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
22 #include "xfs_trans.h"
23 #include "xfs_mount.h"
24 #include "xfs_bmap_btree.h"
25 #include "xfs_dinode.h"
26 #include "xfs_inode.h"
27 #include "xfs_inode_item.h"
28 #include "xfs_alloc.h"
29 #include "xfs_error.h"
30 #include "xfs_iomap.h"
31 #include "xfs_vnodeops.h"
32 #include "xfs_trace.h"
34 #include <linux/aio.h>
35 #include <linux/gfp.h>
36 #include <linux/mpage.h>
37 #include <linux/pagevec.h>
38 #include <linux/writeback.h>
46 struct buffer_head *bh, *head;
48 *delalloc = *unwritten = 0;
50 bh = head = page_buffers(page);
52 if (buffer_unwritten(bh))
54 else if (buffer_delay(bh))
56 } while ((bh = bh->b_this_page) != head);
59 STATIC struct block_device *
60 xfs_find_bdev_for_inode(
63 struct xfs_inode *ip = XFS_I(inode);
64 struct xfs_mount *mp = ip->i_mount;
66 if (XFS_IS_REALTIME_INODE(ip))
67 return mp->m_rtdev_targp->bt_bdev;
69 return mp->m_ddev_targp->bt_bdev;
73 * We're now finished for good with this ioend structure.
74 * Update the page state via the associated buffer_heads,
75 * release holds on the inode and bio, and finally free
76 * up memory. Do not use the ioend after this.
82 struct buffer_head *bh, *next;
84 for (bh = ioend->io_buffer_head; bh; bh = next) {
86 bh->b_end_io(bh, !ioend->io_error);
90 inode_dio_done(ioend->io_inode);
91 if (ioend->io_isasync) {
92 aio_complete(ioend->io_iocb, ioend->io_error ?
93 ioend->io_error : ioend->io_result, 0);
97 mempool_free(ioend, xfs_ioend_pool);
101 * Fast and loose check if this write could update the on-disk inode size.
103 static inline bool xfs_ioend_is_append(struct xfs_ioend *ioend)
105 return ioend->io_offset + ioend->io_size >
106 XFS_I(ioend->io_inode)->i_d.di_size;
110 xfs_setfilesize_trans_alloc(
111 struct xfs_ioend *ioend)
113 struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
114 struct xfs_trans *tp;
117 tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
119 error = xfs_trans_reserve(tp, 0, XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0);
121 xfs_trans_cancel(tp, 0);
125 ioend->io_append_trans = tp;
128 * We may pass freeze protection with a transaction. So tell lockdep
131 rwsem_release(&ioend->io_inode->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
134 * We hand off the transaction to the completion thread now, so
135 * clear the flag here.
137 current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
142 * Update on-disk file size now that data has been written to disk.
146 struct xfs_ioend *ioend)
148 struct xfs_inode *ip = XFS_I(ioend->io_inode);
149 struct xfs_trans *tp = ioend->io_append_trans;
153 * The transaction may have been allocated in the I/O submission thread,
154 * thus we need to mark ourselves as beeing in a transaction manually.
155 * Similarly for freeze protection.
157 current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
158 rwsem_acquire_read(&VFS_I(ip)->i_sb->s_writers.lock_map[SB_FREEZE_FS-1],
161 xfs_ilock(ip, XFS_ILOCK_EXCL);
162 isize = xfs_new_eof(ip, ioend->io_offset + ioend->io_size);
164 xfs_iunlock(ip, XFS_ILOCK_EXCL);
165 xfs_trans_cancel(tp, 0);
169 trace_xfs_setfilesize(ip, ioend->io_offset, ioend->io_size);
171 ip->i_d.di_size = isize;
172 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
173 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
175 return xfs_trans_commit(tp, 0);
179 * Schedule IO completion handling on the final put of an ioend.
181 * If there is no work to do we might as well call it a day and free the
186 struct xfs_ioend *ioend)
188 if (atomic_dec_and_test(&ioend->io_remaining)) {
189 struct xfs_mount *mp = XFS_I(ioend->io_inode)->i_mount;
191 if (ioend->io_type == XFS_IO_UNWRITTEN)
192 queue_work(mp->m_unwritten_workqueue, &ioend->io_work);
193 else if (ioend->io_append_trans ||
194 (ioend->io_isdirect && xfs_ioend_is_append(ioend)))
195 queue_work(mp->m_data_workqueue, &ioend->io_work);
197 xfs_destroy_ioend(ioend);
202 * IO write completion.
206 struct work_struct *work)
208 xfs_ioend_t *ioend = container_of(work, xfs_ioend_t, io_work);
209 struct xfs_inode *ip = XFS_I(ioend->io_inode);
212 if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
213 ioend->io_error = -EIO;
220 * For unwritten extents we need to issue transactions to convert a
221 * range to normal written extens after the data I/O has finished.
223 if (ioend->io_type == XFS_IO_UNWRITTEN) {
224 error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
226 } else if (ioend->io_isdirect && xfs_ioend_is_append(ioend)) {
228 * For direct I/O we do not know if we need to allocate blocks
229 * or not so we can't preallocate an append transaction as that
230 * results in nested reservations and log space deadlocks. Hence
231 * allocate the transaction here. While this is sub-optimal and
232 * can block IO completion for some time, we're stuck with doing
233 * it this way until we can pass the ioend to the direct IO
234 * allocation callbacks and avoid nesting that way.
