1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * aops.c - NTFS kernel address space operations and page cache handling.
5 * Copyright (c) 2001-2014 Anton Altaparmakov and Tuxera Inc.
6 * Copyright (c) 2002 Richard Russon
9 #include <linux/errno.h>
11 #include <linux/gfp.h>
13 #include <linux/pagemap.h>
14 #include <linux/swap.h>
15 #include <linux/buffer_head.h>
16 #include <linux/writeback.h>
17 #include <linux/bit_spinlock.h>
18 #include <linux/bio.h>
30 * ntfs_end_buffer_async_read - async io completion for reading attributes
31 * @bh: buffer head on which io is completed
32 * @uptodate: whether @bh is now uptodate or not
34 * Asynchronous I/O completion handler for reading pages belonging to the
35 * attribute address space of an inode. The inodes can either be files or
36 * directories or they can be fake inodes describing some attribute.
38 * If NInoMstProtected(), perform the post read mst fixups when all IO on the
39 * page has been completed and mark the page uptodate or set the error bit on
40 * the page. To determine the size of the records that need fixing up, we
41 * cheat a little bit by setting the index_block_size in ntfs_inode to the ntfs
42 * record size, and index_block_size_bits, to the log(base 2) of the ntfs
45 static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
48 struct buffer_head *first, *tmp;
52 int page_uptodate = 1;
55 vi = page->mapping->host;
58 if (likely(uptodate)) {
60 s64 file_ofs, init_size;
62 set_buffer_uptodate(bh);
64 file_ofs = ((s64)page->index << PAGE_SHIFT) +
66 read_lock_irqsave(&ni->size_lock, flags);
67 init_size = ni->initialized_size;
68 i_size = i_size_read(vi);
69 read_unlock_irqrestore(&ni->size_lock, flags);
70 if (unlikely(init_size > i_size)) {
71 /* Race with shrinking truncate. */
74 /* Check for the current buffer head overflowing. */
75 if (unlikely(file_ofs + bh->b_size > init_size)) {
80 if (file_ofs < init_size)
81 ofs = init_size - file_ofs;
82 kaddr = kmap_atomic(page);
83 memset(kaddr + bh_offset(bh) + ofs, 0,
85 flush_dcache_page(page);
89 clear_buffer_uptodate(bh);
91 ntfs_error(ni->vol->sb, "Buffer I/O error, logical block "
92 "0x%llx.", (unsigned long long)bh->b_blocknr);
94 first = page_buffers(page);
95 spin_lock_irqsave(&first->b_uptodate_lock, flags);
96 clear_buffer_async_read(bh);
100 if (!buffer_uptodate(tmp))
102 if (buffer_async_read(tmp)) {
103 if (likely(buffer_locked(tmp)))
105 /* Async buffers must be locked. */
108 tmp = tmp->b_this_page;
110 spin_unlock_irqrestore(&first->b_uptodate_lock, flags);
112 * If none of the buffers had errors then we can set the page uptodate,
113 * but we first have to perform the post read mst fixups, if the
114 * attribute is mst protected, i.e. if NInoMstProteced(ni) is true.
115 * Note we ignore fixup errors as those are detected when
116 * map_mft_record() is called which gives us per record granularity
117 * rather than per page granularity.
119 if (!NInoMstProtected(ni)) {
120 if (likely(page_uptodate && !PageError(page)))
121 SetPageUptodate(page);
124 unsigned int i, recs;
127 rec_size = ni->itype.index.block_size;
128 recs = PAGE_SIZE / rec_size;
129 /* Should have been verified before we got here... */
131 kaddr = kmap_atomic(page);
132 for (i = 0; i < recs; i++)
133 post_read_mst_fixup((NTFS_RECORD*)(kaddr +
134 i * rec_size), rec_size);
135 kunmap_atomic(kaddr);
136 flush_dcache_page(page);
137 if (likely(page_uptodate && !PageError(page)))
138 SetPageUptodate(page);
143 spin_unlock_irqrestore(&first->b_uptodate_lock, flags);
148 * ntfs_read_block - fill a @folio of an address space with data
149 * @folio: page cache folio to fill with data
151 * We read each buffer asynchronously and when all buffers are read in, our io
152 * completion handler ntfs_end_buffer_read_async(), if required, automatically
153 * applies the mst fixups to the folio before finally marking it uptodate and
156 * We only enforce allocated_size limit because i_size is checked for in
157 * generic_file_read().
159 * Return 0 on success and -errno on error.
161 * Contains an adapted version of fs/buffer.c::block_read_full_folio().
163 static int ntfs_read_block(struct folio *folio)
173 struct buffer_head *bh, *head, *arr[MAX_BUF_PER_PAGE];
174 sector_t iblock, lblock, zblock;
176 unsigned int blocksize, vcn_ofs;
178 unsigned char blocksize_bits;
180 vi = folio->mapping->host;
184 /* $MFT/$DATA must have its complete runlist in memory at all times. */
185 BUG_ON(!ni->runlist.rl && !ni->mft_no && !NInoAttr(ni));
187 blocksize = vol->sb->s_blocksize;
188 blocksize_bits = vol->sb->s_blocksize_bits;
190 head = folio_buffers(folio);
192 head = create_empty_buffers(folio, blocksize, 0);
196 * We may be racing with truncate. To avoid some of the problems we
197 * now take a snapshot of the various sizes and use those for the whole
198 * of the function. In case of an extending truncate it just means we
199 * may leave some buffers unmapped which are now allocated. This is
200 * not a problem since these buffers will just get mapped when a write
201 * occurs. In case of a shrinking truncate, we will detect this later
202 * on due to the runlist being incomplete and if the folio is being
203 * fully truncated, truncate will throw it away as soon as we unlock
204 * it so no need to worry what we do with it.
