2 * file.c - NTFS kernel file operations. Part of the Linux-NTFS project.
4 * Copyright (c) 2001-2011 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/buffer_head.h>
23 #include <linux/gfp.h>
24 #include <linux/pagemap.h>
25 #include <linux/pagevec.h>
26 #include <linux/sched.h>
27 #include <linux/swap.h>
28 #include <linux/uio.h>
29 #include <linux/writeback.h>
30 #include <linux/aio.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);
332 * ntfs_fault_in_pages_readable -
334 * Fault a number of userspace pages into pagetables.
336 * Unlike include/linux/pagemap.h::fault_in_pages_readable(), this one copes
337 * with more than two userspace pages as well as handling the single page case
340 * If you find this difficult to understand, then think of the while loop being
341 * the following code, except that we do without the integer variable ret:
344 * ret = __get_user(c, uaddr);
345 * uaddr += PAGE_SIZE;
346 * } while (!ret && uaddr < end);
348 * Note, the final __get_user() may well run out-of-bounds of the user buffer,
349 * but _not_ out-of-bounds of the page the user buffer belongs to, and since
350 * this is only a read and not a write, and since it is still in the same page,
351 * it should not matter and this makes the code much simpler.
353 static inline void ntfs_fault_in_pages_readable(const char __user *uaddr,
356 const char __user *end;
359 /* Set @end to the first byte outside the last page we care about. */
360 end = (const char __user*)PAGE_ALIGN((unsigned long)uaddr + bytes);
362 while (!__get_user(c, uaddr) && (uaddr += PAGE_SIZE, uaddr < end))
367 * ntfs_fault_in_pages_readable_iovec -
369 * Same as ntfs_fault_in_pages_readable() but operates on an array of iovecs.
371 static inline void ntfs_fault_in_pages_readable_iovec(const struct iovec *iov,
372 size_t iov_ofs, int bytes)
375 const char __user *buf;
378 buf = iov->iov_base + iov_ofs;
379 len = iov->iov_len - iov_ofs;
382 ntfs_fault_in_pages_readable(buf, len);
390 * __ntfs_grab_cache_pages - obtain a number of locked pages
391 * @mapping: address space mapping from which to obtain page cache pages
392 * @index: starting index in @mapping at which to begin obtaining pages
393 * @nr_pages: number of page cache pages to obtain
394 * @pages: array of pages in which to return the obtained page cache pages
395 * @cached_page: allocated but as yet unused page
397 * Obtain @nr_pages locked page cache pages from the mapping @mapping and
398 * starting at index @index.
400 * If a page is newly created, add it to lru list
402 * Note, the page locks are obtained in ascending page index order.
404 static inline int __ntfs_grab_cache_pages(struct address_space *mapping,
405 pgoff_t index, const unsigned nr_pages, struct page **pages,
406 struct page **cached_page)
413 pages[nr] = find_lock_page(mapping, index);
416 *cached_page = page_cache_alloc(mapping);
417 if (unlikely(!*cached_page)) {
422 err = add_to_page_cache_lru(*cached_page, mapping, index,
429 pages[nr] = *cached_page;
434 } while (nr < nr_pages);
439 unlock_page(pages[--nr]);
440 page_cache_release(pages[nr]);
445 static inline int ntfs_submit_bh_for_read(struct buffer_head *bh)
449 bh->b_end_io = end_buffer_read_sync;
450 return submit_bh(READ, bh);
454 * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data
455 * @pages: array of destination pages
456 * @nr_pages: number of pages in @pages
457 * @pos: byte position in file at which the write begins
458 * @bytes: number of bytes to be written
460 * This is called for non-resident attributes from ntfs_file_buffered_write()
461 * with i_mutex held on the inode (@pages[0]->mapping->host). There are
462 * @nr_pages pages in @pages which are locked but not kmap()ped. The source
463 * data has not yet been copied into the @pages.
465 * Need to fill any holes with actual clusters, allocate buffers if necessary,
466 * ensure all the buffers are mapped, and bring uptodate any buffers that are
467 * only partially being written to.
469 * If @nr_pages is greater than one, we are guaranteed that the cluster size is
470 * greater than PAGE_CACHE_SIZE, that all pages in @pages are entirely inside
471 * the same cluster and that they are the entirety of that cluster, and that
472 * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
474 * i_size is not to be modified yet.
476 * Return 0 on success or -errno on error.
478 static int ntfs_prepare_pages_for_non_resident_write(struct page **pages,
479 unsigned nr_pages, s64 pos, size_t bytes)
481 VCN vcn, highest_vcn = 0, cpos, cend, bh_cpos, bh_cend;
483 s64 bh_pos, vcn_len, end, initialized_size;
487 ntfs_inode *ni, *base_ni = NULL;
489 runlist_element *rl, *rl2;
490 struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
491 ntfs_attr_search_ctx *ctx = NULL;
492 MFT_RECORD *m = NULL;
493 ATTR_RECORD *a = NULL;
495 u32 attr_rec_len = 0;
496 unsigned blocksize, u;
498 bool rl_write_locked, was_hole, is_retry;
499 unsigned char blocksize_bits;
502 u8 mft_attr_mapped:1;
505 } status = { 0, 0, 0, 0 };
510 vi = pages[0]->mapping->host;
513 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
514 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
515 vi->i_ino, ni->type, pages[0]->index, nr_pages,
516 (long long)pos, bytes);
517 blocksize = vol->sb->s_blocksize;
518 blocksize_bits = vol->sb->s_blocksize_bits;
524 * create_empty_buffers() will create uptodate/dirty buffers if
525 * the page is uptodate/dirty.
527 if (!page_has_buffers(page)) {
528 create_empty_buffers(page, blocksize, 0);
529 if (unlikely(!page_has_buffers(page)))
532 } while (++u < nr_pages);
533 rl_write_locked = false;
540 cpos = pos >> vol->cluster_size_bits;
542 cend = (end + vol->cluster_size - 1) >> vol->cluster_size_bits;
544 * Loop over each page and for each page over each buffer. Use goto to
545 * reduce indentation.
550 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
551 bh = head = page_buffers(page);
557 /* Clear buffer_new on all buffers to reinitialise state. */
559 clear_buffer_new(bh);
560 bh_end = bh_pos + blocksize;
561 bh_cpos = bh_pos >> vol->cluster_size_bits;
562 bh_cofs = bh_pos & vol->cluster_size_mask;
563 if (buffer_mapped(bh)) {
565 * The buffer is already mapped. If it is uptodate,
568 if (buffer_uptodate(bh))
571 * The buffer is not uptodate. If the page is uptodate
572 * set the buffer uptodate and otherwise ignore it.
574 if (PageUptodate(page)) {
575 set_buffer_uptodate(bh);
579 * Neither the page nor the buffer are uptodate. If
580 * the buffer is only partially being written to, we
581 * need to read it in before the write, i.e. now.
583 if ((bh_pos < pos && bh_end > pos) ||
584 (bh_pos < end && bh_end > end)) {
586 * If the buffer is fully or partially within
587 * the initialized size, do an actual read.
