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bc859611 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 "libxfs_priv.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" | |
33 | #include "xfs_trace.h" | |
34 | #include "xfs_cksum.h" | |
35 | #include "xfs_trans.h" | |
36 | #include "xfs_bit.h" | |
37 | #include "xfs_refcount.h" | |
38 | ||
56ef8c33 DW |
39 | /* Allowable refcount adjustment amounts. */ |
40 | enum xfs_refc_adjust_op { | |
41 | XFS_REFCOUNT_ADJUST_INCREASE = 1, | |
42 | XFS_REFCOUNT_ADJUST_DECREASE = -1, | |
43 | }; | |
44 | ||
bc859611 DW |
45 | /* |
46 | * Look up the first record less than or equal to [bno, len] in the btree | |
47 | * given by cur. | |
48 | */ | |
49 | int | |
50 | xfs_refcount_lookup_le( | |
51 | struct xfs_btree_cur *cur, | |
52 | xfs_agblock_t bno, | |
53 | int *stat) | |
54 | { | |
55 | trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_private.a.agno, bno, | |
56 | XFS_LOOKUP_LE); | |
57 | cur->bc_rec.rc.rc_startblock = bno; | |
58 | cur->bc_rec.rc.rc_blockcount = 0; | |
59 | return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat); | |
60 | } | |
61 | ||
62 | /* | |
63 | * Look up the first record greater than or equal to [bno, len] in the btree | |
64 | * given by cur. | |
65 | */ | |
66 | int | |
67 | xfs_refcount_lookup_ge( | |
68 | struct xfs_btree_cur *cur, | |
69 | xfs_agblock_t bno, | |
70 | int *stat) | |
71 | { | |
72 | trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_private.a.agno, bno, | |
73 | XFS_LOOKUP_GE); | |
74 | cur->bc_rec.rc.rc_startblock = bno; | |
75 | cur->bc_rec.rc.rc_blockcount = 0; | |
76 | return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat); | |
77 | } | |
78 | ||
79 | /* | |
80 | * Get the data from the pointed-to record. | |
81 | */ | |
82 | int | |
83 | xfs_refcount_get_rec( | |
84 | struct xfs_btree_cur *cur, | |
85 | struct xfs_refcount_irec *irec, | |
86 | int *stat) | |
87 | { | |
88 | union xfs_btree_rec *rec; | |
89 | int error; | |
90 | ||
91 | error = xfs_btree_get_rec(cur, &rec, stat); | |
92 | if (!error && *stat == 1) { | |
93 | irec->rc_startblock = be32_to_cpu(rec->refc.rc_startblock); | |
94 | irec->rc_blockcount = be32_to_cpu(rec->refc.rc_blockcount); | |
95 | irec->rc_refcount = be32_to_cpu(rec->refc.rc_refcount); | |
96 | trace_xfs_refcount_get(cur->bc_mp, cur->bc_private.a.agno, | |
97 | irec); | |
98 | } | |
99 | return error; | |
100 | } | |
101 | ||
102 | /* | |
103 | * Update the record referred to by cur to the value given | |
104 | * by [bno, len, refcount]. | |
105 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
106 | */ | |
107 | STATIC int | |
108 | xfs_refcount_update( | |
109 | struct xfs_btree_cur *cur, | |
110 | struct xfs_refcount_irec *irec) | |
111 | { | |
112 | union xfs_btree_rec rec; | |
113 | int error; | |
114 | ||
115 | trace_xfs_refcount_update(cur->bc_mp, cur->bc_private.a.agno, irec); | |
116 | rec.refc.rc_startblock = cpu_to_be32(irec->rc_startblock); | |
117 | rec.refc.rc_blockcount = cpu_to_be32(irec->rc_blockcount); | |
118 | rec.refc.rc_refcount = cpu_to_be32(irec->rc_refcount); | |
119 | error = xfs_btree_update(cur, &rec); | |
120 | if (error) | |
121 | trace_xfs_refcount_update_error(cur->bc_mp, | |
122 | cur->bc_private.a.agno, error, _RET_IP_); | |
123 | return error; | |
124 | } | |
125 | ||
126 | /* | |
127 | * Insert the record referred to by cur to the value given | |
128 | * by [bno, len, refcount]. | |
129 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
130 | */ | |
131 | STATIC int | |
132 | xfs_refcount_insert( | |
133 | struct xfs_btree_cur *cur, | |
134 | struct xfs_refcount_irec *irec, | |
135 | int *i) | |
136 | { | |
137 | int error; | |
138 | ||
139 | trace_xfs_refcount_insert(cur->bc_mp, cur->bc_private.a.agno, irec); | |
140 | cur->bc_rec.rc.rc_startblock = irec->rc_startblock; | |
141 | cur->bc_rec.rc.rc_blockcount = irec->rc_blockcount; | |
142 | cur->bc_rec.rc.rc_refcount = irec->rc_refcount; | |
143 | error = xfs_btree_insert(cur, i); | |
144 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, *i == 1, out_error); | |
145 | out_error: | |
146 | if (error) | |
147 | trace_xfs_refcount_insert_error(cur->bc_mp, | |
148 | cur->bc_private.a.agno, error, _RET_IP_); | |
149 | return error; | |
150 | } | |
151 | ||
152 | /* | |
153 | * Remove the record referred to by cur, then set the pointer to the spot | |
154 | * where the record could be re-inserted, in case we want to increment or | |
155 | * decrement the cursor. | |
156 | * This either works (return 0) or gets an EFSCORRUPTED error. | |
157 | */ | |
158 | STATIC int | |
159 | xfs_refcount_delete( | |
160 | struct xfs_btree_cur *cur, | |
161 | int *i) | |
162 | { | |
163 | struct xfs_refcount_irec irec; | |
164 | int found_rec; | |
165 | int error; | |
166 | ||
167 | error = xfs_refcount_get_rec(cur, &irec, &found_rec); | |
168 | if (error) | |
169 | goto out_error; | |
170 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
171 | trace_xfs_refcount_delete(cur->bc_mp, cur->bc_private.a.agno, &irec); | |
172 | error = xfs_btree_delete(cur, i); | |
173 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, *i == 1, out_error); | |
174 | if (error) | |
175 | goto out_error; | |
176 | error = xfs_refcount_lookup_ge(cur, irec.rc_startblock, &found_rec); | |
177 | out_error: | |
178 | if (error) | |
179 | trace_xfs_refcount_delete_error(cur->bc_mp, | |
180 | cur->bc_private.a.agno, error, _RET_IP_); | |
181 | return error; | |
182 | } | |
56ef8c33 DW |
183 | |
184 | /* | |
