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>
39 /* flags for direct write completions */
40 #define XFS_DIO_FLAG_UNWRITTEN (1 << 0)
41 #define XFS_DIO_FLAG_APPEND (1 << 1)
44 * structure owned by writepages passed to individual writepage calls
46 struct xfs_writepage_ctx
{
47 struct xfs_bmbt_irec imap
;
50 struct xfs_ioend
*ioend
;
60 struct buffer_head
*bh
, *head
;
62 *delalloc
= *unwritten
= 0;
64 bh
= head
= page_buffers(page
);
66 if (buffer_unwritten(bh
))
68 else if (buffer_delay(bh
))
70 } while ((bh
= bh
->b_this_page
) != head
);
74 xfs_find_bdev_for_inode(
77 struct xfs_inode
*ip
= XFS_I(inode
);
78 struct xfs_mount
*mp
= ip
->i_mount
;
80 if (XFS_IS_REALTIME_INODE(ip
))
81 return mp
->m_rtdev_targp
->bt_bdev
;
83 return mp
->m_ddev_targp
->bt_bdev
;
87 * We're now finished for good with this page. Update the page state via the
88 * associated buffer_heads, paying attention to the start and end offsets that
89 * we need to process on the page.
91 * Landmine Warning: bh->b_end_io() will call end_page_writeback() on the last
92 * buffer in the IO. Once it does this, it is unsafe to access the bufferhead or
93 * the page at all, as we may be racing with memory reclaim and it can free both
94 * the bufferhead chain and the page as it will see the page as clean and
98 xfs_finish_page_writeback(
100 struct bio_vec
*bvec
,
103 unsigned int end
= bvec
->bv_offset
+ bvec
->bv_len
- 1;
104 struct buffer_head
*head
, *bh
, *next
;
105 unsigned int off
= 0;
108 ASSERT(bvec
->bv_offset
< PAGE_SIZE
);
109 ASSERT((bvec
->bv_offset
& ((1 << inode
->i_blkbits
) - 1)) == 0);
110 ASSERT(end
< PAGE_SIZE
);
111 ASSERT((bvec
->bv_len
& ((1 << inode
->i_blkbits
) - 1)) == 0);
113 bh
= head
= page_buffers(bvec
->bv_page
);
117 next
= bh
->b_this_page
;
118 if (off
< bvec
->bv_offset
)
122 bh
->b_end_io(bh
, !error
);
125 } while ((bh
= next
) != head
);
129 * We're now finished for good with this ioend structure. Update the page
130 * state, release holds on bios, and finally free up memory. Do not use the
135 struct xfs_ioend
*ioend
,
138 struct inode
*inode
= ioend
->io_inode
;
139 struct bio
*last
= ioend
->io_bio
;
140 struct bio
*bio
, *next
;
142 for (bio
= &ioend
->io_inline_bio
; bio
; bio
= next
) {
143 struct bio_vec
*bvec
;
147 * For the last bio, bi_private points to the ioend, so we
148 * need to explicitly end the iteration here.
153 next
= bio
->bi_private
;
155 /* walk each page on bio, ending page IO on them */
156 bio_for_each_segment_all(bvec
, bio
, i
)
157 xfs_finish_page_writeback(inode
, bvec
, error
);
164 * Fast and loose check if this write could update the on-disk inode size.
166 static inline bool xfs_ioend_is_append(struct xfs_ioend
*ioend
)
168 return ioend
->io_offset
+ ioend
->io_size
>
169 XFS_I(ioend
->io_inode
)->i_d
.di_size
;
173 xfs_setfilesize_trans_alloc(
174 struct xfs_ioend
*ioend
)
176 struct xfs_mount
*mp
= XFS_I(ioend
->io_inode
)->i_mount
;
177 struct xfs_trans
*tp
;
180 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_fsyncts
, 0, 0, 0, &tp
);
184 ioend
->io_append_trans
= tp
;
187 * We may pass freeze protection with a transaction. So tell lockdep
190 __sb_writers_release(ioend
->io_inode
->i_sb
, SB_FREEZE_FS
);
192 * We hand off the transaction to the completion thread now, so
193 * clear the flag here.
195 current_restore_flags_nested(&tp
->t_pflags
, PF_FSTRANS
);
200 * Update on-disk file size now that data has been written to disk.
204 struct xfs_inode
*ip
,
205 struct xfs_trans
*tp
,
211 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
212 isize
= xfs_new_eof(ip
, offset
+ size
);
214 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
215 xfs_trans_cancel(tp
);
219 trace_xfs_setfilesize(ip
, offset
, size
);
221 ip
->i_d
.di_size
= isize
;
222 xfs_trans_ijoin(tp
, ip
, XFS_ILOCK_EXCL
);
223 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_CORE
);
225 return xfs_trans_commit(tp
);
230 struct xfs_inode
*ip
,
234 struct xfs_mount
*mp
= ip
->i_mount
;
235 struct xfs_trans
*tp
;
238 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_fsyncts
, 0, 0, 0, &tp
);
242 return __xfs_setfilesize(ip
, tp
, offset
, size
);
246 xfs_setfilesize_ioend(
247 struct xfs_ioend
*ioend
,
250 struct xfs_inode
*ip
= XFS_I(ioend
->io_inode
);
251 struct xfs_trans
*tp
= ioend
->io_append_trans
;
254 * The transaction may have been allocated in the I/O submission thread,
255 * thus we need to mark ourselves as being in a transaction manually.
256 * Similarly for freeze protection.
258 current_set_flags_nested(&tp
->t_pflags
, PF_FSTRANS
);
259 __sb_writers_acquired(VFS_I(ip
)->i_sb
, SB_FREEZE_FS
);
261 /* we abort the update if there was an IO error */
263 xfs_trans_cancel(tp
);
267 return __xfs_setfilesize(ip
, tp
, ioend
->io_offset
, ioend
->io_size
);
271 * IO write completion.
