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3993baeb DW |
1 | /* |
2 | * Copyright (C) 2016 Oracle. All Rights Reserved. | |
3 | * | |
4 | * Author: Darrick J. Wong <darrick.wong@oracle.com> | |
5 | * | |
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. | |
10 | * | |
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. | |
15 | * | |
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. | |
19 | */ | |
20 | #include "xfs.h" | |
21 | #include "xfs_fs.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_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" | |
33 | #include "xfs_bmap.h" | |
34 | #include "xfs_bmap_util.h" | |
35 | #include "xfs_error.h" | |
36 | #include "xfs_dir2.h" | |
37 | #include "xfs_dir2_priv.h" | |
38 | #include "xfs_ioctl.h" | |
39 | #include "xfs_trace.h" | |
40 | #include "xfs_log.h" | |
41 | #include "xfs_icache.h" | |
42 | #include "xfs_pnfs.h" | |
174edb0e | 43 | #include "xfs_btree.h" |
3993baeb DW |
44 | #include "xfs_refcount_btree.h" |
45 | #include "xfs_refcount.h" | |
46 | #include "xfs_bmap_btree.h" | |
47 | #include "xfs_trans_space.h" | |
48 | #include "xfs_bit.h" | |
49 | #include "xfs_alloc.h" | |
50 | #include "xfs_quota_defs.h" | |
51 | #include "xfs_quota.h" | |
52 | #include "xfs_btree.h" | |
53 | #include "xfs_bmap_btree.h" | |
54 | #include "xfs_reflink.h" | |
2a06705c | 55 | #include "xfs_iomap.h" |
43caeb18 | 56 | #include "xfs_rmap_btree.h" |
6fa164b8 DW |
57 | #include "xfs_sb.h" |
58 | #include "xfs_ag_resv.h" | |
3993baeb DW |
59 | |
60 | /* | |
61 | * Copy on Write of Shared Blocks | |
62 | * | |
63 | * XFS must preserve "the usual" file semantics even when two files share | |
64 | * the same physical blocks. This means that a write to one file must not | |
65 | * alter the blocks in a different file; the way that we'll do that is | |
66 | * through the use of a copy-on-write mechanism. At a high level, that | |
67 | * means that when we want to write to a shared block, we allocate a new | |
68 | * block, write the data to the new block, and if that succeeds we map the | |
69 | * new block into the file. | |
70 | * | |
71 | * XFS provides a "delayed allocation" mechanism that defers the allocation | |
72 | * of disk blocks to dirty-but-not-yet-mapped file blocks as long as | |
73 | * possible. This reduces fragmentation by enabling the filesystem to ask | |
74 | * for bigger chunks less often, which is exactly what we want for CoW. | |
75 | * | |
76 | * The delalloc mechanism begins when the kernel wants to make a block | |
77 | * writable (write_begin or page_mkwrite). If the offset is not mapped, we | |
78 | * create a delalloc mapping, which is a regular in-core extent, but without | |
79 | * a real startblock. (For delalloc mappings, the startblock encodes both | |
80 | * a flag that this is a delalloc mapping, and a worst-case estimate of how | |
81 | * many blocks might be required to put the mapping into the BMBT.) delalloc | |
82 | * mappings are a reservation against the free space in the filesystem; | |
83 | * adjacent mappings can also be combined into fewer larger mappings. | |
84 | * | |
5eda4300 DW |
85 | * As an optimization, the CoW extent size hint (cowextsz) creates |
86 | * outsized aligned delalloc reservations in the hope of landing out of | |
87 | * order nearby CoW writes in a single extent on disk, thereby reducing | |
88 | * fragmentation and improving future performance. | |
89 | * | |
90 | * D: --RRRRRRSSSRRRRRRRR--- (data fork) | |
91 | * C: ------DDDDDDD--------- (CoW fork) | |
92 | * | |
3993baeb | 93 | * When dirty pages are being written out (typically in writepage), the |
5eda4300 DW |
94 | * delalloc reservations are converted into unwritten mappings by |
95 | * allocating blocks and replacing the delalloc mapping with real ones. | |
96 | * A delalloc mapping can be replaced by several unwritten ones if the | |
97 | * free space is fragmented. | |
98 | * | |
99 | * D: --RRRRRRSSSRRRRRRRR--- | |
100 | * C: ------UUUUUUU--------- | |
3993baeb DW |
101 | * |
102 | * We want to adapt the delalloc mechanism for copy-on-write, since the | |
103 | * write paths are similar. The first two steps (creating the reservation | |
104 | * and allocating the blocks) are exactly the same as delalloc except that | |
105 | * the mappings must be stored in a separate CoW fork because we do not want | |
106 | * to disturb the mapping in the data fork until we're sure that the write | |
107 | * succeeded. IO completion in this case is the process of removing the old | |
108 | * mapping from the data fork and moving the new mapping from the CoW fork to | |
109 | * the data fork. This will be discussed shortly. | |
110 | * | |
111 | * For now, unaligned directio writes will be bounced back to the page cache. | |
112 | * Block-aligned directio writes will use the same mechanism as buffered | |
113 | * writes. | |
114 | * | |
5eda4300 DW |
115 | * Just prior to submitting the actual disk write requests, we convert |
116 | * the extents representing the range of the file actually being written | |
117 | * (as opposed to extra pieces created for the cowextsize hint) to real | |
118 | * extents. This will become important in the next step: | |
119 | * | |
120 | * D: --RRRRRRSSSRRRRRRRR--- | |
121 | * C: ------UUrrUUU--------- | |
122 | * | |
3993baeb DW |
123 | * CoW remapping must be done after the data block write completes, |
124 | * because we don't want to destroy the old data fork map until we're sure | |
125 | * the new block has been written. Since the new mappings are kept in a | |
126 | * separate fork, we can simply iterate these mappings to find the ones | |
127 | * that cover the file blocks that we just CoW'd. For each extent, simply | |
128 | * unmap the corresponding range in the data fork, map the new range into | |
5eda4300 DW |
129 | * the data fork, and remove the extent from the CoW fork. Because of |
130 | * the presence of the cowextsize hint, however, we must be careful | |
131 | * only to remap the blocks that we've actually written out -- we must | |
132 | * never remap delalloc reservations nor CoW staging blocks that have | |
133 | * yet to be written. This corresponds exactly to the real extents in | |
134 | * the CoW fork: | |
135 | * | |
136 | * D: --RRRRRRrrSRRRRRRRR--- | |
137 | * C: ------UU--UUU--------- | |
3993baeb DW |
138 | * |
139 | * Since the remapping operation can be applied to an arbitrary file | |
140 | * range, we record the need for the remap step as a flag in the ioend | |
141 | * instead of declaring a new IO type. This is required for direct io | |
142 | * because we only have ioend for the whole dio, and we have to be able to | |
143 | * remember the presence of unwritten blocks and CoW blocks with a single | |
144 | * ioend structure. Better yet, the more ground we can cover with one | |
145 | * ioend, the better. | |
146 | */ | |
2a06705c DW |
147 | |
148 | /* | |
149 | * Given an AG extent, find the lowest-numbered run of shared blocks | |
150 | * within that range and return the range in fbno/flen. If | |
151 | * find_end_of_shared is true, return the longest contiguous extent of | |
152 | * shared blocks. If there are no shared extents, fbno and flen will | |
153 | * be set to NULLAGBLOCK and 0, respectively. | |
154 | */ | |
