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Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[thirdparty/kernel/stable.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/compat.h>
34 #include <linux/bit_spinlock.h>
35 #include <linux/xattr.h>
36 #include <linux/posix_acl.h>
37 #include <linux/falloc.h>
38 #include <linux/slab.h>
39 #include <linux/ratelimit.h>
40 #include <linux/mount.h>
41 #include <linux/btrfs.h>
42 #include <linux/blkdev.h>
43 #include <linux/posix_acl_xattr.h>
44 #include <linux/uio.h>
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "print-tree.h"
50 #include "ordered-data.h"
51 #include "xattr.h"
52 #include "tree-log.h"
53 #include "volumes.h"
54 #include "compression.h"
55 #include "locking.h"
56 #include "free-space-cache.h"
57 #include "inode-map.h"
58 #include "backref.h"
59 #include "hash.h"
60 #include "props.h"
61 #include "qgroup.h"
62 #include "dedupe.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 int overwrite;
75 };
76
77 static const struct inode_operations btrfs_dir_inode_operations;
78 static const struct inode_operations btrfs_symlink_inode_operations;
79 static const struct inode_operations btrfs_dir_ro_inode_operations;
80 static const struct inode_operations btrfs_special_inode_operations;
81 static const struct inode_operations btrfs_file_inode_operations;
82 static const struct address_space_operations btrfs_aops;
83 static const struct address_space_operations btrfs_symlink_aops;
84 static const struct file_operations btrfs_dir_file_operations;
85 static const struct extent_io_ops btrfs_extent_io_ops;
86
87 static struct kmem_cache *btrfs_inode_cachep;
88 struct kmem_cache *btrfs_trans_handle_cachep;
89 struct kmem_cache *btrfs_transaction_cachep;
90 struct kmem_cache *btrfs_path_cachep;
91 struct kmem_cache *btrfs_free_space_cachep;
92
93 #define S_SHIFT 12
94 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
95 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
96 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
97 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
98 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
99 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
100 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
101 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
102 };
103
104 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
105 static int btrfs_truncate(struct inode *inode);
106 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
107 static noinline int cow_file_range(struct inode *inode,
108 struct page *locked_page,
109 u64 start, u64 end, u64 delalloc_end,
110 int *page_started, unsigned long *nr_written,
111 int unlock, struct btrfs_dedupe_hash *hash);
112 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
113 u64 orig_start, u64 block_start,
114 u64 block_len, u64 orig_block_len,
115 u64 ram_bytes, int compress_type,
116 int type);
117
118 static int btrfs_dirty_inode(struct inode *inode);
119
120 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
121 void btrfs_test_inode_set_ops(struct inode *inode)
122 {
123 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
124 }
125 #endif
126
127 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
128 struct inode *inode, struct inode *dir,
129 const struct qstr *qstr)
130 {
131 int err;
132
133 err = btrfs_init_acl(trans, inode, dir);
134 if (!err)
135 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
136 return err;
137 }
138
139 /*
140 * this does all the hard work for inserting an inline extent into
141 * the btree. The caller should have done a btrfs_drop_extents so that
142 * no overlapping inline items exist in the btree
143 */
144 static int insert_inline_extent(struct btrfs_trans_handle *trans,
145 struct btrfs_path *path, int extent_inserted,
146 struct btrfs_root *root, struct inode *inode,
147 u64 start, size_t size, size_t compressed_size,
148 int compress_type,
149 struct page **compressed_pages)
150 {
151 struct extent_buffer *leaf;
152 struct page *page = NULL;
153 char *kaddr;
154 unsigned long ptr;
155 struct btrfs_file_extent_item *ei;
156 int err = 0;
157 int ret;
158 size_t cur_size = size;
159 unsigned long offset;
160
161 if (compressed_size && compressed_pages)
162 cur_size = compressed_size;
163
164 inode_add_bytes(inode, size);
165
166 if (!extent_inserted) {
167 struct btrfs_key key;
168 size_t datasize;
169
170 key.objectid = btrfs_ino(BTRFS_I(inode));
171 key.offset = start;
172 key.type = BTRFS_EXTENT_DATA_KEY;
173
174 datasize = btrfs_file_extent_calc_inline_size(cur_size);
175 path->leave_spinning = 1;
176 ret = btrfs_insert_empty_item(trans, root, path, &key,
177 datasize);
178 if (ret) {
179 err = ret;
180 goto fail;
181 }
182 }
183 leaf = path->nodes[0];
184 ei = btrfs_item_ptr(leaf, path->slots[0],
185 struct btrfs_file_extent_item);
186 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
187 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
188 btrfs_set_file_extent_encryption(leaf, ei, 0);
189 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
190 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
191 ptr = btrfs_file_extent_inline_start(ei);
192
193 if (compress_type != BTRFS_COMPRESS_NONE) {
194 struct page *cpage;
195 int i = 0;
196 while (compressed_size > 0) {
197 cpage = compressed_pages[i];
198 cur_size = min_t(unsigned long, compressed_size,
199 PAGE_SIZE);
200
201 kaddr = kmap_atomic(cpage);
202 write_extent_buffer(leaf, kaddr, ptr, cur_size);
203 kunmap_atomic(kaddr);
204
205 i++;
206 ptr += cur_size;
207 compressed_size -= cur_size;
208 }
209 btrfs_set_file_extent_compression(leaf, ei,
210 compress_type);
211 } else {
212 page = find_get_page(inode->i_mapping,
213 start >> PAGE_SHIFT);
214 btrfs_set_file_extent_compression(leaf, ei, 0);
215 kaddr = kmap_atomic(page);
216 offset = start & (PAGE_SIZE - 1);
217 write_extent_buffer(leaf, kaddr + offset, ptr, size);
218 kunmap_atomic(kaddr);
219 put_page(page);
220 }
221 btrfs_mark_buffer_dirty(leaf);
222 btrfs_release_path(path);
223
224 /*
225 * we're an inline extent, so nobody can
226 * extend the file past i_size without locking
227 * a page we already have locked.
228 *
229 * We must do any isize and inode updates
230 * before we unlock the pages. Otherwise we
231 * could end up racing with unlink.
232 */
233 BTRFS_I(inode)->disk_i_size = inode->i_size;
234 ret = btrfs_update_inode(trans, root, inode);
235
236 return ret;
237 fail:
238 return err;
239 }
240
241
242 /*
243 * conditionally insert an inline extent into the file. This
244 * does the checks required to make sure the data is small enough
245 * to fit as an inline extent.
246 */
247 static noinline int cow_file_range_inline(struct btrfs_root *root,
248 struct inode *inode, u64 start,
249 u64 end, size_t compressed_size,
250 int compress_type,
251 struct page **compressed_pages)
252 {
253 struct btrfs_fs_info *fs_info = root->fs_info;
254 struct btrfs_trans_handle *trans;
255 u64 isize = i_size_read(inode);
256 u64 actual_end = min(end + 1, isize);
257 u64 inline_len = actual_end - start;
258 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
259 u64 data_len = inline_len;
260 int ret;
261 struct btrfs_path *path;
262 int extent_inserted = 0;
263 u32 extent_item_size;
264
265 if (compressed_size)
266 data_len = compressed_size;
267
268 if (start > 0 ||
269 actual_end > fs_info->sectorsize ||
270 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
271 (!compressed_size &&
272 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
273 end + 1 < isize ||
274 data_len > fs_info->max_inline) {
275 return 1;
276 }
277
278 path = btrfs_alloc_path();
279 if (!path)
280 return -ENOMEM;
281
282 trans = btrfs_join_transaction(root);
283 if (IS_ERR(trans)) {
284 btrfs_free_path(path);
285 return PTR_ERR(trans);
286 }
287 trans->block_rsv = &fs_info->delalloc_block_rsv;
288
289 if (compressed_size && compressed_pages)
290 extent_item_size = btrfs_file_extent_calc_inline_size(
291 compressed_size);
292 else
293 extent_item_size = btrfs_file_extent_calc_inline_size(
294 inline_len);
295
296 ret = __btrfs_drop_extents(trans, root, inode, path,
297 start, aligned_end, NULL,
298 1, 1, extent_item_size, &extent_inserted);
299 if (ret) {
300 btrfs_abort_transaction(trans, ret);
301 goto out;
302 }
303
304 if (isize > actual_end)
305 inline_len = min_t(u64, isize, actual_end);
306 ret = insert_inline_extent(trans, path, extent_inserted,
307 root, inode, start,
308 inline_len, compressed_size,
309 compress_type, compressed_pages);
310 if (ret && ret != -ENOSPC) {
311 btrfs_abort_transaction(trans, ret);
312 goto out;
313 } else if (ret == -ENOSPC) {
314 ret = 1;
315 goto out;
316 }
317
318 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
319 btrfs_delalloc_release_metadata(BTRFS_I(inode), end + 1 - start);
320 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
321 out:
322 /*
323 * Don't forget to free the reserved space, as for inlined extent
324 * it won't count as data extent, free them directly here.
325 * And at reserve time, it's always aligned to page size, so
326 * just free one page here.
327 */
328 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
329 btrfs_free_path(path);
330 btrfs_end_transaction(trans);
331 return ret;
332 }
333
334 struct async_extent {
335 u64 start;
336 u64 ram_size;
337 u64 compressed_size;
338 struct page **pages;
339 unsigned long nr_pages;
340 int compress_type;
341 struct list_head list;
342 };
343
344 struct async_cow {
345 struct inode *inode;
346 struct btrfs_root *root;
347 struct page *locked_page;
348 u64 start;
349 u64 end;
350 struct list_head extents;
351 struct btrfs_work work;
352 };
353
354 static noinline int add_async_extent(struct async_cow *cow,
355 u64 start, u64 ram_size,
356 u64 compressed_size,
357 struct page **pages,
358 unsigned long nr_pages,
359 int compress_type)
360 {
361 struct async_extent *async_extent;
362
363 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
364 BUG_ON(!async_extent); /* -ENOMEM */
365 async_extent->start = start;
366 async_extent->ram_size = ram_size;
367 async_extent->compressed_size = compressed_size;
368 async_extent->pages = pages;
369 async_extent->nr_pages = nr_pages;
370 async_extent->compress_type = compress_type;
371 list_add_tail(&async_extent->list, &cow->extents);
372 return 0;
373 }
374
375 static inline int inode_need_compress(struct inode *inode)
376 {
377 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
378
379 /* force compress */
380 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
381 return 1;
382 /* bad compression ratios */
383 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
384 return 0;
385 if (btrfs_test_opt(fs_info, COMPRESS) ||
386 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
387 BTRFS_I(inode)->force_compress)
388 return 1;
389 return 0;
390 }
391
392 static inline void inode_should_defrag(struct btrfs_inode *inode,
393 u64 start, u64 end, u64 num_bytes, u64 small_write)
394 {
395 /* If this is a small write inside eof, kick off a defrag */
396 if (num_bytes < small_write &&
397 (start > 0 || end + 1 < inode->disk_i_size))
398 btrfs_add_inode_defrag(NULL, inode);
399 }
400
401 /*
402 * we create compressed extents in two phases. The first
403 * phase compresses a range of pages that have already been
404 * locked (both pages and state bits are locked).
405 *
406 * This is done inside an ordered work queue, and the compression
407 * is spread across many cpus. The actual IO submission is step
408 * two, and the ordered work queue takes care of making sure that
409 * happens in the same order things were put onto the queue by
410 * writepages and friends.
411 *
412 * If this code finds it can't get good compression, it puts an
413 * entry onto the work queue to write the uncompressed bytes. This
414 * makes sure that both compressed inodes and uncompressed inodes
415 * are written in the same order that the flusher thread sent them
416 * down.
417 */
418 static noinline void compress_file_range(struct inode *inode,
419 struct page *locked_page,
420 u64 start, u64 end,
421 struct async_cow *async_cow,
422 int *num_added)
423 {
424 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
425 struct btrfs_root *root = BTRFS_I(inode)->root;
426 u64 num_bytes;
427 u64 blocksize = fs_info->sectorsize;
428 u64 actual_end;
429 u64 isize = i_size_read(inode);
430 int ret = 0;
431 struct page **pages = NULL;
432 unsigned long nr_pages;
433 unsigned long total_compressed = 0;
434 unsigned long total_in = 0;
435 int i;
436 int will_compress;
437 int compress_type = fs_info->compress_type;
438 int redirty = 0;
439
440 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
441 SZ_16K);
442
443 actual_end = min_t(u64, isize, end + 1);
444 again:
445 will_compress = 0;
446 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
447 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
448 nr_pages = min_t(unsigned long, nr_pages,
449 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
450
451 /*
452 * we don't want to send crud past the end of i_size through
453 * compression, that's just a waste of CPU time. So, if the
454 * end of the file is before the start of our current
455 * requested range of bytes, we bail out to the uncompressed
456 * cleanup code that can deal with all of this.
457 *
458 * It isn't really the fastest way to fix things, but this is a
459 * very uncommon corner.
460 */
461 if (actual_end <= start)
462 goto cleanup_and_bail_uncompressed;
463
464 total_compressed = actual_end - start;
465
466 /*
467 * skip compression for a small file range(<=blocksize) that
468 * isn't an inline extent, since it doesn't save disk space at all.
469 */
470 if (total_compressed <= blocksize &&
471 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
472 goto cleanup_and_bail_uncompressed;
473
474 total_compressed = min_t(unsigned long, total_compressed,
475 BTRFS_MAX_UNCOMPRESSED);
476 num_bytes = ALIGN(end - start + 1, blocksize);
477 num_bytes = max(blocksize, num_bytes);
478 total_in = 0;
479 ret = 0;
480
481 /*
482 * we do compression for mount -o compress and when the
483 * inode has not been flagged as nocompress. This flag can
484 * change at any time if we discover bad compression ratios.
485 */
486 if (inode_need_compress(inode)) {
487 WARN_ON(pages);
488 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
489 if (!pages) {
490 /* just bail out to the uncompressed code */
491 goto cont;
492 }
493
494 if (BTRFS_I(inode)->force_compress)
495 compress_type = BTRFS_I(inode)->force_compress;
496
497 /*
498 * we need to call clear_page_dirty_for_io on each
499 * page in the range. Otherwise applications with the file
500 * mmap'd can wander in and change the page contents while
501 * we are compressing them.
502 *
503 * If the compression fails for any reason, we set the pages
504 * dirty again later on.
505 */
506 extent_range_clear_dirty_for_io(inode, start, end);
507 redirty = 1;
508 ret = btrfs_compress_pages(compress_type,
509 inode->i_mapping, start,
510 pages,
511 &nr_pages,
512 &total_in,
513 &total_compressed);
514
515 if (!ret) {
516 unsigned long offset = total_compressed &
517 (PAGE_SIZE - 1);
518 struct page *page = pages[nr_pages - 1];
519 char *kaddr;
520
521 /* zero the tail end of the last page, we might be
522 * sending it down to disk
523 */
524 if (offset) {
525 kaddr = kmap_atomic(page);
526 memset(kaddr + offset, 0,
527 PAGE_SIZE - offset);
528 kunmap_atomic(kaddr);
529 }
530 will_compress = 1;
531 }
532 }
533 cont:
534 if (start == 0) {
535 /* lets try to make an inline extent */
536 if (ret || total_in < (actual_end - start)) {
537 /* we didn't compress the entire range, try
538 * to make an uncompressed inline extent.
539 */
540 ret = cow_file_range_inline(root, inode, start, end,
541 0, BTRFS_COMPRESS_NONE, NULL);
542 } else {
543 /* try making a compressed inline extent */
544 ret = cow_file_range_inline(root, inode, start, end,
545 total_compressed,
546 compress_type, pages);
547 }
548 if (ret <= 0) {
549 unsigned long clear_flags = EXTENT_DELALLOC |
550 EXTENT_DEFRAG;
551 unsigned long page_error_op;
552
553 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
554 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
555
556 /*
557 * inline extent creation worked or returned error,
558 * we don't need to create any more async work items.
559 * Unlock and free up our temp pages.
560 */
561 extent_clear_unlock_delalloc(inode, start, end, end,
562 NULL, clear_flags,
563 PAGE_UNLOCK |
564 PAGE_CLEAR_DIRTY |
565 PAGE_SET_WRITEBACK |
566 page_error_op |
567 PAGE_END_WRITEBACK);
568 btrfs_free_reserved_data_space_noquota(inode, start,
569 end - start + 1);
570 goto free_pages_out;
571 }
572 }
573
574 if (will_compress) {
575 /*
576 * we aren't doing an inline extent round the compressed size
577 * up to a block size boundary so the allocator does sane
578 * things
579 */
580 total_compressed = ALIGN(total_compressed, blocksize);
581
582 /*
583 * one last check to make sure the compression is really a
584 * win, compare the page count read with the blocks on disk
585 */
586 total_in = ALIGN(total_in, PAGE_SIZE);
587 if (total_compressed >= total_in) {
588 will_compress = 0;
589 } else {
590 num_bytes = total_in;
591 *num_added += 1;
592
593 /*
594 * The async work queues will take care of doing actual
595 * allocation on disk for these compressed pages, and
596 * will submit them to the elevator.
597 */
598 add_async_extent(async_cow, start, num_bytes,
599 total_compressed, pages, nr_pages,
600 compress_type);
601
602 if (start + num_bytes < end) {
603 start += num_bytes;
604 pages = NULL;
605 cond_resched();
606 goto again;
607 }
608 return;
609 }
610 }
611 if (pages) {
612 /*
613 * the compression code ran but failed to make things smaller,
614 * free any pages it allocated and our page pointer array
615 */
616 for (i = 0; i < nr_pages; i++) {
617 WARN_ON(pages[i]->mapping);
618 put_page(pages[i]);
619 }
620 kfree(pages);
621 pages = NULL;
622 total_compressed = 0;
623 nr_pages = 0;
624
625 /* flag the file so we don't compress in the future */
626 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
627 !(BTRFS_I(inode)->force_compress)) {
628 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
629 }
630 }
631 cleanup_and_bail_uncompressed:
632 /*
633 * No compression, but we still need to write the pages in the file
634 * we've been given so far. redirty the locked page if it corresponds
635 * to our extent and set things up for the async work queue to run
636 * cow_file_range to do the normal delalloc dance.
637 */
638 if (page_offset(locked_page) >= start &&
639 page_offset(locked_page) <= end)
640 __set_page_dirty_nobuffers(locked_page);
641 /* unlocked later on in the async handlers */
642
643 if (redirty)
644 extent_range_redirty_for_io(inode, start, end);
645 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
646 BTRFS_COMPRESS_NONE);
647 *num_added += 1;
648
649 return;
650
651 free_pages_out:
652 for (i = 0; i < nr_pages; i++) {
653 WARN_ON(pages[i]->mapping);
654 put_page(pages[i]);
655 }
656 kfree(pages);
657 }
658
659 static void free_async_extent_pages(struct async_extent *async_extent)
660 {
661 int i;
662
663 if (!async_extent->pages)
664 return;
665
666 for (i = 0; i < async_extent->nr_pages; i++) {
667 WARN_ON(async_extent->pages[i]->mapping);
668 put_page(async_extent->pages[i]);
669 }
670 kfree(async_extent->pages);
671 async_extent->nr_pages = 0;
672 async_extent->pages = NULL;
673 }
674
675 /*
676 * phase two of compressed writeback. This is the ordered portion
677 * of the code, which only gets called in the order the work was
678 * queued. We walk all the async extents created by compress_file_range
679 * and send them down to the disk.
680 */
681 static noinline void submit_compressed_extents(struct inode *inode,
682 struct async_cow *async_cow)
683 {
684 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
685 struct async_extent *async_extent;
686 u64 alloc_hint = 0;
687 struct btrfs_key ins;
688 struct extent_map *em;
689 struct btrfs_root *root = BTRFS_I(inode)->root;
690 struct extent_io_tree *io_tree;
691 int ret = 0;
692
693 again:
694 while (!list_empty(&async_cow->extents)) {
695 async_extent = list_entry(async_cow->extents.next,
696 struct async_extent, list);
697 list_del(&async_extent->list);
698
699 io_tree = &BTRFS_I(inode)->io_tree;
700
701 retry:
702 /* did the compression code fall back to uncompressed IO? */
703 if (!async_extent->pages) {
704 int page_started = 0;
705 unsigned long nr_written = 0;
706
707 lock_extent(io_tree, async_extent->start,
708 async_extent->start +
709 async_extent->ram_size - 1);
710
711 /* allocate blocks */
712 ret = cow_file_range(inode, async_cow->locked_page,
713 async_extent->start,
714 async_extent->start +
715 async_extent->ram_size - 1,
716 async_extent->start +
717 async_extent->ram_size - 1,
718 &page_started, &nr_written, 0,
719 NULL);
720
721 /* JDM XXX */
722
723 /*
724 * if page_started, cow_file_range inserted an
725 * inline extent and took care of all the unlocking
726 * and IO for us. Otherwise, we need to submit
727 * all those pages down to the drive.
728 */
729 if (!page_started && !ret)
730 extent_write_locked_range(io_tree,
731 inode, async_extent->start,
732 async_extent->start +
733 async_extent->ram_size - 1,
734 btrfs_get_extent,
735 WB_SYNC_ALL);
736 else if (ret)
737 unlock_page(async_cow->locked_page);
738 kfree(async_extent);
739 cond_resched();
740 continue;
741 }
742
743 lock_extent(io_tree, async_extent->start,
744 async_extent->start + async_extent->ram_size - 1);
745
746 ret = btrfs_reserve_extent(root, async_extent->ram_size,
747 async_extent->compressed_size,
748 async_extent->compressed_size,
749 0, alloc_hint, &ins, 1, 1);
750 if (ret) {
751 free_async_extent_pages(async_extent);
752
753 if (ret == -ENOSPC) {
754 unlock_extent(io_tree, async_extent->start,
755 async_extent->start +
756 async_extent->ram_size - 1);
757
758 /*
759 * we need to redirty the pages if we decide to
760 * fallback to uncompressed IO, otherwise we
761 * will not submit these pages down to lower
762 * layers.
763 */
764 extent_range_redirty_for_io(inode,
765 async_extent->start,
766 async_extent->start +
767 async_extent->ram_size - 1);
768
769 goto retry;
770 }
771 goto out_free;
772 }
773 /*
774 * here we're doing allocation and writeback of the
775 * compressed pages
776 */
777 em = create_io_em(inode, async_extent->start,
778 async_extent->ram_size, /* len */
779 async_extent->start, /* orig_start */
780 ins.objectid, /* block_start */
781 ins.offset, /* block_len */
782 ins.offset, /* orig_block_len */
783 async_extent->ram_size, /* ram_bytes */
784 async_extent->compress_type,
785 BTRFS_ORDERED_COMPRESSED);
786 if (IS_ERR(em))
787 /* ret value is not necessary due to void function */
788 goto out_free_reserve;
789 free_extent_map(em);
790
791 ret = btrfs_add_ordered_extent_compress(inode,
792 async_extent->start,
793 ins.objectid,
794 async_extent->ram_size,
795 ins.offset,
796 BTRFS_ORDERED_COMPRESSED,
797 async_extent->compress_type);
798 if (ret) {
799 btrfs_drop_extent_cache(BTRFS_I(inode),
800 async_extent->start,
801 async_extent->start +
802 async_extent->ram_size - 1, 0);
803 goto out_free_reserve;
804 }
805 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
806
807 /*
808 * clear dirty, set writeback and unlock the pages.
809 */
810 extent_clear_unlock_delalloc(inode, async_extent->start,
811 async_extent->start +
812 async_extent->ram_size - 1,
813 async_extent->start +
814 async_extent->ram_size - 1,
815 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
816 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
817 PAGE_SET_WRITEBACK);
818 ret = btrfs_submit_compressed_write(inode,
819 async_extent->start,
820 async_extent->ram_size,
821 ins.objectid,
822 ins.offset, async_extent->pages,
823 async_extent->nr_pages);
824 if (ret) {
825 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
826 struct page *p = async_extent->pages[0];
827 const u64 start = async_extent->start;
828 const u64 end = start + async_extent->ram_size - 1;
829
830 p->mapping = inode->i_mapping;
831 tree->ops->writepage_end_io_hook(p, start, end,
832 NULL, 0);
833 p->mapping = NULL;
834 extent_clear_unlock_delalloc(inode, start, end, end,
835 NULL, 0,
836 PAGE_END_WRITEBACK |
837 PAGE_SET_ERROR);
838 free_async_extent_pages(async_extent);
839 }
840 alloc_hint = ins.objectid + ins.offset;
841 kfree(async_extent);
842 cond_resched();
843 }
844 return;
845 out_free_reserve:
846 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
847 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
848 out_free:
849 extent_clear_unlock_delalloc(inode, async_extent->start,
850 async_extent->start +
851 async_extent->ram_size - 1,
852 async_extent->start +
853 async_extent->ram_size - 1,
854 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
855 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
856 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
857 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
858 PAGE_SET_ERROR);
859 free_async_extent_pages(async_extent);
860 kfree(async_extent);
861 goto again;
862 }
863
864 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
865 u64 num_bytes)
866 {
867 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
868 struct extent_map *em;
869 u64 alloc_hint = 0;
870
871 read_lock(&em_tree->lock);
872 em = search_extent_mapping(em_tree, start, num_bytes);
873 if (em) {
874 /*
875 * if block start isn't an actual block number then find the
876 * first block in this inode and use that as a hint. If that
877 * block is also bogus then just don't worry about it.
878 */
879 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
880 free_extent_map(em);
881 em = search_extent_mapping(em_tree, 0, 0);
882 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
883 alloc_hint = em->block_start;
884 if (em)
885 free_extent_map(em);
886 } else {
887 alloc_hint = em->block_start;
888 free_extent_map(em);
889 }
890 }
891 read_unlock(&em_tree->lock);
892
893 return alloc_hint;
894 }
895
896 /*
897 * when extent_io.c finds a delayed allocation range in the file,
898 * the call backs end up in this code. The basic idea is to
899 * allocate extents on disk for the range, and create ordered data structs
900 * in ram to track those extents.
901 *
902 * locked_page is the page that writepage had locked already. We use
903 * it to make sure we don't do extra locks or unlocks.
904 *
905 * *page_started is set to one if we unlock locked_page and do everything
906 * required to start IO on it. It may be clean and already done with
907 * IO when we return.
908 */
909 static noinline int cow_file_range(struct inode *inode,
910 struct page *locked_page,
911 u64 start, u64 end, u64 delalloc_end,
912 int *page_started, unsigned long *nr_written,
913 int unlock, struct btrfs_dedupe_hash *hash)
914 {
915 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
916 struct btrfs_root *root = BTRFS_I(inode)->root;
917 u64 alloc_hint = 0;
918 u64 num_bytes;
919 unsigned long ram_size;
920 u64 disk_num_bytes;
921 u64 cur_alloc_size;
922 u64 blocksize = fs_info->sectorsize;
923 struct btrfs_key ins;
924 struct extent_map *em;
925 int ret = 0;
926
927 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
928 WARN_ON_ONCE(1);
929 ret = -EINVAL;
930 goto out_unlock;
931 }
932
933 num_bytes = ALIGN(end - start + 1, blocksize);
934 num_bytes = max(blocksize, num_bytes);
935 disk_num_bytes = num_bytes;
936
937 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
938
939 if (start == 0) {
940 /* lets try to make an inline extent */
941 ret = cow_file_range_inline(root, inode, start, end, 0,
942 BTRFS_COMPRESS_NONE, NULL);
943 if (ret == 0) {
944 extent_clear_unlock_delalloc(inode, start, end,
945 delalloc_end, NULL,
946 EXTENT_LOCKED | EXTENT_DELALLOC |
947 EXTENT_DEFRAG, PAGE_UNLOCK |
948 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
949 PAGE_END_WRITEBACK);
950 btrfs_free_reserved_data_space_noquota(inode, start,
951 end - start + 1);
952 *nr_written = *nr_written +
953 (end - start + PAGE_SIZE) / PAGE_SIZE;
954 *page_started = 1;
955 goto out;
956 } else if (ret < 0) {
957 goto out_unlock;
958 }
959 }
960
961 BUG_ON(disk_num_bytes >
962 btrfs_super_total_bytes(fs_info->super_copy));
963
964 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
965 btrfs_drop_extent_cache(BTRFS_I(inode), start,
966 start + num_bytes - 1, 0);
967
968 while (disk_num_bytes > 0) {
969 unsigned long op;
970
971 cur_alloc_size = disk_num_bytes;
972 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
973 fs_info->sectorsize, 0, alloc_hint,
974 &ins, 1, 1);
975 if (ret < 0)
976 goto out_unlock;
977
978 ram_size = ins.offset;
979 em = create_io_em(inode, start, ins.offset, /* len */
980 start, /* orig_start */
981 ins.objectid, /* block_start */
982 ins.offset, /* block_len */
983 ins.offset, /* orig_block_len */
984 ram_size, /* ram_bytes */
985 BTRFS_COMPRESS_NONE, /* compress_type */
986 BTRFS_ORDERED_REGULAR /* type */);
987 if (IS_ERR(em))
988 goto out_reserve;
989 free_extent_map(em);
990
991 cur_alloc_size = ins.offset;
992 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
993 ram_size, cur_alloc_size, 0);
994 if (ret)
995 goto out_drop_extent_cache;
996
997 if (root->root_key.objectid ==
998 BTRFS_DATA_RELOC_TREE_OBJECTID) {
999 ret = btrfs_reloc_clone_csums(inode, start,
1000 cur_alloc_size);
1001 if (ret)
1002 goto out_drop_extent_cache;
1003 }
1004
1005 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1006
1007 if (disk_num_bytes < cur_alloc_size)
1008 break;
1009
1010 /* we're not doing compressed IO, don't unlock the first
1011 * page (which the caller expects to stay locked), don't
1012 * clear any dirty bits and don't set any writeback bits
1013 *
1014 * Do set the Private2 bit so we know this page was properly
1015 * setup for writepage
1016 */
1017 op = unlock ? PAGE_UNLOCK : 0;
1018 op |= PAGE_SET_PRIVATE2;
1019
1020 extent_clear_unlock_delalloc(inode, start,
1021 start + ram_size - 1,
1022 delalloc_end, locked_page,
1023 EXTENT_LOCKED | EXTENT_DELALLOC,
1024 op);
1025 disk_num_bytes -= cur_alloc_size;
1026 num_bytes -= cur_alloc_size;
1027 alloc_hint = ins.objectid + ins.offset;
1028 start += cur_alloc_size;
1029 }
1030 out:
1031 return ret;
1032
1033 out_drop_extent_cache:
1034 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1035 out_reserve:
1036 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1037 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1038 out_unlock:
1039 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1040 locked_page,
1041 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1042 EXTENT_DELALLOC | EXTENT_DEFRAG,
1043 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1044 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1045 goto out;
1046 }
1047
1048 /*
1049 * work queue call back to started compression on a file and pages
1050 */
1051 static noinline void async_cow_start(struct btrfs_work *work)
1052 {
1053 struct async_cow *async_cow;
1054 int num_added = 0;
1055 async_cow = container_of(work, struct async_cow, work);
1056
1057 compress_file_range(async_cow->inode, async_cow->locked_page,
1058 async_cow->start, async_cow->end, async_cow,
1059 &num_added);
1060 if (num_added == 0) {
1061 btrfs_add_delayed_iput(async_cow->inode);
1062 async_cow->inode = NULL;
1063 }
1064 }
1065
1066 /*
1067 * work queue call back to submit previously compressed pages
1068 */
1069 static noinline void async_cow_submit(struct btrfs_work *work)
1070 {
1071 struct btrfs_fs_info *fs_info;
1072 struct async_cow *async_cow;
1073 struct btrfs_root *root;
1074 unsigned long nr_pages;
1075
1076 async_cow = container_of(work, struct async_cow, work);
1077
1078 root = async_cow->root;
1079 fs_info = root->fs_info;
1080 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1081 PAGE_SHIFT;
1082
1083 /*
1084 * atomic_sub_return implies a barrier for waitqueue_active
1085 */
1086 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1087 5 * SZ_1M &&
1088 waitqueue_active(&fs_info->async_submit_wait))
1089 wake_up(&fs_info->async_submit_wait);
1090
1091 if (async_cow->inode)
1092 submit_compressed_extents(async_cow->inode, async_cow);
1093 }
1094
1095 static noinline void async_cow_free(struct btrfs_work *work)
1096 {
1097 struct async_cow *async_cow;
1098 async_cow = container_of(work, struct async_cow, work);
1099 if (async_cow->inode)
1100 btrfs_add_delayed_iput(async_cow->inode);
1101 kfree(async_cow);
1102 }
1103
1104 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1105 u64 start, u64 end, int *page_started,
1106 unsigned long *nr_written)
1107 {
1108 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1109 struct async_cow *async_cow;
1110 struct btrfs_root *root = BTRFS_I(inode)->root;
1111 unsigned long nr_pages;
1112 u64 cur_end;
1113
1114 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1115 1, 0, NULL, GFP_NOFS);
1116 while (start < end) {
1117 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1118 BUG_ON(!async_cow); /* -ENOMEM */
1119 async_cow->inode = igrab(inode);
1120 async_cow->root = root;
1121 async_cow->locked_page = locked_page;
1122 async_cow->start = start;
1123
1124 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1125 !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1126 cur_end = end;
1127 else
1128 cur_end = min(end, start + SZ_512K - 1);
1129
1130 async_cow->end = cur_end;
1131 INIT_LIST_HEAD(&async_cow->extents);
1132
1133 btrfs_init_work(&async_cow->work,
1134 btrfs_delalloc_helper,
1135 async_cow_start, async_cow_submit,
1136 async_cow_free);
1137
1138 nr_pages = (cur_end - start + PAGE_SIZE) >>
1139 PAGE_SHIFT;
1140 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1141
1142 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1143
1144 while (atomic_read(&fs_info->async_submit_draining) &&
1145 atomic_read(&fs_info->async_delalloc_pages)) {
1146 wait_event(fs_info->async_submit_wait,
1147 (atomic_read(&fs_info->async_delalloc_pages) ==
1148 0));
1149 }
1150
1151 *nr_written += nr_pages;
1152 start = cur_end + 1;
1153 }
1154 *page_started = 1;
1155 return 0;
1156 }
1157
1158 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1159 u64 bytenr, u64 num_bytes)
1160 {
1161 int ret;
1162 struct btrfs_ordered_sum *sums;
1163 LIST_HEAD(list);
1164
1165 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1166 bytenr + num_bytes - 1, &list, 0);
1167 if (ret == 0 && list_empty(&list))
1168 return 0;
1169
1170 while (!list_empty(&list)) {
1171 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1172 list_del(&sums->list);
1173 kfree(sums);
1174 }
1175 return 1;
1176 }
1177
1178 /*
1179 * when nowcow writeback call back. This checks for snapshots or COW copies
1180 * of the extents that exist in the file, and COWs the file as required.
1181 *
1182 * If no cow copies or snapshots exist, we write directly to the existing
1183 * blocks on disk
1184 */
1185 static noinline int run_delalloc_nocow(struct inode *inode,
1186 struct page *locked_page,
1187 u64 start, u64 end, int *page_started, int force,
1188 unsigned long *nr_written)
1189 {
1190 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1191 struct btrfs_root *root = BTRFS_I(inode)->root;
1192 struct extent_buffer *leaf;
1193 struct btrfs_path *path;
1194 struct btrfs_file_extent_item *fi;
1195 struct btrfs_key found_key;
1196 struct extent_map *em;
1197 u64 cow_start;
1198 u64 cur_offset;
1199 u64 extent_end;
1200 u64 extent_offset;
1201 u64 disk_bytenr;
1202 u64 num_bytes;
1203 u64 disk_num_bytes;
1204 u64 ram_bytes;
1205 int extent_type;
1206 int ret, err;
1207 int type;
1208 int nocow;
1209 int check_prev = 1;
1210 bool nolock;
1211 u64 ino = btrfs_ino(BTRFS_I(inode));
1212
1213 path = btrfs_alloc_path();
1214 if (!path) {
1215 extent_clear_unlock_delalloc(inode, start, end, end,
1216 locked_page,
1217 EXTENT_LOCKED | EXTENT_DELALLOC |
1218 EXTENT_DO_ACCOUNTING |
1219 EXTENT_DEFRAG, PAGE_UNLOCK |
1220 PAGE_CLEAR_DIRTY |
1221 PAGE_SET_WRITEBACK |
1222 PAGE_END_WRITEBACK);
1223 return -ENOMEM;
1224 }
1225
1226 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1227
1228 cow_start = (u64)-1;
1229 cur_offset = start;
1230 while (1) {
1231 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1232 cur_offset, 0);
1233 if (ret < 0)
1234 goto error;
1235 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1236 leaf = path->nodes[0];
1237 btrfs_item_key_to_cpu(leaf, &found_key,
1238 path->slots[0] - 1);
1239 if (found_key.objectid == ino &&
1240 found_key.type == BTRFS_EXTENT_DATA_KEY)
1241 path->slots[0]--;
1242 }
1243 check_prev = 0;
1244 next_slot:
1245 leaf = path->nodes[0];
1246 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1247 ret = btrfs_next_leaf(root, path);
1248 if (ret < 0)
1249 goto error;
1250 if (ret > 0)
1251 break;
1252 leaf = path->nodes[0];
1253 }
1254
1255 nocow = 0;
1256 disk_bytenr = 0;
1257 num_bytes = 0;
1258 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1259
1260 if (found_key.objectid > ino)
1261 break;
1262 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1263 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1264 path->slots[0]++;
1265 goto next_slot;
1266 }
1267 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1268 found_key.offset > end)
1269 break;
1270
1271 if (found_key.offset > cur_offset) {
1272 extent_end = found_key.offset;
1273 extent_type = 0;
1274 goto out_check;
1275 }
1276
1277 fi = btrfs_item_ptr(leaf, path->slots[0],
1278 struct btrfs_file_extent_item);
1279 extent_type = btrfs_file_extent_type(leaf, fi);
1280
1281 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1282 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1283 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1284 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1285 extent_offset = btrfs_file_extent_offset(leaf, fi);
1286 extent_end = found_key.offset +
1287 btrfs_file_extent_num_bytes(leaf, fi);
1288 disk_num_bytes =
1289 btrfs_file_extent_disk_num_bytes(leaf, fi);
1290 if (extent_end <= start) {
1291 path->slots[0]++;
1292 goto next_slot;
1293 }
1294 if (disk_bytenr == 0)
1295 goto out_check;
1296 if (btrfs_file_extent_compression(leaf, fi) ||
1297 btrfs_file_extent_encryption(leaf, fi) ||
1298 btrfs_file_extent_other_encoding(leaf, fi))
1299 goto out_check;
1300 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1301 goto out_check;
1302 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1303 goto out_check;
1304 if (btrfs_cross_ref_exist(root, ino,
1305 found_key.offset -
1306 extent_offset, disk_bytenr))
1307 goto out_check;
1308 disk_bytenr += extent_offset;
1309 disk_bytenr += cur_offset - found_key.offset;
1310 num_bytes = min(end + 1, extent_end) - cur_offset;
1311 /*
1312 * if there are pending snapshots for this root,
1313 * we fall into common COW way.
1314 */
1315 if (!nolock) {
1316 err = btrfs_start_write_no_snapshoting(root);
1317 if (!err)
1318 goto out_check;
1319 }
1320 /*
1321 * force cow if csum exists in the range.
1322 * this ensure that csum for a given extent are
1323 * either valid or do not exist.
