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bdf28630 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_sb.h" | |
27 | #include "xfs_mount.h" | |
28 | #include "xfs_defer.h" | |
29 | #include "xfs_btree.h" | |
30 | #include "xfs_bmap.h" | |
31 | #include "xfs_refcount_btree.h" | |
32 | #include "xfs_alloc.h" | |
e9e899a2 | 33 | #include "xfs_errortag.h" |
bdf28630 DW |
34 | #include "xfs_error.h" |
35 | #include "xfs_trace.h" | |
36 | #include "xfs_cksum.h" | |
37 | #include "xfs_trans.h" | |
38 | #include "xfs_bit.h" | |
39 | #include "xfs_refcount.h" | |
174edb0e | 40 | #include "xfs_rmap.h" |
bdf28630 | 41 | |
31727258 DW |
42 | /* Allowable refcount adjustment amounts. */ |
43 | enum xfs_refc_adjust_op { | |
44 | XFS_REFCOUNT_ADJUST_INCREASE = 1, | |
45 | XFS_REFCOUNT_ADJUST_DECREASE = -1, | |
174edb0e DW |
46 | XFS_REFCOUNT_ADJUST_COW_ALLOC = 0, |
47 | XFS_REFCOUNT_ADJUST_COW_FREE = -1, | |
31727258 DW |
48 | }; |
49 | ||
174edb0e DW |
50 | STATIC int __xfs_refcount_cow_alloc(struct xfs_btree_cur *rcur, |
51 | xfs_agblock_t agbno, xfs_extlen_t aglen, | |
52 | struct xfs_defer_ops *dfops); | |
53 | STATIC int __xfs_refcount_cow_free(struct xfs_btree_cur *rcur, | |
54 | xfs_agblock_t agbno, xfs_extlen_t aglen, | |
55 | struct xfs_defer_ops *dfops); | |
56 | ||
bdf28630 DW |
57 | /* |
58 | * Look up the first record less than or equal to [bno, len] in the btree | |
59 | * given by cur. | |
60 | */ | |
61 | int | |
62 | xfs_refcount_lookup_le( | |
63 | struct xfs_btree_cur *cur, | |
64 | xfs_agblock_t bno, | |
65 | int *stat) | |
66 | { | |
67 | trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_private.a.agno, bno, | |
68 | XFS_LOOKUP_LE); | |
69 | cur->bc_rec.rc.rc_startblock = bno; | |
70 | cur->bc_rec.rc.rc_blockcount = 0; | |
71 | return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat); | |
72 | } | |
73 | ||
74 | /* | |
75 | * Look up the first record greater than or equal to [bno, len] in the btree | |
76 | * given by cur. | |
77 | */ | |
78 | int | |
79 | xfs_refcount_lookup_ge( | |
80 | struct xfs_btree_cur *cur, | |
81 | xfs_agblock_t bno, | |
82 | int *stat) | |
83 | { | |
84 | trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_private.a.agno, bno, | |
85 | XFS_LOOKUP_GE); | |
86 | cur->bc_rec.rc.rc_startblock = bno; | |
87 | cur->bc_rec.rc.rc_blockcount = 0; | |
88 | return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat); | |
89 | } | |
90 | ||
174edb0e DW |
91 | /* Convert on-disk record to in-core format. */ |
92 | static inline void | |
93 | xfs_refcount_btrec_to_irec( | |
94 | union xfs_btree_rec *rec, | |
95 | struct xfs_refcount_irec *irec) | |
96 | { | |
97 | irec->rc_startblock = be32_to_cpu(rec->refc.rc_startblock); | |
98 | irec->rc_blockcount = be32_to_cpu(rec->refc.rc_blockcount); | |
99 | irec->rc_refcount = be32_to_cpu(rec->refc.rc_refcount); | |
100 | } | |
101 | ||
bdf28630 DW |
102 | /* |
103 | * Get the data from the pointed-to record. | |
104 | */ | |
105 | int | |
106 | xfs_refcount_get_rec( | |
107 | struct xfs_btree_cur *cur, | |
108 | struct xfs_refcount_irec *irec, | |
109 | int *stat) | |
110 | { | |
174edb0e DW |
111 | union xfs_btree_rec *rec; |
112 | int error; | |
bdf28630 DW |
113 | |
114 | error = xfs_btree_get_rec(cur, &rec, stat); | |
115 | if (!error && *stat == 1) { | |
174edb0e | 116 | xfs_refcount_btrec_to_irec(rec, irec); |
bdf28630 DW |
117 | trace_xfs_refcount_get(cur->bc_mp, cur->bc_private.a.agno, |
118 | irec); | |
119 | } | |
120 | return error; | |
121 | } | |
122 | ||
123 | /* | |
124 | * Update the record referred to by cur to the value given | |
125 | * by [bno, len, refcount]. | |
126 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
127 | */ | |
128 | STATIC int | |
129 | xfs_refcount_update( | |
130 | struct xfs_btree_cur *cur, | |
131 | struct xfs_refcount_irec *irec) | |
132 | { | |
133 | union xfs_btree_rec rec; | |
134 | int error; | |
135 | ||
136 | trace_xfs_refcount_update(cur->bc_mp, cur->bc_private.a.agno, irec); | |
137 | rec.refc.rc_startblock = cpu_to_be32(irec->rc_startblock); | |
138 | rec.refc.rc_blockcount = cpu_to_be32(irec->rc_blockcount); | |
139 | rec.refc.rc_refcount = cpu_to_be32(irec->rc_refcount); | |
140 | error = xfs_btree_update(cur, &rec); | |
141 | if (error) | |
142 | trace_xfs_refcount_update_error(cur->bc_mp, | |
143 | cur->bc_private.a.agno, error, _RET_IP_); | |
144 | return error; | |
145 | } | |
146 | ||
147 | /* | |
148 | * Insert the record referred to by cur to the value given | |
149 | * by [bno, len, refcount]. | |
150 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
151 | */ | |
152 | STATIC int | |
153 | xfs_refcount_insert( | |
154 | struct xfs_btree_cur *cur, | |
155 | struct xfs_refcount_irec *irec, | |
156 | int *i) | |
157 | { | |
158 | int error; | |
159 | ||
160 | trace_xfs_refcount_insert(cur->bc_mp, cur->bc_private.a.agno, irec); | |
161 | cur->bc_rec.rc.rc_startblock = irec->rc_startblock; | |
162 | cur->bc_rec.rc.rc_blockcount = irec->rc_blockcount; | |
163 | cur->bc_rec.rc.rc_refcount = irec->rc_refcount; | |
164 | error = xfs_btree_insert(cur, i); | |
165 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, *i == 1, out_error); | |
166 | out_error: | |
167 | if (error) | |
168 | trace_xfs_refcount_insert_error(cur->bc_mp, | |
169 | cur->bc_private.a.agno, error, _RET_IP_); | |
170 | return error; | |
171 | } | |
172 | ||
173 | /* | |
174 | * Remove the record referred to by cur, then set the pointer to the spot | |
175 | * where the record could be re-inserted, in case we want to increment or | |
176 | * decrement the cursor. | |
177 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
178 | */ | |
179 | STATIC int | |
180 | xfs_refcount_delete( | |
181 | struct xfs_btree_cur *cur, | |
182 | int *i) | |
183 | { | |
184 | struct xfs_refcount_irec irec; | |
185 | int found_rec; | |
186 | int error; | |
187 | ||
188 | error = xfs_refcount_get_rec(cur, &irec, &found_rec); | |
189 | if (error) | |
190 | goto out_error; | |
191 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
192 | trace_xfs_refcount_delete(cur->bc_mp, cur->bc_private.a.agno, &irec); | |
193 | error = xfs_btree_delete(cur, i); | |
194 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, *i == 1, out_error); | |
195 | if (error) | |
196 | goto out_error; | |
197 | error = xfs_refcount_lookup_ge(cur, irec.rc_startblock, &found_rec); | |
198 | out_error: | |
199 | if (error) | |
200 | trace_xfs_refcount_delete_error(cur->bc_mp, | |
201 | cur->bc_private.a.agno, error, _RET_IP_); | |
202 | return error; | |
203 | } | |
31727258 DW |
204 | |
205 | /* | |
206 | * Adjusting the Reference Count | |
207 | * | |
208 | * As stated elsewhere, the reference count btree (refcbt) stores | |
209 | * >1 reference counts for extents of physical blocks. In this | |
210 | * operation, we're either raising or lowering the reference count of | |
211 | * some subrange stored in the tree: | |
212 | * | |
213 | * <------ adjustment range ------> | |
214 | * ----+ +---+-----+ +--+--------+--------- | |
215 | * 2 | | 3 | 4 | |17| 55 | 10 | |
216 | * ----+ +---+-----+ +--+--------+--------- | |
217 | * X axis is physical blocks number; | |
218 | * reference counts are the numbers inside the rectangles | |
219 | * | |
220 | * The first thing we need to do is to ensure that there are no | |
221 | * refcount extents crossing either boundary of the range to be | |
222 | * adjusted. For any extent that does cross a boundary, split it into | |
223 | * two extents so that we can increment the refcount of one of the | |
224 | * pieces later: | |
225 | * | |
226 | * <------ adjustment range ------> | |
227 | * ----+ +---+-----+ +--+--------+----+---- | |
228 | * 2 | | 3 | 2 | |17| 55 | 10 | 10 | |
