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 ASSERT(atomic_read(&bio
->bi_cnt
) >= 1);
360 ioend
->io_error
= test_bit(BIO_UPTODATE
, &bio
->bi_flags
) ? 0 : error
;
362 /* Toss bio and pass work off to an xfsdatad thread */
363 bio
->bi_private
= NULL
;
364 bio
->bi_end_io
= NULL
;
367 xfs_finish_ioend(ioend
);
371 xfs_submit_ioend_bio(
372 struct writeback_control
*wbc
,
376 atomic_inc(&ioend
->io_remaining
);
377 bio
->bi_private
= ioend
;
378 bio
->bi_end_io
= xfs_end_bio
;
379 submit_bio(wbc
->sync_mode
== WB_SYNC_ALL
? WRITE_SYNC
: WRITE
, bio
);
384 struct buffer_head
*bh
)
386 int nvecs
= bio_get_nr_vecs(bh
->b_bdev
);
387 struct bio
*bio
= bio_alloc(GFP_NOIO
, nvecs
);
389 ASSERT(bio
->bi_private
== NULL
);
390 bio
->bi_iter
.bi_sector
= bh
->b_blocknr
* (bh
->b_size
>> 9);
391 bio
->bi_bdev
= bh
->b_bdev
;
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(
415 ASSERT(PageLocked(page
));
416 ASSERT(!PageWriteback(page
));
419 * if the page was not fully cleaned, we need to ensure that the higher
420 * layers come back to it correctly. That means we need to keep the page
421 * dirty, and for WB_SYNC_ALL writeback we need to ensure the
422 * PAGECACHE_TAG_TOWRITE index mark is not removed so another attempt to
423 * write this page in this writeback sweep will be made.
426 clear_page_dirty_for_io(page
);
427 set_page_writeback(page
);
429 set_page_writeback_keepwrite(page
);
433 /* If no buffers on the page are to be written, finish it here */
435 end_page_writeback(page
);
438 static inline int xfs_bio_add_buffer(struct bio
*bio
, struct buffer_head
*bh
)
440 return bio_add_page(bio
, bh
->b_page
, bh
->b_size
, bh_offset(bh
));
444 * Submit all of the bios for all of the ioends we have saved up, covering the
445 * initial writepage page and also any probed pages.
447 * Because we may have multiple ioends spanning a page, we need to start
448 * writeback on all the buffers before we submit them for I/O. If we mark the
449 * buffers as we got, then we can end up with a page that only has buffers
450 * marked async write and I/O complete on can occur before we mark the other
451 * buffers async write.
453 * The end result of this is that we trip a bug in end_page_writeback() because
454 * we call it twice for the one page as the code in end_buffer_async_write()
455 * assumes that all buffers on the page are started at the same time.
457 * The fix is two passes across the ioend list - one to start writeback on the
458 * buffer_heads, and then submit them for I/O on the second pass.
460 * If @fail is non-zero, it means that we have a situation where some part of
461 * the submission process has failed after we have marked paged for writeback
462 * and unlocked them. In this situation, we need to fail the ioend chain rather
463 * than submit it to IO. This typically only happens on a filesystem shutdown.
467 struct writeback_control
*wbc
,
471 xfs_ioend_t
*head
= ioend
;
473 struct buffer_head
*bh
;
475 sector_t lastblock
= 0;
477 /* Pass 1 - start writeback */
479 next
= ioend
->io_list
;
480 for (bh
= ioend
->io_buffer_head
; bh
; bh
= bh
->b_private
)
481 xfs_start_buffer_writeback(bh
);
482 } while ((ioend
= next
) != NULL
);
484 /* Pass 2 - submit I/O */
487 next
= ioend
->io_list
;
491 * If we are failing the IO now, just mark the ioend with an
492 * error and finish it. This will run IO completion immediately
493 * as there is only one reference to the ioend at this point in
497 ioend
->io_error
= fail
;
498 xfs_finish_ioend(ioend
);
502 for (bh
= ioend
->io_buffer_head
; bh
; bh
= bh
->b_private
) {
506 bio
= xfs_alloc_ioend_bio(bh
);
507 } else if (bh
->b_blocknr
!= lastblock
+ 1) {
508 xfs_submit_ioend_bio(wbc
, ioend
, bio
);
512 if (xfs_bio_add_buffer(bio
, bh
) != bh
->b_size
) {
513 xfs_submit_ioend_bio(wbc
, ioend
, bio
);
517 lastblock
= bh
->b_blocknr
;
520 xfs_submit_ioend_bio(wbc
, ioend
, bio
);
521 xfs_finish_ioend(ioend
);
522 } while ((ioend
= next
) != NULL
);
526 * Cancel submission of all buffer_heads so far in this endio.
527 * Toss the endio too. Only ever called for the initial page
528 * in a writepage request, so only ever one page.
535 struct buffer_head
*bh
, *next_bh
;
538 next
= ioend
->io_list
;
539 bh
= ioend
->io_buffer_head
;
541 next_bh
= bh
->b_private
;
542 clear_buffer_async_write(bh
);
544 * The unwritten flag is cleared when added to the
545 * ioend. We're not submitting for I/O so mark the
546 * buffer unwritten again for next time around.
548 if (ioend
->io_type
== XFS_IO_UNWRITTEN
)
549 set_buffer_unwritten(bh
);
551 } while ((bh
= next_bh
) != NULL
);
553 mempool_free(ioend
, xfs_ioend_pool
);
554 } while ((ioend
= next
) != NULL
);
558 * Test to see if we've been building up a completion structure for
559 * earlier buffers -- if so, we try to append to this ioend if we
560 * can, otherwise we finish off any current ioend and start another.
561 * Return true if we've finished the given ioend.