275 struct work_struct
*work
)
277 struct xfs_ioend
*ioend
=
278 container_of(work
, struct xfs_ioend
, io_work
);
279 struct xfs_inode
*ip
= XFS_I(ioend
->io_inode
);
280 int error
= ioend
->io_bio
->bi_error
;
283 * Set an error if the mount has shut down and proceed with end I/O
284 * processing so it can perform whatever cleanups are necessary.
286 if (XFS_FORCED_SHUTDOWN(ip
->i_mount
))
290 * For unwritten extents we need to issue transactions to convert a
291 * range to normal written extens after the data I/O has finished.
292 * Detecting and handling completion IO errors is done individually
293 * for each case as different cleanup operations need to be performed
296 if (ioend
->io_type
== XFS_IO_UNWRITTEN
) {
299 error
= xfs_iomap_write_unwritten(ip
, ioend
->io_offset
,
301 } else if (ioend
->io_append_trans
) {
302 error
= xfs_setfilesize_ioend(ioend
, error
);
304 ASSERT(!xfs_ioend_is_append(ioend
));
308 xfs_destroy_ioend(ioend
, error
);
315 struct xfs_ioend
*ioend
= bio
->bi_private
;
316 struct xfs_mount
*mp
= XFS_I(ioend
->io_inode
)->i_mount
;
318 if (ioend
->io_type
== XFS_IO_UNWRITTEN
)
319 queue_work(mp
->m_unwritten_workqueue
, &ioend
->io_work
);
320 else if (ioend
->io_append_trans
)
321 queue_work(mp
->m_data_workqueue
, &ioend
->io_work
);
323 xfs_destroy_ioend(ioend
, bio
->bi_error
);
330 struct xfs_bmbt_irec
*imap
,
333 struct xfs_inode
*ip
= XFS_I(inode
);
334 struct xfs_mount
*mp
= ip
->i_mount
;
335 ssize_t count
= 1 << inode
->i_blkbits
;
336 xfs_fileoff_t offset_fsb
, end_fsb
;
338 int bmapi_flags
= XFS_BMAPI_ENTIRE
;
341 if (XFS_FORCED_SHUTDOWN(mp
))
344 if (type
== XFS_IO_UNWRITTEN
)
345 bmapi_flags
|= XFS_BMAPI_IGSTATE
;
347 xfs_ilock(ip
, XFS_ILOCK_SHARED
);
348 ASSERT(ip
->i_d
.di_format
!= XFS_DINODE_FMT_BTREE
||
349 (ip
->i_df
.if_flags
& XFS_IFEXTENTS
));
350 ASSERT(offset
<= mp
->m_super
->s_maxbytes
);
352 if (offset
+ count
> mp
->m_super
->s_maxbytes
)
353 count
= mp
->m_super
->s_maxbytes
- offset
;
354 end_fsb
= XFS_B_TO_FSB(mp
, (xfs_ufsize_t
)offset
+ count
);
355 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
356 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
,
357 imap
, &nimaps
, bmapi_flags
);
358 xfs_iunlock(ip
, XFS_ILOCK_SHARED
);
363 if (type
== XFS_IO_DELALLOC
&&
364 (!nimaps
|| isnullstartblock(imap
->br_startblock
))) {
365 error
= xfs_iomap_write_allocate(ip
, offset
, imap
);
367 trace_xfs_map_blocks_alloc(ip
, offset
, count
, type
, imap
);
372 if (type
== XFS_IO_UNWRITTEN
) {
374 ASSERT(imap
->br_startblock
!= HOLESTARTBLOCK
);
375 ASSERT(imap
->br_startblock
!= DELAYSTARTBLOCK
);
379 trace_xfs_map_blocks_found(ip
, offset
, count
, type
, imap
);
386 struct xfs_bmbt_irec
*imap
,
389 offset
>>= inode
->i_blkbits
;
391 return offset
>= imap
->br_startoff
&&
392 offset
< imap
->br_startoff
+ imap
->br_blockcount
;
396 xfs_start_buffer_writeback(
397 struct buffer_head
*bh
)
399 ASSERT(buffer_mapped(bh
));
400 ASSERT(buffer_locked(bh
));
401 ASSERT(!buffer_delay(bh
));
402 ASSERT(!buffer_unwritten(bh
));
404 mark_buffer_async_write(bh
);
405 set_buffer_uptodate(bh
);
406 clear_buffer_dirty(bh
);
410 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
);
433 static inline int xfs_bio_add_buffer(struct bio
*bio
, struct buffer_head
*bh
)
435 return bio_add_page(bio
, bh
->b_page
, bh
->b_size
, bh_offset(bh
));
439 * Submit the bio for an ioend. We are passed an ioend with a bio attached to
440 * it, and we submit that bio. The ioend may be used for multiple bio
441 * submissions, so we only want to allocate an append transaction for the ioend
442 * once. In the case of multiple bio submission, each bio will take an IO
443 * reference to the ioend to ensure that the ioend completion is only done once
444 * all bios have been submitted and the ioend is really done.