1324 */
1325 if (csum_exist_in_range(fs_info, disk_bytenr,
1326 num_bytes)) {
1327 if (!nolock)
1328 btrfs_end_write_no_snapshoting(root);
1329 goto out_check;
1330 }
1331 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1332 if (!nolock)
1333 btrfs_end_write_no_snapshoting(root);
1334 goto out_check;
1335 }
1336 nocow = 1;
1337 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1338 extent_end = found_key.offset +
1339 btrfs_file_extent_inline_len(leaf,
1340 path->slots[0], fi);
1341 extent_end = ALIGN(extent_end,
1342 fs_info->sectorsize);
1343 } else {
1344 BUG_ON(1);
1345 }
1346 out_check:
1347 if (extent_end <= start) {
1348 path->slots[0]++;
1349 if (!nolock && nocow)
1350 btrfs_end_write_no_snapshoting(root);
1351 if (nocow)
1352 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1353 goto next_slot;
1354 }
1355 if (!nocow) {
1356 if (cow_start == (u64)-1)
1357 cow_start = cur_offset;
1358 cur_offset = extent_end;
1359 if (cur_offset > end)
1360 break;
1361 path->slots[0]++;
1362 goto next_slot;
1363 }
1364
1365 btrfs_release_path(path);
1366 if (cow_start != (u64)-1) {
1367 ret = cow_file_range(inode, locked_page,
1368 cow_start, found_key.offset - 1,
1369 end, page_started, nr_written, 1,
1370 NULL);
1371 if (ret) {
1372 if (!nolock && nocow)
1373 btrfs_end_write_no_snapshoting(root);
1374 if (nocow)
1375 btrfs_dec_nocow_writers(fs_info,
1376 disk_bytenr);
1377 goto error;
1378 }
1379 cow_start = (u64)-1;
1380 }
1381
1382 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1383 u64 orig_start = found_key.offset - extent_offset;
1384
1385 em = create_io_em(inode, cur_offset, num_bytes,
1386 orig_start,
1387 disk_bytenr, /* block_start */
1388 num_bytes, /* block_len */
1389 disk_num_bytes, /* orig_block_len */
1390 ram_bytes, BTRFS_COMPRESS_NONE,
1391 BTRFS_ORDERED_PREALLOC);
1392 if (IS_ERR(em)) {
1393 if (!nolock && nocow)
1394 btrfs_end_write_no_snapshoting(root);
1395 if (nocow)
1396 btrfs_dec_nocow_writers(fs_info,
1397 disk_bytenr);
1398 ret = PTR_ERR(em);
1399 goto error;
1400 }
1401 free_extent_map(em);
1402 }
1403
1404 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1405 type = BTRFS_ORDERED_PREALLOC;
1406 } else {
1407 type = BTRFS_ORDERED_NOCOW;
1408 }
1409
1410 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1411 num_bytes, num_bytes, type);
1412 if (nocow)
1413 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1414 BUG_ON(ret); /* -ENOMEM */
1415
1416 if (root->root_key.objectid ==
1417 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1418 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1419 num_bytes);
1420 if (ret) {
1421 if (!nolock && nocow)
1422 btrfs_end_write_no_snapshoting(root);
1423 goto error;
1424 }
1425 }
1426
1427 extent_clear_unlock_delalloc(inode, cur_offset,
1428 cur_offset + num_bytes - 1, end,
1429 locked_page, EXTENT_LOCKED |
1430 EXTENT_DELALLOC |
1431 EXTENT_CLEAR_DATA_RESV,
1432 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1433
1434 if (!nolock && nocow)
1435 btrfs_end_write_no_snapshoting(root);
1436 cur_offset = extent_end;
1437 if (cur_offset > end)
1438 break;
1439 }
1440 btrfs_release_path(path);
1441
1442 if (cur_offset <= end && cow_start == (u64)-1) {
1443 cow_start = cur_offset;
1444 cur_offset = end;
1445 }
1446
1447 if (cow_start != (u64)-1) {
1448 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1449 page_started, nr_written, 1, NULL);
1450 if (ret)
1451 goto error;
1452 }
1453
1454 error:
1455 if (ret && cur_offset < end)
1456 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1457 locked_page, EXTENT_LOCKED |
1458 EXTENT_DELALLOC | EXTENT_DEFRAG |
1459 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1460 PAGE_CLEAR_DIRTY |
1461 PAGE_SET_WRITEBACK |
1462 PAGE_END_WRITEBACK);
1463 btrfs_free_path(path);
1464 return ret;
1465 }
1466
1467 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1468 {
1469
1470 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1471 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1472 return 0;
1473
1474 /*
1475 * @defrag_bytes is a hint value, no spinlock held here,
1476 * if is not zero, it means the file is defragging.
1477 * Force cow if given extent needs to be defragged.
1478 */
1479 if (BTRFS_I(inode)->defrag_bytes &&
1480 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1481 EXTENT_DEFRAG, 0, NULL))
1482 return 1;
1483
1484 return 0;
1485 }
1486
1487 /*
1488 * extent_io.c call back to do delayed allocation processing
1489 */
1490 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1491 u64 start, u64 end, int *page_started,
1492 unsigned long *nr_written)
1493 {
1494 int ret;
1495 int force_cow = need_force_cow(inode, start, end);
1496
1497 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1498 ret = run_delalloc_nocow(inode, locked_page, start, end,
1499 page_started, 1, nr_written);
1500 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1501 ret = run_delalloc_nocow(inode, locked_page, start, end,
1502 page_started, 0, nr_written);
1503 } else if (!inode_need_compress(inode)) {
1504 ret = cow_file_range(inode, locked_page, start, end, end,
1505 page_started, nr_written, 1, NULL);
1506 } else {
1507 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1508 &BTRFS_I(inode)->runtime_flags);
1509 ret = cow_file_range_async(inode, locked_page, start, end,
1510 page_started, nr_written);
1511 }
1512 return ret;
1513 }
1514
1515 static void btrfs_split_extent_hook(struct inode *inode,
1516 struct extent_state *orig, u64 split)
1517 {
1518 u64 size;
1519
1520 /* not delalloc, ignore it */
1521 if (!(orig->state & EXTENT_DELALLOC))
1522 return;
1523
1524 size = orig->end - orig->start + 1;
1525 if (size > BTRFS_MAX_EXTENT_SIZE) {
1526 u32 num_extents;
1527 u64 new_size;
1528
1529 /*
1530 * See the explanation in btrfs_merge_extent_hook, the same
1531 * applies here, just in reverse.
1532 */
1533 new_size = orig->end - split + 1;
1534 num_extents = count_max_extents(new_size);
1535 new_size = split - orig->start;
1536 num_extents += count_max_extents(new_size);
1537 if (count_max_extents(size) >= num_extents)
1538 return;
1539 }
1540
1541 spin_lock(&BTRFS_I(inode)->lock);
1542 BTRFS_I(inode)->outstanding_extents++;
1543 spin_unlock(&BTRFS_I(inode)->lock);
1544 }
1545
1546 /*
1547 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1548 * extents so we can keep track of new extents that are just merged onto old
1549 * extents, such as when we are doing sequential writes, so we can properly
1550 * account for the metadata space we'll need.
1551 */
1552 static void btrfs_merge_extent_hook(struct inode *inode,
1553 struct extent_state *new,
1554 struct extent_state *other)
1555 {
1556 u64 new_size, old_size;
1557 u32 num_extents;
1558
1559 /* not delalloc, ignore it */
1560 if (!(other->state & EXTENT_DELALLOC))
1561 return;
1562
1563 if (new->start > other->start)
1564 new_size = new->end - other->start + 1;
1565 else
1566 new_size = other->end - new->start + 1;
1567
1568 /* we're not bigger than the max, unreserve the space and go */
1569 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1570 spin_lock(&BTRFS_I(inode)->lock);
1571 BTRFS_I(inode)->outstanding_extents--;
1572 spin_unlock(&BTRFS_I(inode)->lock);
1573 return;
1574 }
1575
1576 /*
1577 * We have to add up either side to figure out how many extents were
1578 * accounted for before we merged into one big extent. If the number of
1579 * extents we accounted for is <= the amount we need for the new range
1580 * then we can return, otherwise drop. Think of it like this
1581 *
1582 * [ 4k][MAX_SIZE]
1583 *
1584 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1585 * need 2 outstanding extents, on one side we have 1 and the other side
1586 * we have 1 so they are == and we can return. But in this case
1587 *
1588 * [MAX_SIZE+4k][MAX_SIZE+4k]
1589 *
1590 * Each range on their own accounts for 2 extents, but merged together
1591 * they are only 3 extents worth of accounting, so we need to drop in
1592 * this case.
1593 */
1594 old_size = other->end - other->start + 1;
1595 num_extents = count_max_extents(old_size);
1596 old_size = new->end - new->start + 1;
1597 num_extents += count_max_extents(old_size);
1598 if (count_max_extents(new_size) >= num_extents)
1599 return;
1600
1601 spin_lock(&BTRFS_I(inode)->lock);
1602 BTRFS_I(inode)->outstanding_extents--;
1603 spin_unlock(&BTRFS_I(inode)->lock);
1604 }
1605
1606 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1607 struct inode *inode)
1608 {
1609 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1610
1611 spin_lock(&root->delalloc_lock);
1612 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1613 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1614 &root->delalloc_inodes);
1615 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1616 &BTRFS_I(inode)->runtime_flags);
1617 root->nr_delalloc_inodes++;
1618 if (root->nr_delalloc_inodes == 1) {
1619 spin_lock(&fs_info->delalloc_root_lock);
1620 BUG_ON(!list_empty(&root->delalloc_root));
1621 list_add_tail(&root->delalloc_root,
1622 &fs_info->delalloc_roots);
1623 spin_unlock(&fs_info->delalloc_root_lock);
1624 }
1625 }
1626 spin_unlock(&root->delalloc_lock);
1627 }
1628
1629 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1630 struct btrfs_inode *inode)
1631 {
1632 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1633
1634 spin_lock(&root->delalloc_lock);
1635 if (!list_empty(&inode->delalloc_inodes)) {
1636 list_del_init(&inode->delalloc_inodes);
1637 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1638 &inode->runtime_flags);
1639 root->nr_delalloc_inodes--;
1640 if (!root->nr_delalloc_inodes) {
1641 spin_lock(&fs_info->delalloc_root_lock);
1642 BUG_ON(list_empty(&root->delalloc_root));
1643 list_del_init(&root->delalloc_root);
1644 spin_unlock(&fs_info->delalloc_root_lock);
1645 }
1646 }
1647 spin_unlock(&root->delalloc_lock);
1648 }
1649
1650 /*
1651 * extent_io.c set_bit_hook, used to track delayed allocation
1652 * bytes in this file, and to maintain the list of inodes that
1653 * have pending delalloc work to be done.
1654 */
1655 static void btrfs_set_bit_hook(struct inode *inode,
1656 struct extent_state *state, unsigned *bits)
1657 {
1658
1659 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1660
1661 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1662 WARN_ON(1);
1663 /*
1664 * set_bit and clear bit hooks normally require _irqsave/restore
1665 * but in this case, we are only testing for the DELALLOC
1666 * bit, which is only set or cleared with irqs on
1667 */
1668 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1669 struct btrfs_root *root = BTRFS_I(inode)->root;
1670 u64 len = state->end + 1 - state->start;
1671 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1672
1673 if (*bits & EXTENT_FIRST_DELALLOC) {
1674 *bits &= ~EXTENT_FIRST_DELALLOC;
1675 } else {
1676 spin_lock(&BTRFS_I(inode)->lock);
1677 BTRFS_I(inode)->outstanding_extents++;
1678 spin_unlock(&BTRFS_I(inode)->lock);
1679 }
1680
1681 /* For sanity tests */
1682 if (btrfs_is_testing(fs_info))
1683 return;
1684
1685 __percpu_counter_add(&fs_info->delalloc_bytes, len,
1686 fs_info->delalloc_batch);
1687 spin_lock(&BTRFS_I(inode)->lock);
1688 BTRFS_I(inode)->delalloc_bytes += len;
1689 if (*bits & EXTENT_DEFRAG)
1690 BTRFS_I(inode)->defrag_bytes += len;
1691 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1692 &BTRFS_I(inode)->runtime_flags))
1693 btrfs_add_delalloc_inodes(root, inode);
1694 spin_unlock(&BTRFS_I(inode)->lock);
1695 }
1696 }
1697
1698 /*
1699 * extent_io.c clear_bit_hook, see set_bit_hook for why
1700 */
1701 static void btrfs_clear_bit_hook(struct btrfs_inode *inode,
1702 struct extent_state *state,
1703 unsigned *bits)
1704 {
1705 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1706 u64 len = state->end + 1 - state->start;
1707 u32 num_extents = count_max_extents(len);
1708
1709 spin_lock(&inode->lock);
1710 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1711 inode->defrag_bytes -= len;
1712 spin_unlock(&inode->lock);
1713
1714 /*
1715 * set_bit and clear bit hooks normally require _irqsave/restore
1716 * but in this case, we are only testing for the DELALLOC
1717 * bit, which is only set or cleared with irqs on
1718 */
1719 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1720 struct btrfs_root *root = inode->root;
1721 bool do_list = !btrfs_is_free_space_inode(inode);
1722
1723 if (*bits & EXTENT_FIRST_DELALLOC) {
1724 *bits &= ~EXTENT_FIRST_DELALLOC;
1725 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1726 spin_lock(&inode->lock);
1727 inode->outstanding_extents -= num_extents;
1728 spin_unlock(&inode->lock);
1729 }
1730
1731 /*
1732 * We don't reserve metadata space for space cache inodes so we
1733 * don't need to call dellalloc_release_metadata if there is an
1734 * error.
1735 */
1736 if (*bits & EXTENT_DO_ACCOUNTING &&
1737 root != fs_info->tree_root)
1738 btrfs_delalloc_release_metadata(inode, len);
1739
1740 /* For sanity tests. */
1741 if (btrfs_is_testing(fs_info))
1742 return;
1743
1744 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1745 && do_list && !(state->state & EXTENT_NORESERVE)
1746 && (*bits & (EXTENT_DO_ACCOUNTING |
1747 EXTENT_CLEAR_DATA_RESV)))
1748 btrfs_free_reserved_data_space_noquota(
1749 &inode->vfs_inode,
1750 state->start, len);
1751
1752 __percpu_counter_add(&fs_info->delalloc_bytes, -len,
1753 fs_info->delalloc_batch);
1754 spin_lock(&inode->lock);
1755 inode->delalloc_bytes -= len;
1756 if (do_list && inode->delalloc_bytes == 0 &&
1757 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1758 &inode->runtime_flags))
1759 btrfs_del_delalloc_inode(root, inode);
1760 spin_unlock(&inode->lock);
1761 }
1762 }
1763
1764 /*
1765 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1766 * we don't create bios that span stripes or chunks
1767 *
1768 * return 1 if page cannot be merged to bio
1769 * return 0 if page can be merged to bio
1770 * return error otherwise
1771 */
1772 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1773 size_t size, struct bio *bio,
1774 unsigned long bio_flags)
1775 {
1776 struct inode *inode = page->mapping->host;
1777 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1778 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1779 u64 length = 0;
1780 u64 map_length;
1781 int ret;
1782
1783 if (bio_flags & EXTENT_BIO_COMPRESSED)
1784 return 0;
1785
1786 length = bio->bi_iter.bi_size;
1787 map_length = length;
1788 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1789 NULL, 0);
1790 if (ret < 0)
1791 return ret;
1792 if (map_length < length + size)
1793 return 1;
1794 return 0;
1795 }
1796
1797 /*
1798 * in order to insert checksums into the metadata in large chunks,
1799 * we wait until bio submission time. All the pages in the bio are
1800 * checksummed and sums are attached onto the ordered extent record.
1801 *
1802 * At IO completion time the cums attached on the ordered extent record
1803 * are inserted into the btree
1804 */
1805 static int __btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
1806 int mirror_num, unsigned long bio_flags,
1807 u64 bio_offset)
1808 {
1809 int ret = 0;
1810
1811 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1812 BUG_ON(ret); /* -ENOMEM */
1813 return 0;
1814 }
1815
1816 /*
1817 * in order to insert checksums into the metadata in large chunks,
1818 * we wait until bio submission time. All the pages in the bio are
1819 * checksummed and sums are attached onto the ordered extent record.
1820 *
1821 * At IO completion time the cums attached on the ordered extent record
1822 * are inserted into the btree
1823 */
1824 static int __btrfs_submit_bio_done(struct inode *inode, struct bio *bio,
1825 int mirror_num, unsigned long bio_flags,
1826 u64 bio_offset)
1827 {
1828 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1829 int ret;
1830
1831 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1832 if (ret) {
1833 bio->bi_error = ret;
1834 bio_endio(bio);
1835 }
1836 return ret;
1837 }
1838
1839 /*
1840 * extent_io.c submission hook. This does the right thing for csum calculation
1841 * on write, or reading the csums from the tree before a read
1842 */
1843 static int btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
1844 int mirror_num, unsigned long bio_flags,
1845 u64 bio_offset)
1846 {
1847 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1848 struct btrfs_root *root = BTRFS_I(inode)->root;
1849 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1850 int ret = 0;
1851 int skip_sum;
1852 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1853
1854 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1855
1856 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
1857 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1858
1859 if (bio_op(bio) != REQ_OP_WRITE) {
1860 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
1861 if (ret)
1862 goto out;
1863
1864 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1865 ret = btrfs_submit_compressed_read(inode, bio,
1866 mirror_num,
1867 bio_flags);
1868 goto out;
1869 } else if (!skip_sum) {
1870 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
1871 if (ret)
1872 goto out;
1873 }
1874 goto mapit;
1875 } else if (async && !skip_sum) {
1876 /* csum items have already been cloned */
1877 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1878 goto mapit;
1879 /* we're doing a write, do the async checksumming */
1880 ret = btrfs_wq_submit_bio(fs_info, inode, bio, mirror_num,
1881 bio_flags, bio_offset,
1882 __btrfs_submit_bio_start,
1883 __btrfs_submit_bio_done);
1884 goto out;
1885 } else if (!skip_sum) {
1886 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1887 if (ret)
1888 goto out;
1889 }
1890
1891 mapit:
1892 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1893
1894 out:
1895 if (ret < 0) {
1896 bio->bi_error = ret;
1897 bio_endio(bio);
1898 }
1899 return ret;
1900 }
1901
1902 /*
1903 * given a list of ordered sums record them in the inode. This happens
1904 * at IO completion time based on sums calculated at bio submission time.
1905 */
1906 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1907 struct inode *inode, struct list_head *list)
1908 {
1909 struct btrfs_ordered_sum *sum;
1910
1911 list_for_each_entry(sum, list, list) {
1912 trans->adding_csums = 1;
1913 btrfs_csum_file_blocks(trans,
1914 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1915 trans->adding_csums = 0;
1916 }
1917 return 0;
1918 }
1919
1920 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1921 struct extent_state **cached_state, int dedupe)
1922 {
1923 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
1924 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1925 cached_state);
1926 }
1927
1928 /* see btrfs_writepage_start_hook for details on why this is required */
1929 struct btrfs_writepage_fixup {
1930 struct page *page;
1931 struct btrfs_work work;
1932 };
1933
1934 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1935 {
1936 struct btrfs_writepage_fixup *fixup;
1937 struct btrfs_ordered_extent *ordered;
1938 struct extent_state *cached_state = NULL;
1939 struct page *page;
1940 struct inode *inode;
1941 u64 page_start;
1942 u64 page_end;
1943 int ret;
1944
1945 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1946 page = fixup->page;
1947 again:
1948 lock_page(page);
1949 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1950 ClearPageChecked(page);
1951 goto out_page;
1952 }
1953
1954 inode = page->mapping->host;
1955 page_start = page_offset(page);
1956 page_end = page_offset(page) + PAGE_SIZE - 1;
1957
1958 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
1959 &cached_state);
1960
1961 /* already ordered? We're done */
1962 if (PagePrivate2(page))
1963 goto out;
1964
1965 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
1966 PAGE_SIZE);
1967 if (ordered) {
1968 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1969 page_end, &cached_state, GFP_NOFS);
1970 unlock_page(page);
1971 btrfs_start_ordered_extent(inode, ordered, 1);
1972 btrfs_put_ordered_extent(ordered);
1973 goto again;
1974 }
1975
1976 ret = btrfs_delalloc_reserve_space(inode, page_start,
1977 PAGE_SIZE);
1978 if (ret) {
1979 mapping_set_error(page->mapping, ret);
1980 end_extent_writepage(page, ret, page_start, page_end);
1981 ClearPageChecked(page);
1982 goto out;
1983 }
1984
1985 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state,
1986 0);
1987 ClearPageChecked(page);
1988 set_page_dirty(page);
1989 out:
1990 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1991 &cached_state, GFP_NOFS);
1992 out_page:
1993 unlock_page(page);
1994 put_page(page);
1995 kfree(fixup);
1996 }
1997
1998 /*
1999 * There are a few paths in the higher layers of the kernel that directly
2000 * set the page dirty bit without asking the filesystem if it is a
2001 * good idea. This causes problems because we want to make sure COW
2002 * properly happens and the data=ordered rules are followed.
2003 *
2004 * In our case any range that doesn't have the ORDERED bit set
2005 * hasn't been properly setup for IO. We kick off an async process
2006 * to fix it up. The async helper will wait for ordered extents, set
2007 * the delalloc bit and make it safe to write the page.
2008 */
2009 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2010 {
2011 struct inode *inode = page->mapping->host;
2012 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2013 struct btrfs_writepage_fixup *fixup;
2014
2015 /* this page is properly in the ordered list */
2016 if (TestClearPagePrivate2(page))
2017 return 0;
2018
2019 if (PageChecked(page))
2020 return -EAGAIN;
2021
2022 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2023 if (!fixup)
2024 return -EAGAIN;
2025
2026 SetPageChecked(page);
2027 get_page(page);
2028 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2029 btrfs_writepage_fixup_worker, NULL, NULL);
2030 fixup->page = page;
2031 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2032 return -EBUSY;
2033 }
2034
2035 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2036 struct inode *inode, u64 file_pos,
2037 u64 disk_bytenr, u64 disk_num_bytes,
2038 u64 num_bytes, u64 ram_bytes,
2039 u8 compression, u8 encryption,
2040 u16 other_encoding, int extent_type)
2041 {
2042 struct btrfs_root *root = BTRFS_I(inode)->root;
2043 struct btrfs_file_extent_item *fi;
2044 struct btrfs_path *path;
2045 struct extent_buffer *leaf;
2046 struct btrfs_key ins;
2047 int extent_inserted = 0;
2048 int ret;
2049
2050 path = btrfs_alloc_path();
2051 if (!path)
2052 return -ENOMEM;
2053
2054 /*
2055 * we may be replacing one extent in the tree with another.
2056 * The new extent is pinned in the extent map, and we don't want
2057 * to drop it from the cache until it is completely in the btree.
2058 *
2059 * So, tell btrfs_drop_extents to leave this extent in the cache.
2060 * the caller is expected to unpin it and allow it to be merged
2061 * with the others.
2062 */
2063 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2064 file_pos + num_bytes, NULL, 0,
2065 1, sizeof(*fi), &extent_inserted);
2066 if (ret)
2067 goto out;
2068
2069 if (!extent_inserted) {
2070 ins.objectid = btrfs_ino(BTRFS_I(inode));
2071 ins.offset = file_pos;
2072 ins.type = BTRFS_EXTENT_DATA_KEY;
2073
2074 path->leave_spinning = 1;
2075 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2076 sizeof(*fi));
2077 if (ret)
2078 goto out;
2079 }
2080 leaf = path->nodes[0];
2081 fi = btrfs_item_ptr(leaf, path->slots[0],
2082 struct btrfs_file_extent_item);
2083 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2084 btrfs_set_file_extent_type(leaf, fi, extent_type);
2085 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2086 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2087 btrfs_set_file_extent_offset(leaf, fi, 0);
2088 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2089 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2090 btrfs_set_file_extent_compression(leaf, fi, compression);
2091 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2092 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2093
2094 btrfs_mark_buffer_dirty(leaf);
2095 btrfs_release_path(path);
2096
2097 inode_add_bytes(inode, num_bytes);
2098
2099 ins.objectid = disk_bytenr;
2100 ins.offset = disk_num_bytes;
2101 ins.type = BTRFS_EXTENT_ITEM_KEY;
2102 ret = btrfs_alloc_reserved_file_extent(trans, root->root_key.objectid,
2103 btrfs_ino(BTRFS_I(inode)), file_pos, ram_bytes, &ins);
2104 /*
2105 * Release the reserved range from inode dirty range map, as it is
2106 * already moved into delayed_ref_head
2107 */
2108 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2109 out:
2110 btrfs_free_path(path);
2111
2112 return ret;
2113 }
2114
2115 /* snapshot-aware defrag */
2116 struct sa_defrag_extent_backref {
2117 struct rb_node node;
2118 struct old_sa_defrag_extent *old;
2119 u64 root_id;
2120 u64 inum;
2121 u64 file_pos;
2122 u64 extent_offset;
2123 u64 num_bytes;
2124 u64 generation;
2125 };
2126
2127 struct old_sa_defrag_extent {
2128 struct list_head list;
2129 struct new_sa_defrag_extent *new;
2130
2131 u64 extent_offset;
2132 u64 bytenr;
2133 u64 offset;
2134 u64 len;
2135 int count;
2136 };
2137
2138 struct new_sa_defrag_extent {
2139 struct rb_root root;
2140 struct list_head head;
2141 struct btrfs_path *path;
2142 struct inode *inode;
2143 u64 file_pos;
2144 u64 len;
2145 u64 bytenr;
2146 u64 disk_len;
2147 u8 compress_type;
2148 };
2149
2150 static int backref_comp(struct sa_defrag_extent_backref *b1,
2151 struct sa_defrag_extent_backref *b2)
2152 {
2153 if (b1->root_id < b2->root_id)
2154 return -1;
2155 else if (b1->root_id > b2->root_id)
2156 return 1;
2157
2158 if (b1->inum < b2->inum)
2159 return -1;
2160 else if (b1->inum > b2->inum)
2161 return 1;
2162
2163 if (b1->file_pos < b2->file_pos)
2164 return -1;
2165 else if (b1->file_pos > b2->file_pos)
2166 return 1;
2167
2168 /*
2169 * [------------------------------] ===> (a range of space)
2170 * |<--->| |<---->| =============> (fs/file tree A)
2171 * |<---------------------------->| ===> (fs/file tree B)
2172 *
2173 * A range of space can refer to two file extents in one tree while
2174 * refer to only one file extent in another tree.
2175 *
2176 * So we may process a disk offset more than one time(two extents in A)
2177 * and locate at the same extent(one extent in B), then insert two same
2178 * backrefs(both refer to the extent in B).
2179 */
2180 return 0;
2181 }
2182
2183 static void backref_insert(struct rb_root *root,
2184 struct sa_defrag_extent_backref *backref)
2185 {
2186 struct rb_node **p = &root->rb_node;
2187 struct rb_node *parent = NULL;
2188 struct sa_defrag_extent_backref *entry;
2189 int ret;
2190
2191 while (*p) {
2192 parent = *p;
2193 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2194
2195 ret = backref_comp(backref, entry);
2196 if (ret < 0)
2197 p = &(*p)->rb_left;
2198 else
2199 p = &(*p)->rb_right;
2200 }
2201
2202 rb_link_node(&backref->node, parent, p);
2203 rb_insert_color(&backref->node, root);
2204 }
2205
2206 /*
2207 * Note the backref might has changed, and in this case we just return 0.
2208 */
2209 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2210 void *ctx)
2211 {
2212 struct btrfs_file_extent_item *extent;
2213 struct old_sa_defrag_extent *old = ctx;
2214 struct new_sa_defrag_extent *new = old->new;
2215 struct btrfs_path *path = new->path;
2216 struct btrfs_key key;
2217 struct btrfs_root *root;
2218 struct sa_defrag_extent_backref *backref;
2219 struct extent_buffer *leaf;
2220 struct inode *inode = new->inode;
2221 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2222 int slot;
2223 int ret;
2224 u64 extent_offset;
2225 u64 num_bytes;
2226
2227 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2228 inum == btrfs_ino(BTRFS_I(inode)))
2229 return 0;
2230
2231 key.objectid = root_id;
2232 key.type = BTRFS_ROOT_ITEM_KEY;
2233 key.offset = (u64)-1;
2234
2235 root = btrfs_read_fs_root_no_name(fs_info, &key);
2236 if (IS_ERR(root)) {
2237 if (PTR_ERR(root) == -ENOENT)
2238 return 0;
2239 WARN_ON(1);
2240 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2241 inum, offset, root_id);
2242 return PTR_ERR(root);
2243 }
2244
2245 key.objectid = inum;
2246 key.type = BTRFS_EXTENT_DATA_KEY;
2247 if (offset > (u64)-1 << 32)
2248 key.offset = 0;
2249 else
2250 key.offset = offset;
2251
2252 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2253 if (WARN_ON(ret < 0))
2254 return ret;
2255 ret = 0;
2256
2257 while (1) {
2258 cond_resched();
2259
2260 leaf = path->nodes[0];
2261 slot = path->slots[0];
2262
2263 if (slot >= btrfs_header_nritems(leaf)) {
2264 ret = btrfs_next_leaf(root, path);
2265 if (ret < 0) {
2266 goto out;
2267 } else if (ret > 0) {
2268 ret = 0;
2269 goto out;
2270 }
2271 continue;
2272 }
2273
2274 path->slots[0]++;
2275
2276 btrfs_item_key_to_cpu(leaf, &key, slot);
2277
2278 if (key.objectid > inum)
2279 goto out;
2280
2281 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2282 continue;
2283
2284 extent = btrfs_item_ptr(leaf, slot,
2285 struct btrfs_file_extent_item);
2286
2287 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2288 continue;
2289
2290 /*
2291 * 'offset' refers to the exact key.offset,
2292 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2293 * (key.offset - extent_offset).
2294 */
2295 if (key.offset != offset)
2296 continue;
2297
2298 extent_offset = btrfs_file_extent_offset(leaf, extent);
2299 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2300
2301 if (extent_offset >= old->extent_offset + old->offset +
2302 old->len || extent_offset + num_bytes <=
2303 old->extent_offset + old->offset)
2304 continue;
2305 break;
2306 }
2307
2308 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2309 if (!backref) {
2310 ret = -ENOENT;
2311 goto out;
2312 }
2313
2314 backref->root_id = root_id;
2315 backref->inum = inum;
2316 backref->file_pos = offset;
2317 backref->num_bytes = num_bytes;
2318 backref->extent_offset = extent_offset;
2319 backref->generation = btrfs_file_extent_generation(leaf, extent);
2320 backref->old = old;
2321 backref_insert(&new->root, backref);
2322 old->count++;
2323 out:
2324 btrfs_release_path(path);
2325 WARN_ON(ret);
2326 return ret;
2327 }
2328
2329 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2330 struct new_sa_defrag_extent *new)
2331 {
2332 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2333 struct old_sa_defrag_extent *old, *tmp;
2334 int ret;
2335
2336 new->path = path;
2337
2338 list_for_each_entry_safe(old, tmp, &new->head, list) {
2339 ret = iterate_inodes_from_logical(old->bytenr +
2340 old->extent_offset, fs_info,
2341 path, record_one_backref,
2342 old);
2343 if (ret < 0 && ret != -ENOENT)
2344 return false;
2345
2346 /* no backref to be processed for this extent */
2347 if (!old->count) {
2348 list_del(&old->list);
2349 kfree(old);
2350 }
2351 }
2352
2353 if (list_empty(&new->head))
2354 return false;
2355
2356 return true;
2357 }
2358
2359 static int relink_is_mergable(struct extent_buffer *leaf,
2360 struct btrfs_file_extent_item *fi,
2361 struct new_sa_defrag_extent *new)
2362 {
2363 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2364 return 0;
2365
2366 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2367 return 0;
2368
2369 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2370 return 0;
2371
2372 if (btrfs_file_extent_encryption(leaf, fi) ||
2373 btrfs_file_extent_other_encoding(leaf, fi))
2374 return 0;
2375
2376 return 1;
2377 }
2378
2379 /*
2380 * Note the backref might has changed, and in this case we just return 0.
2381 */
2382 static noinline int relink_extent_backref(struct btrfs_path *path,
2383 struct sa_defrag_extent_backref *prev,
2384 struct sa_defrag_extent_backref *backref)
2385 {
2386 struct btrfs_file_extent_item *extent;
2387 struct btrfs_file_extent_item *item;
2388 struct btrfs_ordered_extent *ordered;
2389 struct btrfs_trans_handle *trans;
2390 struct btrfs_root *root;
2391 struct btrfs_key key;
2392 struct extent_buffer *leaf;
2393 struct old_sa_defrag_extent *old = backref->old;
2394 struct new_sa_defrag_extent *new = old->new;
2395 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2396 struct inode *inode;
2397 struct extent_state *cached = NULL;
2398 int ret = 0;
2399 u64 start;
2400 u64 len;
2401 u64 lock_start;
2402 u64 lock_end;
2403 bool merge = false;
2404 int index;
2405
2406 if (prev && prev->root_id == backref->root_id &&
2407 prev->inum == backref->inum &&
2408 prev->file_pos + prev->num_bytes == backref->file_pos)
2409 merge = true;
2410
2411 /* step 1: get root */
2412 key.objectid = backref->root_id;
2413 key.type = BTRFS_ROOT_ITEM_KEY;
2414 key.offset = (u64)-1;
2415
2416 index = srcu_read_lock(&fs_info->subvol_srcu);
2417
2418 root = btrfs_read_fs_root_no_name(fs_info, &key);
2419 if (IS_ERR(root)) {
2420 srcu_read_unlock(&fs_info->subvol_srcu, index);
2421 if (PTR_ERR(root) == -ENOENT)
2422 return 0;
2423 return PTR_ERR(root);
2424 }
2425
2426 if (btrfs_root_readonly(root)) {
2427 srcu_read_unlock(&fs_info->subvol_srcu, index);
2428 return 0;
2429 }
2430
2431 /* step 2: get inode */
2432 key.objectid = backref->inum;
2433 key.type = BTRFS_INODE_ITEM_KEY;
2434 key.offset = 0;
2435
2436 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2437 if (IS_ERR(inode)) {
2438 srcu_read_unlock(&fs_info->subvol_srcu, index);
2439 return 0;
2440 }
2441
2442 srcu_read_unlock(&fs_info->subvol_srcu, index);
2443
2444 /* step 3: relink backref */
2445 lock_start = backref->file_pos;
2446 lock_end = backref->file_pos + backref->num_bytes - 1;
2447 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2448 &cached);
2449
2450 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2451 if (ordered) {
2452 btrfs_put_ordered_extent(ordered);
2453 goto out_unlock;
2454 }
2455
2456 trans = btrfs_join_transaction(root);
2457 if (IS_ERR(trans)) {
2458 ret = PTR_ERR(trans);
2459 goto out_unlock;
2460 }
2461
2462 key.objectid = backref->inum;
2463 key.type = BTRFS_EXTENT_DATA_KEY;
2464 key.offset = backref->file_pos;
2465
2466 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2467 if (ret < 0) {
2468 goto out_free_path;
2469 } else if (ret > 0) {
2470 ret = 0;
2471 goto out_free_path;
2472 }
2473
2474 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2475 struct btrfs_file_extent_item);
2476
2477 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2478 backref->generation)
2479 goto out_free_path;
2480
2481 btrfs_release_path(path);
2482
2483 start = backref->file_pos;
2484 if (backref->extent_offset < old->extent_offset + old->offset)
2485 start += old->extent_offset + old->offset -
2486 backref->extent_offset;
2487
2488 len = min(backref->extent_offset + backref->num_bytes,
2489 old->extent_offset + old->offset + old->len);
2490 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2491
2492 ret = btrfs_drop_extents(trans, root, inode, start,
2493 start + len, 1);
2494 if (ret)
2495 goto out_free_path;
2496 again:
2497 key.objectid = btrfs_ino(BTRFS_I(inode));
2498 key.type = BTRFS_EXTENT_DATA_KEY;
2499 key.offset = start;
2500
2501 path->leave_spinning = 1;
2502 if (merge) {
2503 struct btrfs_file_extent_item *fi;
2504 u64 extent_len;
2505 struct btrfs_key found_key;
2506
2507 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2508 if (ret < 0)
2509 goto out_free_path;
2510
2511 path->slots[0]--;
2512 leaf = path->nodes[0];
2513 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2514
2515 fi = btrfs_item_ptr(leaf, path->slots[0],
2516 struct btrfs_file_extent_item);
2517 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2518
2519 if (extent_len + found_key.offset == start &&
2520 relink_is_mergable(leaf, fi, new)) {
2521 btrfs_set_file_extent_num_bytes(leaf, fi,
2522 extent_len + len);
2523 btrfs_mark_buffer_dirty(leaf);
2524 inode_add_bytes(inode, len);
2525
2526 ret = 1;
2527 goto out_free_path;
2528 } else {
2529 merge = false;
2530 btrfs_release_path(path);
2531 goto again;
2532 }
2533 }
2534
2535 ret = btrfs_insert_empty_item(trans, root, path, &key,
2536 sizeof(*extent));
2537 if (ret) {
2538 btrfs_abort_transaction(trans, ret);
2539 goto out_free_path;
2540 }
2541
2542 leaf = path->nodes[0];
2543 item = btrfs_item_ptr(leaf, path->slots[0],
2544 struct btrfs_file_extent_item);
2545 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2546 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2547 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2548 btrfs_set_file_extent_num_bytes(leaf, item, len);
2549 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2550 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2551 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2552 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2553 btrfs_set_file_extent_encryption(leaf, item, 0);
2554 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2555
2556 btrfs_mark_buffer_dirty(leaf);
2557 inode_add_bytes(inode, len);
2558 btrfs_release_path(path);
2559
2560 ret = btrfs_inc_extent_ref(trans, fs_info, new->bytenr,
2561 new->disk_len, 0,
2562 backref->root_id, backref->inum,
2563 new->file_pos); /* start - extent_offset */
2564 if (ret) {
2565 btrfs_abort_transaction(trans, ret);
2566 goto out_free_path;
2567 }
2568
2569 ret = 1;
2570 out_free_path:
2571 btrfs_release_path(path);
2572 path->leave_spinning = 0;
2573 btrfs_end_transaction(trans);
2574 out_unlock:
2575 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2576 &cached, GFP_NOFS);
2577 iput(inode);
2578 return ret;
2579 }
2580
2581 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2582 {
2583 struct old_sa_defrag_extent *old, *tmp;
2584
2585 if (!new)
2586 return;
2587
2588 list_for_each_entry_safe(old, tmp, &new->head, list) {
2589 kfree(old);
2590 }
2591 kfree(new);
2592 }
2593
2594 static void relink_file_extents(struct new_sa_defrag_extent *new)
2595 {
2596 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2597 struct btrfs_path *path;
2598 struct sa_defrag_extent_backref *backref;
2599 struct sa_defrag_extent_backref *prev = NULL;
2600 struct inode *inode;
2601 struct btrfs_root *root;
2602 struct rb_node *node;
2603 int ret;
2604
2605 inode = new->inode;
2606 root = BTRFS_I(inode)->root;
2607
2608 path = btrfs_alloc_path();
2609 if (!path)
2610 return;
2611
2612 if (!record_extent_backrefs(path, new)) {
2613 btrfs_free_path(path);
2614 goto out;
2615 }
2616 btrfs_release_path(path);
2617
2618 while (1) {
2619 node = rb_first(&new->root);
2620 if (!node)
2621 break;
2622 rb_erase(node, &new->root);
2623
2624 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2625
2626 ret = relink_extent_backref(path, prev, backref);
2627 WARN_ON(ret < 0);
2628
2629 kfree(prev);
2630
2631 if (ret == 1)
2632 prev = backref;
2633 else
2634 prev = NULL;
2635 cond_resched();
2636 }
2637 kfree(prev);
2638
2639 btrfs_free_path(path);
2640 out:
2641 free_sa_defrag_extent(new);
2642
2643 atomic_dec(&fs_info->defrag_running);
2644 wake_up(&fs_info->transaction_wait);
2645 }
2646
2647 static struct new_sa_defrag_extent *
2648 record_old_file_extents(struct inode *inode,
2649 struct btrfs_ordered_extent *ordered)
2650 {
2651 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2652 struct btrfs_root *root = BTRFS_I(inode)->root;
2653 struct btrfs_path *path;
2654 struct btrfs_key key;
2655 struct old_sa_defrag_extent *old;
2656 struct new_sa_defrag_extent *new;
2657 int ret;
2658
2659 new = kmalloc(sizeof(*new), GFP_NOFS);
2660 if (!new)
2661 return NULL;
2662
2663 new->inode = inode;
2664 new->file_pos = ordered->file_offset;
2665 new->len = ordered->len;
2666 new->bytenr = ordered->start;
2667 new->disk_len = ordered->disk_len;
2668 new->compress_type = ordered->compress_type;
2669 new->root = RB_ROOT;
2670 INIT_LIST_HEAD(&new->head);
2671
2672 path = btrfs_alloc_path();
2673 if (!path)
2674 goto out_kfree;
2675
2676 key.objectid = btrfs_ino(BTRFS_I(inode));
2677 key.type = BTRFS_EXTENT_DATA_KEY;
2678 key.offset = new->file_pos;
2679
2680 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2681 if (ret < 0)
2682 goto out_free_path;
2683 if (ret > 0 && path->slots[0] > 0)
2684 path->slots[0]--;
2685
2686 /* find out all the old extents for the file range */
2687 while (1) {
2688 struct btrfs_file_extent_item *extent;
2689 struct extent_buffer *l;
2690 int slot;
2691 u64 num_bytes;
2692 u64 offset;
2693 u64 end;
2694 u64 disk_bytenr;
2695 u64 extent_offset;
2696
2697 l = path->nodes[0];
2698 slot = path->slots[0];
2699
2700 if (slot >= btrfs_header_nritems(l)) {
2701 ret = btrfs_next_leaf(root, path);
2702 if (ret < 0)
2703 goto out_free_path;
2704 else if (ret > 0)
2705 break;
2706 continue;
2707 }
2708
2709 btrfs_item_key_to_cpu(l, &key, slot);
2710
2711 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2712 break;
2713 if (key.type != BTRFS_EXTENT_DATA_KEY)
2714 break;
2715 if (key.offset >= new->file_pos + new->len)
2716 break;
2717
2718 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2719
2720 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2721 if (key.offset + num_bytes < new->file_pos)
2722 goto next;
2723
2724 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2725 if (!disk_bytenr)
2726 goto next;
2727
2728 extent_offset = btrfs_file_extent_offset(l, extent);
2729
2730 old = kmalloc(sizeof(*old), GFP_NOFS);
2731 if (!old)
2732 goto out_free_path;
2733
2734 offset = max(new->file_pos, key.offset);
2735 end = min(new->file_pos + new->len, key.offset + num_bytes);
2736
2737 old->bytenr = disk_bytenr;
2738 old->extent_offset = extent_offset;
2739 old->offset = offset - key.offset;
2740 old->len = end - offset;
2741 old->new = new;
2742 old->count = 0;
2743 list_add_tail(&old->list, &new->head);
2744 next:
2745 path->slots[0]++;
2746 cond_resched();
2747 }
2748
2749 btrfs_free_path(path);
2750 atomic_inc(&fs_info->defrag_running);
2751
2752 return new;
2753
2754 out_free_path:
2755 btrfs_free_path(path);
2756 out_kfree:
2757 free_sa_defrag_extent(new);
2758 return NULL;
2759 }
2760
2761 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2762 u64 start, u64 len)
2763 {
2764 struct btrfs_block_group_cache *cache;
2765
2766 cache = btrfs_lookup_block_group(fs_info, start);
2767 ASSERT(cache);
2768
2769 spin_lock(&cache->lock);
2770 cache->delalloc_bytes -= len;
2771 spin_unlock(&cache->lock);
2772
2773 btrfs_put_block_group(cache);
2774 }
2775
2776 /* as ordered data IO finishes, this gets called so we can finish
2777 * an ordered extent if the range of bytes in the file it covers are
2778 * fully written.