185 | * Adjusting the Reference Count | |
186 | * | |
187 | * As stated elsewhere, the reference count btree (refcbt) stores | |
188 | * >1 reference counts for extents of physical blocks. In this | |
189 | * operation, we're either raising or lowering the reference count of | |
190 | * some subrange stored in the tree: | |
191 | * | |
192 | * <------ adjustment range ------> | |
193 | * ----+ +---+-----+ +--+--------+--------- | |
194 | * 2 | | 3 | 4 | |17| 55 | 10 | |
195 | * ----+ +---+-----+ +--+--------+--------- | |
196 | * X axis is physical blocks number; | |
197 | * reference counts are the numbers inside the rectangles | |
198 | * | |
199 | * The first thing we need to do is to ensure that there are no | |
200 | * refcount extents crossing either boundary of the range to be | |
201 | * adjusted. For any extent that does cross a boundary, split it into | |
202 | * two extents so that we can increment the refcount of one of the | |
203 | * pieces later: | |
204 | * | |
205 | * <------ adjustment range ------> | |
206 | * ----+ +---+-----+ +--+--------+----+---- | |
207 | * 2 | | 3 | 2 | |17| 55 | 10 | 10 | |
208 | * ----+ +---+-----+ +--+--------+----+---- | |
209 | * | |
210 | * For this next step, let's assume that all the physical blocks in | |
211 | * the adjustment range are mapped to a file and are therefore in use | |
212 | * at least once. Therefore, we can infer that any gap in the | |
213 | * refcount tree within the adjustment range represents a physical | |
214 | * extent with refcount == 1: | |
215 | * | |
216 | * <------ adjustment range ------> | |
217 | * ----+---+---+-----+-+--+--------+----+---- | |
218 | * 2 |"1"| 3 | 2 |1|17| 55 | 10 | 10 | |
219 | * ----+---+---+-----+-+--+--------+----+---- | |
220 | * ^ | |
221 | * | |
222 | * For each extent that falls within the interval range, figure out | |
223 | * which extent is to the left or the right of that extent. Now we | |
224 | * have a left, current, and right extent. If the new reference count | |
225 | * of the center extent enables us to merge left, center, and right | |
226 | * into one record covering all three, do so. If the center extent is | |
227 | * at the left end of the range, abuts the left extent, and its new | |
228 | * reference count matches the left extent's record, then merge them. | |
229 | * If the center extent is at the right end of the range, abuts the | |
230 | * right extent, and the reference counts match, merge those. In the | |
231 | * example, we can left merge (assuming an increment operation): | |
232 | * | |
233 | * <------ adjustment range ------> | |
234 | * --------+---+-----+-+--+--------+----+---- | |
235 | * 2 | 3 | 2 |1|17| 55 | 10 | 10 | |
236 | * --------+---+-----+-+--+--------+----+---- | |
237 | * ^ | |
238 | * | |
239 | * For all other extents within the range, adjust the reference count | |
240 | * or delete it if the refcount falls below 2. If we were | |
241 | * incrementing, the end result looks like this: | |
242 | * | |
243 | * <------ adjustment range ------> | |
244 | * --------+---+-----+-+--+--------+----+---- | |
245 | * 2 | 4 | 3 |2|18| 56 | 11 | 10 | |
246 | * --------+---+-----+-+--+--------+----+---- | |
247 | * | |
248 | * The result of a decrement operation looks as such: | |
249 | * | |
250 | * <------ adjustment range ------> | |
251 | * ----+ +---+ +--+--------+----+---- | |
252 | * 2 | | 2 | |16| 54 | 9 | 10 | |
253 | * ----+ +---+ +--+--------+----+---- | |
254 | * DDDD 111111DD | |
255 | * | |
256 | * The blocks marked "D" are freed; the blocks marked "1" are only | |
257 | * referenced once and therefore the record is removed from the | |
258 | * refcount btree. | |
259 | */ | |
260 | ||
261 | /* Next block after this extent. */ | |
262 | static inline xfs_agblock_t | |
263 | xfs_refc_next( | |
264 | struct xfs_refcount_irec *rc) | |
265 | { | |
266 | return rc->rc_startblock + rc->rc_blockcount; | |
267 | } | |
268 | ||
269 | /* | |
270 | * Split a refcount extent that crosses agbno. | |
271 | */ | |
272 | STATIC int | |
273 | xfs_refcount_split_extent( | |
274 | struct xfs_btree_cur *cur, | |
275 | xfs_agblock_t agbno, | |
276 | bool *shape_changed) | |
277 | { | |
278 | struct xfs_refcount_irec rcext, tmp; | |
279 | int found_rec; | |
280 | int error; | |
281 | ||
282 | *shape_changed = false; | |
283 | error = xfs_refcount_lookup_le(cur, agbno, &found_rec); | |
284 | if (error) | |
285 | goto out_error; | |
286 | if (!found_rec) | |
287 | return 0; | |
288 | ||
289 | error = xfs_refcount_get_rec(cur, &rcext, &found_rec); | |
290 | if (error) | |
291 | goto out_error; | |
292 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
293 | if (rcext.rc_startblock == agbno || xfs_refc_next(&rcext) <= agbno) | |
294 | return 0; | |
295 | ||
296 | *shape_changed = true; | |
297 | trace_xfs_refcount_split_extent(cur->bc_mp, cur->bc_private.a.agno, | |
298 | &rcext, agbno); | |
299 | ||
300 | /* Establish the right extent. */ | |
301 | tmp = rcext; | |
302 | tmp.rc_startblock = agbno; | |
303 | tmp.rc_blockcount -= (agbno - rcext.rc_startblock); | |
304 | error = xfs_refcount_update(cur, &tmp); | |
305 | if (error) | |
306 | goto out_error; | |
307 | ||
308 | /* Insert the left extent. */ | |
309 | tmp = rcext; | |
310 | tmp.rc_blockcount = agbno - rcext.rc_startblock; | |
311 | error = xfs_refcount_insert(cur, &tmp, &found_rec); | |
312 | if (error) | |
313 | goto out_error; | |
314 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
315 | return error; | |
316 | ||
317 | out_error: | |
