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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 || | |
62c5ac89 CH |
185 | irec->br_startblock == DELAYSTARTBLOCK || |
186 | isnullstartblock(irec->br_startblock)) { | |
2a06705c DW |
187 | *shared = false; |
188 | return 0; | |
189 | } | |
190 | ||
191 | trace_xfs_reflink_trim_around_shared(ip, irec); | |
192 | ||
193 | agno = XFS_FSB_TO_AGNO(ip->i_mount, irec->br_startblock); | |
194 | agbno = XFS_FSB_TO_AGBNO(ip->i_mount, irec->br_startblock); | |
195 | aglen = irec->br_blockcount; | |
196 | ||
197 | error = xfs_reflink_find_shared(ip->i_mount, agno, agbno, | |
198 | aglen, &fbno, &flen, true); | |
199 | if (error) | |
200 | return error; | |
201 | ||
202 | *shared = *trimmed = false; | |
203 | if (fbno == NULLAGBLOCK) { | |
204 | /* No shared blocks at all. */ | |
205 | return 0; | |
206 | } else if (fbno == agbno) { | |
207 | /* | |
208 | * The start of this extent is shared. Truncate the | |
209 | * mapping at the end of the shared region so that a | |
210 | * subsequent iteration starts at the start of the | |
211 | * unshared region. | |
212 | */ | |
213 | irec->br_blockcount = flen; | |
214 | *shared = true; | |
215 | if (flen != aglen) | |
216 | *trimmed = true; | |
217 | return 0; | |
218 | } else { | |
219 | /* | |
220 | * There's a shared extent midway through this extent. | |
221 | * Truncate the mapping at the start of the shared | |
222 | * extent so that a subsequent iteration starts at the | |
223 | * start of the shared region. | |
224 | */ | |
225 | irec->br_blockcount = fbno - agbno; | |
226 | *trimmed = true; | |
227 | return 0; | |
228 | } | |
229 | } | |
230 | ||
3ba020be CH |
231 | /* |
232 | * Trim the passed in imap to the next shared/unshared extent boundary, and | |
233 | * if imap->br_startoff points to a shared extent reserve space for it in the | |
234 | * COW fork. In this case *shared is set to true, else to false. | |
235 | * | |
236 | * Note that imap will always contain the block numbers for the existing blocks | |
237 | * in the data fork, as the upper layers need them for read-modify-write | |
238 | * operations. | |
239 | */ | |
240 | int | |
241 | xfs_reflink_reserve_cow( | |
2a06705c | 242 | struct xfs_inode *ip, |
3ba020be CH |
243 | struct xfs_bmbt_irec *imap, |
244 | bool *shared) | |
2a06705c | 245 | { |
3ba020be CH |
246 | struct xfs_bmbt_irec got, prev; |
247 | xfs_fileoff_t end_fsb, orig_end_fsb; | |
248 | int eof = 0, error = 0; | |
249 | bool trimmed; | |
2a06705c | 250 | xfs_extnum_t idx; |
f7ca3522 | 251 | xfs_extlen_t align; |
2a06705c | 252 | |
3ba020be CH |
253 | /* |
254 | * Search the COW fork extent list first. This serves two purposes: | |
255 | * first this implement the speculative preallocation using cowextisze, | |
256 | * so that we also unshared block adjacent to shared blocks instead | |
257 | * of just the shared blocks themselves. Second the lookup in the | |
258 | * extent list is generally faster than going out to the shared extent | |
259 | * tree. | |
260 | */ | |
261 | xfs_bmap_search_extents(ip, imap->br_startoff, XFS_COW_FORK, &eof, &idx, | |
2a06705c | 262 | &got, &prev); |
3ba020be CH |
263 | if (!eof && got.br_startoff <= imap->br_startoff) { |
264 | trace_xfs_reflink_cow_found(ip, imap); | |
265 | xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); | |
2a06705c | 266 | |
3ba020be CH |
267 | *shared = true; |
268 | return 0; | |
269 | } | |
2a06705c DW |
270 | |
271 | /* Trim the mapping to the nearest shared extent boundary. */ | |
3ba020be | 272 | error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); |
2a06705c | 273 | if (error) |
3ba020be | 274 | return error; |
2a06705c DW |
275 | |
276 | /* Not shared? Just report the (potentially capped) extent. */ | |
3ba020be CH |
277 | if (!*shared) |
278 | return 0; | |
2a06705c DW |
279 | |
280 | /* | |
281 | * Fork all the shared blocks from our write offset until the end of | |
282 | * the extent. | |
283 | */ | |
284 | error = xfs_qm_dqattach_locked(ip, 0); | |
285 | if (error) | |
3ba020be CH |
286 | return error; |
287 | ||
288 | end_fsb = orig_end_fsb = imap->br_startoff + imap->br_blockcount; | |
2a06705c | 289 | |
f7ca3522 DW |
290 | align = xfs_eof_alignment(ip, xfs_get_cowextsz_hint(ip)); |
291 | if (align) | |
292 | end_fsb = roundup_64(end_fsb, align); | |
293 | ||
2a06705c | 294 | retry: |
3ba020be | 295 | error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff, |
65c5f419 | 296 | end_fsb - imap->br_startoff, &got, &idx, eof); |
2a06705c DW |
297 | switch (error) { |
298 | case 0: | |
299 | break; | |
300 | case -ENOSPC: | |
301 | case -EDQUOT: | |
302 | /* retry without any preallocation */ | |
3ba020be | 303 | trace_xfs_reflink_cow_enospc(ip, imap); |
2a06705c DW |
304 | if (end_fsb != orig_end_fsb) { |
305 | end_fsb = orig_end_fsb; | |
306 | goto retry; | |
307 | } | |
308 | /*FALLTHRU*/ | |
309 | default: | |
3ba020be | 310 | return error; |
2a06705c DW |
311 | } |
312 | ||
83104d44 DW |
313 | if (end_fsb != orig_end_fsb) |
314 | xfs_inode_set_cowblocks_tag(ip); | |
315 | ||
2a06705c | 316 | trace_xfs_reflink_cow_alloc(ip, &got); |
3ba020be | 317 | return 0; |
2a06705c | 318 | } |
ef473667 | 319 | |
0613f16c DW |
320 | /* Allocate all CoW reservations covering a range of blocks in a file. */ |
321 | static int | |
322 | __xfs_reflink_allocate_cow( | |
323 | struct xfs_inode *ip, | |
324 | xfs_fileoff_t *offset_fsb, | |
325 | xfs_fileoff_t end_fsb) | |
326 | { | |
327 | struct xfs_mount *mp = ip->i_mount; | |
328 | struct xfs_bmbt_irec imap; | |
329 | struct xfs_defer_ops dfops; | |
330 | struct xfs_trans *tp; | |
331 | xfs_fsblock_t first_block; | |
0613f16c | 332 | int nimaps = 1, error; |
3ba020be | 333 | bool shared; |
0613f16c DW |
334 | |
335 | xfs_defer_init(&dfops, &first_block); | |
336 | ||
337 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, | |
338 | XFS_TRANS_RESERVE, &tp); | |
339 | if (error) | |
340 | return error; | |
341 | ||
342 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
343 | ||
3ba020be CH |
344 | /* Read extent from the source file. */ |
345 | nimaps = 1; | |
346 | error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb, | |
347 | &imap, &nimaps, 0); | |
348 | if (error) | |
349 | goto out_unlock; | |
350 | ASSERT(nimaps == 1); | |
351 | ||
352 | error = xfs_reflink_reserve_cow(ip, &imap, &shared); | |
0613f16c DW |
353 | if (error) |
354 | goto out_trans_cancel; | |
355 | ||
3ba020be CH |
356 | if (!shared) { |
357 | *offset_fsb = imap.br_startoff + imap.br_blockcount; | |
0613f16c DW |
358 | goto out_trans_cancel; |
359 | } | |
360 | ||
361 | xfs_trans_ijoin(tp, ip, 0); | |