566 struct buffer_head
*bh
,
569 xfs_ioend_t
**result
,
572 xfs_ioend_t
*ioend
= *result
;
574 if (!ioend
|| need_ioend
|| type
!= ioend
->io_type
) {
575 xfs_ioend_t
*previous
= *result
;
577 ioend
= xfs_alloc_ioend(inode
, type
);
578 ioend
->io_offset
= offset
;
579 ioend
->io_buffer_head
= bh
;
580 ioend
->io_buffer_tail
= bh
;
582 previous
->io_list
= ioend
;
585 ioend
->io_buffer_tail
->b_private
= bh
;
586 ioend
->io_buffer_tail
= bh
;
589 bh
->b_private
= NULL
;
590 ioend
->io_size
+= bh
->b_size
;
596 struct buffer_head
*bh
,
597 struct xfs_bmbt_irec
*imap
,
601 struct xfs_mount
*m
= XFS_I(inode
)->i_mount
;
602 xfs_off_t iomap_offset
= XFS_FSB_TO_B(m
, imap
->br_startoff
);
603 xfs_daddr_t iomap_bn
= xfs_fsb_to_db(XFS_I(inode
), imap
->br_startblock
);
605 ASSERT(imap
->br_startblock
!= HOLESTARTBLOCK
);
606 ASSERT(imap
->br_startblock
!= DELAYSTARTBLOCK
);
608 bn
= (iomap_bn
>> (inode
->i_blkbits
- BBSHIFT
)) +
609 ((offset
- iomap_offset
) >> inode
->i_blkbits
);
611 ASSERT(bn
|| XFS_IS_REALTIME_INODE(XFS_I(inode
)));
614 set_buffer_mapped(bh
);
620 struct buffer_head
*bh
,
621 struct xfs_bmbt_irec
*imap
,
624 ASSERT(imap
->br_startblock
!= HOLESTARTBLOCK
);
625 ASSERT(imap
->br_startblock
!= DELAYSTARTBLOCK
);
627 xfs_map_buffer(inode
, bh
, imap
, offset
);
628 set_buffer_mapped(bh
);
629 clear_buffer_delay(bh
);
630 clear_buffer_unwritten(bh
);
634 * Test if a given page contains at least one buffer of a given @type.
635 * If @check_all_buffers is true, then we walk all the buffers in the page to
636 * try to find one of the type passed in. If it is not set, then the caller only
637 * needs to check the first buffer on the page for a match.
643 bool check_all_buffers
)
645 struct buffer_head
*bh
;
646 struct buffer_head
*head
;
648 if (PageWriteback(page
))
652 if (!page_has_buffers(page
))
655 bh
= head
= page_buffers(page
);
657 if (buffer_unwritten(bh
)) {
658 if (type
== XFS_IO_UNWRITTEN
)
660 } else if (buffer_delay(bh
)) {
661 if (type
== XFS_IO_DELALLOC
)
663 } else if (buffer_dirty(bh
) && buffer_mapped(bh
)) {
664 if (type
== XFS_IO_OVERWRITE
)
668 /* If we are only checking the first buffer, we are done now. */
669 if (!check_all_buffers
)
671 } while ((bh
= bh
->b_this_page
) != head
);
677 * Allocate & map buffers for page given the extent map. Write it out.
678 * except for the original page of a writepage, this is called on
679 * delalloc/unwritten pages only, for the original page it is possible
680 * that the page has no mapping at all.
687 struct xfs_bmbt_irec
*imap
,
688 xfs_ioend_t
**ioendp
,
689 struct writeback_control
*wbc
)
691 struct buffer_head
*bh
, *head
;
692 xfs_off_t end_offset
;
693 unsigned long p_offset
;
696 int count
= 0, done
= 0, uptodate
= 1;
697 xfs_off_t offset
= page_offset(page
);
699 if (page
->index
!= tindex
)
701 if (!trylock_page(page
))
703 if (PageWriteback(page
))
704 goto fail_unlock_page
;
705 if (page
->mapping
!= inode
->i_mapping
)
706 goto fail_unlock_page
;
707 if (!xfs_check_page_type(page
, (*ioendp
)->io_type
, false))
708 goto fail_unlock_page
;
711 * page_dirty is initially a count of buffers on the page before
712 * EOF and is decremented as we move each into a cleanable state.
716 * End offset is the highest offset that this page should represent.
717 * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
718 * will evaluate non-zero and be less than PAGE_CACHE_SIZE and
719 * hence give us the correct page_dirty count. On any other page,
720 * it will be zero and in that case we need page_dirty to be the
721 * count of buffers on the page.
723 end_offset
= min_t(unsigned long long,
724 (xfs_off_t
)(page
->index
+ 1) << PAGE_CACHE_SHIFT
,
728 * If the current map does not span the entire page we are about to try
729 * to write, then give up. The only way we can write a page that spans
730 * multiple mappings in a single writeback iteration is via the
731 * xfs_vm_writepage() function. Data integrity writeback requires the
732 * entire page to be written in a single attempt, otherwise the part of
733 * the page we don't write here doesn't get written as part of the data
736 * For normal writeback, we also don't attempt to write partial pages
737 * here as it simply means that write_cache_pages() will see it under
738 * writeback and ignore the page until some point in the future, at
739 * which time this will be the only page in the file that needs
740 * writeback. Hence for more optimal IO patterns, we should always
741 * avoid partial page writeback due to multiple mappings on a page here.
743 if (!xfs_imap_valid(inode
, imap
, end_offset
))
744 goto fail_unlock_page
;
746 len
= 1 << inode
->i_blkbits
;
747 p_offset
= min_t(unsigned long, end_offset
& (PAGE_CACHE_SIZE
- 1),
749 p_offset
= p_offset
? roundup(p_offset
, len
) : PAGE_CACHE_SIZE
;
750 page_dirty
= p_offset
/ len
;
753 * The moment we find a buffer that doesn't match our current type
754 * specification or can't be written, abort the loop and start
755 * writeback. As per the above xfs_imap_valid() check, only
756 * xfs_vm_writepage() can handle partial page writeback fully - we are
757 * limited here to the buffers that are contiguous with the current
758 * ioend, and hence a buffer we can't write breaks that contiguity and
759 * we have to defer the rest of the IO to xfs_vm_writepage().