588 * Otherwise, simply zero the buffer.
590 read_lock_irqsave(&ni->size_lock, flags);
591 initialized_size = ni->initialized_size;
592 read_unlock_irqrestore(&ni->size_lock, flags);
593 if (bh_pos < initialized_size) {
594 ntfs_submit_bh_for_read(bh);
597 zero_user(page, bh_offset(bh),
599 set_buffer_uptodate(bh);
604 /* Unmapped buffer. Need to map it. */
605 bh->b_bdev = vol->sb->s_bdev;
607 * If the current buffer is in the same clusters as the map
608 * cache, there is no need to check the runlist again. The
609 * map cache is made up of @vcn, which is the first cached file
610 * cluster, @vcn_len which is the number of cached file
611 * clusters, @lcn is the device cluster corresponding to @vcn,
612 * and @lcn_block is the block number corresponding to @lcn.
614 cdelta = bh_cpos - vcn;
615 if (likely(!cdelta || (cdelta > 0 && cdelta < vcn_len))) {
618 bh->b_blocknr = lcn_block +
619 (cdelta << (vol->cluster_size_bits -
621 (bh_cofs >> blocksize_bits);
622 set_buffer_mapped(bh);
624 * If the page is uptodate so is the buffer. If the
625 * buffer is fully outside the write, we ignore it if
626 * it was already allocated and we mark it dirty so it
627 * gets written out if we allocated it. On the other
628 * hand, if we allocated the buffer but we are not
629 * marking it dirty we set buffer_new so we can do
632 if (PageUptodate(page)) {
633 if (!buffer_uptodate(bh))
634 set_buffer_uptodate(bh);
635 if (unlikely(was_hole)) {
636 /* We allocated the buffer. */
637 unmap_underlying_metadata(bh->b_bdev,
639 if (bh_end <= pos || bh_pos >= end)
640 mark_buffer_dirty(bh);
646 /* Page is _not_ uptodate. */
647 if (likely(!was_hole)) {
649 * Buffer was already allocated. If it is not
650 * uptodate and is only partially being written
651 * to, we need to read it in before the write,
654 if (!buffer_uptodate(bh) && bh_pos < end &&
659 * If the buffer is fully or partially
660 * within the initialized size, do an
661 * actual read. Otherwise, simply zero
664 read_lock_irqsave(&ni->size_lock,
666 initialized_size = ni->initialized_size;
667 read_unlock_irqrestore(&ni->size_lock,
669 if (bh_pos < initialized_size) {
670 ntfs_submit_bh_for_read(bh);
673 zero_user(page, bh_offset(bh),
675 set_buffer_uptodate(bh);
680 /* We allocated the buffer. */
681 unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
683 * If the buffer is fully outside the write, zero it,
684 * set it uptodate, and mark it dirty so it gets
685 * written out. If it is partially being written to,
686 * zero region surrounding the write but leave it to
687 * commit write to do anything else. Finally, if the
688 * buffer is fully being overwritten, do nothing.
690 if (bh_end <= pos || bh_pos >= end) {
691 if (!buffer_uptodate(bh)) {
692 zero_user(page, bh_offset(bh),
694 set_buffer_uptodate(bh);
696 mark_buffer_dirty(bh);
700 if (!buffer_uptodate(bh) &&
701 (bh_pos < pos || bh_end > end)) {
705 kaddr = kmap_atomic(page);
707 pofs = bh_pos & ~PAGE_CACHE_MASK;
708 memset(kaddr + pofs, 0, pos - bh_pos);
711 pofs = end & ~PAGE_CACHE_MASK;
712 memset(kaddr + pofs, 0, bh_end - end);
714 kunmap_atomic(kaddr);
715 flush_dcache_page(page);
720 * Slow path: this is the first buffer in the cluster. If it
721 * is outside allocated size and is not uptodate, zero it and
724 read_lock_irqsave(&ni->size_lock, flags);
725 initialized_size = ni->allocated_size;
726 read_unlock_irqrestore(&ni->size_lock, flags);
727 if (bh_pos > initialized_size) {
728 if (PageUptodate(page)) {
729 if (!buffer_uptodate(bh))
730 set_buffer_uptodate(bh);
731 } else if (!buffer_uptodate(bh)) {
732 zero_user(page, bh_offset(bh), blocksize);
733 set_buffer_uptodate(bh);
739 down_read(&ni->runlist.lock);
743 if (likely(rl != NULL)) {
744 /* Seek to element containing target cluster. */
745 while (rl->length && rl[1].vcn <= bh_cpos)
747 lcn = ntfs_rl_vcn_to_lcn(rl, bh_cpos);
748 if (likely(lcn >= 0)) {
750 * Successful remap, setup the map cache and
751 * use that to deal with the buffer.
755 vcn_len = rl[1].vcn - vcn;
756 lcn_block = lcn << (vol->cluster_size_bits -
760 * If the number of remaining clusters touched
761 * by the write is smaller or equal to the
762 * number of cached clusters, unlock the
763 * runlist as the map cache will be used from
766 if (likely(vcn + vcn_len >= cend)) {
767 if (rl_write_locked) {
768 up_write(&ni->runlist.lock);
769 rl_write_locked = false;
771 up_read(&ni->runlist.lock);
774 goto map_buffer_cached;
777 lcn = LCN_RL_NOT_MAPPED;
779 * If it is not a hole and not out of bounds, the runlist is
780 * probably unmapped so try to map it now.
782 if (unlikely(lcn != LCN_HOLE && lcn != LCN_ENOENT)) {
783 if (likely(!is_retry && lcn == LCN_RL_NOT_MAPPED)) {
784 /* Attempt to map runlist. */
785 if (!rl_write_locked) {
787 * We need the runlist locked for
788 * writing, so if it is locked for
789 * reading relock it now and retry in
790 * case it changed whilst we dropped
793 up_read(&ni->runlist.lock);
794 down_write(&ni->runlist.lock);
795 rl_write_locked = true;
798 err = ntfs_map_runlist_nolock(ni, bh_cpos,
805 * If @vcn is out of bounds, pretend @lcn is
806 * LCN_ENOENT. As long as the buffer is out
807 * of bounds this will work fine.
809 if (err == -ENOENT) {
812 goto rl_not_mapped_enoent;
816 /* Failed to map the buffer, even after retrying. */
818 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
819 "attribute type 0x%x, vcn 0x%llx, "
820 "vcn offset 0x%x, because its "
821 "location on disk could not be "
822 "determined%s (error code %i).",
823 ni->mft_no, ni->type,
824 (unsigned long long)bh_cpos,
826 vol->cluster_size_mask,
827 is_retry ? " even after retrying" : "",
831 rl_not_mapped_enoent:
833 * The buffer is in a hole or out of bounds. We need to fill
834 * the hole, unless the buffer is in a cluster which is not
835 * touched by the write, in which case we just leave the buffer
836 * unmapped. This can only happen when the cluster size is
837 * less than the page cache size.
