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Merge tag 'rtc-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
[people/ms/linux.git] / fs / ntfs / file.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
4 *
5 * Copyright (c) 2001-2015 Anton Altaparmakov and Tuxera Inc.
6 */
7
8 #include <linux/blkdev.h>
9 #include <linux/backing-dev.h>
10 #include <linux/buffer_head.h>
11 #include <linux/gfp.h>
12 #include <linux/pagemap.h>
13 #include <linux/pagevec.h>
14 #include <linux/sched/signal.h>
15 #include <linux/swap.h>
16 #include <linux/uio.h>
17 #include <linux/writeback.h>
18
19 #include <asm/page.h>
20 #include <linux/uaccess.h>
21
22 #include "attrib.h"
23 #include "bitmap.h"
24 #include "inode.h"
25 #include "debug.h"
26 #include "lcnalloc.h"
27 #include "malloc.h"
28 #include "mft.h"
29 #include "ntfs.h"
30
31 /**
32 * ntfs_file_open - called when an inode is about to be opened
33 * @vi: inode to be opened
34 * @filp: file structure describing the inode
35 *
36 * Limit file size to the page cache limit on architectures where unsigned long
37 * is 32-bits. This is the most we can do for now without overflowing the page
38 * cache page index. Doing it this way means we don't run into problems because
39 * of existing too large files. It would be better to allow the user to read
40 * the beginning of the file but I doubt very much anyone is going to hit this
41 * check on a 32-bit architecture, so there is no point in adding the extra
42 * complexity required to support this.
43 *
44 * On 64-bit architectures, the check is hopefully optimized away by the
45 * compiler.
46 *
47 * After the check passes, just call generic_file_open() to do its work.
48 */
49 static int ntfs_file_open(struct inode *vi, struct file *filp)
50 {
51 if (sizeof(unsigned long) < 8) {
52 if (i_size_read(vi) > MAX_LFS_FILESIZE)
53 return -EOVERFLOW;
54 }
55 return generic_file_open(vi, filp);
56 }
57
58 #ifdef NTFS_RW
59
60 /**
61 * ntfs_attr_extend_initialized - extend the initialized size of an attribute
62 * @ni: ntfs inode of the attribute to extend
63 * @new_init_size: requested new initialized size in bytes
64 *
65 * Extend the initialized size of an attribute described by the ntfs inode @ni
66 * to @new_init_size bytes. This involves zeroing any non-sparse space between
67 * the old initialized size and @new_init_size both in the page cache and on
68 * disk (if relevant complete pages are already uptodate in the page cache then
69 * these are simply marked dirty).
70 *
71 * As a side-effect, the file size (vfs inode->i_size) may be incremented as,
72 * in the resident attribute case, it is tied to the initialized size and, in
73 * the non-resident attribute case, it may not fall below the initialized size.
74 *
75 * Note that if the attribute is resident, we do not need to touch the page
76 * cache at all. This is because if the page cache page is not uptodate we
77 * bring it uptodate later, when doing the write to the mft record since we
78 * then already have the page mapped. And if the page is uptodate, the
79 * non-initialized region will already have been zeroed when the page was
80 * brought uptodate and the region may in fact already have been overwritten
81 * with new data via mmap() based writes, so we cannot just zero it. And since
82 * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped
83 * is unspecified, we choose not to do zeroing and thus we do not need to touch
84 * the page at all. For a more detailed explanation see ntfs_truncate() in
85 * fs/ntfs/inode.c.
86 *
87 * Return 0 on success and -errno on error. In the case that an error is
88 * encountered it is possible that the initialized size will already have been
89 * incremented some way towards @new_init_size but it is guaranteed that if
90 * this is the case, the necessary zeroing will also have happened and that all
91 * metadata is self-consistent.
92 *
93 * Locking: i_mutex on the vfs inode corrseponsind to the ntfs inode @ni must be
94 * held by the caller.
95 */
96 static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size)
97 {
98 s64 old_init_size;
99 loff_t old_i_size;
100 pgoff_t index, end_index;
101 unsigned long flags;
102 struct inode *vi = VFS_I(ni);
103 ntfs_inode *base_ni;
104 MFT_RECORD *m = NULL;
105 ATTR_RECORD *a;
106 ntfs_attr_search_ctx *ctx = NULL;
107 struct address_space *mapping;
108 struct page *page = NULL;
109 u8 *kattr;
110 int err;
111 u32 attr_len;
112
113 read_lock_irqsave(&ni->size_lock, flags);
114 old_init_size = ni->initialized_size;
115 old_i_size = i_size_read(vi);
116 BUG_ON(new_init_size > ni->allocated_size);
117 read_unlock_irqrestore(&ni->size_lock, flags);
118 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
119 "old_initialized_size 0x%llx, "
120 "new_initialized_size 0x%llx, i_size 0x%llx.",
121 vi->i_ino, (unsigned)le32_to_cpu(ni->type),
122 (unsigned long long)old_init_size,
123 (unsigned long long)new_init_size, old_i_size);
124 if (!NInoAttr(ni))
125 base_ni = ni;
126 else
127 base_ni = ni->ext.base_ntfs_ino;
128 /* Use goto to reduce indentation and we need the label below anyway. */
129 if (NInoNonResident(ni))
130 goto do_non_resident_extend;
131 BUG_ON(old_init_size != old_i_size);
132 m = map_mft_record(base_ni);
133 if (IS_ERR(m)) {
134 err = PTR_ERR(m);
135 m = NULL;
136 goto err_out;
137 }
138 ctx = ntfs_attr_get_search_ctx(base_ni, m);
139 if (unlikely(!ctx)) {
140 err = -ENOMEM;
141 goto err_out;
142 }
143 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
144 CASE_SENSITIVE, 0, NULL, 0, ctx);
145 if (unlikely(err)) {
146 if (err == -ENOENT)
147 err = -EIO;
148 goto err_out;
149 }
150 m = ctx->mrec;
151 a = ctx->attr;
152 BUG_ON(a->non_resident);
153 /* The total length of the attribute value. */
154 attr_len = le32_to_cpu(a->data.resident.value_length);
155 BUG_ON(old_i_size != (loff_t)attr_len);
156 /*
157 * Do the zeroing in the mft record and update the attribute size in
158 * the mft record.
159 */
160 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
161 memset(kattr + attr_len, 0, new_init_size - attr_len);
162 a->data.resident.value_length = cpu_to_le32((u32)new_init_size);
163 /* Finally, update the sizes in the vfs and ntfs inodes. */
164 write_lock_irqsave(&ni->size_lock, flags);
165 i_size_write(vi, new_init_size);
166 ni->initialized_size = new_init_size;
167 write_unlock_irqrestore(&ni->size_lock, flags);
168 goto done;
169 do_non_resident_extend:
170 /*
171 * If the new initialized size @new_init_size exceeds the current file
172 * size (vfs inode->i_size), we need to extend the file size to the
173 * new initialized size.
174 */
175 if (new_init_size > old_i_size) {
176 m = map_mft_record(base_ni);
177 if (IS_ERR(m)) {
178 err = PTR_ERR(m);
179 m = NULL;
180 goto err_out;
181 }
182 ctx = ntfs_attr_get_search_ctx(base_ni, m);
183 if (unlikely(!ctx)) {
184 err = -ENOMEM;
185 goto err_out;
186 }
187 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
188 CASE_SENSITIVE, 0, NULL, 0, ctx);
189 if (unlikely(err)) {
190 if (err == -ENOENT)
191 err = -EIO;
192 goto err_out;
193 }
194 m = ctx->mrec;
195 a = ctx->attr;
196 BUG_ON(!a->non_resident);
197 BUG_ON(old_i_size != (loff_t)
198 sle64_to_cpu(a->data.non_resident.data_size));
199 a->data.non_resident.data_size = cpu_to_sle64(new_init_size);
200 flush_dcache_mft_record_page(ctx->ntfs_ino);
201 mark_mft_record_dirty(ctx->ntfs_ino);
202 /* Update the file size in the vfs inode. */
203 i_size_write(vi, new_init_size);
204 ntfs_attr_put_search_ctx(ctx);
205 ctx = NULL;
206 unmap_mft_record(base_ni);
207 m = NULL;
208 }
209 mapping = vi->i_mapping;
210 index = old_init_size >> PAGE_SHIFT;
211 end_index = (new_init_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
212 do {
213 /*
214 * Read the page. If the page is not present, this will zero
215 * the uninitialized regions for us.
216 */
217 page = read_mapping_page(mapping, index, NULL);
218 if (IS_ERR(page)) {
219 err = PTR_ERR(page);
220 goto init_err_out;
221 }
222 /*
223 * Update the initialized size in the ntfs inode. This is
224 * enough to make ntfs_writepage() work.
225 */
226 write_lock_irqsave(&ni->size_lock, flags);
227 ni->initialized_size = (s64)(index + 1) << PAGE_SHIFT;
228 if (ni->initialized_size > new_init_size)
229 ni->initialized_size = new_init_size;
230 write_unlock_irqrestore(&ni->size_lock, flags);
231 /* Set the page dirty so it gets written out. */
232 set_page_dirty(page);
233 put_page(page);
234 /*
235 * Play nice with the vm and the rest of the system. This is
236 * very much needed as we can potentially be modifying the
237 * initialised size from a very small value to a really huge
238 * value, e.g.
