2 * Copyright (c) 2000-2006 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
18 #include <linux/iomap.h>
21 #include "xfs_shared.h"
22 #include "xfs_format.h"
23 #include "xfs_log_format.h"
24 #include "xfs_trans_resv.h"
25 #include "xfs_mount.h"
26 #include "xfs_inode.h"
27 #include "xfs_btree.h"
28 #include "xfs_bmap_btree.h"
30 #include "xfs_bmap_util.h"
31 #include "xfs_error.h"
32 #include "xfs_trans.h"
33 #include "xfs_trans_space.h"
34 #include "xfs_iomap.h"
35 #include "xfs_trace.h"
36 #include "xfs_icache.h"
37 #include "xfs_quota.h"
38 #include "xfs_dquot_item.h"
39 #include "xfs_dquot.h"
42 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
44 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
47 xfs_iomap_eof_align_last_fsb(
51 xfs_fileoff_t
*last_fsb
)
53 xfs_extlen_t align
= 0;
56 if (!XFS_IS_REALTIME_INODE(ip
)) {
58 * Round up the allocation request to a stripe unit
59 * (m_dalign) boundary if the file size is >= stripe unit
60 * size, and we are allocating past the allocation eof.
62 * If mounted with the "-o swalloc" option the alignment is
63 * increased from the strip unit size to the stripe width.
65 if (mp
->m_swidth
&& (mp
->m_flags
& XFS_MOUNT_SWALLOC
))
67 else if (mp
->m_dalign
)
70 if (align
&& XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, align
))
75 * Always round up the allocation request to an extent boundary
76 * (when file on a real-time subvolume or has di_extsize hint).
80 align
= roundup_64(align
, extsize
);
86 xfs_fileoff_t new_last_fsb
= roundup_64(*last_fsb
, align
);
87 error
= xfs_bmap_eof(ip
, new_last_fsb
, XFS_DATA_FORK
, &eof
);
91 *last_fsb
= new_last_fsb
;
97 xfs_alert_fsblock_zero(
99 xfs_bmbt_irec_t
*imap
)
101 xfs_alert_tag(ip
->i_mount
, XFS_PTAG_FSBLOCK_ZERO
,
102 "Access to block zero in inode %llu "
103 "start_block: %llx start_off: %llx "
104 "blkcnt: %llx extent-state: %x",
105 (unsigned long long)ip
->i_ino
,
106 (unsigned long long)imap
->br_startblock
,
107 (unsigned long long)imap
->br_startoff
,
108 (unsigned long long)imap
->br_blockcount
,
110 return -EFSCORRUPTED
;
114 xfs_iomap_write_direct(
118 xfs_bmbt_irec_t
*imap
,
121 xfs_mount_t
*mp
= ip
->i_mount
;
122 xfs_fileoff_t offset_fsb
;
123 xfs_fileoff_t last_fsb
;
124 xfs_filblks_t count_fsb
, resaligned
;
125 xfs_fsblock_t firstfsb
;
126 xfs_extlen_t extsz
, temp
;
131 xfs_bmap_free_t free_list
;
132 uint qblocks
, resblks
, resrtextents
;
135 int bmapi_flags
= XFS_BMAPI_PREALLOC
;
138 rt
= XFS_IS_REALTIME_INODE(ip
);
139 extsz
= xfs_get_extsz_hint(ip
);
140 lockmode
= XFS_ILOCK_SHARED
; /* locked by caller */
142 ASSERT(xfs_isilocked(ip
, lockmode
));
144 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
145 last_fsb
= XFS_B_TO_FSB(mp
, ((xfs_ufsize_t
)(offset
+ count
)));
146 if ((offset
+ count
) > XFS_ISIZE(ip
)) {
148 * Assert that the in-core extent list is present since this can
149 * call xfs_iread_extents() and we only have the ilock shared.
