2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3 * Copyright (c) 2016 Christoph Hellwig.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it would be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 #include <linux/iomap.h>
22 #include "xfs_shared.h"
23 #include "xfs_format.h"
24 #include "xfs_log_format.h"
25 #include "xfs_trans_resv.h"
26 #include "xfs_mount.h"
27 #include "xfs_defer.h"
28 #include "xfs_inode.h"
29 #include "xfs_btree.h"
30 #include "xfs_bmap_btree.h"
32 #include "xfs_bmap_util.h"
33 #include "xfs_error.h"
34 #include "xfs_trans.h"
35 #include "xfs_trans_space.h"
36 #include "xfs_iomap.h"
37 #include "xfs_trace.h"
38 #include "xfs_icache.h"
39 #include "xfs_quota.h"
40 #include "xfs_dquot_item.h"
41 #include "xfs_dquot.h"
42 #include "xfs_reflink.h"
45 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
52 struct xfs_bmbt_irec
*imap
)
54 struct xfs_mount
*mp
= ip
->i_mount
;
56 if (imap
->br_startblock
== HOLESTARTBLOCK
) {
57 iomap
->blkno
= IOMAP_NULL_BLOCK
;
58 iomap
->type
= IOMAP_HOLE
;
59 } else if (imap
->br_startblock
== DELAYSTARTBLOCK
) {
60 iomap
->blkno
= IOMAP_NULL_BLOCK
;
61 iomap
->type
= IOMAP_DELALLOC
;
63 iomap
->blkno
= xfs_fsb_to_db(ip
, imap
->br_startblock
);
64 if (imap
->br_state
== XFS_EXT_UNWRITTEN
)
65 iomap
->type
= IOMAP_UNWRITTEN
;
67 iomap
->type
= IOMAP_MAPPED
;
69 iomap
->offset
= XFS_FSB_TO_B(mp
, imap
->br_startoff
);
70 iomap
->length
= XFS_FSB_TO_B(mp
, imap
->br_blockcount
);
71 iomap
->bdev
= xfs_find_bdev_for_inode(VFS_I(ip
));
72 iomap
->dax_dev
= xfs_find_daxdev_for_inode(VFS_I(ip
));
80 struct xfs_mount
*mp
= ip
->i_mount
;
81 xfs_extlen_t align
= 0;
83 if (!XFS_IS_REALTIME_INODE(ip
)) {
85 * Round up the allocation request to a stripe unit
86 * (m_dalign) boundary if the file size is >= stripe unit
87 * size, and we are allocating past the allocation eof.
89 * If mounted with the "-o swalloc" option the alignment is
90 * increased from the strip unit size to the stripe width.
92 if (mp
->m_swidth
&& (mp
->m_flags
& XFS_MOUNT_SWALLOC
))
94 else if (mp
->m_dalign
)
97 if (align
&& XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, align
))
102 * Always round up the allocation request to an extent boundary
103 * (when file on a real-time subvolume or has di_extsize hint).
107 align
= roundup_64(align
, extsize
);
116 xfs_iomap_eof_align_last_fsb(
117 struct xfs_inode
*ip
,
118 xfs_extlen_t extsize
,
119 xfs_fileoff_t
*last_fsb
)
121 xfs_extlen_t align
= xfs_eof_alignment(ip
, extsize
);
124 xfs_fileoff_t new_last_fsb
= roundup_64(*last_fsb
, align
);
127 error
= xfs_bmap_eof(ip
, new_last_fsb
, XFS_DATA_FORK
, &eof
);
131 *last_fsb
= new_last_fsb
;
137 xfs_alert_fsblock_zero(
139 xfs_bmbt_irec_t
*imap
)
141 xfs_alert_tag(ip
->i_mount
, XFS_PTAG_FSBLOCK_ZERO
,
142 "Access to block zero in inode %llu "
143 "start_block: %llx start_off: %llx "
144 "blkcnt: %llx extent-state: %x",
145 (unsigned long long)ip
->i_ino
,
146 (unsigned long long)imap
->br_startblock
,
147 (unsigned long long)imap
->br_startoff
,
148 (unsigned long long)imap
->br_blockcount
,
150 return -EFSCORRUPTED
;
154 xfs_iomap_write_direct(
158 xfs_bmbt_irec_t
*imap
,
161 xfs_mount_t
*mp
= ip
->i_mount
;
162 xfs_fileoff_t offset_fsb
;
163 xfs_fileoff_t last_fsb
;
164 xfs_filblks_t count_fsb
, resaligned
;
165 xfs_fsblock_t firstfsb
;
171 struct xfs_defer_ops dfops
;
172 uint qblocks
, resblks
, resrtextents
;
175 int bmapi_flags
= XFS_BMAPI_PREALLOC
;
178 rt
= XFS_IS_REALTIME_INODE(ip
);
179 extsz
= xfs_get_extsz_hint(ip
);
180 lockmode
= XFS_ILOCK_SHARED
; /* locked by caller */
182 ASSERT(xfs_isilocked(ip
, lockmode
));
184 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
185 last_fsb
= XFS_B_TO_FSB(mp
, ((xfs_ufsize_t
)(offset
+ count
)));
186 if ((offset
+ count
) > XFS_ISIZE(ip
)) {
188 * Assert that the in-core extent list is present since this can
189 * call xfs_iread_extents() and we only have the ilock shared.