318 | trace_xfs_refcount_split_extent_error(cur->bc_mp, | |
319 | cur->bc_private.a.agno, error, _RET_IP_); | |
320 | return error; | |
321 | } | |
322 | ||
323 | /* | |
324 | * Merge the left, center, and right extents. | |
325 | */ | |
326 | STATIC int | |
327 | xfs_refcount_merge_center_extents( | |
328 | struct xfs_btree_cur *cur, | |
329 | struct xfs_refcount_irec *left, | |
330 | struct xfs_refcount_irec *center, | |
331 | struct xfs_refcount_irec *right, | |
332 | unsigned long long extlen, | |
333 | xfs_agblock_t *agbno, | |
334 | xfs_extlen_t *aglen) | |
335 | { | |
336 | int error; | |
337 | int found_rec; | |
338 | ||
339 | trace_xfs_refcount_merge_center_extents(cur->bc_mp, | |
340 | cur->bc_private.a.agno, left, center, right); | |
341 | ||
342 | /* | |
343 | * Make sure the center and right extents are not in the btree. | |
344 | * If the center extent was synthesized, the first delete call | |
345 | * removes the right extent and we skip the second deletion. | |
346 | * If center and right were in the btree, then the first delete | |
347 | * call removes the center and the second one removes the right | |
348 | * extent. | |
349 | */ | |
350 | error = xfs_refcount_lookup_ge(cur, center->rc_startblock, | |
351 | &found_rec); | |
352 | if (error) | |
353 | goto out_error; | |
354 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
355 | ||
356 | error = xfs_refcount_delete(cur, &found_rec); | |
357 | if (error) | |
358 | goto out_error; | |
359 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
360 | ||
361 | if (center->rc_refcount > 1) { | |
362 | error = xfs_refcount_delete(cur, &found_rec); | |
363 | if (error) | |
364 | goto out_error; | |
365 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
366 | out_error); | |
367 | } | |
368 | ||
369 | /* Enlarge the left extent. */ | |
370 | error = xfs_refcount_lookup_le(cur, left->rc_startblock, | |
371 | &found_rec); | |
372 | if (error) | |
373 | goto out_error; | |
374 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
375 | ||
376 | left->rc_blockcount = extlen; | |
377 | error = xfs_refcount_update(cur, left); | |
378 | if (error) | |
379 | goto out_error; | |
380 | ||
381 | *aglen = 0; | |
382 | return error; | |
383 | ||
384 | out_error: | |
385 | trace_xfs_refcount_merge_center_extents_error(cur->bc_mp, | |
386 | cur->bc_private.a.agno, error, _RET_IP_); | |
387 | return error; | |
388 | } | |
389 | ||
390 | /* | |
391 | * Merge with the left extent. | |
392 | */ | |
393 | STATIC int | |
394 | xfs_refcount_merge_left_extent( | |
395 | struct xfs_btree_cur *cur, | |
396 | struct xfs_refcount_irec *left, | |
397 | struct xfs_refcount_irec *cleft, | |
398 | xfs_agblock_t *agbno, | |
399 | xfs_extlen_t *aglen) | |
400 | { | |
401 | int error; | |
402 | int found_rec; | |
403 | ||
404 | trace_xfs_refcount_merge_left_extent(cur->bc_mp, | |
405 | cur->bc_private.a.agno, left, cleft); | |
406 | ||
407 | /* If the extent at agbno (cleft) wasn't synthesized, remove it. */ | |
408 | if (cleft->rc_refcount > 1) { | |
409 | error = xfs_refcount_lookup_le(cur, cleft->rc_startblock, | |
410 | &found_rec); | |
411 | if (error) | |
412 | goto out_error; | |
413 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
414 | out_error); | |
415 | ||
416 | error = xfs_refcount_delete(cur, &found_rec); | |
417 | if (error) | |
418 | goto out_error; | |
419 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
420 | out_error); | |
421 | } | |
422 | ||
423 | /* Enlarge the left extent. */ | |
424 | error = xfs_refcount_lookup_le(cur, left->rc_startblock, | |
425 | &found_rec); | |
426 | if (error) | |
427 | goto out_error; | |
428 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
429 | ||
430 | left->rc_blockcount += cleft->rc_blockcount; | |
431 | error = xfs_refcount_update(cur, left); | |
432 | if (error) | |
433 | goto out_error; | |
434 | ||
435 | *agbno += cleft->rc_blockcount; | |
436 | *aglen -= cleft->rc_blockcount; | |
437 | return error; | |
438 | ||
439 | out_error: | |
440 | trace_xfs_refcount_merge_left_extent_error(cur->bc_mp, | |
441 | cur->bc_private.a.agno, error, _RET_IP_); | |
442 | return error; | |
443 | } | |
444 | ||
445 | /* | |
446 | * Merge with the right extent. | |
447 | */ | |
448 | STATIC int | |
449 | xfs_refcount_merge_right_extent( | |
450 | struct xfs_btree_cur *cur, | |
451 | struct xfs_refcount_irec *right, | |
452 | struct xfs_refcount_irec *cright, | |
453 | xfs_agblock_t *agbno, | |
454 | xfs_extlen_t *aglen) | |
455 | { | |
456 | int error; | |
457 | int found_rec; | |
458 | ||
459 | trace_xfs_refcount_merge_right_extent(cur->bc_mp, | |
460 | cur->bc_private.a.agno, cright, right); | |
461 | ||
462 | /* | |
463 | * If the extent ending at agbno+aglen (cright) wasn't synthesized, | |
464 | * remove it. | |
465 | */ | |
466 | if (cright->rc_refcount > 1) { | |
467 | error = xfs_refcount_lookup_le(cur, cright->rc_startblock, | |
468 | &found_rec); | |
469 | if (error) | |
470 | goto out_error; | |
471 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
472 | out_error); | |
473 | ||
474 | error = xfs_refcount_delete(cur, &found_rec); | |
475 | if (error) | |
476 | goto out_error; | |
477 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
478 | out_error); | |
479 | } | |
480 | ||
481 | /* Enlarge the right extent. */ | |
482 | error = xfs_refcount_lookup_le(cur, right->rc_startblock, | |
483 | &found_rec); | |
484 | if (error) | |
485 | goto out_error; | |
486 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
487 | ||