761 bh
= head
= page_buffers(page
);
763 if (offset
>= end_offset
)
765 if (!buffer_uptodate(bh
))
767 if (!(PageUptodate(page
) || buffer_uptodate(bh
))) {
772 if (buffer_unwritten(bh
) || buffer_delay(bh
) ||
774 if (buffer_unwritten(bh
))
775 type
= XFS_IO_UNWRITTEN
;
776 else if (buffer_delay(bh
))
777 type
= XFS_IO_DELALLOC
;
779 type
= XFS_IO_OVERWRITE
;
782 * imap should always be valid because of the above
783 * partial page end_offset check on the imap.
785 ASSERT(xfs_imap_valid(inode
, imap
, offset
));
788 if (type
!= XFS_IO_OVERWRITE
)
789 xfs_map_at_offset(inode
, bh
, imap
, offset
);
790 xfs_add_to_ioend(inode
, bh
, offset
, type
,
799 } while (offset
+= len
, (bh
= bh
->b_this_page
) != head
);
801 if (uptodate
&& bh
== head
)
802 SetPageUptodate(page
);
805 if (--wbc
->nr_to_write
<= 0 &&
806 wbc
->sync_mode
== WB_SYNC_NONE
)
809 xfs_start_page_writeback(page
, !page_dirty
, count
);
819 * Convert & write out a cluster of pages in the same extent as defined
820 * by mp and following the start page.
826 struct xfs_bmbt_irec
*imap
,
827 xfs_ioend_t
**ioendp
,
828 struct writeback_control
*wbc
,
834 pagevec_init(&pvec
, 0);
835 while (!done
&& tindex
<= tlast
) {
836 unsigned len
= min_t(pgoff_t
, PAGEVEC_SIZE
, tlast
- tindex
+ 1);
838 if (!pagevec_lookup(&pvec
, inode
->i_mapping
, tindex
, len
))
841 for (i
= 0; i
< pagevec_count(&pvec
); i
++) {
842 done
= xfs_convert_page(inode
, pvec
.pages
[i
], tindex
++,
848 pagevec_release(&pvec
);
854 xfs_vm_invalidatepage(
859 trace_xfs_invalidatepage(page
->mapping
->host
, page
, offset
,
861 block_invalidatepage(page
, offset
, length
);
865 * If the page has delalloc buffers on it, we need to punch them out before we
866 * invalidate the page. If we don't, we leave a stale delalloc mapping on the
867 * inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read
868 * is done on that same region - the delalloc extent is returned when none is
869 * supposed to be there.
871 * We prevent this by truncating away the delalloc regions on the page before
872 * invalidating it. Because they are delalloc, we can do this without needing a
873 * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
874 * truncation without a transaction as there is no space left for block
875 * reservation (typically why we see a ENOSPC in writeback).
877 * This is not a performance critical path, so for now just do the punching a
878 * buffer head at a time.
881 xfs_aops_discard_page(
884 struct inode
*inode
= page
->mapping
->host
;
885 struct xfs_inode
*ip
= XFS_I(inode
);
886 struct buffer_head
*bh
, *head
;
887 loff_t offset
= page_offset(page
);
889 if (!xfs_check_page_type(page
, XFS_IO_DELALLOC
, true))
892 if (XFS_FORCED_SHUTDOWN(ip
->i_mount
))
895 xfs_alert(ip
->i_mount
,
896 "page discard on page %p, inode 0x%llx, offset %llu.",
897 page
, ip
->i_ino
, offset
);
899 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
900 bh
= head
= page_buffers(page
);
903 xfs_fileoff_t start_fsb
;
905 if (!buffer_delay(bh
))
908 start_fsb
= XFS_B_TO_FSBT(ip
->i_mount
, offset
);
909 error
= xfs_bmap_punch_delalloc_range(ip
, start_fsb
, 1);
911 /* something screwed, just bail */
912 if (!XFS_FORCED_SHUTDOWN(ip
->i_mount
)) {
913 xfs_alert(ip
->i_mount
,
914 "page discard unable to remove delalloc mapping.");
919 offset
+= 1 << inode
->i_blkbits
;
921 } while ((bh
= bh
->b_this_page
) != head
);
923 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
925 xfs_vm_invalidatepage(page
, 0, PAGE_CACHE_SIZE
);
930 * Write out a dirty page.
932 * For delalloc space on the page we need to allocate space and flush it.
933 * For unwritten space on the page we need to start the conversion to
934 * regular allocated space.
935 * For any other dirty buffer heads on the page we should flush them.
940 struct writeback_control
*wbc
)
942 struct inode
*inode
= page
->mapping
->host
;
943 struct buffer_head
*bh
, *head
;
944 struct xfs_bmbt_irec imap
;
945 xfs_ioend_t
*ioend
= NULL
, *iohead
= NULL
;
948 __uint64_t end_offset
;
949 pgoff_t end_index
, last_index
;
951 int err
, imap_valid
= 0, uptodate
= 1;
955 trace_xfs_writepage(inode
, page
, 0, 0);
957 ASSERT(page_has_buffers(page
));
960 * Refuse to write the page out if we are called from reclaim context.
962 * This avoids stack overflows when called from deeply used stacks in
963 * random callers for direct reclaim or memcg reclaim. We explicitly
964 * allow reclaim from kswapd as the stack usage there is relatively low.
966 * This should never happen except in the case of a VM regression so
969 if (WARN_ON_ONCE((current
->flags
& (PF_MEMALLOC
|PF_KSWAPD
)) ==
974 * Given that we do not allow direct reclaim to call us, we should
975 * never be called while in a filesystem transaction.
977 if (WARN_ON_ONCE(current
->flags
& PF_FSTRANS
))
980 /* Is this page beyond the end of the file? */
981 offset
= i_size_read(inode
);
982 end_index
= offset
>> PAGE_CACHE_SHIFT
;
983 last_index
= (offset
- 1) >> PAGE_CACHE_SHIFT
;
986 * The page index is less than the end_index, adjust the end_offset
987 * to the highest offset that this page should represent.
