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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 | * | |
85 | * When dirty pages are being written out (typically in writepage), the | |
86 | * delalloc reservations are converted into real mappings by allocating | |
87 | * blocks and replacing the delalloc mapping with real ones. A delalloc | |
88 | * mapping can be replaced by several real ones if the free space is | |
89 | * fragmented. | |
90 | * | |
91 | * We want to adapt the delalloc mechanism for copy-on-write, since the | |
92 | * write paths are similar. The first two steps (creating the reservation | |
93 | * and allocating the blocks) are exactly the same as delalloc except that | |
94 | * the mappings must be stored in a separate CoW fork because we do not want | |
95 | * to disturb the mapping in the data fork until we're sure that the write | |
96 | * succeeded. IO completion in this case is the process of removing the old | |
97 | * mapping from the data fork and moving the new mapping from the CoW fork to | |
98 | * the data fork. This will be discussed shortly. | |
99 | * | |
100 | * For now, unaligned directio writes will be bounced back to the page cache. | |
101 | * Block-aligned directio writes will use the same mechanism as buffered | |
102 | * writes. | |
103 | * | |
104 | * CoW remapping must be done after the data block write completes, | |
105 | * because we don't want to destroy the old data fork map until we're sure | |
106 | * the new block has been written. Since the new mappings are kept in a | |
107 | * separate fork, we can simply iterate these mappings to find the ones | |
108 | * that cover the file blocks that we just CoW'd. For each extent, simply | |
109 | * unmap the corresponding range in the data fork, map the new range into | |
110 | * the data fork, and remove the extent from the CoW fork. | |
111 | * | |
112 | * Since the remapping operation can be applied to an arbitrary file | |
113 | * range, we record the need for the remap step as a flag in the ioend | |
114 | * instead of declaring a new IO type. This is required for direct io | |
115 | * because we only have ioend for the whole dio, and we have to be able to | |
116 | * remember the presence of unwritten blocks and CoW blocks with a single | |
117 | * ioend structure. Better yet, the more ground we can cover with one | |
118 | * ioend, the better. | |
119 | */ | |
2a06705c DW |
120 | |
121 | /* | |
122 | * Given an AG extent, find the lowest-numbered run of shared blocks | |
123 | * within that range and return the range in fbno/flen. If | |
124 | * find_end_of_shared is true, return the longest contiguous extent of | |
125 | * shared blocks. If there are no shared extents, fbno and flen will | |
126 | * be set to NULLAGBLOCK and 0, respectively. | |
127 | */ | |
128 | int | |
129 | xfs_reflink_find_shared( | |
130 | struct xfs_mount *mp, | |
131 | xfs_agnumber_t agno, | |
132 | xfs_agblock_t agbno, | |
133 | xfs_extlen_t aglen, | |
134 | xfs_agblock_t *fbno, | |
135 | xfs_extlen_t *flen, | |
136 | bool find_end_of_shared) | |
137 | { | |
138 | struct xfs_buf *agbp; | |
139 | struct xfs_btree_cur *cur; | |
140 | int error; | |
141 | ||
142 | error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp); | |
143 | if (error) | |
144 | return error; | |
145 | ||
146 | cur = xfs_refcountbt_init_cursor(mp, NULL, agbp, agno, NULL); | |
147 | ||
148 | error = xfs_refcount_find_shared(cur, agbno, aglen, fbno, flen, | |
149 | find_end_of_shared); | |
150 | ||
151 | xfs_btree_del_cursor(cur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); | |
152 | ||
153 | xfs_buf_relse(agbp); | |
154 | return error; | |
155 | } | |
156 | ||
157 | /* | |
158 | * Trim the mapping to the next block where there's a change in the | |
159 | * shared/unshared status. More specifically, this means that we | |
160 | * find the lowest-numbered extent of shared blocks that coincides with | |
161 | * the given block mapping. If the shared extent overlaps the start of | |
162 | * the mapping, trim the mapping to the end of the shared extent. If | |
163 | * the shared region intersects the mapping, trim the mapping to the | |
164 | * start of the shared extent. If there are no shared regions that | |
165 | * overlap, just return the original extent. | |
166 | */ | |
167 | int | |
168 | xfs_reflink_trim_around_shared( | |
169 | struct xfs_inode *ip, | |
170 | struct xfs_bmbt_irec *irec, | |
171 | bool *shared, | |
172 | bool *trimmed) | |
173 | { | |
174 | xfs_agnumber_t agno; | |
175 | xfs_agblock_t agbno; | |
176 | xfs_extlen_t aglen; | |
177 | xfs_agblock_t fbno; | |
178 | xfs_extlen_t flen; | |
179 | int error = 0; | |
180 | ||
181 | /* Holes, unwritten, and delalloc extents cannot be shared */ | |
182 | if (!xfs_is_reflink_inode(ip) || | |
183 | ISUNWRITTEN(irec) || | |
184 | irec->br_startblock == HOLESTARTBLOCK || | |
185 | irec->br_startblock == DELAYSTARTBLOCK) { | |
186 | *shared = false; | |
187 | return 0; | |
188 | } | |
189 | ||
190 | trace_xfs_reflink_trim_around_shared(ip, irec); | |
191 | ||
192 | agno = XFS_FSB_TO_AGNO(ip->i_mount, irec->br_startblock); | |
193 | agbno = XFS_FSB_TO_AGBNO(ip->i_mount, irec->br_startblock); | |
194 | aglen = irec->br_blockcount; | |
195 | ||
196 | error = xfs_reflink_find_shared(ip->i_mount, agno, agbno, | |
197 | aglen, &fbno, &flen, true); | |
198 | if (error) | |
199 | return error; | |
200 | ||
201 | *shared = *trimmed = false; | |
202 | if (fbno == NULLAGBLOCK) { | |
203 | /* No shared blocks at all. */ | |
204 | return 0; | |
205 | } else if (fbno == agbno) { | |
206 | /* | |
207 | * The start of this extent is shared. Truncate the | |
208 | * mapping at the end of the shared region so that a | |
209 | * subsequent iteration starts at the start of the | |
210 | * unshared region. | |
211 | */ | |
212 | irec->br_blockcount = flen; | |
213 | *shared = true; | |
214 | if (flen != aglen) | |
215 | *trimmed = true; | |
216 | return 0; | |
217 | } else { | |
218 | /* | |
219 | * There's a shared extent midway through this extent. | |
220 | * Truncate the mapping at the start of the shared | |
221 | * extent so that a subsequent iteration starts at the | |
222 | * start of the shared region. | |
223 | */ | |
224 | irec->br_blockcount = fbno - agbno; | |
225 | *trimmed = true; | |
226 | return 0; | |
227 | } | |
228 | } | |
229 | ||
230 | /* Create a CoW reservation for a range of blocks within a file. */ | |
231 | static int | |
232 | __xfs_reflink_reserve_cow( | |
233 | struct xfs_inode *ip, | |
234 | xfs_fileoff_t *offset_fsb, | |
0613f16c DW |
235 | xfs_fileoff_t end_fsb, |
236 | bool *skipped) | |
2a06705c DW |
237 | { |
238 | struct xfs_bmbt_irec got, prev, imap; | |
239 | xfs_fileoff_t orig_end_fsb; | |
240 | int nimaps, eof = 0, error = 0; | |
241 | bool shared = false, trimmed = false; | |
242 | xfs_extnum_t idx; | |
f7ca3522 | 243 | xfs_extlen_t align; |
2a06705c DW |
244 | |
245 | /* Already reserved? Skip the refcount btree access. */ | |
246 | xfs_bmap_search_extents(ip, *offset_fsb, XFS_COW_FORK, &eof, &idx, | |
247 | &got, &prev); | |
248 | if (!eof && got.br_startoff <= *offset_fsb) { | |
249 | end_fsb = orig_end_fsb = got.br_startoff + got.br_blockcount; | |
250 | trace_xfs_reflink_cow_found(ip, &got); | |
251 | goto done; | |
252 | } | |
253 | ||
254 | /* Read extent from the source file. */ | |
255 | nimaps = 1; | |