239 * f = open(somefile, O_TRUNC);
240 * truncate(f, 10GiB);
241 * seek(f, 10GiB);
242 * write(f, 1);
243 * And this would mean we would be marking dirty hundreds of
244 * thousands of pages or as in the above example more than
245 * two and a half million pages!
246 *
247 * TODO: For sparse pages could optimize this workload by using
248 * the FsMisc / MiscFs page bit as a "PageIsSparse" bit. This
249 * would be set in read_folio for sparse pages and here we would
250 * not need to mark dirty any pages which have this bit set.
251 * The only caveat is that we have to clear the bit everywhere
252 * where we allocate any clusters that lie in the page or that
253 * contain the page.
254 *
255 * TODO: An even greater optimization would be for us to only
256 * call read_folio() on pages which are not in sparse regions as
257 * determined from the runlist. This would greatly reduce the
258 * number of pages we read and make dirty in the case of sparse
259 * files.
260 */
261 balance_dirty_pages_ratelimited(mapping);
262 cond_resched();
263 } while (++index < end_index);
264 read_lock_irqsave(&ni->size_lock, flags);
265 BUG_ON(ni->initialized_size != new_init_size);
266 read_unlock_irqrestore(&ni->size_lock, flags);
267 /* Now bring in sync the initialized_size in the mft record. */
268 m = map_mft_record(base_ni);
269 if (IS_ERR(m)) {
270 err = PTR_ERR(m);
271 m = NULL;
272 goto init_err_out;
273 }
274 ctx = ntfs_attr_get_search_ctx(base_ni, m);
275 if (unlikely(!ctx)) {
276 err = -ENOMEM;
277 goto init_err_out;
278 }
279 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
280 CASE_SENSITIVE, 0, NULL, 0, ctx);
281 if (unlikely(err)) {
282 if (err == -ENOENT)
283 err = -EIO;
284 goto init_err_out;
285 }
286 m = ctx->mrec;
287 a = ctx->attr;
288 BUG_ON(!a->non_resident);
289 a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size);
290 done:
291 flush_dcache_mft_record_page(ctx->ntfs_ino);
292 mark_mft_record_dirty(ctx->ntfs_ino);
293 if (ctx)
294 ntfs_attr_put_search_ctx(ctx);
295 if (m)
296 unmap_mft_record(base_ni);
297 ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.",
298 (unsigned long long)new_init_size, i_size_read(vi));
299 return 0;
300 init_err_out:
301 write_lock_irqsave(&ni->size_lock, flags);
302 ni->initialized_size = old_init_size;
303 write_unlock_irqrestore(&ni->size_lock, flags);
304 err_out:
305 if (ctx)
306 ntfs_attr_put_search_ctx(ctx);
307 if (m)
308 unmap_mft_record(base_ni);
309 ntfs_debug("Failed. Returning error code %i.", err);
310 return err;
311 }
312
313 static ssize_t ntfs_prepare_file_for_write(struct kiocb *iocb,
314 struct iov_iter *from)
315 {
316 loff_t pos;
317 s64 end, ll;
318 ssize_t err;
319 unsigned long flags;
320 struct file *file = iocb->ki_filp;
321 struct inode *vi = file_inode(file);
322 ntfs_inode *ni = NTFS_I(vi);
323 ntfs_volume *vol = ni->vol;
324
325 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
326 "0x%llx, count 0x%zx.", vi->i_ino,
327 (unsigned)le32_to_cpu(ni->type),
328 (unsigned long long)iocb->ki_pos,
329 iov_iter_count(from));
330 err = generic_write_checks(iocb, from);
331 if (unlikely(err <= 0))
332 goto out;
333 /*
334 * All checks have passed. Before we start doing any writing we want
335 * to abort any totally illegal writes.
336 */
337 BUG_ON(NInoMstProtected(ni));
338 BUG_ON(ni->type != AT_DATA);
339 /* If file is encrypted, deny access, just like NT4. */
340 if (NInoEncrypted(ni)) {
341 /* Only $DATA attributes can be encrypted. */
342 /*
343 * Reminder for later: Encrypted files are _always_
344 * non-resident so that the content can always be encrypted.
345 */
346 ntfs_debug("Denying write access to encrypted file.");
347 err = -EACCES;
348 goto out;
349 }
350 if (NInoCompressed(ni)) {
351 /* Only unnamed $DATA attribute can be compressed. */
352 BUG_ON(ni->name_len);
353 /*
354 * Reminder for later: If resident, the data is not actually
355 * compressed. Only on the switch to non-resident does
356 * compression kick in. This is in contrast to encrypted files
357 * (see above).
358 */
359 ntfs_error(vi->i_sb, "Writing to compressed files is not "
360 "implemented yet. Sorry.");
361 err = -EOPNOTSUPP;
362 goto out;
363 }
364 err = file_remove_privs(file);
365 if (unlikely(err))
366 goto out;
367 /*
368 * Our ->update_time method always succeeds thus file_update_time()
369 * cannot fail either so there is no need to check the return code.
370 */
371 file_update_time(file);
372 pos = iocb->ki_pos;
373 /* The first byte after the last cluster being written to. */
374 end = (pos + iov_iter_count(from) + vol->cluster_size_mask) &
375 ~(u64)vol->cluster_size_mask;
376 /*
377 * If the write goes beyond the allocated size, extend the allocation
378 * to cover the whole of the write, rounded up to the nearest cluster.
379 */
380 read_lock_irqsave(&ni->size_lock, flags);
381 ll = ni->allocated_size;
382 read_unlock_irqrestore(&ni->size_lock, flags);
383 if (end > ll) {
384 /*
385 * Extend the allocation without changing the data size.
386 *
387 * Note we ensure the allocation is big enough to at least
388 * write some data but we do not require the allocation to be
389 * complete, i.e. it may be partial.
390 */
391 ll = ntfs_attr_extend_allocation(ni, end, -1, pos);
392 if (likely(ll >= 0)) {
393 BUG_ON(pos >= ll);
394 /* If the extension was partial truncate the write. */
395 if (end > ll) {
396 ntfs_debug("Truncating write to inode 0x%lx, "
397 "attribute type 0x%x, because "
398 "the allocation was only "
399 "partially extended.",
400 vi->i_ino, (unsigned)
401 le32_to_cpu(ni->type));
402 iov_iter_truncate(from, ll - pos);
403 }
404 } else {
405 err = ll;
406 read_lock_irqsave(&ni->size_lock, flags);
407 ll = ni->allocated_size;
408 read_unlock_irqrestore(&ni->size_lock, flags);
409 /* Perform a partial write if possible or fail. */
410 if (pos < ll) {
411 ntfs_debug("Truncating write to inode 0x%lx "
412 "attribute type 0x%x, because "
413 "extending the allocation "
414 "failed (error %d).",
415 vi->i_ino, (unsigned)
416 le32_to_cpu(ni->type),
417 (int)-err);
418 iov_iter_truncate(from, ll - pos);
419 } else {
420 if (err != -ENOSPC)
421 ntfs_error(vi->i_sb, "Cannot perform "
422 "write to inode "
423 "0x%lx, attribute "
424 "type 0x%x, because "
425 "extending the "
426 "allocation failed "
427 "(error %ld).",
428 vi->i_ino, (unsigned)
429 le32_to_cpu(ni->type),
430 (long)-err);
431 else
432 ntfs_debug("Cannot perform write to "
433 "inode 0x%lx, "
434 "attribute type 0x%x, "
435 "because there is not "
436 "space left.",
437 vi->i_ino, (unsigned)
438 le32_to_cpu(ni->type));
439 goto out;
440 }
441 }
442 }
443 /*
444 * If the write starts beyond the initialized size, extend it up to the
445 * beginning of the write and initialize all non-sparse space between
446 * the old initialized size and the new one. This automatically also
447 * increments the vfs inode->i_size to keep it above or equal to the
448 * initialized_size.
449 */
450 read_lock_irqsave(&ni->size_lock, flags);
451 ll = ni->initialized_size;
452 read_unlock_irqrestore(&ni->size_lock, flags);
453 if (pos > ll) {
454 /*
455 * Wait for ongoing direct i/o to complete before proceeding.
456 * New direct i/o cannot start as we hold i_mutex.
457 */
458 inode_dio_wait(vi);
459 err = ntfs_attr_extend_initialized(ni, pos);
460 if (unlikely(err < 0))
461 ntfs_error(vi->i_sb, "Cannot perform write to inode "
462 "0x%lx, attribute type 0x%x, because "
463 "extending the initialized size "
464 "failed (error %d).", vi->i_ino,
465 (unsigned)le32_to_cpu(ni->type),
466 (int)-err);
467 }
468 out:
469 return err;
470 }
471
472 /**
473 * __ntfs_grab_cache_pages - obtain a number of locked pages
474 * @mapping: address space mapping from which to obtain page cache pages
475 * @index: starting index in @mapping at which to begin obtaining pages
476 * @nr_pages: number of page cache pages to obtain
477 * @pages: array of pages in which to return the obtained page cache pages
478 * @cached_page: allocated but as yet unused page
479 *
480 * Obtain @nr_pages locked page cache pages from the mapping @mapping and
481 * starting at index @index.
482 *
483 * If a page is newly created, add it to lru list
484 *
485 * Note, the page locks are obtained in ascending page index order.