988 * -----------------------------------------------------
989 * | file mapping | <EOF> |
990 * -----------------------------------------------------
991 * | Page ... | Page N-2 | Page N-1 | Page N | |
992 * ^--------------------------------^----------|--------
993 * | desired writeback range | see else |
994 * ---------------------------------^------------------|
996 if (page
->index
< end_index
)
997 end_offset
= (xfs_off_t
)(page
->index
+ 1) << PAGE_CACHE_SHIFT
;
1000 * Check whether the page to write out is beyond or straddles
1002 * -------------------------------------------------------
1003 * | file mapping | <EOF> |
1004 * -------------------------------------------------------
1005 * | Page ... | Page N-2 | Page N-1 | Page N | Beyond |
1006 * ^--------------------------------^-----------|---------
1008 * ---------------------------------^-----------|--------|
1010 unsigned offset_into_page
= offset
& (PAGE_CACHE_SIZE
- 1);
1013 * Skip the page if it is fully outside i_size, e.g. due to a
1014 * truncate operation that is in progress. We must redirty the
1015 * page so that reclaim stops reclaiming it. Otherwise
1016 * xfs_vm_releasepage() is called on it and gets confused.
1018 * Note that the end_index is unsigned long, it would overflow
1019 * if the given offset is greater than 16TB on 32-bit system
1020 * and if we do check the page is fully outside i_size or not
1021 * via "if (page->index >= end_index + 1)" as "end_index + 1"
1022 * will be evaluated to 0. Hence this page will be redirtied
1023 * and be written out repeatedly which would result in an
1024 * infinite loop, the user program that perform this operation
1025 * will hang. Instead, we can verify this situation by checking
1026 * if the page to write is totally beyond the i_size or if it's
1027 * offset is just equal to the EOF.
1029 if (page
->index
> end_index
||
1030 (page
->index
== end_index
&& offset_into_page
== 0))
1034 * The page straddles i_size. It must be zeroed out on each
1035 * and every writepage invocation because it may be mmapped.
1036 * "A file is mapped in multiples of the page size. For a file
1037 * that is not a multiple of the page size, the remaining
1038 * memory is zeroed when mapped, and writes to that region are
1039 * not written out to the file."
1041 zero_user_segment(page
, offset_into_page
, PAGE_CACHE_SIZE
);
1043 /* Adjust the end_offset to the end of file */
1044 end_offset
= offset
;
1047 len
= 1 << inode
->i_blkbits
;
1049 bh
= head
= page_buffers(page
);
1050 offset
= page_offset(page
);
1051 type
= XFS_IO_OVERWRITE
;
1053 if (wbc
->sync_mode
== WB_SYNC_NONE
)
1059 if (offset
>= end_offset
)
1061 if (!buffer_uptodate(bh
))
1065 * set_page_dirty dirties all buffers in a page, independent
1066 * of their state. The dirty state however is entirely
1067 * meaningless for holes (!mapped && uptodate), so skip
1068 * buffers covering holes here.
1070 if (!buffer_mapped(bh
) && buffer_uptodate(bh
)) {
1075 if (buffer_unwritten(bh
)) {
1076 if (type
!= XFS_IO_UNWRITTEN
) {
1077 type
= XFS_IO_UNWRITTEN
;
1080 } else if (buffer_delay(bh
)) {
1081 if (type
!= XFS_IO_DELALLOC
) {
1082 type
= XFS_IO_DELALLOC
;
1085 } else if (buffer_uptodate(bh
)) {
1086 if (type
!= XFS_IO_OVERWRITE
) {
1087 type
= XFS_IO_OVERWRITE
;
1091 if (PageUptodate(page
))
1092 ASSERT(buffer_mapped(bh
));
1094 * This buffer is not uptodate and will not be
1095 * written to disk. Ensure that we will put any
1096 * subsequent writeable buffers into a new
1104 imap_valid
= xfs_imap_valid(inode
, &imap
, offset
);
1107 * If we didn't have a valid mapping then we need to
1108 * put the new mapping into a separate ioend structure.
1109 * This ensures non-contiguous extents always have
1110 * separate ioends, which is particularly important
1111 * for unwritten extent conversion at I/O completion
1115 err
= xfs_map_blocks(inode
, offset
, &imap
, type
,
1119 imap_valid
= xfs_imap_valid(inode
, &imap
, offset
);
1123 if (type
!= XFS_IO_OVERWRITE
)
1124 xfs_map_at_offset(inode
, bh
, &imap
, offset
);
1125 xfs_add_to_ioend(inode
, bh
, offset
, type
, &ioend
,
1133 } while (offset
+= len
, ((bh
= bh
->b_this_page
) != head
));
1135 if (uptodate
&& bh
== head
)
1136 SetPageUptodate(page
);
1138 xfs_start_page_writeback(page
, 1, count
);
1140 /* if there is no IO to be submitted for this page, we are done */
1147 * Any errors from this point onwards need tobe reported through the IO
1148 * completion path as we have marked the initial page as under writeback
1152 xfs_off_t end_index
;
1154 end_index
= imap
.br_startoff
+ imap
.br_blockcount
;
1157 end_index
<<= inode
->i_blkbits
;
1160 end_index
= (end_index
- 1) >> PAGE_CACHE_SHIFT
;
1162 /* check against file size */
1163 if (end_index
> last_index
)
1164 end_index
= last_index
;
1166 xfs_cluster_write(inode
, page
->index
+ 1, &imap
, &ioend
,
1172 * Reserve log space if we might write beyond the on-disk inode size.