150 * This should be safe because the lock was held around a bmapi
151 * call in the caller and we only need it to access the in-core
154 ASSERT(XFS_IFORK_PTR(ip
, XFS_DATA_FORK
)->if_flags
&
156 error
= xfs_iomap_eof_align_last_fsb(mp
, ip
, extsz
, &last_fsb
);
160 if (nmaps
&& (imap
->br_startblock
== HOLESTARTBLOCK
))
161 last_fsb
= MIN(last_fsb
, (xfs_fileoff_t
)
162 imap
->br_blockcount
+
165 count_fsb
= last_fsb
- offset_fsb
;
166 ASSERT(count_fsb
> 0);
168 resaligned
= count_fsb
;
169 if (unlikely(extsz
)) {
170 if ((temp
= do_mod(offset_fsb
, extsz
)))
172 if ((temp
= do_mod(resaligned
, extsz
)))
173 resaligned
+= extsz
- temp
;
177 resrtextents
= qblocks
= resaligned
;
178 resrtextents
/= mp
->m_sb
.sb_rextsize
;
179 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0);
180 quota_flag
= XFS_QMOPT_RES_RTBLKS
;
183 resblks
= qblocks
= XFS_DIOSTRAT_SPACE_RES(mp
, resaligned
);
184 quota_flag
= XFS_QMOPT_RES_REGBLKS
;
188 * Drop the shared lock acquired by the caller, attach the dquot if
189 * necessary and move on to transaction setup.
191 xfs_iunlock(ip
, lockmode
);
192 error
= xfs_qm_dqattach(ip
, 0);
197 * For DAX, we do not allocate unwritten extents, but instead we zero
198 * the block before we commit the transaction. Ideally we'd like to do
199 * this outside the transaction context, but if we commit and then crash
200 * we may not have zeroed the blocks and this will be exposed on
201 * recovery of the allocation. Hence we must zero before commit.
203 * Further, if we are mapping unwritten extents here, we need to zero
204 * and convert them to written so that we don't need an unwritten extent
205 * callback for DAX. This also means that we need to be able to dip into
206 * the reserve block pool for bmbt block allocation if there is no space
207 * left but we need to do unwritten extent conversion.
209 if (IS_DAX(VFS_I(ip
))) {
210 bmapi_flags
= XFS_BMAPI_CONVERT
| XFS_BMAPI_ZERO
;
211 if (ISUNWRITTEN(imap
)) {
212 tflags
|= XFS_TRANS_RESERVE
;
213 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0) << 1;
216 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, resrtextents
,
221 lockmode
= XFS_ILOCK_EXCL
;
222 xfs_ilock(ip
, lockmode
);
224 error
= xfs_trans_reserve_quota_nblks(tp
, ip
, qblocks
, 0, quota_flag
);
226 goto out_trans_cancel
;
228 xfs_trans_ijoin(tp
, ip
, 0);
231 * From this point onwards we overwrite the imap pointer that the
234 xfs_bmap_init(&free_list
, &firstfsb
);
236 error
= xfs_bmapi_write(tp
, ip
, offset_fsb
, count_fsb
,
237 bmapi_flags
, &firstfsb
, resblks
, imap
,
238 &nimaps
, &free_list
);
240 goto out_bmap_cancel
;
243 * Complete the transaction
245 error
= xfs_bmap_finish(&tp
, &free_list
, NULL
);
247 goto out_bmap_cancel
;
249 error
= xfs_trans_commit(tp
);
254 * Copy any maps to caller's array and return any error.
261 if (!(imap
->br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
262 error
= xfs_alert_fsblock_zero(ip
, imap
);
265 xfs_iunlock(ip
, lockmode
);
269 xfs_bmap_cancel(&free_list
);
270 xfs_trans_unreserve_quota_nblks(tp
, ip
, (long)qblocks
, 0, quota_flag
);
272 xfs_trans_cancel(tp
);
277 * If the caller is doing a write at the end of the file, then extend the
278 * allocation out to the file system's write iosize. We clean up any extra
279 * space left over when the file is closed in xfs_inactive().
281 * If we find we already have delalloc preallocation beyond EOF, don't do more
282 * preallocation as it it not needed.