488 | right->rc_startblock -= cright->rc_blockcount; | |
489 | right->rc_blockcount += cright->rc_blockcount; | |
490 | error = xfs_refcount_update(cur, right); | |
491 | if (error) | |
492 | goto out_error; | |
493 | ||
494 | *aglen -= cright->rc_blockcount; | |
495 | return error; | |
496 | ||
497 | out_error: | |
498 | trace_xfs_refcount_merge_right_extent_error(cur->bc_mp, | |
499 | cur->bc_private.a.agno, error, _RET_IP_); | |
500 | return error; | |
501 | } | |
502 | ||
503 | /* | |
504 | * Find the left extent and the one after it (cleft). This function assumes | |
505 | * that we've already split any extent crossing agbno. | |
506 | */ | |
507 | STATIC int | |
508 | xfs_refcount_find_left_extents( | |
509 | struct xfs_btree_cur *cur, | |
510 | struct xfs_refcount_irec *left, | |
511 | struct xfs_refcount_irec *cleft, | |
512 | xfs_agblock_t agbno, | |
513 | xfs_extlen_t aglen) | |
514 | { | |
515 | struct xfs_refcount_irec tmp; | |
516 | int error; | |
517 | int found_rec; | |
518 | ||
519 | left->rc_startblock = cleft->rc_startblock = NULLAGBLOCK; | |
520 | error = xfs_refcount_lookup_le(cur, agbno - 1, &found_rec); | |
521 | if (error) | |
522 | goto out_error; | |
523 | if (!found_rec) | |
524 | return 0; | |
525 | ||
526 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
527 | if (error) | |
528 | goto out_error; | |
529 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
530 | ||
531 | if (xfs_refc_next(&tmp) != agbno) | |
532 | return 0; | |
533 | /* We have a left extent; retrieve (or invent) the next right one */ | |
534 | *left = tmp; | |
535 | ||
536 | error = xfs_btree_increment(cur, 0, &found_rec); | |
537 | if (error) | |
538 | goto out_error; | |
539 | if (found_rec) { | |
540 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
541 | if (error) | |
542 | goto out_error; | |
543 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
544 | out_error); | |
545 | ||
546 | /* if tmp starts at the end of our range, just use that */ | |
547 | if (tmp.rc_startblock == agbno) | |
548 | *cleft = tmp; | |
549 | else { | |
550 | /* | |
551 | * There's a gap in the refcntbt at the start of the | |
552 | * range we're interested in (refcount == 1) so | |
553 | * synthesize the implied extent and pass it back. | |
554 | * We assume here that the agbno/aglen range was | |
555 | * passed in from a data fork extent mapping and | |
556 | * therefore is allocated to exactly one owner. | |
557 | */ | |
558 | cleft->rc_startblock = agbno; | |
559 | cleft->rc_blockcount = min(aglen, | |
560 | tmp.rc_startblock - agbno); | |
561 | cleft->rc_refcount = 1; | |
562 | } | |
563 | } else { | |
564 | /* | |
565 | * No extents, so pretend that there's one covering the whole | |
566 | * range. | |
567 | */ | |
568 | cleft->rc_startblock = agbno; | |
569 | cleft->rc_blockcount = aglen; | |
570 | cleft->rc_refcount = 1; | |
571 | } | |
572 | trace_xfs_refcount_find_left_extent(cur->bc_mp, cur->bc_private.a.agno, | |
573 | left, cleft, agbno); | |
574 | return error; | |
575 | ||
576 | out_error: | |
577 | trace_xfs_refcount_find_left_extent_error(cur->bc_mp, | |
578 | cur->bc_private.a.agno, error, _RET_IP_); | |
579 | return error; | |
580 | } | |
581 | ||
582 | /* | |
583 | * Find the right extent and the one before it (cright). This function | |
584 | * assumes that we've already split any extents crossing agbno + aglen. | |
585 | */ | |
586 | STATIC int | |
587 | xfs_refcount_find_right_extents( | |
588 | struct xfs_btree_cur *cur, | |
589 | struct xfs_refcount_irec *right, | |
590 | struct xfs_refcount_irec *cright, | |
591 | xfs_agblock_t agbno, | |
592 | xfs_extlen_t aglen) | |
593 | { | |
594 | struct xfs_refcount_irec tmp; | |
595 | int error; | |
596 | int found_rec; | |
597 | ||
598 | right->rc_startblock = cright->rc_startblock = NULLAGBLOCK; | |
599 | error = xfs_refcount_lookup_ge(cur, agbno + aglen, &found_rec); | |
600 | if (error) | |
601 | goto out_error; | |
602 | if (!found_rec) | |
603 | return 0; | |
604 | ||
605 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
606 | if (error) | |
607 | goto out_error; | |
608 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, out_error); | |
609 | ||
610 | if (tmp.rc_startblock != agbno + aglen) | |
611 | return 0; | |
612 | /* We have a right extent; retrieve (or invent) the next left one */ | |
613 | *right = tmp; | |
614 | ||
615 | error = xfs_btree_decrement(cur, 0, &found_rec); | |
616 | if (error) | |
617 | goto out_error; | |
618 | if (found_rec) { | |
619 | error = xfs_refcount_get_rec(cur, &tmp, &found_rec); | |
620 | if (error) | |
621 | goto out_error; | |
622 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, found_rec == 1, | |
623 | out_error); | |
624 | ||
625 | /* if tmp ends at the end of our range, just use that */ | |
626 | if (xfs_refc_next(&tmp) == agbno + aglen) | |
627 | *cright = tmp; | |
628 | else { | |
629 | /* | |
630 | * There's a gap in the refcntbt at the end of the | |
631 | * range we're interested in (refcount == 1) so | |
632 | * create the implied extent and pass it back. | |
633 | * We assume here that the agbno/aglen range was | |
634 | * passed in from a data fork extent mapping and | |
635 | * therefore is allocated to exactly one owner. | |
636 | */ | |
637 | cright->rc_startblock = max(agbno, xfs_refc_next(&tmp)); | |
638 | cright->rc_blockcount = right->rc_startblock - | |
639 | cright->rc_startblock; | |
640 | cright->rc_refcount = 1; | |
641 | } | |
642 | } else { | |
643 | /* | |
644 | * No extents, so pretend that there's one covering the whole | |
