2 * Copyright (C) 2016 Oracle. All Rights Reserved.
4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it would be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
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_da_format.h"
29 #include "xfs_da_btree.h"
30 #include "xfs_inode.h"
31 #include "xfs_trans.h"
32 #include "xfs_inode_item.h"
34 #include "xfs_bmap_util.h"
35 #include "xfs_error.h"
37 #include "xfs_dir2_priv.h"
38 #include "xfs_ioctl.h"
39 #include "xfs_trace.h"
41 #include "xfs_icache.h"
43 #include "xfs_btree.h"
44 #include "xfs_refcount_btree.h"
45 #include "xfs_refcount.h"
46 #include "xfs_bmap_btree.h"
47 #include "xfs_trans_space.h"
49 #include "xfs_alloc.h"
50 #include "xfs_quota_defs.h"
51 #include "xfs_quota.h"
52 #include "xfs_reflink.h"
53 #include "xfs_iomap.h"
54 #include "xfs_rmap_btree.h"
56 #include "xfs_ag_resv.h"
59 * Copy on Write of Shared Blocks
61 * XFS must preserve "the usual" file semantics even when two files share
62 * the same physical blocks. This means that a write to one file must not
63 * alter the blocks in a different file; the way that we'll do that is
64 * through the use of a copy-on-write mechanism. At a high level, that
65 * means that when we want to write to a shared block, we allocate a new
66 * block, write the data to the new block, and if that succeeds we map the
67 * new block into the file.
69 * XFS provides a "delayed allocation" mechanism that defers the allocation
70 * of disk blocks to dirty-but-not-yet-mapped file blocks as long as
71 * possible. This reduces fragmentation by enabling the filesystem to ask
72 * for bigger chunks less often, which is exactly what we want for CoW.
74 * The delalloc mechanism begins when the kernel wants to make a block
75 * writable (write_begin or page_mkwrite). If the offset is not mapped, we
76 * create a delalloc mapping, which is a regular in-core extent, but without
77 * a real startblock. (For delalloc mappings, the startblock encodes both
78 * a flag that this is a delalloc mapping, and a worst-case estimate of how
79 * many blocks might be required to put the mapping into the BMBT.) delalloc
80 * mappings are a reservation against the free space in the filesystem;
81 * adjacent mappings can also be combined into fewer larger mappings.
83 * As an optimization, the CoW extent size hint (cowextsz) creates
84 * outsized aligned delalloc reservations in the hope of landing out of
85 * order nearby CoW writes in a single extent on disk, thereby reducing
86 * fragmentation and improving future performance.
88 * D: --RRRRRRSSSRRRRRRRR--- (data fork)
89 * C: ------DDDDDDD--------- (CoW fork)
91 * When dirty pages are being written out (typically in writepage), the
92 * delalloc reservations are converted into unwritten mappings by
93 * allocating blocks and replacing the delalloc mapping with real ones.
94 * A delalloc mapping can be replaced by several unwritten ones if the
95 * free space is fragmented.
97 * D: --RRRRRRSSSRRRRRRRR---
98 * C: ------UUUUUUU---------
100 * We want to adapt the delalloc mechanism for copy-on-write, since the
101 * write paths are similar. The first two steps (creating the reservation
102 * and allocating the blocks) are exactly the same as delalloc except that
103 * the mappings must be stored in a separate CoW fork because we do not want
104 * to disturb the mapping in the data fork until we're sure that the write
105 * succeeded. IO completion in this case is the process of removing the old
106 * mapping from the data fork and moving the new mapping from the CoW fork to
107 * the data fork. This will be discussed shortly.
109 * For now, unaligned directio writes will be bounced back to the page cache.
110 * Block-aligned directio writes will use the same mechanism as buffered
113 * Just prior to submitting the actual disk write requests, we convert
114 * the extents representing the range of the file actually being written
115 * (as opposed to extra pieces created for the cowextsize hint) to real
116 * extents. This will become important in the next step:
118 * D: --RRRRRRSSSRRRRRRRR---
119 * C: ------UUrrUUU---------
121 * CoW remapping must be done after the data block write completes,
122 * because we don't want to destroy the old data fork map until we're sure
123 * the new block has been written. Since the new mappings are kept in a
124 * separate fork, we can simply iterate these mappings to find the ones
125 * that cover the file blocks that we just CoW'd. For each extent, simply
126 * unmap the corresponding range in the data fork, map the new range into
127 * the data fork, and remove the extent from the CoW fork. Because of
128 * the presence of the cowextsize hint, however, we must be careful
129 * only to remap the blocks that we've actually written out -- we must
130 * never remap delalloc reservations nor CoW staging blocks that have
131 * yet to be written. This corresponds exactly to the real extents in
134 * D: --RRRRRRrrSRRRRRRRR---
135 * C: ------UU--UUU---------
137 * Since the remapping operation can be applied to an arbitrary file
138 * range, we record the need for the remap step as a flag in the ioend
139 * instead of declaring a new IO type. This is required for direct io
140 * because we only have ioend for the whole dio, and we have to be able to
141 * remember the presence of unwritten blocks and CoW blocks with a single
142 * ioend structure. Better yet, the more ground we can cover with one
147 * Given an AG extent, find the lowest-numbered run of shared blocks
148 * within that range and return the range in fbno/flen. If
149 * find_end_of_shared is true, return the longest contiguous extent of
150 * shared blocks. If there are no shared extents, fbno and flen will
151 * be set to NULLAGBLOCK and 0, respectively.
154 xfs_reflink_find_shared(
155 struct xfs_mount
*mp
,
156 struct xfs_trans
*tp
,
162 bool find_end_of_shared
)
164 struct xfs_buf
*agbp
;
165 struct xfs_btree_cur
*cur
;
168 error
= xfs_alloc_read_agf(mp
, tp
, agno
, 0, &agbp
);
174 cur
= xfs_refcountbt_init_cursor(mp
, tp
, agbp
, agno
, NULL
);
176 error
= xfs_refcount_find_shared(cur
, agbno
, aglen
, fbno
, flen
,
179 xfs_btree_del_cursor(cur
, error
? XFS_BTREE_ERROR
: XFS_BTREE_NOERROR
);
181 xfs_trans_brelse(tp
, agbp
);
186 * Trim the mapping to the next block where there's a change in the
187 * shared/unshared status. More specifically, this means that we
188 * find the lowest-numbered extent of shared blocks that coincides with
189 * the given block mapping. If the shared extent overlaps the start of
190 * the mapping, trim the mapping to the end of the shared extent. If
191 * the shared region intersects the mapping, trim the mapping to the
192 * start of the shared extent. If there are no shared regions that
193 * overlap, just return the original extent.