285 xfs_iomap_eof_want_preallocate(
290 xfs_bmbt_irec_t
*imap
,
294 xfs_fileoff_t start_fsb
;
295 xfs_filblks_t count_fsb
;
297 int found_delalloc
= 0;
300 if (offset
+ count
<= XFS_ISIZE(ip
))
304 * If the file is smaller than the minimum prealloc and we are using
305 * dynamic preallocation, don't do any preallocation at all as it is
306 * likely this is the only write to the file that is going to be done.
308 if (!(mp
->m_flags
& XFS_MOUNT_DFLT_IOSIZE
) &&
309 XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, mp
->m_writeio_blocks
))
313 * If there are any real blocks past eof, then don't
314 * do any speculative allocation.
316 start_fsb
= XFS_B_TO_FSBT(mp
, ((xfs_ufsize_t
)(offset
+ count
- 1)));
317 count_fsb
= XFS_B_TO_FSB(mp
, mp
->m_super
->s_maxbytes
);
318 while (count_fsb
> 0) {
320 error
= xfs_bmapi_read(ip
, start_fsb
, count_fsb
, imap
, &imaps
,
324 for (n
= 0; n
< imaps
; n
++) {
325 if ((imap
[n
].br_startblock
!= HOLESTARTBLOCK
) &&
326 (imap
[n
].br_startblock
!= DELAYSTARTBLOCK
))
328 start_fsb
+= imap
[n
].br_blockcount
;
329 count_fsb
-= imap
[n
].br_blockcount
;
331 if (imap
[n
].br_startblock
== DELAYSTARTBLOCK
)
341 * Determine the initial size of the preallocation. We are beyond the current
342 * EOF here, but we need to take into account whether this is a sparse write or
343 * an extending write when determining the preallocation size. Hence we need to
344 * look up the extent that ends at the current write offset and use the result
345 * to determine the preallocation size.
347 * If the extent is a hole, then preallocation is essentially disabled.
348 * Otherwise we take the size of the preceeding data extent as the basis for the
349 * preallocation size. If the size of the extent is greater than half the
350 * maximum extent length, then use the current offset as the basis. This ensures
351 * that for large files the preallocation size always extends to MAXEXTLEN
352 * rather than falling short due to things like stripe unit/width alignment of
356 xfs_iomap_eof_prealloc_initial_size(
357 struct xfs_mount
*mp
,
358 struct xfs_inode
*ip
,
360 xfs_bmbt_irec_t
*imap
,
363 xfs_fileoff_t start_fsb
;
367 ASSERT(nimaps
>= imaps
);
369 /* if we are using a specific prealloc size, return now */
370 if (mp
->m_flags
& XFS_MOUNT_DFLT_IOSIZE
)
373 /* If the file is small, then use the minimum prealloc */
374 if (XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, mp
->m_dalign
))
378 * As we write multiple pages, the offset will always align to the
379 * start of a page and hence point to a hole at EOF. i.e. if the size is
380 * 4096 bytes, we only have one block at FSB 0, but XFS_B_TO_FSB(4096)
381 * will return FSB 1. Hence if there are blocks in the file, we want to
382 * point to the block prior to the EOF block and not the hole that maps
383 * directly at @offset.