645 | * range. | |
646 | */ | |
647 | cright->rc_startblock = agbno; | |
648 | cright->rc_blockcount = aglen; | |
649 | cright->rc_refcount = 1; | |
650 | } | |
651 | trace_xfs_refcount_find_right_extent(cur->bc_mp, cur->bc_private.a.agno, | |
652 | cright, right, agbno + aglen); | |
653 | return error; | |
654 | ||
655 | out_error: | |
656 | trace_xfs_refcount_find_right_extent_error(cur->bc_mp, | |
657 | cur->bc_private.a.agno, error, _RET_IP_); | |
658 | return error; | |
659 | } | |
660 | ||
661 | /* Is this extent valid? */ | |
662 | static inline bool | |
663 | xfs_refc_valid( | |
664 | struct xfs_refcount_irec *rc) | |
665 | { | |
666 | return rc->rc_startblock != NULLAGBLOCK; | |
667 | } | |
668 | ||
669 | /* | |
670 | * Try to merge with any extents on the boundaries of the adjustment range. | |
671 | */ | |
672 | STATIC int | |
673 | xfs_refcount_merge_extents( | |
674 | struct xfs_btree_cur *cur, | |
675 | xfs_agblock_t *agbno, | |
676 | xfs_extlen_t *aglen, | |
677 | enum xfs_refc_adjust_op adjust, | |
678 | bool *shape_changed) | |
679 | { | |
680 | struct xfs_refcount_irec left = {0}, cleft = {0}; | |
681 | struct xfs_refcount_irec cright = {0}, right = {0}; | |
682 | int error; | |
683 | unsigned long long ulen; | |
684 | bool cequal; | |
685 | ||
686 | *shape_changed = false; | |
687 | /* | |
688 | * Find the extent just below agbno [left], just above agbno [cleft], | |
689 | * just below (agbno + aglen) [cright], and just above (agbno + aglen) | |
690 | * [right]. | |
691 | */ | |
692 | error = xfs_refcount_find_left_extents(cur, &left, &cleft, *agbno, | |
693 | *aglen); | |
694 | if (error) | |
695 | return error; | |
696 | error = xfs_refcount_find_right_extents(cur, &right, &cright, *agbno, | |
697 | *aglen); | |
698 | if (error) | |
699 | return error; | |
700 | ||
701 | /* No left or right extent to merge; exit. */ | |
702 | if (!xfs_refc_valid(&left) && !xfs_refc_valid(&right)) | |
703 | return 0; | |
704 | ||
705 | cequal = (cleft.rc_startblock == cright.rc_startblock) && | |
706 | (cleft.rc_blockcount == cright.rc_blockcount); | |
707 | ||
708 | /* Try to merge left, cleft, and right. cleft must == cright. */ | |
709 | ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount + | |
710 | right.rc_blockcount; | |
711 | if (xfs_refc_valid(&left) && xfs_refc_valid(&right) && | |
712 | xfs_refc_valid(&cleft) && xfs_refc_valid(&cright) && cequal && | |
713 | left.rc_refcount == cleft.rc_refcount + adjust && | |
714 | right.rc_refcount == cleft.rc_refcount + adjust && | |
715 | ulen < MAXREFCEXTLEN) { | |
716 | *shape_changed = true; | |
717 | return xfs_refcount_merge_center_extents(cur, &left, &cleft, | |
718 | &right, ulen, agbno, aglen); | |
719 | } | |
720 | ||
721 | /* Try to merge left and cleft. */ | |
722 | ulen = (unsigned long long)left.rc_blockcount + cleft.rc_blockcount; | |
723 | if (xfs_refc_valid(&left) && xfs_refc_valid(&cleft) && | |
724 | left.rc_refcount == cleft.rc_refcount + adjust && | |
725 | ulen < MAXREFCEXTLEN) { | |
726 | *shape_changed = true; | |
727 | error = xfs_refcount_merge_left_extent(cur, &left, &cleft, | |
728 | agbno, aglen); | |
729 | if (error) | |
730 | return error; | |
731 | ||
732 | /* | |
733 | * If we just merged left + cleft and cleft == cright, | |
734 | * we no longer have a cright to merge with right. We're done. | |
735 | */ | |
736 | if (cequal) | |
737 | return 0; | |
738 | } | |
739 | ||
740 | /* Try to merge cright and right. */ | |
741 | ulen = (unsigned long long)right.rc_blockcount + cright.rc_blockcount; | |
742 | if (xfs_refc_valid(&right) && xfs_refc_valid(&cright) && | |
743 | right.rc_refcount == cright.rc_refcount + adjust && | |
744 | ulen < MAXREFCEXTLEN) { | |
745 | *shape_changed = true; | |
746 | return xfs_refcount_merge_right_extent(cur, &right, &cright, | |
747 | agbno, aglen); | |
748 | } | |
749 | ||
750 | return error; | |
751 | } | |
752 | ||
753 | /* | |
754 | * While we're adjusting the refcounts records of an extent, we have | |
755 | * to keep an eye on the number of extents we're dirtying -- run too | |
756 | * many in a single transaction and we'll exceed the transaction's | |
757 | * reservation and crash the fs. Each record adds 12 bytes to the | |
758 | * log (plus any key updates) so we'll conservatively assume 24 bytes | |
759 | * per record. We must also leave space for btree splits on both ends | |
760 | * of the range and space for the CUD and a new CUI. | |
761 | * | |
762 | * XXX: This is a pretty hand-wavy estimate. The penalty for guessing | |
763 | * true incorrectly is a shutdown FS; the penalty for guessing false | |
764 | * incorrectly is more transaction rolls than might be necessary. | |
765 | * Be conservative here. | |
766 | */ | |
767 | static bool | |
768 | xfs_refcount_still_have_space( | |
769 | struct xfs_btree_cur *cur) | |
770 | { | |
771 | unsigned long overhead; | |
772 | ||
773 | overhead = cur->bc_private.a.priv.refc.shape_changes * | |
774 | xfs_allocfree_log_count(cur->bc_mp, 1); | |
775 | overhead *= cur->bc_mp->m_sb.sb_blocksize; | |
776 | ||
777 | /* | |
778 | * Only allow 2 refcount extent updates per transaction if the | |
779 | * refcount continue update "error" has been injected. | |
780 | */ | |
781 | if (cur->bc_private.a.priv.refc.nr_ops > 2 && | |
782 | XFS_TEST_ERROR(false, cur->bc_mp, | |
783 | XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE, | |
784 | XFS_RANDOM_REFCOUNT_CONTINUE_UPDATE)) | |
785 | return false; | |
786 | ||
787 | if (cur->bc_private.a.priv.refc.nr_ops == 0) | |