486 */
487 static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
488 pgoff_t index, const unsigned nr_pages, struct page **pages,
489 struct page **cached_page)
490 {
491 int err, nr;
492
493 BUG_ON(!nr_pages);
494 err = nr = 0;
495 do {
496 pages[nr] = find_get_page_flags(mapping, index, FGP_LOCK |
497 FGP_ACCESSED);
498 if (!pages[nr]) {
499 if (!*cached_page) {
500 *cached_page = page_cache_alloc(mapping);
501 if (unlikely(!*cached_page)) {
502 err = -ENOMEM;
503 goto err_out;
504 }
505 }
506 err = add_to_page_cache_lru(*cached_page, mapping,
507 index,
508 mapping_gfp_constraint(mapping, GFP_KERNEL));
509 if (unlikely(err)) {
510 if (err == -EEXIST)
511 continue;
512 goto err_out;
513 }
514 pages[nr] = *cached_page;
515 *cached_page = NULL;
516 }
517 index++;
518 nr++;
519 } while (nr < nr_pages);
520 out:
521 return err;
522 err_out:
523 while (nr > 0) {
524 unlock_page(pages[--nr]);
525 put_page(pages[nr]);
526 }
527 goto out;
528 }
529
530 static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
531 {
532 lock_buffer(bh);
533 get_bh(bh);
534 bh->b_end_io = end_buffer_read_sync;
535 return submit_bh(REQ_OP_READ, bh);
536 }
537
538 /**
539 * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data
540 * @pages: array of destination pages
541 * @nr_pages: number of pages in @pages
542 * @pos: byte position in file at which the write begins
543 * @bytes: number of bytes to be written
544 *
545 * This is called for non-resident attributes from ntfs_file_buffered_write()
546 * with i_mutex held on the inode (@pages[0]->mapping->host). There are
547 * @nr_pages pages in @pages which are locked but not kmap()ped. The source
548 * data has not yet been copied into the @pages.
549 *
550 * Need to fill any holes with actual clusters, allocate buffers if necessary,
551 * ensure all the buffers are mapped, and bring uptodate any buffers that are
552 * only partially being written to.
553 *
554 * If @nr_pages is greater than one, we are guaranteed that the cluster size is
555 * greater than PAGE_SIZE, that all pages in @pages are entirely inside
556 * the same cluster and that they are the entirety of that cluster, and that
557 * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
558 *
559 * i_size is not to be modified yet.
560 *
561 * Return 0 on success or -errno on error.
562 */
563 static int ntfs_prepare_pages_for_non_resident_write(struct page **pages,
564 unsigned nr_pages, s64 pos, size_t bytes)
565 {
566 VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend;
567 LCN lcn;
568 s64 bh_pos, vcn_len, end, initialized_size;
569 sector_t lcn_block;
570 struct page *page;
571 struct inode *vi;
572 ntfs_inode *ni, *base_ni = NULL;
573 ntfs_volume *vol;
574 runlist_element *rl, *rl2;
575 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
576 ntfs_attr_search_ctx *ctx = NULL;
577 MFT_RECORD *m = NULL;
578 ATTR_RECORD *a = NULL;
579 unsigned long flags;
580 u32 attr_rec_len = 0;
581 unsigned blocksize, u;
582 int err, mp_size;
583 bool rl_write_locked, was_hole, is_retry;
584 unsigned char blocksize_bits;
585 struct {
586 u8 runlist_merged:1;
587 u8 mft_attr_mapped:1;
588 u8 mp_rebuilt:1;
589 u8 attr_switched:1;
590 } status = { 0, 0, 0, 0 };
591
592 BUG_ON(!nr_pages);
593 BUG_ON(!pages);
594 BUG_ON(!*pages);
595 vi = pages[0]->mapping->host;
596 ni = NTFS_I(vi);
597 vol = ni->vol;
598 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
599 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
600 vi->i_ino, ni->type, pages[0]->index, nr_pages,
601 (long long)pos, bytes);
602 blocksize = vol->sb->s_blocksize;
603 blocksize_bits = vol->sb->s_blocksize_bits;
604 u = 0;
605 do {
606 page = pages[u];
607 BUG_ON(!page);
608 /*
609 * create_empty_buffers() will create uptodate/dirty buffers if
610 * the page is uptodate/dirty.
611 */
612 if (!page_has_buffers(page)) {
613 create_empty_buffers(page, blocksize, 0);
614 if (unlikely(!page_has_buffers(page)))
615 return -ENOMEM;
616 }
617 } while (++u < nr_pages);
618 rl_write_locked = false;
619 rl = NULL;
620 err = 0;
621 vcn = lcn = -1;
622 vcn_len = 0;
623 lcn_block = -1;
624 was_hole = false;
625 cpos = pos >> vol->cluster_size_bits;
626 end = pos + bytes;
627 cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits;
628 /*
629 * Loop over each page and for each page over each buffer. Use goto to
630 * reduce indentation.
631 */
632 u = 0;
633 do_next_page:
634 page = pages[u];
635 bh_pos = (s64)page->index << PAGE_SHIFT;
636 bh = head = page_buffers(page);
637 do {
638 VCN cdelta;
639 s64 bh_end;
640 unsigned bh_cofs;
641
642 /* Clear buffer_new on all buffers to reinitialise state. */
643 if (buffer_new(bh))
644 clear_buffer_new(bh);
645 bh_end = bh_pos + blocksize;
646 bh_cpos = bh_pos >> vol->cluster_size_bits;
647 bh_cofs = bh_pos & vol->cluster_size_mask;
648 if (buffer_mapped(bh)) {
649 /*
650 * The buffer is already mapped. If it is uptodate,
651 * ignore it.
652 */
653 if (buffer_uptodate(bh))
654 continue;
655 /*
656 * The buffer is not uptodate. If the page is uptodate
657 * set the buffer uptodate and otherwise ignore it.
658 */
659 if (PageUptodate(page)) {
660 set_buffer_uptodate(bh);
661 continue;
662 }
663 /*
664 * Neither the page nor the buffer are uptodate. If
665 * the buffer is only partially being written to, we
666 * need to read it in before the write, i.e. now.
667 */
668 if ((bh_pos < pos && bh_end > pos) ||
669 (bh_pos < end && bh_end > end)) {
670 /*
671 * If the buffer is fully or partially within
672 * the initialized size, do an actual read.
673 * Otherwise, simply zero the buffer.
674 */
675 read_lock_irqsave(&ni->size_lock, flags);
676 initialized_size = ni->initialized_size;
677 read_unlock_irqrestore(&ni->size_lock, flags);
678 if (bh_pos < initialized_size) {
679 ntfs_submit_bh_for_read(bh);
680 *wait_bh++ = bh;
681 } else {
682 zero_user(page, bh_offset(bh),
683 blocksize);
684 set_buffer_uptodate(bh);
685 }
686 }
687 continue;
688 }
689 /* Unmapped buffer. Need to map it. */
690 bh->b_bdev = vol->sb->s_bdev;
691 /*
692 * If the current buffer is in the same clusters as the map
693 * cache, there is no need to check the runlist again. The
694 * map cache is made up of @vcn, which is the first cached file
695 * cluster, @vcn_len which is the number of cached file
696 * clusters, @lcn is the device cluster corresponding to @vcn,
697 * and @lcn_block is the block number corresponding to @lcn.
698 */
699 cdelta = bh_cpos - vcn;
700 if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) {
701 map_buffer_cached:
702 BUG_ON(lcn < 0);
703 bh->b_blocknr = lcn_block +
704 (cdelta << (vol->cluster_size_bits -
705 blocksize_bits)) +
706 (bh_cofs >> blocksize_bits);
707 set_buffer_mapped(bh);
708 /*
709 * If the page is uptodate so is the buffer. If the
710 * buffer is fully outside the write, we ignore it if
711 * it was already allocated and we mark it dirty so it
712 * gets written out if we allocated it. On the other
713 * hand, if we allocated the buffer but we are not
714 * marking it dirty we set buffer_new so we can do
715 * error recovery.
716 */
717 if (PageUptodate(page)) {
718 if (!buffer_uptodate(bh))
719 set_buffer_uptodate(bh);
720 if (unlikely(was_hole)) {
721 /* We allocated the buffer. */
722 clean_bdev_bh_alias(bh);
723 if (bh_end <= pos || bh_pos >= end)
724 mark_buffer_dirty(bh);
725 else
726 set_buffer_new(bh);
727 }
728 continue;
729 }
730 /* Page is _not_ uptodate. */
731 if (likely(!was_hole)) {
732 /*
733 * Buffer was already allocated. If it is not
734 * uptodate and is only partially being written
735 * to, we need to read it in before the write,
736 * i.e. now.
737 */
738 if (!buffer_uptodate(bh) && bh_pos < end &&
739 bh_end > pos &&
740 (bh_pos < pos ||
741 bh_end > end)) {
742 /*
743 * If the buffer is fully or partially
744 * within the initialized size, do an
745 * actual read. Otherwise, simply zero
746 * the buffer.