385 start_fsb
= XFS_B_TO_FSB(mp
, offset
);
388 error
= xfs_bmapi_read(ip
, start_fsb
, 1, imap
, &imaps
, XFS_BMAPI_ENTIRE
);
393 if (imap
[0].br_startblock
== HOLESTARTBLOCK
)
395 if (imap
[0].br_blockcount
<= (MAXEXTLEN
>> 1))
396 return imap
[0].br_blockcount
<< 1;
397 return XFS_B_TO_FSB(mp
, offset
);
401 xfs_quota_need_throttle(
402 struct xfs_inode
*ip
,
404 xfs_fsblock_t alloc_blocks
)
406 struct xfs_dquot
*dq
= xfs_inode_dquot(ip
, type
);
408 if (!dq
|| !xfs_this_quota_on(ip
->i_mount
, type
))
411 /* no hi watermark, no throttle */
412 if (!dq
->q_prealloc_hi_wmark
)
415 /* under the lo watermark, no throttle */
416 if (dq
->q_res_bcount
+ alloc_blocks
< dq
->q_prealloc_lo_wmark
)
423 xfs_quota_calc_throttle(
424 struct xfs_inode
*ip
,
426 xfs_fsblock_t
*qblocks
,
432 struct xfs_dquot
*dq
= xfs_inode_dquot(ip
, type
);
434 /* no dq, or over hi wmark, squash the prealloc completely */
435 if (!dq
|| dq
->q_res_bcount
>= dq
->q_prealloc_hi_wmark
) {
441 freesp
= dq
->q_prealloc_hi_wmark
- dq
->q_res_bcount
;
442 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_5_PCNT
]) {
444 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_3_PCNT
])
446 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_1_PCNT
])
450 if (freesp
< *qfreesp
)
453 /* only overwrite the throttle values if we are more aggressive */
454 if ((freesp
>> shift
) < (*qblocks
>> *qshift
)) {
461 * If we don't have a user specified preallocation size, dynamically increase
462 * the preallocation size as the size of the file grows. Cap the maximum size
463 * at a single extent or less if the filesystem is near full. The closer the
464 * filesystem is to full, the smaller the maximum prealocation.
467 xfs_iomap_prealloc_size(
468 struct xfs_mount
*mp
,
469 struct xfs_inode
*ip
,
471 struct xfs_bmbt_irec
*imap
,
474 xfs_fsblock_t alloc_blocks
= 0;
477 xfs_fsblock_t qblocks
;
480 alloc_blocks
= xfs_iomap_eof_prealloc_initial_size(mp
, ip
, offset
,
484 qblocks
= alloc_blocks
;
487 * MAXEXTLEN is not a power of two value but we round the prealloc down
488 * to the nearest power of two value after throttling. To prevent the
489 * round down from unconditionally reducing the maximum supported prealloc
490 * size, we round up first, apply appropriate throttling, round down and
491 * cap the value to MAXEXTLEN.
493 alloc_blocks
= XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN
),
496 freesp
= percpu_counter_read_positive(&mp
->m_fdblocks
);
497 if (freesp
< mp
->m_low_space
[XFS_LOWSP_5_PCNT
]) {
499 if (freesp
< mp
->m_low_space
[XFS_LOWSP_4_PCNT
])
501 if (freesp
< mp
->m_low_space
[XFS_LOWSP_3_PCNT
])
503 if (freesp
< mp
->m_low_space
[XFS_LOWSP_2_PCNT
])
505 if (freesp
< mp
->m_low_space
[XFS_LOWSP_1_PCNT
])
510 * Check each quota to cap the prealloc size, provide a shift value to
511 * throttle with and adjust amount of available space.
513 if (xfs_quota_need_throttle(ip
, XFS_DQ_USER
, alloc_blocks
))
514 xfs_quota_calc_throttle(ip
, XFS_DQ_USER
, &qblocks
, &qshift
,
516 if (xfs_quota_need_throttle(ip
, XFS_DQ_GROUP
, alloc_blocks
))
517 xfs_quota_calc_throttle(ip
, XFS_DQ_GROUP
, &qblocks
, &qshift
,
519 if (xfs_quota_need_throttle(ip
, XFS_DQ_PROJ
, alloc_blocks
))
520 xfs_quota_calc_throttle(ip
, XFS_DQ_PROJ
, &qblocks
, &qshift
,
524 * The final prealloc size is set to the minimum of free space available
525 * in each of the quotas and the overall filesystem.
527 * The shift throttle value is set to the maximum value as determined by
528 * the global low free space values and per-quota low free space values.