206 iblock = (s64)folio->index << (PAGE_SHIFT - blocksize_bits);
207 read_lock_irqsave(&ni->size_lock, flags);
208 lblock = (ni->allocated_size + blocksize - 1) >> blocksize_bits;
209 init_size = ni->initialized_size;
210 i_size = i_size_read(vi);
211 read_unlock_irqrestore(&ni->size_lock, flags);
212 if (unlikely(init_size > i_size)) {
213 /* Race with shrinking truncate. */
216 zblock = (init_size + blocksize - 1) >> blocksize_bits;
218 /* Loop through all the buffers in the folio. */
224 if (unlikely(buffer_uptodate(bh)))
226 if (unlikely(buffer_mapped(bh))) {
230 bh->b_bdev = vol->sb->s_bdev;
231 /* Is the block within the allowed limits? */
232 if (iblock < lblock) {
233 bool is_retry = false;
235 /* Convert iblock into corresponding vcn and offset. */
236 vcn = (VCN)iblock << blocksize_bits >>
237 vol->cluster_size_bits;
238 vcn_ofs = ((VCN)iblock << blocksize_bits) &
239 vol->cluster_size_mask;
242 down_read(&ni->runlist.lock);
245 if (likely(rl != NULL)) {
246 /* Seek to element containing target vcn. */
247 while (rl->length && rl[1].vcn <= vcn)
249 lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
251 lcn = LCN_RL_NOT_MAPPED;
252 /* Successful remap. */
254 /* Setup buffer head to correct block. */
255 bh->b_blocknr = ((lcn << vol->cluster_size_bits)
256 + vcn_ofs) >> blocksize_bits;
257 set_buffer_mapped(bh);
258 /* Only read initialized data blocks. */
259 if (iblock < zblock) {
263 /* Fully non-initialized data block, zero it. */
266 /* It is a hole, need to zero it. */
269 /* If first try and runlist unmapped, map and retry. */
270 if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
273 * Attempt to map runlist, dropping lock for
276 up_read(&ni->runlist.lock);
277 err = ntfs_map_runlist(ni, vcn);
279 goto lock_retry_remap;
282 up_read(&ni->runlist.lock);
284 * If buffer is outside the runlist, treat it as a
285 * hole. This can happen due to concurrent truncate
288 if (err == -ENOENT || lcn == LCN_ENOENT) {
292 /* Hard error, zero out region. */
296 folio_set_error(folio);
297 ntfs_error(vol->sb, "Failed to read from inode 0x%lx, "
298 "attribute type 0x%x, vcn 0x%llx, "
299 "offset 0x%x because its location on "
300 "disk could not be determined%s "
301 "(error code %i).", ni->mft_no,
302 ni->type, (unsigned long long)vcn,
303 vcn_ofs, is_retry ? " even after "
304 "retrying" : "", err);
307 * Either iblock was outside lblock limits or
308 * ntfs_rl_vcn_to_lcn() returned error. Just zero that portion
309 * of the folio and set the buffer uptodate.
312 bh->b_blocknr = -1UL;
313 clear_buffer_mapped(bh);
315 folio_zero_range(folio, i * blocksize, blocksize);
317 set_buffer_uptodate(bh);
318 } while (i++, iblock++, (bh = bh->b_this_page) != head);
320 /* Release the lock if we took it. */
322 up_read(&ni->runlist.lock);
324 /* Check we have at least one buffer ready for i/o. */
326 struct buffer_head *tbh;
328 /* Lock the buffers. */
329 for (i = 0; i < nr; i++) {
332 tbh->b_end_io = ntfs_end_buffer_async_read;
333 set_buffer_async_read(tbh);
335 /* Finally, start i/o on the buffers. */
336 for (i = 0; i < nr; i++) {
338 if (likely(!buffer_uptodate(tbh)))
339 submit_bh(REQ_OP_READ, tbh);
341 ntfs_end_buffer_async_read(tbh, 1);
345 /* No i/o was scheduled on any of the buffers. */
346 if (likely(!folio_test_error(folio)))
347 folio_mark_uptodate(folio);
348 else /* Signal synchronous i/o error. */
355 * ntfs_read_folio - fill a @folio of a @file with data from the device
356 * @file: open file to which the folio @folio belongs or NULL
357 * @folio: page cache folio to fill with data
359 * For non-resident attributes, ntfs_read_folio() fills the @folio of the open
360 * file @file by calling the ntfs version of the generic block_read_full_folio()
361 * function, ntfs_read_block(), which in turn creates and reads in the buffers
362 * associated with the folio asynchronously.
364 * For resident attributes, OTOH, ntfs_read_folio() fills @folio by copying the
365 * data from the mft record (which at this stage is most likely in memory) and
366 * fills the remainder with zeroes. Thus, in this case, I/O is synchronous, as
367 * even if the mft record is not cached at this point in time, we need to wait
368 * for it to be read in before we can do the copy.
370 * Return 0 on success and -errno on error.
372 static int ntfs_read_folio(struct file *file, struct folio *folio)
374 struct page *page = &folio->page;
377 ntfs_inode *ni, *base_ni;
379 ntfs_attr_search_ctx *ctx;
386 BUG_ON(!PageLocked(page));
387 vi = page->mapping->host;
388 i_size = i_size_read(vi);
389 /* Is the page fully outside i_size? (truncate in progress) */
390 if (unlikely(page->index >= (i_size + PAGE_SIZE - 1) >>
392 zero_user(page, 0, PAGE_SIZE);
393 ntfs_debug("Read outside i_size - truncated?");
397 * This can potentially happen because we clear PageUptodate() during
398 * ntfs_writepage() of MstProtected() attributes.
400 if (PageUptodate(page)) {
406 * Only $DATA attributes can be encrypted and only unnamed $DATA
407 * attributes can be compressed. Index root can have the flags set but
408 * this means to create compressed/encrypted files, not that the
409 * attribute is compressed/encrypted. Note we need to check for
410 * AT_INDEX_ALLOCATION since this is the type of both directory and
413 if (ni->type != AT_INDEX_ALLOCATION) {
414 /* If attribute is encrypted, deny access, just like NT4. */
415 if (NInoEncrypted(ni)) {
416 BUG_ON(ni->type != AT_DATA);
420 /* Compressed data streams are handled in compress.c. */
421 if (NInoNonResident(ni) && NInoCompressed(ni)) {
422 BUG_ON(ni->type != AT_DATA);
423 BUG_ON(ni->name_len);
424 return ntfs_read_compressed_block(page);
427 /* NInoNonResident() == NInoIndexAllocPresent() */
428 if (NInoNonResident(ni)) {
429 /* Normal, non-resident data stream. */
430 return ntfs_read_block(folio);
433 * Attribute is resident, implying it is not compressed or encrypted.
434 * This also means the attribute is smaller than an mft record and
435 * hence smaller than a page, so can simply zero out any pages with
436 * index above 0. Note the attribute can actually be marked compressed
437 * but if it is resident the actual data is not compressed so we are
438 * ok to ignore the compressed flag here.
440 if (unlikely(page->index > 0)) {
441 zero_user(page, 0, PAGE_SIZE);
447 base_ni = ni->ext.base_ntfs_ino;
448 /* Map, pin, and lock the mft record. */
449 mrec = map_mft_record(base_ni);
455 * If a parallel write made the attribute non-resident, drop the mft
456 * record and retry the read_folio.
