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mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race
[linux/fpc-iii.git] / fs / xfs / libxfs / xfs_alloc.c
bloba10d9a3c181e4534216214d33830b515fb6b3bf9
1 /*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_format.h"
21 #include "xfs_log_format.h"
22 #include "xfs_shared.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_bit.h"
25 #include "xfs_sb.h"
26 #include "xfs_mount.h"
27 #include "xfs_defer.h"
28 #include "xfs_inode.h"
29 #include "xfs_btree.h"
30 #include "xfs_rmap.h"
31 #include "xfs_alloc_btree.h"
32 #include "xfs_alloc.h"
33 #include "xfs_extent_busy.h"
34 #include "xfs_error.h"
35 #include "xfs_cksum.h"
36 #include "xfs_trace.h"
37 #include "xfs_trans.h"
38 #include "xfs_buf_item.h"
39 #include "xfs_log.h"
40 #include "xfs_ag_resv.h"
41
42 struct workqueue_struct *xfs_alloc_wq;
43
44 #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
45
46 #define XFSA_FIXUP_BNO_OK 1
47 #define XFSA_FIXUP_CNT_OK 2
48
49 STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
50 STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
51 STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
52 STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
53 xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
54
55 /*
56 * Size of the AGFL. For CRC-enabled filesystes we steal a couple of slots in
57 * the beginning of the block for a proper header with the location information
58 * and CRC.
59 */
60 unsigned int
61 xfs_agfl_size(
62 struct xfs_mount *mp)
63 {
64 unsigned int size = mp->m_sb.sb_sectsize;
65
66 if (xfs_sb_version_hascrc(&mp->m_sb))
67 size -= sizeof(struct xfs_agfl);
68
69 return size / sizeof(xfs_agblock_t);
70 }
71
72 unsigned int
73 xfs_refc_block(
74 struct xfs_mount *mp)
75 {
76 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
77 return XFS_RMAP_BLOCK(mp) + 1;
78 if (xfs_sb_version_hasfinobt(&mp->m_sb))
79 return XFS_FIBT_BLOCK(mp) + 1;
80 return XFS_IBT_BLOCK(mp) + 1;
81 }
82
83 xfs_extlen_t
84 xfs_prealloc_blocks(
85 struct xfs_mount *mp)
86 {
87 if (xfs_sb_version_hasreflink(&mp->m_sb))
88 return xfs_refc_block(mp) + 1;
89 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
90 return XFS_RMAP_BLOCK(mp) + 1;
91 if (xfs_sb_version_hasfinobt(&mp->m_sb))
92 return XFS_FIBT_BLOCK(mp) + 1;
93 return XFS_IBT_BLOCK(mp) + 1;
94 }
95
96 /*
97 * In order to avoid ENOSPC-related deadlock caused by out-of-order locking of
98 * AGF buffer (PV 947395), we place constraints on the relationship among
99 * actual allocations for data blocks, freelist blocks, and potential file data
100 * bmap btree blocks. However, these restrictions may result in no actual space
101 * allocated for a delayed extent, for example, a data block in a certain AG is
102 * allocated but there is no additional block for the additional bmap btree
103 * block due to a split of the bmap btree of the file. The result of this may
104 * lead to an infinite loop when the file gets flushed to disk and all delayed
105 * extents need to be actually allocated. To get around this, we explicitly set
106 * aside a few blocks which will not be reserved in delayed allocation.
107 *
108 * We need to reserve 4 fsbs _per AG_ for the freelist and 4 more to handle a
109 * potential split of the file's bmap btree.
110 */
111 unsigned int
112 xfs_alloc_set_aside(
113 struct xfs_mount *mp)
114 {
115 return mp->m_sb.sb_agcount * (XFS_ALLOC_AGFL_RESERVE + 4);
116 }
117
118 /*
119 * When deciding how much space to allocate out of an AG, we limit the
120 * allocation maximum size to the size the AG. However, we cannot use all the
121 * blocks in the AG - some are permanently used by metadata. These
122 * blocks are generally:
123 * - the AG superblock, AGF, AGI and AGFL
124 * - the AGF (bno and cnt) and AGI btree root blocks, and optionally
125 * the AGI free inode and rmap btree root blocks.
126 * - blocks on the AGFL according to xfs_alloc_set_aside() limits
127 * - the rmapbt root block
128 *
129 * The AG headers are sector sized, so the amount of space they take up is
130 * dependent on filesystem geometry. The others are all single blocks.
131 */
132 unsigned int
133 xfs_alloc_ag_max_usable(
134 struct xfs_mount *mp)
135 {
136 unsigned int blocks;
137
138 blocks = XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)); /* ag headers */
139 blocks += XFS_ALLOC_AGFL_RESERVE;
140 blocks += 3; /* AGF, AGI btree root blocks */
141 if (xfs_sb_version_hasfinobt(&mp->m_sb))
142 blocks++; /* finobt root block */
143 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
144 blocks++; /* rmap root block */
145 if (xfs_sb_version_hasreflink(&mp->m_sb))
146 blocks++; /* refcount root block */
147
148 return mp->m_sb.sb_agblocks - blocks;
149 }
150
151 /*
152 * Lookup the record equal to [bno, len] in the btree given by cur.
153 */
154 STATIC int /* error */
155 xfs_alloc_lookup_eq(
156 struct xfs_btree_cur *cur, /* btree cursor */
157 xfs_agblock_t bno, /* starting block of extent */
158 xfs_extlen_t len, /* length of extent */
159 int *stat) /* success/failure */
160 {
161 cur->bc_rec.a.ar_startblock = bno;
162 cur->bc_rec.a.ar_blockcount = len;
163 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
164 }
165
166 /*
167 * Lookup the first record greater than or equal to [bno, len]
168 * in the btree given by cur.
169 */
170 int /* error */
171 xfs_alloc_lookup_ge(
172 struct xfs_btree_cur *cur, /* btree cursor */
173 xfs_agblock_t bno, /* starting block of extent */
174 xfs_extlen_t len, /* length of extent */
175 int *stat) /* success/failure */
176 {
177 cur->bc_rec.a.ar_startblock = bno;
178 cur->bc_rec.a.ar_blockcount = len;
179 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
180 }
181
182 /*
183 * Lookup the first record less than or equal to [bno, len]
184 * in the btree given by cur.
185 */
186 static int /* error */
187 xfs_alloc_lookup_le(
188 struct xfs_btree_cur *cur, /* btree cursor */
189 xfs_agblock_t bno, /* starting block of extent */
190 xfs_extlen_t len, /* length of extent */
191 int *stat) /* success/failure */
192 {
193 cur->bc_rec.a.ar_startblock = bno;
194 cur->bc_rec.a.ar_blockcount = len;
195 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
196 }
197
198 /*
199 * Update the record referred to by cur to the value given
200 * by [bno, len].
201 * This either works (return 0) or gets an EFSCORRUPTED error.
202 */
203 STATIC int /* error */
204 xfs_alloc_update(
205 struct xfs_btree_cur *cur, /* btree cursor */
206 xfs_agblock_t bno, /* starting block of extent */
207 xfs_extlen_t len) /* length of extent */
208 {
209 union xfs_btree_rec rec;
210
211 rec.alloc.ar_startblock = cpu_to_be32(bno);
212 rec.alloc.ar_blockcount = cpu_to_be32(len);
213 return xfs_btree_update(cur, &rec);
214 }
215
216 /*
217 * Get the data from the pointed-to record.
218 */
219 int /* error */
220 xfs_alloc_get_rec(
221 struct xfs_btree_cur *cur, /* btree cursor */
222 xfs_agblock_t *bno, /* output: starting block of extent */
223 xfs_extlen_t *len, /* output: length of extent */
224 int *stat) /* output: success/failure */
225 {
226 union xfs_btree_rec *rec;
227 int error;
228
229 error = xfs_btree_get_rec(cur, &rec, stat);
230 if (!error && *stat == 1) {
231 *bno = be32_to_cpu(rec->alloc.ar_startblock);
232 *len = be32_to_cpu(rec->alloc.ar_blockcount);
233 }
234 return error;
235 }
236
237 /*
238 * Compute aligned version of the found extent.
239 * Takes alignment and min length into account.
240 */
241 STATIC bool
242 xfs_alloc_compute_aligned(
243 xfs_alloc_arg_t *args, /* allocation argument structure */
244 xfs_agblock_t foundbno, /* starting block in found extent */
245 xfs_extlen_t foundlen, /* length in found extent */
246 xfs_agblock_t *resbno, /* result block number */
247 xfs_extlen_t *reslen, /* result length */
248 unsigned *busy_gen)
249 {
250 xfs_agblock_t bno = foundbno;
251 xfs_extlen_t len = foundlen;
252 xfs_extlen_t diff;
253 bool busy;
254
255 /* Trim busy sections out of found extent */
256 busy = xfs_extent_busy_trim(args, &bno, &len, busy_gen);
257
258 /*
259 * If we have a largish extent that happens to start before min_agbno,
260 * see if we can shift it into range...
261 */
262 if (bno < args->min_agbno && bno + len > args->min_agbno) {
263 diff = args->min_agbno - bno;
264 if (len > diff) {
265 bno += diff;
266 len -= diff;
267 }
268 }
269
270 if (args->alignment > 1 && len >= args->minlen) {
271 xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
272
273 diff = aligned_bno - bno;
274
275 *resbno = aligned_bno;
276 *reslen = diff >= len ? 0 : len - diff;
277 } else {
278 *resbno = bno;
279 *reslen = len;
280 }
281
282 return busy;
283 }
284
285 /*
286 * Compute best start block and diff for "near" allocations.