530 alloc_blocks
= MIN(alloc_blocks
, qblocks
);
531 shift
= MAX(shift
, qshift
);
534 alloc_blocks
>>= shift
;
536 * rounddown_pow_of_two() returns an undefined result if we pass in
540 alloc_blocks
= rounddown_pow_of_two(alloc_blocks
);
541 if (alloc_blocks
> MAXEXTLEN
)
542 alloc_blocks
= MAXEXTLEN
;
545 * If we are still trying to allocate more space than is
546 * available, squash the prealloc hard. This can happen if we
547 * have a large file on a small filesystem and the above
548 * lowspace thresholds are smaller than MAXEXTLEN.
550 while (alloc_blocks
&& alloc_blocks
>= freesp
)
554 if (alloc_blocks
< mp
->m_writeio_blocks
)
555 alloc_blocks
= mp
->m_writeio_blocks
;
557 trace_xfs_iomap_prealloc_size(ip
, alloc_blocks
, shift
,
558 mp
->m_writeio_blocks
);
564 xfs_iomap_write_delay(
568 xfs_bmbt_irec_t
*ret_imap
)
570 xfs_mount_t
*mp
= ip
->i_mount
;
571 xfs_fileoff_t offset_fsb
;
572 xfs_fileoff_t last_fsb
;
573 xfs_off_t aligned_offset
;
574 xfs_fileoff_t ioalign
;
577 xfs_bmbt_irec_t imap
[XFS_WRITE_IMAPS
];
581 ASSERT(xfs_isilocked(ip
, XFS_ILOCK_EXCL
));
584 * Make sure that the dquots are there. This doesn't hold
585 * the ilock across a disk read.
587 error
= xfs_qm_dqattach_locked(ip
, 0);
591 extsz
= xfs_get_extsz_hint(ip
);
592 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
594 error
= xfs_iomap_eof_want_preallocate(mp
, ip
, offset
, count
,
595 imap
, XFS_WRITE_IMAPS
, &prealloc
);
601 xfs_fsblock_t alloc_blocks
;
603 alloc_blocks
= xfs_iomap_prealloc_size(mp
, ip
, offset
, imap
,
606 aligned_offset
= XFS_WRITEIO_ALIGN(mp
, (offset
+ count
- 1));
607 ioalign
= XFS_B_TO_FSBT(mp
, aligned_offset
);
608 last_fsb
= ioalign
+ alloc_blocks
;
610 last_fsb
= XFS_B_TO_FSB(mp
, ((xfs_ufsize_t
)(offset
+ count
)));
613 if (prealloc
|| extsz
) {
614 error
= xfs_iomap_eof_align_last_fsb(mp
, ip
, extsz
, &last_fsb
);
620 * Make sure preallocation does not create extents beyond the range we
621 * actually support in this filesystem.
623 if (last_fsb
> XFS_B_TO_FSB(mp
, mp
->m_super
->s_maxbytes
))
624 last_fsb
= XFS_B_TO_FSB(mp
, mp
->m_super
->s_maxbytes
);
626 ASSERT(last_fsb
> offset_fsb
);
628 nimaps
= XFS_WRITE_IMAPS
;
629 error
= xfs_bmapi_delay(ip
, offset_fsb
, last_fsb
- offset_fsb
,
630 imap
, &nimaps
, XFS_BMAPI_ENTIRE
);
641 * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. Retry
642 * without EOF preallocation.
645 trace_xfs_delalloc_enospc(ip
, offset
, count
);
651 return error
? error
: -ENOSPC
;
654 if (!(imap
[0].br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
655 return xfs_alert_fsblock_zero(ip
, &imap
[0]);
658 * Tag the inode as speculatively preallocated so we can reclaim this
659 * space on demand, if necessary.
662 xfs_inode_set_eofblocks_tag(ip
);
669 * Pass in a delayed allocate extent, convert it to real extents;
670 * return to the caller the extent we create which maps on top of
671 * the originating callers request.
673 * Called without a lock on the inode.
675 * We no longer bother to look at the incoming map - all we have to
676 * guarantee is that whatever we allocate fills the required range.
