2 * file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
4 * Copyright (c) 2001-2015 Anton Altaparmakov and Tuxera Inc.
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.
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.
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
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.h>
28 #include <linux/swap.h>
29 #include <linux/uio.h>
30 #include <linux/writeback.h>
33 #include <asm/uaccess.h>
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
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.
57 * On 64-bit architectures, the check is hopefully optimized away by the
60 * After the check passes, just call generic_file_open() to do its work.
62 static int ntfs_file_open(struct inode *vi, struct file *filp)
64 if (sizeof(unsigned long) < 8) {
65 if (i_size_read(vi) > MAX_LFS_FILESIZE)
68 return generic_file_open(vi, filp);
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
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).
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.
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
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.
106 * Locking: i_mutex on the vfs inode corrseponsind to the ntfs inode @ni must be
107 * held by the caller.
109 static int ntfs_attr_extend_initialized(ntfs_inode *ni, const s64 new_init_size)
113 pgoff_t index, end_index;
115 struct inode *vi = VFS_I(ni);
117 MFT_RECORD *m = NULL;
119 ntfs_attr_search_ctx *ctx = NULL;
120 struct address_space *mapping;
121 struct page *page = NULL;
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);
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);
151 ctx = ntfs_attr_get_search_ctx(base_ni, m);
152 if (unlikely(!ctx)) {
156 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
157 CASE_SENSITIVE, 0, NULL, 0, ctx);
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);
170 * Do the zeroing in the mft record and update the attribute size in
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);
182 do_non_resident_extend:
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.
188 if (new_init_size > old_i_size) {
189 m = map_mft_record(base_ni);
195 ctx = ntfs_attr_get_search_ctx(base_ni, m);
196 if (unlikely(!ctx)) {
200 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
201 CASE_SENSITIVE, 0, NULL, 0, ctx);
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);
219 unmap_mft_record(base_ni);
222 mapping = vi->i_mapping;
223 index = old_init_size >> PAGE_CACHE_SHIFT;
224 end_index = (new_init_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
227 * Read the page. If the page is not present, this will zero
228 * the uninitialized regions for us.
230 page = read_mapping_page(mapping, index, NULL);
235 if (unlikely(PageError(page))) {
236 page_cache_release(page);
241 * Update the initialized size in the ntfs inode. This is
242 * enough to make ntfs_writepage() work.
244 write_lock_irqsave(&ni->size_lock, flags);
245 ni->initialized_size = (s64)(index + 1) << PAGE_CACHE_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 page_cache_release(page);
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
257 * f = open(somefile, O_TRUNC);
258 * truncate(f, 10GiB);
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!
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
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
279 balance_dirty_pages_ratelimited(mapping);
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);
292 ctx = ntfs_attr_get_search_ctx(base_ni, m);
293 if (unlikely(!ctx)) {
297 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
298 CASE_SENSITIVE, 0, NULL, 0, ctx);
306 BUG_ON(!a->non_resident);
307 a->data.non_resident.initialized_size = cpu_to_sle64(new_init_size);
309 flush_dcache_mft_record_page(ctx->ntfs_ino);
310 mark_mft_record_dirty(ctx->ntfs_ino);
312 ntfs_attr_put_search_ctx(ctx);
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));
319 write_lock_irqsave(&ni->size_lock, flags);
320 ni->initialized_size = old_init_size;
321 write_unlock_irqrestore(&ni->size_lock, flags);
324 ntfs_attr_put_search_ctx(ctx);
326 unmap_mft_record(base_ni);
327 ntfs_debug("Failed. Returning error code %i.", err);
331 static ssize_t ntfs_prepare_file_for_write(struct kiocb *iocb,
332 struct iov_iter *from)
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;
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))
352 * All checks have passed. Before we start doing any writing we want
353 * to abort any totally illegal writes.
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. */
361 * Reminder for later: Encrypted files are _always_
362 * non-resident so that the content can always be encrypted.
364 ntfs_debug("Denying write access to encrypted file.");
368 if (NInoCompressed(ni)) {
369 /* Only unnamed $DATA attribute can be compressed. */
370 BUG_ON(ni->name_len);
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
377 ntfs_error(vi->i_sb, "Writing to compressed files is not "
378 "implemented yet. Sorry.");
384 base_ni = ni->ext.base_ntfs_ino;
385 err = file_remove_privs(file);
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.
392 file_update_time(file);
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;
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.
401 read_lock_irqsave(&ni->size_lock, flags);
402 ll = ni->allocated_size;
403 read_unlock_irqrestore(&ni->size_lock, flags);
406 * Extend the allocation without changing the data size.
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.
412 ll = ntfs_attr_extend_allocation(ni, end, -1, pos);
413 if (likely(ll >= 0)) {
415 /* If the extension was partial truncate the write. */
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);
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. */
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),
439 iov_iter_truncate(from, ll - pos);
442 ntfs_error(vi->i_sb, "Cannot perform "
445 "type 0x%x, because "
449 vi->i_ino, (unsigned)
450 le32_to_cpu(ni->type),
453 ntfs_debug("Cannot perform write to "
455 "attribute type 0x%x, "
456 "because there is not "
458 vi->i_ino, (unsigned)
459 le32_to_cpu(ni->type));
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
471 read_lock_irqsave(&ni->size_lock, flags);
472 ll = ni->initialized_size;
473 read_unlock_irqrestore(&ni->size_lock, flags);
476 * Wait for ongoing direct i/o to complete before proceeding.
477 * New direct i/o cannot start as we hold i_mutex.
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),
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
501 * Obtain @nr_pages locked page cache pages from the mapping @mapping and
502 * starting at index @index.
504 * If a page is newly created, add it to lru list
506 * Note, the page locks are obtained in ascending page index order.
