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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, | |
158 | xfs_agnumber_t agno, | |
159 | xfs_agblock_t agbno, | |
160 | xfs_extlen_t aglen, | |
161 | xfs_agblock_t *fbno, | |
162 | xfs_extlen_t *flen, | |
163 | bool find_end_of_shared) | |
164 | { | |
165 | struct xfs_buf *agbp; | |
166 | struct xfs_btree_cur *cur; | |
167 | int error; | |
168 | ||
169 | error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); | |
170 | if (error) | |
171 | return error; | |
172 | ||
173 | cur = xfs_refcountbt_init_cursor(mp, NULL, agbp, agno, NULL); | |
174 | ||
175 | error = xfs_refcount_find_shared(cur, agbno, aglen, fbno, flen, | |
176 | find_end_of_shared); | |
177 | ||
178 | xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); | |
179 | ||
180 | xfs_buf_relse(agbp); | |
181 | return error; | |
182 | } | |
183 | ||
184 | /* | |
185 | * Trim the mapping to the next block where there's a change in the | |
186 | * shared/unshared status. More specifically, this means that we | |
187 | * find the lowest-numbered extent of shared blocks that coincides with | |
188 | * the given block mapping. If the shared extent overlaps the start of | |
189 | * the mapping, trim the mapping to the end of the shared extent. If | |
190 | * the shared region intersects the mapping, trim the mapping to the | |
191 | * start of the shared extent. If there are no shared regions that | |
192 | * overlap, just return the original extent. | |
193 | */ | |
194 | int | |
195 | xfs_reflink_trim_around_shared( | |
196 | struct xfs_inode *ip, | |
197 | struct xfs_bmbt_irec *irec, | |
198 | bool *shared, | |
199 | bool *trimmed) | |
200 | { | |
201 | xfs_agnumber_t agno; | |
202 | xfs_agblock_t agbno; | |
203 | xfs_extlen_t aglen; | |
204 | xfs_agblock_t fbno; | |
205 | xfs_extlen_t flen; | |
206 | int error = 0; | |
207 | ||
208 | /* Holes, unwritten, and delalloc extents cannot be shared */ | |
209 | if (!xfs_is_reflink_inode(ip) || | |
210 | ISUNWRITTEN(irec) || | |
211 | irec->br_startblock == HOLESTARTBLOCK || | |
62c5ac89 CH |
212 | irec->br_startblock == DELAYSTARTBLOCK || |
213 | isnullstartblock(irec->br_startblock)) { | |
2a06705c DW |
214 | *shared = false; |
215 | return 0; | |
216 | } | |
217 | ||
218 | trace_xfs_reflink_trim_around_shared(ip, irec); | |
219 | ||
220 | agno = XFS_FSB_TO_AGNO(ip->i_mount, irec->br_startblock); | |
221 | agbno = XFS_FSB_TO_AGBNO(ip->i_mount, irec->br_startblock); | |
222 | aglen = irec->br_blockcount; | |
223 | ||
224 | error = xfs_reflink_find_shared(ip->i_mount, agno, agbno, | |
225 | aglen, &fbno, &flen, true); | |
226 | if (error) | |
227 | return error; | |
228 | ||
229 | *shared = *trimmed = false; | |
230 | if (fbno == NULLAGBLOCK) { | |
231 | /* No shared blocks at all. */ | |
232 | return 0; | |
233 | } else if (fbno == agbno) { | |
234 | /* | |
235 | * The start of this extent is shared. Truncate the | |
236 | * mapping at the end of the shared region so that a | |
237 | * subsequent iteration starts at the start of the | |
238 | * unshared region. | |
239 | */ | |
240 | irec->br_blockcount = flen; | |
241 | *shared = true; | |
242 | if (flen != aglen) | |
243 | *trimmed = true; | |
244 | return 0; | |
245 | } else { | |
246 | /* | |
247 | * There's a shared extent midway through this extent. | |
248 | * Truncate the mapping at the start of the shared | |
249 | * extent so that a subsequent iteration starts at the | |
250 | * start of the shared region. | |
251 | */ | |
252 | irec->br_blockcount = fbno - agbno; | |
253 | *trimmed = true; | |
254 | return 0; | |
255 | } | |
256 | } | |
257 | ||
3ba020be CH |
258 | /* |
259 | * Trim the passed in imap to the next shared/unshared extent boundary, and | |
260 | * if imap->br_startoff points to a shared extent reserve space for it in the | |
261 | * COW fork. In this case *shared is set to true, else to false. | |
262 | * | |
263 | * Note that imap will always contain the block numbers for the existing blocks | |
264 | * in the data fork, as the upper layers need them for read-modify-write | |
265 | * operations. | |
266 | */ | |
267 | int | |
268 | xfs_reflink_reserve_cow( | |
2a06705c | 269 | struct xfs_inode *ip, |
3ba020be CH |
270 | struct xfs_bmbt_irec *imap, |
271 | bool *shared) | |
2a06705c | 272 | { |
2755fc44 CH |
273 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
274 | struct xfs_bmbt_irec got; | |
2755fc44 CH |
275 | int error = 0; |
276 | bool eof = false, trimmed; | |
2a06705c DW |
277 | xfs_extnum_t idx; |
278 | ||
3ba020be CH |
279 | /* |
280 | * Search the COW fork extent list first. This serves two purposes: | |
281 | * first this implement the speculative preallocation using cowextisze, | |
282 | * so that we also unshared block adjacent to shared blocks instead | |
283 | * of just the shared blocks themselves. Second the lookup in the | |
284 | * extent list is generally faster than going out to the shared extent | |
285 | * tree. | |
286 | */ | |
2755fc44 CH |
287 | |
288 | if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &idx, &got)) | |
289 | eof = true; | |
3ba020be CH |
290 | if (!eof && got.br_startoff <= imap->br_startoff) { |
291 | trace_xfs_reflink_cow_found(ip, imap); | |
292 | xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); | |
2a06705c | 293 | |
3ba020be CH |
294 | *shared = true; |
295 | return 0; | |
296 | } | |
2a06705c DW |
297 | |
298 | /* Trim the mapping to the nearest shared extent boundary. */ | |
3ba020be | 299 | error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); |
2a06705c | 300 | if (error) |
3ba020be | 301 | return error; |
2a06705c DW |
302 | |
303 | /* Not shared? Just report the (potentially capped) extent. */ | |
3ba020be CH |
304 | if (!*shared) |
305 | return 0; | |
2a06705c DW |
306 | |
307 | /* | |
308 | * Fork all the shared blocks from our write offset until the end of | |
309 | * the extent. | |
310 | */ | |
311 | error = xfs_qm_dqattach_locked(ip, 0); | |
312 | if (error) | |
3ba020be CH |
313 | return error; |
314 | ||
3ba020be | 315 | error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff, |
0260d8ff BF |
316 | imap->br_blockcount, 0, &got, &idx, eof); |
317 | if (error == -ENOSPC || error == -EDQUOT) | |
3ba020be | 318 | trace_xfs_reflink_cow_enospc(ip, imap); |
0260d8ff | 319 | if (error) |
3ba020be | 320 | return error; |
83104d44 | 321 | |
2a06705c | 322 | trace_xfs_reflink_cow_alloc(ip, &got); |
3ba020be | 323 | return 0; |
2a06705c | 324 | } |
ef473667 | 325 | |
5eda4300 DW |
