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_SHIFT
;
224 end_index
= (new_init_size
+ PAGE_SIZE
- 1) >> PAGE_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
))) {
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_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
);
253 * Play nice with the vm and the rest of the system. This is
254 * very much needed as we can potentially be modifying the
255 * initialised size from a very small value to a really huge
257 * f = open(somefile, O_TRUNC);
258 * truncate(f, 10GiB);
261 * And this would mean we would be marking dirty hundreds of
262 * thousands of pages or as in the above example more than
263 * two and a half million pages!
265 * TODO: For sparse pages could optimize this workload by using
266 * the FsMisc / MiscFs page bit as a "PageIsSparse" bit. This
267 * would be set in readpage for sparse pages and here we would
268 * not need to mark dirty any pages which have this bit set.
269 * The only caveat is that we have to clear the bit everywhere
270 * where we allocate any clusters that lie in the page or that
273 * TODO: An even greater optimization would be for us to only
274 * call readpage() on pages which are not in sparse regions as
275 * determined from the runlist. This would greatly reduce the
276 * number of pages we read and make dirty in the case of sparse
279 balance_dirty_pages_ratelimited(mapping
);
281 } while (++index
< end_index
);
282 read_lock_irqsave(&ni
->size_lock
, flags
);
283 BUG_ON(ni
->initialized_size
!= new_init_size
);
284 read_unlock_irqrestore(&ni
->size_lock
, flags
);
285 /* Now bring in sync the initialized_size in the mft record. */
286 m
= map_mft_record(base_ni
);
292 ctx
= ntfs_attr_get_search_ctx(base_ni
, m
);
293 if (unlikely(!ctx
)) {
297 err
= ntfs_attr_lookup(ni
->type
, ni
->name
, ni
->name_len
,
298 CASE_SENSITIVE
, 0, NULL
, 0, ctx
);
306 BUG_ON(!a
->non_resident
);
307 a
->data
.non_resident
.initialized_size
= cpu_to_sle64(new_init_size
);
309 flush_dcache_mft_record_page(ctx
->ntfs_ino
);
310 mark_mft_record_dirty(ctx
->ntfs_ino
);
312 ntfs_attr_put_search_ctx(ctx
);
314 unmap_mft_record(base_ni
);
315 ntfs_debug("Done, initialized_size 0x%llx, i_size 0x%llx.",
316 (unsigned long long)new_init_size
, i_size_read(vi
));
319 write_lock_irqsave(&ni
->size_lock
, flags
);
320 ni
->initialized_size
= old_init_size
;
321 write_unlock_irqrestore(&ni
->size_lock
, flags
);
324 ntfs_attr_put_search_ctx(ctx
);
326 unmap_mft_record(base_ni
);
327 ntfs_debug("Failed. Returning error code %i.", err
);
331 static ssize_t
ntfs_prepare_file_for_write(struct kiocb
*iocb
,
332 struct iov_iter
*from
)
338 struct file
*file
= iocb
->ki_filp
;
339 struct inode
*vi
= file_inode(file
);
340 ntfs_inode
*base_ni
, *ni
= NTFS_I(vi
);
341 ntfs_volume
*vol
= ni
->vol
;
343 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
344 "0x%llx, count 0x%zx.", vi
->i_ino
,
345 (unsigned)le32_to_cpu(ni
->type
),
346 (unsigned long long)iocb
->ki_pos
,
347 iov_iter_count(from
));
348 err
= generic_write_checks(iocb
, from
);
349 if (unlikely(err
<= 0))
352 * All checks have passed. Before we start doing any writing we want
353 * to abort any totally illegal writes.
355 BUG_ON(NInoMstProtected(ni
));
356 BUG_ON(ni
->type
!= AT_DATA
);
357 /* If file is encrypted, deny access, just like NT4. */
358 if (NInoEncrypted(ni
)) {
359 /* Only $DATA attributes can be encrypted. */
361 * Reminder for later: Encrypted files are _always_
362 * non-resident so that the content can always be encrypted.
364 ntfs_debug("Denying write access to encrypted file.");
368 if (NInoCompressed(ni
)) {
369 /* Only unnamed $DATA attribute can be compressed. */
370 BUG_ON(ni
->name_len
);
372 * Reminder for later: If resident, the data is not actually
373 * compressed. Only on the switch to non-resident does
374 * compression kick in. This is in contrast to encrypted files
377 ntfs_error(vi
->i_sb
, "Writing to compressed files is not "
378 "implemented yet. Sorry.");
384 base_ni
= ni
->ext
.base_ntfs_ino
;
385 err
= file_remove_privs(file
);
389 * Our ->update_time method always succeeds thus file_update_time()
390 * cannot fail either so there is no need to check the return code.
392 file_update_time(file
);
394 /* The first byte after the last cluster being written to. */
395 end
= (pos
+ iov_iter_count(from
) + vol
->cluster_size_mask
) &
396 ~(u64
)vol
->cluster_size_mask
;
398 * If the write goes beyond the allocated size, extend the allocation
399 * to cover the whole of the write, rounded up to the nearest cluster.
401 read_lock_irqsave(&ni
->size_lock
, flags
);
402 ll
= ni
->allocated_size
;
403 read_unlock_irqrestore(&ni
->size_lock
, flags
);
406 * Extend the allocation without changing the data size.
408 * Note we ensure the allocation is big enough to at least
409 * write some data but we do not require the allocation to be
410 * complete, i.e. it may be partial.
412 ll
= ntfs_attr_extend_allocation(ni
, end
, -1, pos
);
413 if (likely(ll
>= 0)) {
415 /* If the extension was partial truncate the write. */
417 ntfs_debug("Truncating write to inode 0x%lx, "
418 "attribute type 0x%x, because "
419 "the allocation was only "
420 "partially extended.",
421 vi
->i_ino
, (unsigned)
422 le32_to_cpu(ni
->type
));
423 iov_iter_truncate(from
, ll
- pos
);
427 read_lock_irqsave(&ni
->size_lock
, flags
);
428 ll
= ni
->allocated_size
;
429 read_unlock_irqrestore(&ni
->size_lock
, flags
);
430 /* Perform a partial write if possible or fail. */
432 ntfs_debug("Truncating write to inode 0x%lx "
433 "attribute type 0x%x, because "
434 "extending the allocation "
435 "failed (error %d).",
436 vi
->i_ino
, (unsigned)
437 le32_to_cpu(ni
->type
),
439 iov_iter_truncate(from
, ll
- pos
);
442 ntfs_error(vi
->i_sb
, "Cannot perform "
445 "type 0x%x, because "
449 vi
->i_ino
, (unsigned)
450 le32_to_cpu(ni
->type
),
453 ntfs_debug("Cannot perform write to "
455 "attribute type 0x%x, "
456 "because there is not "
458 vi
->i_ino
, (unsigned)
459 le32_to_cpu(ni
->type
));
465 * If the write starts beyond the initialized size, extend it up to the
466 * beginning of the write and initialize all non-sparse space between
467 * the old initialized size and the new one. This automatically also
468 * increments the vfs inode->i_size to keep it above or equal to the
471 read_lock_irqsave(&ni
->size_lock
, flags
);
472 ll
= ni
->initialized_size
;
473 read_unlock_irqrestore(&ni
->size_lock
, flags
);
476 * Wait for ongoing direct i/o to complete before proceeding.
