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37b3b4d6 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
bc859611 DW |
2 | /* |
3 | * Copyright (C) 2016 Oracle. All Rights Reserved. | |
bc859611 | 4 | * Author: Darrick J. Wong <darrick.wong@oracle.com> |
bc859611 DW |
5 | */ |
6 | #include "libxfs_priv.h" | |
7 | #include "xfs_fs.h" | |
8 | #include "xfs_shared.h" | |
9 | #include "xfs_format.h" | |
10 | #include "xfs_log_format.h" | |
11 | #include "xfs_trans_resv.h" | |
12 | #include "xfs_sb.h" | |
13 | #include "xfs_mount.h" | |
14 | #include "xfs_defer.h" | |
15 | #include "xfs_btree.h" | |
16 | #include "xfs_bmap.h" | |
17 | #include "xfs_refcount_btree.h" | |
18 | #include "xfs_alloc.h" | |
56d3fc2b | 19 | #include "xfs_errortag.h" |
bc859611 DW |
20 | #include "xfs_trace.h" |
21 | #include "xfs_cksum.h" | |
22 | #include "xfs_trans.h" | |
23 | #include "xfs_bit.h" | |
24 | #include "xfs_refcount.h" | |
10e65503 | 25 | #include "xfs_rmap.h" |
bc859611 | 26 | |
56ef8c33 DW |
27 | /* Allowable refcount adjustment amounts. */ |
28 | enum xfs_refc_adjust_op { | |
29 | XFS_REFCOUNT_ADJUST_INCREASE = 1, | |
30 | XFS_REFCOUNT_ADJUST_DECREASE = -1, | |
10e65503 DW |
31 | XFS_REFCOUNT_ADJUST_COW_ALLOC = 0, |
32 | XFS_REFCOUNT_ADJUST_COW_FREE = -1, | |
56ef8c33 DW |
33 | }; |
34 | ||
10e65503 DW |
35 | STATIC int __xfs_refcount_cow_alloc(struct xfs_btree_cur *rcur, |
36 | xfs_agblock_t agbno, xfs_extlen_t aglen, | |
37 | struct xfs_defer_ops *dfops); | |
38 | STATIC int __xfs_refcount_cow_free(struct xfs_btree_cur *rcur, | |
39 | xfs_agblock_t agbno, xfs_extlen_t aglen, | |
40 | struct xfs_defer_ops *dfops); | |
41 | ||
bc859611 DW |
42 | /* |
43 | * Look up the first record less than or equal to [bno, len] in the btree | |
44 | * given by cur. | |
45 | */ | |
46 | int | |
47 | xfs_refcount_lookup_le( | |
48 | struct xfs_btree_cur *cur, | |
49 | xfs_agblock_t bno, | |
50 | int *stat) | |
51 | { | |
52 | trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_private.a.agno, bno, | |
53 | XFS_LOOKUP_LE); | |
54 | cur->bc_rec.rc.rc_startblock = bno; | |
55 | cur->bc_rec.rc.rc_blockcount = 0; | |
56 | return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat); | |
57 | } | |
58 | ||
59 | /* | |
60 | * Look up the first record greater than or equal to [bno, len] in the btree | |
61 | * given by cur. | |
62 | */ | |
63 | int | |
64 | xfs_refcount_lookup_ge( | |
65 | struct xfs_btree_cur *cur, | |
66 | xfs_agblock_t bno, | |
67 | int *stat) | |
68 | { | |
69 | trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_private.a.agno, bno, | |
70 | XFS_LOOKUP_GE); | |
71 | cur->bc_rec.rc.rc_startblock = bno; | |
72 | cur->bc_rec.rc.rc_blockcount = 0; | |
73 | return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat); | |
74 | } | |
75 | ||
43e73fb0 DW |
76 | /* |
77 | * Look up the first record equal to [bno, len] in the btree | |
78 | * given by cur. | |
79 | */ | |
80 | int | |
81 | xfs_refcount_lookup_eq( | |
82 | struct xfs_btree_cur *cur, | |
83 | xfs_agblock_t bno, | |
84 | int *stat) | |
85 | { | |
86 | trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_private.a.agno, bno, | |
87 | XFS_LOOKUP_LE); | |
88 | cur->bc_rec.rc.rc_startblock = bno; | |
89 | cur->bc_rec.rc.rc_blockcount = 0; | |
90 | return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat); | |
91 | } | |
92 | ||
10e65503 | 93 | /* Convert on-disk record to in-core format. */ |
aa465192 | 94 | void |
10e65503 DW |
95 | xfs_refcount_btrec_to_irec( |
96 | union xfs_btree_rec *rec, | |
97 | struct xfs_refcount_irec *irec) | |
98 | { | |
99 | irec->rc_startblock = be32_to_cpu(rec->refc.rc_startblock); | |
100 | irec->rc_blockcount = be32_to_cpu(rec->refc.rc_blockcount); | |
101 | irec->rc_refcount = be32_to_cpu(rec->refc.rc_refcount); | |
102 | } | |
103 | ||
bc859611 DW |
104 | /* |
105 | * Get the data from the pointed-to record. | |
106 | */ | |
107 | int | |
108 | xfs_refcount_get_rec( | |
109 | struct xfs_btree_cur *cur, | |
110 | struct xfs_refcount_irec *irec, | |
111 | int *stat) | |
112 | { | |
ec291989 DC |
113 | struct xfs_mount *mp = cur->bc_mp; |
114 | xfs_agnumber_t agno = cur->bc_private.a.agno; | |
10e65503 DW |
115 | union xfs_btree_rec *rec; |
116 | int error; | |
ec291989 | 117 | xfs_agblock_t realstart; |
bc859611 DW |
118 | |
119 | error = xfs_btree_get_rec(cur, &rec, stat); | |
ec291989 DC |
120 | if (error || !*stat) |
121 | return error; | |
122 | ||
123 | xfs_refcount_btrec_to_irec(rec, irec); | |
124 | ||
125 | agno = cur->bc_private.a.agno; | |
126 | if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN) | |
127 | goto out_bad_rec; | |
128 | ||
129 | /* handle special COW-staging state */ | |
130 | realstart = irec->rc_startblock; | |
131 | if (realstart & XFS_REFC_COW_START) { | |
132 | if (irec->rc_refcount != 1) | |
133 | goto out_bad_rec; | |
134 | realstart &= ~XFS_REFC_COW_START; | |
135 | } else if (irec->rc_refcount < 2) { | |
136 | goto out_bad_rec; | |
bc859611 | 137 | } |
ec291989 DC |
138 | |
139 | /* check for valid extent range, including overflow */ | |
140 | if (!xfs_verify_agbno(mp, agno, realstart)) | |
141 | goto out_bad_rec; | |
142 | if (realstart > realstart + irec->rc_blockcount) | |
143 | goto out_bad_rec; | |
144 | if (!xfs_verify_agbno(mp, agno, realstart + irec->rc_blockcount - 1)) | |
145 | goto out_bad_rec; | |
146 | ||
147 | if (irec->rc_refcount == 0 || irec->rc_refcount > MAXREFCOUNT) | |
148 | goto out_bad_rec; | |
149 | ||
150 | trace_xfs_refcount_get(cur->bc_mp, cur->bc_private.a.agno, irec); | |
151 | return 0; | |
152 | ||
153 | out_bad_rec: | |
154 | xfs_warn(mp, | |
155 | "Refcount BTree record corruption in AG %d detected!", agno); | |
156 | xfs_warn(mp, | |
157 | "Start block 0x%x, block count 0x%x, references 0x%x", | |
158 | irec->rc_startblock, irec->rc_blockcount, irec->rc_refcount); | |
159 | return -EFSCORRUPTED; | |
bc859611 DW |
160 | } |
161 | ||
162 | /* | |
163 | * Update the record referred to by cur to the value given | |
164 | * by [bno, len, refcount]. | |
165 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
166 | */ | |
167 | STATIC int | |
168 | xfs_refcount_update( | |
169 | struct xfs_btree_cur *cur, | |
170 | struct xfs_refcount_irec *irec) | |
171 | { | |
172 | union xfs_btree_rec rec; | |
173 | int error; | |
174 | ||
175 | trace_xfs_refcount_update(cur->bc_mp, cur->bc_private.a.agno, irec); | |
176 | rec.refc.rc_startblock = cpu_to_be32(irec->rc_startblock); | |
177 | rec.refc.rc_blockcount = cpu_to_be32(irec->rc_blockcount); | |
178 | rec.refc.rc_refcount = cpu_to_be32(irec->rc_refcount); | |
179 | error = xfs_btree_update(cur, &rec); | |
180 | if (error) | |
181 | trace_xfs_refcount_update_error(cur->bc_mp, | |
182 | cur->bc_private.a.agno, error, _RET_IP_); | |
183 | return error; | |
184 | } | |
185 | ||
186 | /* | |
187 | * Insert the record referred to by cur to the value given | |
188 | * by [bno, len, refcount]. | |
189 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
190 | */ | |
aa465192 | 191 | int |
bc859611 DW |
192 | xfs_refcount_insert( |
193 | struct xfs_btree_cur *cur, | |
194 | struct xfs_refcount_irec *irec, | |
195 | int *i) | |
196 | { | |
197 | int error; | |
198 | ||
199 | trace_xfs_refcount_insert(cur->bc_mp, cur->bc_private.a.agno, irec); | |
200 | cur->bc_rec.rc.rc_startblock = irec->rc_startblock; | |
201 | cur->bc_rec.rc.rc_blockcount = irec->rc_blockcount; | |
202 | cur->bc_rec.rc.rc_refcount = irec->rc_refcount; | |
203 | error = xfs_btree_insert(cur, i); | |
02afaae0 DC |
204 | if (error) |
205 | goto out_error; | |
bc859611 | 206 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, *i == 1, out_error); |
02afaae0 | 207 | |
bc859611 DW |
208 | out_error: |
209 | if (error) | |
210 | trace_xfs_refcount_insert_error(cur->bc_mp, | |
211 | cur->bc_private.a.agno, error, _RET_IP_); | |
212 | return error; | |
213 | } | |
214 | ||
215 | /* | |
216 | * Remove the record referred to by cur, then set the pointer to the spot | |
217 | * where the record could be re-inserted, in case we want to increment or | |
218 | * decrement the cursor. | |