236 error = xfs_setfilesize_trans_alloc(ioend);
239 error = xfs_setfilesize(ioend);
240 } else if (ioend->io_append_trans) {
241 error = xfs_setfilesize(ioend);
243 ASSERT(!xfs_ioend_is_append(ioend));
248 ioend->io_error = -error;
249 xfs_destroy_ioend(ioend);
253 * Call IO completion handling in caller context on the final put of an ioend.
256 xfs_finish_ioend_sync(
257 struct xfs_ioend *ioend)
259 if (atomic_dec_and_test(&ioend->io_remaining))
260 xfs_end_io(&ioend->io_work);
264 * Allocate and initialise an IO completion structure.
265 * We need to track unwritten extent write completion here initially.
266 * We'll need to extend this for updating the ondisk inode size later
276 ioend = mempool_alloc(xfs_ioend_pool, GFP_NOFS);
279 * Set the count to 1 initially, which will prevent an I/O
280 * completion callback from happening before we have started
281 * all the I/O from calling the completion routine too early.
283 atomic_set(&ioend->io_remaining, 1);
284 ioend->io_isasync = 0;
285 ioend->io_isdirect = 0;
287 ioend->io_list = NULL;
288 ioend->io_type = type;
289 ioend->io_inode = inode;
290 ioend->io_buffer_head = NULL;
291 ioend->io_buffer_tail = NULL;
292 ioend->io_offset = 0;
294 ioend->io_iocb = NULL;
295 ioend->io_result = 0;
296 ioend->io_append_trans = NULL;
298 INIT_WORK(&ioend->io_work, xfs_end_io);
306 struct xfs_bmbt_irec *imap,
310 struct xfs_inode *ip = XFS_I(inode);
311 struct xfs_mount *mp = ip->i_mount;
312 ssize_t count = 1 << inode->i_blkbits;
313 xfs_fileoff_t offset_fsb, end_fsb;
315 int bmapi_flags = XFS_BMAPI_ENTIRE;
318 if (XFS_FORCED_SHUTDOWN(mp))
319 return -XFS_ERROR(EIO);
321 if (type == XFS_IO_UNWRITTEN)
322 bmapi_flags |= XFS_BMAPI_IGSTATE;
324 if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
326 return -XFS_ERROR(EAGAIN);
327 xfs_ilock(ip, XFS_ILOCK_SHARED);
330 ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
331 (ip->i_df.if_flags & XFS_IFEXTENTS));
332 ASSERT(offset <= mp->m_super->s_maxbytes);
334 if (offset + count > mp->m_super->s_maxbytes)
335 count = mp->m_super->s_maxbytes - offset;
336 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
337 offset_fsb = XFS_B_TO_FSBT(mp, offset);
338 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
339 imap, &nimaps, bmapi_flags);
340 xfs_iunlock(ip, XFS_ILOCK_SHARED);
343 return -XFS_ERROR(error);
345 if (type == XFS_IO_DELALLOC &&
346 (!nimaps || isnullstartblock(imap->br_startblock))) {
347 error = xfs_iomap_write_allocate(ip, offset, count, imap);
349 trace_xfs_map_blocks_alloc(ip, offset, count, type, imap);
350 return -XFS_ERROR(error);
354 if (type == XFS_IO_UNWRITTEN) {
356 ASSERT(imap->br_startblock != HOLESTARTBLOCK);
357 ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
361 trace_xfs_map_blocks_found(ip, offset, count, type, imap);
368 struct xfs_bmbt_irec *imap,
371 offset >>= inode->i_blkbits;
373 return offset >= imap->br_startoff &&
374 offset < imap->br_startoff + imap->br_blockcount;
378 * BIO completion handler for buffered IO.
385 xfs_ioend_t *ioend = bio->bi_private;
387 ASSERT(atomic_read(&bio->bi_cnt) >= 1);
388 ioend->io_error = test_bit(BIO_UPTODATE, &bio->bi_flags) ? 0 : error;
390 /* Toss bio and pass work off to an xfsdatad thread */
391 bio->bi_private = NULL;
392 bio->bi_end_io = NULL;
395 xfs_finish_ioend(ioend);
399 xfs_submit_ioend_bio(
400 struct writeback_control *wbc,
404 atomic_inc(&ioend->io_remaining);
405 bio->bi_private = ioend;
406 bio->bi_end_io = xfs_end_bio;
407 submit_bio(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE, bio);
412 struct buffer_head *bh)
414 int nvecs = bio_get_nr_vecs(bh->b_bdev);
415 struct bio *bio = bio_alloc(GFP_NOIO, nvecs);
417 ASSERT(bio->bi_private == NULL);
418 bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9);
419 bio->bi_bdev = bh->b_bdev;
424 xfs_start_buffer_writeback(
425 struct buffer_head *bh)
427 ASSERT(buffer_mapped(bh));
428 ASSERT(buffer_locked(bh));
429 ASSERT(!buffer_delay(bh));
430 ASSERT(!buffer_unwritten(bh));
432 mark_buffer_async_write(bh);
433 set_buffer_uptodate(bh);
434 clear_buffer_dirty(bh);
438 xfs_start_page_writeback(
443 ASSERT(PageLocked(page));
444 ASSERT(!PageWriteback(page));
446 clear_page_dirty_for_io(page);
447 set_page_writeback(page);
449 /* If no buffers on the page are to be written, finish it here */
451 end_page_writeback(page);
454 static inline int bio_add_buffer(struct bio *bio, struct buffer_head *bh)
456 return bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
460 * Submit all of the bios for all of the ioends we have saved up, covering the
461 * initial writepage page and also any probed pages.