196 xfs_reflink_trim_around_shared(
197 struct xfs_inode
*ip
,
198 struct xfs_bmbt_irec
*irec
,
209 /* Holes, unwritten, and delalloc extents cannot be shared */
210 if (!xfs_is_reflink_inode(ip
) || !xfs_bmap_is_real_extent(irec
)) {
215 trace_xfs_reflink_trim_around_shared(ip
, irec
);
217 agno
= XFS_FSB_TO_AGNO(ip
->i_mount
, irec
->br_startblock
);
218 agbno
= XFS_FSB_TO_AGBNO(ip
->i_mount
, irec
->br_startblock
);
219 aglen
= irec
->br_blockcount
;
221 error
= xfs_reflink_find_shared(ip
->i_mount
, NULL
, agno
, agbno
,
222 aglen
, &fbno
, &flen
, true);
226 *shared
= *trimmed
= false;
227 if (fbno
== NULLAGBLOCK
) {
228 /* No shared blocks at all. */
230 } else if (fbno
== agbno
) {
232 * The start of this extent is shared. Truncate the
233 * mapping at the end of the shared region so that a
234 * subsequent iteration starts at the start of the
237 irec
->br_blockcount
= flen
;
244 * There's a shared extent midway through this extent.
245 * Truncate the mapping at the start of the shared
246 * extent so that a subsequent iteration starts at the
247 * start of the shared region.
249 irec
->br_blockcount
= fbno
- agbno
;
256 * Trim the passed in imap to the next shared/unshared extent boundary, and
257 * if imap->br_startoff points to a shared extent reserve space for it in the
258 * COW fork. In this case *shared is set to true, else to false.
260 * Note that imap will always contain the block numbers for the existing blocks
261 * in the data fork, as the upper layers need them for read-modify-write
265 xfs_reflink_reserve_cow(
266 struct xfs_inode
*ip
,
267 struct xfs_bmbt_irec
*imap
,
270 struct xfs_ifork
*ifp
= XFS_IFORK_PTR(ip
, XFS_COW_FORK
);
271 struct xfs_bmbt_irec got
;
273 bool eof
= false, trimmed
;
274 struct xfs_iext_cursor icur
;
277 * Search the COW fork extent list first. This serves two purposes:
278 * first this implement the speculative preallocation using cowextisze,
279 * so that we also unshared block adjacent to shared blocks instead
280 * of just the shared blocks themselves. Second the lookup in the
281 * extent list is generally faster than going out to the shared extent
285 if (!xfs_iext_lookup_extent(ip
, ifp
, imap
->br_startoff
, &icur
, &got
))
287 if (!eof
&& got
.br_startoff
<= imap
->br_startoff
) {
288 trace_xfs_reflink_cow_found(ip
, imap
);
289 xfs_trim_extent(imap
, got
.br_startoff
, got
.br_blockcount
);
295 /* Trim the mapping to the nearest shared extent boundary. */
296 error
= xfs_reflink_trim_around_shared(ip
, imap
, shared
, &trimmed
);
300 /* Not shared? Just report the (potentially capped) extent. */
305 * Fork all the shared blocks from our write offset until the end of
308 error
= xfs_qm_dqattach_locked(ip
, 0);
312 error
= xfs_bmapi_reserve_delalloc(ip
, XFS_COW_FORK
, imap
->br_startoff
,
313 imap
->br_blockcount
, 0, &got
, &icur
, eof
);
314 if (error
== -ENOSPC
|| error
== -EDQUOT
)
315 trace_xfs_reflink_cow_enospc(ip
, imap
);
319 trace_xfs_reflink_cow_alloc(ip
, &got
);
323 /* Convert part of an unwritten CoW extent to a real one. */
325 xfs_reflink_convert_cow_extent(
326 struct xfs_inode
*ip
,
327 struct xfs_bmbt_irec
*imap
,
328 xfs_fileoff_t offset_fsb
,
329 xfs_filblks_t count_fsb
,
330 struct xfs_defer_ops
*dfops
)
332 xfs_fsblock_t first_block
= NULLFSBLOCK
;
335 if (imap
->br_state
== XFS_EXT_NORM
)
338 xfs_trim_extent(imap
, offset_fsb
, count_fsb
);
339 trace_xfs_reflink_convert_cow(ip
, imap
);
340 if (imap
->br_blockcount
== 0)
342 return xfs_bmapi_write(NULL
, ip
, imap
->br_startoff
, imap
->br_blockcount
,
343 XFS_BMAPI_COWFORK
| XFS_BMAPI_CONVERT
, &first_block
,
344 0, imap
, &nimaps
, dfops
);
347 /* Convert all of the unwritten CoW extents in a file's range to real ones. */
349 xfs_reflink_convert_cow(
350 struct xfs_inode
*ip
,
354 struct xfs_mount
*mp
= ip
->i_mount
;
355 xfs_fileoff_t offset_fsb
= XFS_B_TO_FSBT(mp
, offset
);
356 xfs_fileoff_t end_fsb
= XFS_B_TO_FSB(mp
, offset
+ count
);
357 xfs_filblks_t count_fsb
= end_fsb
- offset_fsb
;
358 struct xfs_bmbt_irec imap
;
359 struct xfs_defer_ops dfops
;
360 xfs_fsblock_t first_block
= NULLFSBLOCK
;
361 int nimaps
= 1, error
= 0;
365 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
366 error
= xfs_bmapi_write(NULL
, ip
, offset_fsb
, count_fsb
,
367 XFS_BMAPI_COWFORK
| XFS_BMAPI_CONVERT
|
368 XFS_BMAPI_CONVERT_ONLY
, &first_block
, 0, &imap
, &nimaps
,
370 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
374 /* Allocate all CoW reservations covering a range of blocks in a file. */
376 xfs_reflink_allocate_cow(
377 struct xfs_inode
*ip
,
378 struct xfs_bmbt_irec
*imap
,
382 struct xfs_mount
*mp
= ip
->i_mount
;
383 xfs_fileoff_t offset_fsb
= imap
->br_startoff
;
384 xfs_filblks_t count_fsb
= imap
->br_blockcount
;
385 struct xfs_bmbt_irec got
;
386 struct xfs_defer_ops dfops
;
387 struct xfs_trans
*tp
= NULL
;
388 xfs_fsblock_t first_block
;
389 int nimaps
, error
= 0;
391 xfs_filblks_t resaligned
;
392 xfs_extlen_t resblks
= 0;
393 struct xfs_iext_cursor icur
;
396 ASSERT(xfs_is_reflink_inode(ip
));
397 ASSERT(xfs_isilocked(ip
, XFS_ILOCK_EXCL
| XFS_ILOCK_SHARED
));
400 * Even if the extent is not shared we might have a preallocation for
401 * it in the COW fork. If so use it.