2779 */
2780 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2781 {
2782 struct inode *inode = ordered_extent->inode;
2783 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2784 struct btrfs_root *root = BTRFS_I(inode)->root;
2785 struct btrfs_trans_handle *trans = NULL;
2786 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2787 struct extent_state *cached_state = NULL;
2788 struct new_sa_defrag_extent *new = NULL;
2789 int compress_type = 0;
2790 int ret = 0;
2791 u64 logical_len = ordered_extent->len;
2792 bool nolock;
2793 bool truncated = false;
2794
2795 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2796
2797 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2798 ret = -EIO;
2799 goto out;
2800 }
2801
2802 btrfs_free_io_failure_record(BTRFS_I(inode),
2803 ordered_extent->file_offset,
2804 ordered_extent->file_offset +
2805 ordered_extent->len - 1);
2806
2807 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2808 truncated = true;
2809 logical_len = ordered_extent->truncated_len;
2810 /* Truncated the entire extent, don't bother adding */
2811 if (!logical_len)
2812 goto out;
2813 }
2814
2815 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2816 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2817
2818 /*
2819 * For mwrite(mmap + memset to write) case, we still reserve
2820 * space for NOCOW range.
2821 * As NOCOW won't cause a new delayed ref, just free the space
2822 */
2823 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2824 ordered_extent->len);
2825 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2826 if (nolock)
2827 trans = btrfs_join_transaction_nolock(root);
2828 else
2829 trans = btrfs_join_transaction(root);
2830 if (IS_ERR(trans)) {
2831 ret = PTR_ERR(trans);
2832 trans = NULL;
2833 goto out;
2834 }
2835 trans->block_rsv = &fs_info->delalloc_block_rsv;
2836 ret = btrfs_update_inode_fallback(trans, root, inode);
2837 if (ret) /* -ENOMEM or corruption */
2838 btrfs_abort_transaction(trans, ret);
2839 goto out;
2840 }
2841
2842 lock_extent_bits(io_tree, ordered_extent->file_offset,
2843 ordered_extent->file_offset + ordered_extent->len - 1,
2844 &cached_state);
2845
2846 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2847 ordered_extent->file_offset + ordered_extent->len - 1,
2848 EXTENT_DEFRAG, 1, cached_state);
2849 if (ret) {
2850 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2851 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2852 /* the inode is shared */
2853 new = record_old_file_extents(inode, ordered_extent);
2854
2855 clear_extent_bit(io_tree, ordered_extent->file_offset,
2856 ordered_extent->file_offset + ordered_extent->len - 1,
2857 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2858 }
2859
2860 if (nolock)
2861 trans = btrfs_join_transaction_nolock(root);
2862 else
2863 trans = btrfs_join_transaction(root);
2864 if (IS_ERR(trans)) {
2865 ret = PTR_ERR(trans);
2866 trans = NULL;
2867 goto out_unlock;
2868 }
2869
2870 trans->block_rsv = &fs_info->delalloc_block_rsv;
2871
2872 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2873 compress_type = ordered_extent->compress_type;
2874 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2875 BUG_ON(compress_type);
2876 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
2877 ordered_extent->file_offset,
2878 ordered_extent->file_offset +
2879 logical_len);
2880 } else {
2881 BUG_ON(root == fs_info->tree_root);
2882 ret = insert_reserved_file_extent(trans, inode,
2883 ordered_extent->file_offset,
2884 ordered_extent->start,
2885 ordered_extent->disk_len,
2886 logical_len, logical_len,
2887 compress_type, 0, 0,
2888 BTRFS_FILE_EXTENT_REG);
2889 if (!ret)
2890 btrfs_release_delalloc_bytes(fs_info,
2891 ordered_extent->start,
2892 ordered_extent->disk_len);
2893 }
2894 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2895 ordered_extent->file_offset, ordered_extent->len,
2896 trans->transid);
2897 if (ret < 0) {
2898 btrfs_abort_transaction(trans, ret);
2899 goto out_unlock;
2900 }
2901
2902 add_pending_csums(trans, inode, &ordered_extent->list);
2903
2904 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2905 ret = btrfs_update_inode_fallback(trans, root, inode);
2906 if (ret) { /* -ENOMEM or corruption */
2907 btrfs_abort_transaction(trans, ret);
2908 goto out_unlock;
2909 }
2910 ret = 0;
2911 out_unlock:
2912 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2913 ordered_extent->file_offset +
2914 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2915 out:
2916 if (root != fs_info->tree_root)
2917 btrfs_delalloc_release_metadata(BTRFS_I(inode),
2918 ordered_extent->len);
2919 if (trans)
2920 btrfs_end_transaction(trans);
2921
2922 if (ret || truncated) {
2923 u64 start, end;
2924
2925 if (truncated)
2926 start = ordered_extent->file_offset + logical_len;
2927 else
2928 start = ordered_extent->file_offset;
2929 end = ordered_extent->file_offset + ordered_extent->len - 1;
2930 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2931
2932 /* Drop the cache for the part of the extent we didn't write. */
2933 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
2934
2935 /*
2936 * If the ordered extent had an IOERR or something else went
2937 * wrong we need to return the space for this ordered extent
2938 * back to the allocator. We only free the extent in the
2939 * truncated case if we didn't write out the extent at all.
2940 */
2941 if ((ret || !logical_len) &&
2942 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2943 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2944 btrfs_free_reserved_extent(fs_info,
2945 ordered_extent->start,
2946 ordered_extent->disk_len, 1);
2947 }
2948
2949
2950 /*
2951 * This needs to be done to make sure anybody waiting knows we are done
2952 * updating everything for this ordered extent.
2953 */
2954 btrfs_remove_ordered_extent(inode, ordered_extent);
2955
2956 /* for snapshot-aware defrag */
2957 if (new) {
2958 if (ret) {
2959 free_sa_defrag_extent(new);
2960 atomic_dec(&fs_info->defrag_running);
2961 } else {
2962 relink_file_extents(new);
2963 }
2964 }
2965
2966 /* once for us */
2967 btrfs_put_ordered_extent(ordered_extent);
2968 /* once for the tree */
2969 btrfs_put_ordered_extent(ordered_extent);
2970
2971 return ret;
2972 }
2973
2974 static void finish_ordered_fn(struct btrfs_work *work)
2975 {
2976 struct btrfs_ordered_extent *ordered_extent;
2977 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2978 btrfs_finish_ordered_io(ordered_extent);
2979 }
2980
2981 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2982 struct extent_state *state, int uptodate)
2983 {
2984 struct inode *inode = page->mapping->host;
2985 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2986 struct btrfs_ordered_extent *ordered_extent = NULL;
2987 struct btrfs_workqueue *wq;
2988 btrfs_work_func_t func;
2989
2990 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2991
2992 ClearPagePrivate2(page);
2993 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2994 end - start + 1, uptodate))
2995 return;
2996
2997 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
2998 wq = fs_info->endio_freespace_worker;
2999 func = btrfs_freespace_write_helper;
3000 } else {
3001 wq = fs_info->endio_write_workers;
3002 func = btrfs_endio_write_helper;
3003 }
3004
3005 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3006 NULL);
3007 btrfs_queue_work(wq, &ordered_extent->work);
3008 }
3009
3010 static int __readpage_endio_check(struct inode *inode,
3011 struct btrfs_io_bio *io_bio,
3012 int icsum, struct page *page,
3013 int pgoff, u64 start, size_t len)
3014 {
3015 char *kaddr;
3016 u32 csum_expected;
3017 u32 csum = ~(u32)0;
3018
3019 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3020
3021 kaddr = kmap_atomic(page);
3022 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3023 btrfs_csum_final(csum, (u8 *)&csum);
3024 if (csum != csum_expected)
3025 goto zeroit;
3026
3027 kunmap_atomic(kaddr);
3028 return 0;
3029 zeroit:
3030 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3031 io_bio->mirror_num);
3032 memset(kaddr + pgoff, 1, len);
3033 flush_dcache_page(page);
3034 kunmap_atomic(kaddr);
3035 if (csum_expected == 0)
3036 return 0;
3037 return -EIO;
3038 }
3039
3040 /*
3041 * when reads are done, we need to check csums to verify the data is correct
3042 * if there's a match, we allow the bio to finish. If not, the code in
3043 * extent_io.c will try to find good copies for us.
3044 */
3045 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3046 u64 phy_offset, struct page *page,
3047 u64 start, u64 end, int mirror)
3048 {
3049 size_t offset = start - page_offset(page);
3050 struct inode *inode = page->mapping->host;
3051 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3052 struct btrfs_root *root = BTRFS_I(inode)->root;
3053
3054 if (PageChecked(page)) {
3055 ClearPageChecked(page);
3056 return 0;
3057 }
3058
3059 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3060 return 0;
3061
3062 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3063 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3064 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3065 return 0;
3066 }
3067
3068 phy_offset >>= inode->i_sb->s_blocksize_bits;
3069 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3070 start, (size_t)(end - start + 1));
3071 }
3072
3073 void btrfs_add_delayed_iput(struct inode *inode)
3074 {
3075 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3076 struct btrfs_inode *binode = BTRFS_I(inode);
3077
3078 if (atomic_add_unless(&inode->i_count, -1, 1))
3079 return;
3080
3081 spin_lock(&fs_info->delayed_iput_lock);
3082 if (binode->delayed_iput_count == 0) {
3083 ASSERT(list_empty(&binode->delayed_iput));
3084 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3085 } else {
3086 binode->delayed_iput_count++;
3087 }
3088 spin_unlock(&fs_info->delayed_iput_lock);
3089 }
3090
3091 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3092 {
3093
3094 spin_lock(&fs_info->delayed_iput_lock);
3095 while (!list_empty(&fs_info->delayed_iputs)) {
3096 struct btrfs_inode *inode;
3097
3098 inode = list_first_entry(&fs_info->delayed_iputs,
3099 struct btrfs_inode, delayed_iput);
3100 if (inode->delayed_iput_count) {
3101 inode->delayed_iput_count--;
3102 list_move_tail(&inode->delayed_iput,
3103 &fs_info->delayed_iputs);
3104 } else {
3105 list_del_init(&inode->delayed_iput);
3106 }
3107 spin_unlock(&fs_info->delayed_iput_lock);
3108 iput(&inode->vfs_inode);
3109 spin_lock(&fs_info->delayed_iput_lock);
3110 }
3111 spin_unlock(&fs_info->delayed_iput_lock);
3112 }
3113
3114 /*
3115 * This is called in transaction commit time. If there are no orphan
3116 * files in the subvolume, it removes orphan item and frees block_rsv
3117 * structure.
3118 */
3119 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3120 struct btrfs_root *root)
3121 {
3122 struct btrfs_fs_info *fs_info = root->fs_info;
3123 struct btrfs_block_rsv *block_rsv;
3124 int ret;
3125
3126 if (atomic_read(&root->orphan_inodes) ||
3127 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3128 return;
3129
3130 spin_lock(&root->orphan_lock);
3131 if (atomic_read(&root->orphan_inodes)) {
3132 spin_unlock(&root->orphan_lock);
3133 return;
3134 }
3135
3136 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3137 spin_unlock(&root->orphan_lock);
3138 return;
3139 }
3140
3141 block_rsv = root->orphan_block_rsv;
3142 root->orphan_block_rsv = NULL;
3143 spin_unlock(&root->orphan_lock);
3144
3145 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3146 btrfs_root_refs(&root->root_item) > 0) {
3147 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3148 root->root_key.objectid);
3149 if (ret)
3150 btrfs_abort_transaction(trans, ret);
3151 else
3152 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3153 &root->state);
3154 }
3155
3156 if (block_rsv) {
3157 WARN_ON(block_rsv->size > 0);
3158 btrfs_free_block_rsv(fs_info, block_rsv);
3159 }
3160 }
3161
3162 /*
3163 * This creates an orphan entry for the given inode in case something goes
3164 * wrong in the middle of an unlink/truncate.
3165 *
3166 * NOTE: caller of this function should reserve 5 units of metadata for
3167 * this function.
3168 */
3169 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3170 struct btrfs_inode *inode)
3171 {
3172 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3173 struct btrfs_root *root = inode->root;
3174 struct btrfs_block_rsv *block_rsv = NULL;
3175 int reserve = 0;
3176 int insert = 0;
3177 int ret;
3178
3179 if (!root->orphan_block_rsv) {
3180 block_rsv = btrfs_alloc_block_rsv(fs_info,
3181 BTRFS_BLOCK_RSV_TEMP);
3182 if (!block_rsv)
3183 return -ENOMEM;
3184 }
3185
3186 spin_lock(&root->orphan_lock);
3187 if (!root->orphan_block_rsv) {
3188 root->orphan_block_rsv = block_rsv;
3189 } else if (block_rsv) {
3190 btrfs_free_block_rsv(fs_info, block_rsv);
3191 block_rsv = NULL;
3192 }
3193
3194 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3195 &inode->runtime_flags)) {
3196 #if 0
3197 /*
3198 * For proper ENOSPC handling, we should do orphan
3199 * cleanup when mounting. But this introduces backward
3200 * compatibility issue.
3201 */
3202 if (!xchg(&root->orphan_item_inserted, 1))
3203 insert = 2;
3204 else
3205 insert = 1;
3206 #endif
3207 insert = 1;
3208 atomic_inc(&root->orphan_inodes);
3209 }
3210
3211 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3212 &inode->runtime_flags))
3213 reserve = 1;
3214 spin_unlock(&root->orphan_lock);
3215
3216 /* grab metadata reservation from transaction handle */
3217 if (reserve) {
3218 ret = btrfs_orphan_reserve_metadata(trans, inode);
3219 ASSERT(!ret);
3220 if (ret) {
3221 atomic_dec(&root->orphan_inodes);
3222 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3223 &inode->runtime_flags);
3224 if (insert)
3225 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3226 &inode->runtime_flags);
3227 return ret;
3228 }
3229 }
3230
3231 /* insert an orphan item to track this unlinked/truncated file */
3232 if (insert >= 1) {
3233 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3234 if (ret) {
3235 atomic_dec(&root->orphan_inodes);
3236 if (reserve) {
3237 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3238 &inode->runtime_flags);
3239 btrfs_orphan_release_metadata(inode);
3240 }
3241 if (ret != -EEXIST) {
3242 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3243 &inode->runtime_flags);
3244 btrfs_abort_transaction(trans, ret);
3245 return ret;
3246 }
3247 }
3248 ret = 0;
3249 }
3250
3251 /* insert an orphan item to track subvolume contains orphan files */
3252 if (insert >= 2) {
3253 ret = btrfs_insert_orphan_item(trans, fs_info->tree_root,
3254 root->root_key.objectid);
3255 if (ret && ret != -EEXIST) {
3256 btrfs_abort_transaction(trans, ret);
3257 return ret;
3258 }
3259 }
3260 return 0;
3261 }
3262
3263 /*
3264 * We have done the truncate/delete so we can go ahead and remove the orphan
3265 * item for this particular inode.
3266 */
3267 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3268 struct btrfs_inode *inode)
3269 {
3270 struct btrfs_root *root = inode->root;
3271 int delete_item = 0;
3272 int release_rsv = 0;
3273 int ret = 0;
3274
3275 spin_lock(&root->orphan_lock);
3276 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3277 &inode->runtime_flags))
3278 delete_item = 1;
3279
3280 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3281 &inode->runtime_flags))
3282 release_rsv = 1;
3283 spin_unlock(&root->orphan_lock);
3284
3285 if (delete_item) {
3286 atomic_dec(&root->orphan_inodes);
3287 if (trans)
3288 ret = btrfs_del_orphan_item(trans, root,
3289 btrfs_ino(inode));
3290 }
3291
3292 if (release_rsv)
3293 btrfs_orphan_release_metadata(inode);
3294
3295 return ret;
3296 }
3297
3298 /*
3299 * this cleans up any orphans that may be left on the list from the last use
3300 * of this root.
3301 */
3302 int btrfs_orphan_cleanup(struct btrfs_root *root)
3303 {
3304 struct btrfs_fs_info *fs_info = root->fs_info;
3305 struct btrfs_path *path;
3306 struct extent_buffer *leaf;
3307 struct btrfs_key key, found_key;
3308 struct btrfs_trans_handle *trans;
3309 struct inode *inode;
3310 u64 last_objectid = 0;
3311 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3312
3313 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3314 return 0;
3315
3316 path = btrfs_alloc_path();
3317 if (!path) {
3318 ret = -ENOMEM;
3319 goto out;
3320 }
3321 path->reada = READA_BACK;
3322
3323 key.objectid = BTRFS_ORPHAN_OBJECTID;
3324 key.type = BTRFS_ORPHAN_ITEM_KEY;
3325 key.offset = (u64)-1;
3326
3327 while (1) {
3328 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3329 if (ret < 0)
3330 goto out;
3331
3332 /*
3333 * if ret == 0 means we found what we were searching for, which
3334 * is weird, but possible, so only screw with path if we didn't
3335 * find the key and see if we have stuff that matches
3336 */
3337 if (ret > 0) {
3338 ret = 0;
3339 if (path->slots[0] == 0)
3340 break;
3341 path->slots[0]--;
3342 }
3343
3344 /* pull out the item */
3345 leaf = path->nodes[0];
3346 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3347
3348 /* make sure the item matches what we want */
3349 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3350 break;
3351 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3352 break;
3353
3354 /* release the path since we're done with it */
3355 btrfs_release_path(path);
3356
3357 /*
3358 * this is where we are basically btrfs_lookup, without the
3359 * crossing root thing. we store the inode number in the
3360 * offset of the orphan item.
3361 */
3362
3363 if (found_key.offset == last_objectid) {
3364 btrfs_err(fs_info,
3365 "Error removing orphan entry, stopping orphan cleanup");
3366 ret = -EINVAL;
3367 goto out;
3368 }
3369
3370 last_objectid = found_key.offset;
3371
3372 found_key.objectid = found_key.offset;
3373 found_key.type = BTRFS_INODE_ITEM_KEY;
3374 found_key.offset = 0;
3375 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3376 ret = PTR_ERR_OR_ZERO(inode);
3377 if (ret && ret != -ENOENT)
3378 goto out;
3379
3380 if (ret == -ENOENT && root == fs_info->tree_root) {
3381 struct btrfs_root *dead_root;
3382 struct btrfs_fs_info *fs_info = root->fs_info;
3383 int is_dead_root = 0;
3384
3385 /*
3386 * this is an orphan in the tree root. Currently these
3387 * could come from 2 sources:
3388 * a) a snapshot deletion in progress
3389 * b) a free space cache inode
3390 * We need to distinguish those two, as the snapshot
3391 * orphan must not get deleted.
3392 * find_dead_roots already ran before us, so if this
3393 * is a snapshot deletion, we should find the root
3394 * in the dead_roots list
3395 */
3396 spin_lock(&fs_info->trans_lock);
3397 list_for_each_entry(dead_root, &fs_info->dead_roots,
3398 root_list) {
3399 if (dead_root->root_key.objectid ==
3400 found_key.objectid) {
3401 is_dead_root = 1;
3402 break;
3403 }
3404 }
3405 spin_unlock(&fs_info->trans_lock);
3406 if (is_dead_root) {
3407 /* prevent this orphan from being found again */
3408 key.offset = found_key.objectid - 1;
3409 continue;
3410 }
3411 }
3412 /*
3413 * Inode is already gone but the orphan item is still there,
3414 * kill the orphan item.
3415 */
3416 if (ret == -ENOENT) {
3417 trans = btrfs_start_transaction(root, 1);
3418 if (IS_ERR(trans)) {
3419 ret = PTR_ERR(trans);
3420 goto out;
3421 }
3422 btrfs_debug(fs_info, "auto deleting %Lu",
3423 found_key.objectid);
3424 ret = btrfs_del_orphan_item(trans, root,
3425 found_key.objectid);
3426 btrfs_end_transaction(trans);
3427 if (ret)
3428 goto out;
3429 continue;
3430 }
3431
3432 /*
3433 * add this inode to the orphan list so btrfs_orphan_del does
3434 * the proper thing when we hit it
3435 */
3436 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3437 &BTRFS_I(inode)->runtime_flags);
3438 atomic_inc(&root->orphan_inodes);
3439
3440 /* if we have links, this was a truncate, lets do that */
3441 if (inode->i_nlink) {
3442 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3443 iput(inode);
3444 continue;
3445 }
3446 nr_truncate++;
3447
3448 /* 1 for the orphan item deletion. */
3449 trans = btrfs_start_transaction(root, 1);
3450 if (IS_ERR(trans)) {
3451 iput(inode);
3452 ret = PTR_ERR(trans);
3453 goto out;
3454 }
3455 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3456 btrfs_end_transaction(trans);
3457 if (ret) {
3458 iput(inode);
3459 goto out;
3460 }
3461
3462 ret = btrfs_truncate(inode);
3463 if (ret)
3464 btrfs_orphan_del(NULL, BTRFS_I(inode));
3465 } else {
3466 nr_unlink++;
3467 }
3468
3469 /* this will do delete_inode and everything for us */
3470 iput(inode);
3471 if (ret)
3472 goto out;
3473 }
3474 /* release the path since we're done with it */
3475 btrfs_release_path(path);
3476
3477 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3478
3479 if (root->orphan_block_rsv)
3480 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3481 (u64)-1);
3482
3483 if (root->orphan_block_rsv ||
3484 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3485 trans = btrfs_join_transaction(root);
3486 if (!IS_ERR(trans))
3487 btrfs_end_transaction(trans);
3488 }
3489
3490 if (nr_unlink)
3491 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3492 if (nr_truncate)
3493 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3494
3495 out:
3496 if (ret)
3497 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3498 btrfs_free_path(path);
3499 return ret;
3500 }
3501
3502 /*
3503 * very simple check to peek ahead in the leaf looking for xattrs. If we
3504 * don't find any xattrs, we know there can't be any acls.
3505 *
3506 * slot is the slot the inode is in, objectid is the objectid of the inode
3507 */
3508 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3509 int slot, u64 objectid,
3510 int *first_xattr_slot)
3511 {
3512 u32 nritems = btrfs_header_nritems(leaf);
3513 struct btrfs_key found_key;
3514 static u64 xattr_access = 0;
3515 static u64 xattr_default = 0;
3516 int scanned = 0;
3517
3518 if (!xattr_access) {
3519 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3520 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3521 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3522 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3523 }
3524
3525 slot++;
3526 *first_xattr_slot = -1;
3527 while (slot < nritems) {
3528 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3529
3530 /* we found a different objectid, there must not be acls */
3531 if (found_key.objectid != objectid)
3532 return 0;
3533
3534 /* we found an xattr, assume we've got an acl */
3535 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3536 if (*first_xattr_slot == -1)
3537 *first_xattr_slot = slot;
3538 if (found_key.offset == xattr_access ||
3539 found_key.offset == xattr_default)
3540 return 1;
3541 }
3542
3543 /*
3544 * we found a key greater than an xattr key, there can't
3545 * be any acls later on
3546 */
3547 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3548 return 0;
3549
3550 slot++;
3551 scanned++;
3552
3553 /*
3554 * it goes inode, inode backrefs, xattrs, extents,
3555 * so if there are a ton of hard links to an inode there can
3556 * be a lot of backrefs. Don't waste time searching too hard,
3557 * this is just an optimization
3558 */
3559 if (scanned >= 8)
3560 break;
3561 }
3562 /* we hit the end of the leaf before we found an xattr or
3563 * something larger than an xattr. We have to assume the inode
3564 * has acls
3565 */
3566 if (*first_xattr_slot == -1)
3567 *first_xattr_slot = slot;
3568 return 1;
3569 }
3570
3571 /*
3572 * read an inode from the btree into the in-memory inode
3573 */
3574 static int btrfs_read_locked_inode(struct inode *inode)
3575 {
3576 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3577 struct btrfs_path *path;
3578 struct extent_buffer *leaf;
3579 struct btrfs_inode_item *inode_item;
3580 struct btrfs_root *root = BTRFS_I(inode)->root;
3581 struct btrfs_key location;
3582 unsigned long ptr;
3583 int maybe_acls;
3584 u32 rdev;
3585 int ret;
3586 bool filled = false;
3587 int first_xattr_slot;
3588
3589 ret = btrfs_fill_inode(inode, &rdev);
3590 if (!ret)
3591 filled = true;
3592
3593 path = btrfs_alloc_path();
3594 if (!path) {
3595 ret = -ENOMEM;
3596 goto make_bad;
3597 }
3598
3599 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3600
3601 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3602 if (ret) {
3603 if (ret > 0)
3604 ret = -ENOENT;
3605 goto make_bad;
3606 }
3607
3608 leaf = path->nodes[0];
3609
3610 if (filled)
3611 goto cache_index;
3612
3613 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3614 struct btrfs_inode_item);
3615 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3616 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3617 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3618 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3619 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3620
3621 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3622 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3623
3624 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3625 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3626
3627 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3628 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3629
3630 BTRFS_I(inode)->i_otime.tv_sec =
3631 btrfs_timespec_sec(leaf, &inode_item->otime);
3632 BTRFS_I(inode)->i_otime.tv_nsec =
3633 btrfs_timespec_nsec(leaf, &inode_item->otime);
3634
3635 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3636 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3637 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3638
3639 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3640 inode->i_generation = BTRFS_I(inode)->generation;
3641 inode->i_rdev = 0;
3642 rdev = btrfs_inode_rdev(leaf, inode_item);
3643
3644 BTRFS_I(inode)->index_cnt = (u64)-1;
3645 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3646
3647 cache_index:
3648 /*
3649 * If we were modified in the current generation and evicted from memory
3650 * and then re-read we need to do a full sync since we don't have any
3651 * idea about which extents were modified before we were evicted from
3652 * cache.
3653 *
3654 * This is required for both inode re-read from disk and delayed inode
3655 * in delayed_nodes_tree.
3656 */
3657 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3658 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3659 &BTRFS_I(inode)->runtime_flags);
3660
3661 /*
3662 * We don't persist the id of the transaction where an unlink operation
3663 * against the inode was last made. So here we assume the inode might
3664 * have been evicted, and therefore the exact value of last_unlink_trans
3665 * lost, and set it to last_trans to avoid metadata inconsistencies
3666 * between the inode and its parent if the inode is fsync'ed and the log
3667 * replayed. For example, in the scenario:
3668 *
3669 * touch mydir/foo
3670 * ln mydir/foo mydir/bar
3671 * sync
3672 * unlink mydir/bar
3673 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3674 * xfs_io -c fsync mydir/foo
3675 * <power failure>
3676 * mount fs, triggers fsync log replay
3677 *
3678 * We must make sure that when we fsync our inode foo we also log its
3679 * parent inode, otherwise after log replay the parent still has the
3680 * dentry with the "bar" name but our inode foo has a link count of 1
3681 * and doesn't have an inode ref with the name "bar" anymore.
3682 *
3683 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3684 * but it guarantees correctness at the expense of occasional full
3685 * transaction commits on fsync if our inode is a directory, or if our
3686 * inode is not a directory, logging its parent unnecessarily.
3687 */
3688 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3689
3690 path->slots[0]++;
3691 if (inode->i_nlink != 1 ||
3692 path->slots[0] >= btrfs_header_nritems(leaf))
3693 goto cache_acl;
3694
3695 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3696 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3697 goto cache_acl;
3698
3699 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3700 if (location.type == BTRFS_INODE_REF_KEY) {
3701 struct btrfs_inode_ref *ref;
3702
3703 ref = (struct btrfs_inode_ref *)ptr;
3704 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3705 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3706 struct btrfs_inode_extref *extref;
3707
3708 extref = (struct btrfs_inode_extref *)ptr;
3709 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3710 extref);
3711 }
3712 cache_acl:
3713 /*
3714 * try to precache a NULL acl entry for files that don't have
3715 * any xattrs or acls
3716 */
3717 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3718 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3719 if (first_xattr_slot != -1) {
3720 path->slots[0] = first_xattr_slot;
3721 ret = btrfs_load_inode_props(inode, path);
3722 if (ret)
3723 btrfs_err(fs_info,
3724 "error loading props for ino %llu (root %llu): %d",
3725 btrfs_ino(BTRFS_I(inode)),
3726 root->root_key.objectid, ret);
3727 }
3728 btrfs_free_path(path);
3729
3730 if (!maybe_acls)
3731 cache_no_acl(inode);
3732
3733 switch (inode->i_mode & S_IFMT) {
3734 case S_IFREG:
3735 inode->i_mapping->a_ops = &btrfs_aops;
3736 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3737 inode->i_fop = &btrfs_file_operations;
3738 inode->i_op = &btrfs_file_inode_operations;
3739 break;
3740 case S_IFDIR:
3741 inode->i_fop = &btrfs_dir_file_operations;
3742 inode->i_op = &btrfs_dir_inode_operations;
3743 break;
3744 case S_IFLNK:
3745 inode->i_op = &btrfs_symlink_inode_operations;
3746 inode_nohighmem(inode);
3747 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3748 break;
3749 default:
3750 inode->i_op = &btrfs_special_inode_operations;
3751 init_special_inode(inode, inode->i_mode, rdev);
3752 break;
3753 }
3754
3755 btrfs_update_iflags(inode);
3756 return 0;
3757
3758 make_bad:
3759 btrfs_free_path(path);
3760 make_bad_inode(inode);
3761 return ret;
3762 }
3763
3764 /*
3765 * given a leaf and an inode, copy the inode fields into the leaf
3766 */
3767 static void fill_inode_item(struct btrfs_trans_handle *trans,
3768 struct extent_buffer *leaf,
3769 struct btrfs_inode_item *item,
3770 struct inode *inode)
3771 {
3772 struct btrfs_map_token token;
3773
3774 btrfs_init_map_token(&token);
3775
3776 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3777 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3778 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3779 &token);
3780 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3781 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3782
3783 btrfs_set_token_timespec_sec(leaf, &item->atime,
3784 inode->i_atime.tv_sec, &token);
3785 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3786 inode->i_atime.tv_nsec, &token);
3787
3788 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3789 inode->i_mtime.tv_sec, &token);
3790 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3791 inode->i_mtime.tv_nsec, &token);
3792
3793 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3794 inode->i_ctime.tv_sec, &token);
3795 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3796 inode->i_ctime.tv_nsec, &token);
3797
3798 btrfs_set_token_timespec_sec(leaf, &item->otime,
3799 BTRFS_I(inode)->i_otime.tv_sec, &token);
3800 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3801 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3802
3803 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3804 &token);
3805 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3806 &token);
3807 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3808 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3809 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3810 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3811 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3812 }
3813
3814 /*
3815 * copy everything in the in-memory inode into the btree.
3816 */
3817 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3818 struct btrfs_root *root, struct inode *inode)
3819 {
3820 struct btrfs_inode_item *inode_item;
3821 struct btrfs_path *path;
3822 struct extent_buffer *leaf;
3823 int ret;
3824
3825 path = btrfs_alloc_path();
3826 if (!path)
3827 return -ENOMEM;
3828
3829 path->leave_spinning = 1;
3830 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3831 1);
3832 if (ret) {
3833 if (ret > 0)
3834 ret = -ENOENT;
3835 goto failed;
3836 }
3837
3838 leaf = path->nodes[0];
3839 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3840 struct btrfs_inode_item);
3841
3842 fill_inode_item(trans, leaf, inode_item, inode);
3843 btrfs_mark_buffer_dirty(leaf);
3844 btrfs_set_inode_last_trans(trans, inode);
3845 ret = 0;
3846 failed:
3847 btrfs_free_path(path);
3848 return ret;
3849 }
3850
3851 /*
3852 * copy everything in the in-memory inode into the btree.
3853 */
3854 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3855 struct btrfs_root *root, struct inode *inode)
3856 {
3857 struct btrfs_fs_info *fs_info = root->fs_info;
3858 int ret;
3859
3860 /*
3861 * If the inode is a free space inode, we can deadlock during commit
3862 * if we put it into the delayed code.
3863 *
3864 * The data relocation inode should also be directly updated
3865 * without delay
3866 */
3867 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
3868 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3869 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
3870 btrfs_update_root_times(trans, root);
3871
3872 ret = btrfs_delayed_update_inode(trans, root, inode);
3873 if (!ret)
3874 btrfs_set_inode_last_trans(trans, inode);
3875 return ret;
3876 }
3877
3878 return btrfs_update_inode_item(trans, root, inode);
3879 }
3880
3881 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3882 struct btrfs_root *root,
3883 struct inode *inode)
3884 {
3885 int ret;
3886
3887 ret = btrfs_update_inode(trans, root, inode);
3888 if (ret == -ENOSPC)
3889 return btrfs_update_inode_item(trans, root, inode);
3890 return ret;
3891 }
3892
3893 /*
3894 * unlink helper that gets used here in inode.c and in the tree logging
3895 * recovery code. It remove a link in a directory with a given name, and
3896 * also drops the back refs in the inode to the directory
3897 */
3898 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3899 struct btrfs_root *root,
3900 struct btrfs_inode *dir,
3901 struct btrfs_inode *inode,
3902 const char *name, int name_len)
3903 {
3904 struct btrfs_fs_info *fs_info = root->fs_info;
3905 struct btrfs_path *path;
3906 int ret = 0;
3907 struct extent_buffer *leaf;
3908 struct btrfs_dir_item *di;
3909 struct btrfs_key key;
3910 u64 index;
3911 u64 ino = btrfs_ino(inode);
3912 u64 dir_ino = btrfs_ino(dir);
3913
3914 path = btrfs_alloc_path();
3915 if (!path) {
3916 ret = -ENOMEM;
3917 goto out;
3918 }
3919
3920 path->leave_spinning = 1;
3921 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3922 name, name_len, -1);
3923 if (IS_ERR(di)) {
3924 ret = PTR_ERR(di);
3925 goto err;
3926 }
3927 if (!di) {
3928 ret = -ENOENT;
3929 goto err;
3930 }
3931 leaf = path->nodes[0];
3932 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3933 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3934 if (ret)
3935 goto err;
3936 btrfs_release_path(path);
3937
3938 /*
3939 * If we don't have dir index, we have to get it by looking up
3940 * the inode ref, since we get the inode ref, remove it directly,
3941 * it is unnecessary to do delayed deletion.
3942 *
3943 * But if we have dir index, needn't search inode ref to get it.
3944 * Since the inode ref is close to the inode item, it is better
3945 * that we delay to delete it, and just do this deletion when
3946 * we update the inode item.
3947 */
3948 if (inode->dir_index) {
3949 ret = btrfs_delayed_delete_inode_ref(inode);
3950 if (!ret) {
3951 index = inode->dir_index;
3952 goto skip_backref;
3953 }
3954 }
3955
3956 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3957 dir_ino, &index);
3958 if (ret) {
3959 btrfs_info(fs_info,
3960 "failed to delete reference to %.*s, inode %llu parent %llu",
3961 name_len, name, ino, dir_ino);
3962 btrfs_abort_transaction(trans, ret);
3963 goto err;
3964 }
3965 skip_backref:
3966 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
3967 if (ret) {
3968 btrfs_abort_transaction(trans, ret);
3969 goto err;
3970 }
3971
3972 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
3973 dir_ino);
3974 if (ret != 0 && ret != -ENOENT) {
3975 btrfs_abort_transaction(trans, ret);
3976 goto err;
3977 }
3978
3979 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
3980 index);
3981 if (ret == -ENOENT)
3982 ret = 0;
3983 else if (ret)
3984 btrfs_abort_transaction(trans, ret);
3985 err:
3986 btrfs_free_path(path);
3987 if (ret)
3988 goto out;
3989
3990 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
3991 inode_inc_iversion(&inode->vfs_inode);
3992 inode_inc_iversion(&dir->vfs_inode);
3993 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
3994 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
3995 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
3996 out:
3997 return ret;
3998 }
3999
4000 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4001 struct btrfs_root *root,
4002 struct btrfs_inode *dir, struct btrfs_inode *inode,
4003 const char *name, int name_len)
4004 {
4005 int ret;
4006 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4007 if (!ret) {
4008 drop_nlink(&inode->vfs_inode);
4009 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4010 }
4011 return ret;
4012 }
4013
4014 /*
4015 * helper to start transaction for unlink and rmdir.
4016 *
4017 * unlink and rmdir are special in btrfs, they do not always free space, so
4018 * if we cannot make our reservations the normal way try and see if there is
4019 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4020 * allow the unlink to occur.
