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_defer.h"
27 #include "xfs_inode.h"
28 #include "xfs_btree.h"
29 #include "xfs_bmap_btree.h"
31 #include "xfs_bmap_util.h"
32 #include "xfs_error.h"
33 #include "xfs_trans.h"
34 #include "xfs_trans_space.h"
35 #include "xfs_iomap.h"
36 #include "xfs_trace.h"
37 #include "xfs_icache.h"
38 #include "xfs_quota.h"
39 #include "xfs_dquot_item.h"
40 #include "xfs_dquot.h"
43 #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
45 #define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
48 xfs_iomap_eof_align_last_fsb(
52 xfs_fileoff_t
*last_fsb
)
54 xfs_extlen_t align
= 0;
57 if (!XFS_IS_REALTIME_INODE(ip
)) {
59 * Round up the allocation request to a stripe unit
60 * (m_dalign) boundary if the file size is >= stripe unit
61 * size, and we are allocating past the allocation eof.
63 * If mounted with the "-o swalloc" option the alignment is
64 * increased from the strip unit size to the stripe width.
66 if (mp
->m_swidth
&& (mp
->m_flags
& XFS_MOUNT_SWALLOC
))
68 else if (mp
->m_dalign
)
71 if (align
&& XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, align
))
76 * Always round up the allocation request to an extent boundary
77 * (when file on a real-time subvolume or has di_extsize hint).
81 align
= roundup_64(align
, extsize
);
87 xfs_fileoff_t new_last_fsb
= roundup_64(*last_fsb
, align
);
88 error
= xfs_bmap_eof(ip
, new_last_fsb
, XFS_DATA_FORK
, &eof
);
92 *last_fsb
= new_last_fsb
;
98 xfs_alert_fsblock_zero(
100 xfs_bmbt_irec_t
*imap
)
102 xfs_alert_tag(ip
->i_mount
, XFS_PTAG_FSBLOCK_ZERO
,
103 "Access to block zero in inode %llu "
104 "start_block: %llx start_off: %llx "
105 "blkcnt: %llx extent-state: %x",
106 (unsigned long long)ip
->i_ino
,
107 (unsigned long long)imap
->br_startblock
,
108 (unsigned long long)imap
->br_startoff
,
109 (unsigned long long)imap
->br_blockcount
,
111 return -EFSCORRUPTED
;
115 xfs_iomap_write_direct(
119 xfs_bmbt_irec_t
*imap
,
122 xfs_mount_t
*mp
= ip
->i_mount
;
123 xfs_fileoff_t offset_fsb
;
124 xfs_fileoff_t last_fsb
;
125 xfs_filblks_t count_fsb
, resaligned
;
126 xfs_fsblock_t firstfsb
;
127 xfs_extlen_t extsz
, temp
;
132 struct xfs_defer_ops dfops
;
133 uint qblocks
, resblks
, resrtextents
;
136 int bmapi_flags
= XFS_BMAPI_PREALLOC
;
139 rt
= XFS_IS_REALTIME_INODE(ip
);
140 extsz
= xfs_get_extsz_hint(ip
);
141 lockmode
= XFS_ILOCK_SHARED
; /* locked by caller */
143 ASSERT(xfs_isilocked(ip
, lockmode
));
145 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
146 last_fsb
= XFS_B_TO_FSB(mp
, ((xfs_ufsize_t
)(offset
+ count
)));
147 if ((offset
+ count
) > XFS_ISIZE(ip
)) {
149 * Assert that the in-core extent list is present since this can
150 * call xfs_iread_extents() and we only have the ilock shared.