229 | * ----+ +---+-----+ +--+--------+----+---- | |
230 | * | |
231 | * For this next step, let's assume that all the physical blocks in | |
232 | * the adjustment range are mapped to a file and are therefore in use | |
233 | * at least once. Therefore, we can infer that any gap in the | |
234 | * refcount tree within the adjustment range represents a physical | |
235 | * extent with refcount == 1: | |
236 | * | |
237 | * <------ adjustment range ------> | |
238 | * ----+---+---+-----+-+--+--------+----+---- | |
239 | * 2 |"1"| 3 | 2 |1|17| 55 | 10 | 10 | |
240 | * ----+---+---+-----+-+--+--------+----+---- | |
241 | * ^ | |
242 | * | |
243 | * For each extent that falls within the interval range, figure out | |
244 | * which extent is to the left or the right of that extent. Now we | |
245 | * have a left, current, and right extent. If the new reference count | |
246 | * of the center extent enables us to merge left, center, and right | |
247 | * into one record covering all three, do so. If the center extent is | |
248 | * at the left end of the range, abuts the left extent, and its new | |
249 | * reference count matches the left extent's record, then merge them. | |
250 | * If the center extent is at the right end of the range, abuts the | |
251 | * right extent, and the reference counts match, merge those. In the | |
252 | * example, we can left merge (assuming an increment operation): | |
253 | * | |
254 | * <------ adjustment range ------> | |
255 | * --------+---+-----+-+--+--------+----+---- | |
256 | * 2 | 3 | 2 |1|17| 55 | 10 | 10 | |
257 | * --------+---+-----+-+--+--------+----+---- | |
258 | * ^ | |
259 | * | |
260 | * For all other extents within the range, adjust the reference count | |
261 | * or delete it if the refcount falls below 2. If we were | |
262 | * incrementing, the end result looks like this: | |
263 | * | |
264 | * <------ adjustment range ------> | |
265 | * --------+---+-----+-+--+--------+----+---- | |
266 | * 2 | 4 | 3 |2|18| 56 | 11 | 10 | |
267 | * --------+---+-----+-+--+--------+----+---- | |
268 | * | |
269 | * The result of a decrement operation looks as such: | |
270 | * | |
271 | * <------ adjustment range ------> | |
272 | * ----+ +---+ +--+--------+----+---- | |
273 | * 2 | | 2 | |16| 54 | 9 | 10 | |
274 | * ----+ +---+ +--+--------+----+---- | |
275 | * DDDD 111111DD | |
276 | * | |
277 | * The blocks marked "D" are freed; the blocks marked "1" are only | |
278 | * referenced once and therefore the record is removed from the | |
279 | * refcount btree. | |
280 | */ | |
281 | ||
282 | /* Next block after this extent. */ | |
283 | static inline xfs_agblock_t | |
284 | xfs_refc_next( | |
285 | struct xfs_refcount_irec *rc) | |
286 | { | |
287 | return rc->rc_startblock + rc->rc_blockcount; | |
288 | } | |
289 | ||
290 | /* | |
291 | * Split a refcount extent that crosses agbno. | |
292 | */ | |
293 | STATIC int | |
294 | xfs_refcount_split_extent( | |
295 | struct xfs_btree_cur *cur, | |
296 | xfs_agblock_t agbno, | |
297 | bool *shape_changed) | |
298 | { | |
299 | struct xfs_refcount_irec rcext, tmp; | |
300 | int found_rec; | |
301 | int error; | |
302 | ||
303 | *shape_changed = false; | |
304 | error = xfs_refcount_lookup_le(cur, agbno, &found_rec); | |
305 | if (error) | |
306 | goto out_error; | |
307 | if (!found_rec) | |
308 | return 0; | |
309 | ||
310 | error = xfs_refcount_get_rec(cur, &rcext, &found_rec); | |
311 | if (error) | |
312 | goto out_error; | |
313 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
314 | if (rcext.rc_startblock == agbno || xfs_refc_next(&rcext) <= agbno) | |
315 | return 0; | |
316 | ||
317 | *shape_changed = true; | |
318 | trace_xfs_refcount_split_extent(cur->bc_mp, cur->bc_private.a.agno, | |
319 | &rcext, agbno); | |
320 | ||
321 | /* Establish the right extent. */ | |
322 | tmp = rcext; | |
323 | tmp.rc_startblock = agbno; | |
324 | tmp.rc_blockcount -= (agbno - rcext.rc_startblock); | |
325 | error = xfs_refcount_update(cur, &tmp); | |
326 | if (error) | |
327 | goto out_error; | |
328 | ||
329 | /* Insert the left extent. */ | |
330 | tmp = rcext; | |
331 | tmp.rc_blockcount = agbno - rcext.rc_startblock; | |
332 | error = xfs_refcount_insert(cur, &tmp, &found_rec); | |
333 | if (error) | |
334 | goto out_error; | |
335 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
336 | return error; | |
337 | ||
338 | out_error: | |
339 | trace_xfs_refcount_split_extent_error(cur->bc_mp, | |
340 | cur->bc_private.a.agno, error, _RET_IP_); | |
341 | return error; | |
342 | } | |
343 | ||
344 | /* | |
345 | * Merge the left, center, and right extents. | |
346 | */ | |
347 | STATIC int | |
348 | xfs_refcount_merge_center_extents( | |
349 | struct xfs_btree_cur *cur, | |
350 | struct xfs_refcount_irec *left, | |
351 | struct xfs_refcount_irec *center, | |
352 | struct xfs_refcount_irec *right, | |
353 | unsigned long long extlen, | |
354 | xfs_agblock_t *agbno, | |
355 | xfs_extlen_t *aglen) | |
356 | { | |
357 | int error; | |
358 | int found_rec; | |
359 | ||
360 | trace_xfs_refcount_merge_center_extents(cur->bc_mp, | |
361 | cur->bc_private.a.agno, left, center, right); | |
362 | ||
363 | /* | |
364 | * Make sure the center and right extents are not in the btree. | |
365 | * If the center extent was synthesized, the first delete call | |
366 | * removes the right extent and we skip the second deletion. | |
367 | * If center and right were in the btree, then the first delete | |
368 | * call removes the center and the second one removes the right | |
369 | * extent. | |
370 | */ | |
371 | error = xfs_refcount_lookup_ge(cur, center->rc_startblock, | |
372 | &found_rec); | |
373 | if (error) | |
374 | goto out_error; | |
375 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
376 | ||
377 | error = xfs_refcount_delete(cur, &found_rec); | |
378 | if (error) | |
379 | goto out_error; | |
380 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
381 | ||
382 | if (center->rc_refcount > 1) { | |
383 | error = xfs_refcount_delete(cur, &found_rec); | |
384 | if (error) | |
385 | goto out_error; | |
386 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
387 | out_error); | |
388 | } | |
389 | ||
390 | /* Enlarge the left extent. */ | |
391 | error = xfs_refcount_lookup_le(cur, left->rc_startblock, | |
392 | &found_rec); | |
393 | if (error) | |
394 | goto out_error; | |
395 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
396 | ||
397 | left->rc_blockcount = extlen; | |
398 | error = xfs_refcount_update(cur, left); | |
399 | if (error) | |
400 | goto out_error; | |
401 | ||
402 | *aglen = 0; | |
403 | return error; | |
404 | ||
405 | out_error: | |
406 | trace_xfs_refcount_merge_center_extents_error(cur->bc_mp, | |
407 | cur->bc_private.a.agno, error, _RET_IP_); | |
408 | return error; | |
409 | } | |
410 | ||
411 | /* | |
412 | * Merge with the left extent. | |
413 | */ | |
414 | STATIC int | |
415 | xfs_refcount_merge_left_extent( | |
416 | struct xfs_btree_cur *cur, | |
417 | struct xfs_refcount_irec *left, | |
418 | struct xfs_refcount_irec *cleft, | |
419 | xfs_agblock_t *agbno, | |
420 | xfs_extlen_t *aglen) | |
421 | { | |
422 | int error; | |
423 | int found_rec; | |
424 | ||
425 | trace_xfs_refcount_merge_left_extent(cur->bc_mp, | |
426 | cur->bc_private.a.agno, left, cleft); | |
427 | ||
428 | /* If the extent at agbno (cleft) wasn't synthesized, remove it. */ | |
429 | if (cleft->rc_refcount > 1) { | |
430 | error = xfs_refcount_lookup_le(cur, cleft->rc_startblock, | |
431 | &found_rec); | |
432 | if (error) | |
433 | goto out_error; | |
434 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
435 | out_error); | |
436 | ||
437 | error = xfs_refcount_delete(cur, &found_rec); | |
438 | if (error) | |