679 xfs_iomap_write_allocate(
682 xfs_bmbt_irec_t
*imap
)
684 xfs_mount_t
*mp
= ip
->i_mount
;
685 xfs_fileoff_t offset_fsb
, last_block
;
686 xfs_fileoff_t end_fsb
, map_start_fsb
;
687 xfs_fsblock_t first_block
;
688 xfs_bmap_free_t free_list
;
689 xfs_filblks_t count_fsb
;
696 * Make sure that the dquots are there.
698 error
= xfs_qm_dqattach(ip
, 0);
702 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
703 count_fsb
= imap
->br_blockcount
;
704 map_start_fsb
= imap
->br_startoff
;
706 XFS_STATS_ADD(mp
, xs_xstrat_bytes
, XFS_FSB_TO_B(mp
, count_fsb
));
708 while (count_fsb
!= 0) {
710 * Set up a transaction with which to allocate the
711 * backing store for the file. Do allocations in a
712 * loop until we get some space in the range we are
713 * interested in. The other space that might be allocated
714 * is in the delayed allocation extent on which we sit
715 * but before our buffer starts.
719 while (nimaps
== 0) {
720 nres
= XFS_EXTENTADD_SPACE_RES(mp
, XFS_DATA_FORK
);
722 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, nres
,
723 0, XFS_TRANS_RESERVE
, &tp
);
727 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
728 xfs_trans_ijoin(tp
, ip
, 0);
730 xfs_bmap_init(&free_list
, &first_block
);
733 * it is possible that the extents have changed since
734 * we did the read call as we dropped the ilock for a
735 * while. We have to be careful about truncates or hole
736 * punchs here - we are not allowed to allocate
737 * non-delalloc blocks here.
739 * The only protection against truncation is the pages
740 * for the range we are being asked to convert are
741 * locked and hence a truncate will block on them
744 * As a result, if we go beyond the range we really
745 * need and hit an delalloc extent boundary followed by
746 * a hole while we have excess blocks in the map, we
747 * will fill the hole incorrectly and overrun the
748 * transaction reservation.
750 * Using a single map prevents this as we are forced to
751 * check each map we look for overlap with the desired
752 * range and abort as soon as we find it. Also, given
753 * that we only return a single map, having one beyond
754 * what we can return is probably a bit silly.
756 * We also need to check that we don't go beyond EOF;
757 * this is a truncate optimisation as a truncate sets
758 * the new file size before block on the pages we
759 * currently have locked under writeback. Because they
760 * are about to be tossed, we don't need to write them
764 end_fsb
= XFS_B_TO_FSB(mp
, XFS_ISIZE(ip
));
765 error
= xfs_bmap_last_offset(ip
, &last_block
,
770 last_block
= XFS_FILEOFF_MAX(last_block
, end_fsb
);
771 if ((map_start_fsb
+ count_fsb
) > last_block
) {
772 count_fsb
= last_block
- map_start_fsb
;
773 if (count_fsb
== 0) {
780 * From this point onwards we overwrite the imap
781 * pointer that the caller gave to us.
783 error
= xfs_bmapi_write(tp
, ip
, map_start_fsb
,
784 count_fsb
, 0, &first_block
,
790 error
= xfs_bmap_finish(&tp
, &free_list
, NULL
);
794 error
= xfs_trans_commit(tp
);
798 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
802 * See if we were able to allocate an extent that
803 * covers at least part of the callers request
805 if (!(imap
->br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
806 return xfs_alert_fsblock_zero(ip
, imap
);
808 if ((offset_fsb
>= imap
->br_startoff
) &&
809 (offset_fsb
< (imap
->br_startoff
+
810 imap
->br_blockcount
))) {
811 XFS_STATS_INC(mp
, xs_xstrat_quick
);
816 * So far we have not mapped the requested part of the
817 * file, just surrounding data, try again.