155 | int | |
156 | xfs_reflink_find_shared( | |
157 | struct xfs_mount *mp, | |
92ff7285 | 158 | struct xfs_trans *tp, |
2a06705c DW |
159 | xfs_agnumber_t agno, |
160 | xfs_agblock_t agbno, | |
161 | xfs_extlen_t aglen, | |
162 | xfs_agblock_t *fbno, | |
163 | xfs_extlen_t *flen, | |
164 | bool find_end_of_shared) | |
165 | { | |
166 | struct xfs_buf *agbp; | |
167 | struct xfs_btree_cur *cur; | |
168 | int error; | |
169 | ||
92ff7285 | 170 | error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp); |
2a06705c DW |
171 | if (error) |
172 | return error; | |
173 | ||
92ff7285 | 174 | cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, NULL); |
2a06705c DW |
175 | |
176 | error = xfs_refcount_find_shared(cur, agbno, aglen, fbno, flen, | |
177 | find_end_of_shared); | |
178 | ||
179 | xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); | |
180 | ||
92ff7285 | 181 | xfs_trans_brelse(tp, agbp); |
2a06705c DW |
182 | return error; |
183 | } | |
184 | ||
185 | /* | |
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. | |
194 | */ | |
195 | int | |
196 | xfs_reflink_trim_around_shared( | |
197 | struct xfs_inode *ip, | |
198 | struct xfs_bmbt_irec *irec, | |
199 | bool *shared, | |
200 | bool *trimmed) | |
201 | { | |
202 | xfs_agnumber_t agno; | |
203 | xfs_agblock_t agbno; | |
204 | xfs_extlen_t aglen; | |
205 | xfs_agblock_t fbno; | |
206 | xfs_extlen_t flen; | |
207 | int error = 0; | |
208 | ||
209 | /* Holes, unwritten, and delalloc extents cannot be shared */ | |
9c4f29d3 | 210 | if (!xfs_is_reflink_inode(ip) || !xfs_bmap_is_real_extent(irec)) { |
2a06705c DW |
211 | *shared = false; |
212 | return 0; | |
213 | } | |
214 | ||
215 | trace_xfs_reflink_trim_around_shared(ip, irec); | |
216 | ||
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; | |
220 | ||
92ff7285 | 221 | error = xfs_reflink_find_shared(ip->i_mount, NULL, agno, agbno, |
2a06705c DW |
222 | aglen, &fbno, &flen, true); |
223 | if (error) | |
224 | return error; | |
225 | ||
226 | *shared = *trimmed = false; | |
227 | if (fbno == NULLAGBLOCK) { | |
228 | /* No shared blocks at all. */ | |
229 | return 0; | |
230 | } else if (fbno == agbno) { | |
231 | /* | |
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 | |
235 | * unshared region. | |
236 | */ | |
237 | irec->br_blockcount = flen; | |
238 | *shared = true; | |
239 | if (flen != aglen) | |
240 | *trimmed = true; | |
241 | return 0; | |
242 | } else { | |
243 | /* | |
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. | |
248 | */ | |
249 | irec->br_blockcount = fbno - agbno; | |
250 | *trimmed = true; | |
251 | return 0; | |
252 | } | |
253 | } | |
254 | ||
3ba020be CH |
255 | /* |
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. | |
259 | * | |
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 | |
262 | * operations. | |
263 | */ | |
264 | int | |
265 | xfs_reflink_reserve_cow( | |
2a06705c | 266 | struct xfs_inode *ip, |
3ba020be CH |
267 | struct xfs_bmbt_irec *imap, |
268 | bool *shared) | |
2a06705c | 269 | { |
2755fc44 CH |
270 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
271 | struct xfs_bmbt_irec got; | |
2755fc44 CH |
272 | int error = 0; |
273 | bool eof = false, trimmed; | |
2a06705c DW |
274 | xfs_extnum_t idx; |
275 | ||
3ba020be CH |
276 | /* |
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 | |
282 | * tree. | |
283 | */ | |
2755fc44 CH |
284 | |
285 | if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &idx, &got)) | |
286 | eof = true; | |
3ba020be CH |
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); | |
2a06705c | 290 | |
3ba020be CH |
291 | *shared = true; |
292 | return 0; | |
293 | } | |
2a06705c DW |
294 | |
295 | /* Trim the mapping to the nearest shared extent boundary. */ | |
3ba020be | 296 | error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); |
2a06705c | 297 | if (error) |
3ba020be | 298 | return error; |
2a06705c DW |
299 | |
300 | /* Not shared? Just report the (potentially capped) extent. */ | |
3ba020be CH |
301 | if (!*shared) |
302 | return 0; | |
2a06705c DW |
303 | |
304 | /* | |
305 | * Fork all the shared blocks from our write offset until the end of | |
306 | * the extent. | |
307 | */ | |
308 | error = xfs_qm_dqattach_locked(ip, 0); | |
309 | if (error) | |
3ba020be CH |
310 | return error; |
311 | ||
3ba020be | 312 | error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff, |
0260d8ff BF |
313 | imap->br_blockcount, 0, &got, &idx, eof); |
314 | if (error == -ENOSPC || error == -EDQUOT) | |
3ba020be | 315 | trace_xfs_reflink_cow_enospc(ip, imap); |
0260d8ff | 316 | if (error) |
3ba020be | 317 | return error; |
83104d44 | 318 | |
2a06705c | 319 | trace_xfs_reflink_cow_alloc(ip, &got); |
3ba020be | 320 | return 0; |
2a06705c | 321 | } |
ef473667 | 322 | |
5eda4300 DW |
323 | /* Convert part of an unwritten CoW extent to a real one. */ |
324 | STATIC int | |
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) | |
331 | { | |
5eda4300 DW |
332 | xfs_fsblock_t first_block; |
333 | int nimaps = 1; | |
334 | ||
335 | if (imap->br_state == XFS_EXT_NORM) | |
336 | return 0; | |
337 | ||
dcf9585a CH |
338 | xfs_trim_extent(imap, offset_fsb, count_fsb); |
339 | trace_xfs_reflink_convert_cow(ip, imap); | |
340 | if (imap->br_blockcount == 0) | |
5eda4300 | 341 | return 0; |
dcf9585a | 342 | return xfs_bmapi_write(NULL, ip, imap->br_startoff, imap->br_blockcount, |
5eda4300 | 343 | XFS_BMAPI_COWFORK | XFS_BMAPI_CONVERT, &first_block, |
dcf9585a | 344 | 0, imap, &nimaps, dfops); |
5eda4300 DW |
345 | } |
346 | ||
347 | /* Convert all of the unwritten CoW extents in a file's range to real ones. */ | |
348 | int | |
349 | xfs_reflink_convert_cow( | |
350 | struct xfs_inode *ip, | |
351 | xfs_off_t offset, | |
352 | xfs_off_t count) | |
353 | { | |
354 | struct xfs_bmbt_irec got; | |
355 | struct xfs_defer_ops dfops; | |
356 | struct xfs_mount *mp = ip->i_mount; | |
357 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
358 | xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
359 | xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count); | |
360 | xfs_extnum_t idx; | |
361 | bool found; | |
93aaead5 | 362 | int error = 0; |
5eda4300 DW |
363 | |
364 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
365 | ||
366 | /* Convert all the extents to real from unwritten. */ | |
367 | for (found = xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got); | |
368 | found && got.br_startoff < end_fsb; | |
369 | found = xfs_iext_get_extent(ifp, ++idx, &got)) { | |
370 | error = xfs_reflink_convert_cow_extent(ip, &got, offset_fsb, | |
371 | end_fsb - offset_fsb, &dfops); | |
372 | if (error) | |
373 | break; | |
374 | } | |
375 | ||
376 | /* Finish up. */ | |
377 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
378 | return error; | |
379 | } | |
380 | ||
0613f16c | 381 | /* Allocate all CoW reservations covering a range of blocks in a file. */ |
3c68d44a CH |
382 | int |
383 | xfs_reflink_allocate_cow( | |
0613f16c | 384 | struct xfs_inode *ip, |
3c68d44a CH |
385 | struct xfs_bmbt_irec *imap, |
386 | bool *shared, | |
387 | uint *lockmode) | |
0613f16c DW |
388 | { |
389 | struct xfs_mount *mp = ip->i_mount; | |
3c68d44a CH |
390 | xfs_fileoff_t offset_fsb = imap->br_startoff; |
391 | xfs_filblks_t count_fsb = imap->br_blockcount; | |
