2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 #include "xfs_shared.h"
20 #include "xfs_format.h"
21 #include "xfs_log_format.h"
22 #include "xfs_trans_resv.h"
23 #include "xfs_mount.h"
24 #include "xfs_inode.h"
25 #include "xfs_trans.h"
26 #include "xfs_inode_item.h"
27 #include "xfs_alloc.h"
28 #include "xfs_error.h"
29 #include "xfs_iomap.h"
30 #include "xfs_trace.h"
32 #include "xfs_bmap_util.h"
33 #include "xfs_bmap_btree.h"
34 #include <linux/gfp.h>
35 #include <linux/mpage.h>
36 #include <linux/pagevec.h>
37 #include <linux/writeback.h>
45 struct buffer_head *bh, *head;
47 *delalloc = *unwritten = 0;
49 bh = head = page_buffers(page);
51 if (buffer_unwritten(bh))
53 else if (buffer_delay(bh))
55 } while ((bh = bh->b_this_page) != head);
58 STATIC struct block_device *
59 xfs_find_bdev_for_inode(
62 struct xfs_inode *ip = XFS_I(inode);
63 struct xfs_mount *mp = ip->i_mount;
65 if (XFS_IS_REALTIME_INODE(ip))
66 return mp->m_rtdev_targp->bt_bdev;
68 return mp->m_ddev_targp->bt_bdev;
72 * We're now finished for good with this ioend structure.
73 * Update the page state via the associated buffer_heads,
74 * release holds on the inode and bio, and finally free
75 * up memory. Do not use the ioend after this.
81 struct buffer_head *bh, *next;
83 for (bh = ioend->io_buffer_head; bh; bh = next) {
85 bh->b_end_io(bh, !ioend->io_error);
88 mempool_free(ioend, xfs_ioend_pool);
92 * Fast and loose check if this write could update the on-disk inode size.
94 static inline bool xfs_ioend_is_append(struct xfs_ioend *ioend)
96 return ioend->io_offset + ioend->io_size >
97 XFS_I(ioend->io_inode)->i_d.di_size;
101 xfs_setfilesize_trans_alloc(
102 struct xfs_ioend *ioend)
104 struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
105 struct xfs_trans *tp;
108 tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
110 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_fsyncts, 0, 0);
112 xfs_trans_cancel(tp, 0);
116 ioend->io_append_trans = tp;
119 * We may pass freeze protection with a transaction. So tell lockdep
122 rwsem_release(&ioend->io_inode->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
125 * We hand off the transaction to the completion thread now, so
126 * clear the flag here.
128 current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
133 * Update on-disk file size now that data has been written to disk.
137 struct xfs_inode *ip,
138 struct xfs_trans *tp,
144 xfs_ilock(ip, XFS_ILOCK_EXCL);
145 isize = xfs_new_eof(ip, offset + size);
147 xfs_iunlock(ip, XFS_ILOCK_EXCL);
148 xfs_trans_cancel(tp, 0);
152 trace_xfs_setfilesize(ip, offset, size);
154 ip->i_d.di_size = isize;
155 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
156 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
158 return xfs_trans_commit(tp, 0);
162 xfs_setfilesize_ioend(
163 struct xfs_ioend *ioend)
165 struct xfs_inode *ip = XFS_I(ioend->io_inode);
166 struct xfs_trans *tp = ioend->io_append_trans;
169 * The transaction may have been allocated in the I/O submission thread,
170 * thus we need to mark ourselves as being in a transaction manually.
171 * Similarly for freeze protection.
173 current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
174 rwsem_acquire_read(&VFS_I(ip)->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
177 return xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size);
181 * Schedule IO completion handling on the final put of an ioend.
183 * If there is no work to do we might as well call it a day and free the
188 struct xfs_ioend *ioend)
190 if (atomic_dec_and_test(&ioend->io_remaining)) {
191 struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
193 if (ioend->io_type == XFS_IO_UNWRITTEN)
194 queue_work(mp->m_unwritten_workqueue, &ioend->io_work);
195 else if (ioend->io_append_trans)
196 queue_work(mp->m_data_workqueue, &ioend->io_work);
198 xfs_destroy_ioend(ioend);
203 * IO write completion.
207 struct work_struct *work)
209 xfs_ioend_t *ioend = container_of(work, xfs_ioend_t, io_work);
210 struct xfs_inode *ip = XFS_I(ioend->io_inode);
213 if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
214 ioend->io_error = -EIO;
221 * For unwritten extents we need to issue transactions to convert a
222 * range to normal written extens after the data I/O has finished.
224 if (ioend->io_type == XFS_IO_UNWRITTEN) {
225 error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
227 } else if (ioend->io_append_trans) {
228 error = xfs_setfilesize_ioend(ioend);
230 ASSERT(!xfs_ioend_is_append(ioend));
235 ioend->io_error = error;
236 xfs_destroy_ioend(ioend);
240 * Allocate and initialise an IO completion structure.
241 * We need to track unwritten extent write completion here initially.
242 * We'll need to extend this for updating the ondisk inode size later
252 ioend = mempool_alloc(xfs_ioend_pool, GFP_NOFS);
255 * Set the count to 1 initially, which will prevent an I/O
256 * completion callback from happening before we have started
257 * all the I/O from calling the completion routine too early.