3ba020be | 362 | error = xfs_bmapi_write(tp, ip, imap.br_startoff, imap.br_blockcount, |
0613f16c DW |
363 | XFS_BMAPI_COWFORK, &first_block, |
364 | XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), | |
365 | &imap, &nimaps, &dfops); | |
366 | if (error) | |
367 | goto out_trans_cancel; | |
368 | ||
0613f16c DW |
369 | error = xfs_defer_finish(&tp, &dfops, NULL); |
370 | if (error) | |
371 | goto out_trans_cancel; | |
372 | ||
373 | error = xfs_trans_commit(tp); | |
374 | ||
3ba020be | 375 | *offset_fsb = imap.br_startoff + imap.br_blockcount; |
0613f16c DW |
376 | out_unlock: |
377 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
378 | return error; | |
379 | out_trans_cancel: | |
380 | xfs_defer_cancel(&dfops); | |
381 | xfs_trans_cancel(tp); | |
382 | goto out_unlock; | |
383 | } | |
384 | ||
385 | /* Allocate all CoW reservations covering a part of a file. */ | |
386 | int | |
387 | xfs_reflink_allocate_cow_range( | |
388 | struct xfs_inode *ip, | |
389 | xfs_off_t offset, | |
390 | xfs_off_t count) | |
391 | { | |
392 | struct xfs_mount *mp = ip->i_mount; | |
393 | xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
394 | xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count); | |
395 | int error; | |
396 | ||
397 | ASSERT(xfs_is_reflink_inode(ip)); | |
398 | ||
399 | trace_xfs_reflink_allocate_cow_range(ip, offset, count); | |
400 | ||
401 | /* | |
402 | * Make sure that the dquots are there. | |
403 | */ | |
404 | error = xfs_qm_dqattach(ip, 0); | |
405 | if (error) | |
406 | return error; | |
407 | ||
408 | while (offset_fsb < end_fsb) { | |
409 | error = __xfs_reflink_allocate_cow(ip, &offset_fsb, end_fsb); | |
410 | if (error) { | |
411 | trace_xfs_reflink_allocate_cow_range_error(ip, error, | |
412 | _RET_IP_); | |
413 | break; | |
414 | } | |
415 | } | |
416 | ||
417 | return error; | |
418 | } | |
419 | ||
ef473667 DW |
420 | /* |
421 | * Find the CoW reservation (and whether or not it needs block allocation) | |
422 | * for a given byte offset of a file. | |
423 | */ | |
424 | bool | |
425 | xfs_reflink_find_cow_mapping( | |
426 | struct xfs_inode *ip, | |
427 | xfs_off_t offset, | |
428 | struct xfs_bmbt_irec *imap, | |
429 | bool *need_alloc) | |
430 | { | |
431 | struct xfs_bmbt_irec irec; | |
432 | struct xfs_ifork *ifp; | |
433 | struct xfs_bmbt_rec_host *gotp; | |
434 | xfs_fileoff_t bno; | |
435 | xfs_extnum_t idx; | |
436 | ||
437 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); | |
438 | ASSERT(xfs_is_reflink_inode(ip)); | |
439 | ||
440 | /* Find the extent in the CoW fork. */ | |
441 | ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
442 | bno = XFS_B_TO_FSBT(ip->i_mount, offset); | |
443 | gotp = xfs_iext_bno_to_ext(ifp, bno, &idx); | |
444 | if (!gotp) | |
445 | return false; | |
446 | ||
447 | xfs_bmbt_get_all(gotp, &irec); | |
448 | if (bno >= irec.br_startoff + irec.br_blockcount || | |
449 | bno < irec.br_startoff) | |
450 | return false; | |
451 | ||
452 | trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE, | |
453 | &irec); | |
454 | ||
455 | /* If it's still delalloc, we must allocate later. */ | |
456 | *imap = irec; | |
457 | *need_alloc = !!(isnullstartblock(irec.br_startblock)); | |
458 | ||
459 | return true; | |
460 | } | |
461 | ||
462 | /* | |
463 | * Trim an extent to end at the next CoW reservation past offset_fsb. | |
464 | */ | |
465 | int | |
466 | xfs_reflink_trim_irec_to_next_cow( | |
467 | struct xfs_inode *ip, | |
468 | xfs_fileoff_t offset_fsb, | |
469 | struct xfs_bmbt_irec *imap) | |
470 | { | |
471 | struct xfs_bmbt_irec irec; | |
472 | struct xfs_ifork *ifp; | |
473 | struct xfs_bmbt_rec_host *gotp; | |
474 | xfs_extnum_t idx; | |
475 | ||
476 | if (!xfs_is_reflink_inode(ip)) | |
477 | return 0; | |
478 | ||
479 | /* Find the extent in the CoW fork. */ | |
480 | ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
481 | gotp = xfs_iext_bno_to_ext(ifp, offset_fsb, &idx); | |
482 | if (!gotp) | |
483 | return 0; | |
484 | xfs_bmbt_get_all(gotp, &irec); | |
485 | ||
486 | /* This is the extent before; try sliding up one. */ | |
487 | if (irec.br_startoff < offset_fsb) { | |
488 | idx++; | |
5d829300 | 489 | if (idx >= xfs_iext_count(ifp)) |
ef473667 DW |
490 | return 0; |
491 | gotp = xfs_iext_get_ext(ifp, idx); | |
492 | xfs_bmbt_get_all(gotp, &irec); | |
493 | } | |
494 | ||
495 | if (irec.br_startoff >= imap->br_startoff + imap->br_blockcount) | |
496 | return 0; | |
497 | ||
498 | imap->br_blockcount = irec.br_startoff - imap->br_startoff; | |
499 | trace_xfs_reflink_trim_irec(ip, imap); | |
500 | ||
501 | return 0; | |
502 | } | |
43caeb18 DW |
503 | |
504 | /* | |
505 | * Cancel all pending CoW reservations for some block range of an inode. | |
506 | */ | |
507 | int | |
508 | xfs_reflink_cancel_cow_blocks( | |
509 | struct xfs_inode *ip, | |
510 | struct xfs_trans **tpp, | |
511 | xfs_fileoff_t offset_fsb, | |
512 | xfs_fileoff_t end_fsb) | |
513 | { | |
3e0ee78f CH |
514 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
515 | struct xfs_bmbt_irec got, prev, del; | |
516 | xfs_extnum_t idx; | |
43caeb18 DW |
517 | xfs_fsblock_t firstfsb; |
518 | struct xfs_defer_ops dfops; | |
3e0ee78f | 519 | int error = 0, eof = 0; |
43caeb18 DW |
520 | |
521 | if (!xfs_is_reflink_inode(ip)) | |
522 | return 0; | |
523 | ||
3e0ee78f CH |
524 | xfs_bmap_search_extents(ip, offset_fsb, XFS_COW_FORK, &eof, &idx, |
525 | &got, &prev); | |
526 | if (eof) | |
527 | return 0; | |
43caeb18 | 528 | |
3e0ee78f CH |
529 | while (got.br_startoff < end_fsb) { |
530 | del = got; | |
531 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
532 | trace_xfs_reflink_cancel_cow(ip, &del); | |
43caeb18 | 533 | |
3e0ee78f CH |
534 | if (isnullstartblock(del.br_startblock)) { |
535 | error = xfs_bmap_del_extent_delay(ip, XFS_COW_FORK, | |
536 | &idx, &got, &del); | |
43caeb18 DW |
537 | if (error) |
538 | break; | |
43caeb18 DW |
539 | } else { |
540 | xfs_trans_ijoin(*tpp, ip, 0); | |
541 | xfs_defer_init(&dfops, &firstfsb); | |
542 | ||
174edb0e DW |
543 | /* Free the CoW orphan record. */ |
544 | error = xfs_refcount_free_cow_extent(ip->i_mount, | |
3e0ee78f CH |
545 | &dfops, del.br_startblock, |
546 | del.br_blockcount); | |
174edb0e DW |
547 | if (error) |
548 | break; | |
549 | ||
43caeb18 | 550 | xfs_bmap_add_free(ip->i_mount, &dfops, |
3e0ee78f | 551 | del.br_startblock, del.br_blockcount, |
43caeb18 DW |
552 | NULL); |
553 | ||
554 | /* Update quota accounting */ | |
555 | xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT, | |
3e0ee78f | 556 | -(long)del.br_blockcount); |
43caeb18 DW |
557 | |
558 | /* Roll the transaction */ | |
559 | error = xfs_defer_finish(tpp, &dfops, ip); | |