4021 */
4022 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4023 {
4024 struct btrfs_root *root = BTRFS_I(dir)->root;
4025
4026 /*
4027 * 1 for the possible orphan item
4028 * 1 for the dir item
4029 * 1 for the dir index
4030 * 1 for the inode ref
4031 * 1 for the inode
4032 */
4033 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4034 }
4035
4036 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4037 {
4038 struct btrfs_root *root = BTRFS_I(dir)->root;
4039 struct btrfs_trans_handle *trans;
4040 struct inode *inode = d_inode(dentry);
4041 int ret;
4042
4043 trans = __unlink_start_trans(dir);
4044 if (IS_ERR(trans))
4045 return PTR_ERR(trans);
4046
4047 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4048 0);
4049
4050 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4051 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4052 dentry->d_name.len);
4053 if (ret)
4054 goto out;
4055
4056 if (inode->i_nlink == 0) {
4057 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4058 if (ret)
4059 goto out;
4060 }
4061
4062 out:
4063 btrfs_end_transaction(trans);
4064 btrfs_btree_balance_dirty(root->fs_info);
4065 return ret;
4066 }
4067
4068 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4069 struct btrfs_root *root,
4070 struct inode *dir, u64 objectid,
4071 const char *name, int name_len)
4072 {
4073 struct btrfs_fs_info *fs_info = root->fs_info;
4074 struct btrfs_path *path;
4075 struct extent_buffer *leaf;
4076 struct btrfs_dir_item *di;
4077 struct btrfs_key key;
4078 u64 index;
4079 int ret;
4080 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4081
4082 path = btrfs_alloc_path();
4083 if (!path)
4084 return -ENOMEM;
4085
4086 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4087 name, name_len, -1);
4088 if (IS_ERR_OR_NULL(di)) {
4089 if (!di)
4090 ret = -ENOENT;
4091 else
4092 ret = PTR_ERR(di);
4093 goto out;
4094 }
4095
4096 leaf = path->nodes[0];
4097 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4098 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4099 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4100 if (ret) {
4101 btrfs_abort_transaction(trans, ret);
4102 goto out;
4103 }
4104 btrfs_release_path(path);
4105
4106 ret = btrfs_del_root_ref(trans, fs_info, objectid,
4107 root->root_key.objectid, dir_ino,
4108 &index, name, name_len);
4109 if (ret < 0) {
4110 if (ret != -ENOENT) {
4111 btrfs_abort_transaction(trans, ret);
4112 goto out;
4113 }
4114 di = btrfs_search_dir_index_item(root, path, dir_ino,
4115 name, name_len);
4116 if (IS_ERR_OR_NULL(di)) {
4117 if (!di)
4118 ret = -ENOENT;
4119 else
4120 ret = PTR_ERR(di);
4121 btrfs_abort_transaction(trans, ret);
4122 goto out;
4123 }
4124
4125 leaf = path->nodes[0];
4126 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4127 btrfs_release_path(path);
4128 index = key.offset;
4129 }
4130 btrfs_release_path(path);
4131
4132 ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4133 if (ret) {
4134 btrfs_abort_transaction(trans, ret);
4135 goto out;
4136 }
4137
4138 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4139 inode_inc_iversion(dir);
4140 dir->i_mtime = dir->i_ctime = current_time(dir);
4141 ret = btrfs_update_inode_fallback(trans, root, dir);
4142 if (ret)
4143 btrfs_abort_transaction(trans, ret);
4144 out:
4145 btrfs_free_path(path);
4146 return ret;
4147 }
4148
4149 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4150 {
4151 struct inode *inode = d_inode(dentry);
4152 int err = 0;
4153 struct btrfs_root *root = BTRFS_I(dir)->root;
4154 struct btrfs_trans_handle *trans;
4155 u64 last_unlink_trans;
4156
4157 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4158 return -ENOTEMPTY;
4159 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4160 return -EPERM;
4161
4162 trans = __unlink_start_trans(dir);
4163 if (IS_ERR(trans))
4164 return PTR_ERR(trans);
4165
4166 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4167 err = btrfs_unlink_subvol(trans, root, dir,
4168 BTRFS_I(inode)->location.objectid,
4169 dentry->d_name.name,
4170 dentry->d_name.len);
4171 goto out;
4172 }
4173
4174 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4175 if (err)
4176 goto out;
4177
4178 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4179
4180 /* now the directory is empty */
4181 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4182 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4183 dentry->d_name.len);
4184 if (!err) {
4185 btrfs_i_size_write(BTRFS_I(inode), 0);
4186 /*
4187 * Propagate the last_unlink_trans value of the deleted dir to
4188 * its parent directory. This is to prevent an unrecoverable
4189 * log tree in the case we do something like this:
4190 * 1) create dir foo
4191 * 2) create snapshot under dir foo
4192 * 3) delete the snapshot
4193 * 4) rmdir foo
4194 * 5) mkdir foo
4195 * 6) fsync foo or some file inside foo
4196 */
4197 if (last_unlink_trans >= trans->transid)
4198 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4199 }
4200 out:
4201 btrfs_end_transaction(trans);
4202 btrfs_btree_balance_dirty(root->fs_info);
4203
4204 return err;
4205 }
4206
4207 static int truncate_space_check(struct btrfs_trans_handle *trans,
4208 struct btrfs_root *root,
4209 u64 bytes_deleted)
4210 {
4211 struct btrfs_fs_info *fs_info = root->fs_info;
4212 int ret;
4213
4214 /*
4215 * This is only used to apply pressure to the enospc system, we don't
4216 * intend to use this reservation at all.
4217 */
4218 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4219 bytes_deleted *= fs_info->nodesize;
4220 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4221 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4222 if (!ret) {
4223 trace_btrfs_space_reservation(fs_info, "transaction",
4224 trans->transid,
4225 bytes_deleted, 1);
4226 trans->bytes_reserved += bytes_deleted;
4227 }
4228 return ret;
4229
4230 }
4231
4232 static int truncate_inline_extent(struct inode *inode,
4233 struct btrfs_path *path,
4234 struct btrfs_key *found_key,
4235 const u64 item_end,
4236 const u64 new_size)
4237 {
4238 struct extent_buffer *leaf = path->nodes[0];
4239 int slot = path->slots[0];
4240 struct btrfs_file_extent_item *fi;
4241 u32 size = (u32)(new_size - found_key->offset);
4242 struct btrfs_root *root = BTRFS_I(inode)->root;
4243
4244 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4245
4246 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4247 loff_t offset = new_size;
4248 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4249
4250 /*
4251 * Zero out the remaining of the last page of our inline extent,
4252 * instead of directly truncating our inline extent here - that
4253 * would be much more complex (decompressing all the data, then
4254 * compressing the truncated data, which might be bigger than
4255 * the size of the inline extent, resize the extent, etc).
4256 * We release the path because to get the page we might need to
4257 * read the extent item from disk (data not in the page cache).
4258 */
4259 btrfs_release_path(path);
4260 return btrfs_truncate_block(inode, offset, page_end - offset,
4261 0);
4262 }
4263
4264 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4265 size = btrfs_file_extent_calc_inline_size(size);
4266 btrfs_truncate_item(root->fs_info, path, size, 1);
4267
4268 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4269 inode_sub_bytes(inode, item_end + 1 - new_size);
4270
4271 return 0;
4272 }
4273
4274 /*
4275 * this can truncate away extent items, csum items and directory items.
4276 * It starts at a high offset and removes keys until it can't find
4277 * any higher than new_size
4278 *
4279 * csum items that cross the new i_size are truncated to the new size
4280 * as well.
4281 *
4282 * min_type is the minimum key type to truncate down to. If set to 0, this
4283 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4284 */
4285 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4286 struct btrfs_root *root,
4287 struct inode *inode,
4288 u64 new_size, u32 min_type)
4289 {
4290 struct btrfs_fs_info *fs_info = root->fs_info;
4291 struct btrfs_path *path;
4292 struct extent_buffer *leaf;
4293 struct btrfs_file_extent_item *fi;
4294 struct btrfs_key key;
4295 struct btrfs_key found_key;
4296 u64 extent_start = 0;
4297 u64 extent_num_bytes = 0;
4298 u64 extent_offset = 0;
4299 u64 item_end = 0;
4300 u64 last_size = new_size;
4301 u32 found_type = (u8)-1;
4302 int found_extent;
4303 int del_item;
4304 int pending_del_nr = 0;
4305 int pending_del_slot = 0;
4306 int extent_type = -1;
4307 int ret;
4308 int err = 0;
4309 u64 ino = btrfs_ino(BTRFS_I(inode));
4310 u64 bytes_deleted = 0;
4311 bool be_nice = 0;
4312 bool should_throttle = 0;
4313 bool should_end = 0;
4314
4315 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4316
4317 /*
4318 * for non-free space inodes and ref cows, we want to back off from
4319 * time to time
4320 */
4321 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4322 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4323 be_nice = 1;
4324
4325 path = btrfs_alloc_path();
4326 if (!path)
4327 return -ENOMEM;
4328 path->reada = READA_BACK;
4329
4330 /*
4331 * We want to drop from the next block forward in case this new size is
4332 * not block aligned since we will be keeping the last block of the
4333 * extent just the way it is.
4334 */
4335 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4336 root == fs_info->tree_root)
4337 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4338 fs_info->sectorsize),
4339 (u64)-1, 0);
4340
4341 /*
4342 * This function is also used to drop the items in the log tree before
4343 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4344 * it is used to drop the loged items. So we shouldn't kill the delayed
4345 * items.
4346 */
4347 if (min_type == 0 && root == BTRFS_I(inode)->root)
4348 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4349
4350 key.objectid = ino;
4351 key.offset = (u64)-1;
4352 key.type = (u8)-1;
4353
4354 search_again:
4355 /*
4356 * with a 16K leaf size and 128MB extents, you can actually queue
4357 * up a huge file in a single leaf. Most of the time that
4358 * bytes_deleted is > 0, it will be huge by the time we get here
4359 */
4360 if (be_nice && bytes_deleted > SZ_32M) {
4361 if (btrfs_should_end_transaction(trans)) {
4362 err = -EAGAIN;
4363 goto error;
4364 }
4365 }
4366
4367
4368 path->leave_spinning = 1;
4369 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4370 if (ret < 0) {
4371 err = ret;
4372 goto out;
4373 }
4374
4375 if (ret > 0) {
4376 /* there are no items in the tree for us to truncate, we're
4377 * done
4378 */
4379 if (path->slots[0] == 0)
4380 goto out;
4381 path->slots[0]--;
4382 }
4383
4384 while (1) {
4385 fi = NULL;
4386 leaf = path->nodes[0];
4387 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4388 found_type = found_key.type;
4389
4390 if (found_key.objectid != ino)
4391 break;
4392
4393 if (found_type < min_type)
4394 break;
4395
4396 item_end = found_key.offset;
4397 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4398 fi = btrfs_item_ptr(leaf, path->slots[0],
4399 struct btrfs_file_extent_item);
4400 extent_type = btrfs_file_extent_type(leaf, fi);
4401 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4402 item_end +=
4403 btrfs_file_extent_num_bytes(leaf, fi);
4404 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4405 item_end += btrfs_file_extent_inline_len(leaf,
4406 path->slots[0], fi);
4407 }
4408 item_end--;
4409 }
4410 if (found_type > min_type) {
4411 del_item = 1;
4412 } else {
4413 if (item_end < new_size)
4414 break;
4415 if (found_key.offset >= new_size)
4416 del_item = 1;
4417 else
4418 del_item = 0;
4419 }
4420 found_extent = 0;
4421 /* FIXME, shrink the extent if the ref count is only 1 */
4422 if (found_type != BTRFS_EXTENT_DATA_KEY)
4423 goto delete;
4424
4425 if (del_item)
4426 last_size = found_key.offset;
4427 else
4428 last_size = new_size;
4429
4430 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4431 u64 num_dec;
4432 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4433 if (!del_item) {
4434 u64 orig_num_bytes =
4435 btrfs_file_extent_num_bytes(leaf, fi);
4436 extent_num_bytes = ALIGN(new_size -
4437 found_key.offset,
4438 fs_info->sectorsize);
4439 btrfs_set_file_extent_num_bytes(leaf, fi,
4440 extent_num_bytes);
4441 num_dec = (orig_num_bytes -
4442 extent_num_bytes);
4443 if (test_bit(BTRFS_ROOT_REF_COWS,
4444 &root->state) &&
4445 extent_start != 0)
4446 inode_sub_bytes(inode, num_dec);
4447 btrfs_mark_buffer_dirty(leaf);
4448 } else {
4449 extent_num_bytes =
4450 btrfs_file_extent_disk_num_bytes(leaf,
4451 fi);
4452 extent_offset = found_key.offset -
4453 btrfs_file_extent_offset(leaf, fi);
4454
4455 /* FIXME blocksize != 4096 */
4456 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4457 if (extent_start != 0) {
4458 found_extent = 1;
4459 if (test_bit(BTRFS_ROOT_REF_COWS,
4460 &root->state))
4461 inode_sub_bytes(inode, num_dec);
4462 }
4463 }
4464 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4465 /*
4466 * we can't truncate inline items that have had
4467 * special encodings
4468 */
4469 if (!del_item &&
4470 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4471 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4472
4473 /*
4474 * Need to release path in order to truncate a
4475 * compressed extent. So delete any accumulated
4476 * extent items so far.
4477 */
4478 if (btrfs_file_extent_compression(leaf, fi) !=
4479 BTRFS_COMPRESS_NONE && pending_del_nr) {
4480 err = btrfs_del_items(trans, root, path,
4481 pending_del_slot,
4482 pending_del_nr);
4483 if (err) {
4484 btrfs_abort_transaction(trans,
4485 err);
4486 goto error;
4487 }
4488 pending_del_nr = 0;
4489 }
4490
4491 err = truncate_inline_extent(inode, path,
4492 &found_key,
4493 item_end,
4494 new_size);
4495 if (err) {
4496 btrfs_abort_transaction(trans, err);
4497 goto error;
4498 }
4499 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4500 &root->state)) {
4501 inode_sub_bytes(inode, item_end + 1 - new_size);
4502 }
4503 }
4504 delete:
4505 if (del_item) {
4506 if (!pending_del_nr) {
4507 /* no pending yet, add ourselves */
4508 pending_del_slot = path->slots[0];
4509 pending_del_nr = 1;
4510 } else if (pending_del_nr &&
4511 path->slots[0] + 1 == pending_del_slot) {
4512 /* hop on the pending chunk */
4513 pending_del_nr++;
4514 pending_del_slot = path->slots[0];
4515 } else {
4516 BUG();
4517 }
4518 } else {
4519 break;
4520 }
4521 should_throttle = 0;
4522
4523 if (found_extent &&
4524 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4525 root == fs_info->tree_root)) {
4526 btrfs_set_path_blocking(path);
4527 bytes_deleted += extent_num_bytes;
4528 ret = btrfs_free_extent(trans, fs_info, extent_start,
4529 extent_num_bytes, 0,
4530 btrfs_header_owner(leaf),
4531 ino, extent_offset);
4532 BUG_ON(ret);
4533 if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4534 btrfs_async_run_delayed_refs(fs_info,
4535 trans->delayed_ref_updates * 2,
4536 trans->transid, 0);
4537 if (be_nice) {
4538 if (truncate_space_check(trans, root,
4539 extent_num_bytes)) {
4540 should_end = 1;
4541 }
4542 if (btrfs_should_throttle_delayed_refs(trans,
4543 fs_info))
4544 should_throttle = 1;
4545 }
4546 }
4547
4548 if (found_type == BTRFS_INODE_ITEM_KEY)
4549 break;
4550
4551 if (path->slots[0] == 0 ||
4552 path->slots[0] != pending_del_slot ||
4553 should_throttle || should_end) {
4554 if (pending_del_nr) {
4555 ret = btrfs_del_items(trans, root, path,
4556 pending_del_slot,
4557 pending_del_nr);
4558 if (ret) {
4559 btrfs_abort_transaction(trans, ret);
4560 goto error;
4561 }
4562 pending_del_nr = 0;
4563 }
4564 btrfs_release_path(path);
4565 if (should_throttle) {
4566 unsigned long updates = trans->delayed_ref_updates;
4567 if (updates) {
4568 trans->delayed_ref_updates = 0;
4569 ret = btrfs_run_delayed_refs(trans,
4570 fs_info,
4571 updates * 2);
4572 if (ret && !err)
4573 err = ret;
4574 }
4575 }
4576 /*
4577 * if we failed to refill our space rsv, bail out
4578 * and let the transaction restart
4579 */
4580 if (should_end) {
4581 err = -EAGAIN;
4582 goto error;
4583 }
4584 goto search_again;
4585 } else {
4586 path->slots[0]--;
4587 }
4588 }
4589 out:
4590 if (pending_del_nr) {
4591 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4592 pending_del_nr);
4593 if (ret)
4594 btrfs_abort_transaction(trans, ret);
4595 }
4596 error:
4597 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4598 ASSERT(last_size >= new_size);
4599 if (!err && last_size > new_size)
4600 last_size = new_size;
4601 btrfs_ordered_update_i_size(inode, last_size, NULL);
4602 }
4603
4604 btrfs_free_path(path);
4605
4606 if (err == 0) {
4607 /* only inline file may have last_size != new_size */
4608 if (new_size >= fs_info->sectorsize ||
4609 new_size > fs_info->max_inline)
4610 ASSERT(last_size == new_size);
4611 }
4612
4613 if (be_nice && bytes_deleted > SZ_32M) {
4614 unsigned long updates = trans->delayed_ref_updates;
4615 if (updates) {
4616 trans->delayed_ref_updates = 0;
4617 ret = btrfs_run_delayed_refs(trans, fs_info,
4618 updates * 2);
4619 if (ret && !err)
4620 err = ret;
4621 }
4622 }
4623 return err;
4624 }
4625
4626 /*
4627 * btrfs_truncate_block - read, zero a chunk and write a block
4628 * @inode - inode that we're zeroing
4629 * @from - the offset to start zeroing
4630 * @len - the length to zero, 0 to zero the entire range respective to the
4631 * offset
4632 * @front - zero up to the offset instead of from the offset on
4633 *
4634 * This will find the block for the "from" offset and cow the block and zero the
4635 * part we want to zero. This is used with truncate and hole punching.
4636 */
4637 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4638 int front)
4639 {
4640 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4641 struct address_space *mapping = inode->i_mapping;
4642 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4643 struct btrfs_ordered_extent *ordered;
4644 struct extent_state *cached_state = NULL;
4645 char *kaddr;
4646 u32 blocksize = fs_info->sectorsize;
4647 pgoff_t index = from >> PAGE_SHIFT;
4648 unsigned offset = from & (blocksize - 1);
4649 struct page *page;
4650 gfp_t mask = btrfs_alloc_write_mask(mapping);
4651 int ret = 0;
4652 u64 block_start;
4653 u64 block_end;
4654
4655 if ((offset & (blocksize - 1)) == 0 &&
4656 (!len || ((len & (blocksize - 1)) == 0)))
4657 goto out;
4658
4659 ret = btrfs_delalloc_reserve_space(inode,
4660 round_down(from, blocksize), blocksize);
4661 if (ret)
4662 goto out;
4663
4664 again:
4665 page = find_or_create_page(mapping, index, mask);
4666 if (!page) {
4667 btrfs_delalloc_release_space(inode,
4668 round_down(from, blocksize),
4669 blocksize);
4670 ret = -ENOMEM;
4671 goto out;
4672 }
4673
4674 block_start = round_down(from, blocksize);
4675 block_end = block_start + blocksize - 1;
4676
4677 if (!PageUptodate(page)) {
4678 ret = btrfs_readpage(NULL, page);
4679 lock_page(page);
4680 if (page->mapping != mapping) {
4681 unlock_page(page);
4682 put_page(page);
4683 goto again;
4684 }
4685 if (!PageUptodate(page)) {
4686 ret = -EIO;
4687 goto out_unlock;
4688 }
4689 }
4690 wait_on_page_writeback(page);
4691
4692 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4693 set_page_extent_mapped(page);
4694
4695 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4696 if (ordered) {
4697 unlock_extent_cached(io_tree, block_start, block_end,
4698 &cached_state, GFP_NOFS);
4699 unlock_page(page);
4700 put_page(page);
4701 btrfs_start_ordered_extent(inode, ordered, 1);
4702 btrfs_put_ordered_extent(ordered);
4703 goto again;
4704 }
4705
4706 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4707 EXTENT_DIRTY | EXTENT_DELALLOC |
4708 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4709 0, 0, &cached_state, GFP_NOFS);
4710
4711 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4712 &cached_state, 0);
4713 if (ret) {
4714 unlock_extent_cached(io_tree, block_start, block_end,
4715 &cached_state, GFP_NOFS);
4716 goto out_unlock;
4717 }
4718
4719 if (offset != blocksize) {
4720 if (!len)
4721 len = blocksize - offset;
4722 kaddr = kmap(page);
4723 if (front)
4724 memset(kaddr + (block_start - page_offset(page)),
4725 0, offset);
4726 else
4727 memset(kaddr + (block_start - page_offset(page)) + offset,
4728 0, len);
4729 flush_dcache_page(page);
4730 kunmap(page);
4731 }
4732 ClearPageChecked(page);
4733 set_page_dirty(page);
4734 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4735 GFP_NOFS);
4736
4737 out_unlock:
4738 if (ret)
4739 btrfs_delalloc_release_space(inode, block_start,
4740 blocksize);
4741 unlock_page(page);
4742 put_page(page);
4743 out:
4744 return ret;
4745 }
4746
4747 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4748 u64 offset, u64 len)
4749 {
4750 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4751 struct btrfs_trans_handle *trans;
4752 int ret;
4753
4754 /*
4755 * Still need to make sure the inode looks like it's been updated so
4756 * that any holes get logged if we fsync.
4757 */
4758 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4759 BTRFS_I(inode)->last_trans = fs_info->generation;
4760 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4761 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4762 return 0;
4763 }
4764
4765 /*
4766 * 1 - for the one we're dropping
4767 * 1 - for the one we're adding
4768 * 1 - for updating the inode.
4769 */
4770 trans = btrfs_start_transaction(root, 3);
4771 if (IS_ERR(trans))
4772 return PTR_ERR(trans);
4773
4774 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4775 if (ret) {
4776 btrfs_abort_transaction(trans, ret);
4777 btrfs_end_transaction(trans);
4778 return ret;
4779 }
4780
4781 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4782 offset, 0, 0, len, 0, len, 0, 0, 0);
4783 if (ret)
4784 btrfs_abort_transaction(trans, ret);
4785 else
4786 btrfs_update_inode(trans, root, inode);
4787 btrfs_end_transaction(trans);
4788 return ret;
4789 }
4790
4791 /*
4792 * This function puts in dummy file extents for the area we're creating a hole
4793 * for. So if we are truncating this file to a larger size we need to insert
4794 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4795 * the range between oldsize and size
4796 */
4797 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4798 {
4799 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4800 struct btrfs_root *root = BTRFS_I(inode)->root;
4801 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4802 struct extent_map *em = NULL;
4803 struct extent_state *cached_state = NULL;
4804 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4805 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4806 u64 block_end = ALIGN(size, fs_info->sectorsize);
4807 u64 last_byte;
4808 u64 cur_offset;
4809 u64 hole_size;
4810 int err = 0;
4811
4812 /*
4813 * If our size started in the middle of a block we need to zero out the
4814 * rest of the block before we expand the i_size, otherwise we could
4815 * expose stale data.
4816 */
4817 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4818 if (err)
4819 return err;
4820
4821 if (size <= hole_start)
4822 return 0;
4823
4824 while (1) {
4825 struct btrfs_ordered_extent *ordered;
4826
4827 lock_extent_bits(io_tree, hole_start, block_end - 1,
4828 &cached_state);
4829 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4830 block_end - hole_start);
4831 if (!ordered)
4832 break;
4833 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4834 &cached_state, GFP_NOFS);
4835 btrfs_start_ordered_extent(inode, ordered, 1);
4836 btrfs_put_ordered_extent(ordered);
4837 }
4838
4839 cur_offset = hole_start;
4840 while (1) {
4841 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4842 block_end - cur_offset, 0);
4843 if (IS_ERR(em)) {
4844 err = PTR_ERR(em);
4845 em = NULL;
4846 break;
4847 }
4848 last_byte = min(extent_map_end(em), block_end);
4849 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4850 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4851 struct extent_map *hole_em;
4852 hole_size = last_byte - cur_offset;
4853
4854 err = maybe_insert_hole(root, inode, cur_offset,
4855 hole_size);
4856 if (err)
4857 break;
4858 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
4859 cur_offset + hole_size - 1, 0);
4860 hole_em = alloc_extent_map();
4861 if (!hole_em) {
4862 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4863 &BTRFS_I(inode)->runtime_flags);
4864 goto next;
4865 }
4866 hole_em->start = cur_offset;
4867 hole_em->len = hole_size;
4868 hole_em->orig_start = cur_offset;
4869
4870 hole_em->block_start = EXTENT_MAP_HOLE;
4871 hole_em->block_len = 0;
4872 hole_em->orig_block_len = 0;
4873 hole_em->ram_bytes = hole_size;
4874 hole_em->bdev = fs_info->fs_devices->latest_bdev;
4875 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4876 hole_em->generation = fs_info->generation;
4877
4878 while (1) {
4879 write_lock(&em_tree->lock);
4880 err = add_extent_mapping(em_tree, hole_em, 1);
4881 write_unlock(&em_tree->lock);
4882 if (err != -EEXIST)
4883 break;
4884 btrfs_drop_extent_cache(BTRFS_I(inode),
4885 cur_offset,
4886 cur_offset +
4887 hole_size - 1, 0);
4888 }
4889 free_extent_map(hole_em);
4890 }
4891 next:
4892 free_extent_map(em);
4893 em = NULL;
4894 cur_offset = last_byte;
4895 if (cur_offset >= block_end)
4896 break;
4897 }
4898 free_extent_map(em);
4899 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4900 GFP_NOFS);
4901 return err;
4902 }
4903
4904 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4905 {
4906 struct btrfs_root *root = BTRFS_I(inode)->root;
4907 struct btrfs_trans_handle *trans;
4908 loff_t oldsize = i_size_read(inode);
4909 loff_t newsize = attr->ia_size;
4910 int mask = attr->ia_valid;
4911 int ret;
4912
4913 /*
4914 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4915 * special case where we need to update the times despite not having
4916 * these flags set. For all other operations the VFS set these flags
4917 * explicitly if it wants a timestamp update.
4918 */
4919 if (newsize != oldsize) {
4920 inode_inc_iversion(inode);
4921 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4922 inode->i_ctime = inode->i_mtime =
4923 current_time(inode);
4924 }
4925
4926 if (newsize > oldsize) {
4927 /*
4928 * Don't do an expanding truncate while snapshoting is ongoing.
4929 * This is to ensure the snapshot captures a fully consistent
4930 * state of this file - if the snapshot captures this expanding
4931 * truncation, it must capture all writes that happened before
4932 * this truncation.
4933 */
4934 btrfs_wait_for_snapshot_creation(root);
4935 ret = btrfs_cont_expand(inode, oldsize, newsize);
4936 if (ret) {
4937 btrfs_end_write_no_snapshoting(root);
4938 return ret;
4939 }
4940
4941 trans = btrfs_start_transaction(root, 1);
4942 if (IS_ERR(trans)) {
4943 btrfs_end_write_no_snapshoting(root);
4944 return PTR_ERR(trans);
4945 }
4946
4947 i_size_write(inode, newsize);
4948 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4949 pagecache_isize_extended(inode, oldsize, newsize);
4950 ret = btrfs_update_inode(trans, root, inode);
4951 btrfs_end_write_no_snapshoting(root);
4952 btrfs_end_transaction(trans);
4953 } else {
4954
4955 /*
4956 * We're truncating a file that used to have good data down to
4957 * zero. Make sure it gets into the ordered flush list so that
4958 * any new writes get down to disk quickly.
4959 */
4960 if (newsize == 0)
4961 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4962 &BTRFS_I(inode)->runtime_flags);
4963
4964 /*
4965 * 1 for the orphan item we're going to add
4966 * 1 for the orphan item deletion.
4967 */
4968 trans = btrfs_start_transaction(root, 2);
4969 if (IS_ERR(trans))
4970 return PTR_ERR(trans);
4971
4972 /*
4973 * We need to do this in case we fail at _any_ point during the
4974 * actual truncate. Once we do the truncate_setsize we could
4975 * invalidate pages which forces any outstanding ordered io to
4976 * be instantly completed which will give us extents that need
4977 * to be truncated. If we fail to get an orphan inode down we
4978 * could have left over extents that were never meant to live,
4979 * so we need to guarantee from this point on that everything
4980 * will be consistent.
4981 */
4982 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4983 btrfs_end_transaction(trans);
4984 if (ret)
4985 return ret;
4986
4987 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4988 truncate_setsize(inode, newsize);
4989
4990 /* Disable nonlocked read DIO to avoid the end less truncate */
4991 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
4992 inode_dio_wait(inode);
4993 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
4994
4995 ret = btrfs_truncate(inode);
4996 if (ret && inode->i_nlink) {
4997 int err;
4998
4999 /* To get a stable disk_i_size */
5000 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5001 if (err) {
5002 btrfs_orphan_del(NULL, BTRFS_I(inode));
5003 return err;
5004 }
5005
5006 /*
5007 * failed to truncate, disk_i_size is only adjusted down
5008 * as we remove extents, so it should represent the true
5009 * size of the inode, so reset the in memory size and
5010 * delete our orphan entry.
5011 */
5012 trans = btrfs_join_transaction(root);
5013 if (IS_ERR(trans)) {
5014 btrfs_orphan_del(NULL, BTRFS_I(inode));
5015 return ret;
5016 }
5017 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5018 err = btrfs_orphan_del(trans, BTRFS_I(inode));
5019 if (err)
5020 btrfs_abort_transaction(trans, err);
5021 btrfs_end_transaction(trans);
5022 }
5023 }
5024
5025 return ret;
5026 }
5027
5028 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5029 {
5030 struct inode *inode = d_inode(dentry);
5031 struct btrfs_root *root = BTRFS_I(inode)->root;
5032 int err;
5033
5034 if (btrfs_root_readonly(root))
5035 return -EROFS;
5036
5037 err = setattr_prepare(dentry, attr);
5038 if (err)
5039 return err;
5040
5041 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5042 err = btrfs_setsize(inode, attr);
5043 if (err)
5044 return err;
5045 }
5046
5047 if (attr->ia_valid) {
5048 setattr_copy(inode, attr);
5049 inode_inc_iversion(inode);
5050 err = btrfs_dirty_inode(inode);
5051
5052 if (!err && attr->ia_valid & ATTR_MODE)
5053 err = posix_acl_chmod(inode, inode->i_mode);
5054 }
5055
5056 return err;
5057 }
5058
5059 /*
5060 * While truncating the inode pages during eviction, we get the VFS calling
5061 * btrfs_invalidatepage() against each page of the inode. This is slow because
5062 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5063 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5064 * extent_state structures over and over, wasting lots of time.
5065 *
5066 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5067 * those expensive operations on a per page basis and do only the ordered io
5068 * finishing, while we release here the extent_map and extent_state structures,
5069 * without the excessive merging and splitting.
5070 */
5071 static void evict_inode_truncate_pages(struct inode *inode)
5072 {
5073 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5074 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5075 struct rb_node *node;
5076
5077 ASSERT(inode->i_state & I_FREEING);
5078 truncate_inode_pages_final(&inode->i_data);
5079
5080 write_lock(&map_tree->lock);
5081 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5082 struct extent_map *em;
5083
5084 node = rb_first(&map_tree->map);
5085 em = rb_entry(node, struct extent_map, rb_node);
5086 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5087 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5088 remove_extent_mapping(map_tree, em);
5089 free_extent_map(em);
5090 if (need_resched()) {
5091 write_unlock(&map_tree->lock);
5092 cond_resched();
5093 write_lock(&map_tree->lock);
5094 }
5095 }
5096 write_unlock(&map_tree->lock);
5097
5098 /*
5099 * Keep looping until we have no more ranges in the io tree.
5100 * We can have ongoing bios started by readpages (called from readahead)
5101 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5102 * still in progress (unlocked the pages in the bio but did not yet
5103 * unlocked the ranges in the io tree). Therefore this means some
5104 * ranges can still be locked and eviction started because before
5105 * submitting those bios, which are executed by a separate task (work
5106 * queue kthread), inode references (inode->i_count) were not taken
5107 * (which would be dropped in the end io callback of each bio).
5108 * Therefore here we effectively end up waiting for those bios and
5109 * anyone else holding locked ranges without having bumped the inode's
5110 * reference count - if we don't do it, when they access the inode's
5111 * io_tree to unlock a range it may be too late, leading to an
5112 * use-after-free issue.
5113 */
5114 spin_lock(&io_tree->lock);
5115 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5116 struct extent_state *state;
5117 struct extent_state *cached_state = NULL;
5118 u64 start;
5119 u64 end;
5120
5121 node = rb_first(&io_tree->state);
5122 state = rb_entry(node, struct extent_state, rb_node);
5123 start = state->start;
5124 end = state->end;
5125 spin_unlock(&io_tree->lock);
5126
5127 lock_extent_bits(io_tree, start, end, &cached_state);
5128
5129 /*
5130 * If still has DELALLOC flag, the extent didn't reach disk,
5131 * and its reserved space won't be freed by delayed_ref.
5132 * So we need to free its reserved space here.
5133 * (Refer to comment in btrfs_invalidatepage, case 2)
5134 *
5135 * Note, end is the bytenr of last byte, so we need + 1 here.
5136 */
5137 if (state->state & EXTENT_DELALLOC)
5138 btrfs_qgroup_free_data(inode, start, end - start + 1);
5139
5140 clear_extent_bit(io_tree, start, end,
5141 EXTENT_LOCKED | EXTENT_DIRTY |
5142 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5143 EXTENT_DEFRAG, 1, 1,
5144 &cached_state, GFP_NOFS);
5145
5146 cond_resched();
5147 spin_lock(&io_tree->lock);
5148 }
5149 spin_unlock(&io_tree->lock);
5150 }
5151
5152 void btrfs_evict_inode(struct inode *inode)
5153 {
5154 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5155 struct btrfs_trans_handle *trans;
5156 struct btrfs_root *root = BTRFS_I(inode)->root;
5157 struct btrfs_block_rsv *rsv, *global_rsv;
5158 int steal_from_global = 0;
5159 u64 min_size;
5160 int ret;
5161
5162 trace_btrfs_inode_evict(inode);
5163
5164 if (!root) {
5165 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5166 return;
5167 }
5168
5169 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5170
5171 evict_inode_truncate_pages(inode);
5172
5173 if (inode->i_nlink &&
5174 ((btrfs_root_refs(&root->root_item) != 0 &&
5175 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5176 btrfs_is_free_space_inode(BTRFS_I(inode))))
5177 goto no_delete;
5178
5179 if (is_bad_inode(inode)) {
5180 btrfs_orphan_del(NULL, BTRFS_I(inode));
5181 goto no_delete;
5182 }
5183 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5184 if (!special_file(inode->i_mode))
5185 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5186
5187 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5188
5189 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5190 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5191 &BTRFS_I(inode)->runtime_flags));
5192 goto no_delete;
5193 }
5194
5195 if (inode->i_nlink > 0) {
5196 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5197 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5198 goto no_delete;
5199 }
5200
5201 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5202 if (ret) {
5203 btrfs_orphan_del(NULL, BTRFS_I(inode));
5204 goto no_delete;
5205 }
5206
5207 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5208 if (!rsv) {
5209 btrfs_orphan_del(NULL, BTRFS_I(inode));
5210 goto no_delete;
5211 }
5212 rsv->size = min_size;
5213 rsv->failfast = 1;
5214 global_rsv = &fs_info->global_block_rsv;
5215
5216 btrfs_i_size_write(BTRFS_I(inode), 0);
5217
5218 /*
5219 * This is a bit simpler than btrfs_truncate since we've already
5220 * reserved our space for our orphan item in the unlink, so we just
5221 * need to reserve some slack space in case we add bytes and update
5222 * inode item when doing the truncate.
5223 */
5224 while (1) {
5225 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5226 BTRFS_RESERVE_FLUSH_LIMIT);
5227
5228 /*
5229 * Try and steal from the global reserve since we will
5230 * likely not use this space anyway, we want to try as
5231 * hard as possible to get this to work.
5232 */
5233 if (ret)
5234 steal_from_global++;
5235 else
5236 steal_from_global = 0;
5237 ret = 0;
5238
5239 /*
5240 * steal_from_global == 0: we reserved stuff, hooray!
5241 * steal_from_global == 1: we didn't reserve stuff, boo!
5242 * steal_from_global == 2: we've committed, still not a lot of
5243 * room but maybe we'll have room in the global reserve this
5244 * time.
5245 * steal_from_global == 3: abandon all hope!
5246 */
5247 if (steal_from_global > 2) {
5248 btrfs_warn(fs_info,
5249 "Could not get space for a delete, will truncate on mount %d",
5250 ret);
5251 btrfs_orphan_del(NULL, BTRFS_I(inode));
5252 btrfs_free_block_rsv(fs_info, rsv);
5253 goto no_delete;
5254 }
5255
5256 trans = btrfs_join_transaction(root);
5257 if (IS_ERR(trans)) {
5258 btrfs_orphan_del(NULL, BTRFS_I(inode));
5259 btrfs_free_block_rsv(fs_info, rsv);
5260 goto no_delete;
5261 }
5262
5263 /*
5264 * We can't just steal from the global reserve, we need to make
5265 * sure there is room to do it, if not we need to commit and try
5266 * again.
5267 */
5268 if (steal_from_global) {
5269 if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5270 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5271 min_size, 0);
5272 else
5273 ret = -ENOSPC;
5274 }
5275
5276 /*
5277 * Couldn't steal from the global reserve, we have too much
5278 * pending stuff built up, commit the transaction and try it
5279 * again.
5280 */
5281 if (ret) {
5282 ret = btrfs_commit_transaction(trans);
5283 if (ret) {
5284 btrfs_orphan_del(NULL, BTRFS_I(inode));
5285 btrfs_free_block_rsv(fs_info, rsv);
5286 goto no_delete;
5287 }
5288 continue;
5289 } else {
5290 steal_from_global = 0;
5291 }
5292
5293 trans->block_rsv = rsv;
5294
5295 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5296 if (ret != -ENOSPC && ret != -EAGAIN)
5297 break;
5298
5299 trans->block_rsv = &fs_info->trans_block_rsv;
5300 btrfs_end_transaction(trans);
5301 trans = NULL;
5302 btrfs_btree_balance_dirty(fs_info);
5303 }
5304
5305 btrfs_free_block_rsv(fs_info, rsv);
5306
5307 /*
5308 * Errors here aren't a big deal, it just means we leave orphan items
5309 * in the tree. They will be cleaned up on the next mount.
5310 */
5311 if (ret == 0) {
5312 trans->block_rsv = root->orphan_block_rsv;
5313 btrfs_orphan_del(trans, BTRFS_I(inode));
5314 } else {
5315 btrfs_orphan_del(NULL, BTRFS_I(inode));
5316 }
5317
5318 trans->block_rsv = &fs_info->trans_block_rsv;
5319 if (!(root == fs_info->tree_root ||
5320 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5321 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5322
5323 btrfs_end_transaction(trans);
5324 btrfs_btree_balance_dirty(fs_info);
5325 no_delete:
5326 btrfs_remove_delayed_node(BTRFS_I(inode));
5327 clear_inode(inode);
5328 }
5329
5330 /*
5331 * this returns the key found in the dir entry in the location pointer.
5332 * If no dir entries were found, location->objectid is 0.
5333 */
5334 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5335 struct btrfs_key *location)
5336 {
5337 const char *name = dentry->d_name.name;
5338 int namelen = dentry->d_name.len;
5339 struct btrfs_dir_item *di;
5340 struct btrfs_path *path;
5341 struct btrfs_root *root = BTRFS_I(dir)->root;
5342 int ret = 0;
5343
5344 path = btrfs_alloc_path();
5345 if (!path)
5346 return -ENOMEM;
5347
5348 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5349 name, namelen, 0);
5350 if (IS_ERR(di))
5351 ret = PTR_ERR(di);
5352
5353 if (IS_ERR_OR_NULL(di))
5354 goto out_err;
5355
5356 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5357 out:
5358 btrfs_free_path(path);
5359 return ret;
5360 out_err:
5361 location->objectid = 0;
5362 goto out;
5363 }
5364
5365 /*
5366 * when we hit a tree root in a directory, the btrfs part of the inode
5367 * needs to be changed to reflect the root directory of the tree root. This
5368 * is kind of like crossing a mount point.