392 | struct xfs_bmbt_irec got; | |
0613f16c | 393 | struct xfs_defer_ops dfops; |
3c68d44a | 394 | struct xfs_trans *tp = NULL; |
0613f16c | 395 | xfs_fsblock_t first_block; |
3c68d44a CH |
396 | int nimaps, error = 0; |
397 | bool trimmed; | |
a14234c7 | 398 | xfs_filblks_t resaligned; |
3c68d44a | 399 | xfs_extlen_t resblks = 0; |
a14234c7 | 400 | xfs_extnum_t idx; |
0613f16c | 401 | |
3c68d44a CH |
402 | retry: |
403 | ASSERT(xfs_is_reflink_inode(ip)); | |
404 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); | |
0613f16c | 405 | |
a14234c7 CH |
406 | /* |
407 | * Even if the extent is not shared we might have a preallocation for | |
408 | * it in the COW fork. If so use it. | |
409 | */ | |
3c68d44a CH |
410 | if (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &idx, &got) && |
411 | got.br_startoff <= offset_fsb) { | |
412 | *shared = true; | |
413 | ||
a14234c7 CH |
414 | /* If we have a real allocation in the COW fork we're done. */ |
415 | if (!isnullstartblock(got.br_startblock)) { | |
3c68d44a CH |
416 | xfs_trim_extent(&got, offset_fsb, count_fsb); |
417 | *imap = got; | |
418 | goto convert; | |
a14234c7 | 419 | } |
3c68d44a CH |
420 | |
421 | xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); | |
a14234c7 | 422 | } else { |
3c68d44a CH |
423 | error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); |
424 | if (error || !*shared) | |
425 | goto out; | |
426 | } | |
a14234c7 | 427 | |
3c68d44a CH |
428 | if (!tp) { |
429 | resaligned = xfs_aligned_fsb_count(imap->br_startoff, | |
430 | imap->br_blockcount, xfs_get_cowextsz_hint(ip)); | |
431 | resblks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); | |
3ba020be | 432 | |
3c68d44a CH |
433 | xfs_iunlock(ip, *lockmode); |
434 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); | |
435 | *lockmode = XFS_ILOCK_EXCL; | |
436 | xfs_ilock(ip, *lockmode); | |
a14234c7 | 437 | |
3c68d44a CH |
438 | if (error) |
439 | return error; | |
440 | ||
441 | error = xfs_qm_dqattach_locked(ip, 0); | |
442 | if (error) | |
443 | goto out; | |
444 | goto retry; | |
a14234c7 CH |
445 | } |
446 | ||
447 | error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0, | |
448 | XFS_QMOPT_RES_REGBLKS); | |
0613f16c | 449 | if (error) |
3c68d44a | 450 | goto out; |
0613f16c | 451 | |
a14234c7 CH |
452 | xfs_trans_ijoin(tp, ip, 0); |
453 | ||
454 | xfs_defer_init(&dfops, &first_block); | |
455 | nimaps = 1; | |
0613f16c | 456 | |
5eda4300 | 457 | /* Allocate the entire reservation as unwritten blocks. */ |
3c68d44a | 458 | error = xfs_bmapi_write(tp, ip, imap->br_startoff, imap->br_blockcount, |
5eda4300 | 459 | XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC, &first_block, |
3c68d44a | 460 | resblks, imap, &nimaps, &dfops); |
0613f16c | 461 | if (error) |
a14234c7 | 462 | goto out_bmap_cancel; |
0613f16c | 463 | |
5eda4300 | 464 | /* Finish up. */ |
0613f16c DW |
465 | error = xfs_defer_finish(&tp, &dfops, NULL); |
466 | if (error) | |
a14234c7 | 467 | goto out_bmap_cancel; |
0613f16c DW |
468 | |
469 | error = xfs_trans_commit(tp); | |
a14234c7 | 470 | if (error) |
3c68d44a CH |
471 | return error; |
472 | convert: | |
473 | return xfs_reflink_convert_cow_extent(ip, imap, offset_fsb, count_fsb, | |
474 | &dfops); | |
a14234c7 | 475 | out_bmap_cancel: |
0613f16c | 476 | xfs_defer_cancel(&dfops); |
a14234c7 CH |
477 | xfs_trans_unreserve_quota_nblks(tp, ip, (long)resblks, 0, |
478 | XFS_QMOPT_RES_REGBLKS); | |
3c68d44a CH |
479 | out: |
480 | if (tp) | |
481 | xfs_trans_cancel(tp); | |
482 | return error; | |
0613f16c DW |
483 | } |
484 | ||
ef473667 | 485 | /* |
092d5d9d | 486 | * Find the CoW reservation for a given byte offset of a file. |
ef473667 DW |
487 | */ |
488 | bool | |
489 | xfs_reflink_find_cow_mapping( | |
490 | struct xfs_inode *ip, | |
491 | xfs_off_t offset, | |
092d5d9d | 492 | struct xfs_bmbt_irec *imap) |
ef473667 | 493 | { |
092d5d9d CH |
494 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
495 | xfs_fileoff_t offset_fsb; | |
496 | struct xfs_bmbt_irec got; | |
ef473667 DW |
497 | xfs_extnum_t idx; |
498 | ||
499 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); | |
500 | ASSERT(xfs_is_reflink_inode(ip)); | |
501 | ||
092d5d9d CH |
502 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); |
503 | if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got)) | |
ef473667 | 504 | return false; |
092d5d9d | 505 | if (got.br_startoff > offset_fsb) |
ef473667 DW |
506 | return false; |
507 | ||
508 | trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE, | |
092d5d9d CH |
509 | &got); |
510 | *imap = got; | |
ef473667 DW |
511 | return true; |
512 | } | |
513 | ||
514 | /* | |
515 | * Trim an extent to end at the next CoW reservation past offset_fsb. | |
516 | */ | |
86f12ab0 | 517 | void |
ef473667 DW |
518 | xfs_reflink_trim_irec_to_next_cow( |
519 | struct xfs_inode *ip, | |
520 | xfs_fileoff_t offset_fsb, | |
521 | struct xfs_bmbt_irec *imap) | |
522 | { | |
86f12ab0 CH |
523 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
524 | struct xfs_bmbt_irec got; | |
ef473667 DW |
525 | xfs_extnum_t idx; |
526 | ||
527 | if (!xfs_is_reflink_inode(ip)) | |
86f12ab0 | 528 | return; |
ef473667 DW |
529 | |
530 | /* Find the extent in the CoW fork. */ | |
86f12ab0 CH |
531 | if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got)) |
532 | return; | |
ef473667 DW |
533 | |
534 | /* This is the extent before; try sliding up one. */ | |
86f12ab0 CH |
535 | if (got.br_startoff < offset_fsb) { |
536 | if (!xfs_iext_get_extent(ifp, idx + 1, &got)) | |
537 | return; | |
ef473667 DW |
538 | } |
539 | ||
86f12ab0 CH |
540 | if (got.br_startoff >= imap->br_startoff + imap->br_blockcount) |
541 | return; | |
ef473667 | 542 | |
86f12ab0 | 543 | imap->br_blockcount = got.br_startoff - imap->br_startoff; |
ef473667 | 544 | trace_xfs_reflink_trim_irec(ip, imap); |
ef473667 | 545 | } |
43caeb18 DW |
546 | |
547 | /* | |
3802a345 CH |
548 | * Cancel CoW reservations for some block range of an inode. |
549 | * | |
550 | * If cancel_real is true this function cancels all COW fork extents for the | |
551 | * inode; if cancel_real is false, real extents are not cleared. | |
43caeb18 DW |
552 | */ |
553 | int | |
554 | xfs_reflink_cancel_cow_blocks( | |
555 | struct xfs_inode *ip, | |
556 | struct xfs_trans **tpp, | |
557 | xfs_fileoff_t offset_fsb, | |
3802a345 CH |
558 | xfs_fileoff_t end_fsb, |
559 | bool cancel_real) | |
43caeb18 | 560 | { |
3e0ee78f | 561 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
df5ab1b5 | 562 | struct xfs_bmbt_irec got, del; |
3e0ee78f | 563 | xfs_extnum_t idx; |
43caeb18 DW |
564 | xfs_fsblock_t firstfsb; |
565 | struct xfs_defer_ops dfops; | |
df5ab1b5 | 566 | int error = 0; |
43caeb18 DW |
567 | |
568 | if (!xfs_is_reflink_inode(ip)) | |
569 | return 0; | |
df5ab1b5 | 570 | if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got)) |
3e0ee78f | 571 | return 0; |
43caeb18 | 572 | |
3e0ee78f CH |
573 | while (got.br_startoff < end_fsb) { |
574 | del = got; | |
575 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
576 | trace_xfs_reflink_cancel_cow(ip, &del); | |
43caeb18 | 577 | |
3e0ee78f CH |
578 | if (isnullstartblock(del.br_startblock)) { |
579 | error = xfs_bmap_del_extent_delay(ip, XFS_COW_FORK, | |
580 | &idx, &got, &del); | |