190 * This should be safe because the lock was held around a bmapi
191 * call in the caller and we only need it to access the in-core
194 ASSERT(XFS_IFORK_PTR(ip
, XFS_DATA_FORK
)->if_flags
&
196 error
= xfs_iomap_eof_align_last_fsb(ip
, extsz
, &last_fsb
);
200 if (nmaps
&& (imap
->br_startblock
== HOLESTARTBLOCK
))
201 last_fsb
= MIN(last_fsb
, (xfs_fileoff_t
)
202 imap
->br_blockcount
+
205 count_fsb
= last_fsb
- offset_fsb
;
206 ASSERT(count_fsb
> 0);
207 resaligned
= xfs_aligned_fsb_count(offset_fsb
, count_fsb
, extsz
);
210 resrtextents
= qblocks
= resaligned
;
211 resrtextents
/= mp
->m_sb
.sb_rextsize
;
212 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0);
213 quota_flag
= XFS_QMOPT_RES_RTBLKS
;
216 resblks
= qblocks
= XFS_DIOSTRAT_SPACE_RES(mp
, resaligned
);
217 quota_flag
= XFS_QMOPT_RES_REGBLKS
;
221 * Drop the shared lock acquired by the caller, attach the dquot if
222 * necessary and move on to transaction setup.
224 xfs_iunlock(ip
, lockmode
);
225 error
= xfs_qm_dqattach(ip
, 0);
230 * For DAX, we do not allocate unwritten extents, but instead we zero
231 * the block before we commit the transaction. Ideally we'd like to do
232 * this outside the transaction context, but if we commit and then crash
233 * we may not have zeroed the blocks and this will be exposed on
234 * recovery of the allocation. Hence we must zero before commit.
236 * Further, if we are mapping unwritten extents here, we need to zero
237 * and convert them to written so that we don't need an unwritten extent
238 * callback for DAX. This also means that we need to be able to dip into
239 * the reserve block pool for bmbt block allocation if there is no space
240 * left but we need to do unwritten extent conversion.
242 if (IS_DAX(VFS_I(ip
))) {
243 bmapi_flags
= XFS_BMAPI_CONVERT
| XFS_BMAPI_ZERO
;
244 if (imap
->br_state
== XFS_EXT_UNWRITTEN
) {
245 tflags
|= XFS_TRANS_RESERVE
;
246 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0) << 1;
249 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, resrtextents
,
254 lockmode
= XFS_ILOCK_EXCL
;
255 xfs_ilock(ip
, lockmode
);
257 error
= xfs_trans_reserve_quota_nblks(tp
, ip
, qblocks
, 0, quota_flag
);
259 goto out_trans_cancel
;
261 xfs_trans_ijoin(tp
, ip
, 0);
264 * From this point onwards we overwrite the imap pointer that the
267 xfs_defer_init(&dfops
, &firstfsb
);
269 error
= xfs_bmapi_write(tp
, ip
, offset_fsb
, count_fsb
,
270 bmapi_flags
, &firstfsb
, resblks
, imap
,
273 goto out_bmap_cancel
;
276 * Complete the transaction
278 error
= xfs_defer_finish(&tp
, &dfops
);
280 goto out_bmap_cancel
;
282 error
= xfs_trans_commit(tp
);
287 * Copy any maps to caller's array and return any error.