256 | error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb, | |
257 | &imap, &nimaps, 0); | |
258 | if (error) | |
259 | goto out_unlock; | |
260 | ASSERT(nimaps == 1); | |
261 | ||
262 | /* Trim the mapping to the nearest shared extent boundary. */ | |
263 | error = xfs_reflink_trim_around_shared(ip, &imap, &shared, &trimmed); | |
264 | if (error) | |
265 | goto out_unlock; | |
266 | ||
267 | end_fsb = orig_end_fsb = imap.br_startoff + imap.br_blockcount; | |
268 | ||
269 | /* Not shared? Just report the (potentially capped) extent. */ | |
0613f16c DW |
270 | if (!shared) { |
271 | *skipped = true; | |
2a06705c | 272 | goto done; |
0613f16c | 273 | } |
2a06705c DW |
274 | |
275 | /* | |
276 | * Fork all the shared blocks from our write offset until the end of | |
277 | * the extent. | |
278 | */ | |
279 | error = xfs_qm_dqattach_locked(ip, 0); | |
280 | if (error) | |
281 | goto out_unlock; | |
282 | ||
f7ca3522 DW |
283 | align = xfs_eof_alignment(ip, xfs_get_cowextsz_hint(ip)); |
284 | if (align) | |
285 | end_fsb = roundup_64(end_fsb, align); | |
286 | ||
2a06705c DW |
287 | retry: |
288 | error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, *offset_fsb, | |
289 | end_fsb - *offset_fsb, &got, | |
290 | &prev, &idx, eof); | |
291 | switch (error) { | |
292 | case 0: | |
293 | break; | |
294 | case -ENOSPC: | |
295 | case -EDQUOT: | |
296 | /* retry without any preallocation */ | |
297 | trace_xfs_reflink_cow_enospc(ip, &imap); | |
298 | if (end_fsb != orig_end_fsb) { | |
299 | end_fsb = orig_end_fsb; | |
300 | goto retry; | |
301 | } | |
302 | /*FALLTHRU*/ | |
303 | default: | |
304 | goto out_unlock; | |
305 | } | |
306 | ||
83104d44 DW |
307 | if (end_fsb != orig_end_fsb) |
308 | xfs_inode_set_cowblocks_tag(ip); | |
309 | ||
2a06705c DW |
310 | trace_xfs_reflink_cow_alloc(ip, &got); |
311 | done: | |
312 | *offset_fsb = end_fsb; | |
313 | out_unlock: | |
314 | return error; | |
315 | } | |
316 | ||
317 | /* Create a CoW reservation for part of a file. */ | |
318 | int | |
319 | xfs_reflink_reserve_cow_range( | |
320 | struct xfs_inode *ip, | |
321 | xfs_off_t offset, | |
322 | xfs_off_t count) | |
323 | { | |
324 | struct xfs_mount *mp = ip->i_mount; | |
325 | xfs_fileoff_t offset_fsb, end_fsb; | |
0613f16c | 326 | bool skipped = false; |
1be7f9be | 327 | int error = 0; |
2a06705c DW |
328 | |
329 | trace_xfs_reflink_reserve_cow_range(ip, offset, count); | |
330 | ||
331 | offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
332 | end_fsb = XFS_B_TO_FSB(mp, offset + count); | |
333 | ||
334 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
335 | while (offset_fsb < end_fsb) { | |
0613f16c DW |
336 | error = __xfs_reflink_reserve_cow(ip, &offset_fsb, end_fsb, |
337 | &skipped); | |
2a06705c DW |
338 | if (error) { |
339 | trace_xfs_reflink_reserve_cow_range_error(ip, error, | |
340 | _RET_IP_); | |
341 | break; | |
342 | } | |
343 | } | |
344 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
345 | ||
346 | return error; | |
347 | } | |
ef473667 | 348 | |
0613f16c DW |
349 | /* Allocate all CoW reservations covering a range of blocks in a file. */ |
350 | static int | |
351 | __xfs_reflink_allocate_cow( | |
352 | struct xfs_inode *ip, | |
353 | xfs_fileoff_t *offset_fsb, | |
354 | xfs_fileoff_t end_fsb) | |
355 | { | |
356 | struct xfs_mount *mp = ip->i_mount; | |
357 | struct xfs_bmbt_irec imap; | |
358 | struct xfs_defer_ops dfops; | |
359 | struct xfs_trans *tp; | |
360 | xfs_fsblock_t first_block; | |
361 | xfs_fileoff_t next_fsb; | |
362 | int nimaps = 1, error; | |
363 | bool skipped = false; | |
364 | ||
365 | xfs_defer_init(&dfops, &first_block); | |
366 | ||
367 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, | |
368 | XFS_TRANS_RESERVE, &tp); | |
369 | if (error) | |
370 | return error; | |
371 | ||
372 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
373 | ||
374 | next_fsb = *offset_fsb; | |
375 | error = __xfs_reflink_reserve_cow(ip, &next_fsb, end_fsb, &skipped); | |
376 | if (error) | |
377 | goto out_trans_cancel; | |
378 | ||
379 | if (skipped) { | |
380 | *offset_fsb = next_fsb; | |
381 | goto out_trans_cancel; | |
382 | } | |
383 | ||
384 | xfs_trans_ijoin(tp, ip, 0); | |
385 | error = xfs_bmapi_write(tp, ip, *offset_fsb, next_fsb - *offset_fsb, | |
386 | XFS_BMAPI_COWFORK, &first_block, | |
387 | XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), | |
388 | &imap, &nimaps, &dfops); | |
389 | if (error) | |
390 | goto out_trans_cancel; | |
391 | ||
392 | /* We might not have been able to map the whole delalloc extent */ | |
393 | *offset_fsb = min(*offset_fsb + imap.br_blockcount, next_fsb); | |
394 | ||
395 | error = xfs_defer_finish(&tp, &dfops, NULL); | |
396 | if (error) | |
397 | goto out_trans_cancel; | |
398 | ||
399 | error = xfs_trans_commit(tp); | |
400 | ||
401 | out_unlock: | |
402 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
403 | return error; | |
404 | out_trans_cancel: | |
405 | xfs_defer_cancel(&dfops); | |
406 | xfs_trans_cancel(tp); | |
407 | goto out_unlock; | |
408 | } | |
409 | ||
410 | /* Allocate all CoW reservations covering a part of a file. */ | |
411 | int | |
412 | xfs_reflink_allocate_cow_range( | |
413 | struct xfs_inode *ip, | |
414 | xfs_off_t offset, | |
415 | xfs_off_t count) | |
416 | { | |
417 | struct xfs_mount *mp = ip->i_mount; | |
418 | xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
419 | xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count); | |
420 | int error; | |
421 | ||
422 | ASSERT(xfs_is_reflink_inode(ip)); | |
423 | ||
424 | trace_xfs_reflink_allocate_cow_range(ip, offset, count); | |
425 | ||
426 | /* | |
427 | * Make sure that the dquots are there. | |
428 | */ | |
429 | error = xfs_qm_dqattach(ip, 0); | |
430 | if (error) | |
431 | return error; | |
432 | ||
433 | while (offset_fsb < end_fsb) { | |
434 | error = __xfs_reflink_allocate_cow(ip, &offset_fsb, end_fsb); | |
435 | if (error) { | |
436 | trace_xfs_reflink_allocate_cow_range_error(ip, error, | |
437 | _RET_IP_); | |
438 | break; | |
439 | } | |
440 | } | |
441 | ||
442 | return error; | |
443 | } | |
444 | ||
ef473667 DW |
445 | /* |
446 | * Find the CoW reservation (and whether or not it needs block allocation) | |
447 | * for a given byte offset of a file. | |
448 | */ | |
449 | bool | |
450 | xfs_reflink_find_cow_mapping( | |
451 | struct xfs_inode *ip, | |
452 | xfs_off_t offset, | |
453 | struct xfs_bmbt_irec *imap, | |
454 | bool *need_alloc) | |
455 | { | |
456 | struct xfs_bmbt_irec irec; | |
457 | struct xfs_ifork *ifp; | |
458 | struct xfs_bmbt_rec_host *gotp; | |
459 | xfs_fileoff_t bno; | |
460 | xfs_extnum_t idx; | |
461 | ||
462 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); | |
463 | ASSERT(xfs_is_reflink_inode(ip)); | |
464 | ||
465 | /* Find the extent in the CoW fork. */ | |
466 | ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
467 | bno = XFS_B_TO_FSBT(ip->i_mount, offset); | |
468 | gotp = xfs_iext_bno_to_ext(ifp, bno, &idx); | |
469 | if (!gotp) | |
470 | return false; | |
471 | ||
472 | xfs_bmbt_get_all(gotp, &irec); | |
473 | if (bno >= irec.br_startoff + irec.br_blockcount || | |
474 | bno < irec.br_startoff) | |
475 | return false; | |
476 | ||
477 | trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE, | |
478 | &irec); | |
479 | ||
480 | /* If it's still delalloc, we must allocate later. */ | |
481 | *imap = irec; | |
