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UBUNTU: Ubuntu-4.13.0-45.50
[mirror_ubuntu-artful-kernel.git] / fs / ntfs / file.c
1 /*
2 * file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
3 *
4 * Copyright (c) 2001-2015 Anton Altaparmakov and Tuxera Inc.
5 *
6 * This program/include file is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as published
8 * by the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program/include file is distributed in the hope that it will be
12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program (in the main directory of the Linux-NTFS
18 * distribution in the file COPYING); if not, write to the Free Software
19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/backing-dev.h>
23 #include <linux/buffer_head.h>
24 #include <linux/gfp.h>
25 #include <linux/pagemap.h>
26 #include <linux/pagevec.h>
27 #include <linux/sched/signal.h>
28 #include <linux/swap.h>
29 #include <linux/uio.h>
30 #include <linux/writeback.h>
31
32 #include <asm/page.h>
33 #include <linux/uaccess.h>
34
35 #include "attrib.h"
36 #include "bitmap.h"
37 #include "inode.h"
38 #include "debug.h"
39 #include "lcnalloc.h"
40 #include "malloc.h"
41 #include "mft.h"
42 #include "ntfs.h"
43
44 /**
45 * ntfs_file_open - called when an inode is about to be opened
46 * @vi: inode to be opened
47 * @filp: file structure describing the inode
48 *
49 * Limit file size to the page cache limit on architectures where unsigned long
50 * is 32-bits. This is the most we can do for now without overflowing the page
51 * cache page index. Doing it this way means we don't run into problems because
52 * of existing too large files. It would be better to allow the user to read
53 * the beginning of the file but I doubt very much anyone is going to hit this
54 * check on a 32-bit architecture, so there is no point in adding the extra
55 * complexity required to support this.
56 *
57 * On 64-bit architectures, the check is hopefully optimized away by the
58 * compiler.
59 *
60 * After the check passes, just call generic_file_open() to do its work.
61 */
62 static int ntfs_file_open(struct inode *vi, struct file *filp)
63 {
64 if (sizeof(unsigned long) < 8) {
65 if (i_size_read(vi) > MAX_LFS_FILESIZE)
66 return -EOVERFLOW;
67 }
68 return generic_file_open(vi, filp);
69 }
70
71 #ifdef NTFS_RW
72
73 /**
74 * ntfs_attr_extend_initialized - extend the initialized size of an attribute
75 * @ni: ntfs inode of the attribute to extend
76 * @new_init_size: requested new initialized size in bytes
77 *
78 * Extend the initialized size of an attribute described by the ntfs inode @ni
79 * to @new_init_size bytes. This involves zeroing any non-sparse space between
80 * the old initialized size and @new_init_size both in the page cache and on
81 * disk (if relevant complete pages are already uptodate in the page cache then
82 * these are simply marked dirty).
83 *
84 * As a side-effect, the file size (vfs inode->i_size) may be incremented as,
85 * in the resident attribute case, it is tied to the initialized size and, in
86 * the non-resident attribute case, it may not fall below the initialized size.
87 *
88 * Note that if the attribute is resident, we do not need to touch the page
89 * cache at all. This is because if the page cache page is not uptodate we
90 * bring it uptodate later, when doing the write to the mft record since we
91 * then already have the page mapped. And if the page is uptodate, the
92 * non-initialized region will already have been zeroed when the page was
93 * brought uptodate and the region may in fact already have been overwritten
94 * with new data via mmap() based writes, so we cannot just zero it. And since
95 * POSIX specifies that the behaviour of resizing a file whilst it is mmap()ped
96 * is unspecified, we choose not to do zeroing and thus we do not need to touch
97 * the page at all. For a more detailed explanation see ntfs_truncate() in
98 * fs/ntfs/inode.c.
99 *
100 * Return 0 on success and -errno on error. In the case that an error is
101 * encountered it is possible that the initialized size will already have been
102 * incremented some way towards @new_init_size but it is guaranteed that if
103 * this is the case, the necessary zeroing will also have happened and that all
104 * metadata is self-consistent.
105 *
106 * Locking: i_mutex on the vfs inode corrseponsind to the ntfs inode @ni must be
107 * held by the caller.
108 */
109 static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size)
110 {
111 s64 old_init_size;
112 loff_t old_i_size;
113 pgoff_t index, end_index;
114 unsigned long flags;
115 struct inode *vi = VFS_I(ni);
116 ntfs_inode *base_ni;
117 MFT_RECORD *m = NULL;
118 ATTR_RECORD *a;
119 ntfs_attr_search_ctx *ctx = NULL;
120 struct address_space *mapping;
121 struct page *page = NULL;
122 u8 *kattr;
123 int err;
124 u32 attr_len;
125
126 read_lock_irqsave(&ni->size_lock, flags);
127 old_init_size = ni->initialized_size;
128 old_i_size = i_size_read(vi);
129 BUG_ON(new_init_size > ni->allocated_size);
130 read_unlock_irqrestore(&ni->size_lock, flags);
131 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
132 "old_initialized_size 0x%llx, "
133 "new_initialized_size 0x%llx, i_size 0x%llx.",
134 vi->i_ino, (unsigned)le32_to_cpu(ni->type),
135 (unsigned long long)old_init_size,
136 (unsigned long long)new_init_size, old_i_size);
137 if (!NInoAttr(ni))
138 base_ni = ni;
139 else
140 base_ni = ni->ext.base_ntfs_ino;
141 /* Use goto to reduce indentation and we need the label below anyway. */
142 if (NInoNonResident(ni))
143 goto do_non_resident_extend;
144 BUG_ON(old_init_size != old_i_size);
145 m = map_mft_record(base_ni);
146 if (IS_ERR(m)) {
147 err = PTR_ERR(m);
148 m = NULL;
149 goto err_out;
150 }
151 ctx = ntfs_attr_get_search_ctx(base_ni, m);
152 if (unlikely(!ctx)) {
153 err = -ENOMEM;
154 goto err_out;
155 }
156 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
157 CASE_SENSITIVE, 0, NULL, 0, ctx);
158 if (unlikely(err)) {
159 if (err == -ENOENT)
160 err = -EIO;
161 goto err_out;
162 }
163 m = ctx->mrec;
164 a = ctx->attr;
165 BUG_ON(a->non_resident);
166 /* The total length of the attribute value. */
167 attr_len = le32_to_cpu(a->data.resident.value_length);
168 BUG_ON(old_i_size != (loff_t)attr_len);
169 /*
170 * Do the zeroing in the mft record and update the attribute size in
171 * the mft record.
172 */
173 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
174 memset(kattr + attr_len, 0, new_init_size - attr_len);
175 a->data.resident.value_length = cpu_to_le32((u32)new_init_size);
176 /* Finally, update the sizes in the vfs and ntfs inodes. */
177 write_lock_irqsave(&ni->size_lock, flags);
178 i_size_write(vi, new_init_size);
179 ni->initialized_size = new_init_size;
180 write_unlock_irqrestore(&ni->size_lock, flags);
181 goto done;
182 do_non_resident_extend:
183 /*
184 * If the new initialized size @new_init_size exceeds the current file
185 * size (vfs inode->i_size), we need to extend the file size to the
186 * new initialized size.
187 */
188 if (new_init_size > old_i_size) {
189 m = map_mft_record(base_ni);
190 if (IS_ERR(m)) {
191 err = PTR_ERR(m);
192 m = NULL;
193 goto err_out;
194 }
195 ctx = ntfs_attr_get_search_ctx(base_ni, m);
196 if (unlikely(!ctx)) {
197 err = -ENOMEM;
198 goto err_out;
199 }
200 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
201 CASE_SENSITIVE, 0, NULL, 0, ctx);
202 if (unlikely(err)) {
203 if (err == -ENOENT)
204 err = -EIO;
205 goto err_out;
206 }
207 m = ctx->mrec;
208 a = ctx->attr;
209 BUG_ON(!a->non_resident);
210 BUG_ON(old_i_size != (loff_t)
211 sle64_to_cpu(a->data.non_resident.data_size));
212 a->data.non_resident.data_size = cpu_to_sle64(new_init_size);
213 flush_dcache_mft_record_page(ctx->ntfs_ino);
214 mark_mft_record_dirty(ctx->ntfs_ino);
215 /* Update the file size in the vfs inode. */
216 i_size_write(vi, new_init_size);
217 ntfs_attr_put_search_ctx(ctx);
218 ctx = NULL;
219 unmap_mft_record(base_ni);
220 m = NULL;
221 }
222 mapping = vi->i_mapping;
223 index = old_init_size >> PAGE_SHIFT;
224 end_index = (new_init_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
225 do {
226 /*
227 * Read the page. If the page is not present, this will zero
228 * the uninitialized regions for us.
229 */
230 page = read_mapping_page(mapping, index, NULL);
231 if (IS_ERR(page)) {
232 err = PTR_ERR(page);
233 goto init_err_out;
234 }
235 if (unlikely(PageError(page))) {
236 put_page(page);
237 err = -EIO;
238 goto init_err_out;
239 }
240 /*
241 * Update the initialized size in the ntfs inode. This is
242 * enough to make ntfs_writepage() work.