43caeb18 DW |
581 | if (error) |
582 | break; | |
3802a345 | 583 | } else if (del.br_state == XFS_EXT_UNWRITTEN || cancel_real) { |
43caeb18 DW |
584 | xfs_trans_ijoin(*tpp, ip, 0); |
585 | xfs_defer_init(&dfops, &firstfsb); | |
586 | ||
174edb0e DW |
587 | /* Free the CoW orphan record. */ |
588 | error = xfs_refcount_free_cow_extent(ip->i_mount, | |
3e0ee78f CH |
589 | &dfops, del.br_startblock, |
590 | del.br_blockcount); | |
174edb0e DW |
591 | if (error) |
592 | break; | |
593 | ||
43caeb18 | 594 | xfs_bmap_add_free(ip->i_mount, &dfops, |
3e0ee78f | 595 | del.br_startblock, del.br_blockcount, |
43caeb18 DW |
596 | NULL); |
597 | ||
598 | /* Update quota accounting */ | |
599 | xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT, | |
3e0ee78f | 600 | -(long)del.br_blockcount); |
43caeb18 DW |
601 | |
602 | /* Roll the transaction */ | |
603 | error = xfs_defer_finish(tpp, &dfops, ip); | |
604 | if (error) { | |
605 | xfs_defer_cancel(&dfops); | |
606 | break; | |
607 | } | |
608 | ||
609 | /* Remove the mapping from the CoW fork. */ | |
3e0ee78f | 610 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); |
43caeb18 DW |
611 | } |
612 | ||
df5ab1b5 | 613 | if (!xfs_iext_get_extent(ifp, ++idx, &got)) |
c17a8ef4 | 614 | break; |
43caeb18 DW |
615 | } |
616 | ||
c17a8ef4 BF |
617 | /* clear tag if cow fork is emptied */ |
618 | if (!ifp->if_bytes) | |
619 | xfs_inode_clear_cowblocks_tag(ip); | |
620 | ||
43caeb18 DW |
621 | return error; |
622 | } | |
623 | ||
624 | /* | |
3802a345 CH |
625 | * Cancel CoW reservations for some byte range of an inode. |
626 | * | |
627 | * If cancel_real is true this function cancels all COW fork extents for the | |
628 | * inode; if cancel_real is false, real extents are not cleared. | |
43caeb18 DW |
629 | */ |
630 | int | |
631 | xfs_reflink_cancel_cow_range( | |
632 | struct xfs_inode *ip, | |
633 | xfs_off_t offset, | |
3802a345 CH |
634 | xfs_off_t count, |
635 | bool cancel_real) | |
43caeb18 DW |
636 | { |
637 | struct xfs_trans *tp; | |
638 | xfs_fileoff_t offset_fsb; | |
639 | xfs_fileoff_t end_fsb; | |
640 | int error; | |
641 | ||
642 | trace_xfs_reflink_cancel_cow_range(ip, offset, count); | |
63646fc5 | 643 | ASSERT(xfs_is_reflink_inode(ip)); |
43caeb18 DW |
644 | |
645 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); | |
646 | if (count == NULLFILEOFF) | |
647 | end_fsb = NULLFILEOFF; | |
648 | else | |
649 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
650 | ||
651 | /* Start a rolling transaction to remove the mappings */ | |
652 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
653 | 0, 0, 0, &tp); | |
654 | if (error) | |
655 | goto out; | |
656 | ||
657 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
658 | xfs_trans_ijoin(tp, ip, 0); | |
659 | ||
660 | /* Scrape out the old CoW reservations */ | |
3802a345 CH |
661 | error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb, |
662 | cancel_real); | |
43caeb18 DW |
663 | if (error) |
664 | goto out_cancel; | |
665 | ||
666 | error = xfs_trans_commit(tp); | |
667 | ||
668 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
669 | return error; | |
670 | ||
671 | out_cancel: | |
672 | xfs_trans_cancel(tp); | |
673 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
674 | out: | |
675 | trace_xfs_reflink_cancel_cow_range_error(ip, error, _RET_IP_); | |
676 | return error; | |
677 | } | |
678 | ||
679 | /* | |
680 | * Remap parts of a file's data fork after a successful CoW. | |
681 | */ | |
682 | int | |
683 | xfs_reflink_end_cow( | |
684 | struct xfs_inode *ip, | |
685 | xfs_off_t offset, | |
686 | xfs_off_t count) | |
687 | { | |
c1112b6e | 688 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
4ab8671c | 689 | struct xfs_bmbt_irec got, del; |
43caeb18 DW |
690 | struct xfs_trans *tp; |
691 | xfs_fileoff_t offset_fsb; | |
692 | xfs_fileoff_t end_fsb; | |
43caeb18 DW |
693 | xfs_fsblock_t firstfsb; |
694 | struct xfs_defer_ops dfops; | |
4ab8671c | 695 | int error; |
43caeb18 | 696 | unsigned int resblks; |
43caeb18 | 697 | xfs_filblks_t rlen; |
c1112b6e | 698 | xfs_extnum_t idx; |
43caeb18 DW |
699 | |
700 | trace_xfs_reflink_end_cow(ip, offset, count); | |
701 | ||
c1112b6e CH |
702 | /* No COW extents? That's easy! */ |
703 | if (ifp->if_bytes == 0) | |
704 | return 0; | |
705 | ||
43caeb18 DW |
706 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); |
707 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
43caeb18 | 708 | |
fe0be23e DW |
709 | /* |
710 | * Start a rolling transaction to switch the mappings. We're | |
711 | * unlikely ever to have to remap 16T worth of single-block | |
712 | * extents, so just cap the worst case extent count to 2^32-1. | |
713 | * Stick a warning in just in case, and avoid 64-bit division. | |
714 | */ | |
715 | BUILD_BUG_ON(MAX_RW_COUNT > UINT_MAX); | |
716 | if (end_fsb - offset_fsb > UINT_MAX) { | |
717 | error = -EFSCORRUPTED; | |
718 | xfs_force_shutdown(ip->i_mount, SHUTDOWN_CORRUPT_INCORE); | |
719 | ASSERT(0); | |
720 | goto out; | |
721 | } | |
722 | resblks = XFS_NEXTENTADD_SPACE_RES(ip->i_mount, | |
723 | (unsigned int)(end_fsb - offset_fsb), | |
724 | XFS_DATA_FORK); | |
43caeb18 DW |
725 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, |
726 | resblks, 0, 0, &tp); | |
727 | if (error) | |
728 | goto out; | |
729 | ||
730 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
731 | xfs_trans_ijoin(tp, ip, 0); | |
732 | ||
c1112b6e | 733 | /* If there is a hole at end_fsb - 1 go to the previous extent */ |
4ab8671c CH |
734 | if (!xfs_iext_lookup_extent(ip, ifp, end_fsb - 1, &idx, &got) || |
735 | got.br_startoff > end_fsb) { | |
c1112b6e | 736 | ASSERT(idx > 0); |
4ab8671c | 737 | xfs_iext_get_extent(ifp, --idx, &got); |
c1112b6e | 738 | } |
43caeb18 | 739 | |
c1112b6e CH |
740 | /* Walk backwards until we're out of the I/O range... */ |
741 | while (got.br_startoff + got.br_blockcount > offset_fsb) { | |
742 | del = got; | |
743 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
744 | ||
745 | /* Extent delete may have bumped idx forward */ | |
746 | if (!del.br_blockcount) { | |
747 | idx--; | |
43caeb18 | 748 | goto next_extent; |
c1112b6e CH |
749 | } |
750 | ||
751 | ASSERT(!isnullstartblock(got.br_startblock)); | |
43caeb18 | 752 | |
5eda4300 DW |
753 | /* |
754 | * Don't remap unwritten extents; these are | |
755 | * speculatively preallocated CoW extents that have been | |
756 | * allocated but have not yet been involved in a write. | |
757 | */ | |
758 | if (got.br_state == XFS_EXT_UNWRITTEN) { | |
759 | idx--; | |
760 | goto next_extent; | |
761 | } | |
762 | ||
43caeb18 | 763 | /* Unmap the old blocks in the data fork. */ |
c1112b6e CH |
764 | xfs_defer_init(&dfops, &firstfsb); |
765 | rlen = del.br_blockcount; | |
766 | error = __xfs_bunmapi(tp, ip, del.br_startoff, &rlen, 0, 1, | |
767 | &firstfsb, &dfops); | |
768 | if (error) | |
769 | goto out_defer; | |
43caeb18 | 770 | |
c1112b6e CH |
771 | /* Trim the extent to whatever got unmapped. */ |
772 | if (rlen) { | |
773 | xfs_trim_extent(&del, del.br_startoff + rlen, | |
774 | del.br_blockcount - rlen); | |
775 | } | |
776 | trace_xfs_reflink_cow_remap(ip, &del); | |
174edb0e | 777 | |
c1112b6e CH |
778 | /* Free the CoW orphan record. */ |
779 | error = xfs_refcount_free_cow_extent(tp->t_mountp, &dfops, | |