477 * New direct i/o cannot start as we hold i_mutex.
480 err
= ntfs_attr_extend_initialized(ni
, pos
);
481 if (unlikely(err
< 0))
482 ntfs_error(vi
->i_sb
, "Cannot perform write to inode "
483 "0x%lx, attribute type 0x%x, because "
484 "extending the initialized size "
485 "failed (error %d).", vi
->i_ino
,
486 (unsigned)le32_to_cpu(ni
->type
),
494 * __ntfs_grab_cache_pages - obtain a number of locked pages
495 * @mapping: address space mapping from which to obtain page cache pages
496 * @index: starting index in @mapping at which to begin obtaining pages
497 * @nr_pages: number of page cache pages to obtain
498 * @pages: array of pages in which to return the obtained page cache pages
499 * @cached_page: allocated but as yet unused page
501 * Obtain @nr_pages locked page cache pages from the mapping @mapping and
502 * starting at index @index.
504 * If a page is newly created, add it to lru list
506 * Note, the page locks are obtained in ascending page index order.
508 static inline int __ntfs_grab_cache_pages(struct address_space
*mapping
,
509 pgoff_t index
, const unsigned nr_pages
, struct page
**pages
,
510 struct page
**cached_page
)
517 pages
[nr
] = find_get_page_flags(mapping
, index
, FGP_LOCK
|
521 *cached_page
= page_cache_alloc(mapping
);
522 if (unlikely(!*cached_page
)) {
527 err
= add_to_page_cache_lru(*cached_page
, mapping
,
529 mapping_gfp_constraint(mapping
, GFP_KERNEL
));
535 pages
[nr
] = *cached_page
;
540 } while (nr
< nr_pages
);
545 unlock_page(pages
[--nr
]);
551 static inline int ntfs_submit_bh_for_read(struct buffer_head
*bh
)
555 bh
->b_end_io
= end_buffer_read_sync
;
556 return submit_bh(READ
, bh
);
560 * ntfs_prepare_pages_for_non_resident_write - prepare pages for receiving data
561 * @pages: array of destination pages
562 * @nr_pages: number of pages in @pages
563 * @pos: byte position in file at which the write begins
564 * @bytes: number of bytes to be written
566 * This is called for non-resident attributes from ntfs_file_buffered_write()
567 * with i_mutex held on the inode (@pages[0]->mapping->host). There are
568 * @nr_pages pages in @pages which are locked but not kmap()ped. The source
569 * data has not yet been copied into the @pages.
571 * Need to fill any holes with actual clusters, allocate buffers if necessary,
572 * ensure all the buffers are mapped, and bring uptodate any buffers that are
573 * only partially being written to.
575 * If @nr_pages is greater than one, we are guaranteed that the cluster size is
576 * greater than PAGE_SIZE, that all pages in @pages are entirely inside
577 * the same cluster and that they are the entirety of that cluster, and that
578 * the cluster is sparse, i.e. we need to allocate a cluster to fill the hole.
580 * i_size is not to be modified yet.
582 * Return 0 on success or -errno on error.
584 static int ntfs_prepare_pages_for_non_resident_write(struct page
**pages
,
585 unsigned nr_pages
, s64 pos
, size_t bytes
)
587 VCN vcn
, highest_vcn
= 0, cpos
, cend
, bh_cpos
, bh_cend
;
589 s64 bh_pos
, vcn_len
, end
, initialized_size
;
593 ntfs_inode
*ni
, *base_ni
= NULL
;
595 runlist_element
*rl
, *rl2
;
596 struct buffer_head
*bh
, *head
, *wait
[2], **wait_bh
= wait
;
597 ntfs_attr_search_ctx
*ctx
= NULL
;
598 MFT_RECORD
*m
= NULL
;
599 ATTR_RECORD
*a
= NULL
;
601 u32 attr_rec_len
= 0;
602 unsigned blocksize
, u
;
604 bool rl_write_locked
, was_hole
, is_retry
;
605 unsigned char blocksize_bits
;
608 u8 mft_attr_mapped
:1;
611 } status
= { 0, 0, 0, 0 };
616 vi
= pages
[0]->mapping
->host
;
619 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
620 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
621 vi
->i_ino
, ni
->type
, pages
[0]->index
, nr_pages
,
622 (long long)pos
, bytes
);
623 blocksize
= vol
->sb
->s_blocksize
;
624 blocksize_bits
= vol
->sb
->s_blocksize_bits
;
630 * create_empty_buffers() will create uptodate/dirty buffers if
631 * the page is uptodate/dirty.
633 if (!page_has_buffers(page
)) {
634 create_empty_buffers(page
, blocksize
, 0);
635 if (unlikely(!page_has_buffers(page
)))
638 } while (++u
< nr_pages
);
639 rl_write_locked
= false;
646 cpos
= pos
>> vol
->cluster_size_bits
;
648 cend
= (end
+ vol
->cluster_size
- 1) >> vol
->cluster_size_bits
;
650 * Loop over each page and for each page over each buffer. Use goto to
651 * reduce indentation.
656 bh_pos
= (s64
)page
->index
<< PAGE_SHIFT
;
657 bh
= head
= page_buffers(page
);
663 /* Clear buffer_new on all buffers to reinitialise state. */
665 clear_buffer_new(bh
);
666 bh_end
= bh_pos
+ blocksize
;
667 bh_cpos
= bh_pos
>> vol
->cluster_size_bits
;
668 bh_cofs
= bh_pos
& vol
->cluster_size_mask
;
669 if (buffer_mapped(bh
)) {
671 * The buffer is already mapped. If it is uptodate,
674 if (buffer_uptodate(bh
))
677 * The buffer is not uptodate. If the page is uptodate
678 * set the buffer uptodate and otherwise ignore it.
680 if (PageUptodate(page
)) {
681 set_buffer_uptodate(bh
);
685 * Neither the page nor the buffer are uptodate. If
686 * the buffer is only partially being written to, we
687 * need to read it in before the write, i.e. now.
689 if ((bh_pos
< pos
&& bh_end
> pos
) ||
690 (bh_pos
< end
&& bh_end
> end
)) {
692 * If the buffer is fully or partially within
693 * the initialized size, do an actual read.
694 * Otherwise, simply zero the buffer.
696 read_lock_irqsave(&ni
->size_lock
, flags
);
697 initialized_size
= ni
->initialized_size
;
698 read_unlock_irqrestore(&ni
->size_lock
, flags
);
699 if (bh_pos
< initialized_size
) {
700 ntfs_submit_bh_for_read(bh
);
703 zero_user(page
, bh_offset(bh
),
705 set_buffer_uptodate(bh
);
710 /* Unmapped buffer. Need to map it. */
711 bh
->b_bdev
= vol
->sb
->s_bdev
;
713 * If the current buffer is in the same clusters as the map
714 * cache, there is no need to check the runlist again. The
715 * map cache is made up of @vcn, which is the first cached file
716 * cluster, @vcn_len which is the number of cached file
717 * clusters, @lcn is the device cluster corresponding to @vcn,
718 * and @lcn_block is the block number corresponding to @lcn.