326 | /* Convert part of an unwritten CoW extent to a real one. */ |
327 | STATIC int | |
328 | xfs_reflink_convert_cow_extent( | |
329 | struct xfs_inode *ip, | |
330 | struct xfs_bmbt_irec *imap, | |
331 | xfs_fileoff_t offset_fsb, | |
332 | xfs_filblks_t count_fsb, | |
333 | struct xfs_defer_ops *dfops) | |
334 | { | |
5eda4300 DW |
335 | xfs_fsblock_t first_block; |
336 | int nimaps = 1; | |
337 | ||
338 | if (imap->br_state == XFS_EXT_NORM) | |
339 | return 0; | |
340 | ||
dcf9585a CH |
341 | xfs_trim_extent(imap, offset_fsb, count_fsb); |
342 | trace_xfs_reflink_convert_cow(ip, imap); | |
343 | if (imap->br_blockcount == 0) | |
5eda4300 | 344 | return 0; |
dcf9585a | 345 | return xfs_bmapi_write(NULL, ip, imap->br_startoff, imap->br_blockcount, |
5eda4300 | 346 | XFS_BMAPI_COWFORK | XFS_BMAPI_CONVERT, &first_block, |
dcf9585a | 347 | 0, imap, &nimaps, dfops); |
5eda4300 DW |
348 | } |
349 | ||
350 | /* Convert all of the unwritten CoW extents in a file's range to real ones. */ | |
351 | int | |
352 | xfs_reflink_convert_cow( | |
353 | struct xfs_inode *ip, | |
354 | xfs_off_t offset, | |
355 | xfs_off_t count) | |
356 | { | |
357 | struct xfs_bmbt_irec got; | |
358 | struct xfs_defer_ops dfops; | |
359 | struct xfs_mount *mp = ip->i_mount; | |
360 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
361 | xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
362 | xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count); | |
363 | xfs_extnum_t idx; | |
364 | bool found; | |
93aaead5 | 365 | int error = 0; |
5eda4300 DW |
366 | |
367 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
368 | ||
369 | /* Convert all the extents to real from unwritten. */ | |
370 | for (found = xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got); | |
371 | found && got.br_startoff < end_fsb; | |
372 | found = xfs_iext_get_extent(ifp, ++idx, &got)) { | |
373 | error = xfs_reflink_convert_cow_extent(ip, &got, offset_fsb, | |
374 | end_fsb - offset_fsb, &dfops); | |
375 | if (error) | |
376 | break; | |
377 | } | |
378 | ||
379 | /* Finish up. */ | |
380 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
381 | return error; | |
382 | } | |
383 | ||
0613f16c | 384 | /* Allocate all CoW reservations covering a range of blocks in a file. */ |
3c68d44a CH |
385 | int |
386 | xfs_reflink_allocate_cow( | |
0613f16c | 387 | struct xfs_inode *ip, |
3c68d44a CH |
388 | struct xfs_bmbt_irec *imap, |
389 | bool *shared, | |
390 | uint *lockmode) | |
0613f16c DW |
391 | { |
392 | struct xfs_mount *mp = ip->i_mount; | |
3c68d44a CH |
393 | xfs_fileoff_t offset_fsb = imap->br_startoff; |
394 | xfs_filblks_t count_fsb = imap->br_blockcount; | |
395 | struct xfs_bmbt_irec got; | |
0613f16c | 396 | struct xfs_defer_ops dfops; |
3c68d44a | 397 | struct xfs_trans *tp = NULL; |
0613f16c | 398 | xfs_fsblock_t first_block; |
3c68d44a CH |
399 | int nimaps, error = 0; |
400 | bool trimmed; | |
a14234c7 | 401 | xfs_filblks_t resaligned; |
3c68d44a | 402 | xfs_extlen_t resblks = 0; |
a14234c7 | 403 | xfs_extnum_t idx; |
0613f16c | 404 | |
3c68d44a CH |
405 | retry: |
406 | ASSERT(xfs_is_reflink_inode(ip)); | |
407 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); | |
0613f16c | 408 | |
a14234c7 CH |
409 | /* |
410 | * Even if the extent is not shared we might have a preallocation for | |
411 | * it in the COW fork. If so use it. | |
412 | */ | |
3c68d44a CH |
413 | if (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &idx, &got) && |
414 | got.br_startoff <= offset_fsb) { | |
415 | *shared = true; | |
416 | ||
a14234c7 CH |
417 | /* If we have a real allocation in the COW fork we're done. */ |
418 | if (!isnullstartblock(got.br_startblock)) { | |
3c68d44a CH |
419 | xfs_trim_extent(&got, offset_fsb, count_fsb); |
420 | *imap = got; | |
421 | goto convert; | |
a14234c7 | 422 | } |
3c68d44a CH |
423 | |
424 | xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); | |
a14234c7 | 425 | } else { |
3c68d44a CH |
426 | error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); |
427 | if (error || !*shared) | |
428 | goto out; | |
429 | } | |
a14234c7 | 430 | |
3c68d44a CH |
431 | if (!tp) { |
432 | resaligned = xfs_aligned_fsb_count(imap->br_startoff, | |
433 | imap->br_blockcount, xfs_get_cowextsz_hint(ip)); | |
434 | resblks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); | |
3ba020be | 435 | |
3c68d44a CH |
436 | xfs_iunlock(ip, *lockmode); |
437 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); | |
438 | *lockmode = XFS_ILOCK_EXCL; | |
439 | xfs_ilock(ip, *lockmode); | |
a14234c7 | 440 | |
3c68d44a CH |
441 | if (error) |
442 | return error; | |
443 | ||
444 | error = xfs_qm_dqattach_locked(ip, 0); | |
445 | if (error) | |
446 | goto out; | |
447 | goto retry; | |
a14234c7 CH |
448 | } |
449 | ||
450 | error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0, | |
451 | XFS_QMOPT_RES_REGBLKS); | |
0613f16c | 452 | if (error) |
3c68d44a | 453 | goto out; |
0613f16c | 454 | |
a14234c7 CH |
455 | xfs_trans_ijoin(tp, ip, 0); |
456 | ||
457 | xfs_defer_init(&dfops, &first_block); | |
458 | nimaps = 1; | |
0613f16c | 459 | |
5eda4300 | 460 | /* Allocate the entire reservation as unwritten blocks. */ |
3c68d44a | 461 | error = xfs_bmapi_write(tp, ip, imap->br_startoff, imap->br_blockcount, |
5eda4300 | 462 | XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC, &first_block, |
3c68d44a | 463 | resblks, imap, &nimaps, &dfops); |
0613f16c | 464 | if (error) |
a14234c7 | 465 | goto out_bmap_cancel; |
0613f16c | 466 | |
5eda4300 | 467 | /* Finish up. */ |
0613f16c DW |
468 | error = xfs_defer_finish(&tp, &dfops, NULL); |
469 | if (error) | |
a14234c7 | 470 | goto out_bmap_cancel; |
0613f16c DW |
471 | |
472 | error = xfs_trans_commit(tp); | |
a14234c7 | 473 | if (error) |
3c68d44a CH |
474 | return error; |
475 | convert: | |
476 | return xfs_reflink_convert_cow_extent(ip, imap, offset_fsb, count_fsb, | |
477 | &dfops); | |
a14234c7 | 478 | out_bmap_cancel: |
0613f16c | 479 | xfs_defer_cancel(&dfops); |
a14234c7 CH |
480 | xfs_trans_unreserve_quota_nblks(tp, ip, (long)resblks, 0, |
481 | XFS_QMOPT_RES_REGBLKS); | |
3c68d44a CH |
482 | out: |
483 | if (tp) | |
484 | xfs_trans_cancel(tp); | |
485 | return error; | |
0613f16c DW |
486 | } |
487 | ||
ef473667 | 488 | /* |
092d5d9d | 489 | * Find the CoW reservation for a given byte offset of a file. |
ef473667 DW |
490 | */ |
491 | bool | |
492 | xfs_reflink_find_cow_mapping( | |
493 | struct xfs_inode *ip, | |
494 | xfs_off_t offset, | |