403 if (xfs_iext_lookup_extent(ip
, ip
->i_cowfp
, offset_fsb
, &icur
, &got
) &&
404 got
.br_startoff
<= offset_fsb
) {
407 /* If we have a real allocation in the COW fork we're done. */
408 if (!isnullstartblock(got
.br_startblock
)) {
409 xfs_trim_extent(&got
, offset_fsb
, count_fsb
);
414 xfs_trim_extent(imap
, got
.br_startoff
, got
.br_blockcount
);
416 error
= xfs_reflink_trim_around_shared(ip
, imap
, shared
, &trimmed
);
417 if (error
|| !*shared
)
422 resaligned
= xfs_aligned_fsb_count(imap
->br_startoff
,
423 imap
->br_blockcount
, xfs_get_cowextsz_hint(ip
));
424 resblks
= XFS_DIOSTRAT_SPACE_RES(mp
, resaligned
);
426 xfs_iunlock(ip
, *lockmode
);
427 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, 0, 0, &tp
);
428 *lockmode
= XFS_ILOCK_EXCL
;
429 xfs_ilock(ip
, *lockmode
);
434 error
= xfs_qm_dqattach_locked(ip
, 0);
440 error
= xfs_trans_reserve_quota_nblks(tp
, ip
, resblks
, 0,
441 XFS_QMOPT_RES_REGBLKS
);
445 xfs_trans_ijoin(tp
, ip
, 0);
447 xfs_defer_init(&dfops
, &first_block
);
450 /* Allocate the entire reservation as unwritten blocks. */
451 error
= xfs_bmapi_write(tp
, ip
, imap
->br_startoff
, imap
->br_blockcount
,
452 XFS_BMAPI_COWFORK
| XFS_BMAPI_PREALLOC
, &first_block
,
453 resblks
, imap
, &nimaps
, &dfops
);
455 goto out_bmap_cancel
;
457 xfs_inode_set_cowblocks_tag(ip
);
460 error
= xfs_defer_finish(&tp
, &dfops
);
462 goto out_bmap_cancel
;
464 error
= xfs_trans_commit(tp
);
468 return xfs_reflink_convert_cow_extent(ip
, imap
, offset_fsb
, count_fsb
,
471 xfs_defer_cancel(&dfops
);
472 xfs_trans_unreserve_quota_nblks(tp
, ip
, (long)resblks
, 0,
473 XFS_QMOPT_RES_REGBLKS
);
476 xfs_trans_cancel(tp
);
481 * Find the CoW reservation for a given byte offset of a file.
484 xfs_reflink_find_cow_mapping(
485 struct xfs_inode
*ip
,
487 struct xfs_bmbt_irec
*imap
)
489 struct xfs_ifork
*ifp
= XFS_IFORK_PTR(ip
, XFS_COW_FORK
);
490 xfs_fileoff_t offset_fsb
;
491 struct xfs_bmbt_irec got
;
492 struct xfs_iext_cursor icur
;
494 ASSERT(xfs_isilocked(ip
, XFS_ILOCK_EXCL
| XFS_ILOCK_SHARED
));
496 if (!xfs_is_reflink_inode(ip
))
498 offset_fsb
= XFS_B_TO_FSBT(ip
->i_mount
, offset
);
499 if (!xfs_iext_lookup_extent(ip
, ifp
, offset_fsb
, &icur
, &got
))
501 if (got
.br_startoff
> offset_fsb
)
504 trace_xfs_reflink_find_cow_mapping(ip
, offset
, 1, XFS_IO_OVERWRITE
,
511 * Trim an extent to end at the next CoW reservation past offset_fsb.
514 xfs_reflink_trim_irec_to_next_cow(
515 struct xfs_inode
*ip
,
516 xfs_fileoff_t offset_fsb
,
517 struct xfs_bmbt_irec
*imap
)
519 struct xfs_ifork
*ifp
= XFS_IFORK_PTR(ip
, XFS_COW_FORK
);
520 struct xfs_bmbt_irec got
;
521 struct xfs_iext_cursor icur
;
523 if (!xfs_is_reflink_inode(ip
))
526 /* Find the extent in the CoW fork. */
527 if (!xfs_iext_lookup_extent(ip
, ifp
, offset_fsb
, &icur
, &got
))
530 /* This is the extent before; try sliding up one. */
531 if (got
.br_startoff
< offset_fsb
) {
532 if (!xfs_iext_next_extent(ifp
, &icur
, &got
))
536 if (got
.br_startoff
>= imap
->br_startoff
+ imap
->br_blockcount
)
539 imap
->br_blockcount
= got
.br_startoff
- imap
->br_startoff
;
540 trace_xfs_reflink_trim_irec(ip
, imap
);
544 * Cancel CoW reservations for some block range of an inode.
546 * If cancel_real is true this function cancels all COW fork extents for the
547 * inode; if cancel_real is false, real extents are not cleared.