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)
517 pages[nr] = find_get_page_flags(mapping, index, FGP_LOCK |
521 *cached_page = page_cache_alloc(mapping);
522 if (unlikely(!*cached_page)) {
527 err = add_to_page_cache_lru(*cached_page, mapping,
529 GFP_KERNEL & mapping_gfp_mask(mapping));
535 pages[nr] = *cached_page;
540 } while (nr < nr_pages);
545 unlock_page(pages[--nr]);
546 page_cache_release(pages[nr]);
551 static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
555 bh->b_end_io = end_buffer_read_sync;
556 return submit_bh(READ, bh);
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
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.
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.
575 * If @nr_pages is greater than one, we are guaranteed that the cluster size is
576 * greater than PAGE_CACHE_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.
580 * i_size is not to be modified yet.
582 * Return 0 on success or -errno on error.
584 static int ntfs_prepare_pages_for_non_resident_write(struct page **pages,
585 unsigned nr_pages, s64 pos, size_t bytes)
587 VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend;
589 s64 bh_pos, vcn_len, end, initialized_size;
593 ntfs_inode *ni, *base_ni = NULL;
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;
601 u32 attr_rec_len = 0;
602 unsigned blocksize, u;
604 bool rl_write_locked, was_hole, is_retry;
605 unsigned char blocksize_bits;
608 u8 mft_attr_mapped:1;
611 } status = { 0, 0, 0, 0 };
616 vi = pages[0]->mapping->host;
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;
630 * create_empty_buffers() will create uptodate/dirty buffers if
631 * the page is uptodate/dirty.
633 if (!page_has_buffers(page)) {
634 create_empty_buffers(page, blocksize, 0);
635 if (unlikely(!page_has_buffers(page)))
638 } while (++u < nr_pages);
639 rl_write_locked = false;
646 cpos = pos >> vol->cluster_size_bits;
648 cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits;
650 * Loop over each page and for each page over each buffer. Use goto to
651 * reduce indentation.
656 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
657 bh = head = page_buffers(page);
663 /* Clear buffer_new on all buffers to reinitialise state. */
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)) {
671 * The buffer is already mapped. If it is uptodate,
674 if (buffer_uptodate(bh))
677 * The buffer is not uptodate. If the page is uptodate
678 * set the buffer uptodate and otherwise ignore it.
680 if (PageUptodate(page)) {
681 set_buffer_uptodate(bh);
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.
689 if ((bh_pos < pos && bh_end > pos) ||
690 (bh_pos < end && bh_end > end)) {
692 * If the buffer is fully or partially within
693 * the initialized size, do an actual read.
694 * Otherwise, simply zero the buffer.
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);
703 zero_user(page, bh_offset(bh),
705 set_buffer_uptodate(bh);
710 /* Unmapped buffer. Need to map it. */
711 bh->b_bdev = vol->sb->s_bdev;
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.
720 cdelta = bh_cpos - vcn;
721 if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) {
724 bh->b_blocknr = lcn_block +
725 (cdelta << (vol->cluster_size_bits -
727 (bh_cofs >> blocksize_bits);
728 set_buffer_mapped(bh);
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
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 unmap_underlying_metadata(bh->b_bdev,
745 if (bh_end <= pos || bh_pos >= end)
746 mark_buffer_dirty(bh);
752 /* Page is _not_ uptodate. */
753 if (likely(!was_hole)) {
755 * Buffer was already allocated. If it is not
756 * uptodate and is only partially being written
757 * to, we need to read it in before the write,
760 if (!buffer_uptodate(bh) && bh_pos < end &&
765 * If the buffer is fully or partially
766 * within the initialized size, do an
767 * actual read. Otherwise, simply zero
770 read_lock_irqsave(&ni->size_lock,
772 initialized_size = ni->initialized_size;
773 read_unlock_irqrestore(&ni->size_lock,
775 if (bh_pos < initialized_size) {
776 ntfs_submit_bh_for_read(bh);
779 zero_user(page, bh_offset(bh),
781 set_buffer_uptodate(bh);
786 /* We allocated the buffer. */
787 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
789 * If the buffer is fully outside the write, zero it,
790 * set it uptodate, and mark it dirty so it gets
791 * written out. If it is partially being written to,
792 * zero region surrounding the write but leave it to
793 * commit write to do anything else. Finally, if the
794 * buffer is fully being overwritten, do nothing.
796 if (bh_end <= pos || bh_pos >= end) {
797 if (!buffer_uptodate(bh)) {
798 zero_user(page, bh_offset(bh),
800 set_buffer_uptodate(bh);
802 mark_buffer_dirty(bh);
806 if (!buffer_uptodate(bh) &&
807 (bh_pos < pos || bh_end > end)) {
811 kaddr = kmap_atomic(page);
813 pofs = bh_pos & ~PAGE_CACHE_MASK;
814 memset(kaddr + pofs, 0, pos - bh_pos);
817 pofs = end & ~PAGE_CACHE_MASK;
818 memset(kaddr + pofs, 0, bh_end - end);
820 kunmap_atomic(kaddr);
821 flush_dcache_page(page);
826 * Slow path: this is the first buffer in the cluster. If it
827 * is outside allocated size and is not uptodate, zero it and
830 read_lock_irqsave(&ni->size_lock, flags);
831 initialized_size = ni->allocated_size;
832 read_unlock_irqrestore(&ni->size_lock, flags);
833 if (bh_pos > initialized_size) {
834 if (PageUptodate(page)) {
835 if (!buffer_uptodate(bh))
836 set_buffer_uptodate(bh);
837 } else if (!buffer_uptodate(bh)) {
838 zero_user(page, bh_offset(bh), blocksize);
839 set_buffer_uptodate(bh);
845 down_read(&ni->runlist.lock);
849 if (likely(rl != NULL)) {
850 /* Seek to element containing target cluster. */
851 while (rl->length && rl[1].vcn <= bh_cpos)
853 lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos);
854 if (likely(lcn >= 0)) {
856 * Successful remap, setup the map cache and
857 * use that to deal with the buffer.