482 | *need_alloc = !!(isnullstartblock(irec.br_startblock)); | |
483 | ||
484 | return true; | |
485 | } | |
486 | ||
487 | /* | |
488 | * Trim an extent to end at the next CoW reservation past offset_fsb. | |
489 | */ | |
490 | int | |
491 | xfs_reflink_trim_irec_to_next_cow( | |
492 | struct xfs_inode *ip, | |
493 | xfs_fileoff_t offset_fsb, | |
494 | struct xfs_bmbt_irec *imap) | |
495 | { | |
496 | struct xfs_bmbt_irec irec; | |
497 | struct xfs_ifork *ifp; | |
498 | struct xfs_bmbt_rec_host *gotp; | |
499 | xfs_extnum_t idx; | |
500 | ||
501 | if (!xfs_is_reflink_inode(ip)) | |
502 | return 0; | |
503 | ||
504 | /* Find the extent in the CoW fork. */ | |
505 | ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
506 | gotp = xfs_iext_bno_to_ext(ifp, offset_fsb, &idx); | |
507 | if (!gotp) | |
508 | return 0; | |
509 | xfs_bmbt_get_all(gotp, &irec); | |
510 | ||
511 | /* This is the extent before; try sliding up one. */ | |
512 | if (irec.br_startoff < offset_fsb) { | |
513 | idx++; | |
514 | if (idx >= ifp->if_bytes / sizeof(xfs_bmbt_rec_t)) | |
515 | return 0; | |
516 | gotp = xfs_iext_get_ext(ifp, idx); | |
517 | xfs_bmbt_get_all(gotp, &irec); | |
518 | } | |
519 | ||
520 | if (irec.br_startoff >= imap->br_startoff + imap->br_blockcount) | |
521 | return 0; | |
522 | ||
523 | imap->br_blockcount = irec.br_startoff - imap->br_startoff; | |
524 | trace_xfs_reflink_trim_irec(ip, imap); | |
525 | ||
526 | return 0; | |
527 | } | |
43caeb18 DW |
528 | |
529 | /* | |
530 | * Cancel all pending CoW reservations for some block range of an inode. | |
531 | */ | |
532 | int | |
533 | xfs_reflink_cancel_cow_blocks( | |
534 | struct xfs_inode *ip, | |
535 | struct xfs_trans **tpp, | |
536 | xfs_fileoff_t offset_fsb, | |
537 | xfs_fileoff_t end_fsb) | |
538 | { | |
539 | struct xfs_bmbt_irec irec; | |
540 | xfs_filblks_t count_fsb; | |
541 | xfs_fsblock_t firstfsb; | |
542 | struct xfs_defer_ops dfops; | |
543 | int error = 0; | |
544 | int nimaps; | |
545 | ||
546 | if (!xfs_is_reflink_inode(ip)) | |
547 | return 0; | |
548 | ||
549 | /* Go find the old extent in the CoW fork. */ | |
550 | while (offset_fsb < end_fsb) { | |
551 | nimaps = 1; | |
552 | count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb); | |
553 | error = xfs_bmapi_read(ip, offset_fsb, count_fsb, &irec, | |
554 | &nimaps, XFS_BMAPI_COWFORK); | |
555 | if (error) | |
556 | break; | |
557 | ASSERT(nimaps == 1); | |
558 | ||
559 | trace_xfs_reflink_cancel_cow(ip, &irec); | |
560 | ||
561 | if (irec.br_startblock == DELAYSTARTBLOCK) { | |
562 | /* Free a delayed allocation. */ | |
563 | xfs_mod_fdblocks(ip->i_mount, irec.br_blockcount, | |
564 | false); | |
565 | ip->i_delayed_blks -= irec.br_blockcount; | |
566 | ||
567 | /* Remove the mapping from the CoW fork. */ | |
568 | error = xfs_bunmapi_cow(ip, &irec); | |
569 | if (error) | |
570 | break; | |
571 | } else if (irec.br_startblock == HOLESTARTBLOCK) { | |
572 | /* empty */ | |
573 | } else { | |
574 | xfs_trans_ijoin(*tpp, ip, 0); | |
575 | xfs_defer_init(&dfops, &firstfsb); | |
576 | ||
174edb0e DW |
577 | /* Free the CoW orphan record. */ |
578 | error = xfs_refcount_free_cow_extent(ip->i_mount, | |
579 | &dfops, irec.br_startblock, | |
580 | irec.br_blockcount); | |
581 | if (error) | |
582 | break; | |
583 | ||
43caeb18 DW |
584 | xfs_bmap_add_free(ip->i_mount, &dfops, |
585 | irec.br_startblock, irec.br_blockcount, | |
586 | NULL); | |
587 | ||
588 | /* Update quota accounting */ | |
589 | xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT, | |
590 | -(long)irec.br_blockcount); | |
591 | ||
592 | /* Roll the transaction */ | |
593 | error = xfs_defer_finish(tpp, &dfops, ip); | |
594 | if (error) { | |
595 | xfs_defer_cancel(&dfops); | |
596 | break; | |
597 | } | |
598 | ||
599 | /* Remove the mapping from the CoW fork. */ | |
600 | error = xfs_bunmapi_cow(ip, &irec); | |
601 | if (error) | |
602 | break; | |
603 | } | |
604 | ||
605 | /* Roll on... */ | |
606 | offset_fsb = irec.br_startoff + irec.br_blockcount; | |
607 | } | |
608 | ||
609 | return error; | |
610 | } | |
611 | ||
612 | /* | |
613 | * Cancel all pending CoW reservations for some byte range of an inode. | |
614 | */ | |
615 | int | |
616 | xfs_reflink_cancel_cow_range( | |
617 | struct xfs_inode *ip, | |
618 | xfs_off_t offset, | |
619 | xfs_off_t count) | |
620 | { | |
621 | struct xfs_trans *tp; | |
622 | xfs_fileoff_t offset_fsb; | |
623 | xfs_fileoff_t end_fsb; | |
624 | int error; | |
625 | ||
626 | trace_xfs_reflink_cancel_cow_range(ip, offset, count); | |
63646fc5 | 627 | ASSERT(xfs_is_reflink_inode(ip)); |
43caeb18 DW |
628 | |
629 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); | |
630 | if (count == NULLFILEOFF) | |
631 | end_fsb = NULLFILEOFF; | |
632 | else | |
633 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
634 | ||
635 | /* Start a rolling transaction to remove the mappings */ | |
636 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
637 | 0, 0, 0, &tp); | |
638 | if (error) | |
639 | goto out; | |
640 | ||
641 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
642 | xfs_trans_ijoin(tp, ip, 0); | |
643 | ||
644 | /* Scrape out the old CoW reservations */ | |
645 | error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb); | |
646 | if (error) | |
647 | goto out_cancel; | |
648 | ||
649 | error = xfs_trans_commit(tp); | |
650 | ||
651 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
652 | return error; | |
653 | ||
654 | out_cancel: | |
655 | xfs_trans_cancel(tp); | |
656 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
657 | out: | |
658 | trace_xfs_reflink_cancel_cow_range_error(ip, error, _RET_IP_); | |
659 | return error; | |
660 | } | |
661 | ||
662 | /* | |
663 | * Remap parts of a file's data fork after a successful CoW. | |
664 | */ | |
665 | int | |
666 | xfs_reflink_end_cow( | |
667 | struct xfs_inode *ip, | |
668 | xfs_off_t offset, | |
669 | xfs_off_t count) | |
670 | { | |
671 | struct xfs_bmbt_irec irec; | |
672 | struct xfs_bmbt_irec uirec; | |
673 | struct xfs_trans *tp; | |
674 | xfs_fileoff_t offset_fsb; | |
675 | xfs_fileoff_t end_fsb; | |
676 | xfs_filblks_t count_fsb; | |
677 | xfs_fsblock_t firstfsb; | |
678 | struct xfs_defer_ops dfops; | |
679 | int error; | |
680 | unsigned int resblks; | |
681 | xfs_filblks_t ilen; | |
682 | xfs_filblks_t rlen; | |
683 | int nimaps; | |
684 | ||
685 | trace_xfs_reflink_end_cow(ip, offset, count); | |
686 | ||
687 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); | |
688 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
689 | count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb); | |
690 | ||
691 | /* Start a rolling transaction to switch the mappings */ | |
692 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
693 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
694 | resblks, 0, 0, &tp); | |
695 | if (error) | |
696 | goto out; | |
697 | ||
698 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
699 | xfs_trans_ijoin(tp, ip, 0); | |
700 | ||
701 | /* Go find the old extent in the CoW fork. */ | |
702 | while (offset_fsb < end_fsb) { | |
703 | /* Read extent from the source file */ | |
704 | nimaps = 1; | |
705 | count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb); | |
706 | error = xfs_bmapi_read(ip, offset_fsb, count_fsb, &irec, | |
707 | &nimaps, XFS_BMAPI_COWFORK); | |
708 | if (error) | |
709 | goto out_cancel; | |