720 cdelta
= bh_cpos
- vcn
;
721 if (likely(!cdelta
|| (cdelta
> 0 && cdelta
< vcn_len
))) {
724 bh
->b_blocknr
= lcn_block
+
725 (cdelta
<< (vol
->cluster_size_bits
-
727 (bh_cofs
>> blocksize_bits
);
728 set_buffer_mapped(bh
);
730 * If the page is uptodate so is the buffer. If the
731 * buffer is fully outside the write, we ignore it if
732 * it was already allocated and we mark it dirty so it
733 * gets written out if we allocated it. On the other
734 * hand, if we allocated the buffer but we are not
735 * marking it dirty we set buffer_new so we can do
738 if (PageUptodate(page
)) {
739 if (!buffer_uptodate(bh
))
740 set_buffer_uptodate(bh
);
741 if (unlikely(was_hole
)) {
742 /* We allocated the buffer. */
743 unmap_underlying_metadata(bh
->b_bdev
,
745 if (bh_end
<= pos
|| bh_pos
>= end
)
746 mark_buffer_dirty(bh
);
752 /* Page is _not_ uptodate. */
753 if (likely(!was_hole
)) {
755 * Buffer was already allocated. If it is not
756 * uptodate and is only partially being written
757 * to, we need to read it in before the write,
760 if (!buffer_uptodate(bh
) && bh_pos
< end
&&
765 * If the buffer is fully or partially
766 * within the initialized size, do an
767 * actual read. Otherwise, simply zero
770 read_lock_irqsave(&ni
->size_lock
,
772 initialized_size
= ni
->initialized_size
;
773 read_unlock_irqrestore(&ni
->size_lock
,
775 if (bh_pos
< initialized_size
) {
776 ntfs_submit_bh_for_read(bh
);
779 zero_user(page
, bh_offset(bh
),
781 set_buffer_uptodate(bh
);
786 /* We allocated the buffer. */
787 unmap_underlying_metadata(bh
->b_bdev
, bh
->b_blocknr
);
789 * If the buffer is fully outside the write, zero it,
790 * set it uptodate, and mark it dirty so it gets
791 * written out. If it is partially being written to,
792 * zero region surrounding the write but leave it to
793 * commit write to do anything else. Finally, if the
794 * buffer is fully being overwritten, do nothing.
796 if (bh_end
<= pos
|| bh_pos
>= end
) {
797 if (!buffer_uptodate(bh
)) {
798 zero_user(page
, bh_offset(bh
),
800 set_buffer_uptodate(bh
);
802 mark_buffer_dirty(bh
);
806 if (!buffer_uptodate(bh
) &&
807 (bh_pos
< pos
|| bh_end
> end
)) {
811 kaddr
= kmap_atomic(page
);
813 pofs
= bh_pos
& ~PAGE_MASK
;
814 memset(kaddr
+ pofs
, 0, pos
- bh_pos
);
817 pofs
= end
& ~PAGE_MASK
;
818 memset(kaddr
+ pofs
, 0, bh_end
- end
);
820 kunmap_atomic(kaddr
);
821 flush_dcache_page(page
);
826 * Slow path: this is the first buffer in the cluster. If it
827 * is outside allocated size and is not uptodate, zero it and
830 read_lock_irqsave(&ni
->size_lock
, flags
);
831 initialized_size
= ni
->allocated_size
;
832 read_unlock_irqrestore(&ni
->size_lock
, flags
);
833 if (bh_pos
> initialized_size
) {
834 if (PageUptodate(page
)) {
835 if (!buffer_uptodate(bh
))
836 set_buffer_uptodate(bh
);
837 } else if (!buffer_uptodate(bh
)) {
838 zero_user(page
, bh_offset(bh
), blocksize
);
839 set_buffer_uptodate(bh
);
845 down_read(&ni
->runlist
.lock
);
849 if (likely(rl
!= NULL
)) {
850 /* Seek to element containing target cluster. */
851 while (rl
->length
&& rl
[1].vcn
<= bh_cpos
)
853 lcn
= ntfs_rl_vcn_to_lcn(rl
, bh_cpos
);
854 if (likely(lcn
>= 0)) {
856 * Successful remap, setup the map cache and
857 * use that to deal with the buffer.
861 vcn_len
= rl
[1].vcn
- vcn
;
862 lcn_block
= lcn
<< (vol
->cluster_size_bits
-
866 * If the number of remaining clusters touched
867 * by the write is smaller or equal to the
868 * number of cached clusters, unlock the
869 * runlist as the map cache will be used from
872 if (likely(vcn
+ vcn_len
>= cend
)) {
873 if (rl_write_locked
) {
874 up_write(&ni
->runlist
.lock
);
875 rl_write_locked
= false;
877 up_read(&ni
->runlist
.lock
);
880 goto map_buffer_cached
;
883 lcn
= LCN_RL_NOT_MAPPED
;
885 * If it is not a hole and not out of bounds, the runlist is
886 * probably unmapped so try to map it now.
888 if (unlikely(lcn
!= LCN_HOLE
&& lcn
!= LCN_ENOENT
)) {
889 if (likely(!is_retry
&& lcn
== LCN_RL_NOT_MAPPED
)) {
890 /* Attempt to map runlist. */
891 if (!rl_write_locked
) {
893 * We need the runlist locked for
894 * writing, so if it is locked for
895 * reading relock it now and retry in
896 * case it changed whilst we dropped
899 up_read(&ni
->runlist
.lock
);
900 down_write(&ni
->runlist
.lock
);
901 rl_write_locked
= true;
904 err
= ntfs_map_runlist_nolock(ni
, bh_cpos
,
911 * If @vcn is out of bounds, pretend @lcn is
912 * LCN_ENOENT. As long as the buffer is out
913 * of bounds this will work fine.
915 if (err
== -ENOENT
) {
918 goto rl_not_mapped_enoent
;
922 /* Failed to map the buffer, even after retrying. */
924 ntfs_error(vol
->sb
, "Failed to write to inode 0x%lx, "
925 "attribute type 0x%x, vcn 0x%llx, "
926 "vcn offset 0x%x, because its "
927 "location on disk could not be "
928 "determined%s (error code %i).",
929 ni
->mft_no
, ni
->type
,
930 (unsigned long long)bh_cpos
,
932 vol
->cluster_size_mask
,
933 is_retry
? " even after retrying" : "",
937 rl_not_mapped_enoent
:
939 * The buffer is in a hole or out of bounds. We need to fill
940 * the hole, unless the buffer is in a cluster which is not
941 * touched by the write, in which case we just leave the buffer
942 * unmapped. This can only happen when the cluster size is
943 * less than the page cache size.
945 if (unlikely(vol
->cluster_size
< PAGE_SIZE
)) {
946 bh_cend
= (bh_end
+ vol
->cluster_size
- 1) >>
947 vol
->cluster_size_bits
;
948 if ((bh_cend
<= cpos
|| bh_cpos
>= cend
)) {
951 * If the buffer is uptodate we skip it. If it
952 * is not but the page is uptodate, we can set
953 * the buffer uptodate. If the page is not
954 * uptodate, we can clear the buffer and set it
955 * uptodate. Whether this is worthwhile is
956 * debatable and this could be removed.
958 if (PageUptodate(page
)) {
959 if (!buffer_uptodate(bh
))
960 set_buffer_uptodate(bh
);
961 } else if (!buffer_uptodate(bh
)) {
962 zero_user(page
, bh_offset(bh
),
964 set_buffer_uptodate(bh
);
970 * Out of bounds buffer is invalid if it was not really out of
973 BUG_ON(lcn
!= LCN_HOLE
);
975 * We need the runlist locked for writing, so if it is locked
976 * for reading relock it now and retry in case it changed
977 * whilst we dropped the lock.