439 | goto out_error; | |
440 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
441 | out_error); | |
442 | } | |
443 | ||
444 | /* Enlarge the left extent. */ | |
445 | error = xfs_refcount_lookup_le(cur, left->rc_startblock, | |
446 | &found_rec); | |
447 | if (error) | |
448 | goto out_error; | |
449 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
450 | ||
451 | left->rc_blockcount += cleft->rc_blockcount; | |
452 | error = xfs_refcount_update(cur, left); | |
453 | if (error) | |
454 | goto out_error; | |
455 | ||
456 | *agbno += cleft->rc_blockcount; | |
457 | *aglen -= cleft->rc_blockcount; | |
458 | return error; | |
459 | ||
460 | out_error: | |
461 | trace_xfs_refcount_merge_left_extent_error(cur->bc_mp, | |
462 | cur->bc_private.a.agno, error, _RET_IP_); | |
463 | return error; | |
464 | } | |
465 | ||
466 | /* | |
467 | * Merge with the right extent. | |
468 | */ | |
469 | STATIC int | |
470 | xfs_refcount_merge_right_extent( | |
471 | struct xfs_btree_cur *cur, | |
472 | struct xfs_refcount_irec *right, | |
473 | struct xfs_refcount_irec *cright, | |
474 | xfs_agblock_t *agbno, | |
475 | xfs_extlen_t *aglen) | |
476 | { | |
477 | int error; | |
478 | int found_rec; | |
479 | ||
480 | trace_xfs_refcount_merge_right_extent(cur->bc_mp, | |
481 | cur->bc_private.a.agno, cright, right); | |
482 | ||
483 | /* | |
484 | * If the extent ending at agbno+aglen (cright) wasn't synthesized, | |
485 | * remove it. | |
486 | */ | |
487 | if (cright->rc_refcount > 1) { | |
488 | error = xfs_refcount_lookup_le(cur, cright->rc_startblock, | |
489 | &found_rec); | |
490 | if (error) | |
491 | goto out_error; | |
492 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
493 | out_error); | |
494 | ||
495 | error = xfs_refcount_delete(cur, &found_rec); | |
496 | if (error) | |
497 | goto out_error; | |
498 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
499 | out_error); | |
500 | } | |
501 | ||
502 | /* Enlarge the right extent. */ | |
503 | error = xfs_refcount_lookup_le(cur, right->rc_startblock, | |
504 | &found_rec); | |
505 | if (error) | |
506 | goto out_error; | |
507 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
508 | ||
509 | right->rc_startblock -= cright->rc_blockcount; | |
510 | right->rc_blockcount += cright->rc_blockcount; | |
511 | error = xfs_refcount_update(cur, right); | |
512 | if (error) | |
513 | goto out_error; | |
514 | ||
515 | *aglen -= cright->rc_blockcount; | |
516 | return error; | |
517 | ||
518 | out_error: | |
519 | trace_xfs_refcount_merge_right_extent_error(cur->bc_mp, | |
520 | cur->bc_private.a.agno, error, _RET_IP_); | |
521 | return error; | |
522 | } | |
523 | ||
174edb0e DW |
524 | #define XFS_FIND_RCEXT_SHARED 1 |
525 | #define XFS_FIND_RCEXT_COW 2 | |
31727258 DW |
526 | /* |
527 | * Find the left extent and the one after it (cleft). This function assumes | |
528 | * that we've already split any extent crossing agbno. | |
529 | */ | |
530 | STATIC int | |
531 | xfs_refcount_find_left_extents( | |
532 | struct xfs_btree_cur *cur, | |
533 | struct xfs_refcount_irec *left, | |
534 | struct xfs_refcount_irec *cleft, | |
535 | xfs_agblock_t agbno, | |
174edb0e DW |
536 | xfs_extlen_t aglen, |
537 | int flags) | |
31727258 DW |
538 | { |
539 | struct xfs_refcount_irec tmp; | |
540 | int error; | |
541 | int found_rec; | |
542 | ||
543 | left->rc_startblock = cleft->rc_startblock = NULLAGBLOCK; | |
544 | error = xfs_refcount_lookup_le(cur, agbno - 1, &found_rec); | |
545 | if (error) | |
546 | goto out_error; | |
547 | if (!found_rec) | |
548 | return 0; | |
549 | ||
550 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
551 | if (error) | |
552 | goto out_error; | |
553 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
554 | ||
555 | if (xfs_refc_next(&tmp) != agbno) | |
556 | return 0; | |
174edb0e DW |
557 | if ((flags & XFS_FIND_RCEXT_SHARED) && tmp.rc_refcount < 2) |
558 | return 0; | |
559 | if ((flags & XFS_FIND_RCEXT_COW) && tmp.rc_refcount > 1) | |
560 | return 0; | |
31727258 DW |
561 | /* We have a left extent; retrieve (or invent) the next right one */ |
562 | *left = tmp; | |
563 | ||
564 | error = xfs_btree_increment(cur, 0, &found_rec); | |
565 | if (error) | |
566 | goto out_error; | |
567 | if (found_rec) { | |
568 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
569 | if (error) | |
570 | goto out_error; | |
571 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
572 | out_error); | |
573 | ||
574 | /* if tmp starts at the end of our range, just use that */ | |
575 | if (tmp.rc_startblock == agbno) | |
576 | *cleft = tmp; | |
577 | else { | |
578 | /* | |
579 | * There's a gap in the refcntbt at the start of the | |
580 | * range we're interested in (refcount == 1) so | |
581 | * synthesize the implied extent and pass it back. | |
582 | * We assume here that the agbno/aglen range was | |
583 | * passed in from a data fork extent mapping and | |
584 | * therefore is allocated to exactly one owner. | |
585 | */ | |
586 | cleft->rc_startblock = agbno; | |
587 | cleft->rc_blockcount = min(aglen, | |
588 | tmp.rc_startblock - agbno); | |
589 | cleft->rc_refcount = 1; | |
590 | } | |
591 | } else { | |
592 | /* | |
593 | * No extents, so pretend that there's one covering the whole | |
594 | * range. | |
595 | */ | |
596 | cleft->rc_startblock = agbno; | |
597 | cleft->rc_blockcount = aglen; | |
598 | cleft->rc_refcount = 1; | |
599 | } | |
600 | trace_xfs_refcount_find_left_extent(cur->bc_mp, cur->bc_private.a.agno, | |
601 | left, cleft, agbno); | |
602 | return error; | |
603 | ||
604 | out_error: | |
605 | trace_xfs_refcount_find_left_extent_error(cur->bc_mp, | |
606 | cur->bc_private.a.agno, error, _RET_IP_); | |
607 | return error; | |
608 | } | |
609 | ||
610 | /* | |
611 | * Find the right extent and the one before it (cright). This function | |
612 | * assumes that we've already split any extents crossing agbno + aglen. | |
613 | */ | |
614 | STATIC int | |
615 | xfs_refcount_find_right_extents( | |
616 | struct xfs_btree_cur *cur, | |
617 | struct xfs_refcount_irec *right, | |
618 | struct xfs_refcount_irec *cright, | |
619 | xfs_agblock_t agbno, | |
174edb0e DW |
620 | xfs_extlen_t aglen, |
621 | int flags) | |
31727258 DW |
622 | { |
623 | struct xfs_refcount_irec tmp; | |
624 | int error; | |
625 | int found_rec; | |
626 | ||
627 | right->rc_startblock = cright->rc_startblock = NULLAGBLOCK; | |
628 | error = xfs_refcount_lookup_ge(cur, agbno + aglen, &found_rec); | |
629 | if (error) | |
630 | goto out_error; | |
631 | if (!found_rec) | |
632 | return 0; | |
633 | ||
634 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
635 | if (error) | |
636 | goto out_error; | |
637 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
638 | ||
639 | if (tmp.rc_startblock != agbno + aglen) | |
640 | return 0; | |
174edb0e DW |
641 | if ((flags & XFS_FIND_RCEXT_SHARED) && tmp.rc_refcount < 2) |
642 | return 0; | |
643 | if ((flags & XFS_FIND_RCEXT_COW) && tmp.rc_refcount > 1) | |
644 | return 0; | |
31727258 DW |
645 | /* We have a right extent; retrieve (or invent) the next left one */ |
646 | *right = tmp; | |
647 | ||
648 | error = xfs_btree_decrement(cur, 0, &found_rec); | |
649 | if (error) | |
650 | goto out_error; | |
651 | if (found_rec) { | |
652 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
653 | if (error) | |
654 | goto out_error; | |
655 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
656 | out_error); | |
657 | ||
658 | /* if tmp ends at the end of our range, just use that */ | |
659 | if (xfs_refc_next(&tmp) == agbno + aglen) | |
660 | *cright = tmp; | |
661 | else { | |
662 | /* | |
663 | * There's a gap in the refcntbt at the end of the | |
664 | * range we're interested in (refcount == 1) so | |