294 if (!(imap
->br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
295 error
= xfs_alert_fsblock_zero(ip
, imap
);
298 xfs_iunlock(ip
, lockmode
);
302 xfs_defer_cancel(&dfops
);
303 xfs_trans_unreserve_quota_nblks(tp
, ip
, (long)qblocks
, 0, quota_flag
);
305 xfs_trans_cancel(tp
);
310 xfs_quota_need_throttle(
311 struct xfs_inode
*ip
,
313 xfs_fsblock_t alloc_blocks
)
315 struct xfs_dquot
*dq
= xfs_inode_dquot(ip
, type
);
317 if (!dq
|| !xfs_this_quota_on(ip
->i_mount
, type
))
320 /* no hi watermark, no throttle */
321 if (!dq
->q_prealloc_hi_wmark
)
324 /* under the lo watermark, no throttle */
325 if (dq
->q_res_bcount
+ alloc_blocks
< dq
->q_prealloc_lo_wmark
)
332 xfs_quota_calc_throttle(
333 struct xfs_inode
*ip
,
335 xfs_fsblock_t
*qblocks
,
341 struct xfs_dquot
*dq
= xfs_inode_dquot(ip
, type
);
343 /* no dq, or over hi wmark, squash the prealloc completely */
344 if (!dq
|| dq
->q_res_bcount
>= dq
->q_prealloc_hi_wmark
) {
350 freesp
= dq
->q_prealloc_hi_wmark
- dq
->q_res_bcount
;
351 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_5_PCNT
]) {
353 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_3_PCNT
])
355 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_1_PCNT
])
359 if (freesp
< *qfreesp
)
362 /* only overwrite the throttle values if we are more aggressive */
363 if ((freesp
>> shift
) < (*qblocks
>> *qshift
)) {
370 * If we are doing a write at the end of the file and there are no allocations
371 * past this one, then extend the allocation out to the file system's write
374 * If we don't have a user specified preallocation size, dynamically increase
375 * the preallocation size as the size of the file grows. Cap the maximum size
376 * at a single extent or less if the filesystem is near full. The closer the
377 * filesystem is to full, the smaller the maximum prealocation.
379 * As an exception we don't do any preallocation at all if the file is smaller
380 * than the minimum preallocation and we are using the default dynamic
381 * preallocation scheme, as it is likely this is the only write to the file that
382 * is going to be done.
384 * We clean up any extra space left over when the file is closed in
388 xfs_iomap_prealloc_size(
389 struct xfs_inode
*ip
,
394 struct xfs_mount
*mp
= ip
->i_mount
;
395 struct xfs_ifork
*ifp
= XFS_IFORK_PTR(ip
, XFS_DATA_FORK
);
396 xfs_fileoff_t offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
397 struct xfs_bmbt_irec prev
;
400 xfs_fsblock_t qblocks
;
402 xfs_fsblock_t alloc_blocks
= 0;
404 if (offset
+ count
<= XFS_ISIZE(ip
))
407 if (!(mp
->m_flags
& XFS_MOUNT_DFLT_IOSIZE
) &&
408 (XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, mp
->m_writeio_blocks
)))
412 * If an explicit allocsize is set, the file is small, or we
413 * are writing behind a hole, then use the minimum prealloc:
415 if ((mp
->m_flags
& XFS_MOUNT_DFLT_IOSIZE
) ||
416 XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, mp
->m_dalign
) ||
417 !xfs_iext_get_extent(ifp
, idx
- 1, &prev
) ||
418 prev
.br_startoff
+ prev
.br_blockcount
< offset_fsb
)
419 return mp
->m_writeio_blocks
;
422 * Determine the initial size of the preallocation. We are beyond the
423 * current EOF here, but we need to take into account whether this is
424 * a sparse write or an extending write when determining the
425 * preallocation size. Hence we need to look up the extent that ends
426 * at the current write offset and use the result to determine the
427 * preallocation size.
429 * If the extent is a hole, then preallocation is essentially disabled.
430 * Otherwise we take the size of the preceding data extent as the basis
431 * for the preallocation size. If the size of the extent is greater than
432 * half the maximum extent length, then use the current offset as the
433 * basis. This ensures that for large files the preallocation size
434 * always extends to MAXEXTLEN rather than falling short due to things
435 * like stripe unit/width alignment of real extents.
437 if (prev
.br_blockcount
<= (MAXEXTLEN
>> 1))
438 alloc_blocks
= prev
.br_blockcount
<< 1;
440 alloc_blocks
= XFS_B_TO_FSB(mp
, offset
);
443 qblocks
= alloc_blocks
;
446 * MAXEXTLEN is not a power of two value but we round the prealloc down
447 * to the nearest power of two value after throttling. To prevent the
448 * round down from unconditionally reducing the maximum supported prealloc
449 * size, we round up first, apply appropriate throttling, round down and
450 * cap the value to MAXEXTLEN.
452 alloc_blocks
= XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN
),
455 freesp
= percpu_counter_read_positive(&mp
->m_fdblocks
);
456 if (freesp
< mp
->m_low_space
[XFS_LOWSP_5_PCNT
]) {
458 if (freesp
< mp
->m_low_space
[XFS_LOWSP_4_PCNT
])
460 if (freesp
< mp
->m_low_space
[XFS_LOWSP_3_PCNT
])
462 if (freesp
< mp
->m_low_space
[XFS_LOWSP_2_PCNT
])
464 if (freesp
< mp
->m_low_space
[XFS_LOWSP_1_PCNT
])
469 * Check each quota to cap the prealloc size, provide a shift value to
470 * throttle with and adjust amount of available space.