151 * This should be safe because the lock was held around a bmapi
152 * call in the caller and we only need it to access the in-core
155 ASSERT(XFS_IFORK_PTR(ip
, XFS_DATA_FORK
)->if_flags
&
157 error
= xfs_iomap_eof_align_last_fsb(mp
, ip
, extsz
, &last_fsb
);
161 if (nmaps
&& (imap
->br_startblock
== HOLESTARTBLOCK
))
162 last_fsb
= MIN(last_fsb
, (xfs_fileoff_t
)
163 imap
->br_blockcount
+
166 count_fsb
= last_fsb
- offset_fsb
;
167 ASSERT(count_fsb
> 0);
169 resaligned
= count_fsb
;
170 if (unlikely(extsz
)) {
171 if ((temp
= do_mod(offset_fsb
, extsz
)))
173 if ((temp
= do_mod(resaligned
, extsz
)))
174 resaligned
+= extsz
- temp
;
178 resrtextents
= qblocks
= resaligned
;
179 resrtextents
/= mp
->m_sb
.sb_rextsize
;
180 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0);
181 quota_flag
= XFS_QMOPT_RES_RTBLKS
;
184 resblks
= qblocks
= XFS_DIOSTRAT_SPACE_RES(mp
, resaligned
);
185 quota_flag
= XFS_QMOPT_RES_REGBLKS
;
189 * Drop the shared lock acquired by the caller, attach the dquot if
190 * necessary and move on to transaction setup.
192 xfs_iunlock(ip
, lockmode
);
193 error
= xfs_qm_dqattach(ip
, 0);
198 * For DAX, we do not allocate unwritten extents, but instead we zero
199 * the block before we commit the transaction. Ideally we'd like to do
200 * this outside the transaction context, but if we commit and then crash
201 * we may not have zeroed the blocks and this will be exposed on
202 * recovery of the allocation. Hence we must zero before commit.
204 * Further, if we are mapping unwritten extents here, we need to zero
205 * and convert them to written so that we don't need an unwritten extent
206 * callback for DAX. This also means that we need to be able to dip into
207 * the reserve block pool for bmbt block allocation if there is no space
208 * left but we need to do unwritten extent conversion.
210 if (IS_DAX(VFS_I(ip
))) {
211 bmapi_flags
= XFS_BMAPI_CONVERT
| XFS_BMAPI_ZERO
;
212 if (ISUNWRITTEN(imap
)) {
213 tflags
|= XFS_TRANS_RESERVE
;
214 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0) << 1;
217 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, resrtextents
,
222 lockmode
= XFS_ILOCK_EXCL
;
223 xfs_ilock(ip
, lockmode
);
225 error
= xfs_trans_reserve_quota_nblks(tp
, ip
, qblocks
, 0, quota_flag
);
227 goto out_trans_cancel
;
229 xfs_trans_ijoin(tp
, ip
, 0);
232 * From this point onwards we overwrite the imap pointer that the
235 xfs_defer_init(&dfops
, &firstfsb
);
237 error
= xfs_bmapi_write(tp
, ip
, offset_fsb
, count_fsb
,
238 bmapi_flags
, &firstfsb
, resblks
, imap
,
241 goto out_bmap_cancel
;
244 * Complete the transaction
246 error
= xfs_defer_finish(&tp
, &dfops
, NULL
);
248 goto out_bmap_cancel
;
250 error
= xfs_trans_commit(tp
);
255 * Copy any maps to caller's array and return any error.
262 if (!(imap
->br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
263 error
= xfs_alert_fsblock_zero(ip
, imap
);
266 xfs_iunlock(ip
, lockmode
);
270 xfs_defer_cancel(&dfops
);
271 xfs_trans_unreserve_quota_nblks(tp
, ip
, (long)qblocks
, 0, quota_flag
);
273 xfs_trans_cancel(tp
);
278 * If the caller is doing a write at the end of the file, then extend the
279 * allocation out to the file system's write iosize. We clean up any extra
280 * space left over when the file is closed in xfs_inactive().
282 * If we find we already have delalloc preallocation beyond EOF, don't do more
283 * preallocation as it it not needed.
286 xfs_iomap_eof_want_preallocate(
291 xfs_bmbt_irec_t
*imap
,
295 xfs_fileoff_t start_fsb
;
296 xfs_filblks_t count_fsb
;
298 int found_delalloc
= 0;
301 if (offset
+ count
<= XFS_ISIZE(ip
))
305 * If the file is smaller than the minimum prealloc and we are using
306 * dynamic preallocation, don't do any preallocation at all as it is
307 * likely this is the only write to the file that is going to be done.
309 if (!(mp
->m_flags
& XFS_MOUNT_DFLT_IOSIZE
) &&
310 XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, mp
->m_writeio_blocks
))
314 * If there are any real blocks past eof, then don't
315 * do any speculative allocation.