243 */
244 write_lock_irqsave(&ni->size_lock, flags);
245 ni->initialized_size = (s64)(index + 1) << PAGE_SHIFT;
246 if (ni->initialized_size > new_init_size)
247 ni->initialized_size = new_init_size;
248 write_unlock_irqrestore(&ni->size_lock, flags);
249 /* Set the page dirty so it gets written out. */
250 set_page_dirty(page);
251 put_page(page);
252 /*
253 * Play nice with the vm and the rest of the system. This is
254 * very much needed as we can potentially be modifying the
255 * initialised size from a very small value to a really huge
256 * value, e.g.
257 * f = open(somefile, O_TRUNC);
258 * truncate(f, 10GiB);
259 * seek(f, 10GiB);
260 * write(f, 1);
261 * And this would mean we would be marking dirty hundreds of
262 * thousands of pages or as in the above example more than
263 * two and a half million pages!
264 *
265 * TODO: For sparse pages could optimize this workload by using
266 * the FsMisc / MiscFs page bit as a "PageIsSparse" bit. This
267 * would be set in readpage for sparse pages and here we would
268 * not need to mark dirty any pages which have this bit set.
269 * The only caveat is that we have to clear the bit everywhere
270 * where we allocate any clusters that lie in the page or that
271 * contain the page.
272 *
273 * TODO: An even greater optimization would be for us to only
274 * call readpage() on pages which are not in sparse regions as
275 * determined from the runlist. This would greatly reduce the
276 * number of pages we read and make dirty in the case of sparse
277 * files.
278 */
279 balance_dirty_pages_ratelimited(mapping);
280 cond_resched();
281 } while (++index < end_index);
282 read_lock_irqsave(&ni->size_lock, flags);
283 BUG_ON(ni->initialized_size != new_init_size);
284 read_unlock_irqrestore(&ni->size_lock, flags);
285 /* Now bring in sync the initialized_size in the mft record. */
286 m = map_mft_record(base_ni);
287 if (IS_ERR(m)) {
288 err = PTR_ERR(m);
289 m = NULL;
290 goto init_err_out;
291 }
292 ctx = ntfs_attr_get_search_ctx(base_ni, m);
293 if (unlikely(!ctx)) {
294 err = -ENOMEM;
295 goto init_err_out;
296 }
297 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
298 CASE_SENSITIVE, 0, NULL, 0, ctx);
299 if (unlikely(err)) {
300 if (err == -ENOENT)
301 err = -EIO;
302 goto init_err_out;
303 }
304 m = ctx->mrec;
305 a = ctx->attr;
306 BUG_ON(!a->non_resident);
307 a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size);
308 done:
309 flush_dcache_mft_record_page(ctx->ntfs_ino);
310 mark_mft_record_dirty(ctx->ntfs_ino);
311 if (ctx)
312 ntfs_attr_put_search_ctx(ctx);
313 if (m)
314 unmap_mft_record(base_ni);
315 ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.",
316 (unsigned long long)new_init_size, i_size_read(vi));
317 return 0;
318 init_err_out:
319 write_lock_irqsave(&ni->size_lock, flags);
320 ni->initialized_size = old_init_size;
321 write_unlock_irqrestore(&ni->size_lock, flags);
322 err_out:
323 if (ctx)
324 ntfs_attr_put_search_ctx(ctx);
325 if (m)
326 unmap_mft_record(base_ni);
327 ntfs_debug("Failed. Returning error code %i.", err);
328 return err;
329 }
330
331 static ssize_t ntfs_prepare_file_for_write(struct kiocb *iocb,
332 struct iov_iter *from)
333 {
334 loff_t pos;
335 s64 end, ll;
336 ssize_t err;
337 unsigned long flags;
338 struct file *file = iocb->ki_filp;
339 struct inode *vi = file_inode(file);
340 ntfs_inode *base_ni, *ni = NTFS_I(vi);
341 ntfs_volume *vol = ni->vol;
342
343 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
344 "0x%llx, count 0x%zx.", vi->i_ino,
345 (unsigned)le32_to_cpu(ni->type),
346 (unsigned long long)iocb->ki_pos,
347 iov_iter_count(from));
348 err = generic_write_checks(iocb, from);
349 if (unlikely(err <= 0))
350 goto out;
351 /*
352 * All checks have passed. Before we start doing any writing we want
353 * to abort any totally illegal writes.
354 */
355 BUG_ON(NInoMstProtected(ni));
356 BUG_ON(ni->type != AT_DATA);
357 /* If file is encrypted, deny access, just like NT4. */
358 if (NInoEncrypted(ni)) {
359 /* Only $DATA attributes can be encrypted. */
360 /*
361 * Reminder for later: Encrypted files are _always_
362 * non-resident so that the content can always be encrypted.
363 */
364 ntfs_debug("Denying write access to encrypted file.");
365 err = -EACCES;
366 goto out;
367 }
368 if (NInoCompressed(ni)) {
369 /* Only unnamed $DATA attribute can be compressed. */
370 BUG_ON(ni->name_len);
371 /*
372 * Reminder for later: If resident, the data is not actually
373 * compressed. Only on the switch to non-resident does
374 * compression kick in. This is in contrast to encrypted files
375 * (see above).
376 */
377 ntfs_error(vi->i_sb, "Writing to compressed files is not "
378 "implemented yet. Sorry.");
379 err = -EOPNOTSUPP;
380 goto out;
381 }
382 base_ni = ni;
383 if (NInoAttr(ni))
384 base_ni = ni->ext.base_ntfs_ino;
385 err = file_remove_privs(file);
386 if (unlikely(err))
387 goto out;
388 /*
389 * Our ->update_time method always succeeds thus file_update_time()
390 * cannot fail either so there is no need to check the return code.
391 */
392 file_update_time(file);
393 pos = iocb->ki_pos;
394 /* The first byte after the last cluster being written to. */
395 end = (pos + iov_iter_count(from) + vol->cluster_size_mask) &
396 ~(u64)vol->cluster_size_mask;
397 /*
398 * If the write goes beyond the allocated size, extend the allocation
399 * to cover the whole of the write, rounded up to the nearest cluster.
400 */
401 read_lock_irqsave(&ni->size_lock, flags);
402 ll = ni->allocated_size;
403 read_unlock_irqrestore(&ni->size_lock, flags);
404 if (end > ll) {
405 /*
406 * Extend the allocation without changing the data size.
407 *
408 * Note we ensure the allocation is big enough to at least
409 * write some data but we do not require the allocation to be
410 * complete, i.e. it may be partial.
411 */
412 ll = ntfs_attr_extend_allocation(ni, end, -1, pos);
413 if (likely(ll >= 0)) {
414 BUG_ON(pos >= ll);
415 /* If the extension was partial truncate the write. */
416 if (end > ll) {
417 ntfs_debug("Truncating write to inode 0x%lx, "
418 "attribute type 0x%x, because "
419 "the allocation was only "
420 "partially extended.",
421 vi->i_ino, (unsigned)
422 le32_to_cpu(ni->type));
423 iov_iter_truncate(from, ll - pos);
424 }
425 } else {
426 err = ll;
427 read_lock_irqsave(&ni->size_lock, flags);
428 ll = ni->allocated_size;
429 read_unlock_irqrestore(&ni->size_lock, flags);
430 /* Perform a partial write if possible or fail. */
431 if (pos < ll) {
432 ntfs_debug("Truncating write to inode 0x%lx "
433 "attribute type 0x%x, because "
434 "extending the allocation "
435 "failed (error %d).",
436 vi->i_ino, (unsigned)
437 le32_to_cpu(ni->type),
438 (int)-err);
439 iov_iter_truncate(from, ll - pos);
440 } else {
441 if (err != -ENOSPC)
442 ntfs_error(vi->i_sb, "Cannot perform "
443 "write to inode "
444 "0x%lx, attribute "
445 "type 0x%x, because "
446 "extending the "
447 "allocation failed "
448 "(error %ld).",
449 vi->i_ino, (unsigned)
450 le32_to_cpu(ni->type),
451 (long)-err);
452 else
453 ntfs_debug("Cannot perform write to "
454 "inode 0x%lx, "
455 "attribute type 0x%x, "
456 "because there is not "
457 "space left.",
458 vi->i_ino, (unsigned)
459 le32_to_cpu(ni->type));
460 goto out;
461 }
462 }
463 }
464 /*
465 * If the write starts beyond the initialized size, extend it up to the
466 * beginning of the write and initialize all non-sparse space between
467 * the old initialized size and the new one. This automatically also
468 * increments the vfs inode->i_size to keep it above or equal to the
469 * initialized_size.
470 */
471 read_lock_irqsave(&ni->size_lock, flags);
472 ll = ni->initialized_size;
473 read_unlock_irqrestore(&ni->size_lock, flags);
474 if (pos > ll) {
475 /*
476 * Wait for ongoing direct i/o to complete before proceeding.
477 * New direct i/o cannot start as we hold i_mutex.
478 */
479 inode_dio_wait(vi);
480 err = ntfs_attr_extend_initialized(ni, pos);
481 if (unlikely(err < 0))
482 ntfs_error(vi->i_sb, "Cannot perform write to inode "
483 "0x%lx, attribute type 0x%x, because "
484 "extending the initialized size "
485 "failed (error %d).", vi->i_ino,
486 (unsigned)le32_to_cpu(ni->type),
487 (int)-err);
488 }
489 out:
490 return err;
491 }
492
493 /**
494 * __ntfs_grab_cache_pages - obtain a number of locked pages
495 * @mapping: address space mapping from which to obtain page cache pages
496 * @index: starting index in @mapping at which to begin obtaining pages
497 * @nr_pages: number of page cache pages to obtain
498 * @pages: array of pages in which to return the obtained page cache pages
499 * @cached_page: allocated but as yet unused page
500 *
501 * Obtain @nr_pages locked page cache pages from the mapping @mapping and
502 * starting at index @index.