788 | return true; | |
789 | else if (overhead > cur->bc_tp->t_log_res) | |
790 | return false; | |
791 | return cur->bc_tp->t_log_res - overhead > | |
792 | cur->bc_private.a.priv.refc.nr_ops * 32; | |
793 | } | |
794 | ||
795 | /* | |
796 | * Adjust the refcounts of middle extents. At this point we should have | |
797 | * split extents that crossed the adjustment range; merged with adjacent | |
798 | * extents; and updated agbno/aglen to reflect the merges. Therefore, | |
799 | * all we have to do is update the extents inside [agbno, agbno + aglen]. | |
800 | */ | |
801 | STATIC int | |
802 | xfs_refcount_adjust_extents( | |
803 | struct xfs_btree_cur *cur, | |
804 | xfs_agblock_t *agbno, | |
805 | xfs_extlen_t *aglen, | |
806 | enum xfs_refc_adjust_op adj, | |
807 | struct xfs_defer_ops *dfops, | |
808 | struct xfs_owner_info *oinfo) | |
809 | { | |
810 | struct xfs_refcount_irec ext, tmp; | |
811 | int error; | |
812 | int found_rec, found_tmp; | |
813 | xfs_fsblock_t fsbno; | |
814 | ||
815 | /* Merging did all the work already. */ | |
816 | if (*aglen == 0) | |
817 | return 0; | |
818 | ||
819 | error = xfs_refcount_lookup_ge(cur, *agbno, &found_rec); | |
820 | if (error) | |
821 | goto out_error; | |
822 | ||
823 | while (*aglen > 0 && xfs_refcount_still_have_space(cur)) { | |
824 | error = xfs_refcount_get_rec(cur, &ext, &found_rec); | |
825 | if (error) | |
826 | goto out_error; | |
827 | if (!found_rec) { | |
828 | ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks; | |
829 | ext.rc_blockcount = 0; | |
830 | ext.rc_refcount = 0; | |
831 | } | |
832 | ||
833 | /* | |
834 | * Deal with a hole in the refcount tree; if a file maps to | |
835 | * these blocks and there's no refcountbt record, pretend that | |
836 | * there is one with refcount == 1. | |
837 | */ | |
838 | if (ext.rc_startblock != *agbno) { | |
839 | tmp.rc_startblock = *agbno; | |
840 | tmp.rc_blockcount = min(*aglen, | |
841 | ext.rc_startblock - *agbno); | |
842 | tmp.rc_refcount = 1 + adj; | |
843 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
844 | cur->bc_private.a.agno, &tmp); | |
845 | ||
846 | /* | |
847 | * Either cover the hole (increment) or | |
848 | * delete the range (decrement). | |
849 | */ | |
850 | if (tmp.rc_refcount) { | |
851 | error = xfs_refcount_insert(cur, &tmp, | |
852 | &found_tmp); | |
853 | if (error) | |
854 | goto out_error; | |
855 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
856 | found_tmp == 1, out_error); | |
857 | cur->bc_private.a.priv.refc.nr_ops++; | |
858 | } else { | |
859 | fsbno = XFS_AGB_TO_FSB(cur->bc_mp, | |
860 | cur->bc_private.a.agno, | |
861 | tmp.rc_startblock); | |
862 | xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, | |
863 | tmp.rc_blockcount, oinfo); | |
864 | } | |
865 | ||
866 | (*agbno) += tmp.rc_blockcount; | |
867 | (*aglen) -= tmp.rc_blockcount; | |
868 | ||
869 | error = xfs_refcount_lookup_ge(cur, *agbno, | |
870 | &found_rec); | |
871 | if (error) | |
872 | goto out_error; | |
873 | } | |
874 | ||
875 | /* Stop if there's nothing left to modify */ | |
876 | if (*aglen == 0 || !xfs_refcount_still_have_space(cur)) | |
877 | break; | |
878 | ||
879 | /* | |
880 | * Adjust the reference count and either update the tree | |
881 | * (incr) or free the blocks (decr). | |
882 | */ | |
883 | if (ext.rc_refcount == MAXREFCOUNT) | |
884 | goto skip; | |
885 | ext.rc_refcount += adj; | |
886 | trace_xfs_refcount_modify_extent(cur->bc_mp, | |
887 | cur->bc_private.a.agno, &ext); | |
888 | if (ext.rc_refcount > 1) { | |
889 | error = xfs_refcount_update(cur, &ext); | |
890 | if (error) | |
891 | goto out_error; | |
892 | cur->bc_private.a.priv.refc.nr_ops++; | |
893 | } else if (ext.rc_refcount == 1) { | |
894 | error = xfs_refcount_delete(cur, &found_rec); | |
895 | if (error) | |
896 | goto out_error; | |
897 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, | |
898 | found_rec == 1, out_error); | |
899 | cur->bc_private.a.priv.refc.nr_ops++; | |
900 | goto advloop; | |
901 | } else { | |
902 | fsbno = XFS_AGB_TO_FSB(cur->bc_mp, | |
903 | cur->bc_private.a.agno, | |
904 | ext.rc_startblock); | |
905 | xfs_bmap_add_free(cur->bc_mp, dfops, fsbno, | |
906 | ext.rc_blockcount, oinfo); | |
907 | } | |
908 | ||
909 | skip: | |
910 | error = xfs_btree_increment(cur, 0, &found_rec); | |
911 | if (error) | |
912 | goto out_error; | |
913 | ||
914 | advloop: | |
915 | (*agbno) += ext.rc_blockcount; | |
916 | (*aglen) -= ext.rc_blockcount; | |
917 | } | |
918 | ||
919 | return error; | |
920 | out_error: | |
921 | trace_xfs_refcount_modify_extent_error(cur->bc_mp, | |
922 | cur->bc_private.a.agno, error, _RET_IP_); | |
923 | return error; | |
924 | } | |
925 | ||
926 | /* Adjust the reference count of a range of AG blocks. */ | |
927 | STATIC int | |
928 | xfs_refcount_adjust( | |
929 | struct xfs_btree_cur *cur, | |
930 | xfs_agblock_t agbno, | |
931 | xfs_extlen_t aglen, | |
932 | xfs_agblock_t *new_agbno, | |
933 | xfs_extlen_t *new_aglen, | |
934 | enum xfs_refc_adjust_op adj, | |
935 | struct xfs_defer_ops *dfops, | |
936 | struct xfs_owner_info *oinfo) | |
937 | { | |
938 | bool shape_changed; | |
939 | int shape_changes = 0; | |
940 | int error; | |
941 | ||
942 | *new_agbno = agbno; | |
943 | *new_aglen = aglen; | |
944 | if (adj == XFS_REFCOUNT_ADJUST_INCREASE) | |
945 | trace_xfs_refcount_increase(cur->bc_mp, cur->bc_private.a.agno, | |
946 | agbno, aglen); | |
947 | else | |
948 | trace_xfs_refcount_decrease(cur->bc_mp, cur->bc_private.a.agno, | |
949 | agbno, aglen); | |
950 | ||