710 | ASSERT(nimaps == 1); | |
711 | ||
712 | ASSERT(irec.br_startblock != DELAYSTARTBLOCK); | |
713 | trace_xfs_reflink_cow_remap(ip, &irec); | |
714 | ||
715 | /* | |
716 | * We can have a hole in the CoW fork if part of a directio | |
717 | * write is CoW but part of it isn't. | |
718 | */ | |
719 | rlen = ilen = irec.br_blockcount; | |
720 | if (irec.br_startblock == HOLESTARTBLOCK) | |
721 | goto next_extent; | |
722 | ||
723 | /* Unmap the old blocks in the data fork. */ | |
724 | while (rlen) { | |
725 | xfs_defer_init(&dfops, &firstfsb); | |
726 | error = __xfs_bunmapi(tp, ip, irec.br_startoff, | |
727 | &rlen, 0, 1, &firstfsb, &dfops); | |
728 | if (error) | |
729 | goto out_defer; | |
730 | ||
731 | /* | |
732 | * Trim the extent to whatever got unmapped. | |
733 | * Remember, bunmapi works backwards. | |
734 | */ | |
735 | uirec.br_startblock = irec.br_startblock + rlen; | |
736 | uirec.br_startoff = irec.br_startoff + rlen; | |
737 | uirec.br_blockcount = irec.br_blockcount - rlen; | |
738 | irec.br_blockcount = rlen; | |
739 | trace_xfs_reflink_cow_remap_piece(ip, &uirec); | |
740 | ||
174edb0e DW |
741 | /* Free the CoW orphan record. */ |
742 | error = xfs_refcount_free_cow_extent(tp->t_mountp, | |
743 | &dfops, uirec.br_startblock, | |
744 | uirec.br_blockcount); | |
745 | if (error) | |
746 | goto out_defer; | |
747 | ||
43caeb18 DW |
748 | /* Map the new blocks into the data fork. */ |
749 | error = xfs_bmap_map_extent(tp->t_mountp, &dfops, | |
750 | ip, &uirec); | |
751 | if (error) | |
752 | goto out_defer; | |
753 | ||
754 | /* Remove the mapping from the CoW fork. */ | |
755 | error = xfs_bunmapi_cow(ip, &uirec); | |
756 | if (error) | |
757 | goto out_defer; | |
758 | ||
759 | error = xfs_defer_finish(&tp, &dfops, ip); | |
760 | if (error) | |
761 | goto out_defer; | |
762 | } | |
763 | ||
764 | next_extent: | |
765 | /* Roll on... */ | |
766 | offset_fsb = irec.br_startoff + ilen; | |
767 | } | |
768 | ||
769 | error = xfs_trans_commit(tp); | |
770 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
771 | if (error) | |
772 | goto out; | |
773 | return 0; | |
774 | ||
775 | out_defer: | |
776 | xfs_defer_cancel(&dfops); | |
777 | out_cancel: | |
778 | xfs_trans_cancel(tp); | |
779 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
780 | out: | |
781 | trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); | |
782 | return error; | |
783 | } | |
174edb0e DW |
784 | |
785 | /* | |
786 | * Free leftover CoW reservations that didn't get cleaned out. | |
787 | */ | |
788 | int | |
789 | xfs_reflink_recover_cow( | |
790 | struct xfs_mount *mp) | |
791 | { | |
792 | xfs_agnumber_t agno; | |
793 | int error = 0; | |
794 | ||
795 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
796 | return 0; | |
797 | ||
798 | for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { | |
799 | error = xfs_refcount_recover_cow_leftovers(mp, agno); | |
800 | if (error) | |
801 | break; | |
802 | } | |
803 | ||
804 | return error; | |
805 | } | |
862bb360 DW |
806 | |
807 | /* | |
808 | * Reflinking (Block) Ranges of Two Files Together | |
809 | * | |
810 | * First, ensure that the reflink flag is set on both inodes. The flag is an | |
811 | * optimization to avoid unnecessary refcount btree lookups in the write path. | |
812 | * | |
813 | * Now we can iteratively remap the range of extents (and holes) in src to the | |
814 | * corresponding ranges in dest. Let drange and srange denote the ranges of | |
815 | * logical blocks in dest and src touched by the reflink operation. | |
816 | * | |
817 | * While the length of drange is greater than zero, | |
818 | * - Read src's bmbt at the start of srange ("imap") | |
819 | * - If imap doesn't exist, make imap appear to start at the end of srange | |
820 | * with zero length. | |
821 | * - If imap starts before srange, advance imap to start at srange. | |
822 | * - If imap goes beyond srange, truncate imap to end at the end of srange. | |
823 | * - Punch (imap start - srange start + imap len) blocks from dest at | |
824 | * offset (drange start). | |
825 | * - If imap points to a real range of pblks, | |
826 | * > Increase the refcount of the imap's pblks | |
827 | * > Map imap's pblks into dest at the offset | |
828 | * (drange start + imap start - srange start) | |
829 | * - Advance drange and srange by (imap start - srange start + imap len) | |
830 | * | |
831 | * Finally, if the reflink made dest longer, update both the in-core and | |
832 | * on-disk file sizes. | |
833 | * | |
834 | * ASCII Art Demonstration: | |
835 | * | |
836 | * Let's say we want to reflink this source file: | |
837 | * | |
838 | * ----SSSSSSS-SSSSS----SSSSSS (src file) | |
839 | * <--------------------> | |
840 | * | |
841 | * into this destination file: | |
842 | * | |
843 | * --DDDDDDDDDDDDDDDDDDD--DDD (dest file) | |
844 | * <--------------------> | |
845 | * '-' means a hole, and 'S' and 'D' are written blocks in the src and dest. | |
846 | * Observe that the range has different logical offsets in either file. | |
847 | * | |
848 | * Consider that the first extent in the source file doesn't line up with our | |
849 | * reflink range. Unmapping and remapping are separate operations, so we can | |
850 | * unmap more blocks from the destination file than we remap. | |
851 | * | |
852 | * ----SSSSSSS-SSSSS----SSSSSS | |
853 | * <-------> | |
854 | * --DDDDD---------DDDDD--DDD | |
855 | * <-------> | |
856 | * | |
857 | * Now remap the source extent into the destination file: | |
858 | * | |
859 | * ----SSSSSSS-SSSSS----SSSSSS | |
860 | * <-------> | |
861 | * --DDDDD--SSSSSSSDDDDD--DDD | |
862 | * <-------> | |
863 | * | |
864 | * Do likewise with the second hole and extent in our range. Holes in the | |
865 | * unmap range don't affect our operation. | |
866 | * | |
867 | * ----SSSSSSS-SSSSS----SSSSSS | |
868 | * <----> | |
869 | * --DDDDD--SSSSSSS-SSSSS-DDD | |
870 | * <----> | |
871 | * | |
872 | * Finally, unmap and remap part of the third extent. This will increase the | |
873 | * size of the destination file. | |
874 | * | |
875 | * ----SSSSSSS-SSSSS----SSSSSS | |
876 | * <-----> | |
877 | * --DDDDD--SSSSSSS-SSSSS----SSS | |
878 | * <-----> | |
879 | * | |
880 | * Once we update the destination file's i_size, we're done. | |
881 | */ | |
882 | ||
883 | /* | |
884 | * Ensure the reflink bit is set in both inodes. | |
885 | */ | |
886 | STATIC int | |
887 | xfs_reflink_set_inode_flag( | |
888 | struct xfs_inode *src, | |
889 | struct xfs_inode *dest) | |
890 | { | |
891 | struct xfs_mount *mp = src->i_mount; | |
892 | int error; | |
893 | struct xfs_trans *tp; | |
894 | ||
895 | if (xfs_is_reflink_inode(src) && xfs_is_reflink_inode(dest)) | |
896 | return 0; | |
897 | ||
898 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
899 | if (error) | |
900 | goto out_error; | |
901 | ||
902 | /* Lock both files against IO */ | |
903 | if (src->i_ino == dest->i_ino) | |
904 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
905 | else | |
906 | xfs_lock_two_inodes(src, dest, XFS_ILOCK_EXCL); | |
907 | ||
908 | if (!xfs_is_reflink_inode(src)) { | |
909 | trace_xfs_reflink_set_inode_flag(src); | |
910 | xfs_trans_ijoin(tp, src, XFS_ILOCK_EXCL); | |
911 | src->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
912 | xfs_trans_log_inode(tp, src, XFS_ILOG_CORE); | |
913 | xfs_ifork_init_cow(src); | |
914 | } else | |
915 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