458 if (unlikely(NInoNonResident(ni))) {
459 unmap_mft_record(base_ni);
462 ctx = ntfs_attr_get_search_ctx(base_ni, mrec);
463 if (unlikely(!ctx)) {
467 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
468 CASE_SENSITIVE, 0, NULL, 0, ctx);
470 goto put_unm_err_out;
471 attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
472 read_lock_irqsave(&ni->size_lock, flags);
473 if (unlikely(attr_len > ni->initialized_size))
474 attr_len = ni->initialized_size;
475 i_size = i_size_read(vi);
476 read_unlock_irqrestore(&ni->size_lock, flags);
477 if (unlikely(attr_len > i_size)) {
478 /* Race with shrinking truncate. */
481 addr = kmap_atomic(page);
482 /* Copy the data to the page. */
483 memcpy(addr, (u8*)ctx->attr +
484 le16_to_cpu(ctx->attr->data.resident.value_offset),
486 /* Zero the remainder of the page. */
487 memset(addr + attr_len, 0, PAGE_SIZE - attr_len);
488 flush_dcache_page(page);
491 ntfs_attr_put_search_ctx(ctx);
493 unmap_mft_record(base_ni);
495 SetPageUptodate(page);
504 * ntfs_write_block - write a @folio to the backing store
505 * @folio: page cache folio to write out
506 * @wbc: writeback control structure
508 * This function is for writing folios belonging to non-resident, non-mst
509 * protected attributes to their backing store.
511 * For a folio with buffers, map and write the dirty buffers asynchronously
512 * under folio writeback. For a folio without buffers, create buffers for the
513 * folio, then proceed as above.
515 * If a folio doesn't have buffers the folio dirty state is definitive. If
516 * a folio does have buffers, the folio dirty state is just a hint,
517 * and the buffer dirty state is definitive. (A hint which has rules:
518 * dirty buffers against a clean folio is illegal. Other combinations are
519 * legal and need to be handled. In particular a dirty folio containing
520 * clean buffers for example.)
522 * Return 0 on success and -errno on error.
524 * Based on ntfs_read_block() and __block_write_full_folio().
526 static int ntfs_write_block(struct folio *folio, struct writeback_control *wbc)
530 s64 initialized_size;
532 sector_t block, dblock, iblock;
537 struct buffer_head *bh, *head;
539 unsigned int blocksize, vcn_ofs;
541 bool need_end_writeback;
542 unsigned char blocksize_bits;
544 vi = folio->mapping->host;
548 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
549 "0x%lx.", ni->mft_no, ni->type, folio->index);
551 BUG_ON(!NInoNonResident(ni));
552 BUG_ON(NInoMstProtected(ni));
553 blocksize = vol->sb->s_blocksize;
554 blocksize_bits = vol->sb->s_blocksize_bits;
555 head = folio_buffers(folio);
557 BUG_ON(!folio_test_uptodate(folio));
558 head = create_empty_buffers(folio, blocksize,
559 (1 << BH_Uptodate) | (1 << BH_Dirty));
563 /* NOTE: Different naming scheme to ntfs_read_block()! */
565 /* The first block in the folio. */
566 block = (s64)folio->index << (PAGE_SHIFT - blocksize_bits);
568 read_lock_irqsave(&ni->size_lock, flags);
569 i_size = i_size_read(vi);
570 initialized_size = ni->initialized_size;
571 read_unlock_irqrestore(&ni->size_lock, flags);
573 /* The first out of bounds block for the data size. */
574 dblock = (i_size + blocksize - 1) >> blocksize_bits;
576 /* The last (fully or partially) initialized block. */
577 iblock = initialized_size >> blocksize_bits;
580 * Be very careful. We have no exclusion from block_dirty_folio
581 * here, and the (potentially unmapped) buffers may become dirty at
582 * any time. If a buffer becomes dirty here after we've inspected it
583 * then we just miss that fact, and the folio stays dirty.
585 * Buffers outside i_size may be dirtied by block_dirty_folio;
586 * handle that here by just cleaning them.
590 * Loop through all the buffers in the folio, mapping all the dirty
591 * buffers to disk addresses and handling any aliases from the
592 * underlying block device's mapping.
597 bool is_retry = false;
599 if (unlikely(block >= dblock)) {
601 * Mapped buffers outside i_size will occur, because
602 * this folio can be outside i_size when there is a
603 * truncate in progress. The contents of such buffers
604 * were zeroed by ntfs_writepage().
606 * FIXME: What about the small race window where
607 * ntfs_writepage() has not done any clearing because
608 * the folio was within i_size but before we get here,
609 * vmtruncate() modifies i_size?
611 clear_buffer_dirty(bh);
612 set_buffer_uptodate(bh);
616 /* Clean buffers are not written out, so no need to map them. */
617 if (!buffer_dirty(bh))
620 /* Make sure we have enough initialized size. */
621 if (unlikely((block >= iblock) &&
622 (initialized_size < i_size))) {
624 * If this folio is fully outside initialized
625 * size, zero out all folios between the current
626 * initialized size and the current folio. Just
627 * use ntfs_read_folio() to do the zeroing
630 if (block > iblock) {
632 // For each folio do:
633 // - read_cache_folio()
634 // Again for each folio do:
635 // - wait_on_folio_locked()
636 // - Check (folio_test_uptodate(folio) &&
637 // !folio_test_error(folio))
638 // Update initialized size in the attribute and
640 // Again, for each folio do:
641 // block_dirty_folio();
643 // We don't need to wait on the writes.
647 * The current folio straddles initialized size. Zero
648 * all non-uptodate buffers and set them uptodate (and
649 * dirty?). Note, there aren't any non-uptodate buffers
650 * if the folio is uptodate.
651 * FIXME: For an uptodate folio, the buffers may need to
652 * be written out because they were not initialized on
655 if (!folio_test_uptodate(folio)) {
657 // Zero any non-uptodate buffers up to i_size.
658 // Set them uptodate and dirty.
661 // Update initialized size in the attribute and in the
662 // inode (up to i_size).
664 // FIXME: This is inefficient. Try to batch the two
665 // size changes to happen in one go.
666 ntfs_error(vol->sb, "Writing beyond initialized size "
667 "is not supported yet. Sorry.");
670 // Do NOT set_buffer_new() BUT DO clear buffer range
671 // outside write request range.
672 // set_buffer_uptodate() on complete buffers as well as
673 // set_buffer_dirty().