819 count_fsb
-= imap
->br_blockcount
;
820 map_start_fsb
= imap
->br_startoff
+ imap
->br_blockcount
;
824 xfs_bmap_cancel(&free_list
);
825 xfs_trans_cancel(tp
);
827 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
832 xfs_iomap_write_unwritten(
837 xfs_mount_t
*mp
= ip
->i_mount
;
838 xfs_fileoff_t offset_fsb
;
839 xfs_filblks_t count_fsb
;
840 xfs_filblks_t numblks_fsb
;
841 xfs_fsblock_t firstfsb
;
844 xfs_bmbt_irec_t imap
;
845 xfs_bmap_free_t free_list
;
850 trace_xfs_unwritten_convert(ip
, offset
, count
);
852 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
853 count_fsb
= XFS_B_TO_FSB(mp
, (xfs_ufsize_t
)offset
+ count
);
854 count_fsb
= (xfs_filblks_t
)(count_fsb
- offset_fsb
);
857 * Reserve enough blocks in this transaction for two complete extent
858 * btree splits. We may be converting the middle part of an unwritten
859 * extent and in this case we will insert two new extents in the btree
860 * each of which could cause a full split.
862 * This reservation amount will be used in the first call to
863 * xfs_bmbt_split() to select an AG with enough space to satisfy the
864 * rest of the operation.
866 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0) << 1;
870 * Set up a transaction to convert the range of extents
871 * from unwritten to real. Do allocations in a loop until
872 * we have covered the range passed in.
874 * Note that we can't risk to recursing back into the filesystem
875 * here as we might be asked to write out the same inode that we
876 * complete here and might deadlock on the iolock.
878 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, 0,
879 XFS_TRANS_RESERVE
| XFS_TRANS_NOFS
, &tp
);
883 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
884 xfs_trans_ijoin(tp
, ip
, 0);
887 * Modify the unwritten extent state of the buffer.
889 xfs_bmap_init(&free_list
, &firstfsb
);
891 error
= xfs_bmapi_write(tp
, ip
, offset_fsb
, count_fsb
,
892 XFS_BMAPI_CONVERT
, &firstfsb
, resblks
,
893 &imap
, &nimaps
, &free_list
);
895 goto error_on_bmapi_transaction
;
898 * Log the updated inode size as we go. We have to be careful
899 * to only log it up to the actual write offset if it is
900 * halfway into a block.
902 i_size
= XFS_FSB_TO_B(mp
, offset_fsb
+ count_fsb
);
903 if (i_size
> offset
+ count
)
904 i_size
= offset
+ count
;
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_bmap_finish(&tp
, &free_list
, NULL
);
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_bmap_cancel(&free_list
);
940 xfs_trans_cancel(tp
);
941 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
947 struct xfs_inode
*ip
,
949 struct xfs_bmbt_irec
*imap
)
951 struct xfs_mount
*mp
= ip
->i_mount
;
953 if (imap
->br_startblock
== HOLESTARTBLOCK
) {
954 iomap
->blkno
= IOMAP_NULL_BLOCK
;
955 iomap
->type
= IOMAP_HOLE
;
956 } else if (imap
->br_startblock
== DELAYSTARTBLOCK
) {
957 iomap
->blkno
= IOMAP_NULL_BLOCK
;
958 iomap
->type
= IOMAP_DELALLOC
;
960 iomap
->blkno
= xfs_fsb_to_db(ip
, imap
->br_startblock
);
961 if (imap
->br_state
== XFS_EXT_UNWRITTEN
)
962 iomap
->type
= IOMAP_UNWRITTEN
;
964 iomap
->type
= IOMAP_MAPPED
;
966 iomap
->offset
= XFS_FSB_TO_B(mp
, imap
->br_startoff
);
967 iomap
->length
= XFS_FSB_TO_B(mp
, imap
->br_blockcount
);
968 iomap
->bdev
= xfs_find_bdev_for_inode(VFS_I(ip
));
971 static inline bool imap_needs_alloc(struct xfs_bmbt_irec
*imap
, int nimaps
)
974 imap
->br_startblock
== HOLESTARTBLOCK
||
975 imap