287 * freelen >= wantlen already checked by caller.
288 */
289 STATIC xfs_extlen_t /* difference value (absolute) */
290 xfs_alloc_compute_diff(
291 xfs_agblock_t wantbno, /* target starting block */
292 xfs_extlen_t wantlen, /* target length */
293 xfs_extlen_t alignment, /* target alignment */
294 int datatype, /* are we allocating data? */
295 xfs_agblock_t freebno, /* freespace's starting block */
296 xfs_extlen_t freelen, /* freespace's length */
297 xfs_agblock_t *newbnop) /* result: best start block from free */
298 {
299 xfs_agblock_t freeend; /* end of freespace extent */
300 xfs_agblock_t newbno1; /* return block number */
301 xfs_agblock_t newbno2; /* other new block number */
302 xfs_extlen_t newlen1=0; /* length with newbno1 */
303 xfs_extlen_t newlen2=0; /* length with newbno2 */
304 xfs_agblock_t wantend; /* end of target extent */
305 bool userdata = xfs_alloc_is_userdata(datatype);
306
307 ASSERT(freelen >= wantlen);
308 freeend = freebno + freelen;
309 wantend = wantbno + wantlen;
310 /*
311 * We want to allocate from the start of a free extent if it is past
312 * the desired block or if we are allocating user data and the free
313 * extent is before desired block. The second case is there to allow
314 * for contiguous allocation from the remaining free space if the file
315 * grows in the short term.
316 */
317 if (freebno >= wantbno || (userdata && freeend < wantend)) {
318 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
319 newbno1 = NULLAGBLOCK;
320 } else if (freeend >= wantend && alignment > 1) {
321 newbno1 = roundup(wantbno, alignment);
322 newbno2 = newbno1 - alignment;
323 if (newbno1 >= freeend)
324 newbno1 = NULLAGBLOCK;
325 else
326 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
327 if (newbno2 < freebno)
328 newbno2 = NULLAGBLOCK;
329 else
330 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
331 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
332 if (newlen1 < newlen2 ||
333 (newlen1 == newlen2 &&
334 XFS_ABSDIFF(newbno1, wantbno) >
335 XFS_ABSDIFF(newbno2, wantbno)))
336 newbno1 = newbno2;
337 } else if (newbno2 != NULLAGBLOCK)
338 newbno1 = newbno2;
339 } else if (freeend >= wantend) {
340 newbno1 = wantbno;
341 } else if (alignment > 1) {
342 newbno1 = roundup(freeend - wantlen, alignment);
343 if (newbno1 > freeend - wantlen &&
344 newbno1 - alignment >= freebno)
345 newbno1 -= alignment;
346 else if (newbno1 >= freeend)
347 newbno1 = NULLAGBLOCK;
348 } else
349 newbno1 = freeend - wantlen;
350 *newbnop = newbno1;
351 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
352 }
353
354 /*
355 * Fix up the length, based on mod and prod.
356 * len should be k * prod + mod for some k.
357 * If len is too small it is returned unchanged.
358 * If len hits maxlen it is left alone.
359 */
360 STATIC void
361 xfs_alloc_fix_len(
362 xfs_alloc_arg_t *args) /* allocation argument structure */
363 {
364 xfs_extlen_t k;
365 xfs_extlen_t rlen;
366
367 ASSERT(args->mod < args->prod);
368 rlen = args->len;
369 ASSERT(rlen >= args->minlen);
370 ASSERT(rlen <= args->maxlen);
371 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
372 (args->mod == 0 && rlen < args->prod))
373 return;
374 k = rlen % args->prod;
375 if (k == args->mod)
376 return;
377 if (k > args->mod)
378 rlen = rlen - (k - args->mod);
379 else
380 rlen = rlen - args->prod + (args->mod - k);
381 /* casts to (int) catch length underflows */
382 if ((int)rlen < (int)args->minlen)
383 return;
384 ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
385 ASSERT(rlen % args->prod == args->mod);
386 ASSERT(args->pag->pagf_freeblks + args->pag->pagf_flcount >=
387 rlen + args->minleft);
388 args->len = rlen;
389 }
390
391 /*
392 * Update the two btrees, logically removing from freespace the extent
393 * starting at rbno, rlen blocks. The extent is contained within the
394 * actual (current) free extent fbno for flen blocks.
395 * Flags are passed in indicating whether the cursors are set to the
396 * relevant records.
397 */
398 STATIC int /* error code */
399 xfs_alloc_fixup_trees(
400 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
401 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
402 xfs_agblock_t fbno, /* starting block of free extent */
403 xfs_extlen_t flen, /* length of free extent */
404 xfs_agblock_t rbno, /* starting block of returned extent */
405 xfs_extlen_t rlen, /* length of returned extent */
406 int flags) /* flags, XFSA_FIXUP_... */
407 {
408 int error; /* error code */
409 int i; /* operation results */
410 xfs_agblock_t nfbno1; /* first new free startblock */
411 xfs_agblock_t nfbno2; /* second new free startblock */
412 xfs_extlen_t nflen1=0; /* first new free length */
413 xfs_extlen_t nflen2=0; /* second new free length */
414 struct xfs_mount *mp;
415
416 mp = cnt_cur->bc_mp;
417
418 /*
419 * Look up the record in the by-size tree if necessary.
420 */
421 if (flags & XFSA_FIXUP_CNT_OK) {
422 #ifdef DEBUG
423 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
424 return error;
425 XFS_WANT_CORRUPTED_RETURN(mp,
426 i == 1 && nfbno1 == fbno && nflen1 == flen);
427 #endif
428 } else {
429 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
430 return error;
431 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
432 }
433 /*
434 * Look up the record in the by-block tree if necessary.
435 */
436 if (flags & XFSA_FIXUP_BNO_OK) {
437 #ifdef DEBUG
438 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
439 return error;
440 XFS_WANT_CORRUPTED_RETURN(mp,
441 i == 1 && nfbno1 == fbno && nflen1 == flen);
442 #endif
443 } else {
444 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
445 return error;
446 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
447 }
448
449 #ifdef DEBUG
450 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
451 struct xfs_btree_block *bnoblock;
452 struct xfs_btree_block *cntblock;
453
454 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
455 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
456
457 XFS_WANT_CORRUPTED_RETURN(mp,
458 bnoblock->bb_numrecs == cntblock->bb_numrecs);
459 }
460 #endif
461
462 /*
463 * Deal with all four cases: the allocated record is contained
464 * within the freespace record, so we can have new freespace
465 * at either (or both) end, or no freespace remaining.
466 */
467 if (rbno == fbno && rlen == flen)
468 nfbno1 = nfbno2 = NULLAGBLOCK;
469 else if (rbno == fbno) {
470 nfbno1 = rbno + rlen;
471 nflen1 = flen - rlen;
472 nfbno2 = NULLAGBLOCK;
473 } else if (rbno + rlen == fbno + flen) {
474 nfbno1 = fbno;
475 nflen1 = flen - rlen;
476 nfbno2 = NULLAGBLOCK;
477 } else {
478 nfbno1 = fbno;
479 nflen1 = rbno - fbno;
480 nfbno2 = rbno + rlen;
481 nflen2 = (fbno + flen) - nfbno2;
482 }
483 /*
484 * Delete the entry from the by-size btree.
485 */
486 if ((error = xfs_btree_delete(cnt_cur, &i)))
487 return error;
488 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
489 /*
490 * Add new by-size btree entry(s).
491 */
492 if (nfbno1 != NULLAGBLOCK) {
493 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
494 return error;
495 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
496 if ((error = xfs_btree_insert(cnt_cur, &i)))
497 return error;
498 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
499 }
500 if (nfbno2 != NULLAGBLOCK) {
501 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
502 return error;
503 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
504 if ((error = xfs_btree_insert(cnt_cur, &i)))
505 return error;
506 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
507 }
508 /*
509 * Fix up the by-block btree entry(s).
510 */
511 if (nfbno1 == NULLAGBLOCK) {
512 /*
513 * No remaining freespace, just delete the by-block tree entry.
514 */
515 if ((error = xfs_btree_delete(bno_cur, &i)))
516 return error;
517 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
518 } else {
519 /*
520 * Update the by-block entry to start later|be shorter.
521 */
522 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
523 return error;
524 }
525 if (nfbno2 != NULLAGBLOCK) {
526 /*
527 * 2 resulting free entries, need to add one.
528 */
529 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
530 return error;
531 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
532 if ((error = xfs_btree_insert(bno_cur, &i)))
533 return error;
534 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
535 }
536 return 0;
537 }
538
539 static bool
540 xfs_agfl_verify(
541 struct xfs_buf *bp)
542 {
543 struct xfs_mount *mp = bp->b_target->bt_mount;
544 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
545 int i;
546
547 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid))
548 return false;
549 if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
550 return false;
551 /*
552 * during growfs operations, the perag is not fully initialised,
553 * so we can't use it for any useful checking. growfs ensures we can't
554 * use it by using uncached buffers that don't have the perag attached
555 * so we can detect and avoid this problem.
556 */
557 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
558 return false;
559
560 for (i = 0; i < xfs_agfl_size(mp); i++) {
561 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
562 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
563 return false;
564 }
565
566 return xfs_log_check_lsn(mp,
567 be64_to_cpu(XFS_BUF_TO_AGFL(bp)->agfl_lsn));
568 }
569
570 static void
571 xfs_agfl_read_verify(
572 struct xfs_buf *bp)
573 {
574 struct xfs_mount *mp = bp->b_target->bt_mount;
575
576 /*
577 * There is no verification of non-crc AGFLs because mkfs does not
578 * initialise the AGFL to zero or NULL. Hence the only valid part of the
579 * AGFL is what the AGF says is active. We can't get to the AGF, so we
580 * can't verify just those entries are valid.
