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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 | { |
2755fc44 CH |
246 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
247 | struct xfs_bmbt_irec got; | |
3ba020be | 248 | xfs_fileoff_t end_fsb, orig_end_fsb; |
2755fc44 CH |
249 | int error = 0; |
250 | bool eof = false, trimmed; | |
2a06705c | 251 | xfs_extnum_t idx; |
f7ca3522 | 252 | xfs_extlen_t align; |
2a06705c | 253 | |
3ba020be CH |
254 | /* |
255 | * Search the COW fork extent list first. This serves two purposes: | |
256 | * first this implement the speculative preallocation using cowextisze, | |
257 | * so that we also unshared block adjacent to shared blocks instead | |
258 | * of just the shared blocks themselves. Second the lookup in the | |
259 | * extent list is generally faster than going out to the shared extent | |
260 | * tree. | |
261 | */ | |
2755fc44 CH |
262 | |
263 | if (!xfs_iext_lookup_extent(ip, ifp, imap->br_startoff, &idx, &got)) | |
264 | eof = true; | |
3ba020be CH |
265 | if (!eof && got.br_startoff <= imap->br_startoff) { |
266 | trace_xfs_reflink_cow_found(ip, imap); | |
267 | xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); | |
2a06705c | 268 | |
3ba020be CH |
269 | *shared = true; |
270 | return 0; | |
271 | } | |
2a06705c DW |
272 | |
273 | /* Trim the mapping to the nearest shared extent boundary. */ | |
3ba020be | 274 | error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); |
2a06705c | 275 | if (error) |
3ba020be | 276 | return error; |
2a06705c DW |
277 | |
278 | /* Not shared? Just report the (potentially capped) extent. */ | |
3ba020be CH |
279 | if (!*shared) |
280 | return 0; | |
2a06705c DW |
281 | |
282 | /* | |
283 | * Fork all the shared blocks from our write offset until the end of | |
284 | * the extent. | |
285 | */ | |
286 | error = xfs_qm_dqattach_locked(ip, 0); | |
287 | if (error) | |
3ba020be CH |
288 | return error; |
289 | ||
290 | end_fsb = orig_end_fsb = imap->br_startoff + imap->br_blockcount; | |
2a06705c | 291 | |
f7ca3522 DW |
292 | align = xfs_eof_alignment(ip, xfs_get_cowextsz_hint(ip)); |
293 | if (align) | |
294 | end_fsb = roundup_64(end_fsb, align); | |
295 | ||
2a06705c | 296 | retry: |
3ba020be | 297 | error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff, |
65c5f419 | 298 | end_fsb - imap->br_startoff, &got, &idx, eof); |
2a06705c DW |
299 | switch (error) { |
300 | case 0: | |
301 | break; | |
302 | case -ENOSPC: | |
303 | case -EDQUOT: | |
304 | /* retry without any preallocation */ | |
3ba020be | 305 | trace_xfs_reflink_cow_enospc(ip, imap); |
2a06705c DW |
306 | if (end_fsb != orig_end_fsb) { |
307 | end_fsb = orig_end_fsb; | |
308 | goto retry; | |
309 | } | |
310 | /*FALLTHRU*/ | |
311 | default: | |
3ba020be | 312 | return error; |
2a06705c DW |
313 | } |
314 | ||
83104d44 DW |
315 | if (end_fsb != orig_end_fsb) |
316 | xfs_inode_set_cowblocks_tag(ip); | |
317 | ||
2a06705c | 318 | trace_xfs_reflink_cow_alloc(ip, &got); |
3ba020be | 319 | return 0; |
2a06705c | 320 | } |
ef473667 | 321 | |
0613f16c DW |
322 | /* Allocate all CoW reservations covering a range of blocks in a file. */ |
323 | static int | |
324 | __xfs_reflink_allocate_cow( | |
325 | struct xfs_inode *ip, | |
326 | xfs_fileoff_t *offset_fsb, | |
327 | xfs_fileoff_t end_fsb) | |
328 | { | |
329 | struct xfs_mount *mp = ip->i_mount; | |
330 | struct xfs_bmbt_irec imap; | |
331 | struct xfs_defer_ops dfops; | |
332 | struct xfs_trans *tp; | |
333 | xfs_fsblock_t first_block; | |
0613f16c | 334 | int nimaps = 1, error; |
3ba020be | 335 | bool shared; |
0613f16c DW |
336 | |
337 | xfs_defer_init(&dfops, &first_block); | |
338 | ||
339 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, | |
340 | XFS_TRANS_RESERVE, &tp); | |
341 | if (error) | |
342 | return error; | |
343 | ||
344 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
345 | ||
3ba020be CH |
346 | /* Read extent from the source file. */ |
347 | nimaps = 1; | |
348 | error = xfs_bmapi_read(ip, *offset_fsb, end_fsb - *offset_fsb, | |
349 | &imap, &nimaps, 0); | |
350 | if (error) | |
351 | goto out_unlock; | |
352 | ASSERT(nimaps == 1); | |
353 | ||
354 | error = xfs_reflink_reserve_cow(ip, &imap, &shared); | |
0613f16c DW |
355 | if (error) |
356 | goto out_trans_cancel; | |
357 | ||
3ba020be CH |
358 | if (!shared) { |
359 | *offset_fsb = imap.br_startoff + imap.br_blockcount; | |
0613f16c DW |
360 | goto out_trans_cancel; |
361 | } | |
362 | ||
363 | xfs_trans_ijoin(tp, ip, 0); | |
3ba020be | 364 | error = xfs_bmapi_write(tp, ip, imap.br_startoff, imap.br_blockcount, |
0613f16c DW |
365 | XFS_BMAPI_COWFORK, &first_block, |
366 | XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), | |
367 | &imap, &nimaps, &dfops); | |
368 | if (error) | |
369 | goto out_trans_cancel; | |
370 | ||
0613f16c DW |
371 | error = xfs_defer_finish(&tp, &dfops, NULL); |
372 | if (error) | |
373 | goto out_trans_cancel; | |
374 | ||
375 | error = xfs_trans_commit(tp); | |
376 | ||
3ba020be | 377 | *offset_fsb = imap.br_startoff + imap.br_blockcount; |
0613f16c DW |
378 | out_unlock: |
379 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
380 | return error; | |
381 | out_trans_cancel: | |
382 | xfs_defer_cancel(&dfops); | |
383 | xfs_trans_cancel(tp); | |
384 | goto out_unlock; | |
385 | } | |
386 | ||
387 | /* Allocate all CoW reservations covering a part of a file. */ | |
388 | int | |
389 | xfs_reflink_allocate_cow_range( | |
390 | struct xfs_inode *ip, | |
391 | xfs_off_t offset, | |
392 | xfs_off_t count) | |
393 | { | |
394 | struct xfs_mount *mp = ip->i_mount; | |
395 | xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
396 | xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count); | |
397 | int error; | |
398 | ||
399 | ASSERT(xfs_is_reflink_inode(ip)); | |
400 | ||
401 | trace_xfs_reflink_allocate_cow_range(ip, offset, count); | |
402 | ||
403 | /* | |
404 | * Make sure that the dquots are there. | |
405 | */ | |
406 | error = xfs_qm_dqattach(ip, 0); | |
407 | if (error) | |
408 | return error; | |
409 | ||
410 | while (offset_fsb < end_fsb) { | |
411 | error = __xfs_reflink_allocate_cow(ip, &offset_fsb, end_fsb); | |
412 | if (error) { | |
413 | trace_xfs_reflink_allocate_cow_range_error(ip, error, | |
414 | _RET_IP_); | |
415 | break; | |
416 | } | |
417 | } | |
418 | ||
419 | return error; | |
420 | } | |
421 | ||
ef473667 DW |
422 | /* |