861 vcn_len = rl[1].vcn - vcn;
862 lcn_block = lcn << (vol->cluster_size_bits -
866 * If the number of remaining clusters touched
867 * by the write is smaller or equal to the
868 * number of cached clusters, unlock the
869 * runlist as the map cache will be used from
872 if (likely(vcn + vcn_len >= cend)) {
873 if (rl_write_locked) {
874 up_write(&ni->runlist.lock);
875 rl_write_locked = false;
877 up_read(&ni->runlist.lock);
880 goto map_buffer_cached;
883 lcn = LCN_RL_NOT_MAPPED;
885 * If it is not a hole and not out of bounds, the runlist is
886 * probably unmapped so try to map it now.
888 if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) {
889 if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) {
890 /* Attempt to map runlist. */
891 if (!rl_write_locked) {
893 * We need the runlist locked for
894 * writing, so if it is locked for
895 * reading relock it now and retry in
896 * case it changed whilst we dropped
899 up_read(&ni->runlist.lock);
900 down_write(&ni->runlist.lock);
901 rl_write_locked = true;
904 err = ntfs_map_runlist_nolock(ni, bh_cpos,
911 * If @vcn is out of bounds, pretend @lcn is
912 * LCN_ENOENT. As long as the buffer is out
913 * of bounds this will work fine.
915 if (err == -ENOENT) {
918 goto rl_not_mapped_enoent;
922 /* Failed to map the buffer, even after retrying. */
924 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
925 "attribute type 0x%x, vcn 0x%llx, "
926 "vcn offset 0x%x, because its "
927 "location on disk could not be "
928 "determined%s (error code %i).",
929 ni->mft_no, ni->type,
930 (unsigned long long)bh_cpos,
932 vol->cluster_size_mask,
933 is_retry ? " even after retrying" : "",
937 rl_not_mapped_enoent:
939 * The buffer is in a hole or out of bounds. We need to fill
940 * the hole, unless the buffer is in a cluster which is not
941 * touched by the write, in which case we just leave the buffer
942 * unmapped. This can only happen when the cluster size is
943 * less than the page cache size.
945 if (unlikely(vol->cluster_size < PAGE_CACHE_SIZE)) {
946 bh_cend = (bh_end + vol->cluster_size - 1) >>
947 vol->cluster_size_bits;
948 if ((bh_cend <= cpos || bh_cpos >= cend)) {
951 * If the buffer is uptodate we skip it. If it
952 * is not but the page is uptodate, we can set
953 * the buffer uptodate. If the page is not
954 * uptodate, we can clear the buffer and set it
955 * uptodate. Whether this is worthwhile is
956 * debatable and this could be removed.
958 if (PageUptodate(page)) {
959 if (!buffer_uptodate(bh))
960 set_buffer_uptodate(bh);
961 } else if (!buffer_uptodate(bh)) {
962 zero_user(page, bh_offset(bh),
964 set_buffer_uptodate(bh);
970 * Out of bounds buffer is invalid if it was not really out of
973 BUG_ON(lcn != LCN_HOLE);
975 * We need the runlist locked for writing, so if it is locked
976 * for reading relock it now and retry in case it changed
977 * whilst we dropped the lock.
980 if (!rl_write_locked) {
981 up_read(&ni->runlist.lock);
982 down_write(&ni->runlist.lock);
983 rl_write_locked = true;
986 /* Find the previous last allocated cluster. */
987 BUG_ON(rl->lcn != LCN_HOLE);
990 while (--rl2 >= ni->runlist.rl) {
992 lcn = rl2->lcn + rl2->length;
996 rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE,
1000 ntfs_debug("Failed to allocate cluster, error code %i.",
1005 rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
1010 if (ntfs_cluster_free_from_rl(vol, rl2)) {
1011 ntfs_error(vol->sb, "Failed to release "
1012 "allocated cluster in error "
1013 "code path. Run chkdsk to "
1014 "recover the lost cluster.");
1020 ni->runlist.rl = rl;
1021 status.runlist_merged = 1;
1022 ntfs_debug("Allocated cluster, lcn 0x%llx.",
1023 (unsigned long long)lcn);
1024 /* Map and lock the mft record and get the attribute record. */
1028 base_ni = ni->ext.base_ntfs_ino;
1029 m = map_mft_record(base_ni);
1034 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1035 if (unlikely(!ctx)) {
1037 unmap_mft_record(base_ni);
1040 status.mft_attr_mapped = 1;
1041 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1042 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx);
1043 if (unlikely(err)) {
1051 * Find the runlist element with which the attribute extent
1052 * starts. Note, we cannot use the _attr_ version because we
1053 * have mapped the mft record. That is ok because we know the
1054 * runlist fragment must be mapped already to have ever gotten
1055 * here, so we can just use the _rl_ version.
1057 vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn);
1058 rl2 = ntfs_rl_find_vcn_nolock(rl, vcn);
1060 BUG_ON(!rl2->length);
1061 BUG_ON(rl2->lcn < LCN_HOLE);
1062 highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
1064 * If @highest_vcn is zero, calculate the real highest_vcn
1065 * (which can really be zero).
1068 highest_vcn = (sle64_to_cpu(
1069 a->data.non_resident.allocated_size) >>
1070 vol->cluster_size_bits) - 1;
1072 * Determine the size of the mapping pairs array for the new
1073 * extent, i.e. the old extent with the hole filled.