676 /* No need to map buffers that are already mapped. */
677 if (buffer_mapped(bh))
680 /* Unmapped, dirty buffer. Need to map it. */
681 bh->b_bdev = vol->sb->s_bdev;
683 /* Convert block into corresponding vcn and offset. */
684 vcn = (VCN)block << blocksize_bits;
685 vcn_ofs = vcn & vol->cluster_size_mask;
686 vcn >>= vol->cluster_size_bits;
689 down_read(&ni->runlist.lock);
692 if (likely(rl != NULL)) {
693 /* Seek to element containing target vcn. */
694 while (rl->length && rl[1].vcn <= vcn)
696 lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
698 lcn = LCN_RL_NOT_MAPPED;
699 /* Successful remap. */
701 /* Setup buffer head to point to correct block. */
702 bh->b_blocknr = ((lcn << vol->cluster_size_bits) +
703 vcn_ofs) >> blocksize_bits;
704 set_buffer_mapped(bh);
707 /* It is a hole, need to instantiate it. */
708 if (lcn == LCN_HOLE) {
710 unsigned long *bpos, *bend;
712 /* Check if the buffer is zero. */
713 kaddr = kmap_local_folio(folio, bh_offset(bh));
714 bpos = (unsigned long *)kaddr;
715 bend = (unsigned long *)(kaddr + blocksize);
719 } while (likely(++bpos < bend));
723 * Buffer is zero and sparse, no need to write
727 clear_buffer_dirty(bh);
730 // TODO: Instantiate the hole.
731 // clear_buffer_new(bh);
732 // clean_bdev_bh_alias(bh);
733 ntfs_error(vol->sb, "Writing into sparse regions is "
734 "not supported yet. Sorry.");
738 /* If first try and runlist unmapped, map and retry. */
739 if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
742 * Attempt to map runlist, dropping lock for
745 up_read(&ni->runlist.lock);
746 err = ntfs_map_runlist(ni, vcn);
748 goto lock_retry_remap;
751 up_read(&ni->runlist.lock);
753 * If buffer is outside the runlist, truncate has cut it out
754 * of the runlist. Just clean and clear the buffer and set it
755 * uptodate so it can get discarded by the VM.
757 if (err == -ENOENT || lcn == LCN_ENOENT) {
759 clear_buffer_dirty(bh);
760 folio_zero_range(folio, bh_offset(bh), blocksize);
761 set_buffer_uptodate(bh);
765 /* Failed to map the buffer, even after retrying. */
769 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
770 "attribute type 0x%x, vcn 0x%llx, offset 0x%x "
771 "because its location on disk could not be "
772 "determined%s (error code %i).", ni->mft_no,
773 ni->type, (unsigned long long)vcn,
774 vcn_ofs, is_retry ? " even after "
775 "retrying" : "", err);
777 } while (block++, (bh = bh->b_this_page) != head);
779 /* Release the lock if we took it. */
781 up_read(&ni->runlist.lock);
783 /* For the error case, need to reset bh to the beginning. */
786 /* Just an optimization, so ->read_folio() is not called later. */
787 if (unlikely(!folio_test_uptodate(folio))) {
790 if (!buffer_uptodate(bh)) {
795 } while ((bh = bh->b_this_page) != head);
797 folio_mark_uptodate(folio);
800 /* Setup all mapped, dirty buffers for async write i/o. */
802 if (buffer_mapped(bh) && buffer_dirty(bh)) {
804 if (test_clear_buffer_dirty(bh)) {
805 BUG_ON(!buffer_uptodate(bh));
806 mark_buffer_async_write(bh);
809 } else if (unlikely(err)) {
811 * For the error case. The buffer may have been set
812 * dirty during attachment to a dirty folio.
815 clear_buffer_dirty(bh);
817 } while ((bh = bh->b_this_page) != head);
820 // TODO: Remove the -EOPNOTSUPP check later on...
821 if (unlikely(err == -EOPNOTSUPP))
823 else if (err == -ENOMEM) {
824 ntfs_warning(vol->sb, "Error allocating memory. "
825 "Redirtying folio so we try again "
828 * Put the folio back on mapping->dirty_pages, but
829 * leave its buffer's dirty state as-is.
831 folio_redirty_for_writepage(wbc, folio);
834 folio_set_error(folio);
837 BUG_ON(folio_test_writeback(folio));
838 folio_start_writeback(folio); /* Keeps try_to_free_buffers() away. */
840 /* Submit the prepared buffers for i/o. */
841 need_end_writeback = true;
843 struct buffer_head *next = bh->b_this_page;
844 if (buffer_async_write(bh)) {
845 submit_bh(REQ_OP_WRITE, bh);
846 need_end_writeback = false;
849 } while (bh != head);
852 /* If no i/o was started, need to end writeback here. */
853 if (unlikely(need_end_writeback))
854 folio_end_writeback(folio);
861 * ntfs_write_mst_block - write a @page to the backing store
862 * @page: page cache page to write out
863 * @wbc: writeback control structure
865 * This function is for writing pages belonging to non-resident, mst protected
866 * attributes to their backing store. The only supported attributes are index
867 * allocation and $MFT/$DATA. Both directory inodes and index inodes are
868 * supported for the index allocation case.
870 * The page must remain locked for the duration of the write because we apply
871 * the mst fixups, write, and then undo the fixups, so if we were to unlock the
872 * page before undoing the fixups, any other user of the page will see the
873 * page contents as corrupt.
875 * We clear the page uptodate flag for the duration of the function to ensure
876 * exclusion for the $MFT/$DATA case against someone mapping an mft record we
877 * are about to apply the mst fixups to.
879 * Return 0 on success and -errno on error.
881 * Based on ntfs_write_block(), ntfs_mft_writepage(), and
882 * write_mft_record_nolock().
884 static int ntfs_write_mst_block(struct page *page,
885 struct writeback_control *wbc)
887 sector_t block, dblock, rec_block;
888 struct inode *vi = page->mapping->host;
889 ntfs_inode *ni = NTFS_I(vi);
890 ntfs_volume *vol = ni->vol;
892 unsigned int rec_size = ni->itype.index.block_size;
893 ntfs_inode *locked_nis[PAGE_SIZE / NTFS_BLOCK_SIZE];
894 struct buffer_head *bh, *head, *tbh, *rec_start_bh;
895 struct buffer_head *bhs[MAX_BUF_PER_PAGE];
897 int i, nr_locked_nis, nr_recs, nr_bhs, max_bhs, bhs_per_rec, err, err2;
898 unsigned bh_size, rec_size_bits;
899 bool sync, is_mft, page_is_dirty, rec_is_dirty;
900 unsigned char bh_size_bits;
902 if (WARN_ON(rec_size < NTFS_BLOCK_SIZE))
905 ntfs_debug("Entering for inode 0x%lx, attribute type 0x%x, page index "
906 "0x%lx.", vi->i_ino, ni->type, page->index);
907 BUG_ON(!NInoNonResident(ni));
908 BUG_ON(!NInoMstProtected(ni));
909 is_mft = (S_ISREG(vi->i_mode) && !vi->i_ino);
911 * NOTE: ntfs_write_mst_block() would be called for $MFTMirr if a page
912 * in its page cache were to be marked dirty. However this should
913 * never happen with the current driver and considering we do not
914 * handle this case here we do want to BUG(), at least for now.