980 if (!rl_write_locked
) {
981 up_read(&ni
->runlist
.lock
);
982 down_write(&ni
->runlist
.lock
);
983 rl_write_locked
= true;
986 /* Find the previous last allocated cluster. */
987 BUG_ON(rl
->lcn
!= LCN_HOLE
);
990 while (--rl2
>= ni
->runlist
.rl
) {
992 lcn
= rl2
->lcn
+ rl2
->length
;
996 rl2
= ntfs_cluster_alloc(vol
, bh_cpos
, 1, lcn
, DATA_ZONE
,
1000 ntfs_debug("Failed to allocate cluster, error code %i.",
1005 rl
= ntfs_runlists_merge(ni
->runlist
.rl
, rl2
);
1010 if (ntfs_cluster_free_from_rl(vol
, rl2
)) {
1011 ntfs_error(vol
->sb
, "Failed to release "
1012 "allocated cluster in error "
1013 "code path. Run chkdsk to "
1014 "recover the lost cluster.");
1020 ni
->runlist
.rl
= rl
;
1021 status
.runlist_merged
= 1;
1022 ntfs_debug("Allocated cluster, lcn 0x%llx.",
1023 (unsigned long long)lcn
);
1024 /* Map and lock the mft record and get the attribute record. */
1028 base_ni
= ni
->ext
.base_ntfs_ino
;
1029 m
= map_mft_record(base_ni
);
1034 ctx
= ntfs_attr_get_search_ctx(base_ni
, m
);
1035 if (unlikely(!ctx
)) {
1037 unmap_mft_record(base_ni
);
1040 status
.mft_attr_mapped
= 1;
1041 err
= ntfs_attr_lookup(ni
->type
, ni
->name
, ni
->name_len
,
1042 CASE_SENSITIVE
, bh_cpos
, NULL
, 0, ctx
);
1043 if (unlikely(err
)) {
1051 * Find the runlist element with which the attribute extent
1052 * starts. Note, we cannot use the _attr_ version because we
1053 * have mapped the mft record. That is ok because we know the
1054 * runlist fragment must be mapped already to have ever gotten
1055 * here, so we can just use the _rl_ version.
1057 vcn
= sle64_to_cpu(a
->data
.non_resident
.lowest_vcn
);
1058 rl2
= ntfs_rl_find_vcn_nolock(rl
, vcn
);
1060 BUG_ON(!rl2
->length
);
1061 BUG_ON(rl2
->lcn
< LCN_HOLE
);
1062 highest_vcn
= sle64_to_cpu(a
->data
.non_resident
.highest_vcn
);
1064 * If @highest_vcn is zero, calculate the real highest_vcn
1065 * (which can really be zero).
1068 highest_vcn
= (sle64_to_cpu(
1069 a
->data
.non_resident
.allocated_size
) >>
1070 vol
->cluster_size_bits
) - 1;
1072 * Determine the size of the mapping pairs array for the new
1073 * extent, i.e. the old extent with the hole filled.
1075 mp_size
= ntfs_get_size_for_mapping_pairs(vol
, rl2
, vcn
,
1077 if (unlikely(mp_size
<= 0)) {
1078 if (!(err
= mp_size
))
1080 ntfs_debug("Failed to get size for mapping pairs "
1081 "array, error code %i.", err
);
1085 * Resize the attribute record to fit the new mapping pairs
1088 attr_rec_len
= le32_to_cpu(a
->length
);
1089 err
= ntfs_attr_record_resize(m
, a
, mp_size
+ le16_to_cpu(
1090 a
->data
.non_resident
.mapping_pairs_offset
));
1091 if (unlikely(err
)) {
1092 BUG_ON(err
!= -ENOSPC
);
1093 // TODO: Deal with this by using the current attribute
1094 // and fill it with as much of the mapping pairs
1095 // array as possible. Then loop over each attribute
1096 // extent rewriting the mapping pairs arrays as we go
1097 // along and if when we reach the end we have not
1098 // enough space, try to resize the last attribute
1099 // extent and if even that fails, add a new attribute
1101 // We could also try to resize at each step in the hope
1102 // that we will not need to rewrite every single extent.
1103 // Note, we may need to decompress some extents to fill
1104 // the runlist as we are walking the extents...
1105 ntfs_error(vol
->sb
, "Not enough space in the mft "
1106 "record for the extended attribute "
1107 "record. This case is not "
1108 "implemented yet.");
1112 status
.mp_rebuilt
= 1;
1114 * Generate the mapping pairs array directly into the attribute
1117 err
= ntfs_mapping_pairs_build(vol
, (u8
*)a
+ le16_to_cpu(
1118 a
->data
.non_resident
.mapping_pairs_offset
),
1119 mp_size
, rl2
, vcn
, highest_vcn
, NULL
);
1120 if (unlikely(err
)) {
1121 ntfs_error(vol
->sb
, "Cannot fill hole in inode 0x%lx, "
1122 "attribute type 0x%x, because building "
1123 "the mapping pairs failed with error "
1124 "code %i.", vi
->i_ino
,
1125 (unsigned)le32_to_cpu(ni
->type
), err
);
1129 /* Update the highest_vcn but only if it was not set. */
1130 if (unlikely(!a
->data
.non_resident
.highest_vcn
))
1131 a
->data
.non_resident
.highest_vcn
=
1132 cpu_to_sle64(highest_vcn
);
1134 * If the attribute is sparse/compressed, update the compressed
1135 * size in the ntfs_inode structure and the attribute record.
1137 if (likely(NInoSparse(ni
) || NInoCompressed(ni
))) {
1139 * If we are not in the first attribute extent, switch
1140 * to it, but first ensure the changes will make it to
1143 if (a
->data
.non_resident
.lowest_vcn
) {
1144 flush_dcache_mft_record_page(ctx
->ntfs_ino
);
1145 mark_mft_record_dirty(ctx
->ntfs_ino
);
1146 ntfs_attr_reinit_search_ctx(ctx
);
1147 err
= ntfs_attr_lookup(ni
->type
, ni
->name
,
1148 ni
->name_len
, CASE_SENSITIVE
,
1150 if (unlikely(err
)) {
1151 status
.attr_switched
= 1;
1154 /* @m is not used any more so do not set it. */
1157 write_lock_irqsave(&ni
->size_lock
, flags
);
1158 ni
->itype
.compressed
.size
+= vol
->cluster_size
;
1159 a
->data
.non_resident
.compressed_size
=
1160 cpu_to_sle64(ni
->itype
.compressed
.size
);
1161 write_unlock_irqrestore(&ni
->size_lock
, flags
);
1163 /* Ensure the changes make it to disk. */
1164 flush_dcache_mft_record_page(ctx
->ntfs_ino
);
1165 mark_mft_record_dirty(ctx
->ntfs_ino
);
1166 ntfs_attr_put_search_ctx(ctx
);
1167 unmap_mft_record(base_ni
);
1168 /* Successfully filled the hole. */
1169 status
.runlist_merged
= 0;
1170 status
.mft_attr_mapped
= 0;
1171 status
.mp_rebuilt
= 0;
1172 /* Setup the map cache and use that to deal with the buffer. */
1176 lcn_block
= lcn
<< (vol
->cluster_size_bits
- blocksize_bits
);
1179 * If the number of remaining clusters in the @pages is smaller
1180 * or equal to the number of cached clusters, unlock the
1181 * runlist as the map cache will be used from now on.