1075 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn,
1077 if (unlikely(mp_size <= 0)) {
1078 if (!(err = mp_size))
1080 ntfs_debug("Failed to get size for mapping pairs "
1081 "array, error code %i.", err);
1085 * Resize the attribute record to fit the new mapping pairs
1088 attr_rec_len = le32_to_cpu(a->length);
1089 err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu(
1090 a->data.non_resident.mapping_pairs_offset));
1091 if (unlikely(err)) {
1092 BUG_ON(err != -ENOSPC);
1093 // TODO: Deal with this by using the current attribute
1094 // and fill it with as much of the mapping pairs
1095 // array as possible. Then loop over each attribute
1096 // extent rewriting the mapping pairs arrays as we go
1097 // along and if when we reach the end we have not
1098 // enough space, try to resize the last attribute
1099 // extent and if even that fails, add a new attribute
1101 // We could also try to resize at each step in the hope
1102 // that we will not need to rewrite every single extent.
1103 // Note, we may need to decompress some extents to fill
1104 // the runlist as we are walking the extents...
1105 ntfs_error(vol->sb, "Not enough space in the mft "
1106 "record for the extended attribute "
1107 "record. This case is not "
1108 "implemented yet.");
1112 status.mp_rebuilt = 1;
1114 * Generate the mapping pairs array directly into the attribute
1117 err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1118 a->data.non_resident.mapping_pairs_offset),
1119 mp_size, rl2, vcn, highest_vcn, NULL);
1120 if (unlikely(err)) {
1121 ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, "
1122 "attribute type 0x%x, because building "
1123 "the mapping pairs failed with error "
1124 "code %i.", vi->i_ino,
1125 (unsigned)le32_to_cpu(ni->type), err);
1129 /* Update the highest_vcn but only if it was not set. */
1130 if (unlikely(!a->data.non_resident.highest_vcn))
1131 a->data.non_resident.highest_vcn =
1132 cpu_to_sle64(highest_vcn);
1134 * If the attribute is sparse/compressed, update the compressed
1135 * size in the ntfs_inode structure and the attribute record.
1137 if (likely(NInoSparse(ni) || NInoCompressed(ni))) {
1139 * If we are not in the first attribute extent, switch
1140 * to it, but first ensure the changes will make it to
1143 if (a->data.non_resident.lowest_vcn) {
1144 flush_dcache_mft_record_page(ctx->ntfs_ino);
1145 mark_mft_record_dirty(ctx->ntfs_ino);
1146 ntfs_attr_reinit_search_ctx(ctx);
1147 err = ntfs_attr_lookup(ni->type, ni->name,
1148 ni->name_len, CASE_SENSITIVE,
1150 if (unlikely(err)) {
1151 status.attr_switched = 1;
1154 /* @m is not used any more so do not set it. */
1157 write_lock_irqsave(&ni->size_lock, flags);
1158 ni->itype.compressed.size += vol->cluster_size;
1159 a->data.non_resident.compressed_size =
1160 cpu_to_sle64(ni->itype.compressed.size);
1161 write_unlock_irqrestore(&ni->size_lock, flags);
1163 /* Ensure the changes make it to disk. */
1164 flush_dcache_mft_record_page(ctx->ntfs_ino);
1165 mark_mft_record_dirty(ctx->ntfs_ino);
1166 ntfs_attr_put_search_ctx(ctx);
1167 unmap_mft_record(base_ni);
1168 /* Successfully filled the hole. */
1169 status.runlist_merged = 0;
1170 status.mft_attr_mapped = 0;
1171 status.mp_rebuilt = 0;
1172 /* Setup the map cache and use that to deal with the buffer. */
1176 lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits);
1179 * If the number of remaining clusters in the @pages is smaller
1180 * or equal to the number of cached clusters, unlock the
1181 * runlist as the map cache will be used from now on.
1183 if (likely(vcn + vcn_len >= cend)) {
1184 up_write(&ni->runlist.lock);
1185 rl_write_locked = false;
1188 goto map_buffer_cached;
1189 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1190 /* If there are no errors, do the next page. */
1191 if (likely(!err && ++u < nr_pages))
1193 /* If there are no errors, release the runlist lock if we took it. */
1195 if (unlikely(rl_write_locked)) {
1196 up_write(&ni->runlist.lock);
1197 rl_write_locked = false;
1198 } else if (unlikely(rl))
1199 up_read(&ni->runlist.lock);
1202 /* If we issued read requests, let them complete. */
1203 read_lock_irqsave(&ni->size_lock, flags);
1204 initialized_size = ni->initialized_size;
1205 read_unlock_irqrestore(&ni->size_lock, flags);
1206 while (wait_bh > wait) {
1209 if (likely(buffer_uptodate(bh))) {
1211 bh_pos = ((s64)page->index << PAGE_CACHE_SHIFT) +
1214 * If the buffer overflows the initialized size, need
1215 * to zero the overflowing region.
1217 if (unlikely(bh_pos + blocksize > initialized_size)) {
1220 if (likely(bh_pos < initialized_size))
1221 ofs = initialized_size - bh_pos;
1222 zero_user_segment(page, bh_offset(bh) + ofs,
1225 } else /* if (unlikely(!buffer_uptodate(bh))) */
1229 /* Clear buffer_new on all buffers. */
1232 bh = head = page_buffers(pages[u]);
1235 clear_buffer_new(bh);
1236 } while ((bh = bh->b_this_page) != head);
1237 } while (++u < nr_pages);
1238 ntfs_debug("Done.");
1241 if (status.attr_switched) {
1242 /* Get back to the attribute extent we modified. */
1243 ntfs_attr_reinit_search_ctx(ctx);
1244 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1245 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) {
1246 ntfs_error(vol->sb, "Failed to find required "
1247 "attribute extent of attribute in "
1248 "error code path. Run chkdsk to "
1250 write_lock_irqsave(&ni->size_lock, flags);
1251 ni->itype.compressed.size += vol->cluster_size;
1252 write_unlock_irqrestore(&ni->size_lock, flags);
1253 flush_dcache_mft_record_page(ctx->ntfs_ino);
1254 mark_mft_record_dirty(ctx->ntfs_ino);
1256 * The only thing that is now wrong is the compressed
1257 * size of the base attribute extent which chkdsk
1258 * should be able to fix.