472 if (xfs_quota_need_throttle(ip
, XFS_DQ_USER
, alloc_blocks
))
473 xfs_quota_calc_throttle(ip
, XFS_DQ_USER
, &qblocks
, &qshift
,
475 if (xfs_quota_need_throttle(ip
, XFS_DQ_GROUP
, alloc_blocks
))
476 xfs_quota_calc_throttle(ip
, XFS_DQ_GROUP
, &qblocks
, &qshift
,
478 if (xfs_quota_need_throttle(ip
, XFS_DQ_PROJ
, alloc_blocks
))
479 xfs_quota_calc_throttle(ip
, XFS_DQ_PROJ
, &qblocks
, &qshift
,
483 * The final prealloc size is set to the minimum of free space available
484 * in each of the quotas and the overall filesystem.
486 * The shift throttle value is set to the maximum value as determined by
487 * the global low free space values and per-quota low free space values.
489 alloc_blocks
= MIN(alloc_blocks
, qblocks
);
490 shift
= MAX(shift
, qshift
);
493 alloc_blocks
>>= shift
;
495 * rounddown_pow_of_two() returns an undefined result if we pass in
499 alloc_blocks
= rounddown_pow_of_two(alloc_blocks
);
500 if (alloc_blocks
> MAXEXTLEN
)
501 alloc_blocks
= MAXEXTLEN
;
504 * If we are still trying to allocate more space than is
505 * available, squash the prealloc hard. This can happen if we
506 * have a large file on a small filesystem and the above
507 * lowspace thresholds are smaller than MAXEXTLEN.
509 while (alloc_blocks
&& alloc_blocks
>= freesp
)
512 if (alloc_blocks
< mp
->m_writeio_blocks
)
513 alloc_blocks
= mp
->m_writeio_blocks
;
514 trace_xfs_iomap_prealloc_size(ip
, alloc_blocks
, shift
,
515 mp
->m_writeio_blocks
);
520 xfs_file_iomap_begin_delay(
526 struct xfs_inode
*ip
= XFS_I(inode
);
527 struct xfs_mount
*mp
= ip
->i_mount
;
528 struct xfs_ifork
*ifp
= XFS_IFORK_PTR(ip
, XFS_DATA_FORK
);
529 xfs_fileoff_t offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
530 xfs_fileoff_t maxbytes_fsb
=
531 XFS_B_TO_FSB(mp
, mp
->m_super
->s_maxbytes
);
532 xfs_fileoff_t end_fsb
;
533 int error
= 0, eof
= 0;
534 struct xfs_bmbt_irec got
;
536 xfs_fsblock_t prealloc_blocks
= 0;
538 ASSERT(!XFS_IS_REALTIME_INODE(ip
));
539 ASSERT(!xfs_get_extsz_hint(ip
));
541 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
543 if (unlikely(XFS_TEST_ERROR(
544 (XFS_IFORK_FORMAT(ip
, XFS_DATA_FORK
) != XFS_DINODE_FMT_EXTENTS
&&
545 XFS_IFORK_FORMAT(ip
, XFS_DATA_FORK
) != XFS_DINODE_FMT_BTREE
),
546 mp
, XFS_ERRTAG_BMAPIFORMAT
))) {
547 XFS_ERROR_REPORT(__func__
, XFS_ERRLEVEL_LOW
, mp
);
548 error
= -EFSCORRUPTED
;
552 XFS_STATS_INC(mp
, xs_blk_mapw
);
554 if (!(ifp
->if_flags
& XFS_IFEXTENTS
)) {
555 error
= xfs_iread_extents(NULL
, ip
, XFS_DATA_FORK
);
560 eof
= !xfs_iext_lookup_extent(ip
, ifp
, offset_fsb
, &idx
, &got
);
561 if (!eof
&& got
.br_startoff
<= offset_fsb
) {
562 if (xfs_is_reflink_inode(ip
)) {
565 end_fsb
= min(XFS_B_TO_FSB(mp
, offset
+ count
),
567 xfs_trim_extent(&got
, offset_fsb
, end_fsb
- offset_fsb
);
568 error
= xfs_reflink_reserve_cow(ip
, &got
, &shared
);
573 trace_xfs_iomap_found(ip
, offset
, count
, 0, &got
);
577 error
= xfs_qm_dqattach_locked(ip
, 0);
582 * We cap the maximum length we map here to MAX_WRITEBACK_PAGES pages
583 * to keep the chunks of work done where somewhat symmetric with the
584 * work writeback does. This is a completely arbitrary number pulled
585 * out of thin air as a best guess for initial testing.