463 * Because we may have multiple ioends spanning a page, we need to start
464 * writeback on all the buffers before we submit them for I/O. If we mark the
465 * buffers as we got, then we can end up with a page that only has buffers
466 * marked async write and I/O complete on can occur before we mark the other
467 * buffers async write.
469 * The end result of this is that we trip a bug in end_page_writeback() because
470 * we call it twice for the one page as the code in end_buffer_async_write()
471 * assumes that all buffers on the page are started at the same time.
473 * The fix is two passes across the ioend list - one to start writeback on the
474 * buffer_heads, and then submit them for I/O on the second pass.
476 * If @fail is non-zero, it means that we have a situation where some part of
477 * the submission process has failed after we have marked paged for writeback
478 * and unlocked them. In this situation, we need to fail the ioend chain rather
479 * than submit it to IO. This typically only happens on a filesystem shutdown.
483 struct writeback_control *wbc,
487 xfs_ioend_t *head = ioend;
489 struct buffer_head *bh;
491 sector_t lastblock = 0;
493 /* Pass 1 - start writeback */
495 next = ioend->io_list;
496 for (bh = ioend->io_buffer_head; bh; bh = bh->b_private)
497 xfs_start_buffer_writeback(bh);
498 } while ((ioend = next) != NULL);
500 /* Pass 2 - submit I/O */
503 next = ioend->io_list;
507 * If we are failing the IO now, just mark the ioend with an
508 * error and finish it. This will run IO completion immediately
509 * as there is only one reference to the ioend at this point in
513 ioend->io_error = -fail;
514 xfs_finish_ioend(ioend);
518 for (bh = ioend->io_buffer_head; bh; bh = bh->b_private) {
522 bio = xfs_alloc_ioend_bio(bh);
523 } else if (bh->b_blocknr != lastblock + 1) {
524 xfs_submit_ioend_bio(wbc, ioend, bio);
528 if (bio_add_buffer(bio, bh) != bh->b_size) {
529 xfs_submit_ioend_bio(wbc, ioend, bio);
533 lastblock = bh->b_blocknr;
536 xfs_submit_ioend_bio(wbc, ioend, bio);
537 xfs_finish_ioend(ioend);
538 } while ((ioend = next) != NULL);
542 * Cancel submission of all buffer_heads so far in this endio.
543 * Toss the endio too. Only ever called for the initial page
544 * in a writepage request, so only ever one page.
551 struct buffer_head *bh, *next_bh;
554 next = ioend->io_list;
555 bh = ioend->io_buffer_head;
557 next_bh = bh->b_private;
558 clear_buffer_async_write(bh);
560 } while ((bh = next_bh) != NULL);
562 mempool_free(ioend, xfs_ioend_pool);
563 } while ((ioend = next) != NULL);
567 * Test to see if we've been building up a completion structure for
568 * earlier buffers -- if so, we try to append to this ioend if we
569 * can, otherwise we finish off any current ioend and start another.
570 * Return true if we've finished the given ioend.
575 struct buffer_head *bh,
578 xfs_ioend_t **result,
581 xfs_ioend_t *ioend = *result;
583 if (!ioend || need_ioend || type != ioend->io_type) {
584 xfs_ioend_t *previous = *result;
586 ioend = xfs_alloc_ioend(inode, type);
587 ioend->io_offset = offset;
588 ioend->io_buffer_head = bh;
589 ioend->io_buffer_tail = bh;
591 previous->io_list = ioend;
594 ioend->io_buffer_tail->b_private = bh;
595 ioend->io_buffer_tail = bh;
598 bh->b_private = NULL;
599 ioend->io_size += bh->b_size;
605 struct buffer_head *bh,
606 struct xfs_bmbt_irec *imap,
610 struct xfs_mount *m = XFS_I(inode)->i_mount;
611 xfs_off_t iomap_offset = XFS_FSB_TO_B(m, imap->br_startoff);
612 xfs_daddr_t iomap_bn = xfs_fsb_to_db(XFS_I(inode), imap->br_startblock);
614 ASSERT(imap->br_startblock != HOLESTARTBLOCK);
615 ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
617 bn = (iomap_bn >> (inode->i_blkbits - BBSHIFT)) +
618 ((offset - iomap_offset) >> inode->i_blkbits);
620 ASSERT(bn || XFS_IS_REALTIME_INODE(XFS_I(inode)));
623 set_buffer_mapped(bh);
629 struct buffer_head *bh,
630 struct xfs_bmbt_irec *imap,
633 ASSERT(imap->br_startblock != HOLESTARTBLOCK);
634 ASSERT(imap->br_startblock != DELAYSTARTBLOCK);
636 xfs_map_buffer(inode, bh, imap, offset);
637 set_buffer_mapped(bh);
638 clear_buffer_delay(bh);
639 clear_buffer_unwritten(bh);
643 * Test if a given page is suitable for writing as part of an unwritten
644 * or delayed allocate extent.