780 | del.br_startblock, del.br_blockcount); | |
781 | if (error) | |
782 | goto out_defer; | |
43caeb18 | 783 | |
c1112b6e CH |
784 | /* Map the new blocks into the data fork. */ |
785 | error = xfs_bmap_map_extent(tp->t_mountp, &dfops, ip, &del); | |
786 | if (error) | |
787 | goto out_defer; | |
43caeb18 | 788 | |
c1112b6e CH |
789 | /* Remove the mapping from the CoW fork. */ |
790 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); | |
791 | ||
792 | error = xfs_defer_finish(&tp, &dfops, ip); | |
793 | if (error) | |
794 | goto out_defer; | |
43caeb18 | 795 | next_extent: |
4ab8671c | 796 | if (!xfs_iext_get_extent(ifp, idx, &got)) |
c1112b6e | 797 | break; |
43caeb18 DW |
798 | } |
799 | ||
800 | error = xfs_trans_commit(tp); | |
801 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
802 | if (error) | |
803 | goto out; | |
804 | return 0; | |
805 | ||
806 | out_defer: | |
807 | xfs_defer_cancel(&dfops); | |
43caeb18 DW |
808 | xfs_trans_cancel(tp); |
809 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
810 | out: | |
811 | trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); | |
812 | return error; | |
813 | } | |
174edb0e DW |
814 | |
815 | /* | |
816 | * Free leftover CoW reservations that didn't get cleaned out. | |
817 | */ | |
818 | int | |
819 | xfs_reflink_recover_cow( | |
820 | struct xfs_mount *mp) | |
821 | { | |
822 | xfs_agnumber_t agno; | |
823 | int error = 0; | |
824 | ||
825 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
826 | return 0; | |
827 | ||
828 | for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { | |
829 | error = xfs_refcount_recover_cow_leftovers(mp, agno); | |
830 | if (error) | |
831 | break; | |
832 | } | |
833 | ||
834 | return error; | |
835 | } | |
862bb360 DW |
836 | |
837 | /* | |
838 | * Reflinking (Block) Ranges of Two Files Together | |
839 | * | |
840 | * First, ensure that the reflink flag is set on both inodes. The flag is an | |
841 | * optimization to avoid unnecessary refcount btree lookups in the write path. | |
842 | * | |
843 | * Now we can iteratively remap the range of extents (and holes) in src to the | |
844 | * corresponding ranges in dest. Let drange and srange denote the ranges of | |
845 | * logical blocks in dest and src touched by the reflink operation. | |
846 | * | |
847 | * While the length of drange is greater than zero, | |
848 | * - Read src's bmbt at the start of srange ("imap") | |
849 | * - If imap doesn't exist, make imap appear to start at the end of srange | |
850 | * with zero length. | |
851 | * - If imap starts before srange, advance imap to start at srange. | |
852 | * - If imap goes beyond srange, truncate imap to end at the end of srange. | |
853 | * - Punch (imap start - srange start + imap len) blocks from dest at | |
854 | * offset (drange start). | |
855 | * - If imap points to a real range of pblks, | |
856 | * > Increase the refcount of the imap's pblks | |
857 | * > Map imap's pblks into dest at the offset | |
858 | * (drange start + imap start - srange start) | |
859 | * - Advance drange and srange by (imap start - srange start + imap len) | |
860 | * | |
861 | * Finally, if the reflink made dest longer, update both the in-core and | |
862 | * on-disk file sizes. | |
863 | * | |
864 | * ASCII Art Demonstration: | |
865 | * | |
866 | * Let's say we want to reflink this source file: | |
867 | * | |
868 | * ----SSSSSSS-SSSSS----SSSSSS (src file) | |
869 | * <--------------------> | |
870 | * | |
871 | * into this destination file: | |
872 | * | |
873 | * --DDDDDDDDDDDDDDDDDDD--DDD (dest file) | |
874 | * <--------------------> | |
875 | * '-' means a hole, and 'S' and 'D' are written blocks in the src and dest. | |
876 | * Observe that the range has different logical offsets in either file. | |
877 | * | |
878 | * Consider that the first extent in the source file doesn't line up with our | |
879 | * reflink range. Unmapping and remapping are separate operations, so we can | |
880 | * unmap more blocks from the destination file than we remap. | |
881 | * | |
882 | * ----SSSSSSS-SSSSS----SSSSSS | |
883 | * <-------> | |
884 | * --DDDDD---------DDDDD--DDD | |
885 | * <-------> | |
886 | * | |
887 | * Now remap the source extent into the destination file: | |
888 | * | |
889 | * ----SSSSSSS-SSSSS----SSSSSS | |
890 | * <-------> | |
891 | * --DDDDD--SSSSSSSDDDDD--DDD | |
892 | * <-------> | |
893 | * | |
894 | * Do likewise with the second hole and extent in our range. Holes in the | |
895 | * unmap range don't affect our operation. | |
896 | * | |
897 | * ----SSSSSSS-SSSSS----SSSSSS | |
898 | * <----> | |
899 | * --DDDDD--SSSSSSS-SSSSS-DDD | |
900 | * <----> | |
901 | * | |
902 | * Finally, unmap and remap part of the third extent. This will increase the | |
903 | * size of the destination file. | |
904 | * | |
905 | * ----SSSSSSS-SSSSS----SSSSSS | |
906 | * <-----> | |
907 | * --DDDDD--SSSSSSS-SSSSS----SSS | |
908 | * <-----> | |
909 | * | |
910 | * Once we update the destination file's i_size, we're done. | |
911 | */ | |
912 | ||
913 | /* | |
914 | * Ensure the reflink bit is set in both inodes. | |
915 | */ | |
916 | STATIC int | |
917 | xfs_reflink_set_inode_flag( | |
918 | struct xfs_inode *src, | |
919 | struct xfs_inode *dest) | |
920 | { | |
921 | struct xfs_mount *mp = src->i_mount; | |
922 | int error; | |
923 | struct xfs_trans *tp; | |
924 | ||
925 | if (xfs_is_reflink_inode(src) && xfs_is_reflink_inode(dest)) | |
926 | return 0; | |
927 | ||
928 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
929 | if (error) | |
930 | goto out_error; | |
931 | ||
932 | /* Lock both files against IO */ | |
933 | if (src->i_ino == dest->i_ino) | |
934 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
935 | else | |
936 | xfs_lock_two_inodes(src, dest, XFS_ILOCK_EXCL); | |
937 | ||
938 | if (!xfs_is_reflink_inode(src)) { | |
939 | trace_xfs_reflink_set_inode_flag(src); | |
940 | xfs_trans_ijoin(tp, src, XFS_ILOCK_EXCL); | |
941 | src->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
942 | xfs_trans_log_inode(tp, src, XFS_ILOG_CORE); | |
943 | xfs_ifork_init_cow(src); | |
944 | } else | |
945 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
946 | ||
947 | if (src->i_ino == dest->i_ino) | |
948 | goto commit_flags; | |
949 | ||
950 | if (!xfs_is_reflink_inode(dest)) { | |
951 | trace_xfs_reflink_set_inode_flag(dest); | |
952 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
953 | dest->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
954 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); | |
955 | xfs_ifork_init_cow(dest); | |
956 | } else | |
957 | xfs_iunlock(dest, XFS_ILOCK_EXCL); | |
958 | ||
959 | commit_flags: | |
960 | error = xfs_trans_commit(tp); | |
961 | if (error) | |
962 | goto out_error; | |
963 | return error; | |
964 | ||
965 | out_error: | |
966 | trace_xfs_reflink_set_inode_flag_error(dest, error, _RET_IP_); | |
967 | return error; | |
968 | } | |
969 | ||
970 | /* | |
f7ca3522 | 971 | * Update destination inode size & cowextsize hint, if necessary. |
862bb360 DW |
972 | */ |
973 | STATIC int | |
974 | xfs_reflink_update_dest( | |
975 | struct xfs_inode *dest, | |
f7ca3522 | 976 | xfs_off_t newlen, |
c5ecb423 CH |
977 | xfs_extlen_t cowextsize, |
978 | bool is_dedupe) | |
862bb360 DW |
979 | { |