259 atomic_set(&ioend->io_remaining, 1);
261 ioend->io_list = NULL;
262 ioend->io_type = type;
263 ioend->io_inode = inode;
264 ioend->io_buffer_head = NULL;
265 ioend->io_buffer_tail = NULL;
266 ioend->io_offset = 0;
268 ioend->io_append_trans = NULL;
270 INIT_WORK(&ioend->io_work, xfs_end_io);
278 struct xfs_bmbt_irec *imap,
282 struct xfs_inode *ip = XFS_I(inode);
283 struct xfs_mount *mp = ip->i_mount;
284 ssize_t count = 1 << inode->i_blkbits;
285 xfs_fileoff_t offset_fsb, end_fsb;
287 int bmapi_flags = XFS_BMAPI_ENTIRE;
290 if (XFS_FORCED_SHUTDOWN(mp))
293 if (type == XFS_IO_UNWRITTEN)
294 bmapi_flags |= XFS_BMAPI_IGSTATE;
296 if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
299 xfs_ilock(ip, XFS_ILOCK_SHARED);
302 ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
303 (ip->i_df.if_flags & XFS_IFEXTENTS));
304 ASSERT(offset <= mp->m_super->s_maxbytes);
306 if (offset + count > mp->m_super->s_maxbytes)
307 count = mp->m_super->s_maxbytes - offset;
308 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
309 offset_fsb = XFS_B_TO_FSBT(mp, offset);
310 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
311 imap, &nimaps, bmapi_flags);
312 xfs_iunlock(ip, XFS_ILOCK_SHARED);
317 if (type == XFS_IO_DELALLOC &&
318 (!nimaps || isnullstartblock(imap->br_startblock))) {
319 error = xfs_iomap_write_allocate(ip, offset, imap);
321 trace_xfs_map_blocks_alloc(ip, offset, count, type, imap);
326 if (type == XFS_IO_UNWRITTEN) {
328 ASSERT(imap->br_startblock != HOLESTARTBLOCK);
329 ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
333 trace_xfs_map_blocks_found(ip, offset, count, type, imap);
340 struct xfs_bmbt_irec *imap,
343 offset >>= inode->i_blkbits;
345 return offset >= imap->br_startoff &&
346 offset < imap->br_startoff + imap->br_blockcount;
350 * BIO completion handler for buffered IO.
357 xfs_ioend_t *ioend = bio->bi_private;
359 ioend->io_error = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : error;
361 /* Toss bio and pass work off to an xfsdatad thread */
362 bio->bi_private = NULL;
363 bio->bi_end_io = NULL;
366 xfs_finish_ioend(ioend);
370 xfs_submit_ioend_bio(
371 struct writeback_control *wbc,
375 atomic_inc(&ioend->io_remaining);
376 bio->bi_private = ioend;
377 bio->bi_end_io = xfs_end_bio;
378 submit_bio(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE, bio);
383 struct buffer_head *bh)
385 int nvecs = bio_get_nr_vecs(bh->b_bdev);
386 struct bio *bio = bio_alloc(GFP_NOIO, nvecs);
388 ASSERT(bio->bi_private == NULL);
389 bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
390 bio->bi_bdev = bh->b_bdev;
395 xfs_start_buffer_writeback(
396 struct buffer_head *bh)
398 ASSERT(buffer_mapped(bh));
399 ASSERT(buffer_locked(bh));
400 ASSERT(!buffer_delay(bh));
401 ASSERT(!buffer_unwritten(bh));
403 mark_buffer_async_write(bh);
404 set_buffer_uptodate(bh);
405 clear_buffer_dirty(bh);
409 xfs_start_page_writeback(
414 ASSERT(PageLocked(page));
415 ASSERT(!PageWriteback(page));
418 * if the page was not fully cleaned, we need to ensure that the higher
419 * layers come back to it correctly. That means we need to keep the page
420 * dirty, and for WB_SYNC_ALL writeback we need to ensure the
421 * PAGECACHE_TAG_TOWRITE index mark is not removed so another attempt to
422 * write this page in this writeback sweep will be made.
425 clear_page_dirty_for_io(page);
426 set_page_writeback(page);
428 set_page_writeback_keepwrite(page);
432 /* If no buffers on the page are to be written, finish it here */
434 end_page_writeback(page);
437 static inline int xfs_bio_add_buffer(struct bio *bio, struct buffer_head *bh)
439 return bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
443 * Submit all of the bios for all of the ioends we have saved up, covering the
444 * initial writepage page and also any probed pages.
446 * Because we may have multiple ioends spanning a page, we need to start
447 * writeback on all the buffers before we submit them for I/O. If we mark the
448 * buffers as we got, then we can end up with a page that only has buffers
449 * marked async write and I/O complete on can occur before we mark the other
450 * buffers async write.
452 * The end result of this is that we trip a bug in end_page_writeback() because
453 * we call it twice for the one page as the code in end_buffer_async_write()
454 * assumes that all buffers on the page are started at the same time.
456 * The fix is two passes across the ioend list - one to start writeback on the
457 * buffer_heads, and then submit them for I/O on the second pass.
459 * If @fail is non-zero, it means that we have a situation where some part of
460 * the submission process has failed after we have marked paged for writeback
461 * and unlocked them. In this situation, we need to fail the ioend chain rather
462 * than submit it to IO. This typically only happens on a filesystem shutdown.
466 struct writeback_control *wbc,
470 xfs_ioend_t *head = ioend;
472 struct buffer_head *bh;
474 sector_t lastblock = 0;
476 /* Pass 1 - start writeback */
478 next = ioend->io_list;
479 for (bh = ioend->io_buffer_head; bh; bh = bh->b_private)
480 xfs_start_buffer_writeback(bh);
481 } while ((ioend = next) != NULL);
483 /* Pass 2 - submit I/O */
486 next = ioend->io_list;
490 * If we are failing the IO now, just mark the ioend with an
491 * error and finish it. This will run IO completion immediately
492 * as there is only one reference to the ioend at this point in
496 ioend->io_error = fail;
497 xfs_finish_ioend(ioend);
501 for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) {
505 bio = xfs_alloc_ioend_bio(bh);
506 } else if (bh->b_blocknr != lastblock + 1) {
507 xfs_submit_ioend_bio(wbc, ioend, bio);
511 if (xfs_bio_add_buffer(bio, bh) != bh->b_size) {
512 xfs_submit_ioend_bio(wbc, ioend, bio);
516 lastblock = bh->b_blocknr;
519 xfs_submit_ioend_bio(wbc, ioend, bio);
520 xfs_finish_ioend(ioend);
521 } while ((ioend = next) != NULL);
525 * Cancel submission of all buffer_heads so far in this endio.
526 * Toss the endio too. Only ever called for the initial page
527 * in a writepage request, so only ever one page.
534 struct buffer_head *bh, *next_bh;
537 next = ioend->io_list;
538 bh = ioend->io_buffer_head;
540 next_bh = bh->b_private;
541 clear_buffer_async_write(bh);
543 * The unwritten flag is cleared when added to the
544 * ioend. We're not submitting for I/O so mark the
545 * buffer unwritten again for next time around.
547 if (ioend->io_type == XFS_IO_UNWRITTEN)
548 set_buffer_unwritten(bh);
550 } while ((bh = next_bh) != NULL);
552 mempool_free(ioend, xfs_ioend_pool);
553 } while ((ioend = next) != NULL);
557 * Test to see if we've been building up a completion structure for
558 * earlier buffers -- if so, we try to append to this ioend if we
559 * can, otherwise we finish off any current ioend and start another.