423 | * Find the CoW reservation (and whether or not it needs block allocation) | |
424 | * for a given byte offset of a file. | |
425 | */ | |
426 | bool | |
427 | xfs_reflink_find_cow_mapping( | |
428 | struct xfs_inode *ip, | |
429 | xfs_off_t offset, | |
430 | struct xfs_bmbt_irec *imap, | |
431 | bool *need_alloc) | |
432 | { | |
433 | struct xfs_bmbt_irec irec; | |
434 | struct xfs_ifork *ifp; | |
435 | struct xfs_bmbt_rec_host *gotp; | |
436 | xfs_fileoff_t bno; | |
437 | xfs_extnum_t idx; | |
438 | ||
439 | ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); | |
440 | ASSERT(xfs_is_reflink_inode(ip)); | |
441 | ||
442 | /* Find the extent in the CoW fork. */ | |
443 | ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
444 | bno = XFS_B_TO_FSBT(ip->i_mount, offset); | |
445 | gotp = xfs_iext_bno_to_ext(ifp, bno, &idx); | |
446 | if (!gotp) | |
447 | return false; | |
448 | ||
449 | xfs_bmbt_get_all(gotp, &irec); | |
450 | if (bno >= irec.br_startoff + irec.br_blockcount || | |
451 | bno < irec.br_startoff) | |
452 | return false; | |
453 | ||
454 | trace_xfs_reflink_find_cow_mapping(ip, offset, 1, XFS_IO_OVERWRITE, | |
455 | &irec); | |
456 | ||
457 | /* If it's still delalloc, we must allocate later. */ | |
458 | *imap = irec; | |
459 | *need_alloc = !!(isnullstartblock(irec.br_startblock)); | |
460 | ||
461 | return true; | |
462 | } | |
463 | ||
464 | /* | |
465 | * Trim an extent to end at the next CoW reservation past offset_fsb. | |
466 | */ | |
467 | int | |
468 | xfs_reflink_trim_irec_to_next_cow( | |
469 | struct xfs_inode *ip, | |
470 | xfs_fileoff_t offset_fsb, | |
471 | struct xfs_bmbt_irec *imap) | |
472 | { | |
473 | struct xfs_bmbt_irec irec; | |
474 | struct xfs_ifork *ifp; | |
475 | struct xfs_bmbt_rec_host *gotp; | |
476 | xfs_extnum_t idx; | |
477 | ||
478 | if (!xfs_is_reflink_inode(ip)) | |
479 | return 0; | |
480 | ||
481 | /* Find the extent in the CoW fork. */ | |
482 | ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); | |
483 | gotp = xfs_iext_bno_to_ext(ifp, offset_fsb, &idx); | |
484 | if (!gotp) | |
485 | return 0; | |
486 | xfs_bmbt_get_all(gotp, &irec); | |
487 | ||
488 | /* This is the extent before; try sliding up one. */ | |
489 | if (irec.br_startoff < offset_fsb) { | |
490 | idx++; | |
5d829300 | 491 | if (idx >= xfs_iext_count(ifp)) |
ef473667 DW |
492 | return 0; |
493 | gotp = xfs_iext_get_ext(ifp, idx); | |
494 | xfs_bmbt_get_all(gotp, &irec); | |
495 | } | |
496 | ||
497 | if (irec.br_startoff >= imap->br_startoff + imap->br_blockcount) | |
498 | return 0; | |
499 | ||
500 | imap->br_blockcount = irec.br_startoff - imap->br_startoff; | |
501 | trace_xfs_reflink_trim_irec(ip, imap); | |
502 | ||
503 | return 0; | |
504 | } | |
43caeb18 DW |
505 | |
506 | /* | |
507 | * Cancel all pending CoW reservations for some block range of an inode. | |
508 | */ | |
509 | int | |
510 | xfs_reflink_cancel_cow_blocks( | |
511 | struct xfs_inode *ip, | |
512 | struct xfs_trans **tpp, | |
513 | xfs_fileoff_t offset_fsb, | |
514 | xfs_fileoff_t end_fsb) | |
515 | { | |
3e0ee78f CH |
516 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
517 | struct xfs_bmbt_irec got, prev, del; | |
518 | xfs_extnum_t idx; | |
43caeb18 DW |
519 | xfs_fsblock_t firstfsb; |
520 | struct xfs_defer_ops dfops; | |
3e0ee78f | 521 | int error = 0, eof = 0; |
43caeb18 DW |
522 | |
523 | if (!xfs_is_reflink_inode(ip)) | |
524 | return 0; | |
525 | ||
3e0ee78f CH |
526 | xfs_bmap_search_extents(ip, offset_fsb, XFS_COW_FORK, &eof, &idx, |
527 | &got, &prev); | |
528 | if (eof) | |
529 | return 0; | |
43caeb18 | 530 | |
3e0ee78f CH |
531 | while (got.br_startoff < end_fsb) { |
532 | del = got; | |
533 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
534 | trace_xfs_reflink_cancel_cow(ip, &del); | |
43caeb18 | 535 | |
3e0ee78f CH |
536 | if (isnullstartblock(del.br_startblock)) { |
537 | error = xfs_bmap_del_extent_delay(ip, XFS_COW_FORK, | |
538 | &idx, &got, &del); | |
43caeb18 DW |
539 | if (error) |
540 | break; | |
43caeb18 DW |
541 | } else { |
542 | xfs_trans_ijoin(*tpp, ip, 0); | |
543 | xfs_defer_init(&dfops, &firstfsb); | |
544 | ||
174edb0e DW |
545 | /* Free the CoW orphan record. */ |
546 | error = xfs_refcount_free_cow_extent(ip->i_mount, | |
3e0ee78f CH |
547 | &dfops, del.br_startblock, |
548 | del.br_blockcount); | |
174edb0e DW |
549 | if (error) |
550 | break; | |
551 | ||
43caeb18 | 552 | xfs_bmap_add_free(ip->i_mount, &dfops, |
3e0ee78f | 553 | del.br_startblock, del.br_blockcount, |
43caeb18 DW |
554 | NULL); |
555 | ||
556 | /* Update quota accounting */ | |
557 | xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT, | |
3e0ee78f | 558 | -(long)del.br_blockcount); |
43caeb18 DW |
559 | |
560 | /* Roll the transaction */ | |
561 | error = xfs_defer_finish(tpp, &dfops, ip); | |
562 | if (error) { | |
563 | xfs_defer_cancel(&dfops); | |
564 | break; | |
565 | } | |
566 | ||
567 | /* Remove the mapping from the CoW fork. */ | |
3e0ee78f | 568 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); |
43caeb18 DW |
569 | } |
570 | ||
5d829300 | 571 | if (++idx >= xfs_iext_count(ifp)) |
c17a8ef4 | 572 | break; |
3e0ee78f | 573 | xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got); |
43caeb18 DW |
574 | } |
575 | ||
c17a8ef4 BF |
576 | /* clear tag if cow fork is emptied */ |
577 | if (!ifp->if_bytes) | |
578 | xfs_inode_clear_cowblocks_tag(ip); | |
579 | ||
43caeb18 DW |
580 | return error; |
581 | } | |
582 | ||
583 | /* | |
584 | * Cancel all pending CoW reservations for some byte range of an inode. | |
585 | */ | |
586 | int | |
587 | xfs_reflink_cancel_cow_range( | |
588 | struct xfs_inode *ip, | |
589 | xfs_off_t offset, | |
590 | xfs_off_t count) | |
591 | { | |
592 | struct xfs_trans *tp; | |
593 | xfs_fileoff_t offset_fsb; | |
594 | xfs_fileoff_t end_fsb; | |
595 | int error; | |
596 | ||
597 | trace_xfs_reflink_cancel_cow_range(ip, offset, count); | |
63646fc5 | 598 | ASSERT(xfs_is_reflink_inode(ip)); |
43caeb18 DW |
599 | |
600 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); | |
601 | if (count == NULLFILEOFF) | |
602 | end_fsb = NULLFILEOFF; | |
603 | else | |
604 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
605 | ||
606 | /* Start a rolling transaction to remove the mappings */ | |
607 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
608 | 0, 0, 0, &tp); | |
609 | if (error) | |
610 | goto out; | |
611 | ||