1264 status.attr_switched = 0;
1268 * If the runlist has been modified, need to restore it by punching a
1269 * hole into it and we then need to deallocate the on-disk cluster as
1270 * well. Note, we only modify the runlist if we are able to generate a
1271 * new mapping pairs array, i.e. only when the mapped attribute extent
1274 if (status.runlist_merged && !status.attr_switched) {
1275 BUG_ON(!rl_write_locked);
1276 /* Make the file cluster we allocated sparse in the runlist. */
1277 if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) {
1278 ntfs_error(vol->sb, "Failed to punch hole into "
1279 "attribute runlist in error code "
1280 "path. Run chkdsk to recover the "
1283 } else /* if (success) */ {
1284 status.runlist_merged = 0;
1286 * Deallocate the on-disk cluster we allocated but only
1287 * if we succeeded in punching its vcn out of the
1290 down_write(&vol->lcnbmp_lock);
1291 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
1292 ntfs_error(vol->sb, "Failed to release "
1293 "allocated cluster in error "
1294 "code path. Run chkdsk to "
1295 "recover the lost cluster.");
1298 up_write(&vol->lcnbmp_lock);
1302 * Resize the attribute record to its old size and rebuild the mapping
1303 * pairs array. Note, we only can do this if the runlist has been
1304 * restored to its old state which also implies that the mapped
1305 * attribute extent is not switched.
1307 if (status.mp_rebuilt && !status.runlist_merged) {
1308 if (ntfs_attr_record_resize(m, a, attr_rec_len)) {
1309 ntfs_error(vol->sb, "Failed to restore attribute "
1310 "record in error code path. Run "
1311 "chkdsk to recover.");
1313 } else /* if (success) */ {
1314 if (ntfs_mapping_pairs_build(vol, (u8*)a +
1315 le16_to_cpu(a->data.non_resident.
1316 mapping_pairs_offset), attr_rec_len -
1317 le16_to_cpu(a->data.non_resident.
1318 mapping_pairs_offset), ni->runlist.rl,
1319 vcn, highest_vcn, NULL)) {
1320 ntfs_error(vol->sb, "Failed to restore "
1321 "mapping pairs array in error "
1322 "code path. Run chkdsk to "
1326 flush_dcache_mft_record_page(ctx->ntfs_ino);
1327 mark_mft_record_dirty(ctx->ntfs_ino);
1330 /* Release the mft record and the attribute. */
1331 if (status.mft_attr_mapped) {
1332 ntfs_attr_put_search_ctx(ctx);
1333 unmap_mft_record(base_ni);
1335 /* Release the runlist lock. */
1336 if (rl_write_locked)
1337 up_write(&ni->runlist.lock);
1339 up_read(&ni->runlist.lock);
1341 * Zero out any newly allocated blocks to avoid exposing stale data.
1342 * If BH_New is set, we know that the block was newly allocated above
1343 * and that it has not been fully zeroed and marked dirty yet.
1347 end = bh_cpos << vol->cluster_size_bits;
1350 bh = head = page_buffers(page);
1352 if (u == nr_pages &&
1353 ((s64)page->index << PAGE_CACHE_SHIFT) +
1354 bh_offset(bh) >= end)
1356 if (!buffer_new(bh))
1358 clear_buffer_new(bh);
1359 if (!buffer_uptodate(bh)) {
1360 if (PageUptodate(page))
1361 set_buffer_uptodate(bh);
1363 zero_user(page, bh_offset(bh),
1365 set_buffer_uptodate(bh);
1368 mark_buffer_dirty(bh);
1369 } while ((bh = bh->b_this_page) != head);
1370 } while (++u <= nr_pages);
1371 ntfs_error(vol->sb, "Failed. Returning error code %i.", err);
1375 static inline void ntfs_flush_dcache_pages(struct page **pages,
1380 * Warning: Do not do the decrement at the same time as the call to
1381 * flush_dcache_page() because it is a NULL macro on i386 and hence the
1382 * decrement never happens so the loop never terminates.
1386 flush_dcache_page(pages[nr_pages]);
1387 } while (nr_pages > 0);
1391 * ntfs_commit_pages_after_non_resident_write - commit the received data
1392 * @pages: array of destination pages
1393 * @nr_pages: number of pages in @pages
1394 * @pos: byte position in file at which the write begins
1395 * @bytes: number of bytes to be written
1397 * See description of ntfs_commit_pages_after_write(), below.