503 *
504 * If a page is newly created, add it to lru list
505 *
506 * Note, the page locks are obtained in ascending page index order.
507 */
508 static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
509 pgoff_t index, const unsigned nr_pages, struct page **pages,
510 struct page **cached_page)
511 {
512 int err, nr;
513
514 BUG_ON(!nr_pages);
515 err = nr = 0;
516 do {
517 pages[nr] = find_get_page_flags(mapping, index, FGP_LOCK |
518 FGP_ACCESSED);
519 if (!pages[nr]) {
520 if (!*cached_page) {
521 *cached_page = page_cache_alloc(mapping);
522 if (unlikely(!*cached_page)) {
523 err = -ENOMEM;
524 goto err_out;
525 }
526 }
527 err = add_to_page_cache_lru(*cached_page, mapping,
528 index,
529 mapping_gfp_constraint(mapping, GFP_KERNEL));
530 if (unlikely(err)) {
531 if (err == -EEXIST)
532 continue;
533 goto err_out;
534 }
535 pages[nr] = *cached_page;
536 *cached_page = NULL;
537 }
538 index++;
539 nr++;
540 } while (nr < nr_pages);
541 out:
542 return err;
543 err_out:
544 while (nr > 0) {
545 unlock_page(pages[--nr]);
546 put_page(pages[nr]);
547 }
548 goto out;
549 }
550
551 static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
552 {
553 lock_buffer(bh);
554 get_bh(bh);
555 bh->b_end_io = end_buffer_read_sync;
556 return submit_bh(REQ_OP_READ, 0, bh);
557 }
558
559 /**
560 * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data
561 * @pages: array of destination pages
562 * @nr_pages: number of pages in @pages
563 * @pos: byte position in file at which the write begins
564 * @bytes: number of bytes to be written
565 *
566 * This is called for non-resident attributes from ntfs_file_buffered_write()
567 * with i_mutex held on the inode (@pages[0]->mapping->host). There are
568 * @nr_pages pages in @pages which are locked but not kmap()ped. The source
569 * data has not yet been copied into the @pages.
570 *
571 * Need to fill any holes with actual clusters, allocate buffers if necessary,
572 * ensure all the buffers are mapped, and bring uptodate any buffers that are
573 * only partially being written to.
574 *
575 * If @nr_pages is greater than one, we are guaranteed that the cluster size is
576 * greater than PAGE_SIZE, that all pages in @pages are entirely inside
577 * the same cluster and that they are the entirety of that cluster, and that
578 * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
579 *
580 * i_size is not to be modified yet.
581 *
582 * Return 0 on success or -errno on error.
583 */
584 static int ntfs_prepare_pages_for_non_resident_write(struct page **pages,
585 unsigned nr_pages, s64 pos, size_t bytes)
586 {
587 VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend;
588 LCN lcn;
589 s64 bh_pos, vcn_len, end, initialized_size;
590 sector_t lcn_block;
591 struct page *page;
592 struct inode *vi;
593 ntfs_inode *ni, *base_ni = NULL;
594 ntfs_volume *vol;
595 runlist_element *rl, *rl2;
596 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
597 ntfs_attr_search_ctx *ctx = NULL;
598 MFT_RECORD *m = NULL;
599 ATTR_RECORD *a = NULL;
600 unsigned long flags;
601 u32 attr_rec_len = 0;
602 unsigned blocksize, u;
603 int err, mp_size;
604 bool rl_write_locked, was_hole, is_retry;
605 unsigned char blocksize_bits;
606 struct {
607 u8 runlist_merged:1;
608 u8 mft_attr_mapped:1;
609 u8 mp_rebuilt:1;
610 u8 attr_switched:1;
611 } status = { 0, 0, 0, 0 };
612
613 BUG_ON(!nr_pages);
614 BUG_ON(!pages);
615 BUG_ON(!*pages);
616 vi = pages[0]->mapping->host;
617 ni = NTFS_I(vi);
618 vol = ni->vol;
619 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
620 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
621 vi->i_ino, ni->type, pages[0]->index, nr_pages,
622 (long long)pos, bytes);
623 blocksize = vol->sb->s_blocksize;
624 blocksize_bits = vol->sb->s_blocksize_bits;
625 u = 0;
626 do {
627 page = pages[u];
628 BUG_ON(!page);
629 /*
630 * create_empty_buffers() will create uptodate/dirty buffers if
631 * the page is uptodate/dirty.
632 */
633 if (!page_has_buffers(page)) {
634 create_empty_buffers(page, blocksize, 0);
635 if (unlikely(!page_has_buffers(page)))
636 return -ENOMEM;
637 }
638 } while (++u < nr_pages);
639 rl_write_locked = false;
640 rl = NULL;
641 err = 0;
642 vcn = lcn = -1;
643 vcn_len = 0;
644 lcn_block = -1;
645 was_hole = false;
646 cpos = pos >> vol->cluster_size_bits;
647 end = pos + bytes;
648 cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits;
649 /*
650 * Loop over each page and for each page over each buffer. Use goto to
651 * reduce indentation.
652 */
653 u = 0;
654 do_next_page:
655 page = pages[u];
656 bh_pos = (s64)page->index << PAGE_SHIFT;
657 bh = head = page_buffers(page);
658 do {
659 VCN cdelta;
660 s64 bh_end;
661 unsigned bh_cofs;
662
663 /* Clear buffer_new on all buffers to reinitialise state. */
664 if (buffer_new(bh))
665 clear_buffer_new(bh);
666 bh_end = bh_pos + blocksize;
667 bh_cpos = bh_pos >> vol->cluster_size_bits;
668 bh_cofs = bh_pos & vol->cluster_size_mask;
669 if (buffer_mapped(bh)) {
670 /*
671 * The buffer is already mapped. If it is uptodate,
672 * ignore it.
673 */
674 if (buffer_uptodate(bh))
675 continue;
676 /*
677 * The buffer is not uptodate. If the page is uptodate
678 * set the buffer uptodate and otherwise ignore it.
679 */
680 if (PageUptodate(page)) {
681 set_buffer_uptodate(bh);
682 continue;
683 }
684 /*
685 * Neither the page nor the buffer are uptodate. If
686 * the buffer is only partially being written to, we
687 * need to read it in before the write, i.e. now.
688 */
689 if ((bh_pos < pos && bh_end > pos) ||
690 (bh_pos < end && bh_end > end)) {
691 /*
692 * If the buffer is fully or partially within
693 * the initialized size, do an actual read.
694 * Otherwise, simply zero the buffer.
695 */
696 read_lock_irqsave(&ni->size_lock, flags);
697 initialized_size = ni->initialized_size;
698 read_unlock_irqrestore(&ni->size_lock, flags);
699 if (bh_pos < initialized_size) {
700 ntfs_submit_bh_for_read(bh);
701 *wait_bh++ = bh;
702 } else {
703 zero_user(page, bh_offset(bh),
704 blocksize);
705 set_buffer_uptodate(bh);
706 }
707 }
708 continue;
709 }
710 /* Unmapped buffer. Need to map it. */
711 bh->b_bdev = vol->sb->s_bdev;
712 /*
713 * If the current buffer is in the same clusters as the map
714 * cache, there is no need to check the runlist again. The
715 * map cache is made up of @vcn, which is the first cached file
716 * cluster, @vcn_len which is the number of cached file
717 * clusters, @lcn is the device cluster corresponding to @vcn,
718 * and @lcn_block is the block number corresponding to @lcn.
719 */
720 cdelta = bh_cpos - vcn;
721 if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) {
722 map_buffer_cached:
723 BUG_ON(lcn < 0);
724 bh->b_blocknr = lcn_block +
725 (cdelta << (vol->cluster_size_bits -
726 blocksize_bits)) +
727 (bh_cofs >> blocksize_bits);
728 set_buffer_mapped(bh);
729 /*
730 * If the page is uptodate so is the buffer. If the
731 * buffer is fully outside the write, we ignore it if
732 * it was already allocated and we mark it dirty so it
733 * gets written out if we allocated it. On the other
734 * hand, if we allocated the buffer but we are not
735 * marking it dirty we set buffer_new so we can do
736 * error recovery.
737 */
738 if (PageUptodate(page)) {
739 if (!buffer_uptodate(bh))
740 set_buffer_uptodate(bh);
741 if (unlikely(was_hole)) {
742 /* We allocated the buffer. */
743 clean_bdev_bh_alias(bh);
744 if (bh_end <= pos || bh_pos >= end)
745 mark_buffer_dirty(bh);
746 else
747 set_buffer_new(bh);
748 }
749 continue;
750 }
751 /* Page is _not_ uptodate. */
752 if (likely(!was_hole)) {
753 /*
754 * Buffer was already allocated. If it is not
755 * uptodate and is only partially being written
756 * to, we need to read it in before the write,
757 * i.e. now.
758 */
759 if (!buffer_uptodate(bh) && bh_pos < end &&
760 bh_end > pos &&
761 (bh_pos < pos ||
762 bh_end > end)) {
763 /*
764 * If the buffer is fully or partially
765 * within the initialized size, do an
766 * actual read. Otherwise, simply zero
767 * the buffer.
