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;
342 size_t count = iov_iter_count(from);
344 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
345 "0x%llx, count 0x%zx.", vi->i_ino,
346 (unsigned)le32_to_cpu(ni->type),
347 (unsigned long long)iocb->ki_pos, count);
348 err = generic_write_checks(file, &iocb->ki_pos, &count);
351 iov_iter_truncate(from, count);
355 * All checks have passed. Before we start doing any writing we want
356 * to abort any totally illegal writes.
358 BUG_ON(NInoMstProtected(ni));
359 BUG_ON(ni->type != AT_DATA);
360 /* If file is encrypted, deny access, just like NT4. */
361 if (NInoEncrypted(ni)) {
362 /* Only $DATA attributes can be encrypted. */
364 * Reminder for later: Encrypted files are _always_
365 * non-resident so that the content can always be encrypted.
367 ntfs_debug("Denying write access to encrypted file.");
371 if (NInoCompressed(ni)) {
372 /* Only unnamed $DATA attribute can be compressed. */
373 BUG_ON(ni->name_len);
375 * Reminder for later: If resident, the data is not actually
376 * compressed. Only on the switch to non-resident does
377 * compression kick in. This is in contrast to encrypted files
380 ntfs_error(vi->i_sb, "Writing to compressed files is not "
381 "implemented yet. Sorry.");
387 base_ni = ni->ext.base_ntfs_ino;
388 err = file_remove_suid(file);
392 * Our ->update_time method always succeeds thus file_update_time()
393 * cannot fail either so there is no need to check the return code.
395 file_update_time(file);
397 /* The first byte after the last cluster being written to. */
398 end = (pos + iov_iter_count(from) + vol->cluster_size_mask) &
399 ~(u64)vol->cluster_size_mask;
401 * If the write goes beyond the allocated size, extend the allocation
402 * to cover the whole of the write, rounded up to the nearest cluster.
404 read_lock_irqsave(&ni->size_lock, flags);
405 ll = ni->allocated_size;
406 read_unlock_irqrestore(&ni->size_lock, flags);
409 * Extend the allocation without changing the data size.
411 * Note we ensure the allocation is big enough to at least
412 * write some data but we do not require the allocation to be
413 * complete, i.e. it may be partial.
415 ll = ntfs_attr_extend_allocation(ni, end, -1, pos);
416 if (likely(ll >= 0)) {
418 /* If the extension was partial truncate the write. */
420 ntfs_debug("Truncating write to inode 0x%lx, "
421 "attribute type 0x%x, because "
422 "the allocation was only "
423 "partially extended.",
424 vi->i_ino, (unsigned)
425 le32_to_cpu(ni->type));
426 iov_iter_truncate(from, ll - pos);
430 read_lock_irqsave(&ni->size_lock, flags);
431 ll = ni->allocated_size;
432 read_unlock_irqrestore(&ni->size_lock, flags);
433 /* Perform a partial write if possible or fail. */
435 ntfs_debug("Truncating write to inode 0x%lx "
436 "attribute type 0x%x, because "
437 "extending the allocation "
438 "failed (error %d).",
439 vi->i_ino, (unsigned)
440 le32_to_cpu(ni->type),
442 iov_iter_truncate(from, ll - pos);
445 ntfs_error(vi->i_sb, "Cannot perform "
448 "type 0x%x, because "
452 vi->i_ino, (unsigned)
453 le32_to_cpu(ni->type),
456 ntfs_debug("Cannot perform write to "
458 "attribute type 0x%x, "
459 "because there is not "
461 vi->i_ino, (unsigned)
462 le32_to_cpu(ni->type));
468 * If the write starts beyond the initialized size, extend it up to the
469 * beginning of the write and initialize all non-sparse space between
470 * the old initialized size and the new one. This automatically also
471 * increments the vfs inode->i_size to keep it above or equal to the
474 read_lock_irqsave(&ni->size_lock, flags);
475 ll = ni->initialized_size;
476 read_unlock_irqrestore(&ni->size_lock, flags);
479 * Wait for ongoing direct i/o to complete before proceeding.
480 * New direct i/o cannot start as we hold i_mutex.
483 err = ntfs_attr_extend_initialized(ni, pos);
484 if (unlikely(err < 0))
485 ntfs_error(vi->i_sb, "Cannot perform write to inode "
486 "0x%lx, attribute type 0x%x, because "
487 "extending the initialized size "
488 "failed (error %d).", vi->i_ino,
489 (unsigned)le32_to_cpu(ni->type),
497 * __ntfs_grab_cache_pages - obtain a number of locked pages
498 * @mapping: address space mapping from which to obtain page cache pages
499 * @index: starting index in @mapping at which to begin obtaining pages
500 * @nr_pages: number of page cache pages to obtain
501 * @pages: array of pages in which to return the obtained page cache pages
502 * @cached_page: allocated but as yet unused page
504 * Obtain @nr_pages locked page cache pages from the mapping @mapping and
505 * starting at index @index.
507 * If a page is newly created, add it to lru list
509 * Note, the page locks are obtained in ascending page index order.
511 static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
512 pgoff_t index, const unsigned nr_pages, struct page **pages,
513 struct page **cached_page)
520 pages[nr] = find_get_page_flags(mapping, index, FGP_LOCK |
524 *cached_page = page_cache_alloc(mapping);
525 if (unlikely(!*cached_page)) {
530 err = add_to_page_cache_lru(*cached_page, mapping,
537 pages[nr] = *cached_page;
542 } while (nr < nr_pages);
547 unlock_page(pages[--nr]);
548 page_cache_release(pages[nr]);
553 static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
557 bh->b_end_io = end_buffer_read_sync;
558 return submit_bh(READ, bh);
562 * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data
563 * @pages: array of destination pages
564 * @nr_pages: number of pages in @pages
565 * @pos: byte position in file at which the write begins
566 * @bytes: number of bytes to be written
568 * This is called for non-resident attributes from ntfs_file_buffered_write()
569 * with i_mutex held on the inode (@pages[0]->mapping->host). There are
570 * @nr_pages pages in @pages which are locked but not kmap()ped. The source
571 * data has not yet been copied into the @pages.