1175 if (ioend
->io_type
!= XFS_IO_UNWRITTEN
&& xfs_ioend_is_append(ioend
))
1176 err
= xfs_setfilesize_trans_alloc(ioend
);
1178 xfs_submit_ioend(wbc
, iohead
, err
);
1184 xfs_cancel_ioend(iohead
);
1189 xfs_aops_discard_page(page
);
1190 ClearPageUptodate(page
);
1195 redirty_page_for_writepage(wbc
, page
);
1202 struct address_space
*mapping
,
1203 struct writeback_control
*wbc
)
1205 xfs_iflags_clear(XFS_I(mapping
->host
), XFS_ITRUNCATED
);
1206 return generic_writepages(mapping
, wbc
);
1210 * Called to move a page into cleanable state - and from there
1211 * to be released. The page should already be clean. We always
1212 * have buffer heads in this call.
1214 * Returns 1 if the page is ok to release, 0 otherwise.
1221 int delalloc
, unwritten
;
1223 trace_xfs_releasepage(page
->mapping
->host
, page
, 0, 0);
1225 xfs_count_page_state(page
, &delalloc
, &unwritten
);
1227 if (WARN_ON_ONCE(delalloc
))
1229 if (WARN_ON_ONCE(unwritten
))
1232 return try_to_free_buffers(page
);
1236 * When we map a DIO buffer, we may need to attach an ioend that describes the
1237 * type of write IO we are doing. This passes to the completion function the
1238 * operations it needs to perform. If the mapping is for an overwrite wholly
1239 * within the EOF then we don't need an ioend and so we don't allocate one.
1240 * This avoids the unnecessary overhead of allocating and freeing ioends for
1241 * workloads that don't require transactions on IO completion.
1243 * If we get multiple mappings in a single IO, we might be mapping different
1244 * types. But because the direct IO can only have a single private pointer, we
1245 * need to ensure that:
1247 * a) i) the ioend spans the entire region of unwritten mappings; or
1248 * ii) the ioend spans all the mappings that cross or are beyond EOF; and
1249 * b) if it contains unwritten extents, it is *permanently* marked as such
1251 * We could do this by chaining ioends like buffered IO does, but we only
1252 * actually get one IO completion callback from the direct IO, and that spans
1253 * the entire IO regardless of how many mappings and IOs are needed to complete
1254 * the DIO. There is only going to be one reference to the ioend and its life
1255 * cycle is constrained by the DIO completion code. hence we don't need
1256 * reference counting here.
1260 struct inode
*inode
,
1261 struct buffer_head
*bh_result
,
1262 struct xfs_bmbt_irec
*imap
,
1265 struct xfs_ioend
*ioend
;
1266 xfs_off_t size
= bh_result
->b_size
;
1269 if (ISUNWRITTEN(imap
))
1270 type
= XFS_IO_UNWRITTEN
;
1272 type
= XFS_IO_OVERWRITE
;
1274 trace_xfs_gbmap_direct(XFS_I(inode
), offset
, size
, type
, imap
);
1276 if (bh_result
->b_private
) {
1277 ioend
= bh_result
->b_private
;
1278 ASSERT(ioend
->io_size
> 0);
1279 ASSERT(offset
>= ioend
->io_offset
);
1280 if (offset
+ size
> ioend
->io_offset
+ ioend
->io_size
)
1281 ioend
->io_size
= offset
- ioend
->io_offset
+ size
;
1283 if (type
== XFS_IO_UNWRITTEN
&& type
!= ioend
->io_type
)
1284 ioend
->io_type
= XFS_IO_UNWRITTEN
;
1286 trace_xfs_gbmap_direct_update(XFS_I(inode
), ioend
->io_offset
,
1287 ioend
->io_size
, ioend
->io_type
,
1289 } else if (type
== XFS_IO_UNWRITTEN
||
1290 offset
+ size
> i_size_read(inode
)) {
1291 ioend
= xfs_alloc_ioend(inode
, type
);
1292 ioend
->io_offset
= offset
;
1293 ioend
->io_size
= size
;
1295 bh_result
->b_private
= ioend
;
1296 set_buffer_defer_completion(bh_result
);
1298 trace_xfs_gbmap_direct_new(XFS_I(inode
), offset
, size
, type
,
1301 trace_xfs_gbmap_direct_none(XFS_I(inode
), offset
, size
, type
,
1307 * If this is O_DIRECT or the mpage code calling tell them how large the mapping
1308 * is, so that we can avoid repeated get_blocks calls.
1310 * If the mapping spans EOF, then we have to break the mapping up as the mapping
1311 * for blocks beyond EOF must be marked new so that sub block regions can be
1312 * correctly zeroed. We can't do this for mappings within EOF unless the mapping
1313 * was just allocated or is unwritten, otherwise the callers would overwrite
1314 * existing data with zeros. Hence we have to split the mapping into a range up
1315 * to and including EOF, and a second mapping for beyond EOF.
1319 struct inode
*inode
,
1321 struct buffer_head
*bh_result
,
1322 struct xfs_bmbt_irec
*imap
,
1326 xfs_off_t mapping_size
;
1328 mapping_size
= imap
->br_startoff
+ imap
->br_blockcount
- iblock
;
1329 mapping_size
<<= inode
->i_blkbits
;
1331 ASSERT(mapping_size
> 0);
1332 if (mapping_size
> size
)
1333 mapping_size
= size
;
1334 if (offset
< i_size_read(inode
) &&
1335 offset
+ mapping_size
>= i_size_read(inode
)) {
1336 /* limit mapping to block that spans EOF */
1337 mapping_size
= roundup_64(i_size_read(inode
) - offset
,
1338 1 << inode
->i_blkbits
);
1340 if (mapping_size
> LONG_MAX
)
1341 mapping_size
= LONG_MAX
;
1343 bh_result
->b_size
= mapping_size
;
1348 struct inode
*inode
,
1350 struct buffer_head
*bh_result
,
1354 struct xfs_inode
*ip
= XFS_I(inode
);
1355 struct xfs_mount
*mp
= ip
->i_mount
;
1356 xfs_fileoff_t offset_fsb
, end_fsb
;
1359 struct xfs_bmbt_irec imap
;
1365 if (XFS_FORCED_SHUTDOWN(mp
))
1368 offset
= (xfs_off_t
)iblock
<< inode
->i_blkbits
;
1369 ASSERT(bh_result
->b_size
>= (1 << inode
->i_blkbits
));
1370 size
= bh_result
->b_size
;
1372 if (!create
&& direct
&& offset
>= i_size_read(inode
))
1376 * Direct I/O is usually done on preallocated files, so try getting
1377 * a block mapping without an exclusive lock first. For buffered
1378 * writes we already have the exclusive iolock anyway, so avoiding
1379 * a lock roundtrip here by taking the ilock exclusive from the
1380 * beginning is a useful micro optimization.