560 * Return true if we've finished the given ioend.
565 struct buffer_head *bh,
568 xfs_ioend_t **result,
571 xfs_ioend_t *ioend = *result;
573 if (!ioend || need_ioend || type != ioend->io_type) {
574 xfs_ioend_t *previous = *result;
576 ioend = xfs_alloc_ioend(inode, type);
577 ioend->io_offset = offset;
578 ioend->io_buffer_head = bh;
579 ioend->io_buffer_tail = bh;
581 previous->io_list = ioend;
584 ioend->io_buffer_tail->b_private = bh;
585 ioend->io_buffer_tail = bh;
588 bh->b_private = NULL;
589 ioend->io_size += bh->b_size;
595 struct buffer_head *bh,
596 struct xfs_bmbt_irec *imap,
600 struct xfs_mount *m = XFS_I(inode)->i_mount;
601 xfs_off_t iomap_offset = XFS_FSB_TO_B(m, imap->br_startoff);
602 xfs_daddr_t iomap_bn = xfs_fsb_to_db(XFS_I(inode), imap->br_startblock);
604 ASSERT(imap->br_startblock != HOLESTARTBLOCK);
605 ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
607 bn = (iomap_bn >> (inode->i_blkbits - BBSHIFT)) +
608 ((offset - iomap_offset) >> inode->i_blkbits);
610 ASSERT(bn || XFS_IS_REALTIME_INODE(XFS_I(inode)));
613 set_buffer_mapped(bh);
619 struct buffer_head *bh,
620 struct xfs_bmbt_irec *imap,
623 ASSERT(imap->br_startblock != HOLESTARTBLOCK);
624 ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
626 xfs_map_buffer(inode, bh, imap, offset);
627 set_buffer_mapped(bh);
628 clear_buffer_delay(bh);
629 clear_buffer_unwritten(bh);
633 * Test if a given page contains at least one buffer of a given @type.
634 * If @check_all_buffers is true, then we walk all the buffers in the page to
635 * try to find one of the type passed in. If it is not set, then the caller only
636 * needs to check the first buffer on the page for a match.
642 bool check_all_buffers)
644 struct buffer_head *bh;
645 struct buffer_head *head;
647 if (PageWriteback(page))
651 if (!page_has_buffers(page))
654 bh = head = page_buffers(page);
656 if (buffer_unwritten(bh)) {
657 if (type == XFS_IO_UNWRITTEN)
659 } else if (buffer_delay(bh)) {
660 if (type == XFS_IO_DELALLOC)
662 } else if (buffer_dirty(bh) && buffer_mapped(bh)) {
663 if (type == XFS_IO_OVERWRITE)
667 /* If we are only checking the first buffer, we are done now. */
668 if (!check_all_buffers)
670 } while ((bh = bh->b_this_page) != head);
676 * Allocate & map buffers for page given the extent map. Write it out.
677 * except for the original page of a writepage, this is called on
678 * delalloc/unwritten pages only, for the original page it is possible
679 * that the page has no mapping at all.
686 struct xfs_bmbt_irec *imap,
687 xfs_ioend_t **ioendp,
688 struct writeback_control *wbc)
690 struct buffer_head *bh, *head;
691 xfs_off_t end_offset;
692 unsigned long p_offset;
695 int count = 0, done = 0, uptodate = 1;
696 xfs_off_t offset = page_offset(page);
698 if (page->index != tindex)
700 if (!trylock_page(page))
702 if (PageWriteback(page))
703 goto fail_unlock_page;
704 if (page->mapping != inode->i_mapping)
705 goto fail_unlock_page;
706 if (!xfs_check_page_type(page, (*ioendp)->io_type, false))
707 goto fail_unlock_page;
710 * page_dirty is initially a count of buffers on the page before
711 * EOF and is decremented as we move each into a cleanable state.
715 * End offset is the highest offset that this page should represent.
716 * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
717 * will evaluate non-zero and be less than PAGE_CACHE_SIZE and
718 * hence give us the correct page_dirty count. On any other page,
719 * it will be zero and in that case we need page_dirty to be the
720 * count of buffers on the page.
722 end_offset = min_t(unsigned long long,
723 (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
727 * If the current map does not span the entire page we are about to try
728 * to write, then give up. The only way we can write a page that spans
729 * multiple mappings in a single writeback iteration is via the
730 * xfs_vm_writepage() function. Data integrity writeback requires the
731 * entire page to be written in a single attempt, otherwise the part of
732 * the page we don't write here doesn't get written as part of the data
735 * For normal writeback, we also don't attempt to write partial pages
736 * here as it simply means that write_cache_pages() will see it under
737 * writeback and ignore the page until some point in the future, at
738 * which time this will be the only page in the file that needs
739 * writeback. Hence for more optimal IO patterns, we should always
740 * avoid partial page writeback due to multiple mappings on a page here.
742 if (!xfs_imap_valid(inode, imap, end_offset))
743 goto fail_unlock_page;
745 len = 1 << inode->i_blkbits;
746 p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
748 p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
749 page_dirty = p_offset / len;
752 * The moment we find a buffer that doesn't match our current type
753 * specification or can't be written, abort the loop and start
754 * writeback. As per the above xfs_imap_valid() check, only
755 * xfs_vm_writepage() can handle partial page writeback fully - we are
756 * limited here to the buffers that are contiguous with the current
757 * ioend, and hence a buffer we can't write breaks that contiguity and
758 * we have to defer the rest of the IO to xfs_vm_writepage().
760 bh = head = page_buffers(page);
762 if (offset >= end_offset)
764 if (!buffer_uptodate(bh))
766 if (!(PageUptodate(page) || buffer_uptodate(bh))) {
771 if (buffer_unwritten(bh) || buffer_delay(bh) ||
773 if (buffer_unwritten(bh))
774 type = XFS_IO_UNWRITTEN;
775 else if (buffer_delay(bh))
776 type = XFS_IO_DELALLOC;
778 type = XFS_IO_OVERWRITE;
781 * imap should always be valid because of the above
782 * partial page end_offset check on the imap.