317 start_fsb
= XFS_B_TO_FSBT(mp
, ((xfs_ufsize_t
)(offset
+ count
- 1)));
318 count_fsb
= XFS_B_TO_FSB(mp
, mp
->m_super
->s_maxbytes
);
319 while (count_fsb
> 0) {
321 error
= xfs_bmapi_read(ip
, start_fsb
, count_fsb
, imap
, &imaps
,
325 for (n
= 0; n
< imaps
; n
++) {
326 if ((imap
[n
].br_startblock
!= HOLESTARTBLOCK
) &&
327 (imap
[n
].br_startblock
!= DELAYSTARTBLOCK
))
329 start_fsb
+= imap
[n
].br_blockcount
;
330 count_fsb
-= imap
[n
].br_blockcount
;
332 if (imap
[n
].br_startblock
== DELAYSTARTBLOCK
)
342 * Determine the initial size of the preallocation. We are beyond the current
343 * EOF here, but we need to take into account whether this is a sparse write or
344 * an extending write when determining the preallocation size. Hence we need to
345 * look up the extent that ends at the current write offset and use the result
346 * to determine the preallocation size.
348 * If the extent is a hole, then preallocation is essentially disabled.
349 * Otherwise we take the size of the preceeding data extent as the basis for the
350 * preallocation size. If the size of the extent is greater than half the
351 * maximum extent length, then use the current offset as the basis. This ensures
352 * that for large files the preallocation size always extends to MAXEXTLEN
353 * rather than falling short due to things like stripe unit/width alignment of
357 xfs_iomap_eof_prealloc_initial_size(
358 struct xfs_mount
*mp
,
359 struct xfs_inode
*ip
,
361 xfs_bmbt_irec_t
*imap
,
364 xfs_fileoff_t start_fsb
;
368 ASSERT(nimaps
>= imaps
);
370 /* if we are using a specific prealloc size, return now */
371 if (mp
->m_flags
& XFS_MOUNT_DFLT_IOSIZE
)
374 /* If the file is small, then use the minimum prealloc */
375 if (XFS_ISIZE(ip
) < XFS_FSB_TO_B(mp
, mp
->m_dalign
))
379 * As we write multiple pages, the offset will always align to the
380 * start of a page and hence point to a hole at EOF. i.e. if the size is
381 * 4096 bytes, we only have one block at FSB 0, but XFS_B_TO_FSB(4096)
382 * will return FSB 1. Hence if there are blocks in the file, we want to
383 * point to the block prior to the EOF block and not the hole that maps
384 * directly at @offset.
386 start_fsb
= XFS_B_TO_FSB(mp
, offset
);
389 error
= xfs_bmapi_read(ip
, start_fsb
, 1, imap
, &imaps
, XFS_BMAPI_ENTIRE
);
394 if (imap
[0].br_startblock
== HOLESTARTBLOCK
)
396 if (imap
[0].br_blockcount
<= (MAXEXTLEN
>> 1))
397 return imap
[0].br_blockcount
<< 1;
398 return XFS_B_TO_FSB(mp
, offset
);
402 xfs_quota_need_throttle(
403 struct xfs_inode
*ip
,
405 xfs_fsblock_t alloc_blocks
)
407 struct xfs_dquot
*dq
= xfs_inode_dquot(ip
, type
);
409 if (!dq
|| !xfs_this_quota_on(ip
->i_mount
, type
))
412 /* no hi watermark, no throttle */
413 if (!dq
->q_prealloc_hi_wmark
)
416 /* under the lo watermark, no throttle */
417 if (dq
->q_res_bcount
+ alloc_blocks
< dq
->q_prealloc_lo_wmark
)
424 xfs_quota_calc_throttle(
425 struct xfs_inode
*ip
,
427 xfs_fsblock_t
*qblocks
,
433 struct xfs_dquot
*dq
= xfs_inode_dquot(ip
, type
);
435 /* no dq, or over hi wmark, squash the prealloc completely */
436 if (!dq
|| dq
->q_res_bcount
>= dq
->q_prealloc_hi_wmark
) {
442 freesp
= dq
->q_prealloc_hi_wmark
- dq
->q_res_bcount
;
443 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_5_PCNT
]) {
445 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_3_PCNT
])
447 if (freesp
< dq
->q_low_space
[XFS_QLOWSP_1_PCNT
])
451 if (freesp
< *qfreesp
)
454 /* only overwrite the throttle values if we are more aggressive */
455 if ((freesp
>> shift
) < (*qblocks
>> *qshift
)) {
462 * If we don't have a user specified preallocation size, dynamically increase
463 * the preallocation size as the size of the file grows. Cap the maximum size
464 * at a single extent or less if the filesystem is near full. The closer the
465 * filesystem is to full, the smaller the maximum prealocation.