587 * Note that the values needs to be less than 32-bits wide until
588 * the lower level functions are updated.
590 count
= min_t(loff_t
, count
, 1024 * PAGE_SIZE
);
591 end_fsb
= min(XFS_B_TO_FSB(mp
, offset
+ count
), maxbytes_fsb
);
594 prealloc_blocks
= xfs_iomap_prealloc_size(ip
, offset
, count
, idx
);
595 if (prealloc_blocks
) {
597 xfs_off_t end_offset
;
598 xfs_fileoff_t p_end_fsb
;
600 end_offset
= XFS_WRITEIO_ALIGN(mp
, offset
+ count
- 1);
601 p_end_fsb
= XFS_B_TO_FSBT(mp
, end_offset
) +
604 align
= xfs_eof_alignment(ip
, 0);
606 p_end_fsb
= roundup_64(p_end_fsb
, align
);
608 p_end_fsb
= min(p_end_fsb
, maxbytes_fsb
);
609 ASSERT(p_end_fsb
> offset_fsb
);
610 prealloc_blocks
= p_end_fsb
- end_fsb
;
615 error
= xfs_bmapi_reserve_delalloc(ip
, XFS_DATA_FORK
, offset_fsb
,
616 end_fsb
- offset_fsb
, prealloc_blocks
, &got
, &idx
, eof
);
622 /* retry without any preallocation */
623 trace_xfs_delalloc_enospc(ip
, offset
, count
);
624 if (prealloc_blocks
) {
634 * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
635 * them out if the write happens to fail.
637 iomap
->flags
= IOMAP_F_NEW
;
638 trace_xfs_iomap_alloc(ip
, offset
, count
, 0, &got
);
640 if (isnullstartblock(got
.br_startblock
))
641 got
.br_startblock
= DELAYSTARTBLOCK
;
643 if (!got
.br_startblock
) {
644 error
= xfs_alert_fsblock_zero(ip
, &got
);
649 xfs_bmbt_to_iomap(ip
, iomap
, &got
);
652 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
657 * Pass in a delayed allocate extent, convert it to real extents;
658 * return to the caller the extent we create which maps on top of
659 * the originating callers request.
661 * Called without a lock on the inode.
663 * We no longer bother to look at the incoming map - all we have to
664 * guarantee is that whatever we allocate fills the required range.
667 xfs_iomap_write_allocate(
671 xfs_bmbt_irec_t
*imap
)
673 xfs_mount_t
*mp
= ip
->i_mount
;
674 xfs_fileoff_t offset_fsb
, last_block
;
675 xfs_fileoff_t end_fsb
, map_start_fsb
;
676 xfs_fsblock_t first_block
;
677 struct xfs_defer_ops dfops
;
678 xfs_filblks_t count_fsb
;
682 int flags
= XFS_BMAPI_DELALLOC
;
685 if (whichfork
== XFS_COW_FORK
)
686 flags
|= XFS_BMAPI_COWFORK
| XFS_BMAPI_PREALLOC
;
689 * Make sure that the dquots are there.
691 error
= xfs_qm_dqattach(ip
, 0);
695 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
696 count_fsb
= imap
->br_blockcount
;
697 map_start_fsb
= imap
->br_startoff
;
699 XFS_STATS_ADD(mp
, xs_xstrat_bytes
, XFS_FSB_TO_B(mp
, count_fsb
));
701 while (count_fsb
!= 0) {
703 * Set up a transaction with which to allocate the
704 * backing store for the file. Do allocations in a
705 * loop until we get some space in the range we are
706 * interested in. The other space that might be allocated
707 * is in the delayed allocation extent on which we sit
708 * but before our buffer starts.
711 while (nimaps
== 0) {
712 nres
= XFS_EXTENTADD_SPACE_RES(mp
, XFS_DATA_FORK
);
714 * We have already reserved space for the extent and any
715 * indirect blocks when creating the delalloc extent,
716 * there is no need to reserve space in this transaction
719 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, 0,
720 0, XFS_TRANS_RESERVE
, &tp
);
724 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
725 xfs_trans_ijoin(tp
, ip
, 0);
727 xfs_defer_init(&dfops
, &first_block
);
730 * it is possible that the extents have changed since
731 * we did the read call as we dropped the ilock for a
732 * while. We have to be careful about truncates or hole
733 * punchs here - we are not allowed to allocate
734 * non-delalloc blocks here.
736 * The only protection against truncation is the pages
737 * for the range we are being asked to convert are
738 * locked and hence a truncate will block on them
741 * As a result, if we go beyond the range we really
742 * need and hit an delalloc extent boundary followed by
743 * a hole while we have excess blocks in the map, we
744 * will fill the hole incorrectly and overrun the
745 * transaction reservation.