560 | if (error) { | |
561 | xfs_defer_cancel(&dfops); | |
562 | break; | |
563 | } | |
564 | ||
565 | /* Remove the mapping from the CoW fork. */ | |
3e0ee78f | 566 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); |
43caeb18 DW |
567 | } |
568 | ||
5d829300 | 569 | if (++idx >= xfs_iext_count(ifp)) |
c17a8ef4 | 570 | break; |
3e0ee78f | 571 | xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got); |
43caeb18 DW |
572 | } |
573 | ||
c17a8ef4 BF |
574 | /* clear tag if cow fork is emptied */ |
575 | if (!ifp->if_bytes) | |
576 | xfs_inode_clear_cowblocks_tag(ip); | |
577 | ||
43caeb18 DW |
578 | return error; |
579 | } | |
580 | ||
581 | /* | |
582 | * Cancel all pending CoW reservations for some byte range of an inode. | |
583 | */ | |
584 | int | |
585 | xfs_reflink_cancel_cow_range( | |
586 | struct xfs_inode *ip, | |
587 | xfs_off_t offset, | |
588 | xfs_off_t count) | |
589 | { | |
590 | struct xfs_trans *tp; | |
591 | xfs_fileoff_t offset_fsb; | |
592 | xfs_fileoff_t end_fsb; | |
593 | int error; | |
594 | ||
595 | trace_xfs_reflink_cancel_cow_range(ip, offset, count); | |
63646fc5 | 596 | ASSERT(xfs_is_reflink_inode(ip)); |
43caeb18 DW |
597 | |
598 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); | |
599 | if (count == NULLFILEOFF) | |
600 | end_fsb = NULLFILEOFF; | |
601 | else | |
602 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
603 | ||
604 | /* Start a rolling transaction to remove the mappings */ | |
605 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
606 | 0, 0, 0, &tp); | |
607 | if (error) | |
608 | goto out; | |
609 | ||
610 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
611 | xfs_trans_ijoin(tp, ip, 0); | |
612 | ||
613 | /* Scrape out the old CoW reservations */ | |
614 | error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb); | |
615 | if (error) | |
616 | goto out_cancel; | |
617 | ||
618 | error = xfs_trans_commit(tp); | |
619 | ||
620 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
621 | return error; | |
622 | ||
623 | out_cancel: | |
624 | xfs_trans_cancel(tp); | |
625 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
626 | out: | |
627 | trace_xfs_reflink_cancel_cow_range_error(ip, error, _RET_IP_); | |
628 | return error; | |
629 | } | |
630 | ||
631 | /* | |
632 | * Remap parts of a file's data fork after a successful CoW. | |
633 | */ | |
634 | int | |
635 | xfs_reflink_end_cow( | |
636 | struct xfs_inode *ip, | |
637 | xfs_off_t offset, | |
638 | xfs_off_t count) | |
639 | { | |
c1112b6e CH |
640 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
641 | struct xfs_bmbt_irec got, prev, del; | |
43caeb18 DW |
642 | struct xfs_trans *tp; |
643 | xfs_fileoff_t offset_fsb; | |
644 | xfs_fileoff_t end_fsb; | |
43caeb18 DW |
645 | xfs_fsblock_t firstfsb; |
646 | struct xfs_defer_ops dfops; | |
c1112b6e | 647 | int error, eof = 0; |
43caeb18 | 648 | unsigned int resblks; |
43caeb18 | 649 | xfs_filblks_t rlen; |
c1112b6e | 650 | xfs_extnum_t idx; |
43caeb18 DW |
651 | |
652 | trace_xfs_reflink_end_cow(ip, offset, count); | |
653 | ||
c1112b6e CH |
654 | /* No COW extents? That's easy! */ |
655 | if (ifp->if_bytes == 0) | |
656 | return 0; | |
657 | ||
43caeb18 DW |
658 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); |
659 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
43caeb18 DW |
660 | |
661 | /* Start a rolling transaction to switch the mappings */ | |
662 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
663 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
664 | resblks, 0, 0, &tp); | |
665 | if (error) | |
666 | goto out; | |
667 | ||
668 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
669 | xfs_trans_ijoin(tp, ip, 0); | |
670 | ||
c1112b6e CH |
671 | xfs_bmap_search_extents(ip, end_fsb - 1, XFS_COW_FORK, &eof, &idx, |
672 | &got, &prev); | |
43caeb18 | 673 | |
c1112b6e CH |
674 | /* If there is a hole at end_fsb - 1 go to the previous extent */ |
675 | if (eof || got.br_startoff > end_fsb) { | |
676 | ASSERT(idx > 0); | |
677 | xfs_bmbt_get_all(xfs_iext_get_ext(ifp, --idx), &got); | |
678 | } | |
43caeb18 | 679 | |
c1112b6e CH |
680 | /* Walk backwards until we're out of the I/O range... */ |
681 | while (got.br_startoff + got.br_blockcount > offset_fsb) { | |
682 | del = got; | |
683 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
684 | ||
685 | /* Extent delete may have bumped idx forward */ | |
686 | if (!del.br_blockcount) { | |
687 | idx--; | |
43caeb18 | 688 | goto next_extent; |
c1112b6e CH |
689 | } |
690 | ||
691 | ASSERT(!isnullstartblock(got.br_startblock)); | |
43caeb18 DW |
692 | |
693 | /* Unmap the old blocks in the data fork. */ | |
c1112b6e CH |
694 | xfs_defer_init(&dfops, &firstfsb); |
695 | rlen = del.br_blockcount; | |
696 | error = __xfs_bunmapi(tp, ip, del.br_startoff, &rlen, 0, 1, | |
697 | &firstfsb, &dfops); | |
698 | if (error) | |
699 | goto out_defer; | |
43caeb18 | 700 | |
c1112b6e CH |
701 | /* Trim the extent to whatever got unmapped. */ |
702 | if (rlen) { | |
703 | xfs_trim_extent(&del, del.br_startoff + rlen, | |
704 | del.br_blockcount - rlen); | |
705 | } | |
706 | trace_xfs_reflink_cow_remap(ip, &del); | |
174edb0e | 707 | |
c1112b6e CH |
708 | /* Free the CoW orphan record. */ |
709 | error = xfs_refcount_free_cow_extent(tp->t_mountp, &dfops, | |
710 | del.br_startblock, del.br_blockcount); | |
711 | if (error) | |
712 | goto out_defer; | |
43caeb18 | 713 | |
c1112b6e CH |
714 | /* Map the new blocks into the data fork. */ |
715 | error = xfs_bmap_map_extent(tp->t_mountp, &dfops, ip, &del); | |
716 | if (error) | |
717 | goto out_defer; | |
43caeb18 | 718 | |
c1112b6e CH |
719 | /* Remove the mapping from the CoW fork. */ |
720 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); | |
721 | ||
722 | error = xfs_defer_finish(&tp, &dfops, ip); | |
723 | if (error) | |
724 | goto out_defer; | |
43caeb18 DW |
725 | |
726 | next_extent: | |
c1112b6e CH |
727 | if (idx < 0) |
728 | break; | |
729 | xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got); | |
43caeb18 DW |
730 | } |
731 | ||
732 | error = xfs_trans_commit(tp); | |
733 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
734 | if (error) | |
735 | goto out; | |
736 | return 0; | |
737 | ||
738 | out_defer: | |
739 | xfs_defer_cancel(&dfops); | |
43caeb18 DW |
740 | xfs_trans_cancel(tp); |
741 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
742 | out: | |
743 | trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); | |
744 | return error; | |
745 | } | |
174edb0e DW |
746 | |
747 | /* | |
748 | * Free leftover CoW reservations that didn't get cleaned out. | |
749 | */ | |
750 | int | |
751 | xfs_reflink_recover_cow( | |