581 */
582 if (!xfs_sb_version_hascrc(&mp->m_sb))
583 return;
584
585 if (!xfs_buf_verify_cksum(bp, XFS_AGFL_CRC_OFF))
586 xfs_buf_ioerror(bp, -EFSBADCRC);
587 else if (!xfs_agfl_verify(bp))
588 xfs_buf_ioerror(bp, -EFSCORRUPTED);
589
590 if (bp->b_error)
591 xfs_verifier_error(bp);
592 }
593
594 static void
595 xfs_agfl_write_verify(
596 struct xfs_buf *bp)
597 {
598 struct xfs_mount *mp = bp->b_target->bt_mount;
599 struct xfs_buf_log_item *bip = bp->b_fspriv;
600
601 /* no verification of non-crc AGFLs */
602 if (!xfs_sb_version_hascrc(&mp->m_sb))
603 return;
604
605 if (!xfs_agfl_verify(bp)) {
606 xfs_buf_ioerror(bp, -EFSCORRUPTED);
607 xfs_verifier_error(bp);
608 return;
609 }
610
611 if (bip)
612 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
613
614 xfs_buf_update_cksum(bp, XFS_AGFL_CRC_OFF);
615 }
616
617 const struct xfs_buf_ops xfs_agfl_buf_ops = {
618 .name = "xfs_agfl",
619 .verify_read = xfs_agfl_read_verify,
620 .verify_write = xfs_agfl_write_verify,
621 };
622
623 /*
624 * Read in the allocation group free block array.
625 */
626 int /* error */
627 xfs_alloc_read_agfl(
628 xfs_mount_t *mp, /* mount point structure */
629 xfs_trans_t *tp, /* transaction pointer */
630 xfs_agnumber_t agno, /* allocation group number */
631 xfs_buf_t **bpp) /* buffer for the ag free block array */
632 {
633 xfs_buf_t *bp; /* return value */
634 int error;
635
636 ASSERT(agno != NULLAGNUMBER);
637 error = xfs_trans_read_buf(
638 mp, tp, mp->m_ddev_targp,
639 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
640 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
641 if (error)
642 return error;
643 xfs_buf_set_ref(bp, XFS_AGFL_REF);
644 *bpp = bp;
645 return 0;
646 }
647
648 STATIC int
649 xfs_alloc_update_counters(
650 struct xfs_trans *tp,
651 struct xfs_perag *pag,
652 struct xfs_buf *agbp,
653 long len)
654 {
655 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
656
657 pag->pagf_freeblks += len;
658 be32_add_cpu(&agf->agf_freeblks, len);
659
660 xfs_trans_agblocks_delta(tp, len);
661 if (unlikely(be32_to_cpu(agf->agf_freeblks) >
662 be32_to_cpu(agf->agf_length)))
663 return -EFSCORRUPTED;
664
665 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
666 return 0;
667 }
668
669 /*
670 * Allocation group level functions.
671 */
672
673 /*
674 * Allocate a variable extent in the allocation group agno.
675 * Type and bno are used to determine where in the allocation group the
676 * extent will start.
677 * Extent's length (returned in *len) will be between minlen and maxlen,
678 * and of the form k * prod + mod unless there's nothing that large.
679 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
680 */
681 STATIC int /* error */
682 xfs_alloc_ag_vextent(
683 xfs_alloc_arg_t *args) /* argument structure for allocation */
684 {
685 int error=0;
686
687 ASSERT(args->minlen > 0);
688 ASSERT(args->maxlen > 0);
689 ASSERT(args->minlen <= args->maxlen);
690 ASSERT(args->mod < args->prod);
691 ASSERT(args->alignment > 0);
692
693 /*
694 * Branch to correct routine based on the type.
695 */
696 args->wasfromfl = 0;
697 switch (args->type) {
698 case XFS_ALLOCTYPE_THIS_AG:
699 error = xfs_alloc_ag_vextent_size(args);
700 break;
701 case XFS_ALLOCTYPE_NEAR_BNO:
702 error = xfs_alloc_ag_vextent_near(args);
703 break;
704 case XFS_ALLOCTYPE_THIS_BNO:
705 error = xfs_alloc_ag_vextent_exact(args);
706 break;
707 default:
708 ASSERT(0);
709 /* NOTREACHED */
710 }
711
712 if (error || args->agbno == NULLAGBLOCK)
713 return error;
714
715 ASSERT(args->len >= args->minlen);
716 ASSERT(args->len <= args->maxlen);
717 ASSERT(!args->wasfromfl || args->resv != XFS_AG_RESV_AGFL);
718 ASSERT(args->agbno % args->alignment == 0);
719
720 /* if not file data, insert new block into the reverse map btree */
721 if (args->oinfo.oi_owner != XFS_RMAP_OWN_UNKNOWN) {
722 error = xfs_rmap_alloc(args->tp, args->agbp, args->agno,
723 args->agbno, args->len, &args->oinfo);
724 if (error)
725 return error;
726 }
727
728 if (!args->wasfromfl) {
729 error = xfs_alloc_update_counters(args->tp, args->pag,
730 args->agbp,
731 -((long)(args->len)));
732 if (error)
733 return error;
734
735 ASSERT(!xfs_extent_busy_search(args->mp, args->agno,
736 args->agbno, args->len));
737 }
738
739 xfs_ag_resv_alloc_extent(args->pag, args->resv, args);
740
741 XFS_STATS_INC(args->mp, xs_allocx);
742 XFS_STATS_ADD(args->mp, xs_allocb, args->len);
743 return error;
744 }
745
746 /*
747 * Allocate a variable extent at exactly agno/bno.
748 * Extent's length (returned in *len) will be between minlen and maxlen,
749 * and of the form k * prod + mod unless there's nothing that large.
750 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
751 */
752 STATIC int /* error */
753 xfs_alloc_ag_vextent_exact(
754 xfs_alloc_arg_t *args) /* allocation argument structure */
755 {
756 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
757 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
758 int error;
759 xfs_agblock_t fbno; /* start block of found extent */
760 xfs_extlen_t flen; /* length of found extent */
761 xfs_agblock_t tbno; /* start block of busy extent */
762 xfs_extlen_t tlen; /* length of busy extent */
763 xfs_agblock_t tend; /* end block of busy extent */
764 int i; /* success/failure of operation */
765 unsigned busy_gen;
766
767 ASSERT(args->alignment == 1);
768
769 /*
770 * Allocate/initialize a cursor for the by-number freespace btree.
771 */
772 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
773 args->agno, XFS_BTNUM_BNO);
774
775 /*
776 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
777 * Look for the closest free block <= bno, it must contain bno
778 * if any free block does.
779 */
780 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
781 if (error)
782 goto error0;
783 if (!i)
784 goto not_found;
785
786 /*
787 * Grab the freespace record.
788 */
789 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
790 if (error)
791 goto error0;
792 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
793 ASSERT(fbno <= args->agbno);
794
795 /*
796 * Check for overlapping busy extents.
797 */
798 tbno = fbno;
799 tlen = flen;
800 xfs_extent_busy_trim(args, &tbno, &tlen, &busy_gen);
801
802 /*
803 * Give up if the start of the extent is busy, or the freespace isn't
804 * long enough for the minimum request.
805 */
806 if (tbno > args->agbno)
807 goto not_found;
808 if (tlen < args->minlen)
809 goto not_found;
810 tend = tbno + tlen;
811 if (tend < args->agbno + args->minlen)
812 goto not_found;
813
814 /*
815 * End of extent will be smaller of the freespace end and the
816 * maximal requested end.
817 *
818 * Fix the length according to mod and prod if given.
819 */
820 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
821 - args->agbno;
822 xfs_alloc_fix_len(args);
823 ASSERT(args->agbno + args->len <= tend);
824
825 /*
826 * We are allocating agbno for args->len
827 * Allocate/initialize a cursor for the by-size btree.
828 */
829 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
830 args->agno, XFS_BTNUM_CNT);
831 ASSERT(args->agbno + args->len <=
832 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
833 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
834 args->len, XFSA_FIXUP_BNO_OK);
835 if (error) {
836 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
837 goto error0;
838 }
839
840 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
841 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
842
843 args->wasfromfl = 0;
844 trace_xfs_alloc_exact_done(args);
845 return 0;
846
847 not_found:
848 /* Didn't find it, return null. */
849 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
850 args->agbno = NULLAGBLOCK;
851 trace_xfs_alloc_exact_notfound(args);
852 return 0;
853
854 error0:
855 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
856 trace_xfs_alloc_exact_error(args);
857 return error;
858 }
859
860 /*
861 * Search the btree in a given direction via the search cursor and compare
862 * the records found against the good extent we've already found.
863 */
864 STATIC int
865 xfs_alloc_find_best_extent(
866 struct xfs_alloc_arg *args, /* allocation argument structure */
867 struct xfs_btree_cur **gcur, /* good cursor */
868 struct xfs_btree_cur **scur, /* searching cursor */
869 xfs_agblock_t gdiff, /* difference for search comparison */
870 xfs_agblock_t *sbno, /* extent found by search */
871 xfs_extlen_t *slen, /* extent length */
872 xfs_agblock_t *sbnoa, /* aligned extent found by search */
873 xfs_extlen_t *slena, /* aligned extent length */
874 int dir) /* 0 = search right, 1 = search left */
875 {
876 xfs_agblock_t new;
877 xfs_agblock_t sdiff;
878 int error;
879 int i;
880 unsigned busy_gen;
881
882 /* The good extent is perfect, no need to search. */
883 if (!gdiff)
884 goto out_use_good;
885
886 /*
887 * Look until we find a better one, run out of space or run off the end.