550 xfs_reflink_cancel_cow_blocks(
551 struct xfs_inode
*ip
,
552 struct xfs_trans
**tpp
,
553 xfs_fileoff_t offset_fsb
,
554 xfs_fileoff_t end_fsb
,
557 struct xfs_ifork
*ifp
= XFS_IFORK_PTR(ip
, XFS_COW_FORK
);
558 struct xfs_bmbt_irec got
, del
;
559 struct xfs_iext_cursor icur
;
560 xfs_fsblock_t firstfsb
;
561 struct xfs_defer_ops dfops
;
564 if (!xfs_is_reflink_inode(ip
))
566 if (!xfs_iext_lookup_extent_before(ip
, ifp
, &end_fsb
, &icur
, &got
))
569 /* Walk backwards until we're out of the I/O range... */
570 while (got
.br_startoff
+ got
.br_blockcount
> offset_fsb
) {
572 xfs_trim_extent(&del
, offset_fsb
, end_fsb
- offset_fsb
);
574 /* Extent delete may have bumped ext forward */
575 if (!del
.br_blockcount
) {
576 xfs_iext_prev(ifp
, &icur
);
580 trace_xfs_reflink_cancel_cow(ip
, &del
);
582 if (isnullstartblock(del
.br_startblock
)) {
583 error
= xfs_bmap_del_extent_delay(ip
, XFS_COW_FORK
,
587 } else if (del
.br_state
== XFS_EXT_UNWRITTEN
|| cancel_real
) {
588 xfs_trans_ijoin(*tpp
, ip
, 0);
589 xfs_defer_init(&dfops
, &firstfsb
);
591 /* Free the CoW orphan record. */
592 error
= xfs_refcount_free_cow_extent(ip
->i_mount
,
593 &dfops
, del
.br_startblock
,
598 xfs_bmap_add_free(ip
->i_mount
, &dfops
,
599 del
.br_startblock
, del
.br_blockcount
,
602 /* Update quota accounting */
603 xfs_trans_mod_dquot_byino(*tpp
, ip
, XFS_TRANS_DQ_BCOUNT
,
604 -(long)del
.br_blockcount
);
606 /* Roll the transaction */
607 xfs_defer_ijoin(&dfops
, ip
);
608 error
= xfs_defer_finish(tpp
, &dfops
);
610 xfs_defer_cancel(&dfops
);
614 /* Remove the mapping from the CoW fork. */
615 xfs_bmap_del_extent_cow(ip
, &icur
, &got
, &del
);
617 /* Didn't do anything, push cursor back. */
618 xfs_iext_prev(ifp
, &icur
);
621 if (!xfs_iext_get_extent(ifp
, &icur
, &got
))
625 /* clear tag if cow fork is emptied */
627 xfs_inode_clear_cowblocks_tag(ip
);
633 * Cancel CoW reservations for some byte range of an inode.
635 * If cancel_real is true this function cancels all COW fork extents for the
636 * inode; if cancel_real is false, real extents are not cleared.
639 xfs_reflink_cancel_cow_range(
640 struct xfs_inode
*ip
,
645 struct xfs_trans
*tp
;
646 xfs_fileoff_t offset_fsb
;
647 xfs_fileoff_t end_fsb
;
650 trace_xfs_reflink_cancel_cow_range(ip
, offset
, count
);
651 ASSERT(xfs_is_reflink_inode(ip
));
653 offset_fsb
= XFS_B_TO_FSBT(ip
->i_mount
, offset
);
654 if (count
== NULLFILEOFF
)
655 end_fsb
= NULLFILEOFF
;
657 end_fsb
= XFS_B_TO_FSB(ip
->i_mount
, offset
+ count
);
659 /* Start a rolling transaction to remove the mappings */
660 error
= xfs_trans_alloc(ip
->i_mount
, &M_RES(ip
->i_mount
)->tr_write
,
665 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
666 xfs_trans_ijoin(tp
, ip
, 0);
668 /* Scrape out the old CoW reservations */
669 error
= xfs_reflink_cancel_cow_blocks(ip
, &tp
, offset_fsb
, end_fsb
,
674 error
= xfs_trans_commit(tp
);
676 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
680 xfs_trans_cancel(tp
);
681 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
683 trace_xfs_reflink_cancel_cow_range_error(ip
, error
, _RET_IP_
);
688 * Remap parts of a file's data fork after a successful CoW.
692 struct xfs_inode
*ip
,
696 struct xfs_ifork
*ifp
= XFS_IFORK_PTR(ip
, XFS_COW_FORK
);
697 struct xfs_bmbt_irec got
, del
;
698 struct xfs_trans
*tp
;
699 xfs_fileoff_t offset_fsb
;
700 xfs_fileoff_t end_fsb
;
701 xfs_fsblock_t firstfsb
;
702 struct xfs_defer_ops dfops
;
704 unsigned int resblks
;
706 struct xfs_iext_cursor icur
;
708 trace_xfs_reflink_end_cow(ip
, offset
, count
);
710 /* No COW extents? That's easy! */
711 if (ifp
->if_bytes
== 0)
714 offset_fsb
= XFS_B_TO_FSBT(ip
->i_mount
, offset
);
715 end_fsb
= XFS_B_TO_FSB(ip
->i_mount
, offset
+ count
);
718 * Start a rolling transaction to switch the mappings. We're
719 * unlikely ever to have to remap 16T worth of single-block
720 * extents, so just cap the worst case extent count to 2^32-1.
721 * Stick a warning in just in case, and avoid 64-bit division.
723 BUILD_BUG_ON(MAX_RW_COUNT
> UINT_MAX
);
724 if (end_fsb
- offset_fsb
> UINT_MAX
) {
725 error
= -EFSCORRUPTED
;
726 xfs_force_shutdown(ip
->i_mount
, SHUTDOWN_CORRUPT_INCORE
);
730 resblks
= XFS_NEXTENTADD_SPACE_RES(ip
->i_mount
,
731 (unsigned int)(end_fsb
- offset_fsb
),
733 error
= xfs_trans_alloc(ip
->i_mount
, &M_RES(ip
->i_mount
)->tr_write
,
734 resblks
, 0, XFS_TRANS_RESERVE
, &tp
);
738 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
739 xfs_trans_ijoin(tp
, ip
, 0);
742 * In case of racing, overlapping AIO writes no COW extents might be
743 * left by the time I/O completes for the loser of the race. In that
746 if (!xfs_iext_lookup_extent_before(ip
, ifp
, &end_fsb
, &icur
, &got
))
749 /* Walk backwards until we're out of the I/O range... */
750 while (got
.br_startoff
+ got
.br_blockcount
> offset_fsb
) {
752 xfs_trim_extent(&del
, offset_fsb
, end_fsb
- offset_fsb
);
754 /* Extent delete may have bumped ext forward */
755 if (!del
.br_blockcount
) {
756 xfs_iext_prev(ifp
, &icur
);
760 ASSERT(!isnullstartblock(got
.br_startblock
));
763 * Don't remap unwritten extents; these are
764 * speculatively preallocated CoW extents that have been
765 * allocated but have not yet been involved in a write.