752 | struct xfs_mount *mp) | |
753 | { | |
754 | xfs_agnumber_t agno; | |
755 | int error = 0; | |
756 | ||
757 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
758 | return 0; | |
759 | ||
760 | for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { | |
761 | error = xfs_refcount_recover_cow_leftovers(mp, agno); | |
762 | if (error) | |
763 | break; | |
764 | } | |
765 | ||
766 | return error; | |
767 | } | |
862bb360 DW |
768 | |
769 | /* | |
770 | * Reflinking (Block) Ranges of Two Files Together | |
771 | * | |
772 | * First, ensure that the reflink flag is set on both inodes. The flag is an | |
773 | * optimization to avoid unnecessary refcount btree lookups in the write path. | |
774 | * | |
775 | * Now we can iteratively remap the range of extents (and holes) in src to the | |
776 | * corresponding ranges in dest. Let drange and srange denote the ranges of | |
777 | * logical blocks in dest and src touched by the reflink operation. | |
778 | * | |
779 | * While the length of drange is greater than zero, | |
780 | * - Read src's bmbt at the start of srange ("imap") | |
781 | * - If imap doesn't exist, make imap appear to start at the end of srange | |
782 | * with zero length. | |
783 | * - If imap starts before srange, advance imap to start at srange. | |
784 | * - If imap goes beyond srange, truncate imap to end at the end of srange. | |
785 | * - Punch (imap start - srange start + imap len) blocks from dest at | |
786 | * offset (drange start). | |
787 | * - If imap points to a real range of pblks, | |
788 | * > Increase the refcount of the imap's pblks | |
789 | * > Map imap's pblks into dest at the offset | |
790 | * (drange start + imap start - srange start) | |
791 | * - Advance drange and srange by (imap start - srange start + imap len) | |
792 | * | |
793 | * Finally, if the reflink made dest longer, update both the in-core and | |
794 | * on-disk file sizes. | |
795 | * | |
796 | * ASCII Art Demonstration: | |
797 | * | |
798 | * Let's say we want to reflink this source file: | |
799 | * | |
800 | * ----SSSSSSS-SSSSS----SSSSSS (src file) | |
801 | * <--------------------> | |
802 | * | |
803 | * into this destination file: | |
804 | * | |
805 | * --DDDDDDDDDDDDDDDDDDD--DDD (dest file) | |
806 | * <--------------------> | |
807 | * '-' means a hole, and 'S' and 'D' are written blocks in the src and dest. | |
808 | * Observe that the range has different logical offsets in either file. | |
809 | * | |
810 | * Consider that the first extent in the source file doesn't line up with our | |
811 | * reflink range. Unmapping and remapping are separate operations, so we can | |
812 | * unmap more blocks from the destination file than we remap. | |
813 | * | |
814 | * ----SSSSSSS-SSSSS----SSSSSS | |
815 | * <-------> | |
816 | * --DDDDD---------DDDDD--DDD | |
817 | * <-------> | |
818 | * | |
819 | * Now remap the source extent into the destination file: | |
820 | * | |
821 | * ----SSSSSSS-SSSSS----SSSSSS | |
822 | * <-------> | |
823 | * --DDDDD--SSSSSSSDDDDD--DDD | |
824 | * <-------> | |
825 | * | |
826 | * Do likewise with the second hole and extent in our range. Holes in the | |
827 | * unmap range don't affect our operation. | |
828 | * | |
829 | * ----SSSSSSS-SSSSS----SSSSSS | |
830 | * <----> | |
831 | * --DDDDD--SSSSSSS-SSSSS-DDD | |
832 | * <----> | |
833 | * | |
834 | * Finally, unmap and remap part of the third extent. This will increase the | |
835 | * size of the destination file. | |
836 | * | |
837 | * ----SSSSSSS-SSSSS----SSSSSS | |
838 | * <-----> | |
839 | * --DDDDD--SSSSSSS-SSSSS----SSS | |
840 | * <-----> | |
841 | * | |
842 | * Once we update the destination file's i_size, we're done. | |
843 | */ | |
844 | ||
845 | /* | |
846 | * Ensure the reflink bit is set in both inodes. | |
847 | */ | |
848 | STATIC int | |
849 | xfs_reflink_set_inode_flag( | |
850 | struct xfs_inode *src, | |
851 | struct xfs_inode *dest) | |
852 | { | |
853 | struct xfs_mount *mp = src->i_mount; | |
854 | int error; | |
855 | struct xfs_trans *tp; | |
856 | ||
857 | if (xfs_is_reflink_inode(src) && xfs_is_reflink_inode(dest)) | |
858 | return 0; | |
859 | ||
860 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
861 | if (error) | |
862 | goto out_error; | |
863 | ||
864 | /* Lock both files against IO */ | |
865 | if (src->i_ino == dest->i_ino) | |
866 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
867 | else | |
868 | xfs_lock_two_inodes(src, dest, XFS_ILOCK_EXCL); | |
869 | ||
870 | if (!xfs_is_reflink_inode(src)) { | |
871 | trace_xfs_reflink_set_inode_flag(src); | |
872 | xfs_trans_ijoin(tp, src, XFS_ILOCK_EXCL); | |
873 | src->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
874 | xfs_trans_log_inode(tp, src, XFS_ILOG_CORE); | |
875 | xfs_ifork_init_cow(src); | |
876 | } else | |
877 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
878 | ||
879 | if (src->i_ino == dest->i_ino) | |
880 | goto commit_flags; | |
881 | ||
882 | if (!xfs_is_reflink_inode(dest)) { | |
883 | trace_xfs_reflink_set_inode_flag(dest); | |
884 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
885 | dest->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
886 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); | |
887 | xfs_ifork_init_cow(dest); | |
888 | } else | |
889 | xfs_iunlock(dest, XFS_ILOCK_EXCL); | |
890 | ||
891 | commit_flags: | |
892 | error = xfs_trans_commit(tp); | |
893 | if (error) | |
894 | goto out_error; | |
895 | return error; | |
896 | ||
897 | out_error: | |
898 | trace_xfs_reflink_set_inode_flag_error(dest, error, _RET_IP_); | |
899 | return error; | |
900 | } | |
901 | ||
902 | /* | |
f7ca3522 | 903 | * Update destination inode size & cowextsize hint, if necessary. |
862bb360 DW |
904 | */ |
905 | STATIC int | |
906 | xfs_reflink_update_dest( | |
907 | struct xfs_inode *dest, | |
f7ca3522 DW |
908 | xfs_off_t newlen, |
909 | xfs_extlen_t cowextsize) | |
862bb360 DW |
910 | { |
911 | struct xfs_mount *mp = dest->i_mount; | |
912 | struct xfs_trans *tp; | |
913 | int error; | |
914 | ||
f7ca3522 | 915 | if (newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0) |
862bb360 DW |
916 | return 0; |
917 | ||
918 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
919 | if (error) | |
920 | goto out_error; | |
921 | ||
922 | xfs_ilock(dest, XFS_ILOCK_EXCL); | |
923 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
924 | ||
f7ca3522 DW |
925 | if (newlen > i_size_read(VFS_I(dest))) { |
926 | trace_xfs_reflink_update_inode_size(dest, newlen); | |
927 | i_size_write(VFS_I(dest), newlen); | |
928 | dest->i_d.di_size = newlen; | |
929 | } | |
930 | ||
931 | if (cowextsize) { | |
932 | dest->i_d.di_cowextsize = cowextsize; | |