219 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
220 | */ | |
221 | STATIC int | |
222 | xfs_refcount_delete( | |
223 | struct xfs_btree_cur *cur, | |
224 | int *i) | |
225 | { | |
226 | struct xfs_refcount_irec irec; | |
227 | int found_rec; | |
228 | int error; | |
229 | ||
230 | error = xfs_refcount_get_rec(cur, &irec, &found_rec); | |
231 | if (error) | |
232 | goto out_error; | |
233 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
234 | trace_xfs_refcount_delete(cur->bc_mp, cur->bc_private.a.agno, &irec); | |
235 | error = xfs_btree_delete(cur, i); | |
236 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, *i == 1, out_error); | |
237 | if (error) | |
238 | goto out_error; | |
239 | error = xfs_refcount_lookup_ge(cur, irec.rc_startblock, &found_rec); | |
240 | out_error: | |
241 | if (error) | |
242 | trace_xfs_refcount_delete_error(cur->bc_mp, | |
243 | cur->bc_private.a.agno, error, _RET_IP_); | |
244 | return error; | |
245 | } | |
56ef8c33 DW |
246 | |
247 | /* | |
248 | * Adjusting the Reference Count | |
249 | * | |
250 | * As stated elsewhere, the reference count btree (refcbt) stores | |
251 | * >1 reference counts for extents of physical blocks. In this | |
252 | * operation, we're either raising or lowering the reference count of | |
253 | * some subrange stored in the tree: | |
254 | * | |
255 | * <------ adjustment range ------> | |
256 | * ----+ +---+-----+ +--+--------+--------- | |
257 | * 2 | | 3 | 4 | |17| 55 | 10 | |
258 | * ----+ +---+-----+ +--+--------+--------- | |
259 | * X axis is physical blocks number; | |
260 | * reference counts are the numbers inside the rectangles | |
261 | * | |
262 | * The first thing we need to do is to ensure that there are no | |
263 | * refcount extents crossing either boundary of the range to be | |
264 | * adjusted. For any extent that does cross a boundary, split it into | |
265 | * two extents so that we can increment the refcount of one of the | |
266 | * pieces later: | |
267 | * | |
268 | * <------ adjustment range ------> | |
269 | * ----+ +---+-----+ +--+--------+----+---- | |
270 | * 2 | | 3 | 2 | |17| 55 | 10 | 10 | |
271 | * ----+ +---+-----+ +--+--------+----+---- | |
272 | * | |
273 | * For this next step, let's assume that all the physical blocks in | |
274 | * the adjustment range are mapped to a file and are therefore in use | |
275 | * at least once. Therefore, we can infer that any gap in the | |
276 | * refcount tree within the adjustment range represents a physical | |
277 | * extent with refcount == 1: | |
278 | * | |
279 | * <------ adjustment range ------> | |
280 | * ----+---+---+-----+-+--+--------+----+---- | |
281 | * 2 |"1"| 3 | 2 |1|17| 55 | 10 | 10 | |
282 | * ----+---+---+-----+-+--+--------+----+---- | |
283 | * ^ | |
284 | * | |
285 | * For each extent that falls within the interval range, figure out | |
286 | * which extent is to the left or the right of that extent. Now we | |
287 | * have a left, current, and right extent. If the new reference count | |
288 | * of the center extent enables us to merge left, center, and right | |
289 | * into one record covering all three, do so. If the center extent is | |
290 | * at the left end of the range, abuts the left extent, and its new | |
291 | * reference count matches the left extent's record, then merge them. | |
292 | * If the center extent is at the right end of the range, abuts the | |
293 | * right extent, and the reference counts match, merge those. In the | |
294 | * example, we can left merge (assuming an increment operation): | |
295 | * | |
296 | * <------ adjustment range ------> | |
297 | * --------+---+-----+-+--+--------+----+---- | |
298 | * 2 | 3 | 2 |1|17| 55 | 10 | 10 | |
299 | * --------+---+-----+-+--+--------+----+---- | |
300 | * ^ | |
301 | * | |
302 | * For all other extents within the range, adjust the reference count | |
303 | * or delete it if the refcount falls below 2. If we were | |
304 | * incrementing, the end result looks like this: | |
305 | * | |
306 | * <------ adjustment range ------> | |
307 | * --------+---+-----+-+--+--------+----+---- | |
308 | * 2 | 4 | 3 |2|18| 56 | 11 | 10 | |
309 | * --------+---+-----+-+--+--------+----+---- | |
310 | * | |
311 | * The result of a decrement operation looks as such: | |
312 | * | |
313 | * <------ adjustment range ------> | |
314 | * ----+ +---+ +--+--------+----+---- | |
315 | * 2 | | 2 | |16| 54 | 9 | 10 | |
316 | * ----+ +---+ +--+--------+----+---- | |
317 | * DDDD 111111DD | |
318 | * | |
319 | * The blocks marked "D" are freed; the blocks marked "1" are only | |
320 | * referenced once and therefore the record is removed from the | |
321 | * refcount btree. | |
322 | */ | |
323 | ||
324 | /* Next block after this extent. */ | |
325 | static inline xfs_agblock_t | |
326 | xfs_refc_next( | |
327 | struct xfs_refcount_irec *rc) | |
328 | { | |
329 | return rc->rc_startblock + rc->rc_blockcount; | |
330 | } | |
331 | ||
332 | /* | |
333 | * Split a refcount extent that crosses agbno. | |
334 | */ | |
335 | STATIC int | |
336 | xfs_refcount_split_extent( | |
337 | struct xfs_btree_cur *cur, | |
338 | xfs_agblock_t agbno, | |
339 | bool *shape_changed) | |
340 | { | |
341 | struct xfs_refcount_irec rcext, tmp; | |
342 | int found_rec; | |
343 | int error; | |
344 | ||
345 | *shape_changed = false; | |
346 | error = xfs_refcount_lookup_le(cur, agbno, &found_rec); | |
347 | if (error) | |
348 | goto out_error; | |
349 | if (!found_rec) | |
350 | return 0; | |
351 | ||
352 | error = xfs_refcount_get_rec(cur, &rcext, &found_rec); | |
353 | if (error) | |
354 | goto out_error; | |
355 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
356 | if (rcext.rc_startblock == agbno || xfs_refc_next(&rcext) <= agbno) | |
357 | return 0; | |
358 | ||
359 | *shape_changed = true; | |
360 | trace_xfs_refcount_split_extent(cur->bc_mp, cur->bc_private.a.agno, | |
361 | &rcext, agbno); | |
362 | ||
363 | /* Establish the right extent. */ | |
364 | tmp = rcext; | |
365 | tmp.rc_startblock = agbno; | |
366 | tmp.rc_blockcount -= (agbno - rcext.rc_startblock); | |
367 | error = xfs_refcount_update(cur, &tmp); | |
368 | if (error) | |
369 | goto out_error; | |
370 | ||
371 | /* Insert the left extent. */ | |
372 | tmp = rcext; | |
373 | tmp.rc_blockcount = agbno - rcext.rc_startblock; | |
374 | error = xfs_refcount_insert(cur, &tmp, &found_rec); | |
375 | if (error) | |
376 | goto out_error; | |
377 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
378 | return error; | |
379 | ||
380 | out_error: | |
381 | trace_xfs_refcount_split_extent_error(cur->bc_mp, | |
382 | cur->bc_private.a.agno, error, _RET_IP_); | |
383 | return error; | |
384 | } | |
385 | ||
386 | /* | |
387 | * Merge the left, center, and right extents. | |
388 | */ | |
389 | STATIC int | |
390 | xfs_refcount_merge_center_extents( | |
391 | struct xfs_btree_cur *cur, | |
392 | struct xfs_refcount_irec *left, | |
393 | struct xfs_refcount_irec *center, | |
394 | struct xfs_refcount_irec *right, | |
395 | unsigned long long extlen, | |
56ef8c33 DW |
396 | xfs_extlen_t *aglen) |
397 | { | |
398 | int error; | |
399 | int found_rec; | |
400 | ||
401 | trace_xfs_refcount_merge_center_extents(cur->bc_mp, | |
402 | cur->bc_private.a.agno, left, center, right); | |
403 | ||
404 | /* | |
405 | * Make sure the center and right extents are not in the btree. | |
406 | * If the center extent was synthesized, the first delete call | |
407 | * removes the right extent and we skip the second deletion. | |
408 | * If center and right were in the btree, then the first delete | |
409 | * call removes the center and the second one removes the right | |
410 | * extent. | |
411 | */ | |
412 | error = xfs_refcount_lookup_ge(cur, center->rc_startblock, | |
413 | &found_rec); | |
414 | if (error) | |
415 | goto out_error; | |
416 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
417 | ||
418 | error = xfs_refcount_delete(cur, &found_rec); | |
419 | if (error) | |
420 | goto out_error; | |
421 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
422 | ||
423 | if (center->rc_refcount > 1) { | |
424 | error = xfs_refcount_delete(cur, &found_rec); | |