446 * If @fail is non-zero, it means that we have a situation where some part of
447 * the submission process has failed after we have marked paged for writeback
448 * and unlocked them. In this situation, we need to fail the bio and ioend
449 * rather than submit it to IO. This typically only happens on a filesystem
454 struct writeback_control
*wbc
,
455 struct xfs_ioend
*ioend
,
458 /* Reserve log space if we might write beyond the on-disk inode size. */
460 ioend
->io_type
!= XFS_IO_UNWRITTEN
&&
461 xfs_ioend_is_append(ioend
) &&
462 !ioend
->io_append_trans
)
463 status
= xfs_setfilesize_trans_alloc(ioend
);
465 ioend
->io_bio
->bi_private
= ioend
;
466 ioend
->io_bio
->bi_end_io
= xfs_end_bio
;
467 bio_set_op_attrs(ioend
->io_bio
, REQ_OP_WRITE
,
468 (wbc
->sync_mode
== WB_SYNC_ALL
) ? WRITE_SYNC
: 0);
470 * If we are failing the IO now, just mark the ioend with an
471 * error and finish it. This will run IO completion immediately
472 * as there is only one reference to the ioend at this point in
476 ioend
->io_bio
->bi_error
= status
;
477 bio_endio(ioend
->io_bio
);
481 submit_bio(ioend
->io_bio
);
486 xfs_init_bio_from_bh(
488 struct buffer_head
*bh
)
490 bio
->bi_iter
.bi_sector
= bh
->b_blocknr
* (bh
->b_size
>> 9);
491 bio
->bi_bdev
= bh
->b_bdev
;
494 static struct xfs_ioend
*
499 struct buffer_head
*bh
)
501 struct xfs_ioend
*ioend
;
504 bio
= bio_alloc_bioset(GFP_NOFS
, BIO_MAX_PAGES
, xfs_ioend_bioset
);
505 xfs_init_bio_from_bh(bio
, bh
);
507 ioend
= container_of(bio
, struct xfs_ioend
, io_inline_bio
);
508 INIT_LIST_HEAD(&ioend
->io_list
);
509 ioend
->io_type
= type
;
510 ioend
->io_inode
= inode
;
512 ioend
->io_offset
= offset
;
513 INIT_WORK(&ioend
->io_work
, xfs_end_io
);
514 ioend
->io_append_trans
= NULL
;
520 * Allocate a new bio, and chain the old bio to the new one.
522 * Note that we have to do perform the chaining in this unintuitive order
523 * so that the bi_private linkage is set up in the right direction for the
524 * traversal in xfs_destroy_ioend().
528 struct xfs_ioend
*ioend
,
529 struct writeback_control
*wbc
,
530 struct buffer_head
*bh
)
534 new = bio_alloc(GFP_NOFS
, BIO_MAX_PAGES
);
535 xfs_init_bio_from_bh(new, bh
);
537 bio_chain(ioend
->io_bio
, new);
538 bio_get(ioend
->io_bio
); /* for xfs_destroy_ioend */
539 bio_set_op_attrs(ioend
->io_bio
, REQ_OP_WRITE
,
540 (wbc
->sync_mode
== WB_SYNC_ALL
) ? WRITE_SYNC
: 0);
541 submit_bio(ioend
->io_bio
);
546 * Test to see if we've been building up a completion structure for
547 * earlier buffers -- if so, we try to append to this ioend if we
548 * can, otherwise we finish off any current ioend and start another.
549 * Return the ioend we finished off so that the caller can submit it
550 * once it has finished processing the dirty page.
555 struct buffer_head
*bh
,
557 struct xfs_writepage_ctx
*wpc
,
558 struct writeback_control
*wbc
,
559 struct list_head
*iolist
)
561 if (!wpc
->ioend
|| wpc
->io_type
!= wpc
->ioend
->io_type
||
562 bh
->b_blocknr
!= wpc
->last_block
+ 1 ||
563 offset
!= wpc
->ioend
->io_offset
+ wpc
->ioend
->io_size
) {
565 list_add(&wpc
->ioend
->io_list
, iolist
);
566 wpc
->ioend
= xfs_alloc_ioend(inode
, wpc
->io_type
, offset
, bh
);
570 * If the buffer doesn't fit into the bio we need to allocate a new
571 * one. This shouldn't happen more than once for a given buffer.
573 while (xfs_bio_add_buffer(wpc
->ioend
->io_bio
, bh
) != bh
->b_size
)
574 xfs_chain_bio(wpc
->ioend
, wbc
, bh
);
576 wpc
->ioend
->io_size
+= bh
->b_size
;
577 wpc
->last_block
= bh
->b_blocknr
;
578 xfs_start_buffer_writeback(bh
);
584 struct buffer_head
*bh
,
585 struct xfs_bmbt_irec
*imap
,
589 struct xfs_mount
*m
= XFS_I(inode
)->i_mount
;
590 xfs_off_t iomap_offset
= XFS_FSB_TO_B(m
, imap
->br_startoff
);
591 xfs_daddr_t iomap_bn
= xfs_fsb_to_db(XFS_I(inode
), imap
->br_startblock
);
593 ASSERT(imap
->br_startblock
!= HOLESTARTBLOCK
);
594 ASSERT(imap
->br_startblock
!= DELAYSTARTBLOCK
);
596 bn
= (iomap_bn
>> (inode
->i_blkbits
- BBSHIFT
)) +
597 ((offset
- iomap_offset
) >> inode
->i_blkbits
);
599 ASSERT(bn
|| XFS_IS_REALTIME_INODE(XFS_I(inode
)));
602 set_buffer_mapped(bh
);
608 struct buffer_head
*bh
,
609 struct xfs_bmbt_irec
*imap
,
612 ASSERT(imap
->br_startblock
!= HOLESTARTBLOCK
);
613 ASSERT(imap
->br_startblock
!= DELAYSTARTBLOCK
);
615 xfs_map_buffer(inode
, bh
, imap
, offset
);
616 set_buffer_mapped(bh
);
617 clear_buffer_delay(bh
);
618 clear_buffer_unwritten(bh
);
622 * Test if a given page contains at least one buffer of a given @type.
623 * If @check_all_buffers is true, then we walk all the buffers in the page to
624 * try to find one of the type passed in. If it is not set, then the caller only
625 * needs to check the first buffer on the page for a match.