1183 if (likely(vcn
+ vcn_len
>= cend
)) {
1184 up_write(&ni
->runlist
.lock
);
1185 rl_write_locked
= false;
1188 goto map_buffer_cached
;
1189 } while (bh_pos
+= blocksize
, (bh
= bh
->b_this_page
) != head
);
1190 /* If there are no errors, do the next page. */
1191 if (likely(!err
&& ++u
< nr_pages
))
1193 /* If there are no errors, release the runlist lock if we took it. */
1195 if (unlikely(rl_write_locked
)) {
1196 up_write(&ni
->runlist
.lock
);
1197 rl_write_locked
= false;
1198 } else if (unlikely(rl
))
1199 up_read(&ni
->runlist
.lock
);
1202 /* If we issued read requests, let them complete. */
1203 read_lock_irqsave(&ni
->size_lock
, flags
);
1204 initialized_size
= ni
->initialized_size
;
1205 read_unlock_irqrestore(&ni
->size_lock
, flags
);
1206 while (wait_bh
> wait
) {
1209 if (likely(buffer_uptodate(bh
))) {
1211 bh_pos
= ((s64
)page
->index
<< PAGE_SHIFT
) +
1214 * If the buffer overflows the initialized size, need
1215 * to zero the overflowing region.
1217 if (unlikely(bh_pos
+ blocksize
> initialized_size
)) {
1220 if (likely(bh_pos
< initialized_size
))
1221 ofs
= initialized_size
- bh_pos
;
1222 zero_user_segment(page
, bh_offset(bh
) + ofs
,
1225 } else /* if (unlikely(!buffer_uptodate(bh))) */
1229 /* Clear buffer_new on all buffers. */
1232 bh
= head
= page_buffers(pages
[u
]);
1235 clear_buffer_new(bh
);
1236 } while ((bh
= bh
->b_this_page
) != head
);
1237 } while (++u
< nr_pages
);
1238 ntfs_debug("Done.");
1241 if (status
.attr_switched
) {
1242 /* Get back to the attribute extent we modified. */
1243 ntfs_attr_reinit_search_ctx(ctx
);
1244 if (ntfs_attr_lookup(ni
->type
, ni
->name
, ni
->name_len
,
1245 CASE_SENSITIVE
, bh_cpos
, NULL
, 0, ctx
)) {
1246 ntfs_error(vol
->sb
, "Failed to find required "
1247 "attribute extent of attribute in "
1248 "error code path. Run chkdsk to "
1250 write_lock_irqsave(&ni
->size_lock
, flags
);
1251 ni
->itype
.compressed
.size
+= vol
->cluster_size
;
1252 write_unlock_irqrestore(&ni
->size_lock
, flags
);
1253 flush_dcache_mft_record_page(ctx
->ntfs_ino
);
1254 mark_mft_record_dirty(ctx
->ntfs_ino
);
1256 * The only thing that is now wrong is the compressed
1257 * size of the base attribute extent which chkdsk
1258 * should be able to fix.
1264 status
.attr_switched
= 0;
1268 * If the runlist has been modified, need to restore it by punching a
1269 * hole into it and we then need to deallocate the on-disk cluster as
1270 * well. Note, we only modify the runlist if we are able to generate a
1271 * new mapping pairs array, i.e. only when the mapped attribute extent
1274 if (status
.runlist_merged
&& !status
.attr_switched
) {
1275 BUG_ON(!rl_write_locked
);
1276 /* Make the file cluster we allocated sparse in the runlist. */
1277 if (ntfs_rl_punch_nolock(vol
, &ni
->runlist
, bh_cpos
, 1)) {
1278 ntfs_error(vol
->sb
, "Failed to punch hole into "
1279 "attribute runlist in error code "
1280 "path. Run chkdsk to recover the "
1283 } else /* if (success) */ {
1284 status
.runlist_merged
= 0;
1286 * Deallocate the on-disk cluster we allocated but only
1287 * if we succeeded in punching its vcn out of the
1290 down_write(&vol
->lcnbmp_lock
);
1291 if (ntfs_bitmap_clear_bit(vol
->lcnbmp_ino
, lcn
)) {
1292 ntfs_error(vol
->sb
, "Failed to release "
1293 "allocated cluster in error "
1294 "code path. Run chkdsk to "
1295 "recover the lost cluster.");
1298 up_write(&vol
->lcnbmp_lock
);
1302 * Resize the attribute record to its old size and rebuild the mapping
1303 * pairs array. Note, we only can do this if the runlist has been
1304 * restored to its old state which also implies that the mapped
1305 * attribute extent is not switched.
1307 if (status
.mp_rebuilt
&& !status
.runlist_merged
) {
1308 if (ntfs_attr_record_resize(m
, a
, attr_rec_len
)) {
1309 ntfs_error(vol
->sb
, "Failed to restore attribute "
1310 "record in error code path. Run "
1311 "chkdsk to recover.");
1313 } else /* if (success) */ {
1314 if (ntfs_mapping_pairs_build(vol
, (u8
*)a
+
1315 le16_to_cpu(a
->data
.non_resident
.
1316 mapping_pairs_offset
), attr_rec_len
-
1317 le16_to_cpu(a
->data
.non_resident
.
1318 mapping_pairs_offset
), ni
->runlist
.rl
,
1319 vcn
, highest_vcn
, NULL
)) {
1320 ntfs_error(vol
->sb
, "Failed to restore "
1321 "mapping pairs array in error "
1322 "code path. Run chkdsk to "
1326 flush_dcache_mft_record_page(ctx
->ntfs_ino
);
1327 mark_mft_record_dirty(ctx
->ntfs_ino
);
1330 /* Release the mft record and the attribute. */
1331 if (status
.mft_attr_mapped
) {
1332 ntfs_attr_put_search_ctx(ctx
);
1333 unmap_mft_record(base_ni
);
1335 /* Release the runlist lock. */
1336 if (rl_write_locked
)
1337 up_write(&ni
->runlist
.lock
);
1339 up_read(&ni
->runlist
.lock
);
1341 * Zero out any newly allocated blocks to avoid exposing stale data.
1342 * If BH_New is set, we know that the block was newly allocated above
1343 * and that it has not been fully zeroed and marked dirty yet.
1347 end
= bh_cpos
<< vol
->cluster_size_bits
;
1350 bh
= head
= page_buffers(page
);
1352 if (u
== nr_pages
&&
1353 ((s64
)page
->index
<< PAGE_SHIFT
) +
1354 bh_offset(bh
) >= end
)
1356 if (!buffer_new(bh
))
1358 clear_buffer_new(bh
);
1359 if (!buffer_uptodate(bh
)) {
1360 if (PageUptodate(page
))
1361 set_buffer_uptodate(bh
);
1363 zero_user(page
, bh_offset(bh
),
1365 set_buffer_uptodate(bh
);
1368 mark_buffer_dirty(bh
);
1369 } while ((bh
= bh
->b_this_page
) != head
);
1370 } while (++u
<= nr_pages
);
1371 ntfs_error(vol
->sb
, "Failed. Returning error code %i.", err
);
1375 static inline void ntfs_flush_dcache_pages(struct page
**pages
,
1380 * Warning: Do not do the decrement at the same time as the call to
1381 * flush_dcache_page() because it is a NULL macro on i386 and hence the
1382 * decrement never happens so the loop never terminates.