612 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
613 | xfs_trans_ijoin(tp, ip, 0); | |
614 | ||
615 | /* Scrape out the old CoW reservations */ | |
616 | error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb); | |
617 | if (error) | |
618 | goto out_cancel; | |
619 | ||
620 | error = xfs_trans_commit(tp); | |
621 | ||
622 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
623 | return error; | |
624 | ||
625 | out_cancel: | |
626 | xfs_trans_cancel(tp); | |
627 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
628 | out: | |
629 | trace_xfs_reflink_cancel_cow_range_error(ip, error, _RET_IP_); | |
630 | return error; | |
631 | } | |
632 | ||
633 | /* | |
634 | * Remap parts of a file's data fork after a successful CoW. | |
635 | */ | |
636 | int | |
637 | xfs_reflink_end_cow( | |
638 | struct xfs_inode *ip, | |
639 | xfs_off_t offset, | |
640 | xfs_off_t count) | |
641 | { | |
c1112b6e CH |
642 | struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); |
643 | struct xfs_bmbt_irec got, prev, del; | |
43caeb18 DW |
644 | struct xfs_trans *tp; |
645 | xfs_fileoff_t offset_fsb; | |
646 | xfs_fileoff_t end_fsb; | |
43caeb18 DW |
647 | xfs_fsblock_t firstfsb; |
648 | struct xfs_defer_ops dfops; | |
c1112b6e | 649 | int error, eof = 0; |
43caeb18 | 650 | unsigned int resblks; |
43caeb18 | 651 | xfs_filblks_t rlen; |
c1112b6e | 652 | xfs_extnum_t idx; |
43caeb18 DW |
653 | |
654 | trace_xfs_reflink_end_cow(ip, offset, count); | |
655 | ||
c1112b6e CH |
656 | /* No COW extents? That's easy! */ |
657 | if (ifp->if_bytes == 0) | |
658 | return 0; | |
659 | ||
43caeb18 DW |
660 | offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); |
661 | end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); | |
43caeb18 DW |
662 | |
663 | /* Start a rolling transaction to switch the mappings */ | |
664 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
665 | error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, | |
666 | resblks, 0, 0, &tp); | |
667 | if (error) | |
668 | goto out; | |
669 | ||
670 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
671 | xfs_trans_ijoin(tp, ip, 0); | |
672 | ||
c1112b6e CH |
673 | xfs_bmap_search_extents(ip, end_fsb - 1, XFS_COW_FORK, &eof, &idx, |
674 | &got, &prev); | |
43caeb18 | 675 | |
c1112b6e CH |
676 | /* If there is a hole at end_fsb - 1 go to the previous extent */ |
677 | if (eof || got.br_startoff > end_fsb) { | |
678 | ASSERT(idx > 0); | |
679 | xfs_bmbt_get_all(xfs_iext_get_ext(ifp, --idx), &got); | |
680 | } | |
43caeb18 | 681 | |
c1112b6e CH |
682 | /* Walk backwards until we're out of the I/O range... */ |
683 | while (got.br_startoff + got.br_blockcount > offset_fsb) { | |
684 | del = got; | |
685 | xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); | |
686 | ||
687 | /* Extent delete may have bumped idx forward */ | |
688 | if (!del.br_blockcount) { | |
689 | idx--; | |
43caeb18 | 690 | goto next_extent; |
c1112b6e CH |
691 | } |
692 | ||
693 | ASSERT(!isnullstartblock(got.br_startblock)); | |
43caeb18 DW |
694 | |
695 | /* Unmap the old blocks in the data fork. */ | |
c1112b6e CH |
696 | xfs_defer_init(&dfops, &firstfsb); |
697 | rlen = del.br_blockcount; | |
698 | error = __xfs_bunmapi(tp, ip, del.br_startoff, &rlen, 0, 1, | |
699 | &firstfsb, &dfops); | |
700 | if (error) | |
701 | goto out_defer; | |
43caeb18 | 702 | |
c1112b6e CH |
703 | /* Trim the extent to whatever got unmapped. */ |
704 | if (rlen) { | |
705 | xfs_trim_extent(&del, del.br_startoff + rlen, | |
706 | del.br_blockcount - rlen); | |
707 | } | |
708 | trace_xfs_reflink_cow_remap(ip, &del); | |
174edb0e | 709 | |
c1112b6e CH |
710 | /* Free the CoW orphan record. */ |
711 | error = xfs_refcount_free_cow_extent(tp->t_mountp, &dfops, | |
712 | del.br_startblock, del.br_blockcount); | |
713 | if (error) | |
714 | goto out_defer; | |
43caeb18 | 715 | |
c1112b6e CH |
716 | /* Map the new blocks into the data fork. */ |
717 | error = xfs_bmap_map_extent(tp->t_mountp, &dfops, ip, &del); | |
718 | if (error) | |
719 | goto out_defer; | |
43caeb18 | 720 | |
c1112b6e CH |
721 | /* Remove the mapping from the CoW fork. */ |
722 | xfs_bmap_del_extent_cow(ip, &idx, &got, &del); | |
723 | ||
724 | error = xfs_defer_finish(&tp, &dfops, ip); | |
725 | if (error) | |
726 | goto out_defer; | |
43caeb18 DW |
727 | |
728 | next_extent: | |
c1112b6e CH |
729 | if (idx < 0) |
730 | break; | |
731 | xfs_bmbt_get_all(xfs_iext_get_ext(ifp, idx), &got); | |
43caeb18 DW |
732 | } |
733 | ||
734 | error = xfs_trans_commit(tp); | |
735 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
736 | if (error) | |
737 | goto out; | |
738 | return 0; | |
739 | ||
740 | out_defer: | |
741 | xfs_defer_cancel(&dfops); | |
43caeb18 DW |
742 | xfs_trans_cancel(tp); |
743 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
744 | out: | |
745 | trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); | |
746 | return error; | |
747 | } | |
174edb0e DW |
748 | |
749 | /* | |
750 | * Free leftover CoW reservations that didn't get cleaned out. | |
751 | */ | |
752 | int | |
753 | xfs_reflink_recover_cow( | |
754 | struct xfs_mount *mp) | |
755 | { | |
756 | xfs_agnumber_t agno; | |
757 | int error = 0; | |
758 | ||
759 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
760 | return 0; | |
761 | ||
762 | for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { | |
763 | error = xfs_refcount_recover_cow_leftovers(mp, agno); | |
764 | if (error) | |
765 | break; | |
766 | } | |
767 | ||
768 | return error; | |
769 | } | |
862bb360 DW |
770 | |
771 | /* | |
772 | * Reflinking (Block) Ranges of Two Files Together | |
773 | * | |
774 | * First, ensure that the reflink flag is set on both inodes. The flag is an | |
775 | * optimization to avoid unnecessary refcount btree lookups in the write path. | |
776 | * | |
777 | * Now we can iteratively remap the range of extents (and holes) in src to the | |
778 | * corresponding ranges in dest. Let drange and srange denote the ranges of | |
779 | * logical blocks in dest and src touched by the reflink operation. | |
780 | * | |
781 | * While the length of drange is greater than zero, | |
782 | * - Read src's bmbt at the start of srange ("imap") | |
783 | * - If imap doesn't exist, make imap appear to start at the end of srange | |
784 | * with zero length. | |
785 | * - If imap starts before srange, advance imap to start at srange. | |