573 * Need to fill any holes with actual clusters, allocate buffers if necessary,
574 * ensure all the buffers are mapped, and bring uptodate any buffers that are
575 * only partially being written to.
577 * If @nr_pages is greater than one, we are guaranteed that the cluster size is
578 * greater than PAGE_CACHE_SIZE, that all pages in @pages are entirely inside
579 * the same cluster and that they are the entirety of that cluster, and that
580 * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
582 * i_size is not to be modified yet.
584 * Return 0 on success or -errno on error.
586 static int ntfs_prepare_pages_for_non_resident_write(struct page **pages,
587 unsigned nr_pages, s64 pos, size_t bytes)
589 VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend;
591 s64 bh_pos, vcn_len, end, initialized_size;
595 ntfs_inode *ni, *base_ni = NULL;
597 runlist_element *rl, *rl2;
598 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
599 ntfs_attr_search_ctx *ctx = NULL;
600 MFT_RECORD *m = NULL;
601 ATTR_RECORD *a = NULL;
603 u32 attr_rec_len = 0;
604 unsigned blocksize, u;
606 bool rl_write_locked, was_hole, is_retry;
607 unsigned char blocksize_bits;
610 u8 mft_attr_mapped:1;
613 } status = { 0, 0, 0, 0 };
618 vi = pages[0]->mapping->host;
621 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
622 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
623 vi->i_ino, ni->type, pages[0]->index, nr_pages,
624 (long long)pos, bytes);
625 blocksize = vol->sb->s_blocksize;
626 blocksize_bits = vol->sb->s_blocksize_bits;
632 * create_empty_buffers() will create uptodate/dirty buffers if
633 * the page is uptodate/dirty.
635 if (!page_has_buffers(page)) {
636 create_empty_buffers(page, blocksize, 0);
637 if (unlikely(!page_has_buffers(page)))
640 } while (++u < nr_pages);
641 rl_write_locked = false;
648 cpos = pos >> vol->cluster_size_bits;
650 cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits;
652 * Loop over each page and for each page over each buffer. Use goto to
653 * reduce indentation.
658 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
659 bh = head = page_buffers(page);
665 /* Clear buffer_new on all buffers to reinitialise state. */
667 clear_buffer_new(bh);
668 bh_end = bh_pos + blocksize;
669 bh_cpos = bh_pos >> vol->cluster_size_bits;
670 bh_cofs = bh_pos & vol->cluster_size_mask;
671 if (buffer_mapped(bh)) {
673 * The buffer is already mapped. If it is uptodate,
676 if (buffer_uptodate(bh))
679 * The buffer is not uptodate. If the page is uptodate
680 * set the buffer uptodate and otherwise ignore it.
682 if (PageUptodate(page)) {
683 set_buffer_uptodate(bh);
687 * Neither the page nor the buffer are uptodate. If
688 * the buffer is only partially being written to, we
689 * need to read it in before the write, i.e. now.
691 if ((bh_pos < pos && bh_end > pos) ||
692 (bh_pos < end && bh_end > end)) {
694 * If the buffer is fully or partially within
695 * the initialized size, do an actual read.
696 * Otherwise, simply zero the buffer.
698 read_lock_irqsave(&ni->size_lock, flags);
699 initialized_size = ni->initialized_size;
700 read_unlock_irqrestore(&ni->size_lock, flags);
701 if (bh_pos < initialized_size) {
702 ntfs_submit_bh_for_read(bh);
705 zero_user(page, bh_offset(bh),
707 set_buffer_uptodate(bh);
712 /* Unmapped buffer. Need to map it. */
713 bh->b_bdev = vol->sb->s_bdev;
715 * If the current buffer is in the same clusters as the map
716 * cache, there is no need to check the runlist again. The
717 * map cache is made up of @vcn, which is the first cached file
718 * cluster, @vcn_len which is the number of cached file
719 * clusters, @lcn is the device cluster corresponding to @vcn,
720 * and @lcn_block is the block number corresponding to @lcn.
722 cdelta = bh_cpos - vcn;
723 if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) {
726 bh->b_blocknr = lcn_block +
727 (cdelta << (vol->cluster_size_bits -
729 (bh_cofs >> blocksize_bits);
730 set_buffer_mapped(bh);
732 * If the page is uptodate so is the buffer. If the
733 * buffer is fully outside the write, we ignore it if
734 * it was already allocated and we mark it dirty so it
735 * gets written out if we allocated it. On the other
736 * hand, if we allocated the buffer but we are not
737 * marking it dirty we set buffer_new so we can do
740 if (PageUptodate(page)) {
741 if (!buffer_uptodate(bh))
742 set_buffer_uptodate(bh);
743 if (unlikely(was_hole)) {
744 /* We allocated the buffer. */
745 unmap_underlying_metadata(bh->b_bdev,
747 if (bh_end <= pos || bh_pos >= end)
748 mark_buffer_dirty(bh);
754 /* Page is _not_ uptodate. */
755 if (likely(!was_hole)) {
757 * Buffer was already allocated. If it is not
758 * uptodate and is only partially being written
759 * to, we need to read it in before the write,
762 if (!buffer_uptodate(bh) && bh_pos < end &&
767 * If the buffer is fully or partially
768 * within the initialized size, do an
769 * actual read. Otherwise, simply zero
772 read_lock_irqsave(&ni->size_lock,
774 initialized_size = ni->initialized_size;
775 read_unlock_irqrestore(&ni->size_lock,
777 if (bh_pos < initialized_size) {
778 ntfs_submit_bh_for_read(bh);
781 zero_user(page, bh_offset(bh),
783 set_buffer_uptodate(bh);
788 /* We allocated the buffer. */
789 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
791 * If the buffer is fully outside the write, zero it,
792 * set it uptodate, and mark it dirty so it gets
793 * written out. If it is partially being written to,
794 * zero region surrounding the write but leave it to
795 * commit write to do anything else. Finally, if the
796 * buffer is fully being overwritten, do nothing.