784 ASSERT(xfs_imap_valid(inode, imap, offset));
787 if (type != XFS_IO_OVERWRITE)
788 xfs_map_at_offset(inode, bh, imap, offset);
789 xfs_add_to_ioend(inode, bh, offset, type,
798 } while (offset += len, (bh = bh->b_this_page) != head);
800 if (uptodate && bh == head)
801 SetPageUptodate(page);
804 if (--wbc->nr_to_write <= 0 &&
805 wbc->sync_mode == WB_SYNC_NONE)
808 xfs_start_page_writeback(page, !page_dirty, count);
818 * Convert & write out a cluster of pages in the same extent as defined
819 * by mp and following the start page.
825 struct xfs_bmbt_irec *imap,
826 xfs_ioend_t **ioendp,
827 struct writeback_control *wbc,
833 pagevec_init(&pvec, 0);
834 while (!done && tindex <= tlast) {
835 unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1);
837 if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len))
840 for (i = 0; i < pagevec_count(&pvec); i++) {
841 done = xfs_convert_page(inode, pvec.pages[i], tindex++,
847 pagevec_release(&pvec);
853 xfs_vm_invalidatepage(
858 trace_xfs_invalidatepage(page->mapping->host, page, offset,
860 block_invalidatepage(page, offset, length);
864 * If the page has delalloc buffers on it, we need to punch them out before we
865 * invalidate the page. If we don't, we leave a stale delalloc mapping on the
866 * inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read
867 * is done on that same region - the delalloc extent is returned when none is
868 * supposed to be there.
870 * We prevent this by truncating away the delalloc regions on the page before
871 * invalidating it. Because they are delalloc, we can do this without needing a
872 * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
873 * truncation without a transaction as there is no space left for block
874 * reservation (typically why we see a ENOSPC in writeback).
876 * This is not a performance critical path, so for now just do the punching a
877 * buffer head at a time.
880 xfs_aops_discard_page(
883 struct inode *inode = page->mapping->host;
884 struct xfs_inode *ip = XFS_I(inode);
885 struct buffer_head *bh, *head;
886 loff_t offset = page_offset(page);
888 if (!xfs_check_page_type(page, XFS_IO_DELALLOC, true))
891 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
894 xfs_alert(ip->i_mount,
895 "page discard on page %p, inode 0x%llx, offset %llu.",
896 page, ip->i_ino, offset);
898 xfs_ilock(ip, XFS_ILOCK_EXCL);
899 bh = head = page_buffers(page);
902 xfs_fileoff_t start_fsb;
904 if (!buffer_delay(bh))
907 start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
908 error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1);
910 /* something screwed, just bail */
911 if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
912 xfs_alert(ip->i_mount,
913 "page discard unable to remove delalloc mapping.");
918 offset += 1 << inode->i_blkbits;
920 } while ((bh = bh->b_this_page) != head);
922 xfs_iunlock(ip, XFS_ILOCK_EXCL);
924 xfs_vm_invalidatepage(page, 0, PAGE_CACHE_SIZE);
929 * Write out a dirty page.
931 * For delalloc space on the page we need to allocate space and flush it.
932 * For unwritten space on the page we need to start the conversion to
933 * regular allocated space.
934 * For any other dirty buffer heads on the page we should flush them.
939 struct writeback_control *wbc)
941 struct inode *inode = page->mapping->host;
942 struct buffer_head *bh, *head;
943 struct xfs_bmbt_irec imap;
944 xfs_ioend_t *ioend = NULL, *iohead = NULL;
947 __uint64_t end_offset;
948 pgoff_t end_index, last_index;
950 int err, imap_valid = 0, uptodate = 1;
954 trace_xfs_writepage(inode, page, 0, 0);
956 ASSERT(page_has_buffers(page));
959 * Refuse to write the page out if we are called from reclaim context.
961 * This avoids stack overflows when called from deeply used stacks in
962 * random callers for direct reclaim or memcg reclaim. We explicitly
963 * allow reclaim from kswapd as the stack usage there is relatively low.
965 * This should never happen except in the case of a VM regression so
968 if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
973 * Given that we do not allow direct reclaim to call us, we should
974 * never be called while in a filesystem transaction.
976 if (WARN_ON_ONCE(current->flags & PF_FSTRANS))
979 /* Is this page beyond the end of the file? */
980 offset = i_size_read(inode);
981 end_index = offset >> PAGE_CACHE_SHIFT;
982 last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
985 * The page index is less than the end_index, adjust the end_offset
986 * to the highest offset that this page should represent.
987 * -----------------------------------------------------
988 * | file mapping | <EOF> |
989 * -----------------------------------------------------
990 * | Page ... | Page N-2 | Page N-1 | Page N | |
991 * ^--------------------------------^----------|--------
992 * | desired writeback range | see else |
993 * ---------------------------------^------------------|
995 if (page->index < end_index)
996 end_offset = (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT;
999 * Check whether the page to write out is beyond or straddles
1001 * -------------------------------------------------------
1002 * | file mapping | <EOF> |
1003 * -------------------------------------------------------
1004 * | Page ... | Page N-2 | Page N-1 | Page N | Beyond |
1005 * ^--------------------------------^-----------|---------
1007 * ---------------------------------^-----------|--------|
1009 unsigned offset_into_page = offset & (PAGE_CACHE_SIZE - 1);
1012 * Skip the page if it is fully outside i_size, e.g. due to a
1013 * truncate operation that is in progress. We must redirty the
1014 * page so that reclaim stops reclaiming it. Otherwise
1015 * xfs_vm_releasepage() is called on it and gets confused.
1017 * Note that the end_index is unsigned long, it would overflow
1018 * if the given offset is greater than 16TB on 32-bit system
1019 * and if we do check the page is fully outside i_size or not
1020 * via "if (page->index >= end_index + 1)" as "end_index + 1"
1021 * will be evaluated to 0. Hence this page will be redirtied
1022 * and be written out repeatedly which would result in an
1023 * infinite loop, the user program that perform this operation
1024 * will hang. Instead, we can verify this situation by checking
1025 * if the page to write is totally beyond the i_size or if it's
1026 * offset is just equal to the EOF.
1028 if (page->index > end_index ||
1029 (page->index == end_index && offset_into_page == 0))
1033 * The page straddles i_size. It must be zeroed out on each
1034 * and every writepage invocation because it may be mmapped.
1035 * "A file is mapped in multiples of the page size. For a file
1036 * that is not a multiple of the page size, the remaining
1037 * memory is zeroed when mapped, and writes to that region are
1038 * not written out to the file."