->br_startblock
== DELAYSTARTBLOCK
;
979 xfs_file_iomap_begin(
986 struct xfs_inode
*ip
= XFS_I(inode
);
987 struct xfs_mount
*mp
= ip
->i_mount
;
988 struct xfs_bmbt_irec imap
;
989 xfs_fileoff_t offset_fsb
, end_fsb
;
990 int nimaps
= 1, error
= 0;
992 if (XFS_FORCED_SHUTDOWN(mp
))
995 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
997 ASSERT(offset
<= mp
->m_super
->s_maxbytes
);
998 if ((xfs_fsize_t
)offset
+ length
> mp
->m_super
->s_maxbytes
)
999 length
= mp
->m_super
->s_maxbytes
- offset
;
1000 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1001 end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1003 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
, &imap
,
1004 &nimaps
, XFS_BMAPI_ENTIRE
);
1006 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1010 if ((flags
& IOMAP_WRITE
) && imap_needs_alloc(&imap
, nimaps
)) {
1012 * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
1013 * pages to keep the chunks of work done where somewhat symmetric
1014 * with the work writeback does. This is a completely arbitrary
1015 * number pulled out of thin air as a best guess for initial
1018 * Note that the values needs to be less than 32-bits wide until
1019 * the lower level functions are updated.
1021 length
= min_t(loff_t
, length
, 1024 * PAGE_SIZE
);
1022 if (xfs_get_extsz_hint(ip
)) {
1024 * xfs_iomap_write_direct() expects the shared lock. It
1025 * is unlocked on return.
1027 xfs_ilock_demote(ip
, XFS_ILOCK_EXCL
);
1028 error
= xfs_iomap_write_direct(ip
, offset
, length
, &imap
,
1031 error
= xfs_iomap_write_delay(ip
, offset
, length
, &imap
);
1032 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1038 trace_xfs_iomap_alloc(ip
, offset
, length
, 0, &imap
);
1039 xfs_bmbt_to_iomap(ip
, iomap
, &imap
);
1040 } else if (nimaps
) {
1041 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1042 trace_xfs_iomap_found(ip
, offset
, length
, 0, &imap
);
1043 xfs_bmbt_to_iomap(ip
, iomap
, &imap
);
1045 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1046 trace_xfs_iomap_not_found(ip
, offset
, length
, 0, &imap
);
1047 iomap
->blkno
= IOMAP_NULL_BLOCK
;
1048 iomap
->type
= IOMAP_HOLE
;
1049 iomap
->offset
= offset
;
1050 iomap
->length
= length
;
1057 xfs_file_iomap_end_delalloc(
1058 struct xfs_inode
*ip
,
1063 struct xfs_mount
*mp
= ip
->i_mount
;
1064 xfs_fileoff_t start_fsb
;
1065 xfs_fileoff_t end_fsb
;
1068 start_fsb
= XFS_B_TO_FSB(mp
, offset
+ written
);
1069 end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1072 * Trim back delalloc blocks if we didn't manage to write the whole
1075 * We don't need to care about racing delalloc as we hold i_mutex
1076 * across the reserve/allocate/unreserve calls. If there are delalloc
1077 * blocks in the range, they are ours.
1079 if (start_fsb
< end_fsb
) {
1080 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1081 error
= xfs_bmap_punch_delalloc_range(ip
, start_fsb
,
1082 end_fsb
- start_fsb
);
1083 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1085 if (error
&& !XFS_FORCED_SHUTDOWN(mp
)) {
1086 xfs_alert(mp
, "%s: unable to clean up ino %lld",
1087 __func__
, ip
->i_ino
);
1097 struct inode
*inode
,
1102 struct iomap
*iomap
)
1104 if ((flags
& IOMAP_WRITE
) && iomap
->type
== IOMAP_DELALLOC
)
1105 return xfs_file_iomap_end_delalloc(XFS_I(inode
), offset
,
1110 struct iomap_ops xfs_iomap_ops
= {
1111 .iomap_begin
= xfs_file_iomap_begin
,
1112 .iomap_end
= xfs_file_iomap_end
,