092d5d9d | 495 | struct xfs_bmbt_irec *imap) |
ef473667 | 496 | { |
092d5d9d CH |
497 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
498 | xfs_fileoff_t offset_fsb; | |
499 | struct xfs_bmbt_irec got; | |
ef473667 DW |
500 | xfs_extnum_t idx; |
501 | ||
502 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); | |
503 | ASSERT(xfs_is_reflink_inode(ip)); | |
504 | ||
092d5d9d CH |
505 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); |
506 | if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got)) | |
ef473667 | 507 | return false; |
092d5d9d | 508 | if (got.br_startoff > offset_fsb) |
ef473667 DW |
509 | return false; |
510 | ||
511 | trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE, | |
092d5d9d CH |
512 | &got); |
513 | *imap = got; | |
ef473667 DW |
514 | return true; |
515 | } | |
516 | ||
517 | /* | |
518 | * Trim an extent to end at the next CoW reservation past offset_fsb. | |
519 | */ | |
86f12ab0 | 520 | void |
ef473667 DW |
521 | xfs_reflink_trim_irec_to_next_cow( |
522 | struct xfs_inode *ip, | |
523 | xfs_fileoff_t offset_fsb, | |
524 | struct xfs_bmbt_irec *imap) | |
525 | { | |
86f12ab0 CH |
526 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
527 | struct xfs_bmbt_irec got; | |
ef473667 DW |
528 | xfs_extnum_t idx; |
529 | ||
530 | if (!xfs_is_reflink_inode(ip)) | |
86f12ab0 | 531 | return; |
ef473667 DW |
532 | |
533 | /* Find the extent in the CoW fork. */ | |
86f12ab0 CH |
534 | if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got)) |
535 | return; | |
ef473667 DW |
536 | |
537 | /* This is the extent before; try sliding up one. */ | |
86f12ab0 CH |
538 | if (got.br_startoff < offset_fsb) { |
539 | if (!xfs_iext_get_extent(ifp, idx + 1, &got)) | |
540 | return; | |
ef473667 DW |
541 | } |
542 | ||
86f12ab0 CH |
543 | if (got.br_startoff >= imap->br_startoff + imap->br_blockcount) |
544 | return; | |
ef473667 | 545 | |
86f12ab0 | 546 | imap->br_blockcount = got.br_startoff - imap->br_startoff; |
ef473667 | 547 | trace_xfs_reflink_trim_irec(ip, imap); |
ef473667 | 548 | } |
43caeb18 DW |
549 | |
550 | /* | |
3802a345 CH |
551 | * Cancel CoW reservations for some block range of an inode. |
552 | * | |
553 | * If cancel_real is true this function cancels all COW fork extents for the | |
554 | * inode; if cancel_real is false, real extents are not cleared. | |
43caeb18 DW |
555 | */ |
556 | int | |
557 | xfs_reflink_cancel_cow_blocks( | |
558 | struct xfs_inode *ip, | |
559 | struct xfs_trans **tpp, | |
560 | xfs_fileoff_t offset_fsb, | |
3802a345 CH |
561 | xfs_fileoff_t end_fsb, |
562 | bool cancel_real) | |
43caeb18 | 563 | { |
3e0ee78f | 564 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
df5ab1b5 | 565 | struct xfs_bmbt_irec got, del; |
3e0ee78f | 566 | xfs_extnum_t idx; |
43caeb18 DW |
567 | xfs_fsblock_t firstfsb; |
568 | struct xfs_defer_ops dfops; | |
df5ab1b5 | 569 | int error = 0; |
43caeb18 DW |
570 | |
571 | if (!xfs_is_reflink_inode(ip)) | |
572 | return 0; | |
df5ab1b5 | 573 | if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &idx, &got)) |
3e0ee78f | 574 | return 0; |
43caeb18 | 575 | |
3e0ee78f CH |
576 | while (got.br_startoff < end_fsb) { |
577 | del = got; | |
578 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
579 | trace_xfs_reflink_cancel_cow(ip, &del); | |
43caeb18 | 580 | |
3e0ee78f CH |
581 | if (isnullstartblock(del.br_startblock)) { |
582 | error = xfs_bmap_del_extent_delay(ip, XFS_COW_FORK, | |
583 | &idx, &got, &del); | |
43caeb18 DW |
584 | if (error) |
585 | break; | |
3802a345 | 586 | } else if (del.br_state == XFS_EXT_UNWRITTEN || cancel_real) { |
43caeb18 DW |
587 | xfs_trans_ijoin(*tpp, ip, 0); |
588 | xfs_defer_init(&dfops, &firstfsb); | |
589 | ||
174edb0e DW |
590 | /* Free the CoW orphan record. */ |
591 | error = xfs_refcount_free_cow_extent(ip->i_mount, | |
3e0ee78f CH |
592 | &dfops, del.br_startblock, |
593 | del.br_blockcount); | |
174edb0e DW |
594 | if (error) |
595 | break; | |
596 | ||
43caeb18 | 597 | xfs_bmap_add_free(ip->i_mount, &dfops, |
3e0ee78f | 598 | del.br_startblock, del.br_blockcount, |
43caeb18 DW |
599 | NULL); |
600 | ||
601 | /* Update quota accounting */ | |
602 | xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT, | |
3e0ee78f | 603 | -(long)del.br_blockcount); |
43caeb18 DW |
604 | |
605 | /* Roll the transaction */ | |
606 | error = xfs_defer_finish(tpp, &dfops, ip); | |
607 | if (error) { | |
608 | xfs_defer_cancel(&dfops); | |
609 | break; | |
610 | } | |
611 | ||
612 | /* Remove the mapping from the CoW fork. */ | |
3e0ee78f | 613 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); |
43caeb18 DW |
614 | } |
615 | ||
df5ab1b5 | 616 | if (!xfs_iext_get_extent(ifp, ++idx, &got)) |
c17a8ef4 | 617 | break; |
43caeb18 DW |
618 | } |
619 | ||
c17a8ef4 BF |
620 | /* clear tag if cow fork is emptied */ |
621 | if (!ifp->if_bytes) | |
622 | xfs_inode_clear_cowblocks_tag(ip); | |
623 | ||
43caeb18 DW |
624 | return error; |
625 | } | |
626 | ||
627 | /* | |
3802a345 CH |
628 | * Cancel CoW reservations for some byte range of an inode. |
629 | * | |
630 | * If cancel_real is true this function cancels all COW fork extents for the | |
631 | * inode; if cancel_real is false, real extents are not cleared. | |
43caeb18 DW |
632 | */ |
633 | int | |
634 | xfs_reflink_cancel_cow_range( | |
635 | struct xfs_inode *ip, | |
636 | xfs_off_t offset, | |
3802a345 CH |
637 | xfs_off_t count, |
638 | bool cancel_real) | |
43caeb18 DW |
639 | { |
640 | struct xfs_trans *tp; | |
641 | xfs_fileoff_t offset_fsb; | |
642 | xfs_fileoff_t end_fsb; | |
643 | int error; | |
644 | ||
645 | trace_xfs_reflink_cancel_cow_range(ip, offset, count); | |
63646fc5 | 646 | ASSERT(xfs_is_reflink_inode(ip)); |
43caeb18 DW |
647 | |
648 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); | |
649 | if (count == NULLFILEOFF) | |
650 | end_fsb = NULLFILEOFF; | |
651 | else | |
652 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
653 | ||
654 | /* Start a rolling transaction to remove the mappings */ | |
655 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
656 | 0, 0, 0, &tp); | |
657 | if (error) | |
658 | goto out; | |
659 | ||
660 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
661 | xfs_trans_ijoin(tp, ip, 0); | |
662 | ||
663 | /* Scrape out the old CoW reservations */ | |
3802a345 CH |
664 | error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb, |
665 | cancel_real); | |
43caeb18 DW |
666 | if (error) |
667 | goto out_cancel; | |
668 | ||
669 | error = xfs_trans_commit(tp); | |