747 * Using a single map prevents this as we are forced to
748 * check each map we look for overlap with the desired
749 * range and abort as soon as we find it. Also, given
750 * that we only return a single map, having one beyond
751 * what we can return is probably a bit silly.
753 * We also need to check that we don't go beyond EOF;
754 * this is a truncate optimisation as a truncate sets
755 * the new file size before block on the pages we
756 * currently have locked under writeback. Because they
757 * are about to be tossed, we don't need to write them
761 end_fsb
= XFS_B_TO_FSB(mp
, XFS_ISIZE(ip
));
762 error
= xfs_bmap_last_offset(ip
, &last_block
,
767 last_block
= XFS_FILEOFF_MAX(last_block
, end_fsb
);
768 if ((map_start_fsb
+ count_fsb
) > last_block
) {
769 count_fsb
= last_block
- map_start_fsb
;
770 if (count_fsb
== 0) {
777 * From this point onwards we overwrite the imap
778 * pointer that the caller gave to us.
780 error
= xfs_bmapi_write(tp
, ip
, map_start_fsb
,
781 count_fsb
, flags
, &first_block
,
787 error
= xfs_defer_finish(&tp
, &dfops
);
791 error
= xfs_trans_commit(tp
);
795 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
799 * See if we were able to allocate an extent that
800 * covers at least part of the callers request
802 if (!(imap
->br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
803 return xfs_alert_fsblock_zero(ip
, imap
);
805 if ((offset_fsb
>= imap
->br_startoff
) &&
806 (offset_fsb
< (imap
->br_startoff
+
807 imap
->br_blockcount
))) {
808 XFS_STATS_INC(mp
, xs_xstrat_quick
);
813 * So far we have not mapped the requested part of the
814 * file, just surrounding data, try again.
816 count_fsb
-= imap
->br_blockcount
;
817 map_start_fsb
= imap
->br_startoff
+ imap
->br_blockcount
;
821 xfs_defer_cancel(&dfops
);
822 xfs_trans_cancel(tp
);
824 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
829 xfs_iomap_write_unwritten(
835 xfs_mount_t
*mp
= ip
->i_mount
;
836 xfs_fileoff_t offset_fsb
;
837 xfs_filblks_t count_fsb
;
838 xfs_filblks_t numblks_fsb
;
839 xfs_fsblock_t firstfsb
;
842 xfs_bmbt_irec_t imap
;
843 struct xfs_defer_ops dfops
;
844 struct inode
*inode
= VFS_I(ip
);
849 trace_xfs_unwritten_convert(ip
, offset
, count
);
851 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
852 count_fsb
= XFS_B_TO_FSB(mp
, (xfs_ufsize_t
)offset
+ count
);
853 count_fsb
= (xfs_filblks_t
)(count_fsb
- offset_fsb
);
856 * Reserve enough blocks in this transaction for two complete extent
857 * btree splits. We may be converting the middle part of an unwritten
858 * extent and in this case we will insert two new extents in the btree
859 * each of which could cause a full split.
861 * This reservation amount will be used in the first call to
862 * xfs_bmbt_split() to select an AG with enough space to satisfy the
863 * rest of the operation.
865 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0) << 1;
869 * Set up a transaction to convert the range of extents
870 * from unwritten to real. Do allocations in a loop until
871 * we have covered the range passed in.
873 * Note that we can't risk to recursing back into the filesystem
874 * here as we might be asked to write out the same inode that we
875 * complete here and might deadlock on the iolock.
877 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, 0,
878 XFS_TRANS_RESERVE
| XFS_TRANS_NOFS
, &tp
);
882 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
883 xfs_trans_ijoin(tp
, ip
, 0);
886 * Modify the unwritten extent state of the buffer.
888 xfs_defer_init(&dfops
, &firstfsb
);
890 error
= xfs_bmapi_write(tp
, ip
, offset_fsb
, count_fsb
,
891 XFS_BMAPI_CONVERT
, &firstfsb
, resblks
,
892 &imap
, &nimaps
, &dfops
);
894 goto error_on_bmapi_transaction
;
897 * Log the updated inode size as we go. We have to be careful
898 * to only log it up to the actual write offset if it is
899 * halfway into a block.