1399 static inline int ntfs_commit_pages_after_non_resident_write(
1400 struct page **pages, const unsigned nr_pages,
1401 s64 pos, size_t bytes)
1403 s64 end, initialized_size;
1405 ntfs_inode *ni, *base_ni;
1406 struct buffer_head *bh, *head;
1407 ntfs_attr_search_ctx *ctx;
1410 unsigned long flags;
1411 unsigned blocksize, u;
1414 vi = pages[0]->mapping->host;
1416 blocksize = vi->i_sb->s_blocksize;
1425 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
1426 bh = head = page_buffers(page);
1431 bh_end = bh_pos + blocksize;
1432 if (bh_end <= pos || bh_pos >= end) {
1433 if (!buffer_uptodate(bh))
1436 set_buffer_uptodate(bh);
1437 mark_buffer_dirty(bh);
1439 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1441 * If all buffers are now uptodate but the page is not, set the
1444 if (!partial && !PageUptodate(page))
1445 SetPageUptodate(page);
1446 } while (++u < nr_pages);
1448 * Finally, if we do not need to update initialized_size or i_size we
1451 read_lock_irqsave(&ni->size_lock, flags);
1452 initialized_size = ni->initialized_size;
1453 read_unlock_irqrestore(&ni->size_lock, flags);
1454 if (end <= initialized_size) {
1455 ntfs_debug("Done.");
1459 * Update initialized_size/i_size as appropriate, both in the inode and
1465 base_ni = ni->ext.base_ntfs_ino;
1466 /* Map, pin, and lock the mft record. */
1467 m = map_mft_record(base_ni);
1474 BUG_ON(!NInoNonResident(ni));
1475 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1476 if (unlikely(!ctx)) {
1480 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1481 CASE_SENSITIVE, 0, NULL, 0, ctx);
1482 if (unlikely(err)) {
1488 BUG_ON(!a->non_resident);
1489 write_lock_irqsave(&ni->size_lock, flags);
1490 BUG_ON(end > ni->allocated_size);
1491 ni->initialized_size = end;
1492 a->data.non_resident.initialized_size = cpu_to_sle64(end);
1493 if (end > i_size_read(vi)) {
1494 i_size_write(vi, end);
1495 a->data.non_resident.data_size =
1496 a->data.non_resident.initialized_size;
1498 write_unlock_irqrestore(&ni->size_lock, flags);
1499 /* Mark the mft record dirty, so it gets written back. */
1500 flush_dcache_mft_record_page(ctx->ntfs_ino);
1501 mark_mft_record_dirty(ctx->ntfs_ino);
1502 ntfs_attr_put_search_ctx(ctx);
1503 unmap_mft_record(base_ni);
1504 ntfs_debug("Done.");
1508 ntfs_attr_put_search_ctx(ctx);
1510 unmap_mft_record(base_ni);
1511 ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error "
1514 NVolSetErrors(ni->vol);
1519 * ntfs_commit_pages_after_write - commit the received data
1520 * @pages: array of destination pages
1521 * @nr_pages: number of pages in @pages
1522 * @pos: byte position in file at which the write begins
1523 * @bytes: number of bytes to be written
1525 * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
1526 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
1527 * locked but not kmap()ped. The source data has already been copied into the
1528 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before
1529 * the data was copied (for non-resident attributes only) and it returned
1532 * Need to set uptodate and mark dirty all buffers within the boundary of the
1533 * write. If all buffers in a page are uptodate we set the page uptodate, too.
1535 * Setting the buffers dirty ensures that they get written out later when
1536 * ntfs_writepage() is invoked by the VM.
1538 * Finally, we need to update i_size and initialized_size as appropriate both
1539 * in the inode and the mft record.
1541 * This is modelled after fs/buffer.c::generic_commit_write(), which marks
1542 * buffers uptodate and dirty, sets the page uptodate if all buffers in the
1543 * page are uptodate, and updates i_size if the end of io is beyond i_size. In
1544 * that case, it also marks the inode dirty.
1546 * If things have gone as outlined in
1547 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
1548 * content modifications here for non-resident attributes. For resident
1549 * attributes we need to do the uptodate bringing here which we combine with
1550 * the copying into the mft record which means we save one atomic kmap.
1552 * Return 0 on success or -errno on error.
1554 static int ntfs_commit_pages_after_write(struct page **pages,
1555 const unsigned nr_pages, s64 pos, size_t bytes)
1557 s64 end, initialized_size;
1560 ntfs_inode *ni, *base_ni;
1562 ntfs_attr_search_ctx *ctx;
1565 char *kattr, *kaddr;
1566 unsigned long flags;
1574 vi = page->mapping->host;
1576 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
1577 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
1578 vi->i_ino, ni->type, page->index, nr_pages,
1579 (long long)pos, bytes);
1580 if (NInoNonResident(ni))
1581 return ntfs_commit_pages_after_non_resident_write(pages,
1582 nr_pages, pos, bytes);
1583 BUG_ON(nr_pages > 1);
1585 * Attribute is resident, implying it is not compressed, encrypted, or
1591 base_ni = ni->ext.base_ntfs_ino;
1592 BUG_ON(NInoNonResident(ni));
1593 /* Map, pin, and lock the mft record. */
1594 m = map_mft_record(base_ni);
1601 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1602 if (unlikely(!ctx)) {
1606 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1607 CASE_SENSITIVE, 0, NULL, 0, ctx);
1608 if (unlikely(err)) {
1614 BUG_ON(a->non_resident);
1615 /* The total length of the attribute value. */
1616 attr_len = le32_to_cpu(a->data.resident.value_length);
1617 i_size = i_size_read(vi);
1618 BUG_ON(attr_len != i_size);
1619 BUG_ON(pos > attr_len);
1621 BUG_ON(end > le32_to_cpu(a->length) -
1622 le16_to_cpu(a->data.resident.value_offset));
1623 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
1624 kaddr = kmap_atomic(page);
1625 /* Copy the received data from the page to the mft record. */
1626 memcpy(kattr + pos, kaddr + pos, bytes);
1627 /* Update the attribute length if necessary. */
1628 if (end > attr_len) {
1630 a->data.resident.value_length = cpu_to_le32(attr_len);
1633 * If the page is not uptodate, bring the out of bounds area(s)
1634 * uptodate by copying data from the mft record to the page.
