 * here rather than later.
10626 */
10627 btrfs_warn(fs_info, "swapfile must not be inline");
10628 ret = -EINVAL;
10629 goto out;
10630 }
10631 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
10632 btrfs_warn(fs_info, "swapfile must not be compressed");
10633 ret = -EINVAL;
10634 goto out;
10635 }
10636
10637 logical_block_start = em->block_start + (start - em->start);
10638 len = min(len, em->len - (start - em->start));
10639 free_extent_map(em);
10640 em = NULL;
10641
10642 ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL);
10643 if (ret < 0) {
10644 goto out;
10645 } else if (ret) {
10646 ret = 0;
10647 } else {
10648 btrfs_warn(fs_info,
10649 "swapfile must not be copy-on-write");
10650 ret = -EINVAL;
10651 goto out;
10652 }
10653
10654 em = btrfs_get_chunk_map(fs_info, logical_block_start, len);
10655 if (IS_ERR(em)) {
10656 ret = PTR_ERR(em);
10657 goto out;
10658 }
10659
10660 if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
10661 btrfs_warn(fs_info,
10662 "swapfile must have single data profile");
10663 ret = -EINVAL;
10664 goto out;
10665 }
10666
10667 if (device == NULL) {
10668 device = em->map_lookup->stripes[0].dev;
10669 ret = btrfs_add_swapfile_pin(inode, device, false);
10670 if (ret == 1)
10671 ret = 0;
10672 else if (ret)
10673 goto out;
10674 } else if (device != em->map_lookup->stripes[0].dev) {
10675 btrfs_warn(fs_info, "swapfile must be on one device");
10676 ret = -EINVAL;
10677 goto out;
10678 }
10679
10680 physical_block_start = (em->map_lookup->stripes[0].physical +
10681 (logical_block_start - em->start));
10682 len = min(len, em->len - (logical_block_start - em->start));
10683 free_extent_map(em);
10684 em = NULL;
10685
10686 bg = btrfs_lookup_block_group(fs_info, logical_block_start);
10687 if (!bg) {
10688 btrfs_warn(fs_info,
10689 "could not find block group containing swapfile");
10690 ret = -EINVAL;
10691 goto out;
10692 }
10693
10694 ret = btrfs_add_swapfile_pin(inode, bg, true);
10695 if (ret) {
10696 btrfs_put_block_group(bg);
10697 if (ret == 1)
10698 ret = 0;
10699 else
10700 goto out;
10701 }
10702
10703 if (bsi.block_len &&
10704 bsi.block_start + bsi.block_len == physical_block_start) {
10705 bsi.block_len += len;
10706 } else {
10707 if (bsi.block_len) {
10708 ret = btrfs_add_swap_extent(sis, &bsi);
10709 if (ret)
10710 goto out;
10711 }
10712 bsi.start = start;
10713 bsi.block_start = physical_block_start;
10714 bsi.block_len = len;
10715 }
10716
10717 start += len;
10718 }
10719
10720 if (bsi.block_len)
10721 ret = btrfs_add_swap_extent(sis, &bsi);
10722
10723 out:
10724 if (!IS_ERR_OR_NULL(em))
10725 free_extent_map(em);
10726
10727 unlock_extent_cached(io_tree, 0, isize - 1, &cached_state);
10728
10729 if (ret)
10730 btrfs_swap_deactivate(file);
10731
10732 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
10733
10734 if (ret)
10735 return ret;
10736
10737 if (device)
10738 sis->bdev = device->bdev;
10739 *span = bsi.highest_ppage - bsi.lowest_ppage + 1;
10740 sis->max = bsi.nr_pages;
10741 sis->pages = bsi.nr_pages - 1;
10742 sis->highest_bit = bsi.nr_pages - 1;
10743 return bsi.nr_extents;
10744 }
10745 #else
10746 static void btrfs_swap_deactivate(struct file *file)
10747 {
10748 }
10749
10750 static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
10751 sector_t *span)
10752 {
10753 return -EOPNOTSUPP;
10754 }
10755 #endif
10756
10757 static const struct inode_operations btrfs_dir_inode_operations = {
10758 .getattr = btrfs_getattr,
10759 .lookup = btrfs_lookup,
10760 .create = btrfs_create,