839 if (unlikely(vol->cluster_size < PAGE_CACHE_SIZE)) {
840 bh_cend = (bh_end + vol->cluster_size - 1) >>
841 vol->cluster_size_bits;
842 if ((bh_cend <= cpos || bh_cpos >= cend)) {
845 * If the buffer is uptodate we skip it. If it
846 * is not but the page is uptodate, we can set
847 * the buffer uptodate. If the page is not
848 * uptodate, we can clear the buffer and set it
849 * uptodate. Whether this is worthwhile is
850 * debatable and this could be removed.
852 if (PageUptodate(page)) {
853 if (!buffer_uptodate(bh))
854 set_buffer_uptodate(bh);
855 } else if (!buffer_uptodate(bh)) {
856 zero_user(page, bh_offset(bh),
858 set_buffer_uptodate(bh);
864 * Out of bounds buffer is invalid if it was not really out of
867 BUG_ON(lcn != LCN_HOLE);
869 * We need the runlist locked for writing, so if it is locked
870 * for reading relock it now and retry in case it changed
871 * whilst we dropped the lock.
874 if (!rl_write_locked) {
875 up_read(&ni->runlist.lock);
876 down_write(&ni->runlist.lock);
877 rl_write_locked = true;
880 /* Find the previous last allocated cluster. */
881 BUG_ON(rl->lcn != LCN_HOLE);
884 while (--rl2 >= ni->runlist.rl) {
886 lcn = rl2->lcn + rl2->length;
890 rl2 = ntfs_cluster_alloc(vol, bh_cpos, 1, lcn, DATA_ZONE,
894 ntfs_debug("Failed to allocate cluster, error code %i.",
899 rl = ntfs_runlists_merge(ni->runlist.rl, rl2);
904 if (ntfs_cluster_free_from_rl(vol, rl2)) {
905 ntfs_error(vol->sb, "Failed to release "
906 "allocated cluster in error "
907 "code path. Run chkdsk to "
908 "recover the lost cluster.");
915 status.runlist_merged = 1;
916 ntfs_debug("Allocated cluster, lcn 0x%llx.",
917 (unsigned long long)lcn);
918 /* Map and lock the mft record and get the attribute record. */
922 base_ni = ni->ext.base_ntfs_ino;
923 m = map_mft_record(base_ni);
928 ctx = ntfs_attr_get_search_ctx(base_ni, m);
929 if (unlikely(!ctx)) {
931 unmap_mft_record(base_ni);
934 status.mft_attr_mapped = 1;
935 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
936 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx);
945 * Find the runlist element with which the attribute extent
946 * starts. Note, we cannot use the _attr_ version because we
947 * have mapped the mft record. That is ok because we know the
948 * runlist fragment must be mapped already to have ever gotten
949 * here, so we can just use the _rl_ version.
951 vcn = sle64_to_cpu(a->data.non_resident.lowest_vcn);
952 rl2 = ntfs_rl_find_vcn_nolock(rl, vcn);
954 BUG_ON(!rl2->length);
955 BUG_ON(rl2->lcn < LCN_HOLE);
956 highest_vcn = sle64_to_cpu(a->data.non_resident.highest_vcn);
958 * If @highest_vcn is zero, calculate the real highest_vcn
959 * (which can really be zero).
962 highest_vcn = (sle64_to_cpu(
963 a->data.non_resident.allocated_size) >>
964 vol->cluster_size_bits) - 1;
966 * Determine the size of the mapping pairs array for the new
967 * extent, i.e. the old extent with the hole filled.
969 mp_size = ntfs_get_size_for_mapping_pairs(vol, rl2, vcn,
971 if (unlikely(mp_size <= 0)) {
972 if (!(err = mp_size))
974 ntfs_debug("Failed to get size for mapping pairs "
975 "array, error code %i.", err);
979 * Resize the attribute record to fit the new mapping pairs
982 attr_rec_len = le32_to_cpu(a->length);
983 err = ntfs_attr_record_resize(m, a, mp_size + le16_to_cpu(
984 a->data.non_resident.mapping_pairs_offset));
986 BUG_ON(err != -ENOSPC);
987 // TODO: Deal with this by using the current attribute
988 // and fill it with as much of the mapping pairs
989 // array as possible. Then loop over each attribute
990 // extent rewriting the mapping pairs arrays as we go
991 // along and if when we reach the end we have not
992 // enough space, try to resize the last attribute
993 // extent and if even that fails, add a new attribute
995 // We could also try to resize at each step in the hope
996 // that we will not need to rewrite every single extent.
997 // Note, we may need to decompress some extents to fill
998 // the runlist as we are walking the extents...
999 ntfs_error(vol->sb, "Not enough space in the mft "
1000 "record for the extended attribute "
1001 "record. This case is not "
1002 "implemented yet.");
1006 status.mp_rebuilt = 1;
1008 * Generate the mapping pairs array directly into the attribute
1011 err = ntfs_mapping_pairs_build(vol, (u8*)a + le16_to_cpu(
1012 a->data.non_resident.mapping_pairs_offset),
1013 mp_size, rl2, vcn, highest_vcn, NULL);
1014 if (unlikely(err)) {
1015 ntfs_error(vol->sb, "Cannot fill hole in inode 0x%lx, "
1016 "attribute type 0x%x, because building "
1017 "the mapping pairs failed with error "
1018 "code %i.", vi->i_ino,
1019 (unsigned)le32_to_cpu(ni->type), err);
1023 /* Update the highest_vcn but only if it was not set. */
1024 if (unlikely(!a->data.non_resident.highest_vcn))
1025 a->data.non_resident.highest_vcn =
1026 cpu_to_sle64(highest_vcn);
1028 * If the attribute is sparse/compressed, update the compressed
1029 * size in the ntfs_inode structure and the attribute record.
1031 if (likely(NInoSparse(ni) || NInoCompressed(ni))) {
1033 * If we are not in the first attribute extent, switch
1034 * to it, but first ensure the changes will make it to
1037 if (a->data.non_resident.lowest_vcn) {
1038 flush_dcache_mft_record_page(ctx->ntfs_ino);
1039 mark_mft_record_dirty(ctx->ntfs_ino);
1040 ntfs_attr_reinit_search_ctx(ctx);
1041 err = ntfs_attr_lookup(ni->type, ni->name,
1042 ni->name_len, CASE_SENSITIVE,
1044 if (unlikely(err)) {
1045 status.attr_switched = 1;
1048 /* @m is not used any more so do not set it. */
1051 write_lock_irqsave(&ni->size_lock, flags);
1052 ni->itype.compressed.size += vol->cluster_size;
1053 a->data.non_resident.compressed_size =
1054 cpu_to_sle64(ni->itype.compressed.size);
1055 write_unlock_irqrestore(&ni->size_lock, flags);
1057 /* Ensure the changes make it to disk. */
1058 flush_dcache_mft_record_page(ctx->ntfs_ino);
1059 mark_mft_record_dirty(ctx->ntfs_ino);
1060 ntfs_attr_put_search_ctx(ctx);
1061 unmap_mft_record(base_ni);
1062 /* Successfully filled the hole. */
1063 status.runlist_merged = 0;
1064 status.mft_attr_mapped = 0;
1065 status.mp_rebuilt = 0;
1066 /* Setup the map cache and use that to deal with the buffer. */
1070 lcn_block = lcn << (vol->cluster_size_bits - blocksize_bits);
1073 * If the number of remaining clusters in the @pages is smaller
1074 * or equal to the number of cached clusters, unlock the
1075 * runlist as the map cache will be used from now on.