1382 if (create
&& !direct
) {
1383 lockmode
= XFS_ILOCK_EXCL
;
1384 xfs_ilock(ip
, lockmode
);
1386 lockmode
= xfs_ilock_data_map_shared(ip
);
1389 ASSERT(offset
<= mp
->m_super
->s_maxbytes
);
1390 if (offset
+ size
> mp
->m_super
->s_maxbytes
)
1391 size
= mp
->m_super
->s_maxbytes
- offset
;
1392 end_fsb
= XFS_B_TO_FSB(mp
, (xfs_ufsize_t
)offset
+ size
);
1393 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1395 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
,
1396 &imap
, &nimaps
, XFS_BMAPI_ENTIRE
);
1402 (imap
.br_startblock
== HOLESTARTBLOCK
||
1403 imap
.br_startblock
== DELAYSTARTBLOCK
))) {
1404 if (direct
|| xfs_get_extsz_hint(ip
)) {
1406 * Drop the ilock in preparation for starting the block
1407 * allocation transaction. It will be retaken
1408 * exclusively inside xfs_iomap_write_direct for the
1409 * actual allocation.
1411 xfs_iunlock(ip
, lockmode
);
1412 error
= xfs_iomap_write_direct(ip
, offset
, size
,
1419 * Delalloc reservations do not require a transaction,
1420 * we can go on without dropping the lock here. If we
1421 * are allocating a new delalloc block, make sure that
1422 * we set the new flag so that we mark the buffer new so
1423 * that we know that it is newly allocated if the write
1426 if (nimaps
&& imap
.br_startblock
== HOLESTARTBLOCK
)
1428 error
= xfs_iomap_write_delay(ip
, offset
, size
, &imap
);
1432 xfs_iunlock(ip
, lockmode
);
1434 trace_xfs_get_blocks_alloc(ip
, offset
, size
,
1435 ISUNWRITTEN(&imap
) ? XFS_IO_UNWRITTEN
1436 : XFS_IO_DELALLOC
, &imap
);
1437 } else if (nimaps
) {
1438 trace_xfs_get_blocks_found(ip
, offset
, size
,
1439 ISUNWRITTEN(&imap
) ? XFS_IO_UNWRITTEN
1440 : XFS_IO_OVERWRITE
, &imap
);
1441 xfs_iunlock(ip
, lockmode
);
1443 trace_xfs_get_blocks_notfound(ip
, offset
, size
);
1447 /* trim mapping down to size requested */
1448 if (direct
|| size
> (1 << inode
->i_blkbits
))
1449 xfs_map_trim_size(inode
, iblock
, bh_result
,
1450 &imap
, offset
, size
);
1453 * For unwritten extents do not report a disk address in the buffered
1454 * read case (treat as if we're reading into a hole).
1456 if (imap
.br_startblock
!= HOLESTARTBLOCK
&&
1457 imap
.br_startblock
!= DELAYSTARTBLOCK
&&
1458 (create
|| !ISUNWRITTEN(&imap
))) {
1459 xfs_map_buffer(inode
, bh_result
, &imap
, offset
);
1460 if (ISUNWRITTEN(&imap
))
1461 set_buffer_unwritten(bh_result
);
1462 /* direct IO needs special help */
1463 if (create
&& direct
)
1464 xfs_map_direct(inode
, bh_result
, &imap
, offset
);
1468 * If this is a realtime file, data may be on a different device.
1469 * to that pointed to from the buffer_head b_bdev currently.
1471 bh_result
->b_bdev
= xfs_find_bdev_for_inode(inode
);
1474 * If we previously allocated a block out beyond eof and we are now
1475 * coming back to use it then we will need to flag it as new even if it
1476 * has a disk address.
1478 * With sub-block writes into unwritten extents we also need to mark
1479 * the buffer as new so that the unwritten parts of the buffer gets
1483 ((!buffer_mapped(bh_result
) && !buffer_uptodate(bh_result
)) ||
1484 (offset
>= i_size_read(inode
)) ||
1485 (new || ISUNWRITTEN(&imap
))))
1486 set_buffer_new(bh_result
);
1488 if (imap
.br_startblock
== DELAYSTARTBLOCK
) {
1491 set_buffer_uptodate(bh_result
);
1492 set_buffer_mapped(bh_result
);
1493 set_buffer_delay(bh_result
);
1500 xfs_iunlock(ip
, lockmode
);
1506 struct inode
*inode
,
1508 struct buffer_head
*bh_result
,
1511 return __xfs_get_blocks(inode
, iblock
, bh_result
, create
, 0);
1515 xfs_get_blocks_direct(
1516 struct inode
*inode
,
1518 struct buffer_head
*bh_result
,
1521 return __xfs_get_blocks(inode
, iblock
, bh_result
, create
, 1);
1525 * Complete a direct I/O write request.
1527 * The ioend structure is passed from __xfs_get_blocks() to tell us what to do.
1528 * If no ioend exists (i.e. @private == NULL) then the write IO is an overwrite
1529 * wholly within the EOF and so there is nothing for us to do. Note that in this
1530 * case the completion can be called in interrupt context, whereas if we have an
1531 * ioend we will always be called in task context (i.e. from a workqueue).