798 if (bh_end <= pos || bh_pos >= end) {
799 if (!buffer_uptodate(bh)) {
800 zero_user(page, bh_offset(bh),
802 set_buffer_uptodate(bh);
804 mark_buffer_dirty(bh);
808 if (!buffer_uptodate(bh) &&
809 (bh_pos < pos || bh_end > end)) {
813 kaddr = kmap_atomic(page);
815 pofs = bh_pos & ~PAGE_CACHE_MASK;
816 memset(kaddr + pofs, 0, pos - bh_pos);
819 pofs = end & ~PAGE_CACHE_MASK;
820 memset(kaddr + pofs, 0, bh_end - end);
822 kunmap_atomic(kaddr);
823 flush_dcache_page(page);
828 * Slow path: this is the first buffer in the cluster. If it
829 * is outside allocated size and is not uptodate, zero it and
832 read_lock_irqsave(&ni->size_lock, flags);
833 initialized_size = ni->allocated_size;
834 read_unlock_irqrestore(&ni->size_lock, flags);
835 if (bh_pos > initialized_size) {
836 if (PageUptodate(page)) {
837 if (!buffer_uptodate(bh))
838 set_buffer_uptodate(bh);
839 } else if (!buffer_uptodate(bh)) {
840 zero_user(page, bh_offset(bh), blocksize);
841 set_buffer_uptodate(bh);
847 down_read(&ni->runlist.lock);
851 if (likely(rl != NULL)) {
852 /* Seek to element containing target cluster. */
853 while (rl->length && rl[1].vcn <= bh_cpos)
855 lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos);
856 if (likely(lcn >= 0)) {
858 * Successful remap, setup the map cache and
859 * use that to deal with the buffer.
863 vcn_len = rl[1].vcn - vcn;
864 lcn_block = lcn << (vol->cluster_size_bits -
868 * If the number of remaining clusters touched
869 * by the write is smaller or equal to the
870 * number of cached clusters, unlock the
871 * runlist as the map cache will be used from
874 if (likely(vcn + vcn_len >= cend)) {
875 if (rl_write_locked) {
876 up_write(&ni->runlist.lock);
877 rl_write_locked = false;
879 up_read(&ni->runlist.lock);
882 goto map_buffer_cached;
885 lcn = LCN_RL_NOT_MAPPED;
887 * If it is not a hole and not out of bounds, the runlist is
888 * probably unmapped so try to map it now.
890 if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) {
891 if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) {
892 /* Attempt to map runlist. */
893 if (!rl_write_locked) {
895 * We need the runlist locked for
896 * writing, so if it is locked for
897 * reading relock it now and retry in
898 * case it changed whilst we dropped
901 up_read(&ni->runlist.lock);
902 down_write(&ni->runlist.lock);
903 rl_write_locked = true;
906 err = ntfs_map_runlist_nolock(ni, bh_cpos,
913 * If @vcn is out of bounds, pretend @lcn is
914 * LCN_ENOENT. As long as the buffer is out
915 * of bounds this will work fine.
917 if (err == -ENOENT) {
920 goto rl_not_mapped_enoent;
924 /* Failed to map the buffer, even after retrying. */
926 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
927 "attribute type 0x%x, vcn 0x%llx, "
928 "vcn offset 0x%x, because its "
929 "location on disk could not be "
930 "determined%s (error code %i).",
931 ni->mft_no, ni->type,
932 (unsigned long long)bh_cpos,
934 vol->cluster_size_mask,
935 is_retry ? " even after retrying" : "",
939 rl_not_mapped_enoent:
941 * The buffer is in a hole or out of bounds. We need to fill
942 * the hole, unless the buffer is in a cluster which is not
943 * touched by the write, in which case we just leave the buffer
944 * unmapped. This can only happen when the cluster size is
945 * less than the page cache size.
947 if (unlikely(vol->cluster_size < PAGE_CACHE_SIZE)) {
948 bh_cend = (bh_end + vol->cluster_size - 1) >>
949 vol->cluster_size_bits;
950 if ((bh_cend <= cpos || bh_cpos >= cend)) {
953 * If the buffer is uptodate we skip it. If it
954 * is not but the page is uptodate, we can set
955 * the buffer uptodate. If the page is not
956 * uptodate, we can clear the buffer and set it
957 * uptodate. Whether this is worthwhile is
958 * debatable and this could be removed.
960 if (PageUptodate(page)) {
961 if (!buffer_uptodate(bh))
962 set_buffer_uptodate(bh);
963 } else if (!buffer_uptodate(bh)) {
964 zero_user(page, bh_offset(bh),
966 set_buffer_uptodate(bh);
972 * Out of bounds buffer is invalid if it was not really out of
975 BUG_ON(lcn != LCN_HOLE);
977 * We need the runlist locked for writing, so if it is locked
978 * for reading relock it now and retry in case it changed
979 * whilst we dropped the lock.
982 if (!rl_write_locked) {
983 up_read(&ni->runlist.lock);
984 down_write(&ni->runlist.lock);
985 rl_write_locked = true;
988 /* Find the previous last allocated cluster. */
989 BUG_ON(rl->lcn != LCN_HOLE);
992 while (--rl2 >= ni->runlist.rl) {
994 lcn = rl2->lcn + rl2->length;
998 rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE,
1002 ntfs_debug("Failed to allocate cluster, error code %i.",
1007 rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
1012 if (ntfs_cluster_free_from_rl(vol, rl2)) {
1013 ntfs_error(vol->sb, "Failed to release "
1014 "allocated cluster in error "
1015 "code path. Run chkdsk to "
1016 "recover the lost cluster.");
1022 ni->runlist.rl = rl;
1023 status.runlist_merged = 1;
1024 ntfs_debug("Allocated cluster, lcn 0x%llx.",
1025 (unsigned long long)lcn);
1026 /* Map and lock the mft record and get the attribute record. */
1030 base_ni = ni->ext.base_ntfs_ino;
1031 m = map_mft_record(base_ni);
1036 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1037 if (unlikely(!ctx)) {
1039 unmap_mft_record(base_ni);
1042 status.mft_attr_mapped = 1;
1043 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1044 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx);
1045 if (unlikely(err)) {
1053 * Find the runlist element with which the attribute extent
1054 * starts. Note, we cannot use the _attr_ version because we
1055 * have mapped the mft record. That is ok because we know the
1056 * runlist fragment must be mapped already to have ever gotten
1057 * here, so we can just use the _rl_ version.