468 xfs_iomap_prealloc_size(
469 struct xfs_mount
*mp
,
470 struct xfs_inode
*ip
,
472 struct xfs_bmbt_irec
*imap
,
475 xfs_fsblock_t alloc_blocks
= 0;
478 xfs_fsblock_t qblocks
;
481 alloc_blocks
= xfs_iomap_eof_prealloc_initial_size(mp
, ip
, offset
,
485 qblocks
= alloc_blocks
;
488 * MAXEXTLEN is not a power of two value but we round the prealloc down
489 * to the nearest power of two value after throttling. To prevent the
490 * round down from unconditionally reducing the maximum supported prealloc
491 * size, we round up first, apply appropriate throttling, round down and
492 * cap the value to MAXEXTLEN.
494 alloc_blocks
= XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN
),
497 freesp
= percpu_counter_read_positive(&mp
->m_fdblocks
);
498 if (freesp
< mp
->m_low_space
[XFS_LOWSP_5_PCNT
]) {
500 if (freesp
< mp
->m_low_space
[XFS_LOWSP_4_PCNT
])
502 if (freesp
< mp
->m_low_space
[XFS_LOWSP_3_PCNT
])
504 if (freesp
< mp
->m_low_space
[XFS_LOWSP_2_PCNT
])
506 if (freesp
< mp
->m_low_space
[XFS_LOWSP_1_PCNT
])
511 * Check each quota to cap the prealloc size, provide a shift value to
512 * throttle with and adjust amount of available space.
514 if (xfs_quota_need_throttle(ip
, XFS_DQ_USER
, alloc_blocks
))
515 xfs_quota_calc_throttle(ip
, XFS_DQ_USER
, &qblocks
, &qshift
,
517 if (xfs_quota_need_throttle(ip
, XFS_DQ_GROUP
, alloc_blocks
))
518 xfs_quota_calc_throttle(ip
, XFS_DQ_GROUP
, &qblocks
, &qshift
,
520 if (xfs_quota_need_throttle(ip
, XFS_DQ_PROJ
, alloc_blocks
))
521 xfs_quota_calc_throttle(ip
, XFS_DQ_PROJ
, &qblocks
, &qshift
,
525 * The final prealloc size is set to the minimum of free space available
526 * in each of the quotas and the overall filesystem.
528 * The shift throttle value is set to the maximum value as determined by
529 * the global low free space values and per-quota low free space values.
531 alloc_blocks
= MIN(alloc_blocks
, qblocks
);
532 shift
= MAX(shift
, qshift
);
535 alloc_blocks
>>= shift
;
537 * rounddown_pow_of_two() returns an undefined result if we pass in
541 alloc_blocks
= rounddown_pow_of_two(alloc_blocks
);
542 if (alloc_blocks
> MAXEXTLEN
)
543 alloc_blocks
= MAXEXTLEN
;
546 * If we are still trying to allocate more space than is
547 * available, squash the prealloc hard. This can happen if we
548 * have a large file on a small filesystem and the above
549 * lowspace thresholds are smaller than MAXEXTLEN.
551 while (alloc_blocks
&& alloc_blocks
>= freesp
)
555 if (alloc_blocks
< mp
->m_writeio_blocks
)
556 alloc_blocks
= mp
->m_writeio_blocks
;
558 trace_xfs_iomap_prealloc_size(ip
, alloc_blocks
, shift
,
559 mp
->m_writeio_blocks
);
565 xfs_iomap_write_delay(
569 xfs_bmbt_irec_t
*ret_imap
)
571 xfs_mount_t
*mp
= ip
->i_mount
;
572 xfs_fileoff_t offset_fsb
;
573 xfs_fileoff_t last_fsb
;
574 xfs_off_t aligned_offset
;
575 xfs_fileoff_t ioalign
;
578 xfs_bmbt_irec_t imap
[XFS_WRITE_IMAPS
];
582 ASSERT(xfs_isilocked(ip
, XFS_ILOCK_EXCL
));
585 * Make sure that the dquots are there. This doesn't hold
586 * the ilock across a disk read.