916 | ||
917 | if (src->i_ino == dest->i_ino) | |
918 | goto commit_flags; | |
919 | ||
920 | if (!xfs_is_reflink_inode(dest)) { | |
921 | trace_xfs_reflink_set_inode_flag(dest); | |
922 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
923 | dest->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
924 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); | |
925 | xfs_ifork_init_cow(dest); | |
926 | } else | |
927 | xfs_iunlock(dest, XFS_ILOCK_EXCL); | |
928 | ||
929 | commit_flags: | |
930 | error = xfs_trans_commit(tp); | |
931 | if (error) | |
932 | goto out_error; | |
933 | return error; | |
934 | ||
935 | out_error: | |
936 | trace_xfs_reflink_set_inode_flag_error(dest, error, _RET_IP_); | |
937 | return error; | |
938 | } | |
939 | ||
940 | /* | |
f7ca3522 | 941 | * Update destination inode size & cowextsize hint, if necessary. |
862bb360 DW |
942 | */ |
943 | STATIC int | |
944 | xfs_reflink_update_dest( | |
945 | struct xfs_inode *dest, | |
f7ca3522 DW |
946 | xfs_off_t newlen, |
947 | xfs_extlen_t cowextsize) | |
862bb360 DW |
948 | { |
949 | struct xfs_mount *mp = dest->i_mount; | |
950 | struct xfs_trans *tp; | |
951 | int error; | |
952 | ||
f7ca3522 | 953 | if (newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0) |
862bb360 DW |
954 | return 0; |
955 | ||
956 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
957 | if (error) | |
958 | goto out_error; | |
959 | ||
960 | xfs_ilock(dest, XFS_ILOCK_EXCL); | |
961 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
962 | ||
f7ca3522 DW |
963 | if (newlen > i_size_read(VFS_I(dest))) { |
964 | trace_xfs_reflink_update_inode_size(dest, newlen); | |
965 | i_size_write(VFS_I(dest), newlen); | |
966 | dest->i_d.di_size = newlen; | |
967 | } | |
968 | ||
969 | if (cowextsize) { | |
970 | dest->i_d.di_cowextsize = cowextsize; | |
971 | dest->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE; | |
972 | } | |
973 | ||
862bb360 DW |
974 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); |
975 | ||
976 | error = xfs_trans_commit(tp); | |
977 | if (error) | |
978 | goto out_error; | |
979 | return error; | |
980 | ||
981 | out_error: | |
982 | trace_xfs_reflink_update_inode_size_error(dest, error, _RET_IP_); | |
983 | return error; | |
984 | } | |
985 | ||
6fa164b8 DW |
986 | /* |
987 | * Do we have enough reserve in this AG to handle a reflink? The refcount | |
988 | * btree already reserved all the space it needs, but the rmap btree can grow | |
989 | * infinitely, so we won't allow more reflinks when the AG is down to the | |
990 | * btree reserves. | |
991 | */ | |
992 | static int | |
993 | xfs_reflink_ag_has_free_space( | |
994 | struct xfs_mount *mp, | |
995 | xfs_agnumber_t agno) | |
996 | { | |
997 | struct xfs_perag *pag; | |
998 | int error = 0; | |
999 | ||
1000 | if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) | |
1001 | return 0; | |
1002 | ||
1003 | pag = xfs_perag_get(mp, agno); | |
1004 | if (xfs_ag_resv_critical(pag, XFS_AG_RESV_AGFL) || | |
1005 | xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA)) | |
1006 | error = -ENOSPC; | |
1007 | xfs_perag_put(pag); | |
1008 | return error; | |
1009 | } | |
1010 | ||
862bb360 DW |
1011 | /* |
1012 | * Unmap a range of blocks from a file, then map other blocks into the hole. | |
1013 | * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount). | |
1014 | * The extent irec is mapped into dest at irec->br_startoff. | |
1015 | */ | |
1016 | STATIC int | |
1017 | xfs_reflink_remap_extent( | |
1018 | struct xfs_inode *ip, | |
1019 | struct xfs_bmbt_irec *irec, | |
1020 | xfs_fileoff_t destoff, | |
1021 | xfs_off_t new_isize) | |
1022 | { | |
1023 | struct xfs_mount *mp = ip->i_mount; | |
1024 | struct xfs_trans *tp; | |
1025 | xfs_fsblock_t firstfsb; | |
1026 | unsigned int resblks; | |
1027 | struct xfs_defer_ops dfops; | |
1028 | struct xfs_bmbt_irec uirec; | |
1029 | bool real_extent; | |
1030 | xfs_filblks_t rlen; | |
1031 | xfs_filblks_t unmap_len; | |
1032 | xfs_off_t newlen; | |
1033 | int error; | |
1034 | ||
1035 | unmap_len = irec->br_startoff + irec->br_blockcount - destoff; | |
1036 | trace_xfs_reflink_punch_range(ip, destoff, unmap_len); | |
1037 | ||
1038 | /* Only remap normal extents. */ | |
1039 | real_extent = (irec->br_startblock != HOLESTARTBLOCK && | |
1040 | irec->br_startblock != DELAYSTARTBLOCK && | |
1041 | !ISUNWRITTEN(irec)); | |
1042 | ||
6fa164b8 DW |
1043 | /* No reflinking if we're low on space */ |
1044 | if (real_extent) { | |
1045 | error = xfs_reflink_ag_has_free_space(mp, | |
1046 | XFS_FSB_TO_AGNO(mp, irec->br_startblock)); | |
1047 | if (error) | |
1048 | goto out; | |
1049 | } | |
1050 | ||
862bb360 DW |
1051 | /* Start a rolling transaction to switch the mappings */ |
1052 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
1053 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); | |
1054 | if (error) | |
1055 | goto out; | |
1056 | ||
1057 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1058 | xfs_trans_ijoin(tp, ip, 0); | |
1059 | ||
1060 | /* If we're not just clearing space, then do we have enough quota? */ | |
1061 | if (real_extent) { | |
1062 | error = xfs_trans_reserve_quota_nblks(tp, ip, | |
1063 | irec->br_blockcount, 0, XFS_QMOPT_RES_REGBLKS); | |
1064 | if (error) | |
1065 | goto out_cancel; | |
1066 | } | |
1067 | ||
1068 | trace_xfs_reflink_remap(ip, irec->br_startoff, | |
1069 | irec->br_blockcount, irec->br_startblock); | |
1070 | ||
1071 | /* Unmap the old blocks in the data fork. */ | |
1072 | rlen = unmap_len; | |
1073 | while (rlen) { | |
1074 | xfs_defer_init(&dfops, &firstfsb); | |
1075 | error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1, | |
1076 | &firstfsb, &dfops); | |
1077 | if (error) | |
1078 | goto out_defer; | |
1079 | ||
1080 | /* | |
1081 | * Trim the extent to whatever got unmapped. | |
1082 | * Remember, bunmapi works backwards. | |
1083 | */ | |
1084 | uirec.br_startblock = irec->br_startblock + rlen; | |
1085 | uirec.br_startoff = irec->br_startoff + rlen; | |
1086 | uirec.br_blockcount = unmap_len - rlen; | |
1087 | unmap_len = rlen; | |
1088 | ||
1089 | /* If this isn't a real mapping, we're done. */ | |
1090 | if (!real_extent || uirec.br_blockcount == 0) | |
1091 | goto next_extent; | |
1092 | ||
1093 | trace_xfs_reflink_remap(ip, uirec.br_startoff, | |
1094 | uirec.br_blockcount, uirec.br_startblock); | |
1095 | ||
1096 | /* Update the refcount tree */ | |
1097 | error = xfs_refcount_increase_extent(mp, &dfops, &uirec); | |
1098 | if (error) | |
1099 | goto out_defer; | |
1100 | ||
1101 | /* Map the new blocks into the data fork. */ | |
1102 | error = xfs_bmap_map_extent(mp, &dfops, ip, &uirec); | |
1103 | if (error) | |
1104 | goto out_defer; | |
1105 | ||
1106 | /* Update quota accounting. */ | |
1107 | xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, | |
1108 | uirec.br_blockcount); | |
1109 | ||
1110 | /* Update dest isize if needed. */ | |
1111 | newlen = XFS_FSB_TO_B(mp, | |
1112 | uirec.br_startoff + uirec.br_blockcount); | |
1113 | newlen = min_t(xfs_off_t, newlen, new_isize); | |
1114 | if (newlen > i_size_read(VFS_I(ip))) { | |
1115 | trace_xfs_reflink_update_inode_size(ip, newlen); | |
1116 | i_size_write(VFS_I(ip), newlen); | |
1117 | ip->i_d.di_size = newlen; | |
1118 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
1119 | } | |
1120 | ||
1121 | next_extent: | |