933 | dest->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE; | |
934 | } | |
935 | ||
862bb360 DW |
936 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); |
937 | ||
938 | error = xfs_trans_commit(tp); | |
939 | if (error) | |
940 | goto out_error; | |
941 | return error; | |
942 | ||
943 | out_error: | |
944 | trace_xfs_reflink_update_inode_size_error(dest, error, _RET_IP_); | |
945 | return error; | |
946 | } | |
947 | ||
6fa164b8 DW |
948 | /* |
949 | * Do we have enough reserve in this AG to handle a reflink? The refcount | |
950 | * btree already reserved all the space it needs, but the rmap btree can grow | |
951 | * infinitely, so we won't allow more reflinks when the AG is down to the | |
952 | * btree reserves. | |
953 | */ | |
954 | static int | |
955 | xfs_reflink_ag_has_free_space( | |
956 | struct xfs_mount *mp, | |
957 | xfs_agnumber_t agno) | |
958 | { | |
959 | struct xfs_perag *pag; | |
960 | int error = 0; | |
961 | ||
962 | if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) | |
963 | return 0; | |
964 | ||
965 | pag = xfs_perag_get(mp, agno); | |
966 | if (xfs_ag_resv_critical(pag, XFS_AG_RESV_AGFL) || | |
967 | xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA)) | |
968 | error = -ENOSPC; | |
969 | xfs_perag_put(pag); | |
970 | return error; | |
971 | } | |
972 | ||
862bb360 DW |
973 | /* |
974 | * Unmap a range of blocks from a file, then map other blocks into the hole. | |
975 | * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount). | |
976 | * The extent irec is mapped into dest at irec->br_startoff. | |
977 | */ | |
978 | STATIC int | |
979 | xfs_reflink_remap_extent( | |
980 | struct xfs_inode *ip, | |
981 | struct xfs_bmbt_irec *irec, | |
982 | xfs_fileoff_t destoff, | |
983 | xfs_off_t new_isize) | |
984 | { | |
985 | struct xfs_mount *mp = ip->i_mount; | |
986 | struct xfs_trans *tp; | |
987 | xfs_fsblock_t firstfsb; | |
988 | unsigned int resblks; | |
989 | struct xfs_defer_ops dfops; | |
990 | struct xfs_bmbt_irec uirec; | |
991 | bool real_extent; | |
992 | xfs_filblks_t rlen; | |
993 | xfs_filblks_t unmap_len; | |
994 | xfs_off_t newlen; | |
995 | int error; | |
996 | ||
997 | unmap_len = irec->br_startoff + irec->br_blockcount - destoff; | |
998 | trace_xfs_reflink_punch_range(ip, destoff, unmap_len); | |
999 | ||
1000 | /* Only remap normal extents. */ | |
1001 | real_extent = (irec->br_startblock != HOLESTARTBLOCK && | |
1002 | irec->br_startblock != DELAYSTARTBLOCK && | |
1003 | !ISUNWRITTEN(irec)); | |
1004 | ||
6fa164b8 DW |
1005 | /* No reflinking if we're low on space */ |
1006 | if (real_extent) { | |
1007 | error = xfs_reflink_ag_has_free_space(mp, | |
1008 | XFS_FSB_TO_AGNO(mp, irec->br_startblock)); | |
1009 | if (error) | |
1010 | goto out; | |
1011 | } | |
1012 | ||
862bb360 DW |
1013 | /* Start a rolling transaction to switch the mappings */ |
1014 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
1015 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); | |
1016 | if (error) | |
1017 | goto out; | |
1018 | ||
1019 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1020 | xfs_trans_ijoin(tp, ip, 0); | |
1021 | ||
1022 | /* If we're not just clearing space, then do we have enough quota? */ | |
1023 | if (real_extent) { | |
1024 | error = xfs_trans_reserve_quota_nblks(tp, ip, | |
1025 | irec->br_blockcount, 0, XFS_QMOPT_RES_REGBLKS); | |
1026 | if (error) | |
1027 | goto out_cancel; | |
1028 | } | |
1029 | ||
1030 | trace_xfs_reflink_remap(ip, irec->br_startoff, | |
1031 | irec->br_blockcount, irec->br_startblock); | |
1032 | ||
1033 | /* Unmap the old blocks in the data fork. */ | |
1034 | rlen = unmap_len; | |
1035 | while (rlen) { | |
1036 | xfs_defer_init(&dfops, &firstfsb); | |
1037 | error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1, | |
1038 | &firstfsb, &dfops); | |
1039 | if (error) | |
1040 | goto out_defer; | |
1041 | ||
1042 | /* | |
1043 | * Trim the extent to whatever got unmapped. | |
1044 | * Remember, bunmapi works backwards. | |
1045 | */ | |
1046 | uirec.br_startblock = irec->br_startblock + rlen; | |
1047 | uirec.br_startoff = irec->br_startoff + rlen; | |
1048 | uirec.br_blockcount = unmap_len - rlen; | |
1049 | unmap_len = rlen; | |
1050 | ||
1051 | /* If this isn't a real mapping, we're done. */ | |
1052 | if (!real_extent || uirec.br_blockcount == 0) | |
1053 | goto next_extent; | |
1054 | ||
1055 | trace_xfs_reflink_remap(ip, uirec.br_startoff, | |
1056 | uirec.br_blockcount, uirec.br_startblock); | |
1057 | ||
1058 | /* Update the refcount tree */ | |
1059 | error = xfs_refcount_increase_extent(mp, &dfops, &uirec); | |
1060 | if (error) | |
1061 | goto out_defer; | |
1062 | ||
1063 | /* Map the new blocks into the data fork. */ | |
1064 | error = xfs_bmap_map_extent(mp, &dfops, ip, &uirec); | |
1065 | if (error) | |
1066 | goto out_defer; | |
1067 | ||
1068 | /* Update quota accounting. */ | |
1069 | xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, | |
1070 | uirec.br_blockcount); | |
1071 | ||
1072 | /* Update dest isize if needed. */ | |
1073 | newlen = XFS_FSB_TO_B(mp, | |
1074 | uirec.br_startoff + uirec.br_blockcount); | |
1075 | newlen = min_t(xfs_off_t, newlen, new_isize); | |
1076 | if (newlen > i_size_read(VFS_I(ip))) { | |
1077 | trace_xfs_reflink_update_inode_size(ip, newlen); | |
1078 | i_size_write(VFS_I(ip), newlen); | |
1079 | ip->i_d.di_size = newlen; | |
1080 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
1081 | } | |
1082 | ||
1083 | next_extent: | |
1084 | /* Process all the deferred stuff. */ | |
1085 | error = xfs_defer_finish(&tp, &dfops, ip); | |
1086 | if (error) | |
1087 | goto out_defer; | |
1088 | } | |
1089 | ||
1090 | error = xfs_trans_commit(tp); | |
1091 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1092 | if (error) | |
1093 | goto out; | |
1094 | return 0; | |
1095 | ||
1096 | out_defer: | |
1097 | xfs_defer_cancel(&dfops); | |
1098 | out_cancel: | |
1099 | xfs_trans_cancel(tp); | |
1100 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1101 | out: | |
1102 | trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_); | |
1103 | return error; | |
1104 | } | |
1105 | ||
1106 | /* | |
1107 | * Iteratively remap one file's extents (and holes) to another's. | |
1108 | */ | |
1109 | STATIC int | |
1110 | xfs_reflink_remap_blocks( | |
1111 | struct xfs_inode *src, | |
1112 | xfs_fileoff_t srcoff, | |
1113 | struct xfs_inode *dest, | |
1114 | xfs_fileoff_t destoff, | |
1115 | xfs_filblks_t len, | |
1116 | xfs_off_t new_isize) | |
1117 | { | |
1118 | struct xfs_bmbt_irec imap; | |
1119 | int nimaps; | |
1120 | int error = 0; | |
1121 | xfs_filblks_t range_len; | |
1122 | ||