1059 vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn);
1060 rl2 = ntfs_rl_find_vcn_nolock(rl, vcn);
1062 BUG_ON(!rl2->length);
1063 BUG_ON(rl2->lcn < LCN_HOLE);
1064 highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
1066 * If @highest_vcn is zero, calculate the real highest_vcn
1067 * (which can really be zero).
1070 highest_vcn = (sle64_to_cpu(
1071 a->data.non_resident.allocated_size) >>
1072 vol->cluster_size_bits) - 1;
1074 * Determine the size of the mapping pairs array for the new
1075 * extent, i.e. the old extent with the hole filled.
1077 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn,
1079 if (unlikely(mp_size <= 0)) {
1080 if (!(err = mp_size))
1082 ntfs_debug("Failed to get size for mapping pairs "
1083 "array, error code %i.", err);
1087 * Resize the attribute record to fit the new mapping pairs
1090 attr_rec_len = le32_to_cpu(a->length);
1091 err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu(
1092 a->data.non_resident.mapping_pairs_offset));
1093 if (unlikely(err)) {
1094 BUG_ON(err != -ENOSPC);
1095 // TODO: Deal with this by using the current attribute
1096 // and fill it with as much of the mapping pairs
1097 // array as possible. Then loop over each attribute
1098 // extent rewriting the mapping pairs arrays as we go
1099 // along and if when we reach the end we have not
1100 // enough space, try to resize the last attribute
1101 // extent and if even that fails, add a new attribute
1103 // We could also try to resize at each step in the hope
1104 // that we will not need to rewrite every single extent.
1105 // Note, we may need to decompress some extents to fill
1106 // the runlist as we are walking the extents...
1107 ntfs_error(vol->sb, "Not enough space in the mft "
1108 "record for the extended attribute "
1109 "record. This case is not "
1110 "implemented yet.");
1114 status.mp_rebuilt = 1;
1116 * Generate the mapping pairs array directly into the attribute
1119 err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1120 a->data.non_resident.mapping_pairs_offset),
1121 mp_size, rl2, vcn, highest_vcn, NULL);
1122 if (unlikely(err)) {
1123 ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, "
1124 "attribute type 0x%x, because building "
1125 "the mapping pairs failed with error "
1126 "code %i.", vi->i_ino,
1127 (unsigned)le32_to_cpu(ni->type), err);
1131 /* Update the highest_vcn but only if it was not set. */
1132 if (unlikely(!a->data.non_resident.highest_vcn))
1133 a->data.non_resident.highest_vcn =
1134 cpu_to_sle64(highest_vcn);
1136 * If the attribute is sparse/compressed, update the compressed
1137 * size in the ntfs_inode structure and the attribute record.
1139 if (likely(NInoSparse(ni) || NInoCompressed(ni))) {
1141 * If we are not in the first attribute extent, switch
1142 * to it, but first ensure the changes will make it to
1145 if (a->data.non_resident.lowest_vcn) {
1146 flush_dcache_mft_record_page(ctx->ntfs_ino);
1147 mark_mft_record_dirty(ctx->ntfs_ino);
1148 ntfs_attr_reinit_search_ctx(ctx);
1149 err = ntfs_attr_lookup(ni->type, ni->name,
1150 ni->name_len, CASE_SENSITIVE,
1152 if (unlikely(err)) {
1153 status.attr_switched = 1;
1156 /* @m is not used any more so do not set it. */
1159 write_lock_irqsave(&ni->size_lock, flags);
1160 ni->itype.compressed.size += vol->cluster_size;
1161 a->data.non_resident.compressed_size =
1162 cpu_to_sle64(ni->itype.compressed.size);
1163 write_unlock_irqrestore(&ni->size_lock, flags);
1165 /* Ensure the changes make it to disk. */
1166 flush_dcache_mft_record_page(ctx->ntfs_ino);
1167 mark_mft_record_dirty(ctx->ntfs_ino);
1168 ntfs_attr_put_search_ctx(ctx);
1169 unmap_mft_record(base_ni);
1170 /* Successfully filled the hole. */
1171 status.runlist_merged = 0;
1172 status.mft_attr_mapped = 0;
1173 status.mp_rebuilt = 0;
1174 /* Setup the map cache and use that to deal with the buffer. */
1178 lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits);
1181 * If the number of remaining clusters in the @pages is smaller
1182 * or equal to the number of cached clusters, unlock the
1183 * runlist as the map cache will be used from now on.
1185 if (likely(vcn + vcn_len >= cend)) {
1186 up_write(&ni->runlist.lock);
1187 rl_write_locked = false;
1190 goto map_buffer_cached;
1191 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1192 /* If there are no errors, do the next page. */
1193 if (likely(!err && ++u < nr_pages))
1195 /* If there are no errors, release the runlist lock if we took it. */
1197 if (unlikely(rl_write_locked)) {
1198 up_write(&ni->runlist.lock);
1199 rl_write_locked = false;
1200 } else if (unlikely(rl))
1201 up_read(&ni->runlist.lock);
1204 /* If we issued read requests, let them complete. */
1205 read_lock_irqsave(&ni->size_lock, flags);
1206 initialized_size = ni->initialized_size;
1207 read_unlock_irqrestore(&ni->size_lock, flags);
1208 while (wait_bh > wait) {
1211 if (likely(buffer_uptodate(bh))) {
1213 bh_pos = ((s64)page->index << PAGE_CACHE_SHIFT) +
1216 * If the buffer overflows the initialized size, need
1217 * to zero the overflowing region.