916 BUG_ON(!(is_mft || S_ISDIR(vi->i_mode) ||
917 (NInoAttr(ni) && ni->type == AT_INDEX_ALLOCATION)));
918 bh_size = vol->sb->s_blocksize;
919 bh_size_bits = vol->sb->s_blocksize_bits;
920 max_bhs = PAGE_SIZE / bh_size;
922 BUG_ON(max_bhs > MAX_BUF_PER_PAGE);
924 /* Were we called for sync purposes? */
925 sync = (wbc->sync_mode == WB_SYNC_ALL);
927 /* Make sure we have mapped buffers. */
928 bh = head = page_buffers(page);
931 rec_size_bits = ni->itype.index.block_size_bits;
932 BUG_ON(!(PAGE_SIZE >> rec_size_bits));
933 bhs_per_rec = rec_size >> bh_size_bits;
934 BUG_ON(!bhs_per_rec);
936 /* The first block in the page. */
937 rec_block = block = (sector_t)page->index <<
938 (PAGE_SHIFT - bh_size_bits);
940 /* The first out of bounds block for the data size. */
941 dblock = (i_size_read(vi) + bh_size - 1) >> bh_size_bits;
944 err = err2 = nr_bhs = nr_recs = nr_locked_nis = 0;
945 page_is_dirty = rec_is_dirty = false;
948 bool is_retry = false;
950 if (likely(block < rec_block)) {
951 if (unlikely(block >= dblock)) {
952 clear_buffer_dirty(bh);
953 set_buffer_uptodate(bh);
957 * This block is not the first one in the record. We
958 * ignore the buffer's dirty state because we could
959 * have raced with a parallel mark_ntfs_record_dirty().
963 if (unlikely(err2)) {
965 clear_buffer_dirty(bh);
968 } else /* if (block == rec_block) */ {
969 BUG_ON(block > rec_block);
970 /* This block is the first one in the record. */
971 rec_block += bhs_per_rec;
973 if (unlikely(block >= dblock)) {
974 clear_buffer_dirty(bh);
977 if (!buffer_dirty(bh)) {
978 /* Clean records are not written out. */
979 rec_is_dirty = false;
985 /* Need to map the buffer if it is not mapped already. */
986 if (unlikely(!buffer_mapped(bh))) {
989 unsigned int vcn_ofs;
991 bh->b_bdev = vol->sb->s_bdev;
992 /* Obtain the vcn and offset of the current block. */
993 vcn = (VCN)block << bh_size_bits;
994 vcn_ofs = vcn & vol->cluster_size_mask;
995 vcn >>= vol->cluster_size_bits;
998 down_read(&ni->runlist.lock);
1001 if (likely(rl != NULL)) {
1002 /* Seek to element containing target vcn. */
1003 while (rl->length && rl[1].vcn <= vcn)
1005 lcn = ntfs_rl_vcn_to_lcn(rl, vcn);
1007 lcn = LCN_RL_NOT_MAPPED;
1008 /* Successful remap. */
1009 if (likely(lcn >= 0)) {
1010 /* Setup buffer head to correct block. */
1011 bh->b_blocknr = ((lcn <<
1012 vol->cluster_size_bits) +
1013 vcn_ofs) >> bh_size_bits;
1014 set_buffer_mapped(bh);
1017 * Remap failed. Retry to map the runlist once
1018 * unless we are working on $MFT which always
1019 * has the whole of its runlist in memory.
1021 if (!is_mft && !is_retry &&
1022 lcn == LCN_RL_NOT_MAPPED) {
1025 * Attempt to map runlist, dropping
1026 * lock for the duration.
1028 up_read(&ni->runlist.lock);
1029 err2 = ntfs_map_runlist(ni, vcn);
1031 goto lock_retry_remap;
1032 if (err2 == -ENOMEM)
1033 page_is_dirty = true;
1038 up_read(&ni->runlist.lock);
1040 /* Hard error. Abort writing this record. */
1041 if (!err || err == -ENOMEM)
1044 ntfs_error(vol->sb, "Cannot write ntfs record "
1045 "0x%llx (inode 0x%lx, "
1046 "attribute type 0x%x) because "
1047 "its location on disk could "
1048 "not be determined (error "
1052 vol->mft_record_size_bits,
1053 ni->mft_no, ni->type,
1056 * If this is not the first buffer, remove the
1057 * buffers in this record from the list of
1058 * buffers to write and clear their dirty bit
1059 * if not error -ENOMEM.
1061 if (rec_start_bh != bh) {
1062 while (bhs[--nr_bhs] != rec_start_bh)
1064 if (err2 != -ENOMEM) {
1068 } while ((rec_start_bh =
1077 BUG_ON(!buffer_uptodate(bh));
1078 BUG_ON(nr_bhs >= max_bhs);
1080 } while (block++, (bh = bh->b_this_page) != head);
1082 up_read(&ni->runlist.lock);
1083 /* If there were no dirty buffers, we are done. */
1086 /* Map the page so we can access its contents. */
1088 /* Clear the page uptodate flag whilst the mst fixups are applied. */
1089 BUG_ON(!PageUptodate(page));
1090 ClearPageUptodate(page);
1091 for (i = 0; i < nr_bhs; i++) {
1094 /* Skip buffers which are not at the beginning of records. */
1095 if (i % bhs_per_rec)
1098 ofs = bh_offset(tbh);
1101 unsigned long mft_no;
1103 /* Get the mft record number. */
1104 mft_no = (((s64)page->index << PAGE_SHIFT) + ofs)
1106 /* Check whether to write this mft record. */
1108 if (!ntfs_may_write_mft_record(vol, mft_no,
1109 (MFT_RECORD*)(kaddr + ofs), &tni)) {
1111 * The record should not be written. This
1112 * means we need to redirty the page before
1115 page_is_dirty = true;
1117 * Remove the buffers in this mft record from
1118 * the list of buffers to write.
1122 } while (++i % bhs_per_rec);
1126 * The record should be written. If a locked ntfs
1127 * inode was returned, add it to the array of locked
1131 locked_nis[nr_locked_nis++] = tni;
1133 /* Apply the mst protection fixups. */
1134 err2 = pre_write_mst_fixup((NTFS_RECORD*)(kaddr + ofs),
1136 if (unlikely(err2)) {
1137 if (!err || err == -ENOMEM)
1139 ntfs_error(vol->sb, "Failed to apply mst fixups "
1140 "(inode 0x%lx, attribute type 0x%x, "
1141 "page index 0x%lx, page offset 0x%x)!"
1142 " Unmount and run chkdsk.", vi->i_ino,
1143 ni->type, page->index, ofs);
1145 * Mark all the buffers in this record clean as we do
1146 * not want to write corrupt data to disk.