1077 if (likely(vcn + vcn_len >= cend)) {
1078 up_write(&ni->runlist.lock);
1079 rl_write_locked = false;
1082 goto map_buffer_cached;
1083 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1084 /* If there are no errors, do the next page. */
1085 if (likely(!err && ++u < nr_pages))
1087 /* If there are no errors, release the runlist lock if we took it. */
1089 if (unlikely(rl_write_locked)) {
1090 up_write(&ni->runlist.lock);
1091 rl_write_locked = false;
1092 } else if (unlikely(rl))
1093 up_read(&ni->runlist.lock);
1096 /* If we issued read requests, let them complete. */
1097 read_lock_irqsave(&ni->size_lock, flags);
1098 initialized_size = ni->initialized_size;
1099 read_unlock_irqrestore(&ni->size_lock, flags);
1100 while (wait_bh > wait) {
1103 if (likely(buffer_uptodate(bh))) {
1105 bh_pos = ((s64)page->index << PAGE_CACHE_SHIFT) +
1108 * If the buffer overflows the initialized size, need
1109 * to zero the overflowing region.
1111 if (unlikely(bh_pos + blocksize > initialized_size)) {
1114 if (likely(bh_pos < initialized_size))
1115 ofs = initialized_size - bh_pos;
1116 zero_user_segment(page, bh_offset(bh) + ofs,
1119 } else /* if (unlikely(!buffer_uptodate(bh))) */
1123 /* Clear buffer_new on all buffers. */
1126 bh = head = page_buffers(pages[u]);
1129 clear_buffer_new(bh);
1130 } while ((bh = bh->b_this_page) != head);
1131 } while (++u < nr_pages);
1132 ntfs_debug("Done.");
1135 if (status.attr_switched) {
1136 /* Get back to the attribute extent we modified. */
1137 ntfs_attr_reinit_search_ctx(ctx);
1138 if (ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1139 CASE_SENSITIVE, bh_cpos, NULL, 0, ctx)) {
1140 ntfs_error(vol->sb, "Failed to find required "
1141 "attribute extent of attribute in "
1142 "error code path. Run chkdsk to "
1144 write_lock_irqsave(&ni->size_lock, flags);
1145 ni->itype.compressed.size += vol->cluster_size;
1146 write_unlock_irqrestore(&ni->size_lock, flags);
1147 flush_dcache_mft_record_page(ctx->ntfs_ino);
1148 mark_mft_record_dirty(ctx->ntfs_ino);
1150 * The only thing that is now wrong is the compressed
1151 * size of the base attribute extent which chkdsk
1152 * should be able to fix.
1158 status.attr_switched = 0;
1162 * If the runlist has been modified, need to restore it by punching a
1163 * hole into it and we then need to deallocate the on-disk cluster as
1164 * well. Note, we only modify the runlist if we are able to generate a
1165 * new mapping pairs array, i.e. only when the mapped attribute extent
1168 if (status.runlist_merged && !status.attr_switched) {
1169 BUG_ON(!rl_write_locked);
1170 /* Make the file cluster we allocated sparse in the runlist. */
1171 if (ntfs_rl_punch_nolock(vol, &ni->runlist, bh_cpos, 1)) {
1172 ntfs_error(vol->sb, "Failed to punch hole into "
1173 "attribute runlist in error code "
1174 "path. Run chkdsk to recover the "
1177 } else /* if (success) */ {
1178 status.runlist_merged = 0;
1180 * Deallocate the on-disk cluster we allocated but only
1181 * if we succeeded in punching its vcn out of the
1184 down_write(&vol->lcnbmp_lock);
1185 if (ntfs_bitmap_clear_bit(vol->lcnbmp_ino, lcn)) {
1186 ntfs_error(vol->sb, "Failed to release "
1187 "allocated cluster in error "
1188 "code path. Run chkdsk to "
1189 "recover the lost cluster.");
1192 up_write(&vol->lcnbmp_lock);
1196 * Resize the attribute record to its old size and rebuild the mapping
1197 * pairs array. Note, we only can do this if the runlist has been
1198 * restored to its old state which also implies that the mapped
1199 * attribute extent is not switched.
1201 if (status.mp_rebuilt && !status.runlist_merged) {
1202 if (ntfs_attr_record_resize(m, a, attr_rec_len)) {
1203 ntfs_error(vol->sb, "Failed to restore attribute "
1204 "record in error code path. Run "
1205 "chkdsk to recover.");
1207 } else /* if (success) */ {
1208 if (ntfs_mapping_pairs_build(vol, (u8*)a +
1209 le16_to_cpu(a->data.non_resident.
1210 mapping_pairs_offset), attr_rec_len -
1211 le16_to_cpu(a->data.non_resident.
1212 mapping_pairs_offset), ni->runlist.rl,
1213 vcn, highest_vcn, NULL)) {
1214 ntfs_error(vol->sb, "Failed to restore "
1215 "mapping pairs array in error "
1216 "code path. Run chkdsk to "
1220 flush_dcache_mft_record_page(ctx->ntfs_ino);
1221 mark_mft_record_dirty(ctx->ntfs_ino);
1224 /* Release the mft record and the attribute. */
1225 if (status.mft_attr_mapped) {
1226 ntfs_attr_put_search_ctx(ctx);
1227 unmap_mft_record(base_ni);
1229 /* Release the runlist lock. */
1230 if (rl_write_locked)
1231 up_write(&ni->runlist.lock);
1233 up_read(&ni->runlist.lock);
1235 * Zero out any newly allocated blocks to avoid exposing stale data.
1236 * If BH_New is set, we know that the block was newly allocated above
1237 * and that it has not been fully zeroed and marked dirty yet.
1241 end = bh_cpos << vol->cluster_size_bits;
1244 bh = head = page_buffers(page);
1246 if (u == nr_pages &&
1247 ((s64)page->index << PAGE_CACHE_SHIFT) +
1248 bh_offset(bh) >= end)
1250 if (!buffer_new(bh))
1252 clear_buffer_new(bh);
1253 if (!buffer_uptodate(bh)) {
1254 if (PageUptodate(page))
1255 set_buffer_uptodate(bh);
1257 zero_user(page, bh_offset(bh),
1259 set_buffer_uptodate(bh);
1262 mark_buffer_dirty(bh);
1263 } while ((bh = bh->b_this_page) != head);
1264 } while (++u <= nr_pages);
1265 ntfs_error(vol->sb, "Failed. Returning error code %i.", err);
1270 * Copy as much as we can into the pages and return the number of bytes which
1271 * were successfully copied. If a fault is encountered then clear the pages
1272 * out to (ofs + bytes) and return the number of bytes which were copied.