1636 if (!PageUptodate(page)) {
1638 memcpy(kaddr, kattr, pos);
1640 memcpy(kaddr + end, kattr + end, attr_len - end);
1641 /* Zero the region outside the end of the attribute value. */
1642 memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
1643 flush_dcache_page(page);
1644 SetPageUptodate(page);
1646 kunmap_atomic(kaddr);
1647 /* Update initialized_size/i_size if necessary. */
1648 read_lock_irqsave(&ni->size_lock, flags);
1649 initialized_size = ni->initialized_size;
1650 BUG_ON(end > ni->allocated_size);
1651 read_unlock_irqrestore(&ni->size_lock, flags);
1652 BUG_ON(initialized_size != i_size);
1653 if (end > initialized_size) {
1654 write_lock_irqsave(&ni->size_lock, flags);
1655 ni->initialized_size = end;
1656 i_size_write(vi, end);
1657 write_unlock_irqrestore(&ni->size_lock, flags);
1659 /* Mark the mft record dirty, so it gets written back. */
1660 flush_dcache_mft_record_page(ctx->ntfs_ino);
1661 mark_mft_record_dirty(ctx->ntfs_ino);
1662 ntfs_attr_put_search_ctx(ctx);
1663 unmap_mft_record(base_ni);
1664 ntfs_debug("Done.");
1667 if (err == -ENOMEM) {
1668 ntfs_warning(vi->i_sb, "Error allocating memory required to "
1669 "commit the write.");
1670 if (PageUptodate(page)) {
1671 ntfs_warning(vi->i_sb, "Page is uptodate, setting "
1672 "dirty so the write will be retried "
1673 "later on by the VM.");
1675 * Put the page on mapping->dirty_pages, but leave its
1676 * buffers' dirty state as-is.
1678 __set_page_dirty_nobuffers(page);
1681 ntfs_error(vi->i_sb, "Page is not uptodate. Written "
1682 "data has been lost.");
1684 ntfs_error(vi->i_sb, "Resident attribute commit write failed "
1685 "with error %i.", err);
1686 NVolSetErrors(ni->vol);
1689 ntfs_attr_put_search_ctx(ctx);
1691 unmap_mft_record(base_ni);
1696 * Copy as much as we can into the pages and return the number of bytes which
1697 * were successfully copied. If a fault is encountered then clear the pages
1698 * out to (ofs + bytes) and return the number of bytes which were copied.
1700 static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages,
1701 unsigned ofs, struct iov_iter *i, size_t bytes)
1703 struct page **last_page = pages + nr_pages;
1705 struct iov_iter data = *i;
1706 unsigned len, copied;
1709 len = PAGE_CACHE_SIZE - ofs;
1712 copied = iov_iter_copy_from_user_atomic(*pages, &data, ofs,
1718 iov_iter_advance(&data, copied);
1722 } while (++pages < last_page);
1726 /* Zero the rest of the target like __copy_from_user(). */
1727 len = PAGE_CACHE_SIZE - copied;
1731 zero_user(*pages, copied, len);
1734 len = PAGE_CACHE_SIZE;
1735 } while (++pages < last_page);
1740 * ntfs_perform_write - perform buffered write to a file
1741 * @file: file to write to
1742 * @i: iov_iter with data to write
1743 * @pos: byte offset in file at which to begin writing to
1745 static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i,
1748 struct address_space *mapping = file->f_mapping;
1749 struct inode *vi = mapping->host;
1750 ntfs_inode *ni = NTFS_I(vi);
1751 ntfs_volume *vol = ni->vol;
1752 struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER];
1753 struct page *cached_page = NULL;
1757 ssize_t status, written = 0;
1760 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
1761 "0x%llx, count 0x%lx.", vi->i_ino,
1762 (unsigned)le32_to_cpu(ni->type),
1763 (unsigned long long)pos,
1764 (unsigned long)iov_iter_count(i));
1766 * If a previous ntfs_truncate() failed, repeat it and abort if it
1769 if (unlikely(NInoTruncateFailed(ni))) {
1773 err = ntfs_truncate(vi);
1774 if (err || NInoTruncateFailed(ni)) {
1777 ntfs_error(vol->sb, "Cannot perform write to inode "
1778 "0x%lx, attribute type 0x%x, because "
1779 "ntfs_truncate() failed (error code "
1781 (unsigned)le32_to_cpu(ni->type), err);
1786 * Determine the number of pages per cluster for non-resident
1790 if (vol->cluster_size > PAGE_CACHE_SIZE && NInoNonResident(ni))
1791 nr_pages = vol->cluster_size >> PAGE_CACHE_SHIFT;
1795 pgoff_t idx, start_idx;
1796 unsigned ofs, do_pages, u;
1799 start_idx = idx = pos >> PAGE_CACHE_SHIFT;
1800 ofs = pos & ~PAGE_CACHE_MASK;
1801 bytes = PAGE_CACHE_SIZE - ofs;
1804 vcn = pos >> vol->cluster_size_bits;
1805 if (vcn != last_vcn) {
1808 * Get the lcn of the vcn the write is in. If
1809 * it is a hole, need to lock down all pages in
1812 down_read(&ni->runlist.lock);
1813 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >>
1814 vol->cluster_size_bits, false);
1815 up_read(&ni->runlist.lock);
1816 if (unlikely(lcn < LCN_HOLE)) {
1817 if (lcn == LCN_ENOMEM)
1821 ntfs_error(vol->sb, "Cannot "
1824 "attribute type 0x%x, "
1825 "because the attribute "
1827 vi->i_ino, (unsigned)
1828 le32_to_cpu(ni->type));
1832 if (lcn == LCN_HOLE) {
1833 start_idx = (pos & ~(s64)
1834 vol->cluster_size_mask)
1835 >> PAGE_CACHE_SHIFT;
1836 bytes = vol->cluster_size - (pos &
1837 vol->cluster_size_mask);
1838 do_pages = nr_pages;
1842 if (bytes > iov_iter_count(i))
1843 bytes = iov_iter_count(i);
1846 * Bring in the user page(s) that we will copy from _first_.
1847 * Otherwise there is a nasty deadlock on copying from the same
1848 * page(s) as we are writing to, without it/them being marked
1849 * up-to-date. Note, at present there is nothing to stop the
1850 * pages being swapped out between us bringing them into memory
1851 * and doing the actual copying.