1149 clear_buffer_dirty(bhs[i]);
1151 } while (++i % bhs_per_rec);
1156 /* If no records are to be written out, we are done. */
1159 flush_dcache_page(page);
1160 /* Lock buffers and start synchronous write i/o on them. */
1161 for (i = 0; i < nr_bhs; i++) {
1165 if (!trylock_buffer(tbh))
1167 /* The buffer dirty state is now irrelevant, just clean it. */
1168 clear_buffer_dirty(tbh);
1169 BUG_ON(!buffer_uptodate(tbh));
1170 BUG_ON(!buffer_mapped(tbh));
1172 tbh->b_end_io = end_buffer_write_sync;
1173 submit_bh(REQ_OP_WRITE, tbh);
1175 /* Synchronize the mft mirror now if not @sync. */
1176 if (is_mft && !sync)
1179 /* Wait on i/o completion of buffers. */
1180 for (i = 0; i < nr_bhs; i++) {
1184 wait_on_buffer(tbh);
1185 if (unlikely(!buffer_uptodate(tbh))) {
1186 ntfs_error(vol->sb, "I/O error while writing ntfs "
1187 "record buffer (inode 0x%lx, "
1188 "attribute type 0x%x, page index "
1189 "0x%lx, page offset 0x%lx)! Unmount "
1190 "and run chkdsk.", vi->i_ino, ni->type,
1191 page->index, bh_offset(tbh));
1192 if (!err || err == -ENOMEM)
1195 * Set the buffer uptodate so the page and buffer
1196 * states do not become out of sync.
1198 set_buffer_uptodate(tbh);
1201 /* If @sync, now synchronize the mft mirror. */
1202 if (is_mft && sync) {
1204 for (i = 0; i < nr_bhs; i++) {
1205 unsigned long mft_no;
1209 * Skip buffers which are not at the beginning of
1212 if (i % bhs_per_rec)
1215 /* Skip removed buffers (and hence records). */
1218 ofs = bh_offset(tbh);
1219 /* Get the mft record number. */
1220 mft_no = (((s64)page->index << PAGE_SHIFT) + ofs)
1222 if (mft_no < vol->mftmirr_size)
1223 ntfs_sync_mft_mirror(vol, mft_no,
1224 (MFT_RECORD*)(kaddr + ofs),
1230 /* Remove the mst protection fixups again. */
1231 for (i = 0; i < nr_bhs; i++) {
1232 if (!(i % bhs_per_rec)) {
1236 post_write_mst_fixup((NTFS_RECORD*)(kaddr +
1240 flush_dcache_page(page);
1242 /* Unlock any locked inodes. */
1243 while (nr_locked_nis-- > 0) {
1244 ntfs_inode *tni, *base_tni;
1246 tni = locked_nis[nr_locked_nis];
1247 /* Get the base inode. */
1248 mutex_lock(&tni->extent_lock);
1249 if (tni->nr_extents >= 0)
1252 base_tni = tni->ext.base_ntfs_ino;
1255 mutex_unlock(&tni->extent_lock);
1256 ntfs_debug("Unlocking %s inode 0x%lx.",
1257 tni == base_tni ? "base" : "extent",
1259 mutex_unlock(&tni->mrec_lock);
1260 atomic_dec(&tni->count);
1261 iput(VFS_I(base_tni));
1263 SetPageUptodate(page);
1266 if (unlikely(err && err != -ENOMEM)) {
1268 * Set page error if there is only one ntfs record in the page.
1269 * Otherwise we would loose per-record granularity.
1271 if (ni->itype.index.block_size == PAGE_SIZE)
1275 if (page_is_dirty) {
1276 ntfs_debug("Page still contains one or more dirty ntfs "
1277 "records. Redirtying the page starting at "
1278 "record 0x%lx.", page->index <<
1279 (PAGE_SHIFT - rec_size_bits));
1280 redirty_page_for_writepage(wbc, page);
1284 * Keep the VM happy. This must be done otherwise the
1285 * radix-tree tag PAGECACHE_TAG_DIRTY remains set even though
1286 * the page is clean.
1288 BUG_ON(PageWriteback(page));
1289 set_page_writeback(page);
1291 end_page_writeback(page);
1294 ntfs_debug("Done.");
1299 * ntfs_writepage - write a @page to the backing store
1300 * @page: page cache page to write out
1301 * @wbc: writeback control structure
1303 * This is called from the VM when it wants to have a dirty ntfs page cache
1304 * page cleaned. The VM has already locked the page and marked it clean.
1306 * For non-resident attributes, ntfs_writepage() writes the @page by calling
1307 * the ntfs version of the generic block_write_full_page() function,
1308 * ntfs_write_block(), which in turn if necessary creates and writes the
1309 * buffers associated with the page asynchronously.
1311 * For resident attributes, OTOH, ntfs_writepage() writes the @page by copying
1312 * the data to the mft record (which at this stage is most likely in memory).
1313 * The mft record is then marked dirty and written out asynchronously via the
1314 * vfs inode dirty code path for the inode the mft record belongs to or via the
1315 * vm page dirty code path for the page the mft record is in.
1317 * Based on ntfs_read_folio() and fs/buffer.c::block_write_full_page().
1319 * Return 0 on success and -errno on error.
1321 static int ntfs_writepage(struct page *page, struct writeback_control *wbc)
1323 struct folio *folio = page_folio(page);
1325 struct inode *vi = folio->mapping->host;
1326 ntfs_inode *base_ni = NULL, *ni = NTFS_I(vi);
1328 ntfs_attr_search_ctx *ctx = NULL;
1329 MFT_RECORD *m = NULL;
1334 BUG_ON(!folio_test_locked(folio));
1335 i_size = i_size_read(vi);
1336 /* Is the folio fully outside i_size? (truncate in progress) */
1337 if (unlikely(folio->index >= (i_size + PAGE_SIZE - 1) >>
1340 * The folio may have dirty, unmapped buffers. Make them
1341 * freeable here, so the page does not leak.
1343 block_invalidate_folio(folio, 0, folio_size(folio));
1344 folio_unlock(folio);
1345 ntfs_debug("Write outside i_size - truncated?");
1349 * Only $DATA attributes can be encrypted and only unnamed $DATA
1350 * attributes can be compressed. Index root can have the flags set but
1351 * this means to create compressed/encrypted files, not that the
1352 * attribute is compressed/encrypted. Note we need to check for
1353 * AT_INDEX_ALLOCATION since this is the type of both directory and
1356 if (ni->type != AT_INDEX_ALLOCATION) {
1357 /* If file is encrypted, deny access, just like NT4. */
1358 if (NInoEncrypted(ni)) {
1359 folio_unlock(folio);
1360 BUG_ON(ni->type != AT_DATA);
1361 ntfs_debug("Denying write access to encrypted file.");
1364 /* Compressed data streams are handled in compress.c. */
1365 if (NInoNonResident(ni) && NInoCompressed(ni)) {
1366 BUG_ON(ni->type != AT_DATA);
1367 BUG_ON(ni->name_len);
1368 // TODO: Implement and replace this with
1369 // return ntfs_write_compressed_block(page);
1370 folio_unlock(folio);
1371 ntfs_error(vi->i_sb, "Writing to compressed files is "
1372 "not supported yet. Sorry.");
1375 // TODO: Implement and remove this check.