768 */
769 read_lock_irqsave(&ni->size_lock,
770 flags);
771 initialized_size = ni->initialized_size;
772 read_unlock_irqrestore(&ni->size_lock,
773 flags);
774 if (bh_pos < initialized_size) {
775 ntfs_submit_bh_for_read(bh);
776 *wait_bh++ = bh;
777 } else {
778 zero_user(page, bh_offset(bh),
779 blocksize);
780 set_buffer_uptodate(bh);
781 }
782 }
783 continue;
784 }
785 /* We allocated the buffer. */
786 clean_bdev_bh_alias(bh);
787 /*
788 * If the buffer is fully outside the write, zero it,
789 * set it uptodate, and mark it dirty so it gets
790 * written out. If it is partially being written to,
791 * zero region surrounding the write but leave it to
792 * commit write to do anything else. Finally, if the
793 * buffer is fully being overwritten, do nothing.
794 */
795 if (bh_end <= pos || bh_pos >= end) {
796 if (!buffer_uptodate(bh)) {
797 zero_user(page, bh_offset(bh),
798 blocksize);
799 set_buffer_uptodate(bh);
800 }
801 mark_buffer_dirty(bh);
802 continue;
803 }
804 set_buffer_new(bh);
805 if (!buffer_uptodate(bh) &&
806 (bh_pos < pos || bh_end > end)) {
807 u8 *kaddr;
808 unsigned pofs;
809
810 kaddr = kmap_atomic(page);
811 if (bh_pos < pos) {
812 pofs = bh_pos & ~PAGE_MASK;
813 memset(kaddr + pofs, 0, pos - bh_pos);
814 }
815 if (bh_end > end) {
816 pofs = end & ~PAGE_MASK;
817 memset(kaddr + pofs, 0, bh_end - end);
818 }
819 kunmap_atomic(kaddr);
820 flush_dcache_page(page);
821 }
822 continue;
823 }
824 /*
825 * Slow path: this is the first buffer in the cluster. If it
826 * is outside allocated size and is not uptodate, zero it and
827 * set it uptodate.
828 */
829 read_lock_irqsave(&ni->size_lock, flags);
830 initialized_size = ni->allocated_size;
831 read_unlock_irqrestore(&ni->size_lock, flags);
832 if (bh_pos > initialized_size) {
833 if (PageUptodate(page)) {
834 if (!buffer_uptodate(bh))
835 set_buffer_uptodate(bh);
836 } else if (!buffer_uptodate(bh)) {
837 zero_user(page, bh_offset(bh), blocksize);
838 set_buffer_uptodate(bh);
839 }
840 continue;
841 }
842 is_retry = false;
843 if (!rl) {
844 down_read(&ni->runlist.lock);
845 retry_remap:
846 rl = ni->runlist.rl;
847 }
848 if (likely(rl != NULL)) {
849 /* Seek to element containing target cluster. */
850 while (rl->length && rl[1].vcn <= bh_cpos)
851 rl++;
852 lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos);
853 if (likely(lcn >= 0)) {
854 /*
855 * Successful remap, setup the map cache and
856 * use that to deal with the buffer.
857 */
858 was_hole = false;
859 vcn = bh_cpos;
860 vcn_len = rl[1].vcn - vcn;
861 lcn_block = lcn << (vol->cluster_size_bits -
862 blocksize_bits);
863 cdelta = 0;
864 /*
865 * If the number of remaining clusters touched
866 * by the write is smaller or equal to the
867 * number of cached clusters, unlock the
868 * runlist as the map cache will be used from
869 * now on.
870 */
871 if (likely(vcn + vcn_len >= cend)) {
872 if (rl_write_locked) {
873 up_write(&ni->runlist.lock);
874 rl_write_locked = false;
875 } else
876 up_read(&ni->runlist.lock);
877 rl = NULL;
878 }
879 goto map_buffer_cached;
880 }
881 } else
882 lcn = LCN_RL_NOT_MAPPED;
883 /*
884 * If it is not a hole and not out of bounds, the runlist is
885 * probably unmapped so try to map it now.
886 */
887 if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) {
888 if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) {
889 /* Attempt to map runlist. */
890 if (!rl_write_locked) {
891 /*
892 * We need the runlist locked for
893 * writing, so if it is locked for
894 * reading relock it now and retry in
895 * case it changed whilst we dropped
896 * the lock.
897 */
898 up_read(&ni->runlist.lock);
899 down_write(&ni->runlist.lock);
900 rl_write_locked = true;
901 goto retry_remap;
902 }
903 err = ntfs_map_runlist_nolock(ni, bh_cpos,
904 NULL);
905 if (likely(!err)) {
906 is_retry = true;
907 goto retry_remap;
908 }
909 /*
910 * If @vcn is out of bounds, pretend @lcn is
911 * LCN_ENOENT. As long as the buffer is out
912 * of bounds this will work fine.
913 */
914 if (err == -ENOENT) {
915 lcn = LCN_ENOENT;
916 err = 0;
917 goto rl_not_mapped_enoent;
918 }
919 } else
920 err = -EIO;
921 /* Failed to map the buffer, even after retrying. */
922 bh->b_blocknr = -1;
923 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
924 "attribute type 0x%x, vcn 0x%llx, "
925 "vcn offset 0x%x, because its "
926 "location on disk could not be "
927 "determined%s (error code %i).",
928 ni->mft_no, ni->type,
929 (unsigned long long)bh_cpos,
930 (unsigned)bh_pos &
931 vol->cluster_size_mask,
932 is_retry ? " even after retrying" : "",
933 err);
934 break;
935 }
936 rl_not_mapped_enoent:
937 /*
938 * The buffer is in a hole or out of bounds. We need to fill
939 * the hole, unless the buffer is in a cluster which is not
940 * touched by the write, in which case we just leave the buffer
941 * unmapped. This can only happen when the cluster size is
942 * less than the page cache size.
943 */
944 if (unlikely(vol->cluster_size < PAGE_SIZE)) {
945 bh_cend = (bh_end + vol->cluster_size - 1) >>
946 vol->cluster_size_bits;
947 if ((bh_cend <= cpos || bh_cpos >= cend)) {
948 bh->b_blocknr = -1;
949 /*
950 * If the buffer is uptodate we skip it. If it
951 * is not but the page is uptodate, we can set
952 * the buffer uptodate. If the page is not
953 * uptodate, we can clear the buffer and set it
954 * uptodate. Whether this is worthwhile is
955 * debatable and this could be removed.
956 */
957 if (PageUptodate(page)) {
958 if (!buffer_uptodate(bh))
959 set_buffer_uptodate(bh);
960 } else if (!buffer_uptodate(bh)) {
961 zero_user(page, bh_offset(bh),
962 blocksize);
963 set_buffer_uptodate(bh);
964 }
965 continue;
966 }
967 }
968 /*
969 * Out of bounds buffer is invalid if it was not really out of
970 * bounds.
971 */
972 BUG_ON(lcn != LCN_HOLE);
973 /*
974 * We need the runlist locked for writing, so if it is locked
975 * for reading relock it now and retry in case it changed
976 * whilst we dropped the lock.
977 */
978 BUG_ON(!rl);
979 if (!rl_write_locked) {
980 up_read(&ni->runlist.lock);
981 down_write(&ni->runlist.lock);
982 rl_write_locked = true;
983 goto retry_remap;
984 }
985 /* Find the previous last allocated cluster. */
986 BUG_ON(rl->lcn != LCN_HOLE);
987 lcn = -1;
988 rl2 = rl;
989 while (--rl2 >= ni->runlist.rl) {
990 if (rl2->lcn >= 0) {
991 lcn = rl2->lcn + rl2->length;
992 break;
993 }
994 }
995 rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE,
996 false);
997 if (IS_ERR(rl2)) {
998 err = PTR_ERR(rl2);
999 ntfs_debug("Failed to allocate cluster, error code %i.",
1000 err);
1001 break;
1002 }
1003 lcn = rl2->lcn;
1004 rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
1005 if (IS_ERR(rl)) {
1006 err = PTR_ERR(rl);
1007 if (err != -ENOMEM)
1008 err = -EIO;
1009 if (ntfs_cluster_free_from_rl(vol, rl2)) {
1010 ntfs_error(vol->sb, "Failed to release "
1011 "allocated cluster in error "
1012 "code path. Run chkdsk to "
1013 "recover the lost cluster.");
1014 NVolSetErrors(vol);
1015 }
1016 ntfs_free(rl2);
1017 break;
1018 }
1019 ni->runlist.rl = rl;
1020 status.runlist_merged = 1;
1021 ntfs_debug("Allocated cluster, lcn 0x%llx.",
1022 (unsigned long long)lcn);
1023 /* Map and lock the mft record and get the attribute record. */
1024 if (!NInoAttr(ni))
1025 base_ni = ni;
1026 else
1027 base_ni = ni->ext.base_ntfs_ino;
1028 m = map_mft_record(base_ni);
1029 if (IS_ERR(m)) {
1030 err = PTR_ERR(m);
1031 break;
1032 }
1033 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1034 if (unlikely(!ctx)) {
1035 err = -ENOMEM;
1036 unmap_mft_record(base_ni);
1037 break;
1038 }
1039 status.mft_attr_mapped = 1;
1040 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1041 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx);
1042 if (unlikely(err)) {
1043 if (err == -ENOENT)
1044 err = -EIO;
1045 break;
1046 }
1047 m = ctx->mrec;
1048 a = ctx->attr;
1049 /*
1050 * Find the runlist element with which the attribute extent
1051 * starts. Note, we cannot use the _attr_ version because we
1052 * have mapped the mft record. That is ok because we know the
1053 * runlist fragment must be mapped already to have ever gotten
1054 * here, so we can just use the _rl_ version.