1123 | /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ | |
1124 | while (len) { | |
1125 | trace_xfs_reflink_remap_blocks_loop(src, srcoff, len, | |
1126 | dest, destoff); | |
1127 | /* Read extent from the source file */ | |
1128 | nimaps = 1; | |
1129 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
1130 | error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); | |
1131 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
1132 | if (error) | |
1133 | goto err; | |
1134 | ASSERT(nimaps == 1); | |
1135 | ||
1136 | trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE, | |
1137 | &imap); | |
1138 | ||
1139 | /* Translate imap into the destination file. */ | |
1140 | range_len = imap.br_startoff + imap.br_blockcount - srcoff; | |
1141 | imap.br_startoff += destoff - srcoff; | |
1142 | ||
1143 | /* Clear dest from destoff to the end of imap and map it in. */ | |
1144 | error = xfs_reflink_remap_extent(dest, &imap, destoff, | |
1145 | new_isize); | |
1146 | if (error) | |
1147 | goto err; | |
1148 | ||
1149 | if (fatal_signal_pending(current)) { | |
1150 | error = -EINTR; | |
1151 | goto err; | |
1152 | } | |
1153 | ||
1154 | /* Advance drange/srange */ | |
1155 | srcoff += range_len; | |
1156 | destoff += range_len; | |
1157 | len -= range_len; | |
1158 | } | |
1159 | ||
1160 | return 0; | |
1161 | ||
1162 | err: | |
1163 | trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_); | |
1164 | return error; | |
1165 | } | |
1166 | ||
cc714660 DW |
1167 | /* |
1168 | * Read a page's worth of file data into the page cache. Return the page | |
1169 | * locked. | |
1170 | */ | |
1171 | static struct page * | |
1172 | xfs_get_page( | |
1173 | struct inode *inode, | |
1174 | xfs_off_t offset) | |
1175 | { | |
1176 | struct address_space *mapping; | |
1177 | struct page *page; | |
1178 | pgoff_t n; | |
1179 | ||
1180 | n = offset >> PAGE_SHIFT; | |
1181 | mapping = inode->i_mapping; | |
1182 | page = read_mapping_page(mapping, n, NULL); | |
1183 | if (IS_ERR(page)) | |
1184 | return page; | |
1185 | if (!PageUptodate(page)) { | |
1186 | put_page(page); | |
1187 | return ERR_PTR(-EIO); | |
1188 | } | |
1189 | lock_page(page); | |
1190 | return page; | |
1191 | } | |
1192 | ||
1193 | /* | |
1194 | * Compare extents of two files to see if they are the same. | |
1195 | */ | |
1196 | static int | |
1197 | xfs_compare_extents( | |
1198 | struct inode *src, | |
1199 | xfs_off_t srcoff, | |
1200 | struct inode *dest, | |
1201 | xfs_off_t destoff, | |
1202 | xfs_off_t len, | |
1203 | bool *is_same) | |
1204 | { | |
1205 | xfs_off_t src_poff; | |
1206 | xfs_off_t dest_poff; | |
1207 | void *src_addr; | |
1208 | void *dest_addr; | |
1209 | struct page *src_page; | |
1210 | struct page *dest_page; | |
1211 | xfs_off_t cmp_len; | |
1212 | bool same; | |
1213 | int error; | |
1214 | ||
1215 | error = -EINVAL; | |
1216 | same = true; | |
1217 | while (len) { | |
1218 | src_poff = srcoff & (PAGE_SIZE - 1); | |
1219 | dest_poff = destoff & (PAGE_SIZE - 1); | |
1220 | cmp_len = min(PAGE_SIZE - src_poff, | |
1221 | PAGE_SIZE - dest_poff); | |
1222 | cmp_len = min(cmp_len, len); | |
1223 | ASSERT(cmp_len > 0); | |
1224 | ||
1225 | trace_xfs_reflink_compare_extents(XFS_I(src), srcoff, cmp_len, | |
1226 | XFS_I(dest), destoff); | |
1227 | ||
1228 | src_page = xfs_get_page(src, srcoff); | |
1229 | if (IS_ERR(src_page)) { | |
1230 | error = PTR_ERR(src_page); | |
1231 | goto out_error; | |
1232 | } | |
1233 | dest_page = xfs_get_page(dest, destoff); | |
1234 | if (IS_ERR(dest_page)) { | |
1235 | error = PTR_ERR(dest_page); | |
1236 | unlock_page(src_page); | |
1237 | put_page(src_page); | |
1238 | goto out_error; | |
1239 | } | |
1240 | src_addr = kmap_atomic(src_page); | |
1241 | dest_addr = kmap_atomic(dest_page); | |
1242 | ||
1243 | flush_dcache_page(src_page); | |
1244 | flush_dcache_page(dest_page); | |
1245 | ||
1246 | if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len)) | |
1247 | same = false; | |
1248 | ||
1249 | kunmap_atomic(dest_addr); | |
1250 | kunmap_atomic(src_addr); | |
1251 | unlock_page(dest_page); | |
1252 | unlock_page(src_page); | |
1253 | put_page(dest_page); | |
1254 | put_page(src_page); | |
1255 | ||
1256 | if (!same) | |
1257 | break; | |
1258 | ||
1259 | srcoff += cmp_len; | |
1260 | destoff += cmp_len; | |
1261 | len -= cmp_len; | |
1262 | } | |
1263 | ||
1264 | *is_same = same; | |
1265 | return 0; | |
1266 | ||
1267 | out_error: | |
1268 | trace_xfs_reflink_compare_extents_error(XFS_I(dest), error, _RET_IP_); | |
1269 | return error; | |
1270 | } | |
1271 | ||
862bb360 DW |
1272 | /* |
1273 | * Link a range of blocks from one file to another. | |
1274 | */ | |
1275 | int | |
1276 | xfs_reflink_remap_range( | |
5faaf4fa CH |
1277 | struct file *file_in, |
1278 | loff_t pos_in, | |
1279 | struct file *file_out, | |
1280 | loff_t pos_out, | |
1281 | u64 len, | |
1282 | bool is_dedupe) | |
862bb360 | 1283 | { |
5faaf4fa CH |
1284 | struct inode *inode_in = file_inode(file_in); |
1285 | struct xfs_inode *src = XFS_I(inode_in); | |
1286 | struct inode *inode_out = file_inode(file_out); | |
1287 | struct xfs_inode *dest = XFS_I(inode_out); | |
862bb360 | 1288 | struct xfs_mount *mp = src->i_mount; |
5faaf4fa CH |
1289 | loff_t bs = inode_out->i_sb->s_blocksize; |
1290 | bool same_inode = (inode_in == inode_out); | |
862bb360 DW |
1291 | xfs_fileoff_t sfsbno, dfsbno; |
1292 | xfs_filblks_t fsblen; | |
f7ca3522 | 1293 | xfs_extlen_t cowextsize; |
5faaf4fa CH |
1294 | loff_t isize; |
1295 | ssize_t ret; | |
1296 | loff_t blen; | |
862bb360 DW |
1297 | |
1298 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1299 | return -EOPNOTSUPP; | |
1300 | ||
1301 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1302 | return -EIO; | |
1303 | ||
5faaf4fa CH |
1304 | /* Lock both files against IO */ |
1305 | if (same_inode) { | |
1306 | xfs_ilock(src, XFS_IOLOCK_EXCL); | |
1307 | xfs_ilock(src, XFS_MMAPLOCK_EXCL); | |
1308 | } else { | |
1309 | xfs_lock_two_inodes(src, dest, XFS_IOLOCK_EXCL); | |
1310 | xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL); | |
1311 | } | |
1312 | ||
1313 | /* Don't touch certain kinds of inodes */ | |
1314 | ret = -EPERM; | |
1315 | if (IS_IMMUTABLE(inode_out)) | |
1316 | goto out_unlock; | |
1317 | ||
1318 | ret = -ETXTBSY; | |
1319 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1320 | goto out_unlock; | |
1321 | ||
1322 | ||
1323 | /* Don't reflink dirs, pipes, sockets... */ | |
1324 | ret = -EISDIR; | |
1325 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
1326 | goto out_unlock; | |
1327 | ret = -EINVAL; | |
1328 | if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode)) | |
1329 | goto out_unlock; | |