1853 if (unlikely(iov_iter_fault_in_multipages_readable(i, bytes))) {
1857 /* Get and lock @do_pages starting at index @start_idx. */
1858 status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages,
1859 pages, &cached_page);
1860 if (unlikely(status))
1863 * For non-resident attributes, we need to fill any holes with
1864 * actual clusters and ensure all bufferes are mapped. We also
1865 * need to bring uptodate any buffers that are only partially
1868 if (NInoNonResident(ni)) {
1869 status = ntfs_prepare_pages_for_non_resident_write(
1870 pages, do_pages, pos, bytes);
1871 if (unlikely(status)) {
1873 unlock_page(pages[--do_pages]);
1874 page_cache_release(pages[do_pages]);
1879 u = (pos >> PAGE_CACHE_SHIFT) - pages[0]->index;
1880 copied = ntfs_copy_from_user_iter(pages + u, do_pages - u, ofs,
1882 ntfs_flush_dcache_pages(pages + u, do_pages - u);
1884 if (likely(copied == bytes)) {
1885 status = ntfs_commit_pages_after_write(pages, do_pages,
1891 unlock_page(pages[--do_pages]);
1892 page_cache_release(pages[do_pages]);
1894 if (unlikely(status < 0))
1898 if (unlikely(!copied)) {
1902 * We failed to copy anything. Fall back to single
1903 * segment length write.
1905 * This is needed to avoid possible livelock in the
1906 * case that all segments in the iov cannot be copied
1907 * at once without a pagefault.
1909 sc = iov_iter_single_seg_count(i);
1914 iov_iter_advance(i, copied);
1917 balance_dirty_pages_ratelimited(mapping);
1918 if (fatal_signal_pending(current)) {
1922 } while (iov_iter_count(i));
1924 page_cache_release(cached_page);
1925 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).",
1926 written ? "written" : "status", (unsigned long)written,
1928 return written ? written : status;
1932 * ntfs_file_write_iter - simple wrapper for ntfs_file_write_iter_nolock()
1933 * @iocb: IO state structure
1934 * @from: iov_iter with data to write
1936 * Basically the same as generic_file_write_iter() except that it ends up
1937 * up calling ntfs_perform_write() instead of generic_perform_write() and that
1938 * O_DIRECT is not implemented.
1940 static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1942 struct file *file = iocb->ki_filp;
1943 struct inode *vi = file_inode(file);
1944 ssize_t written = 0;
1947 mutex_lock(&vi->i_mutex);
1948 /* We can write back this queue in page reclaim. */
1949 current->backing_dev_info = inode_to_bdi(vi);
1950 err = ntfs_prepare_file_for_write(iocb, from);
1951 if (iov_iter_count(from) && !err)
1952 written = ntfs_perform_write(file, from, iocb->ki_pos);
1953 current->backing_dev_info = NULL;
1954 mutex_unlock(&vi->i_mutex);
1955 if (likely(written > 0)) {
1956 err = generic_write_sync(file, iocb->ki_pos, written);
1960 iocb->ki_pos += written;
1961 return written ? written : err;
1965 * ntfs_file_fsync - sync a file to disk
1966 * @filp: file to be synced
1967 * @datasync: if non-zero only flush user data and not metadata
1969 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
1970 * system calls. This function is inspired by fs/buffer.c::file_fsync().
1972 * If @datasync is false, write the mft record and all associated extent mft
1973 * records as well as the $DATA attribute and then sync the block device.
1975 * If @datasync is true and the attribute is non-resident, we skip the writing
1976 * of the mft record and all associated extent mft records (this might still
1977 * happen due to the write_inode_now() call).
1979 * Also, if @datasync is true, we do not wait on the inode to be written out
1980 * but we always wait on the page cache pages to be written out.
1982 * Locking: Caller must hold i_mutex on the inode.
1984 * TODO: We should probably also write all attribute/index inodes associated
1985 * with this inode but since we have no simple way of getting to them we ignore
1986 * this problem for now.
1988 static int ntfs_file_fsync(struct file *filp, loff_t start, loff_t end,
1991 struct inode *vi = filp->f_mapping->host;
1994 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
1996 err = filemap_write_and_wait_range(vi->i_mapping, start, end);
1999 mutex_lock(&vi->i_mutex);
2001 BUG_ON(S_ISDIR(vi->i_mode));
2002 if (!datasync || !NInoNonResident(NTFS_I(vi)))
2003 ret = __ntfs_write_inode(vi, 1);
2004 write_inode_now(vi, !datasync);
2006 * NOTE: If we were to use mapping->private_list (see ext2 and
2007 * fs/buffer.c) for dirty blocks then we could optimize the below to be
2008 * sync_mapping_buffers(vi->i_mapping).
2010 err = sync_blockdev(vi->i_sb->s_bdev);
2011 if (unlikely(err && !ret))
2014 ntfs_debug("Done.");
2016 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
2017 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
2018 mutex_unlock(&vi->i_mutex);
2022 #endif /* NTFS_RW */
2024 const struct file_operations ntfs_file_ops = {
2025 .llseek = generic_file_llseek,
2026 .read_iter = generic_file_read_iter,
2028 .write_iter = ntfs_file_write_iter,
2029 .fsync = ntfs_file_fsync,
2030 #endif /* NTFS_RW */
2031 .mmap = generic_file_mmap,
2032 .open = ntfs_file_open,
2033 .splice_read = generic_file_splice_read,
2036 const struct inode_operations ntfs_file_inode_ops = {
2038 .setattr = ntfs_setattr,
2039 #endif /* NTFS_RW */
2042 const struct file_operations ntfs_empty_file_ops = {};
2044 const struct inode_operations ntfs_empty_inode_ops = {};