1122 | /* Process all the deferred stuff. */ | |
1123 | error = xfs_defer_finish(&tp, &dfops, ip); | |
1124 | if (error) | |
1125 | goto out_defer; | |
1126 | } | |
1127 | ||
1128 | error = xfs_trans_commit(tp); | |
1129 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1130 | if (error) | |
1131 | goto out; | |
1132 | return 0; | |
1133 | ||
1134 | out_defer: | |
1135 | xfs_defer_cancel(&dfops); | |
1136 | out_cancel: | |
1137 | xfs_trans_cancel(tp); | |
1138 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1139 | out: | |
1140 | trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_); | |
1141 | return error; | |
1142 | } | |
1143 | ||
1144 | /* | |
1145 | * Iteratively remap one file's extents (and holes) to another's. | |
1146 | */ | |
1147 | STATIC int | |
1148 | xfs_reflink_remap_blocks( | |
1149 | struct xfs_inode *src, | |
1150 | xfs_fileoff_t srcoff, | |
1151 | struct xfs_inode *dest, | |
1152 | xfs_fileoff_t destoff, | |
1153 | xfs_filblks_t len, | |
1154 | xfs_off_t new_isize) | |
1155 | { | |
1156 | struct xfs_bmbt_irec imap; | |
1157 | int nimaps; | |
1158 | int error = 0; | |
1159 | xfs_filblks_t range_len; | |
1160 | ||
1161 | /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ | |
1162 | while (len) { | |
1163 | trace_xfs_reflink_remap_blocks_loop(src, srcoff, len, | |
1164 | dest, destoff); | |
1165 | /* Read extent from the source file */ | |
1166 | nimaps = 1; | |
1167 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
1168 | error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); | |
1169 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
1170 | if (error) | |
1171 | goto err; | |
1172 | ASSERT(nimaps == 1); | |
1173 | ||
1174 | trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE, | |
1175 | &imap); | |
1176 | ||
1177 | /* Translate imap into the destination file. */ | |
1178 | range_len = imap.br_startoff + imap.br_blockcount - srcoff; | |
1179 | imap.br_startoff += destoff - srcoff; | |
1180 | ||
1181 | /* Clear dest from destoff to the end of imap and map it in. */ | |
1182 | error = xfs_reflink_remap_extent(dest, &imap, destoff, | |
1183 | new_isize); | |
1184 | if (error) | |
1185 | goto err; | |
1186 | ||
1187 | if (fatal_signal_pending(current)) { | |
1188 | error = -EINTR; | |
1189 | goto err; | |
1190 | } | |
1191 | ||
1192 | /* Advance drange/srange */ | |
1193 | srcoff += range_len; | |
1194 | destoff += range_len; | |
1195 | len -= range_len; | |
1196 | } | |
1197 | ||
1198 | return 0; | |
1199 | ||
1200 | err: | |
1201 | trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_); | |
1202 | return error; | |
1203 | } | |
1204 | ||
cc714660 DW |
1205 | /* |
1206 | * Read a page's worth of file data into the page cache. Return the page | |
1207 | * locked. | |
1208 | */ | |
1209 | static struct page * | |
1210 | xfs_get_page( | |
1211 | struct inode *inode, | |
1212 | xfs_off_t offset) | |
1213 | { | |
1214 | struct address_space *mapping; | |
1215 | struct page *page; | |
1216 | pgoff_t n; | |
1217 | ||
1218 | n = offset >> PAGE_SHIFT; | |
1219 | mapping = inode->i_mapping; | |
1220 | page = read_mapping_page(mapping, n, NULL); | |
1221 | if (IS_ERR(page)) | |
1222 | return page; | |
1223 | if (!PageUptodate(page)) { | |
1224 | put_page(page); | |
1225 | return ERR_PTR(-EIO); | |
1226 | } | |
1227 | lock_page(page); | |
1228 | return page; | |
1229 | } | |
1230 | ||
1231 | /* | |
1232 | * Compare extents of two files to see if they are the same. | |
1233 | */ | |
1234 | static int | |
1235 | xfs_compare_extents( | |
1236 | struct inode *src, | |
1237 | xfs_off_t srcoff, | |
1238 | struct inode *dest, | |
1239 | xfs_off_t destoff, | |
1240 | xfs_off_t len, | |
1241 | bool *is_same) | |
1242 | { | |
1243 | xfs_off_t src_poff; | |
1244 | xfs_off_t dest_poff; | |
1245 | void *src_addr; | |
1246 | void *dest_addr; | |
1247 | struct page *src_page; | |
1248 | struct page *dest_page; | |
1249 | xfs_off_t cmp_len; | |
1250 | bool same; | |
1251 | int error; | |
1252 | ||
1253 | error = -EINVAL; | |
1254 | same = true; | |
1255 | while (len) { | |
1256 | src_poff = srcoff & (PAGE_SIZE - 1); | |
1257 | dest_poff = destoff & (PAGE_SIZE - 1); | |
1258 | cmp_len = min(PAGE_SIZE - src_poff, | |
1259 | PAGE_SIZE - dest_poff); | |
1260 | cmp_len = min(cmp_len, len); | |
1261 | ASSERT(cmp_len > 0); | |
1262 | ||
1263 | trace_xfs_reflink_compare_extents(XFS_I(src), srcoff, cmp_len, | |
1264 | XFS_I(dest), destoff); | |
1265 | ||
1266 | src_page = xfs_get_page(src, srcoff); | |
1267 | if (IS_ERR(src_page)) { | |
1268 | error = PTR_ERR(src_page); | |
1269 | goto out_error; | |
1270 | } | |
1271 | dest_page = xfs_get_page(dest, destoff); | |
1272 | if (IS_ERR(dest_page)) { | |
1273 | error = PTR_ERR(dest_page); | |
1274 | unlock_page(src_page); | |
1275 | put_page(src_page); | |
1276 | goto out_error; | |
1277 | } | |
1278 | src_addr = kmap_atomic(src_page); | |
1279 | dest_addr = kmap_atomic(dest_page); | |
1280 | ||
1281 | flush_dcache_page(src_page); | |
1282 | flush_dcache_page(dest_page); | |
1283 | ||
1284 | if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len)) | |
1285 | same = false; | |
1286 | ||
1287 | kunmap_atomic(dest_addr); | |
1288 | kunmap_atomic(src_addr); | |
1289 | unlock_page(dest_page); | |
1290 | unlock_page(src_page); | |
1291 | put_page(dest_page); | |
1292 | put_page(src_page); | |
1293 | ||
1294 | if (!same) | |
1295 | break; | |
1296 | ||
1297 | srcoff += cmp_len; | |
1298 | destoff += cmp_len; | |
1299 | len -= cmp_len; | |
1300 | } | |
1301 | ||
1302 | *is_same = same; | |
1303 | return 0; | |
1304 | ||
1305 | out_error: | |
1306 | trace_xfs_reflink_compare_extents_error(XFS_I(dest), error, _RET_IP_); | |
1307 | return error; | |
1308 | } | |
1309 | ||
862bb360 DW |
1310 | /* |
1311 | * Link a range of blocks from one file to another. | |
1312 | */ | |
1313 | int | |
1314 | xfs_reflink_remap_range( | |
5faaf4fa CH |
1315 | struct file *file_in, |
1316 | loff_t pos_in, | |
1317 | struct file *file_out, | |
1318 | loff_t pos_out, | |
1319 | u64 len, | |
1320 | bool is_dedupe) | |
862bb360 | 1321 | { |
5faaf4fa CH |
1322 | struct inode *inode_in = file_inode(file_in); |
1323 | struct xfs_inode *src = XFS_I(inode_in); | |
1324 | struct inode *inode_out = file_inode(file_out); | |
1325 | struct xfs_inode *dest = XFS_I(inode_out); | |
862bb360 | 1326 | struct xfs_mount *mp = src->i_mount; |
5faaf4fa CH |
1327 | loff_t bs = inode_out->i_sb->s_blocksize; |
1328 | bool same_inode = (inode_in == inode_out); | |
862bb360 DW |
1329 | xfs_fileoff_t sfsbno, dfsbno; |
1330 | xfs_filblks_t fsblen; | |
f7ca3522 | 1331 | xfs_extlen_t cowextsize; |
5faaf4fa CH |
1332 | loff_t isize; |
1333 | ssize_t ret; | |
1334 | loff_t blen; | |
862bb360 DW |
1335 | |
1336 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1337 | return -EOPNOTSUPP; | |
1338 | ||
1339 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1340 | return -EIO; | |
1341 | ||
5faaf4fa CH |
1342 | /* Lock both files against IO */ |
1343 | if (same_inode) { | |
1344 | xfs_ilock(src, XFS_IOLOCK_EXCL); | |
1345 | xfs_ilock(src, XFS_MMAPLOCK_EXCL); | |
1346 | } else { | |
1347 | xfs_lock_two_inodes(src, dest, XFS_IOLOCK_EXCL); | |
1348 | xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL); | |
1349 | } | |
1350 | ||
1351 | /* Don't touch certain kinds of inodes */ | |
1352 | ret = -EPERM; | |
1353 | if (IS_IMMUTABLE(inode_out)) | |
1354 | goto out_unlock; | |