665 | * create the implied extent and pass it back. | |
666 | * We assume here that the agbno/aglen range was | |
667 | * passed in from a data fork extent mapping and | |
668 | * therefore is allocated to exactly one owner. | |
669 | */ | |
670 | cright->rc_startblock = max(agbno, xfs_refc_next(&tmp)); | |
671 | cright->rc_blockcount = right->rc_startblock - | |
672 | cright->rc_startblock; | |
673 | cright->rc_refcount = 1; | |
674 | } | |
675 | } else { | |
676 | /* | |
677 | * No extents, so pretend that there's one covering the whole | |
678 | * range. | |
679 | */ | |
680 | cright->rc_startblock = agbno; | |
681 | cright->rc_blockcount = aglen; | |
682 | cright->rc_refcount = 1; | |
683 | } | |
684 | trace_xfs_refcount_find_right_extent(cur->bc_mp, cur->bc_private.a.agno, | |
685 | cright, right, agbno + aglen); | |
686 | return error; | |
687 | ||
688 | out_error: | |
689 | trace_xfs_refcount_find_right_extent_error(cur->bc_mp, | |
690 | cur->bc_private.a.agno, error, _RET_IP_); | |
691 | return error; | |
692 | } | |
693 | ||
694 | /* Is this extent valid? */ | |
695 | static inline bool | |
696 | xfs_refc_valid( | |
697 | struct xfs_refcount_irec *rc) | |
698 | { | |
699 | return rc->rc_startblock != NULLAGBLOCK; | |
700 | } | |
701 | ||
702 | /* | |
703 | * Try to merge with any extents on the boundaries of the adjustment range. | |
704 | */ | |
705 | STATIC int | |
706 | xfs_refcount_merge_extents( | |
707 | struct xfs_btree_cur *cur, | |
708 | xfs_agblock_t *agbno, | |
709 | xfs_extlen_t *aglen, | |
710 | enum xfs_refc_adjust_op adjust, | |
174edb0e | 711 | int flags, |
31727258 DW |
712 | bool *shape_changed) |
713 | { | |
714 | struct xfs_refcount_irec left = {0}, cleft = {0}; | |
715 | struct xfs_refcount_irec cright = {0}, right = {0}; | |
716 | int error; | |
717 | unsigned long long ulen; | |
718 | bool cequal; | |
719 | ||
720 | *shape_changed = false; | |
721 | /* | |
722 | * Find the extent just below agbno [left], just above agbno [cleft], | |
723 | * just below (agbno + aglen) [cright], and just above (agbno + aglen) | |
724 | * [right]. | |
725 | */ | |
726 | error = xfs_refcount_find_left_extents(cur, &left, &cleft, *agbno, | |
174edb0e | 727 | *aglen, flags); |
31727258 DW |
728 | if (error) |
729 | return error; | |
730 | error = xfs_refcount_find_right_extents(cur, &right, &cright, *agbno, | |
174edb0e | 731 | *aglen, flags); |
31727258 DW |
732 | if (error) |
733 | return error; | |
734 | ||
735 | /* No left or right extent to merge; exit. */ | |
736 | if (!xfs_refc_valid(&left) && !xfs_refc_valid(&right)) | |
737 | return 0; | |
738 | ||
739 | cequal = (cleft.rc_startblock == cright.rc_startblock) && | |
740 | (cleft.rc_blockcount == cright.rc_blockcount); | |
741 | ||
742 | /* Try to merge left, cleft, and right. cleft must == cright. */ | |
743 | ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount + | |
744 | right.rc_blockcount; | |
745 | if (xfs_refc_valid(&left) && xfs_refc_valid(&right) && | |
746 | xfs_refc_valid(&cleft) && xfs_refc_valid(&cright) && cequal && | |
747 | left.rc_refcount == cleft.rc_refcount + adjust && | |
748 | right.rc_refcount == cleft.rc_refcount + adjust && | |
749 | ulen < MAXREFCEXTLEN) { | |
750 | *shape_changed = true; | |
751 | return xfs_refcount_merge_center_extents(cur, &left, &cleft, | |
752 | &right, ulen, agbno, aglen); | |
753 | } | |
754 | ||
755 | /* Try to merge left and cleft. */ | |
756 | ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount; | |
757 | if (xfs_refc_valid(&left) && xfs_refc_valid(&cleft) && | |
758 | left.rc_refcount == cleft.rc_refcount + adjust && | |
759 | ulen < MAXREFCEXTLEN) { | |
760 | *shape_changed = true; | |
761 | error = xfs_refcount_merge_left_extent(cur, &left, &cleft, | |
762 | agbno, aglen); | |
763 | if (error) | |
764 | return error; | |
765 | ||
766 | /* | |
767 | * If we just merged left + cleft and cleft == cright, | |
768 | * we no longer have a cright to merge with right. We're done. | |
769 | */ | |
770 | if (cequal) | |
771 | return 0; | |
772 | } | |
773 | ||
774 | /* Try to merge cright and right. */ | |
775 | ulen = (unsigned long long)right.rc_blockcount + cright.rc_blockcount; | |
776 | if (xfs_refc_valid(&right) && xfs_refc_valid(&cright) && | |
777 | right.rc_refcount == cright.rc_refcount + adjust && | |
778 | ulen < MAXREFCEXTLEN) { | |
779 | *shape_changed = true; | |
780 | return xfs_refcount_merge_right_extent(cur, &right, &cright, | |
781 | agbno, aglen); | |
782 | } | |
783 | ||
784 | return error; | |
785 | } | |
786 | ||
787 | /* | |
31727258 DW |
788 | * XXX: This is a pretty hand-wavy estimate. The penalty for guessing |
789 | * true incorrectly is a shutdown FS; the penalty for guessing false | |
790 | * incorrectly is more transaction rolls than might be necessary. | |
791 | * Be conservative here. | |
792 | */ | |
793 | static bool | |
794 | xfs_refcount_still_have_space( | |
795 | struct xfs_btree_cur *cur) | |
796 | { | |
797 | unsigned long overhead; | |
798 | ||
799 | overhead = cur->bc_private.a.priv.refc.shape_changes * | |
800 | xfs_allocfree_log_count(cur->bc_mp, 1); | |
801 | overhead *= cur->bc_mp->m_sb.sb_blocksize; | |
802 | ||
803 | /* | |
804 | * Only allow 2 refcount extent updates per transaction if the | |
805 | * refcount continue update "error" has been injected. | |
806 | */ | |
807 | if (cur->bc_private.a.priv.refc.nr_ops > 2 && | |
808 | XFS_TEST_ERROR(false, cur->bc_mp, | |
9e24cfd0 | 809 | XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE)) |
31727258 DW |
810 | return false; |
811 | ||
812 | if (cur->bc_private.a.priv.refc.nr_ops == 0) | |
813 | return true; | |
814 | else if (overhead > cur->bc_tp->t_log_res) | |
815 | return false; | |
816 | return cur->bc_tp->t_log_res - overhead > | |
e1a4e37c | 817 | cur->bc_private.a.priv.refc.nr_ops * XFS_REFCOUNT_ITEM_OVERHEAD; |
31727258 DW |
818 | } |
819 | ||
820 | /* | |
821 | * Adjust the refcounts of middle extents. At this point we should have | |
822 | * split extents that crossed the adjustment range; merged with adjacent | |
823 | * extents; and updated agbno/aglen to reflect the merges. Therefore, | |
824 | * all we have to do is update the extents inside [agbno, agbno + aglen]. | |
825 | */ | |
826 | STATIC int | |
827 | xfs_refcount_adjust_extents( | |
828 | struct xfs_btree_cur *cur, | |
829 | xfs_agblock_t *agbno, | |
830 | xfs_extlen_t *aglen, | |
831 | enum xfs_refc_adjust_op adj, | |
832 | struct xfs_defer_ops *dfops, | |
833 | struct xfs_owner_info *oinfo) | |
834 | { | |
835 | struct xfs_refcount_irec ext, tmp; | |
836 | int error; | |
837 | int found_rec, found_tmp; | |
838 | xfs_fsblock_t fsbno; | |
839 | ||
840 | /* Merging did all the work already. */ | |
841 | if (*aglen == 0) | |
842 | return 0; | |
843 | ||
844 | error = xfs_refcount_lookup_ge(cur, *agbno, &found_rec); | |
845 | if (error) | |
846 | goto out_error; | |
847 | ||
848 | while (*aglen > 0 && xfs_refcount_still_have_space(cur)) { | |
849 | error = xfs_refcount_get_rec(cur, &ext, &found_rec); | |
850 | if (error) | |
851 | goto out_error; | |
852 | if (!found_rec) { | |
853 | ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks; | |
854 | ext.rc_blockcount = 0; | |
855 | ext.rc_refcount = 0; | |
856 | } | |
857 | ||
858 | /* | |
859 | * Deal with a hole in the refcount tree; if a file maps to | |
860 | * these blocks and there's no refcountbt record, pretend that | |
861 | * there is one with refcount == 1. | |
862 | */ | |
863 | if (ext.rc_startblock != *agbno) { | |
864 | tmp.rc_startblock = *agbno; | |
865 | tmp.rc_blockcount = min(*aglen, | |
866 | ext.rc_startblock - *agbno); | |
867 | tmp.rc_refcount = 1 + adj; | |
868 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