1055 */
1056 vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn);
1057 rl2 = ntfs_rl_find_vcn_nolock(rl, vcn);
1058 BUG_ON(!rl2);
1059 BUG_ON(!rl2->length);
1060 BUG_ON(rl2->lcn < LCN_HOLE);
1061 highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
1062 /*
1063 * If @highest_vcn is zero, calculate the real highest_vcn
1064 * (which can really be zero).
1065 */
1066 if (!highest_vcn)
1067 highest_vcn = (sle64_to_cpu(
1068 a->data.non_resident.allocated_size) >>
1069 vol->cluster_size_bits) - 1;
1070 /*
1071 * Determine the size of the mapping pairs array for the new
1072 * extent, i.e. the old extent with the hole filled.
1073 */
1074 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn,
1075 highest_vcn);
1076 if (unlikely(mp_size <= 0)) {
1077 if (!(err = mp_size))
1078 err = -EIO;
1079 ntfs_debug("Failed to get size for mapping pairs "
1080 "array, error code %i.", err);
1081 break;
1082 }
1083 /*
1084 * Resize the attribute record to fit the new mapping pairs
1085 * array.
1086 */
1087 attr_rec_len = le32_to_cpu(a->length);
1088 err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu(
1089 a->data.non_resident.mapping_pairs_offset));
1090 if (unlikely(err)) {
1091 BUG_ON(err != -ENOSPC);
1092 // TODO: Deal with this by using the current attribute
1093 // and fill it with as much of the mapping pairs
1094 // array as possible. Then loop over each attribute
1095 // extent rewriting the mapping pairs arrays as we go
1096 // along and if when we reach the end we have not
1097 // enough space, try to resize the last attribute
1098 // extent and if even that fails, add a new attribute
1099 // extent.
1100 // We could also try to resize at each step in the hope
1101 // that we will not need to rewrite every single extent.
1102 // Note, we may need to decompress some extents to fill
1103 // the runlist as we are walking the extents...
1104 ntfs_error(vol->sb, "Not enough space in the mft "
1105 "record for the extended attribute "
1106 "record. This case is not "
1107 "implemented yet.");
1108 err = -EOPNOTSUPP;
1109 break ;
1110 }
1111 status.mp_rebuilt = 1;
1112 /*
1113 * Generate the mapping pairs array directly into the attribute
1114 * record.
1115 */
1116 err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1117 a->data.non_resident.mapping_pairs_offset),
1118 mp_size, rl2, vcn, highest_vcn, NULL);
1119 if (unlikely(err)) {
1120 ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, "
1121 "attribute type 0x%x, because building "
1122 "the mapping pairs failed with error "
1123 "code %i.", vi->i_ino,
1124 (unsigned)le32_to_cpu(ni->type), err);
1125 err = -EIO;
1126 break;
1127 }
1128 /* Update the highest_vcn but only if it was not set. */
1129 if (unlikely(!a->data.non_resident.highest_vcn))
1130 a->data.non_resident.highest_vcn =
1131 cpu_to_sle64(highest_vcn);
1132 /*
1133 * If the attribute is sparse/compressed, update the compressed
1134 * size in the ntfs_inode structure and the attribute record.
1135 */
1136 if (likely(NInoSparse(ni) || NInoCompressed(ni))) {
1137 /*
1138 * If we are not in the first attribute extent, switch
1139 * to it, but first ensure the changes will make it to
1140 * disk later.
1141 */
1142 if (a->data.non_resident.lowest_vcn) {
1143 flush_dcache_mft_record_page(ctx->ntfs_ino);
1144 mark_mft_record_dirty(ctx->ntfs_ino);
1145 ntfs_attr_reinit_search_ctx(ctx);
1146 err = ntfs_attr_lookup(ni->type, ni->name,
1147 ni->name_len, CASE_SENSITIVE,
1148 0, NULL, 0, ctx);
1149 if (unlikely(err)) {
1150 status.attr_switched = 1;
1151 break;
1152 }
1153 /* @m is not used any more so do not set it. */
1154 a = ctx->attr;
1155 }
1156 write_lock_irqsave(&ni->size_lock, flags);
1157 ni->itype.compressed.size += vol->cluster_size;
1158 a->data.non_resident.compressed_size =
1159 cpu_to_sle64(ni->itype.compressed.size);
1160 write_unlock_irqrestore(&ni->size_lock, flags);
1161 }
1162 /* Ensure the changes make it to disk. */
1163 flush_dcache_mft_record_page(ctx->ntfs_ino);
1164 mark_mft_record_dirty(ctx->ntfs_ino);
1165 ntfs_attr_put_search_ctx(ctx);
1166 unmap_mft_record(base_ni);
1167 /* Successfully filled the hole. */
1168 status.runlist_merged = 0;
1169 status.mft_attr_mapped = 0;
1170 status.mp_rebuilt = 0;
1171 /* Setup the map cache and use that to deal with the buffer. */
1172 was_hole = true;
1173 vcn = bh_cpos;
1174 vcn_len = 1;
1175 lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits);
1176 cdelta = 0;
1177 /*
1178 * If the number of remaining clusters in the @pages is smaller
1179 * or equal to the number of cached clusters, unlock the
1180 * runlist as the map cache will be used from now on.
1181 */
1182 if (likely(vcn + vcn_len >= cend)) {
1183 up_write(&ni->runlist.lock);
1184 rl_write_locked = false;
1185 rl = NULL;
1186 }
1187 goto map_buffer_cached;
1188 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1189 /* If there are no errors, do the next page. */
1190 if (likely(!err && ++u < nr_pages))
1191 goto do_next_page;
1192 /* If there are no errors, release the runlist lock if we took it. */
1193 if (likely(!err)) {
1194 if (unlikely(rl_write_locked)) {
1195 up_write(&ni->runlist.lock);
1196 rl_write_locked = false;
1197 } else if (unlikely(rl))
1198 up_read(&ni->runlist.lock);
1199 rl = NULL;
1200 }
1201 /* If we issued read requests, let them complete. */
1202 read_lock_irqsave(&ni->size_lock, flags);
1203 initialized_size = ni->initialized_size;
1204 read_unlock_irqrestore(&ni->size_lock, flags);
1205 while (wait_bh > wait) {
1206 bh = *--wait_bh;
1207 wait_on_buffer(bh);
1208 if (likely(buffer_uptodate(bh))) {
1209 page = bh->b_page;
1210 bh_pos = ((s64)page->index << PAGE_SHIFT) +
1211 bh_offset(bh);
1212 /*
1213 * If the buffer overflows the initialized size, need
1214 * to zero the overflowing region.
1215 */
1216 if (unlikely(bh_pos + blocksize > initialized_size)) {
1217 int ofs = 0;
1218
1219 if (likely(bh_pos < initialized_size))
1220 ofs = initialized_size - bh_pos;
1221 zero_user_segment(page, bh_offset(bh) + ofs,
1222 blocksize);
1223 }
1224 } else /* if (unlikely(!buffer_uptodate(bh))) */
1225 err = -EIO;
1226 }
1227 if (likely(!err)) {
1228 /* Clear buffer_new on all buffers. */
1229 u = 0;
1230 do {
1231 bh = head = page_buffers(pages[u]);
1232 do {
1233 if (buffer_new(bh))
1234 clear_buffer_new(bh);
1235 } while ((bh = bh->b_this_page) != head);
1236 } while (++u < nr_pages);
1237 ntfs_debug("Done.");
1238 return err;
1239 }
1240 if (status.attr_switched) {
1241 /* Get back to the attribute extent we modified. */
1242 ntfs_attr_reinit_search_ctx(ctx);
1243 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1244 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) {
1245 ntfs_error(vol->sb, "Failed to find required "
1246 "attribute extent of attribute in "
1247 "error code path. Run chkdsk to "
1248 "recover.");
1249 write_lock_irqsave(&ni->size_lock, flags);
1250 ni->itype.compressed.size += vol->cluster_size;
1251 write_unlock_irqrestore(&ni->size_lock, flags);
1252 flush_dcache_mft_record_page(ctx->ntfs_ino);
1253 mark_mft_record_dirty(ctx->ntfs_ino);
1254 /*
1255 * The only thing that is now wrong is the compressed
1256 * size of the base attribute extent which chkdsk
1257 * should be able to fix.
1258 */
1259 NVolSetErrors(vol);
1260 } else {
1261 m = ctx->mrec;
1262 a = ctx->attr;
1263 status.attr_switched = 0;
1264 }
1265 }
1266 /*
1267 * If the runlist has been modified, need to restore it by punching a
1268 * hole into it and we then need to deallocate the on-disk cluster as
1269 * well. Note, we only modify the runlist if we are able to generate a
1270 * new mapping pairs array, i.e. only when the mapped attribute extent
1271 * is not switched.
1272 */
1273 if (status.runlist_merged && !status.attr_switched) {
1274 BUG_ON(!rl_write_locked);
1275 /* Make the file cluster we allocated sparse in the runlist. */
1276 if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) {
1277 ntfs_error(vol->sb, "Failed to punch hole into "
1278 "attribute runlist in error code "
1279 "path. Run chkdsk to recover the "
1280 "lost cluster.");
1281 NVolSetErrors(vol);
1282 } else /* if (success) */ {
1283 status.runlist_merged = 0;
1284 /*
1285 * Deallocate the on-disk cluster we allocated but only
1286 * if we succeeded in punching its vcn out of the
1287 * runlist.