651 if (PageWriteback(page))
654 if (page->mapping && page_has_buffers(page)) {
655 struct buffer_head *bh, *head;
658 bh = head = page_buffers(page);
660 if (buffer_unwritten(bh))
661 acceptable += (type == XFS_IO_UNWRITTEN);
662 else if (buffer_delay(bh))
663 acceptable += (type == XFS_IO_DELALLOC);
664 else if (buffer_dirty(bh) && buffer_mapped(bh))
665 acceptable += (type == XFS_IO_OVERWRITE);
668 } while ((bh = bh->b_this_page) != head);
678 * Allocate & map buffers for page given the extent map. Write it out.
679 * except for the original page of a writepage, this is called on
680 * delalloc/unwritten pages only, for the original page it is possible
681 * that the page has no mapping at all.
688 struct xfs_bmbt_irec *imap,
689 xfs_ioend_t **ioendp,
690 struct writeback_control *wbc)
692 struct buffer_head *bh, *head;
693 xfs_off_t end_offset;
694 unsigned long p_offset;
697 int count = 0, done = 0, uptodate = 1;
698 xfs_off_t offset = page_offset(page);
700 if (page->index != tindex)
702 if (!trylock_page(page))
704 if (PageWriteback(page))
705 goto fail_unlock_page;
706 if (page->mapping != inode->i_mapping)
707 goto fail_unlock_page;
708 if (!xfs_check_page_type(page, (*ioendp)->io_type))
709 goto fail_unlock_page;
712 * page_dirty is initially a count of buffers on the page before
713 * EOF and is decremented as we move each into a cleanable state.
717 * End offset is the highest offset that this page should represent.
718 * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
719 * will evaluate non-zero and be less than PAGE_CACHE_SIZE and
720 * hence give us the correct page_dirty count. On any other page,
721 * it will be zero and in that case we need page_dirty to be the
722 * count of buffers on the page.
724 end_offset = min_t(unsigned long long,
725 (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
729 * If the current map does not span the entire page we are about to try
730 * to write, then give up. The only way we can write a page that spans
731 * multiple mappings in a single writeback iteration is via the
732 * xfs_vm_writepage() function. Data integrity writeback requires the
733 * entire page to be written in a single attempt, otherwise the part of
734 * the page we don't write here doesn't get written as part of the data
737 * For normal writeback, we also don't attempt to write partial pages
738 * here as it simply means that write_cache_pages() will see it under
739 * writeback and ignore the page until some point in the future, at
740 * which time this will be the only page in the file that needs
741 * writeback. Hence for more optimal IO patterns, we should always
742 * avoid partial page writeback due to multiple mappings on a page here.
744 if (!xfs_imap_valid(inode, imap, end_offset))
745 goto fail_unlock_page;
747 len = 1 << inode->i_blkbits;
748 p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
750 p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
751 page_dirty = p_offset / len;
753 bh = head = page_buffers(page);
755 if (offset >= end_offset)
757 if (!buffer_uptodate(bh))
759 if (!(PageUptodate(page) || buffer_uptodate(bh))) {
764 if (buffer_unwritten(bh) || buffer_delay(bh) ||
766 if (buffer_unwritten(bh))
767 type = XFS_IO_UNWRITTEN;
768 else if (buffer_delay(bh))
769 type = XFS_IO_DELALLOC;
771 type = XFS_IO_OVERWRITE;
773 if (!xfs_imap_valid(inode, imap, offset)) {
779 if (type != XFS_IO_OVERWRITE)
780 xfs_map_at_offset(inode, bh, imap, offset);
781 xfs_add_to_ioend(inode, bh, offset, type,
789 } while (offset += len, (bh = bh->b_this_page) != head);
791 if (uptodate && bh == head)
792 SetPageUptodate(page);
795 if (--wbc->nr_to_write <= 0 &&
796 wbc->sync_mode == WB_SYNC_NONE)
799 xfs_start_page_writeback(page, !page_dirty, count);
809 * Convert & write out a cluster of pages in the same extent as defined
810 * by mp and following the start page.
816 struct xfs_bmbt_irec *imap,
817 xfs_ioend_t **ioendp,
818 struct writeback_control *wbc,
824 pagevec_init(&pvec, 0);
825 while (!done && tindex <= tlast) {
826 unsigned len = min_t(pgoff_t, PAGEVEC_SIZE, tlast - tindex + 1);
828 if (!pagevec_lookup(&pvec, inode->i_mapping, tindex, len))
831 for (i = 0; i < pagevec_count(&pvec); i++) {
832 done = xfs_convert_page(inode, pvec.pages[i], tindex++,
838 pagevec_release(&pvec);
844 xfs_vm_invalidatepage(
849 trace_xfs_invalidatepage(page->mapping->host, page, offset,
851 block_invalidatepage(page, offset, length);
855 * If the page has delalloc buffers on it, we need to punch them out before we
856 * invalidate the page. If we don't, we leave a stale delalloc mapping on the
857 * inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read
858 * is done on that same region - the delalloc extent is returned when none is
859 * supposed to be there.