1355 | ||
1356 | ret = -ETXTBSY; | |
1357 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1358 | goto out_unlock; | |
1359 | ||
1360 | ||
1361 | /* Don't reflink dirs, pipes, sockets... */ | |
1362 | ret = -EISDIR; | |
1363 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
1364 | goto out_unlock; | |
1365 | ret = -EINVAL; | |
1366 | if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode)) | |
1367 | goto out_unlock; | |
1368 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) | |
1369 | goto out_unlock; | |
1370 | ||
862bb360 DW |
1371 | /* Don't reflink realtime inodes */ |
1372 | if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest)) | |
5faaf4fa CH |
1373 | goto out_unlock; |
1374 | ||
1375 | /* Don't share DAX file data for now. */ | |
1376 | if (IS_DAX(inode_in) || IS_DAX(inode_out)) | |
1377 | goto out_unlock; | |
1378 | ||
1379 | /* Are we going all the way to the end? */ | |
1380 | isize = i_size_read(inode_in); | |
1381 | if (isize == 0) { | |
1382 | ret = 0; | |
1383 | goto out_unlock; | |
1384 | } | |
1385 | ||
1386 | if (len == 0) | |
1387 | len = isize - pos_in; | |
1388 | ||
1389 | /* Ensure offsets don't wrap and the input is inside i_size */ | |
1390 | if (pos_in + len < pos_in || pos_out + len < pos_out || | |
1391 | pos_in + len > isize) | |
1392 | goto out_unlock; | |
862bb360 | 1393 | |
5faaf4fa CH |
1394 | /* Don't allow dedupe past EOF in the dest file */ |
1395 | if (is_dedupe) { | |
1396 | loff_t disize; | |
cc714660 | 1397 | |
5faaf4fa CH |
1398 | disize = i_size_read(inode_out); |
1399 | if (pos_out >= disize || pos_out + len > disize) | |
1400 | goto out_unlock; | |
1401 | } | |
1402 | ||
1403 | /* If we're linking to EOF, continue to the block boundary. */ | |
1404 | if (pos_in + len == isize) | |
1405 | blen = ALIGN(isize, bs) - pos_in; | |
1406 | else | |
1407 | blen = len; | |
1408 | ||
1409 | /* Only reflink if we're aligned to block boundaries */ | |
1410 | if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) || | |
1411 | !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs)) | |
1412 | goto out_unlock; | |
1413 | ||
1414 | /* Don't allow overlapped reflink within the same file */ | |
1415 | if (same_inode) { | |
1416 | if (pos_out + blen > pos_in && pos_out < pos_in + blen) | |
1417 | goto out_unlock; | |
1418 | } | |
1419 | ||
1420 | /* Wait for the completion of any pending IOs on both files */ | |
1421 | inode_dio_wait(inode_in); | |
1422 | if (!same_inode) | |
1423 | inode_dio_wait(inode_out); | |
1424 | ||
1425 | ret = filemap_write_and_wait_range(inode_in->i_mapping, | |
1426 | pos_in, pos_in + len - 1); | |
1427 | if (ret) | |
1428 | goto out_unlock; | |
1429 | ||
1430 | ret = filemap_write_and_wait_range(inode_out->i_mapping, | |
1431 | pos_out, pos_out + len - 1); | |
1432 | if (ret) | |
1433 | goto out_unlock; | |
1434 | ||
1435 | trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); | |
862bb360 | 1436 | |
cc714660 DW |
1437 | /* |
1438 | * Check that the extents are the same. | |
1439 | */ | |
5faaf4fa CH |
1440 | if (is_dedupe) { |
1441 | bool is_same = false; | |
1442 | ||
1443 | ret = xfs_compare_extents(inode_in, pos_in, inode_out, pos_out, | |
1444 | len, &is_same); | |
1445 | if (ret) | |
1446 | goto out_unlock; | |
cc714660 | 1447 | if (!is_same) { |
5faaf4fa CH |
1448 | ret = -EBADE; |
1449 | goto out_unlock; | |
cc714660 DW |
1450 | } |
1451 | } | |
1452 | ||
5faaf4fa CH |
1453 | ret = xfs_reflink_set_inode_flag(src, dest); |
1454 | if (ret) | |
1455 | goto out_unlock; | |
862bb360 DW |
1456 | |
1457 | /* | |
1458 | * Invalidate the page cache so that we can clear any CoW mappings | |
1459 | * in the destination file. | |
1460 | */ | |
5faaf4fa CH |
1461 | truncate_inode_pages_range(&inode_out->i_data, pos_out, |
1462 | PAGE_ALIGN(pos_out + len) - 1); | |
862bb360 | 1463 | |
5faaf4fa CH |
1464 | dfsbno = XFS_B_TO_FSBT(mp, pos_out); |
1465 | sfsbno = XFS_B_TO_FSBT(mp, pos_in); | |
862bb360 | 1466 | fsblen = XFS_B_TO_FSB(mp, len); |
5faaf4fa CH |
1467 | ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, |
1468 | pos_out + len); | |
1469 | if (ret) | |
1470 | goto out_unlock; | |
862bb360 | 1471 | |
f7ca3522 DW |
1472 | /* |
1473 | * Carry the cowextsize hint from src to dest if we're sharing the | |
1474 | * entire source file to the entire destination file, the source file | |
1475 | * has a cowextsize hint, and the destination file does not. | |
1476 | */ | |
1477 | cowextsize = 0; | |
5faaf4fa | 1478 | if (pos_in == 0 && len == i_size_read(inode_in) && |
f7ca3522 | 1479 | (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) && |
5faaf4fa | 1480 | pos_out == 0 && len >= i_size_read(inode_out) && |
f7ca3522 DW |
1481 | !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)) |
1482 | cowextsize = src->i_d.di_cowextsize; | |
1483 | ||
5faaf4fa | 1484 | ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize); |
862bb360 | 1485 | |
5faaf4fa CH |
1486 | out_unlock: |
1487 | xfs_iunlock(src, XFS_MMAPLOCK_EXCL); | |
1488 | xfs_iunlock(src, XFS_IOLOCK_EXCL); | |
1489 | if (src->i_ino != dest->i_ino) { | |
1490 | xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); | |
1491 | xfs_iunlock(dest, XFS_IOLOCK_EXCL); | |
1492 | } | |
1493 | if (ret) | |
1494 | trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); | |
1495 | return ret; | |
862bb360 | 1496 | } |
98cc2db5 DW |
1497 | |
1498 | /* | |
1499 | * The user wants to preemptively CoW all shared blocks in this file, | |
1500 | * which enables us to turn off the reflink flag. Iterate all | |
1501 | * extents which are not prealloc/delalloc to see which ranges are | |
1502 | * mentioned in the refcount tree, then read those blocks into the | |
1503 | * pagecache, dirty them, fsync them back out, and then we can update | |
1504 | * the inode flag. What happens if we run out of memory? :) | |
1505 | */ | |
1506 | STATIC int | |
1507 | xfs_reflink_dirty_extents( | |
1508 | struct xfs_inode *ip, | |
1509 | xfs_fileoff_t fbno, | |
1510 | xfs_filblks_t end, | |
1511 | xfs_off_t isize) | |
1512 | { | |
1513 | struct xfs_mount *mp = ip->i_mount; | |
1514 | xfs_agnumber_t agno; | |
1515 | xfs_agblock_t agbno; | |
1516 | xfs_extlen_t aglen; | |
1517 | xfs_agblock_t rbno; | |
1518 | xfs_extlen_t rlen; | |
1519 | xfs_off_t fpos; | |
1520 | xfs_off_t flen; | |
1521 | struct xfs_bmbt_irec map[2]; | |
1522 | int nmaps; | |
9780643c | 1523 | int error = 0; |
98cc2db5 DW |
1524 | |
1525 | while (end - fbno > 0) { | |
1526 | nmaps = 1; | |
1527 | /* | |
1528 | * Look for extents in the file. Skip holes, delalloc, or | |
1529 | * unwritten extents; they can't be reflinked. | |
1530 | */ | |
1531 | error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); | |
1532 | if (error) | |
1533 | goto out; | |
1534 | if (nmaps == 0) | |
1535 | break; | |
1536 | if (map[0].br_startblock == HOLESTARTBLOCK || | |
1537 | map[0].br_startblock == DELAYSTARTBLOCK || | |
1538 | ISUNWRITTEN(&map[0])) | |
1539 | goto next; | |
1540 | ||
1541 | map[1] = map[0]; | |
1542 | while (map[1].br_blockcount) { | |
1543 | agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); | |
1544 | agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); | |
1545 | aglen = map[1].br_blockcount; | |
1546 | ||
1547 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, | |
1548 | &rbno, &rlen, true); | |
1549 | if (error) | |
1550 | goto out; | |
1551 | if (rbno == NULLAGBLOCK) | |