425 | if (error) | |
426 | goto out_error; | |
427 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
428 | out_error); | |
429 | } | |
430 | ||
431 | /* Enlarge the left extent. */ | |
432 | error = xfs_refcount_lookup_le(cur, left->rc_startblock, | |
433 | &found_rec); | |
434 | if (error) | |
435 | goto out_error; | |
436 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
437 | ||
438 | left->rc_blockcount = extlen; | |
439 | error = xfs_refcount_update(cur, left); | |
440 | if (error) | |
441 | goto out_error; | |
442 | ||
443 | *aglen = 0; | |
444 | return error; | |
445 | ||
446 | out_error: | |
447 | trace_xfs_refcount_merge_center_extents_error(cur->bc_mp, | |
448 | cur->bc_private.a.agno, error, _RET_IP_); | |
449 | return error; | |
450 | } | |
451 | ||
452 | /* | |
453 | * Merge with the left extent. | |
454 | */ | |
455 | STATIC int | |
456 | xfs_refcount_merge_left_extent( | |
457 | struct xfs_btree_cur *cur, | |
458 | struct xfs_refcount_irec *left, | |
459 | struct xfs_refcount_irec *cleft, | |
460 | xfs_agblock_t *agbno, | |
461 | xfs_extlen_t *aglen) | |
462 | { | |
463 | int error; | |
464 | int found_rec; | |
465 | ||
466 | trace_xfs_refcount_merge_left_extent(cur->bc_mp, | |
467 | cur->bc_private.a.agno, left, cleft); | |
468 | ||
469 | /* If the extent at agbno (cleft) wasn't synthesized, remove it. */ | |
470 | if (cleft->rc_refcount > 1) { | |
471 | error = xfs_refcount_lookup_le(cur, cleft->rc_startblock, | |
472 | &found_rec); | |
473 | if (error) | |
474 | goto out_error; | |
475 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
476 | out_error); | |
477 | ||
478 | error = xfs_refcount_delete(cur, &found_rec); | |
479 | if (error) | |
480 | goto out_error; | |
481 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
482 | out_error); | |
483 | } | |
484 | ||
485 | /* Enlarge the left extent. */ | |
486 | error = xfs_refcount_lookup_le(cur, left->rc_startblock, | |
487 | &found_rec); | |
488 | if (error) | |
489 | goto out_error; | |
490 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
491 | ||
492 | left->rc_blockcount += cleft->rc_blockcount; | |
493 | error = xfs_refcount_update(cur, left); | |
494 | if (error) | |
495 | goto out_error; | |
496 | ||
497 | *agbno += cleft->rc_blockcount; | |
498 | *aglen -= cleft->rc_blockcount; | |
499 | return error; | |
500 | ||
501 | out_error: | |
502 | trace_xfs_refcount_merge_left_extent_error(cur->bc_mp, | |
503 | cur->bc_private.a.agno, error, _RET_IP_); | |
504 | return error; | |
505 | } | |
506 | ||
507 | /* | |
508 | * Merge with the right extent. | |
509 | */ | |
510 | STATIC int | |
511 | xfs_refcount_merge_right_extent( | |
512 | struct xfs_btree_cur *cur, | |
513 | struct xfs_refcount_irec *right, | |
514 | struct xfs_refcount_irec *cright, | |
56ef8c33 DW |
515 | xfs_extlen_t *aglen) |
516 | { | |
517 | int error; | |
518 | int found_rec; | |
519 | ||
520 | trace_xfs_refcount_merge_right_extent(cur->bc_mp, | |
521 | cur->bc_private.a.agno, cright, right); | |
522 | ||
523 | /* | |
524 | * If the extent ending at agbno+aglen (cright) wasn't synthesized, | |
525 | * remove it. | |
526 | */ | |
527 | if (cright->rc_refcount > 1) { | |
528 | error = xfs_refcount_lookup_le(cur, cright->rc_startblock, | |
529 | &found_rec); | |
530 | if (error) | |
531 | goto out_error; | |
532 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
533 | out_error); | |
534 | ||
535 | error = xfs_refcount_delete(cur, &found_rec); | |
536 | if (error) | |
537 | goto out_error; | |
538 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
539 | out_error); | |
540 | } | |
541 | ||
542 | /* Enlarge the right extent. */ | |
543 | error = xfs_refcount_lookup_le(cur, right->rc_startblock, | |
544 | &found_rec); | |
545 | if (error) | |
546 | goto out_error; | |
547 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
548 | ||
549 | right->rc_startblock -= cright->rc_blockcount; | |
550 | right->rc_blockcount += cright->rc_blockcount; | |
551 | error = xfs_refcount_update(cur, right); | |
552 | if (error) | |
553 | goto out_error; | |
554 | ||
555 | *aglen -= cright->rc_blockcount; | |
556 | return error; | |
557 | ||
558 | out_error: | |
559 | trace_xfs_refcount_merge_right_extent_error(cur->bc_mp, | |
560 | cur->bc_private.a.agno, error, _RET_IP_); | |
561 | return error; | |
562 | } | |
563 | ||
10e65503 DW |
564 | #define XFS_FIND_RCEXT_SHARED 1 |
565 | #define XFS_FIND_RCEXT_COW 2 | |
56ef8c33 DW |
566 | /* |
567 | * Find the left extent and the one after it (cleft). This function assumes | |
568 | * that we've already split any extent crossing agbno. | |
569 | */ | |
570 | STATIC int | |
571 | xfs_refcount_find_left_extents( | |
572 | struct xfs_btree_cur *cur, | |
573 | struct xfs_refcount_irec *left, | |
574 | struct xfs_refcount_irec *cleft, | |
575 | xfs_agblock_t agbno, | |
10e65503 DW |
576 | xfs_extlen_t aglen, |
577 | int flags) | |
56ef8c33 DW |
578 | { |
579 | struct xfs_refcount_irec tmp; | |
580 | int error; | |
581 | int found_rec; | |
582 | ||
583 | left->rc_startblock = cleft->rc_startblock = NULLAGBLOCK; | |
584 | error = xfs_refcount_lookup_le(cur, agbno - 1, &found_rec); | |
585 | if (error) | |
586 | goto out_error; | |
587 | if (!found_rec) | |
588 | return 0; | |
589 | ||
590 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
591 | if (error) | |
592 | goto out_error; | |
593 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
594 | ||
595 | if (xfs_refc_next(&tmp) != agbno) | |
596 | return 0; | |
10e65503 DW |
597 | if ((flags & XFS_FIND_RCEXT_SHARED) && tmp.rc_refcount < 2) |
598 | return 0; | |
599 | if ((flags & XFS_FIND_RCEXT_COW) && tmp.rc_refcount > 1) | |
600 | return 0; | |
56ef8c33 DW |
601 | /* We have a left extent; retrieve (or invent) the next right one */ |
602 | *left = tmp; | |
603 | ||
604 | error = xfs_btree_increment(cur, 0, &found_rec); | |
605 | if (error) | |
606 | goto out_error; | |
607 | if (found_rec) { | |
608 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
609 | if (error) | |
610 | goto out_error; | |
611 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
612 | out_error); | |
613 | ||
614 | /* if tmp starts at the end of our range, just use that */ | |
615 | if (tmp.rc_startblock == agbno) | |
616 | *cleft = tmp; | |
617 | else { | |
618 | /* | |
619 | * There's a gap in the refcntbt at the start of the | |
620 | * range we're interested in (refcount == 1) so | |
621 | * synthesize the implied extent and pass it back. | |
622 | * We assume here that the agbno/aglen range was | |
623 | * passed in from a data fork extent mapping and | |
624 | * therefore is allocated to exactly one owner. | |
625 | */ | |
626 | cleft->rc_startblock = agbno; | |
627 | cleft->rc_blockcount = min(aglen, | |
628 | tmp.rc_startblock - agbno); | |
629 | cleft->rc_refcount = 1; | |
630 | } | |
631 | } else { | |
632 | /* | |
633 | * No extents, so pretend that there's one covering the whole | |
634 | * range. | |
635 | */ | |
636 | cleft->rc_startblock = agbno; | |
637 | cleft->rc_blockcount = aglen; | |
638 | cleft->rc_refcount = 1; | |
639 | } | |
640 | trace_xfs_refcount_find_left_extent(cur->bc_mp, cur->bc_private.a.agno, | |
641 | left, cleft, agbno); | |
642 | return error; | |
643 | ||
644 | out_error: | |
645 | trace_xfs_refcount_find_left_extent_error(cur->bc_mp, | |
646 | cur->bc_private.a.agno, error, _RET_IP_); | |
647 | return error; | |
648 | } | |
649 | ||
650 | /* | |
651 | * Find the right extent and the one before it (cright). This function | |
652 | * assumes that we've already split any extents crossing agbno + aglen. | |
653 | */ | |
654 | STATIC int | |
655 | xfs_refcount_find_right_extents( | |
656 | struct xfs_btree_cur *cur, | |
657 | struct xfs_refcount_irec *right, | |
658 | struct xfs_refcount_irec *cright, | |
659 | xfs_agblock_t agbno, | |
10e65503 DW |
660 | xfs_extlen_t aglen, |
661 | int flags) | |
56ef8c33 DW |
662 | { |
663 | struct xfs_refcount_irec tmp; | |
664 | int error; | |
665 | int found_rec; | |
666 | ||
667 | right->rc_startblock = cright->rc_startblock = NULLAGBLOCK; | |