1219 if (unlikely(bh_pos + blocksize > initialized_size)) {
1222 if (likely(bh_pos < initialized_size))
1223 ofs = initialized_size - bh_pos;
1224 zero_user_segment(page, bh_offset(bh) + ofs,
1227 } else /* if (unlikely(!buffer_uptodate(bh))) */
1231 /* Clear buffer_new on all buffers. */
1234 bh = head = page_buffers(pages[u]);
1237 clear_buffer_new(bh);
1238 } while ((bh = bh->b_this_page) != head);
1239 } while (++u < nr_pages);
1240 ntfs_debug("Done.");
1243 if (status.attr_switched) {
1244 /* Get back to the attribute extent we modified. */
1245 ntfs_attr_reinit_search_ctx(ctx);
1246 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1247 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) {
1248 ntfs_error(vol->sb, "Failed to find required "
1249 "attribute extent of attribute in "
1250 "error code path. Run chkdsk to "
1252 write_lock_irqsave(&ni->size_lock, flags);
1253 ni->itype.compressed.size += vol->cluster_size;
1254 write_unlock_irqrestore(&ni->size_lock, flags);
1255 flush_dcache_mft_record_page(ctx->ntfs_ino);
1256 mark_mft_record_dirty(ctx->ntfs_ino);
1258 * The only thing that is now wrong is the compressed
1259 * size of the base attribute extent which chkdsk
1260 * should be able to fix.
1266 status.attr_switched = 0;
1270 * If the runlist has been modified, need to restore it by punching a
1271 * hole into it and we then need to deallocate the on-disk cluster as
1272 * well. Note, we only modify the runlist if we are able to generate a
1273 * new mapping pairs array, i.e. only when the mapped attribute extent
1276 if (status.runlist_merged && !status.attr_switched) {
1277 BUG_ON(!rl_write_locked);
1278 /* Make the file cluster we allocated sparse in the runlist. */
1279 if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) {
1280 ntfs_error(vol->sb, "Failed to punch hole into "
1281 "attribute runlist in error code "
1282 "path. Run chkdsk to recover the "
1285 } else /* if (success) */ {
1286 status.runlist_merged = 0;
1288 * Deallocate the on-disk cluster we allocated but only
1289 * if we succeeded in punching its vcn out of the
1292 down_write(&vol->lcnbmp_lock);
1293 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
1294 ntfs_error(vol->sb, "Failed to release "
1295 "allocated cluster in error "
1296 "code path. Run chkdsk to "
1297 "recover the lost cluster.");
1300 up_write(&vol->lcnbmp_lock);
1304 * Resize the attribute record to its old size and rebuild the mapping
1305 * pairs array. Note, we only can do this if the runlist has been
1306 * restored to its old state which also implies that the mapped
1307 * attribute extent is not switched.
1309 if (status.mp_rebuilt && !status.runlist_merged) {
1310 if (ntfs_attr_record_resize(m, a, attr_rec_len)) {
1311 ntfs_error(vol->sb, "Failed to restore attribute "
1312 "record in error code path. Run "
1313 "chkdsk to recover.");
1315 } else /* if (success) */ {
1316 if (ntfs_mapping_pairs_build(vol, (u8*)a +
1317 le16_to_cpu(a->data.non_resident.
1318 mapping_pairs_offset), attr_rec_len -
1319 le16_to_cpu(a->data.non_resident.
1320 mapping_pairs_offset), ni->runlist.rl,
1321 vcn, highest_vcn, NULL)) {
1322 ntfs_error(vol->sb, "Failed to restore "
1323 "mapping pairs array in error "
1324 "code path. Run chkdsk to "
1328 flush_dcache_mft_record_page(ctx->ntfs_ino);
1329 mark_mft_record_dirty(ctx->ntfs_ino);
1332 /* Release the mft record and the attribute. */
1333 if (status.mft_attr_mapped) {
1334 ntfs_attr_put_search_ctx(ctx);
1335 unmap_mft_record(base_ni);
1337 /* Release the runlist lock. */
1338 if (rl_write_locked)
1339 up_write(&ni->runlist.lock);
1341 up_read(&ni->runlist.lock);
1343 * Zero out any newly allocated blocks to avoid exposing stale data.
1344 * If BH_New is set, we know that the block was newly allocated above
1345 * and that it has not been fully zeroed and marked dirty yet.
1349 end = bh_cpos << vol->cluster_size_bits;
1352 bh = head = page_buffers(page);
1354 if (u == nr_pages &&
1355 ((s64)page->index << PAGE_CACHE_SHIFT) +
1356 bh_offset(bh) >= end)
1358 if (!buffer_new(bh))
1360 clear_buffer_new(bh);
1361 if (!buffer_uptodate(bh)) {
1362 if (PageUptodate(page))
1363 set_buffer_uptodate(bh);
1365 zero_user(page, bh_offset(bh),
1367 set_buffer_uptodate(bh);
1370 mark_buffer_dirty(bh);
1371 } while ((bh = bh->b_this_page) != head);
1372 } while (++u <= nr_pages);
1373 ntfs_error(vol->sb, "Failed. Returning error code %i.", err);
1377 static inline void ntfs_flush_dcache_pages(struct page **pages,
1382 * Warning: Do not do the decrement at the same time as the call to
1383 * flush_dcache_page() because it is a NULL macro on i386 and hence the
1384 * decrement never happens so the loop never terminates.
1388 flush_dcache_page(pages[nr_pages]);
1389 } while (nr_pages > 0);
1393 * ntfs_commit_pages_after_non_resident_write - commit the received data
1394 * @pages: array of destination pages
1395 * @nr_pages: number of pages in @pages
1396 * @pos: byte position in file at which the write begins
1397 * @bytes: number of bytes to be written
1399 * See description of ntfs_commit_pages_after_write(), below.