767 if (got
.br_state
== XFS_EXT_UNWRITTEN
) {
768 xfs_iext_prev(ifp
, &icur
);
772 /* Unmap the old blocks in the data fork. */
773 xfs_defer_init(&dfops
, &firstfsb
);
774 rlen
= del
.br_blockcount
;
775 error
= __xfs_bunmapi(tp
, ip
, del
.br_startoff
, &rlen
, 0, 1,
780 /* Trim the extent to whatever got unmapped. */
782 xfs_trim_extent(&del
, del
.br_startoff
+ rlen
,
783 del
.br_blockcount
- rlen
);
785 trace_xfs_reflink_cow_remap(ip
, &del
);
787 /* Free the CoW orphan record. */
788 error
= xfs_refcount_free_cow_extent(tp
->t_mountp
, &dfops
,
789 del
.br_startblock
, del
.br_blockcount
);
793 /* Map the new blocks into the data fork. */
794 error
= xfs_bmap_map_extent(tp
->t_mountp
, &dfops
, ip
, &del
);
798 /* Remove the mapping from the CoW fork. */
799 xfs_bmap_del_extent_cow(ip
, &icur
, &got
, &del
);
801 xfs_defer_ijoin(&dfops
, ip
);
802 error
= xfs_defer_finish(&tp
, &dfops
);
806 if (!xfs_iext_get_extent(ifp
, &icur
, &got
))
810 error
= xfs_trans_commit(tp
);
811 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
817 xfs_defer_cancel(&dfops
);
819 xfs_trans_cancel(tp
);
820 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
822 trace_xfs_reflink_end_cow_error(ip
, error
, _RET_IP_
);
827 * Free leftover CoW reservations that didn't get cleaned out.
830 xfs_reflink_recover_cow(
831 struct xfs_mount
*mp
)
836 if (!xfs_sb_version_hasreflink(&mp
->m_sb
))
839 for (agno
= 0; agno
< mp
->m_sb
.sb_agcount
; agno
++) {
840 error
= xfs_refcount_recover_cow_leftovers(mp
, agno
);
849 * Reflinking (Block) Ranges of Two Files Together
851 * First, ensure that the reflink flag is set on both inodes. The flag is an
852 * optimization to avoid unnecessary refcount btree lookups in the write path.
854 * Now we can iteratively remap the range of extents (and holes) in src to the
855 * corresponding ranges in dest. Let drange and srange denote the ranges of
856 * logical blocks in dest and src touched by the reflink operation.
858 * While the length of drange is greater than zero,
859 * - Read src's bmbt at the start of srange ("imap")
860 * - If imap doesn't exist, make imap appear to start at the end of srange
862 * - If imap starts before srange, advance imap to start at srange.
863 * - If imap goes beyond srange, truncate imap to end at the end of srange.
864 * - Punch (imap start - srange start + imap len) blocks from dest at
865 * offset (drange start).
866 * - If imap points to a real range of pblks,
867 * > Increase the refcount of the imap's pblks
868 * > Map imap's pblks into dest at the offset
869 * (drange start + imap start - srange start)
870 * - Advance drange and srange by (imap start - srange start + imap len)
872 * Finally, if the reflink made dest longer, update both the in-core and
873 * on-disk file sizes.
875 * ASCII Art Demonstration:
877 * Let's say we want to reflink this source file:
879 * ----SSSSSSS-SSSSS----SSSSSS (src file)
880 * <-------------------->
882 * into this destination file:
884 * --DDDDDDDDDDDDDDDDDDD--DDD (dest file)
885 * <-------------------->
886 * '-' means a hole, and 'S' and 'D' are written blocks in the src and dest.
887 * Observe that the range has different logical offsets in either file.
889 * Consider that the first extent in the source file doesn't line up with our
890 * reflink range. Unmapping and remapping are separate operations, so we can
891 * unmap more blocks from the destination file than we remap.
893 * ----SSSSSSS-SSSSS----SSSSSS
895 * --DDDDD---------DDDDD--DDD
898 * Now remap the source extent into the destination file:
900 * ----SSSSSSS-SSSSS----SSSSSS
902 * --DDDDD--SSSSSSSDDDDD--DDD
905 * Do likewise with the second hole and extent in our range. Holes in the
906 * unmap range don't affect our operation.
908 * ----SSSSSSS-SSSSS----SSSSSS
910 * --DDDDD--SSSSSSS-SSSSS-DDD
913 * Finally, unmap and remap part of the third extent. This will increase the
914 * size of the destination file.
916 * ----SSSSSSS-SSSSS----SSSSSS
918 * --DDDDD--SSSSSSS-SSSSS----SSS
921 * Once we update the destination file's i_size, we're done.
925 * Ensure the reflink bit is set in both inodes.
928 xfs_reflink_set_inode_flag(
929 struct xfs_inode
*src
,
930 struct xfs_inode
*dest
)
932 struct xfs_mount
*mp
= src
->i_mount
;
934 struct xfs_trans
*tp
;
936 if (xfs_is_reflink_inode(src
) && xfs_is_reflink_inode(dest
))
939 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_ichange
, 0, 0, 0, &tp
);
943 /* Lock both files against IO */
944 if (src
->i_ino
== dest
->i_ino
)
945 xfs_ilock(src
, XFS_ILOCK_EXCL
);
947 xfs_lock_two_inodes(src
, dest
, XFS_ILOCK_EXCL
);
949 if (!xfs_is_reflink_inode(src
)) {
950 trace_xfs_reflink_set_inode_flag(src
);
951 xfs_trans_ijoin(tp
, src
, XFS_ILOCK_EXCL
);
952 src
->i_d
.di_flags2
|= XFS_DIFLAG2_REFLINK
;
953 xfs_trans_log_inode(tp
, src
, XFS_ILOG_CORE
);
954 xfs_ifork_init_cow(src
);
956 xfs_iunlock(src
, XFS_ILOCK_EXCL
);
958 if (src
->i_ino
== dest
->i_ino
)
961 if (!xfs_is_reflink_inode(dest
)) {
962 trace_xfs_reflink_set_inode_flag(dest
);
963 xfs_trans_ijoin(tp
, dest
, XFS_ILOCK_EXCL
);
964 dest
->i_d
.di_flags2
|= XFS_DIFLAG2_REFLINK
;
965 xfs_trans_log_inode(tp
, dest
, XFS_ILOG_CORE
);
966 xfs_ifork_init_cow(dest
);
968 xfs_iunlock(dest
, XFS_ILOCK_EXCL
);
971 error
= xfs_trans_commit(tp
);
977 trace_xfs_reflink_set_inode_flag_error(dest
, error
, _RET_IP_
);
982 * Update destination inode size & cowextsize hint, if necessary.