668 | error = xfs_refcount_lookup_ge(cur, agbno + aglen, &found_rec); | |
669 | if (error) | |
670 | goto out_error; | |
671 | if (!found_rec) | |
672 | return 0; | |
673 | ||
674 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
675 | if (error) | |
676 | goto out_error; | |
677 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
678 | ||
679 | if (tmp.rc_startblock != agbno + aglen) | |
680 | return 0; | |
10e65503 DW |
681 | if ((flags & XFS_FIND_RCEXT_SHARED) && tmp.rc_refcount < 2) |
682 | return 0; | |
683 | if ((flags & XFS_FIND_RCEXT_COW) && tmp.rc_refcount > 1) | |
684 | return 0; | |
56ef8c33 DW |
685 | /* We have a right extent; retrieve (or invent) the next left one */ |
686 | *right = tmp; | |
687 | ||
688 | error = xfs_btree_decrement(cur, 0, &found_rec); | |
689 | if (error) | |
690 | goto out_error; | |
691 | if (found_rec) { | |
692 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
693 | if (error) | |
694 | goto out_error; | |
695 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
696 | out_error); | |
697 | ||
698 | /* if tmp ends at the end of our range, just use that */ | |
699 | if (xfs_refc_next(&tmp) == agbno + aglen) | |
700 | *cright = tmp; | |
701 | else { | |
702 | /* | |
703 | * There's a gap in the refcntbt at the end of the | |
704 | * range we're interested in (refcount == 1) so | |
705 | * create the implied extent and pass it back. | |
706 | * We assume here that the agbno/aglen range was | |
707 | * passed in from a data fork extent mapping and | |
708 | * therefore is allocated to exactly one owner. | |
709 | */ | |
710 | cright->rc_startblock = max(agbno, xfs_refc_next(&tmp)); | |
711 | cright->rc_blockcount = right->rc_startblock - | |
712 | cright->rc_startblock; | |
713 | cright->rc_refcount = 1; | |
714 | } | |
715 | } else { | |
716 | /* | |
717 | * No extents, so pretend that there's one covering the whole | |
718 | * range. | |
719 | */ | |
720 | cright->rc_startblock = agbno; | |
721 | cright->rc_blockcount = aglen; | |
722 | cright->rc_refcount = 1; | |
723 | } | |
724 | trace_xfs_refcount_find_right_extent(cur->bc_mp, cur->bc_private.a.agno, | |
725 | cright, right, agbno + aglen); | |
726 | return error; | |
727 | ||
728 | out_error: | |
729 | trace_xfs_refcount_find_right_extent_error(cur->bc_mp, | |
730 | cur->bc_private.a.agno, error, _RET_IP_); | |
731 | return error; | |
732 | } | |
733 | ||
734 | /* Is this extent valid? */ | |
735 | static inline bool | |
736 | xfs_refc_valid( | |
737 | struct xfs_refcount_irec *rc) | |
738 | { | |
739 | return rc->rc_startblock != NULLAGBLOCK; | |
740 | } | |
741 | ||
742 | /* | |
743 | * Try to merge with any extents on the boundaries of the adjustment range. | |
744 | */ | |
745 | STATIC int | |
746 | xfs_refcount_merge_extents( | |
747 | struct xfs_btree_cur *cur, | |
748 | xfs_agblock_t *agbno, | |
749 | xfs_extlen_t *aglen, | |
750 | enum xfs_refc_adjust_op adjust, | |
10e65503 | 751 | int flags, |
56ef8c33 DW |
752 | bool *shape_changed) |
753 | { | |
754 | struct xfs_refcount_irec left = {0}, cleft = {0}; | |
755 | struct xfs_refcount_irec cright = {0}, right = {0}; | |
756 | int error; | |
757 | unsigned long long ulen; | |
758 | bool cequal; | |
759 | ||
760 | *shape_changed = false; | |
761 | /* | |
762 | * Find the extent just below agbno [left], just above agbno [cleft], | |
763 | * just below (agbno + aglen) [cright], and just above (agbno + aglen) | |
764 | * [right]. | |
765 | */ | |
766 | error = xfs_refcount_find_left_extents(cur, &left, &cleft, *agbno, | |
10e65503 | 767 | *aglen, flags); |
56ef8c33 DW |
768 | if (error) |
769 | return error; | |
770 | error = xfs_refcount_find_right_extents(cur, &right, &cright, *agbno, | |
10e65503 | 771 | *aglen, flags); |
56ef8c33 DW |
772 | if (error) |
773 | return error; | |
774 | ||
775 | /* No left or right extent to merge; exit. */ | |
776 | if (!xfs_refc_valid(&left) && !xfs_refc_valid(&right)) | |
777 | return 0; | |
778 | ||
779 | cequal = (cleft.rc_startblock == cright.rc_startblock) && | |
780 | (cleft.rc_blockcount == cright.rc_blockcount); | |
781 | ||
782 | /* Try to merge left, cleft, and right. cleft must == cright. */ | |
783 | ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount + | |
784 | right.rc_blockcount; | |
785 | if (xfs_refc_valid(&left) && xfs_refc_valid(&right) && | |
786 | xfs_refc_valid(&cleft) && xfs_refc_valid(&cright) && cequal && | |
787 | left.rc_refcount == cleft.rc_refcount + adjust && | |
788 | right.rc_refcount == cleft.rc_refcount + adjust && | |
789 | ulen < MAXREFCEXTLEN) { | |
790 | *shape_changed = true; | |
791 | return xfs_refcount_merge_center_extents(cur, &left, &cleft, | |
1421de38 | 792 | &right, ulen, aglen); |
56ef8c33 DW |
793 | } |
794 | ||
795 | /* Try to merge left and cleft. */ | |
796 | ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount; | |
797 | if (xfs_refc_valid(&left) && xfs_refc_valid(&cleft) && | |
798 | left.rc_refcount == cleft.rc_refcount + adjust && | |
799 | ulen < MAXREFCEXTLEN) { | |
800 | *shape_changed = true; | |
801 | error = xfs_refcount_merge_left_extent(cur, &left, &cleft, | |
802 | agbno, aglen); | |
803 | if (error) | |
804 | return error; | |
805 | ||
806 | /* | |
807 | * If we just merged left + cleft and cleft == cright, | |
808 | * we no longer have a cright to merge with right. We're done. | |
809 | */ | |
810 | if (cequal) | |
811 | return 0; | |
812 | } | |
813 | ||
814 | /* Try to merge cright and right. */ | |
815 | ulen = (unsigned long long)right.rc_blockcount + cright.rc_blockcount; | |
816 | if (xfs_refc_valid(&right) && xfs_refc_valid(&cright) && | |
817 | right.rc_refcount == cright.rc_refcount + adjust && | |
818 | ulen < MAXREFCEXTLEN) { | |
819 | *shape_changed = true; | |
820 | return xfs_refcount_merge_right_extent(cur, &right, &cright, | |
1421de38 | 821 | aglen); |
56ef8c33 DW |
822 | } |
823 | ||
824 | return error; | |
825 | } | |
826 | ||
827 | /* | |
56ef8c33 DW |
828 | * XXX: This is a pretty hand-wavy estimate. The penalty for guessing |
829 | * true incorrectly is a shutdown FS; the penalty for guessing false | |
830 | * incorrectly is more transaction rolls than might be necessary. | |
831 | * Be conservative here. | |
832 | */ | |
833 | static bool | |
834 | xfs_refcount_still_have_space( | |
835 | struct xfs_btree_cur *cur) | |
836 | { | |
837 | unsigned long overhead; | |
838 | ||
839 | overhead = cur->bc_private.a.priv.refc.shape_changes * | |
840 | xfs_allocfree_log_count(cur->bc_mp, 1); | |
841 | overhead *= cur->bc_mp->m_sb.sb_blocksize; | |
842 | ||
843 | /* | |
844 | * Only allow 2 refcount extent updates per transaction if the | |
845 | * refcount continue update "error" has been injected. | |
846 | */ | |
847 | if (cur->bc_private.a.priv.refc.nr_ops > 2 && | |
848 | XFS_TEST_ERROR(false, cur->bc_mp, | |
e2a190dd | 849 | XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE)) |
56ef8c33 DW |
850 | return false; |
851 | ||
852 | if (cur->bc_private.a.priv.refc.nr_ops == 0) | |
853 | return true; | |
854 | else if (overhead > cur->bc_tp->t_log_res) | |
855 | return false; | |
856 | return cur->bc_tp->t_log_res - overhead > | |
594956fa | 857 | cur->bc_private.a.priv.refc.nr_ops * XFS_REFCOUNT_ITEM_OVERHEAD; |
56ef8c33 DW |
858 | } |
859 | ||
860 | /* | |
861 | * Adjust the refcounts of middle extents. At this point we should have | |
862 | * split extents that crossed the adjustment range; merged with adjacent | |
863 | * extents; and updated agbno/aglen to reflect the merges. Therefore, | |
864 | * all we have to do is update the extents inside [agbno, agbno + aglen]. | |
865 | */ | |
866 | STATIC int | |
867 | xfs_refcount_adjust_extents( | |
868 | struct xfs_btree_cur *cur, | |
869 | xfs_agblock_t *agbno, | |
870 | xfs_extlen_t *aglen, | |
871 | enum xfs_refc_adjust_op adj, | |
872 | struct xfs_defer_ops *dfops, | |
873 | struct xfs_owner_info *oinfo) | |
874 | { | |
875 | struct xfs_refcount_irec ext, tmp; | |
876 | int error; | |
877 | int found_rec, found_tmp; | |
878 | xfs_fsblock_t fsbno; | |
879 | ||
880 | /* Merging did all the work already. */ | |
881 | if (*aglen == 0) | |
882 | return 0; | |