588 error
= xfs_qm_dqattach_locked(ip
, 0);
592 extsz
= xfs_get_extsz_hint(ip
);
593 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
595 error
= xfs_iomap_eof_want_preallocate(mp
, ip
, offset
, count
,
596 imap
, XFS_WRITE_IMAPS
, &prealloc
);
602 xfs_fsblock_t alloc_blocks
;
604 alloc_blocks
= xfs_iomap_prealloc_size(mp
, ip
, offset
, imap
,
607 aligned_offset
= XFS_WRITEIO_ALIGN(mp
, (offset
+ count
- 1));
608 ioalign
= XFS_B_TO_FSBT(mp
, aligned_offset
);
609 last_fsb
= ioalign
+ alloc_blocks
;
611 last_fsb
= XFS_B_TO_FSB(mp
, ((xfs_ufsize_t
)(offset
+ count
)));
614 if (prealloc
|| extsz
) {
615 error
= xfs_iomap_eof_align_last_fsb(mp
, ip
, extsz
, &last_fsb
);
621 * Make sure preallocation does not create extents beyond the range we
622 * actually support in this filesystem.
624 if (last_fsb
> XFS_B_TO_FSB(mp
, mp
->m_super
->s_maxbytes
))
625 last_fsb
= XFS_B_TO_FSB(mp
, mp
->m_super
->s_maxbytes
);
627 ASSERT(last_fsb
> offset_fsb
);
629 nimaps
= XFS_WRITE_IMAPS
;
630 error
= xfs_bmapi_delay(ip
, offset_fsb
, last_fsb
- offset_fsb
,
631 imap
, &nimaps
, XFS_BMAPI_ENTIRE
);
642 * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. Retry
643 * without EOF preallocation.
646 trace_xfs_delalloc_enospc(ip
, offset
, count
);
652 return error
? error
: -ENOSPC
;
655 if (!(imap
[0].br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
656 return xfs_alert_fsblock_zero(ip
, &imap
[0]);
659 * Tag the inode as speculatively preallocated so we can reclaim this
660 * space on demand, if necessary.
663 xfs_inode_set_eofblocks_tag(ip
);
670 * Pass in a delayed allocate extent, convert it to real extents;
671 * return to the caller the extent we create which maps on top of
672 * the originating callers request.
674 * Called without a lock on the inode.
676 * We no longer bother to look at the incoming map - all we have to
677 * guarantee is that whatever we allocate fills the required range.
680 xfs_iomap_write_allocate(
683 xfs_bmbt_irec_t
*imap
)
685 xfs_mount_t
*mp
= ip
->i_mount
;
686 xfs_fileoff_t offset_fsb
, last_block
;
687 xfs_fileoff_t end_fsb
, map_start_fsb
;
688 xfs_fsblock_t first_block
;
689 struct xfs_defer_ops dfops
;
690 xfs_filblks_t count_fsb
;
697 * Make sure that the dquots are there.
699 error
= xfs_qm_dqattach(ip
, 0);
703 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
704 count_fsb
= imap
->br_blockcount
;
705 map_start_fsb
= imap
->br_startoff
;
707 XFS_STATS_ADD(mp
, xs_xstrat_bytes
, XFS_FSB_TO_B(mp
, count_fsb
));
709 while (count_fsb
!= 0) {
711 * Set up a transaction with which to allocate the
712 * backing store for the file. Do allocations in a
713 * loop until we get some space in the range we are
714 * interested in. The other space that might be allocated
715 * is in the delayed allocation extent on which we sit
716 * but before our buffer starts.