861 * We prevent this by truncating away the delalloc regions on the page before
862 * invalidating it. Because they are delalloc, we can do this without needing a
863 * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
864 * truncation without a transaction as there is no space left for block
865 * reservation (typically why we see a ENOSPC in writeback).
867 * This is not a performance critical path, so for now just do the punching a
868 * buffer head at a time.
871 xfs_aops_discard_page(
874 struct inode *inode = page->mapping->host;
875 struct xfs_inode *ip = XFS_I(inode);
876 struct buffer_head *bh, *head;
877 loff_t offset = page_offset(page);
879 if (!xfs_check_page_type(page, XFS_IO_DELALLOC))
882 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
885 xfs_alert(ip->i_mount,
886 "page discard on page %p, inode 0x%llx, offset %llu.",
887 page, ip->i_ino, offset);
889 xfs_ilock(ip, XFS_ILOCK_EXCL);
890 bh = head = page_buffers(page);
893 xfs_fileoff_t start_fsb;
895 if (!buffer_delay(bh))
898 start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
899 error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1);
901 /* something screwed, just bail */
902 if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
903 xfs_alert(ip->i_mount,
904 "page discard unable to remove delalloc mapping.");
909 offset += 1 << inode->i_blkbits;
911 } while ((bh = bh->b_this_page) != head);
913 xfs_iunlock(ip, XFS_ILOCK_EXCL);
915 xfs_vm_invalidatepage(page, 0, PAGE_CACHE_SIZE);
920 * Write out a dirty page.
922 * For delalloc space on the page we need to allocate space and flush it.
923 * For unwritten space on the page we need to start the conversion to
924 * regular allocated space.
925 * For any other dirty buffer heads on the page we should flush them.
930 struct writeback_control *wbc)
932 struct inode *inode = page->mapping->host;
933 struct buffer_head *bh, *head;
934 struct xfs_bmbt_irec imap;
935 xfs_ioend_t *ioend = NULL, *iohead = NULL;
938 __uint64_t end_offset;
939 pgoff_t end_index, last_index;
941 int err, imap_valid = 0, uptodate = 1;
945 trace_xfs_writepage(inode, page, 0, 0);
947 ASSERT(page_has_buffers(page));
950 * Refuse to write the page out if we are called from reclaim context.
952 * This avoids stack overflows when called from deeply used stacks in
953 * random callers for direct reclaim or memcg reclaim. We explicitly
954 * allow reclaim from kswapd as the stack usage there is relatively low.
956 * This should never happen except in the case of a VM regression so
959 if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
964 * Given that we do not allow direct reclaim to call us, we should
965 * never be called while in a filesystem transaction.
967 if (WARN_ON(current->flags & PF_FSTRANS))
970 /* Is this page beyond the end of the file? */
971 offset = i_size_read(inode);
972 end_index = offset >> PAGE_CACHE_SHIFT;
973 last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
974 if (page->index >= end_index) {
975 unsigned offset_into_page = offset & (PAGE_CACHE_SIZE - 1);
978 * Skip the page if it is fully outside i_size, e.g. due to a
979 * truncate operation that is in progress. We must redirty the
980 * page so that reclaim stops reclaiming it. Otherwise
981 * xfs_vm_releasepage() is called on it and gets confused.
983 if (page->index >= end_index + 1 || offset_into_page == 0)
987 * The page straddles i_size. It must be zeroed out on each
988 * and every writepage invocation because it may be mmapped.
989 * "A file is mapped in multiples of the page size. For a file
990 * that is not a multiple of the page size, the remaining
991 * memory is zeroed when mapped, and writes to that region are
992 * not written out to the file."
994 zero_user_segment(page, offset_into_page, PAGE_CACHE_SIZE);
997 end_offset = min_t(unsigned long long,
998 (xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
1000 len = 1 << inode->i_blkbits;
1002 bh = head = page_buffers(page);
1003 offset = page_offset(page);
1004 type = XFS_IO_OVERWRITE;
1006 if (wbc->sync_mode == WB_SYNC_NONE)
1012 if (offset >= end_offset)
1014 if (!buffer_uptodate(bh))
1018 * set_page_dirty dirties all buffers in a page, independent
1019 * of their state. The dirty state however is entirely
1020 * meaningless for holes (!mapped && uptodate), so skip
1021 * buffers covering holes here.
1023 if (!buffer_mapped(bh) && buffer_uptodate(bh)) {
1028 if (buffer_unwritten(bh)) {
1029 if (type != XFS_IO_UNWRITTEN) {
1030 type = XFS_IO_UNWRITTEN;
1033 } else if (buffer_delay(bh)) {
1034 if (type != XFS_IO_DELALLOC) {
1035 type = XFS_IO_DELALLOC;
1038 } else if (buffer_uptodate(bh)) {
1039 if (type != XFS_IO_OVERWRITE) {
1040 type = XFS_IO_OVERWRITE;
1044 if (PageUptodate(page))
1045 ASSERT(buffer_mapped(bh));
1047 * This buffer is not uptodate and will not be
1048 * written to disk. Ensure that we will put any
1049 * subsequent writeable buffers into a new
1057 imap_valid = xfs_imap_valid(inode, &imap, offset);
1060 * If we didn't have a valid mapping then we need to
1061 * put the new mapping into a separate ioend structure.