888 */
889 do {
890 error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
891 if (error)
892 goto error0;
893 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
894 xfs_alloc_compute_aligned(args, *sbno, *slen,
895 sbnoa, slena, &busy_gen);
896
897 /*
898 * The good extent is closer than this one.
899 */
900 if (!dir) {
901 if (*sbnoa > args->max_agbno)
902 goto out_use_good;
903 if (*sbnoa >= args->agbno + gdiff)
904 goto out_use_good;
905 } else {
906 if (*sbnoa < args->min_agbno)
907 goto out_use_good;
908 if (*sbnoa <= args->agbno - gdiff)
909 goto out_use_good;
910 }
911
912 /*
913 * Same distance, compare length and pick the best.
914 */
915 if (*slena >= args->minlen) {
916 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
917 xfs_alloc_fix_len(args);
918
919 sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
920 args->alignment,
921 args->datatype, *sbnoa,
922 *slena, &new);
923
924 /*
925 * Choose closer size and invalidate other cursor.
926 */
927 if (sdiff < gdiff)
928 goto out_use_search;
929 goto out_use_good;
930 }
931
932 if (!dir)
933 error = xfs_btree_increment(*scur, 0, &i);
934 else
935 error = xfs_btree_decrement(*scur, 0, &i);
936 if (error)
937 goto error0;
938 } while (i);
939
940 out_use_good:
941 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
942 *scur = NULL;
943 return 0;
944
945 out_use_search:
946 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
947 *gcur = NULL;
948 return 0;
949
950 error0:
951 /* caller invalidates cursors */
952 return error;
953 }
954
955 /*
956 * Allocate a variable extent near bno in the allocation group agno.
957 * Extent's length (returned in len) will be between minlen and maxlen,
958 * and of the form k * prod + mod unless there's nothing that large.
959 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
960 */
961 STATIC int /* error */
962 xfs_alloc_ag_vextent_near(
963 xfs_alloc_arg_t *args) /* allocation argument structure */
964 {
965 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
966 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
967 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
968 xfs_agblock_t gtbno; /* start bno of right side entry */
969 xfs_agblock_t gtbnoa; /* aligned ... */
970 xfs_extlen_t gtdiff; /* difference to right side entry */
971 xfs_extlen_t gtlen; /* length of right side entry */
972 xfs_extlen_t gtlena; /* aligned ... */
973 xfs_agblock_t gtnew; /* useful start bno of right side */
974 int error; /* error code */
975 int i; /* result code, temporary */
976 int j; /* result code, temporary */
977 xfs_agblock_t ltbno; /* start bno of left side entry */
978 xfs_agblock_t ltbnoa; /* aligned ... */
979 xfs_extlen_t ltdiff; /* difference to left side entry */
980 xfs_extlen_t ltlen; /* length of left side entry */
981 xfs_extlen_t ltlena; /* aligned ... */
982 xfs_agblock_t ltnew; /* useful start bno of left side */
983 xfs_extlen_t rlen; /* length of returned extent */
984 bool busy;
985 unsigned busy_gen;
986 #ifdef DEBUG
987 /*
988 * Randomly don't execute the first algorithm.
989 */
990 int dofirst; /* set to do first algorithm */
991
992 dofirst = prandom_u32() & 1;
993 #endif
994
995 /* handle unitialized agbno range so caller doesn't have to */
996 if (!args->min_agbno && !args->max_agbno)
997 args->max_agbno = args->mp->m_sb.sb_agblocks - 1;
998 ASSERT(args->min_agbno <= args->max_agbno);
999
1000 /* clamp agbno to the range if it's outside */
1001 if (args->agbno < args->min_agbno)
1002 args->agbno = args->min_agbno;
1003 if (args->agbno > args->max_agbno)
1004 args->agbno = args->max_agbno;
1005
1006 restart:
1007 bno_cur_lt = NULL;
1008 bno_cur_gt = NULL;
1009 ltlen = 0;
1010 gtlena = 0;
1011 ltlena = 0;
1012 busy = false;
1013
1014 /*
1015 * Get a cursor for the by-size btree.
1016 */
1017 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1018 args->agno, XFS_BTNUM_CNT);
1019
1020 /*
1021 * See if there are any free extents as big as maxlen.
1022 */
1023 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
1024 goto error0;
1025 /*
1026 * If none, then pick up the last entry in the tree unless the
1027 * tree is empty.
1028 */
1029 if (!i) {
1030 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
1031 &ltlen, &i)))
1032 goto error0;
1033 if (i == 0 || ltlen == 0) {
1034 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1035 trace_xfs_alloc_near_noentry(args);
1036 return 0;
1037 }
1038 ASSERT(i == 1);
1039 }
1040 args->wasfromfl = 0;
1041
1042 /*
1043 * First algorithm.
1044 * If the requested extent is large wrt the freespaces available
1045 * in this a.g., then the cursor will be pointing to a btree entry
1046 * near the right edge of the tree. If it's in the last btree leaf
1047 * block, then we just examine all the entries in that block
1048 * that are big enough, and pick the best one.
1049 * This is written as a while loop so we can break out of it,
1050 * but we never loop back to the top.
1051 */
1052 while (xfs_btree_islastblock(cnt_cur, 0)) {
1053 xfs_extlen_t bdiff;
1054 int besti=0;
1055 xfs_extlen_t blen=0;
1056 xfs_agblock_t bnew=0;
1057
1058 #ifdef DEBUG
1059 if (dofirst)
1060 break;
1061 #endif
1062 /*
1063 * Start from the entry that lookup found, sequence through
1064 * all larger free blocks. If we're actually pointing at a
1065 * record smaller than maxlen, go to the start of this block,
1066 * and skip all those smaller than minlen.
1067 */
1068 if (ltlen || args->alignment > 1) {
1069 cnt_cur->bc_ptrs[0] = 1;
1070 do {
1071 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
1072 &ltlen, &i)))
1073 goto error0;
1074 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1075 if (ltlen >= args->minlen)
1076 break;
1077 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
1078 goto error0;
1079 } while (i);
1080 ASSERT(ltlen >= args->minlen);
1081 if (!i)
1082 break;
1083 }
1084 i = cnt_cur->bc_ptrs[0];
1085 for (j = 1, blen = 0, bdiff = 0;
1086 !error && j && (blen < args->maxlen || bdiff > 0);
1087 error = xfs_btree_increment(cnt_cur, 0, &j)) {
1088 /*
1089 * For each entry, decide if it's better than
1090 * the previous best entry.
1091 */
1092 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
1093 goto error0;
1094 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1095 busy = xfs_alloc_compute_aligned(args, ltbno, ltlen,
1096 &ltbnoa, &ltlena, &busy_gen);
1097 if (ltlena < args->minlen)
1098 continue;
1099 if (ltbnoa < args->min_agbno || ltbnoa > args->max_agbno)
1100 continue;
1101 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1102 xfs_alloc_fix_len(args);
1103 ASSERT(args->len >= args->minlen);
1104 if (args->len < blen)
1105 continue;
1106 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1107 args->alignment, args->datatype, ltbnoa,
1108 ltlena, &ltnew);
1109 if (ltnew != NULLAGBLOCK &&
1110 (args->len > blen || ltdiff < bdiff)) {
1111 bdiff = ltdiff;
1112 bnew = ltnew;
1113 blen = args->len;
1114 besti = cnt_cur->bc_ptrs[0];
1115 }
1116 }
1117 /*
1118 * It didn't work. We COULD be in a case where
1119 * there's a good record somewhere, so try again.
1120 */
1121 if (blen == 0)
1122 break;
1123 /*
1124 * Point at the best entry, and retrieve it again.
1125 */
1126 cnt_cur->bc_ptrs[0] = besti;
1127 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
1128 goto error0;
1129 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1130 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1131 args->len = blen;
1132
1133 /*
1134 * We are allocating starting at bnew for blen blocks.
1135 */
1136 args->agbno = bnew;
1137 ASSERT(bnew >= ltbno);
1138 ASSERT(bnew + blen <= ltbno + ltlen);
1139 /*
1140 * Set up a cursor for the by-bno tree.
1141 */
1142 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1143 args->agbp, args->agno, XFS_BTNUM_BNO);
1144 /*
1145 * Fix up the btree entries.
1146 */
1147 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1148 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1149 goto error0;
1150 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1151 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1152
1153 trace_xfs_alloc_near_first(args);
1154 return 0;
1155 }
1156 /*
1157 * Second algorithm.
1158 * Search in the by-bno tree to the left and to the right
1159 * simultaneously, until in each case we find a space big enough,
1160 * or run into the edge of the tree. When we run into the edge,
1161 * we deallocate that cursor.
1162 * If both searches succeed, we compare the two spaces and pick
1163 * the better one.
1164 * With alignment, it's possible for both to fail; the upper
1165 * level algorithm that picks allocation groups for allocations
1166 * is not supposed to do this.
1167 */
1168 /*
1169 * Allocate and initialize the cursor for the leftward search.
1170 */
1171 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1172 args->agno, XFS_BTNUM_BNO);
1173 /*
1174 * Lookup <= bno to find the leftward search's starting point.
1175 */
1176 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1177 goto error0;
1178 if (!i) {
1179 /*
1180 * Didn't find anything; use this cursor for the rightward
1181 * search.
1182 */
1183 bno_cur_gt = bno_cur_lt;
1184 bno_cur_lt = NULL;
1185 }
1186 /*
1187 * Found something. Duplicate the cursor for the rightward search.