901 i_size
= XFS_FSB_TO_B(mp
, offset_fsb
+ count_fsb
);
902 if (i_size
> offset
+ count
)
903 i_size
= offset
+ count
;
904 if (update_isize
&& i_size
> i_size_read(inode
))
905 i_size_write(inode
, i_size
);
906 i_size
= xfs_new_eof(ip
, i_size
);
908 ip
->i_d
.di_size
= i_size
;
909 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_CORE
);
912 error
= xfs_defer_finish(&tp
, &dfops
);
914 goto error_on_bmapi_transaction
;
916 error
= xfs_trans_commit(tp
);
917 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
921 if (!(imap
.br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
922 return xfs_alert_fsblock_zero(ip
, &imap
);
924 if ((numblks_fsb
= imap
.br_blockcount
) == 0) {
926 * The numblks_fsb value should always get
927 * smaller, otherwise the loop is stuck.
929 ASSERT(imap
.br_blockcount
);
932 offset_fsb
+= numblks_fsb
;
933 count_fsb
-= numblks_fsb
;
934 } while (count_fsb
> 0);
938 error_on_bmapi_transaction
:
939 xfs_defer_cancel(&dfops
);
940 xfs_trans_cancel(tp
);
941 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
945 static inline bool imap_needs_alloc(struct inode
*inode
,
946 struct xfs_bmbt_irec
*imap
, int nimaps
)
949 imap
->br_startblock
== HOLESTARTBLOCK
||
950 imap
->br_startblock
== DELAYSTARTBLOCK
||
951 (IS_DAX(inode
) && imap
->br_state
== XFS_EXT_UNWRITTEN
);
954 static inline bool need_excl_ilock(struct xfs_inode
*ip
, unsigned flags
)
957 * COW writes will allocate delalloc space, so we need to make sure
958 * to take the lock exclusively here.
960 if (xfs_is_reflink_inode(ip
) && (flags
& (IOMAP_WRITE
| IOMAP_ZERO
)))
962 if ((flags
& IOMAP_DIRECT
) && (flags
& IOMAP_WRITE
))
968 xfs_file_iomap_begin(
975 struct xfs_inode
*ip
= XFS_I(inode
);
976 struct xfs_mount
*mp
= ip
->i_mount
;
977 struct xfs_bmbt_irec imap
;
978 xfs_fileoff_t offset_fsb
, end_fsb
;
979 int nimaps
= 1, error
= 0;
980 bool shared
= false, trimmed
= false;
983 if (XFS_FORCED_SHUTDOWN(mp
))
986 if (((flags
& (IOMAP_WRITE
| IOMAP_DIRECT
)) == IOMAP_WRITE
) &&
987 !IS_DAX(inode
) && !xfs_get_extsz_hint(ip
)) {
988 /* Reserve delalloc blocks for regular writeback. */
989 return xfs_file_iomap_begin_delay(inode
, offset
, length
, iomap
);
992 if (need_excl_ilock(ip
, flags
)) {
993 lockmode
= XFS_ILOCK_EXCL
;
994 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
996 lockmode
= xfs_ilock_data_map_shared(ip
);
999 if ((flags
& IOMAP_NOWAIT
) && !(ip
->i_df
.if_flags
& XFS_IFEXTENTS
)) {
1004 ASSERT(offset
<= mp
->m_super
->s_maxbytes
);
1005 if ((xfs_fsize_t
)offset
+ length
> mp
->m_super
->s_maxbytes
)
1006 length
= mp
->m_super
->s_maxbytes
- offset
;
1007 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1008 end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1010 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
, &imap
,
1015 if (flags
& IOMAP_REPORT
) {
1016 /* Trim the mapping to the nearest shared extent boundary. */
1017 error
= xfs_reflink_trim_around_shared(ip
, &imap
, &shared
,
1023 if ((flags
& (IOMAP_WRITE
| IOMAP_ZERO
)) && xfs_is_reflink_inode(ip
)) {
1024 if (flags
& IOMAP_DIRECT
) {
1026 * A reflinked inode will result in CoW alloc.
1027 * FIXME: It could still overwrite on unshared extents
1028 * and not need allocation.
1030 if (flags
& IOMAP_NOWAIT
) {
1034 /* may drop and re-acquire the ilock */
1035 error
= xfs_reflink_allocate_cow(ip
, &imap
, &shared
,
1040 error
= xfs_reflink_reserve_cow(ip
, &imap
, &shared
);
1045 end_fsb
= imap
.br_startoff
+ imap
.br_blockcount
;
1046 length
= XFS_FSB_TO_B(mp
, end_fsb
) - offset
;
1049 if ((flags
& IOMAP_WRITE
) && imap_needs_alloc(inode
, &imap
, nimaps
)) {
1051 * If nowait is set bail since we are going to make
1054 if (flags
& IOMAP_NOWAIT
) {
1059 * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
1060 * pages to keep the chunks of work done where somewhat symmetric
1061 * with the work writeback does. This is a completely arbitrary
1062 * number pulled out of thin air as a best guess for initial
1065 * Note that the values needs to be less than 32-bits wide until
1066 * the lower level functions are updated.