786 | * - If imap goes beyond srange, truncate imap to end at the end of srange. | |
787 | * - Punch (imap start - srange start + imap len) blocks from dest at | |
788 | * offset (drange start). | |
789 | * - If imap points to a real range of pblks, | |
790 | * > Increase the refcount of the imap's pblks | |
791 | * > Map imap's pblks into dest at the offset | |
792 | * (drange start + imap start - srange start) | |
793 | * - Advance drange and srange by (imap start - srange start + imap len) | |
794 | * | |
795 | * Finally, if the reflink made dest longer, update both the in-core and | |
796 | * on-disk file sizes. | |
797 | * | |
798 | * ASCII Art Demonstration: | |
799 | * | |
800 | * Let's say we want to reflink this source file: | |
801 | * | |
802 | * ----SSSSSSS-SSSSS----SSSSSS (src file) | |
803 | * <--------------------> | |
804 | * | |
805 | * into this destination file: | |
806 | * | |
807 | * --DDDDDDDDDDDDDDDDDDD--DDD (dest file) | |
808 | * <--------------------> | |
809 | * '-' means a hole, and 'S' and 'D' are written blocks in the src and dest. | |
810 | * Observe that the range has different logical offsets in either file. | |
811 | * | |
812 | * Consider that the first extent in the source file doesn't line up with our | |
813 | * reflink range. Unmapping and remapping are separate operations, so we can | |
814 | * unmap more blocks from the destination file than we remap. | |
815 | * | |
816 | * ----SSSSSSS-SSSSS----SSSSSS | |
817 | * <-------> | |
818 | * --DDDDD---------DDDDD--DDD | |
819 | * <-------> | |
820 | * | |
821 | * Now remap the source extent into the destination file: | |
822 | * | |
823 | * ----SSSSSSS-SSSSS----SSSSSS | |
824 | * <-------> | |
825 | * --DDDDD--SSSSSSSDDDDD--DDD | |
826 | * <-------> | |
827 | * | |
828 | * Do likewise with the second hole and extent in our range. Holes in the | |
829 | * unmap range don't affect our operation. | |
830 | * | |
831 | * ----SSSSSSS-SSSSS----SSSSSS | |
832 | * <----> | |
833 | * --DDDDD--SSSSSSS-SSSSS-DDD | |
834 | * <----> | |
835 | * | |
836 | * Finally, unmap and remap part of the third extent. This will increase the | |
837 | * size of the destination file. | |
838 | * | |
839 | * ----SSSSSSS-SSSSS----SSSSSS | |
840 | * <-----> | |
841 | * --DDDDD--SSSSSSS-SSSSS----SSS | |
842 | * <-----> | |
843 | * | |
844 | * Once we update the destination file's i_size, we're done. | |
845 | */ | |
846 | ||
847 | /* | |
848 | * Ensure the reflink bit is set in both inodes. | |
849 | */ | |
850 | STATIC int | |
851 | xfs_reflink_set_inode_flag( | |
852 | struct xfs_inode *src, | |
853 | struct xfs_inode *dest) | |
854 | { | |
855 | struct xfs_mount *mp = src->i_mount; | |
856 | int error; | |
857 | struct xfs_trans *tp; | |
858 | ||
859 | if (xfs_is_reflink_inode(src) && xfs_is_reflink_inode(dest)) | |
860 | return 0; | |
861 | ||
862 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
863 | if (error) | |
864 | goto out_error; | |
865 | ||
866 | /* Lock both files against IO */ | |
867 | if (src->i_ino == dest->i_ino) | |
868 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
869 | else | |
870 | xfs_lock_two_inodes(src, dest, XFS_ILOCK_EXCL); | |
871 | ||
872 | if (!xfs_is_reflink_inode(src)) { | |
873 | trace_xfs_reflink_set_inode_flag(src); | |
874 | xfs_trans_ijoin(tp, src, XFS_ILOCK_EXCL); | |
875 | src->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
876 | xfs_trans_log_inode(tp, src, XFS_ILOG_CORE); | |
877 | xfs_ifork_init_cow(src); | |
878 | } else | |
879 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
880 | ||
881 | if (src->i_ino == dest->i_ino) | |
882 | goto commit_flags; | |
883 | ||
884 | if (!xfs_is_reflink_inode(dest)) { | |
885 | trace_xfs_reflink_set_inode_flag(dest); | |
886 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
887 | dest->i_d.di_flags2 |= XFS_DIFLAG2_REFLINK; | |
888 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); | |
889 | xfs_ifork_init_cow(dest); | |
890 | } else | |
891 | xfs_iunlock(dest, XFS_ILOCK_EXCL); | |
892 | ||
893 | commit_flags: | |
894 | error = xfs_trans_commit(tp); | |
895 | if (error) | |
896 | goto out_error; | |
897 | return error; | |
898 | ||
899 | out_error: | |
900 | trace_xfs_reflink_set_inode_flag_error(dest, error, _RET_IP_); | |
901 | return error; | |
902 | } | |
903 | ||
904 | /* | |
f7ca3522 | 905 | * Update destination inode size & cowextsize hint, if necessary. |
862bb360 DW |
906 | */ |
907 | STATIC int | |
908 | xfs_reflink_update_dest( | |
909 | struct xfs_inode *dest, | |
f7ca3522 DW |
910 | xfs_off_t newlen, |
911 | xfs_extlen_t cowextsize) | |
862bb360 DW |
912 | { |
913 | struct xfs_mount *mp = dest->i_mount; | |
914 | struct xfs_trans *tp; | |
915 | int error; | |
916 | ||
f7ca3522 | 917 | if (newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0) |
862bb360 DW |
918 | return 0; |
919 | ||
920 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); | |
921 | if (error) | |
922 | goto out_error; | |
923 | ||
924 | xfs_ilock(dest, XFS_ILOCK_EXCL); | |
925 | xfs_trans_ijoin(tp, dest, XFS_ILOCK_EXCL); | |
926 | ||
f7ca3522 DW |
927 | if (newlen > i_size_read(VFS_I(dest))) { |
928 | trace_xfs_reflink_update_inode_size(dest, newlen); | |
929 | i_size_write(VFS_I(dest), newlen); | |
930 | dest->i_d.di_size = newlen; | |
931 | } | |
932 | ||
933 | if (cowextsize) { | |
934 | dest->i_d.di_cowextsize = cowextsize; | |
935 | dest->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE; | |
936 | } | |
937 | ||
862bb360 DW |
938 | xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); |
939 | ||
940 | error = xfs_trans_commit(tp); | |
941 | if (error) | |
942 | goto out_error; | |
943 | return error; | |
944 | ||
945 | out_error: | |
946 | trace_xfs_reflink_update_inode_size_error(dest, error, _RET_IP_); | |
947 | return error; | |
948 | } | |
949 | ||
6fa164b8 DW |
950 | /* |
951 | * Do we have enough reserve in this AG to handle a reflink? The refcount | |
952 | * btree already reserved all the space it needs, but the rmap btree can grow | |
953 | * infinitely, so we won't allow more reflinks when the AG is down to the | |
954 | * btree reserves. | |
955 | */ | |
956 | static int | |
957 | xfs_reflink_ag_has_free_space( | |
958 | struct xfs_mount *mp, | |
959 | xfs_agnumber_t agno) | |
960 | { | |
961 | struct xfs_perag *pag; | |
962 | int error = 0; | |
963 | ||
964 | if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) | |