1386 flush_dcache_page(pages
[nr_pages
]);
1387 } while (nr_pages
> 0);
1391 * ntfs_commit_pages_after_non_resident_write - commit the received data
1392 * @pages: array of destination pages
1393 * @nr_pages: number of pages in @pages
1394 * @pos: byte position in file at which the write begins
1395 * @bytes: number of bytes to be written
1397 * See description of ntfs_commit_pages_after_write(), below.
1399 static inline int ntfs_commit_pages_after_non_resident_write(
1400 struct page
**pages
, const unsigned nr_pages
,
1401 s64 pos
, size_t bytes
)
1403 s64 end
, initialized_size
;
1405 ntfs_inode
*ni
, *base_ni
;
1406 struct buffer_head
*bh
, *head
;
1407 ntfs_attr_search_ctx
*ctx
;
1410 unsigned long flags
;
1411 unsigned blocksize
, u
;
1414 vi
= pages
[0]->mapping
->host
;
1416 blocksize
= vi
->i_sb
->s_blocksize
;
1425 bh_pos
= (s64
)page
->index
<< PAGE_SHIFT
;
1426 bh
= head
= page_buffers(page
);
1431 bh_end
= bh_pos
+ blocksize
;
1432 if (bh_end
<= pos
|| bh_pos
>= end
) {
1433 if (!buffer_uptodate(bh
))
1436 set_buffer_uptodate(bh
);
1437 mark_buffer_dirty(bh
);
1439 } while (bh_pos
+= blocksize
, (bh
= bh
->b_this_page
) != head
);
1441 * If all buffers are now uptodate but the page is not, set the
1444 if (!partial
&& !PageUptodate(page
))
1445 SetPageUptodate(page
);
1446 } while (++u
< nr_pages
);
1448 * Finally, if we do not need to update initialized_size or i_size we
1451 read_lock_irqsave(&ni
->size_lock
, flags
);
1452 initialized_size
= ni
->initialized_size
;
1453 read_unlock_irqrestore(&ni
->size_lock
, flags
);
1454 if (end
<= initialized_size
) {
1455 ntfs_debug("Done.");
1459 * Update initialized_size/i_size as appropriate, both in the inode and
1465 base_ni
= ni
->ext
.base_ntfs_ino
;
1466 /* Map, pin, and lock the mft record. */
1467 m
= map_mft_record(base_ni
);
1474 BUG_ON(!NInoNonResident(ni
));
1475 ctx
= ntfs_attr_get_search_ctx(base_ni
, m
);
1476 if (unlikely(!ctx
)) {
1480 err
= ntfs_attr_lookup(ni
->type
, ni
->name
, ni
->name_len
,
1481 CASE_SENSITIVE
, 0, NULL
, 0, ctx
);
1482 if (unlikely(err
)) {
1488 BUG_ON(!a
->non_resident
);
1489 write_lock_irqsave(&ni
->size_lock
, flags
);
1490 BUG_ON(end
> ni
->allocated_size
);
1491 ni
->initialized_size
= end
;
1492 a
->data
.non_resident
.initialized_size
= cpu_to_sle64(end
);
1493 if (end
> i_size_read(vi
)) {
1494 i_size_write(vi
, end
);
1495 a
->data
.non_resident
.data_size
=
1496 a
->data
.non_resident
.initialized_size
;
1498 write_unlock_irqrestore(&ni
->size_lock
, flags
);
1499 /* Mark the mft record dirty, so it gets written back. */
1500 flush_dcache_mft_record_page(ctx
->ntfs_ino
);
1501 mark_mft_record_dirty(ctx
->ntfs_ino
);
1502 ntfs_attr_put_search_ctx(ctx
);
1503 unmap_mft_record(base_ni
);
1504 ntfs_debug("Done.");
1508 ntfs_attr_put_search_ctx(ctx
);
1510 unmap_mft_record(base_ni
);
1511 ntfs_error(vi
->i_sb
, "Failed to update initialized_size/i_size (error "
1514 NVolSetErrors(ni
->vol
);
1519 * ntfs_commit_pages_after_write - commit the received data
1520 * @pages: array of destination pages
1521 * @nr_pages: number of pages in @pages
1522 * @pos: byte position in file at which the write begins
1523 * @bytes: number of bytes to be written
1525 * This is called from ntfs_file_buffered_write() with i_mutex held on the inode
1526 * (@pages[0]->mapping->host). There are @nr_pages pages in @pages which are
1527 * locked but not kmap()ped. The source data has already been copied into the
1528 * @page. ntfs_prepare_pages_for_non_resident_write() has been called before
1529 * the data was copied (for non-resident attributes only) and it returned
1532 * Need to set uptodate and mark dirty all buffers within the boundary of the
1533 * write. If all buffers in a page are uptodate we set the page uptodate, too.
1535 * Setting the buffers dirty ensures that they get written out later when
1536 * ntfs_writepage() is invoked by the VM.
1538 * Finally, we need to update i_size and initialized_size as appropriate both
1539 * in the inode and the mft record.
1541 * This is modelled after fs/buffer.c::generic_commit_write(), which marks
1542 * buffers uptodate and dirty, sets the page uptodate if all buffers in the
1543 * page are uptodate, and updates i_size if the end of io is beyond i_size. In
1544 * that case, it also marks the inode dirty.
1546 * If things have gone as outlined in
1547 * ntfs_prepare_pages_for_non_resident_write(), we do not need to do any page
1548 * content modifications here for non-resident attributes. For resident
1549 * attributes we need to do the uptodate bringing here which we combine with
1550 * the copying into the mft record which means we save one atomic kmap.
1552 * Return 0 on success or -errno on error.
1554 static int ntfs_commit_pages_after_write(struct page
**pages
,
1555 const unsigned nr_pages
, s64 pos
, size_t bytes
)
1557 s64 end
, initialized_size
;
1560 ntfs_inode
*ni
, *base_ni
;
1562 ntfs_attr_search_ctx
*ctx
;
1565 char *kattr
, *kaddr
;
1566 unsigned long flags
;
1574 vi
= page
->mapping
->host
;
1576 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, start page "
1577 "index 0x%lx, nr_pages 0x%x, pos 0x%llx, bytes 0x%zx.",
1578 vi
->i_ino
, ni
->type
, page
->index
, nr_pages
,
1579 (long long)pos
, bytes
);
1580 if (NInoNonResident(ni
))
1581 return ntfs_commit_pages_after_non_resident_write(pages
,
1582 nr_pages
, pos
, bytes
);
1583 BUG_ON(nr_pages
> 1);
1585 * Attribute is resident, implying it is not compressed, encrypted, or
1591 base_ni
= ni
->ext
.base_ntfs_ino
;
1592 BUG_ON(NInoNonResident(ni
));
1593 /* Map, pin, and lock the mft record. */
1594 m
= map_mft_record(base_ni
);
1601 ctx
= ntfs_attr_get_search_ctx(base_ni
, m
);
1602 if (unlikely(!ctx
)) {
1606 err
= ntfs_attr_lookup(ni
->type
, ni
->name
, ni
->name_len
,
1607 CASE_SENSITIVE
, 0, NULL
, 0, ctx
);
1608 if (unlikely(err
)) {
1614 BUG_ON(a
->non_resident
);
1615 /* The total length of the attribute value. */
1616 attr_len
= le32_to_cpu(a
->data
.resident
.value_length
);
1617 i_size
= i_size_read(vi
);
1618 BUG_ON(attr_len
!= i_size
);
1619 BUG_ON(pos
> attr_len
);
1621 BUG_ON(end
> le32_to_cpu(a
->length
) -
1622 le16_to_cpu(a
->data
.resident
.value_offset
));
1623 kattr
= (u8
*)a
+ le16_to_cpu(a
->data
.resident
.value_offset
);
1624 kaddr
= kmap_atomic(page
);
1625 /* Copy the received data from the page to the mft record. */
1626 memcpy(kattr
+ pos
, kaddr
+ pos
, bytes
);
1627 /* Update the attribute length if necessary. */
1628 if (end
> attr_len
) {
1630 a
->data
.resident
.value_length
= cpu_to_le32(attr_len
);
1633 * If the page is not uptodate, bring the out of bounds area(s)
1634 * uptodate by copying data from the mft record to the page.