670 | ||
671 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
672 | return error; | |
673 | ||
674 | out_cancel: | |
675 | xfs_trans_cancel(tp); | |
676 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
677 | out: | |
678 | trace_xfs_reflink_cancel_cow_range_error(ip, error, _RET_IP_); | |
679 | return error; | |
680 | } | |
681 | ||
682 | /* | |
683 | * Remap parts of a file's data fork after a successful CoW. | |
684 | */ | |
685 | int | |
686 | xfs_reflink_end_cow( | |
687 | struct xfs_inode *ip, | |
688 | xfs_off_t offset, | |
689 | xfs_off_t count) | |
690 | { | |
c1112b6e | 691 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
4ab8671c | 692 | struct xfs_bmbt_irec got, del; |
43caeb18 DW |
693 | struct xfs_trans *tp; |
694 | xfs_fileoff_t offset_fsb; | |
695 | xfs_fileoff_t end_fsb; | |
43caeb18 DW |
696 | xfs_fsblock_t firstfsb; |
697 | struct xfs_defer_ops dfops; | |
4ab8671c | 698 | int error; |
43caeb18 | 699 | unsigned int resblks; |
43caeb18 | 700 | xfs_filblks_t rlen; |
c1112b6e | 701 | xfs_extnum_t idx; |
43caeb18 DW |
702 | |
703 | trace_xfs_reflink_end_cow(ip, offset, count); | |
704 | ||
c1112b6e CH |
705 | /* No COW extents? That's easy! */ |
706 | if (ifp->if_bytes == 0) | |
707 | return 0; | |
708 | ||
43caeb18 DW |
709 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); |
710 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
43caeb18 DW |
711 | |
712 | /* Start a rolling transaction to switch the mappings */ | |
713 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
714 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
715 | resblks, 0, 0, &tp); | |
716 | if (error) | |
717 | goto out; | |
718 | ||
719 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
720 | xfs_trans_ijoin(tp, ip, 0); | |
721 | ||
c1112b6e | 722 | /* If there is a hole at end_fsb - 1 go to the previous extent */ |
4ab8671c CH |
723 | if (!xfs_iext_lookup_extent(ip, ifp, end_fsb - 1, &idx, &got) || |
724 | got.br_startoff > end_fsb) { | |
c1112b6e | 725 | ASSERT(idx > 0); |
4ab8671c | 726 | xfs_iext_get_extent(ifp, --idx, &got); |
c1112b6e | 727 | } |
43caeb18 | 728 | |
c1112b6e CH |
729 | /* Walk backwards until we're out of the I/O range... */ |
730 | while (got.br_startoff + got.br_blockcount > offset_fsb) { | |
731 | del = got; | |
732 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
733 | ||
734 | /* Extent delete may have bumped idx forward */ | |
735 | if (!del.br_blockcount) { | |
736 | idx--; | |
43caeb18 | 737 | goto next_extent; |
c1112b6e CH |
738 | } |
739 | ||
740 | ASSERT(!isnullstartblock(got.br_startblock)); | |
43caeb18 | 741 | |
5eda4300 DW |
742 | /* |
743 | * Don't remap unwritten extents; these are | |
744 | * speculatively preallocated CoW extents that have been | |
745 | * allocated but have not yet been involved in a write. | |
746 | */ | |
747 | if (got.br_state == XFS_EXT_UNWRITTEN) { | |
748 | idx--; | |
749 | goto next_extent; | |
750 | } | |
751 | ||
43caeb18 | 752 | /* Unmap the old blocks in the data fork. */ |
c1112b6e CH |
753 | xfs_defer_init(&dfops, &firstfsb); |
754 | rlen = del.br_blockcount; | |
755 | error = __xfs_bunmapi(tp, ip, del.br_startoff, &rlen, 0, 1, | |
756 | &firstfsb, &dfops); | |
757 | if (error) | |
758 | goto out_defer; | |
43caeb18 | 759 | |
c1112b6e CH |
760 | /* Trim the extent to whatever got unmapped. */ |
761 | if (rlen) { | |
762 | xfs_trim_extent(&del, del.br_startoff + rlen, | |
763 | del.br_blockcount - rlen); | |
764 | } | |
765 | trace_xfs_reflink_cow_remap(ip, &del); | |
174edb0e | 766 | |
c1112b6e CH |
767 | /* Free the CoW orphan record. */ |
768 | error = xfs_refcount_free_cow_extent(tp->t_mountp, &dfops, | |
769 | del.br_startblock, del.br_blockcount); | |
770 | if (error) | |
771 | goto out_defer; | |
43caeb18 | 772 | |
c1112b6e CH |
773 | /* Map the new blocks into the data fork. */ |
774 | error = xfs_bmap_map_extent(tp->t_mountp, &dfops, ip, &del); | |
775 | if (error) | |
776 | goto out_defer; | |
43caeb18 | 777 | |
c1112b6e CH |
778 | /* Remove the mapping from the CoW fork. */ |
779 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); | |
780 | ||
781 | error = xfs_defer_finish(&tp, &dfops, ip); | |
782 | if (error) | |
783 | goto out_defer; | |
43caeb18 | 784 | next_extent: |
4ab8671c | 785 | if (!xfs_iext_get_extent(ifp, idx, &got)) |
c1112b6e | 786 | break; |
43caeb18 DW |
787 | } |
788 | ||
789 | error = xfs_trans_commit(tp); | |
790 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
791 | if (error) | |
792 | goto out; | |
793 | return 0; | |
794 | ||
795 | out_defer: | |
796 | xfs_defer_cancel(&dfops); | |
43caeb18 DW |
797 | xfs_trans_cancel(tp); |
798 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
799 | out: | |
800 | trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); | |
801 | return error; | |
802 | } | |
174edb0e DW |
803 | |
804 | /* | |
805 | * Free leftover CoW reservations that didn't get cleaned out. | |
806 | */ | |
807 | int | |
808 | xfs_reflink_recover_cow( | |
809 | struct xfs_mount *mp) | |
810 | { | |
811 | xfs_agnumber_t agno; | |
812 | int error = 0; | |
813 | ||
814 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
815 | return 0; | |
816 | ||
817 | for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { | |
818 | error = xfs_refcount_recover_cow_leftovers(mp, agno); | |
819 | if (error) | |
820 | break; | |
821 | } | |
822 | ||
823 | return error; | |
824 | } | |
862bb360 DW |
825 | |
826 | /* | |
827 | * Reflinking (Block) Ranges of Two Files Together | |
828 | * | |
829 | * First, ensure that the reflink flag is set on both inodes. The flag is an | |
830 | * optimization to avoid unnecessary refcount btree lookups in the write path. | |
831 | * | |
832 | * Now we can iteratively remap the range of extents (and holes) in src to the | |
833 | * corresponding ranges in dest. Let drange and srange denote the ranges of | |
834 | * logical blocks in dest and src touched by the reflink operation. | |
835 | * | |
836 | * While the length of drange is greater than zero, | |
837 | * - Read src's bmbt at the start of srange ("imap") | |
838 | * - If imap doesn't exist, make imap appear to start at the end of srange | |
839 | * with zero length. | |
840 | * - If imap starts before srange, advance imap to start at srange. | |
841 | * - If imap goes beyond srange, truncate imap to end at the end of srange. | |
842 | * - Punch (imap start - srange start + imap len) blocks from dest at | |
843 | * offset (drange start). | |
844 | * - If imap points to a real range of pblks, | |