719 while (nimaps
== 0) {
720 nres
= XFS_EXTENTADD_SPACE_RES(mp
, XFS_DATA_FORK
);
722 * We have already reserved space for the extent and any
723 * indirect blocks when creating the delalloc extent,
724 * there is no need to reserve space in this transaction
727 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, 0,
728 0, XFS_TRANS_RESERVE
, &tp
);
732 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
733 xfs_trans_ijoin(tp
, ip
, 0);
735 xfs_defer_init(&dfops
, &first_block
);
738 * it is possible that the extents have changed since
739 * we did the read call as we dropped the ilock for a
740 * while. We have to be careful about truncates or hole
741 * punchs here - we are not allowed to allocate
742 * non-delalloc blocks here.
744 * The only protection against truncation is the pages
745 * for the range we are being asked to convert are
746 * locked and hence a truncate will block on them
749 * As a result, if we go beyond the range we really
750 * need and hit an delalloc extent boundary followed by
751 * a hole while we have excess blocks in the map, we
752 * will fill the hole incorrectly and overrun the
753 * transaction reservation.
755 * Using a single map prevents this as we are forced to
756 * check each map we look for overlap with the desired
757 * range and abort as soon as we find it. Also, given
758 * that we only return a single map, having one beyond
759 * what we can return is probably a bit silly.
761 * We also need to check that we don't go beyond EOF;
762 * this is a truncate optimisation as a truncate sets
763 * the new file size before block on the pages we
764 * currently have locked under writeback. Because they
765 * are about to be tossed, we don't need to write them
769 end_fsb
= XFS_B_TO_FSB(mp
, XFS_ISIZE(ip
));
770 error
= xfs_bmap_last_offset(ip
, &last_block
,
775 last_block
= XFS_FILEOFF_MAX(last_block
, end_fsb
);
776 if ((map_start_fsb
+ count_fsb
) > last_block
) {
777 count_fsb
= last_block
- map_start_fsb
;
778 if (count_fsb
== 0) {
785 * From this point onwards we overwrite the imap
786 * pointer that the caller gave to us.
788 error
= xfs_bmapi_write(tp
, ip
, map_start_fsb
,
789 count_fsb
, 0, &first_block
,
795 error
= xfs_defer_finish(&tp
, &dfops
, NULL
);
799 error
= xfs_trans_commit(tp
);
803 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
807 * See if we were able to allocate an extent that
808 * covers at least part of the callers request
810 if (!(imap
->br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
811 return xfs_alert_fsblock_zero(ip
, imap
);
813 if ((offset_fsb
>= imap
->br_startoff
) &&
814 (offset_fsb
< (imap
->br_startoff
+
815 imap
->br_blockcount
))) {
816 XFS_STATS_INC(mp
, xs_xstrat_quick
);
821 * So far we have not mapped the requested part of the
822 * file, just surrounding data, try again.
824 count_fsb
-= imap
->br_blockcount
;
825 map_start_fsb
= imap
->br_startoff
+ imap
->br_blockcount
;
829 xfs_defer_cancel(&dfops
);
830 xfs_trans_cancel(tp
);
832 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
837 xfs_iomap_write_unwritten(
842 xfs_mount_t
*mp
= ip
->i_mount
;
843 xfs_fileoff_t offset_fsb
;
844 xfs_filblks_t count_fsb
;
845 xfs_filblks_t numblks_fsb
;
846 xfs_fsblock_t firstfsb
;
849 xfs_bmbt_irec_t imap
;
850 struct xfs_defer_ops dfops
;
855 trace_xfs_unwritten_convert(ip
, offset
, count
);
857 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
858 count_fsb
= XFS_B_TO_FSB(mp
, (xfs_ufsize_t
)offset
+ count
);
859 count_fsb
= (xfs_filblks_t
)(count_fsb
- offset_fsb
);
862 * Reserve enough blocks in this transaction for two complete extent
863 * btree splits. We may be converting the middle part of an unwritten
864 * extent and in this case we will insert two new extents in the btree
865 * each of which could cause a full split.
867 * This reservation amount will be used in the first call to
868 * xfs_bmbt_split() to select an AG with enough space to satisfy the
869 * rest of the operation.
871 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, 0) << 1;
875 * Set up a transaction to convert the range of extents
876 * from unwritten to real. Do allocations in a loop until
877 * we have covered the range passed in.
879 * Note that we can't risk to recursing back into the filesystem
880 * here as we might be asked to write out the same inode that we
881 * complete here and might deadlock on the iolock.