747 */
748 read_lock_irqsave(&ni->size_lock,
749 flags);
750 initialized_size = ni->initialized_size;
751 read_unlock_irqrestore(&ni->size_lock,
752 flags);
753 if (bh_pos < initialized_size) {
754 ntfs_submit_bh_for_read(bh);
755 *wait_bh++ = bh;
756 } else {
757 zero_user(page, bh_offset(bh),
758 blocksize);
759 set_buffer_uptodate(bh);
760 }
761 }
762 continue;
763 }
764 /* We allocated the buffer. */
765 clean_bdev_bh_alias(bh);
766 /*
767 * If the buffer is fully outside the write, zero it,
768 * set it uptodate, and mark it dirty so it gets
769 * written out. If it is partially being written to,
770 * zero region surrounding the write but leave it to
771 * commit write to do anything else. Finally, if the
772 * buffer is fully being overwritten, do nothing.
773 */
774 if (bh_end <= pos || bh_pos >= end) {
775 if (!buffer_uptodate(bh)) {
776 zero_user(page, bh_offset(bh),
777 blocksize);
778 set_buffer_uptodate(bh);
779 }
780 mark_buffer_dirty(bh);
781 continue;
782 }
783 set_buffer_new(bh);
784 if (!buffer_uptodate(bh) &&
785 (bh_pos < pos || bh_end > end)) {
786 u8 *kaddr;
787 unsigned pofs;
788
789 kaddr = kmap_atomic(page);
790 if (bh_pos < pos) {
791 pofs = bh_pos & ~PAGE_MASK;
792 memset(kaddr + pofs, 0, pos - bh_pos);
793 }
794 if (bh_end > end) {
795 pofs = end & ~PAGE_MASK;
796 memset(kaddr + pofs, 0, bh_end - end);
797 }
798 kunmap_atomic(kaddr);
799 flush_dcache_page(page);
800 }
801 continue;
802 }
803 /*
804 * Slow path: this is the first buffer in the cluster. If it
805 * is outside allocated size and is not uptodate, zero it and
806 * set it uptodate.
807 */
808 read_lock_irqsave(&ni->size_lock, flags);
809 initialized_size = ni->allocated_size;
810 read_unlock_irqrestore(&ni->size_lock, flags);
811 if (bh_pos > initialized_size) {
812 if (PageUptodate(page)) {
813 if (!buffer_uptodate(bh))
814 set_buffer_uptodate(bh);
815 } else if (!buffer_uptodate(bh)) {
816 zero_user(page, bh_offset(bh), blocksize);
817 set_buffer_uptodate(bh);
818 }
819 continue;
820 }
821 is_retry = false;
822 if (!rl) {
823 down_read(&ni->runlist.lock);
824 retry_remap:
825 rl = ni->runlist.rl;
826 }
827 if (likely(rl != NULL)) {
828 /* Seek to element containing target cluster. */
829 while (rl->length && rl[1].vcn <= bh_cpos)
830 rl++;
831 lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos);
832 if (likely(lcn >= 0)) {
833 /*
834 * Successful remap, setup the map cache and
835 * use that to deal with the buffer.
836 */
837 was_hole = false;
838 vcn = bh_cpos;
839 vcn_len = rl[1].vcn - vcn;
840 lcn_block = lcn << (vol->cluster_size_bits -
841 blocksize_bits);
842 cdelta = 0;
843 /*
844 * If the number of remaining clusters touched
845 * by the write is smaller or equal to the
846 * number of cached clusters, unlock the
847 * runlist as the map cache will be used from
848 * now on.
849 */
850 if (likely(vcn + vcn_len >= cend)) {
851 if (rl_write_locked) {
852 up_write(&ni->runlist.lock);
853 rl_write_locked = false;
854 } else
855 up_read(&ni->runlist.lock);
856 rl = NULL;
857 }
858 goto map_buffer_cached;
859 }
860 } else
861 lcn = LCN_RL_NOT_MAPPED;
862 /*
863 * If it is not a hole and not out of bounds, the runlist is
864 * probably unmapped so try to map it now.
865 */
866 if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) {
867 if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) {
868 /* Attempt to map runlist. */
869 if (!rl_write_locked) {
870 /*
871 * We need the runlist locked for
872 * writing, so if it is locked for
873 * reading relock it now and retry in
874 * case it changed whilst we dropped
875 * the lock.
876 */
877 up_read(&ni->runlist.lock);
878 down_write(&ni->runlist.lock);
879 rl_write_locked = true;
880 goto retry_remap;
881 }
882 err = ntfs_map_runlist_nolock(ni, bh_cpos,
883 NULL);
884 if (likely(!err)) {
885 is_retry = true;
886 goto retry_remap;
887 }
888 /*
889 * If @vcn is out of bounds, pretend @lcn is
890 * LCN_ENOENT. As long as the buffer is out
891 * of bounds this will work fine.
892 */
893 if (err == -ENOENT) {
894 lcn = LCN_ENOENT;
895 err = 0;
896 goto rl_not_mapped_enoent;
897 }
898 } else
899 err = -EIO;
900 /* Failed to map the buffer, even after retrying. */
901 bh->b_blocknr = -1;
902 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
903 "attribute type 0x%x, vcn 0x%llx, "
904 "vcn offset 0x%x, because its "
905 "location on disk could not be "
906 "determined%s (error code %i).",
907 ni->mft_no, ni->type,
908 (unsigned long long)bh_cpos,
909 (unsigned)bh_pos &
910 vol->cluster_size_mask,
911 is_retry ? " even after retrying" : "",
912 err);
913 break;
914 }
915 rl_not_mapped_enoent:
916 /*
917 * The buffer is in a hole or out of bounds. We need to fill
918 * the hole, unless the buffer is in a cluster which is not
919 * touched by the write, in which case we just leave the buffer
920 * unmapped. This can only happen when the cluster size is
921 * less than the page cache size.
922 */
923 if (unlikely(vol->cluster_size < PAGE_SIZE)) {
924 bh_cend = (bh_end + vol->cluster_size - 1) >>
925 vol->cluster_size_bits;
926 if ((bh_cend <= cpos || bh_cpos >= cend)) {
927 bh->b_blocknr = -1;
928 /*
929 * If the buffer is uptodate we skip it. If it
930 * is not but the page is uptodate, we can set
931 * the buffer uptodate. If the page is not
932 * uptodate, we can clear the buffer and set it
933 * uptodate. Whether this is worthwhile is
934 * debatable and this could be removed.
935 */
936 if (PageUptodate(page)) {
937 if (!buffer_uptodate(bh))
938 set_buffer_uptodate(bh);
939 } else if (!buffer_uptodate(bh)) {
940 zero_user(page, bh_offset(bh),
941 blocksize);
942 set_buffer_uptodate(bh);
943 }
944 continue;
945 }
946 }
947 /*
948 * Out of bounds buffer is invalid if it was not really out of
949 * bounds.
950 */
951 BUG_ON(lcn != LCN_HOLE);
952 /*
953 * We need the runlist locked for writing, so if it is locked
954 * for reading relock it now and retry in case it changed
955 * whilst we dropped the lock.
956 */
957 BUG_ON(!rl);
958 if (!rl_write_locked) {
959 up_read(&ni->runlist.lock);
960 down_write(&ni->runlist.lock);
961 rl_write_locked = true;
962 goto retry_remap;
963 }
964 /* Find the previous last allocated cluster. */
965 BUG_ON(rl->lcn != LCN_HOLE);
966 lcn = -1;
967 rl2 = rl;
968 while (--rl2 >= ni->runlist.rl) {
969 if (rl2->lcn >= 0) {
970 lcn = rl2->lcn + rl2->length;
971 break;
972 }
973 }
974 rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE,
975 false);
976 if (IS_ERR(rl2)) {
977 err = PTR_ERR(rl2);
978 ntfs_debug("Failed to allocate cluster, error code %i.",
979 err);
980 break;
981 }
982 lcn = rl2->lcn;
983 rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
984 if (IS_ERR(rl)) {
985 err = PTR_ERR(rl);
986 if (err != -ENOMEM)
987 err = -EIO;
988 if (ntfs_cluster_free_from_rl(vol, rl2)) {
989 ntfs_error(vol->sb, "Failed to release "
990 "allocated cluster in error "
991 "code path. Run chkdsk to "
992 "recover the lost cluster.");
993 NVolSetErrors(vol);
994 }
995 ntfs_free(rl2);
996 break;
997 }
998 ni->runlist.rl = rl;
999 status.runlist_merged = 1;
1000 ntfs_debug("Allocated cluster, lcn 0x%llx.",
1001 (unsigned long long)lcn);
1002 /* Map and lock the mft record and get the attribute record. */
1003 if (!NInoAttr(ni))
1004 base_ni = ni;
1005 else
1006 base_ni = ni->ext.base_ntfs_ino;
1007 m = map_mft_record(base_ni);
1008 if (IS_ERR(m)) {
1009 err = PTR_ERR(m);
1010 break;
1011 }
1012 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1013 if (unlikely(!ctx)) {
1014 err = -ENOMEM;
1015 unmap_mft_record(base_ni);
1016 break;
1017 }
1018 status.mft_attr_mapped = 1;
1019 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1020 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx);
1021 if (unlikely(err)) {
1022 if (err == -ENOENT)
1023 err = -EIO;
1024 break;
1025 }
1026 m = ctx->mrec;
1027 a = ctx->attr;
1028 /*
1029 * Find the runlist element with which the attribute extent
1030 * starts. Note, we cannot use the _attr_ version because we
1031 * have mapped the mft record. That is ok because we know the
1032 * runlist fragment must be mapped already to have ever gotten
1033 * here, so we can just use the _rl_ version.