951 | /* | |
952 | * Ensure that no rcextents cross the boundary of the adjustment range. | |
953 | */ | |
954 | error = xfs_refcount_split_extent(cur, agbno, &shape_changed); | |
955 | if (error) | |
956 | goto out_error; | |
957 | if (shape_changed) | |
958 | shape_changes++; | |
959 | ||
960 | error = xfs_refcount_split_extent(cur, agbno + aglen, &shape_changed); | |
961 | if (error) | |
962 | goto out_error; | |
963 | if (shape_changed) | |
964 | shape_changes++; | |
965 | ||
966 | /* | |
967 | * Try to merge with the left or right extents of the range. | |
968 | */ | |
969 | error = xfs_refcount_merge_extents(cur, new_agbno, new_aglen, adj, | |
970 | &shape_changed); | |
971 | if (error) | |
972 | goto out_error; | |
973 | if (shape_changed) | |
974 | shape_changes++; | |
975 | if (shape_changes) | |
976 | cur->bc_private.a.priv.refc.shape_changes++; | |
977 | ||
978 | /* Now that we've taken care of the ends, adjust the middle extents */ | |
979 | error = xfs_refcount_adjust_extents(cur, new_agbno, new_aglen, | |
980 | adj, dfops, oinfo); | |
981 | if (error) | |
982 | goto out_error; | |
983 | ||
984 | return 0; | |
985 | ||
986 | out_error: | |
987 | trace_xfs_refcount_adjust_error(cur->bc_mp, cur->bc_private.a.agno, | |
988 | error, _RET_IP_); | |
989 | return error; | |
990 | } | |
23a15a6c DW |
991 | |
992 | /* Clean up after calling xfs_refcount_finish_one. */ | |
993 | void | |
994 | xfs_refcount_finish_one_cleanup( | |
995 | struct xfs_trans *tp, | |
996 | struct xfs_btree_cur *rcur, | |
997 | int error) | |
998 | { | |
999 | struct xfs_buf *agbp; | |
1000 | ||
1001 | if (rcur == NULL) | |
1002 | return; | |
1003 | agbp = rcur->bc_private.a.agbp; | |
1004 | xfs_btree_del_cursor(rcur, error ? XFS_BTREE_ERROR : XFS_BTREE_NOERROR); | |
1005 | if (error) | |
1006 | xfs_trans_brelse(tp, agbp); | |
1007 | } | |
1008 | ||
1009 | /* | |
1010 | * Process one of the deferred refcount operations. We pass back the | |
1011 | * btree cursor to maintain our lock on the btree between calls. | |
1012 | * This saves time and eliminates a buffer deadlock between the | |
1013 | * superblock and the AGF because we'll always grab them in the same | |
1014 | * order. | |
1015 | */ | |
1016 | int | |
1017 | xfs_refcount_finish_one( | |
1018 | struct xfs_trans *tp, | |
1019 | struct xfs_defer_ops *dfops, | |
1020 | enum xfs_refcount_intent_type type, | |
1021 | xfs_fsblock_t startblock, | |
1022 | xfs_extlen_t blockcount, | |
1023 | xfs_fsblock_t *new_fsb, | |
1024 | xfs_extlen_t *new_len, | |
1025 | struct xfs_btree_cur **pcur) | |
1026 | { | |
1027 | struct xfs_mount *mp = tp->t_mountp; | |
1028 | struct xfs_btree_cur *rcur; | |
1029 | struct xfs_buf *agbp = NULL; | |
1030 | int error = 0; | |
1031 | xfs_agnumber_t agno; | |
1032 | xfs_agblock_t bno; | |
1033 | xfs_agblock_t new_agbno; | |
1034 | unsigned long nr_ops = 0; | |
1035 | int shape_changes = 0; | |
1036 | ||
1037 | agno = XFS_FSB_TO_AGNO(mp, startblock); | |
1038 | ASSERT(agno != NULLAGNUMBER); | |
1039 | bno = XFS_FSB_TO_AGBNO(mp, startblock); | |
1040 | ||
1041 | trace_xfs_refcount_deferred(mp, XFS_FSB_TO_AGNO(mp, startblock), | |
1042 | type, XFS_FSB_TO_AGBNO(mp, startblock), | |
1043 | blockcount); | |
1044 | ||
1045 | if (XFS_TEST_ERROR(false, mp, | |
1046 | XFS_ERRTAG_REFCOUNT_FINISH_ONE, | |
1047 | XFS_RANDOM_REFCOUNT_FINISH_ONE)) | |
1048 | return -EIO; | |
1049 | ||
1050 | /* | |
1051 | * If we haven't gotten a cursor or the cursor AG doesn't match | |
1052 | * the startblock, get one now. | |
1053 | */ | |
1054 | rcur = *pcur; | |
1055 | if (rcur != NULL && rcur->bc_private.a.agno != agno) { | |
1056 | nr_ops = rcur->bc_private.a.priv.refc.nr_ops; | |
1057 | shape_changes = rcur->bc_private.a.priv.refc.shape_changes; | |
1058 | xfs_refcount_finish_one_cleanup(tp, rcur, 0); | |
1059 | rcur = NULL; | |
1060 | *pcur = NULL; | |
1061 | } | |
1062 | if (rcur == NULL) { | |
1063 | error = xfs_alloc_read_agf(tp->t_mountp, tp, agno, | |
1064 | XFS_ALLOC_FLAG_FREEING, &agbp); | |
1065 | if (error) | |
1066 | return error; | |
1067 | if (!agbp) | |
1068 | return -EFSCORRUPTED; | |
1069 | ||
1070 | rcur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, dfops); | |
1071 | if (!rcur) { | |
1072 | error = -ENOMEM; | |
1073 | goto out_cur; | |
1074 | } | |
1075 | rcur->bc_private.a.priv.refc.nr_ops = nr_ops; | |
1076 | rcur->bc_private.a.priv.refc.shape_changes = shape_changes; | |
1077 | } | |
1078 | *pcur = rcur; | |
1079 | ||
1080 | switch (type) { | |
1081 | case XFS_REFCOUNT_INCREASE: | |
1082 | error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, | |
1083 | new_len, XFS_REFCOUNT_ADJUST_INCREASE, dfops, NULL); | |
1084 | *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); | |
1085 | break; | |
1086 | case XFS_REFCOUNT_DECREASE: | |
1087 | error = xfs_refcount_adjust(rcur, bno, blockcount, &new_agbno, | |
1088 | new_len, XFS_REFCOUNT_ADJUST_DECREASE, dfops, NULL); | |
1089 | *new_fsb = XFS_AGB_TO_FSB(mp, agno, new_agbno); | |
1090 | break; | |
1091 | default: | |
1092 | ASSERT(0); | |
1093 | error = -EFSCORRUPTED; | |
1094 | } | |
1095 | if (!error && *new_len > 0) | |
1096 | trace_xfs_refcount_finish_one_leftover(mp, agno, type, | |
1097 | bno, blockcount, new_agbno, *new_len); | |
1098 | return error; | |
1099 | ||
1100 | out_cur: | |
1101 | xfs_trans_brelse(tp, agbp); | |
1102 | ||
1103 | return error; | |
1104 | } | |
1105 | ||
1106 | /* | |
1107 | * Record a refcount intent for later processing. | |
1108 | */ | |
1109 | static int | |
1110 | __xfs_refcount_add( | |