1274 static inline size_t ntfs_copy_from_user(struct page **pages,
1275 unsigned nr_pages, unsigned ofs, const char __user *buf,
1278 struct page **last_page = pages + nr_pages;
1285 len = PAGE_CACHE_SIZE - ofs;
1288 addr = kmap_atomic(*pages);
1289 left = __copy_from_user_inatomic(addr + ofs, buf, len);
1290 kunmap_atomic(addr);
1291 if (unlikely(left)) {
1292 /* Do it the slow way. */
1293 addr = kmap(*pages);
1294 left = __copy_from_user(addr + ofs, buf, len);
1305 } while (++pages < last_page);
1309 total += len - left;
1310 /* Zero the rest of the target like __copy_from_user(). */
1311 while (++pages < last_page) {
1315 len = PAGE_CACHE_SIZE;
1318 zero_user(*pages, 0, len);
1323 static size_t __ntfs_copy_from_user_iovec_inatomic(char *vaddr,
1324 const struct iovec *iov, size_t iov_ofs, size_t bytes)
1329 const char __user *buf = iov->iov_base + iov_ofs;
1333 len = iov->iov_len - iov_ofs;
1336 left = __copy_from_user_inatomic(vaddr, buf, len);
1340 if (unlikely(left)) {
1352 static inline void ntfs_set_next_iovec(const struct iovec **iovp,
1353 size_t *iov_ofsp, size_t bytes)
1355 const struct iovec *iov = *iovp;
1356 size_t iov_ofs = *iov_ofsp;
1361 len = iov->iov_len - iov_ofs;
1366 if (iov->iov_len == iov_ofs) {
1372 *iov_ofsp = iov_ofs;
1376 * This has the same side-effects and return value as ntfs_copy_from_user().
1377 * The difference is that on a fault we need to memset the remainder of the
1378 * pages (out to offset + bytes), to emulate ntfs_copy_from_user()'s
1379 * single-segment behaviour.
1381 * We call the same helper (__ntfs_copy_from_user_iovec_inatomic()) both when
1382 * atomic and when not atomic. This is ok because it calls
1383 * __copy_from_user_inatomic() and it is ok to call this when non-atomic. In
1384 * fact, the only difference between __copy_from_user_inatomic() and
1385 * __copy_from_user() is that the latter calls might_sleep() and the former
1386 * should not zero the tail of the buffer on error. And on many architectures
1387 * __copy_from_user_inatomic() is just defined to __copy_from_user() so it
1388 * makes no difference at all on those architectures.
1390 static inline size_t ntfs_copy_from_user_iovec(struct page **pages,
1391 unsigned nr_pages, unsigned ofs, const struct iovec **iov,
1392 size_t *iov_ofs, size_t bytes)
1394 struct page **last_page = pages + nr_pages;
1396 size_t copied, len, total = 0;
1399 len = PAGE_CACHE_SIZE - ofs;
1402 addr = kmap_atomic(*pages);
1403 copied = __ntfs_copy_from_user_iovec_inatomic(addr + ofs,
1404 *iov, *iov_ofs, len);
1405 kunmap_atomic(addr);
1406 if (unlikely(copied != len)) {
1407 /* Do it the slow way. */
1408 addr = kmap(*pages);
1409 copied = __ntfs_copy_from_user_iovec_inatomic(addr +
1410 ofs, *iov, *iov_ofs, len);
1411 if (unlikely(copied != len))
1416 ntfs_set_next_iovec(iov, iov_ofs, len);
1421 } while (++pages < last_page);
1425 BUG_ON(copied > len);
1426 /* Zero the rest of the target like __copy_from_user(). */
1427 memset(addr + ofs + copied, 0, len - copied);
1430 ntfs_set_next_iovec(iov, iov_ofs, copied);
1431 while (++pages < last_page) {
1435 len = PAGE_CACHE_SIZE;
1438 zero_user(*pages, 0, len);
1443 static inline void ntfs_flush_dcache_pages(struct page **pages,
1448 * Warning: Do not do the decrement at the same time as the call to
1449 * flush_dcache_page() because it is a NULL macro on i386 and hence the
1450 * decrement never happens so the loop never terminates.
1454 flush_dcache_page(pages[nr_pages]);
1455 } while (nr_pages > 0);
1459 * ntfs_commit_pages_after_non_resident_write - commit the received data
1460 * @pages: array of destination pages
1461 * @nr_pages: number of pages in @pages
1462 * @pos: byte position in file at which the write begins
1463 * @bytes: number of bytes to be written
1465 * See description of ntfs_commit_pages_after_write(), below.
1467 static inline int ntfs_commit_pages_after_non_resident_write(
1468 struct page **pages, const unsigned nr_pages,
1469 s64 pos, size_t bytes)
1471 s64 end, initialized_size;
1473 ntfs_inode *ni, *base_ni;
1474 struct buffer_head *bh, *head;
1475 ntfs_attr_search_ctx *ctx;
1478 unsigned long flags;
1479 unsigned blocksize, u;
1482 vi = pages[0]->mapping->host;
1484 blocksize = vi->i_sb->s_blocksize;
1493 bh_pos = (s64)page->index << PAGE_CACHE_SHIFT;
1494 bh = head = page_buffers(page);
1499 bh_end = bh_pos + blocksize;
1500 if (bh_end <= pos || bh_pos >= end) {
1501 if (!buffer_uptodate(bh))
1504 set_buffer_uptodate(bh);
1505 mark_buffer_dirty(bh);
1507 } while (bh_pos += blocksize, (bh = bh->b_this_page) != head);
1509 * If all buffers are now uptodate but the page is not, set the
1512 if (!partial && !PageUptodate(page))
1513 SetPageUptodate(page);
1514 } while (++u < nr_pages);
1516 * Finally, if we do not need to update initialized_size or i_size we
1519 read_lock_irqsave(&ni->size_lock, flags);
1520 initialized_size = ni->initialized_size;
1521 read_unlock_irqrestore(&ni->size_lock, flags);
1522 if (end <= initialized_size) {
1523 ntfs_debug("Done.");
1527 * Update initialized_size/i_size as appropriate, both in the inode and
1533 base_ni = ni->ext.base_ntfs_ino;
1534 /* Map, pin, and lock the mft record. */
1535 m = map_mft_record(base_ni);
1542 BUG_ON(!NInoNonResident(ni));
1543 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1544 if (unlikely(!ctx)) {
1548 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1549 CASE_SENSITIVE, 0, NULL, 0, ctx);
1550 if (unlikely(err)) {
1556 BUG_ON(!a->non_resident);
1557 write_lock_irqsave(&ni->size_lock, flags);
1558 BUG_ON(end > ni->allocated_size);
1559 ni->initialized_size = end;
1560 a->data.non_resident.initialized_size = cpu_to_sle64(end);
1561 if (end > i_size_read(vi)) {
1562 i_size_write(vi, end);
1563 a->data.non_resident.data_size =
1564 a->data.non_resident.initialized_size;
1566 write_unlock_irqrestore(&ni->size_lock, flags);
1567 /* Mark the mft record dirty, so it gets written back. */
1568 flush_dcache_mft_record_page(ctx->ntfs_ino);
1569 mark_mft_record_dirty(ctx->ntfs_ino);
1570 ntfs_attr_put_search_ctx(ctx);
1571 unmap_mft_record(base_ni);
1572 ntfs_debug("Done.");
1576 ntfs_attr_put_search_ctx(ctx);
1578 unmap_mft_record(base_ni);
1579 ntfs_error(vi->i_sb, "Failed to update initialized_size/i_size (error "
1582 NVolSetErrors(ni->vol);
1587 * ntfs_commit_pages_after_write - commit the received data
1588 * @pages: array of destination pages
1589 * @nr_pages: number of pages in @pages
1590 * @pos: byte position in file at which the write begins
1591 * @bytes: number of bytes to be written
1593 * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
1594 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
1595 * locked but not kmap()ped. The source data has already been copied into the
1596 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before
1597 * the data was copied (for non-resident attributes only) and it returned
1600 * Need to set uptodate and mark dirty all buffers within the boundary of the
1601 * write. If all buffers in a page are uptodate we set the page uptodate, too.