883 | ||
884 | error = xfs_refcount_lookup_ge(cur, *agbno, &found_rec); | |
885 | if (error) | |
886 | goto out_error; | |
887 | ||
888 | while (*aglen > 0 && xfs_refcount_still_have_space(cur)) { | |
889 | error = xfs_refcount_get_rec(cur, &ext, &found_rec); | |
890 | if (error) | |
891 | goto out_error; | |
892 | if (!found_rec) { | |
893 | ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks; | |
894 | ext.rc_blockcount = 0; | |
895 | ext.rc_refcount = 0; | |
896 | } | |
897 | ||
898 | /* | |
899 | * Deal with a hole in the refcount tree; if a file maps to | |
900 | * these blocks and there's no refcountbt record, pretend that | |
901 | * there is one with refcount == 1. | |
902 | */ | |
903 | if (ext.rc_startblock != *agbno) { | |
904 | tmp.rc_startblock = *agbno; | |
905 | tmp.rc_blockcount = min(*aglen, | |
906 | ext.rc_startblock - *agbno); | |
907 | tmp.rc_refcount = 1 + adj; | |
908 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
909 | cur->bc_private.a.agno, &tmp); | |
910 | ||
911 | /* | |
912 | * Either cover the hole (increment) or | |
913 | * delete the range (decrement). | |
914 | */ | |
915 | if (tmp.rc_refcount) { | |
916 | error = xfs_refcount_insert(cur, &tmp, | |
917 | &found_tmp); | |
918 | if (error) | |
919 | goto out_error; | |
920 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
921 | found_tmp == 1, out_error); | |
922 | cur->bc_private.a.priv.refc.nr_ops++; | |
923 | } else { | |
924 | fsbno = XFS_AGB_TO_FSB(cur->bc_mp, | |
925 | cur->bc_private.a.agno, | |
926 | tmp.rc_startblock); | |
927 | xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, | |
928 | tmp.rc_blockcount, oinfo); | |
929 | } | |
930 | ||
931 | (*agbno) += tmp.rc_blockcount; | |
932 | (*aglen) -= tmp.rc_blockcount; | |
933 | ||
934 | error = xfs_refcount_lookup_ge(cur, *agbno, | |
935 | &found_rec); | |
936 | if (error) | |
937 | goto out_error; | |
938 | } | |
939 | ||
940 | /* Stop if there's nothing left to modify */ | |
941 | if (*aglen == 0 || !xfs_refcount_still_have_space(cur)) | |
942 | break; | |
943 | ||
944 | /* | |
945 | * Adjust the reference count and either update the tree | |
946 | * (incr) or free the blocks (decr). | |
947 | */ | |
948 | if (ext.rc_refcount == MAXREFCOUNT) | |
949 | goto skip; | |
950 | ext.rc_refcount += adj; | |
951 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
952 | cur->bc_private.a.agno, &ext); | |
953 | if (ext.rc_refcount > 1) { | |
954 | error = xfs_refcount_update(cur, &ext); | |
955 | if (error) | |
956 | goto out_error; | |
957 | cur->bc_private.a.priv.refc.nr_ops++; | |
958 | } else if (ext.rc_refcount == 1) { | |
959 | error = xfs_refcount_delete(cur, &found_rec); | |
960 | if (error) | |
961 | goto out_error; | |
962 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
963 | found_rec == 1, out_error); | |
964 | cur->bc_private.a.priv.refc.nr_ops++; | |
965 | goto advloop; | |
966 | } else { | |
967 | fsbno = XFS_AGB_TO_FSB(cur->bc_mp, | |
968 | cur->bc_private.a.agno, | |
969 | ext.rc_startblock); | |
970 | xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, | |
971 | ext.rc_blockcount, oinfo); | |
972 | } | |
973 | ||
974 | skip: | |
975 | error = xfs_btree_increment(cur, 0, &found_rec); | |
976 | if (error) | |
977 | goto out_error; | |
978 | ||
979 | advloop: | |
980 | (*agbno) += ext.rc_blockcount; | |
981 | (*aglen) -= ext.rc_blockcount; | |
982 | } | |
983 | ||
984 | return error; | |
985 | out_error: | |
986 | trace_xfs_refcount_modify_extent_error(cur->bc_mp, | |
987 | cur->bc_private.a.agno, error, _RET_IP_); | |
988 | return error; | |
989 | } | |
990 | ||
991 | /* Adjust the reference count of a range of AG blocks. */ | |
992 | STATIC int | |
993 | xfs_refcount_adjust( | |
994 | struct xfs_btree_cur *cur, | |
995 | xfs_agblock_t agbno, | |
996 | xfs_extlen_t aglen, | |
997 | xfs_agblock_t *new_agbno, | |
998 | xfs_extlen_t *new_aglen, | |
999 | enum xfs_refc_adjust_op adj, | |
1000 | struct xfs_defer_ops *dfops, | |
1001 | struct xfs_owner_info *oinfo) | |
1002 | { | |
1003 | bool shape_changed; | |
1004 | int shape_changes = 0; | |
1005 | int error; | |
1006 | ||
1007 | *new_agbno = agbno; | |
1008 | *new_aglen = aglen; | |
1009 | if (adj == XFS_REFCOUNT_ADJUST_INCREASE) | |
1010 | trace_xfs_refcount_increase(cur->bc_mp, cur->bc_private.a.agno, | |
1011 | agbno, aglen); | |
1012 | else | |
1013 | trace_xfs_refcount_decrease(cur->bc_mp, cur->bc_private.a.agno, | |
1014 | agbno, aglen); | |
1015 | ||
1016 | /* | |
1017 | * Ensure that no rcextents cross the boundary of the adjustment range. | |
1018 | */ | |
1019 | error = xfs_refcount_split_extent(cur, agbno, &shape_changed); | |
1020 | if (error) | |
1021 | goto out_error; | |
1022 | if (shape_changed) | |
1023 | shape_changes++; | |
1024 | ||
1025 | error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); | |
1026 | if (error) | |
1027 | goto out_error; | |
1028 | if (shape_changed) | |
1029 | shape_changes++; | |
1030 | ||
1031 | /* | |
1032 | * Try to merge with the left or right extents of the range. | |
1033 | */ | |
1034 | error = xfs_refcount_merge_extents(cur, new_agbno, new_aglen, adj, | |
10e65503 | 1035 | XFS_FIND_RCEXT_SHARED, &shape_changed); |
56ef8c33 DW |
1036 | if (error) |
1037 | goto out_error; | |
1038 | if (shape_changed) | |
1039 | shape_changes++; | |
1040 | if (shape_changes) | |
1041 | cur->bc_private.a.priv.refc.shape_changes++; | |
1042 | ||
1043 | /* Now that we've taken care of the ends, adjust the middle extents */ | |
1044 | error = xfs_refcount_adjust_extents(cur, new_agbno, new_aglen, | |
1045 | adj, dfops, oinfo); | |
1046 | if (error) | |
1047 | goto out_error; | |
1048 | ||
1049 | return 0; | |
1050 | ||
1051 | out_error: | |
1052 | trace_xfs_refcount_adjust_error(cur->bc_mp, cur->bc_private.a.agno, | |
1053 | error, _RET_IP_); | |
1054 | return error; | |
1055 | } | |
23a15a6c DW |
1056 | |
1057 | /* Clean up after calling xfs_refcount_finish_one. */ | |
1058 | void | |
1059 | xfs_refcount_finish_one_cleanup( | |
1060 | struct xfs_trans *tp, | |
1061 | struct xfs_btree_cur *rcur, | |
1062 | int error) | |
1063 | { | |
1064 | struct xfs_buf *agbp; | |
1065 | ||
1066 | if (rcur == NULL) | |
1067 | return; | |
1068 | agbp = rcur->bc_private.a.agbp; | |
1069 | xfs_btree_del_cursor(rcur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); | |
1070 | if (error) | |
1071 | xfs_trans_brelse(tp, agbp); | |
1072 | } | |
1073 | ||
1074 | /* | |
1075 | * Process one of the deferred refcount operations. We pass back the | |
1076 | * btree cursor to maintain our lock on the btree between calls. | |
1077 | * This saves time and eliminates a buffer deadlock between the | |
1078 | * superblock and the AGF because we'll always grab them in the same | |
1079 | * order. | |
1080 | */ | |
1081 | int | |
1082 | xfs_refcount_finish_one( | |
1083 | struct xfs_trans *tp, | |
1084 | struct xfs_defer_ops *dfops, | |
1085 | enum xfs_refcount_intent_type type, | |
1086 | xfs_fsblock_t startblock, | |
1087 | xfs_extlen_t blockcount, | |
1088 | xfs_fsblock_t *new_fsb, | |
1089 | xfs_extlen_t *new_len, | |
1090 | struct xfs_btree_cur **pcur) | |
1091 | { | |
1092 | struct xfs_mount *mp = tp->t_mountp; | |
1093 | struct xfs_btree_cur *rcur; | |
1094 | struct xfs_buf *agbp = NULL; | |
1095 | int error = 0; | |
1096 | xfs_agnumber_t agno; | |
1097 | xfs_agblock_t bno; | |
1098 | xfs_agblock_t new_agbno; | |
1099 | unsigned long nr_ops = 0; | |
1100 | int shape_changes = 0; | |
1101 | ||
1102 | agno = XFS_FSB_TO_AGNO(mp, startblock); | |
1103 | ASSERT(agno != NULLAGNUMBER); | |
1104 | bno = XFS_FSB_TO_AGBNO(mp, startblock); | |
1105 | ||
1106 | trace_xfs_refcount_deferred(mp, XFS_FSB_TO_AGNO(mp, startblock), | |
1107 | type, XFS_FSB_TO_AGBNO(mp, startblock), | |
1108 | blockcount); | |
1109 | ||
1110 | if (XFS_TEST_ERROR(false, mp, | |
e2a190dd | 1111 | XFS_ERRTAG_REFCOUNT_FINISH_ONE)) |
23a15a6c DW |
1112 | return -EIO; |
1113 | ||
1114 | /* | |
1115 | * If we haven't gotten a cursor or the cursor AG doesn't match | |
1116 | * the startblock, get one now. | |
1117 | */ | |
1118 | rcur = *pcur; | |