869 | cur->bc_private.a.agno, &tmp); | |
870 | ||
871 | /* | |
872 | * Either cover the hole (increment) or | |
873 | * delete the range (decrement). | |
874 | */ | |
875 | if (tmp.rc_refcount) { | |
876 | error = xfs_refcount_insert(cur, &tmp, | |
877 | &found_tmp); | |
878 | if (error) | |
879 | goto out_error; | |
880 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
881 | found_tmp == 1, out_error); | |
882 | cur->bc_private.a.priv.refc.nr_ops++; | |
883 | } else { | |
884 | fsbno = XFS_AGB_TO_FSB(cur->bc_mp, | |
885 | cur->bc_private.a.agno, | |
886 | tmp.rc_startblock); | |
887 | xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, | |
888 | tmp.rc_blockcount, oinfo); | |
889 | } | |
890 | ||
891 | (*agbno) += tmp.rc_blockcount; | |
892 | (*aglen) -= tmp.rc_blockcount; | |
893 | ||
894 | error = xfs_refcount_lookup_ge(cur, *agbno, | |
895 | &found_rec); | |
896 | if (error) | |
897 | goto out_error; | |
898 | } | |
899 | ||
900 | /* Stop if there's nothing left to modify */ | |
901 | if (*aglen == 0 || !xfs_refcount_still_have_space(cur)) | |
902 | break; | |
903 | ||
904 | /* | |
905 | * Adjust the reference count and either update the tree | |
906 | * (incr) or free the blocks (decr). | |
907 | */ | |
908 | if (ext.rc_refcount == MAXREFCOUNT) | |
909 | goto skip; | |
910 | ext.rc_refcount += adj; | |
911 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
912 | cur->bc_private.a.agno, &ext); | |
913 | if (ext.rc_refcount > 1) { | |
914 | error = xfs_refcount_update(cur, &ext); | |
915 | if (error) | |
916 | goto out_error; | |
917 | cur->bc_private.a.priv.refc.nr_ops++; | |
918 | } else if (ext.rc_refcount == 1) { | |
919 | error = xfs_refcount_delete(cur, &found_rec); | |
920 | if (error) | |
921 | goto out_error; | |
922 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
923 | found_rec == 1, out_error); | |
924 | cur->bc_private.a.priv.refc.nr_ops++; | |
925 | goto advloop; | |
926 | } else { | |
927 | fsbno = XFS_AGB_TO_FSB(cur->bc_mp, | |
928 | cur->bc_private.a.agno, | |
929 | ext.rc_startblock); | |
930 | xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, | |
931 | ext.rc_blockcount, oinfo); | |
932 | } | |
933 | ||
934 | skip: | |
935 | error = xfs_btree_increment(cur, 0, &found_rec); | |
936 | if (error) | |
937 | goto out_error; | |
938 | ||
939 | advloop: | |
940 | (*agbno) += ext.rc_blockcount; | |
941 | (*aglen) -= ext.rc_blockcount; | |
942 | } | |
943 | ||
944 | return error; | |
945 | out_error: | |
946 | trace_xfs_refcount_modify_extent_error(cur->bc_mp, | |
947 | cur->bc_private.a.agno, error, _RET_IP_); | |
948 | return error; | |
949 | } | |
950 | ||
951 | /* Adjust the reference count of a range of AG blocks. */ | |
952 | STATIC int | |
953 | xfs_refcount_adjust( | |
954 | struct xfs_btree_cur *cur, | |
955 | xfs_agblock_t agbno, | |
956 | xfs_extlen_t aglen, | |
957 | xfs_agblock_t *new_agbno, | |
958 | xfs_extlen_t *new_aglen, | |
959 | enum xfs_refc_adjust_op adj, | |
960 | struct xfs_defer_ops *dfops, | |
961 | struct xfs_owner_info *oinfo) | |
962 | { | |
963 | bool shape_changed; | |
964 | int shape_changes = 0; | |
965 | int error; | |
966 | ||
967 | *new_agbno = agbno; | |
968 | *new_aglen = aglen; | |
969 | if (adj == XFS_REFCOUNT_ADJUST_INCREASE) | |
970 | trace_xfs_refcount_increase(cur->bc_mp, cur->bc_private.a.agno, | |
971 | agbno, aglen); | |
972 | else | |
973 | trace_xfs_refcount_decrease(cur->bc_mp, cur->bc_private.a.agno, | |
974 | agbno, aglen); | |
975 | ||
976 | /* | |
977 | * Ensure that no rcextents cross the boundary of the adjustment range. | |
978 | */ | |
979 | error = xfs_refcount_split_extent(cur, agbno, &shape_changed); | |
980 | if (error) | |
981 | goto out_error; | |
982 | if (shape_changed) | |
983 | shape_changes++; | |
984 | ||
985 | error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); | |
986 | if (error) | |
987 | goto out_error; | |
988 | if (shape_changed) | |
989 | shape_changes++; | |
990 | ||
991 | /* | |
992 | * Try to merge with the left or right extents of the range. | |
993 | */ | |
994 | error = xfs_refcount_merge_extents(cur, new_agbno, new_aglen, adj, | |
174edb0e | 995 | XFS_FIND_RCEXT_SHARED, &shape_changed); |
31727258 DW |
996 | if (error) |
997 | goto out_error; | |
998 | if (shape_changed) | |
999 | shape_changes++; | |
1000 | if (shape_changes) | |
1001 | cur->bc_private.a.priv.refc.shape_changes++; | |
1002 | ||
1003 | /* Now that we've taken care of the ends, adjust the middle extents */ | |
1004 | error = xfs_refcount_adjust_extents(cur, new_agbno, new_aglen, | |
1005 | adj, dfops, oinfo); | |
1006 | if (error) | |
1007 | goto out_error; | |
1008 | ||
1009 | return 0; | |
1010 | ||
1011 | out_error: | |
1012 | trace_xfs_refcount_adjust_error(cur->bc_mp, cur->bc_private.a.agno, | |
1013 | error, _RET_IP_); | |
1014 | return error; | |
1015 | } | |
33ba6129 DW |
1016 | |
1017 | /* Clean up after calling xfs_refcount_finish_one. */ | |
1018 | void | |
1019 | xfs_refcount_finish_one_cleanup( | |
1020 | struct xfs_trans *tp, | |
1021 | struct xfs_btree_cur *rcur, | |
1022 | int error) | |
1023 | { | |
1024 | struct xfs_buf *agbp; | |
1025 | ||
1026 | if (rcur == NULL) | |
1027 | return; | |
1028 | agbp = rcur->bc_private.a.agbp; | |
1029 | xfs_btree_del_cursor(rcur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); | |
1030 | if (error) | |
1031 | xfs_trans_brelse(tp, agbp); | |
1032 | } | |
1033 | ||
1034 | /* | |
1035 | * Process one of the deferred refcount operations. We pass back the | |
1036 | * btree cursor to maintain our lock on the btree between calls. | |
1037 | * This saves time and eliminates a buffer deadlock between the | |
1038 | * superblock and the AGF because we'll always grab them in the same | |
1039 | * order. | |
1040 | */ | |
1041 | int | |
1042 | xfs_refcount_finish_one( | |
1043 | struct xfs_trans *tp, | |
1044 | struct xfs_defer_ops *dfops, | |
1045 | enum xfs_refcount_intent_type type, | |
1046 | xfs_fsblock_t startblock, | |
1047 | xfs_extlen_t blockcount, | |
1048 | xfs_fsblock_t *new_fsb, | |
1049 | xfs_extlen_t *new_len, | |
1050 | struct xfs_btree_cur **pcur) | |
1051 | { | |
1052 | struct xfs_mount *mp = tp->t_mountp; | |
1053 | struct xfs_btree_cur *rcur; | |
1054 | struct xfs_buf *agbp = NULL; | |
1055 | int error = 0; | |
1056 | xfs_agnumber_t agno; | |
1057 | xfs_agblock_t bno; | |
1058 | xfs_agblock_t new_agbno; | |
1059 | unsigned long nr_ops = 0; | |
1060 | int shape_changes = 0; | |
1061 | ||
1062 | agno = XFS_FSB_TO_AGNO(mp, startblock); | |
1063 | ASSERT(agno != NULLAGNUMBER); | |
1064 | bno = XFS_FSB_TO_AGBNO(mp, startblock); | |
1065 | ||
1066 | trace_xfs_refcount_deferred(mp, XFS_FSB_TO_AGNO(mp, startblock), | |
1067 | type, XFS_FSB_TO_AGBNO(mp, startblock), | |
1068 | blockcount); | |
1069 | ||
1070 | if (XFS_TEST_ERROR(false, mp, | |
9e24cfd0 | 1071 | XFS_ERRTAG_REFCOUNT_FINISH_ONE)) |
33ba6129 DW |
1072 | return -EIO; |
1073 | ||
1074 | /* | |
1075 | * If we haven't gotten a cursor or the cursor AG doesn't match | |
1076 | * the startblock, get one now. | |
1077 | */ | |
1078 | rcur = *pcur; | |
1079 | if (rcur != NULL && rcur->bc_private.a.agno != agno) { | |
1080 | nr_ops = rcur->bc_private.a.priv.refc.nr_ops; | |
1081 | shape_changes = rcur->bc_private.a.priv.refc.shape_changes; | |
1082 | xfs_refcount_finish_one_cleanup(tp, rcur, 0); | |
1083 | rcur = NULL; | |
1084 | *pcur = NULL; | |
1085 | } | |
1086 | if (rcur == NULL) { | |
1087 | error = xfs_alloc_read_agf(tp->t_mountp, tp, agno, | |
1088 | XFS_ALLOC_FLAG_FREEING, &agbp); | |
1089 | if (error) | |
1090 | return error; | |
1091 | if (!agbp) | |
1092 | return -EFSCORRUPTED; | |
1093 | ||
1094 | rcur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, dfops); | |