1040 zero_user_segment(page, offset_into_page, PAGE_CACHE_SIZE);
1042 /* Adjust the end_offset to the end of file */
1043 end_offset = offset;
1046 len = 1 << inode->i_blkbits;
1048 bh = head = page_buffers(page);
1049 offset = page_offset(page);
1050 type = XFS_IO_OVERWRITE;
1052 if (wbc->sync_mode == WB_SYNC_NONE)
1058 if (offset >= end_offset)
1060 if (!buffer_uptodate(bh))
1064 * set_page_dirty dirties all buffers in a page, independent
1065 * of their state. The dirty state however is entirely
1066 * meaningless for holes (!mapped && uptodate), so skip
1067 * buffers covering holes here.
1069 if (!buffer_mapped(bh) && buffer_uptodate(bh)) {
1074 if (buffer_unwritten(bh)) {
1075 if (type != XFS_IO_UNWRITTEN) {
1076 type = XFS_IO_UNWRITTEN;
1079 } else if (buffer_delay(bh)) {
1080 if (type != XFS_IO_DELALLOC) {
1081 type = XFS_IO_DELALLOC;
1084 } else if (buffer_uptodate(bh)) {
1085 if (type != XFS_IO_OVERWRITE) {
1086 type = XFS_IO_OVERWRITE;
1090 if (PageUptodate(page))
1091 ASSERT(buffer_mapped(bh));
1093 * This buffer is not uptodate and will not be
1094 * written to disk. Ensure that we will put any
1095 * subsequent writeable buffers into a new
1103 imap_valid = xfs_imap_valid(inode, &imap, offset);
1106 * If we didn't have a valid mapping then we need to
1107 * put the new mapping into a separate ioend structure.
1108 * This ensures non-contiguous extents always have
1109 * separate ioends, which is particularly important
1110 * for unwritten extent conversion at I/O completion
1114 err = xfs_map_blocks(inode, offset, &imap, type,
1118 imap_valid = xfs_imap_valid(inode, &imap, offset);
1122 if (type != XFS_IO_OVERWRITE)
1123 xfs_map_at_offset(inode, bh, &imap, offset);
1124 xfs_add_to_ioend(inode, bh, offset, type, &ioend,
1132 } while (offset += len, ((bh = bh->b_this_page) != head));
1134 if (uptodate && bh == head)
1135 SetPageUptodate(page);
1137 xfs_start_page_writeback(page, 1, count);
1139 /* if there is no IO to be submitted for this page, we are done */
1146 * Any errors from this point onwards need tobe reported through the IO
1147 * completion path as we have marked the initial page as under writeback
1151 xfs_off_t end_index;
1153 end_index = imap.br_startoff + imap.br_blockcount;
1156 end_index <<= inode->i_blkbits;
1159 end_index = (end_index - 1) >> PAGE_CACHE_SHIFT;
1161 /* check against file size */
1162 if (end_index > last_index)
1163 end_index = last_index;
1165 xfs_cluster_write(inode, page->index + 1, &imap, &ioend,
1171 * Reserve log space if we might write beyond the on-disk inode size.
1174 if (ioend->io_type != XFS_IO_UNWRITTEN && xfs_ioend_is_append(ioend))
1175 err = xfs_setfilesize_trans_alloc(ioend);
1177 xfs_submit_ioend(wbc, iohead, err);
1183 xfs_cancel_ioend(iohead);
1188 xfs_aops_discard_page(page);
1189 ClearPageUptodate(page);
1194 redirty_page_for_writepage(wbc, page);
1201 struct address_space *mapping,
1202 struct writeback_control *wbc)
1204 xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
1205 return generic_writepages(mapping, wbc);
1209 * Called to move a page into cleanable state - and from there
1210 * to be released. The page should already be clean. We always
1211 * have buffer heads in this call.
1213 * Returns 1 if the page is ok to release, 0 otherwise.
1220 int delalloc, unwritten;
1222 trace_xfs_releasepage(page->mapping->host, page, 0, 0);
1224 xfs_count_page_state(page, &delalloc, &unwritten);
1226 if (WARN_ON_ONCE(delalloc))
1228 if (WARN_ON_ONCE(unwritten))
1231 return try_to_free_buffers(page);
1235 * When we map a DIO buffer, we may need to attach an ioend that describes the
1236 * type of write IO we are doing. This passes to the completion function the
1237 * operations it needs to perform. If the mapping is for an overwrite wholly
1238 * within the EOF then we don't need an ioend and so we don't allocate one.
1239 * This avoids the unnecessary overhead of allocating and freeing ioends for
1240 * workloads that don't require transactions on IO completion.
1242 * If we get multiple mappings in a single IO, we might be mapping different
1243 * types. But because the direct IO can only have a single private pointer, we
1244 * need to ensure that:
1246 * a) i) the ioend spans the entire region of unwritten mappings; or
1247 * ii) the ioend spans all the mappings that cross or are beyond EOF; and
1248 * b) if it contains unwritten extents, it is *permanently* marked as such
1250 * We could do this by chaining ioends like buffered IO does, but we only
1251 * actually get one IO completion callback from the direct IO, and that spans
1252 * the entire IO regardless of how many mappings and IOs are needed to complete
1253 * the DIO. There is only going to be one reference to the ioend and its life
1254 * cycle is constrained by the DIO completion code. hence we don't need
1255 * reference counting here.
1259 struct inode *inode,
1260 struct buffer_head *bh_result,
1261 struct xfs_bmbt_irec *imap,
1264 struct xfs_ioend *ioend;
1265 xfs_off_t size = bh_result->b_size;
1268 if (ISUNWRITTEN(imap))
1269 type = XFS_IO_UNWRITTEN;
1271 type = XFS_IO_OVERWRITE;
1273 trace_xfs_gbmap_direct(XFS_I(inode), offset, size, type, imap);
1275 if (bh_result->b_private) {
1276 ioend = bh_result->b_private;
1277 ASSERT(ioend->io_size > 0);
1278 ASSERT(offset >= ioend->io_offset);
1279 if (offset + size > ioend->io_offset + ioend->io_size)
1280 ioend->io_size = offset - ioend->io_offset + size;
1282 if (type == XFS_IO_UNWRITTEN && type != ioend->io_type)
1283 ioend->io_type = XFS_IO_UNWRITTEN;
1285 trace_xfs_gbmap_direct_update(XFS_I(inode), ioend->io_offset,
1286 ioend->io_size, ioend->io_type,
1288 } else if (type == XFS_IO_UNWRITTEN ||
1289 offset + size > i_size_read(inode)) {
1290 ioend = xfs_alloc_ioend(inode, type);
1291 ioend->io_offset = offset;
1292 ioend->io_size = size;
1294 bh_result->b_private = ioend;
1295 set_buffer_defer_completion(bh_result);
1297 trace_xfs_gbmap_direct_new(XFS_I(inode), offset, size, type,
1300 trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type,
1306 * If this is O_DIRECT or the mpage code calling tell them how large the mapping
1307 * is, so that we can avoid repeated get_blocks calls.