1376 if (NInoNonResident(ni) && NInoSparse(ni)) {
1377 folio_unlock(folio);
1378 ntfs_error(vi->i_sb, "Writing to sparse files is not "
1379 "supported yet. Sorry.");
1383 /* NInoNonResident() == NInoIndexAllocPresent() */
1384 if (NInoNonResident(ni)) {
1385 /* We have to zero every time due to mmap-at-end-of-file. */
1386 if (folio->index >= (i_size >> PAGE_SHIFT)) {
1387 /* The folio straddles i_size. */
1388 unsigned int ofs = i_size & (folio_size(folio) - 1);
1389 folio_zero_segment(folio, ofs, folio_size(folio));
1391 /* Handle mst protected attributes. */
1392 if (NInoMstProtected(ni))
1393 return ntfs_write_mst_block(page, wbc);
1394 /* Normal, non-resident data stream. */
1395 return ntfs_write_block(folio, wbc);
1398 * Attribute is resident, implying it is not compressed, encrypted, or
1399 * mst protected. This also means the attribute is smaller than an mft
1400 * record and hence smaller than a folio, so can simply return error on
1401 * any folios with index above 0. Note the attribute can actually be
1402 * marked compressed but if it is resident the actual data is not
1403 * compressed so we are ok to ignore the compressed flag here.
1405 BUG_ON(folio_buffers(folio));
1406 BUG_ON(!folio_test_uptodate(folio));
1407 if (unlikely(folio->index > 0)) {
1408 ntfs_error(vi->i_sb, "BUG()! folio->index (0x%lx) > 0. "
1409 "Aborting write.", folio->index);
1410 BUG_ON(folio_test_writeback(folio));
1411 folio_start_writeback(folio);
1412 folio_unlock(folio);
1413 folio_end_writeback(folio);
1419 base_ni = ni->ext.base_ntfs_ino;
1420 /* Map, pin, and lock the mft record. */
1421 m = map_mft_record(base_ni);
1429 * If a parallel write made the attribute non-resident, drop the mft
1430 * record and retry the writepage.
1432 if (unlikely(NInoNonResident(ni))) {
1433 unmap_mft_record(base_ni);
1434 goto retry_writepage;
1436 ctx = ntfs_attr_get_search_ctx(base_ni, m);
1437 if (unlikely(!ctx)) {
1441 err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
1442 CASE_SENSITIVE, 0, NULL, 0, ctx);
1446 * Keep the VM happy. This must be done otherwise
1447 * PAGECACHE_TAG_DIRTY remains set even though the folio is clean.
1449 BUG_ON(folio_test_writeback(folio));
1450 folio_start_writeback(folio);
1451 folio_unlock(folio);
1452 attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
1453 i_size = i_size_read(vi);
1454 if (unlikely(attr_len > i_size)) {
1455 /* Race with shrinking truncate or a failed truncate. */
1458 * If the truncate failed, fix it up now. If a concurrent
1459 * truncate, we do its job, so it does not have to do anything.
1461 err = ntfs_resident_attr_value_resize(ctx->mrec, ctx->attr,
1463 /* Shrinking cannot fail. */
1466 addr = kmap_local_folio(folio, 0);
1467 /* Copy the data from the folio to the mft record. */
1468 memcpy((u8*)ctx->attr +
1469 le16_to_cpu(ctx->attr->data.resident.value_offset),
1471 /* Zero out of bounds area in the page cache folio. */
1472 memset(addr + attr_len, 0, folio_size(folio) - attr_len);
1474 flush_dcache_folio(folio);
1475 flush_dcache_mft_record_page(ctx->ntfs_ino);
1476 /* We are done with the folio. */
1477 folio_end_writeback(folio);
1478 /* Finally, mark the mft record dirty, so it gets written back. */
1479 mark_mft_record_dirty(ctx->ntfs_ino);
1480 ntfs_attr_put_search_ctx(ctx);
1481 unmap_mft_record(base_ni);
1484 if (err == -ENOMEM) {
1485 ntfs_warning(vi->i_sb, "Error allocating memory. Redirtying "
1486 "page so we try again later.");
1488 * Put the folio back on mapping->dirty_pages, but leave its
1489 * buffers' dirty state as-is.
1491 folio_redirty_for_writepage(wbc, folio);
1494 ntfs_error(vi->i_sb, "Resident attribute write failed with "
1496 folio_set_error(folio);
1497 NVolSetErrors(ni->vol);
1499 folio_unlock(folio);
1501 ntfs_attr_put_search_ctx(ctx);
1503 unmap_mft_record(base_ni);
1507 #endif /* NTFS_RW */
1510 * ntfs_bmap - map logical file block to physical device block
1511 * @mapping: address space mapping to which the block to be mapped belongs
1512 * @block: logical block to map to its physical device block
1514 * For regular, non-resident files (i.e. not compressed and not encrypted), map
1515 * the logical @block belonging to the file described by the address space
1516 * mapping @mapping to its physical device block.
1518 * The size of the block is equal to the @s_blocksize field of the super block
1519 * of the mounted file system which is guaranteed to be smaller than or equal
1520 * to the cluster size thus the block is guaranteed to fit entirely inside the
1521 * cluster which means we do not need to care how many contiguous bytes are
1522 * available after the beginning of the block.
1524 * Return the physical device block if the mapping succeeded or 0 if the block
1525 * is sparse or there was an error.
1527 * Note: This is a problem if someone tries to run bmap() on $Boot system file
1528 * as that really is in block zero but there is nothing we can do. bmap() is
1529 * just broken in that respect (just like it cannot distinguish sparse from
1530 * not available or error).