1636 if (!PageUptodate(page
)) {
1638 memcpy(kaddr
, kattr
, pos
);
1640 memcpy(kaddr
+ end
, kattr
+ end
, attr_len
- end
);
1641 /* Zero the region outside the end of the attribute value. */
1642 memset(kaddr
+ attr_len
, 0, PAGE_SIZE
- attr_len
);
1643 flush_dcache_page(page
);
1644 SetPageUptodate(page
);
1646 kunmap_atomic(kaddr
);
1647 /* Update initialized_size/i_size if necessary. */
1648 read_lock_irqsave(&ni
->size_lock
, flags
);
1649 initialized_size
= ni
->initialized_size
;
1650 BUG_ON(end
> ni
->allocated_size
);
1651 read_unlock_irqrestore(&ni
->size_lock
, flags
);
1652 BUG_ON(initialized_size
!= i_size
);
1653 if (end
> initialized_size
) {
1654 write_lock_irqsave(&ni
->size_lock
, flags
);
1655 ni
->initialized_size
= end
;
1656 i_size_write(vi
, end
);
1657 write_unlock_irqrestore(&ni
->size_lock
, flags
);
1659 /* Mark the mft record dirty, so it gets written back. */
1660 flush_dcache_mft_record_page(ctx
->ntfs_ino
);
1661 mark_mft_record_dirty(ctx
->ntfs_ino
);
1662 ntfs_attr_put_search_ctx(ctx
);
1663 unmap_mft_record(base_ni
);
1664 ntfs_debug("Done.");
1667 if (err
== -ENOMEM
) {
1668 ntfs_warning(vi
->i_sb
, "Error allocating memory required to "
1669 "commit the write.");
1670 if (PageUptodate(page
)) {
1671 ntfs_warning(vi
->i_sb
, "Page is uptodate, setting "
1672 "dirty so the write will be retried "
1673 "later on by the VM.");
1675 * Put the page on mapping->dirty_pages, but leave its
1676 * buffers' dirty state as-is.
1678 __set_page_dirty_nobuffers(page
);
1681 ntfs_error(vi
->i_sb
, "Page is not uptodate. Written "
1682 "data has been lost.");
1684 ntfs_error(vi
->i_sb
, "Resident attribute commit write failed "
1685 "with error %i.", err
);
1686 NVolSetErrors(ni
->vol
);
1689 ntfs_attr_put_search_ctx(ctx
);
1691 unmap_mft_record(base_ni
);
1696 * Copy as much as we can into the pages and return the number of bytes which
1697 * were successfully copied. If a fault is encountered then clear the pages
1698 * out to (ofs + bytes) and return the number of bytes which were copied.
1700 static size_t ntfs_copy_from_user_iter(struct page
**pages
, unsigned nr_pages
,
1701 unsigned ofs
, struct iov_iter
*i
, size_t bytes
)
1703 struct page
**last_page
= pages
+ nr_pages
;
1705 struct iov_iter data
= *i
;
1706 unsigned len
, copied
;
1709 len
= PAGE_SIZE
- ofs
;
1712 copied
= iov_iter_copy_from_user_atomic(*pages
, &data
, ofs
,
1718 iov_iter_advance(&data
, copied
);
1722 } while (++pages
< last_page
);
1726 /* Zero the rest of the target like __copy_from_user(). */
1727 len
= PAGE_SIZE
- copied
;
1731 zero_user(*pages
, copied
, len
);
1735 } while (++pages
< last_page
);
1740 * ntfs_perform_write - perform buffered write to a file
1741 * @file: file to write to
1742 * @i: iov_iter with data to write
1743 * @pos: byte offset in file at which to begin writing to
1745 static ssize_t
ntfs_perform_write(struct file
*file
, struct iov_iter
*i
,
1748 struct address_space
*mapping
= file
->f_mapping
;
1749 struct inode
*vi
= mapping
->host
;
1750 ntfs_inode
*ni
= NTFS_I(vi
);
1751 ntfs_volume
*vol
= ni
->vol
;
1752 struct page
*pages
[NTFS_MAX_PAGES_PER_CLUSTER
];
1753 struct page
*cached_page
= NULL
;
1757 ssize_t status
, written
= 0;
1760 ntfs_debug("Entering for i_ino 0x%lx, attribute type 0x%x, pos "
1761 "0x%llx, count 0x%lx.", vi
->i_ino
,
1762 (unsigned)le32_to_cpu(ni
->type
),
1763 (unsigned long long)pos
,
1764 (unsigned long)iov_iter_count(i
));
1766 * If a previous ntfs_truncate() failed, repeat it and abort if it
1769 if (unlikely(NInoTruncateFailed(ni
))) {
1773 err
= ntfs_truncate(vi
);
1774 if (err
|| NInoTruncateFailed(ni
)) {
1777 ntfs_error(vol
->sb
, "Cannot perform write to inode "
1778 "0x%lx, attribute type 0x%x, because "
1779 "ntfs_truncate() failed (error code "
1781 (unsigned)le32_to_cpu(ni
->type
), err
);
1786 * Determine the number of pages per cluster for non-resident
1790 if (vol
->cluster_size
> PAGE_SIZE
&& NInoNonResident(ni
))
1791 nr_pages
= vol
->cluster_size
>> PAGE_SHIFT
;
1795 pgoff_t idx
, start_idx
;
1796 unsigned ofs
, do_pages
, u
;
1799 start_idx
= idx
= pos
>> PAGE_SHIFT
;
1800 ofs
= pos
& ~PAGE_MASK
;
1801 bytes
= PAGE_SIZE
- ofs
;
1804 vcn
= pos
>> vol
->cluster_size_bits
;
1805 if (vcn
!= last_vcn
) {
1808 * Get the lcn of the vcn the write is in. If
1809 * it is a hole, need to lock down all pages in
1812 down_read(&ni
->runlist
.lock
);
1813 lcn
= ntfs_attr_vcn_to_lcn_nolock(ni
, pos
>>
1814 vol
->cluster_size_bits
, false);
1815 up_read(&ni
->runlist
.lock
);
1816 if (unlikely(lcn
< LCN_HOLE
)) {
1817 if (lcn
== LCN_ENOMEM
)
1821 ntfs_error(vol
->sb
, "Cannot "
1824 "attribute type 0x%x, "
1825 "because the attribute "
1827 vi
->i_ino
, (unsigned)
1828 le32_to_cpu(ni
->type
));
1832 if (lcn
== LCN_HOLE
) {
1833 start_idx
= (pos
& ~(s64
)
1834 vol
->cluster_size_mask
)
1836 bytes
= vol
->cluster_size
- (pos
&
1837 vol
->cluster_size_mask
);
1838 do_pages
= nr_pages
;
1842 if (bytes
> iov_iter_count(i
))
1843 bytes
= iov_iter_count(i
);
1846 * Bring in the user page(s) that we will copy from _first_.