1288 */
1289 down_write(&vol->lcnbmp_lock);
1290 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
1291 ntfs_error(vol->sb, "Failed to release "
1292 "allocated cluster in error "
1293 "code path. Run chkdsk to "
1294 "recover the lost cluster.");
1295 NVolSetErrors(vol);
1296 }
1297 up_write(&vol->lcnbmp_lock);
1298 }
1299 }
1300 /*
1301 * Resize the attribute record to its old size and rebuild the mapping
1302 * pairs array. Note, we only can do this if the runlist has been
1303 * restored to its old state which also implies that the mapped
1304 * attribute extent is not switched.
1305 */
1306 if (status.mp_rebuilt && !status.runlist_merged) {
1307 if (ntfs_attr_record_resize(m, a, attr_rec_len)) {
1308 ntfs_error(vol->sb, "Failed to restore attribute "
1309 "record in error code path. Run "
1310 "chkdsk to recover.");
1311 NVolSetErrors(vol);
1312 } else /* if (success) */ {
1313 if (ntfs_mapping_pairs_build(vol, (u8*)a +
1314 le16_to_cpu(a->data.non_resident.
1315 mapping_pairs_offset), attr_rec_len -
1316 le16_to_cpu(a->data.non_resident.
1317 mapping_pairs_offset), ni->runlist.rl,
1318 vcn, highest_vcn, NULL)) {
1319 ntfs_error(vol->sb, "Failed to restore "
1320 "mapping pairs array in error "
1321 "code path. Run chkdsk to "
1322 "recover.");
1323 NVolSetErrors(vol);
1324 }
1325 flush_dcache_mft_record_page(ctx->ntfs_ino);
1326 mark_mft_record_dirty(ctx->ntfs_ino);
1327 }
1328 }
1329 /* Release the mft record and the attribute. */
1330 if (status.mft_attr_mapped) {
1331 ntfs_attr_put_search_ctx(ctx);
1332 unmap_mft_record(base_ni);
1333 }
1334 /* Release the runlist lock. */
1335 if (rl_write_locked)
1336 up_write(&ni->runlist.lock);
1337 else if (rl)
1338 up_read(&ni->runlist.lock);
1339 /*
1340 * Zero out any newly allocated blocks to avoid exposing stale data.
1341 * If BH_New is set, we know that the block was newly allocated above
1342 * and that it has not been fully zeroed and marked dirty yet.
1343 */
1344 nr_pages = u;
1345 u = 0;
1346 end = bh_cpos << vol->cluster_size_bits;
1347 do {
1348 page = pages[u];
1349 bh = head = page_buffers(page);
1350 do {
1351 if (u == nr_pages &&
1352 ((s64)page->index << PAGE_SHIFT) +
1353 bh_offset(bh) >= end)
1354 break;
1355 if (!buffer_new(bh))
1356 continue;
1357 clear_buffer_new(bh);
1358 if (!buffer_uptodate(bh)) {
1359 if (PageUptodate(page))
1360 set_buffer_uptodate(bh);
1361 else {
1362 zero_user(page, bh_offset(bh),
1363 blocksize);
1364 set_buffer_uptodate(bh);
1365 }
1366 }
1367 mark_buffer_dirty(bh);
1368 } while ((bh = bh->b_this_page) != head);
1369 } while (++u <= nr_pages);
1370 ntfs_error(vol->sb, "Failed. Returning error code %i.", err);
1371 return err;
1372 }
1373
1374 static inline void ntfs_flush_dcache_pages(struct page **pages,
1375 unsigned nr_pages)
1376 {
1377 BUG_ON(!nr_pages);
1378 /*
1379 * Warning: Do not do the decrement at the same time as the call to
1380 * flush_dcache_page() because it is a NULL macro on i386 and hence the
1381 * decrement never happens so the loop never terminates.
1382 */
1383 do {
1384 --nr_pages;
1385 flush_dcache_page(pages[nr_pages]);
1386 } while (nr_pages > 0);
1387 }
1388
1389 /**
1390 * ntfs_commit_pages_after_non_resident_write - commit the received data
1391 * @pages: array of destination pages
1392 * @nr_pages: number of pages in @pages
1393 * @pos: byte position in file at which the write begins
1394 * @bytes: number of bytes to be written
1395 *
1396 * See description of ntfs_commit_pages_after_write(), below.
1397 */
1398 static inline int ntfs_commit_pages_after_non_resident_write(
1399 struct page **pages, const unsigned nr_pages,
1400 s64 pos, size_t bytes)
1401 {
1402 s64 end, initialized_size;
1403 struct inode *vi;
1404 ntfs_inode *ni, *base_ni;
1405 struct buffer_head *bh, *head;
1406 ntfs_attr_search_ctx *ctx;
1407 MFT_RECORD *m;
1408 ATTR_RECORD *a;
1409 unsigned long flags;
1410 unsigned blocksize, u;
1411 int err;
1412
1413 vi = pages[0]->mapping->host;
1414 ni = NTFS_I(vi);
1415 blocksize = vi->i_sb->s_blocksize;
1416 end = pos + bytes;
1417 u = 0;
1418 do {
1419 s64 bh_pos;
1420 struct page *page;
1421 bool partial;
1422
1423 page = pages[u];
1424 bh_pos = (s64)page->index << PAGE_SHIFT;
1425 bh = head = page_buffers(page);
1426 partial = false;
1427 do {
1428 s64 bh_end;
1429
1430 bh_end = bh_pos + blocksize;
1431 if (bh_end <= pos || bh_pos >= end) {
1432 if (!buffer_uptodate(bh))
1433 partial = true;
1434 } else {
1435 set_buffer_uptodate(bh);
1436 mark_buffer_dirty(bh);
1437 }
1438 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1439 /*
1440 * If all buffers are now uptodate but the page is not, set the
1441 * page uptodate.
1442 */
1443 if (!partial && !PageUptodate(page))
1444 SetPageUptodate(page);
1445 } while (++u < nr_pages);
1446 /*
1447 * Finally, if we do not need to update initialized_size or i_size we
1448 * are finished.
1449 */
1450 read_lock_irqsave(&ni->size_lock, flags);
1451 initialized_size = ni->initialized_size;
1452 read_unlock_irqrestore(&ni->size_lock, flags);
1453 if (end <= initialized_size) {
1454 ntfs_debug("Done.");
1455 return 0;
1456 }
1457 /*
1458 * Update initialized_size/i_size as appropriate, both in the inode and
1459 * the mft record.
1460 */
1461 if (!NInoAttr(ni))
1462 base_ni = ni;
1463 else
1464 base_ni = ni->ext.base_ntfs_ino;
1465 /* Map, pin, and lock the mft record. */
1466 m = map_mft_record(base_ni);
1467 if (IS_ERR(m)) {
1468 err = PTR_ERR(m);
1469 m = NULL;
1470 ctx = NULL;
1471 goto err_out;
1472 }
1473 BUG_ON(!NInoNonResident(ni));
1474 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1475 if (unlikely(!ctx)) {
1476 err = -ENOMEM;
1477 goto err_out;
1478 }
1479 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1480 CASE_SENSITIVE, 0, NULL, 0, ctx);
1481 if (unlikely(err)) {
1482 if (err == -ENOENT)
1483 err = -EIO;
1484 goto err_out;
1485 }
1486 a = ctx->attr;
1487 BUG_ON(!a->non_resident);
1488 write_lock_irqsave(&ni->size_lock, flags);
1489 BUG_ON(end > ni->allocated_size);
1490 ni->initialized_size = end;
1491 a->data.non_resident.initialized_size = cpu_to_sle64(end);
1492 if (end > i_size_read(vi)) {
1493 i_size_write(vi, end);
1494 a->data.non_resident.data_size =
1495 a->data.non_resident.initialized_size;
1496 }
1497 write_unlock_irqrestore(&ni->size_lock, flags);
1498 /* Mark the mft record dirty, so it gets written back. */
1499 flush_dcache_mft_record_page(ctx->ntfs_ino);
1500 mark_mft_record_dirty(ctx->ntfs_ino);
1501 ntfs_attr_put_search_ctx(ctx);
1502 unmap_mft_record(base_ni);
1503 ntfs_debug("Done.");
1504 return 0;
1505 err_out:
1506 if (ctx)
1507 ntfs_attr_put_search_ctx(ctx);
1508 if (m)
1509 unmap_mft_record(base_ni);
1510 ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error "
1511 "code %i).", err);
1512 if (err != -ENOMEM)
1513 NVolSetErrors(ni->vol);
1514 return err;
1515 }
1516
1517 /**
1518 * ntfs_commit_pages_after_write - commit the received data
1519 * @pages: array of destination pages
1520 * @nr_pages: number of pages in @pages
1521 * @pos: byte position in file at which the write begins
1522 * @bytes: number of bytes to be written
1523 *
1524 * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
1525 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
1526 * locked but not kmap()ped. The source data has already been copied into the
1527 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before
1528 * the data was copied (for non-resident attributes only) and it returned
1529 * success.
1530 *
1531 * Need to set uptodate and mark dirty all buffers within the boundary of the
1532 * write. If all buffers in a page are uptodate we set the page uptodate, too.
1533 *
1534 * Setting the buffers dirty ensures that they get written out later when
1535 * ntfs_writepage() is invoked by the VM.