1119 | if (rcur != NULL && rcur->bc_private.a.agno != agno) { | |
1120 | nr_ops = rcur->bc_private.a.priv.refc.nr_ops; | |
1121 | shape_changes = rcur->bc_private.a.priv.refc.shape_changes; | |
1122 | xfs_refcount_finish_one_cleanup(tp, rcur, 0); | |
1123 | rcur = NULL; | |
1124 | *pcur = NULL; | |
1125 | } | |
1126 | if (rcur == NULL) { | |
1127 | error = xfs_alloc_read_agf(tp->t_mountp, tp, agno, | |
1128 | XFS_ALLOC_FLAG_FREEING, &agbp); | |
1129 | if (error) | |
1130 | return error; | |
1131 | if (!agbp) | |
1132 | return -EFSCORRUPTED; | |
1133 | ||
5ff5ced0 | 1134 | rcur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno); |
23a15a6c DW |
1135 | if (!rcur) { |
1136 | error = -ENOMEM; | |
1137 | goto out_cur; | |
1138 | } | |
1139 | rcur->bc_private.a.priv.refc.nr_ops = nr_ops; | |
1140 | rcur->bc_private.a.priv.refc.shape_changes = shape_changes; | |
1141 | } | |
1142 | *pcur = rcur; | |
1143 | ||
1144 | switch (type) { | |
1145 | case XFS_REFCOUNT_INCREASE: | |
1146 | error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, | |
1147 | new_len, XFS_REFCOUNT_ADJUST_INCREASE, dfops, NULL); | |
1148 | *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); | |
1149 | break; | |
1150 | case XFS_REFCOUNT_DECREASE: | |
1151 | error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, | |
1152 | new_len, XFS_REFCOUNT_ADJUST_DECREASE, dfops, NULL); | |
1153 | *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); | |
1154 | break; | |
10e65503 DW |
1155 | case XFS_REFCOUNT_ALLOC_COW: |
1156 | *new_fsb = startblock + blockcount; | |
1157 | *new_len = 0; | |
1158 | error = __xfs_refcount_cow_alloc(rcur, bno, blockcount, dfops); | |
1159 | break; | |
1160 | case XFS_REFCOUNT_FREE_COW: | |
1161 | *new_fsb = startblock + blockcount; | |
1162 | *new_len = 0; | |
1163 | error = __xfs_refcount_cow_free(rcur, bno, blockcount, dfops); | |
1164 | break; | |
23a15a6c DW |
1165 | default: |
1166 | ASSERT(0); | |
1167 | error = -EFSCORRUPTED; | |
1168 | } | |
1169 | if (!error && *new_len > 0) | |
1170 | trace_xfs_refcount_finish_one_leftover(mp, agno, type, | |
1171 | bno, blockcount, new_agbno, *new_len); | |
1172 | return error; | |
1173 | ||
1174 | out_cur: | |
1175 | xfs_trans_brelse(tp, agbp); | |
1176 | ||
1177 | return error; | |
1178 | } | |
1179 | ||
1180 | /* | |
1181 | * Record a refcount intent for later processing. | |
1182 | */ | |
1183 | static int | |
1184 | __xfs_refcount_add( | |
1185 | struct xfs_mount *mp, | |
1186 | struct xfs_defer_ops *dfops, | |
1187 | enum xfs_refcount_intent_type type, | |
1188 | xfs_fsblock_t startblock, | |
1189 | xfs_extlen_t blockcount) | |
1190 | { | |
1191 | struct xfs_refcount_intent *ri; | |
1192 | ||
1193 | trace_xfs_refcount_defer(mp, XFS_FSB_TO_AGNO(mp, startblock), | |
1194 | type, XFS_FSB_TO_AGBNO(mp, startblock), | |
1195 | blockcount); | |
1196 | ||
1197 | ri = kmem_alloc(sizeof(struct xfs_refcount_intent), | |
1198 | KM_SLEEP | KM_NOFS); | |
1199 | INIT_LIST_HEAD(&ri->ri_list); | |
1200 | ri->ri_type = type; | |
1201 | ri->ri_startblock = startblock; | |
1202 | ri->ri_blockcount = blockcount; | |
1203 | ||
1204 | xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_REFCOUNT, &ri->ri_list); | |
1205 | return 0; | |
1206 | } | |
1207 | ||
1208 | /* | |
1209 | * Increase the reference count of the blocks backing a file's extent. | |
1210 | */ | |
1211 | int | |
1212 | xfs_refcount_increase_extent( | |
1213 | struct xfs_mount *mp, | |
1214 | struct xfs_defer_ops *dfops, | |
1215 | struct xfs_bmbt_irec *PREV) | |
1216 | { | |
1217 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1218 | return 0; | |
1219 | ||
1220 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_INCREASE, | |
1221 | PREV->br_startblock, PREV->br_blockcount); | |
1222 | } | |
1223 | ||
1224 | /* | |
1225 | * Decrease the reference count of the blocks backing a file's extent. | |
1226 | */ | |
1227 | int | |
1228 | xfs_refcount_decrease_extent( | |
1229 | struct xfs_mount *mp, | |
1230 | struct xfs_defer_ops *dfops, | |
1231 | struct xfs_bmbt_irec *PREV) | |
1232 | { | |
1233 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1234 | return 0; | |
1235 | ||
1236 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_DECREASE, | |
1237 | PREV->br_startblock, PREV->br_blockcount); | |
1238 | } | |
94097330 DW |
1239 | |
1240 | /* | |
1241 | * Given an AG extent, find the lowest-numbered run of shared blocks | |
1242 | * within that range and return the range in fbno/flen. If | |
1243 | * find_end_of_shared is set, return the longest contiguous extent of | |
1244 | * shared blocks; if not, just return the first extent we find. If no | |
1245 | * shared blocks are found, fbno and flen will be set to NULLAGBLOCK | |
1246 | * and 0, respectively. | |
1247 | */ | |
1248 | int | |
1249 | xfs_refcount_find_shared( | |
1250 | struct xfs_btree_cur *cur, | |
1251 | xfs_agblock_t agbno, | |
1252 | xfs_extlen_t aglen, | |
1253 | xfs_agblock_t *fbno, | |
1254 | xfs_extlen_t *flen, | |
1255 | bool find_end_of_shared) | |
1256 | { | |
1257 | struct xfs_refcount_irec tmp; | |
1258 | int i; | |
1259 | int have; | |
1260 | int error; | |
1261 | ||
1262 | trace_xfs_refcount_find_shared(cur->bc_mp, cur->bc_private.a.agno, | |
1263 | agbno, aglen); | |
1264 | ||
1265 | /* By default, skip the whole range */ | |
1266 | *fbno = NULLAGBLOCK; | |
1267 | *flen = 0; | |
1268 | ||
1269 | /* Try to find a refcount extent that crosses the start */ | |
1270 | error = xfs_refcount_lookup_le(cur, agbno, &have); | |
1271 | if (error) | |
1272 | goto out_error; | |
1273 | if (!have) { | |
1274 | /* No left extent, look at the next one */ | |
1275 | error = xfs_btree_increment(cur, 0, &have); | |
1276 | if (error) | |
1277 | goto out_error; | |
1278 | if (!have) | |
1279 | goto done; | |
1280 | } | |
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 | ||
1286 | /* If the extent ends before the start, look at the next one */ | |
1287 | if (tmp.rc_startblock + tmp.rc_blockcount <= agbno) { | |
1288 | error = xfs_btree_increment(cur, 0, &have); | |
1289 | if (error) | |
1290 | goto out_error; | |
1291 | if (!have) | |
1292 | goto done; | |
1293 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1294 | if (error) | |
1295 | goto out_error; | |
1296 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1297 | } | |
1298 | ||
1299 | /* If the extent starts after the range we want, bail out */ | |
1300 | if (tmp.rc_startblock >= agbno + aglen) | |
1301 | goto done; | |
1302 | ||
1303 | /* We found the start of a shared extent! */ | |
1304 | if (tmp.rc_startblock < agbno) { | |
1305 | tmp.rc_blockcount -= (agbno - tmp.rc_startblock); | |
1306 | tmp.rc_startblock = agbno; | |
1307 | } | |
1308 | ||
1309 | *fbno = tmp.rc_startblock; | |
1310 | *flen = min(tmp.rc_blockcount, agbno + aglen - *fbno); | |
1311 | if (!find_end_of_shared) | |
1312 | goto done; | |
1313 | ||
1314 | /* Otherwise, find the end of this shared extent */ | |
1315 | while (*fbno + *flen < agbno + aglen) { | |
1316 | error = xfs_btree_increment(cur, 0, &have); | |
1317 | if (error) | |
1318 | goto out_error; | |
1319 | if (!have) | |
1320 | break; | |
1321 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1322 | if (error) | |
1323 | goto out_error; | |
1324 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1325 | if (tmp.rc_startblock >= agbno + aglen || | |
1326 | tmp.rc_startblock != *fbno + *flen) | |
1327 | break; | |
1328 | *flen = min(*flen + tmp.rc_blockcount, agbno + aglen - *fbno); | |
1329 | } | |
1330 | ||
1331 | done: | |
1332 | trace_xfs_refcount_find_shared_result(cur->bc_mp, | |
1333 | cur->bc_private.a.agno, *fbno, *flen); | |
1334 | ||
1335 | out_error: | |
1336 | if (error) | |
1337 | trace_xfs_refcount_find_shared_error(cur->bc_mp, | |
1338 | cur->bc_private.a.agno, error, _RET_IP_); | |
1339 | return error; | |
1340 | } | |
10e65503 DW |
1341 | |
1342 | /* | |
1343 | * Recovering CoW Blocks After a Crash | |
1344 | * | |
1345 | * Due to the way that the copy on write mechanism works, there's a window of | |
1346 | * opportunity in which we can lose track of allocated blocks during a crash. | |