1603 * Setting the buffers dirty ensures that they get written out later when
1604 * ntfs_writepage() is invoked by the VM.
1606 * Finally, we need to update i_size and initialized_size as appropriate both
1607 * in the inode and the mft record.
1609 * This is modelled after fs/buffer.c::generic_commit_write(), which marks
1610 * buffers uptodate and dirty, sets the page uptodate if all buffers in the
1611 * page are uptodate, and updates i_size if the end of io is beyond i_size. In
1612 * that case, it also marks the inode dirty.
1614 * If things have gone as outlined in
1615 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
1616 * content modifications here for non-resident attributes. For resident
1617 * attributes we need to do the uptodate bringing here which we combine with
1618 * the copying into the mft record which means we save one atomic kmap.
1620 * Return 0 on success or -errno on error.
1622 static int ntfs_commit_pages_after_write(struct page **pages,
1623 const unsigned nr_pages, s64 pos, size_t bytes)
1625 s64 end, initialized_size;
1628 ntfs_inode *ni, *base_ni;
1630 ntfs_attr_search_ctx *ctx;
1633 char *kattr, *kaddr;
1634 unsigned long flags;
1642 vi = page->mapping->host;
1644 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
1645 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
1646 vi->i_ino, ni->type, page->index, nr_pages,
1647 (long long)pos, bytes);
1648 if (NInoNonResident(ni))
1649 return ntfs_commit_pages_after_non_resident_write(pages,
1650 nr_pages, pos, bytes);
1651 BUG_ON(nr_pages > 1);
1653 * Attribute is resident, implying it is not compressed, encrypted, or
1659 base_ni = ni->ext.base_ntfs_ino;
1660 BUG_ON(NInoNonResident(ni));
1661 /* Map, pin, and lock the mft record. */
1662 m = map_mft_record(base_ni);
1669 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1670 if (unlikely(!ctx)) {
1674 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1675 CASE_SENSITIVE, 0, NULL, 0, ctx);
1676 if (unlikely(err)) {
1682 BUG_ON(a->non_resident);
1683 /* The total length of the attribute value. */
1684 attr_len = le32_to_cpu(a->data.resident.value_length);
1685 i_size = i_size_read(vi);
1686 BUG_ON(attr_len != i_size);
1687 BUG_ON(pos > attr_len);
1689 BUG_ON(end > le32_to_cpu(a->length) -
1690 le16_to_cpu(a->data.resident.value_offset));
1691 kattr = (u8*)a + le16_to_cpu(a->data.resident.value_offset);
1692 kaddr = kmap_atomic(page);
1693 /* Copy the received data from the page to the mft record. */
1694 memcpy(kattr + pos, kaddr + pos, bytes);
1695 /* Update the attribute length if necessary. */
1696 if (end > attr_len) {
1698 a->data.resident.value_length = cpu_to_le32(attr_len);
1701 * If the page is not uptodate, bring the out of bounds area(s)
1702 * uptodate by copying data from the mft record to the page.
1704 if (!PageUptodate(page)) {
1706 memcpy(kaddr, kattr, pos);
1708 memcpy(kaddr + end, kattr + end, attr_len - end);
1709 /* Zero the region outside the end of the attribute value. */
1710 memset(kaddr + attr_len, 0, PAGE_CACHE_SIZE - attr_len);
1711 flush_dcache_page(page);
1712 SetPageUptodate(page);
1714 kunmap_atomic(kaddr);
1715 /* Update initialized_size/i_size if necessary. */
1716 read_lock_irqsave(&ni->size_lock, flags);
1717 initialized_size = ni->initialized_size;
1718 BUG_ON(end > ni->allocated_size);
1719 read_unlock_irqrestore(&ni->size_lock, flags);
1720 BUG_ON(initialized_size != i_size);
1721 if (end > initialized_size) {
1722 write_lock_irqsave(&ni->size_lock, flags);
1723 ni->initialized_size = end;
1724 i_size_write(vi, end);
1725 write_unlock_irqrestore(&ni->size_lock, flags);
1727 /* Mark the mft record dirty, so it gets written back. */
1728 flush_dcache_mft_record_page(ctx->ntfs_ino);
1729 mark_mft_record_dirty(ctx->ntfs_ino);
1730 ntfs_attr_put_search_ctx(ctx);
1731 unmap_mft_record(base_ni);
1732 ntfs_debug("Done.");
1735 if (err == -ENOMEM) {
1736 ntfs_warning(vi->i_sb, "Error allocating memory required to "
1737 "commit the write.");
1738 if (PageUptodate(page)) {
1739 ntfs_warning(vi->i_sb, "Page is uptodate, setting "
1740 "dirty so the write will be retried "
1741 "later on by the VM.");
1743 * Put the page on mapping->dirty_pages, but leave its
1744 * buffers' dirty state as-is.
1746 __set_page_dirty_nobuffers(page);
1749 ntfs_error(vi->i_sb, "Page is not uptodate. Written "
1750 "data has been lost.");
1752 ntfs_error(vi->i_sb, "Resident attribute commit write failed "
1753 "with error %i.", err);
1754 NVolSetErrors(ni->vol);
1757 ntfs_attr_put_search_ctx(ctx);
1759 unmap_mft_record(base_ni);
1763 static void ntfs_write_failed(struct address_space *mapping, loff_t to)
1765 struct inode *inode = mapping->host;
1767 if (to > inode->i_size) {
1768 truncate_pagecache(inode, inode->i_size);
1769 ntfs_truncate_vfs(inode);
1774 * ntfs_file_buffered_write -
1776 * Locking: The vfs is holding ->i_mutex on the inode.