631 bool check_all_buffers
)
633 struct buffer_head
*bh
;
634 struct buffer_head
*head
;
636 if (PageWriteback(page
))
640 if (!page_has_buffers(page
))
643 bh
= head
= page_buffers(page
);
645 if (buffer_unwritten(bh
)) {
646 if (type
== XFS_IO_UNWRITTEN
)
648 } else if (buffer_delay(bh
)) {
649 if (type
== XFS_IO_DELALLOC
)
651 } else if (buffer_dirty(bh
) && buffer_mapped(bh
)) {
652 if (type
== XFS_IO_OVERWRITE
)
656 /* If we are only checking the first buffer, we are done now. */
657 if (!check_all_buffers
)
659 } while ((bh
= bh
->b_this_page
) != head
);
665 xfs_vm_invalidatepage(
670 trace_xfs_invalidatepage(page
->mapping
->host
, page
, offset
,
672 block_invalidatepage(page
, offset
, length
);
676 * If the page has delalloc buffers on it, we need to punch them out before we
677 * invalidate the page. If we don't, we leave a stale delalloc mapping on the
678 * inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read
679 * is done on that same region - the delalloc extent is returned when none is
680 * supposed to be there.
682 * We prevent this by truncating away the delalloc regions on the page before
683 * invalidating it. Because they are delalloc, we can do this without needing a
684 * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
685 * truncation without a transaction as there is no space left for block
686 * reservation (typically why we see a ENOSPC in writeback).
688 * This is not a performance critical path, so for now just do the punching a
689 * buffer head at a time.
692 xfs_aops_discard_page(
695 struct inode
*inode
= page
->mapping
->host
;
696 struct xfs_inode
*ip
= XFS_I(inode
);
697 struct buffer_head
*bh
, *head
;
698 loff_t offset
= page_offset(page
);
700 if (!xfs_check_page_type(page
, XFS_IO_DELALLOC
, true))
703 if (XFS_FORCED_SHUTDOWN(ip
->i_mount
))
706 xfs_alert(ip
->i_mount
,
707 "page discard on page %p, inode 0x%llx, offset %llu.",
708 page
, ip
->i_ino
, offset
);
710 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
711 bh
= head
= page_buffers(page
);
714 xfs_fileoff_t start_fsb
;
716 if (!buffer_delay(bh
))
719 start_fsb
= XFS_B_TO_FSBT(ip
->i_mount
, offset
);
720 error
= xfs_bmap_punch_delalloc_range(ip
, start_fsb
, 1);
722 /* something screwed, just bail */
723 if (!XFS_FORCED_SHUTDOWN(ip
->i_mount
)) {
724 xfs_alert(ip
->i_mount
,
725 "page discard unable to remove delalloc mapping.");
730 offset
+= 1 << inode
->i_blkbits
;
732 } while ((bh
= bh
->b_this_page
) != head
);
734 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
736 xfs_vm_invalidatepage(page
, 0, PAGE_SIZE
);
741 * We implement an immediate ioend submission policy here to avoid needing to
742 * chain multiple ioends and hence nest mempool allocations which can violate
743 * forward progress guarantees we need to provide. The current ioend we are
744 * adding buffers to is cached on the writepage context, and if the new buffer
745 * does not append to the cached ioend it will create a new ioend and cache that
748 * If a new ioend is created and cached, the old ioend is returned and queued
749 * locally for submission once the entire page is processed or an error has been
750 * detected. While ioends are submitted immediately after they are completed,
751 * batching optimisations are provided by higher level block plugging.
753 * At the end of a writeback pass, there will be a cached ioend remaining on the
754 * writepage context that the caller will need to submit.
758 struct xfs_writepage_ctx
*wpc
,
759 struct writeback_control
*wbc
,
763 __uint64_t end_offset
)
765 LIST_HEAD(submit_list
);
766 struct xfs_ioend
*ioend
, *next
;
767 struct buffer_head
*bh
, *head
;
768 ssize_t len
= 1 << inode
->i_blkbits
;
773 bh
= head
= page_buffers(page
);
774 offset
= page_offset(page
);
776 if (offset
>= end_offset
)
778 if (!buffer_uptodate(bh
))
782 * set_page_dirty dirties all buffers in a page, independent
783 * of their state. The dirty state however is entirely
784 * meaningless for holes (!mapped && uptodate), so skip
785 * buffers covering holes here.
787 if (!buffer_mapped(bh
) && buffer_uptodate(bh
)) {
788 wpc
->imap_valid
= false;
792 if (buffer_unwritten(bh
)) {
793 if (wpc
->io_type
!= XFS_IO_UNWRITTEN
) {
794 wpc
->io_type
= XFS_IO_UNWRITTEN
;
795 wpc
->imap_valid
= false;
797 } else if (buffer_delay(bh
)) {
798 if (wpc
->io_type
!= XFS_IO_DELALLOC
) {
799 wpc
->io_type
= XFS_IO_DELALLOC
;
800 wpc
->imap_valid
= false;
802 } else if (buffer_uptodate(bh
)) {
803 if (wpc
->io_type
!= XFS_IO_OVERWRITE
) {
804 wpc
->io_type
= XFS_IO_OVERWRITE
;
805 wpc
->imap_valid
= false;
808 if (PageUptodate(page
))
809 ASSERT(buffer_mapped(bh
));
811 * This buffer is not uptodate and will not be
812 * written to disk. Ensure that we will put any
813 * subsequent writeable buffers into a new
816 wpc
->imap_valid
= false;
821 wpc
->imap_valid
= xfs_imap_valid(inode
, &wpc
->imap
,
823 if (!wpc
->imap_valid
) {
824 error
= xfs_map_blocks(inode
, offset
, &wpc
->imap
,
828 wpc
->imap_valid
= xfs_imap_valid(inode
, &wpc
->imap
,
831 if (wpc
->imap_valid
) {
833 if (wpc
->io_type
!= XFS_IO_OVERWRITE
)
834 xfs_map_at_offset(inode
, bh
, &wpc
->imap
, offset
);
835 xfs_add_to_ioend(inode
, bh
, offset
, wpc
, wbc
, &submit_list
);
839 } while (offset
+= len
, ((bh
= bh
->b_this_page
) != head
));
841 if (uptodate
&& bh
== head
)
842 SetPageUptodate(page
);
844 ASSERT(wpc
->ioend
|| list_empty(&submit_list
));
848 * On error, we have to fail the ioend here because we have locked
849 * buffers in the ioend. If we don't do this, we'll deadlock
850 * invalidating the page as that tries to lock the buffers on the page.