1095 | if (!rcur) { | |
1096 | error = -ENOMEM; | |
1097 | goto out_cur; | |
1098 | } | |
1099 | rcur->bc_private.a.priv.refc.nr_ops = nr_ops; | |
1100 | rcur->bc_private.a.priv.refc.shape_changes = shape_changes; | |
1101 | } | |
1102 | *pcur = rcur; | |
1103 | ||
1104 | switch (type) { | |
1105 | case XFS_REFCOUNT_INCREASE: | |
1106 | error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, | |
1107 | new_len, XFS_REFCOUNT_ADJUST_INCREASE, dfops, NULL); | |
1108 | *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); | |
1109 | break; | |
1110 | case XFS_REFCOUNT_DECREASE: | |
1111 | error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, | |
1112 | new_len, XFS_REFCOUNT_ADJUST_DECREASE, dfops, NULL); | |
1113 | *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); | |
1114 | break; | |
174edb0e DW |
1115 | case XFS_REFCOUNT_ALLOC_COW: |
1116 | *new_fsb = startblock + blockcount; | |
1117 | *new_len = 0; | |
1118 | error = __xfs_refcount_cow_alloc(rcur, bno, blockcount, dfops); | |
1119 | break; | |
1120 | case XFS_REFCOUNT_FREE_COW: | |
1121 | *new_fsb = startblock + blockcount; | |
1122 | *new_len = 0; | |
1123 | error = __xfs_refcount_cow_free(rcur, bno, blockcount, dfops); | |
1124 | break; | |
33ba6129 DW |
1125 | default: |
1126 | ASSERT(0); | |
1127 | error = -EFSCORRUPTED; | |
1128 | } | |
1129 | if (!error && *new_len > 0) | |
1130 | trace_xfs_refcount_finish_one_leftover(mp, agno, type, | |
1131 | bno, blockcount, new_agbno, *new_len); | |
1132 | return error; | |
1133 | ||
1134 | out_cur: | |
1135 | xfs_trans_brelse(tp, agbp); | |
1136 | ||
1137 | return error; | |
1138 | } | |
1139 | ||
1140 | /* | |
1141 | * Record a refcount intent for later processing. | |
1142 | */ | |
1143 | static int | |
1144 | __xfs_refcount_add( | |
1145 | struct xfs_mount *mp, | |
1146 | struct xfs_defer_ops *dfops, | |
1147 | enum xfs_refcount_intent_type type, | |
1148 | xfs_fsblock_t startblock, | |
1149 | xfs_extlen_t blockcount) | |
1150 | { | |
1151 | struct xfs_refcount_intent *ri; | |
1152 | ||
1153 | trace_xfs_refcount_defer(mp, XFS_FSB_TO_AGNO(mp, startblock), | |
1154 | type, XFS_FSB_TO_AGBNO(mp, startblock), | |
1155 | blockcount); | |
1156 | ||
1157 | ri = kmem_alloc(sizeof(struct xfs_refcount_intent), | |
1158 | KM_SLEEP | KM_NOFS); | |
1159 | INIT_LIST_HEAD(&ri->ri_list); | |
1160 | ri->ri_type = type; | |
1161 | ri->ri_startblock = startblock; | |
1162 | ri->ri_blockcount = blockcount; | |
1163 | ||
1164 | xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_REFCOUNT, &ri->ri_list); | |
1165 | return 0; | |
1166 | } | |
1167 | ||
1168 | /* | |
1169 | * Increase the reference count of the blocks backing a file's extent. | |
1170 | */ | |
1171 | int | |
1172 | xfs_refcount_increase_extent( | |
1173 | struct xfs_mount *mp, | |
1174 | struct xfs_defer_ops *dfops, | |
1175 | struct xfs_bmbt_irec *PREV) | |
1176 | { | |
1177 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1178 | return 0; | |
1179 | ||
1180 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_INCREASE, | |
1181 | PREV->br_startblock, PREV->br_blockcount); | |
1182 | } | |
1183 | ||
1184 | /* | |
1185 | * Decrease the reference count of the blocks backing a file's extent. | |
1186 | */ | |
1187 | int | |
1188 | xfs_refcount_decrease_extent( | |
1189 | struct xfs_mount *mp, | |
1190 | struct xfs_defer_ops *dfops, | |
1191 | struct xfs_bmbt_irec *PREV) | |
1192 | { | |
1193 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1194 | return 0; | |
1195 | ||
1196 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_DECREASE, | |
1197 | PREV->br_startblock, PREV->br_blockcount); | |
1198 | } | |
350a27a6 DW |
1199 | |
1200 | /* | |
1201 | * Given an AG extent, find the lowest-numbered run of shared blocks | |
1202 | * within that range and return the range in fbno/flen. If | |
1203 | * find_end_of_shared is set, return the longest contiguous extent of | |
1204 | * shared blocks; if not, just return the first extent we find. If no | |
1205 | * shared blocks are found, fbno and flen will be set to NULLAGBLOCK | |
1206 | * and 0, respectively. | |
1207 | */ | |
1208 | int | |
1209 | xfs_refcount_find_shared( | |
1210 | struct xfs_btree_cur *cur, | |
1211 | xfs_agblock_t agbno, | |
1212 | xfs_extlen_t aglen, | |
1213 | xfs_agblock_t *fbno, | |
1214 | xfs_extlen_t *flen, | |
1215 | bool find_end_of_shared) | |
1216 | { | |
1217 | struct xfs_refcount_irec tmp; | |
1218 | int i; | |
1219 | int have; | |
1220 | int error; | |
1221 | ||
1222 | trace_xfs_refcount_find_shared(cur->bc_mp, cur->bc_private.a.agno, | |
1223 | agbno, aglen); | |
1224 | ||
1225 | /* By default, skip the whole range */ | |
1226 | *fbno = NULLAGBLOCK; | |
1227 | *flen = 0; | |
1228 | ||
1229 | /* Try to find a refcount extent that crosses the start */ | |
1230 | error = xfs_refcount_lookup_le(cur, agbno, &have); | |
1231 | if (error) | |
1232 | goto out_error; | |
1233 | if (!have) { | |
1234 | /* No left extent, look at the next one */ | |
1235 | error = xfs_btree_increment(cur, 0, &have); | |
1236 | if (error) | |
1237 | goto out_error; | |
1238 | if (!have) | |
1239 | goto done; | |
1240 | } | |
1241 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1242 | if (error) | |
1243 | goto out_error; | |
1244 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1245 | ||
1246 | /* If the extent ends before the start, look at the next one */ | |
1247 | if (tmp.rc_startblock + tmp.rc_blockcount <= agbno) { | |
1248 | error = xfs_btree_increment(cur, 0, &have); | |
1249 | if (error) | |
1250 | goto out_error; | |
1251 | if (!have) | |
1252 | goto done; | |
1253 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1254 | if (error) | |
1255 | goto out_error; | |
1256 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1257 | } | |
1258 | ||
1259 | /* If the extent starts after the range we want, bail out */ | |
1260 | if (tmp.rc_startblock >= agbno + aglen) | |
1261 | goto done; | |
1262 | ||
1263 | /* We found the start of a shared extent! */ | |
1264 | if (tmp.rc_startblock < agbno) { | |
1265 | tmp.rc_blockcount -= (agbno - tmp.rc_startblock); | |
1266 | tmp.rc_startblock = agbno; | |
1267 | } | |
1268 | ||
1269 | *fbno = tmp.rc_startblock; | |
1270 | *flen = min(tmp.rc_blockcount, agbno + aglen - *fbno); | |
1271 | if (!find_end_of_shared) | |
1272 | goto done; | |
1273 | ||
1274 | /* Otherwise, find the end of this shared extent */ | |
1275 | while (*fbno + *flen < agbno + aglen) { | |
1276 | error = xfs_btree_increment(cur, 0, &have); | |
1277 | if (error) | |
1278 | goto out_error; | |
1279 | if (!have) | |
1280 | break; | |
1281 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1282 | if (error) | |
1283 | goto out_error; | |
1284 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1285 | if (tmp.rc_startblock >= agbno + aglen || | |
1286 | tmp.rc_startblock != *fbno + *flen) | |
1287 | break; | |
1288 | *flen = min(*flen + tmp.rc_blockcount, agbno + aglen - *fbno); | |
1289 | } | |
1290 | ||
1291 | done: | |
1292 | trace_xfs_refcount_find_shared_result(cur->bc_mp, | |
1293 | cur->bc_private.a.agno, *fbno, *flen); | |
1294 | ||
1295 | out_error: | |
1296 | if (error) | |
1297 | trace_xfs_refcount_find_shared_error(cur->bc_mp, | |
1298 | cur->bc_private.a.agno, error, _RET_IP_); | |
1299 | return error; | |
1300 | } | |
174edb0e DW |
1301 | |
1302 | /* | |
1303 | * Recovering CoW Blocks After a Crash | |
1304 | * | |
1305 | * Due to the way that the copy on write mechanism works, there's a window of | |
1306 | * opportunity in which we can lose track of allocated blocks during a crash. | |
1307 | * Because CoW uses delayed allocation in the in-core CoW fork, writeback | |
1308 | * causes blocks to be allocated and stored in the CoW fork. The blocks are | |