5369 */
5370 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5371 struct inode *dir,
5372 struct dentry *dentry,
5373 struct btrfs_key *location,
5374 struct btrfs_root **sub_root)
5375 {
5376 struct btrfs_path *path;
5377 struct btrfs_root *new_root;
5378 struct btrfs_root_ref *ref;
5379 struct extent_buffer *leaf;
5380 struct btrfs_key key;
5381 int ret;
5382 int err = 0;
5383
5384 path = btrfs_alloc_path();
5385 if (!path) {
5386 err = -ENOMEM;
5387 goto out;
5388 }
5389
5390 err = -ENOENT;
5391 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5392 key.type = BTRFS_ROOT_REF_KEY;
5393 key.offset = location->objectid;
5394
5395 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5396 if (ret) {
5397 if (ret < 0)
5398 err = ret;
5399 goto out;
5400 }
5401
5402 leaf = path->nodes[0];
5403 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5404 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5405 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5406 goto out;
5407
5408 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5409 (unsigned long)(ref + 1),
5410 dentry->d_name.len);
5411 if (ret)
5412 goto out;
5413
5414 btrfs_release_path(path);
5415
5416 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5417 if (IS_ERR(new_root)) {
5418 err = PTR_ERR(new_root);
5419 goto out;
5420 }
5421
5422 *sub_root = new_root;
5423 location->objectid = btrfs_root_dirid(&new_root->root_item);
5424 location->type = BTRFS_INODE_ITEM_KEY;
5425 location->offset = 0;
5426 err = 0;
5427 out:
5428 btrfs_free_path(path);
5429 return err;
5430 }
5431
5432 static void inode_tree_add(struct inode *inode)
5433 {
5434 struct btrfs_root *root = BTRFS_I(inode)->root;
5435 struct btrfs_inode *entry;
5436 struct rb_node **p;
5437 struct rb_node *parent;
5438 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5439 u64 ino = btrfs_ino(BTRFS_I(inode));
5440
5441 if (inode_unhashed(inode))
5442 return;
5443 parent = NULL;
5444 spin_lock(&root->inode_lock);
5445 p = &root->inode_tree.rb_node;
5446 while (*p) {
5447 parent = *p;
5448 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5449
5450 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5451 p = &parent->rb_left;
5452 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5453 p = &parent->rb_right;
5454 else {
5455 WARN_ON(!(entry->vfs_inode.i_state &
5456 (I_WILL_FREE | I_FREEING)));
5457 rb_replace_node(parent, new, &root->inode_tree);
5458 RB_CLEAR_NODE(parent);
5459 spin_unlock(&root->inode_lock);
5460 return;
5461 }
5462 }
5463 rb_link_node(new, parent, p);
5464 rb_insert_color(new, &root->inode_tree);
5465 spin_unlock(&root->inode_lock);
5466 }
5467
5468 static void inode_tree_del(struct inode *inode)
5469 {
5470 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5471 struct btrfs_root *root = BTRFS_I(inode)->root;
5472 int empty = 0;
5473
5474 spin_lock(&root->inode_lock);
5475 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5476 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5477 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5478 empty = RB_EMPTY_ROOT(&root->inode_tree);
5479 }
5480 spin_unlock(&root->inode_lock);
5481
5482 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5483 synchronize_srcu(&fs_info->subvol_srcu);
5484 spin_lock(&root->inode_lock);
5485 empty = RB_EMPTY_ROOT(&root->inode_tree);
5486 spin_unlock(&root->inode_lock);
5487 if (empty)
5488 btrfs_add_dead_root(root);
5489 }
5490 }
5491
5492 void btrfs_invalidate_inodes(struct btrfs_root *root)
5493 {
5494 struct btrfs_fs_info *fs_info = root->fs_info;
5495 struct rb_node *node;
5496 struct rb_node *prev;
5497 struct btrfs_inode *entry;
5498 struct inode *inode;
5499 u64 objectid = 0;
5500
5501 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5502 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5503
5504 spin_lock(&root->inode_lock);
5505 again:
5506 node = root->inode_tree.rb_node;
5507 prev = NULL;
5508 while (node) {
5509 prev = node;
5510 entry = rb_entry(node, struct btrfs_inode, rb_node);
5511
5512 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5513 node = node->rb_left;
5514 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5515 node = node->rb_right;
5516 else
5517 break;
5518 }
5519 if (!node) {
5520 while (prev) {
5521 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5522 if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
5523 node = prev;
5524 break;
5525 }
5526 prev = rb_next(prev);
5527 }
5528 }
5529 while (node) {
5530 entry = rb_entry(node, struct btrfs_inode, rb_node);
5531 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
5532 inode = igrab(&entry->vfs_inode);
5533 if (inode) {
5534 spin_unlock(&root->inode_lock);
5535 if (atomic_read(&inode->i_count) > 1)
5536 d_prune_aliases(inode);
5537 /*
5538 * btrfs_drop_inode will have it removed from
5539 * the inode cache when its usage count
5540 * hits zero.
5541 */
5542 iput(inode);
5543 cond_resched();
5544 spin_lock(&root->inode_lock);
5545 goto again;
5546 }
5547
5548 if (cond_resched_lock(&root->inode_lock))
5549 goto again;
5550
5551 node = rb_next(node);
5552 }
5553 spin_unlock(&root->inode_lock);
5554 }
5555
5556 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5557 {
5558 struct btrfs_iget_args *args = p;
5559 inode->i_ino = args->location->objectid;
5560 memcpy(&BTRFS_I(inode)->location, args->location,
5561 sizeof(*args->location));
5562 BTRFS_I(inode)->root = args->root;
5563 return 0;
5564 }
5565
5566 static int btrfs_find_actor(struct inode *inode, void *opaque)
5567 {
5568 struct btrfs_iget_args *args = opaque;
5569 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5570 args->root == BTRFS_I(inode)->root;
5571 }
5572
5573 static struct inode *btrfs_iget_locked(struct super_block *s,
5574 struct btrfs_key *location,
5575 struct btrfs_root *root)
5576 {
5577 struct inode *inode;
5578 struct btrfs_iget_args args;
5579 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5580
5581 args.location = location;
5582 args.root = root;
5583
5584 inode = iget5_locked(s, hashval, btrfs_find_actor,
5585 btrfs_init_locked_inode,
5586 (void *)&args);
5587 return inode;
5588 }
5589
5590 /* Get an inode object given its location and corresponding root.
5591 * Returns in *is_new if the inode was read from disk
5592 */
5593 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5594 struct btrfs_root *root, int *new)
5595 {
5596 struct inode *inode;
5597
5598 inode = btrfs_iget_locked(s, location, root);
5599 if (!inode)
5600 return ERR_PTR(-ENOMEM);
5601
5602 if (inode->i_state & I_NEW) {
5603 int ret;
5604
5605 ret = btrfs_read_locked_inode(inode);
5606 if (!is_bad_inode(inode)) {
5607 inode_tree_add(inode);
5608 unlock_new_inode(inode);
5609 if (new)
5610 *new = 1;
5611 } else {
5612 unlock_new_inode(inode);
5613 iput(inode);
5614 ASSERT(ret < 0);
5615 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5616 }
5617 }
5618
5619 return inode;
5620 }
5621
5622 static struct inode *new_simple_dir(struct super_block *s,
5623 struct btrfs_key *key,
5624 struct btrfs_root *root)
5625 {
5626 struct inode *inode = new_inode(s);
5627
5628 if (!inode)
5629 return ERR_PTR(-ENOMEM);
5630
5631 BTRFS_I(inode)->root = root;
5632 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5633 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5634
5635 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5636 inode->i_op = &btrfs_dir_ro_inode_operations;
5637 inode->i_opflags &= ~IOP_XATTR;
5638 inode->i_fop = &simple_dir_operations;
5639 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5640 inode->i_mtime = current_time(inode);
5641 inode->i_atime = inode->i_mtime;
5642 inode->i_ctime = inode->i_mtime;
5643 BTRFS_I(inode)->i_otime = inode->i_mtime;
5644
5645 return inode;
5646 }
5647
5648 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5649 {
5650 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5651 struct inode *inode;
5652 struct btrfs_root *root = BTRFS_I(dir)->root;
5653 struct btrfs_root *sub_root = root;
5654 struct btrfs_key location;
5655 int index;
5656 int ret = 0;
5657
5658 if (dentry->d_name.len > BTRFS_NAME_LEN)
5659 return ERR_PTR(-ENAMETOOLONG);
5660
5661 ret = btrfs_inode_by_name(dir, dentry, &location);
5662 if (ret < 0)
5663 return ERR_PTR(ret);
5664
5665 if (location.objectid == 0)
5666 return ERR_PTR(-ENOENT);
5667
5668 if (location.type == BTRFS_INODE_ITEM_KEY) {
5669 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5670 return inode;
5671 }
5672
5673 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5674
5675 index = srcu_read_lock(&fs_info->subvol_srcu);
5676 ret = fixup_tree_root_location(fs_info, dir, dentry,
5677 &location, &sub_root);
5678 if (ret < 0) {
5679 if (ret != -ENOENT)
5680 inode = ERR_PTR(ret);
5681 else
5682 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5683 } else {
5684 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5685 }
5686 srcu_read_unlock(&fs_info->subvol_srcu, index);
5687
5688 if (!IS_ERR(inode) && root != sub_root) {
5689 down_read(&fs_info->cleanup_work_sem);
5690 if (!(inode->i_sb->s_flags & MS_RDONLY))
5691 ret = btrfs_orphan_cleanup(sub_root);
5692 up_read(&fs_info->cleanup_work_sem);
5693 if (ret) {
5694 iput(inode);
5695 inode = ERR_PTR(ret);
5696 }
5697 }
5698
5699 return inode;
5700 }
5701
5702 static int btrfs_dentry_delete(const struct dentry *dentry)
5703 {
5704 struct btrfs_root *root;
5705 struct inode *inode = d_inode(dentry);
5706
5707 if (!inode && !IS_ROOT(dentry))
5708 inode = d_inode(dentry->d_parent);
5709
5710 if (inode) {
5711 root = BTRFS_I(inode)->root;
5712 if (btrfs_root_refs(&root->root_item) == 0)
5713 return 1;
5714
5715 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5716 return 1;
5717 }
5718 return 0;
5719 }
5720
5721 static void btrfs_dentry_release(struct dentry *dentry)
5722 {
5723 kfree(dentry->d_fsdata);
5724 }
5725
5726 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5727 unsigned int flags)
5728 {
5729 struct inode *inode;
5730
5731 inode = btrfs_lookup_dentry(dir, dentry);
5732 if (IS_ERR(inode)) {
5733 if (PTR_ERR(inode) == -ENOENT)
5734 inode = NULL;
5735 else
5736 return ERR_CAST(inode);
5737 }
5738
5739 return d_splice_alias(inode, dentry);
5740 }
5741
5742 unsigned char btrfs_filetype_table[] = {
5743 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5744 };
5745
5746 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5747 {
5748 struct inode *inode = file_inode(file);
5749 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5750 struct btrfs_root *root = BTRFS_I(inode)->root;
5751 struct btrfs_item *item;
5752 struct btrfs_dir_item *di;
5753 struct btrfs_key key;
5754 struct btrfs_key found_key;
5755 struct btrfs_path *path;
5756 struct list_head ins_list;
5757 struct list_head del_list;
5758 int ret;
5759 struct extent_buffer *leaf;
5760 int slot;
5761 unsigned char d_type;
5762 int over = 0;
5763 char tmp_name[32];
5764 char *name_ptr;
5765 int name_len;
5766 bool put = false;
5767 struct btrfs_key location;
5768
5769 if (!dir_emit_dots(file, ctx))
5770 return 0;
5771
5772 path = btrfs_alloc_path();
5773 if (!path)
5774 return -ENOMEM;
5775
5776 path->reada = READA_FORWARD;
5777
5778 INIT_LIST_HEAD(&ins_list);
5779 INIT_LIST_HEAD(&del_list);
5780 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5781
5782 key.type = BTRFS_DIR_INDEX_KEY;
5783 key.offset = ctx->pos;
5784 key.objectid = btrfs_ino(BTRFS_I(inode));
5785
5786 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5787 if (ret < 0)
5788 goto err;
5789
5790 while (1) {
5791 leaf = path->nodes[0];
5792 slot = path->slots[0];
5793 if (slot >= btrfs_header_nritems(leaf)) {
5794 ret = btrfs_next_leaf(root, path);
5795 if (ret < 0)
5796 goto err;
5797 else if (ret > 0)
5798 break;
5799 continue;
5800 }
5801
5802 item = btrfs_item_nr(slot);
5803 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5804
5805 if (found_key.objectid != key.objectid)
5806 break;
5807 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5808 break;
5809 if (found_key.offset < ctx->pos)
5810 goto next;
5811 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5812 goto next;
5813
5814 ctx->pos = found_key.offset;
5815
5816 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5817 if (verify_dir_item(fs_info, leaf, di))
5818 goto next;
5819
5820 name_len = btrfs_dir_name_len(leaf, di);
5821 if (name_len <= sizeof(tmp_name)) {
5822 name_ptr = tmp_name;
5823 } else {
5824 name_ptr = kmalloc(name_len, GFP_KERNEL);
5825 if (!name_ptr) {
5826 ret = -ENOMEM;
5827 goto err;
5828 }
5829 }
5830 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
5831 name_len);
5832
5833 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5834 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5835
5836 over = !dir_emit(ctx, name_ptr, name_len, location.objectid,
5837 d_type);
5838
5839 if (name_ptr != tmp_name)
5840 kfree(name_ptr);
5841
5842 if (over)
5843 goto nopos;
5844 ctx->pos++;
5845 next:
5846 path->slots[0]++;
5847 }
5848
5849 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5850 if (ret)
5851 goto nopos;
5852
5853 /*
5854 * Stop new entries from being returned after we return the last
5855 * entry.
5856 *
5857 * New directory entries are assigned a strictly increasing
5858 * offset. This means that new entries created during readdir
5859 * are *guaranteed* to be seen in the future by that readdir.
5860 * This has broken buggy programs which operate on names as
5861 * they're returned by readdir. Until we re-use freed offsets
5862 * we have this hack to stop new entries from being returned
5863 * under the assumption that they'll never reach this huge
5864 * offset.
5865 *
5866 * This is being careful not to overflow 32bit loff_t unless the
5867 * last entry requires it because doing so has broken 32bit apps
5868 * in the past.
5869 */
5870 if (ctx->pos >= INT_MAX)
5871 ctx->pos = LLONG_MAX;
5872 else
5873 ctx->pos = INT_MAX;
5874 nopos:
5875 ret = 0;
5876 err:
5877 if (put)
5878 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
5879 btrfs_free_path(path);
5880 return ret;
5881 }
5882
5883 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5884 {
5885 struct btrfs_root *root = BTRFS_I(inode)->root;
5886 struct btrfs_trans_handle *trans;
5887 int ret = 0;
5888 bool nolock = false;
5889
5890 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5891 return 0;
5892
5893 if (btrfs_fs_closing(root->fs_info) &&
5894 btrfs_is_free_space_inode(BTRFS_I(inode)))
5895 nolock = true;
5896
5897 if (wbc->sync_mode == WB_SYNC_ALL) {
5898 if (nolock)
5899 trans = btrfs_join_transaction_nolock(root);
5900 else
5901 trans = btrfs_join_transaction(root);
5902 if (IS_ERR(trans))
5903 return PTR_ERR(trans);
5904 ret = btrfs_commit_transaction(trans);
5905 }
5906 return ret;
5907 }
5908
5909 /*
5910 * This is somewhat expensive, updating the tree every time the
5911 * inode changes. But, it is most likely to find the inode in cache.
5912 * FIXME, needs more benchmarking...there are no reasons other than performance
5913 * to keep or drop this code.
5914 */
5915 static int btrfs_dirty_inode(struct inode *inode)
5916 {
5917 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5918 struct btrfs_root *root = BTRFS_I(inode)->root;
5919 struct btrfs_trans_handle *trans;
5920 int ret;
5921
5922 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5923 return 0;
5924
5925 trans = btrfs_join_transaction(root);
5926 if (IS_ERR(trans))
5927 return PTR_ERR(trans);
5928
5929 ret = btrfs_update_inode(trans, root, inode);
5930 if (ret && ret == -ENOSPC) {
5931 /* whoops, lets try again with the full transaction */
5932 btrfs_end_transaction(trans);
5933 trans = btrfs_start_transaction(root, 1);
5934 if (IS_ERR(trans))
5935 return PTR_ERR(trans);
5936
5937 ret = btrfs_update_inode(trans, root, inode);
5938 }
5939 btrfs_end_transaction(trans);
5940 if (BTRFS_I(inode)->delayed_node)
5941 btrfs_balance_delayed_items(fs_info);
5942
5943 return ret;
5944 }
5945
5946 /*
5947 * This is a copy of file_update_time. We need this so we can return error on
5948 * ENOSPC for updating the inode in the case of file write and mmap writes.
5949 */
5950 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5951 int flags)
5952 {
5953 struct btrfs_root *root = BTRFS_I(inode)->root;
5954
5955 if (btrfs_root_readonly(root))
5956 return -EROFS;
5957
5958 if (flags & S_VERSION)
5959 inode_inc_iversion(inode);
5960 if (flags & S_CTIME)
5961 inode->i_ctime = *now;
5962 if (flags & S_MTIME)
5963 inode->i_mtime = *now;
5964 if (flags & S_ATIME)
5965 inode->i_atime = *now;
5966 return btrfs_dirty_inode(inode);
5967 }
5968
5969 /*
5970 * find the highest existing sequence number in a directory
5971 * and then set the in-memory index_cnt variable to reflect
5972 * free sequence numbers
5973 */
5974 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
5975 {
5976 struct btrfs_root *root = inode->root;
5977 struct btrfs_key key, found_key;
5978 struct btrfs_path *path;
5979 struct extent_buffer *leaf;
5980 int ret;
5981
5982 key.objectid = btrfs_ino(inode);
5983 key.type = BTRFS_DIR_INDEX_KEY;
5984 key.offset = (u64)-1;
5985
5986 path = btrfs_alloc_path();
5987 if (!path)
5988 return -ENOMEM;
5989
5990 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5991 if (ret < 0)
5992 goto out;
5993 /* FIXME: we should be able to handle this */
5994 if (ret == 0)
5995 goto out;
5996 ret = 0;
5997
5998 /*
5999 * MAGIC NUMBER EXPLANATION:
6000 * since we search a directory based on f_pos we have to start at 2
6001 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6002 * else has to start at 2
6003 */
6004 if (path->slots[0] == 0) {
6005 inode->index_cnt = 2;
6006 goto out;
6007 }
6008
6009 path->slots[0]--;
6010
6011 leaf = path->nodes[0];
6012 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6013
6014 if (found_key.objectid != btrfs_ino(inode) ||
6015 found_key.type != BTRFS_DIR_INDEX_KEY) {
6016 inode->index_cnt = 2;
6017 goto out;
6018 }
6019
6020 inode->index_cnt = found_key.offset + 1;
6021 out:
6022 btrfs_free_path(path);
6023 return ret;
6024 }
6025
6026 /*
6027 * helper to find a free sequence number in a given directory. This current
6028 * code is very simple, later versions will do smarter things in the btree
6029 */
6030 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6031 {
6032 int ret = 0;
6033
6034 if (dir->index_cnt == (u64)-1) {
6035 ret = btrfs_inode_delayed_dir_index_count(dir);
6036 if (ret) {
6037 ret = btrfs_set_inode_index_count(dir);
6038 if (ret)
6039 return ret;
6040 }
6041 }
6042
6043 *index = dir->index_cnt;
6044 dir->index_cnt++;
6045
6046 return ret;
6047 }
6048
6049 static int btrfs_insert_inode_locked(struct inode *inode)
6050 {
6051 struct btrfs_iget_args args;
6052 args.location = &BTRFS_I(inode)->location;
6053 args.root = BTRFS_I(inode)->root;
6054
6055 return insert_inode_locked4(inode,
6056 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6057 btrfs_find_actor, &args);
6058 }
6059
6060 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6061 struct btrfs_root *root,
6062 struct inode *dir,
6063 const char *name, int name_len,
6064 u64 ref_objectid, u64 objectid,
6065 umode_t mode, u64 *index)
6066 {
6067 struct btrfs_fs_info *fs_info = root->fs_info;
6068 struct inode *inode;
6069 struct btrfs_inode_item *inode_item;
6070 struct btrfs_key *location;
6071 struct btrfs_path *path;
6072 struct btrfs_inode_ref *ref;
6073 struct btrfs_key key[2];
6074 u32 sizes[2];
6075 int nitems = name ? 2 : 1;
6076 unsigned long ptr;
6077 int ret;
6078
6079 path = btrfs_alloc_path();
6080 if (!path)
6081 return ERR_PTR(-ENOMEM);
6082
6083 inode = new_inode(fs_info->sb);
6084 if (!inode) {
6085 btrfs_free_path(path);
6086 return ERR_PTR(-ENOMEM);
6087 }
6088
6089 /*
6090 * O_TMPFILE, set link count to 0, so that after this point,
6091 * we fill in an inode item with the correct link count.
6092 */
6093 if (!name)
6094 set_nlink(inode, 0);
6095
6096 /*
6097 * we have to initialize this early, so we can reclaim the inode
6098 * number if we fail afterwards in this function.
6099 */
6100 inode->i_ino = objectid;
6101
6102 if (dir && name) {
6103 trace_btrfs_inode_request(dir);
6104
6105 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6106 if (ret) {
6107 btrfs_free_path(path);
6108 iput(inode);
6109 return ERR_PTR(ret);
6110 }
6111 } else if (dir) {
6112 *index = 0;
6113 }
6114 /*
6115 * index_cnt is ignored for everything but a dir,
6116 * btrfs_get_inode_index_count has an explanation for the magic
6117 * number
6118 */
6119 BTRFS_I(inode)->index_cnt = 2;
6120 BTRFS_I(inode)->dir_index = *index;
6121 BTRFS_I(inode)->root = root;
6122 BTRFS_I(inode)->generation = trans->transid;
6123 inode->i_generation = BTRFS_I(inode)->generation;
6124
6125 /*
6126 * We could have gotten an inode number from somebody who was fsynced
6127 * and then removed in this same transaction, so let's just set full
6128 * sync since it will be a full sync anyway and this will blow away the
6129 * old info in the log.
6130 */
6131 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6132
6133 key[0].objectid = objectid;
6134 key[0].type = BTRFS_INODE_ITEM_KEY;
6135 key[0].offset = 0;
6136
6137 sizes[0] = sizeof(struct btrfs_inode_item);
6138
6139 if (name) {
6140 /*
6141 * Start new inodes with an inode_ref. This is slightly more
6142 * efficient for small numbers of hard links since they will
6143 * be packed into one item. Extended refs will kick in if we
6144 * add more hard links than can fit in the ref item.
6145 */
6146 key[1].objectid = objectid;
6147 key[1].type = BTRFS_INODE_REF_KEY;
6148 key[1].offset = ref_objectid;
6149
6150 sizes[1] = name_len + sizeof(*ref);
6151 }
6152
6153 location = &BTRFS_I(inode)->location;
6154 location->objectid = objectid;
6155 location->offset = 0;
6156 location->type = BTRFS_INODE_ITEM_KEY;
6157
6158 ret = btrfs_insert_inode_locked(inode);
6159 if (ret < 0)
6160 goto fail;
6161
6162 path->leave_spinning = 1;
6163 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6164 if (ret != 0)
6165 goto fail_unlock;
6166
6167 inode_init_owner(inode, dir, mode);
6168 inode_set_bytes(inode, 0);
6169
6170 inode->i_mtime = current_time(inode);
6171 inode->i_atime = inode->i_mtime;
6172 inode->i_ctime = inode->i_mtime;
6173 BTRFS_I(inode)->i_otime = inode->i_mtime;
6174
6175 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6176 struct btrfs_inode_item);
6177 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6178 sizeof(*inode_item));
6179 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6180
6181 if (name) {
6182 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6183 struct btrfs_inode_ref);
6184 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6185 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6186 ptr = (unsigned long)(ref + 1);
6187 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6188 }
6189
6190 btrfs_mark_buffer_dirty(path->nodes[0]);
6191 btrfs_free_path(path);
6192
6193 btrfs_inherit_iflags(inode, dir);
6194
6195 if (S_ISREG(mode)) {
6196 if (btrfs_test_opt(fs_info, NODATASUM))
6197 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6198 if (btrfs_test_opt(fs_info, NODATACOW))
6199 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6200 BTRFS_INODE_NODATASUM;
6201 }
6202
6203 inode_tree_add(inode);
6204
6205 trace_btrfs_inode_new(inode);
6206 btrfs_set_inode_last_trans(trans, inode);
6207
6208 btrfs_update_root_times(trans, root);
6209
6210 ret = btrfs_inode_inherit_props(trans, inode, dir);
6211 if (ret)
6212 btrfs_err(fs_info,
6213 "error inheriting props for ino %llu (root %llu): %d",
6214 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6215
6216 return inode;
6217
6218 fail_unlock:
6219 unlock_new_inode(inode);
6220 fail:
6221 if (dir && name)
6222 BTRFS_I(dir)->index_cnt--;
6223 btrfs_free_path(path);
6224 iput(inode);
6225 return ERR_PTR(ret);
6226 }
6227
6228 static inline u8 btrfs_inode_type(struct inode *inode)
6229 {
6230 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6231 }
6232
6233 /*
6234 * utility function to add 'inode' into 'parent_inode' with
6235 * a give name and a given sequence number.
6236 * if 'add_backref' is true, also insert a backref from the
6237 * inode to the parent directory.
6238 */
6239 int btrfs_add_link(struct btrfs_trans_handle *trans,
6240 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6241 const char *name, int name_len, int add_backref, u64 index)
6242 {
6243 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6244 int ret = 0;
6245 struct btrfs_key key;
6246 struct btrfs_root *root = parent_inode->root;
6247 u64 ino = btrfs_ino(inode);
6248 u64 parent_ino = btrfs_ino(parent_inode);
6249
6250 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6251 memcpy(&key, &inode->root->root_key, sizeof(key));
6252 } else {
6253 key.objectid = ino;
6254 key.type = BTRFS_INODE_ITEM_KEY;
6255 key.offset = 0;
6256 }
6257
6258 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6259 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6260 root->root_key.objectid, parent_ino,
6261 index, name, name_len);
6262 } else if (add_backref) {
6263 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6264 parent_ino, index);
6265 }
6266
6267 /* Nothing to clean up yet */
6268 if (ret)
6269 return ret;
6270
6271 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6272 parent_inode, &key,
6273 btrfs_inode_type(&inode->vfs_inode), index);
6274 if (ret == -EEXIST || ret == -EOVERFLOW)
6275 goto fail_dir_item;
6276 else if (ret) {
6277 btrfs_abort_transaction(trans, ret);
6278 return ret;
6279 }
6280
6281 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6282 name_len * 2);
6283 inode_inc_iversion(&parent_inode->vfs_inode);
6284 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6285 current_time(&parent_inode->vfs_inode);
6286 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6287 if (ret)
6288 btrfs_abort_transaction(trans, ret);
6289 return ret;
6290
6291 fail_dir_item:
6292 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6293 u64 local_index;
6294 int err;
6295 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6296 root->root_key.objectid, parent_ino,
6297 &local_index, name, name_len);
6298
6299 } else if (add_backref) {
6300 u64 local_index;
6301 int err;
6302
6303 err = btrfs_del_inode_ref(trans, root, name, name_len,
6304 ino, parent_ino, &local_index);
6305 }
6306 return ret;
6307 }
6308
6309 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6310 struct btrfs_inode *dir, struct dentry *dentry,
6311 struct btrfs_inode *inode, int backref, u64 index)
6312 {
6313 int err = btrfs_add_link(trans, dir, inode,
6314 dentry->d_name.name, dentry->d_name.len,
6315 backref, index);
6316 if (err > 0)
6317 err = -EEXIST;
6318 return err;
6319 }
6320
6321 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6322 umode_t mode, dev_t rdev)
6323 {
6324 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6325 struct btrfs_trans_handle *trans;
6326 struct btrfs_root *root = BTRFS_I(dir)->root;
6327 struct inode *inode = NULL;
6328 int err;
6329 int drop_inode = 0;
6330 u64 objectid;
6331 u64 index = 0;
6332
6333 /*
6334 * 2 for inode item and ref
6335 * 2 for dir items
6336 * 1 for xattr if selinux is on
6337 */
6338 trans = btrfs_start_transaction(root, 5);
6339 if (IS_ERR(trans))
6340 return PTR_ERR(trans);
6341
6342 err = btrfs_find_free_ino(root, &objectid);
6343 if (err)
6344 goto out_unlock;
6345
6346 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6347 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6348 mode, &index);
6349 if (IS_ERR(inode)) {
6350 err = PTR_ERR(inode);
6351 goto out_unlock;
6352 }
6353
6354 /*
6355 * If the active LSM wants to access the inode during
6356 * d_instantiate it needs these. Smack checks to see
6357 * if the filesystem supports xattrs by looking at the
6358 * ops vector.
6359 */
6360 inode->i_op = &btrfs_special_inode_operations;
6361 init_special_inode(inode, inode->i_mode, rdev);
6362
6363 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6364 if (err)
6365 goto out_unlock_inode;
6366
6367 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6368 0, index);
6369 if (err) {
6370 goto out_unlock_inode;
6371 } else {
6372 btrfs_update_inode(trans, root, inode);
6373 unlock_new_inode(inode);
6374 d_instantiate(dentry, inode);
6375 }
6376
6377 out_unlock:
6378 btrfs_end_transaction(trans);
6379 btrfs_balance_delayed_items(fs_info);
6380 btrfs_btree_balance_dirty(fs_info);
6381 if (drop_inode) {
6382 inode_dec_link_count(inode);
6383 iput(inode);
6384 }
6385 return err;
6386
6387 out_unlock_inode:
6388 drop_inode = 1;
6389 unlock_new_inode(inode);
6390 goto out_unlock;
6391
6392 }
6393
6394 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6395 umode_t mode, bool excl)
6396 {
6397 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6398 struct btrfs_trans_handle *trans;
6399 struct btrfs_root *root = BTRFS_I(dir)->root;
6400 struct inode *inode = NULL;
6401 int drop_inode_on_err = 0;
6402 int err;
6403 u64 objectid;
6404 u64 index = 0;
6405
6406 /*
6407 * 2 for inode item and ref
6408 * 2 for dir items
6409 * 1 for xattr if selinux is on
6410 */
6411 trans = btrfs_start_transaction(root, 5);
6412 if (IS_ERR(trans))
6413 return PTR_ERR(trans);
6414
6415 err = btrfs_find_free_ino(root, &objectid);
6416 if (err)
6417 goto out_unlock;
6418
6419 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6420 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6421 mode, &index);
6422 if (IS_ERR(inode)) {
6423 err = PTR_ERR(inode);
6424 goto out_unlock;
6425 }
6426 drop_inode_on_err = 1;
6427 /*
6428 * If the active LSM wants to access the inode during
6429 * d_instantiate it needs these. Smack checks to see
6430 * if the filesystem supports xattrs by looking at the
6431 * ops vector.
6432 */
6433 inode->i_fop = &btrfs_file_operations;
6434 inode->i_op = &btrfs_file_inode_operations;
6435 inode->i_mapping->a_ops = &btrfs_aops;
6436
6437 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6438 if (err)
6439 goto out_unlock_inode;
6440
6441 err = btrfs_update_inode(trans, root, inode);
6442 if (err)
6443 goto out_unlock_inode;
6444
6445 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6446 0, index);
6447 if (err)
6448 goto out_unlock_inode;
6449
6450 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6451 unlock_new_inode(inode);
6452 d_instantiate(dentry, inode);
6453
6454 out_unlock:
6455 btrfs_end_transaction(trans);
6456 if (err && drop_inode_on_err) {
6457 inode_dec_link_count(inode);
6458 iput(inode);
6459 }
6460 btrfs_balance_delayed_items(fs_info);
6461 btrfs_btree_balance_dirty(fs_info);
6462 return err;
6463
6464 out_unlock_inode:
6465 unlock_new_inode(inode);
6466 goto out_unlock;
6467
6468 }
6469
6470 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6471 struct dentry *dentry)
6472 {
6473 struct btrfs_trans_handle *trans = NULL;
6474 struct btrfs_root *root = BTRFS_I(dir)->root;
6475 struct inode *inode = d_inode(old_dentry);
6476 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6477 u64 index;
6478 int err;
6479 int drop_inode = 0;
6480
6481 /* do not allow sys_link's with other subvols of the same device */
6482 if (root->objectid != BTRFS_I(inode)->root->objectid)
6483 return -EXDEV;
6484
6485 if (inode->i_nlink >= BTRFS_LINK_MAX)
6486 return -EMLINK;
6487
6488 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6489 if (err)
6490 goto fail;
6491
6492 /*
6493 * 2 items for inode and inode ref
6494 * 2 items for dir items
6495 * 1 item for parent inode
6496 */
6497 trans = btrfs_start_transaction(root, 5);
6498 if (IS_ERR(trans)) {
6499 err = PTR_ERR(trans);
6500 trans = NULL;
6501 goto fail;
6502 }
6503
6504 /* There are several dir indexes for this inode, clear the cache. */
6505 BTRFS_I(inode)->dir_index = 0ULL;
6506 inc_nlink(inode);
6507 inode_inc_iversion(inode);
6508 inode->i_ctime = current_time(inode);
6509 ihold(inode);
6510 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6511
6512 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6513 1, index);
6514
6515 if (err) {
6516 drop_inode = 1;
6517 } else {
6518 struct dentry *parent = dentry->d_parent;
6519 err = btrfs_update_inode(trans, root, inode);
6520 if (err)
6521 goto fail;
6522 if (inode->i_nlink == 1) {
6523 /*
6524 * If new hard link count is 1, it's a file created
6525 * with open(2) O_TMPFILE flag.
6526 */
6527 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6528 if (err)
6529 goto fail;
6530 }
6531 d_instantiate(dentry, inode);
6532 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6533 }
6534
6535 btrfs_balance_delayed_items(fs_info);
6536 fail:
6537 if (trans)
6538 btrfs_end_transaction(trans);
6539 if (drop_inode) {
6540 inode_dec_link_count(inode);
6541 iput(inode);
6542 }
6543 btrfs_btree_balance_dirty(fs_info);
6544 return err;
6545 }
6546
6547 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6548 {
6549 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6550 struct inode *inode = NULL;
6551 struct btrfs_trans_handle *trans;
6552 struct btrfs_root *root = BTRFS_I(dir)->root;
6553 int err = 0;
6554 int drop_on_err = 0;
6555 u64 objectid = 0;
6556 u64 index = 0;
6557
6558 /*
6559 * 2 items for inode and ref
6560 * 2 items for dir items
6561 * 1 for xattr if selinux is on
6562 */
6563 trans = btrfs_start_transaction(root, 5);
6564 if (IS_ERR(trans))
6565 return PTR_ERR(trans);
6566
6567 err = btrfs_find_free_ino(root, &objectid);
6568 if (err)
6569 goto out_fail;
6570
6571 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6572 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6573 S_IFDIR | mode, &index);
6574 if (IS_ERR(inode)) {
6575 err = PTR_ERR(inode);
6576 goto out_fail;
6577 }
6578
6579 drop_on_err = 1;
6580 /* these must be set before we unlock the inode */
6581 inode->i_op = &btrfs_dir_inode_operations;
6582 inode->i_fop = &btrfs_dir_file_operations;
6583
6584 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6585 if (err)
6586 goto out_fail_inode;
6587
6588 btrfs_i_size_write(BTRFS_I(inode), 0);
6589 err = btrfs_update_inode(trans, root, inode);
6590 if (err)
6591 goto out_fail_inode;
6592
6593 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6594 dentry->d_name.name,
6595 dentry->d_name.len, 0, index);
6596 if (err)
6597 goto out_fail_inode;
6598
6599 d_instantiate(dentry, inode);
6600 /*
6601 * mkdir is special. We're unlocking after we call d_instantiate
6602 * to avoid a race with nfsd calling d_instantiate.
6603 */
6604 unlock_new_inode(inode);
6605 drop_on_err = 0;
6606
6607 out_fail:
6608 btrfs_end_transaction(trans);
6609 if (drop_on_err) {
6610 inode_dec_link_count(inode);
6611 iput(inode);
6612 }
6613 btrfs_balance_delayed_items(fs_info);
6614 btrfs_btree_balance_dirty(fs_info);
6615 return err;
6616
6617 out_fail_inode:
6618 unlock_new_inode(inode);
6619 goto out_fail;
6620 }
6621
6622 /* Find next extent map of a given extent map, caller needs to ensure locks */
6623 static struct extent_map *next_extent_map(struct extent_map *em)
6624 {
6625 struct rb_node *next;
6626
6627 next = rb_next(&em->rb_node);
6628 if (!next)
6629 return NULL;
6630 return container_of(next, struct extent_map, rb_node);
6631 }
6632
6633 static struct extent_map *prev_extent_map(struct extent_map *em)
6634 {
6635 struct rb_node *prev;
6636
6637 prev = rb_prev(&em->rb_node);
6638 if (!prev)
6639 return NULL;
6640 return container_of(prev, struct extent_map, rb_node);
6641 }
6642
6643 /* helper for btfs_get_extent. Given an existing extent in the tree,
6644 * the existing extent is the nearest extent to map_start,
6645 * and an extent that you want to insert, deal with overlap and insert
6646 * the best fitted new extent into the tree.
6647 */
6648 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6649 struct extent_map *existing,
6650 struct extent_map *em,
6651 u64 map_start)
6652 {
6653 struct extent_map *prev;
6654 struct extent_map *next;
6655 u64 start;
6656 u64 end;
6657 u64 start_diff;
6658
6659 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6660
6661 if (existing->start > map_start) {
6662 next = existing;
6663 prev = prev_extent_map(next);
6664 } else {
6665 prev = existing;
6666 next = next_extent_map(prev);
6667 }
6668
6669 start = prev ? extent_map_end(prev) : em->start;
6670 start = max_t(u64, start, em->start);
6671 end = next ? next->start : extent_map_end(em);
6672 end = min_t(u64, end, extent_map_end(em));
6673 start_diff = start - em->start;
6674 em->start = start;
6675 em->len = end - start;
6676 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6677 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6678 em->block_start += start_diff;
6679 em->block_len -= start_diff;
6680 }
6681 return add_extent_mapping(em_tree, em, 0);
6682 }
6683
6684 static noinline int uncompress_inline(struct btrfs_path *path,
6685 struct page *page,
6686 size_t pg_offset, u64 extent_offset,
6687 struct btrfs_file_extent_item *item)
6688 {
6689 int ret;
6690 struct extent_buffer *leaf = path->nodes[0];
6691 char *tmp;
6692 size_t max_size;
6693 unsigned long inline_size;
6694 unsigned long ptr;
6695 int compress_type;
6696
6697 WARN_ON(pg_offset != 0);
6698 compress_type = btrfs_file_extent_compression(leaf, item);
6699 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6700 inline_size = btrfs_file_extent_inline_item_len(leaf,
6701 btrfs_item_nr(path->slots[0]));
6702 tmp = kmalloc(inline_size, GFP_NOFS);
6703 if (!tmp)
6704 return -ENOMEM;
6705 ptr = btrfs_file_extent_inline_start(item);
6706
6707 read_extent_buffer(leaf, tmp, ptr, inline_size);
6708
6709 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6710 ret = btrfs_decompress(compress_type, tmp, page,
6711 extent_offset, inline_size, max_size);
6712
6713 /*
6714 * decompression code contains a memset to fill in any space between the end
6715 * of the uncompressed data and the end of max_size in case the decompressed
6716 * data ends up shorter than ram_bytes. That doesn't cover the hole between
6717 * the end of an inline extent and the beginning of the next block, so we
6718 * cover that region here.
6719 */
6720
6721 if (max_size + pg_offset < PAGE_SIZE) {
6722 char *map = kmap(page);
6723 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6724 kunmap(page);
6725 }
6726 kfree(tmp);
6727 return ret;
6728 }
6729
6730 /*
6731 * a bit scary, this does extent mapping from logical file offset to the disk.
6732 * the ugly parts come from merging extents from the disk with the in-ram
6733 * representation. This gets more complex because of the data=ordered code,
6734 * where the in-ram extents might be locked pending data=ordered completion.
6735 *
6736 * This also copies inline extents directly into the page.