985 xfs_reflink_update_dest(
986 struct xfs_inode
*dest
,
988 xfs_extlen_t cowextsize
,
991 struct xfs_mount
*mp
= dest
->i_mount
;
992 struct xfs_trans
*tp
;
995 if (is_dedupe
&& newlen
<= i_size_read(VFS_I(dest
)) && cowextsize
== 0)
998 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_ichange
, 0, 0, 0, &tp
);
1002 xfs_ilock(dest
, XFS_ILOCK_EXCL
);
1003 xfs_trans_ijoin(tp
, dest
, XFS_ILOCK_EXCL
);
1005 if (newlen
> i_size_read(VFS_I(dest
))) {
1006 trace_xfs_reflink_update_inode_size(dest
, newlen
);
1007 i_size_write(VFS_I(dest
), newlen
);
1008 dest
->i_d
.di_size
= newlen
;
1012 dest
->i_d
.di_cowextsize
= cowextsize
;
1013 dest
->i_d
.di_flags2
|= XFS_DIFLAG2_COWEXTSIZE
;
1017 xfs_trans_ichgtime(tp
, dest
,
1018 XFS_ICHGTIME_MOD
| XFS_ICHGTIME_CHG
);
1020 xfs_trans_log_inode(tp
, dest
, XFS_ILOG_CORE
);
1022 error
= xfs_trans_commit(tp
);
1028 trace_xfs_reflink_update_inode_size_error(dest
, error
, _RET_IP_
);
1033 * Do we have enough reserve in this AG to handle a reflink? The refcount
1034 * btree already reserved all the space it needs, but the rmap btree can grow
1035 * infinitely, so we won't allow more reflinks when the AG is down to the
1039 xfs_reflink_ag_has_free_space(
1040 struct xfs_mount
*mp
,
1041 xfs_agnumber_t agno
)
1043 struct xfs_perag
*pag
;
1046 if (!xfs_sb_version_hasrmapbt(&mp
->m_sb
))
1049 pag
= xfs_perag_get(mp
, agno
);
1050 if (xfs_ag_resv_critical(pag
, XFS_AG_RESV_AGFL
) ||
1051 xfs_ag_resv_critical(pag
, XFS_AG_RESV_METADATA
))
1058 * Unmap a range of blocks from a file, then map other blocks into the hole.
1059 * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount).
1060 * The extent irec is mapped into dest at irec->br_startoff.
1063 xfs_reflink_remap_extent(
1064 struct xfs_inode
*ip
,
1065 struct xfs_bmbt_irec
*irec
,
1066 xfs_fileoff_t destoff
,
1067 xfs_off_t new_isize
)
1069 struct xfs_mount
*mp
= ip
->i_mount
;
1070 bool real_extent
= xfs_bmap_is_real_extent(irec
);
1071 struct xfs_trans
*tp
;
1072 xfs_fsblock_t firstfsb
;
1073 unsigned int resblks
;
1074 struct xfs_defer_ops dfops
;
1075 struct xfs_bmbt_irec uirec
;
1077 xfs_filblks_t unmap_len
;
1081 unmap_len
= irec
->br_startoff
+ irec
->br_blockcount
- destoff
;
1082 trace_xfs_reflink_punch_range(ip
, destoff
, unmap_len
);
1084 /* No reflinking if we're low on space */
1086 error
= xfs_reflink_ag_has_free_space(mp
,
1087 XFS_FSB_TO_AGNO(mp
, irec
->br_startblock
));
1092 /* Start a rolling transaction to switch the mappings */
1093 resblks
= XFS_EXTENTADD_SPACE_RES(ip
->i_mount
, XFS_DATA_FORK
);
1094 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, resblks
, 0, 0, &tp
);
1098 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1099 xfs_trans_ijoin(tp
, ip
, 0);
1101 /* If we're not just clearing space, then do we have enough quota? */
1103 error
= xfs_trans_reserve_quota_nblks(tp
, ip
,
1104 irec
->br_blockcount
, 0, XFS_QMOPT_RES_REGBLKS
);
1109 trace_xfs_reflink_remap(ip
, irec
->br_startoff
,
1110 irec
->br_blockcount
, irec
->br_startblock
);
1112 /* Unmap the old blocks in the data fork. */
1115 xfs_defer_init(&dfops
, &firstfsb
);
1116 error
= __xfs_bunmapi(tp
, ip
, destoff
, &rlen
, 0, 1,
1122 * Trim the extent to whatever got unmapped.
1123 * Remember, bunmapi works backwards.
1125 uirec
.br_startblock
= irec
->br_startblock
+ rlen
;
1126 uirec
.br_startoff
= irec
->br_startoff
+ rlen
;
1127 uirec
.br_blockcount
= unmap_len
- rlen
;
1130 /* If this isn't a real mapping, we're done. */
1131 if (!real_extent
|| uirec
.br_blockcount
== 0)
1134 trace_xfs_reflink_remap(ip
, uirec
.br_startoff
,
1135 uirec
.br_blockcount
, uirec
.br_startblock
);
1137 /* Update the refcount tree */
1138 error
= xfs_refcount_increase_extent(mp
, &dfops
, &uirec
);
1142 /* Map the new blocks into the data fork. */
1143 error
= xfs_bmap_map_extent(mp
, &dfops
, ip
, &uirec
);
1147 /* Update quota accounting. */
1148 xfs_trans_mod_dquot_byino(tp
, ip
, XFS_TRANS_DQ_BCOUNT
,
1149 uirec
.br_blockcount
);
1151 /* Update dest isize if needed. */
1152 newlen
= XFS_FSB_TO_B(mp
,
1153 uirec
.br_startoff
+ uirec
.br_blockcount
);
1154 newlen
= min_t(xfs_off_t
, newlen
, new_isize
);
1155 if (newlen
> i_size_read(VFS_I(ip
))) {
1156 trace_xfs_reflink_update_inode_size(ip
, newlen
);
1157 i_size_write(VFS_I(ip
), newlen
);
1158 ip
->i_d
.di_size
= newlen
;
1159 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_CORE
);
1163 /* Process all the deferred stuff. */
1164 xfs_defer_ijoin(&dfops
, ip
);
1165 error
= xfs_defer_finish(&tp
, &dfops
);
1170 error
= xfs_trans_commit(tp
);
1171 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1177 xfs_defer_cancel(&dfops
);
1179 xfs_trans_cancel(tp
);
1180 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1182 trace_xfs_reflink_remap_extent_error(ip
, error
, _RET_IP_
);
1187 * Iteratively remap one file's extents (and holes) to another's.