1309 | * no longer in the free space btree but are not otherwise recorded anywhere | |
1310 | * until the write completes and the blocks are mapped into the file. A crash | |
1311 | * in between allocation and remapping results in the replacement blocks being | |
1312 | * lost. This situation is exacerbated by the CoW extent size hint because | |
1313 | * allocations can hang around for long time. | |
1314 | * | |
1315 | * However, there is a place where we can record these allocations before they | |
1316 | * become mappings -- the reference count btree. The btree does not record | |
1317 | * extents with refcount == 1, so we can record allocations with a refcount of | |
1318 | * 1. Blocks being used for CoW writeout cannot be shared, so there should be | |
1319 | * no conflict with shared block records. These mappings should be created | |
1320 | * when we allocate blocks to the CoW fork and deleted when they're removed | |
1321 | * from the CoW fork. | |
1322 | * | |
1323 | * Minor nit: records for in-progress CoW allocations and records for shared | |
1324 | * extents must never be merged, to preserve the property that (except for CoW | |
1325 | * allocations) there are no refcount btree entries with refcount == 1. The | |
1326 | * only time this could potentially happen is when unsharing a block that's | |
1327 | * adjacent to CoW allocations, so we must be careful to avoid this. | |
1328 | * | |
1329 | * At mount time we recover lost CoW allocations by searching the refcount | |
1330 | * btree for these refcount == 1 mappings. These represent CoW allocations | |
1331 | * that were in progress at the time the filesystem went down, so we can free | |
1332 | * them to get the space back. | |
1333 | * | |
1334 | * This mechanism is superior to creating EFIs for unmapped CoW extents for | |
1335 | * several reasons -- first, EFIs pin the tail of the log and would have to be | |
1336 | * periodically relogged to avoid filling up the log. Second, CoW completions | |
1337 | * will have to file an EFD and create new EFIs for whatever remains in the | |
1338 | * CoW fork; this partially takes care of (1) but extent-size reservations | |
1339 | * will have to periodically relog even if there's no writeout in progress. | |
1340 | * This can happen if the CoW extent size hint is set, which you really want. | |
1341 | * Third, EFIs cannot currently be automatically relogged into newer | |
1342 | * transactions to advance the log tail. Fourth, stuffing the log full of | |
1343 | * EFIs places an upper bound on the number of CoW allocations that can be | |
1344 | * held filesystem-wide at any given time. Recording them in the refcount | |
1345 | * btree doesn't require us to maintain any state in memory and doesn't pin | |
1346 | * the log. | |
1347 | */ | |
1348 | /* | |
1349 | * Adjust the refcounts of CoW allocations. These allocations are "magic" | |
1350 | * in that they're not referenced anywhere else in the filesystem, so we | |
1351 | * stash them in the refcount btree with a refcount of 1 until either file | |
1352 | * remapping (or CoW cancellation) happens. | |
1353 | */ | |
1354 | STATIC int | |
1355 | xfs_refcount_adjust_cow_extents( | |
1356 | struct xfs_btree_cur *cur, | |
1357 | xfs_agblock_t agbno, | |
1358 | xfs_extlen_t aglen, | |
1359 | enum xfs_refc_adjust_op adj, | |
1360 | struct xfs_defer_ops *dfops, | |
1361 | struct xfs_owner_info *oinfo) | |
1362 | { | |
1363 | struct xfs_refcount_irec ext, tmp; | |
1364 | int error; | |
1365 | int found_rec, found_tmp; | |
1366 | ||
1367 | if (aglen == 0) | |
1368 | return 0; | |
1369 | ||
1370 | /* Find any overlapping refcount records */ | |
1371 | error = xfs_refcount_lookup_ge(cur, agbno, &found_rec); | |
1372 | if (error) | |
1373 | goto out_error; | |
1374 | error = xfs_refcount_get_rec(cur, &ext, &found_rec); | |
1375 | if (error) | |
1376 | goto out_error; | |
1377 | if (!found_rec) { | |
1378 | ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks + | |
1379 | XFS_REFC_COW_START; | |
1380 | ext.rc_blockcount = 0; | |
1381 | ext.rc_refcount = 0; | |
1382 | } | |
1383 | ||
1384 | switch (adj) { | |
1385 | case XFS_REFCOUNT_ADJUST_COW_ALLOC: | |
1386 | /* Adding a CoW reservation, there should be nothing here. */ | |
1387 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1388 | ext.rc_startblock >= agbno + aglen, out_error); | |
1389 | ||
1390 | tmp.rc_startblock = agbno; | |
1391 | tmp.rc_blockcount = aglen; | |
1392 | tmp.rc_refcount = 1; | |
1393 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
1394 | cur->bc_private.a.agno, &tmp); | |
1395 | ||
1396 | error = xfs_refcount_insert(cur, &tmp, | |
1397 | &found_tmp); | |
1398 | if (error) | |
1399 | goto out_error; | |
1400 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1401 | found_tmp == 1, out_error); | |
1402 | break; | |
1403 | case XFS_REFCOUNT_ADJUST_COW_FREE: | |
1404 | /* Removing a CoW reservation, there should be one extent. */ | |
1405 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1406 | ext.rc_startblock == agbno, out_error); | |
1407 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1408 | ext.rc_blockcount == aglen, out_error); | |
1409 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1410 | ext.rc_refcount == 1, out_error); | |
1411 | ||
1412 | ext.rc_refcount = 0; | |
1413 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
1414 | cur->bc_private.a.agno, &ext); | |
1415 | error = xfs_refcount_delete(cur, &found_rec); | |
1416 | if (error) | |
1417 | goto out_error; | |
1418 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1419 | found_rec == 1, out_error); | |
1420 | break; | |
1421 | default: | |
1422 | ASSERT(0); | |
1423 | } | |
1424 | ||
1425 | return error; | |
1426 | out_error: | |
1427 | trace_xfs_refcount_modify_extent_error(cur->bc_mp, | |
1428 | cur->bc_private.a.agno, error, _RET_IP_); | |
1429 | return error; | |
1430 | } | |
1431 | ||
1432 | /* | |
1433 | * Add or remove refcount btree entries for CoW reservations. | |
1434 | */ | |
1435 | STATIC int | |
1436 | xfs_refcount_adjust_cow( | |
1437 | struct xfs_btree_cur *cur, | |
1438 | xfs_agblock_t agbno, | |
1439 | xfs_extlen_t aglen, | |
1440 | enum xfs_refc_adjust_op adj, | |
1441 | struct xfs_defer_ops *dfops) | |
1442 | { | |
1443 | bool shape_changed; | |
1444 | int error; | |
1445 | ||
1446 | agbno += XFS_REFC_COW_START; | |
1447 | ||
1448 | /* | |
1449 | * Ensure that no rcextents cross the boundary of the adjustment range. | |
1450 | */ | |
1451 | error = xfs_refcount_split_extent(cur, agbno, &shape_changed); | |
1452 | if (error) | |
1453 | goto out_error; | |
1454 | ||
1455 | error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); | |
1456 | if (error) | |
1457 | goto out_error; | |
1458 | ||
1459 | /* | |
1460 | * Try to merge with the left or right extents of the range. | |
1461 | */ | |
1462 | error = xfs_refcount_merge_extents(cur, &agbno, &aglen, adj, | |
1463 | XFS_FIND_RCEXT_COW, &shape_changed); | |
1464 | if (error) | |
1465 | goto out_error; | |
1466 | ||
1467 | /* Now that we've taken care of the ends, adjust the middle extents */ | |
1468 | error = xfs_refcount_adjust_cow_extents(cur, agbno, aglen, adj, | |
1469 | dfops, NULL); | |
1470 | if (error) | |
1471 | goto out_error; | |
1472 | ||
1473 | return 0; | |
1474 | ||
1475 | out_error: | |
1476 | trace_xfs_refcount_adjust_cow_error(cur->bc_mp, cur->bc_private.a.agno, | |
1477 | error, _RET_IP_); | |
1478 | return error; | |
1479 | } | |
1480 | ||
1481 | /* | |
1482 | * Record a CoW allocation in the refcount btree. | |
1483 | */ | |
1484 | STATIC int | |
1485 | __xfs_refcount_cow_alloc( | |
1486 | struct xfs_btree_cur *rcur, | |
1487 | xfs_agblock_t agbno, | |