6737 */
6738
6739 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6740 struct page *page,
6741 size_t pg_offset, u64 start, u64 len,
6742 int create)
6743 {
6744 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6745 int ret;
6746 int err = 0;
6747 u64 extent_start = 0;
6748 u64 extent_end = 0;
6749 u64 objectid = btrfs_ino(inode);
6750 u32 found_type;
6751 struct btrfs_path *path = NULL;
6752 struct btrfs_root *root = inode->root;
6753 struct btrfs_file_extent_item *item;
6754 struct extent_buffer *leaf;
6755 struct btrfs_key found_key;
6756 struct extent_map *em = NULL;
6757 struct extent_map_tree *em_tree = &inode->extent_tree;
6758 struct extent_io_tree *io_tree = &inode->io_tree;
6759 struct btrfs_trans_handle *trans = NULL;
6760 const bool new_inline = !page || create;
6761
6762 again:
6763 read_lock(&em_tree->lock);
6764 em = lookup_extent_mapping(em_tree, start, len);
6765 if (em)
6766 em->bdev = fs_info->fs_devices->latest_bdev;
6767 read_unlock(&em_tree->lock);
6768
6769 if (em) {
6770 if (em->start > start || em->start + em->len <= start)
6771 free_extent_map(em);
6772 else if (em->block_start == EXTENT_MAP_INLINE && page)
6773 free_extent_map(em);
6774 else
6775 goto out;
6776 }
6777 em = alloc_extent_map();
6778 if (!em) {
6779 err = -ENOMEM;
6780 goto out;
6781 }
6782 em->bdev = fs_info->fs_devices->latest_bdev;
6783 em->start = EXTENT_MAP_HOLE;
6784 em->orig_start = EXTENT_MAP_HOLE;
6785 em->len = (u64)-1;
6786 em->block_len = (u64)-1;
6787
6788 if (!path) {
6789 path = btrfs_alloc_path();
6790 if (!path) {
6791 err = -ENOMEM;
6792 goto out;
6793 }
6794 /*
6795 * Chances are we'll be called again, so go ahead and do
6796 * readahead
6797 */
6798 path->reada = READA_FORWARD;
6799 }
6800
6801 ret = btrfs_lookup_file_extent(trans, root, path,
6802 objectid, start, trans != NULL);
6803 if (ret < 0) {
6804 err = ret;
6805 goto out;
6806 }
6807
6808 if (ret != 0) {
6809 if (path->slots[0] == 0)
6810 goto not_found;
6811 path->slots[0]--;
6812 }
6813
6814 leaf = path->nodes[0];
6815 item = btrfs_item_ptr(leaf, path->slots[0],
6816 struct btrfs_file_extent_item);
6817 /* are we inside the extent that was found? */
6818 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6819 found_type = found_key.type;
6820 if (found_key.objectid != objectid ||
6821 found_type != BTRFS_EXTENT_DATA_KEY) {
6822 /*
6823 * If we backup past the first extent we want to move forward
6824 * and see if there is an extent in front of us, otherwise we'll
6825 * say there is a hole for our whole search range which can
6826 * cause problems.
6827 */
6828 extent_end = start;
6829 goto next;
6830 }
6831
6832 found_type = btrfs_file_extent_type(leaf, item);
6833 extent_start = found_key.offset;
6834 if (found_type == BTRFS_FILE_EXTENT_REG ||
6835 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6836 extent_end = extent_start +
6837 btrfs_file_extent_num_bytes(leaf, item);
6838 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6839 size_t size;
6840 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6841 extent_end = ALIGN(extent_start + size,
6842 fs_info->sectorsize);
6843 }
6844 next:
6845 if (start >= extent_end) {
6846 path->slots[0]++;
6847 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6848 ret = btrfs_next_leaf(root, path);
6849 if (ret < 0) {
6850 err = ret;
6851 goto out;
6852 }
6853 if (ret > 0)
6854 goto not_found;
6855 leaf = path->nodes[0];
6856 }
6857 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6858 if (found_key.objectid != objectid ||
6859 found_key.type != BTRFS_EXTENT_DATA_KEY)
6860 goto not_found;
6861 if (start + len <= found_key.offset)
6862 goto not_found;
6863 if (start > found_key.offset)
6864 goto next;
6865 em->start = start;
6866 em->orig_start = start;
6867 em->len = found_key.offset - start;
6868 goto not_found_em;
6869 }
6870
6871 btrfs_extent_item_to_extent_map(inode, path, item,
6872 new_inline, em);
6873
6874 if (found_type == BTRFS_FILE_EXTENT_REG ||
6875 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6876 goto insert;
6877 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6878 unsigned long ptr;
6879 char *map;
6880 size_t size;
6881 size_t extent_offset;
6882 size_t copy_size;
6883
6884 if (new_inline)
6885 goto out;
6886
6887 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6888 extent_offset = page_offset(page) + pg_offset - extent_start;
6889 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6890 size - extent_offset);
6891 em->start = extent_start + extent_offset;
6892 em->len = ALIGN(copy_size, fs_info->sectorsize);
6893 em->orig_block_len = em->len;
6894 em->orig_start = em->start;
6895 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6896 if (create == 0 && !PageUptodate(page)) {
6897 if (btrfs_file_extent_compression(leaf, item) !=
6898 BTRFS_COMPRESS_NONE) {
6899 ret = uncompress_inline(path, page, pg_offset,
6900 extent_offset, item);
6901 if (ret) {
6902 err = ret;
6903 goto out;
6904 }
6905 } else {
6906 map = kmap(page);
6907 read_extent_buffer(leaf, map + pg_offset, ptr,
6908 copy_size);
6909 if (pg_offset + copy_size < PAGE_SIZE) {
6910 memset(map + pg_offset + copy_size, 0,
6911 PAGE_SIZE - pg_offset -
6912 copy_size);
6913 }
6914 kunmap(page);
6915 }
6916 flush_dcache_page(page);
6917 } else if (create && PageUptodate(page)) {
6918 BUG();
6919 if (!trans) {
6920 kunmap(page);
6921 free_extent_map(em);
6922 em = NULL;
6923
6924 btrfs_release_path(path);
6925 trans = btrfs_join_transaction(root);
6926
6927 if (IS_ERR(trans))
6928 return ERR_CAST(trans);
6929 goto again;
6930 }
6931 map = kmap(page);
6932 write_extent_buffer(leaf, map + pg_offset, ptr,
6933 copy_size);
6934 kunmap(page);
6935 btrfs_mark_buffer_dirty(leaf);
6936 }
6937 set_extent_uptodate(io_tree, em->start,
6938 extent_map_end(em) - 1, NULL, GFP_NOFS);
6939 goto insert;
6940 }
6941 not_found:
6942 em->start = start;
6943 em->orig_start = start;
6944 em->len = len;
6945 not_found_em:
6946 em->block_start = EXTENT_MAP_HOLE;
6947 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6948 insert:
6949 btrfs_release_path(path);
6950 if (em->start > start || extent_map_end(em) <= start) {
6951 btrfs_err(fs_info,
6952 "bad extent! em: [%llu %llu] passed [%llu %llu]",
6953 em->start, em->len, start, len);
6954 err = -EIO;
6955 goto out;
6956 }
6957
6958 err = 0;
6959 write_lock(&em_tree->lock);
6960 ret = add_extent_mapping(em_tree, em, 0);
6961 /* it is possible that someone inserted the extent into the tree
6962 * while we had the lock dropped. It is also possible that
6963 * an overlapping map exists in the tree
6964 */
6965 if (ret == -EEXIST) {
6966 struct extent_map *existing;
6967
6968 ret = 0;
6969
6970 existing = search_extent_mapping(em_tree, start, len);
6971 /*
6972 * existing will always be non-NULL, since there must be
6973 * extent causing the -EEXIST.
6974 */
6975 if (existing->start == em->start &&
6976 extent_map_end(existing) >= extent_map_end(em) &&
6977 em->block_start == existing->block_start) {
6978 /*
6979 * The existing extent map already encompasses the
6980 * entire extent map we tried to add.
6981 */
6982 free_extent_map(em);
6983 em = existing;
6984 err = 0;
6985
6986 } else if (start >= extent_map_end(existing) ||
6987 start <= existing->start) {
6988 /*
6989 * The existing extent map is the one nearest to
6990 * the [start, start + len) range which overlaps
6991 */
6992 err = merge_extent_mapping(em_tree, existing,
6993 em, start);
6994 free_extent_map(existing);
6995 if (err) {
6996 free_extent_map(em);
6997 em = NULL;
6998 }
6999 } else {
7000 free_extent_map(em);
7001 em = existing;
7002 err = 0;
7003 }
7004 }
7005 write_unlock(&em_tree->lock);
7006 out:
7007
7008 trace_btrfs_get_extent(root, inode, em);
7009
7010 btrfs_free_path(path);
7011 if (trans) {
7012 ret = btrfs_end_transaction(trans);
7013 if (!err)
7014 err = ret;
7015 }
7016 if (err) {
7017 free_extent_map(em);
7018 return ERR_PTR(err);
7019 }
7020 BUG_ON(!em); /* Error is always set */
7021 return em;
7022 }
7023
7024 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7025 struct page *page,
7026 size_t pg_offset, u64 start, u64 len,
7027 int create)
7028 {
7029 struct extent_map *em;
7030 struct extent_map *hole_em = NULL;
7031 u64 range_start = start;
7032 u64 end;
7033 u64 found;
7034 u64 found_end;
7035 int err = 0;
7036
7037 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7038 if (IS_ERR(em))
7039 return em;
7040 if (em) {
7041 /*
7042 * if our em maps to
7043 * - a hole or
7044 * - a pre-alloc extent,
7045 * there might actually be delalloc bytes behind it.
7046 */
7047 if (em->block_start != EXTENT_MAP_HOLE &&
7048 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7049 return em;
7050 else
7051 hole_em = em;
7052 }
7053
7054 /* check to see if we've wrapped (len == -1 or similar) */
7055 end = start + len;
7056 if (end < start)
7057 end = (u64)-1;
7058 else
7059 end -= 1;
7060
7061 em = NULL;
7062
7063 /* ok, we didn't find anything, lets look for delalloc */
7064 found = count_range_bits(&inode->io_tree, &range_start,
7065 end, len, EXTENT_DELALLOC, 1);
7066 found_end = range_start + found;
7067 if (found_end < range_start)
7068 found_end = (u64)-1;
7069
7070 /*
7071 * we didn't find anything useful, return
7072 * the original results from get_extent()
7073 */
7074 if (range_start > end || found_end <= start) {
7075 em = hole_em;
7076 hole_em = NULL;
7077 goto out;
7078 }
7079
7080 /* adjust the range_start to make sure it doesn't
7081 * go backwards from the start they passed in
7082 */
7083 range_start = max(start, range_start);
7084 found = found_end - range_start;
7085
7086 if (found > 0) {
7087 u64 hole_start = start;
7088 u64 hole_len = len;
7089
7090 em = alloc_extent_map();
7091 if (!em) {
7092 err = -ENOMEM;
7093 goto out;
7094 }
7095 /*
7096 * when btrfs_get_extent can't find anything it
7097 * returns one huge hole
7098 *
7099 * make sure what it found really fits our range, and
7100 * adjust to make sure it is based on the start from
7101 * the caller
7102 */
7103 if (hole_em) {
7104 u64 calc_end = extent_map_end(hole_em);
7105
7106 if (calc_end <= start || (hole_em->start > end)) {
7107 free_extent_map(hole_em);
7108 hole_em = NULL;
7109 } else {
7110 hole_start = max(hole_em->start, start);
7111 hole_len = calc_end - hole_start;
7112 }
7113 }
7114 em->bdev = NULL;
7115 if (hole_em && range_start > hole_start) {
7116 /* our hole starts before our delalloc, so we
7117 * have to return just the parts of the hole
7118 * that go until the delalloc starts
7119 */
7120 em->len = min(hole_len,
7121 range_start - hole_start);
7122 em->start = hole_start;
7123 em->orig_start = hole_start;
7124 /*
7125 * don't adjust block start at all,
7126 * it is fixed at EXTENT_MAP_HOLE
7127 */
7128 em->block_start = hole_em->block_start;
7129 em->block_len = hole_len;
7130 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7131 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7132 } else {
7133 em->start = range_start;
7134 em->len = found;
7135 em->orig_start = range_start;
7136 em->block_start = EXTENT_MAP_DELALLOC;
7137 em->block_len = found;
7138 }
7139 } else if (hole_em) {
7140 return hole_em;
7141 }
7142 out:
7143
7144 free_extent_map(hole_em);
7145 if (err) {
7146 free_extent_map(em);
7147 return ERR_PTR(err);
7148 }
7149 return em;
7150 }
7151
7152 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7153 const u64 start,
7154 const u64 len,
7155 const u64 orig_start,
7156 const u64 block_start,
7157 const u64 block_len,
7158 const u64 orig_block_len,
7159 const u64 ram_bytes,
7160 const int type)
7161 {
7162 struct extent_map *em = NULL;
7163 int ret;
7164
7165 if (type != BTRFS_ORDERED_NOCOW) {
7166 em = create_io_em(inode, start, len, orig_start,
7167 block_start, block_len, orig_block_len,
7168 ram_bytes,
7169 BTRFS_COMPRESS_NONE, /* compress_type */
7170 type);
7171 if (IS_ERR(em))
7172 goto out;
7173 }
7174 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7175 len, block_len, type);
7176 if (ret) {
7177 if (em) {
7178 free_extent_map(em);
7179 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7180 start + len - 1, 0);
7181 }
7182 em = ERR_PTR(ret);
7183 }
7184 out:
7185
7186 return em;
7187 }
7188
7189 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7190 u64 start, u64 len)
7191 {
7192 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7193 struct btrfs_root *root = BTRFS_I(inode)->root;
7194 struct extent_map *em;
7195 struct btrfs_key ins;
7196 u64 alloc_hint;
7197 int ret;
7198
7199 alloc_hint = get_extent_allocation_hint(inode, start, len);
7200 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7201 0, alloc_hint, &ins, 1, 1);
7202 if (ret)
7203 return ERR_PTR(ret);
7204
7205 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7206 ins.objectid, ins.offset, ins.offset,
7207 ins.offset, BTRFS_ORDERED_REGULAR);
7208 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7209 if (IS_ERR(em))
7210 btrfs_free_reserved_extent(fs_info, ins.objectid,
7211 ins.offset, 1);
7212
7213 return em;
7214 }
7215
7216 /*
7217 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7218 * block must be cow'd
7219 */
7220 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7221 u64 *orig_start, u64 *orig_block_len,
7222 u64 *ram_bytes)
7223 {
7224 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7225 struct btrfs_path *path;
7226 int ret;
7227 struct extent_buffer *leaf;
7228 struct btrfs_root *root = BTRFS_I(inode)->root;
7229 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7230 struct btrfs_file_extent_item *fi;
7231 struct btrfs_key key;
7232 u64 disk_bytenr;
7233 u64 backref_offset;
7234 u64 extent_end;
7235 u64 num_bytes;
7236 int slot;
7237 int found_type;
7238 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7239
7240 path = btrfs_alloc_path();
7241 if (!path)
7242 return -ENOMEM;
7243
7244 ret = btrfs_lookup_file_extent(NULL, root, path,
7245 btrfs_ino(BTRFS_I(inode)), offset, 0);
7246 if (ret < 0)
7247 goto out;
7248
7249 slot = path->slots[0];
7250 if (ret == 1) {
7251 if (slot == 0) {
7252 /* can't find the item, must cow */
7253 ret = 0;
7254 goto out;
7255 }
7256 slot--;
7257 }
7258 ret = 0;
7259 leaf = path->nodes[0];
7260 btrfs_item_key_to_cpu(leaf, &key, slot);
7261 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7262 key.type != BTRFS_EXTENT_DATA_KEY) {
7263 /* not our file or wrong item type, must cow */
7264 goto out;
7265 }
7266
7267 if (key.offset > offset) {
7268 /* Wrong offset, must cow */
7269 goto out;
7270 }
7271
7272 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7273 found_type = btrfs_file_extent_type(leaf, fi);
7274 if (found_type != BTRFS_FILE_EXTENT_REG &&
7275 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7276 /* not a regular extent, must cow */
7277 goto out;
7278 }
7279
7280 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7281 goto out;
7282
7283 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7284 if (extent_end <= offset)
7285 goto out;
7286
7287 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7288 if (disk_bytenr == 0)
7289 goto out;
7290
7291 if (btrfs_file_extent_compression(leaf, fi) ||
7292 btrfs_file_extent_encryption(leaf, fi) ||
7293 btrfs_file_extent_other_encoding(leaf, fi))
7294 goto out;
7295
7296 backref_offset = btrfs_file_extent_offset(leaf, fi);
7297
7298 if (orig_start) {
7299 *orig_start = key.offset - backref_offset;
7300 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7301 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7302 }
7303
7304 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7305 goto out;
7306
7307 num_bytes = min(offset + *len, extent_end) - offset;
7308 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7309 u64 range_end;
7310
7311 range_end = round_up(offset + num_bytes,
7312 root->fs_info->sectorsize) - 1;
7313 ret = test_range_bit(io_tree, offset, range_end,
7314 EXTENT_DELALLOC, 0, NULL);
7315 if (ret) {
7316 ret = -EAGAIN;
7317 goto out;
7318 }
7319 }
7320
7321 btrfs_release_path(path);
7322
7323 /*
7324 * look for other files referencing this extent, if we
7325 * find any we must cow
7326 */
7327
7328 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7329 key.offset - backref_offset, disk_bytenr);
7330 if (ret) {
7331 ret = 0;
7332 goto out;
7333 }
7334
7335 /*
7336 * adjust disk_bytenr and num_bytes to cover just the bytes
7337 * in this extent we are about to write. If there
7338 * are any csums in that range we have to cow in order
7339 * to keep the csums correct
7340 */
7341 disk_bytenr += backref_offset;
7342 disk_bytenr += offset - key.offset;
7343 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7344 goto out;
7345 /*
7346 * all of the above have passed, it is safe to overwrite this extent
7347 * without cow
7348 */
7349 *len = num_bytes;
7350 ret = 1;
7351 out:
7352 btrfs_free_path(path);
7353 return ret;
7354 }
7355
7356 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7357 {
7358 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7359 int found = false;
7360 void **pagep = NULL;
7361 struct page *page = NULL;
7362 int start_idx;
7363 int end_idx;
7364
7365 start_idx = start >> PAGE_SHIFT;
7366
7367 /*
7368 * end is the last byte in the last page. end == start is legal
7369 */
7370 end_idx = end >> PAGE_SHIFT;
7371
7372 rcu_read_lock();
7373
7374 /* Most of the code in this while loop is lifted from
7375 * find_get_page. It's been modified to begin searching from a
7376 * page and return just the first page found in that range. If the
7377 * found idx is less than or equal to the end idx then we know that
7378 * a page exists. If no pages are found or if those pages are
7379 * outside of the range then we're fine (yay!) */
7380 while (page == NULL &&
7381 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7382 page = radix_tree_deref_slot(pagep);
7383 if (unlikely(!page))
7384 break;
7385
7386 if (radix_tree_exception(page)) {
7387 if (radix_tree_deref_retry(page)) {
7388 page = NULL;
7389 continue;
7390 }
7391 /*
7392 * Otherwise, shmem/tmpfs must be storing a swap entry
7393 * here as an exceptional entry: so return it without
7394 * attempting to raise page count.
7395 */
7396 page = NULL;
7397 break; /* TODO: Is this relevant for this use case? */
7398 }
7399
7400 if (!page_cache_get_speculative(page)) {
7401 page = NULL;
7402 continue;
7403 }
7404
7405 /*
7406 * Has the page moved?
7407 * This is part of the lockless pagecache protocol. See
7408 * include/linux/pagemap.h for details.
7409 */
7410 if (unlikely(page != *pagep)) {
7411 put_page(page);
7412 page = NULL;
7413 }
7414 }
7415
7416 if (page) {
7417 if (page->index <= end_idx)
7418 found = true;
7419 put_page(page);
7420 }
7421
7422 rcu_read_unlock();
7423 return found;
7424 }
7425
7426 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7427 struct extent_state **cached_state, int writing)
7428 {
7429 struct btrfs_ordered_extent *ordered;
7430 int ret = 0;
7431
7432 while (1) {
7433 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7434 cached_state);
7435 /*
7436 * We're concerned with the entire range that we're going to be
7437 * doing DIO to, so we need to make sure there's no ordered
7438 * extents in this range.
7439 */
7440 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7441 lockend - lockstart + 1);
7442
7443 /*
7444 * We need to make sure there are no buffered pages in this
7445 * range either, we could have raced between the invalidate in
7446 * generic_file_direct_write and locking the extent. The
7447 * invalidate needs to happen so that reads after a write do not
7448 * get stale data.
7449 */
7450 if (!ordered &&
7451 (!writing ||
7452 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7453 break;
7454
7455 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7456 cached_state, GFP_NOFS);
7457
7458 if (ordered) {
7459 /*
7460 * If we are doing a DIO read and the ordered extent we
7461 * found is for a buffered write, we can not wait for it
7462 * to complete and retry, because if we do so we can
7463 * deadlock with concurrent buffered writes on page
7464 * locks. This happens only if our DIO read covers more
7465 * than one extent map, if at this point has already
7466 * created an ordered extent for a previous extent map
7467 * and locked its range in the inode's io tree, and a
7468 * concurrent write against that previous extent map's
7469 * range and this range started (we unlock the ranges
7470 * in the io tree only when the bios complete and
7471 * buffered writes always lock pages before attempting
7472 * to lock range in the io tree).
7473 */
7474 if (writing ||
7475 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7476 btrfs_start_ordered_extent(inode, ordered, 1);
7477 else
7478 ret = -ENOTBLK;
7479 btrfs_put_ordered_extent(ordered);
7480 } else {
7481 /*
7482 * We could trigger writeback for this range (and wait
7483 * for it to complete) and then invalidate the pages for
7484 * this range (through invalidate_inode_pages2_range()),
7485 * but that can lead us to a deadlock with a concurrent
7486 * call to readpages() (a buffered read or a defrag call
7487 * triggered a readahead) on a page lock due to an
7488 * ordered dio extent we created before but did not have
7489 * yet a corresponding bio submitted (whence it can not
7490 * complete), which makes readpages() wait for that
7491 * ordered extent to complete while holding a lock on
7492 * that page.
7493 */
7494 ret = -ENOTBLK;
7495 }
7496
7497 if (ret)
7498 break;
7499
7500 cond_resched();
7501 }
7502
7503 return ret;
7504 }
7505
7506 /* The callers of this must take lock_extent() */
7507 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7508 u64 orig_start, u64 block_start,
7509 u64 block_len, u64 orig_block_len,
7510 u64 ram_bytes, int compress_type,
7511 int type)
7512 {
7513 struct extent_map_tree *em_tree;
7514 struct extent_map *em;
7515 struct btrfs_root *root = BTRFS_I(inode)->root;
7516 int ret;
7517
7518 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7519 type == BTRFS_ORDERED_COMPRESSED ||
7520 type == BTRFS_ORDERED_NOCOW ||
7521 type == BTRFS_ORDERED_REGULAR);
7522
7523 em_tree = &BTRFS_I(inode)->extent_tree;
7524 em = alloc_extent_map();
7525 if (!em)
7526 return ERR_PTR(-ENOMEM);
7527
7528 em->start = start;
7529 em->orig_start = orig_start;
7530 em->len = len;
7531 em->block_len = block_len;
7532 em->block_start = block_start;
7533 em->bdev = root->fs_info->fs_devices->latest_bdev;
7534 em->orig_block_len = orig_block_len;
7535 em->ram_bytes = ram_bytes;
7536 em->generation = -1;
7537 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7538 if (type == BTRFS_ORDERED_PREALLOC) {
7539 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7540 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7541 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7542 em->compress_type = compress_type;
7543 }
7544
7545 do {
7546 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7547 em->start + em->len - 1, 0);
7548 write_lock(&em_tree->lock);
7549 ret = add_extent_mapping(em_tree, em, 1);
7550 write_unlock(&em_tree->lock);
7551 /*
7552 * The caller has taken lock_extent(), who could race with us
7553 * to add em?
7554 */
7555 } while (ret == -EEXIST);
7556
7557 if (ret) {
7558 free_extent_map(em);
7559 return ERR_PTR(ret);
7560 }
7561
7562 /* em got 2 refs now, callers needs to do free_extent_map once. */
7563 return em;
7564 }
7565
7566 static void adjust_dio_outstanding_extents(struct inode *inode,
7567 struct btrfs_dio_data *dio_data,
7568 const u64 len)
7569 {
7570 unsigned num_extents = count_max_extents(len);
7571
7572 /*
7573 * If we have an outstanding_extents count still set then we're
7574 * within our reservation, otherwise we need to adjust our inode
7575 * counter appropriately.
7576 */
7577 if (dio_data->outstanding_extents >= num_extents) {
7578 dio_data->outstanding_extents -= num_extents;
7579 } else {
7580 /*
7581 * If dio write length has been split due to no large enough
7582 * contiguous space, we need to compensate our inode counter
7583 * appropriately.
7584 */
7585 u64 num_needed = num_extents - dio_data->outstanding_extents;
7586
7587 spin_lock(&BTRFS_I(inode)->lock);
7588 BTRFS_I(inode)->outstanding_extents += num_needed;
7589 spin_unlock(&BTRFS_I(inode)->lock);
7590 }
7591 }
7592
7593 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7594 struct buffer_head *bh_result, int create)
7595 {
7596 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7597 struct extent_map *em;
7598 struct extent_state *cached_state = NULL;
7599 struct btrfs_dio_data *dio_data = NULL;
7600 u64 start = iblock << inode->i_blkbits;
7601 u64 lockstart, lockend;
7602 u64 len = bh_result->b_size;
7603 int unlock_bits = EXTENT_LOCKED;
7604 int ret = 0;
7605
7606 if (create)
7607 unlock_bits |= EXTENT_DIRTY;
7608 else
7609 len = min_t(u64, len, fs_info->sectorsize);
7610
7611 lockstart = start;
7612 lockend = start + len - 1;
7613
7614 if (current->journal_info) {
7615 /*
7616 * Need to pull our outstanding extents and set journal_info to NULL so
7617 * that anything that needs to check if there's a transaction doesn't get
7618 * confused.
7619 */
7620 dio_data = current->journal_info;
7621 current->journal_info = NULL;
7622 }
7623
7624 /*
7625 * If this errors out it's because we couldn't invalidate pagecache for
7626 * this range and we need to fallback to buffered.
7627 */
7628 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7629 create)) {
7630 ret = -ENOTBLK;
7631 goto err;
7632 }
7633
7634 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7635 if (IS_ERR(em)) {
7636 ret = PTR_ERR(em);
7637 goto unlock_err;
7638 }
7639
7640 /*
7641 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7642 * io. INLINE is special, and we could probably kludge it in here, but
7643 * it's still buffered so for safety lets just fall back to the generic
7644 * buffered path.
7645 *
7646 * For COMPRESSED we _have_ to read the entire extent in so we can
7647 * decompress it, so there will be buffering required no matter what we
7648 * do, so go ahead and fallback to buffered.
7649 *
7650 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7651 * to buffered IO. Don't blame me, this is the price we pay for using
7652 * the generic code.
7653 */
7654 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7655 em->block_start == EXTENT_MAP_INLINE) {
7656 free_extent_map(em);
7657 ret = -ENOTBLK;
7658 goto unlock_err;
7659 }
7660
7661 /* Just a good old fashioned hole, return */
7662 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7663 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7664 free_extent_map(em);
7665 goto unlock_err;
7666 }
7667
7668 /*
7669 * We don't allocate a new extent in the following cases
7670 *
7671 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7672 * existing extent.
7673 * 2) The extent is marked as PREALLOC. We're good to go here and can
7674 * just use the extent.
7675 *
7676 */
7677 if (!create) {
7678 len = min(len, em->len - (start - em->start));
7679 lockstart = start + len;
7680 goto unlock;
7681 }
7682
7683 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7684 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7685 em->block_start != EXTENT_MAP_HOLE)) {
7686 int type;
7687 u64 block_start, orig_start, orig_block_len, ram_bytes;
7688
7689 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7690 type = BTRFS_ORDERED_PREALLOC;
7691 else
7692 type = BTRFS_ORDERED_NOCOW;
7693 len = min(len, em->len - (start - em->start));
7694 block_start = em->block_start + (start - em->start);
7695
7696 if (can_nocow_extent(inode, start, &len, &orig_start,
7697 &orig_block_len, &ram_bytes) == 1 &&
7698 btrfs_inc_nocow_writers(fs_info, block_start)) {
7699 struct extent_map *em2;
7700
7701 em2 = btrfs_create_dio_extent(inode, start, len,
7702 orig_start, block_start,
7703 len, orig_block_len,
7704 ram_bytes, type);
7705 btrfs_dec_nocow_writers(fs_info, block_start);
7706 if (type == BTRFS_ORDERED_PREALLOC) {
7707 free_extent_map(em);
7708 em = em2;
7709 }
7710 if (em2 && IS_ERR(em2)) {
7711 ret = PTR_ERR(em2);
7712 goto unlock_err;
7713 }
7714 /*
7715 * For inode marked NODATACOW or extent marked PREALLOC,
7716 * use the existing or preallocated extent, so does not
7717 * need to adjust btrfs_space_info's bytes_may_use.
7718 */
7719 btrfs_free_reserved_data_space_noquota(inode,
7720 start, len);
7721 goto unlock;
7722 }
7723 }
7724
7725 /*
7726 * this will cow the extent, reset the len in case we changed
7727 * it above
7728 */
7729 len = bh_result->b_size;
7730 free_extent_map(em);
7731 em = btrfs_new_extent_direct(inode, start, len);
7732 if (IS_ERR(em)) {
7733 ret = PTR_ERR(em);
7734 goto unlock_err;
7735 }
7736 len = min(len, em->len - (start - em->start));
7737 unlock:
7738 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7739 inode->i_blkbits;
7740 bh_result->b_size = len;
7741 bh_result->b_bdev = em->bdev;
7742 set_buffer_mapped(bh_result);
7743 if (create) {
7744 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7745 set_buffer_new(bh_result);
7746
7747 /*
7748 * Need to update the i_size under the extent lock so buffered
7749 * readers will get the updated i_size when we unlock.
7750 */
7751 if (!dio_data->overwrite && start + len > i_size_read(inode))
7752 i_size_write(inode, start + len);
7753
7754 adjust_dio_outstanding_extents(inode, dio_data, len);
7755 WARN_ON(dio_data->reserve < len);
7756 dio_data->reserve -= len;
7757 dio_data->unsubmitted_oe_range_end = start + len;
7758 current->journal_info = dio_data;
7759 }
7760
7761 /*
7762 * In the case of write we need to clear and unlock the entire range,
7763 * in the case of read we need to unlock only the end area that we
7764 * aren't using if there is any left over space.
7765 */
7766 if (lockstart < lockend) {
7767 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7768 lockend, unlock_bits, 1, 0,
7769 &cached_state, GFP_NOFS);
7770 } else {
7771 free_extent_state(cached_state);
7772 }
7773
7774 free_extent_map(em);
7775
7776 return 0;
7777
7778 unlock_err:
7779 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7780 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7781 err:
7782 if (dio_data)
7783 current->journal_info = dio_data;
7784 /*
7785 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7786 * write less data then expected, so that we don't underflow our inode's
7787 * outstanding extents counter.
7788 */
7789 if (create && dio_data)
7790 adjust_dio_outstanding_extents(inode, dio_data, len);
7791
7792 return ret;
7793 }
7794
7795 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7796 int mirror_num)
7797 {
7798 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7799 int ret;
7800
7801 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7802
7803 bio_get(bio);
7804
7805 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7806 if (ret)
7807 goto err;
7808
7809 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7810 err:
7811 bio_put(bio);
7812 return ret;
7813 }
7814
7815 static int btrfs_check_dio_repairable(struct inode *inode,
7816 struct bio *failed_bio,
7817 struct io_failure_record *failrec,
7818 int failed_mirror)
7819 {
7820 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7821 int num_copies;
7822
7823 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7824 if (num_copies == 1) {
7825 /*
7826 * we only have a single copy of the data, so don't bother with
7827 * all the retry and error correction code that follows. no
7828 * matter what the error is, it is very likely to persist.
7829 */
7830 btrfs_debug(fs_info,
7831 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7832 num_copies, failrec->this_mirror, failed_mirror);
7833 return 0;
7834 }
7835
7836 failrec->failed_mirror = failed_mirror;
7837 failrec->this_mirror++;
7838 if (failrec->this_mirror == failed_mirror)
7839 failrec->this_mirror++;
7840
7841 if (failrec->this_mirror > num_copies) {
7842 btrfs_debug(fs_info,
7843 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7844 num_copies, failrec->this_mirror, failed_mirror);
7845 return 0;
7846 }
7847
7848 return 1;
7849 }
7850
7851 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7852 struct page *page, unsigned int pgoff,
7853 u64 start, u64 end, int failed_mirror,
7854 bio_end_io_t *repair_endio, void *repair_arg)
7855 {
7856 struct io_failure_record *failrec;
7857 struct bio *bio;
7858 int isector;
7859 int read_mode = 0;
7860 int ret;
7861
7862 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7863
7864 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7865 if (ret)
7866 return ret;
7867
7868 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7869 failed_mirror);
7870 if (!ret) {
7871 free_io_failure(BTRFS_I(inode), failrec);
7872 return -EIO;
7873 }
7874
7875 if ((failed_bio->bi_vcnt > 1)
7876 || (failed_bio->bi_io_vec->bv_len
7877 > btrfs_inode_sectorsize(inode)))
7878 read_mode |= REQ_FAILFAST_DEV;
7879
7880 isector = start - btrfs_io_bio(failed_bio)->logical;
7881 isector >>= inode->i_sb->s_blocksize_bits;
7882 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7883 pgoff, isector, repair_endio, repair_arg);
7884 if (!bio) {
7885 free_io_failure(BTRFS_I(inode), failrec);
7886 return -EIO;
7887 }
7888 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7889
7890 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7891 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7892 read_mode, failrec->this_mirror, failrec->in_validation);
7893
7894 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7895 if (ret) {
7896 free_io_failure(BTRFS_I(inode), failrec);
7897 bio_put(bio);
7898 }
7899
7900 return ret;
7901 }
7902
7903 struct btrfs_retry_complete {
7904 struct completion done;
7905 struct inode *inode;
7906 u64 start;
7907 int uptodate;
7908 };
7909
7910 static void btrfs_retry_endio_nocsum(struct bio *bio)
7911 {
7912 struct btrfs_retry_complete *done = bio->bi_private;
7913 struct bio_vec *bvec;
7914 int i;
7915
7916 if (bio->bi_error)
7917 goto end;
7918
7919 ASSERT(bio->bi_vcnt == 1);
7920 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode));
7921
7922 done->uptodate = 1;
7923 bio_for_each_segment_all(bvec, bio, i)
7924 clean_io_failure(BTRFS_I(done->inode), done->start,
7925 bvec->bv_page, 0);
7926 end:
7927 complete(&done->done);
7928 bio_put(bio);
7929 }
7930
7931 static int __btrfs_correct_data_nocsum(struct inode *inode,
7932 struct btrfs_io_bio *io_bio)
7933 {
7934 struct btrfs_fs_info *fs_info;
7935 struct bio_vec *bvec;
7936 struct btrfs_retry_complete done;
7937 u64 start;
7938 unsigned int pgoff;
7939 u32 sectorsize;
7940 int nr_sectors;
7941 int i;
7942 int ret;
7943
7944 fs_info = BTRFS_I(inode)->root->fs_info;
7945 sectorsize = fs_info->sectorsize;
7946
7947 start = io_bio->logical;
7948 done.inode = inode;
7949
7950 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7951 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
7952 pgoff = bvec->bv_offset;
7953
7954 next_block_or_try_again:
7955 done.uptodate = 0;
7956 done.start = start;
7957 init_completion(&done.done);
7958
7959 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
7960 pgoff, start, start + sectorsize - 1,
7961 io_bio->mirror_num,
7962 btrfs_retry_endio_nocsum, &done);
7963 if (ret)
7964 return ret;
7965
7966 wait_for_completion(&done.done);
7967
7968 if (!done.uptodate) {
7969 /* We might have another mirror, so try again */
7970 goto next_block_or_try_again;
7971 }
7972
7973 start += sectorsize;
7974
7975 nr_sectors--;
7976 if (nr_sectors) {
7977 pgoff += sectorsize;
7978 ASSERT(pgoff < PAGE_SIZE);
7979 goto next_block_or_try_again;
7980 }
7981 }
7982
7983 return 0;
7984 }
7985
7986 static void btrfs_retry_endio(struct bio *bio)
7987 {
7988 struct btrfs_retry_complete *done = bio->bi_private;
7989 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7990 struct bio_vec *bvec;
7991 int uptodate;
7992 int ret;
7993 int i;
7994
7995 if (bio->bi_error)
7996 goto end;
7997
7998 uptodate = 1;
7999
8000 ASSERT(bio->bi_vcnt == 1);
8001 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode));
8002
8003 bio_for_each_segment_all(bvec, bio, i) {
8004 ret = __readpage_endio_check(done->inode, io_bio, i,
8005 bvec->bv_page, bvec->bv_offset,
8006 done->start, bvec->bv_len);
8007 if (!ret)
8008 clean_io_failure(BTRFS_I(done->inode), done->start,
8009 bvec->bv_page, bvec->bv_offset);
8010 else
8011 uptodate = 0;
8012 }
8013
8014 done->uptodate = uptodate;
8015 end:
8016 complete(&done->done);
8017 bio_put(bio);
8018 }
8019
8020 static int __btrfs_subio_endio_read(struct inode *inode,
8021 struct btrfs_io_bio *io_bio, int err)
8022 {
8023 struct btrfs_fs_info *fs_info;
8024 struct bio_vec *bvec;
8025 struct btrfs_retry_complete done;
8026 u64 start;
8027 u64 offset = 0;
8028 u32 sectorsize;
8029 int nr_sectors;
8030 unsigned int pgoff;
8031 int csum_pos;
8032 int i;
8033 int ret;
8034
8035 fs_info = BTRFS_I(inode)->root->fs_info;
8036 sectorsize = fs_info->sectorsize;
8037
8038 err = 0;
8039 start = io_bio->logical;
8040 done.inode = inode;
8041
8042 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8043 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8044
8045 pgoff = bvec->bv_offset;
8046 next_block:
8047 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8048 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8049 bvec->bv_page, pgoff, start,
8050 sectorsize);
8051 if (likely(!ret))
8052 goto next;
8053 try_again:
8054 done.uptodate = 0;
8055 done.start = start;
8056 init_completion(&done.done);
8057
8058 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8059 pgoff, start, start + sectorsize - 1,
8060 io_bio->mirror_num,
8061 btrfs_retry_endio, &done);
8062 if (ret) {
8063 err = ret;
8064 goto next;
8065 }
8066
8067 wait_for_completion(&done.done);
8068
8069 if (!done.uptodate) {
8070 /* We might have another mirror, so try again */
8071 goto try_again;
8072 }
8073 next:
8074 offset += sectorsize;
8075 start += sectorsize;
8076
8077 ASSERT(nr_sectors);
8078
8079 nr_sectors--;
8080 if (nr_sectors) {
8081 pgoff += sectorsize;
8082 ASSERT(pgoff < PAGE_SIZE);
8083 goto next_block;
8084 }
8085 }
8086
8087 return err;
8088 }
8089
8090 static int btrfs_subio_endio_read(struct inode *inode,
8091 struct btrfs_io_bio *io_bio, int err)
8092 {
8093 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8094
8095 if (skip_csum) {
8096 if (unlikely(err))
8097 return __btrfs_correct_data_nocsum(inode, io_bio);
8098 else
8099 return 0;
8100 } else {
8101 return __btrfs_subio_endio_read(inode, io_bio, err);
8102 }
8103 }
8104
8105 static void btrfs_endio_direct_read(struct bio *bio)
8106 {
8107 struct btrfs_dio_private *dip = bio->bi_private;
8108 struct inode *inode = dip->inode;
8109 struct bio *dio_bio;
8110 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8111 int err = bio->bi_error;
8112
8113 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8114 err = btrfs_subio_endio_read(inode, io_bio, err);
8115
8116 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8117 dip->logical_offset + dip->bytes - 1);
8118 dio_bio = dip->dio_bio;
8119
8120 kfree(dip);
8121
8122 dio_bio->bi_error = bio->bi_error;
8123 dio_end_io(dio_bio, bio->bi_error);
8124
8125 if (io_bio->end_io)
8126 io_bio->end_io(io_bio, err);
8127 bio_put(bio);
8128 }
8129
8130 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8131 const u64 offset,
8132 const u64 bytes,
8133 const int uptodate)
8134 {
8135 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8136 struct btrfs_ordered_extent *ordered = NULL;
8137 u64 ordered_offset = offset;
8138 u64 ordered_bytes = bytes;
8139 int ret;
8140
8141 again:
8142 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8143 &ordered_offset,
8144 ordered_bytes,
8145 uptodate);
8146 if (!ret)
8147 goto out_test;
8148
8149 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8150 finish_ordered_fn, NULL, NULL);
8151 btrfs_queue_work(fs_info->endio_write_workers, &ordered->work);
8152 out_test:
8153 /*
8154 * our bio might span multiple ordered extents. If we haven't
8155 * completed the accounting for the whole dio, go back and try again
8156 */
8157 if (ordered_offset < offset + bytes) {
8158 ordered_bytes = offset + bytes - ordered_offset;
8159 ordered = NULL;
8160 goto again;
8161 }
8162 }
8163
8164 static void btrfs_endio_direct_write(struct bio *bio)
8165 {
8166 struct btrfs_dio_private *dip = bio->bi_private;
8167 struct bio *dio_bio = dip->dio_bio;
8168
8169 btrfs_endio_direct_write_update_ordered(dip->inode,
8170 dip->logical_offset,
8171 dip->bytes,
8172 !bio->bi_error);
8173
8174 kfree(dip);
8175
8176 dio_bio->bi_error = bio->bi_error;
8177 dio_end_io(dio_bio, bio->bi_error);
8178 bio_put(bio);
8179 }
8180
8181 static int __btrfs_submit_bio_start_direct_io(struct inode *inode,
8182 struct bio *bio, int mirror_num,
8183 unsigned long bio_flags, u64 offset)
8184 {
8185 int ret;
8186 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8187 BUG_ON(ret); /* -ENOMEM */
8188 return 0;
8189 }
8190
8191 static void btrfs_end_dio_bio(struct bio *bio)
8192 {
8193 struct btrfs_dio_private *dip = bio->bi_private;
8194 int err = bio->bi_error;
8195
8196 if (err)
8197 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8198 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8199 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8200 bio->bi_opf,
8201 (unsigned long long)bio->bi_iter.bi_sector,
8202 bio->bi_iter.bi_size, err);
8203
8204 if (dip->subio_endio)
8205 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8206
8207 if (err) {
8208 dip->errors = 1;
8209
8210 /*
8211 * before atomic variable goto zero, we must make sure
8212 * dip->errors is perceived to be set.