1347 | * Because CoW uses delayed allocation in the in-core CoW fork, writeback | |
1348 | * causes blocks to be allocated and stored in the CoW fork. The blocks are | |
1349 | * no longer in the free space btree but are not otherwise recorded anywhere | |
1350 | * until the write completes and the blocks are mapped into the file. A crash | |
1351 | * in between allocation and remapping results in the replacement blocks being | |
1352 | * lost. This situation is exacerbated by the CoW extent size hint because | |
1353 | * allocations can hang around for long time. | |
1354 | * | |
1355 | * However, there is a place where we can record these allocations before they | |
1356 | * become mappings -- the reference count btree. The btree does not record | |
1357 | * extents with refcount == 1, so we can record allocations with a refcount of | |
1358 | * 1. Blocks being used for CoW writeout cannot be shared, so there should be | |
1359 | * no conflict with shared block records. These mappings should be created | |
1360 | * when we allocate blocks to the CoW fork and deleted when they're removed | |
1361 | * from the CoW fork. | |
1362 | * | |
1363 | * Minor nit: records for in-progress CoW allocations and records for shared | |
1364 | * extents must never be merged, to preserve the property that (except for CoW | |
1365 | * allocations) there are no refcount btree entries with refcount == 1. The | |
1366 | * only time this could potentially happen is when unsharing a block that's | |
1367 | * adjacent to CoW allocations, so we must be careful to avoid this. | |
1368 | * | |
1369 | * At mount time we recover lost CoW allocations by searching the refcount | |
1370 | * btree for these refcount == 1 mappings. These represent CoW allocations | |
1371 | * that were in progress at the time the filesystem went down, so we can free | |
1372 | * them to get the space back. | |
1373 | * | |
1374 | * This mechanism is superior to creating EFIs for unmapped CoW extents for | |
1375 | * several reasons -- first, EFIs pin the tail of the log and would have to be | |
1376 | * periodically relogged to avoid filling up the log. Second, CoW completions | |
1377 | * will have to file an EFD and create new EFIs for whatever remains in the | |
1378 | * CoW fork; this partially takes care of (1) but extent-size reservations | |
1379 | * will have to periodically relog even if there's no writeout in progress. | |
1380 | * This can happen if the CoW extent size hint is set, which you really want. | |
1381 | * Third, EFIs cannot currently be automatically relogged into newer | |
1382 | * transactions to advance the log tail. Fourth, stuffing the log full of | |
1383 | * EFIs places an upper bound on the number of CoW allocations that can be | |
1384 | * held filesystem-wide at any given time. Recording them in the refcount | |
1385 | * btree doesn't require us to maintain any state in memory and doesn't pin | |
1386 | * the log. | |
1387 | */ | |
1388 | /* | |
1389 | * Adjust the refcounts of CoW allocations. These allocations are "magic" | |
1390 | * in that they're not referenced anywhere else in the filesystem, so we | |
1391 | * stash them in the refcount btree with a refcount of 1 until either file | |
1392 | * remapping (or CoW cancellation) happens. | |
1393 | */ | |
1394 | STATIC int | |
1395 | xfs_refcount_adjust_cow_extents( | |
1396 | struct xfs_btree_cur *cur, | |
1397 | xfs_agblock_t agbno, | |
1398 | xfs_extlen_t aglen, | |
1421de38 | 1399 | enum xfs_refc_adjust_op adj) |
10e65503 DW |
1400 | { |
1401 | struct xfs_refcount_irec ext, tmp; | |
1402 | int error; | |
1403 | int found_rec, found_tmp; | |
1404 | ||
1405 | if (aglen == 0) | |
1406 | return 0; | |
1407 | ||
1408 | /* Find any overlapping refcount records */ | |
1409 | error = xfs_refcount_lookup_ge(cur, agbno, &found_rec); | |
1410 | if (error) | |
1411 | goto out_error; | |
1412 | error = xfs_refcount_get_rec(cur, &ext, &found_rec); | |
1413 | if (error) | |
1414 | goto out_error; | |
1415 | if (!found_rec) { | |
1416 | ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks + | |
1417 | XFS_REFC_COW_START; | |
1418 | ext.rc_blockcount = 0; | |
1419 | ext.rc_refcount = 0; | |
1420 | } | |
1421 | ||
1422 | switch (adj) { | |
1423 | case XFS_REFCOUNT_ADJUST_COW_ALLOC: | |
1424 | /* Adding a CoW reservation, there should be nothing here. */ | |
1425 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1426 | ext.rc_startblock >= agbno + aglen, out_error); | |
1427 | ||
1428 | tmp.rc_startblock = agbno; | |
1429 | tmp.rc_blockcount = aglen; | |
1430 | tmp.rc_refcount = 1; | |
1431 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
1432 | cur->bc_private.a.agno, &tmp); | |
1433 | ||
1434 | error = xfs_refcount_insert(cur, &tmp, | |
1435 | &found_tmp); | |
1436 | if (error) | |
1437 | goto out_error; | |
1438 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1439 | found_tmp == 1, out_error); | |
1440 | break; | |
1441 | case XFS_REFCOUNT_ADJUST_COW_FREE: | |
1442 | /* Removing a CoW reservation, there should be one extent. */ | |
1443 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1444 | ext.rc_startblock == agbno, out_error); | |
1445 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1446 | ext.rc_blockcount == aglen, out_error); | |
1447 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1448 | ext.rc_refcount == 1, out_error); | |
1449 | ||
1450 | ext.rc_refcount = 0; | |
1451 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
1452 | cur->bc_private.a.agno, &ext); | |
1453 | error = xfs_refcount_delete(cur, &found_rec); | |
1454 | if (error) | |
1455 | goto out_error; | |
1456 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
1457 | found_rec == 1, out_error); | |
1458 | break; | |
1459 | default: | |
1460 | ASSERT(0); | |
1461 | } | |
1462 | ||
1463 | return error; | |
1464 | out_error: | |
1465 | trace_xfs_refcount_modify_extent_error(cur->bc_mp, | |
1466 | cur->bc_private.a.agno, error, _RET_IP_); | |
1467 | return error; | |
1468 | } | |
1469 | ||
1470 | /* | |
1471 | * Add or remove refcount btree entries for CoW reservations. | |
1472 | */ | |
1473 | STATIC int | |
1474 | xfs_refcount_adjust_cow( | |
1475 | struct xfs_btree_cur *cur, | |
1476 | xfs_agblock_t agbno, | |
1477 | xfs_extlen_t aglen, | |
1421de38 | 1478 | enum xfs_refc_adjust_op adj) |
10e65503 DW |
1479 | { |
1480 | bool shape_changed; | |
1481 | int error; | |
1482 | ||
1483 | agbno += XFS_REFC_COW_START; | |
1484 | ||
1485 | /* | |
1486 | * Ensure that no rcextents cross the boundary of the adjustment range. | |
1487 | */ | |
1488 | error = xfs_refcount_split_extent(cur, agbno, &shape_changed); | |
1489 | if (error) | |
1490 | goto out_error; | |
1491 | ||
1492 | error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); | |
1493 | if (error) | |
1494 | goto out_error; | |
1495 | ||
1496 | /* | |
1497 | * Try to merge with the left or right extents of the range. | |
1498 | */ | |
1499 | error = xfs_refcount_merge_extents(cur, &agbno, &aglen, adj, | |
1500 | XFS_FIND_RCEXT_COW, &shape_changed); | |
1501 | if (error) | |
1502 | goto out_error; | |
1503 | ||
1504 | /* Now that we've taken care of the ends, adjust the middle extents */ | |
1421de38 | 1505 | error = xfs_refcount_adjust_cow_extents(cur, agbno, aglen, adj); |
10e65503 DW |
1506 | if (error) |
1507 | goto out_error; | |
1508 | ||
1509 | return 0; | |
1510 | ||
1511 | out_error: | |
1512 | trace_xfs_refcount_adjust_cow_error(cur->bc_mp, cur->bc_private.a.agno, | |
1513 | error, _RET_IP_); | |
1514 | return error; | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * Record a CoW allocation in the refcount btree. | |
1519 | */ | |
1520 | STATIC int | |
1521 | __xfs_refcount_cow_alloc( | |
1522 | struct xfs_btree_cur *rcur, | |
1523 | xfs_agblock_t agbno, | |
1524 | xfs_extlen_t aglen, | |
1525 | struct xfs_defer_ops *dfops) | |
1526 | { | |
10e65503 DW |
1527 | trace_xfs_refcount_cow_increase(rcur->bc_mp, rcur->bc_private.a.agno, |
1528 | agbno, aglen); | |
1529 | ||
1530 | /* Add refcount btree reservation */ | |
a44b23a0 | 1531 | return xfs_refcount_adjust_cow(rcur, agbno, aglen, |