1330 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) | |
1331 | goto out_unlock; | |
1332 | ||
862bb360 DW |
1333 | /* Don't reflink realtime inodes */ |
1334 | if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest)) | |
5faaf4fa CH |
1335 | goto out_unlock; |
1336 | ||
1337 | /* Don't share DAX file data for now. */ | |
1338 | if (IS_DAX(inode_in) || IS_DAX(inode_out)) | |
1339 | goto out_unlock; | |
1340 | ||
1341 | /* Are we going all the way to the end? */ | |
1342 | isize = i_size_read(inode_in); | |
1343 | if (isize == 0) { | |
1344 | ret = 0; | |
1345 | goto out_unlock; | |
1346 | } | |
1347 | ||
1348 | if (len == 0) | |
1349 | len = isize - pos_in; | |
1350 | ||
1351 | /* Ensure offsets don't wrap and the input is inside i_size */ | |
1352 | if (pos_in + len < pos_in || pos_out + len < pos_out || | |
1353 | pos_in + len > isize) | |
1354 | goto out_unlock; | |
862bb360 | 1355 | |
5faaf4fa CH |
1356 | /* Don't allow dedupe past EOF in the dest file */ |
1357 | if (is_dedupe) { | |
1358 | loff_t disize; | |
cc714660 | 1359 | |
5faaf4fa CH |
1360 | disize = i_size_read(inode_out); |
1361 | if (pos_out >= disize || pos_out + len > disize) | |
1362 | goto out_unlock; | |
1363 | } | |
1364 | ||
1365 | /* If we're linking to EOF, continue to the block boundary. */ | |
1366 | if (pos_in + len == isize) | |
1367 | blen = ALIGN(isize, bs) - pos_in; | |
1368 | else | |
1369 | blen = len; | |
1370 | ||
1371 | /* Only reflink if we're aligned to block boundaries */ | |
1372 | if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) || | |
1373 | !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs)) | |
1374 | goto out_unlock; | |
1375 | ||
1376 | /* Don't allow overlapped reflink within the same file */ | |
1377 | if (same_inode) { | |
1378 | if (pos_out + blen > pos_in && pos_out < pos_in + blen) | |
1379 | goto out_unlock; | |
1380 | } | |
1381 | ||
1382 | /* Wait for the completion of any pending IOs on both files */ | |
1383 | inode_dio_wait(inode_in); | |
1384 | if (!same_inode) | |
1385 | inode_dio_wait(inode_out); | |
1386 | ||
1387 | ret = filemap_write_and_wait_range(inode_in->i_mapping, | |
1388 | pos_in, pos_in + len - 1); | |
1389 | if (ret) | |
1390 | goto out_unlock; | |
1391 | ||
1392 | ret = filemap_write_and_wait_range(inode_out->i_mapping, | |
1393 | pos_out, pos_out + len - 1); | |
1394 | if (ret) | |
1395 | goto out_unlock; | |
1396 | ||
1397 | trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); | |
862bb360 | 1398 | |
cc714660 DW |
1399 | /* |
1400 | * Check that the extents are the same. | |
1401 | */ | |
5faaf4fa CH |
1402 | if (is_dedupe) { |
1403 | bool is_same = false; | |
1404 | ||
1405 | ret = xfs_compare_extents(inode_in, pos_in, inode_out, pos_out, | |
1406 | len, &is_same); | |
1407 | if (ret) | |
1408 | goto out_unlock; | |
cc714660 | 1409 | if (!is_same) { |
5faaf4fa CH |
1410 | ret = -EBADE; |
1411 | goto out_unlock; | |
cc714660 DW |
1412 | } |
1413 | } | |
1414 | ||
5faaf4fa CH |
1415 | ret = xfs_reflink_set_inode_flag(src, dest); |
1416 | if (ret) | |
1417 | goto out_unlock; | |
862bb360 DW |
1418 | |
1419 | /* | |
1420 | * Invalidate the page cache so that we can clear any CoW mappings | |
1421 | * in the destination file. | |
1422 | */ | |
5faaf4fa CH |
1423 | truncate_inode_pages_range(&inode_out->i_data, pos_out, |
1424 | PAGE_ALIGN(pos_out + len) - 1); | |
862bb360 | 1425 | |
5faaf4fa CH |
1426 | dfsbno = XFS_B_TO_FSBT(mp, pos_out); |
1427 | sfsbno = XFS_B_TO_FSBT(mp, pos_in); | |
862bb360 | 1428 | fsblen = XFS_B_TO_FSB(mp, len); |
5faaf4fa CH |
1429 | ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, |
1430 | pos_out + len); | |
1431 | if (ret) | |
1432 | goto out_unlock; | |
862bb360 | 1433 | |
f7ca3522 DW |
1434 | /* |
1435 | * Carry the cowextsize hint from src to dest if we're sharing the | |
1436 | * entire source file to the entire destination file, the source file | |
1437 | * has a cowextsize hint, and the destination file does not. | |
1438 | */ | |
1439 | cowextsize = 0; | |
5faaf4fa | 1440 | if (pos_in == 0 && len == i_size_read(inode_in) && |
f7ca3522 | 1441 | (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) && |
5faaf4fa | 1442 | pos_out == 0 && len >= i_size_read(inode_out) && |
f7ca3522 DW |
1443 | !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)) |
1444 | cowextsize = src->i_d.di_cowextsize; | |
1445 | ||
5faaf4fa | 1446 | ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize); |
862bb360 | 1447 | |
5faaf4fa CH |
1448 | out_unlock: |
1449 | xfs_iunlock(src, XFS_MMAPLOCK_EXCL); | |
1450 | xfs_iunlock(src, XFS_IOLOCK_EXCL); | |
1451 | if (src->i_ino != dest->i_ino) { | |
1452 | xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); | |
1453 | xfs_iunlock(dest, XFS_IOLOCK_EXCL); | |
1454 | } | |
1455 | if (ret) | |
1456 | trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); | |
1457 | return ret; | |
862bb360 | 1458 | } |
98cc2db5 DW |
1459 | |
1460 | /* | |
1461 | * The user wants to preemptively CoW all shared blocks in this file, | |
1462 | * which enables us to turn off the reflink flag. Iterate all | |
1463 | * extents which are not prealloc/delalloc to see which ranges are | |
1464 | * mentioned in the refcount tree, then read those blocks into the | |
1465 | * pagecache, dirty them, fsync them back out, and then we can update | |
1466 | * the inode flag. What happens if we run out of memory? :) | |
1467 | */ | |
1468 | STATIC int | |
1469 | xfs_reflink_dirty_extents( | |
1470 | struct xfs_inode *ip, | |
1471 | xfs_fileoff_t fbno, | |
1472 | xfs_filblks_t end, | |
1473 | xfs_off_t isize) | |
1474 | { | |
1475 | struct xfs_mount *mp = ip->i_mount; | |
1476 | xfs_agnumber_t agno; | |
1477 | xfs_agblock_t agbno; | |
1478 | xfs_extlen_t aglen; | |
1479 | xfs_agblock_t rbno; | |
1480 | xfs_extlen_t rlen; | |
1481 | xfs_off_t fpos; | |
1482 | xfs_off_t flen; | |
1483 | struct xfs_bmbt_irec map[2]; | |
1484 | int nmaps; | |
9780643c | 1485 | int error = 0; |
98cc2db5 DW |
1486 | |
1487 | while (end - fbno > 0) { | |
1488 | nmaps = 1; | |
1489 | /* | |
1490 | * Look for extents in the file. Skip holes, delalloc, or | |
1491 | * unwritten extents; they can't be reflinked. | |
1492 | */ | |
1493 | error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); | |
1494 | if (error) | |
1495 | goto out; | |
1496 | if (nmaps == 0) | |
1497 | break; | |
1498 | if (map[0].br_startblock == HOLESTARTBLOCK || | |
1499 | map[0].br_startblock == DELAYSTARTBLOCK || | |
1500 | ISUNWRITTEN(&map[0])) | |
1501 | goto next; | |
1502 | ||
1503 | map[1] = map[0]; | |
1504 | while (map[1].br_blockcount) { | |
1505 | agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); | |