965 | return 0; | |
966 | ||
967 | pag = xfs_perag_get(mp, agno); | |
968 | if (xfs_ag_resv_critical(pag, XFS_AG_RESV_AGFL) || | |
969 | xfs_ag_resv_critical(pag, XFS_AG_RESV_METADATA)) | |
970 | error = -ENOSPC; | |
971 | xfs_perag_put(pag); | |
972 | return error; | |
973 | } | |
974 | ||
862bb360 DW |
975 | /* |
976 | * Unmap a range of blocks from a file, then map other blocks into the hole. | |
977 | * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount). | |
978 | * The extent irec is mapped into dest at irec->br_startoff. | |
979 | */ | |
980 | STATIC int | |
981 | xfs_reflink_remap_extent( | |
982 | struct xfs_inode *ip, | |
983 | struct xfs_bmbt_irec *irec, | |
984 | xfs_fileoff_t destoff, | |
985 | xfs_off_t new_isize) | |
986 | { | |
987 | struct xfs_mount *mp = ip->i_mount; | |
988 | struct xfs_trans *tp; | |
989 | xfs_fsblock_t firstfsb; | |
990 | unsigned int resblks; | |
991 | struct xfs_defer_ops dfops; | |
992 | struct xfs_bmbt_irec uirec; | |
993 | bool real_extent; | |
994 | xfs_filblks_t rlen; | |
995 | xfs_filblks_t unmap_len; | |
996 | xfs_off_t newlen; | |
997 | int error; | |
998 | ||
999 | unmap_len = irec->br_startoff + irec->br_blockcount - destoff; | |
1000 | trace_xfs_reflink_punch_range(ip, destoff, unmap_len); | |
1001 | ||
1002 | /* Only remap normal extents. */ | |
1003 | real_extent = (irec->br_startblock != HOLESTARTBLOCK && | |
1004 | irec->br_startblock != DELAYSTARTBLOCK && | |
1005 | !ISUNWRITTEN(irec)); | |
1006 | ||
6fa164b8 DW |
1007 | /* No reflinking if we're low on space */ |
1008 | if (real_extent) { | |
1009 | error = xfs_reflink_ag_has_free_space(mp, | |
1010 | XFS_FSB_TO_AGNO(mp, irec->br_startblock)); | |
1011 | if (error) | |
1012 | goto out; | |
1013 | } | |
1014 | ||
862bb360 DW |
1015 | /* Start a rolling transaction to switch the mappings */ |
1016 | resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); | |
1017 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); | |
1018 | if (error) | |
1019 | goto out; | |
1020 | ||
1021 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1022 | xfs_trans_ijoin(tp, ip, 0); | |
1023 | ||
1024 | /* If we're not just clearing space, then do we have enough quota? */ | |
1025 | if (real_extent) { | |
1026 | error = xfs_trans_reserve_quota_nblks(tp, ip, | |
1027 | irec->br_blockcount, 0, XFS_QMOPT_RES_REGBLKS); | |
1028 | if (error) | |
1029 | goto out_cancel; | |
1030 | } | |
1031 | ||
1032 | trace_xfs_reflink_remap(ip, irec->br_startoff, | |
1033 | irec->br_blockcount, irec->br_startblock); | |
1034 | ||
1035 | /* Unmap the old blocks in the data fork. */ | |
1036 | rlen = unmap_len; | |
1037 | while (rlen) { | |
1038 | xfs_defer_init(&dfops, &firstfsb); | |
1039 | error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1, | |
1040 | &firstfsb, &dfops); | |
1041 | if (error) | |
1042 | goto out_defer; | |
1043 | ||
1044 | /* | |
1045 | * Trim the extent to whatever got unmapped. | |
1046 | * Remember, bunmapi works backwards. | |
1047 | */ | |
1048 | uirec.br_startblock = irec->br_startblock + rlen; | |
1049 | uirec.br_startoff = irec->br_startoff + rlen; | |
1050 | uirec.br_blockcount = unmap_len - rlen; | |
1051 | unmap_len = rlen; | |
1052 | ||
1053 | /* If this isn't a real mapping, we're done. */ | |
1054 | if (!real_extent || uirec.br_blockcount == 0) | |
1055 | goto next_extent; | |
1056 | ||
1057 | trace_xfs_reflink_remap(ip, uirec.br_startoff, | |
1058 | uirec.br_blockcount, uirec.br_startblock); | |
1059 | ||
1060 | /* Update the refcount tree */ | |
1061 | error = xfs_refcount_increase_extent(mp, &dfops, &uirec); | |
1062 | if (error) | |
1063 | goto out_defer; | |
1064 | ||
1065 | /* Map the new blocks into the data fork. */ | |
1066 | error = xfs_bmap_map_extent(mp, &dfops, ip, &uirec); | |
1067 | if (error) | |
1068 | goto out_defer; | |
1069 | ||
1070 | /* Update quota accounting. */ | |
1071 | xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, | |
1072 | uirec.br_blockcount); | |
1073 | ||
1074 | /* Update dest isize if needed. */ | |
1075 | newlen = XFS_FSB_TO_B(mp, | |
1076 | uirec.br_startoff + uirec.br_blockcount); | |
1077 | newlen = min_t(xfs_off_t, newlen, new_isize); | |
1078 | if (newlen > i_size_read(VFS_I(ip))) { | |
1079 | trace_xfs_reflink_update_inode_size(ip, newlen); | |
1080 | i_size_write(VFS_I(ip), newlen); | |
1081 | ip->i_d.di_size = newlen; | |
1082 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
1083 | } | |
1084 | ||
1085 | next_extent: | |
1086 | /* Process all the deferred stuff. */ | |
1087 | error = xfs_defer_finish(&tp, &dfops, ip); | |
1088 | if (error) | |
1089 | goto out_defer; | |
1090 | } | |
1091 | ||
1092 | error = xfs_trans_commit(tp); | |
1093 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1094 | if (error) | |
1095 | goto out; | |
1096 | return 0; | |
1097 | ||
1098 | out_defer: | |
1099 | xfs_defer_cancel(&dfops); | |
1100 | out_cancel: | |
1101 | xfs_trans_cancel(tp); | |
1102 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1103 | out: | |
1104 | trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_); | |
1105 | return error; | |
1106 | } | |
1107 | ||
1108 | /* | |
1109 | * Iteratively remap one file's extents (and holes) to another's. | |
1110 | */ | |
1111 | STATIC int | |
1112 | xfs_reflink_remap_blocks( | |
1113 | struct xfs_inode *src, | |
1114 | xfs_fileoff_t srcoff, | |
1115 | struct xfs_inode *dest, | |
1116 | xfs_fileoff_t destoff, | |
1117 | xfs_filblks_t len, | |
1118 | xfs_off_t new_isize) | |
1119 | { | |
1120 | struct xfs_bmbt_irec imap; | |
1121 | int nimaps; | |
1122 | int error = 0; | |
1123 | xfs_filblks_t range_len; | |
1124 | ||
1125 | /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ | |
1126 | while (len) { | |
1127 | trace_xfs_reflink_remap_blocks_loop(src, srcoff, len, | |
1128 | dest, destoff); | |
1129 | /* Read extent from the source file */ | |
1130 | nimaps = 1; | |
1131 | xfs_ilock(src, XFS_ILOCK_EXCL); | |
1132 | error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); | |
1133 | xfs_iunlock(src, XFS_ILOCK_EXCL); | |
1134 | if (error) | |
1135 | goto err; | |
1136 | ASSERT(nimaps == 1); | |
1137 | ||
1138 | trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE, | |
1139 | &imap); | |
1140 | ||
1141 | /* Translate imap into the destination file. */ | |
1142 | range_len = imap.br_startoff + imap.br_blockcount - srcoff; | |
1143 | imap.br_startoff += destoff - srcoff; | |