1309 * If the mapping spans EOF, then we have to break the mapping up as the mapping
1310 * for blocks beyond EOF must be marked new so that sub block regions can be
1311 * correctly zeroed. We can't do this for mappings within EOF unless the mapping
1312 * was just allocated or is unwritten, otherwise the callers would overwrite
1313 * existing data with zeros. Hence we have to split the mapping into a range up
1314 * to and including EOF, and a second mapping for beyond EOF.
1318 struct inode *inode,
1320 struct buffer_head *bh_result,
1321 struct xfs_bmbt_irec *imap,
1325 xfs_off_t mapping_size;
1327 mapping_size = imap->br_startoff + imap->br_blockcount - iblock;
1328 mapping_size <<= inode->i_blkbits;
1330 ASSERT(mapping_size > 0);
1331 if (mapping_size > size)
1332 mapping_size = size;
1333 if (offset < i_size_read(inode) &&
1334 offset + mapping_size >= i_size_read(inode)) {
1335 /* limit mapping to block that spans EOF */
1336 mapping_size = roundup_64(i_size_read(inode) - offset,
1337 1 << inode->i_blkbits);
1339 if (mapping_size > LONG_MAX)
1340 mapping_size = LONG_MAX;
1342 bh_result->b_size = mapping_size;
1347 struct inode *inode,
1349 struct buffer_head *bh_result,
1353 struct xfs_inode *ip = XFS_I(inode);
1354 struct xfs_mount *mp = ip->i_mount;
1355 xfs_fileoff_t offset_fsb, end_fsb;
1358 struct xfs_bmbt_irec imap;
1364 if (XFS_FORCED_SHUTDOWN(mp))
1367 offset = (xfs_off_t)iblock << inode->i_blkbits;
1368 ASSERT(bh_result->b_size >= (1 << inode->i_blkbits));
1369 size = bh_result->b_size;
1371 if (!create && direct && offset >= i_size_read(inode))
1375 * Direct I/O is usually done on preallocated files, so try getting
1376 * a block mapping without an exclusive lock first. For buffered
1377 * writes we already have the exclusive iolock anyway, so avoiding
1378 * a lock roundtrip here by taking the ilock exclusive from the
1379 * beginning is a useful micro optimization.
1381 if (create && !direct) {
1382 lockmode = XFS_ILOCK_EXCL;
1383 xfs_ilock(ip, lockmode);
1385 lockmode = xfs_ilock_data_map_shared(ip);
1388 ASSERT(offset <= mp->m_super->s_maxbytes);
1389 if (offset + size > mp->m_super->s_maxbytes)
1390 size = mp->m_super->s_maxbytes - offset;
1391 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
1392 offset_fsb = XFS_B_TO_FSBT(mp, offset);
1394 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
1395 &imap, &nimaps, XFS_BMAPI_ENTIRE);
1401 (imap.br_startblock == HOLESTARTBLOCK ||
1402 imap.br_startblock == DELAYSTARTBLOCK))) {
1403 if (direct || xfs_get_extsz_hint(ip)) {
1405 * Drop the ilock in preparation for starting the block
1406 * allocation transaction. It will be retaken
1407 * exclusively inside xfs_iomap_write_direct for the
1408 * actual allocation.
1410 xfs_iunlock(ip, lockmode);
1411 error = xfs_iomap_write_direct(ip, offset, size,
1418 * Delalloc reservations do not require a transaction,
1419 * we can go on without dropping the lock here. If we
1420 * are allocating a new delalloc block, make sure that
1421 * we set the new flag so that we mark the buffer new so
1422 * that we know that it is newly allocated if the write
1425 if (nimaps && imap.br_startblock == HOLESTARTBLOCK)
1427 error = xfs_iomap_write_delay(ip, offset, size, &imap);
1431 xfs_iunlock(ip, lockmode);
1433 trace_xfs_get_blocks_alloc(ip, offset, size,
1434 ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN
1435 : XFS_IO_DELALLOC, &imap);
1436 } else if (nimaps) {
1437 trace_xfs_get_blocks_found(ip, offset, size,
1438 ISUNWRITTEN(&imap) ? XFS_IO_UNWRITTEN
1439 : XFS_IO_OVERWRITE, &imap);
1440 xfs_iunlock(ip, lockmode);
1442 trace_xfs_get_blocks_notfound(ip, offset, size);
1446 /* trim mapping down to size requested */
1447 if (direct || size > (1 << inode->i_blkbits))
1448 xfs_map_trim_size(inode, iblock, bh_result,
1449 &imap, offset, size);
1452 * For unwritten extents do not report a disk address in the buffered
1453 * read case (treat as if we're reading into a hole).
1455 if (imap.br_startblock != HOLESTARTBLOCK &&
1456 imap.br_startblock != DELAYSTARTBLOCK &&
1457 (create || !ISUNWRITTEN(&imap))) {
1458 xfs_map_buffer(inode, bh_result, &imap, offset);
1459 if (ISUNWRITTEN(&imap))
1460 set_buffer_unwritten(bh_result);
1461 /* direct IO needs special help */
1462 if (create && direct)
1463 xfs_map_direct(inode, bh_result, &imap, offset);
1467 * If this is a realtime file, data may be on a different device.
1468 * to that pointed to from the buffer_head b_bdev currently.
1470 bh_result->b_bdev = xfs_find_bdev_for_inode(inode);
1473 * If we previously allocated a block out beyond eof and we are now
1474 * coming back to use it then we will need to flag it as new even if it
1475 * has a disk address.