1401 static inline int ntfs_commit_pages_after_non_resident_write(
1402 struct page **pages, const unsigned nr_pages,
1403 s64 pos, size_t bytes)
1405 s64 end, initialized_size;
1407 ntfs_inode *ni, *base_ni;
1408 struct buffer_head *bh, *head;
1409 ntfs_attr_search_ctx *ctx;
1412 unsigned long flags;
1413 unsigned blocksize, u;
1416 vi = pages[0]->mapping->host;
1418 blocksize = vi->i_sb->s_blocksize;
1427 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
1428 bh = head = page_buffers(page);
1433 bh_end = bh_pos + blocksize;
1434 if (bh_end <= pos || bh_pos >= end) {
1435 if (!buffer_uptodate(bh))
1438 set_buffer_uptodate(bh);
1439 mark_buffer_dirty(bh);
1441 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1443 * If all buffers are now uptodate but the page is not, set the
1446 if (!partial && !PageUptodate(page))
1447 SetPageUptodate(page);
1448 } while (++u < nr_pages);
1450 * Finally, if we do not need to update initialized_size or i_size we
1453 read_lock_irqsave(&ni->size_lock, flags);
1454 initialized_size = ni->initialized_size;
1455 read_unlock_irqrestore(&ni->size_lock, flags);
1456 if (end <= initialized_size) {
1457 ntfs_debug("Done.");
1461 * Update initialized_size/i_size as appropriate, both in the inode and
1467 base_ni = ni->ext.base_ntfs_ino;
1468 /* Map, pin, and lock the mft record. */
1469 m = map_mft_record(base_ni);
1476 BUG_ON(!NInoNonResident(ni));
1477 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1478 if (unlikely(!ctx)) {
1482 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1483 CASE_SENSITIVE, 0, NULL, 0, ctx);
1484 if (unlikely(err)) {
1490 BUG_ON(!a->non_resident);
1491 write_lock_irqsave(&ni->size_lock, flags);
1492 BUG_ON(end > ni->allocated_size);
1493 ni->initialized_size = end;
1494 a->data.non_resident.initialized_size = cpu_to_sle64(end);
1495 if (end > i_size_read(vi)) {
1496 i_size_write(vi, end);
1497 a->data.non_resident.data_size =
1498 a->data.non_resident.initialized_size;
1500 write_unlock_irqrestore(&ni->size_lock, flags);
1501 /* Mark the mft record dirty, so it gets written back. */
1502 flush_dcache_mft_record_page(ctx->ntfs_ino);
1503 mark_mft_record_dirty(ctx->ntfs_ino);
1504 ntfs_attr_put_search_ctx(ctx);
1505 unmap_mft_record(base_ni);
1506 ntfs_debug("Done.");
1510 ntfs_attr_put_search_ctx(ctx);
1512 unmap_mft_record(base_ni);
1513 ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error "
1516 NVolSetErrors(ni->vol);
1521 * ntfs_commit_pages_after_write - commit the received data
1522 * @pages: array of destination pages
1523 * @nr_pages: number of pages in @pages
1524 * @pos: byte position in file at which the write begins
1525 * @bytes: number of bytes to be written
1527 * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
1528 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
1529 * locked but not kmap()ped. The source data has already been copied into the
1530 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before
1531 * the data was copied (for non-resident attributes only) and it returned
1534 * Need to set uptodate and mark dirty all buffers within the boundary of the
1535 * write. If all buffers in a page are uptodate we set the page uptodate, too.
1537 * Setting the buffers dirty ensures that they get written out later when
1538 * ntfs_writepage() is invoked by the VM.
1540 * Finally, we need to update i_size and initialized_size as appropriate both
1541 * in the inode and the mft record.
1543 * This is modelled after fs/buffer.c::generic_commit_write(), which marks
1544 * buffers uptodate and dirty, sets the page uptodate if all buffers in the
1545 * page are uptodate, and updates i_size if the end of io is beyond i_size. In
1546 * that case, it also marks the inode dirty.
1548 * If things have gone as outlined in
1549 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
1550 * content modifications here for non-resident attributes. For resident
1551 * attributes we need to do the uptodate bringing here which we combine with
1552 * the copying into the mft record which means we save one atomic kmap.
1554 * Return 0 on success or -errno on error.
1556 static int ntfs_commit_pages_after_write(struct page **pages,
1557 const unsigned nr_pages, s64 pos, size_t bytes)
1559 s64 end, initialized_size;
1562 ntfs_inode *ni, *base_ni;
1564 ntfs_attr_search_ctx *ctx;
1567 char *kattr, *kaddr;
1568 unsigned long flags;
1576 vi = page->mapping->host;
1578 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
1579 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
1580 vi->i_ino, ni->type, page->index, nr_pages,
1581 (long long)pos, bytes);
1582 if (NInoNonResident(ni))
1583 return ntfs_commit_pages_after_non_resident_write(pages,
1584 nr_pages, pos, bytes);
1585 BUG_ON(nr_pages > 1);
1587 * Attribute is resident, implying it is not compressed, encrypted, or
1593 base_ni = ni->ext.base_ntfs_ino;
1594 BUG_ON(NInoNonResident(ni));
1595 /* Map, pin, and lock the mft record. */
1596 m = map_mft_record(base_ni);
1603 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1604 if (unlikely(!ctx)) {
1608 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1609 CASE_SENSITIVE, 0, NULL, 0, ctx);
1610 if (unlikely(err)) {
1616 BUG_ON(a->non_resident);
1617 /* The total length of the attribute value. */
1618 attr_len = le32_to_cpu(a->data.resident.value_length);
1619 i_size = i_size_read(vi);
1620 BUG_ON(attr_len != i_size);
1621 BUG_ON(pos > attr_len);
1623 BUG_ON(end > le32_to_cpu(a->length) -
1624 le16_to_cpu(a->data.resident.value_offset));
1625 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
1626 kaddr = kmap_atomic(page);
1627 /* Copy the received data from the page to the mft record. */
1628 memcpy(kattr + pos, kaddr + pos, bytes);
1629 /* Update the attribute length if necessary. */
1630 if (end > attr_len) {
1632 a->data.resident.value_length = cpu_to_le32(attr_len);
1635 * If the page is not uptodate, bring the out of bounds area(s)
1636 * uptodate by copying data from the mft record to the page.