1068 length
= min_t(loff_t
, length
, 1024 * PAGE_SIZE
);
1070 * xfs_iomap_write_direct() expects the shared lock. It
1071 * is unlocked on return.
1073 if (lockmode
== XFS_ILOCK_EXCL
)
1074 xfs_ilock_demote(ip
, lockmode
);
1075 error
= xfs_iomap_write_direct(ip
, offset
, length
, &imap
,
1080 iomap
->flags
= IOMAP_F_NEW
;
1081 trace_xfs_iomap_alloc(ip
, offset
, length
, 0, &imap
);
1085 xfs_iunlock(ip
, lockmode
);
1086 trace_xfs_iomap_found(ip
, offset
, length
, 0, &imap
);
1089 xfs_bmbt_to_iomap(ip
, iomap
, &imap
);
1092 iomap
->flags
|= IOMAP_F_SHARED
;
1095 xfs_iunlock(ip
, lockmode
);
1100 xfs_file_iomap_end_delalloc(
1101 struct xfs_inode
*ip
,
1105 struct iomap
*iomap
)
1107 struct xfs_mount
*mp
= ip
->i_mount
;
1108 xfs_fileoff_t start_fsb
;
1109 xfs_fileoff_t end_fsb
;
1113 * Behave as if the write failed if drop writes is enabled. Set the NEW
1114 * flag to force delalloc cleanup.
1116 if (XFS_TEST_ERROR(false, mp
, XFS_ERRTAG_DROP_WRITES
)) {
1117 iomap
->flags
|= IOMAP_F_NEW
;
1122 * start_fsb refers to the first unused block after a short write. If
1123 * nothing was written, round offset down to point at the first block in
1126 if (unlikely(!written
))
1127 start_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1129 start_fsb
= XFS_B_TO_FSB(mp
, offset
+ written
);
1130 end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1133 * Trim delalloc blocks if they were allocated by this write and we
1134 * didn't manage to write the whole range.
1136 * We don't need to care about racing delalloc as we hold i_mutex
1137 * across the reserve/allocate/unreserve calls. If there are delalloc
1138 * blocks in the range, they are ours.
1140 if ((iomap
->flags
& IOMAP_F_NEW
) && start_fsb
< end_fsb
) {
1141 truncate_pagecache_range(VFS_I(ip
), XFS_FSB_TO_B(mp
, start_fsb
),
1142 XFS_FSB_TO_B(mp
, end_fsb
) - 1);
1144 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1145 error
= xfs_bmap_punch_delalloc_range(ip
, start_fsb
,
1146 end_fsb
- start_fsb
);
1147 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1149 if (error
&& !XFS_FORCED_SHUTDOWN(mp
)) {
1150 xfs_alert(mp
, "%s: unable to clean up ino %lld",
1151 __func__
, ip
->i_ino
);
1161 struct inode
*inode
,
1166 struct iomap
*iomap
)
1168 if ((flags
& IOMAP_WRITE
) && iomap
->type
== IOMAP_DELALLOC
)
1169 return xfs_file_iomap_end_delalloc(XFS_I(inode
), offset
,
1170 length
, written
, iomap
);
1174 const struct iomap_ops xfs_iomap_ops
= {
1175 .iomap_begin
= xfs_file_iomap_begin
,
1176 .iomap_end
= xfs_file_iomap_end
,
1180 xfs_xattr_iomap_begin(
1181 struct inode
*inode
,
1185 struct iomap
*iomap
)
1187 struct xfs_inode
*ip
= XFS_I(inode
);
1188 struct xfs_mount
*mp
= ip
->i_mount
;
1189 xfs_fileoff_t offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1190 xfs_fileoff_t end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1191 struct xfs_bmbt_irec imap
;
1192 int nimaps
= 1, error
= 0;
1195 if (XFS_FORCED_SHUTDOWN(mp
))
1198 lockmode
= xfs_ilock_attr_map_shared(ip
);
1200 /* if there are no attribute fork or extents, return ENOENT */
1201 if (!XFS_IFORK_Q(ip
) || !ip
->i_d
.di_anextents
) {
1206 ASSERT(ip
->i_d
.di_aformat
!= XFS_DINODE_FMT_LOCAL
);
1207 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
, &imap
,
1208 &nimaps
, XFS_BMAPI_ENTIRE
| XFS_BMAPI_ATTRFORK
);
1210 xfs_iunlock(ip
, lockmode
);
1214 xfs_bmbt_to_iomap(ip
, iomap
, &imap
);
1220 const struct iomap_ops xfs_xattr_iomap_ops
= {
1221 .iomap_begin
= xfs_xattr_iomap_begin
,