845 | * > Increase the refcount of the imap's pblks | |
846 | * > Map imap's pblks into dest at the offset | |
847 | * (drange start + imap start - srange start) | |
848 | * - Advance drange and srange by (imap start - srange start + imap len) | |
849 | * | |
850 | * Finally, if the reflink made dest longer, update both the in-core and | |
851 | * on-disk file sizes. | |
852 | * | |
853 | * ASCII Art Demonstration: | |
854 | * | |
855 | * Let's say we want to reflink this source file: | |
856 | * | |
857 | * ----SSSSSSS-SSSSS----SSSSSS (src file) | |
858 | * <--------------------> | |
859 | * | |
860 | * into this destination file: | |
861 | * | |
862 | * --DDDDDDDDDDDDDDDDDDD--DDD (dest file) | |
863 | * <--------------------> | |
864 | * '-' means a hole, and 'S' and 'D' are written blocks in the src and dest. | |
865 | * Observe that the range has different logical offsets in either file. | |
866 | * | |
867 | * Consider that the first extent in the source file doesn't line up with our | |
868 | * reflink range. Unmapping and remapping are separate operations, so we can | |
869 | * unmap more blocks from the destination file than we remap. | |
870 | * | |
871 | * ----SSSSSSS-SSSSS----SSSSSS | |
872 | * <-------> | |
873 | * --DDDDD---------DDDDD--DDD | |
874 | * <-------> | |
875 | * | |
876 | * Now remap the source extent into the destination file: | |
877 | * | |
878 | * ----SSSSSSS-SSSSS----SSSSSS | |
879 | * <-------> | |
880 | * --DDDDD--SSSSSSSDDDDD--DDD | |
881 | * <-------> | |
882 | * | |
883 | * Do likewise with the second hole and extent in our range. Holes in the | |
884 | * unmap range don't affect our operation. | |
885 | * | |
886 | * ----SSSSSSS-SSSSS----SSSSSS | |
887 | * <----> | |
888 | * --DDDDD--SSSSSSS-SSSSS-DDD | |
889 | * <----> | |
890 | * | |
891 | * Finally, unmap and remap part of the third extent. This will increase the | |
892 | * size of the destination file. | |
893 | * | |
894 | * ----SSSSSSS-SSSSS----SSSSSS | |
895 | * <-----> | |
896 | * --DDDDD--SSSSSSS-SSSSS----SSS | |
897 | * <-----> | |
898 | * | |
899 | * Once we update the destination file's i_size, we're done. | |
900 | */ | |
901 | ||
902 | /* | |
903 | * Ensure the reflink bit is set in both inodes. | |
904 | */ | |
905 | STATIC int | |
906 | xfs_reflink_set_inode_flag( | |
907 | struct xfs_inode *src, | |
908 | struct xfs_inode *dest) | |
909 | { | |
910 | struct xfs_mount *mp = src->i_mount; | |
911 | int error; | |
912 | struct xfs_trans *tp; | |
913 | ||
914 | if (xfs_is_reflink_inode(src) && xfs_is_reflink_inode(dest)) | |
915 | return 0; | |
916 | ||
917 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
918 | if (error) | |
919 | goto out_error; | |
920 | ||
921 | /* Lock both files against IO */ | |
922 | if (src->i_ino == dest->i_ino) | |
923 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
924 | else | |
925 | xfs_lock_two_inodes(src, dest, XFS_ILOCK_EXCL); | |
926 | ||
927 | if (!xfs_is_reflink_inode(src)) { | |
928 | trace_xfs_reflink_set_inode_flag(src); | |
929 | xfs_trans_ijoin(tp, src, XFS_ILOCK_EXCL); | |
930 | src->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
931 | xfs_trans_log_inode(tp, src, XFS_ILOG_CORE); | |
932 | xfs_ifork_init_cow(src); | |
933 | } else | |
934 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
935 | ||
936 | if (src->i_ino == dest->i_ino) | |
937 | goto commit_flags; | |
938 | ||
939 | if (!xfs_is_reflink_inode(dest)) { | |
940 | trace_xfs_reflink_set_inode_flag(dest); | |
941 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
942 | dest->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
943 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); | |
944 | xfs_ifork_init_cow(dest); | |
945 | } else | |
946 | xfs_iunlock(dest, XFS_ILOCK_EXCL); | |
947 | ||
948 | commit_flags: | |
949 | error = xfs_trans_commit(tp); | |
950 | if (error) | |
951 | goto out_error; | |
952 | return error; | |
953 | ||
954 | out_error: | |
955 | trace_xfs_reflink_set_inode_flag_error(dest, error, _RET_IP_); | |
956 | return error; | |
957 | } | |
958 | ||
959 | /* | |
f7ca3522 | 960 | * Update destination inode size & cowextsize hint, if necessary. |
862bb360 DW |
961 | */ |
962 | STATIC int | |
963 | xfs_reflink_update_dest( | |
964 | struct xfs_inode *dest, | |
f7ca3522 | 965 | xfs_off_t newlen, |
c5ecb423 CH |
966 | xfs_extlen_t cowextsize, |
967 | bool is_dedupe) | |
862bb360 DW |
968 | { |
969 | struct xfs_mount *mp = dest->i_mount; | |
970 | struct xfs_trans *tp; | |
971 | int error; | |
972 | ||
c5ecb423 | 973 | if (is_dedupe && newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0) |
862bb360 DW |
974 | return 0; |
975 | ||
976 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
977 | if (error) | |
978 | goto out_error; | |
979 | ||
980 | xfs_ilock(dest, XFS_ILOCK_EXCL); | |
981 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
982 | ||
f7ca3522 DW |
983 | if (newlen > i_size_read(VFS_I(dest))) { |
984 | trace_xfs_reflink_update_inode_size(dest, newlen); | |
985 | i_size_write(VFS_I(dest), newlen); | |
986 | dest->i_d.di_size = newlen; | |
987 | } | |
988 | ||
989 | if (cowextsize) { | |
990 | dest->i_d.di_cowextsize = cowextsize; | |
991 | dest->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE; | |
992 | } | |
993 | ||
c5ecb423 CH |
994 | if (!is_dedupe) { |
995 | xfs_trans_ichgtime(tp, dest, | |
996 | XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); | |
997 | } | |
862bb360 DW |
998 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); |
999 | ||
1000 | error = xfs_trans_commit(tp); | |
1001 | if (error) | |
1002 | goto out_error; | |
1003 | return error; | |
1004 | ||
1005 | out_error: | |
1006 | trace_xfs_reflink_update_inode_size_error(dest, error, _RET_IP_); | |
1007 | return error; | |
1008 | } | |
1009 | ||
6fa164b8 DW |
1010 | /* |
1011 | * Do we have enough reserve in this AG to handle a reflink? The refcount | |
1012 | * btree already reserved all the space it needs, but the rmap btree can grow | |
1013 | * infinitely, so we won't allow more reflinks when the AG is down to the | |
1014 | * btree reserves. | |
1015 | */ | |
1016 | static int | |
1017 | xfs_reflink_ag_has_free_space( | |
1018 | struct xfs_mount *mp, | |
1019 | xfs_agnumber_t agno) | |
1020 | { | |
1021 | struct xfs_perag *pag; | |
1022 | int error = 0; | |
1023 | ||
1024 | if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) | |
1025 | return 0; | |
1026 | ||
1027 | pag = xfs_perag_get(mp, agno); | |