1144 | ||
1145 | /* Clear dest from destoff to the end of imap and map it in. */ | |
1146 | error = xfs_reflink_remap_extent(dest, &imap, destoff, | |
1147 | new_isize); | |
1148 | if (error) | |
1149 | goto err; | |
1150 | ||
1151 | if (fatal_signal_pending(current)) { | |
1152 | error = -EINTR; | |
1153 | goto err; | |
1154 | } | |
1155 | ||
1156 | /* Advance drange/srange */ | |
1157 | srcoff += range_len; | |
1158 | destoff += range_len; | |
1159 | len -= range_len; | |
1160 | } | |
1161 | ||
1162 | return 0; | |
1163 | ||
1164 | err: | |
1165 | trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_); | |
1166 | return error; | |
1167 | } | |
1168 | ||
cc714660 DW |
1169 | /* |
1170 | * Read a page's worth of file data into the page cache. Return the page | |
1171 | * locked. | |
1172 | */ | |
1173 | static struct page * | |
1174 | xfs_get_page( | |
1175 | struct inode *inode, | |
1176 | xfs_off_t offset) | |
1177 | { | |
1178 | struct address_space *mapping; | |
1179 | struct page *page; | |
1180 | pgoff_t n; | |
1181 | ||
1182 | n = offset >> PAGE_SHIFT; | |
1183 | mapping = inode->i_mapping; | |
1184 | page = read_mapping_page(mapping, n, NULL); | |
1185 | if (IS_ERR(page)) | |
1186 | return page; | |
1187 | if (!PageUptodate(page)) { | |
1188 | put_page(page); | |
1189 | return ERR_PTR(-EIO); | |
1190 | } | |
1191 | lock_page(page); | |
1192 | return page; | |
1193 | } | |
1194 | ||
1195 | /* | |
1196 | * Compare extents of two files to see if they are the same. | |
1197 | */ | |
1198 | static int | |
1199 | xfs_compare_extents( | |
1200 | struct inode *src, | |
1201 | xfs_off_t srcoff, | |
1202 | struct inode *dest, | |
1203 | xfs_off_t destoff, | |
1204 | xfs_off_t len, | |
1205 | bool *is_same) | |
1206 | { | |
1207 | xfs_off_t src_poff; | |
1208 | xfs_off_t dest_poff; | |
1209 | void *src_addr; | |
1210 | void *dest_addr; | |
1211 | struct page *src_page; | |
1212 | struct page *dest_page; | |
1213 | xfs_off_t cmp_len; | |
1214 | bool same; | |
1215 | int error; | |
1216 | ||
1217 | error = -EINVAL; | |
1218 | same = true; | |
1219 | while (len) { | |
1220 | src_poff = srcoff & (PAGE_SIZE - 1); | |
1221 | dest_poff = destoff & (PAGE_SIZE - 1); | |
1222 | cmp_len = min(PAGE_SIZE - src_poff, | |
1223 | PAGE_SIZE - dest_poff); | |
1224 | cmp_len = min(cmp_len, len); | |
1225 | ASSERT(cmp_len > 0); | |
1226 | ||
1227 | trace_xfs_reflink_compare_extents(XFS_I(src), srcoff, cmp_len, | |
1228 | XFS_I(dest), destoff); | |
1229 | ||
1230 | src_page = xfs_get_page(src, srcoff); | |
1231 | if (IS_ERR(src_page)) { | |
1232 | error = PTR_ERR(src_page); | |
1233 | goto out_error; | |
1234 | } | |
1235 | dest_page = xfs_get_page(dest, destoff); | |
1236 | if (IS_ERR(dest_page)) { | |
1237 | error = PTR_ERR(dest_page); | |
1238 | unlock_page(src_page); | |
1239 | put_page(src_page); | |
1240 | goto out_error; | |
1241 | } | |
1242 | src_addr = kmap_atomic(src_page); | |
1243 | dest_addr = kmap_atomic(dest_page); | |
1244 | ||
1245 | flush_dcache_page(src_page); | |
1246 | flush_dcache_page(dest_page); | |
1247 | ||
1248 | if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len)) | |
1249 | same = false; | |
1250 | ||
1251 | kunmap_atomic(dest_addr); | |
1252 | kunmap_atomic(src_addr); | |
1253 | unlock_page(dest_page); | |
1254 | unlock_page(src_page); | |
1255 | put_page(dest_page); | |
1256 | put_page(src_page); | |
1257 | ||
1258 | if (!same) | |
1259 | break; | |
1260 | ||
1261 | srcoff += cmp_len; | |
1262 | destoff += cmp_len; | |
1263 | len -= cmp_len; | |
1264 | } | |
1265 | ||
1266 | *is_same = same; | |
1267 | return 0; | |
1268 | ||
1269 | out_error: | |
1270 | trace_xfs_reflink_compare_extents_error(XFS_I(dest), error, _RET_IP_); | |
1271 | return error; | |
1272 | } | |
1273 | ||
862bb360 DW |
1274 | /* |
1275 | * Link a range of blocks from one file to another. | |
1276 | */ | |
1277 | int | |
1278 | xfs_reflink_remap_range( | |
5faaf4fa CH |
1279 | struct file *file_in, |
1280 | loff_t pos_in, | |
1281 | struct file *file_out, | |
1282 | loff_t pos_out, | |
1283 | u64 len, | |
1284 | bool is_dedupe) | |
862bb360 | 1285 | { |
5faaf4fa CH |
1286 | struct inode *inode_in = file_inode(file_in); |
1287 | struct xfs_inode *src = XFS_I(inode_in); | |
1288 | struct inode *inode_out = file_inode(file_out); | |
1289 | struct xfs_inode *dest = XFS_I(inode_out); | |
862bb360 | 1290 | struct xfs_mount *mp = src->i_mount; |
5faaf4fa CH |
1291 | loff_t bs = inode_out->i_sb->s_blocksize; |
1292 | bool same_inode = (inode_in == inode_out); | |
862bb360 DW |
1293 | xfs_fileoff_t sfsbno, dfsbno; |
1294 | xfs_filblks_t fsblen; | |
f7ca3522 | 1295 | xfs_extlen_t cowextsize; |
5faaf4fa CH |
1296 | loff_t isize; |
1297 | ssize_t ret; | |
1298 | loff_t blen; | |
862bb360 DW |
1299 | |
1300 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1301 | return -EOPNOTSUPP; | |
1302 | ||
1303 | if (XFS_FORCED_SHUTDOWN(mp)) | |
1304 | return -EIO; | |
1305 | ||
5faaf4fa CH |
1306 | /* Lock both files against IO */ |
1307 | if (same_inode) { | |
1308 | xfs_ilock(src, XFS_IOLOCK_EXCL); | |
1309 | xfs_ilock(src, XFS_MMAPLOCK_EXCL); | |
1310 | } else { | |
1311 | xfs_lock_two_inodes(src, dest, XFS_IOLOCK_EXCL); | |
1312 | xfs_lock_two_inodes(src, dest, XFS_MMAPLOCK_EXCL); | |
1313 | } | |
1314 | ||
1315 | /* Don't touch certain kinds of inodes */ | |
1316 | ret = -EPERM; | |
1317 | if (IS_IMMUTABLE(inode_out)) | |
1318 | goto out_unlock; | |
1319 | ||
1320 | ret = -ETXTBSY; | |
1321 | if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) | |
1322 | goto out_unlock; | |
1323 | ||
1324 | ||
1325 | /* Don't reflink dirs, pipes, sockets... */ | |
1326 | ret = -EISDIR; | |
1327 | if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) | |
1328 | goto out_unlock; | |
1329 | ret = -EINVAL; | |
1330 | if (S_ISFIFO(inode_in->i_mode) || S_ISFIFO(inode_out->i_mode)) | |
1331 | goto out_unlock; | |
1332 | if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) | |
1333 | goto out_unlock; | |
1334 | ||
862bb360 DW |
1335 | /* Don't reflink realtime inodes */ |
1336 | if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest)) | |
5faaf4fa CH |
1337 | goto out_unlock; |
1338 | ||
1339 | /* Don't share DAX file data for now. */ | |
1340 | if (IS_DAX(inode_in) || IS_DAX(inode_out)) | |
1341 | goto out_unlock; | |
1342 | ||
1343 | /* Are we going all the way to the end? */ | |
1344 | isize = i_size_read(inode_in); | |