1421de38 | 1532 | XFS_REFCOUNT_ADJUST_COW_ALLOC); |
10e65503 DW |
1533 | } |
1534 | ||
1535 | /* | |
1536 | * Remove a CoW allocation from the refcount btree. | |
1537 | */ | |
1538 | STATIC int | |
1539 | __xfs_refcount_cow_free( | |
1540 | struct xfs_btree_cur *rcur, | |
1541 | xfs_agblock_t agbno, | |
1542 | xfs_extlen_t aglen, | |
1543 | struct xfs_defer_ops *dfops) | |
1544 | { | |
10e65503 DW |
1545 | trace_xfs_refcount_cow_decrease(rcur->bc_mp, rcur->bc_private.a.agno, |
1546 | agbno, aglen); | |
1547 | ||
1548 | /* Remove refcount btree reservation */ | |
a44b23a0 | 1549 | return xfs_refcount_adjust_cow(rcur, agbno, aglen, |
1421de38 | 1550 | XFS_REFCOUNT_ADJUST_COW_FREE); |
10e65503 DW |
1551 | } |
1552 | ||
1553 | /* Record a CoW staging extent in the refcount btree. */ | |
1554 | int | |
1555 | xfs_refcount_alloc_cow_extent( | |
1556 | struct xfs_mount *mp, | |
1557 | struct xfs_defer_ops *dfops, | |
1558 | xfs_fsblock_t fsb, | |
1559 | xfs_extlen_t len) | |
1560 | { | |
a44b23a0 DW |
1561 | int error; |
1562 | ||
10e65503 DW |
1563 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) |
1564 | return 0; | |
1565 | ||
a44b23a0 | 1566 | error = __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_ALLOC_COW, |
10e65503 | 1567 | fsb, len); |
a44b23a0 DW |
1568 | if (error) |
1569 | return error; | |
1570 | ||
1571 | /* Add rmap entry */ | |
1572 | return xfs_rmap_alloc_extent(mp, dfops, XFS_FSB_TO_AGNO(mp, fsb), | |
1573 | XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW); | |
10e65503 DW |
1574 | } |
1575 | ||
1576 | /* Forget a CoW staging event in the refcount btree. */ | |
1577 | int | |
1578 | xfs_refcount_free_cow_extent( | |
1579 | struct xfs_mount *mp, | |
1580 | struct xfs_defer_ops *dfops, | |
1581 | xfs_fsblock_t fsb, | |
1582 | xfs_extlen_t len) | |
1583 | { | |
a44b23a0 DW |
1584 | int error; |
1585 | ||
10e65503 DW |
1586 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) |
1587 | return 0; | |
1588 | ||
a44b23a0 DW |
1589 | /* Remove rmap entry */ |
1590 | error = xfs_rmap_free_extent(mp, dfops, XFS_FSB_TO_AGNO(mp, fsb), | |
1591 | XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW); | |
1592 | if (error) | |
1593 | return error; | |
1594 | ||
10e65503 DW |
1595 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_FREE_COW, |
1596 | fsb, len); | |
1597 | } | |
1598 | ||
1599 | struct xfs_refcount_recovery { | |
1600 | struct list_head rr_list; | |
1601 | struct xfs_refcount_irec rr_rrec; | |
1602 | }; | |
1603 | ||
1604 | /* Stuff an extent on the recovery list. */ | |
1605 | STATIC int | |
1606 | xfs_refcount_recover_extent( | |
1421de38 | 1607 | struct xfs_btree_cur *cur, |
10e65503 DW |
1608 | union xfs_btree_rec *rec, |
1609 | void *priv) | |
1610 | { | |
1611 | struct list_head *debris = priv; | |
1612 | struct xfs_refcount_recovery *rr; | |
1613 | ||
1614 | if (be32_to_cpu(rec->refc.rc_refcount) != 1) | |
1615 | return -EFSCORRUPTED; | |
1616 | ||
1617 | rr = kmem_alloc(sizeof(struct xfs_refcount_recovery), KM_SLEEP); | |
1618 | xfs_refcount_btrec_to_irec(rec, &rr->rr_rrec); | |
1619 | list_add_tail(&rr->rr_list, debris); | |
1620 | ||
1621 | return 0; | |
1622 | } | |
1623 | ||
1624 | /* Find and remove leftover CoW reservations. */ | |
1625 | int | |
1626 | xfs_refcount_recover_cow_leftovers( | |
1627 | struct xfs_mount *mp, | |
1628 | xfs_agnumber_t agno) | |
1629 | { | |
1630 | struct xfs_trans *tp; | |
1631 | struct xfs_btree_cur *cur; | |
1632 | struct xfs_buf *agbp; | |
1633 | struct xfs_refcount_recovery *rr, *n; | |
1634 | struct list_head debris; | |
1635 | union xfs_btree_irec low; | |
1636 | union xfs_btree_irec high; | |
1637 | struct xfs_defer_ops dfops; | |
1638 | xfs_fsblock_t fsb; | |
1639 | xfs_agblock_t agbno; | |
1640 | int error; | |
1641 | ||
1642 | if (mp->m_sb.sb_agblocks >= XFS_REFC_COW_START) | |
1643 | return -EOPNOTSUPP; | |
1644 | ||
d4e8eb2e DW |
1645 | INIT_LIST_HEAD(&debris); |
1646 | ||
1647 | /* | |
1648 | * In this first part, we use an empty transaction to gather up | |
1649 | * all the leftover CoW extents so that we can subsequently | |
1650 | * delete them. The empty transaction is used to avoid | |
1651 | * a buffer lock deadlock if there happens to be a loop in the | |
1652 | * refcountbt because we're allowed to re-grab a buffer that is | |
1653 | * already attached to our transaction. When we're done | |
1654 | * recording the CoW debris we cancel the (empty) transaction | |
1655 | * and everything goes away cleanly. | |
1656 | */ | |
1657 | error = xfs_trans_alloc_empty(mp, &tp); | |
10e65503 DW |
1658 | if (error) |
1659 | return error; | |
d4e8eb2e DW |
1660 | |
1661 | error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp); | |
1662 | if (error) | |
1663 | goto out_trans; | |
d705962a DW |
1664 | if (!agbp) { |
1665 | error = -ENOMEM; | |
1666 | goto out_trans; | |
1667 | } | |
5ff5ced0 | 1668 | cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno); |
10e65503 DW |
1669 | |
1670 | /* Find all the leftover CoW staging extents. */ | |
10e65503 DW |
1671 | memset(&low, 0, sizeof(low)); |
1672 | memset(&high, 0, sizeof(high)); | |
1673 | low.rc.rc_startblock = XFS_REFC_COW_START; | |
1674 | high.rc.rc_startblock = -1U; | |
1675 | error = xfs_btree_query_range(cur, &low, &high, | |
1676 | xfs_refcount_recover_extent, &debris); | |
1677 | if (error) | |
22a69322 | 1678 | goto out_cursor; |
10e65503 | 1679 | xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR); |
d4e8eb2e DW |
1680 | xfs_trans_brelse(tp, agbp); |
1681 | xfs_trans_cancel(tp); | |
10e65503 DW |
1682 | |
1683 | /* Now iterate the list to free the leftovers */ | |
d4e8eb2e | 1684 | list_for_each_entry_safe(rr, n, &debris, rr_list) { |
10e65503 DW |
1685 | /* Set up transaction. */ |
1686 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp); | |
1687 | if (error) | |
1688 | goto out_free; | |
1689 | ||
1690 | trace_xfs_refcount_recover_extent(mp, agno, &rr->rr_rrec); | |
1691 | ||
1692 | /* Free the orphan record */ | |
5cebfb23 | 1693 | xfs_defer_init(tp, &dfops); |
10e65503 DW |
1694 | agbno = rr->rr_rrec.rc_startblock - XFS_REFC_COW_START; |
1695 | fsb = XFS_AGB_TO_FSB(mp, agno, agbno); | |
f50f99f4 | 1696 | error = xfs_refcount_free_cow_extent(mp, tp->t_dfops, fsb, |
10e65503 DW |
1697 | rr->rr_rrec.rc_blockcount); |
1698 | if (error) | |
1699 | goto out_defer; | |
1700 | ||
1701 | /* Free the block. */ | |
f50f99f4 | 1702 | xfs_bmap_add_free(mp, tp->t_dfops, fsb, |
10e65503 DW |
1703 | rr->rr_rrec.rc_blockcount, NULL); |
1704 | ||
f50f99f4 | 1705 | error = xfs_defer_finish(&tp, tp->t_dfops); |
10e65503 DW |
1706 | if (error) |
1707 | goto out_defer; | |
1708 | ||
1709 | error = xfs_trans_commit(tp); | |
1710 | if (error) | |
22a69322 | 1711 | goto out_free; |
d4e8eb2e DW |
1712 | |
1713 | list_del(&rr->rr_list); | |
1714 | kmem_free(rr); | |
10e65503 | 1715 | } |
10e65503 | 1716 | |
d4e8eb2e DW |
1717 | return error; |
1718 | out_defer: | |
f50f99f4 | 1719 | xfs_defer_cancel(tp->t_dfops); |
d4e8eb2e DW |
1720 | out_trans: |
1721 | xfs_trans_cancel(tp); | |
10e65503 DW |
1722 | out_free: |
1723 | /* Free the leftover list */ | |
1724 | list_for_each_entry_safe(rr, n, &debris, rr_list) { | |
1725 | list_del(&rr->rr_list); | |
1726 | kmem_free(rr); | |
1727 | } | |
10e65503 DW |
1728 | return error; |
1729 | ||
22a69322 | 1730 | out_cursor: |
10e65503 | 1731 | xfs_btree_del_cursor(cur, XFS_BTREE_ERROR); |
d4e8eb2e DW |
1732 | xfs_trans_brelse(tp, agbp); |
1733 | goto out_trans; | |
10e65503 | 1734 | } |
1048d0e2 DW |
1735 | |
1736 | /* Is there a record covering a given extent? */ | |
1737 | int | |
1738 | xfs_refcount_has_record( | |
1739 | struct xfs_btree_cur *cur, | |
1740 | xfs_agblock_t bno, | |
1741 | xfs_extlen_t len, | |
1742 | bool *exists) | |
1743 | { | |
1744 | union xfs_btree_irec low; | |
1745 | union xfs_btree_irec high; | |
1746 | ||
1747 | memset(&low, 0, sizeof(low)); | |
1748 | low.rc.rc_startblock = bno; | |
1749 | memset(&high, 0xFF, sizeof(high)); | |
1750 | high.rc.rc_startblock = bno + len - 1; | |
1751 | ||
1752 | return xfs_btree_has_record(cur, &low, &high, exists); | |
1753 | } |