1028 | if (xfs_ag_resv_critical(pag, XFS_AG_RESV_AGFL) || | |
1029 | xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA)) | |
1030 | error = -ENOSPC; | |
1031 | xfs_perag_put(pag); | |
1032 | return error; | |
1033 | } | |
1034 | ||
862bb360 DW |
1035 | /* |
1036 | * Unmap a range of blocks from a file, then map other blocks into the hole. | |
1037 | * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount). | |
1038 | * The extent irec is mapped into dest at irec->br_startoff. | |
1039 | */ | |
1040 | STATIC int | |
1041 | xfs_reflink_remap_extent( | |
1042 | struct xfs_inode *ip, | |
1043 | struct xfs_bmbt_irec *irec, | |
1044 | xfs_fileoff_t destoff, | |
1045 | xfs_off_t new_isize) | |
1046 | { | |
1047 | struct xfs_mount *mp = ip->i_mount; | |
1048 | struct xfs_trans *tp; | |
1049 | xfs_fsblock_t firstfsb; | |
1050 | unsigned int resblks; | |
1051 | struct xfs_defer_ops dfops; | |
1052 | struct xfs_bmbt_irec uirec; | |
1053 | bool real_extent; | |
1054 | xfs_filblks_t rlen; | |
1055 | xfs_filblks_t unmap_len; | |
1056 | xfs_off_t newlen; | |
1057 | int error; | |
1058 | ||
1059 | unmap_len = irec->br_startoff + irec->br_blockcount - destoff; | |
1060 | trace_xfs_reflink_punch_range(ip, destoff, unmap_len); | |
1061 | ||
1062 | /* Only remap normal extents. */ | |
1063 | real_extent = (irec->br_startblock != HOLESTARTBLOCK && | |
1064 | irec->br_startblock != DELAYSTARTBLOCK && | |
1065 | !ISUNWRITTEN(irec)); | |
1066 | ||
6fa164b8 DW |
1067 | /* No reflinking if we're low on space */ |
1068 | if (real_extent) { | |
1069 | error = xfs_reflink_ag_has_free_space(mp, | |
1070 | XFS_FSB_TO_AGNO(mp, irec->br_startblock)); | |
1071 | if (error) | |
1072 | goto out; | |
1073 | } | |
1074 | ||
862bb360 DW |
1075 | /* Start a rolling transaction to switch the mappings */ |
1076 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
1077 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); | |
1078 | if (error) | |
1079 | goto out; | |
1080 | ||
1081 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1082 | xfs_trans_ijoin(tp, ip, 0); | |
1083 | ||
1084 | /* If we're not just clearing space, then do we have enough quota? */ | |
1085 | if (real_extent) { | |
1086 | error = xfs_trans_reserve_quota_nblks(tp, ip, | |
1087 | irec->br_blockcount, 0, XFS_QMOPT_RES_REGBLKS); | |
1088 | if (error) | |
1089 | goto out_cancel; | |
1090 | } | |
1091 | ||
1092 | trace_xfs_reflink_remap(ip, irec->br_startoff, | |
1093 | irec->br_blockcount, irec->br_startblock); | |
1094 | ||
1095 | /* Unmap the old blocks in the data fork. */ | |
1096 | rlen = unmap_len; | |
1097 | while (rlen) { | |
1098 | xfs_defer_init(&dfops, &firstfsb); | |
1099 | error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1, | |
1100 | &firstfsb, &dfops); | |
1101 | if (error) | |
1102 | goto out_defer; | |
1103 | ||
1104 | /* | |
1105 | * Trim the extent to whatever got unmapped. | |
1106 | * Remember, bunmapi works backwards. | |
1107 | */ | |
1108 | uirec.br_startblock = irec->br_startblock + rlen; | |
1109 | uirec.br_startoff = irec->br_startoff + rlen; | |
1110 | uirec.br_blockcount = unmap_len - rlen; | |
1111 | unmap_len = rlen; | |
1112 | ||
1113 | /* If this isn't a real mapping, we're done. */ | |
1114 | if (!real_extent || uirec.br_blockcount == 0) | |
1115 | goto next_extent; | |
1116 | ||
1117 | trace_xfs_reflink_remap(ip, uirec.br_startoff, | |
1118 | uirec.br_blockcount, uirec.br_startblock); | |
1119 | ||
1120 | /* Update the refcount tree */ | |
1121 | error = xfs_refcount_increase_extent(mp, &dfops, &uirec); | |
1122 | if (error) | |
1123 | goto out_defer; | |
1124 | ||
1125 | /* Map the new blocks into the data fork. */ | |
1126 | error = xfs_bmap_map_extent(mp, &dfops, ip, &uirec); | |
1127 | if (error) | |
1128 | goto out_defer; | |
1129 | ||
1130 | /* Update quota accounting. */ | |
1131 | xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, | |
1132 | uirec.br_blockcount); | |
1133 | ||
1134 | /* Update dest isize if needed. */ | |
1135 | newlen = XFS_FSB_TO_B(mp, | |
1136 | uirec.br_startoff + uirec.br_blockcount); | |
1137 | newlen = min_t(xfs_off_t, newlen, new_isize); | |
1138 | if (newlen > i_size_read(VFS_I(ip))) { | |
1139 | trace_xfs_reflink_update_inode_size(ip, newlen); | |
1140 | i_size_write(VFS_I(ip), newlen); | |
1141 | ip->i_d.di_size = newlen; | |
1142 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
1143 | } | |
1144 | ||
1145 | next_extent: | |
1146 | /* Process all the deferred stuff. */ | |
1147 | error = xfs_defer_finish(&tp, &dfops, ip); | |
1148 | if (error) | |
1149 | goto out_defer; | |
1150 | } | |
1151 | ||
1152 | error = xfs_trans_commit(tp); | |
1153 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1154 | if (error) | |
1155 | goto out; | |
1156 | return 0; | |
1157 | ||
1158 | out_defer: | |
1159 | xfs_defer_cancel(&dfops); | |
1160 | out_cancel: | |
1161 | xfs_trans_cancel(tp); | |
1162 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1163 | out: | |
1164 | trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_); | |
1165 | return error; | |
1166 | } | |
1167 | ||
1168 | /* | |
1169 | * Iteratively remap one file's extents (and holes) to another's. | |
1170 | */ | |
1171 | STATIC int | |
1172 | xfs_reflink_remap_blocks( | |
1173 | struct xfs_inode *src, | |
1174 | xfs_fileoff_t srcoff, | |
1175 | struct xfs_inode *dest, | |
1176 | xfs_fileoff_t destoff, | |
1177 | xfs_filblks_t len, | |
1178 | xfs_off_t new_isize) | |
1179 | { | |
1180 | struct xfs_bmbt_irec imap; | |
1181 | int nimaps; | |
1182 | int error = 0; | |
1183 | xfs_filblks_t range_len; | |
1184 | ||
1185 | /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ | |
1186 | while (len) { | |
1187 | trace_xfs_reflink_remap_blocks_loop(src, srcoff, len, | |
1188 | dest, destoff); | |
1189 | /* Read extent from the source file */ | |
1190 | nimaps = 1; | |
1191 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
1192 | error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); | |
1193 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
1194 | if (error) | |
1195 | goto err; | |
1196 | ASSERT(nimaps == 1); | |
1197 | ||
1198 | trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE, | |
1199 | &imap); | |
1200 | ||
1201 | /* Translate imap into the destination file. */ | |
1202 | range_len = imap.br_startoff + imap.br_blockcount - srcoff; | |
1203 | imap.br_startoff += destoff - srcoff; | |
1204 | ||
1205 | /* Clear dest from destoff to the end of imap and map it in. */ | |
1206 | error = xfs_reflink_remap_extent(dest, &imap, destoff, | |