1188 */
1189 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1190 goto error0;
1191 /*
1192 * Increment the cursor, so we will point at the entry just right
1193 * of the leftward entry if any, or to the leftmost entry.
1194 */
1195 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1196 goto error0;
1197 if (!i) {
1198 /*
1199 * It failed, there are no rightward entries.
1200 */
1201 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1202 bno_cur_gt = NULL;
1203 }
1204 /*
1205 * Loop going left with the leftward cursor, right with the
1206 * rightward cursor, until either both directions give up or
1207 * we find an entry at least as big as minlen.
1208 */
1209 do {
1210 if (bno_cur_lt) {
1211 if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
1212 goto error0;
1213 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1214 busy |= xfs_alloc_compute_aligned(args, ltbno, ltlen,
1215 &ltbnoa, &ltlena, &busy_gen);
1216 if (ltlena >= args->minlen && ltbnoa >= args->min_agbno)
1217 break;
1218 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
1219 goto error0;
1220 if (!i || ltbnoa < args->min_agbno) {
1221 xfs_btree_del_cursor(bno_cur_lt,
1222 XFS_BTREE_NOERROR);
1223 bno_cur_lt = NULL;
1224 }
1225 }
1226 if (bno_cur_gt) {
1227 if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
1228 goto error0;
1229 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1230 busy |= xfs_alloc_compute_aligned(args, gtbno, gtlen,
1231 &gtbnoa, &gtlena, &busy_gen);
1232 if (gtlena >= args->minlen && gtbnoa <= args->max_agbno)
1233 break;
1234 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1235 goto error0;
1236 if (!i || gtbnoa > args->max_agbno) {
1237 xfs_btree_del_cursor(bno_cur_gt,
1238 XFS_BTREE_NOERROR);
1239 bno_cur_gt = NULL;
1240 }
1241 }
1242 } while (bno_cur_lt || bno_cur_gt);
1243
1244 /*
1245 * Got both cursors still active, need to find better entry.
1246 */
1247 if (bno_cur_lt && bno_cur_gt) {
1248 if (ltlena >= args->minlen) {
1249 /*
1250 * Left side is good, look for a right side entry.
1251 */
1252 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1253 xfs_alloc_fix_len(args);
1254 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1255 args->alignment, args->datatype, ltbnoa,
1256 ltlena, &ltnew);
1257
1258 error = xfs_alloc_find_best_extent(args,
1259 &bno_cur_lt, &bno_cur_gt,
1260 ltdiff, &gtbno, &gtlen,
1261 &gtbnoa, &gtlena,
1262 0 /* search right */);
1263 } else {
1264 ASSERT(gtlena >= args->minlen);
1265
1266 /*
1267 * Right side is good, look for a left side entry.
1268 */
1269 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1270 xfs_alloc_fix_len(args);
1271 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1272 args->alignment, args->datatype, gtbnoa,
1273 gtlena, &gtnew);
1274
1275 error = xfs_alloc_find_best_extent(args,
1276 &bno_cur_gt, &bno_cur_lt,
1277 gtdiff, &ltbno, &ltlen,
1278 &ltbnoa, &ltlena,
1279 1 /* search left */);
1280 }
1281
1282 if (error)
1283 goto error0;
1284 }
1285
1286 /*
1287 * If we couldn't get anything, give up.
1288 */
1289 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1290 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1291
1292 if (busy) {
1293 trace_xfs_alloc_near_busy(args);
1294 xfs_extent_busy_flush(args->mp, args->pag, busy_gen);
1295 goto restart;
1296 }
1297 trace_xfs_alloc_size_neither(args);
1298 args->agbno = NULLAGBLOCK;
1299 return 0;
1300 }
1301
1302 /*
1303 * At this point we have selected a freespace entry, either to the
1304 * left or to the right. If it's on the right, copy all the
1305 * useful variables to the "left" set so we only have one
1306 * copy of this code.
1307 */
1308 if (bno_cur_gt) {
1309 bno_cur_lt = bno_cur_gt;
1310 bno_cur_gt = NULL;
1311 ltbno = gtbno;
1312 ltbnoa = gtbnoa;
1313 ltlen = gtlen;
1314 ltlena = gtlena;
1315 j = 1;
1316 } else
1317 j = 0;
1318
1319 /*
1320 * Fix up the length and compute the useful address.
1321 */
1322 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1323 xfs_alloc_fix_len(args);
1324 rlen = args->len;
1325 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
1326 args->datatype, ltbnoa, ltlena, &ltnew);
1327 ASSERT(ltnew >= ltbno);
1328 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
1329 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1330 ASSERT(ltnew >= args->min_agbno && ltnew <= args->max_agbno);
1331 args->agbno = ltnew;
1332
1333 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1334 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1335 goto error0;
1336
1337 if (j)
1338 trace_xfs_alloc_near_greater(args);
1339 else
1340 trace_xfs_alloc_near_lesser(args);
1341
1342 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1343 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1344 return 0;
1345
1346 error0:
1347 trace_xfs_alloc_near_error(args);
1348 if (cnt_cur != NULL)
1349 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1350 if (bno_cur_lt != NULL)
1351 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1352 if (bno_cur_gt != NULL)
1353 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1354 return error;
1355 }
1356
1357 /*
1358 * Allocate a variable extent anywhere in the allocation group agno.
1359 * Extent's length (returned in len) will be between minlen and maxlen,
1360 * and of the form k * prod + mod unless there's nothing that large.
1361 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1362 */
1363 STATIC int /* error */
1364 xfs_alloc_ag_vextent_size(
1365 xfs_alloc_arg_t *args) /* allocation argument structure */
1366 {
1367 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1368 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1369 int error; /* error result */
1370 xfs_agblock_t fbno; /* start of found freespace */
1371 xfs_extlen_t flen; /* length of found freespace */
1372 int i; /* temp status variable */
1373 xfs_agblock_t rbno; /* returned block number */
1374 xfs_extlen_t rlen; /* length of returned extent */
1375 bool busy;
1376 unsigned busy_gen;
1377
1378 restart:
1379 /*
1380 * Allocate and initialize a cursor for the by-size btree.
1381 */
1382 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1383 args->agno, XFS_BTNUM_CNT);
1384 bno_cur = NULL;
1385 busy = false;
1386
1387 /*
1388 * Look for an entry >= maxlen+alignment-1 blocks.
1389 */
1390 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1391 args->maxlen + args->alignment - 1, &i)))
1392 goto error0;
1393
1394 /*
1395 * If none then we have to settle for a smaller extent. In the case that
1396 * there are no large extents, this will return the last entry in the
1397 * tree unless the tree is empty. In the case that there are only busy
1398 * large extents, this will return the largest small extent unless there
1399 * are no smaller extents available.
1400 */
1401 if (!i) {
1402 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1403 &fbno, &flen, &i);
1404 if (error)
1405 goto error0;
1406 if (i == 0 || flen == 0) {
1407 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1408 trace_xfs_alloc_size_noentry(args);
1409 return 0;
1410 }
1411 ASSERT(i == 1);
1412 busy = xfs_alloc_compute_aligned(args, fbno, flen, &rbno,
1413 &rlen, &busy_gen);
1414 } else {
1415 /*
1416 * Search for a non-busy extent that is large enough.
1417 */
1418 for (;;) {
1419 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1420 if (error)
1421 goto error0;
1422 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1423
1424 busy = xfs_alloc_compute_aligned(args, fbno, flen,
1425 &rbno, &rlen, &busy_gen);
1426
1427 if (rlen >= args->maxlen)
1428 break;
1429
1430 error = xfs_btree_increment(cnt_cur, 0, &i);
1431 if (error)
1432 goto error0;
1433 if (i == 0) {
1434 /*
1435 * Our only valid extents must have been busy.
1436 * Make it unbusy by forcing the log out and
1437 * retrying.
1438 */
1439 xfs_btree_del_cursor(cnt_cur,
1440 XFS_BTREE_NOERROR);
1441 trace_xfs_alloc_size_busy(args);
1442 xfs_extent_busy_flush(args->mp,
1443 args->pag, busy_gen);
1444 goto restart;
1445 }
1446 }
1447 }
1448
1449 /*
1450 * In the first case above, we got the last entry in the
1451 * by-size btree. Now we check to see if the space hits maxlen
1452 * once aligned; if not, we search left for something better.
1453 * This can't happen in the second case above.
1454 */
1455 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1456 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 ||
1457 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1458 if (rlen < args->maxlen) {
1459 xfs_agblock_t bestfbno;
1460 xfs_extlen_t bestflen;
1461 xfs_agblock_t bestrbno;
1462 xfs_extlen_t bestrlen;
1463
1464 bestrlen = rlen;
1465 bestrbno = rbno;
1466 bestflen = flen;
1467 bestfbno = fbno;
1468 for (;;) {
1469 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
1470 goto error0;
1471 if (i == 0)
1472 break;
1473 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1474 &i)))
1475 goto error0;
1476 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1477 if (flen < bestrlen)
1478 break;
1479 busy = xfs_alloc_compute_aligned(args, fbno, flen,
1480 &rbno, &rlen, &busy_gen);
1481 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1482 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 ||
1483 (rlen <= flen && rbno + rlen <= fbno + flen),
1484 error0);
1485 if (rlen > bestrlen) {
1486 bestrlen = rlen;
1487 bestrbno = rbno;
1488 bestflen = flen;
1489 bestfbno = fbno;
1490 if (rlen == args->maxlen)
1491 break;
1492 }
1493 }
1494 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1495 &i)))
1496 goto error0;
1497 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1498 rlen = bestrlen;
1499 rbno = bestrbno;
1500 flen = bestflen;
1501 fbno = bestfbno;
1502 }
1503 args->wasfromfl = 0;
1504 /*
1505 * Fix up the length.