1536 *
1537 * Finally, we need to update i_size and initialized_size as appropriate both
1538 * in the inode and the mft record.
1539 *
1540 * This is modelled after fs/buffer.c::generic_commit_write(), which marks
1541 * buffers uptodate and dirty, sets the page uptodate if all buffers in the
1542 * page are uptodate, and updates i_size if the end of io is beyond i_size. In
1543 * that case, it also marks the inode dirty.
1544 *
1545 * If things have gone as outlined in
1546 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
1547 * content modifications here for non-resident attributes. For resident
1548 * attributes we need to do the uptodate bringing here which we combine with
1549 * the copying into the mft record which means we save one atomic kmap.
1550 *
1551 * Return 0 on success or -errno on error.
1552 */
1553 static int ntfs_commit_pages_after_write(struct page **pages,
1554 const unsigned nr_pages, s64 pos, size_t bytes)
1555 {
1556 s64 end, initialized_size;
1557 loff_t i_size;
1558 struct inode *vi;
1559 ntfs_inode *ni, *base_ni;
1560 struct page *page;
1561 ntfs_attr_search_ctx *ctx;
1562 MFT_RECORD *m;
1563 ATTR_RECORD *a;
1564 char *kattr, *kaddr;
1565 unsigned long flags;
1566 u32 attr_len;
1567 int err;
1568
1569 BUG_ON(!nr_pages);
1570 BUG_ON(!pages);
1571 page = pages[0];
1572 BUG_ON(!page);
1573 vi = page->mapping->host;
1574 ni = NTFS_I(vi);
1575 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
1576 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
1577 vi->i_ino, ni->type, page->index, nr_pages,
1578 (long long)pos, bytes);
1579 if (NInoNonResident(ni))
1580 return ntfs_commit_pages_after_non_resident_write(pages,
1581 nr_pages, pos, bytes);
1582 BUG_ON(nr_pages > 1);
1583 /*
1584 * Attribute is resident, implying it is not compressed, encrypted, or
1585 * sparse.
1586 */
1587 if (!NInoAttr(ni))
1588 base_ni = ni;
1589 else
1590 base_ni = ni->ext.base_ntfs_ino;
1591 BUG_ON(NInoNonResident(ni));
1592 /* Map, pin, and lock the mft record. */
1593 m = map_mft_record(base_ni);
1594 if (IS_ERR(m)) {
1595 err = PTR_ERR(m);
1596 m = NULL;
1597 ctx = NULL;
1598 goto err_out;
1599 }
1600 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1601 if (unlikely(!ctx)) {
1602 err = -ENOMEM;
1603 goto err_out;
1604 }
1605 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1606 CASE_SENSITIVE, 0, NULL, 0, ctx);
1607 if (unlikely(err)) {
1608 if (err == -ENOENT)
1609 err = -EIO;
1610 goto err_out;
1611 }
1612 a = ctx->attr;
1613 BUG_ON(a->non_resident);
1614 /* The total length of the attribute value. */
1615 attr_len = le32_to_cpu(a->data.resident.value_length);
1616 i_size = i_size_read(vi);
1617 BUG_ON(attr_len != i_size);
1618 BUG_ON(pos > attr_len);
1619 end = pos + bytes;
1620 BUG_ON(end > le32_to_cpu(a->length) -
1621 le16_to_cpu(a->data.resident.value_offset));
1622 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
1623 kaddr = kmap_atomic(page);
1624 /* Copy the received data from the page to the mft record. */
1625 memcpy(kattr + pos, kaddr + pos, bytes);
1626 /* Update the attribute length if necessary. */
1627 if (end > attr_len) {
1628 attr_len = end;
1629 a->data.resident.value_length = cpu_to_le32(attr_len);
1630 }
1631 /*
1632 * If the page is not uptodate, bring the out of bounds area(s)
1633 * uptodate by copying data from the mft record to the page.
1634 */
1635 if (!PageUptodate(page)) {
1636 if (pos > 0)
1637 memcpy(kaddr, kattr, pos);
1638 if (end < attr_len)
1639 memcpy(kaddr + end, kattr + end, attr_len - end);
1640 /* Zero the region outside the end of the attribute value. */
1641 memset(kaddr + attr_len, 0, PAGE_SIZE - attr_len);
1642 flush_dcache_page(page);
1643 SetPageUptodate(page);
1644 }
1645 kunmap_atomic(kaddr);
1646 /* Update initialized_size/i_size if necessary. */
1647 read_lock_irqsave(&ni->size_lock, flags);
1648 initialized_size = ni->initialized_size;
1649 BUG_ON(end > ni->allocated_size);
1650 read_unlock_irqrestore(&ni->size_lock, flags);
1651 BUG_ON(initialized_size != i_size);
1652 if (end > initialized_size) {
1653 write_lock_irqsave(&ni->size_lock, flags);
1654 ni->initialized_size = end;
1655 i_size_write(vi, end);
1656 write_unlock_irqrestore(&ni->size_lock, flags);
1657 }
1658 /* Mark the mft record dirty, so it gets written back. */
1659 flush_dcache_mft_record_page(ctx->ntfs_ino);
1660 mark_mft_record_dirty(ctx->ntfs_ino);
1661 ntfs_attr_put_search_ctx(ctx);
1662 unmap_mft_record(base_ni);
1663 ntfs_debug("Done.");
1664 return 0;
1665 err_out:
1666 if (err == -ENOMEM) {
1667 ntfs_warning(vi->i_sb, "Error allocating memory required to "
1668 "commit the write.");
1669 if (PageUptodate(page)) {
1670 ntfs_warning(vi->i_sb, "Page is uptodate, setting "
1671 "dirty so the write will be retried "
1672 "later on by the VM.");
1673 /*
1674 * Put the page on mapping->dirty_pages, but leave its
1675 * buffers' dirty state as-is.
1676 */
1677 __set_page_dirty_nobuffers(page);
1678 err = 0;
1679 } else
1680 ntfs_error(vi->i_sb, "Page is not uptodate. Written "
1681 "data has been lost.");
1682 } else {
1683 ntfs_error(vi->i_sb, "Resident attribute commit write failed "
1684 "with error %i.", err);
1685 NVolSetErrors(ni->vol);
1686 }
1687 if (ctx)
1688 ntfs_attr_put_search_ctx(ctx);
1689 if (m)
1690 unmap_mft_record(base_ni);
1691 return err;
1692 }
1693
1694 /*
1695 * Copy as much as we can into the pages and return the number of bytes which
1696 * were successfully copied. If a fault is encountered then clear the pages
1697 * out to (ofs + bytes) and return the number of bytes which were copied.
1698 */
1699 static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages,
1700 unsigned ofs, struct iov_iter *i, size_t bytes)
1701 {
1702 struct page **last_page = pages + nr_pages;
1703 size_t total = 0;
1704 struct iov_iter data = *i;
1705 unsigned len, copied;
1706
1707 do {
1708 len = PAGE_SIZE - ofs;
1709 if (len > bytes)
1710 len = bytes;
1711 copied = iov_iter_copy_from_user_atomic(*pages, &data, ofs,
1712 len);
1713 total += copied;
1714 bytes -= copied;
1715 if (!bytes)
1716 break;
1717 iov_iter_advance(&data, copied);
1718 if (copied < len)
1719 goto err;
1720 ofs = 0;
1721 } while (++pages < last_page);
1722 out:
1723 return total;
1724 err:
1725 /* Zero the rest of the target like __copy_from_user(). */
1726 len = PAGE_SIZE - copied;
1727 do {
1728 if (len > bytes)
1729 len = bytes;
1730 zero_user(*pages, copied, len);
1731 bytes -= len;
1732 copied = 0;
1733 len = PAGE_SIZE;
1734 } while (++pages < last_page);
1735 goto out;
1736 }
1737
1738 /**
1739 * ntfs_perform_write - perform buffered write to a file
1740 * @file: file to write to
1741 * @i: iov_iter with data to write
1742 * @pos: byte offset in file at which to begin writing to
1743 */
1744 static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i,
1745 loff_t pos)
1746 {
1747 struct address_space *mapping = file->f_mapping;
1748 struct inode *vi = mapping->host;
1749 ntfs_inode *ni = NTFS_I(vi);
1750 ntfs_volume *vol = ni->vol;
1751 struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER];
1752 struct page *cached_page = NULL;
1753 VCN last_vcn;
1754 LCN lcn;
1755 size_t bytes;
1756 ssize_t status, written = 0;
1757 unsigned nr_pages;
1758
1759 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
1760 "0x%llx, count 0x%lx.", vi->i_ino,
1761 (unsigned)le32_to_cpu(ni->type),
1762 (unsigned long long)pos,
1763 (unsigned long)iov_iter_count(i));
1764 /*
1765 * If a previous ntfs_truncate() failed, repeat it and abort if it
1766 * fails again.
1767 */
1768 if (unlikely(NInoTruncateFailed(ni))) {
1769 int err;
1770
1771 inode_dio_wait(vi);
1772 err = ntfs_truncate(vi);
1773 if (err || NInoTruncateFailed(ni)) {
1774 if (!err)
1775 err = -EIO;
1776 ntfs_error(vol->sb, "Cannot perform write to inode "
1777 "0x%lx, attribute type 0x%x, because "
1778 "ntfs_truncate() failed (error code "
1779 "%i).", vi->i_ino,
1780 (unsigned)le32_to_cpu(ni->type), err);
1781 return err;
1782 }
1783 }
1784 /*
1785 * Determine the number of pages per cluster for non-resident
1786 * attributes.