1638 if (!PageUptodate(page)) {
1640 memcpy(kaddr, kattr, pos);
1642 memcpy(kaddr + end, kattr + end, attr_len - end);
1643 /* Zero the region outside the end of the attribute value. */
1644 memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
1645 flush_dcache_page(page);
1646 SetPageUptodate(page);
1648 kunmap_atomic(kaddr);
1649 /* Update initialized_size/i_size if necessary. */
1650 read_lock_irqsave(&ni->size_lock, flags);
1651 initialized_size = ni->initialized_size;
1652 BUG_ON(end > ni->allocated_size);
1653 read_unlock_irqrestore(&ni->size_lock, flags);
1654 BUG_ON(initialized_size != i_size);
1655 if (end > initialized_size) {
1656 write_lock_irqsave(&ni->size_lock, flags);
1657 ni->initialized_size = end;
1658 i_size_write(vi, end);
1659 write_unlock_irqrestore(&ni->size_lock, flags);
1661 /* Mark the mft record dirty, so it gets written back. */
1662 flush_dcache_mft_record_page(ctx->ntfs_ino);
1663 mark_mft_record_dirty(ctx->ntfs_ino);
1664 ntfs_attr_put_search_ctx(ctx);
1665 unmap_mft_record(base_ni);
1666 ntfs_debug("Done.");
1669 if (err == -ENOMEM) {
1670 ntfs_warning(vi->i_sb, "Error allocating memory required to "
1671 "commit the write.");
1672 if (PageUptodate(page)) {
1673 ntfs_warning(vi->i_sb, "Page is uptodate, setting "
1674 "dirty so the write will be retried "
1675 "later on by the VM.");
1677 * Put the page on mapping->dirty_pages, but leave its
1678 * buffers' dirty state as-is.
1680 __set_page_dirty_nobuffers(page);
1683 ntfs_error(vi->i_sb, "Page is not uptodate. Written "
1684 "data has been lost.");
1686 ntfs_error(vi->i_sb, "Resident attribute commit write failed "
1687 "with error %i.", err);
1688 NVolSetErrors(ni->vol);
1691 ntfs_attr_put_search_ctx(ctx);
1693 unmap_mft_record(base_ni);
1698 * Copy as much as we can into the pages and return the number of bytes which
1699 * were successfully copied. If a fault is encountered then clear the pages
1700 * out to (ofs + bytes) and return the number of bytes which were copied.
1702 static size_t ntfs_copy_from_user_iter(struct page **pages, unsigned nr_pages,
1703 unsigned ofs, struct iov_iter *i, size_t bytes)
1705 struct page **last_page = pages + nr_pages;
1707 struct iov_iter data = *i;
1708 unsigned len, copied;
1711 len = PAGE_CACHE_SIZE - ofs;
1714 copied = iov_iter_copy_from_user_atomic(*pages, &data, ofs,
1720 iov_iter_advance(&data, copied);
1724 } while (++pages < last_page);
1728 /* Zero the rest of the target like __copy_from_user(). */
1729 len = PAGE_CACHE_SIZE - copied;
1733 zero_user(*pages, copied, len);
1736 len = PAGE_CACHE_SIZE;
1737 } while (++pages < last_page);
1742 * ntfs_perform_write - perform buffered write to a file
1743 * @file: file to write to
1744 * @i: iov_iter with data to write
1745 * @pos: byte offset in file at which to begin writing to
1747 static ssize_t ntfs_perform_write(struct file *file, struct iov_iter *i,
1750 struct address_space *mapping = file->f_mapping;
1751 struct inode *vi = mapping->host;
1752 ntfs_inode *ni = NTFS_I(vi);
1753 ntfs_volume *vol = ni->vol;
1754 struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER];
1755 struct page *cached_page = NULL;
1759 ssize_t status, written = 0;
1762 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
1763 "0x%llx, count 0x%lx.", vi->i_ino,
1764 (unsigned)le32_to_cpu(ni->type),
1765 (unsigned long long)pos,
1766 (unsigned long)iov_iter_count(i));
1768 * If a previous ntfs_truncate() failed, repeat it and abort if it
1771 if (unlikely(NInoTruncateFailed(ni))) {
1775 err = ntfs_truncate(vi);
1776 if (err || NInoTruncateFailed(ni)) {
1779 ntfs_error(vol->sb, "Cannot perform write to inode "
1780 "0x%lx, attribute type 0x%x, because "
1781 "ntfs_truncate() failed (error code "
1783 (unsigned)le32_to_cpu(ni->type), err);
1788 * Determine the number of pages per cluster for non-resident
1792 if (vol->cluster_size > PAGE_CACHE_SIZE && NInoNonResident(ni))
1793 nr_pages = vol->cluster_size >> PAGE_CACHE_SHIFT;
1797 pgoff_t idx, start_idx;
1798 unsigned ofs, do_pages, u;
1801 start_idx = idx = pos >> PAGE_CACHE_SHIFT;
1802 ofs = pos & ~PAGE_CACHE_MASK;
1803 bytes = PAGE_CACHE_SIZE - ofs;
1806 vcn = pos >> vol->cluster_size_bits;
1807 if (vcn != last_vcn) {
1810 * Get the lcn of the vcn the write is in. If
1811 * it is a hole, need to lock down all pages in
1814 down_read(&ni->runlist.lock);
1815 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >>
1816 vol->cluster_size_bits, false);
1817 up_read(&ni->runlist.lock);
1818 if (unlikely(lcn < LCN_HOLE)) {
1819 if (lcn == LCN_ENOMEM)
1823 ntfs_error(vol->sb, "Cannot "
1826 "attribute type 0x%x, "
1827 "because the attribute "
1829 vi->i_ino, (unsigned)
1830 le32_to_cpu(ni->type));
1834 if (lcn == LCN_HOLE) {
1835 start_idx = (pos & ~(s64)
1836 vol->cluster_size_mask)
1837 >> PAGE_CACHE_SHIFT;
1838 bytes = vol->cluster_size - (pos &
1839 vol->cluster_size_mask);
1840 do_pages = nr_pages;
1844 if (bytes > iov_iter_count(i))
1845 bytes = iov_iter_count(i);
1848 * Bring in the user page(s) that we will copy from _first_.