1778 static ssize_t ntfs_file_buffered_write(struct kiocb *iocb,
1779 const struct iovec *iov, unsigned long nr_segs,
1780 loff_t pos, loff_t *ppos, size_t count)
1782 struct file *file = iocb->ki_filp;
1783 struct address_space *mapping = file->f_mapping;
1784 struct inode *vi = mapping->host;
1785 ntfs_inode *ni = NTFS_I(vi);
1786 ntfs_volume *vol = ni->vol;
1787 struct page *pages[NTFS_MAX_PAGES_PER_CLUSTER];
1788 struct page *cached_page = NULL;
1789 char __user *buf = NULL;
1793 unsigned long flags;
1794 size_t bytes, iov_ofs = 0; /* Offset in the current iovec. */
1795 ssize_t status, written;
1799 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, "
1800 "pos 0x%llx, count 0x%lx.",
1801 vi->i_ino, (unsigned)le32_to_cpu(ni->type),
1802 (unsigned long long)pos, (unsigned long)count);
1803 if (unlikely(!count))
1805 BUG_ON(NInoMstProtected(ni));
1807 * If the attribute is not an index root and it is encrypted or
1808 * compressed, we cannot write to it yet. Note we need to check for
1809 * AT_INDEX_ALLOCATION since this is the type of both directory and
1812 if (ni->type != AT_INDEX_ALLOCATION) {
1813 /* If file is encrypted, deny access, just like NT4. */
1814 if (NInoEncrypted(ni)) {
1816 * Reminder for later: Encrypted files are _always_
1817 * non-resident so that the content can always be
1820 ntfs_debug("Denying write access to encrypted file.");
1823 if (NInoCompressed(ni)) {
1824 /* Only unnamed $DATA attribute can be compressed. */
1825 BUG_ON(ni->type != AT_DATA);
1826 BUG_ON(ni->name_len);
1828 * Reminder for later: If resident, the data is not
1829 * actually compressed. Only on the switch to non-
1830 * resident does compression kick in. This is in
1831 * contrast to encrypted files (see above).
1833 ntfs_error(vi->i_sb, "Writing to compressed files is "
1834 "not implemented yet. Sorry.");
1839 * If a previous ntfs_truncate() failed, repeat it and abort if it
1842 if (unlikely(NInoTruncateFailed(ni))) {
1844 err = ntfs_truncate(vi);
1845 if (err || NInoTruncateFailed(ni)) {
1848 ntfs_error(vol->sb, "Cannot perform write to inode "
1849 "0x%lx, attribute type 0x%x, because "
1850 "ntfs_truncate() failed (error code "
1852 (unsigned)le32_to_cpu(ni->type), err);
1856 /* The first byte after the write. */
1859 * If the write goes beyond the allocated size, extend the allocation
1860 * to cover the whole of the write, rounded up to the nearest cluster.
1862 read_lock_irqsave(&ni->size_lock, flags);
1863 ll = ni->allocated_size;
1864 read_unlock_irqrestore(&ni->size_lock, flags);
1866 /* Extend the allocation without changing the data size. */
1867 ll = ntfs_attr_extend_allocation(ni, end, -1, pos);
1868 if (likely(ll >= 0)) {
1870 /* If the extension was partial truncate the write. */
1872 ntfs_debug("Truncating write to inode 0x%lx, "
1873 "attribute type 0x%x, because "
1874 "the allocation was only "
1875 "partially extended.",
1876 vi->i_ino, (unsigned)
1877 le32_to_cpu(ni->type));
1883 read_lock_irqsave(&ni->size_lock, flags);
1884 ll = ni->allocated_size;
1885 read_unlock_irqrestore(&ni->size_lock, flags);
1886 /* Perform a partial write if possible or fail. */
1888 ntfs_debug("Truncating write to inode 0x%lx, "
1889 "attribute type 0x%x, because "
1890 "extending the allocation "
1891 "failed (error code %i).",
1892 vi->i_ino, (unsigned)
1893 le32_to_cpu(ni->type), err);
1897 ntfs_error(vol->sb, "Cannot perform write to "
1898 "inode 0x%lx, attribute type "
1899 "0x%x, because extending the "
1900 "allocation failed (error "
1901 "code %i).", vi->i_ino,
1903 le32_to_cpu(ni->type), err);
1910 * If the write starts beyond the initialized size, extend it up to the
1911 * beginning of the write and initialize all non-sparse space between
1912 * the old initialized size and the new one. This automatically also
1913 * increments the vfs inode->i_size to keep it above or equal to the
1916 read_lock_irqsave(&ni->size_lock, flags);
1917 ll = ni->initialized_size;
1918 read_unlock_irqrestore(&ni->size_lock, flags);
1920 err = ntfs_attr_extend_initialized(ni, pos);
1922 ntfs_error(vol->sb, "Cannot perform write to inode "
1923 "0x%lx, attribute type 0x%x, because "
1924 "extending the initialized size "
1925 "failed (error code %i).", vi->i_ino,
1926 (unsigned)le32_to_cpu(ni->type), err);
1932 * Determine the number of pages per cluster for non-resident
1936 if (vol->cluster_size > PAGE_CACHE_SIZE && NInoNonResident(ni))
1937 nr_pages = vol->cluster_size >> PAGE_CACHE_SHIFT;
1938 /* Finally, perform the actual write. */
1940 if (likely(nr_segs == 1))
1941 buf = iov->iov_base;
1944 pgoff_t idx, start_idx;
1945 unsigned ofs, do_pages, u;
1948 start_idx = idx = pos >> PAGE_CACHE_SHIFT;
1949 ofs = pos & ~PAGE_CACHE_MASK;
1950 bytes = PAGE_CACHE_SIZE - ofs;
1953 vcn = pos >> vol->cluster_size_bits;
1954 if (vcn != last_vcn) {
1957 * Get the lcn of the vcn the write is in. If
1958 * it is a hole, need to lock down all pages in
1961 down_read(&ni->runlist.lock);
1962 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, pos >>
1963 vol->cluster_size_bits, false);
1964 up_read(&ni->runlist.lock);
1965 if (unlikely(lcn < LCN_HOLE)) {
1967 if (lcn == LCN_ENOMEM)
1970 ntfs_error(vol->sb, "Cannot "
1973 "attribute type 0x%x, "
1974 "because the attribute "
1976 vi->i_ino, (unsigned)
1977 le32_to_cpu(ni->type));
1980 if (lcn == LCN_HOLE) {
1981 start_idx = (pos & ~(s64)
1982 vol->cluster_size_mask)
1983 >> PAGE_CACHE_SHIFT;
1984 bytes = vol->cluster_size - (pos &
1985 vol->cluster_size_mask);
1986 do_pages = nr_pages;
1993 * Bring in the user page(s) that we will copy from _first_.
1994 * Otherwise there is a nasty deadlock on copying from the same
1995 * page(s) as we are writing to, without it/them being marked
1996 * up-to-date. Note, at present there is nothing to stop the
1997 * pages being swapped out between us bringing them into memory
1998 * and doing the actual copying.