1034 */
1035 vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn);
1036 rl2 = ntfs_rl_find_vcn_nolock(rl, vcn);
1037 BUG_ON(!rl2);
1038 BUG_ON(!rl2->length);
1039 BUG_ON(rl2->lcn < LCN_HOLE);
1040 highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
1041 /*
1042 * If @highest_vcn is zero, calculate the real highest_vcn
1043 * (which can really be zero).
1044 */
1045 if (!highest_vcn)
1046 highest_vcn = (sle64_to_cpu(
1047 a->data.non_resident.allocated_size) >>
1048 vol->cluster_size_bits) - 1;
1049 /*
1050 * Determine the size of the mapping pairs array for the new
1051 * extent, i.e. the old extent with the hole filled.
1052 */
1053 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn,
1054 highest_vcn);
1055 if (unlikely(mp_size <= 0)) {
1056 if (!(err = mp_size))
1057 err = -EIO;
1058 ntfs_debug("Failed to get size for mapping pairs "
1059 "array, error code %i.", err);
1060 break;
1061 }
1062 /*
1063 * Resize the attribute record to fit the new mapping pairs
1064 * array.
1065 */
1066 attr_rec_len = le32_to_cpu(a->length);
1067 err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu(
1068 a->data.non_resident.mapping_pairs_offset));
1069 if (unlikely(err)) {
1070 BUG_ON(err != -ENOSPC);
1071 // TODO: Deal with this by using the current attribute
1072 // and fill it with as much of the mapping pairs
1073 // array as possible. Then loop over each attribute
1074 // extent rewriting the mapping pairs arrays as we go
1075 // along and if when we reach the end we have not
1076 // enough space, try to resize the last attribute
1077 // extent and if even that fails, add a new attribute
1078 // extent.
1079 // We could also try to resize at each step in the hope
1080 // that we will not need to rewrite every single extent.
1081 // Note, we may need to decompress some extents to fill
1082 // the runlist as we are walking the extents...
1083 ntfs_error(vol->sb, "Not enough space in the mft "
1084 "record for the extended attribute "
1085 "record. This case is not "
1086 "implemented yet.");
1087 err = -EOPNOTSUPP;
1088 break ;
1089 }
1090 status.mp_rebuilt = 1;
1091 /*
1092 * Generate the mapping pairs array directly into the attribute
1093 * record.
1094 */
1095 err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1096 a->data.non_resident.mapping_pairs_offset),
1097 mp_size, rl2, vcn, highest_vcn, NULL);
1098 if (unlikely(err)) {
1099 ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, "
1100 "attribute type 0x%x, because building "
1101 "the mapping pairs failed with error "
1102 "code %i.", vi->i_ino,
1103 (unsigned)le32_to_cpu(ni->type), err);
1104 err = -EIO;
1105 break;
1106 }
1107 /* Update the highest_vcn but only if it was not set. */
1108 if (unlikely(!a->data.non_resident.highest_vcn))
1109 a->data.non_resident.highest_vcn =
1110 cpu_to_sle64(highest_vcn);
1111 /*
1112 * If the attribute is sparse/compressed, update the compressed
1113 * size in the ntfs_inode structure and the attribute record.
1114 */
1115 if (likely(NInoSparse(ni) || NInoCompressed(ni))) {
1116 /*
1117 * If we are not in the first attribute extent, switch
1118 * to it, but first ensure the changes will make it to
1119 * disk later.
1120 */
1121 if (a->data.non_resident.lowest_vcn) {
1122 flush_dcache_mft_record_page(ctx->ntfs_ino);
1123 mark_mft_record_dirty(ctx->ntfs_ino);
1124 ntfs_attr_reinit_search_ctx(ctx);
1125 err = ntfs_attr_lookup(ni->type, ni->name,
1126 ni->name_len, CASE_SENSITIVE,
1127 0, NULL, 0, ctx);
1128 if (unlikely(err)) {
1129 status.attr_switched = 1;
1130 break;
1131 }
1132 /* @m is not used any more so do not set it. */
1133 a = ctx->attr;
1134 }
1135 write_lock_irqsave(&ni->size_lock, flags);
1136 ni->itype.compressed.size += vol->cluster_size;
1137 a->data.non_resident.compressed_size =
1138 cpu_to_sle64(ni->itype.compressed.size);
1139 write_unlock_irqrestore(&ni->size_lock, flags);
1140 }
1141 /* Ensure the changes make it to disk. */
1142 flush_dcache_mft_record_page(ctx->ntfs_ino);
1143 mark_mft_record_dirty(ctx->ntfs_ino);
1144 ntfs_attr_put_search_ctx(ctx);
1145 unmap_mft_record(base_ni);
1146 /* Successfully filled the hole. */
1147 status.runlist_merged = 0;
1148 status.mft_attr_mapped = 0;
1149 status.mp_rebuilt = 0;
1150 /* Setup the map cache and use that to deal with the buffer. */
1151 was_hole = true;
1152 vcn = bh_cpos;
1153 vcn_len = 1;
1154 lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits);
1155 cdelta = 0;
1156 /*
1157 * If the number of remaining clusters in the @pages is smaller
1158 * or equal to the number of cached clusters, unlock the
1159 * runlist as the map cache will be used from now on.
1160 */
1161 if (likely(vcn + vcn_len >= cend)) {
1162 up_write(&ni->runlist.lock);
1163 rl_write_locked = false;
1164 rl = NULL;
1165 }
1166 goto map_buffer_cached;
1167 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1168 /* If there are no errors, do the next page. */
1169 if (likely(!err && ++u < nr_pages))
1170 goto do_next_page;
1171 /* If there are no errors, release the runlist lock if we took it. */
1172 if (likely(!err)) {
1173 if (unlikely(rl_write_locked)) {
1174 up_write(&ni->runlist.lock);
1175 rl_write_locked = false;
1176 } else if (unlikely(rl))
1177 up_read(&ni->runlist.lock);
1178 rl = NULL;
1179 }
1180 /* If we issued read requests, let them complete. */
1181 read_lock_irqsave(&ni->size_lock, flags);
1182 initialized_size = ni->initialized_size;
1183 read_unlock_irqrestore(&ni->size_lock, flags);
1184 while (wait_bh > wait) {
1185 bh = *--wait_bh;
1186 wait_on_buffer(bh);
1187 if (likely(buffer_uptodate(bh))) {
1188 page = bh->b_page;
1189 bh_pos = ((s64)page->index << PAGE_SHIFT) +
1190 bh_offset(bh);
1191 /*
1192 * If the buffer overflows the initialized size, need
1193 * to zero the overflowing region.
1194 */
1195 if (unlikely(bh_pos + blocksize > initialized_size)) {
1196 int ofs = 0;
1197
1198 if (likely(bh_pos < initialized_size))
1199 ofs = initialized_size - bh_pos;
1200 zero_user_segment(page, bh_offset(bh) + ofs,
1201 blocksize);
1202 }
1203 } else /* if (unlikely(!buffer_uptodate(bh))) */
1204 err = -EIO;
1205 }
1206 if (likely(!err)) {
1207 /* Clear buffer_new on all buffers. */
1208 u = 0;
1209 do {
1210 bh = head = page_buffers(pages[u]);
1211 do {
1212 if (buffer_new(bh))
1213 clear_buffer_new(bh);
1214 } while ((bh = bh->b_this_page) != head);
1215 } while (++u < nr_pages);
1216 ntfs_debug("Done.");
1217 return err;
1218 }
1219 if (status.attr_switched) {
1220 /* Get back to the attribute extent we modified. */
1221 ntfs_attr_reinit_search_ctx(ctx);
1222 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1223 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) {
1224 ntfs_error(vol->sb, "Failed to find required "
1225 "attribute extent of attribute in "
1226 "error code path. Run chkdsk to "
1227 "recover.");
1228 write_lock_irqsave(&ni->size_lock, flags);
1229 ni->itype.compressed.size += vol->cluster_size;
1230 write_unlock_irqrestore(&ni->size_lock, flags);
1231 flush_dcache_mft_record_page(ctx->ntfs_ino);
1232 mark_mft_record_dirty(ctx->ntfs_ino);
1233 /*
1234 * The only thing that is now wrong is the compressed
1235 * size of the base attribute extent which chkdsk
1236 * should be able to fix.
1237 */
1238 NVolSetErrors(vol);
1239 } else {
1240 m = ctx->mrec;
1241 a = ctx->attr;
1242 status.attr_switched = 0;
1243 }
1244 }
1245 /*
1246 * If the runlist has been modified, need to restore it by punching a
1247 * hole into it and we then need to deallocate the on-disk cluster as
1248 * well. Note, we only modify the runlist if we are able to generate a
1249 * new mapping pairs array, i.e. only when the mapped attribute extent
1250 * is not switched.
1251 */
1252 if (status.runlist_merged && !status.attr_switched) {
1253 BUG_ON(!rl_write_locked);
1254 /* Make the file cluster we allocated sparse in the runlist. */
1255 if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) {
1256 ntfs_error(vol->sb, "Failed to punch hole into "
1257 "attribute runlist in error code "
1258 "path. Run chkdsk to recover the "
1259 "lost cluster.");
1260 NVolSetErrors(vol);
1261 } else /* if (success) */ {
1262 status.runlist_merged = 0;
1263 /*
1264 * Deallocate the on-disk cluster we allocated but only
1265 * if we succeeded in punching its vcn out of the
1266 * runlist.