851 * Also, because we may have set pages under writeback, we have to make
852 * sure we run IO completion to mark the error state of the IO
853 * appropriately, so we can't cancel the ioend directly here. That means
854 * we have to mark this page as under writeback if we included any
855 * buffers from it in the ioend chain so that completion treats it
858 * If we didn't include the page in the ioend, the on error we can
859 * simply discard and unlock it as there are no other users of the page
860 * or it's buffers right now. The caller will still need to trigger
861 * submission of outstanding ioends on the writepage context so they are
862 * treated correctly on error.
865 xfs_start_page_writeback(page
, !error
);
868 * Preserve the original error if there was one, otherwise catch
869 * submission errors here and propagate into subsequent ioend
872 list_for_each_entry_safe(ioend
, next
, &submit_list
, io_list
) {
875 list_del_init(&ioend
->io_list
);
876 error2
= xfs_submit_ioend(wbc
, ioend
, error
);
877 if (error2
&& !error
)
881 xfs_aops_discard_page(page
);
882 ClearPageUptodate(page
);
886 * We can end up here with no error and nothing to write if we
887 * race with a partial page truncate on a sub-page block sized
888 * filesystem. In that case we need to mark the page clean.
890 xfs_start_page_writeback(page
, 1);
891 end_page_writeback(page
);
894 mapping_set_error(page
->mapping
, error
);
899 * Write out a dirty page.
901 * For delalloc space on the page we need to allocate space and flush it.
902 * For unwritten space on the page we need to start the conversion to
903 * regular allocated space.
904 * For any other dirty buffer heads on the page we should flush them.
909 struct writeback_control
*wbc
,
912 struct xfs_writepage_ctx
*wpc
= data
;
913 struct inode
*inode
= page
->mapping
->host
;
915 __uint64_t end_offset
;
918 trace_xfs_writepage(inode
, page
, 0, 0);
920 ASSERT(page_has_buffers(page
));
923 * Refuse to write the page out if we are called from reclaim context.
925 * This avoids stack overflows when called from deeply used stacks in
926 * random callers for direct reclaim or memcg reclaim. We explicitly
927 * allow reclaim from kswapd as the stack usage there is relatively low.
929 * This should never happen except in the case of a VM regression so
932 if (WARN_ON_ONCE((current
->flags
& (PF_MEMALLOC
|PF_KSWAPD
)) ==
937 * Given that we do not allow direct reclaim to call us, we should
938 * never be called while in a filesystem transaction.
940 if (WARN_ON_ONCE(current
->flags
& PF_FSTRANS
))
944 * Is this page beyond the end of the file?
946 * The page index is less than the end_index, adjust the end_offset
947 * to the highest offset that this page should represent.
948 * -----------------------------------------------------
949 * | file mapping | <EOF> |
950 * -----------------------------------------------------
951 * | Page ... | Page N-2 | Page N-1 | Page N | |
952 * ^--------------------------------^----------|--------
953 * | desired writeback range | see else |
954 * ---------------------------------^------------------|
956 offset
= i_size_read(inode
);
957 end_index
= offset
>> PAGE_SHIFT
;
958 if (page
->index
< end_index
)
959 end_offset
= (xfs_off_t
)(page
->index
+ 1) << PAGE_SHIFT
;
962 * Check whether the page to write out is beyond or straddles
964 * -------------------------------------------------------
965 * | file mapping | <EOF> |
966 * -------------------------------------------------------
967 * | Page ... | Page N-2 | Page N-1 | Page N | Beyond |
968 * ^--------------------------------^-----------|---------
970 * ---------------------------------^-----------|--------|
972 unsigned offset_into_page
= offset
& (PAGE_SIZE
- 1);
975 * Skip the page if it is fully outside i_size, e.g. due to a
976 * truncate operation that is in progress. We must redirty the
977 * page so that reclaim stops reclaiming it. Otherwise
978 * xfs_vm_releasepage() is called on it and gets confused.
980 * Note that the end_index is unsigned long, it would overflow
981 * if the given offset is greater than 16TB on 32-bit system
982 * and if we do check the page is fully outside i_size or not
983 * via "if (page->index >= end_index + 1)" as "end_index + 1"
984 * will be evaluated to 0. Hence this page will be redirtied
985 * and be written out repeatedly which would result in an
986 * infinite loop, the user program that perform this operation
987 * will hang. Instead, we can verify this situation by checking
988 * if the page to write is totally beyond the i_size or if it's
989 * offset is just equal to the EOF.
991 if (page
->index
> end_index
||
992 (page
->index
== end_index
&& offset_into_page
== 0))
996 * The page straddles i_size. It must be zeroed out on each
997 * and every writepage invocation because it may be mmapped.
998 * "A file is mapped in multiples of the page size. For a file
999 * that is not a multiple of the page size, the remaining
1000 * memory is zeroed when mapped, and writes to that region are
1001 * not written out to the file."