1488 | xfs_extlen_t aglen, | |
1489 | struct xfs_defer_ops *dfops) | |
1490 | { | |
174edb0e DW |
1491 | trace_xfs_refcount_cow_increase(rcur->bc_mp, rcur->bc_private.a.agno, |
1492 | agbno, aglen); | |
1493 | ||
1494 | /* Add refcount btree reservation */ | |
0525e952 | 1495 | return xfs_refcount_adjust_cow(rcur, agbno, aglen, |
174edb0e | 1496 | XFS_REFCOUNT_ADJUST_COW_ALLOC, dfops); |
174edb0e DW |
1497 | } |
1498 | ||
1499 | /* | |
1500 | * Remove a CoW allocation from the refcount btree. | |
1501 | */ | |
1502 | STATIC int | |
1503 | __xfs_refcount_cow_free( | |
1504 | struct xfs_btree_cur *rcur, | |
1505 | xfs_agblock_t agbno, | |
1506 | xfs_extlen_t aglen, | |
1507 | struct xfs_defer_ops *dfops) | |
1508 | { | |
174edb0e DW |
1509 | trace_xfs_refcount_cow_decrease(rcur->bc_mp, rcur->bc_private.a.agno, |
1510 | agbno, aglen); | |
1511 | ||
1512 | /* Remove refcount btree reservation */ | |
0525e952 | 1513 | return xfs_refcount_adjust_cow(rcur, agbno, aglen, |
174edb0e | 1514 | XFS_REFCOUNT_ADJUST_COW_FREE, dfops); |
174edb0e DW |
1515 | } |
1516 | ||
1517 | /* Record a CoW staging extent in the refcount btree. */ | |
1518 | int | |
1519 | xfs_refcount_alloc_cow_extent( | |
1520 | struct xfs_mount *mp, | |
1521 | struct xfs_defer_ops *dfops, | |
1522 | xfs_fsblock_t fsb, | |
1523 | xfs_extlen_t len) | |
1524 | { | |
0525e952 DW |
1525 | int error; |
1526 | ||
174edb0e DW |
1527 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) |
1528 | return 0; | |
1529 | ||
0525e952 | 1530 | error = __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_ALLOC_COW, |
174edb0e | 1531 | fsb, len); |
0525e952 DW |
1532 | if (error) |
1533 | return error; | |
1534 | ||
1535 | /* Add rmap entry */ | |
1536 | return xfs_rmap_alloc_extent(mp, dfops, XFS_FSB_TO_AGNO(mp, fsb), | |
1537 | XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW); | |
174edb0e DW |
1538 | } |
1539 | ||
1540 | /* Forget a CoW staging event in the refcount btree. */ | |
1541 | int | |
1542 | xfs_refcount_free_cow_extent( | |
1543 | struct xfs_mount *mp, | |
1544 | struct xfs_defer_ops *dfops, | |
1545 | xfs_fsblock_t fsb, | |
1546 | xfs_extlen_t len) | |
1547 | { | |
0525e952 DW |
1548 | int error; |
1549 | ||
174edb0e DW |
1550 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) |
1551 | return 0; | |
1552 | ||
0525e952 DW |
1553 | /* Remove rmap entry */ |
1554 | error = xfs_rmap_free_extent(mp, dfops, XFS_FSB_TO_AGNO(mp, fsb), | |
1555 | XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW); | |
1556 | if (error) | |
1557 | return error; | |
1558 | ||
174edb0e DW |
1559 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_FREE_COW, |
1560 | fsb, len); | |
1561 | } | |
1562 | ||
1563 | struct xfs_refcount_recovery { | |
1564 | struct list_head rr_list; | |
1565 | struct xfs_refcount_irec rr_rrec; | |
1566 | }; | |
1567 | ||
1568 | /* Stuff an extent on the recovery list. */ | |
1569 | STATIC int | |
1570 | xfs_refcount_recover_extent( | |
1571 | struct xfs_btree_cur *cur, | |
1572 | union xfs_btree_rec *rec, | |
1573 | void *priv) | |
1574 | { | |
1575 | struct list_head *debris = priv; | |
1576 | struct xfs_refcount_recovery *rr; | |
1577 | ||
1578 | if (be32_to_cpu(rec->refc.rc_refcount) != 1) | |
1579 | return -EFSCORRUPTED; | |
1580 | ||
1581 | rr = kmem_alloc(sizeof(struct xfs_refcount_recovery), KM_SLEEP); | |
1582 | xfs_refcount_btrec_to_irec(rec, &rr->rr_rrec); | |
1583 | list_add_tail(&rr->rr_list, debris); | |
1584 | ||
1585 | return 0; | |
1586 | } | |
1587 | ||
1588 | /* Find and remove leftover CoW reservations. */ | |
1589 | int | |
1590 | xfs_refcount_recover_cow_leftovers( | |
1591 | struct xfs_mount *mp, | |
1592 | xfs_agnumber_t agno) | |
1593 | { | |
1594 | struct xfs_trans *tp; | |
1595 | struct xfs_btree_cur *cur; | |
1596 | struct xfs_buf *agbp; | |
1597 | struct xfs_refcount_recovery *rr, *n; | |
1598 | struct list_head debris; | |
1599 | union xfs_btree_irec low; | |
1600 | union xfs_btree_irec high; | |
1601 | struct xfs_defer_ops dfops; | |
1602 | xfs_fsblock_t fsb; | |
1603 | xfs_agblock_t agbno; | |
1604 | int error; | |
1605 | ||
1606 | if (mp->m_sb.sb_agblocks >= XFS_REFC_COW_START) | |
1607 | return -EOPNOTSUPP; | |
1608 | ||
3ecb3ac7 DW |
1609 | INIT_LIST_HEAD(&debris); |
1610 | ||
1611 | /* | |
1612 | * In this first part, we use an empty transaction to gather up | |
1613 | * all the leftover CoW extents so that we can subsequently | |
1614 | * delete them. The empty transaction is used to avoid | |
1615 | * a buffer lock deadlock if there happens to be a loop in the | |
1616 | * refcountbt because we're allowed to re-grab a buffer that is | |
1617 | * already attached to our transaction. When we're done | |
1618 | * recording the CoW debris we cancel the (empty) transaction | |
1619 | * and everything goes away cleanly. | |
1620 | */ | |
1621 | error = xfs_trans_alloc_empty(mp, &tp); | |
174edb0e DW |
1622 | if (error) |
1623 | return error; | |
3ecb3ac7 DW |
1624 | |
1625 | error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp); | |
1626 | if (error) | |
1627 | goto out_trans; | |
10479e2d DW |
1628 | if (!agbp) { |
1629 | error = -ENOMEM; | |
1630 | goto out_trans; | |
1631 | } | |
3ecb3ac7 | 1632 | cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, NULL); |
174edb0e DW |
1633 | |
1634 | /* Find all the leftover CoW staging extents. */ | |
174edb0e DW |
1635 | memset(&low, 0, sizeof(low)); |
1636 | memset(&high, 0, sizeof(high)); | |
1637 | low.rc.rc_startblock = XFS_REFC_COW_START; | |
1638 | high.rc.rc_startblock = -1U; | |
1639 | error = xfs_btree_query_range(cur, &low, &high, | |
1640 | xfs_refcount_recover_extent, &debris); | |
1641 | if (error) | |
6f97077f | 1642 | goto out_cursor; |
174edb0e | 1643 | xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); |
3ecb3ac7 DW |
1644 | xfs_trans_brelse(tp, agbp); |
1645 | xfs_trans_cancel(tp); | |
174edb0e DW |
1646 | |
1647 | /* Now iterate the list to free the leftovers */ | |
3ecb3ac7 | 1648 | list_for_each_entry_safe(rr, n, &debris, rr_list) { |
174edb0e DW |
1649 | /* Set up transaction. */ |
1650 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); | |
1651 | if (error) | |
1652 | goto out_free; | |
1653 | ||
1654 | trace_xfs_refcount_recover_extent(mp, agno, &rr->rr_rrec); | |
1655 | ||
1656 | /* Free the orphan record */ | |
1657 | xfs_defer_init(&dfops, &fsb); | |
1658 | agbno = rr->rr_rrec.rc_startblock - XFS_REFC_COW_START; | |
1659 | fsb = XFS_AGB_TO_FSB(mp, agno, agbno); | |
1660 | error = xfs_refcount_free_cow_extent(mp, &dfops, fsb, | |
1661 | rr->rr_rrec.rc_blockcount); | |
1662 | if (error) | |
1663 | goto out_defer; | |
1664 | ||
1665 | /* Free the block. */ | |
1666 | xfs_bmap_add_free(mp, &dfops, fsb, | |
1667 | rr->rr_rrec.rc_blockcount, NULL); | |
1668 | ||
8ad7c629 | 1669 | error = xfs_defer_finish(&tp, &dfops); |
174edb0e DW |
1670 | if (error) |
1671 | goto out_defer; | |
1672 | ||
1673 | error = xfs_trans_commit(tp); | |
1674 | if (error) | |
6f97077f | 1675 | goto out_free; |
3ecb3ac7 DW |
1676 | |
1677 | list_del(&rr->rr_list); | |
1678 | kmem_free(rr); | |
174edb0e | 1679 | } |
174edb0e | 1680 | |
3ecb3ac7 DW |
1681 | return error; |
1682 | out_defer: | |
1683 | xfs_defer_cancel(&dfops); | |
1684 | out_trans: | |
1685 | xfs_trans_cancel(tp); | |
174edb0e DW |
1686 | out_free: |
1687 | /* Free the leftover list */ | |
1688 | list_for_each_entry_safe(rr, n, &debris, rr_list) { | |
1689 | list_del(&rr->rr_list); | |
1690 | kmem_free(rr); | |
1691 | } | |
174edb0e DW |
1692 | return error; |
1693 | ||
6f97077f | 1694 | out_cursor: |
174edb0e | 1695 | xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); |
3ecb3ac7 DW |
1696 | xfs_trans_brelse(tp, agbp); |
1697 | goto out_trans; | |
174edb0e | 1698 | } |