1207 | new_isize); | |
1208 | if (error) | |
1209 | goto err; | |
1210 | ||
1211 | if (fatal_signal_pending(current)) { | |
1212 | error = -EINTR; | |
1213 | goto err; | |
1214 | } | |
1215 | ||
1216 | /* Advance drange/srange */ | |
1217 | srcoff += range_len; | |
1218 | destoff += range_len; | |
1219 | len -= range_len; | |
1220 | } | |
1221 | ||
1222 | return 0; | |
1223 | ||
1224 | err: | |
1225 | trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_); | |
1226 | return error; | |
1227 | } | |
1228 | ||
1229 | /* | |
1230 | * Link a range of blocks from one file to another. | |
1231 | */ | |
1232 | int | |
1233 | xfs_reflink_remap_range( | |
5faaf4fa CH |
1234 | struct file *file_in, |
1235 | loff_t pos_in, | |
1236 | struct file *file_out, | |
1237 | loff_t pos_out, | |
1238 | u64 len, | |
1239 | bool is_dedupe) | |
862bb360 | 1240 | { |
5faaf4fa CH |
1241 | struct inode *inode_in = file_inode(file_in); |
1242 | struct xfs_inode *src = XFS_I(inode_in); | |
1243 | struct inode *inode_out = file_inode(file_out); | |
1244 | struct xfs_inode *dest = XFS_I(inode_out); | |
862bb360 | 1245 | struct xfs_mount *mp = src->i_mount; |
5faaf4fa | 1246 | bool same_inode = (inode_in == inode_out); |
862bb360 DW |
1247 | xfs_fileoff_t sfsbno, dfsbno; |
1248 | xfs_filblks_t fsblen; | |
f7ca3522 | 1249 | xfs_extlen_t cowextsize; |
5faaf4fa | 1250 | ssize_t ret; |
862bb360 DW |
1251 | |
1252 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1253 | return -EOPNOTSUPP; | |
1254 | ||
1255 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1256 | return -EIO; | |
1257 | ||
5faaf4fa | 1258 | /* Lock both files against IO */ |
65523218 CH |
1259 | lock_two_nondirectories(inode_in, inode_out); |
1260 | if (same_inode) | |
5faaf4fa | 1261 | xfs_ilock(src, XFS_MMAPLOCK_EXCL); |
65523218 | 1262 | else |
5faaf4fa | 1263 | xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL); |
5faaf4fa | 1264 | |
876bec6f | 1265 | /* Check file eligibility and prepare for block sharing. */ |
5faaf4fa | 1266 | ret = -EINVAL; |
862bb360 DW |
1267 | /* Don't reflink realtime inodes */ |
1268 | if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest)) | |
5faaf4fa CH |
1269 | goto out_unlock; |
1270 | ||
1271 | /* Don't share DAX file data for now. */ | |
1272 | if (IS_DAX(inode_in) || IS_DAX(inode_out)) | |
1273 | goto out_unlock; | |
1274 | ||
876bec6f DW |
1275 | ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out, |
1276 | &len, is_dedupe); | |
22725ce4 | 1277 | if (ret <= 0) |
5faaf4fa CH |
1278 | goto out_unlock; |
1279 | ||
1280 | trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); | |
862bb360 | 1281 | |
876bec6f | 1282 | /* Set flags and remap blocks. */ |
5faaf4fa CH |
1283 | ret = xfs_reflink_set_inode_flag(src, dest); |
1284 | if (ret) | |
1285 | goto out_unlock; | |
862bb360 | 1286 | |
5faaf4fa CH |
1287 | dfsbno = XFS_B_TO_FSBT(mp, pos_out); |
1288 | sfsbno = XFS_B_TO_FSBT(mp, pos_in); | |
862bb360 | 1289 | fsblen = XFS_B_TO_FSB(mp, len); |
5faaf4fa CH |
1290 | ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, |
1291 | pos_out + len); | |
1292 | if (ret) | |
1293 | goto out_unlock; | |
862bb360 | 1294 | |
876bec6f DW |
1295 | /* Zap any page cache for the destination file's range. */ |
1296 | truncate_inode_pages_range(&inode_out->i_data, pos_out, | |
1297 | PAGE_ALIGN(pos_out + len) - 1); | |
1298 | ||
f7ca3522 DW |
1299 | /* |
1300 | * Carry the cowextsize hint from src to dest if we're sharing the | |
1301 | * entire source file to the entire destination file, the source file | |
1302 | * has a cowextsize hint, and the destination file does not. | |
1303 | */ | |
1304 | cowextsize = 0; | |
5faaf4fa | 1305 | if (pos_in == 0 && len == i_size_read(inode_in) && |
f7ca3522 | 1306 | (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) && |
5faaf4fa | 1307 | pos_out == 0 && len >= i_size_read(inode_out) && |
f7ca3522 DW |
1308 | !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)) |
1309 | cowextsize = src->i_d.di_cowextsize; | |
1310 | ||
c5ecb423 CH |
1311 | ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize, |
1312 | is_dedupe); | |
862bb360 | 1313 | |
5faaf4fa CH |
1314 | out_unlock: |
1315 | xfs_iunlock(src, XFS_MMAPLOCK_EXCL); | |
65523218 | 1316 | if (!same_inode) |
5faaf4fa | 1317 | xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); |
65523218 | 1318 | unlock_two_nondirectories(inode_in, inode_out); |
5faaf4fa CH |
1319 | if (ret) |
1320 | trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); | |
1321 | return ret; | |
862bb360 | 1322 | } |
98cc2db5 DW |
1323 | |
1324 | /* | |
1325 | * The user wants to preemptively CoW all shared blocks in this file, | |
1326 | * which enables us to turn off the reflink flag. Iterate all | |
1327 | * extents which are not prealloc/delalloc to see which ranges are | |
1328 | * mentioned in the refcount tree, then read those blocks into the | |
1329 | * pagecache, dirty them, fsync them back out, and then we can update | |
1330 | * the inode flag. What happens if we run out of memory? :) | |
1331 | */ | |
1332 | STATIC int | |
1333 | xfs_reflink_dirty_extents( | |
1334 | struct xfs_inode *ip, | |
1335 | xfs_fileoff_t fbno, | |
1336 | xfs_filblks_t end, | |
1337 | xfs_off_t isize) | |
1338 | { | |
1339 | struct xfs_mount *mp = ip->i_mount; | |
1340 | xfs_agnumber_t agno; | |
1341 | xfs_agblock_t agbno; | |
1342 | xfs_extlen_t aglen; | |
1343 | xfs_agblock_t rbno; | |
1344 | xfs_extlen_t rlen; | |
1345 | xfs_off_t fpos; | |
1346 | xfs_off_t flen; | |
1347 | struct xfs_bmbt_irec map[2]; | |
1348 | int nmaps; | |
9780643c | 1349 | int error = 0; |
98cc2db5 DW |
1350 | |
1351 | while (end - fbno > 0) { | |
1352 | nmaps = 1; | |
1353 | /* | |
1354 | * Look for extents in the file. Skip holes, delalloc, or | |
1355 | * unwritten extents; they can't be reflinked. | |
1356 | */ | |
1357 | error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); | |
1358 | if (error) | |
1359 | goto out; | |
1360 | if (nmaps == 0) | |
1361 | break; | |
1362 | if (map[0].br_startblock == HOLESTARTBLOCK || | |
1363 | map[0].br_startblock == DELAYSTARTBLOCK || | |
1364 | ISUNWRITTEN(&map[0])) | |
1365 | goto next; | |
1366 | ||
1367 | map[1] = map[0]; | |
1368 | while (map[1].br_blockcount) { | |
1369 | agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); | |
1370 | agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); | |
1371 | aglen = map[1].br_blockcount; | |
1372 | ||
1373 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, | |