1534 xfs_end_io_direct_write(
1540 struct inode
*inode
= file_inode(iocb
->ki_filp
);
1541 struct xfs_inode
*ip
= XFS_I(inode
);
1542 struct xfs_mount
*mp
= ip
->i_mount
;
1543 struct xfs_ioend
*ioend
= private;
1545 trace_xfs_gbmap_direct_endio(ip
, offset
, size
,
1546 ioend
? ioend
->io_type
: 0, NULL
);
1549 ASSERT(offset
+ size
<= i_size_read(inode
));
1553 if (XFS_FORCED_SHUTDOWN(mp
))
1557 * dio completion end_io functions are only called on writes if more
1558 * than 0 bytes was written.
1563 * The ioend only maps whole blocks, while the IO may be sector aligned.
1564 * Hence the ioend offset/size may not match the IO offset/size exactly.
1565 * Because we don't map overwrites within EOF into the ioend, the offset
1566 * may not match, but only if the endio spans EOF. Either way, write
1567 * the IO sizes into the ioend so that completion processing does the
1570 ASSERT(offset
+ size
<= ioend
->io_offset
+ ioend
->io_size
);
1571 ioend
->io_size
= size
;
1572 ioend
->io_offset
= offset
;
1575 * The ioend tells us whether we are doing unwritten extent conversion
1576 * or an append transaction that updates the on-disk file size. These
1577 * cases are the only cases where we should *potentially* be needing
1578 * to update the VFS inode size.
1580 * We need to update the in-core inode size here so that we don't end up
1581 * with the on-disk inode size being outside the in-core inode size. We
1582 * have no other method of updating EOF for AIO, so always do it here
1585 * We need to lock the test/set EOF update as we can be racing with
1586 * other IO completions here to update the EOF. Failing to serialise
1587 * here can result in EOF moving backwards and Bad Things Happen when
1590 spin_lock(&ip
->i_flags_lock
);
1591 if (offset
+ size
> i_size_read(inode
))
1592 i_size_write(inode
, offset
+ size
);
1593 spin_unlock(&ip
->i_flags_lock
);
1596 * If we are doing an append IO that needs to update the EOF on disk,
1597 * do the transaction reserve now so we can use common end io
1598 * processing. Stashing the error (if there is one) in the ioend will
1599 * result in the ioend processing passing on the error if it is
1600 * possible as we can't return it from here.
1602 if (ioend
->io_type
== XFS_IO_OVERWRITE
)
1603 ioend
->io_error
= xfs_setfilesize_trans_alloc(ioend
);
1606 xfs_end_io(&ioend
->io_work
);
1613 struct iov_iter
*iter
,
1616 struct inode
*inode
= iocb
->ki_filp
->f_mapping
->host
;
1617 struct block_device
*bdev
= xfs_find_bdev_for_inode(inode
);
1619 if (iov_iter_rw(iter
) == WRITE
) {
1620 return __blockdev_direct_IO(iocb
, inode
, bdev
, iter
, offset
,
1621 xfs_get_blocks_direct
,
1622 xfs_end_io_direct_write
, NULL
,
1625 return __blockdev_direct_IO(iocb
, inode
, bdev
, iter
, offset
,
1626 xfs_get_blocks_direct
, NULL
, NULL
, 0);
1630 * Punch out the delalloc blocks we have already allocated.
1632 * Don't bother with xfs_setattr given that nothing can have made it to disk yet
1633 * as the page is still locked at this point.
1636 xfs_vm_kill_delalloc_range(
1637 struct inode
*inode
,
1641 struct xfs_inode
*ip
= XFS_I(inode
);
1642 xfs_fileoff_t start_fsb
;
1643 xfs_fileoff_t end_fsb
;
1646 start_fsb
= XFS_B_TO_FSB(ip
->i_mount
, start
);
1647 end_fsb
= XFS_B_TO_FSB(ip
->i_mount
, end
);
1648 if (end_fsb
<= start_fsb
)
1651 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1652 error
= xfs_bmap_punch_delalloc_range(ip
, start_fsb
,
1653 end_fsb
- start_fsb
);
1655 /* something screwed, just bail */
1656 if (!XFS_FORCED_SHUTDOWN(ip
->i_mount
)) {
1657 xfs_alert(ip
->i_mount
,
1658 "xfs_vm_write_failed: unable to clean up ino %lld",
1662 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1666 xfs_vm_write_failed(
1667 struct inode
*inode
,
1672 loff_t block_offset
;
1675 loff_t from
= pos
& (PAGE_CACHE_SIZE
- 1);
1676 loff_t to
= from
+ len
;
1677 struct buffer_head
*bh
, *head
;
1680 * The request pos offset might be 32 or 64 bit, this is all fine
1681 * on 64-bit platform. However, for 64-bit pos request on 32-bit
1682 * platform, the high 32-bit will be masked off if we evaluate the
1683 * block_offset via (pos & PAGE_MASK) because the PAGE_MASK is
1684 * 0xfffff000 as an unsigned long, hence the result is incorrect
1685 * which could cause the following ASSERT failed in most cases.
1686 * In order to avoid this, we can evaluate the block_offset of the
1687 * start of the page by using shifts rather than masks the mismatch
1690 block_offset
= (pos
>> PAGE_CACHE_SHIFT
) << PAGE_CACHE_SHIFT
;
1692 ASSERT(block_offset
+ from
== pos
);
1694 head
= page_buffers(page
);
1696 for (bh
= head
; bh
!= head
|| !block_start
;
1697 bh
= bh
->b_this_page
, block_start
= block_end
,
1698 block_offset
+= bh
->b_size
) {
1699 block_end
= block_start
+ bh
->b_size
;
1701 /* skip buffers before the write */
1702 if (block_end
<= from
)
1705 /* if the buffer is after the write, we're done */
1706 if (block_start
>= to
)
1709 if (!buffer_delay(bh
))
1712 if (!buffer_new(bh
) && block_offset
< i_size_read(inode
))
1715 xfs_vm_kill_delalloc_range(inode
, block_offset
,
1716 block_offset
+ bh
->b_size
);
1719 * This buffer does not contain data anymore. make sure anyone
1720 * who finds it knows that for certain.