10761 .unlink = btrfs_unlink,
10762 .link = btrfs_link,
10763 .mkdir = btrfs_mkdir,
10764 .rmdir = btrfs_rmdir,
10765 .rename = btrfs_rename2,
10766 .symlink = btrfs_symlink,
10767 .setattr = btrfs_setattr,
10768 .mknod = btrfs_mknod,
10769 .listxattr = btrfs_listxattr,
10770 .permission = btrfs_permission,
10771 .get_acl = btrfs_get_acl,
10772 .set_acl = btrfs_set_acl,
10773 .update_time = btrfs_update_time,
10774 .tmpfile = btrfs_tmpfile,
10775 };
10776 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10777 .lookup = btrfs_lookup,
10778 .permission = btrfs_permission,
10779 .update_time = btrfs_update_time,
10780 };
10781
10782 static const struct file_operations btrfs_dir_file_operations = {
10783 .llseek = generic_file_llseek,
10784 .read = generic_read_dir,
10785 .iterate_shared = btrfs_real_readdir,
10786 .open = btrfs_opendir,
10787 .unlocked_ioctl = btrfs_ioctl,
10788 #ifdef CONFIG_COMPAT
10789 .compat_ioctl = btrfs_compat_ioctl,
10790 #endif
10791 .release = btrfs_release_file,
10792 .fsync = btrfs_sync_file,
10793 };
10794
10795 static const struct extent_io_ops btrfs_extent_io_ops = {
10796 /* mandatory callbacks */
10797 .submit_bio_hook = btrfs_submit_bio_hook,
10798 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10799 };
10800
10801 /*
10802 * btrfs doesn't support the bmap operation because swapfiles
10803 * use bmap to make a mapping of extents in the file. They assume
10804 * these extents won't change over the life of the file and they
10805 * use the bmap result to do IO directly to the drive.
10806 *
10807 * the btrfs bmap call would return logical addresses that aren't
10808 * suitable for IO and they also will change frequently as COW
10809 * operations happen. So, swapfile + btrfs == corruption.
10810 *
10811 * For now we're avoiding this by dropping bmap.
10812 */
10813 static const struct address_space_operations btrfs_aops = {
10814 .readpage = btrfs_readpage,
10815 .writepage = btrfs_writepage,
10816 .writepages = btrfs_writepages,
10817 .readpages = btrfs_readpages,
10818 .direct_IO = btrfs_direct_IO,
10819 .invalidatepage = btrfs_invalidatepage,
10820 .releasepage = btrfs_releasepage,
10821 .set_page_dirty = btrfs_set_page_dirty,
10822 .error_remove_page = generic_error_remove_page,
10823 .swap_activate = btrfs_swap_activate,
10824 .swap_deactivate = btrfs_swap_deactivate,
10825 };
10826
10827 static const struct inode_operations btrfs_file_inode_operations = {
10828 .getattr = btrfs_getattr,
10829 .setattr = btrfs_setattr,
10830 .listxattr = btrfs_listxattr,
10831 .permission = btrfs_permission,
10832 .fiemap = btrfs_fiemap,
10833 .get_acl = btrfs_get_acl,
10834 .set_acl = btrfs_set_acl,
10835 .update_time = btrfs_update_time,
10836 };
10837 static const struct inode_operations btrfs_special_inode_operations = {
10838 .getattr = btrfs_getattr,
10839 .setattr = btrfs_setattr,
10840 .permission = btrfs_permission,
10841 .listxattr = btrfs_listxattr,
10842 .get_acl = btrfs_get_acl,
10843 .set_acl = btrfs_set_acl,
10844 .update_time = btrfs_update_time,
10845 };
10846 static const struct inode_operations btrfs_symlink_inode_operations = {
10847 .get_link = page_get_link,
10848 .getattr = btrfs_getattr,
10849 .setattr = btrfs_setattr,
10850 .permission = btrfs_permission,
10851 .listxattr = btrfs_listxattr,
10852 .update_time = btrfs_update_time,
10853 };
10854
10855 const struct dentry_operations btrfs_dentry_operations = {
10856 .d_delete = btrfs_dentry_delete,
10857 };
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