980 | struct xfs_mount *mp = dest->i_mount; | |
981 | struct xfs_trans *tp; | |
982 | int error; | |
983 | ||
c5ecb423 | 984 | if (is_dedupe && newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0) |
862bb360 DW |
985 | return 0; |
986 | ||
987 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
988 | if (error) | |
989 | goto out_error; | |
990 | ||
991 | xfs_ilock(dest, XFS_ILOCK_EXCL); | |
992 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
993 | ||
f7ca3522 DW |
994 | if (newlen > i_size_read(VFS_I(dest))) { |
995 | trace_xfs_reflink_update_inode_size(dest, newlen); | |
996 | i_size_write(VFS_I(dest), newlen); | |
997 | dest->i_d.di_size = newlen; | |
998 | } | |
999 | ||
1000 | if (cowextsize) { | |
1001 | dest->i_d.di_cowextsize = cowextsize; | |
1002 | dest->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE; | |
1003 | } | |
1004 | ||
c5ecb423 CH |
1005 | if (!is_dedupe) { |
1006 | xfs_trans_ichgtime(tp, dest, | |
1007 | XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); | |
1008 | } | |
862bb360 DW |
1009 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); |
1010 | ||
1011 | error = xfs_trans_commit(tp); | |
1012 | if (error) | |
1013 | goto out_error; | |
1014 | return error; | |
1015 | ||
1016 | out_error: | |
1017 | trace_xfs_reflink_update_inode_size_error(dest, error, _RET_IP_); | |
1018 | return error; | |
1019 | } | |
1020 | ||
6fa164b8 DW |
1021 | /* |
1022 | * Do we have enough reserve in this AG to handle a reflink? The refcount | |
1023 | * btree already reserved all the space it needs, but the rmap btree can grow | |
1024 | * infinitely, so we won't allow more reflinks when the AG is down to the | |
1025 | * btree reserves. | |
1026 | */ | |
1027 | static int | |
1028 | xfs_reflink_ag_has_free_space( | |
1029 | struct xfs_mount *mp, | |
1030 | xfs_agnumber_t agno) | |
1031 | { | |
1032 | struct xfs_perag *pag; | |
1033 | int error = 0; | |
1034 | ||
1035 | if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) | |
1036 | return 0; | |
1037 | ||
1038 | pag = xfs_perag_get(mp, agno); | |
1039 | if (xfs_ag_resv_critical(pag, XFS_AG_RESV_AGFL) || | |
1040 | xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA)) | |
1041 | error = -ENOSPC; | |
1042 | xfs_perag_put(pag); | |
1043 | return error; | |
1044 | } | |
1045 | ||
862bb360 DW |
1046 | /* |
1047 | * Unmap a range of blocks from a file, then map other blocks into the hole. | |
1048 | * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount). | |
1049 | * The extent irec is mapped into dest at irec->br_startoff. | |
1050 | */ | |
1051 | STATIC int | |
1052 | xfs_reflink_remap_extent( | |
1053 | struct xfs_inode *ip, | |
1054 | struct xfs_bmbt_irec *irec, | |
1055 | xfs_fileoff_t destoff, | |
1056 | xfs_off_t new_isize) | |
1057 | { | |
1058 | struct xfs_mount *mp = ip->i_mount; | |
9c4f29d3 | 1059 | bool real_extent = xfs_bmap_is_real_extent(irec); |
862bb360 DW |
1060 | struct xfs_trans *tp; |
1061 | xfs_fsblock_t firstfsb; | |
1062 | unsigned int resblks; | |
1063 | struct xfs_defer_ops dfops; | |
1064 | struct xfs_bmbt_irec uirec; | |
862bb360 DW |
1065 | xfs_filblks_t rlen; |
1066 | xfs_filblks_t unmap_len; | |
1067 | xfs_off_t newlen; | |
1068 | int error; | |
1069 | ||
1070 | unmap_len = irec->br_startoff + irec->br_blockcount - destoff; | |
1071 | trace_xfs_reflink_punch_range(ip, destoff, unmap_len); | |
1072 | ||
6fa164b8 DW |
1073 | /* No reflinking if we're low on space */ |
1074 | if (real_extent) { | |
1075 | error = xfs_reflink_ag_has_free_space(mp, | |
1076 | XFS_FSB_TO_AGNO(mp, irec->br_startblock)); | |
1077 | if (error) | |
1078 | goto out; | |
1079 | } | |
1080 | ||
862bb360 DW |
1081 | /* Start a rolling transaction to switch the mappings */ |
1082 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
1083 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); | |
1084 | if (error) | |
1085 | goto out; | |
1086 | ||
1087 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1088 | xfs_trans_ijoin(tp, ip, 0); | |
1089 | ||
1090 | /* If we're not just clearing space, then do we have enough quota? */ | |
1091 | if (real_extent) { | |
1092 | error = xfs_trans_reserve_quota_nblks(tp, ip, | |
1093 | irec->br_blockcount, 0, XFS_QMOPT_RES_REGBLKS); | |
1094 | if (error) | |
1095 | goto out_cancel; | |
1096 | } | |
1097 | ||
1098 | trace_xfs_reflink_remap(ip, irec->br_startoff, | |
1099 | irec->br_blockcount, irec->br_startblock); | |
1100 | ||
1101 | /* Unmap the old blocks in the data fork. */ | |
1102 | rlen = unmap_len; | |
1103 | while (rlen) { | |
1104 | xfs_defer_init(&dfops, &firstfsb); | |
1105 | error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1, | |
1106 | &firstfsb, &dfops); | |
1107 | if (error) | |
1108 | goto out_defer; | |
1109 | ||
1110 | /* | |
1111 | * Trim the extent to whatever got unmapped. | |
1112 | * Remember, bunmapi works backwards. | |
1113 | */ | |
1114 | uirec.br_startblock = irec->br_startblock + rlen; | |
1115 | uirec.br_startoff = irec->br_startoff + rlen; | |
1116 | uirec.br_blockcount = unmap_len - rlen; | |
1117 | unmap_len = rlen; | |
1118 | ||
1119 | /* If this isn't a real mapping, we're done. */ | |
1120 | if (!real_extent || uirec.br_blockcount == 0) | |
1121 | goto next_extent; | |
1122 | ||
1123 | trace_xfs_reflink_remap(ip, uirec.br_startoff, | |
1124 | uirec.br_blockcount, uirec.br_startblock); | |
1125 | ||
1126 | /* Update the refcount tree */ | |
1127 | error = xfs_refcount_increase_extent(mp, &dfops, &uirec); | |
1128 | if (error) | |
1129 | goto out_defer; | |
1130 | ||
1131 | /* Map the new blocks into the data fork. */ | |
1132 | error = xfs_bmap_map_extent(mp, &dfops, ip, &uirec); | |
1133 | if (error) | |
1134 | goto out_defer; | |
1135 | ||
1136 | /* Update quota accounting. */ | |
1137 | xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, | |
1138 | uirec.br_blockcount); | |
1139 | ||
1140 | /* Update dest isize if needed. */ | |
1141 | newlen = XFS_FSB_TO_B(mp, | |
1142 | uirec.br_startoff + uirec.br_blockcount); | |
1143 | newlen = min_t(xfs_off_t, newlen, new_isize); | |
1144 | if (newlen > i_size_read(VFS_I(ip))) { | |
1145 | trace_xfs_reflink_update_inode_size(ip, newlen); | |
1146 | i_size_write(VFS_I(ip), newlen); | |
1147 | ip->i_d.di_size = newlen; | |
1148 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
1149 | } | |
1150 | ||
1151 | next_extent: | |
1152 | /* Process all the deferred stuff. */ | |
1153 | error = xfs_defer_finish(&tp, &dfops, ip); | |
1154 | if (error) | |
1155 | goto out_defer; | |
1156 | } | |
1157 | ||
1158 | error = xfs_trans_commit(tp); | |
1159 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1160 | if (error) | |
1161 | goto out; | |
1162 | return 0; | |
1163 | ||
1164 | out_defer: | |
1165 | xfs_defer_cancel(&dfops); | |
1166 | out_cancel: | |
1167 | xfs_trans_cancel(tp); | |
1168 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1169 | out: | |
1170 | trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_); | |
1171 | return error; | |
1172 | } | |
1173 | ||
1174 | /* | |
1175 | * Iteratively remap one file's extents (and holes) to another's. | |
1176 | */ | |
1177 | STATIC int | |
1178 | xfs_reflink_remap_blocks( | |
1179 | struct xfs_inode *src, | |
1180 | xfs_fileoff_t srcoff, | |
1181 | struct xfs_inode *dest, | |
1182 | xfs_fileoff_t destoff, | |