1003 zero_user_segment(page
, offset_into_page
, PAGE_SIZE
);
1005 /* Adjust the end_offset to the end of file */
1006 end_offset
= offset
;
1009 return xfs_writepage_map(wpc
, wbc
, inode
, page
, offset
, end_offset
);
1012 redirty_page_for_writepage(wbc
, page
);
1020 struct writeback_control
*wbc
)
1022 struct xfs_writepage_ctx wpc
= {
1023 .io_type
= XFS_IO_INVALID
,
1027 ret
= xfs_do_writepage(page
, wbc
, &wpc
);
1029 ret
= xfs_submit_ioend(wbc
, wpc
.ioend
, ret
);
1035 struct address_space
*mapping
,
1036 struct writeback_control
*wbc
)
1038 struct xfs_writepage_ctx wpc
= {
1039 .io_type
= XFS_IO_INVALID
,
1043 xfs_iflags_clear(XFS_I(mapping
->host
), XFS_ITRUNCATED
);
1044 if (dax_mapping(mapping
))
1045 return dax_writeback_mapping_range(mapping
,
1046 xfs_find_bdev_for_inode(mapping
->host
), wbc
);
1048 ret
= write_cache_pages(mapping
, wbc
, xfs_do_writepage
, &wpc
);
1050 ret
= xfs_submit_ioend(wbc
, wpc
.ioend
, ret
);
1055 * Called to move a page into cleanable state - and from there
1056 * to be released. The page should already be clean. We always
1057 * have buffer heads in this call.
1059 * Returns 1 if the page is ok to release, 0 otherwise.
1066 int delalloc
, unwritten
;
1068 trace_xfs_releasepage(page
->mapping
->host
, page
, 0, 0);
1071 * mm accommodates an old ext3 case where clean pages might not have had
1072 * the dirty bit cleared. Thus, it can send actual dirty pages to
1073 * ->releasepage() via shrink_active_list(). Conversely,
1074 * block_invalidatepage() can send pages that are still marked dirty
1075 * but otherwise have invalidated buffers.
1077 * We've historically freed buffers on the latter. Instead, quietly
1078 * filter out all dirty pages to avoid spurious buffer state warnings.
1079 * This can likely be removed once shrink_active_list() is fixed.
1081 if (PageDirty(page
))
1084 xfs_count_page_state(page
, &delalloc
, &unwritten
);
1086 if (WARN_ON_ONCE(delalloc
))
1088 if (WARN_ON_ONCE(unwritten
))
1091 return try_to_free_buffers(page
);
1095 * When we map a DIO buffer, we may need to pass flags to
1096 * xfs_end_io_direct_write to tell it what kind of write IO we are doing.
1098 * Note that for DIO, an IO to the highest supported file block offset (i.e.
1099 * 2^63 - 1FSB bytes) will result in the offset + count overflowing a signed 64
1100 * bit variable. Hence if we see this overflow, we have to assume that the IO is
1101 * extending the file size. We won't know for sure until IO completion is run
1102 * and the actual max write offset is communicated to the IO completion
1107 struct inode
*inode
,
1108 struct buffer_head
*bh_result
,
1109 struct xfs_bmbt_irec
*imap
,
1112 uintptr_t *flags
= (uintptr_t *)&bh_result
->b_private
;
1113 xfs_off_t size
= bh_result
->b_size
;
1115 trace_xfs_get_blocks_map_direct(XFS_I(inode
), offset
, size
,
1116 ISUNWRITTEN(imap
) ? XFS_IO_UNWRITTEN
: XFS_IO_OVERWRITE
, imap
);
1118 if (ISUNWRITTEN(imap
)) {
1119 *flags
|= XFS_DIO_FLAG_UNWRITTEN
;
1120 set_buffer_defer_completion(bh_result
);
1121 } else if (offset
+ size
> i_size_read(inode
) || offset
+ size
< 0) {
1122 *flags
|= XFS_DIO_FLAG_APPEND
;
1123 set_buffer_defer_completion(bh_result
);
1128 * If this is O_DIRECT or the mpage code calling tell them how large the mapping
1129 * is, so that we can avoid repeated get_blocks calls.
1131 * If the mapping spans EOF, then we have to break the mapping up as the mapping
1132 * for blocks beyond EOF must be marked new so that sub block regions can be
1133 * correctly zeroed. We can't do this for mappings within EOF unless the mapping
1134 * was just allocated or is unwritten, otherwise the callers would overwrite
1135 * existing data with zeros. Hence we have to split the mapping into a range up
1136 * to and including EOF, and a second mapping for beyond EOF.
1140 struct inode
*inode
,
1142 struct buffer_head
*bh_result
,
1143 struct xfs_bmbt_irec
*imap
,
1147 xfs_off_t mapping_size
;
1149 mapping_size
= imap
->br_startoff
+ imap
->br_blockcount
- iblock
;
1150 mapping_size
<<= inode
->i_blkbits
;
1152 ASSERT(mapping_size
> 0);
1153 if (mapping_size
> size
)
1154 mapping_size
= size
;
1155 if (offset
< i_size_read(inode
) &&
1156 offset
+ mapping_size
>= i_size_read(inode
)) {
1157 /* limit mapping to block that spans EOF */
1158 mapping_size
= roundup_64(i_size_read(inode
) - offset
,
1159 1 << inode
->i_blkbits
);
1161 if (mapping_size
> LONG_MAX
)
1162 mapping_size
= LONG_MAX
;
1164 bh_result
->b_size
= mapping_size
;
1169 struct inode
*inode
,
1171 struct buffer_head
*bh_result
,
1176 struct xfs_inode
*ip
= XFS_I(inode
);
1177 struct xfs_mount
*mp
= ip
->i_mount
;
1178 xfs_fileoff_t offset_fsb
, end_fsb
;
1181 struct xfs_bmbt_irec imap
;
1187 BUG_ON(create
&& !direct
);
1189 if (XFS_FORCED_SHUTDOWN(mp
))
1192 offset
= (xfs_off_t
)iblock
<< inode
->i_blkbits
;
1193 ASSERT(bh_result
->b_size
>= (1 << inode
->i_blkbits
));
1194 size
= bh_result
->b_size
;
1196 if (!create
&& offset
>= i_size_read(inode
))
1200 * Direct I/O is usually done on preallocated files, so try getting
1201 * a block mapping without an exclusive lock first.