8213 */
8214 smp_mb__before_atomic();
8215 }
8216
8217 /* if there are more bios still pending for this dio, just exit */
8218 if (!atomic_dec_and_test(&dip->pending_bios))
8219 goto out;
8220
8221 if (dip->errors) {
8222 bio_io_error(dip->orig_bio);
8223 } else {
8224 dip->dio_bio->bi_error = 0;
8225 bio_endio(dip->orig_bio);
8226 }
8227 out:
8228 bio_put(bio);
8229 }
8230
8231 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8232 u64 first_sector, gfp_t gfp_flags)
8233 {
8234 struct bio *bio;
8235 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8236 if (bio)
8237 bio_associate_current(bio);
8238 return bio;
8239 }
8240
8241 static inline int btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8242 struct btrfs_dio_private *dip,
8243 struct bio *bio,
8244 u64 file_offset)
8245 {
8246 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8247 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8248 int ret;
8249
8250 /*
8251 * We load all the csum data we need when we submit
8252 * the first bio to reduce the csum tree search and
8253 * contention.
8254 */
8255 if (dip->logical_offset == file_offset) {
8256 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8257 file_offset);
8258 if (ret)
8259 return ret;
8260 }
8261
8262 if (bio == dip->orig_bio)
8263 return 0;
8264
8265 file_offset -= dip->logical_offset;
8266 file_offset >>= inode->i_sb->s_blocksize_bits;
8267 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8268
8269 return 0;
8270 }
8271
8272 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8273 u64 file_offset, int skip_sum,
8274 int async_submit)
8275 {
8276 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8277 struct btrfs_dio_private *dip = bio->bi_private;
8278 bool write = bio_op(bio) == REQ_OP_WRITE;
8279 int ret;
8280
8281 if (async_submit)
8282 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8283
8284 bio_get(bio);
8285
8286 if (!write) {
8287 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8288 if (ret)
8289 goto err;
8290 }
8291
8292 if (skip_sum)
8293 goto map;
8294
8295 if (write && async_submit) {
8296 ret = btrfs_wq_submit_bio(fs_info, inode, bio, 0, 0,
8297 file_offset,
8298 __btrfs_submit_bio_start_direct_io,
8299 __btrfs_submit_bio_done);
8300 goto err;
8301 } else if (write) {
8302 /*
8303 * If we aren't doing async submit, calculate the csum of the
8304 * bio now.
8305 */
8306 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8307 if (ret)
8308 goto err;
8309 } else {
8310 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8311 file_offset);
8312 if (ret)
8313 goto err;
8314 }
8315 map:
8316 ret = btrfs_map_bio(fs_info, bio, 0, async_submit);
8317 err:
8318 bio_put(bio);
8319 return ret;
8320 }
8321
8322 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
8323 int skip_sum)
8324 {
8325 struct inode *inode = dip->inode;
8326 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8327 struct btrfs_root *root = BTRFS_I(inode)->root;
8328 struct bio *bio;
8329 struct bio *orig_bio = dip->orig_bio;
8330 struct bio_vec *bvec;
8331 u64 start_sector = orig_bio->bi_iter.bi_sector;
8332 u64 file_offset = dip->logical_offset;
8333 u64 submit_len = 0;
8334 u64 map_length;
8335 u32 blocksize = fs_info->sectorsize;
8336 int async_submit = 0;
8337 int nr_sectors;
8338 int ret;
8339 int i, j;
8340
8341 map_length = orig_bio->bi_iter.bi_size;
8342 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8343 &map_length, NULL, 0);
8344 if (ret)
8345 return -EIO;
8346
8347 if (map_length >= orig_bio->bi_iter.bi_size) {
8348 bio = orig_bio;
8349 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8350 goto submit;
8351 }
8352
8353 /* async crcs make it difficult to collect full stripe writes. */
8354 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8355 async_submit = 0;
8356 else
8357 async_submit = 1;
8358
8359 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8360 if (!bio)
8361 return -ENOMEM;
8362
8363 bio->bi_opf = orig_bio->bi_opf;
8364 bio->bi_private = dip;
8365 bio->bi_end_io = btrfs_end_dio_bio;
8366 btrfs_io_bio(bio)->logical = file_offset;
8367 atomic_inc(&dip->pending_bios);
8368
8369 bio_for_each_segment_all(bvec, orig_bio, j) {
8370 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8371 i = 0;
8372 next_block:
8373 if (unlikely(map_length < submit_len + blocksize ||
8374 bio_add_page(bio, bvec->bv_page, blocksize,
8375 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8376 /*
8377 * inc the count before we submit the bio so
8378 * we know the end IO handler won't happen before
8379 * we inc the count. Otherwise, the dip might get freed
8380 * before we're done setting it up
8381 */
8382 atomic_inc(&dip->pending_bios);
8383 ret = __btrfs_submit_dio_bio(bio, inode,
8384 file_offset, skip_sum,
8385 async_submit);
8386 if (ret) {
8387 bio_put(bio);
8388 atomic_dec(&dip->pending_bios);
8389 goto out_err;
8390 }
8391
8392 start_sector += submit_len >> 9;
8393 file_offset += submit_len;
8394
8395 submit_len = 0;
8396
8397 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8398 start_sector, GFP_NOFS);
8399 if (!bio)
8400 goto out_err;
8401 bio->bi_opf = orig_bio->bi_opf;
8402 bio->bi_private = dip;
8403 bio->bi_end_io = btrfs_end_dio_bio;
8404 btrfs_io_bio(bio)->logical = file_offset;
8405
8406 map_length = orig_bio->bi_iter.bi_size;
8407 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8408 start_sector << 9,
8409 &map_length, NULL, 0);
8410 if (ret) {
8411 bio_put(bio);
8412 goto out_err;
8413 }
8414
8415 goto next_block;
8416 } else {
8417 submit_len += blocksize;
8418 if (--nr_sectors) {
8419 i++;
8420 goto next_block;
8421 }
8422 }
8423 }
8424
8425 submit:
8426 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
8427 async_submit);
8428 if (!ret)
8429 return 0;
8430
8431 bio_put(bio);
8432 out_err:
8433 dip->errors = 1;
8434 /*
8435 * before atomic variable goto zero, we must
8436 * make sure dip->errors is perceived to be set.
8437 */
8438 smp_mb__before_atomic();
8439 if (atomic_dec_and_test(&dip->pending_bios))
8440 bio_io_error(dip->orig_bio);
8441
8442 /* bio_end_io() will handle error, so we needn't return it */
8443 return 0;
8444 }
8445
8446 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8447 loff_t file_offset)
8448 {
8449 struct btrfs_dio_private *dip = NULL;
8450 struct bio *io_bio = NULL;
8451 struct btrfs_io_bio *btrfs_bio;
8452 int skip_sum;
8453 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8454 int ret = 0;
8455
8456 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8457
8458 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8459 if (!io_bio) {
8460 ret = -ENOMEM;
8461 goto free_ordered;
8462 }
8463
8464 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8465 if (!dip) {
8466 ret = -ENOMEM;
8467 goto free_ordered;
8468 }
8469
8470 dip->private = dio_bio->bi_private;
8471 dip->inode = inode;
8472 dip->logical_offset = file_offset;
8473 dip->bytes = dio_bio->bi_iter.bi_size;
8474 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8475 io_bio->bi_private = dip;
8476 dip->orig_bio = io_bio;
8477 dip->dio_bio = dio_bio;
8478 atomic_set(&dip->pending_bios, 0);
8479 btrfs_bio = btrfs_io_bio(io_bio);
8480 btrfs_bio->logical = file_offset;
8481
8482 if (write) {
8483 io_bio->bi_end_io = btrfs_endio_direct_write;
8484 } else {
8485 io_bio->bi_end_io = btrfs_endio_direct_read;
8486 dip->subio_endio = btrfs_subio_endio_read;
8487 }
8488
8489 /*
8490 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8491 * even if we fail to submit a bio, because in such case we do the
8492 * corresponding error handling below and it must not be done a second
8493 * time by btrfs_direct_IO().
8494 */
8495 if (write) {
8496 struct btrfs_dio_data *dio_data = current->journal_info;
8497
8498 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8499 dip->bytes;
8500 dio_data->unsubmitted_oe_range_start =
8501 dio_data->unsubmitted_oe_range_end;
8502 }
8503
8504 ret = btrfs_submit_direct_hook(dip, skip_sum);
8505 if (!ret)
8506 return;
8507
8508 if (btrfs_bio->end_io)
8509 btrfs_bio->end_io(btrfs_bio, ret);
8510
8511 free_ordered:
8512 /*
8513 * If we arrived here it means either we failed to submit the dip
8514 * or we either failed to clone the dio_bio or failed to allocate the
8515 * dip. If we cloned the dio_bio and allocated the dip, we can just
8516 * call bio_endio against our io_bio so that we get proper resource
8517 * cleanup if we fail to submit the dip, otherwise, we must do the
8518 * same as btrfs_endio_direct_[write|read] because we can't call these
8519 * callbacks - they require an allocated dip and a clone of dio_bio.
8520 */
8521 if (io_bio && dip) {
8522 io_bio->bi_error = -EIO;
8523 bio_endio(io_bio);
8524 /*
8525 * The end io callbacks free our dip, do the final put on io_bio
8526 * and all the cleanup and final put for dio_bio (through
8527 * dio_end_io()).
8528 */
8529 dip = NULL;
8530 io_bio = NULL;
8531 } else {
8532 if (write)
8533 btrfs_endio_direct_write_update_ordered(inode,
8534 file_offset,
8535 dio_bio->bi_iter.bi_size,
8536 0);
8537 else
8538 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8539 file_offset + dio_bio->bi_iter.bi_size - 1);
8540
8541 dio_bio->bi_error = -EIO;
8542 /*
8543 * Releases and cleans up our dio_bio, no need to bio_put()
8544 * nor bio_endio()/bio_io_error() against dio_bio.
8545 */
8546 dio_end_io(dio_bio, ret);
8547 }
8548 if (io_bio)
8549 bio_put(io_bio);
8550 kfree(dip);
8551 }
8552
8553 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8554 struct kiocb *iocb,
8555 const struct iov_iter *iter, loff_t offset)
8556 {
8557 int seg;
8558 int i;
8559 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8560 ssize_t retval = -EINVAL;
8561
8562 if (offset & blocksize_mask)
8563 goto out;
8564
8565 if (iov_iter_alignment(iter) & blocksize_mask)
8566 goto out;
8567
8568 /* If this is a write we don't need to check anymore */
8569 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8570 return 0;
8571 /*
8572 * Check to make sure we don't have duplicate iov_base's in this
8573 * iovec, if so return EINVAL, otherwise we'll get csum errors
8574 * when reading back.
8575 */
8576 for (seg = 0; seg < iter->nr_segs; seg++) {
8577 for (i = seg + 1; i < iter->nr_segs; i++) {
8578 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8579 goto out;
8580 }
8581 }
8582 retval = 0;
8583 out:
8584 return retval;
8585 }
8586
8587 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8588 {
8589 struct file *file = iocb->ki_filp;
8590 struct inode *inode = file->f_mapping->host;
8591 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8592 struct btrfs_dio_data dio_data = { 0 };
8593 loff_t offset = iocb->ki_pos;
8594 size_t count = 0;
8595 int flags = 0;
8596 bool wakeup = true;
8597 bool relock = false;
8598 ssize_t ret;
8599
8600 if (check_direct_IO(fs_info, iocb, iter, offset))
8601 return 0;
8602
8603 inode_dio_begin(inode);
8604 smp_mb__after_atomic();
8605
8606 /*
8607 * The generic stuff only does filemap_write_and_wait_range, which
8608 * isn't enough if we've written compressed pages to this area, so
8609 * we need to flush the dirty pages again to make absolutely sure
8610 * that any outstanding dirty pages are on disk.
8611 */
8612 count = iov_iter_count(iter);
8613 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8614 &BTRFS_I(inode)->runtime_flags))
8615 filemap_fdatawrite_range(inode->i_mapping, offset,
8616 offset + count - 1);
8617
8618 if (iov_iter_rw(iter) == WRITE) {
8619 /*
8620 * If the write DIO is beyond the EOF, we need update
8621 * the isize, but it is protected by i_mutex. So we can
8622 * not unlock the i_mutex at this case.
8623 */
8624 if (offset + count <= inode->i_size) {
8625 dio_data.overwrite = 1;
8626 inode_unlock(inode);
8627 relock = true;
8628 }
8629 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8630 if (ret)
8631 goto out;
8632 dio_data.outstanding_extents = count_max_extents(count);
8633
8634 /*
8635 * We need to know how many extents we reserved so that we can
8636 * do the accounting properly if we go over the number we
8637 * originally calculated. Abuse current->journal_info for this.
8638 */
8639 dio_data.reserve = round_up(count,
8640 fs_info->sectorsize);
8641 dio_data.unsubmitted_oe_range_start = (u64)offset;
8642 dio_data.unsubmitted_oe_range_end = (u64)offset;
8643 current->journal_info = &dio_data;
8644 down_read(&BTRFS_I(inode)->dio_sem);
8645 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8646 &BTRFS_I(inode)->runtime_flags)) {
8647 inode_dio_end(inode);
8648 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8649 wakeup = false;
8650 }
8651
8652 ret = __blockdev_direct_IO(iocb, inode,
8653 fs_info->fs_devices->latest_bdev,
8654 iter, btrfs_get_blocks_direct, NULL,
8655 btrfs_submit_direct, flags);
8656 if (iov_iter_rw(iter) == WRITE) {
8657 up_read(&BTRFS_I(inode)->dio_sem);
8658 current->journal_info = NULL;
8659 if (ret < 0 && ret != -EIOCBQUEUED) {
8660 if (dio_data.reserve)
8661 btrfs_delalloc_release_space(inode, offset,
8662 dio_data.reserve);
8663 /*
8664 * On error we might have left some ordered extents
8665 * without submitting corresponding bios for them, so
8666 * cleanup them up to avoid other tasks getting them
8667 * and waiting for them to complete forever.
8668 */
8669 if (dio_data.unsubmitted_oe_range_start <
8670 dio_data.unsubmitted_oe_range_end)
8671 btrfs_endio_direct_write_update_ordered(inode,
8672 dio_data.unsubmitted_oe_range_start,
8673 dio_data.unsubmitted_oe_range_end -
8674 dio_data.unsubmitted_oe_range_start,
8675 0);
8676 } else if (ret >= 0 && (size_t)ret < count)
8677 btrfs_delalloc_release_space(inode, offset,
8678 count - (size_t)ret);
8679 }
8680 out:
8681 if (wakeup)
8682 inode_dio_end(inode);
8683 if (relock)
8684 inode_lock(inode);
8685
8686 return ret;
8687 }
8688
8689 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8690
8691 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8692 __u64 start, __u64 len)
8693 {
8694 int ret;
8695
8696 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8697 if (ret)
8698 return ret;
8699
8700 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8701 }
8702
8703 int btrfs_readpage(struct file *file, struct page *page)
8704 {
8705 struct extent_io_tree *tree;
8706 tree = &BTRFS_I(page->mapping->host)->io_tree;
8707 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8708 }
8709
8710 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8711 {
8712 struct extent_io_tree *tree;
8713 struct inode *inode = page->mapping->host;
8714 int ret;
8715
8716 if (current->flags & PF_MEMALLOC) {
8717 redirty_page_for_writepage(wbc, page);
8718 unlock_page(page);
8719 return 0;
8720 }
8721
8722 /*
8723 * If we are under memory pressure we will call this directly from the
8724 * VM, we need to make sure we have the inode referenced for the ordered
8725 * extent. If not just return like we didn't do anything.
8726 */
8727 if (!igrab(inode)) {
8728 redirty_page_for_writepage(wbc, page);
8729 return AOP_WRITEPAGE_ACTIVATE;
8730 }
8731 tree = &BTRFS_I(page->mapping->host)->io_tree;
8732 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8733 btrfs_add_delayed_iput(inode);
8734 return ret;
8735 }
8736
8737 static int btrfs_writepages(struct address_space *mapping,
8738 struct writeback_control *wbc)
8739 {
8740 struct extent_io_tree *tree;
8741
8742 tree = &BTRFS_I(mapping->host)->io_tree;
8743 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8744 }
8745
8746 static int
8747 btrfs_readpages(struct file *file, struct address_space *mapping,
8748 struct list_head *pages, unsigned nr_pages)
8749 {
8750 struct extent_io_tree *tree;
8751 tree = &BTRFS_I(mapping->host)->io_tree;
8752 return extent_readpages(tree, mapping, pages, nr_pages,
8753 btrfs_get_extent);
8754 }
8755 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8756 {
8757 struct extent_io_tree *tree;
8758 struct extent_map_tree *map;
8759 int ret;
8760
8761 tree = &BTRFS_I(page->mapping->host)->io_tree;
8762 map = &BTRFS_I(page->mapping->host)->extent_tree;
8763 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8764 if (ret == 1) {
8765 ClearPagePrivate(page);
8766 set_page_private(page, 0);
8767 put_page(page);
8768 }
8769 return ret;
8770 }
8771
8772 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8773 {
8774 if (PageWriteback(page) || PageDirty(page))
8775 return 0;
8776 return __btrfs_releasepage(page, gfp_flags);
8777 }
8778
8779 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8780 unsigned int length)
8781 {
8782 struct inode *inode = page->mapping->host;
8783 struct extent_io_tree *tree;
8784 struct btrfs_ordered_extent *ordered;
8785 struct extent_state *cached_state = NULL;
8786 u64 page_start = page_offset(page);
8787 u64 page_end = page_start + PAGE_SIZE - 1;
8788 u64 start;
8789 u64 end;
8790 int inode_evicting = inode->i_state & I_FREEING;
8791
8792 /*
8793 * we have the page locked, so new writeback can't start,
8794 * and the dirty bit won't be cleared while we are here.
8795 *
8796 * Wait for IO on this page so that we can safely clear
8797 * the PagePrivate2 bit and do ordered accounting
8798 */
8799 wait_on_page_writeback(page);
8800
8801 tree = &BTRFS_I(inode)->io_tree;
8802 if (offset) {
8803 btrfs_releasepage(page, GFP_NOFS);
8804 return;
8805 }
8806
8807 if (!inode_evicting)
8808 lock_extent_bits(tree, page_start, page_end, &cached_state);
8809 again:
8810 start = page_start;
8811 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8812 page_end - start + 1);
8813 if (ordered) {
8814 end = min(page_end, ordered->file_offset + ordered->len - 1);
8815 /*
8816 * IO on this page will never be started, so we need
8817 * to account for any ordered extents now
8818 */
8819 if (!inode_evicting)
8820 clear_extent_bit(tree, start, end,
8821 EXTENT_DIRTY | EXTENT_DELALLOC |
8822 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8823 EXTENT_DEFRAG, 1, 0, &cached_state,
8824 GFP_NOFS);
8825 /*
8826 * whoever cleared the private bit is responsible
8827 * for the finish_ordered_io
8828 */
8829 if (TestClearPagePrivate2(page)) {
8830 struct btrfs_ordered_inode_tree *tree;
8831 u64 new_len;
8832
8833 tree = &BTRFS_I(inode)->ordered_tree;
8834
8835 spin_lock_irq(&tree->lock);
8836 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8837 new_len = start - ordered->file_offset;
8838 if (new_len < ordered->truncated_len)
8839 ordered->truncated_len = new_len;
8840 spin_unlock_irq(&tree->lock);
8841
8842 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8843 start,
8844 end - start + 1, 1))
8845 btrfs_finish_ordered_io(ordered);
8846 }
8847 btrfs_put_ordered_extent(ordered);
8848 if (!inode_evicting) {
8849 cached_state = NULL;
8850 lock_extent_bits(tree, start, end,
8851 &cached_state);
8852 }
8853
8854 start = end + 1;
8855 if (start < page_end)
8856 goto again;
8857 }
8858
8859 /*
8860 * Qgroup reserved space handler
8861 * Page here will be either
8862 * 1) Already written to disk
8863 * In this case, its reserved space is released from data rsv map
8864 * and will be freed by delayed_ref handler finally.
8865 * So even we call qgroup_free_data(), it won't decrease reserved
8866 * space.
8867 * 2) Not written to disk
8868 * This means the reserved space should be freed here. However,
8869 * if a truncate invalidates the page (by clearing PageDirty)
8870 * and the page is accounted for while allocating extent
8871 * in btrfs_check_data_free_space() we let delayed_ref to
8872 * free the entire extent.
8873 */
8874 if (PageDirty(page))
8875 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8876 if (!inode_evicting) {
8877 clear_extent_bit(tree, page_start, page_end,
8878 EXTENT_LOCKED | EXTENT_DIRTY |
8879 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8880 EXTENT_DEFRAG, 1, 1,
8881 &cached_state, GFP_NOFS);
8882
8883 __btrfs_releasepage(page, GFP_NOFS);
8884 }
8885
8886 ClearPageChecked(page);
8887 if (PagePrivate(page)) {
8888 ClearPagePrivate(page);
8889 set_page_private(page, 0);
8890 put_page(page);
8891 }
8892 }
8893
8894 /*
8895 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8896 * called from a page fault handler when a page is first dirtied. Hence we must
8897 * be careful to check for EOF conditions here. We set the page up correctly
8898 * for a written page which means we get ENOSPC checking when writing into
8899 * holes and correct delalloc and unwritten extent mapping on filesystems that
8900 * support these features.
8901 *
8902 * We are not allowed to take the i_mutex here so we have to play games to
8903 * protect against truncate races as the page could now be beyond EOF. Because
8904 * vmtruncate() writes the inode size before removing pages, once we have the
8905 * page lock we can determine safely if the page is beyond EOF. If it is not
8906 * beyond EOF, then the page is guaranteed safe against truncation until we
8907 * unlock the page.
8908 */
8909 int btrfs_page_mkwrite(struct vm_fault *vmf)
8910 {
8911 struct page *page = vmf->page;
8912 struct inode *inode = file_inode(vmf->vma->vm_file);
8913 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8914 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8915 struct btrfs_ordered_extent *ordered;
8916 struct extent_state *cached_state = NULL;
8917 char *kaddr;
8918 unsigned long zero_start;
8919 loff_t size;
8920 int ret;
8921 int reserved = 0;
8922 u64 reserved_space;
8923 u64 page_start;
8924 u64 page_end;
8925 u64 end;
8926
8927 reserved_space = PAGE_SIZE;
8928
8929 sb_start_pagefault(inode->i_sb);
8930 page_start = page_offset(page);
8931 page_end = page_start + PAGE_SIZE - 1;
8932 end = page_end;
8933
8934 /*
8935 * Reserving delalloc space after obtaining the page lock can lead to
8936 * deadlock. For example, if a dirty page is locked by this function
8937 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8938 * dirty page write out, then the btrfs_writepage() function could
8939 * end up waiting indefinitely to get a lock on the page currently
8940 * being processed by btrfs_page_mkwrite() function.
8941 */
8942 ret = btrfs_delalloc_reserve_space(inode, page_start,
8943 reserved_space);
8944 if (!ret) {
8945 ret = file_update_time(vmf->vma->vm_file);
8946 reserved = 1;
8947 }
8948 if (ret) {
8949 if (ret == -ENOMEM)
8950 ret = VM_FAULT_OOM;
8951 else /* -ENOSPC, -EIO, etc */
8952 ret = VM_FAULT_SIGBUS;
8953 if (reserved)
8954 goto out;
8955 goto out_noreserve;
8956 }
8957
8958 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8959 again:
8960 lock_page(page);
8961 size = i_size_read(inode);
8962
8963 if ((page->mapping != inode->i_mapping) ||
8964 (page_start >= size)) {
8965 /* page got truncated out from underneath us */
8966 goto out_unlock;
8967 }
8968 wait_on_page_writeback(page);
8969
8970 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8971 set_page_extent_mapped(page);
8972
8973 /*
8974 * we can't set the delalloc bits if there are pending ordered
8975 * extents. Drop our locks and wait for them to finish
8976 */
8977 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
8978 PAGE_SIZE);
8979 if (ordered) {
8980 unlock_extent_cached(io_tree, page_start, page_end,
8981 &cached_state, GFP_NOFS);
8982 unlock_page(page);
8983 btrfs_start_ordered_extent(inode, ordered, 1);
8984 btrfs_put_ordered_extent(ordered);
8985 goto again;
8986 }
8987
8988 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8989 reserved_space = round_up(size - page_start,
8990 fs_info->sectorsize);
8991 if (reserved_space < PAGE_SIZE) {
8992 end = page_start + reserved_space - 1;
8993 spin_lock(&BTRFS_I(inode)->lock);
8994 BTRFS_I(inode)->outstanding_extents++;
8995 spin_unlock(&BTRFS_I(inode)->lock);
8996 btrfs_delalloc_release_space(inode, page_start,
8997 PAGE_SIZE - reserved_space);
8998 }
8999 }
9000
9001 /*
9002 * page_mkwrite gets called when the page is firstly dirtied after it's
9003 * faulted in, but write(2) could also dirty a page and set delalloc
9004 * bits, thus in this case for space account reason, we still need to
9005 * clear any delalloc bits within this page range since we have to
9006 * reserve data&meta space before lock_page() (see above comments).
9007 */
9008 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9009 EXTENT_DIRTY | EXTENT_DELALLOC |
9010 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9011 0, 0, &cached_state, GFP_NOFS);
9012
9013 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9014 &cached_state, 0);
9015 if (ret) {
9016 unlock_extent_cached(io_tree, page_start, page_end,
9017 &cached_state, GFP_NOFS);
9018 ret = VM_FAULT_SIGBUS;
9019 goto out_unlock;
9020 }
9021 ret = 0;
9022
9023 /* page is wholly or partially inside EOF */
9024 if (page_start + PAGE_SIZE > size)
9025 zero_start = size & ~PAGE_MASK;
9026 else
9027 zero_start = PAGE_SIZE;
9028
9029 if (zero_start != PAGE_SIZE) {
9030 kaddr = kmap(page);
9031 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9032 flush_dcache_page(page);
9033 kunmap(page);
9034 }
9035 ClearPageChecked(page);
9036 set_page_dirty(page);
9037 SetPageUptodate(page);
9038
9039 BTRFS_I(inode)->last_trans = fs_info->generation;
9040 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9041 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9042
9043 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9044
9045 out_unlock:
9046 if (!ret) {
9047 sb_end_pagefault(inode->i_sb);
9048 return VM_FAULT_LOCKED;
9049 }
9050 unlock_page(page);
9051 out:
9052 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9053 out_noreserve:
9054 sb_end_pagefault(inode->i_sb);
9055 return ret;
9056 }
9057
9058 static int btrfs_truncate(struct inode *inode)
9059 {
9060 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9061 struct btrfs_root *root = BTRFS_I(inode)->root;
9062 struct btrfs_block_rsv *rsv;
9063 int ret = 0;
9064 int err = 0;
9065 struct btrfs_trans_handle *trans;
9066 u64 mask = fs_info->sectorsize - 1;
9067 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9068
9069 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9070 (u64)-1);
9071 if (ret)
9072 return ret;
9073
9074 /*
9075 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9076 * 3 things going on here
9077 *
9078 * 1) We need to reserve space for our orphan item and the space to
9079 * delete our orphan item. Lord knows we don't want to have a dangling
9080 * orphan item because we didn't reserve space to remove it.
9081 *
9082 * 2) We need to reserve space to update our inode.
9083 *
9084 * 3) We need to have something to cache all the space that is going to
9085 * be free'd up by the truncate operation, but also have some slack
9086 * space reserved in case it uses space during the truncate (thank you
9087 * very much snapshotting).
9088 *
9089 * And we need these to all be separate. The fact is we can use a lot of
9090 * space doing the truncate, and we have no earthly idea how much space
9091 * we will use, so we need the truncate reservation to be separate so it
9092 * doesn't end up using space reserved for updating the inode or
9093 * removing the orphan item. We also need to be able to stop the
9094 * transaction and start a new one, which means we need to be able to
9095 * update the inode several times, and we have no idea of knowing how
9096 * many times that will be, so we can't just reserve 1 item for the
9097 * entirety of the operation, so that has to be done separately as well.
9098 * Then there is the orphan item, which does indeed need to be held on
9099 * to for the whole operation, and we need nobody to touch this reserved
9100 * space except the orphan code.
9101 *
9102 * So that leaves us with
9103 *
9104 * 1) root->orphan_block_rsv - for the orphan deletion.
9105 * 2) rsv - for the truncate reservation, which we will steal from the
9106 * transaction reservation.
9107 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9108 * updating the inode.
9109 */
9110 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9111 if (!rsv)
9112 return -ENOMEM;
9113 rsv->size = min_size;
9114 rsv->failfast = 1;
9115
9116 /*
9117 * 1 for the truncate slack space
9118 * 1 for updating the inode.
9119 */
9120 trans = btrfs_start_transaction(root, 2);
9121 if (IS_ERR(trans)) {
9122 err = PTR_ERR(trans);
9123 goto out;
9124 }
9125
9126 /* Migrate the slack space for the truncate to our reserve */
9127 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9128 min_size, 0);
9129 BUG_ON(ret);
9130
9131 /*
9132 * So if we truncate and then write and fsync we normally would just
9133 * write the extents that changed, which is a problem if we need to
9134 * first truncate that entire inode. So set this flag so we write out
9135 * all of the extents in the inode to the sync log so we're completely
9136 * safe.
9137 */
9138 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9139 trans->block_rsv = rsv;
9140
9141 while (1) {
9142 ret = btrfs_truncate_inode_items(trans, root, inode,
9143 inode->i_size,
9144 BTRFS_EXTENT_DATA_KEY);
9145 if (ret != -ENOSPC && ret != -EAGAIN) {
9146 err = ret;
9147 break;
9148 }
9149
9150 trans->block_rsv = &fs_info->trans_block_rsv;
9151 ret = btrfs_update_inode(trans, root, inode);
9152 if (ret) {
9153 err = ret;
9154 break;
9155 }
9156
9157 btrfs_end_transaction(trans);
9158 btrfs_btree_balance_dirty(fs_info);
9159
9160 trans = btrfs_start_transaction(root, 2);
9161 if (IS_ERR(trans)) {
9162 ret = err = PTR_ERR(trans);
9163 trans = NULL;
9164 break;
9165 }
9166
9167 btrfs_block_rsv_release(fs_info, rsv, -1);
9168 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9169 rsv, min_size, 0);
9170 BUG_ON(ret); /* shouldn't happen */
9171 trans->block_rsv = rsv;
9172 }
9173
9174 if (ret == 0 && inode->i_nlink > 0) {
9175 trans->block_rsv = root->orphan_block_rsv;
9176 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9177 if (ret)
9178 err = ret;
9179 }
9180
9181 if (trans) {
9182 trans->block_rsv = &fs_info->trans_block_rsv;
9183 ret = btrfs_update_inode(trans, root, inode);
9184 if (ret && !err)
9185 err = ret;
9186
9187 ret = btrfs_end_transaction(trans);
9188 btrfs_btree_balance_dirty(fs_info);
9189 }
9190 out:
9191 btrfs_free_block_rsv(fs_info, rsv);
9192
9193 if (ret && !err)
9194 err = ret;
9195
9196 return err;
9197 }
9198
9199 /*
9200 * create a new subvolume directory/inode (helper for the ioctl).
9201 */
9202 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9203 struct btrfs_root *new_root,
9204 struct btrfs_root *parent_root,
9205 u64 new_dirid)
9206 {
9207 struct inode *inode;
9208 int err;
9209 u64 index = 0;
9210
9211 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9212 new_dirid, new_dirid,
9213 S_IFDIR | (~current_umask() & S_IRWXUGO),
9214 &index);
9215 if (IS_ERR(inode))
9216 return PTR_ERR(inode);
9217 inode->i_op = &btrfs_dir_inode_operations;
9218 inode->i_fop = &btrfs_dir_file_operations;
9219
9220 set_nlink(inode, 1);
9221 btrfs_i_size_write(BTRFS_I(inode), 0);
9222 unlock_new_inode(inode);
9223
9224 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9225 if (err)
9226 btrfs_err(new_root->fs_info,
9227 "error inheriting subvolume %llu properties: %d",
9228 new_root->root_key.objectid, err);
9229
9230 err = btrfs_update_inode(trans, new_root, inode);
9231
9232 iput(inode);
9233 return err;
9234 }
9235
9236 struct inode *btrfs_alloc_inode(struct super_block *sb)
9237 {
9238 struct btrfs_inode *ei;
9239 struct inode *inode;
9240
9241 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9242 if (!ei)
9243 return NULL;
9244
9245 ei->root = NULL;
9246 ei->generation = 0;
9247 ei->last_trans = 0;
9248 ei->last_sub_trans = 0;
9249 ei->logged_trans = 0;
9250 ei->delalloc_bytes = 0;
9251 ei->defrag_bytes = 0;
9252 ei->disk_i_size = 0;
9253 ei->flags = 0;
9254 ei->csum_bytes = 0;
9255 ei->index_cnt = (u64)-1;
9256 ei->dir_index = 0;
9257 ei->last_unlink_trans = 0;
9258 ei->last_log_commit = 0;
9259 ei->delayed_iput_count = 0;
9260
9261 spin_lock_init(&ei->lock);
9262 ei->outstanding_extents = 0;
9263 ei->reserved_extents = 0;
9264
9265 ei->runtime_flags = 0;
9266 ei->force_compress = BTRFS_COMPRESS_NONE;
9267
9268 ei->delayed_node = NULL;
9269
9270 ei->i_otime.tv_sec = 0;
9271 ei->i_otime.tv_nsec = 0;
9272
9273 inode = &ei->vfs_inode;
9274 extent_map_tree_init(&ei->extent_tree);
9275 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9276 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9277 ei->io_tree.track_uptodate = 1;
9278 ei->io_failure_tree.track_uptodate = 1;
9279 atomic_set(&ei->sync_writers, 0);
9280 mutex_init(&ei->log_mutex);
9281 mutex_init(&ei->delalloc_mutex);
9282 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9283 INIT_LIST_HEAD(&ei->delalloc_inodes);
9284 INIT_LIST_HEAD(&ei->delayed_iput);
9285 RB_CLEAR_NODE(&ei->rb_node);
9286 init_rwsem(&ei->dio_sem);
9287
9288 return inode;
9289 }
9290
9291 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9292 void btrfs_test_destroy_inode(struct inode *inode)
9293 {
9294 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9295 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9296 }
9297 #endif
9298
9299 static void btrfs_i_callback(struct rcu_head *head)
9300 {
9301 struct inode *inode = container_of(head, struct inode, i_rcu);
9302 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9303 }
9304
9305 void btrfs_destroy_inode(struct inode *inode)
9306 {
9307 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9308 struct btrfs_ordered_extent *ordered;
9309 struct btrfs_root *root = BTRFS_I(inode)->root;
9310
9311 WARN_ON(!hlist_empty(&inode->i_dentry));
9312 WARN_ON(inode->i_data.nrpages);
9313 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9314 WARN_ON(BTRFS_I(inode)->reserved_extents);
9315 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9316 WARN_ON(BTRFS_I(inode)->csum_bytes);
9317 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9318
9319 /*
9320 * This can happen where we create an inode, but somebody else also
9321 * created the same inode and we need to destroy the one we already
9322 * created.
9323 */
9324 if (!root)
9325 goto free;
9326
9327 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9328 &BTRFS_I(inode)->runtime_flags)) {
9329 btrfs_info(fs_info, "inode %llu still on the orphan list",
9330 btrfs_ino(BTRFS_I(inode)));
9331 atomic_dec(&root->orphan_inodes);
9332 }
9333
9334 while (1) {
9335 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9336 if (!ordered)
9337 break;
9338 else {
9339 btrfs_err(fs_info,
9340 "found ordered extent %llu %llu on inode cleanup",
9341 ordered->file_offset, ordered->len);
9342 btrfs_remove_ordered_extent(inode, ordered);
9343 btrfs_put_ordered_extent(ordered);
9344 btrfs_put_ordered_extent(ordered);
9345 }
9346 }
9347 btrfs_qgroup_check_reserved_leak(inode);
9348 inode_tree_del(inode);
9349 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9350 free:
9351 call_rcu(&inode->i_rcu, btrfs_i_callback);
9352 }
9353
9354 int btrfs_drop_inode(struct inode *inode)
9355 {
9356 struct btrfs_root *root = BTRFS_I(inode)->root;
9357
9358 if (root == NULL)
9359 return 1;
9360
9361 /* the snap/subvol tree is on deleting */
9362 if (btrfs_root_refs(&root->root_item) == 0)
9363 return 1;
9364 else
9365 return generic_drop_inode(inode);
9366 }
9367
9368 static void init_once(void *foo)
9369 {
9370 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9371
9372 inode_init_once(&ei->vfs_inode);
9373 }
9374
9375 void btrfs_destroy_cachep(void)
9376 {
9377 /*
9378 * Make sure all delayed rcu free inodes are flushed before we
9379 * destroy cache.