1345 | if (isize == 0) { | |
1346 | ret = 0; | |
1347 | goto out_unlock; | |
1348 | } | |
1349 | ||
1350 | if (len == 0) | |
1351 | len = isize - pos_in; | |
1352 | ||
1353 | /* Ensure offsets don't wrap and the input is inside i_size */ | |
1354 | if (pos_in + len < pos_in || pos_out + len < pos_out || | |
1355 | pos_in + len > isize) | |
1356 | goto out_unlock; | |
862bb360 | 1357 | |
5faaf4fa CH |
1358 | /* Don't allow dedupe past EOF in the dest file */ |
1359 | if (is_dedupe) { | |
1360 | loff_t disize; | |
cc714660 | 1361 | |
5faaf4fa CH |
1362 | disize = i_size_read(inode_out); |
1363 | if (pos_out >= disize || pos_out + len > disize) | |
1364 | goto out_unlock; | |
1365 | } | |
1366 | ||
1367 | /* If we're linking to EOF, continue to the block boundary. */ | |
1368 | if (pos_in + len == isize) | |
1369 | blen = ALIGN(isize, bs) - pos_in; | |
1370 | else | |
1371 | blen = len; | |
1372 | ||
1373 | /* Only reflink if we're aligned to block boundaries */ | |
1374 | if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) || | |
1375 | !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs)) | |
1376 | goto out_unlock; | |
1377 | ||
1378 | /* Don't allow overlapped reflink within the same file */ | |
1379 | if (same_inode) { | |
1380 | if (pos_out + blen > pos_in && pos_out < pos_in + blen) | |
1381 | goto out_unlock; | |
1382 | } | |
1383 | ||
1384 | /* Wait for the completion of any pending IOs on both files */ | |
1385 | inode_dio_wait(inode_in); | |
1386 | if (!same_inode) | |
1387 | inode_dio_wait(inode_out); | |
1388 | ||
1389 | ret = filemap_write_and_wait_range(inode_in->i_mapping, | |
1390 | pos_in, pos_in + len - 1); | |
1391 | if (ret) | |
1392 | goto out_unlock; | |
1393 | ||
1394 | ret = filemap_write_and_wait_range(inode_out->i_mapping, | |
1395 | pos_out, pos_out + len - 1); | |
1396 | if (ret) | |
1397 | goto out_unlock; | |
1398 | ||
1399 | trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); | |
862bb360 | 1400 | |
cc714660 DW |
1401 | /* |
1402 | * Check that the extents are the same. | |
1403 | */ | |
5faaf4fa CH |
1404 | if (is_dedupe) { |
1405 | bool is_same = false; | |
1406 | ||
1407 | ret = xfs_compare_extents(inode_in, pos_in, inode_out, pos_out, | |
1408 | len, &is_same); | |
1409 | if (ret) | |
1410 | goto out_unlock; | |
cc714660 | 1411 | if (!is_same) { |
5faaf4fa CH |
1412 | ret = -EBADE; |
1413 | goto out_unlock; | |
cc714660 DW |
1414 | } |
1415 | } | |
1416 | ||
5faaf4fa CH |
1417 | ret = xfs_reflink_set_inode_flag(src, dest); |
1418 | if (ret) | |
1419 | goto out_unlock; | |
862bb360 DW |
1420 | |
1421 | /* | |
1422 | * Invalidate the page cache so that we can clear any CoW mappings | |
1423 | * in the destination file. | |
1424 | */ | |
5faaf4fa CH |
1425 | truncate_inode_pages_range(&inode_out->i_data, pos_out, |
1426 | PAGE_ALIGN(pos_out + len) - 1); | |
862bb360 | 1427 | |
5faaf4fa CH |
1428 | dfsbno = XFS_B_TO_FSBT(mp, pos_out); |
1429 | sfsbno = XFS_B_TO_FSBT(mp, pos_in); | |
862bb360 | 1430 | fsblen = XFS_B_TO_FSB(mp, len); |
5faaf4fa CH |
1431 | ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, |
1432 | pos_out + len); | |
1433 | if (ret) | |
1434 | goto out_unlock; | |
862bb360 | 1435 | |
f7ca3522 DW |
1436 | /* |
1437 | * Carry the cowextsize hint from src to dest if we're sharing the | |
1438 | * entire source file to the entire destination file, the source file | |
1439 | * has a cowextsize hint, and the destination file does not. | |
1440 | */ | |
1441 | cowextsize = 0; | |
5faaf4fa | 1442 | if (pos_in == 0 && len == i_size_read(inode_in) && |
f7ca3522 | 1443 | (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) && |
5faaf4fa | 1444 | pos_out == 0 && len >= i_size_read(inode_out) && |
f7ca3522 DW |
1445 | !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)) |
1446 | cowextsize = src->i_d.di_cowextsize; | |
1447 | ||
5faaf4fa | 1448 | ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize); |
862bb360 | 1449 | |
5faaf4fa CH |
1450 | out_unlock: |
1451 | xfs_iunlock(src, XFS_MMAPLOCK_EXCL); | |
1452 | xfs_iunlock(src, XFS_IOLOCK_EXCL); | |
1453 | if (src->i_ino != dest->i_ino) { | |
1454 | xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); | |
1455 | xfs_iunlock(dest, XFS_IOLOCK_EXCL); | |
1456 | } | |
1457 | if (ret) | |
1458 | trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); | |
1459 | return ret; | |
862bb360 | 1460 | } |
98cc2db5 DW |
1461 | |
1462 | /* | |
1463 | * The user wants to preemptively CoW all shared blocks in this file, | |
1464 | * which enables us to turn off the reflink flag. Iterate all | |
1465 | * extents which are not prealloc/delalloc to see which ranges are | |
1466 | * mentioned in the refcount tree, then read those blocks into the | |
1467 | * pagecache, dirty them, fsync them back out, and then we can update | |
1468 | * the inode flag. What happens if we run out of memory? :) | |
1469 | */ | |
1470 | STATIC int | |
1471 | xfs_reflink_dirty_extents( | |
1472 | struct xfs_inode *ip, | |
1473 | xfs_fileoff_t fbno, | |
1474 | xfs_filblks_t end, | |
1475 | xfs_off_t isize) | |
1476 | { | |
1477 | struct xfs_mount *mp = ip->i_mount; | |
1478 | xfs_agnumber_t agno; | |
1479 | xfs_agblock_t agbno; | |
1480 | xfs_extlen_t aglen; | |
1481 | xfs_agblock_t rbno; | |
1482 | xfs_extlen_t rlen; | |
1483 | xfs_off_t fpos; | |
1484 | xfs_off_t flen; | |
1485 | struct xfs_bmbt_irec map[2]; | |
1486 | int nmaps; | |
9780643c | 1487 | int error = 0; |
98cc2db5 DW |
1488 | |
1489 | while (end - fbno > 0) { | |
1490 | nmaps = 1; | |
1491 | /* | |
1492 | * Look for extents in the file. Skip holes, delalloc, or | |
1493 | * unwritten extents; they can't be reflinked. | |
1494 | */ | |
1495 | error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); | |
1496 | if (error) | |
1497 | goto out; | |
1498 | if (nmaps == 0) | |
1499 | break; | |
1500 | if (map[0].br_startblock == HOLESTARTBLOCK || | |
1501 | map[0].br_startblock == DELAYSTARTBLOCK || | |
1502 | ISUNWRITTEN(&map[0])) | |
1503 | goto next; | |
1504 | ||
1505 | map[1] = map[0]; | |
1506 | while (map[1].br_blockcount) { | |
1507 | agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); | |
1508 | agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); | |
1509 | aglen = map[1].br_blockcount; | |
1510 | ||
1511 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, | |
1512 | &rbno, &rlen, true); | |
1513 | if (error) | |