1374 | &rbno, &rlen, true); | |
1375 | if (error) | |
1376 | goto out; | |
1377 | if (rbno == NULLAGBLOCK) | |
1378 | break; | |
1379 | ||
1380 | /* Dirty the pages */ | |
1381 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1382 | fpos = XFS_FSB_TO_B(mp, map[1].br_startoff + | |
1383 | (rbno - agbno)); | |
1384 | flen = XFS_FSB_TO_B(mp, rlen); | |
1385 | if (fpos + flen > isize) | |
1386 | flen = isize - fpos; | |
1387 | error = iomap_file_dirty(VFS_I(ip), fpos, flen, | |
1388 | &xfs_iomap_ops); | |
1389 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1390 | if (error) | |
1391 | goto out; | |
1392 | ||
1393 | map[1].br_blockcount -= (rbno - agbno + rlen); | |
1394 | map[1].br_startoff += (rbno - agbno + rlen); | |
1395 | map[1].br_startblock += (rbno - agbno + rlen); | |
1396 | } | |
1397 | ||
1398 | next: | |
1399 | fbno = map[0].br_startoff + map[0].br_blockcount; | |
1400 | } | |
1401 | out: | |
1402 | return error; | |
1403 | } | |
1404 | ||
1405 | /* Clear the inode reflink flag if there are no shared extents. */ | |
1406 | int | |
1407 | xfs_reflink_clear_inode_flag( | |
1408 | struct xfs_inode *ip, | |
1409 | struct xfs_trans **tpp) | |
1410 | { | |
1411 | struct xfs_mount *mp = ip->i_mount; | |
1412 | xfs_fileoff_t fbno; | |
1413 | xfs_filblks_t end; | |
1414 | xfs_agnumber_t agno; | |
1415 | xfs_agblock_t agbno; | |
1416 | xfs_extlen_t aglen; | |
1417 | xfs_agblock_t rbno; | |
1418 | xfs_extlen_t rlen; | |
024adf48 | 1419 | struct xfs_bmbt_irec map; |
98cc2db5 DW |
1420 | int nmaps; |
1421 | int error = 0; | |
1422 | ||
63646fc5 | 1423 | ASSERT(xfs_is_reflink_inode(ip)); |
98cc2db5 DW |
1424 | |
1425 | fbno = 0; | |
1426 | end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip))); | |
1427 | while (end - fbno > 0) { | |
1428 | nmaps = 1; | |
1429 | /* | |
1430 | * Look for extents in the file. Skip holes, delalloc, or | |
1431 | * unwritten extents; they can't be reflinked. | |
1432 | */ | |
024adf48 | 1433 | error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0); |
98cc2db5 DW |
1434 | if (error) |
1435 | return error; | |
1436 | if (nmaps == 0) | |
1437 | break; | |
024adf48 DW |
1438 | if (map.br_startblock == HOLESTARTBLOCK || |
1439 | map.br_startblock == DELAYSTARTBLOCK || | |
1440 | ISUNWRITTEN(&map)) | |
98cc2db5 DW |
1441 | goto next; |
1442 | ||
024adf48 DW |
1443 | agno = XFS_FSB_TO_AGNO(mp, map.br_startblock); |
1444 | agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock); | |
1445 | aglen = map.br_blockcount; | |
98cc2db5 | 1446 | |
024adf48 DW |
1447 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, |
1448 | &rbno, &rlen, false); | |
1449 | if (error) | |
1450 | return error; | |
1451 | /* Is there still a shared block here? */ | |
1452 | if (rbno != NULLAGBLOCK) | |
1453 | return 0; | |
98cc2db5 | 1454 | next: |
024adf48 | 1455 | fbno = map.br_startoff + map.br_blockcount; |
98cc2db5 DW |
1456 | } |
1457 | ||
1458 | /* | |
1459 | * We didn't find any shared blocks so turn off the reflink flag. | |
1460 | * First, get rid of any leftover CoW mappings. | |
1461 | */ | |
3802a345 | 1462 | error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, true); |
98cc2db5 DW |
1463 | if (error) |
1464 | return error; | |
1465 | ||
1466 | /* Clear the inode flag. */ | |
1467 | trace_xfs_reflink_unset_inode_flag(ip); | |
1468 | ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; | |
83104d44 | 1469 | xfs_inode_clear_cowblocks_tag(ip); |
98cc2db5 DW |
1470 | xfs_trans_ijoin(*tpp, ip, 0); |
1471 | xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE); | |
1472 | ||
1473 | return error; | |
1474 | } | |
1475 | ||
1476 | /* | |
1477 | * Clear the inode reflink flag if there are no shared extents and the size | |
1478 | * hasn't changed. | |
1479 | */ | |
1480 | STATIC int | |
1481 | xfs_reflink_try_clear_inode_flag( | |
97a1b87e | 1482 | struct xfs_inode *ip) |
98cc2db5 DW |
1483 | { |
1484 | struct xfs_mount *mp = ip->i_mount; | |
1485 | struct xfs_trans *tp; | |
1486 | int error = 0; | |
1487 | ||
1488 | /* Start a rolling transaction to remove the mappings */ | |
1489 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); | |
1490 | if (error) | |
1491 | return error; | |
1492 | ||
1493 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1494 | xfs_trans_ijoin(tp, ip, 0); | |
1495 | ||
98cc2db5 DW |
1496 | error = xfs_reflink_clear_inode_flag(ip, &tp); |
1497 | if (error) | |
1498 | goto cancel; | |
1499 | ||
1500 | error = xfs_trans_commit(tp); | |
1501 | if (error) | |
1502 | goto out; | |
1503 | ||
1504 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1505 | return 0; | |
1506 | cancel: | |
1507 | xfs_trans_cancel(tp); | |
1508 | out: | |
1509 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1510 | return error; | |
1511 | } | |
1512 | ||
1513 | /* | |
1514 | * Pre-COW all shared blocks within a given byte range of a file and turn off | |
1515 | * the reflink flag if we unshare all of the file's blocks. | |
1516 | */ | |
1517 | int | |
1518 | xfs_reflink_unshare( | |
1519 | struct xfs_inode *ip, | |
1520 | xfs_off_t offset, | |
1521 | xfs_off_t len) | |
1522 | { | |
1523 | struct xfs_mount *mp = ip->i_mount; | |
1524 | xfs_fileoff_t fbno; | |
1525 | xfs_filblks_t end; | |
1526 | xfs_off_t isize; | |
1527 | int error; | |
1528 | ||
1529 | if (!xfs_is_reflink_inode(ip)) | |
1530 | return 0; | |
1531 | ||
1532 | trace_xfs_reflink_unshare(ip, offset, len); | |
1533 | ||
1534 | inode_dio_wait(VFS_I(ip)); | |
1535 | ||
1536 | /* Try to CoW the selected ranges */ | |
1537 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
97a1b87e | 1538 | fbno = XFS_B_TO_FSBT(mp, offset); |
98cc2db5 DW |
1539 | isize = i_size_read(VFS_I(ip)); |
1540 | end = XFS_B_TO_FSB(mp, offset + len); | |
1541 | error = xfs_reflink_dirty_extents(ip, fbno, end, isize); | |
1542 | if (error) | |
1543 | goto out_unlock; | |
1544 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1545 | ||
1546 | /* Wait for the IO to finish */ | |
1547 | error = filemap_write_and_wait(VFS_I(ip)->i_mapping); | |
1548 | if (error) | |
1549 | goto out; | |
1550 | ||
97a1b87e DW |
1551 | /* Turn off the reflink flag if possible. */ |
1552 | error = xfs_reflink_try_clear_inode_flag(ip); | |
1553 | if (error) | |
1554 | goto out; | |
98cc2db5 DW |
1555 | |
1556 | return 0; | |
1557 | ||
1558 | out_unlock: | |
1559 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1560 | out: | |
1561 | trace_xfs_reflink_unshare_error(ip, error, _RET_IP_); | |
1562 | return error; | |
1563 | } |