1849 * Otherwise there is a nasty deadlock on copying from the same
1850 * page(s) as we are writing to, without it/them being marked
1851 * up-to-date. Note, at present there is nothing to stop the
1852 * pages being swapped out between us bringing them into memory
1853 * and doing the actual copying.
1855 if (unlikely(iov_iter_fault_in_multipages_readable(i, bytes))) {
1859 /* Get and lock @do_pages starting at index @start_idx. */
1860 status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages,
1861 pages, &cached_page);
1862 if (unlikely(status))
1865 * For non-resident attributes, we need to fill any holes with
1866 * actual clusters and ensure all bufferes are mapped. We also
1867 * need to bring uptodate any buffers that are only partially
1870 if (NInoNonResident(ni)) {
1871 status = ntfs_prepare_pages_for_non_resident_write(
1872 pages, do_pages, pos, bytes);
1873 if (unlikely(status)) {
1875 unlock_page(pages[--do_pages]);
1876 page_cache_release(pages[do_pages]);
1881 u = (pos >> PAGE_CACHE_SHIFT) - pages[0]->index;
1882 copied = ntfs_copy_from_user_iter(pages + u, do_pages - u, ofs,
1884 ntfs_flush_dcache_pages(pages + u, do_pages - u);
1886 if (likely(copied == bytes)) {
1887 status = ntfs_commit_pages_after_write(pages, do_pages,
1893 unlock_page(pages[--do_pages]);
1894 page_cache_release(pages[do_pages]);
1896 if (unlikely(status < 0))
1900 if (unlikely(!copied)) {
1904 * We failed to copy anything. Fall back to single
1905 * segment length write.
1907 * This is needed to avoid possible livelock in the
1908 * case that all segments in the iov cannot be copied
1909 * at once without a pagefault.
1911 sc = iov_iter_single_seg_count(i);
1916 iov_iter_advance(i, copied);
1919 balance_dirty_pages_ratelimited(mapping);
1920 if (fatal_signal_pending(current)) {
1924 } while (iov_iter_count(i));
1926 page_cache_release(cached_page);
1927 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).",
1928 written ? "written" : "status", (unsigned long)written,
1930 return written ? written : status;
1934 * ntfs_file_write_iter - simple wrapper for ntfs_file_write_iter_nolock()
1935 * @iocb: IO state structure
1936 * @from: iov_iter with data to write
1938 * Basically the same as generic_file_write_iter() except that it ends up
1939 * up calling ntfs_perform_write() instead of generic_perform_write() and that
1940 * O_DIRECT is not implemented.
1942 static ssize_t ntfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1944 struct file *file = iocb->ki_filp;
1945 struct inode *vi = file_inode(file);
1946 ssize_t written = 0;
1949 mutex_lock(&vi->i_mutex);
1950 /* We can write back this queue in page reclaim. */
1951 current->backing_dev_info = inode_to_bdi(vi);
1952 err = ntfs_prepare_file_for_write(iocb, from);
1953 if (iov_iter_count(from) && !err)
1954 written = ntfs_perform_write(file, from, iocb->ki_pos);
1955 current->backing_dev_info = NULL;
1956 mutex_unlock(&vi->i_mutex);
1957 if (likely(written > 0)) {
1958 err = generic_write_sync(file, iocb->ki_pos, written);
1962 iocb->ki_pos += written;
1963 return written ? written : err;
1967 * ntfs_file_fsync - sync a file to disk
1968 * @filp: file to be synced
1969 * @datasync: if non-zero only flush user data and not metadata
1971 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
1972 * system calls. This function is inspired by fs/buffer.c::file_fsync().
1974 * If @datasync is false, write the mft record and all associated extent mft
1975 * records as well as the $DATA attribute and then sync the block device.
1977 * If @datasync is true and the attribute is non-resident, we skip the writing
1978 * of the mft record and all associated extent mft records (this might still
1979 * happen due to the write_inode_now() call).
1981 * Also, if @datasync is true, we do not wait on the inode to be written out
1982 * but we always wait on the page cache pages to be written out.
1984 * Locking: Caller must hold i_mutex on the inode.
1986 * TODO: We should probably also write all attribute/index inodes associated
1987 * with this inode but since we have no simple way of getting to them we ignore
1988 * this problem for now.
1990 static int ntfs_file_fsync(struct file *filp, loff_t start, loff_t end,
1993 struct inode *vi = filp->f_mapping->host;
1996 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
1998 err = filemap_write_and_wait_range(vi->i_mapping, start, end);
2001 mutex_lock(&vi->i_mutex);
2003 BUG_ON(S_ISDIR(vi->i_mode));
2004 if (!datasync || !NInoNonResident(NTFS_I(vi)))
2005 ret = __ntfs_write_inode(vi, 1);
2006 write_inode_now(vi, !datasync);
2008 * NOTE: If we were to use mapping->private_list (see ext2 and
2009 * fs/buffer.c) for dirty blocks then we could optimize the below to be
2010 * sync_mapping_buffers(vi->i_mapping).
2012 err = sync_blockdev(vi->i_sb->s_bdev);
2013 if (unlikely(err && !ret))
2016 ntfs_debug("Done.");
2018 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
2019 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
2020 mutex_unlock(&vi->i_mutex);
2024 #endif /* NTFS_RW */
2026 const struct file_operations ntfs_file_ops = {
2027 .llseek = generic_file_llseek,
2028 .read_iter = generic_file_read_iter,
2030 .write_iter = ntfs_file_write_iter,
2031 .fsync = ntfs_file_fsync,
2032 #endif /* NTFS_RW */
2033 .mmap = generic_file_mmap,
2034 .open = ntfs_file_open,
2035 .splice_read = generic_file_splice_read,
2038 const struct inode_operations ntfs_file_inode_ops = {
2040 .setattr = ntfs_setattr,
2041 #endif /* NTFS_RW */
2044 const struct file_operations ntfs_empty_file_ops = {};
2046 const struct inode_operations ntfs_empty_inode_ops = {};