1183 | xfs_filblks_t len, | |
1184 | xfs_off_t new_isize) | |
1185 | { | |
1186 | struct xfs_bmbt_irec imap; | |
1187 | int nimaps; | |
1188 | int error = 0; | |
1189 | xfs_filblks_t range_len; | |
1190 | ||
1191 | /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ | |
1192 | while (len) { | |
1193 | trace_xfs_reflink_remap_blocks_loop(src, srcoff, len, | |
1194 | dest, destoff); | |
1195 | /* Read extent from the source file */ | |
1196 | nimaps = 1; | |
1197 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
1198 | error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); | |
1199 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
1200 | if (error) | |
1201 | goto err; | |
1202 | ASSERT(nimaps == 1); | |
1203 | ||
1204 | trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE, | |
1205 | &imap); | |
1206 | ||
1207 | /* Translate imap into the destination file. */ | |
1208 | range_len = imap.br_startoff + imap.br_blockcount - srcoff; | |
1209 | imap.br_startoff += destoff - srcoff; | |
1210 | ||
1211 | /* Clear dest from destoff to the end of imap and map it in. */ | |
1212 | error = xfs_reflink_remap_extent(dest, &imap, destoff, | |
1213 | new_isize); | |
1214 | if (error) | |
1215 | goto err; | |
1216 | ||
1217 | if (fatal_signal_pending(current)) { | |
1218 | error = -EINTR; | |
1219 | goto err; | |
1220 | } | |
1221 | ||
1222 | /* Advance drange/srange */ | |
1223 | srcoff += range_len; | |
1224 | destoff += range_len; | |
1225 | len -= range_len; | |
1226 | } | |
1227 | ||
1228 | return 0; | |
1229 | ||
1230 | err: | |
1231 | trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_); | |
1232 | return error; | |
1233 | } | |
1234 | ||
1235 | /* | |
1236 | * Link a range of blocks from one file to another. | |
1237 | */ | |
1238 | int | |
1239 | xfs_reflink_remap_range( | |
5faaf4fa CH |
1240 | struct file *file_in, |
1241 | loff_t pos_in, | |
1242 | struct file *file_out, | |
1243 | loff_t pos_out, | |
1244 | u64 len, | |
1245 | bool is_dedupe) | |
862bb360 | 1246 | { |
5faaf4fa CH |
1247 | struct inode *inode_in = file_inode(file_in); |
1248 | struct xfs_inode *src = XFS_I(inode_in); | |
1249 | struct inode *inode_out = file_inode(file_out); | |
1250 | struct xfs_inode *dest = XFS_I(inode_out); | |
862bb360 | 1251 | struct xfs_mount *mp = src->i_mount; |
5faaf4fa | 1252 | bool same_inode = (inode_in == inode_out); |
862bb360 DW |
1253 | xfs_fileoff_t sfsbno, dfsbno; |
1254 | xfs_filblks_t fsblen; | |
f7ca3522 | 1255 | xfs_extlen_t cowextsize; |
5faaf4fa | 1256 | ssize_t ret; |
862bb360 DW |
1257 | |
1258 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1259 | return -EOPNOTSUPP; | |
1260 | ||
1261 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1262 | return -EIO; | |
1263 | ||
5faaf4fa | 1264 | /* Lock both files against IO */ |
65523218 CH |
1265 | lock_two_nondirectories(inode_in, inode_out); |
1266 | if (same_inode) | |
5faaf4fa | 1267 | xfs_ilock(src, XFS_MMAPLOCK_EXCL); |
65523218 | 1268 | else |
5faaf4fa | 1269 | xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL); |
5faaf4fa | 1270 | |
876bec6f | 1271 | /* Check file eligibility and prepare for block sharing. */ |
5faaf4fa | 1272 | ret = -EINVAL; |
862bb360 DW |
1273 | /* Don't reflink realtime inodes */ |
1274 | if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest)) | |
5faaf4fa CH |
1275 | goto out_unlock; |
1276 | ||
1277 | /* Don't share DAX file data for now. */ | |
1278 | if (IS_DAX(inode_in) || IS_DAX(inode_out)) | |
1279 | goto out_unlock; | |
1280 | ||
876bec6f DW |
1281 | ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out, |
1282 | &len, is_dedupe); | |
22725ce4 | 1283 | if (ret <= 0) |
5faaf4fa CH |
1284 | goto out_unlock; |
1285 | ||
1286 | trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); | |
862bb360 | 1287 | |
876bec6f | 1288 | /* Set flags and remap blocks. */ |
5faaf4fa CH |
1289 | ret = xfs_reflink_set_inode_flag(src, dest); |
1290 | if (ret) | |
1291 | goto out_unlock; | |
862bb360 | 1292 | |
5faaf4fa CH |
1293 | dfsbno = XFS_B_TO_FSBT(mp, pos_out); |
1294 | sfsbno = XFS_B_TO_FSBT(mp, pos_in); | |
862bb360 | 1295 | fsblen = XFS_B_TO_FSB(mp, len); |
5faaf4fa CH |
1296 | ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, |
1297 | pos_out + len); | |
1298 | if (ret) | |
1299 | goto out_unlock; | |
862bb360 | 1300 | |
876bec6f DW |
1301 | /* Zap any page cache for the destination file's range. */ |
1302 | truncate_inode_pages_range(&inode_out->i_data, pos_out, | |
1303 | PAGE_ALIGN(pos_out + len) - 1); | |
1304 | ||
f7ca3522 DW |
1305 | /* |
1306 | * Carry the cowextsize hint from src to dest if we're sharing the | |
1307 | * entire source file to the entire destination file, the source file | |
1308 | * has a cowextsize hint, and the destination file does not. | |
1309 | */ | |
1310 | cowextsize = 0; | |
5faaf4fa | 1311 | if (pos_in == 0 && len == i_size_read(inode_in) && |
f7ca3522 | 1312 | (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) && |
5faaf4fa | 1313 | pos_out == 0 && len >= i_size_read(inode_out) && |
f7ca3522 DW |
1314 | !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)) |
1315 | cowextsize = src->i_d.di_cowextsize; | |
1316 | ||
c5ecb423 CH |
1317 | ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize, |
1318 | is_dedupe); | |
862bb360 | 1319 | |
5faaf4fa CH |
1320 | out_unlock: |
1321 | xfs_iunlock(src, XFS_MMAPLOCK_EXCL); | |
65523218 | 1322 | if (!same_inode) |
5faaf4fa | 1323 | xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); |
65523218 | 1324 | unlock_two_nondirectories(inode_in, inode_out); |
5faaf4fa CH |
1325 | if (ret) |
1326 | trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); | |
1327 | return ret; | |
862bb360 | 1328 | } |
98cc2db5 DW |
1329 | |
1330 | /* | |
1331 | * The user wants to preemptively CoW all shared blocks in this file, | |
1332 | * which enables us to turn off the reflink flag. Iterate all | |
1333 | * extents which are not prealloc/delalloc to see which ranges are | |
1334 | * mentioned in the refcount tree, then read those blocks into the | |
1335 | * pagecache, dirty them, fsync them back out, and then we can update | |
1336 | * the inode flag. What happens if we run out of memory? :) | |
1337 | */ | |
1338 | STATIC int | |
1339 | xfs_reflink_dirty_extents( | |
1340 | struct xfs_inode *ip, | |
1341 | xfs_fileoff_t fbno, | |
1342 | xfs_filblks_t end, | |
1343 | xfs_off_t isize) | |
1344 | { | |
1345 | struct xfs_mount *mp = ip->i_mount; | |
1346 | xfs_agnumber_t agno; | |
1347 | xfs_agblock_t agbno; | |
1348 | xfs_extlen_t aglen; | |
1349 | xfs_agblock_t rbno; | |
1350 | xfs_extlen_t rlen; | |
1351 | xfs_off_t fpos; | |
1352 | xfs_off_t flen; | |
1353 | struct xfs_bmbt_irec map[2]; | |
1354 | int nmaps; | |
9780643c | 1355 | int error = 0; |
98cc2db5 DW |
1356 | |
1357 | while (end - fbno > 0) { | |
1358 | nmaps = 1; | |
1359 | /* | |
1360 | * Look for extents in the file. Skip holes, delalloc, or | |
1361 | * unwritten extents; they can't be reflinked. | |
1362 | */ | |
1363 | error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); | |
1364 | if (error) | |
1365 | goto out; | |
1366 | if (nmaps == 0) | |
1367 | break; | |
9c4f29d3 | 1368 | if (!xfs_bmap_is_real_extent(&map[0])) |
98cc2db5 DW |
1369 | goto next; |
1370 | ||
1371 | map[1] = map[0]; | |