1062 * This ensures non-contiguous extents always have
1063 * separate ioends, which is particularly important
1064 * for unwritten extent conversion at I/O completion
1068 err = xfs_map_blocks(inode, offset, &imap, type,
1072 imap_valid = xfs_imap_valid(inode, &imap, offset);
1076 if (type != XFS_IO_OVERWRITE)
1077 xfs_map_at_offset(inode, bh, &imap, offset);
1078 xfs_add_to_ioend(inode, bh, offset, type, &ioend,
1086 } while (offset += len, ((bh = bh->b_this_page) != head));
1088 if (uptodate && bh == head)
1089 SetPageUptodate(page);
1091 xfs_start_page_writeback(page, 1, count);
1093 /* if there is no IO to be submitted for this page, we are done */
1100 * Any errors from this point onwards need tobe reported through the IO
1101 * completion path as we have marked the initial page as under writeback
1105 xfs_off_t end_index;
1107 end_index = imap.br_startoff + imap.br_blockcount;
1110 end_index <<= inode->i_blkbits;
1113 end_index = (end_index - 1) >> PAGE_CACHE_SHIFT;
1115 /* check against file size */
1116 if (end_index > last_index)
1117 end_index = last_index;
1119 xfs_cluster_write(inode, page->index + 1, &imap, &ioend,
1125 * Reserve log space if we might write beyond the on-disk inode size.
1128 if (ioend->io_type != XFS_IO_UNWRITTEN && xfs_ioend_is_append(ioend))
1129 err = xfs_setfilesize_trans_alloc(ioend);
1131 xfs_submit_ioend(wbc, iohead, err);
1137 xfs_cancel_ioend(iohead);
1142 xfs_aops_discard_page(page);
1143 ClearPageUptodate(page);
1148 redirty_page_for_writepage(wbc, page);
1155 struct address_space *mapping,
1156 struct writeback_control *wbc)
1158 xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
1159 return generic_writepages(mapping, wbc);
1163 * Called to move a page into cleanable state - and from there
1164 * to be released. The page should already be clean. We always
1165 * have buffer heads in this call.
1167 * Returns 1 if the page is ok to release, 0 otherwise.
1174 int delalloc, unwritten;
1176 trace_xfs_releasepage(page->mapping->host, page, 0, 0);
1178 xfs_count_page_state(page, &delalloc, &unwritten);
1180 if (WARN_ON(delalloc))
1182 if (WARN_ON(unwritten))
1185 return try_to_free_buffers(page);
1190 struct inode *inode,
1192 struct buffer_head *bh_result,
1196 struct xfs_inode *ip = XFS_I(inode);
1197 struct xfs_mount *mp = ip->i_mount;
1198 xfs_fileoff_t offset_fsb, end_fsb;
1201 struct xfs_bmbt_irec imap;
1207 if (XFS_FORCED_SHUTDOWN(mp))
1208 return -XFS_ERROR(EIO);
1210 offset = (xfs_off_t)iblock << inode->i_blkbits;
1211 ASSERT(bh_result->b_size >= (1 << inode->i_blkbits));
1212 size = bh_result->b_size;
1214 if (!create && direct && offset >= i_size_read(inode))
1218 * Direct I/O is usually done on preallocated files, so try getting
1219 * a block mapping without an exclusive lock first. For buffered
1220 * writes we already have the exclusive iolock anyway, so avoiding
1221 * a lock roundtrip here by taking the ilock exclusive from the
1222 * beginning is a useful micro optimization.
1224 if (create && !direct) {
1225 lockmode = XFS_ILOCK_EXCL;
1226 xfs_ilock(ip, lockmode);
1228 lockmode = xfs_ilock_map_shared(ip);
1231 ASSERT(offset <= mp->m_super->s_maxbytes);
1232 if (offset + size > mp->m_super->s_maxbytes)
1233 size = mp->m_super->s_maxbytes - offset;
1234 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
1235 offset_fsb = XFS_B_TO_FSBT(mp, offset);
1237 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
1238 &imap, &nimaps, XFS_BMAPI_ENTIRE);
1244 (imap.br_startblock == HOLESTARTBLOCK ||
1245 imap.br_startblock == DELAYSTARTBLOCK))) {
1246 if (direct || xfs_get_extsz_hint(ip)) {
1248 * Drop the ilock in preparation for starting the block
1249 * allocation transaction. It will be retaken
1250 * exclusively inside xfs_iomap_write_direct for the
1251 * actual allocation.