883 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, 0,
884 XFS_TRANS_RESERVE
| XFS_TRANS_NOFS
, &tp
);
888 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
889 xfs_trans_ijoin(tp
, ip
, 0);
892 * Modify the unwritten extent state of the buffer.
894 xfs_defer_init(&dfops
, &firstfsb
);
896 error
= xfs_bmapi_write(tp
, ip
, offset_fsb
, count_fsb
,
897 XFS_BMAPI_CONVERT
, &firstfsb
, resblks
,
898 &imap
, &nimaps
, &dfops
);
900 goto error_on_bmapi_transaction
;
903 * Log the updated inode size as we go. We have to be careful
904 * to only log it up to the actual write offset if it is
905 * halfway into a block.
907 i_size
= XFS_FSB_TO_B(mp
, offset_fsb
+ count_fsb
);
908 if (i_size
> offset
+ count
)
909 i_size
= offset
+ count
;
911 i_size
= xfs_new_eof(ip
, i_size
);
913 ip
->i_d
.di_size
= i_size
;
914 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_CORE
);
917 error
= xfs_defer_finish(&tp
, &dfops
, NULL
);
919 goto error_on_bmapi_transaction
;
921 error
= xfs_trans_commit(tp
);
922 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
926 if (!(imap
.br_startblock
|| XFS_IS_REALTIME_INODE(ip
)))
927 return xfs_alert_fsblock_zero(ip
, &imap
);
929 if ((numblks_fsb
= imap
.br_blockcount
) == 0) {
931 * The numblks_fsb value should always get
932 * smaller, otherwise the loop is stuck.
934 ASSERT(imap
.br_blockcount
);
937 offset_fsb
+= numblks_fsb
;
938 count_fsb
-= numblks_fsb
;
939 } while (count_fsb
> 0);
943 error_on_bmapi_transaction
:
944 xfs_defer_cancel(&dfops
);
945 xfs_trans_cancel(tp
);
946 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
952 struct xfs_inode
*ip
,
954 struct xfs_bmbt_irec
*imap
)
956 struct xfs_mount
*mp
= ip
->i_mount
;
958 if (imap
->br_startblock
== HOLESTARTBLOCK
) {
959 iomap
->blkno
= IOMAP_NULL_BLOCK
;
960 iomap
->type
= IOMAP_HOLE
;
961 } else if (imap
->br_startblock
== DELAYSTARTBLOCK
) {
962 iomap
->blkno
= IOMAP_NULL_BLOCK
;
963 iomap
->type
= IOMAP_DELALLOC
;
965 iomap
->blkno
= xfs_fsb_to_db(ip
, imap
->br_startblock
);
966 if (imap
->br_state
== XFS_EXT_UNWRITTEN
)
967 iomap
->type
= IOMAP_UNWRITTEN
;
969 iomap
->type
= IOMAP_MAPPED
;
971 iomap
->offset
= XFS_FSB_TO_B(mp
, imap
->br_startoff
);
972 iomap
->length
= XFS_FSB_TO_B(mp
, imap
->br_blockcount
);
973 iomap
->bdev
= xfs_find_bdev_for_inode(VFS_I(ip
));
976 static inline bool imap_needs_alloc(struct xfs_bmbt_irec
*imap
, int nimaps
)
979 imap
->br_startblock
== HOLESTARTBLOCK
||
980 imap
->br_startblock
== DELAYSTARTBLOCK
;
984 xfs_file_iomap_begin(
991 struct xfs_inode
*ip
= XFS_I(inode
);
992 struct xfs_mount
*mp
= ip
->i_mount
;
993 struct xfs_bmbt_irec imap
;
994 xfs_fileoff_t offset_fsb
, end_fsb
;
995 int nimaps
= 1, error
= 0;
997 if (XFS_FORCED_SHUTDOWN(mp
))
1000 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1002 ASSERT(offset
<= mp
->m_super
->s_maxbytes
);
1003 if ((xfs_fsize_t
)offset
+ length
> mp
->m_super
->s_maxbytes
)
1004 length
= mp
->m_super
->s_maxbytes
- offset
;
1005 offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1006 end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1008 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
, &imap
,
1009 &nimaps
, XFS_BMAPI_ENTIRE
);
1011 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1015 if ((flags
& IOMAP_WRITE
) && imap_needs_alloc(&imap
, nimaps
)) {
1017 * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
1018 * pages to keep the chunks of work done where somewhat symmetric
1019 * with the work writeback does. This is a completely arbitrary
1020 * number pulled out of thin air as a best guess for initial
1023 * Note that the values needs to be less than 32-bits wide until
1024 * the lower level functions are updated.