1477 * With sub-block writes into unwritten extents we also need to mark
1478 * the buffer as new so that the unwritten parts of the buffer gets
1482 ((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
1483 (offset >= i_size_read(inode)) ||
1484 (new || ISUNWRITTEN(&imap))))
1485 set_buffer_new(bh_result);
1487 if (imap.br_startblock == DELAYSTARTBLOCK) {
1490 set_buffer_uptodate(bh_result);
1491 set_buffer_mapped(bh_result);
1492 set_buffer_delay(bh_result);
1499 xfs_iunlock(ip, lockmode);
1505 struct inode *inode,
1507 struct buffer_head *bh_result,
1510 return __xfs_get_blocks(inode, iblock, bh_result, create, 0);
1514 xfs_get_blocks_direct(
1515 struct inode *inode,
1517 struct buffer_head *bh_result,
1520 return __xfs_get_blocks(inode, iblock, bh_result, create, 1);
1524 * Complete a direct I/O write request.
1526 * The ioend structure is passed from __xfs_get_blocks() to tell us what to do.
1527 * If no ioend exists (i.e. @private == NULL) then the write IO is an overwrite
1528 * wholly within the EOF and so there is nothing for us to do. Note that in this
1529 * case the completion can be called in interrupt context, whereas if we have an
1530 * ioend we will always be called in task context (i.e. from a workqueue).
1533 xfs_end_io_direct_write(
1539 struct inode *inode = file_inode(iocb->ki_filp);
1540 struct xfs_inode *ip = XFS_I(inode);
1541 struct xfs_mount *mp = ip->i_mount;
1542 struct xfs_ioend *ioend = private;
1544 trace_xfs_gbmap_direct_endio(ip, offset, size,
1545 ioend ? ioend->io_type : 0, NULL);
1548 ASSERT(offset + size <= i_size_read(inode));
1552 if (XFS_FORCED_SHUTDOWN(mp))
1556 * dio completion end_io functions are only called on writes if more
1557 * than 0 bytes was written.
1562 * The ioend only maps whole blocks, while the IO may be sector aligned.
1563 * Hence the ioend offset/size may not match the IO offset/size exactly.
1564 * Because we don't map overwrites within EOF into the ioend, the offset
1565 * may not match, but only if the endio spans EOF. Either way, write
1566 * the IO sizes into the ioend so that completion processing does the
1569 ASSERT(offset + size <= ioend->io_offset + ioend->io_size);
1570 ioend->io_size = size;
1571 ioend->io_offset = offset;
1574 * The ioend tells us whether we are doing unwritten extent conversion
1575 * or an append transaction that updates the on-disk file size. These
1576 * cases are the only cases where we should *potentially* be needing
1577 * to update the VFS inode size.
1579 * We need to update the in-core inode size here so that we don't end up
1580 * with the on-disk inode size being outside the in-core inode size. We
1581 * have no other method of updating EOF for AIO, so always do it here
1584 * We need to lock the test/set EOF update as we can be racing with
1585 * other IO completions here to update the EOF. Failing to serialise
1586 * here can result in EOF moving backwards and Bad Things Happen when
1589 spin_lock(&ip->i_flags_lock);
1590 if (offset + size > i_size_read(inode))
1591 i_size_write(inode, offset + size);
1592 spin_unlock(&ip->i_flags_lock);
1595 * If we are doing an append IO that needs to update the EOF on disk,
1596 * do the transaction reserve now so we can use common end io
1597 * processing. Stashing the error (if there is one) in the ioend will
1598 * result in the ioend processing passing on the error if it is
1599 * possible as we can't return it from here.
1601 if (ioend->io_type == XFS_IO_OVERWRITE)
1602 ioend->io_error = xfs_setfilesize_trans_alloc(ioend);
1605 xfs_end_io(&ioend->io_work);
1612 struct iov_iter *iter,
1615 struct inode *inode = iocb->ki_filp->f_mapping->host;
1616 struct block_device *bdev = xfs_find_bdev_for_inode(inode);
1618 if (iov_iter_rw(iter) == WRITE) {
1619 return __blockdev_direct_IO(iocb, inode, bdev, iter, offset,
1620 xfs_get_blocks_direct,
1621 xfs_end_io_direct_write, NULL,
1624 return __blockdev_direct_IO(iocb, inode, bdev, iter, offset,
1625 xfs_get_blocks_direct, NULL, NULL, 0);
1629 * Punch out the delalloc blocks we have already allocated.
1631 * Don't bother with xfs_setattr given that nothing can have made it to disk yet
1632 * as the page is still locked at this point.
1635 xfs_vm_kill_delalloc_range(
1636 struct inode *inode,
1640 struct xfs_inode *ip = XFS_I(inode);
1641 xfs_fileoff_t start_fsb;
1642 xfs_fileoff_t end_fsb;
1645 start_fsb = XFS_B_TO_FSB(ip->i_mount, start);
1646 end_fsb = XFS_B_TO_FSB(ip->i_mount, end);
1647 if (end_fsb <= start_fsb)
1650 xfs_ilock(ip, XFS_ILOCK_EXCL);
1651 error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
1652 end_fsb - start_fsb);
1654 /* something screwed, just bail */
1655 if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
1656 xfs_alert(ip->i_mount,
1657 "xfs_vm_write_failed: unable to clean up ino %lld",
1661 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1665 xfs_vm_write_failed(
1666 struct inode *inode,
1671 loff_t block_offset;
1674 loff_t from = pos & (PAGE_CACHE_SIZE - 1);
1675 loff_t to = from + len;
1676 struct buffer_head *bh, *head;
1679 * The request pos offset might be 32 or 64 bit, this is all fine
1680 * on 64-bit platform. However, for 64-bit pos request on 32-bit
1681 * platform, the high 32-bit will be masked off if we evaluate the
1682 * block_offset via (pos & PAGE_MASK) because the PAGE_MASK is
1683 * 0xfffff000 as an unsigned long, hence the result is incorrect
1684 * which could cause the following ASSERT failed in most cases.
1685 * In order to avoid this, we can evaluate the block_offset of the
1686 * start of the page by using shifts rather than masks the mismatch
1689 block_offset = (pos >> PAGE_CACHE_SHIFT) << PAGE_CACHE_SHIFT;
1691 ASSERT(block_offset + from == pos);
1693 head = page_buffers(page);
1695 for (bh = head; bh != head || !block_start;
1696 bh = bh->b_this_page, block_start = block_end,
1697 block_offset += bh->b_size) {
1698 block_end = block_start + bh->b_size;
1700 /* skip buffers before the write */
1701 if (block_end <= from)
1704 /* if the buffer is after the write, we're done */
1705 if (block_start >= to)
1708 if (!buffer_delay(bh))
1711 if (!buffer_new(bh) && block_offset < i_size_read(inode))
1714 xfs_vm_kill_delalloc_range(inode, block_offset,
1715 block_offset + bh->b_size);
1718 * This buffer does not contain data anymore. make sure anyone
1719 * who finds it knows that for certain.