1506 */
1507 args->len = rlen;
1508 if (rlen < args->minlen) {
1509 if (busy) {
1510 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1511 trace_xfs_alloc_size_busy(args);
1512 xfs_extent_busy_flush(args->mp, args->pag, busy_gen);
1513 goto restart;
1514 }
1515 goto out_nominleft;
1516 }
1517 xfs_alloc_fix_len(args);
1518
1519 rlen = args->len;
1520 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen <= flen, error0);
1521 /*
1522 * Allocate and initialize a cursor for the by-block tree.
1523 */
1524 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1525 args->agno, XFS_BTNUM_BNO);
1526 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1527 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1528 goto error0;
1529 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1530 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1531 cnt_cur = bno_cur = NULL;
1532 args->len = rlen;
1533 args->agbno = rbno;
1534 XFS_WANT_CORRUPTED_GOTO(args->mp,
1535 args->agbno + args->len <=
1536 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1537 error0);
1538 trace_xfs_alloc_size_done(args);
1539 return 0;
1540
1541 error0:
1542 trace_xfs_alloc_size_error(args);
1543 if (cnt_cur)
1544 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1545 if (bno_cur)
1546 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1547 return error;
1548
1549 out_nominleft:
1550 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1551 trace_xfs_alloc_size_nominleft(args);
1552 args->agbno = NULLAGBLOCK;
1553 return 0;
1554 }
1555
1556 /*
1557 * Deal with the case where only small freespaces remain.
1558 * Either return the contents of the last freespace record,
1559 * or allocate space from the freelist if there is nothing in the tree.
1560 */
1561 STATIC int /* error */
1562 xfs_alloc_ag_vextent_small(
1563 xfs_alloc_arg_t *args, /* allocation argument structure */
1564 xfs_btree_cur_t *ccur, /* by-size cursor */
1565 xfs_agblock_t *fbnop, /* result block number */
1566 xfs_extlen_t *flenp, /* result length */
1567 int *stat) /* status: 0-freelist, 1-normal/none */
1568 {
1569 struct xfs_owner_info oinfo;
1570 struct xfs_perag *pag;
1571 int error;
1572 xfs_agblock_t fbno;
1573 xfs_extlen_t flen;
1574 int i;
1575
1576 if ((error = xfs_btree_decrement(ccur, 0, &i)))
1577 goto error0;
1578 if (i) {
1579 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1580 goto error0;
1581 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1582 }
1583 /*
1584 * Nothing in the btree, try the freelist. Make sure
1585 * to respect minleft even when pulling from the
1586 * freelist.
1587 */
1588 else if (args->minlen == 1 && args->alignment == 1 &&
1589 args->resv != XFS_AG_RESV_AGFL &&
1590 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1591 > args->minleft)) {
1592 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
1593 if (error)
1594 goto error0;
1595 if (fbno != NULLAGBLOCK) {
1596 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
1597 xfs_alloc_allow_busy_reuse(args->datatype));
1598
1599 if (xfs_alloc_is_userdata(args->datatype)) {
1600 xfs_buf_t *bp;
1601
1602 bp = xfs_btree_get_bufs(args->mp, args->tp,
1603 args->agno, fbno, 0);
1604 if (!bp) {
1605 error = -EFSCORRUPTED;
1606 goto error0;
1607 }
1608 xfs_trans_binval(args->tp, bp);
1609 }
1610 args->len = 1;
1611 args->agbno = fbno;
1612 XFS_WANT_CORRUPTED_GOTO(args->mp,
1613 args->agbno + args->len <=
1614 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1615 error0);
1616 args->wasfromfl = 1;
1617 trace_xfs_alloc_small_freelist(args);
1618
1619 /*
1620 * If we're feeding an AGFL block to something that
1621 * doesn't live in the free space, we need to clear
1622 * out the OWN_AG rmap and add the block back to
1623 * the AGFL per-AG reservation.
1624 */
1625 xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
1626 error = xfs_rmap_free(args->tp, args->agbp, args->agno,
1627 fbno, 1, &oinfo);
1628 if (error)
1629 goto error0;
1630 pag = xfs_perag_get(args->mp, args->agno);
1631 xfs_ag_resv_free_extent(pag, XFS_AG_RESV_AGFL,
1632 args->tp, 1);
1633 xfs_perag_put(pag);
1634
1635 *stat = 0;
1636 return 0;
1637 }
1638 /*
1639 * Nothing in the freelist.
1640 */
1641 else
1642 flen = 0;
1643 }
1644 /*
1645 * Can't allocate from the freelist for some reason.
1646 */
1647 else {
1648 fbno = NULLAGBLOCK;
1649 flen = 0;
1650 }
1651 /*
1652 * Can't do the allocation, give up.
1653 */
1654 if (flen < args->minlen) {
1655 args->agbno = NULLAGBLOCK;
1656 trace_xfs_alloc_small_notenough(args);
1657 flen = 0;
1658 }
1659 *fbnop = fbno;
1660 *flenp = flen;
1661 *stat = 1;
1662 trace_xfs_alloc_small_done(args);
1663 return 0;
1664
1665 error0:
1666 trace_xfs_alloc_small_error(args);
1667 return error;
1668 }
1669
1670 /*
1671 * Free the extent starting at agno/bno for length.
1672 */
1673 STATIC int
1674 xfs_free_ag_extent(
1675 xfs_trans_t *tp,
1676 xfs_buf_t *agbp,
1677 xfs_agnumber_t agno,
1678 xfs_agblock_t bno,
1679 xfs_extlen_t len,
1680 struct xfs_owner_info *oinfo,
1681 enum xfs_ag_resv_type type)
1682 {
1683 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1684 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1685 int error; /* error return value */
1686 xfs_agblock_t gtbno; /* start of right neighbor block */
1687 xfs_extlen_t gtlen; /* length of right neighbor block */
1688 int haveleft; /* have a left neighbor block */
1689 int haveright; /* have a right neighbor block */
1690 int i; /* temp, result code */
1691 xfs_agblock_t ltbno; /* start of left neighbor block */
1692 xfs_extlen_t ltlen; /* length of left neighbor block */
1693 xfs_mount_t *mp; /* mount point struct for filesystem */
1694 xfs_agblock_t nbno; /* new starting block of freespace */
1695 xfs_extlen_t nlen; /* new length of freespace */
1696 xfs_perag_t *pag; /* per allocation group data */
1697
1698 bno_cur = cnt_cur = NULL;
1699 mp = tp->t_mountp;
1700
1701 if (oinfo->oi_owner != XFS_RMAP_OWN_UNKNOWN) {
1702 error = xfs_rmap_free(tp, agbp, agno, bno, len, oinfo);
1703 if (error)
1704 goto error0;
1705 }
1706
1707 /*
1708 * Allocate and initialize a cursor for the by-block btree.
1709 */
1710 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
1711 /*
1712 * Look for a neighboring block on the left (lower block numbers)
1713 * that is contiguous with this space.
1714 */
1715 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1716 goto error0;
1717 if (haveleft) {
1718 /*
1719 * There is a block to our left.
1720 */
1721 if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
1722 goto error0;
1723 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1724 /*
1725 * It's not contiguous, though.
1726 */
1727 if (ltbno + ltlen < bno)
1728 haveleft = 0;
1729 else {
1730 /*
1731 * If this failure happens the request to free this
1732 * space was invalid, it's (partly) already free.
1733 * Very bad.
1734 */
1735 XFS_WANT_CORRUPTED_GOTO(mp,
1736 ltbno + ltlen <= bno, error0);
1737 }
1738 }
1739 /*
1740 * Look for a neighboring block on the right (higher block numbers)
1741 * that is contiguous with this space.
1742 */
1743 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
1744 goto error0;
1745 if (haveright) {
1746 /*
1747 * There is a block to our right.
1748 */
1749 if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
1750 goto error0;
1751 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1752 /*
1753 * It's not contiguous, though.
1754 */
1755 if (bno + len < gtbno)
1756 haveright = 0;
1757 else {
1758 /*
1759 * If this failure happens the request to free this
1760 * space was invalid, it's (partly) already free.
1761 * Very bad.
1762 */
1763 XFS_WANT_CORRUPTED_GOTO(mp, gtbno >= bno + len, error0);
1764 }
1765 }
1766 /*
1767 * Now allocate and initialize a cursor for the by-size tree.
1768 */
1769 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
1770 /*
1771 * Have both left and right contiguous neighbors.
1772 * Merge all three into a single free block.
1773 */
1774 if (haveleft && haveright) {
1775 /*
1776 * Delete the old by-size entry on the left.
1777 */
1778 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1779 goto error0;
1780 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1781 if ((error = xfs_btree_delete(cnt_cur, &i)))
1782 goto error0;
1783 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1784 /*
1785 * Delete the old by-size entry on the right.
1786 */
1787 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1788 goto error0;
1789 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1790 if ((error = xfs_btree_delete(cnt_cur, &i)))
1791 goto error0;
1792 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1793 /*
1794 * Delete the old by-block entry for the right block.
1795 */
1796 if ((error = xfs_btree_delete(bno_cur, &i)))
1797 goto error0;
1798 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1799 /*
1800 * Move the by-block cursor back to the left neighbor.
1801 */
1802 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1803 goto error0;
1804 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1805 #ifdef DEBUG
1806 /*
1807 * Check that this is the right record: delete didn't
1808 * mangle the cursor.