1267 */
1268 down_write(&vol->lcnbmp_lock);
1269 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
1270 ntfs_error(vol->sb, "Failed to release "
1271 "allocated cluster in error "
1272 "code path. Run chkdsk to "
1273 "recover the lost cluster.");
1274 NVolSetErrors(vol);
1275 }
1276 up_write(&vol->lcnbmp_lock);
1277 }
1278 }
1279 /*
1280 * Resize the attribute record to its old size and rebuild the mapping
1281 * pairs array. Note, we only can do this if the runlist has been
1282 * restored to its old state which also implies that the mapped
1283 * attribute extent is not switched.
1284 */
1285 if (status.mp_rebuilt && !status.runlist_merged) {
1286 if (ntfs_attr_record_resize(m, a, attr_rec_len)) {
1287 ntfs_error(vol->sb, "Failed to restore attribute "
1288 "record in error code path. Run "
1289 "chkdsk to recover.");
1290 NVolSetErrors(vol);
1291 } else /* if (success) */ {
1292 if (ntfs_mapping_pairs_build(vol, (u8*)a +
1293 le16_to_cpu(a->data.non_resident.
1294 mapping_pairs_offset), attr_rec_len -
1295 le16_to_cpu(a->data.non_resident.
1296 mapping_pairs_offset), ni->runlist.rl,
1297 vcn, highest_vcn, NULL)) {
1298 ntfs_error(vol->sb, "Failed to restore "
1299 "mapping pairs array in error "
1300 "code path. Run chkdsk to "
1301 "recover.");
1302 NVolSetErrors(vol);
1303 }
1304 flush_dcache_mft_record_page(ctx->ntfs_ino);
1305 mark_mft_record_dirty(ctx->ntfs_ino);
1306 }
1307 }
1308 /* Release the mft record and the attribute. */
1309 if (status.mft_attr_mapped) {
1310 ntfs_attr_put_search_ctx(ctx);
1311 unmap_mft_record(base_ni);
1312 }
1313 /* Release the runlist lock. */
1314 if (rl_write_locked)
1315 up_write(&ni->runlist.lock);
1316 else if (rl)
1317 up_read(&ni->runlist.lock);
1318 /*
1319 * Zero out any newly allocated blocks to avoid exposing stale data.
1320 * If BH_New is set, we know that the block was newly allocated above
1321 * and that it has not been fully zeroed and marked dirty yet.
1322 */
1323 nr_pages = u;
1324 u = 0;
1325 end = bh_cpos << vol->cluster_size_bits;
1326 do {
1327 page = pages[u];
1328 bh = head = page_buffers(page);
1329 do {
1330 if (u == nr_pages &&
1331 ((s64)page->index << PAGE_SHIFT) +
1332 bh_offset(bh) >= end)
1333 break;
1334 if (!buffer_new(bh))
1335 continue;
1336 clear_buffer_new(bh);
1337 if (!buffer_uptodate(bh)) {
1338 if (PageUptodate(page))
1339 set_buffer_uptodate(bh);
1340 else {
1341 zero_user(page, bh_offset(bh),
1342 blocksize);
1343 set_buffer_uptodate(bh);
1344 }
1345 }
1346 mark_buffer_dirty(bh);
1347 } while ((bh = bh->b_this_page) != head);
1348 } while (++u <= nr_pages);
1349 ntfs_error(vol->sb, "Failed. Returning error code %i.", err);
1350 return err;
1351 }
1352
1353 static inline void ntfs_flush_dcache_pages(struct page **pages,
1354 unsigned nr_pages)
1355 {
1356 BUG_ON(!nr_pages);
1357 /*
1358 * Warning: Do not do the decrement at the same time as the call to
1359 * flush_dcache_page() because it is a NULL macro on i386 and hence the
1360 * decrement never happens so the loop never terminates.
1361 */
1362 do {
1363 --nr_pages;
1364 flush_dcache_page(pages[nr_pages]);
1365 } while (nr_pages > 0);
1366 }
1367
1368 /**
1369 * ntfs_commit_pages_after_non_resident_write - commit the received data
1370 * @pages: array of destination pages
1371 * @nr_pages: number of pages in @pages
1372 * @pos: byte position in file at which the write begins
1373 * @bytes: number of bytes to be written
1374 *
1375 * See description of ntfs_commit_pages_after_write(), below.
1376 */
1377 static inline int ntfs_commit_pages_after_non_resident_write(
1378 struct page **pages, const unsigned nr_pages,
1379 s64 pos, size_t bytes)
1380 {
1381 s64 end, initialized_size;
1382 struct inode *vi;
1383 ntfs_inode *ni, *base_ni;
1384 struct buffer_head *bh, *head;
1385 ntfs_attr_search_ctx *ctx;
1386 MFT_RECORD *m;
1387 ATTR_RECORD *a;
1388 unsigned long flags;
1389 unsigned blocksize, u;
1390 int err;
1391
1392 vi = pages[0]->mapping->host;
1393 ni = NTFS_I(vi);
1394 blocksize = vi->i_sb->s_blocksize;
1395 end = pos + bytes;
1396 u = 0;
1397 do {
1398 s64 bh_pos;
1399 struct page *page;
1400 bool partial;
1401
1402 page = pages[u];
1403 bh_pos = (s64)page->index << PAGE_SHIFT;
1404 bh = head = page_buffers(page);
1405 partial = false;
1406 do {
1407 s64 bh_end;
1408
1409 bh_end = bh_pos + blocksize;
1410 if (bh_end <= pos || bh_pos >= end) {
1411 if (!buffer_uptodate(bh))
1412 partial = true;
1413 } else {
1414 set_buffer_uptodate(bh);
1415 mark_buffer_dirty(bh);
1416 }
1417 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1418 /*
1419 * If all buffers are now uptodate but the page is not, set the
1420 * page uptodate.
1421 */
1422 if (!partial && !PageUptodate(page))
1423 SetPageUptodate(page);
1424 } while (++u < nr_pages);
1425 /*
1426 * Finally, if we do not need to update initialized_size or i_size we
1427 * are finished.
1428 */
1429 read_lock_irqsave(&ni->size_lock, flags);
1430 initialized_size = ni->initialized_size;
1431 read_unlock_irqrestore(&ni->size_lock, flags);
1432 if (end <= initialized_size) {
1433 ntfs_debug("Done.");
1434 return 0;
1435 }
1436 /*
1437 * Update initialized_size/i_size as appropriate, both in the inode and
1438 * the mft record.
1439 */
1440 if (!NInoAttr(ni))
1441 base_ni = ni;
1442 else
1443 base_ni = ni->ext.base_ntfs_ino;
1444 /* Map, pin, and lock the mft record. */
1445 m = map_mft_record(base_ni);
1446 if (IS_ERR(m)) {
1447 err = PTR_ERR(m);
1448 m = NULL;
1449 ctx = NULL;
1450 goto err_out;
1451 }
1452 BUG_ON(!NInoNonResident(ni));
1453 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1454 if (unlikely(!ctx)) {
1455 err = -ENOMEM;
1456 goto err_out;
1457 }
1458 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1459 CASE_SENSITIVE, 0, NULL, 0, ctx);
1460 if (unlikely(err)) {
1461 if (err == -ENOENT)
1462 err = -EIO;
1463 goto err_out;
1464 }
1465 a = ctx->attr;
1466 BUG_ON(!a->non_resident);
1467 write_lock_irqsave(&ni->size_lock, flags);
1468 BUG_ON(end > ni->allocated_size);
1469 ni->initialized_size = end;
1470 a->data.non_resident.initialized_size = cpu_to_sle64(end);
1471 if (end > i_size_read(vi)) {
1472 i_size_write(vi, end);
1473 a->data.non_resident.data_size =
1474 a->data.non_resident.initialized_size;
1475 }
1476 write_unlock_irqrestore(&ni->size_lock, flags);
1477 /* Mark the mft record dirty, so it gets written back. */
1478 flush_dcache_mft_record_page(ctx->ntfs_ino);
1479 mark_mft_record_dirty(ctx->ntfs_ino);
1480 ntfs_attr_put_search_ctx(ctx);
1481 unmap_mft_record(base_ni);
1482 ntfs_debug("Done.");
1483 return 0;
1484 err_out:
1485 if (ctx)
1486 ntfs_attr_put_search_ctx(ctx);
1487 if (m)
1488 unmap_mft_record(base_ni);
1489 ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error "
1490 "code %i).", err);
1491 if (err != -ENOMEM)
1492 NVolSetErrors(ni->vol);
1493 return err;
1494 }
1495
1496 /**
1497 * ntfs_commit_pages_after_write - commit the received data
1498 * @pages: array of destination pages
1499 * @nr_pages: number of pages in @pages
1500 * @pos: byte position in file at which the write begins
1501 * @bytes: number of bytes to be written
1502 *
1503 * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
1504 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
1505 * locked but not kmap()ped. The source data has already been copied into the
1506 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before
1507 * the data was copied (for non-resident attributes only) and it returned
1508 * success.
1509 *
1510 * Need to set uptodate and mark dirty all buffers within the boundary of the
1511 * write. If all buffers in a page are uptodate we set the page uptodate, too.