1552 | break; | |
1553 | ||
1554 | /* Dirty the pages */ | |
1555 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1556 | fpos = XFS_FSB_TO_B(mp, map[1].br_startoff + | |
1557 | (rbno - agbno)); | |
1558 | flen = XFS_FSB_TO_B(mp, rlen); | |
1559 | if (fpos + flen > isize) | |
1560 | flen = isize - fpos; | |
1561 | error = iomap_file_dirty(VFS_I(ip), fpos, flen, | |
1562 | &xfs_iomap_ops); | |
1563 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1564 | if (error) | |
1565 | goto out; | |
1566 | ||
1567 | map[1].br_blockcount -= (rbno - agbno + rlen); | |
1568 | map[1].br_startoff += (rbno - agbno + rlen); | |
1569 | map[1].br_startblock += (rbno - agbno + rlen); | |
1570 | } | |
1571 | ||
1572 | next: | |
1573 | fbno = map[0].br_startoff + map[0].br_blockcount; | |
1574 | } | |
1575 | out: | |
1576 | return error; | |
1577 | } | |
1578 | ||
1579 | /* Clear the inode reflink flag if there are no shared extents. */ | |
1580 | int | |
1581 | xfs_reflink_clear_inode_flag( | |
1582 | struct xfs_inode *ip, | |
1583 | struct xfs_trans **tpp) | |
1584 | { | |
1585 | struct xfs_mount *mp = ip->i_mount; | |
1586 | xfs_fileoff_t fbno; | |
1587 | xfs_filblks_t end; | |
1588 | xfs_agnumber_t agno; | |
1589 | xfs_agblock_t agbno; | |
1590 | xfs_extlen_t aglen; | |
1591 | xfs_agblock_t rbno; | |
1592 | xfs_extlen_t rlen; | |
024adf48 | 1593 | struct xfs_bmbt_irec map; |
98cc2db5 DW |
1594 | int nmaps; |
1595 | int error = 0; | |
1596 | ||
63646fc5 | 1597 | ASSERT(xfs_is_reflink_inode(ip)); |
98cc2db5 DW |
1598 | |
1599 | fbno = 0; | |
1600 | end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip))); | |
1601 | while (end - fbno > 0) { | |
1602 | nmaps = 1; | |
1603 | /* | |
1604 | * Look for extents in the file. Skip holes, delalloc, or | |
1605 | * unwritten extents; they can't be reflinked. | |
1606 | */ | |
024adf48 | 1607 | error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0); |
98cc2db5 DW |
1608 | if (error) |
1609 | return error; | |
1610 | if (nmaps == 0) | |
1611 | break; | |
024adf48 DW |
1612 | if (map.br_startblock == HOLESTARTBLOCK || |
1613 | map.br_startblock == DELAYSTARTBLOCK || | |
1614 | ISUNWRITTEN(&map)) | |
98cc2db5 DW |
1615 | goto next; |
1616 | ||
024adf48 DW |
1617 | agno = XFS_FSB_TO_AGNO(mp, map.br_startblock); |
1618 | agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock); | |
1619 | aglen = map.br_blockcount; | |
98cc2db5 | 1620 | |
024adf48 DW |
1621 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, |
1622 | &rbno, &rlen, false); | |
1623 | if (error) | |
1624 | return error; | |
1625 | /* Is there still a shared block here? */ | |
1626 | if (rbno != NULLAGBLOCK) | |
1627 | return 0; | |
98cc2db5 | 1628 | next: |
024adf48 | 1629 | fbno = map.br_startoff + map.br_blockcount; |
98cc2db5 DW |
1630 | } |
1631 | ||
1632 | /* | |
1633 | * We didn't find any shared blocks so turn off the reflink flag. | |
1634 | * First, get rid of any leftover CoW mappings. | |
1635 | */ | |
1636 | error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF); | |
1637 | if (error) | |
1638 | return error; | |
1639 | ||
1640 | /* Clear the inode flag. */ | |
1641 | trace_xfs_reflink_unset_inode_flag(ip); | |
1642 | ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; | |
83104d44 | 1643 | xfs_inode_clear_cowblocks_tag(ip); |
98cc2db5 DW |
1644 | xfs_trans_ijoin(*tpp, ip, 0); |
1645 | xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE); | |
1646 | ||
1647 | return error; | |
1648 | } | |
1649 | ||
1650 | /* | |
1651 | * Clear the inode reflink flag if there are no shared extents and the size | |
1652 | * hasn't changed. | |
1653 | */ | |
1654 | STATIC int | |
1655 | xfs_reflink_try_clear_inode_flag( | |
97a1b87e | 1656 | struct xfs_inode *ip) |
98cc2db5 DW |
1657 | { |
1658 | struct xfs_mount *mp = ip->i_mount; | |
1659 | struct xfs_trans *tp; | |
1660 | int error = 0; | |
1661 | ||
1662 | /* Start a rolling transaction to remove the mappings */ | |
1663 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); | |
1664 | if (error) | |
1665 | return error; | |
1666 | ||
1667 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1668 | xfs_trans_ijoin(tp, ip, 0); | |
1669 | ||
98cc2db5 DW |
1670 | error = xfs_reflink_clear_inode_flag(ip, &tp); |
1671 | if (error) | |
1672 | goto cancel; | |
1673 | ||
1674 | error = xfs_trans_commit(tp); | |
1675 | if (error) | |
1676 | goto out; | |
1677 | ||
1678 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1679 | return 0; | |
1680 | cancel: | |
1681 | xfs_trans_cancel(tp); | |
1682 | out: | |
1683 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1684 | return error; | |
1685 | } | |
1686 | ||
1687 | /* | |
1688 | * Pre-COW all shared blocks within a given byte range of a file and turn off | |
1689 | * the reflink flag if we unshare all of the file's blocks. | |
1690 | */ | |
1691 | int | |
1692 | xfs_reflink_unshare( | |
1693 | struct xfs_inode *ip, | |
1694 | xfs_off_t offset, | |
1695 | xfs_off_t len) | |
1696 | { | |
1697 | struct xfs_mount *mp = ip->i_mount; | |
1698 | xfs_fileoff_t fbno; | |
1699 | xfs_filblks_t end; | |
1700 | xfs_off_t isize; | |
1701 | int error; | |
1702 | ||
1703 | if (!xfs_is_reflink_inode(ip)) | |
1704 | return 0; | |
1705 | ||
1706 | trace_xfs_reflink_unshare(ip, offset, len); | |
1707 | ||
1708 | inode_dio_wait(VFS_I(ip)); | |
1709 | ||
1710 | /* Try to CoW the selected ranges */ | |
1711 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
97a1b87e | 1712 | fbno = XFS_B_TO_FSBT(mp, offset); |
98cc2db5 DW |
1713 | isize = i_size_read(VFS_I(ip)); |
1714 | end = XFS_B_TO_FSB(mp, offset + len); | |
1715 | error = xfs_reflink_dirty_extents(ip, fbno, end, isize); | |
1716 | if (error) | |
1717 | goto out_unlock; | |
1718 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1719 | ||
1720 | /* Wait for the IO to finish */ | |
1721 | error = filemap_write_and_wait(VFS_I(ip)->i_mapping); | |
1722 | if (error) | |
1723 | goto out; | |
1724 | ||
97a1b87e DW |
1725 | /* Turn off the reflink flag if possible. */ |
1726 | error = xfs_reflink_try_clear_inode_flag(ip); | |
1727 | if (error) | |
1728 | goto out; | |
98cc2db5 DW |
1729 | |
1730 | return 0; | |
1731 | ||
1732 | out_unlock: | |
1733 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1734 | out: | |
1735 | trace_xfs_reflink_unshare_error(ip, error, _RET_IP_); | |
1736 | return error; | |
1737 | } | |
83104d44 DW |
1738 | |
1739 | /* | |
1740 | * Does this inode have any real CoW reservations? | |
1741 | */ | |
1742 | bool | |
1743 | xfs_reflink_has_real_cow_blocks( | |
1744 | struct xfs_inode *ip) | |
1745 | { | |
1746 | struct xfs_bmbt_irec irec; | |
1747 | struct xfs_ifork *ifp; | |
1748 | struct xfs_bmbt_rec_host *gotp; | |
1749 | xfs_extnum_t idx; | |
1750 | ||
1751 | if (!xfs_is_reflink_inode(ip)) | |
1752 | return false; | |
1753 | ||
1754 | /* Go find the old extent in the CoW fork. */ | |
1755 | ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
1756 | gotp = xfs_iext_bno_to_ext(ifp, 0, &idx); | |
1757 | while (gotp) { | |
1758 | xfs_bmbt_get_all(gotp, &irec); | |
1759 | ||
1760 | if (!isnullstartblock(irec.br_startblock)) | |
1761 | return true; | |
1762 | ||
1763 | /* Roll on... */ | |
1764 | idx++; | |
1765 | if (idx >= ifp->if_bytes / sizeof(xfs_bmbt_rec_t)) | |
1766 | break; | |
1767 | gotp = xfs_iext_get_ext(ifp, idx); | |
1768 | } | |
1769 | ||
1770 | return false; | |
1771 | } |