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,