9380 */
9381 rcu_barrier();
9382 kmem_cache_destroy(btrfs_inode_cachep);
9383 kmem_cache_destroy(btrfs_trans_handle_cachep);
9384 kmem_cache_destroy(btrfs_transaction_cachep);
9385 kmem_cache_destroy(btrfs_path_cachep);
9386 kmem_cache_destroy(btrfs_free_space_cachep);
9387 }
9388
9389 int btrfs_init_cachep(void)
9390 {
9391 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9392 sizeof(struct btrfs_inode), 0,
9393 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9394 init_once);
9395 if (!btrfs_inode_cachep)
9396 goto fail;
9397
9398 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9399 sizeof(struct btrfs_trans_handle), 0,
9400 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9401 if (!btrfs_trans_handle_cachep)
9402 goto fail;
9403
9404 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9405 sizeof(struct btrfs_transaction), 0,
9406 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9407 if (!btrfs_transaction_cachep)
9408 goto fail;
9409
9410 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9411 sizeof(struct btrfs_path), 0,
9412 SLAB_MEM_SPREAD, NULL);
9413 if (!btrfs_path_cachep)
9414 goto fail;
9415
9416 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9417 sizeof(struct btrfs_free_space), 0,
9418 SLAB_MEM_SPREAD, NULL);
9419 if (!btrfs_free_space_cachep)
9420 goto fail;
9421
9422 return 0;
9423 fail:
9424 btrfs_destroy_cachep();
9425 return -ENOMEM;
9426 }
9427
9428 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9429 u32 request_mask, unsigned int flags)
9430 {
9431 u64 delalloc_bytes;
9432 struct inode *inode = d_inode(path->dentry);
9433 u32 blocksize = inode->i_sb->s_blocksize;
9434
9435 generic_fillattr(inode, stat);
9436 stat->dev = BTRFS_I(inode)->root->anon_dev;
9437
9438 spin_lock(&BTRFS_I(inode)->lock);
9439 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9440 spin_unlock(&BTRFS_I(inode)->lock);
9441 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9442 ALIGN(delalloc_bytes, blocksize)) >> 9;
9443 return 0;
9444 }
9445
9446 static int btrfs_rename_exchange(struct inode *old_dir,
9447 struct dentry *old_dentry,
9448 struct inode *new_dir,
9449 struct dentry *new_dentry)
9450 {
9451 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9452 struct btrfs_trans_handle *trans;
9453 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9454 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9455 struct inode *new_inode = new_dentry->d_inode;
9456 struct inode *old_inode = old_dentry->d_inode;
9457 struct timespec ctime = current_time(old_inode);
9458 struct dentry *parent;
9459 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9460 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9461 u64 old_idx = 0;
9462 u64 new_idx = 0;
9463 u64 root_objectid;
9464 int ret;
9465 bool root_log_pinned = false;
9466 bool dest_log_pinned = false;
9467
9468 /* we only allow rename subvolume link between subvolumes */
9469 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9470 return -EXDEV;
9471
9472 /* close the race window with snapshot create/destroy ioctl */
9473 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9474 down_read(&fs_info->subvol_sem);
9475 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9476 down_read(&fs_info->subvol_sem);
9477
9478 /*
9479 * We want to reserve the absolute worst case amount of items. So if
9480 * both inodes are subvols and we need to unlink them then that would
9481 * require 4 item modifications, but if they are both normal inodes it
9482 * would require 5 item modifications, so we'll assume their normal
9483 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9484 * should cover the worst case number of items we'll modify.
9485 */
9486 trans = btrfs_start_transaction(root, 12);
9487 if (IS_ERR(trans)) {
9488 ret = PTR_ERR(trans);
9489 goto out_notrans;
9490 }
9491
9492 /*
9493 * We need to find a free sequence number both in the source and
9494 * in the destination directory for the exchange.
9495 */
9496 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9497 if (ret)
9498 goto out_fail;
9499 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9500 if (ret)
9501 goto out_fail;
9502
9503 BTRFS_I(old_inode)->dir_index = 0ULL;
9504 BTRFS_I(new_inode)->dir_index = 0ULL;
9505
9506 /* Reference for the source. */
9507 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9508 /* force full log commit if subvolume involved. */
9509 btrfs_set_log_full_commit(fs_info, trans);
9510 } else {
9511 btrfs_pin_log_trans(root);
9512 root_log_pinned = true;
9513 ret = btrfs_insert_inode_ref(trans, dest,
9514 new_dentry->d_name.name,
9515 new_dentry->d_name.len,
9516 old_ino,
9517 btrfs_ino(BTRFS_I(new_dir)),
9518 old_idx);
9519 if (ret)
9520 goto out_fail;
9521 }
9522
9523 /* And now for the dest. */
9524 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9525 /* force full log commit if subvolume involved. */
9526 btrfs_set_log_full_commit(fs_info, trans);
9527 } else {
9528 btrfs_pin_log_trans(dest);
9529 dest_log_pinned = true;
9530 ret = btrfs_insert_inode_ref(trans, root,
9531 old_dentry->d_name.name,
9532 old_dentry->d_name.len,
9533 new_ino,
9534 btrfs_ino(BTRFS_I(old_dir)),
9535 new_idx);
9536 if (ret)
9537 goto out_fail;
9538 }
9539
9540 /* Update inode version and ctime/mtime. */
9541 inode_inc_iversion(old_dir);
9542 inode_inc_iversion(new_dir);
9543 inode_inc_iversion(old_inode);
9544 inode_inc_iversion(new_inode);
9545 old_dir->i_ctime = old_dir->i_mtime = ctime;
9546 new_dir->i_ctime = new_dir->i_mtime = ctime;
9547 old_inode->i_ctime = ctime;
9548 new_inode->i_ctime = ctime;
9549
9550 if (old_dentry->d_parent != new_dentry->d_parent) {
9551 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9552 BTRFS_I(old_inode), 1);
9553 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9554 BTRFS_I(new_inode), 1);
9555 }
9556
9557 /* src is a subvolume */
9558 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9559 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9560 ret = btrfs_unlink_subvol(trans, root, old_dir,
9561 root_objectid,
9562 old_dentry->d_name.name,
9563 old_dentry->d_name.len);
9564 } else { /* src is an inode */
9565 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9566 BTRFS_I(old_dentry->d_inode),
9567 old_dentry->d_name.name,
9568 old_dentry->d_name.len);
9569 if (!ret)
9570 ret = btrfs_update_inode(trans, root, old_inode);
9571 }
9572 if (ret) {
9573 btrfs_abort_transaction(trans, ret);
9574 goto out_fail;
9575 }
9576
9577 /* dest is a subvolume */
9578 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9579 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9580 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9581 root_objectid,
9582 new_dentry->d_name.name,
9583 new_dentry->d_name.len);
9584 } else { /* dest is an inode */
9585 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9586 BTRFS_I(new_dentry->d_inode),
9587 new_dentry->d_name.name,
9588 new_dentry->d_name.len);
9589 if (!ret)
9590 ret = btrfs_update_inode(trans, dest, new_inode);
9591 }
9592 if (ret) {
9593 btrfs_abort_transaction(trans, ret);
9594 goto out_fail;
9595 }
9596
9597 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9598 new_dentry->d_name.name,
9599 new_dentry->d_name.len, 0, old_idx);
9600 if (ret) {
9601 btrfs_abort_transaction(trans, ret);
9602 goto out_fail;
9603 }
9604
9605 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9606 old_dentry->d_name.name,
9607 old_dentry->d_name.len, 0, new_idx);
9608 if (ret) {
9609 btrfs_abort_transaction(trans, ret);
9610 goto out_fail;
9611 }
9612
9613 if (old_inode->i_nlink == 1)
9614 BTRFS_I(old_inode)->dir_index = old_idx;
9615 if (new_inode->i_nlink == 1)
9616 BTRFS_I(new_inode)->dir_index = new_idx;
9617
9618 if (root_log_pinned) {
9619 parent = new_dentry->d_parent;
9620 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9621 parent);
9622 btrfs_end_log_trans(root);
9623 root_log_pinned = false;
9624 }
9625 if (dest_log_pinned) {
9626 parent = old_dentry->d_parent;
9627 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9628 parent);
9629 btrfs_end_log_trans(dest);
9630 dest_log_pinned = false;
9631 }
9632 out_fail:
9633 /*
9634 * If we have pinned a log and an error happened, we unpin tasks
9635 * trying to sync the log and force them to fallback to a transaction
9636 * commit if the log currently contains any of the inodes involved in
9637 * this rename operation (to ensure we do not persist a log with an
9638 * inconsistent state for any of these inodes or leading to any
9639 * inconsistencies when replayed). If the transaction was aborted, the
9640 * abortion reason is propagated to userspace when attempting to commit
9641 * the transaction. If the log does not contain any of these inodes, we
9642 * allow the tasks to sync it.
9643 */
9644 if (ret && (root_log_pinned || dest_log_pinned)) {
9645 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9646 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9647 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9648 (new_inode &&
9649 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9650 btrfs_set_log_full_commit(fs_info, trans);
9651
9652 if (root_log_pinned) {
9653 btrfs_end_log_trans(root);
9654 root_log_pinned = false;
9655 }
9656 if (dest_log_pinned) {
9657 btrfs_end_log_trans(dest);
9658 dest_log_pinned = false;
9659 }
9660 }
9661 ret = btrfs_end_transaction(trans);
9662 out_notrans:
9663 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9664 up_read(&fs_info->subvol_sem);
9665 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9666 up_read(&fs_info->subvol_sem);
9667
9668 return ret;
9669 }
9670
9671 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9672 struct btrfs_root *root,
9673 struct inode *dir,
9674 struct dentry *dentry)
9675 {
9676 int ret;
9677 struct inode *inode;
9678 u64 objectid;
9679 u64 index;
9680
9681 ret = btrfs_find_free_ino(root, &objectid);
9682 if (ret)
9683 return ret;
9684
9685 inode = btrfs_new_inode(trans, root, dir,
9686 dentry->d_name.name,
9687 dentry->d_name.len,
9688 btrfs_ino(BTRFS_I(dir)),
9689 objectid,
9690 S_IFCHR | WHITEOUT_MODE,
9691 &index);
9692
9693 if (IS_ERR(inode)) {
9694 ret = PTR_ERR(inode);
9695 return ret;
9696 }
9697
9698 inode->i_op = &btrfs_special_inode_operations;
9699 init_special_inode(inode, inode->i_mode,
9700 WHITEOUT_DEV);
9701
9702 ret = btrfs_init_inode_security(trans, inode, dir,
9703 &dentry->d_name);
9704 if (ret)
9705 goto out;
9706
9707 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9708 BTRFS_I(inode), 0, index);
9709 if (ret)
9710 goto out;
9711
9712 ret = btrfs_update_inode(trans, root, inode);
9713 out:
9714 unlock_new_inode(inode);
9715 if (ret)
9716 inode_dec_link_count(inode);
9717 iput(inode);
9718
9719 return ret;
9720 }
9721
9722 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9723 struct inode *new_dir, struct dentry *new_dentry,
9724 unsigned int flags)
9725 {
9726 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9727 struct btrfs_trans_handle *trans;
9728 unsigned int trans_num_items;
9729 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9730 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9731 struct inode *new_inode = d_inode(new_dentry);
9732 struct inode *old_inode = d_inode(old_dentry);
9733 u64 index = 0;
9734 u64 root_objectid;
9735 int ret;
9736 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9737 bool log_pinned = false;
9738
9739 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9740 return -EPERM;
9741
9742 /* we only allow rename subvolume link between subvolumes */
9743 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9744 return -EXDEV;
9745
9746 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9747 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9748 return -ENOTEMPTY;
9749
9750 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9751 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9752 return -ENOTEMPTY;
9753
9754
9755 /* check for collisions, even if the name isn't there */
9756 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9757 new_dentry->d_name.name,
9758 new_dentry->d_name.len);
9759
9760 if (ret) {
9761 if (ret == -EEXIST) {
9762 /* we shouldn't get
9763 * eexist without a new_inode */
9764 if (WARN_ON(!new_inode)) {
9765 return ret;
9766 }
9767 } else {
9768 /* maybe -EOVERFLOW */
9769 return ret;
9770 }
9771 }
9772 ret = 0;
9773
9774 /*
9775 * we're using rename to replace one file with another. Start IO on it
9776 * now so we don't add too much work to the end of the transaction
9777 */
9778 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9779 filemap_flush(old_inode->i_mapping);
9780
9781 /* close the racy window with snapshot create/destroy ioctl */
9782 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9783 down_read(&fs_info->subvol_sem);
9784 /*
9785 * We want to reserve the absolute worst case amount of items. So if
9786 * both inodes are subvols and we need to unlink them then that would
9787 * require 4 item modifications, but if they are both normal inodes it
9788 * would require 5 item modifications, so we'll assume they are normal
9789 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9790 * should cover the worst case number of items we'll modify.
9791 * If our rename has the whiteout flag, we need more 5 units for the
9792 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9793 * when selinux is enabled).
9794 */
9795 trans_num_items = 11;
9796 if (flags & RENAME_WHITEOUT)
9797 trans_num_items += 5;
9798 trans = btrfs_start_transaction(root, trans_num_items);
9799 if (IS_ERR(trans)) {
9800 ret = PTR_ERR(trans);
9801 goto out_notrans;
9802 }
9803
9804 if (dest != root)
9805 btrfs_record_root_in_trans(trans, dest);
9806
9807 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9808 if (ret)
9809 goto out_fail;
9810
9811 BTRFS_I(old_inode)->dir_index = 0ULL;
9812 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9813 /* force full log commit if subvolume involved. */
9814 btrfs_set_log_full_commit(fs_info, trans);
9815 } else {
9816 btrfs_pin_log_trans(root);
9817 log_pinned = true;
9818 ret = btrfs_insert_inode_ref(trans, dest,
9819 new_dentry->d_name.name,
9820 new_dentry->d_name.len,
9821 old_ino,
9822 btrfs_ino(BTRFS_I(new_dir)), index);
9823 if (ret)
9824 goto out_fail;
9825 }
9826
9827 inode_inc_iversion(old_dir);
9828 inode_inc_iversion(new_dir);
9829 inode_inc_iversion(old_inode);
9830 old_dir->i_ctime = old_dir->i_mtime =
9831 new_dir->i_ctime = new_dir->i_mtime =
9832 old_inode->i_ctime = current_time(old_dir);
9833
9834 if (old_dentry->d_parent != new_dentry->d_parent)
9835 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9836 BTRFS_I(old_inode), 1);
9837
9838 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9839 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9840 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9841 old_dentry->d_name.name,
9842 old_dentry->d_name.len);
9843 } else {
9844 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9845 BTRFS_I(d_inode(old_dentry)),
9846 old_dentry->d_name.name,
9847 old_dentry->d_name.len);
9848 if (!ret)
9849 ret = btrfs_update_inode(trans, root, old_inode);
9850 }
9851 if (ret) {
9852 btrfs_abort_transaction(trans, ret);
9853 goto out_fail;
9854 }
9855
9856 if (new_inode) {
9857 inode_inc_iversion(new_inode);
9858 new_inode->i_ctime = current_time(new_inode);
9859 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
9860 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9861 root_objectid = BTRFS_I(new_inode)->location.objectid;
9862 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9863 root_objectid,
9864 new_dentry->d_name.name,
9865 new_dentry->d_name.len);
9866 BUG_ON(new_inode->i_nlink == 0);
9867 } else {
9868 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9869 BTRFS_I(d_inode(new_dentry)),
9870 new_dentry->d_name.name,
9871 new_dentry->d_name.len);
9872 }
9873 if (!ret && new_inode->i_nlink == 0)
9874 ret = btrfs_orphan_add(trans,
9875 BTRFS_I(d_inode(new_dentry)));
9876 if (ret) {
9877 btrfs_abort_transaction(trans, ret);
9878 goto out_fail;
9879 }
9880 }
9881
9882 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9883 new_dentry->d_name.name,
9884 new_dentry->d_name.len, 0, index);
9885 if (ret) {
9886 btrfs_abort_transaction(trans, ret);
9887 goto out_fail;
9888 }
9889
9890 if (old_inode->i_nlink == 1)
9891 BTRFS_I(old_inode)->dir_index = index;
9892
9893 if (log_pinned) {
9894 struct dentry *parent = new_dentry->d_parent;
9895
9896 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9897 parent);
9898 btrfs_end_log_trans(root);
9899 log_pinned = false;
9900 }
9901
9902 if (flags & RENAME_WHITEOUT) {
9903 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9904 old_dentry);
9905
9906 if (ret) {
9907 btrfs_abort_transaction(trans, ret);
9908 goto out_fail;
9909 }
9910 }
9911 out_fail:
9912 /*
9913 * If we have pinned the log and an error happened, we unpin tasks
9914 * trying to sync the log and force them to fallback to a transaction
9915 * commit if the log currently contains any of the inodes involved in
9916 * this rename operation (to ensure we do not persist a log with an
9917 * inconsistent state for any of these inodes or leading to any
9918 * inconsistencies when replayed). If the transaction was aborted, the
9919 * abortion reason is propagated to userspace when attempting to commit
9920 * the transaction. If the log does not contain any of these inodes, we
9921 * allow the tasks to sync it.
9922 */
9923 if (ret && log_pinned) {
9924 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9925 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9926 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9927 (new_inode &&
9928 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9929 btrfs_set_log_full_commit(fs_info, trans);
9930
9931 btrfs_end_log_trans(root);
9932 log_pinned = false;
9933 }
9934 btrfs_end_transaction(trans);
9935 out_notrans:
9936 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9937 up_read(&fs_info->subvol_sem);
9938
9939 return ret;
9940 }
9941
9942 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9943 struct inode *new_dir, struct dentry *new_dentry,
9944 unsigned int flags)
9945 {
9946 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9947 return -EINVAL;
9948
9949 if (flags & RENAME_EXCHANGE)
9950 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9951 new_dentry);
9952
9953 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9954 }
9955
9956 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9957 {
9958 struct btrfs_delalloc_work *delalloc_work;
9959 struct inode *inode;
9960
9961 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9962 work);
9963 inode = delalloc_work->inode;
9964 filemap_flush(inode->i_mapping);
9965 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9966 &BTRFS_I(inode)->runtime_flags))
9967 filemap_flush(inode->i_mapping);
9968
9969 if (delalloc_work->delay_iput)
9970 btrfs_add_delayed_iput(inode);
9971 else
9972 iput(inode);
9973 complete(&delalloc_work->completion);
9974 }
9975
9976 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9977 int delay_iput)
9978 {
9979 struct btrfs_delalloc_work *work;
9980
9981 work = kmalloc(sizeof(*work), GFP_NOFS);
9982 if (!work)
9983 return NULL;
9984
9985 init_completion(&work->completion);
9986 INIT_LIST_HEAD(&work->list);
9987 work->inode = inode;
9988 work->delay_iput = delay_iput;
9989 WARN_ON_ONCE(!inode);
9990 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9991 btrfs_run_delalloc_work, NULL, NULL);
9992
9993 return work;
9994 }
9995
9996 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9997 {
9998 wait_for_completion(&work->completion);
9999 kfree(work);
10000 }
10001
10002 /*
10003 * some fairly slow code that needs optimization. This walks the list
10004 * of all the inodes with pending delalloc and forces them to disk.
10005 */
10006 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10007 int nr)
10008 {
10009 struct btrfs_inode *binode;
10010 struct inode *inode;
10011 struct btrfs_delalloc_work *work, *next;
10012 struct list_head works;
10013 struct list_head splice;
10014 int ret = 0;
10015
10016 INIT_LIST_HEAD(&works);
10017 INIT_LIST_HEAD(&splice);
10018
10019 mutex_lock(&root->delalloc_mutex);
10020 spin_lock(&root->delalloc_lock);
10021 list_splice_init(&root->delalloc_inodes, &splice);
10022 while (!list_empty(&splice)) {
10023 binode = list_entry(splice.next, struct btrfs_inode,
10024 delalloc_inodes);
10025
10026 list_move_tail(&binode->delalloc_inodes,
10027 &root->delalloc_inodes);
10028 inode = igrab(&binode->vfs_inode);
10029 if (!inode) {
10030 cond_resched_lock(&root->delalloc_lock);
10031 continue;
10032 }
10033 spin_unlock(&root->delalloc_lock);
10034
10035 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10036 if (!work) {
10037 if (delay_iput)
10038 btrfs_add_delayed_iput(inode);
10039 else
10040 iput(inode);
10041 ret = -ENOMEM;
10042 goto out;
10043 }
10044 list_add_tail(&work->list, &works);
10045 btrfs_queue_work(root->fs_info->flush_workers,
10046 &work->work);
10047 ret++;
10048 if (nr != -1 && ret >= nr)
10049 goto out;
10050 cond_resched();
10051 spin_lock(&root->delalloc_lock);
10052 }
10053 spin_unlock(&root->delalloc_lock);
10054
10055 out:
10056 list_for_each_entry_safe(work, next, &works, list) {
10057 list_del_init(&work->list);
10058 btrfs_wait_and_free_delalloc_work(work);
10059 }
10060
10061 if (!list_empty_careful(&splice)) {
10062 spin_lock(&root->delalloc_lock);
10063 list_splice_tail(&splice, &root->delalloc_inodes);
10064 spin_unlock(&root->delalloc_lock);
10065 }
10066 mutex_unlock(&root->delalloc_mutex);
10067 return ret;
10068 }
10069
10070 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10071 {
10072 struct btrfs_fs_info *fs_info = root->fs_info;
10073 int ret;
10074
10075 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10076 return -EROFS;
10077
10078 ret = __start_delalloc_inodes(root, delay_iput, -1);
10079 if (ret > 0)
10080 ret = 0;
10081 /*
10082 * the filemap_flush will queue IO into the worker threads, but
10083 * we have to make sure the IO is actually started and that
10084 * ordered extents get created before we return
10085 */
10086 atomic_inc(&fs_info->async_submit_draining);
10087 while (atomic_read(&fs_info->nr_async_submits) ||
10088 atomic_read(&fs_info->async_delalloc_pages)) {
10089 wait_event(fs_info->async_submit_wait,
10090 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10091 atomic_read(&fs_info->async_delalloc_pages) == 0));
10092 }
10093 atomic_dec(&fs_info->async_submit_draining);
10094 return ret;
10095 }
10096
10097 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10098 int nr)
10099 {
10100 struct btrfs_root *root;
10101 struct list_head splice;
10102 int ret;
10103
10104 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10105 return -EROFS;
10106
10107 INIT_LIST_HEAD(&splice);
10108
10109 mutex_lock(&fs_info->delalloc_root_mutex);
10110 spin_lock(&fs_info->delalloc_root_lock);
10111 list_splice_init(&fs_info->delalloc_roots, &splice);
10112 while (!list_empty(&splice) && nr) {
10113 root = list_first_entry(&splice, struct btrfs_root,
10114 delalloc_root);
10115 root = btrfs_grab_fs_root(root);
10116 BUG_ON(!root);
10117 list_move_tail(&root->delalloc_root,
10118 &fs_info->delalloc_roots);
10119 spin_unlock(&fs_info->delalloc_root_lock);
10120
10121 ret = __start_delalloc_inodes(root, delay_iput, nr);
10122 btrfs_put_fs_root(root);
10123 if (ret < 0)
10124 goto out;
10125
10126 if (nr != -1) {
10127 nr -= ret;
10128 WARN_ON(nr < 0);
10129 }
10130 spin_lock(&fs_info->delalloc_root_lock);
10131 }
10132 spin_unlock(&fs_info->delalloc_root_lock);
10133
10134 ret = 0;
10135 atomic_inc(&fs_info->async_submit_draining);
10136 while (atomic_read(&fs_info->nr_async_submits) ||
10137 atomic_read(&fs_info->async_delalloc_pages)) {
10138 wait_event(fs_info->async_submit_wait,
10139 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10140 atomic_read(&fs_info->async_delalloc_pages) == 0));
10141 }
10142 atomic_dec(&fs_info->async_submit_draining);
10143 out:
10144 if (!list_empty_careful(&splice)) {
10145 spin_lock(&fs_info->delalloc_root_lock);
10146 list_splice_tail(&splice, &fs_info->delalloc_roots);
10147 spin_unlock(&fs_info->delalloc_root_lock);
10148 }
10149 mutex_unlock(&fs_info->delalloc_root_mutex);
10150 return ret;
10151 }
10152
10153 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10154 const char *symname)
10155 {
10156 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10157 struct btrfs_trans_handle *trans;
10158 struct btrfs_root *root = BTRFS_I(dir)->root;
10159 struct btrfs_path *path;
10160 struct btrfs_key key;
10161 struct inode *inode = NULL;
10162 int err;
10163 int drop_inode = 0;
10164 u64 objectid;
10165 u64 index = 0;
10166 int name_len;
10167 int datasize;
10168 unsigned long ptr;
10169 struct btrfs_file_extent_item *ei;
10170 struct extent_buffer *leaf;
10171
10172 name_len = strlen(symname);
10173 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10174 return -ENAMETOOLONG;
10175
10176 /*
10177 * 2 items for inode item and ref
10178 * 2 items for dir items
10179 * 1 item for updating parent inode item
10180 * 1 item for the inline extent item
10181 * 1 item for xattr if selinux is on
10182 */
10183 trans = btrfs_start_transaction(root, 7);
10184 if (IS_ERR(trans))
10185 return PTR_ERR(trans);
10186
10187 err = btrfs_find_free_ino(root, &objectid);
10188 if (err)
10189 goto out_unlock;
10190
10191 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10192 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10193 objectid, S_IFLNK|S_IRWXUGO, &index);
10194 if (IS_ERR(inode)) {
10195 err = PTR_ERR(inode);
10196 goto out_unlock;
10197 }
10198
10199 /*
10200 * If the active LSM wants to access the inode during
10201 * d_instantiate it needs these. Smack checks to see
10202 * if the filesystem supports xattrs by looking at the
10203 * ops vector.
10204 */
10205 inode->i_fop = &btrfs_file_operations;
10206 inode->i_op = &btrfs_file_inode_operations;
10207 inode->i_mapping->a_ops = &btrfs_aops;
10208 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10209
10210 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10211 if (err)
10212 goto out_unlock_inode;
10213
10214 path = btrfs_alloc_path();
10215 if (!path) {
10216 err = -ENOMEM;
10217 goto out_unlock_inode;
10218 }
10219 key.objectid = btrfs_ino(BTRFS_I(inode));
10220 key.offset = 0;
10221 key.type = BTRFS_EXTENT_DATA_KEY;
10222 datasize = btrfs_file_extent_calc_inline_size(name_len);
10223 err = btrfs_insert_empty_item(trans, root, path, &key,
10224 datasize);
10225 if (err) {
10226 btrfs_free_path(path);
10227 goto out_unlock_inode;
10228 }
10229 leaf = path->nodes[0];
10230 ei = btrfs_item_ptr(leaf, path->slots[0],
10231 struct btrfs_file_extent_item);
10232 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10233 btrfs_set_file_extent_type(leaf, ei,
10234 BTRFS_FILE_EXTENT_INLINE);
10235 btrfs_set_file_extent_encryption(leaf, ei, 0);
10236 btrfs_set_file_extent_compression(leaf, ei, 0);
10237 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10238 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10239
10240 ptr = btrfs_file_extent_inline_start(ei);
10241 write_extent_buffer(leaf, symname, ptr, name_len);
10242 btrfs_mark_buffer_dirty(leaf);
10243 btrfs_free_path(path);
10244
10245 inode->i_op = &btrfs_symlink_inode_operations;
10246 inode_nohighmem(inode);
10247 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10248 inode_set_bytes(inode, name_len);
10249 btrfs_i_size_write(BTRFS_I(inode), name_len);
10250 err = btrfs_update_inode(trans, root, inode);
10251 /*
10252 * Last step, add directory indexes for our symlink inode. This is the
10253 * last step to avoid extra cleanup of these indexes if an error happens
10254 * elsewhere above.
10255 */
10256 if (!err)
10257 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10258 BTRFS_I(inode), 0, index);
10259 if (err) {
10260 drop_inode = 1;
10261 goto out_unlock_inode;
10262 }
10263
10264 unlock_new_inode(inode);
10265 d_instantiate(dentry, inode);
10266
10267 out_unlock:
10268 btrfs_end_transaction(trans);
10269 if (drop_inode) {
10270 inode_dec_link_count(inode);
10271 iput(inode);
10272 }
10273 btrfs_btree_balance_dirty(fs_info);
10274 return err;
10275
10276 out_unlock_inode:
10277 drop_inode = 1;
10278 unlock_new_inode(inode);
10279 goto out_unlock;
10280 }
10281
10282 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10283 u64 start, u64 num_bytes, u64 min_size,
10284 loff_t actual_len, u64 *alloc_hint,
10285 struct btrfs_trans_handle *trans)
10286 {
10287 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10288 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10289 struct extent_map *em;
10290 struct btrfs_root *root = BTRFS_I(inode)->root;
10291 struct btrfs_key ins;
10292 u64 cur_offset = start;
10293 u64 i_size;
10294 u64 cur_bytes;
10295 u64 last_alloc = (u64)-1;
10296 int ret = 0;
10297 bool own_trans = true;
10298 u64 end = start + num_bytes - 1;
10299
10300 if (trans)
10301 own_trans = false;
10302 while (num_bytes > 0) {
10303 if (own_trans) {
10304 trans = btrfs_start_transaction(root, 3);
10305 if (IS_ERR(trans)) {
10306 ret = PTR_ERR(trans);
10307 break;
10308 }
10309 }
10310
10311 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10312 cur_bytes = max(cur_bytes, min_size);
10313 /*
10314 * If we are severely fragmented we could end up with really
10315 * small allocations, so if the allocator is returning small
10316 * chunks lets make its job easier by only searching for those
10317 * sized chunks.
10318 */
10319 cur_bytes = min(cur_bytes, last_alloc);
10320 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10321 min_size, 0, *alloc_hint, &ins, 1, 0);
10322 if (ret) {
10323 if (own_trans)
10324 btrfs_end_transaction(trans);
10325 break;
10326 }
10327 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10328
10329 last_alloc = ins.offset;
10330 ret = insert_reserved_file_extent(trans, inode,
10331 cur_offset, ins.objectid,
10332 ins.offset, ins.offset,
10333 ins.offset, 0, 0, 0,
10334 BTRFS_FILE_EXTENT_PREALLOC);
10335 if (ret) {
10336 btrfs_free_reserved_extent(fs_info, ins.objectid,
10337 ins.offset, 0);
10338 btrfs_abort_transaction(trans, ret);
10339 if (own_trans)
10340 btrfs_end_transaction(trans);
10341 break;
10342 }
10343
10344 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10345 cur_offset + ins.offset -1, 0);
10346
10347 em = alloc_extent_map();
10348 if (!em) {
10349 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10350 &BTRFS_I(inode)->runtime_flags);
10351 goto next;
10352 }
10353
10354 em->start = cur_offset;
10355 em->orig_start = cur_offset;
10356 em->len = ins.offset;
10357 em->block_start = ins.objectid;
10358 em->block_len = ins.offset;
10359 em->orig_block_len = ins.offset;
10360 em->ram_bytes = ins.offset;
10361 em->bdev = fs_info->fs_devices->latest_bdev;
10362 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10363 em->generation = trans->transid;
10364
10365 while (1) {
10366 write_lock(&em_tree->lock);
10367 ret = add_extent_mapping(em_tree, em, 1);
10368 write_unlock(&em_tree->lock);
10369 if (ret != -EEXIST)
10370 break;
10371 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10372 cur_offset + ins.offset - 1,
10373 0);
10374 }
10375 free_extent_map(em);
10376 next:
10377 num_bytes -= ins.offset;
10378 cur_offset += ins.offset;
10379 *alloc_hint = ins.objectid + ins.offset;
10380
10381 inode_inc_iversion(inode);
10382 inode->i_ctime = current_time(inode);
10383 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10384 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10385 (actual_len > inode->i_size) &&
10386 (cur_offset > inode->i_size)) {
10387 if (cur_offset > actual_len)
10388 i_size = actual_len;
10389 else
10390 i_size = cur_offset;
10391 i_size_write(inode, i_size);
10392 btrfs_ordered_update_i_size(inode, i_size, NULL);
10393 }
10394
10395 ret = btrfs_update_inode(trans, root, inode);
10396
10397 if (ret) {
10398 btrfs_abort_transaction(trans, ret);
10399 if (own_trans)
10400 btrfs_end_transaction(trans);
10401 break;
10402 }
10403
10404 if (own_trans)
10405 btrfs_end_transaction(trans);
10406 }
10407 if (cur_offset < end)
10408 btrfs_free_reserved_data_space(inode, cur_offset,
10409 end - cur_offset + 1);
10410 return ret;
10411 }
10412
10413 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10414 u64 start, u64 num_bytes, u64 min_size,
10415 loff_t actual_len, u64 *alloc_hint)
10416 {
10417 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10418 min_size, actual_len, alloc_hint,
10419 NULL);
10420 }
10421
10422 int btrfs_prealloc_file_range_trans(struct inode *inode,
10423 struct btrfs_trans_handle *trans, int mode,
10424 u64 start, u64 num_bytes, u64 min_size,
10425 loff_t actual_len, u64 *alloc_hint)
10426 {
10427 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10428 min_size, actual_len, alloc_hint, trans);
10429 }
10430
10431 static int btrfs_set_page_dirty(struct page *page)
10432 {
10433 return __set_page_dirty_nobuffers(page);
10434 }
10435
10436 static int btrfs_permission(struct inode *inode, int mask)
10437 {
10438 struct btrfs_root *root = BTRFS_I(inode)->root;
10439 umode_t mode = inode->i_mode;
10440
10441 if (mask & MAY_WRITE &&
10442 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10443 if (btrfs_root_readonly(root))
10444 return -EROFS;
10445 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10446 return -EACCES;
10447 }
10448 return generic_permission(inode, mask);
10449 }
10450
10451 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10452 {
10453 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10454 struct btrfs_trans_handle *trans;
10455 struct btrfs_root *root = BTRFS_I(dir)->root;
10456 struct inode *inode = NULL;
10457 u64 objectid;
10458 u64 index;
10459 int ret = 0;
10460
10461 /*
10462 * 5 units required for adding orphan entry
10463 */
10464 trans = btrfs_start_transaction(root, 5);
10465 if (IS_ERR(trans))
10466 return PTR_ERR(trans);
10467
10468 ret = btrfs_find_free_ino(root, &objectid);
10469 if (ret)
10470 goto out;
10471
10472 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10473 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10474 if (IS_ERR(inode)) {
10475 ret = PTR_ERR(inode);
10476 inode = NULL;
10477 goto out;
10478 }
10479
10480 inode->i_fop = &btrfs_file_operations;
10481 inode->i_op = &btrfs_file_inode_operations;
10482
10483 inode->i_mapping->a_ops = &btrfs_aops;
10484 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10485
10486 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10487 if (ret)
10488 goto out_inode;
10489
10490 ret = btrfs_update_inode(trans, root, inode);
10491 if (ret)
10492 goto out_inode;
10493 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10494 if (ret)
10495 goto out_inode;
10496
10497 /*
10498 * We set number of links to 0 in btrfs_new_inode(), and here we set
10499 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10500 * through:
10501 *
10502 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10503 */
10504 set_nlink(inode, 1);
10505 unlock_new_inode(inode);
10506 d_tmpfile(dentry, inode);
10507 mark_inode_dirty(inode);
10508
10509 out:
10510 btrfs_end_transaction(trans);
10511 if (ret)
10512 iput(inode);
10513 btrfs_balance_delayed_items(fs_info);
10514 btrfs_btree_balance_dirty(fs_info);
10515 return ret;
10516
10517 out_inode:
10518 unlock_new_inode(inode);
10519 goto out;
10520
10521 }
10522
10523 __attribute__((const))
10524 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10525 {
10526 return -EAGAIN;
10527 }
10528
10529 static const struct inode_operations btrfs_dir_inode_operations = {
10530 .getattr = btrfs_getattr,
10531 .lookup = btrfs_lookup,
10532 .create = btrfs_create,
10533 .unlink = btrfs_unlink,
10534 .link = btrfs_link,
10535 .mkdir = btrfs_mkdir,
10536 .rmdir = btrfs_rmdir,
10537 .rename = btrfs_rename2,
10538 .symlink = btrfs_symlink,
10539 .setattr = btrfs_setattr,
10540 .mknod = btrfs_mknod,
10541 .listxattr = btrfs_listxattr,
10542 .permission = btrfs_permission,
10543 .get_acl = btrfs_get_acl,
10544 .set_acl = btrfs_set_acl,
10545 .update_time = btrfs_update_time,
10546 .tmpfile = btrfs_tmpfile,
10547 };
10548 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10549 .lookup = btrfs_lookup,
10550 .permission = btrfs_permission,
10551 .update_time = btrfs_update_time,
10552 };
10553
10554 static const struct file_operations btrfs_dir_file_operations = {
10555 .llseek = generic_file_llseek,
10556 .read = generic_read_dir,
10557 .iterate_shared = btrfs_real_readdir,
10558 .unlocked_ioctl = btrfs_ioctl,
10559 #ifdef CONFIG_COMPAT
10560 .compat_ioctl = btrfs_compat_ioctl,
10561 #endif
10562 .release = btrfs_release_file,
10563 .fsync = btrfs_sync_file,
10564 };
10565
10566 static const struct extent_io_ops btrfs_extent_io_ops = {
10567 /* mandatory callbacks */
10568 .submit_bio_hook = btrfs_submit_bio_hook,
10569 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10570 .merge_bio_hook = btrfs_merge_bio_hook,
10571 .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10572
10573 /* optional callbacks */
10574 .fill_delalloc = run_delalloc_range,
10575 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10576 .writepage_start_hook = btrfs_writepage_start_hook,
10577 .set_bit_hook = btrfs_set_bit_hook,
10578 .clear_bit_hook = btrfs_clear_bit_hook,
10579 .merge_extent_hook = btrfs_merge_extent_hook,
10580 .split_extent_hook = btrfs_split_extent_hook,
10581 };
10582
10583 /*
10584 * btrfs doesn't support the bmap operation because swapfiles
10585 * use bmap to make a mapping of extents in the file. They assume
10586 * these extents won't change over the life of the file and they
10587 * use the bmap result to do IO directly to the drive.
10588 *
10589 * the btrfs bmap call would return logical addresses that aren't
10590 * suitable for IO and they also will change frequently as COW
10591 * operations happen. So, swapfile + btrfs == corruption.
10592 *
10593 * For now we're avoiding this by dropping bmap.
10594 */
10595 static const struct address_space_operations btrfs_aops = {
10596 .readpage = btrfs_readpage,
10597 .writepage = btrfs_writepage,
10598 .writepages = btrfs_writepages,
10599 .readpages = btrfs_readpages,
10600 .direct_IO = btrfs_direct_IO,
10601 .invalidatepage = btrfs_invalidatepage,
10602 .releasepage = btrfs_releasepage,
10603 .set_page_dirty = btrfs_set_page_dirty,
10604 .error_remove_page = generic_error_remove_page,
10605 };
10606
10607 static const struct address_space_operations btrfs_symlink_aops = {
10608 .readpage = btrfs_readpage,
10609 .writepage = btrfs_writepage,
10610 .invalidatepage = btrfs_invalidatepage,
10611 .releasepage = btrfs_releasepage,
10612 };
10613
10614 static const struct inode_operations btrfs_file_inode_operations = {
10615 .getattr = btrfs_getattr,
10616 .setattr = btrfs_setattr,
10617 .listxattr = btrfs_listxattr,
10618 .permission = btrfs_permission,
10619 .fiemap = btrfs_fiemap,
10620 .get_acl = btrfs_get_acl,
10621 .set_acl = btrfs_set_acl,
10622 .update_time = btrfs_update_time,
10623 };
10624 static const struct inode_operations btrfs_special_inode_operations = {
10625 .getattr = btrfs_getattr,
10626 .setattr = btrfs_setattr,
10627 .permission = btrfs_permission,
10628 .listxattr = btrfs_listxattr,
10629 .get_acl = btrfs_get_acl,
10630 .set_acl = btrfs_set_acl,
10631 .update_time = btrfs_update_time,
10632 };
10633 static const struct inode_operations btrfs_symlink_inode_operations = {
10634 .get_link = page_get_link,
10635 .getattr = btrfs_getattr,
10636 .setattr = btrfs_setattr,
10637 .permission = btrfs_permission,
10638 .listxattr = btrfs_listxattr,
10639 .update_time = btrfs_update_time,
10640 };
10641
10642 const struct dentry_operations btrfs_dentry_operations = {
10643 .d_delete = btrfs_dentry_delete,
10644 .d_release = btrfs_dentry_release,
10645 };
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git