1372 | while (map[1].br_blockcount) { | |
1373 | agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); | |
1374 | agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); | |
1375 | aglen = map[1].br_blockcount; | |
1376 | ||
92ff7285 DW |
1377 | error = xfs_reflink_find_shared(mp, NULL, agno, agbno, |
1378 | aglen, &rbno, &rlen, true); | |
98cc2db5 DW |
1379 | if (error) |
1380 | goto out; | |
1381 | if (rbno == NULLAGBLOCK) | |
1382 | break; | |
1383 | ||
1384 | /* Dirty the pages */ | |
1385 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1386 | fpos = XFS_FSB_TO_B(mp, map[1].br_startoff + | |
1387 | (rbno - agbno)); | |
1388 | flen = XFS_FSB_TO_B(mp, rlen); | |
1389 | if (fpos + flen > isize) | |
1390 | flen = isize - fpos; | |
1391 | error = iomap_file_dirty(VFS_I(ip), fpos, flen, | |
1392 | &xfs_iomap_ops); | |
1393 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1394 | if (error) | |
1395 | goto out; | |
1396 | ||
1397 | map[1].br_blockcount -= (rbno - agbno + rlen); | |
1398 | map[1].br_startoff += (rbno - agbno + rlen); | |
1399 | map[1].br_startblock += (rbno - agbno + rlen); | |
1400 | } | |
1401 | ||
1402 | next: | |
1403 | fbno = map[0].br_startoff + map[0].br_blockcount; | |
1404 | } | |
1405 | out: | |
1406 | return error; | |
1407 | } | |
1408 | ||
ea7cdd7b | 1409 | /* Does this inode need the reflink flag? */ |
98cc2db5 | 1410 | int |
ea7cdd7b DW |
1411 | xfs_reflink_inode_has_shared_extents( |
1412 | struct xfs_trans *tp, | |
1413 | struct xfs_inode *ip, | |
1414 | bool *has_shared) | |
98cc2db5 | 1415 | { |
ea7cdd7b DW |
1416 | struct xfs_bmbt_irec got; |
1417 | struct xfs_mount *mp = ip->i_mount; | |
1418 | struct xfs_ifork *ifp; | |
1419 | xfs_agnumber_t agno; | |
1420 | xfs_agblock_t agbno; | |
1421 | xfs_extlen_t aglen; | |
1422 | xfs_agblock_t rbno; | |
1423 | xfs_extlen_t rlen; | |
1424 | xfs_extnum_t idx; | |
1425 | bool found; | |
1426 | int error; | |
98cc2db5 | 1427 | |
ea7cdd7b DW |
1428 | ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK); |
1429 | if (!(ifp->if_flags & XFS_IFEXTENTS)) { | |
1430 | error = xfs_iread_extents(tp, ip, XFS_DATA_FORK); | |
98cc2db5 DW |
1431 | if (error) |
1432 | return error; | |
ea7cdd7b | 1433 | } |
98cc2db5 | 1434 | |
ea7cdd7b DW |
1435 | *has_shared = false; |
1436 | found = xfs_iext_lookup_extent(ip, ifp, 0, &idx, &got); | |
1437 | while (found) { | |
1438 | if (isnullstartblock(got.br_startblock) || | |
1439 | got.br_state != XFS_EXT_NORM) | |
1440 | goto next; | |
1441 | agno = XFS_FSB_TO_AGNO(mp, got.br_startblock); | |
1442 | agbno = XFS_FSB_TO_AGBNO(mp, got.br_startblock); | |
1443 | aglen = got.br_blockcount; | |
98cc2db5 | 1444 | |
ea7cdd7b | 1445 | error = xfs_reflink_find_shared(mp, tp, agno, agbno, aglen, |
024adf48 DW |
1446 | &rbno, &rlen, false); |
1447 | if (error) | |
1448 | return error; | |
1449 | /* Is there still a shared block here? */ | |
ea7cdd7b DW |
1450 | if (rbno != NULLAGBLOCK) { |
1451 | *has_shared = true; | |
024adf48 | 1452 | return 0; |
ea7cdd7b | 1453 | } |
98cc2db5 | 1454 | next: |
ea7cdd7b | 1455 | found = xfs_iext_get_extent(ifp, ++idx, &got); |
98cc2db5 DW |
1456 | } |
1457 | ||
ea7cdd7b DW |
1458 | return 0; |
1459 | } | |
1460 | ||
1461 | /* Clear the inode reflink flag if there are no shared extents. */ | |
1462 | int | |
1463 | xfs_reflink_clear_inode_flag( | |
1464 | struct xfs_inode *ip, | |
1465 | struct xfs_trans **tpp) | |
1466 | { | |
1467 | bool needs_flag; | |
1468 | int error = 0; | |
1469 | ||
1470 | ASSERT(xfs_is_reflink_inode(ip)); | |
1471 | ||
1472 | error = xfs_reflink_inode_has_shared_extents(*tpp, ip, &needs_flag); | |
1473 | if (error || needs_flag) | |
1474 | return error; | |
1475 | ||
98cc2db5 DW |
1476 | /* |
1477 | * We didn't find any shared blocks so turn off the reflink flag. | |
1478 | * First, get rid of any leftover CoW mappings. | |
1479 | */ | |
3802a345 | 1480 | error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, true); |
98cc2db5 DW |
1481 | if (error) |
1482 | return error; | |
1483 | ||
1484 | /* Clear the inode flag. */ | |
1485 | trace_xfs_reflink_unset_inode_flag(ip); | |
1486 | ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; | |
83104d44 | 1487 | xfs_inode_clear_cowblocks_tag(ip); |
98cc2db5 DW |
1488 | xfs_trans_ijoin(*tpp, ip, 0); |
1489 | xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE); | |
1490 | ||
1491 | return error; | |
1492 | } | |
1493 | ||
1494 | /* | |
1495 | * Clear the inode reflink flag if there are no shared extents and the size | |
1496 | * hasn't changed. | |
1497 | */ | |
1498 | STATIC int | |
1499 | xfs_reflink_try_clear_inode_flag( | |
97a1b87e | 1500 | struct xfs_inode *ip) |
98cc2db5 DW |
1501 | { |
1502 | struct xfs_mount *mp = ip->i_mount; | |
1503 | struct xfs_trans *tp; | |
1504 | int error = 0; | |
1505 | ||
1506 | /* Start a rolling transaction to remove the mappings */ | |
1507 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); | |
1508 | if (error) | |
1509 | return error; | |
1510 | ||
1511 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1512 | xfs_trans_ijoin(tp, ip, 0); | |
1513 | ||
98cc2db5 DW |
1514 | error = xfs_reflink_clear_inode_flag(ip, &tp); |
1515 | if (error) | |
1516 | goto cancel; | |
1517 | ||
1518 | error = xfs_trans_commit(tp); | |
1519 | if (error) | |
1520 | goto out; | |
1521 | ||
1522 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1523 | return 0; | |
1524 | cancel: | |
1525 | xfs_trans_cancel(tp); | |
1526 | out: | |
1527 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1528 | return error; | |
1529 | } | |
1530 | ||
1531 | /* | |
1532 | * Pre-COW all shared blocks within a given byte range of a file and turn off | |
1533 | * the reflink flag if we unshare all of the file's blocks. | |
1534 | */ | |
1535 | int | |
1536 | xfs_reflink_unshare( | |
1537 | struct xfs_inode *ip, | |
1538 | xfs_off_t offset, | |
1539 | xfs_off_t len) | |
1540 | { | |
1541 | struct xfs_mount *mp = ip->i_mount; | |
1542 | xfs_fileoff_t fbno; | |
1543 | xfs_filblks_t end; | |
1544 | xfs_off_t isize; | |
1545 | int error; | |
1546 | ||
1547 | if (!xfs_is_reflink_inode(ip)) | |
1548 | return 0; | |
1549 | ||
1550 | trace_xfs_reflink_unshare(ip, offset, len); | |
1551 | ||
1552 | inode_dio_wait(VFS_I(ip)); | |
1553 | ||
1554 | /* Try to CoW the selected ranges */ | |
1555 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
97a1b87e | 1556 | fbno = XFS_B_TO_FSBT(mp, offset); |
98cc2db5 DW |
1557 | isize = i_size_read(VFS_I(ip)); |
1558 | end = XFS_B_TO_FSB(mp, offset + len); | |
1559 | error = xfs_reflink_dirty_extents(ip, fbno, end, isize); | |
1560 | if (error) | |
1561 | goto out_unlock; | |
1562 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1563 | ||
1564 | /* Wait for the IO to finish */ | |
1565 | error = filemap_write_and_wait(VFS_I(ip)->i_mapping); | |
1566 | if (error) | |
1567 | goto out; | |
1568 | ||
97a1b87e DW |
1569 | /* Turn off the reflink flag if possible. */ |
1570 | error = xfs_reflink_try_clear_inode_flag(ip); | |
1571 | if (error) | |
1572 | goto out; | |
98cc2db5 DW |
1573 | |
1574 | return 0; | |
1575 | ||
1576 | out_unlock: | |
1577 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1578 | out: | |
1579 | trace_xfs_reflink_unshare_error(ip, error, _RET_IP_); | |
1580 | return error; | |
1581 | } |