1532 static sector_t ntfs_bmap(struct address_space *mapping, sector_t block)
1537 unsigned long blocksize, flags;
1538 ntfs_inode *ni = NTFS_I(mapping->host);
1539 ntfs_volume *vol = ni->vol;
1541 unsigned char blocksize_bits, cluster_size_shift;
1543 ntfs_debug("Entering for mft_no 0x%lx, logical block 0x%llx.",
1544 ni->mft_no, (unsigned long long)block);
1545 if (ni->type != AT_DATA || !NInoNonResident(ni) || NInoEncrypted(ni)) {
1546 ntfs_error(vol->sb, "BMAP does not make sense for %s "
1547 "attributes, returning 0.",
1548 (ni->type != AT_DATA) ? "non-data" :
1549 (!NInoNonResident(ni) ? "resident" :
1553 /* None of these can happen. */
1554 BUG_ON(NInoCompressed(ni));
1555 BUG_ON(NInoMstProtected(ni));
1556 blocksize = vol->sb->s_blocksize;
1557 blocksize_bits = vol->sb->s_blocksize_bits;
1558 ofs = (s64)block << blocksize_bits;
1559 read_lock_irqsave(&ni->size_lock, flags);
1560 size = ni->initialized_size;
1561 i_size = i_size_read(VFS_I(ni));
1562 read_unlock_irqrestore(&ni->size_lock, flags);
1564 * If the offset is outside the initialized size or the block straddles
1565 * the initialized size then pretend it is a hole unless the
1566 * initialized size equals the file size.
1568 if (unlikely(ofs >= size || (ofs + blocksize > size && size < i_size)))
1570 cluster_size_shift = vol->cluster_size_bits;
1571 down_read(&ni->runlist.lock);
1572 lcn = ntfs_attr_vcn_to_lcn_nolock(ni, ofs >> cluster_size_shift, false);
1573 up_read(&ni->runlist.lock);
1574 if (unlikely(lcn < LCN_HOLE)) {
1576 * Step down to an integer to avoid gcc doing a long long
1577 * comparision in the switch when we know @lcn is between
1578 * LCN_HOLE and LCN_EIO (i.e. -1 to -5).
1580 * Otherwise older gcc (at least on some architectures) will
1581 * try to use __cmpdi2() which is of course not available in
1587 * If the offset is out of bounds then pretend it is a
1592 ntfs_error(vol->sb, "Not enough memory to complete "
1593 "mapping for inode 0x%lx. "
1594 "Returning 0.", ni->mft_no);
1597 ntfs_error(vol->sb, "Failed to complete mapping for "
1598 "inode 0x%lx. Run chkdsk. "
1599 "Returning 0.", ni->mft_no);
1607 ntfs_debug("Done (returning hole).");
1611 * The block is really allocated and fullfils all our criteria.
1612 * Convert the cluster to units of block size and return the result.
1614 delta = ofs & vol->cluster_size_mask;
1615 if (unlikely(sizeof(block) < sizeof(lcn))) {
1616 block = lcn = ((lcn << cluster_size_shift) + delta) >>
1618 /* If the block number was truncated return 0. */
1619 if (unlikely(block != lcn)) {
1620 ntfs_error(vol->sb, "Physical block 0x%llx is too "
1621 "large to be returned, returning 0.",
1626 block = ((lcn << cluster_size_shift) + delta) >>
1628 ntfs_debug("Done (returning block 0x%llx).", (unsigned long long)lcn);
1633 * ntfs_normal_aops - address space operations for normal inodes and attributes
1635 * Note these are not used for compressed or mst protected inodes and
1638 const struct address_space_operations ntfs_normal_aops = {
1639 .read_folio = ntfs_read_folio,
1641 .writepage = ntfs_writepage,
1642 .dirty_folio = block_dirty_folio,
1643 #endif /* NTFS_RW */
1645 .migrate_folio = buffer_migrate_folio,
1646 .is_partially_uptodate = block_is_partially_uptodate,
1647 .error_remove_page = generic_error_remove_page,
1651 * ntfs_compressed_aops - address space operations for compressed inodes
1653 const struct address_space_operations ntfs_compressed_aops = {
1654 .read_folio = ntfs_read_folio,
1656 .writepage = ntfs_writepage,
1657 .dirty_folio = block_dirty_folio,
1658 #endif /* NTFS_RW */
1659 .migrate_folio = buffer_migrate_folio,
1660 .is_partially_uptodate = block_is_partially_uptodate,
1661 .error_remove_page = generic_error_remove_page,
1665 * ntfs_mst_aops - general address space operations for mst protecteed inodes
1668 const struct address_space_operations ntfs_mst_aops = {
1669 .read_folio = ntfs_read_folio, /* Fill page with data. */
1671 .writepage = ntfs_writepage, /* Write dirty page to disk. */
1672 .dirty_folio = filemap_dirty_folio,
1673 #endif /* NTFS_RW */
1674 .migrate_folio = buffer_migrate_folio,
1675 .is_partially_uptodate = block_is_partially_uptodate,
1676 .error_remove_page = generic_error_remove_page,
1682 * mark_ntfs_record_dirty - mark an ntfs record dirty
1683 * @page: page containing the ntfs record to mark dirty
1684 * @ofs: byte offset within @page at which the ntfs record begins
1686 * Set the buffers and the page in which the ntfs record is located dirty.
1688 * The latter also marks the vfs inode the ntfs record belongs to dirty
1689 * (I_DIRTY_PAGES only).
1691 * If the page does not have buffers, we create them and set them uptodate.
1692 * The page may not be locked which is why we need to handle the buffers under
1693 * the mapping->private_lock. Once the buffers are marked dirty we no longer
1694 * need the lock since try_to_free_buffers() does not free dirty buffers.
1696 void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) {
1697 struct address_space *mapping = page->mapping;
1698 ntfs_inode *ni = NTFS_I(mapping->host);
1699 struct buffer_head *bh, *head, *buffers_to_free = NULL;
1700 unsigned int end, bh_size, bh_ofs;
1702 BUG_ON(!PageUptodate(page));
1703 end = ofs + ni->itype.index.block_size;
1704 bh_size = VFS_I(ni)->i_sb->s_blocksize;
1705 spin_lock(&mapping->private_lock);
1706 if (unlikely(!page_has_buffers(page))) {
1707 spin_unlock(&mapping->private_lock);
1708 bh = head = alloc_page_buffers(page, bh_size, true);
1709 spin_lock(&mapping->private_lock);
1710 if (likely(!page_has_buffers(page))) {
1711 struct buffer_head *tail;
1714 set_buffer_uptodate(bh);
1716 bh = bh->b_this_page;
1718 tail->b_this_page = head;
1719 attach_page_private(page, head);
1721 buffers_to_free = bh;
1723 bh = head = page_buffers(page);
1726 bh_ofs = bh_offset(bh);
1727 if (bh_ofs + bh_size <= ofs)
1729 if (unlikely(bh_ofs >= end))
1731 set_buffer_dirty(bh);
1732 } while ((bh = bh->b_this_page) != head);
1733 spin_unlock(&mapping->private_lock);
1734 filemap_dirty_folio(mapping, page_folio(page));
1735 if (unlikely(buffers_to_free)) {
1737 bh = buffers_to_free->b_this_page;
1738 free_buffer_head(buffers_to_free);
1739 buffers_to_free = bh;
1740 } while (buffers_to_free);
1744 #endif /* NTFS_RW */