1514 | goto out; | |
1515 | if (rbno == NULLAGBLOCK) | |
1516 | break; | |
1517 | ||
1518 | /* Dirty the pages */ | |
1519 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1520 | fpos = XFS_FSB_TO_B(mp, map[1].br_startoff + | |
1521 | (rbno - agbno)); | |
1522 | flen = XFS_FSB_TO_B(mp, rlen); | |
1523 | if (fpos + flen > isize) | |
1524 | flen = isize - fpos; | |
1525 | error = iomap_file_dirty(VFS_I(ip), fpos, flen, | |
1526 | &xfs_iomap_ops); | |
1527 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1528 | if (error) | |
1529 | goto out; | |
1530 | ||
1531 | map[1].br_blockcount -= (rbno - agbno + rlen); | |
1532 | map[1].br_startoff += (rbno - agbno + rlen); | |
1533 | map[1].br_startblock += (rbno - agbno + rlen); | |
1534 | } | |
1535 | ||
1536 | next: | |
1537 | fbno = map[0].br_startoff + map[0].br_blockcount; | |
1538 | } | |
1539 | out: | |
1540 | return error; | |
1541 | } | |
1542 | ||
1543 | /* Clear the inode reflink flag if there are no shared extents. */ | |
1544 | int | |
1545 | xfs_reflink_clear_inode_flag( | |
1546 | struct xfs_inode *ip, | |
1547 | struct xfs_trans **tpp) | |
1548 | { | |
1549 | struct xfs_mount *mp = ip->i_mount; | |
1550 | xfs_fileoff_t fbno; | |
1551 | xfs_filblks_t end; | |
1552 | xfs_agnumber_t agno; | |
1553 | xfs_agblock_t agbno; | |
1554 | xfs_extlen_t aglen; | |
1555 | xfs_agblock_t rbno; | |
1556 | xfs_extlen_t rlen; | |
024adf48 | 1557 | struct xfs_bmbt_irec map; |
98cc2db5 DW |
1558 | int nmaps; |
1559 | int error = 0; | |
1560 | ||
63646fc5 | 1561 | ASSERT(xfs_is_reflink_inode(ip)); |
98cc2db5 DW |
1562 | |
1563 | fbno = 0; | |
1564 | end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip))); | |
1565 | while (end - fbno > 0) { | |
1566 | nmaps = 1; | |
1567 | /* | |
1568 | * Look for extents in the file. Skip holes, delalloc, or | |
1569 | * unwritten extents; they can't be reflinked. | |
1570 | */ | |
024adf48 | 1571 | error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0); |
98cc2db5 DW |
1572 | if (error) |
1573 | return error; | |
1574 | if (nmaps == 0) | |
1575 | break; | |
024adf48 DW |
1576 | if (map.br_startblock == HOLESTARTBLOCK || |
1577 | map.br_startblock == DELAYSTARTBLOCK || | |
1578 | ISUNWRITTEN(&map)) | |
98cc2db5 DW |
1579 | goto next; |
1580 | ||
024adf48 DW |
1581 | agno = XFS_FSB_TO_AGNO(mp, map.br_startblock); |
1582 | agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock); | |
1583 | aglen = map.br_blockcount; | |
98cc2db5 | 1584 | |
024adf48 DW |
1585 | error = xfs_reflink_find_shared(mp, agno, agbno, aglen, |
1586 | &rbno, &rlen, false); | |
1587 | if (error) | |
1588 | return error; | |
1589 | /* Is there still a shared block here? */ | |
1590 | if (rbno != NULLAGBLOCK) | |
1591 | return 0; | |
98cc2db5 | 1592 | next: |
024adf48 | 1593 | fbno = map.br_startoff + map.br_blockcount; |
98cc2db5 DW |
1594 | } |
1595 | ||
1596 | /* | |
1597 | * We didn't find any shared blocks so turn off the reflink flag. | |
1598 | * First, get rid of any leftover CoW mappings. | |
1599 | */ | |
1600 | error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF); | |
1601 | if (error) | |
1602 | return error; | |
1603 | ||
1604 | /* Clear the inode flag. */ | |
1605 | trace_xfs_reflink_unset_inode_flag(ip); | |
1606 | ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; | |
83104d44 | 1607 | xfs_inode_clear_cowblocks_tag(ip); |
98cc2db5 DW |
1608 | xfs_trans_ijoin(*tpp, ip, 0); |
1609 | xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE); | |
1610 | ||
1611 | return error; | |
1612 | } | |
1613 | ||
1614 | /* | |
1615 | * Clear the inode reflink flag if there are no shared extents and the size | |
1616 | * hasn't changed. | |
1617 | */ | |
1618 | STATIC int | |
1619 | xfs_reflink_try_clear_inode_flag( | |
97a1b87e | 1620 | struct xfs_inode *ip) |
98cc2db5 DW |
1621 | { |
1622 | struct xfs_mount *mp = ip->i_mount; | |
1623 | struct xfs_trans *tp; | |
1624 | int error = 0; | |
1625 | ||
1626 | /* Start a rolling transaction to remove the mappings */ | |
1627 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); | |
1628 | if (error) | |
1629 | return error; | |
1630 | ||
1631 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
1632 | xfs_trans_ijoin(tp, ip, 0); | |
1633 | ||
98cc2db5 DW |
1634 | error = xfs_reflink_clear_inode_flag(ip, &tp); |
1635 | if (error) | |
1636 | goto cancel; | |
1637 | ||
1638 | error = xfs_trans_commit(tp); | |
1639 | if (error) | |
1640 | goto out; | |
1641 | ||
1642 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1643 | return 0; | |
1644 | cancel: | |
1645 | xfs_trans_cancel(tp); | |
1646 | out: | |
1647 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1648 | return error; | |
1649 | } | |
1650 | ||
1651 | /* | |
1652 | * Pre-COW all shared blocks within a given byte range of a file and turn off | |
1653 | * the reflink flag if we unshare all of the file's blocks. | |
1654 | */ | |
1655 | int | |
1656 | xfs_reflink_unshare( | |
1657 | struct xfs_inode *ip, | |
1658 | xfs_off_t offset, | |
1659 | xfs_off_t len) | |
1660 | { | |
1661 | struct xfs_mount *mp = ip->i_mount; | |
1662 | xfs_fileoff_t fbno; | |
1663 | xfs_filblks_t end; | |
1664 | xfs_off_t isize; | |
1665 | int error; | |
1666 | ||
1667 | if (!xfs_is_reflink_inode(ip)) | |
1668 | return 0; | |
1669 | ||
1670 | trace_xfs_reflink_unshare(ip, offset, len); | |
1671 | ||
1672 | inode_dio_wait(VFS_I(ip)); | |
1673 | ||
1674 | /* Try to CoW the selected ranges */ | |
1675 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
97a1b87e | 1676 | fbno = XFS_B_TO_FSBT(mp, offset); |
98cc2db5 DW |
1677 | isize = i_size_read(VFS_I(ip)); |
1678 | end = XFS_B_TO_FSB(mp, offset + len); | |
1679 | error = xfs_reflink_dirty_extents(ip, fbno, end, isize); | |
1680 | if (error) | |
1681 | goto out_unlock; | |
1682 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1683 | ||
1684 | /* Wait for the IO to finish */ | |
1685 | error = filemap_write_and_wait(VFS_I(ip)->i_mapping); | |
1686 | if (error) | |
1687 | goto out; | |
1688 | ||
97a1b87e DW |
1689 | /* Turn off the reflink flag if possible. */ |
1690 | error = xfs_reflink_try_clear_inode_flag(ip); | |
1691 | if (error) | |
1692 | goto out; | |
98cc2db5 DW |
1693 | |
1694 | return 0; | |
1695 | ||
1696 | out_unlock: | |
1697 | xfs_iunlock(ip, XFS_ILOCK_EXCL); | |
1698 | out: | |
1699 | trace_xfs_reflink_unshare_error(ip, error, _RET_IP_); | |
1700 | return error; | |
1701 | } |