1787 */
1788 nr_pages = 1;
1789 if (vol->cluster_size > PAGE_SIZE && NInoNonResident(ni))
1790 nr_pages = vol->cluster_size >> PAGE_SHIFT;
1791 last_vcn = -1;
1792 do {
1793 VCN vcn;
1794 pgoff_t idx, start_idx;
1795 unsigned ofs, do_pages, u;
1796 size_t copied;
1797
1798 start_idx = idx = pos >> PAGE_SHIFT;
1799 ofs = pos & ~PAGE_MASK;
1800 bytes = PAGE_SIZE - ofs;
1801 do_pages = 1;
1802 if (nr_pages > 1) {
1803 vcn = pos >> vol->cluster_size_bits;
1804 if (vcn != last_vcn) {
1805 last_vcn = vcn;
1806 /*
1807 * Get the lcn of the vcn the write is in. If
1808 * it is a hole, need to lock down all pages in
1809 * the cluster.
1810 */
1811 down_read(&ni->runlist.lock);
1812 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >>
1813 vol->cluster_size_bits, false);
1814 up_read(&ni->runlist.lock);
1815 if (unlikely(lcn < LCN_HOLE)) {
1816 if (lcn == LCN_ENOMEM)
1817 status = -ENOMEM;
1818 else {
1819 status = -EIO;
1820 ntfs_error(vol->sb, "Cannot "
1821 "perform write to "
1822 "inode 0x%lx, "
1823 "attribute type 0x%x, "
1824 "because the attribute "
1825 "is corrupt.",
1826 vi->i_ino, (unsigned)
1827 le32_to_cpu(ni->type));
1828 }
1829 break;
1830 }
1831 if (lcn == LCN_HOLE) {
1832 start_idx = (pos & ~(s64)
1833 vol->cluster_size_mask)
1834 >> PAGE_SHIFT;
1835 bytes = vol->cluster_size - (pos &
1836 vol->cluster_size_mask);
1837 do_pages = nr_pages;
1838 }
1839 }
1840 }
1841 if (bytes > iov_iter_count(i))
1842 bytes = iov_iter_count(i);
1843 again:
1844 /*
1845 * Bring in the user page(s) that we will copy from _first_.
1846 * Otherwise there is a nasty deadlock on copying from the same
1847 * page(s) as we are writing to, without it/them being marked
1848 * up-to-date. Note, at present there is nothing to stop the
1849 * pages being swapped out between us bringing them into memory
1850 * and doing the actual copying.
1851 */
1852 if (unlikely(iov_iter_fault_in_readable(i, bytes))) {
1853 status = -EFAULT;
1854 break;
1855 }
1856 /* Get and lock @do_pages starting at index @start_idx. */
1857 status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages,
1858 pages, &cached_page);
1859 if (unlikely(status))
1860 break;
1861 /*
1862 * For non-resident attributes, we need to fill any holes with
1863 * actual clusters and ensure all bufferes are mapped. We also
1864 * need to bring uptodate any buffers that are only partially
1865 * being written to.
1866 */
1867 if (NInoNonResident(ni)) {
1868 status = ntfs_prepare_pages_for_non_resident_write(
1869 pages, do_pages, pos, bytes);
1870 if (unlikely(status)) {
1871 do {
1872 unlock_page(pages[--do_pages]);
1873 put_page(pages[do_pages]);
1874 } while (do_pages);
1875 break;
1876 }
1877 }
1878 u = (pos >> PAGE_SHIFT) - pages[0]->index;
1879 copied = ntfs_copy_from_user_iter(pages + u, do_pages - u, ofs,
1880 i, bytes);
1881 ntfs_flush_dcache_pages(pages + u, do_pages - u);
1882 status = 0;
1883 if (likely(copied == bytes)) {
1884 status = ntfs_commit_pages_after_write(pages, do_pages,
1885 pos, bytes);
1886 if (!status)
1887 status = bytes;
1888 }
1889 do {
1890 unlock_page(pages[--do_pages]);
1891 put_page(pages[do_pages]);
1892 } while (do_pages);
1893 if (unlikely(status < 0))
1894 break;
1895 copied = status;
1896 cond_resched();
1897 if (unlikely(!copied)) {
1898 size_t sc;
1899
1900 /*
1901 * We failed to copy anything. Fall back to single
1902 * segment length write.
1903 *
1904 * This is needed to avoid possible livelock in the
1905 * case that all segments in the iov cannot be copied
1906 * at once without a pagefault.
1907 */
1908 sc = iov_iter_single_seg_count(i);
1909 if (bytes > sc)
1910 bytes = sc;
1911 goto again;
1912 }
1913 iov_iter_advance(i, copied);
1914 pos += copied;
1915 written += copied;
1916 balance_dirty_pages_ratelimited(mapping);
1917 if (fatal_signal_pending(current)) {
1918 status = -EINTR;
1919 break;
1920 }
1921 } while (iov_iter_count(i));
1922 if (cached_page)
1923 put_page(cached_page);
1924 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).",
1925 written ? "written" : "status", (unsigned long)written,
1926 (long)status);
1927 return written ? written : status;
1928 }
1929
1930 /**
1931 * ntfs_file_write_iter - simple wrapper for ntfs_file_write_iter_nolock()
1932 * @iocb: IO state structure
1933 * @from: iov_iter with data to write
1934 *
1935 * Basically the same as generic_file_write_iter() except that it ends up
1936 * up calling ntfs_perform_write() instead of generic_perform_write() and that
1937 * O_DIRECT is not implemented.
1938 */
1939 static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1940 {
1941 struct file *file = iocb->ki_filp;
1942 struct inode *vi = file_inode(file);
1943 ssize_t written = 0;
1944 ssize_t err;
1945
1946 inode_lock(vi);
1947 /* We can write back this queue in page reclaim. */
1948 current->backing_dev_info = inode_to_bdi(vi);
1949 err = ntfs_prepare_file_for_write(iocb, from);
1950 if (iov_iter_count(from) && !err)
1951 written = ntfs_perform_write(file, from, iocb->ki_pos);
1952 current->backing_dev_info = NULL;
1953 inode_unlock(vi);
1954 iocb->ki_pos += written;
1955 if (likely(written > 0))
1956 written = generic_write_sync(iocb, written);
1957 return written ? written : err;
1958 }
1959
1960 /**
1961 * ntfs_file_fsync - sync a file to disk
1962 * @filp: file to be synced
1963 * @datasync: if non-zero only flush user data and not metadata
1964 *
1965 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
1966 * system calls. This function is inspired by fs/buffer.c::file_fsync().
1967 *
1968 * If @datasync is false, write the mft record and all associated extent mft
1969 * records as well as the $DATA attribute and then sync the block device.
1970 *
1971 * If @datasync is true and the attribute is non-resident, we skip the writing
1972 * of the mft record and all associated extent mft records (this might still
1973 * happen due to the write_inode_now() call).
1974 *
1975 * Also, if @datasync is true, we do not wait on the inode to be written out
1976 * but we always wait on the page cache pages to be written out.
1977 *
1978 * Locking: Caller must hold i_mutex on the inode.
1979 *
1980 * TODO: We should probably also write all attribute/index inodes associated
1981 * with this inode but since we have no simple way of getting to them we ignore
1982 * this problem for now.
1983 */
1984 static int ntfs_file_fsync(struct file *filp, loff_t start, loff_t end,
1985 int datasync)
1986 {
1987 struct inode *vi = filp->f_mapping->host;
1988 int err, ret = 0;
1989
1990 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
1991
1992 err = filemap_write_and_wait_range(vi->i_mapping, start, end);
1993 if (err)
1994 return err;
1995 inode_lock(vi);
1996
1997 BUG_ON(S_ISDIR(vi->i_mode));
1998 if (!datasync || !NInoNonResident(NTFS_I(vi)))
1999 ret = __ntfs_write_inode(vi, 1);
2000 write_inode_now(vi, !datasync);
2001 /*
2002 * NOTE: If we were to use mapping->private_list (see ext2 and
2003 * fs/buffer.c) for dirty blocks then we could optimize the below to be
2004 * sync_mapping_buffers(vi->i_mapping).
2005 */
2006 err = sync_blockdev(vi->i_sb->s_bdev);
2007 if (unlikely(err && !ret))
2008 ret = err;
2009 if (likely(!ret))
2010 ntfs_debug("Done.");
2011 else
2012 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
2013 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
2014 inode_unlock(vi);
2015 return ret;
2016 }
2017
2018 #endif /* NTFS_RW */
2019
2020 const struct file_operations ntfs_file_ops = {
2021 .llseek = generic_file_llseek,
2022 .read_iter = generic_file_read_iter,
2023 #ifdef NTFS_RW
2024 .write_iter = ntfs_file_write_iter,
2025 .fsync = ntfs_file_fsync,
2026 #endif /* NTFS_RW */
2027 .mmap = generic_file_mmap,
2028 .open = ntfs_file_open,
2029 .splice_read = generic_file_splice_read,
2030 };
2031
2032 const struct inode_operations ntfs_file_inode_ops = {
2033 #ifdef NTFS_RW
2034 .setattr = ntfs_setattr,
2035 #endif /* NTFS_RW */
2036 };
2037
2038 const struct file_operations ntfs_empty_file_ops = {};
2039
2040 const struct inode_operations ntfs_empty_inode_ops = {};
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