1512 *
1513 * Setting the buffers dirty ensures that they get written out later when
1514 * ntfs_writepage() is invoked by the VM.
1515 *
1516 * Finally, we need to update i_size and initialized_size as appropriate both
1517 * in the inode and the mft record.
1518 *
1519 * This is modelled after fs/buffer.c::generic_commit_write(), which marks
1520 * buffers uptodate and dirty, sets the page uptodate if all buffers in the
1521 * page are uptodate, and updates i_size if the end of io is beyond i_size. In
1522 * that case, it also marks the inode dirty.
1523 *
1524 * If things have gone as outlined in
1525 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
1526 * content modifications here for non-resident attributes. For resident
1527 * attributes we need to do the uptodate bringing here which we combine with
1528 * the copying into the mft record which means we save one atomic kmap.
1529 *
1530 * Return 0 on success or -errno on error.
1531 */
1532 static int ntfs_commit_pages_after_write(struct page **pages,
1533 const unsigned nr_pages, s64 pos, size_t bytes)
1534 {
1535 s64 end, initialized_size;
1536 loff_t i_size;
1537 struct inode *vi;
1538 ntfs_inode *ni, *base_ni;
1539 struct page *page;
1540 ntfs_attr_search_ctx *ctx;
1541 MFT_RECORD *m;
1542 ATTR_RECORD *a;
1543 char *kattr, *kaddr;
1544 unsigned long flags;
1545 u32 attr_len;
1546 int err;
1547
1548 BUG_ON(!nr_pages);
1549 BUG_ON(!pages);
1550 page = pages[0];
1551 BUG_ON(!page);
1552 vi = page->mapping->host;
1553 ni = NTFS_I(vi);
1554 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
1555 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
1556 vi->i_ino, ni->type, page->index, nr_pages,
1557 (long long)pos, bytes);
1558 if (NInoNonResident(ni))
1559 return ntfs_commit_pages_after_non_resident_write(pages,
1560 nr_pages, pos, bytes);
1561 BUG_ON(nr_pages > 1);
1562 /*
1563 * Attribute is resident, implying it is not compressed, encrypted, or
1564 * sparse.
1565 */
1566 if (!NInoAttr(ni))
1567 base_ni = ni;
1568 else
1569 base_ni = ni->ext.base_ntfs_ino;
1570 BUG_ON(NInoNonResident(ni));
1571 /* Map, pin, and lock the mft record. */
1572 m = map_mft_record(base_ni);
1573 if (IS_ERR(m)) {
1574 err = PTR_ERR(m);
1575 m = NULL;
1576 ctx = NULL;
1577 goto err_out;
1578 }
1579 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1580 if (unlikely(!ctx)) {
1581 err = -ENOMEM;
1582 goto err_out;
1583 }
1584 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1585 CASE_SENSITIVE, 0, NULL, 0, ctx);
1586 if (unlikely(err)) {
1587 if (err == -ENOENT)
1588 err = -EIO;
1589 goto err_out;
1590 }
1591 a = ctx->attr;
1592 BUG_ON(a->non_resident);
1593 /* The total length of the attribute value. */
1594 attr_len = le32_to_cpu(a->data.resident.value_length);
1595 i_size = i_size_read(vi);
1596 BUG_ON(attr_len != i_size);
1597 BUG_ON(pos > attr_len);
1598 end = pos + bytes;
1599 BUG_ON(end > le32_to_cpu(a->length) -
1600 le16_to_cpu(a->data.resident.value_offset));
1601 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
1602 kaddr = kmap_atomic(page);
1603 /* Copy the received data from the page to the mft record. */
1604 memcpy(kattr + pos, kaddr + pos, bytes);
1605 /* Update the attribute length if necessary. */
1606 if (end > attr_len) {
1607 attr_len = end;
1608 a->data.resident.value_length = cpu_to_le32(attr_len);
1609 }
1610 /*
1611 * If the page is not uptodate, bring the out of bounds area(s)
1612 * uptodate by copying data from the mft record to the page.
1613 */
1614 if (!PageUptodate(page)) {
1615 if (pos > 0)
1616 memcpy(kaddr, kattr, pos);
1617 if (end < attr_len)
1618 memcpy(kaddr + end, kattr + end, attr_len - end);
1619 /* Zero the region outside the end of the attribute value. */
1620 memset(kaddr + attr_len, 0, PAGE_SIZE - attr_len);
1621 flush_dcache_page(page);
1622 SetPageUptodate(page);
1623 }
1624 kunmap_atomic(kaddr);
1625 /* Update initialized_size/i_size if necessary. */
1626 read_lock_irqsave(&ni->size_lock, flags);
1627 initialized_size = ni->initialized_size;
1628 BUG_ON(end > ni->allocated_size);
1629 read_unlock_irqrestore(&ni->size_lock, flags);
1630 BUG_ON(initialized_size != i_size);
1631 if (end > initialized_size) {
1632 write_lock_irqsave(&ni->size_lock, flags);
1633 ni->initialized_size = end;
1634 i_size_write(vi, end);
1635 write_unlock_irqrestore(&ni->size_lock, flags);
1636 }
1637 /* Mark the mft record dirty, so it gets written back. */
1638 flush_dcache_mft_record_page(ctx->ntfs_ino);
1639 mark_mft_record_dirty(ctx->ntfs_ino);
1640 ntfs_attr_put_search_ctx(ctx);
1641 unmap_mft_record(base_ni);
1642 ntfs_debug("Done.");
1643 return 0;
1644 err_out:
1645 if (err == -ENOMEM) {
1646 ntfs_warning(vi->i_sb, "Error allocating memory required to "
1647 "commit the write.");
1648 if (PageUptodate(page)) {
1649 ntfs_warning(vi->i_sb, "Page is uptodate, setting "
1650 "dirty so the write will be retried "
1651 "later on by the VM.");
1652 /*
1653 * Put the page on mapping->dirty_pages, but leave its
1654 * buffers' dirty state as-is.
1655 */
1656 __set_page_dirty_nobuffers(page);
1657 err = 0;
1658 } else
1659 ntfs_error(vi->i_sb, "Page is not uptodate. Written "
1660 "data has been lost.");
1661 } else {
1662 ntfs_error(vi->i_sb, "Resident attribute commit write failed "
1663 "with error %i.", err);
1664 NVolSetErrors(ni->vol);
1665 }
1666 if (ctx)
1667 ntfs_attr_put_search_ctx(ctx);
1668 if (m)
1669 unmap_mft_record(base_ni);
1670 return err;
1671 }
1672
1673 /*
1674 * Copy as much as we can into the pages and return the number of bytes which
1675 * were successfully copied. If a fault is encountered then clear the pages
1676 * out to (ofs + bytes) and return the number of bytes which were copied.
1677 */
1678 static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages,
1679 unsigned ofs, struct iov_iter *i, size_t bytes)
1680 {
1681 struct page **last_page = pages + nr_pages;
1682 size_t total = 0;
1683 unsigned len, copied;
1684
1685 do {
1686 len = PAGE_SIZE - ofs;
1687 if (len > bytes)
1688 len = bytes;
1689 copied = copy_page_from_iter_atomic(*pages, ofs, len, i);
1690 total += copied;
1691 bytes -= copied;
1692 if (!bytes)
1693 break;
1694 if (copied < len)
1695 goto err;
1696 ofs = 0;
1697 } while (++pages < last_page);
1698 out:
1699 return total;
1700 err:
1701 /* Zero the rest of the target like __copy_from_user(). */
1702 len = PAGE_SIZE - copied;
1703 do {
1704 if (len > bytes)
1705 len = bytes;
1706 zero_user(*pages, copied, len);
1707 bytes -= len;
1708 copied = 0;
1709 len = PAGE_SIZE;
1710 } while (++pages < last_page);
1711 goto out;
1712 }
1713
1714 /**
1715 * ntfs_perform_write - perform buffered write to a file
1716 * @file: file to write to
1717 * @i: iov_iter with data to write
1718 * @pos: byte offset in file at which to begin writing to
1719 */
1720 static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i,
1721 loff_t pos)
1722 {
1723 struct address_space *mapping = file->f_mapping;
1724 struct inode *vi = mapping->host;
1725 ntfs_inode *ni = NTFS_I(vi);
1726 ntfs_volume *vol = ni->vol;
1727 struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER];
1728 struct page *cached_page = NULL;
1729 VCN last_vcn;
1730 LCN lcn;
1731 size_t bytes;
1732 ssize_t status, written = 0;
1733 unsigned nr_pages;
1734
1735 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
1736 "0x%llx, count 0x%lx.", vi->i_ino,
1737 (unsigned)le32_to_cpu(ni->type),
1738 (unsigned long long)pos,
1739 (unsigned long)iov_iter_count(i));
1740 /*
1741 * If a previous ntfs_truncate() failed, repeat it and abort if it
1742 * fails again.
1743 */
1744 if (unlikely(NInoTruncateFailed(ni))) {
1745 int err;
1746
1747 inode_dio_wait(vi);
1748 err = ntfs_truncate(vi);
1749 if (err || NInoTruncateFailed(ni)) {
1750 if (!err)
1751 err = -EIO;
1752 ntfs_error(vol->sb, "Cannot perform write to inode "
1753 "0x%lx, attribute type 0x%x, because "
1754 "ntfs_truncate() failed (error code "
1755 "%i).", vi->i_ino,
1756 (unsigned)le32_to_cpu(ni->type), err);
1757 return err;
1758 }
1759 }
1760 /*
1761 * Determine the number of pages per cluster for non-resident
1762 * attributes.