1190 xfs_reflink_remap_blocks(
1191 struct xfs_inode
*src
,
1192 xfs_fileoff_t srcoff
,
1193 struct xfs_inode
*dest
,
1194 xfs_fileoff_t destoff
,
1196 xfs_off_t new_isize
)
1198 struct xfs_bmbt_irec imap
;
1201 xfs_filblks_t range_len
;
1203 /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */
1205 trace_xfs_reflink_remap_blocks_loop(src
, srcoff
, len
,
1207 /* Read extent from the source file */
1209 xfs_ilock(src
, XFS_ILOCK_EXCL
);
1210 error
= xfs_bmapi_read(src
, srcoff
, len
, &imap
, &nimaps
, 0);
1211 xfs_iunlock(src
, XFS_ILOCK_EXCL
);
1214 ASSERT(nimaps
== 1);
1216 trace_xfs_reflink_remap_imap(src
, srcoff
, len
, XFS_IO_OVERWRITE
,
1219 /* Translate imap into the destination file. */
1220 range_len
= imap
.br_startoff
+ imap
.br_blockcount
- srcoff
;
1221 imap
.br_startoff
+= destoff
- srcoff
;
1223 /* Clear dest from destoff to the end of imap and map it in. */
1224 error
= xfs_reflink_remap_extent(dest
, &imap
, destoff
,
1229 if (fatal_signal_pending(current
)) {
1234 /* Advance drange/srange */
1235 srcoff
+= range_len
;
1236 destoff
+= range_len
;
1243 trace_xfs_reflink_remap_blocks_error(dest
, error
, _RET_IP_
);
1248 * Link a range of blocks from one file to another.
1251 xfs_reflink_remap_range(
1252 struct file
*file_in
,
1254 struct file
*file_out
,
1259 struct inode
*inode_in
= file_inode(file_in
);
1260 struct xfs_inode
*src
= XFS_I(inode_in
);
1261 struct inode
*inode_out
= file_inode(file_out
);
1262 struct xfs_inode
*dest
= XFS_I(inode_out
);
1263 struct xfs_mount
*mp
= src
->i_mount
;
1264 bool same_inode
= (inode_in
== inode_out
);
1265 xfs_fileoff_t sfsbno
, dfsbno
;
1266 xfs_filblks_t fsblen
;
1267 xfs_extlen_t cowextsize
;
1270 if (!xfs_sb_version_hasreflink(&mp
->m_sb
))
1273 if (XFS_FORCED_SHUTDOWN(mp
))
1276 /* Lock both files against IO */
1277 lock_two_nondirectories(inode_in
, inode_out
);
1279 xfs_ilock(src
, XFS_MMAPLOCK_EXCL
);
1281 xfs_lock_two_inodes(src
, dest
, XFS_MMAPLOCK_EXCL
);
1283 /* Check file eligibility and prepare for block sharing. */
1285 /* Don't reflink realtime inodes */
1286 if (XFS_IS_REALTIME_INODE(src
) || XFS_IS_REALTIME_INODE(dest
))
1289 /* Don't share DAX file data for now. */
1290 if (IS_DAX(inode_in
) || IS_DAX(inode_out
))
1293 ret
= vfs_clone_file_prep_inodes(inode_in
, pos_in
, inode_out
, pos_out
,
1298 trace_xfs_reflink_remap_range(src
, pos_in
, len
, dest
, pos_out
);
1301 * Clear out post-eof preallocations because we don't have page cache
1302 * backing the delayed allocations and they'll never get freed on
1305 if (xfs_can_free_eofblocks(dest
, true)) {
1306 ret
= xfs_free_eofblocks(dest
);
1311 /* Set flags and remap blocks. */
1312 ret
= xfs_reflink_set_inode_flag(src
, dest
);
1316 dfsbno
= XFS_B_TO_FSBT(mp
, pos_out
);
1317 sfsbno
= XFS_B_TO_FSBT(mp
, pos_in
);
1318 fsblen
= XFS_B_TO_FSB(mp
, len
);
1319 ret
= xfs_reflink_remap_blocks(src
, sfsbno
, dest
, dfsbno
, fsblen
,
1324 /* Zap any page cache for the destination file's range. */
1325 truncate_inode_pages_range(&inode_out
->i_data
, pos_out
,
1326 PAGE_ALIGN(pos_out
+ len
) - 1);
1329 * Carry the cowextsize hint from src to dest if we're sharing the
1330 * entire source file to the entire destination file, the source file
1331 * has a cowextsize hint, and the destination file does not.
1334 if (pos_in
== 0 && len
== i_size_read(inode_in
) &&
1335 (src
->i_d
.di_flags2
& XFS_DIFLAG2_COWEXTSIZE
) &&
1336 pos_out
== 0 && len
>= i_size_read(inode_out
) &&
1337 !(dest
->i_d
.di_flags2
& XFS_DIFLAG2_COWEXTSIZE
))
1338 cowextsize
= src
->i_d
.di_cowextsize
;
1340 ret
= xfs_reflink_update_dest(dest
, pos_out
+ len
, cowextsize
,
1344 xfs_iunlock(src
, XFS_MMAPLOCK_EXCL
);
1346 xfs_iunlock(dest
, XFS_MMAPLOCK_EXCL
);
1347 unlock_two_nondirectories(inode_in
, inode_out
);
1349 trace_xfs_reflink_remap_range_error(dest
, ret
, _RET_IP_
);
1354 * The user wants to preemptively CoW all shared blocks in this file,
1355 * which enables us to turn off the reflink flag. Iterate all
1356 * extents which are not prealloc/delalloc to see which ranges are
1357 * mentioned in the refcount tree, then read those blocks into the
1358 * pagecache, dirty them, fsync them back out, and then we can update
1359 * the inode flag. What happens if we run out of memory? :)
1362 xfs_reflink_dirty_extents(
1363 struct xfs_inode
*ip
,
1368 struct xfs_mount
*mp
= ip
->i_mount
;
1369 xfs_agnumber_t agno
;
1370 xfs_agblock_t agbno
;
1376 struct xfs_bmbt_irec map
[2];
1380 while (end
- fbno
> 0) {
1383 * Look for extents in the file. Skip holes, delalloc, or
1384 * unwritten extents; they can't be reflinked.