1506 | agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); | |
1507 | aglen = map[1].br_blockcount; | |
1508 | ||
1509 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, | |
1510 | &rbno, &rlen, true); | |
1511 | if (error) | |
1512 | goto out; | |
1513 | if (rbno == NULLAGBLOCK) | |
1514 | break; | |
1515 | ||
1516 | /* Dirty the pages */ | |
1517 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1518 | fpos = XFS_FSB_TO_B(mp, map[1].br_startoff + | |
1519 | (rbno - agbno)); | |
1520 | flen = XFS_FSB_TO_B(mp, rlen); | |
1521 | if (fpos + flen > isize) | |
1522 | flen = isize - fpos; | |
1523 | error = iomap_file_dirty(VFS_I(ip), fpos, flen, | |
1524 | &xfs_iomap_ops); | |
1525 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1526 | if (error) | |
1527 | goto out; | |
1528 | ||
1529 | map[1].br_blockcount -= (rbno - agbno + rlen); | |
1530 | map[1].br_startoff += (rbno - agbno + rlen); | |
1531 | map[1].br_startblock += (rbno - agbno + rlen); | |
1532 | } | |
1533 | ||
1534 | next: | |
1535 | fbno = map[0].br_startoff + map[0].br_blockcount; | |
1536 | } | |
1537 | out: | |
1538 | return error; | |
1539 | } | |
1540 | ||
1541 | /* Clear the inode reflink flag if there are no shared extents. */ | |
1542 | int | |
1543 | xfs_reflink_clear_inode_flag( | |
1544 | struct xfs_inode *ip, | |
1545 | struct xfs_trans **tpp) | |
1546 | { | |
1547 | struct xfs_mount *mp = ip->i_mount; | |
1548 | xfs_fileoff_t fbno; | |
1549 | xfs_filblks_t end; | |
1550 | xfs_agnumber_t agno; | |
1551 | xfs_agblock_t agbno; | |
1552 | xfs_extlen_t aglen; | |
1553 | xfs_agblock_t rbno; | |
1554 | xfs_extlen_t rlen; | |
024adf48 | 1555 | struct xfs_bmbt_irec map; |
98cc2db5 DW |
1556 | int nmaps; |
1557 | int error = 0; | |
1558 | ||
63646fc5 | 1559 | ASSERT(xfs_is_reflink_inode(ip)); |
98cc2db5 DW |
1560 | |
1561 | fbno = 0; | |
1562 | end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip))); | |
1563 | while (end - fbno > 0) { | |
1564 | nmaps = 1; | |
1565 | /* | |
1566 | * Look for extents in the file. Skip holes, delalloc, or | |
1567 | * unwritten extents; they can't be reflinked. | |
1568 | */ | |
024adf48 | 1569 | error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0); |
98cc2db5 DW |
1570 | if (error) |
1571 | return error; | |
1572 | if (nmaps == 0) | |
1573 | break; | |
024adf48 DW |
1574 | if (map.br_startblock == HOLESTARTBLOCK || |
1575 | map.br_startblock == DELAYSTARTBLOCK || | |
1576 | ISUNWRITTEN(&map)) | |
98cc2db5 DW |
1577 | goto next; |
1578 | ||
024adf48 DW |
1579 | agno = XFS_FSB_TO_AGNO(mp, map.br_startblock); |
1580 | agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock); | |
1581 | aglen = map.br_blockcount; | |
98cc2db5 | 1582 | |
024adf48 DW |
1583 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, |
1584 | &rbno, &rlen, false); | |
1585 | if (error) | |
1586 | return error; | |
1587 | /* Is there still a shared block here? */ | |
1588 | if (rbno != NULLAGBLOCK) | |
1589 | return 0; | |
98cc2db5 | 1590 | next: |
024adf48 | 1591 | fbno = map.br_startoff + map.br_blockcount; |
98cc2db5 DW |
1592 | } |
1593 | ||
1594 | /* | |
1595 | * We didn't find any shared blocks so turn off the reflink flag. | |
1596 | * First, get rid of any leftover CoW mappings. | |
1597 | */ | |
1598 | error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF); | |
1599 | if (error) | |
1600 | return error; | |
1601 | ||
1602 | /* Clear the inode flag. */ | |
1603 | trace_xfs_reflink_unset_inode_flag(ip); | |
1604 | ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; | |
83104d44 | 1605 | xfs_inode_clear_cowblocks_tag(ip); |
98cc2db5 DW |
1606 | xfs_trans_ijoin(*tpp, ip, 0); |
1607 | xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE); | |
1608 | ||
1609 | return error; | |
1610 | } | |
1611 | ||
1612 | /* | |
1613 | * Clear the inode reflink flag if there are no shared extents and the size | |
1614 | * hasn't changed. | |
1615 | */ | |
1616 | STATIC int | |
1617 | xfs_reflink_try_clear_inode_flag( | |
97a1b87e | 1618 | struct xfs_inode *ip) |
98cc2db5 DW |
1619 | { |
1620 | struct xfs_mount *mp = ip->i_mount; | |
1621 | struct xfs_trans *tp; | |
1622 | int error = 0; | |
1623 | ||
1624 | /* Start a rolling transaction to remove the mappings */ | |
1625 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); | |
1626 | if (error) | |
1627 | return error; | |
1628 | ||
1629 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1630 | xfs_trans_ijoin(tp, ip, 0); | |
1631 | ||
98cc2db5 DW |
1632 | error = xfs_reflink_clear_inode_flag(ip, &tp); |
1633 | if (error) | |
1634 | goto cancel; | |
1635 | ||
1636 | error = xfs_trans_commit(tp); | |
1637 | if (error) | |
1638 | goto out; | |
1639 | ||
1640 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1641 | return 0; | |
1642 | cancel: | |
1643 | xfs_trans_cancel(tp); | |
1644 | out: | |
1645 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1646 | return error; | |
1647 | } | |
1648 | ||
1649 | /* | |
1650 | * Pre-COW all shared blocks within a given byte range of a file and turn off | |
1651 | * the reflink flag if we unshare all of the file's blocks. | |
1652 | */ | |
1653 | int | |
1654 | xfs_reflink_unshare( | |
1655 | struct xfs_inode *ip, | |
1656 | xfs_off_t offset, | |
1657 | xfs_off_t len) | |
1658 | { | |
1659 | struct xfs_mount *mp = ip->i_mount; | |
1660 | xfs_fileoff_t fbno; | |
1661 | xfs_filblks_t end; | |
1662 | xfs_off_t isize; | |
1663 | int error; | |
1664 | ||
1665 | if (!xfs_is_reflink_inode(ip)) | |
1666 | return 0; | |
1667 | ||
1668 | trace_xfs_reflink_unshare(ip, offset, len); | |
1669 | ||
1670 | inode_dio_wait(VFS_I(ip)); | |
1671 | ||
1672 | /* Try to CoW the selected ranges */ | |
1673 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
97a1b87e | 1674 | fbno = XFS_B_TO_FSBT(mp, offset); |
98cc2db5 DW |
1675 | isize = i_size_read(VFS_I(ip)); |
1676 | end = XFS_B_TO_FSB(mp, offset + len); | |
1677 | error = xfs_reflink_dirty_extents(ip, fbno, end, isize); | |
1678 | if (error) | |
1679 | goto out_unlock; | |
1680 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1681 | ||
1682 | /* Wait for the IO to finish */ | |
1683 | error = filemap_write_and_wait(VFS_I(ip)->i_mapping); | |
1684 | if (error) | |
1685 | goto out; | |
1686 | ||
97a1b87e DW |
1687 | /* Turn off the reflink flag if possible. */ |
1688 | error = xfs_reflink_try_clear_inode_flag(ip); | |
1689 | if (error) | |
1690 | goto out; | |
98cc2db5 DW |
1691 | |
1692 | return 0; | |
1693 | ||
1694 | out_unlock: | |
1695 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1696 | out: | |
1697 | trace_xfs_reflink_unshare_error(ip, error, _RET_IP_); | |
1698 | return error; | |
1699 | } |