1253 xfs_iunlock(ip, lockmode);
1254 error = xfs_iomap_write_direct(ip, offset, size,
1261 * Delalloc reservations do not require a transaction,
1262 * we can go on without dropping the lock here. If we
1263 * are allocating a new delalloc block, make sure that
1264 * we set the new flag so that we mark the buffer new so
1265 * that we know that it is newly allocated if the write
1268 if (nimaps && imap.br_startblock == HOLESTARTBLOCK)
1270 error = xfs_iomap_write_delay(ip, offset, size, &imap);
1274 xfs_iunlock(ip, lockmode);
1277 trace_xfs_get_blocks_alloc(ip, offset, size, 0, &imap);
1278 } else if (nimaps) {
1279 trace_xfs_get_blocks_found(ip, offset, size, 0, &imap);
1280 xfs_iunlock(ip, lockmode);
1282 trace_xfs_get_blocks_notfound(ip, offset, size);
1286 if (imap.br_startblock != HOLESTARTBLOCK &&
1287 imap.br_startblock != DELAYSTARTBLOCK) {
1289 * For unwritten extents do not report a disk address on
1290 * the read case (treat as if we're reading into a hole).
1292 if (create || !ISUNWRITTEN(&imap))
1293 xfs_map_buffer(inode, bh_result, &imap, offset);
1294 if (create && ISUNWRITTEN(&imap)) {
1296 bh_result->b_private = inode;
1297 set_buffer_unwritten(bh_result);
1302 * If this is a realtime file, data may be on a different device.
1303 * to that pointed to from the buffer_head b_bdev currently.
1305 bh_result->b_bdev = xfs_find_bdev_for_inode(inode);
1308 * If we previously allocated a block out beyond eof and we are now
1309 * coming back to use it then we will need to flag it as new even if it
1310 * has a disk address.
1312 * With sub-block writes into unwritten extents we also need to mark
1313 * the buffer as new so that the unwritten parts of the buffer gets
1317 ((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
1318 (offset >= i_size_read(inode)) ||
1319 (new || ISUNWRITTEN(&imap))))
1320 set_buffer_new(bh_result);
1322 if (imap.br_startblock == DELAYSTARTBLOCK) {
1325 set_buffer_uptodate(bh_result);
1326 set_buffer_mapped(bh_result);
1327 set_buffer_delay(bh_result);
1332 * If this is O_DIRECT or the mpage code calling tell them how large
1333 * the mapping is, so that we can avoid repeated get_blocks calls.
1335 if (direct || size > (1 << inode->i_blkbits)) {
1336 xfs_off_t mapping_size;
1338 mapping_size = imap.br_startoff + imap.br_blockcount - iblock;
1339 mapping_size <<= inode->i_blkbits;
1341 ASSERT(mapping_size > 0);
1342 if (mapping_size > size)
1343 mapping_size = size;
1344 if (mapping_size > LONG_MAX)
1345 mapping_size = LONG_MAX;
1347 bh_result->b_size = mapping_size;
1353 xfs_iunlock(ip, lockmode);
1359 struct inode *inode,
1361 struct buffer_head *bh_result,
1364 return __xfs_get_blocks(inode, iblock, bh_result, create, 0);
1368 xfs_get_blocks_direct(
1369 struct inode *inode,
1371 struct buffer_head *bh_result,
1374 return __xfs_get_blocks(inode, iblock, bh_result, create, 1);
1378 * Complete a direct I/O write request.
1380 * If the private argument is non-NULL __xfs_get_blocks signals us that we
1381 * need to issue a transaction to convert the range from unwritten to written
1382 * extents. In case this is regular synchronous I/O we just call xfs_end_io
1383 * to do this and we are done. But in case this was a successful AIO
1384 * request this handler is called from interrupt context, from which we
1385 * can't start transactions. In that case offload the I/O completion to
1386 * the workqueues we also use for buffered I/O completion.
1389 xfs_end_io_direct_write(
1397 struct xfs_ioend *ioend = iocb->private;
1400 * While the generic direct I/O code updates the inode size, it does
1401 * so only after the end_io handler is called, which means our
1402 * end_io handler thinks the on-disk size is outside the in-core
1403 * size. To prevent this just update it a little bit earlier here.
1405 if (offset + size > i_size_read(ioend->io_inode))
1406 i_size_write(ioend->io_inode, offset + size);
1409 * blockdev_direct_IO can return an error even after the I/O
1410 * completion handler was called. Thus we need to protect
1411 * against double-freeing.
1413 iocb->private = NULL;
1415 ioend->io_offset = offset;
1416 ioend->io_size = size;
1417 ioend->io_iocb = iocb;
1418 ioend->io_result = ret;
1419 if (private && size > 0)
1420 ioend->io_type = XFS_IO_UNWRITTEN;
1423 ioend->io_isasync = 1;
1424 xfs_finish_ioend(ioend);
1426 xfs_finish_ioend_sync(ioend);
1434 const struct iovec *iov,
1436 unsigned long nr_segs)
1438 struct inode *inode = iocb->ki_filp->f_mapping->host;
1439 struct block_device *bdev = xfs_find_bdev_for_inode(inode);
1440 struct xfs_ioend *ioend = NULL;
1444 size_t size = iov_length(iov, nr_segs);
1447 * We cannot preallocate a size update transaction here as we
1448 * don't know whether allocation is necessary or not. Hence we
1449 * can only tell IO completion that one is necessary if we are
1450 * not doing unwritten extent conversion.