1809 */
1810 {
1811 xfs_agblock_t xxbno;
1812 xfs_extlen_t xxlen;
1813
1814 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1815 &i)))
1816 goto error0;
1817 XFS_WANT_CORRUPTED_GOTO(mp,
1818 i == 1 && xxbno == ltbno && xxlen == ltlen,
1819 error0);
1820 }
1821 #endif
1822 /*
1823 * Update remaining by-block entry to the new, joined block.
1824 */
1825 nbno = ltbno;
1826 nlen = len + ltlen + gtlen;
1827 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1828 goto error0;
1829 }
1830 /*
1831 * Have only a left contiguous neighbor.
1832 * Merge it together with the new freespace.
1833 */
1834 else if (haveleft) {
1835 /*
1836 * Delete the old by-size entry on the left.
1837 */
1838 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1839 goto error0;
1840 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1841 if ((error = xfs_btree_delete(cnt_cur, &i)))
1842 goto error0;
1843 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1844 /*
1845 * Back up the by-block cursor to the left neighbor, and
1846 * update its length.
1847 */
1848 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1849 goto error0;
1850 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1851 nbno = ltbno;
1852 nlen = len + ltlen;
1853 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1854 goto error0;
1855 }
1856 /*
1857 * Have only a right contiguous neighbor.
1858 * Merge it together with the new freespace.
1859 */
1860 else if (haveright) {
1861 /*
1862 * Delete the old by-size entry on the right.
1863 */
1864 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1865 goto error0;
1866 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1867 if ((error = xfs_btree_delete(cnt_cur, &i)))
1868 goto error0;
1869 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1870 /*
1871 * Update the starting block and length of the right
1872 * neighbor in the by-block tree.
1873 */
1874 nbno = bno;
1875 nlen = len + gtlen;
1876 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1877 goto error0;
1878 }
1879 /*
1880 * No contiguous neighbors.
1881 * Insert the new freespace into the by-block tree.
1882 */
1883 else {
1884 nbno = bno;
1885 nlen = len;
1886 if ((error = xfs_btree_insert(bno_cur, &i)))
1887 goto error0;
1888 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1889 }
1890 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1891 bno_cur = NULL;
1892 /*
1893 * In all cases we need to insert the new freespace in the by-size tree.
1894 */
1895 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1896 goto error0;
1897 XFS_WANT_CORRUPTED_GOTO(mp, i == 0, error0);
1898 if ((error = xfs_btree_insert(cnt_cur, &i)))
1899 goto error0;
1900 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1901 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1902 cnt_cur = NULL;
1903
1904 /*
1905 * Update the freespace totals in the ag and superblock.
1906 */
1907 pag = xfs_perag_get(mp, agno);
1908 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1909 xfs_ag_resv_free_extent(pag, type, tp, len);
1910 xfs_perag_put(pag);
1911 if (error)
1912 goto error0;
1913
1914 XFS_STATS_INC(mp, xs_freex);
1915 XFS_STATS_ADD(mp, xs_freeb, len);
1916
1917 trace_xfs_free_extent(mp, agno, bno, len, type == XFS_AG_RESV_AGFL,
1918 haveleft, haveright);
1919
1920 return 0;
1921
1922 error0:
1923 trace_xfs_free_extent(mp, agno, bno, len, type == XFS_AG_RESV_AGFL,
1924 -1, -1);
1925 if (bno_cur)
1926 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1927 if (cnt_cur)
1928 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1929 return error;
1930 }
1931
1932 /*
1933 * Visible (exported) allocation/free functions.
1934 * Some of these are used just by xfs_alloc_btree.c and this file.
1935 */
1936
1937 /*
1938 * Compute and fill in value of m_ag_maxlevels.
1939 */
1940 void
1941 xfs_alloc_compute_maxlevels(
1942 xfs_mount_t *mp) /* file system mount structure */
1943 {
1944 mp->m_ag_maxlevels = xfs_btree_compute_maxlevels(mp, mp->m_alloc_mnr,
1945 (mp->m_sb.sb_agblocks + 1) / 2);
1946 }
1947
1948 /*
1949 * Find the length of the longest extent in an AG. The 'need' parameter
1950 * specifies how much space we're going to need for the AGFL and the
1951 * 'reserved' parameter tells us how many blocks in this AG are reserved for
1952 * other callers.
1953 */
1954 xfs_extlen_t
1955 xfs_alloc_longest_free_extent(
1956 struct xfs_mount *mp,
1957 struct xfs_perag *pag,
1958 xfs_extlen_t need,
1959 xfs_extlen_t reserved)
1960 {
1961 xfs_extlen_t delta = 0;
1962
1963 /*
1964 * If the AGFL needs a recharge, we'll have to subtract that from the
1965 * longest extent.
1966 */
1967 if (need > pag->pagf_flcount)
1968 delta = need - pag->pagf_flcount;
1969
1970 /*
1971 * If we cannot maintain others' reservations with space from the
1972 * not-longest freesp extents, we'll have to subtract /that/ from
1973 * the longest extent too.
1974 */
1975 if (pag->pagf_freeblks - pag->pagf_longest < reserved)
1976 delta += reserved - (pag->pagf_freeblks - pag->pagf_longest);
1977
1978 /*
1979 * If the longest extent is long enough to satisfy all the
1980 * reservations and AGFL rules in place, we can return this extent.
1981 */
1982 if (pag->pagf_longest > delta)
1983 return pag->pagf_longest - delta;
1984
1985 /* Otherwise, let the caller try for 1 block if there's space. */
1986 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1987 }
1988
1989 unsigned int
1990 xfs_alloc_min_freelist(
1991 struct xfs_mount *mp,
1992 struct xfs_perag *pag)
1993 {
1994 unsigned int min_free;
1995
1996 /* space needed by-bno freespace btree */
1997 min_free = min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_BNOi] + 1,
1998 mp->m_ag_maxlevels);
1999 /* space needed by-size freespace btree */
2000 min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1,
2001 mp->m_ag_maxlevels);
2002 /* space needed reverse mapping used space btree */
2003 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
2004 min_free += min_t(unsigned int,
2005 pag->pagf_levels[XFS_BTNUM_RMAPi] + 1,
2006 mp->m_rmap_maxlevels);
2007
2008 return min_free;
2009 }
2010
2011 /*
2012 * Check if the operation we are fixing up the freelist for should go ahead or
2013 * not. If we are freeing blocks, we always allow it, otherwise the allocation
2014 * is dependent on whether the size and shape of free space available will
2015 * permit the requested allocation to take place.
2016 */
2017 static bool
2018 xfs_alloc_space_available(
2019 struct xfs_alloc_arg *args,
2020 xfs_extlen_t min_free,
2021 int flags)
2022 {
2023 struct xfs_perag *pag = args->pag;
2024 xfs_extlen_t alloc_len, longest;
2025 xfs_extlen_t reservation; /* blocks that are still reserved */
2026 int available;
2027
2028 if (flags & XFS_ALLOC_FLAG_FREEING)
2029 return true;
2030
2031 reservation = xfs_ag_resv_needed(pag, args->resv);
2032
2033 /* do we have enough contiguous free space for the allocation? */
2034 alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop;
2035 longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free,
2036 reservation);
2037 if (longest < alloc_len)
2038 return false;
2039
2040 /* do we have enough free space remaining for the allocation? */
2041 available = (int)(pag->pagf_freeblks + pag->pagf_flcount -
2042 reservation - min_free - args->minleft);
2043 if (available < (int)max(args->total, alloc_len))
2044 return false;
2045
2046 /*
2047 * Clamp maxlen to the amount of free space available for the actual
2048 * extent allocation.
2049 */
2050 if (available < (int)args->maxlen && !(flags & XFS_ALLOC_FLAG_CHECK)) {
2051 args->maxlen = available;
2052 ASSERT(args->maxlen > 0);
2053 ASSERT(args->maxlen >= args->minlen);
2054 }
2055
2056 return true;
2057 }
2058
2059 /*
2060 * Check the agfl fields of the agf for inconsistency or corruption. The purpose
2061 * is to detect an agfl header padding mismatch between current and early v5
2062 * kernels. This problem manifests as a 1-slot size difference between the
2063 * on-disk flcount and the active [first, last] range of a wrapped agfl. This
2064 * may also catch variants of agfl count corruption unrelated to padding. Either
2065 * way, we'll reset the agfl and warn the user.
2066 *
2067 * Return true if a reset is required before the agfl can be used, false
2068 * otherwise.
2069 */
2070 static bool
2071 xfs_agfl_needs_reset(
2072 struct xfs_mount *mp,
2073 struct xfs_agf *agf)
2074 {
2075 uint32_t f = be32_to_cpu(agf->agf_flfirst);
2076 uint32_t l = be32_to_cpu(agf->agf_fllast);
2077 uint32_t c = be32_to_cpu(agf->agf_flcount);
2078 int agfl_size = xfs_agfl_size(mp);
2079 int active;
2080
2081 /* no agfl header on v4 supers */
2082 if (!xfs_sb_version_hascrc(&mp->m_sb))
2083 return false;
2084
2085 /*
2086 * The agf read verifier catches severe corruption of these fields.
2087 * Repeat some sanity checks to cover a packed -> unpacked mismatch if
2088 * the verifier allows it.
2089 */
2090 if (f >= agfl_size || l >= agfl_size)
2091 return true;
2092 if (c > agfl_size)
2093 return true;
2094
2095 /*
2096 * Check consistency between the on-disk count and the active range. An
2097 * agfl padding mismatch manifests as an inconsistent flcount.