1722 clear_buffer_delay(bh
);
1723 clear_buffer_uptodate(bh
);
1724 clear_buffer_mapped(bh
);
1725 clear_buffer_new(bh
);
1726 clear_buffer_dirty(bh
);
1732 * This used to call block_write_begin(), but it unlocks and releases the page
1733 * on error, and we need that page to be able to punch stale delalloc blocks out
1734 * on failure. hence we copy-n-waste it here and call xfs_vm_write_failed() at
1735 * the appropriate point.
1740 struct address_space
*mapping
,
1744 struct page
**pagep
,
1747 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
1751 ASSERT(len
<= PAGE_CACHE_SIZE
);
1753 page
= grab_cache_page_write_begin(mapping
, index
, flags
);
1757 status
= __block_write_begin(page
, pos
, len
, xfs_get_blocks
);
1758 if (unlikely(status
)) {
1759 struct inode
*inode
= mapping
->host
;
1760 size_t isize
= i_size_read(inode
);
1762 xfs_vm_write_failed(inode
, page
, pos
, len
);
1766 * If the write is beyond EOF, we only want to kill blocks
1767 * allocated in this write, not blocks that were previously
1768 * written successfully.
1770 if (pos
+ len
> isize
) {
1771 ssize_t start
= max_t(ssize_t
, pos
, isize
);
1773 truncate_pagecache_range(inode
, start
, pos
+ len
);
1776 page_cache_release(page
);
1785 * On failure, we only need to kill delalloc blocks beyond EOF in the range of
1786 * this specific write because they will never be written. Previous writes
1787 * beyond EOF where block allocation succeeded do not need to be trashed, so
1788 * only new blocks from this write should be trashed. For blocks within
1789 * EOF, generic_write_end() zeros them so they are safe to leave alone and be
1790 * written with all the other valid data.
1795 struct address_space
*mapping
,
1804 ASSERT(len
<= PAGE_CACHE_SIZE
);
1806 ret
= generic_write_end(file
, mapping
, pos
, len
, copied
, page
, fsdata
);
1807 if (unlikely(ret
< len
)) {
1808 struct inode
*inode
= mapping
->host
;
1809 size_t isize
= i_size_read(inode
);
1810 loff_t to
= pos
+ len
;
1813 /* only kill blocks in this write beyond EOF */
1816 xfs_vm_kill_delalloc_range(inode
, isize
, to
);
1817 truncate_pagecache_range(inode
, isize
, to
);
1825 struct address_space
*mapping
,
1828 struct inode
*inode
= (struct inode
*)mapping
->host
;
1829 struct xfs_inode
*ip
= XFS_I(inode
);
1831 trace_xfs_vm_bmap(XFS_I(inode
));
1832 xfs_ilock(ip
, XFS_IOLOCK_SHARED
);
1833 filemap_write_and_wait(mapping
);
1834 xfs_iunlock(ip
, XFS_IOLOCK_SHARED
);
1835 return generic_block_bmap(mapping
, block
, xfs_get_blocks
);
1840 struct file
*unused
,
1843 return mpage_readpage(page
, xfs_get_blocks
);
1848 struct file
*unused
,
1849 struct address_space
*mapping
,
1850 struct list_head
*pages
,
1853 return mpage_readpages(mapping
, pages
, nr_pages
, xfs_get_blocks
);
1857 * This is basically a copy of __set_page_dirty_buffers() with one
1858 * small tweak: buffers beyond EOF do not get marked dirty. If we mark them
1859 * dirty, we'll never be able to clean them because we don't write buffers
1860 * beyond EOF, and that means we can't invalidate pages that span EOF
1861 * that have been marked dirty. Further, the dirty state can leak into
1862 * the file interior if the file is extended, resulting in all sorts of
1863 * bad things happening as the state does not match the underlying data.
1865 * XXX: this really indicates that bufferheads in XFS need to die. Warts like
1866 * this only exist because of bufferheads and how the generic code manages them.
1869 xfs_vm_set_page_dirty(
1872 struct address_space
*mapping
= page
->mapping
;
1873 struct inode
*inode
= mapping
->host
;
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
);
1896 newly_dirty
= !TestSetPageDirty(page
);
1897 spin_unlock(&mapping
->private_lock
);
1900 /* sigh - __set_page_dirty() is static, so copy it here, too */
1901 unsigned long flags
;
1903 spin_lock_irqsave(&mapping
->tree_lock
, flags
);
1904 if (page
->mapping
) { /* Race with truncate? */
1905 WARN_ON_ONCE(!PageUptodate(page
));
1906 account_page_dirtied(page
, mapping
);
1907 radix_tree_tag_set(&mapping
->page_tree
,
1908 page_index(page
), PAGECACHE_TAG_DIRTY
);
1910 spin_unlock_irqrestore(&mapping
->tree_lock
, flags
);
1911 __mark_inode_dirty(mapping
->host
, I_DIRTY_PAGES
);
1916 const struct address_space_operations xfs_address_space_operations
= {
1917 .readpage
= xfs_vm_readpage
,
1918 .readpages
= xfs_vm_readpages
,
1919 .writepage
= xfs_vm_writepage
,
1920 .writepages
= xfs_vm_writepages
,
1921 .set_page_dirty
= xfs_vm_set_page_dirty
,
1922 .releasepage
= xfs_vm_releasepage
,
1923 .invalidatepage
= xfs_vm_invalidatepage
,
1924 .write_begin
= xfs_vm_write_begin
,
1925 .write_end
= xfs_vm_write_end
,
1926 .bmap
= xfs_vm_bmap
,
1927 .direct_IO
= xfs_vm_direct_IO
,
1928 .migratepage
= buffer_migrate_page
,
1929 .is_partially_uptodate
= block_is_partially_uptodate
,
1930 .error_remove_page
= generic_error_remove_page
,