1452 iocb->private = ioend = xfs_alloc_ioend(inode, XFS_IO_DIRECT);
1453 if (offset + size > XFS_I(inode)->i_d.di_size)
1454 ioend->io_isdirect = 1;
1456 ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov,
1458 xfs_get_blocks_direct,
1459 xfs_end_io_direct_write, NULL, 0);
1460 if (ret != -EIOCBQUEUED && iocb->private)
1461 goto out_destroy_ioend;
1463 ret = __blockdev_direct_IO(rw, iocb, inode, bdev, iov,
1465 xfs_get_blocks_direct,
1472 xfs_destroy_ioend(ioend);
1477 * Punch out the delalloc blocks we have already allocated.
1479 * Don't bother with xfs_setattr given that nothing can have made it to disk yet
1480 * as the page is still locked at this point.
1483 xfs_vm_kill_delalloc_range(
1484 struct inode *inode,
1488 struct xfs_inode *ip = XFS_I(inode);
1489 xfs_fileoff_t start_fsb;
1490 xfs_fileoff_t end_fsb;
1493 start_fsb = XFS_B_TO_FSB(ip->i_mount, start);
1494 end_fsb = XFS_B_TO_FSB(ip->i_mount, end);
1495 if (end_fsb <= start_fsb)
1498 xfs_ilock(ip, XFS_ILOCK_EXCL);
1499 error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
1500 end_fsb - start_fsb);
1502 /* something screwed, just bail */
1503 if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
1504 xfs_alert(ip->i_mount,
1505 "xfs_vm_write_failed: unable to clean up ino %lld",
1509 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1513 xfs_vm_write_failed(
1514 struct inode *inode,
1519 loff_t block_offset = pos & PAGE_MASK;
1522 loff_t from = pos & (PAGE_CACHE_SIZE - 1);
1523 loff_t to = from + len;
1524 struct buffer_head *bh, *head;
1526 ASSERT(block_offset + from == pos);
1528 head = page_buffers(page);
1530 for (bh = head; bh != head || !block_start;
1531 bh = bh->b_this_page, block_start = block_end,
1532 block_offset += bh->b_size) {
1533 block_end = block_start + bh->b_size;
1535 /* skip buffers before the write */
1536 if (block_end <= from)
1539 /* if the buffer is after the write, we're done */
1540 if (block_start >= to)
1543 if (!buffer_delay(bh))
1546 if (!buffer_new(bh) && block_offset < i_size_read(inode))
1549 xfs_vm_kill_delalloc_range(inode, block_offset,
1550 block_offset + bh->b_size);
1556 * This used to call block_write_begin(), but it unlocks and releases the page
1557 * on error, and we need that page to be able to punch stale delalloc blocks out
1558 * on failure. hence we copy-n-waste it here and call xfs_vm_write_failed() at
1559 * the appropriate point.
1564 struct address_space *mapping,
1568 struct page **pagep,
1571 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1575 ASSERT(len <= PAGE_CACHE_SIZE);
1577 page = grab_cache_page_write_begin(mapping, index,
1578 flags | AOP_FLAG_NOFS);
1582 status = __block_write_begin(page, pos, len, xfs_get_blocks);
1583 if (unlikely(status)) {
1584 struct inode *inode = mapping->host;
1586 xfs_vm_write_failed(inode, page, pos, len);
1589 if (pos + len > i_size_read(inode))
1590 truncate_pagecache(inode, pos + len, i_size_read(inode));
1592 page_cache_release(page);
1601 * On failure, we only need to kill delalloc blocks beyond EOF because they
1602 * will never be written. For blocks within EOF, generic_write_end() zeros them
1603 * so they are safe to leave alone and be written with all the other valid data.
1608 struct address_space *mapping,
1617 ASSERT(len <= PAGE_CACHE_SIZE);
1619 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
1620 if (unlikely(ret < len)) {
1621 struct inode *inode = mapping->host;
1622 size_t isize = i_size_read(inode);
1623 loff_t to = pos + len;
1626 truncate_pagecache(inode, to, isize);
1627 xfs_vm_kill_delalloc_range(inode, isize, to);
1635 struct address_space *mapping,
1638 struct inode *inode = (struct inode *)mapping->host;
1639 struct xfs_inode *ip = XFS_I(inode);
1641 trace_xfs_vm_bmap(XFS_I(inode));
1642 xfs_ilock(ip, XFS_IOLOCK_SHARED);
1643 filemap_write_and_wait(mapping);
1644 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
1645 return generic_block_bmap(mapping, block, xfs_get_blocks);
1650 struct file *unused,
1653 return mpage_readpage(page, xfs_get_blocks);
1658 struct file *unused,
1659 struct address_space *mapping,
1660 struct list_head *pages,
1663 return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
1666 const struct address_space_operations xfs_address_space_operations = {
1667 .readpage = xfs_vm_readpage,
1668 .readpages = xfs_vm_readpages,
1669 .writepage = xfs_vm_writepage,
1670 .writepages = xfs_vm_writepages,
1671 .releasepage = xfs_vm_releasepage,
1672 .invalidatepage = xfs_vm_invalidatepage,
1673 .write_begin = xfs_vm_write_begin,
1674 .write_end = xfs_vm_write_end,
1675 .bmap = xfs_vm_bmap,
1676 .direct_IO = xfs_vm_direct_IO,
1677 .migratepage = buffer_migrate_page,
1678 .is_partially_uptodate = block_is_partially_uptodate,
1679 .error_remove_page = generic_error_remove_page,