1026 length
= min_t(loff_t
, length
, 1024 * PAGE_SIZE
);
1027 if (xfs_get_extsz_hint(ip
)) {
1029 * xfs_iomap_write_direct() expects the shared lock. It
1030 * is unlocked on return.
1032 xfs_ilock_demote(ip
, XFS_ILOCK_EXCL
);
1033 error
= xfs_iomap_write_direct(ip
, offset
, length
, &imap
,
1036 error
= xfs_iomap_write_delay(ip
, offset
, length
, &imap
);
1037 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1043 trace_xfs_iomap_alloc(ip
, offset
, length
, 0, &imap
);
1047 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1048 trace_xfs_iomap_found(ip
, offset
, length
, 0, &imap
);
1051 xfs_bmbt_to_iomap(ip
, iomap
, &imap
);
1056 xfs_file_iomap_end_delalloc(
1057 struct xfs_inode
*ip
,
1062 struct xfs_mount
*mp
= ip
->i_mount
;
1063 xfs_fileoff_t start_fsb
;
1064 xfs_fileoff_t end_fsb
;
1067 start_fsb
= XFS_B_TO_FSB(mp
, offset
+ written
);
1068 end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1071 * Trim back delalloc blocks if we didn't manage to write the whole
1074 * We don't need to care about racing delalloc as we hold i_mutex
1075 * across the reserve/allocate/unreserve calls. If there are delalloc
1076 * blocks in the range, they are ours.
1078 if (start_fsb
< end_fsb
) {
1079 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1080 error
= xfs_bmap_punch_delalloc_range(ip
, start_fsb
,
1081 end_fsb
- start_fsb
);
1082 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1084 if (error
&& !XFS_FORCED_SHUTDOWN(mp
)) {
1085 xfs_alert(mp
, "%s: unable to clean up ino %lld",
1086 __func__
, ip
->i_ino
);
1096 struct inode
*inode
,
1101 struct iomap
*iomap
)
1103 if ((flags
& IOMAP_WRITE
) && iomap
->type
== IOMAP_DELALLOC
)
1104 return xfs_file_iomap_end_delalloc(XFS_I(inode
), offset
,
1109 struct iomap_ops xfs_iomap_ops
= {
1110 .iomap_begin
= xfs_file_iomap_begin
,
1111 .iomap_end
= xfs_file_iomap_end
,
1115 xfs_xattr_iomap_begin(
1116 struct inode
*inode
,
1120 struct iomap
*iomap
)
1122 struct xfs_inode
*ip
= XFS_I(inode
);
1123 struct xfs_mount
*mp
= ip
->i_mount
;
1124 xfs_fileoff_t offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
1125 xfs_fileoff_t end_fsb
= XFS_B_TO_FSB(mp
, offset
+ length
);
1126 struct xfs_bmbt_irec imap
;
1127 int nimaps
= 1, error
= 0;
1130 if (XFS_FORCED_SHUTDOWN(mp
))
1133 lockmode
= xfs_ilock_data_map_shared(ip
);
1135 /* if there are no attribute fork or extents, return ENOENT */
1136 if (XFS_IFORK_Q(ip
) || !ip
->i_d
.di_anextents
) {
1141 ASSERT(ip
->i_d
.di_aformat
!= XFS_DINODE_FMT_LOCAL
);
1142 error
= xfs_bmapi_read(ip
, offset_fsb
, end_fsb
- offset_fsb
, &imap
,
1143 &nimaps
, XFS_BMAPI_ENTIRE
| XFS_BMAPI_ATTRFORK
);
1145 xfs_iunlock(ip
, lockmode
);
1149 xfs_bmbt_to_iomap(ip
, iomap
, &imap
);
1155 struct iomap_ops xfs_xattr_iomap_ops
= {
1156 .iomap_begin
= xfs_xattr_iomap_begin
,