1111 | struct xfs_mount *mp, | |
1112 | struct xfs_defer_ops *dfops, | |
1113 | enum xfs_refcount_intent_type type, | |
1114 | xfs_fsblock_t startblock, | |
1115 | xfs_extlen_t blockcount) | |
1116 | { | |
1117 | struct xfs_refcount_intent *ri; | |
1118 | ||
1119 | trace_xfs_refcount_defer(mp, XFS_FSB_TO_AGNO(mp, startblock), | |
1120 | type, XFS_FSB_TO_AGBNO(mp, startblock), | |
1121 | blockcount); | |
1122 | ||
1123 | ri = kmem_alloc(sizeof(struct xfs_refcount_intent), | |
1124 | KM_SLEEP | KM_NOFS); | |
1125 | INIT_LIST_HEAD(&ri->ri_list); | |
1126 | ri->ri_type = type; | |
1127 | ri->ri_startblock = startblock; | |
1128 | ri->ri_blockcount = blockcount; | |
1129 | ||
1130 | xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_REFCOUNT, &ri->ri_list); | |
1131 | return 0; | |
1132 | } | |
1133 | ||
1134 | /* | |
1135 | * Increase the reference count of the blocks backing a file's extent. | |
1136 | */ | |
1137 | int | |
1138 | xfs_refcount_increase_extent( | |
1139 | struct xfs_mount *mp, | |
1140 | struct xfs_defer_ops *dfops, | |
1141 | struct xfs_bmbt_irec *PREV) | |
1142 | { | |
1143 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1144 | return 0; | |
1145 | ||
1146 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_INCREASE, | |
1147 | PREV->br_startblock, PREV->br_blockcount); | |
1148 | } | |
1149 | ||
1150 | /* | |
1151 | * Decrease the reference count of the blocks backing a file's extent. | |
1152 | */ | |
1153 | int | |
1154 | xfs_refcount_decrease_extent( | |
1155 | struct xfs_mount *mp, | |
1156 | struct xfs_defer_ops *dfops, | |
1157 | struct xfs_bmbt_irec *PREV) | |
1158 | { | |
1159 | if (!xfs_sb_version_hasreflink(&mp->m_sb)) | |
1160 | return 0; | |
1161 | ||
1162 | return __xfs_refcount_add(mp, dfops, XFS_REFCOUNT_DECREASE, | |
1163 | PREV->br_startblock, PREV->br_blockcount); | |
1164 | } | |
94097330 DW |
1165 | |
1166 | /* | |
1167 | * Given an AG extent, find the lowest-numbered run of shared blocks | |
1168 | * within that range and return the range in fbno/flen. If | |
1169 | * find_end_of_shared is set, return the longest contiguous extent of | |
1170 | * shared blocks; if not, just return the first extent we find. If no | |
1171 | * shared blocks are found, fbno and flen will be set to NULLAGBLOCK | |
1172 | * and 0, respectively. | |
1173 | */ | |
1174 | int | |
1175 | xfs_refcount_find_shared( | |
1176 | struct xfs_btree_cur *cur, | |
1177 | xfs_agblock_t agbno, | |
1178 | xfs_extlen_t aglen, | |
1179 | xfs_agblock_t *fbno, | |
1180 | xfs_extlen_t *flen, | |
1181 | bool find_end_of_shared) | |
1182 | { | |
1183 | struct xfs_refcount_irec tmp; | |
1184 | int i; | |
1185 | int have; | |
1186 | int error; | |
1187 | ||
1188 | trace_xfs_refcount_find_shared(cur->bc_mp, cur->bc_private.a.agno, | |
1189 | agbno, aglen); | |
1190 | ||
1191 | /* By default, skip the whole range */ | |
1192 | *fbno = NULLAGBLOCK; | |
1193 | *flen = 0; | |
1194 | ||
1195 | /* Try to find a refcount extent that crosses the start */ | |
1196 | error = xfs_refcount_lookup_le(cur, agbno, &have); | |
1197 | if (error) | |
1198 | goto out_error; | |
1199 | if (!have) { | |
1200 | /* No left extent, look at the next one */ | |
1201 | error = xfs_btree_increment(cur, 0, &have); | |
1202 | if (error) | |
1203 | goto out_error; | |
1204 | if (!have) | |
1205 | goto done; | |
1206 | } | |
1207 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1208 | if (error) | |
1209 | goto out_error; | |
1210 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1211 | ||
1212 | /* If the extent ends before the start, look at the next one */ | |
1213 | if (tmp.rc_startblock + tmp.rc_blockcount <= agbno) { | |
1214 | error = xfs_btree_increment(cur, 0, &have); | |
1215 | if (error) | |
1216 | goto out_error; | |
1217 | if (!have) | |
1218 | goto done; | |
1219 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1220 | if (error) | |
1221 | goto out_error; | |
1222 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1223 | } | |
1224 | ||
1225 | /* If the extent starts after the range we want, bail out */ | |
1226 | if (tmp.rc_startblock >= agbno + aglen) | |
1227 | goto done; | |
1228 | ||
1229 | /* We found the start of a shared extent! */ | |
1230 | if (tmp.rc_startblock < agbno) { | |
1231 | tmp.rc_blockcount -= (agbno - tmp.rc_startblock); | |
1232 | tmp.rc_startblock = agbno; | |
1233 | } | |
1234 | ||
1235 | *fbno = tmp.rc_startblock; | |
1236 | *flen = min(tmp.rc_blockcount, agbno + aglen - *fbno); | |
1237 | if (!find_end_of_shared) | |
1238 | goto done; | |
1239 | ||
1240 | /* Otherwise, find the end of this shared extent */ | |
1241 | while (*fbno + *flen < agbno + aglen) { | |
1242 | error = xfs_btree_increment(cur, 0, &have); | |
1243 | if (error) | |
1244 | goto out_error; | |
1245 | if (!have) | |
1246 | break; | |
1247 | error = xfs_refcount_get_rec(cur, &tmp, &i); | |
1248 | if (error) | |
1249 | goto out_error; | |
1250 | XFS_WANT_CORRUPTED_GOTO(cur->bc_mp, i == 1, out_error); | |
1251 | if (tmp.rc_startblock >= agbno + aglen || | |
1252 | tmp.rc_startblock != *fbno + *flen) | |
1253 | break; | |
1254 | *flen = min(*flen + tmp.rc_blockcount, agbno + aglen - *fbno); | |
1255 | } | |
1256 | ||
1257 | done: | |
1258 | trace_xfs_refcount_find_shared_result(cur->bc_mp, | |
1259 | cur->bc_private.a.agno, *fbno, *flen); | |
1260 | ||
1261 | out_error: | |
1262 | if (error) | |
1263 | trace_xfs_refcount_find_shared_error(cur->bc_mp, | |
1264 | cur->bc_private.a.agno, error, _RET_IP_); | |
1265 | return error; | |
1266 | } |