1847 * Otherwise there is a nasty deadlock on copying from the same
1848 * page(s) as we are writing to, without it/them being marked
1849 * up-to-date. Note, at present there is nothing to stop the
1850 * pages being swapped out between us bringing them into memory
1851 * and doing the actual copying.
1853 if (unlikely(iov_iter_fault_in_multipages_readable(i
, bytes
))) {
1857 /* Get and lock @do_pages starting at index @start_idx. */
1858 status
= __ntfs_grab_cache_pages(mapping
, start_idx
, do_pages
,
1859 pages
, &cached_page
);
1860 if (unlikely(status
))
1863 * For non-resident attributes, we need to fill any holes with
1864 * actual clusters and ensure all bufferes are mapped. We also
1865 * need to bring uptodate any buffers that are only partially
1868 if (NInoNonResident(ni
)) {
1869 status
= ntfs_prepare_pages_for_non_resident_write(
1870 pages
, do_pages
, pos
, bytes
);
1871 if (unlikely(status
)) {
1873 unlock_page(pages
[--do_pages
]);
1874 put_page(pages
[do_pages
]);
1879 u
= (pos
>> PAGE_SHIFT
) - pages
[0]->index
;
1880 copied
= ntfs_copy_from_user_iter(pages
+ u
, do_pages
- u
, ofs
,
1882 ntfs_flush_dcache_pages(pages
+ u
, do_pages
- u
);
1884 if (likely(copied
== bytes
)) {
1885 status
= ntfs_commit_pages_after_write(pages
, do_pages
,
1891 unlock_page(pages
[--do_pages
]);
1892 put_page(pages
[do_pages
]);
1894 if (unlikely(status
< 0))
1898 if (unlikely(!copied
)) {
1902 * We failed to copy anything. Fall back to single
1903 * segment length write.
1905 * This is needed to avoid possible livelock in the
1906 * case that all segments in the iov cannot be copied
1907 * at once without a pagefault.
1909 sc
= iov_iter_single_seg_count(i
);
1914 iov_iter_advance(i
, copied
);
1917 balance_dirty_pages_ratelimited(mapping
);
1918 if (fatal_signal_pending(current
)) {
1922 } while (iov_iter_count(i
));
1924 put_page(cached_page
);
1925 ntfs_debug("Done. Returning %s (written 0x%lx, status %li).",
1926 written
? "written" : "status", (unsigned long)written
,
1928 return written
? written
: status
;
1932 * ntfs_file_write_iter - simple wrapper for ntfs_file_write_iter_nolock()
1933 * @iocb: IO state structure
1934 * @from: iov_iter with data to write
1936 * Basically the same as generic_file_write_iter() except that it ends up
1937 * up calling ntfs_perform_write() instead of generic_perform_write() and that
1938 * O_DIRECT is not implemented.
1940 static ssize_t
ntfs_file_write_iter(struct kiocb
*iocb
, struct iov_iter
*from
)
1942 struct file
*file
= iocb
->ki_filp
;
1943 struct inode
*vi
= file_inode(file
);
1944 ssize_t written
= 0;
1948 /* We can write back this queue in page reclaim. */
1949 current
->backing_dev_info
= inode_to_bdi(vi
);
1950 err
= ntfs_prepare_file_for_write(iocb
, from
);
1951 if (iov_iter_count(from
) && !err
)
1952 written
= ntfs_perform_write(file
, from
, iocb
->ki_pos
);
1953 current
->backing_dev_info
= NULL
;
1955 if (likely(written
> 0)) {
1956 err
= generic_write_sync(file
, iocb
->ki_pos
, written
);
1960 iocb
->ki_pos
+= written
;
1961 return written
? written
: err
;
1965 * ntfs_file_fsync - sync a file to disk
1966 * @filp: file to be synced
1967 * @datasync: if non-zero only flush user data and not metadata
1969 * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync
1970 * system calls. This function is inspired by fs/buffer.c::file_fsync().
1972 * If @datasync is false, write the mft record and all associated extent mft
1973 * records as well as the $DATA attribute and then sync the block device.
1975 * If @datasync is true and the attribute is non-resident, we skip the writing
1976 * of the mft record and all associated extent mft records (this might still
1977 * happen due to the write_inode_now() call).
1979 * Also, if @datasync is true, we do not wait on the inode to be written out
1980 * but we always wait on the page cache pages to be written out.
1982 * Locking: Caller must hold i_mutex on the inode.
1984 * TODO: We should probably also write all attribute/index inodes associated
1985 * with this inode but since we have no simple way of getting to them we ignore
1986 * this problem for now.
1988 static int ntfs_file_fsync(struct file
*filp
, loff_t start
, loff_t end
,
1991 struct inode
*vi
= filp
->f_mapping
->host
;
1994 ntfs_debug("Entering for inode 0x%lx.", vi
->i_ino
);
1996 err
= filemap_write_and_wait_range(vi
->i_mapping
, start
, end
);
2001 BUG_ON(S_ISDIR(vi
->i_mode
));
2002 if (!datasync
|| !NInoNonResident(NTFS_I(vi
)))
2003 ret
= __ntfs_write_inode(vi
, 1);
2004 write_inode_now(vi
, !datasync
);
2006 * NOTE: If we were to use mapping->private_list (see ext2 and
2007 * fs/buffer.c) for dirty blocks then we could optimize the below to be
2008 * sync_mapping_buffers(vi->i_mapping).
2010 err
= sync_blockdev(vi
->i_sb
->s_bdev
);
2011 if (unlikely(err
&& !ret
))
2014 ntfs_debug("Done.");
2016 ntfs_warning(vi
->i_sb
, "Failed to f%ssync inode 0x%lx. Error "
2017 "%u.", datasync
? "data" : "", vi
->i_ino
, -ret
);
2022 #endif /* NTFS_RW */
2024 const struct file_operations ntfs_file_ops
= {
2025 .llseek
= generic_file_llseek
,
2026 .read_iter
= generic_file_read_iter
,
2028 .write_iter
= ntfs_file_write_iter
,
2029 .fsync
= ntfs_file_fsync
,
2030 #endif /* NTFS_RW */
2031 .mmap
= generic_file_mmap
,
2032 .open
= ntfs_file_open
,
2033 .splice_read
= generic_file_splice_read
,
2036 const struct inode_operations ntfs_file_inode_ops
= {
2038 .setattr
= ntfs_setattr
,
2039 #endif /* NTFS_RW */
2042 const struct file_operations ntfs_empty_file_ops
= {};
2044 const struct inode_operations ntfs_empty_inode_ops
= {};