1763 */
1764 nr_pages = 1;
1765 if (vol->cluster_size > PAGE_SIZE && NInoNonResident(ni))
1766 nr_pages = vol->cluster_size >> PAGE_SHIFT;
1767 last_vcn = -1;
1768 do {
1769 VCN vcn;
1770 pgoff_t start_idx;
1771 unsigned ofs, do_pages, u;
1772 size_t copied;
1773
1774 start_idx = pos >> PAGE_SHIFT;
1775 ofs = pos & ~PAGE_MASK;
1776 bytes = PAGE_SIZE - ofs;
1777 do_pages = 1;
1778 if (nr_pages > 1) {
1779 vcn = pos >> vol->cluster_size_bits;
1780 if (vcn != last_vcn) {
1781 last_vcn = vcn;
1782 /*
1783 * Get the lcn of the vcn the write is in. If
1784 * it is a hole, need to lock down all pages in
1785 * the cluster.
1786 */
1787 down_read(&ni->runlist.lock);
1788 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >>
1789 vol->cluster_size_bits, false);
1790 up_read(&ni->runlist.lock);
1791 if (unlikely(lcn < LCN_HOLE)) {
1792 if (lcn == LCN_ENOMEM)
1793 status = -ENOMEM;
1794 else {
1795 status = -EIO;
1796 ntfs_error(vol->sb, "Cannot "
1797 "perform write to "
1798 "inode 0x%lx, "
1799 "attribute type 0x%x, "
1800 "because the attribute "
1801 "is corrupt.",
1802 vi->i_ino, (unsigned)
1803 le32_to_cpu(ni->type));
1804 }
1805 break;
1806 }
1807 if (lcn == LCN_HOLE) {
1808 start_idx = (pos & ~(s64)
1809 vol->cluster_size_mask)
1810 >> PAGE_SHIFT;
1811 bytes = vol->cluster_size - (pos &
1812 vol->cluster_size_mask);
1813 do_pages = nr_pages;
1814 }
1815 }
1816 }
1817 if (bytes > iov_iter_count(i))
1818 bytes = iov_iter_count(i);
1819 again:
1820 /*
1821 * Bring in the user page(s) that we will copy from _first_.
1822 * Otherwise there is a nasty deadlock on copying from the same
1823 * page(s) as we are writing to, without it/them being marked
1824 * up-to-date. Note, at present there is nothing to stop the
1825 * pages being swapped out between us bringing them into memory
1826 * and doing the actual copying.
1827 */
1828 if (unlikely(fault_in_iov_iter_readable(i, bytes))) {
1829 status = -EFAULT;
1830 break;
1831 }
1832 /* Get and lock @do_pages starting at index @start_idx. */
1833 status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages,
1834 pages, &cached_page);
1835 if (unlikely(status))
1836 break;
1837 /*
1838 * For non-resident attributes, we need to fill any holes with
1839 * actual clusters and ensure all bufferes are mapped. We also
1840 * need to bring uptodate any buffers that are only partially
1841 * being written to.
1842 */
1843 if (NInoNonResident(ni)) {
1844 status = ntfs_prepare_pages_for_non_resident_write(
1845 pages, do_pages, pos, bytes);
1846 if (unlikely(status)) {
1847 do {
1848 unlock_page(pages[--do_pages]);
1849 put_page(pages[do_pages]);
1850 } while (do_pages);
1851 break;
1852 }
1853 }
1854 u = (pos >> PAGE_SHIFT) - pages[0]->index;
1855 copied = ntfs_copy_from_user_iter(pages + u, do_pages - u, ofs,
1856 i, bytes);
1857 ntfs_flush_dcache_pages(pages + u, do_pages - u);
1858 status = 0;
1859 if (likely(copied == bytes)) {
1860 status = ntfs_commit_pages_after_write(pages, do_pages,
1861 pos, bytes);
1862 }
1863 do {
1864 unlock_page(pages[--do_pages]);
1865 put_page(pages[do_pages]);
1866 } while (do_pages);
1867 if (unlikely(status < 0)) {
1868 iov_iter_revert(i, copied);
1869 break;
1870 }
1871 cond_resched();
1872 if (unlikely(copied < bytes)) {
1873 iov_iter_revert(i, copied);
1874 if (copied)
1875 bytes = copied;
1876 else if (bytes > PAGE_SIZE - ofs)
1877 bytes = PAGE_SIZE - ofs;
1878 goto again;
1879 }
1880 pos += copied;
1881 written += copied;
1882 balance_dirty_pages_ratelimited(mapping);
1883 if (fatal_signal_pending(current)) {
1884 status = -EINTR;
1885 break;
1886 }
1887 } while (iov_iter_count(i));
1888 if (cached_page)
1889 put_page(cached_page);
1890 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).",
1891 written ? "written" : "status", (unsigned long)written,
1892 (long)status);
1893 return written ? written : status;
1894 }
1895
1896 /**
1897 * ntfs_file_write_iter - simple wrapper for ntfs_file_write_iter_nolock()
1898 * @iocb: IO state structure
1899 * @from: iov_iter with data to write
1900 *
1901 * Basically the same as generic_file_write_iter() except that it ends up
1902 * up calling ntfs_perform_write() instead of generic_perform_write() and that
1903 * O_DIRECT is not implemented.
1904 */
1905 static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1906 {
1907 struct file *file = iocb->ki_filp;
1908 struct inode *vi = file_inode(file);
1909 ssize_t written = 0;
1910 ssize_t err;
1911
1912 inode_lock(vi);
1913 /* We can write back this queue in page reclaim. */
1914 current->backing_dev_info = inode_to_bdi(vi);
1915 err = ntfs_prepare_file_for_write(iocb, from);
1916 if (iov_iter_count(from) && !err)
1917 written = ntfs_perform_write(file, from, iocb->ki_pos);
1918 current->backing_dev_info = NULL;
1919 inode_unlock(vi);
1920 iocb->ki_pos += written;
1921 if (likely(written > 0))
1922 written = generic_write_sync(iocb, written);
1923 return written ? written : err;
1924 }
1925
1926 /**
1927 * ntfs_file_fsync - sync a file to disk
1928 * @filp: file to be synced
1929 * @datasync: if non-zero only flush user data and not metadata
1930 *
1931 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
1932 * system calls. This function is inspired by fs/buffer.c::file_fsync().
1933 *
1934 * If @datasync is false, write the mft record and all associated extent mft
1935 * records as well as the $DATA attribute and then sync the block device.
1936 *
1937 * If @datasync is true and the attribute is non-resident, we skip the writing
1938 * of the mft record and all associated extent mft records (this might still
1939 * happen due to the write_inode_now() call).
1940 *
1941 * Also, if @datasync is true, we do not wait on the inode to be written out
1942 * but we always wait on the page cache pages to be written out.
1943 *
1944 * Locking: Caller must hold i_mutex on the inode.
1945 *
1946 * TODO: We should probably also write all attribute/index inodes associated
1947 * with this inode but since we have no simple way of getting to them we ignore
1948 * this problem for now.
1949 */
1950 static int ntfs_file_fsync(struct file *filp, loff_t start, loff_t end,
1951 int datasync)
1952 {
1953 struct inode *vi = filp->f_mapping->host;
1954 int err, ret = 0;
1955
1956 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
1957
1958 err = file_write_and_wait_range(filp, start, end);
1959 if (err)
1960 return err;
1961 inode_lock(vi);
1962
1963 BUG_ON(S_ISDIR(vi->i_mode));
1964 if (!datasync || !NInoNonResident(NTFS_I(vi)))
1965 ret = __ntfs_write_inode(vi, 1);
1966 write_inode_now(vi, !datasync);
1967 /*
1968 * NOTE: If we were to use mapping->private_list (see ext2 and
1969 * fs/buffer.c) for dirty blocks then we could optimize the below to be
1970 * sync_mapping_buffers(vi->i_mapping).
1971 */
1972 err = sync_blockdev(vi->i_sb->s_bdev);
1973 if (unlikely(err && !ret))
1974 ret = err;
1975 if (likely(!ret))
1976 ntfs_debug("Done.");
1977 else
1978 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
1979 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
1980 inode_unlock(vi);
1981 return ret;
1982 }
1983
1984 #endif /* NTFS_RW */
1985
1986 const struct file_operations ntfs_file_ops = {
1987 .llseek = generic_file_llseek,
1988 .read_iter = generic_file_read_iter,
1989 #ifdef NTFS_RW
1990 .write_iter = ntfs_file_write_iter,
1991 .fsync = ntfs_file_fsync,
1992 #endif /* NTFS_RW */
1993 .mmap = generic_file_mmap,
1994 .open = ntfs_file_open,
1995 .splice_read = generic_file_splice_read,
1996 };
1997
1998 const struct inode_operations ntfs_file_inode_ops = {
1999 #ifdef NTFS_RW
2000 .setattr = ntfs_setattr,
2001 #endif /* NTFS_RW */
2002 };
2003
2004 const struct file_operations ntfs_empty_file_ops = {};
2005
2006 const struct inode_operations ntfs_empty_inode_ops = {};
Michael's Linux tree.