1721 clear_buffer_delay(bh);
1722 clear_buffer_uptodate(bh);
1723 clear_buffer_mapped(bh);
1724 clear_buffer_new(bh);
1725 clear_buffer_dirty(bh);
1731 * This used to call block_write_begin(), but it unlocks and releases the page
1732 * on error, and we need that page to be able to punch stale delalloc blocks out
1733 * on failure. hence we copy-n-waste it here and call xfs_vm_write_failed() at
1734 * the appropriate point.
1739 struct address_space *mapping,
1743 struct page **pagep,
1746 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1750 ASSERT(len <= PAGE_CACHE_SIZE);
1752 page = grab_cache_page_write_begin(mapping, index, flags);
1756 status = __block_write_begin(page, pos, len, xfs_get_blocks);
1757 if (unlikely(status)) {
1758 struct inode *inode = mapping->host;
1759 size_t isize = i_size_read(inode);
1761 xfs_vm_write_failed(inode, page, pos, len);
1765 * If the write is beyond EOF, we only want to kill blocks
1766 * allocated in this write, not blocks that were previously
1767 * written successfully.
1769 if (pos + len > isize) {
1770 ssize_t start = max_t(ssize_t, pos, isize);
1772 truncate_pagecache_range(inode, start, pos + len);
1775 page_cache_release(page);
1784 * On failure, we only need to kill delalloc blocks beyond EOF in the range of
1785 * this specific write because they will never be written. Previous writes
1786 * beyond EOF where block allocation succeeded do not need to be trashed, so
1787 * only new blocks from this write should be trashed. For blocks within
1788 * EOF, generic_write_end() zeros them so they are safe to leave alone and be
1789 * written with all the other valid data.
1794 struct address_space *mapping,
1803 ASSERT(len <= PAGE_CACHE_SIZE);
1805 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
1806 if (unlikely(ret < len)) {
1807 struct inode *inode = mapping->host;
1808 size_t isize = i_size_read(inode);
1809 loff_t to = pos + len;
1812 /* only kill blocks in this write beyond EOF */
1815 xfs_vm_kill_delalloc_range(inode, isize, to);
1816 truncate_pagecache_range(inode, isize, to);
1824 struct address_space *mapping,
1827 struct inode *inode = (struct inode *)mapping->host;
1828 struct xfs_inode *ip = XFS_I(inode);
1830 trace_xfs_vm_bmap(XFS_I(inode));
1831 xfs_ilock(ip, XFS_IOLOCK_SHARED);
1832 filemap_write_and_wait(mapping);
1833 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
1834 return generic_block_bmap(mapping, block, xfs_get_blocks);
1839 struct file *unused,
1842 return mpage_readpage(page, xfs_get_blocks);
1847 struct file *unused,
1848 struct address_space *mapping,
1849 struct list_head *pages,
1852 return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
1856 * This is basically a copy of __set_page_dirty_buffers() with one
1857 * small tweak: buffers beyond EOF do not get marked dirty. If we mark them
1858 * dirty, we'll never be able to clean them because we don't write buffers
1859 * beyond EOF, and that means we can't invalidate pages that span EOF
1860 * that have been marked dirty. Further, the dirty state can leak into
1861 * the file interior if the file is extended, resulting in all sorts of
1862 * bad things happening as the state does not match the underlying data.
1864 * XXX: this really indicates that bufferheads in XFS need to die. Warts like
1865 * this only exist because of bufferheads and how the generic code manages them.
1868 xfs_vm_set_page_dirty(
1871 struct address_space *mapping = page->mapping;
1872 struct inode *inode = mapping->host;
1876 struct mem_cgroup *memcg;
1878 if (unlikely(!mapping))
1879 return !TestSetPageDirty(page);
1881 end_offset = i_size_read(inode);
1882 offset = page_offset(page);
1884 spin_lock(&mapping->private_lock);
1885 if (page_has_buffers(page)) {
1886 struct buffer_head *head = page_buffers(page);
1887 struct buffer_head *bh = head;
1890 if (offset < end_offset)
1891 set_buffer_dirty(bh);
1892 bh = bh->b_this_page;
1893 offset += 1 << inode->i_blkbits;
1894 } while (bh != head);
1897 * Use mem_group_begin_page_stat() to keep PageDirty synchronized with
1898 * per-memcg dirty page counters.
1900 memcg = mem_cgroup_begin_page_stat(page);
1901 newly_dirty = !TestSetPageDirty(page);
1902 spin_unlock(&mapping->private_lock);
1905 /* sigh - __set_page_dirty() is static, so copy it here, too */
1906 unsigned long flags;
1908 spin_lock_irqsave(&mapping->tree_lock, flags);
1909 if (page->mapping) { /* Race with truncate? */
1910 WARN_ON_ONCE(!PageUptodate(page));
1911 account_page_dirtied(page, mapping, memcg);
1912 radix_tree_tag_set(&mapping->page_tree,
1913 page_index(page), PAGECACHE_TAG_DIRTY);
1915 spin_unlock_irqrestore(&mapping->tree_lock, flags);
1917 mem_cgroup_end_page_stat(memcg);
1919 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
1923 const struct address_space_operations xfs_address_space_operations = {
1924 .readpage = xfs_vm_readpage,
1925 .readpages = xfs_vm_readpages,
1926 .writepage = xfs_vm_writepage,
1927 .writepages = xfs_vm_writepages,
1928 .set_page_dirty = xfs_vm_set_page_dirty,
1929 .releasepage = xfs_vm_releasepage,
1930 .invalidatepage = xfs_vm_invalidatepage,
1931 .write_begin = xfs_vm_write_begin,
1932 .write_end = xfs_vm_write_end,
1933 .bmap = xfs_vm_bmap,
1934 .direct_IO = xfs_vm_direct_IO,
1935 .migratepage = buffer_migrate_page,
1936 .is_partially_uptodate = block_is_partially_uptodate,
1937 .error_remove_page = generic_error_remove_page,