2000 if (likely(nr_segs == 1))
2001 ntfs_fault_in_pages_readable(buf, bytes);
2003 ntfs_fault_in_pages_readable_iovec(iov, iov_ofs, bytes);
2004 /* Get and lock @do_pages starting at index @start_idx. */
2005 status = __ntfs_grab_cache_pages(mapping, start_idx, do_pages,
2006 pages, &cached_page);
2007 if (unlikely(status))
2010 * For non-resident attributes, we need to fill any holes with
2011 * actual clusters and ensure all bufferes are mapped. We also
2012 * need to bring uptodate any buffers that are only partially
2015 if (NInoNonResident(ni)) {
2016 status = ntfs_prepare_pages_for_non_resident_write(
2017 pages, do_pages, pos, bytes);
2018 if (unlikely(status)) {
2022 unlock_page(pages[--do_pages]);
2023 page_cache_release(pages[do_pages]);
2026 * The write preparation may have instantiated
2027 * allocated space outside i_size. Trim this
2028 * off again. We can ignore any errors in this
2029 * case as we will just be waisting a bit of
2030 * allocated space, which is not a disaster.
2032 i_size = i_size_read(vi);
2033 if (pos + bytes > i_size) {
2034 ntfs_write_failed(mapping, pos + bytes);
2039 u = (pos >> PAGE_CACHE_SHIFT) - pages[0]->index;
2040 if (likely(nr_segs == 1)) {
2041 copied = ntfs_copy_from_user(pages + u, do_pages - u,
2045 copied = ntfs_copy_from_user_iovec(pages + u,
2046 do_pages - u, ofs, &iov, &iov_ofs,
2048 ntfs_flush_dcache_pages(pages + u, do_pages - u);
2049 status = ntfs_commit_pages_after_write(pages, do_pages, pos,
2051 if (likely(!status)) {
2055 if (unlikely(copied != bytes))
2059 unlock_page(pages[--do_pages]);
2060 page_cache_release(pages[do_pages]);
2062 if (unlikely(status))
2064 balance_dirty_pages_ratelimited(mapping);
2070 page_cache_release(cached_page);
2071 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).",
2072 written ? "written" : "status", (unsigned long)written,
2074 return written ? written : status;
2078 * ntfs_file_aio_write_nolock -
2080 static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb,
2081 const struct iovec *iov, unsigned long nr_segs, loff_t *ppos)
2083 struct file *file = iocb->ki_filp;
2084 struct address_space *mapping = file->f_mapping;
2085 struct inode *inode = mapping->host;
2087 size_t count; /* after file limit checks */
2088 ssize_t written, err;
2090 count = iov_length(iov, nr_segs);
2092 /* We can write back this queue in page reclaim. */
2093 current->backing_dev_info = mapping->backing_dev_info;
2095 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
2100 err = file_remove_suid(file);
2103 err = file_update_time(file);
2106 written = ntfs_file_buffered_write(iocb, iov, nr_segs, pos, ppos,
2109 current->backing_dev_info = NULL;
2110 return written ? written : err;
2114 * ntfs_file_aio_write -
2116 static ssize_t ntfs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
2117 unsigned long nr_segs, loff_t pos)
2119 struct file *file = iocb->ki_filp;
2120 struct address_space *mapping = file->f_mapping;
2121 struct inode *inode = mapping->host;
2124 BUG_ON(iocb->ki_pos != pos);
2126 mutex_lock(&inode->i_mutex);
2127 ret = ntfs_file_aio_write_nolock(iocb, iov, nr_segs, &iocb->ki_pos);
2128 mutex_unlock(&inode->i_mutex);
2130 int err = generic_write_sync(file, iocb->ki_pos - ret, ret);
2138 * ntfs_file_fsync - sync a file to disk
2139 * @filp: file to be synced
2140 * @datasync: if non-zero only flush user data and not metadata
2142 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
2143 * system calls. This function is inspired by fs/buffer.c::file_fsync().
2145 * If @datasync is false, write the mft record and all associated extent mft
2146 * records as well as the $DATA attribute and then sync the block device.
2148 * If @datasync is true and the attribute is non-resident, we skip the writing
2149 * of the mft record and all associated extent mft records (this might still
2150 * happen due to the write_inode_now() call).
2152 * Also, if @datasync is true, we do not wait on the inode to be written out
2153 * but we always wait on the page cache pages to be written out.
2155 * Locking: Caller must hold i_mutex on the inode.
2157 * TODO: We should probably also write all attribute/index inodes associated
2158 * with this inode but since we have no simple way of getting to them we ignore
2159 * this problem for now.
2161 static int ntfs_file_fsync(struct file *filp, loff_t start, loff_t end,
2164 struct inode *vi = filp->f_mapping->host;
2167 ntfs_debug("Entering for inode 0x%lx.", vi->i_ino);
2169 err = filemap_write_and_wait_range(vi->i_mapping, start, end);
2172 mutex_lock(&vi->i_mutex);
2174 BUG_ON(S_ISDIR(vi->i_mode));
2175 if (!datasync || !NInoNonResident(NTFS_I(vi)))
2176 ret = __ntfs_write_inode(vi, 1);
2177 write_inode_now(vi, !datasync);
2179 * NOTE: If we were to use mapping->private_list (see ext2 and
2180 * fs/buffer.c) for dirty blocks then we could optimize the below to be
2181 * sync_mapping_buffers(vi->i_mapping).
2183 err = sync_blockdev(vi->i_sb->s_bdev);
2184 if (unlikely(err && !ret))
2187 ntfs_debug("Done.");
2189 ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error "
2190 "%u.", datasync ? "data" : "", vi->i_ino, -ret);
2191 mutex_unlock(&vi->i_mutex);
2195 #endif /* NTFS_RW */
2197 const struct file_operations ntfs_file_ops = {
2198 .llseek = generic_file_llseek, /* Seek inside file. */
2199 .read = new_sync_read, /* Read from file. */
2200 .read_iter = generic_file_read_iter, /* Async read from file. */
2202 .write = do_sync_write, /* Write to file. */
2203 .aio_write = ntfs_file_aio_write, /* Async write to file. */
2204 /*.release = ,*/ /* Last file is closed. See
2206 ext2_release_file() for
2207 how to use this to discard
2208 preallocated space for
2209 write opened files. */
2210 .fsync = ntfs_file_fsync, /* Sync a file to disk. */
2211 /*.aio_fsync = ,*/ /* Sync all outstanding async
2214 #endif /* NTFS_RW */
2215 /*.ioctl = ,*/ /* Perform function on the
2216 mounted filesystem. */
2217 .mmap = generic_file_mmap, /* Mmap file. */
2218 .open = ntfs_file_open, /* Open file. */
2219 .splice_read = generic_file_splice_read /* Zero-copy data send with
2220 the data source being on
2221 the ntfs partition. We do
2222 not need to care about the
2223 data destination. */
2224 /*.sendpage = ,*/ /* Zero-copy data send with
2225 the data destination being
2226 on the ntfs partition. We
2227 do not need to care about
2231 const struct inode_operations ntfs_file_inode_ops = {
2233 .setattr = ntfs_setattr,
2234 #endif /* NTFS_RW */
2237 const struct file_operations ntfs_empty_file_ops = {};
2239 const struct inode_operations ntfs_empty_inode_ops = {};