1203 lockmode
= xfs_ilock_data_map_shared(ip
);
1205 ASSERT(offset
<= mp
->m_super
->s_maxbytes
);
1206 if (offset
+ size
> mp
->m_super
->s_maxbytes
)
1207 size
= mp
->m_super
->s_maxbytes
- offset
;
1208 end_fsb
= XFS_B_TO_FSB(mp
, (xfs_ufsize_t
)offset
+ size
);
1209 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1211 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
,
1212 &imap
, &nimaps
, XFS_BMAPI_ENTIRE
);
1216 /* for DAX, we convert unwritten extents directly */
1219 (imap
.br_startblock
== HOLESTARTBLOCK
||
1220 imap
.br_startblock
== DELAYSTARTBLOCK
) ||
1221 (IS_DAX(inode
) && ISUNWRITTEN(&imap
)))) {
1223 * xfs_iomap_write_direct() expects the shared lock. It
1224 * is unlocked on return.
1226 if (lockmode
== XFS_ILOCK_EXCL
)
1227 xfs_ilock_demote(ip
, lockmode
);
1229 error
= xfs_iomap_write_direct(ip
, offset
, size
,
1235 trace_xfs_get_blocks_alloc(ip
, offset
, size
,
1236 ISUNWRITTEN(&imap
) ? XFS_IO_UNWRITTEN
1237 : XFS_IO_DELALLOC
, &imap
);
1238 } else if (nimaps
) {
1239 trace_xfs_get_blocks_found(ip
, offset
, size
,
1240 ISUNWRITTEN(&imap
) ? XFS_IO_UNWRITTEN
1241 : XFS_IO_OVERWRITE
, &imap
);
1242 xfs_iunlock(ip
, lockmode
);
1244 trace_xfs_get_blocks_notfound(ip
, offset
, size
);
1248 if (IS_DAX(inode
) && create
) {
1249 ASSERT(!ISUNWRITTEN(&imap
));
1250 /* zeroing is not needed at a higher layer */
1254 /* trim mapping down to size requested */
1255 xfs_map_trim_size(inode
, iblock
, bh_result
, &imap
, offset
, size
);
1258 * For unwritten extents do not report a disk address in the buffered
1259 * read case (treat as if we're reading into a hole).
1261 if (imap
.br_startblock
!= HOLESTARTBLOCK
&&
1262 imap
.br_startblock
!= DELAYSTARTBLOCK
&&
1263 (create
|| !ISUNWRITTEN(&imap
))) {
1264 xfs_map_buffer(inode
, bh_result
, &imap
, offset
);
1265 if (ISUNWRITTEN(&imap
))
1266 set_buffer_unwritten(bh_result
);
1267 /* direct IO needs special help */
1270 ASSERT(!ISUNWRITTEN(&imap
));
1272 xfs_map_direct(inode
, bh_result
, &imap
, offset
);
1277 * If this is a realtime file, data may be on a different device.
1278 * to that pointed to from the buffer_head b_bdev currently.
1280 bh_result
->b_bdev
= xfs_find_bdev_for_inode(inode
);
1283 * If we previously allocated a block out beyond eof and we are now
1284 * coming back to use it then we will need to flag it as new even if it
1285 * has a disk address.
1287 * With sub-block writes into unwritten extents we also need to mark
1288 * the buffer as new so that the unwritten parts of the buffer gets
1292 ((!buffer_mapped(bh_result
) && !buffer_uptodate(bh_result
)) ||
1293 (offset
>= i_size_read(inode
)) ||
1294 (new || ISUNWRITTEN(&imap
))))
1295 set_buffer_new(bh_result
);
1297 BUG_ON(direct
&& imap
.br_startblock
== DELAYSTARTBLOCK
);
1302 xfs_iunlock(ip
, lockmode
);
1308 struct inode
*inode
,
1310 struct buffer_head
*bh_result
,
1313 return __xfs_get_blocks(inode
, iblock
, bh_result
, create
, false, false);
1317 xfs_get_blocks_direct(
1318 struct inode
*inode
,
1320 struct buffer_head
*bh_result
,
1323 return __xfs_get_blocks(inode
, iblock
, bh_result
, create
, true, false);
1327 xfs_get_blocks_dax_fault(
1328 struct inode
*inode
,
1330 struct buffer_head
*bh_result
,
1333 return __xfs_get_blocks(inode
, iblock
, bh_result
, create
, true, true);
1337 * Complete a direct I/O write request.
1339 * xfs_map_direct passes us some flags in the private data to tell us what to
1340 * do. If no flags are set, then the write IO is an overwrite wholly within
1341 * the existing allocated file size and so there is nothing for us to do.
1343 * Note that in this case the completion can be called in interrupt context,
1344 * whereas if we have flags set we will always be called in task context
1345 * (i.e. from a workqueue).
1348 xfs_end_io_direct_write(
1354 struct inode
*inode
= file_inode(iocb
->ki_filp
);
1355 struct xfs_inode
*ip
= XFS_I(inode
);
1356 uintptr_t flags
= (uintptr_t)private;
1359 trace_xfs_end_io_direct_write(ip
, offset
, size
);
1361 if (XFS_FORCED_SHUTDOWN(ip
->i_mount
))
1368 * The flags tell us whether we are doing unwritten extent conversions
1369 * or an append transaction that updates the on-disk file size. These
1370 * cases are the only cases where we should *potentially* be needing
1371 * to update the VFS inode size.