1386 error
= xfs_bmapi_read(ip
, fbno
, end
- fbno
, map
, &nmaps
, 0);
1391 if (!xfs_bmap_is_real_extent(&map
[0]))
1395 while (map
[1].br_blockcount
) {
1396 agno
= XFS_FSB_TO_AGNO(mp
, map
[1].br_startblock
);
1397 agbno
= XFS_FSB_TO_AGBNO(mp
, map
[1].br_startblock
);
1398 aglen
= map
[1].br_blockcount
;
1400 error
= xfs_reflink_find_shared(mp
, NULL
, agno
, agbno
,
1401 aglen
, &rbno
, &rlen
, true);
1404 if (rbno
== NULLAGBLOCK
)
1407 /* Dirty the pages */
1408 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1409 fpos
= XFS_FSB_TO_B(mp
, map
[1].br_startoff
+
1411 flen
= XFS_FSB_TO_B(mp
, rlen
);
1412 if (fpos
+ flen
> isize
)
1413 flen
= isize
- fpos
;
1414 error
= iomap_file_dirty(VFS_I(ip
), fpos
, flen
,
1416 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1420 map
[1].br_blockcount
-= (rbno
- agbno
+ rlen
);
1421 map
[1].br_startoff
+= (rbno
- agbno
+ rlen
);
1422 map
[1].br_startblock
+= (rbno
- agbno
+ rlen
);
1426 fbno
= map
[0].br_startoff
+ map
[0].br_blockcount
;
1432 /* Does this inode need the reflink flag? */
1434 xfs_reflink_inode_has_shared_extents(
1435 struct xfs_trans
*tp
,
1436 struct xfs_inode
*ip
,
1439 struct xfs_bmbt_irec got
;
1440 struct xfs_mount
*mp
= ip
->i_mount
;
1441 struct xfs_ifork
*ifp
;
1442 xfs_agnumber_t agno
;
1443 xfs_agblock_t agbno
;
1447 struct xfs_iext_cursor icur
;
1451 ifp
= XFS_IFORK_PTR(ip
, XFS_DATA_FORK
);
1452 if (!(ifp
->if_flags
& XFS_IFEXTENTS
)) {
1453 error
= xfs_iread_extents(tp
, ip
, XFS_DATA_FORK
);
1458 *has_shared
= false;
1459 found
= xfs_iext_lookup_extent(ip
, ifp
, 0, &icur
, &got
);
1461 if (isnullstartblock(got
.br_startblock
) ||
1462 got
.br_state
!= XFS_EXT_NORM
)
1464 agno
= XFS_FSB_TO_AGNO(mp
, got
.br_startblock
);
1465 agbno
= XFS_FSB_TO_AGBNO(mp
, got
.br_startblock
);
1466 aglen
= got
.br_blockcount
;
1468 error
= xfs_reflink_find_shared(mp
, tp
, agno
, agbno
, aglen
,
1469 &rbno
, &rlen
, false);
1472 /* Is there still a shared block here? */
1473 if (rbno
!= NULLAGBLOCK
) {
1478 found
= xfs_iext_next_extent(ifp
, &icur
, &got
);
1484 /* Clear the inode reflink flag if there are no shared extents. */
1486 xfs_reflink_clear_inode_flag(
1487 struct xfs_inode
*ip
,
1488 struct xfs_trans
**tpp
)
1493 ASSERT(xfs_is_reflink_inode(ip
));
1495 error
= xfs_reflink_inode_has_shared_extents(*tpp
, ip
, &needs_flag
);
1496 if (error
|| needs_flag
)
1500 * We didn't find any shared blocks so turn off the reflink flag.
1501 * First, get rid of any leftover CoW mappings.
1503 error
= xfs_reflink_cancel_cow_blocks(ip
, tpp
, 0, NULLFILEOFF
, true);
1507 /* Clear the inode flag. */
1508 trace_xfs_reflink_unset_inode_flag(ip
);
1509 ip
->i_d
.di_flags2
&= ~XFS_DIFLAG2_REFLINK
;
1510 xfs_inode_clear_cowblocks_tag(ip
);
1511 xfs_trans_ijoin(*tpp
, ip
, 0);
1512 xfs_trans_log_inode(*tpp
, ip
, XFS_ILOG_CORE
);
1518 * Clear the inode reflink flag if there are no shared extents and the size
1522 xfs_reflink_try_clear_inode_flag(
1523 struct xfs_inode
*ip
)
1525 struct xfs_mount
*mp
= ip
->i_mount
;
1526 struct xfs_trans
*tp
;
1529 /* Start a rolling transaction to remove the mappings */
1530 error
= xfs_trans_alloc(mp
, &M_RES(mp
)->tr_write
, 0, 0, 0, &tp
);
1534 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1535 xfs_trans_ijoin(tp
, ip
, 0);
1537 error
= xfs_reflink_clear_inode_flag(ip
, &tp
);
1541 error
= xfs_trans_commit(tp
);
1545 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1548 xfs_trans_cancel(tp
);
1550 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1555 * Pre-COW all shared blocks within a given byte range of a file and turn off
1556 * the reflink flag if we unshare all of the file's blocks.
1559 xfs_reflink_unshare(
1560 struct xfs_inode
*ip
,
1564 struct xfs_mount
*mp
= ip
->i_mount
;
1570 if (!xfs_is_reflink_inode(ip
))
1573 trace_xfs_reflink_unshare(ip
, offset
, len
);
1575 inode_dio_wait(VFS_I(ip
));
1577 /* Try to CoW the selected ranges */
1578 xfs_ilock(ip
, XFS_ILOCK_EXCL
);
1579 fbno
= XFS_B_TO_FSBT(mp
, offset
);
1580 isize
= i_size_read(VFS_I(ip
));
1581 end
= XFS_B_TO_FSB(mp
, offset
+ len
);
1582 error
= xfs_reflink_dirty_extents(ip
, fbno
, end
, isize
);
1585 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1587 /* Wait for the IO to finish */
1588 error
= filemap_write_and_wait(VFS_I(ip
)->i_mapping
);
1592 /* Turn off the reflink flag if possible. */
1593 error
= xfs_reflink_try_clear_inode_flag(ip
);
1600 xfs_iunlock(ip
, XFS_ILOCK_EXCL
);
1602 trace_xfs_reflink_unshare_error(ip
, error
, _RET_IP_
);