1374 ASSERT(offset
+ size
<= i_size_read(inode
));
1379 * We need to update the in-core inode size here so that we don't end up
1380 * with the on-disk inode size being outside the in-core inode size. We
1381 * have no other method of updating EOF for AIO, so always do it here
1384 * We need to lock the test/set EOF update as we can be racing with
1385 * other IO completions here to update the EOF. Failing to serialise
1386 * here can result in EOF moving backwards and Bad Things Happen when
1389 spin_lock(&ip
->i_flags_lock
);
1390 if (offset
+ size
> i_size_read(inode
))
1391 i_size_write(inode
, offset
+ size
);
1392 spin_unlock(&ip
->i_flags_lock
);
1394 if (flags
& XFS_DIO_FLAG_UNWRITTEN
) {
1395 trace_xfs_end_io_direct_write_unwritten(ip
, offset
, size
);
1397 error
= xfs_iomap_write_unwritten(ip
, offset
, size
);
1398 } else if (flags
& XFS_DIO_FLAG_APPEND
) {
1399 trace_xfs_end_io_direct_write_append(ip
, offset
, size
);
1401 error
= xfs_setfilesize(ip
, offset
, size
);
1410 struct iov_iter
*iter
)
1413 * We just need the method present so that open/fcntl allow direct I/O.
1420 struct address_space
*mapping
,
1423 struct inode
*inode
= (struct inode
*)mapping
->host
;
1424 struct xfs_inode
*ip
= XFS_I(inode
);
1426 trace_xfs_vm_bmap(XFS_I(inode
));
1427 xfs_ilock(ip
, XFS_IOLOCK_SHARED
);
1428 filemap_write_and_wait(mapping
);
1429 xfs_iunlock(ip
, XFS_IOLOCK_SHARED
);
1430 return generic_block_bmap(mapping
, block
, xfs_get_blocks
);
1435 struct file
*unused
,
1438 trace_xfs_vm_readpage(page
->mapping
->host
, 1);
1439 return mpage_readpage(page
, xfs_get_blocks
);
1444 struct file
*unused
,
1445 struct address_space
*mapping
,
1446 struct list_head
*pages
,
1449 trace_xfs_vm_readpages(mapping
->host
, nr_pages
);
1450 return mpage_readpages(mapping
, pages
, nr_pages
, xfs_get_blocks
);
1454 * This is basically a copy of __set_page_dirty_buffers() with one
1455 * small tweak: buffers beyond EOF do not get marked dirty. If we mark them
1456 * dirty, we'll never be able to clean them because we don't write buffers
1457 * beyond EOF, and that means we can't invalidate pages that span EOF
1458 * that have been marked dirty. Further, the dirty state can leak into
1459 * the file interior if the file is extended, resulting in all sorts of
1460 * bad things happening as the state does not match the underlying data.
1462 * XXX: this really indicates that bufferheads in XFS need to die. Warts like
1463 * this only exist because of bufferheads and how the generic code manages them.
1466 xfs_vm_set_page_dirty(
1469 struct address_space
*mapping
= page
->mapping
;
1470 struct inode
*inode
= mapping
->host
;
1475 if (unlikely(!mapping
))
1476 return !TestSetPageDirty(page
);
1478 end_offset
= i_size_read(inode
);
1479 offset
= page_offset(page
);
1481 spin_lock(&mapping
->private_lock
);
1482 if (page_has_buffers(page
)) {
1483 struct buffer_head
*head
= page_buffers(page
);
1484 struct buffer_head
*bh
= head
;
1487 if (offset
< end_offset
)
1488 set_buffer_dirty(bh
);
1489 bh
= bh
->b_this_page
;
1490 offset
+= 1 << inode
->i_blkbits
;
1491 } while (bh
!= head
);
1494 * Lock out page->mem_cgroup migration to keep PageDirty
1495 * synchronized with per-memcg dirty page counters.
1497 lock_page_memcg(page
);
1498 newly_dirty
= !TestSetPageDirty(page
);
1499 spin_unlock(&mapping
->private_lock
);
1502 /* sigh - __set_page_dirty() is static, so copy it here, too */
1503 unsigned long flags
;
1505 spin_lock_irqsave(&mapping
->tree_lock
, flags
);
1506 if (page
->mapping
) { /* Race with truncate? */
1507 WARN_ON_ONCE(!PageUptodate(page
));
1508 account_page_dirtied(page
, mapping
);
1509 radix_tree_tag_set(&mapping
->page_tree
,
1510 page_index(page
), PAGECACHE_TAG_DIRTY
);
1512 spin_unlock_irqrestore(&mapping
->tree_lock
, flags
);
1514 unlock_page_memcg(page
);
1516 __mark_inode_dirty(mapping
->host
, I_DIRTY_PAGES
);
1520 const struct address_space_operations xfs_address_space_operations
= {
1521 .readpage
= xfs_vm_readpage
,
1522 .readpages
= xfs_vm_readpages
,
1523 .writepage
= xfs_vm_writepage
,
1524 .writepages
= xfs_vm_writepages
,
1525 .set_page_dirty
= xfs_vm_set_page_dirty
,
1526 .releasepage
= xfs_vm_releasepage
,
1527 .invalidatepage
= xfs_vm_invalidatepage
,
1528 .bmap
= xfs_vm_bmap
,
1529 .direct_IO
= xfs_vm_direct_IO
,
1530 .migratepage
= buffer_migrate_page
,
1531 .is_partially_uptodate
= block_is_partially_uptodate
,
1532 .error_remove_page
= generic_error_remove_page
,