2098 */
2099 if (c && l >= f)
2100 active = l - f + 1;
2101 else if (c)
2102 active = agfl_size - f + l + 1;
2103 else
2104 active = 0;
2105
2106 return active != c;
2107 }
2108
2109 /*
2110 * Reset the agfl to an empty state. Ignore/drop any existing blocks since the
2111 * agfl content cannot be trusted. Warn the user that a repair is required to
2112 * recover leaked blocks.
2113 *
2114 * The purpose of this mechanism is to handle filesystems affected by the agfl
2115 * header padding mismatch problem. A reset keeps the filesystem online with a
2116 * relatively minor free space accounting inconsistency rather than suffer the
2117 * inevitable crash from use of an invalid agfl block.
2118 */
2119 static void
2120 xfs_agfl_reset(
2121 struct xfs_trans *tp,
2122 struct xfs_buf *agbp,
2123 struct xfs_perag *pag)
2124 {
2125 struct xfs_mount *mp = tp->t_mountp;
2126 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
2127
2128 ASSERT(pag->pagf_agflreset);
2129 trace_xfs_agfl_reset(mp, agf, 0, _RET_IP_);
2130
2131 xfs_warn(mp,
2132 "WARNING: Reset corrupted AGFL on AG %u. %d blocks leaked. "
2133 "Please unmount and run xfs_repair.",
2134 pag->pag_agno, pag->pagf_flcount);
2135
2136 agf->agf_flfirst = 0;
2137 agf->agf_fllast = cpu_to_be32(xfs_agfl_size(mp) - 1);
2138 agf->agf_flcount = 0;
2139 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLLAST |
2140 XFS_AGF_FLCOUNT);
2141
2142 pag->pagf_flcount = 0;
2143 pag->pagf_agflreset = false;
2144 }
2145
2146 /*
2147 * Decide whether to use this allocation group for this allocation.
2148 * If so, fix up the btree freelist's size.
2149 */
2150 int /* error */
2151 xfs_alloc_fix_freelist(
2152 struct xfs_alloc_arg *args, /* allocation argument structure */
2153 int flags) /* XFS_ALLOC_FLAG_... */
2154 {
2155 struct xfs_mount *mp = args->mp;
2156 struct xfs_perag *pag = args->pag;
2157 struct xfs_trans *tp = args->tp;
2158 struct xfs_buf *agbp = NULL;
2159 struct xfs_buf *agflbp = NULL;
2160 struct xfs_alloc_arg targs; /* local allocation arguments */
2161 xfs_agblock_t bno; /* freelist block */
2162 xfs_extlen_t need; /* total blocks needed in freelist */
2163 int error = 0;
2164
2165 if (!pag->pagf_init) {
2166 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
2167 if (error)
2168 goto out_no_agbp;
2169 if (!pag->pagf_init) {
2170 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
2171 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
2172 goto out_agbp_relse;
2173 }
2174 }
2175
2176 /*
2177 * If this is a metadata preferred pag and we are user data then try
2178 * somewhere else if we are not being asked to try harder at this
2179 * point
2180 */
2181 if (pag->pagf_metadata && xfs_alloc_is_userdata(args->datatype) &&
2182 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
2183 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
2184 goto out_agbp_relse;
2185 }
2186
2187 need = xfs_alloc_min_freelist(mp, pag);
2188 if (!xfs_alloc_space_available(args, need, flags |
2189 XFS_ALLOC_FLAG_CHECK))
2190 goto out_agbp_relse;
2191
2192 /*
2193 * Get the a.g. freespace buffer.
2194 * Can fail if we're not blocking on locks, and it's held.
2195 */
2196 if (!agbp) {
2197 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
2198 if (error)
2199 goto out_no_agbp;
2200 if (!agbp) {
2201 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
2202 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
2203 goto out_no_agbp;
2204 }
2205 }
2206
2207 /* reset a padding mismatched agfl before final free space check */
2208 if (pag->pagf_agflreset)
2209 xfs_agfl_reset(tp, agbp, pag);
2210
2211 /* If there isn't enough total space or single-extent, reject it. */
2212 need = xfs_alloc_min_freelist(mp, pag);
2213 if (!xfs_alloc_space_available(args, need, flags))
2214 goto out_agbp_relse;
2215
2216 /*
2217 * Make the freelist shorter if it's too long.
2218 *
2219 * Note that from this point onwards, we will always release the agf and
2220 * agfl buffers on error. This handles the case where we error out and
2221 * the buffers are clean or may not have been joined to the transaction
2222 * and hence need to be released manually. If they have been joined to
2223 * the transaction, then xfs_trans_brelse() will handle them
2224 * appropriately based on the recursion count and dirty state of the
2225 * buffer.
2226 *
2227 * XXX (dgc): When we have lots of free space, does this buy us
2228 * anything other than extra overhead when we need to put more blocks
2229 * back on the free list? Maybe we should only do this when space is
2230 * getting low or the AGFL is more than half full?
2231 *
2232 * The NOSHRINK flag prevents the AGFL from being shrunk if it's too
2233 * big; the NORMAP flag prevents AGFL expand/shrink operations from
2234 * updating the rmapbt. Both flags are used in xfs_repair while we're
2235 * rebuilding the rmapbt, and neither are used by the kernel. They're
2236 * both required to ensure that rmaps are correctly recorded for the
2237 * regenerated AGFL, bnobt, and cntbt. See repair/phase5.c and
2238 * repair/rmap.c in xfsprogs for details.
2239 */
2240 memset(&targs, 0, sizeof(targs));
2241 if (flags & XFS_ALLOC_FLAG_NORMAP)
2242 xfs_rmap_skip_owner_update(&targs.oinfo);
2243 else
2244 xfs_rmap_ag_owner(&targs.oinfo, XFS_RMAP_OWN_AG);
2245 while (!(flags & XFS_ALLOC_FLAG_NOSHRINK) && pag->pagf_flcount > need) {
2246 struct xfs_buf *bp;
2247
2248 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
2249 if (error)
2250 goto out_agbp_relse;
2251 error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1,
2252 &targs.oinfo, XFS_AG_RESV_AGFL);
2253 if (error)
2254 goto out_agbp_relse;
2255 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
2256 if (!bp) {
2257 error = -EFSCORRUPTED;
2258 goto out_agbp_relse;
2259 }
2260 xfs_trans_binval(tp, bp);
2261 }
2262
2263 targs.tp = tp;
2264 targs.mp = mp;
2265 targs.agbp = agbp;
2266 targs.agno = args->agno;
2267 targs.alignment = targs.minlen = targs.prod = 1;
2268 targs.type = XFS_ALLOCTYPE_THIS_AG;
2269 targs.pag = pag;
2270 error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);
2271 if (error)
2272 goto out_agbp_relse;
2273
2274 /* Make the freelist longer if it's too short. */
2275 while (pag->pagf_flcount < need) {
2276 targs.agbno = 0;
2277 targs.maxlen = need - pag->pagf_flcount;
2278 targs.resv = XFS_AG_RESV_AGFL;
2279
2280 /* Allocate as many blocks as possible at once. */
2281 error = xfs_alloc_ag_vextent(&targs);
2282 if (error)
2283 goto out_agflbp_relse;
2284
2285 /*
2286 * Stop if we run out. Won't happen if callers are obeying
2287 * the restrictions correctly. Can happen for free calls
2288 * on a completely full ag.
2289 */
2290 if (targs.agbno == NULLAGBLOCK) {
2291 if (flags & XFS_ALLOC_FLAG_FREEING)
2292 break;
2293 goto out_agflbp_relse;
2294 }
2295 /*
2296 * Put each allocated block on the list.
2297 */
2298 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
2299 error = xfs_alloc_put_freelist(tp, agbp,
2300 agflbp, bno, 0);
2301 if (error)
2302 goto out_agflbp_relse;
2303 }
2304 }
2305 xfs_trans_brelse(tp, agflbp);
2306 args->agbp = agbp;
2307 return 0;
2308
2309 out_agflbp_relse:
2310 xfs_trans_brelse(tp, agflbp);
2311 out_agbp_relse:
2312 if (agbp)
2313 xfs_trans_brelse(tp, agbp);
2314 out_no_agbp:
2315 args->agbp = NULL;
2316 return error;
2317 }
2318
2319 /*
2320 * Get a block from the freelist.
2321 * Returns with the buffer for the block gotten.
2322 */
2323 int /* error */
2324 xfs_alloc_get_freelist(
2325 xfs_trans_t *tp, /* transaction pointer */
2326 xfs_buf_t *agbp, /* buffer containing the agf structure */
2327 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2328 int btreeblk) /* destination is a AGF btree */
2329 {
2330 xfs_agf_t *agf; /* a.g. freespace structure */
2331 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2332 xfs_agblock_t bno; /* block number returned */
2333 __be32 *agfl_bno;
2334 int error;
2335 int logflags;
2336 xfs_mount_t *mp = tp->t_mountp;
2337 xfs_perag_t *pag; /* per allocation group data */
2338
2339 /*
2340 * Freelist is empty, give up.
2341 */
2342 agf = XFS_BUF_TO_AGF(agbp);
2343 if (!agf->agf_flcount) {
2344 *bnop = NULLAGBLOCK;
2345 return 0;
2346 }
2347 /*
2348 * Read the array of free blocks.
2349 */
2350 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2351 &agflbp);
2352 if (error)
2353 return error;
2354
2355
2356 /*
2357 * Get the block number and update the data structures.
2358 */
2359 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2360 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2361 be32_add_cpu(&agf->agf_flfirst, 1);
2362 xfs_trans_brelse(tp, agflbp);
2363 if (be32_to_cpu(agf->agf_flfirst) == xfs_agfl_size(mp))
2364 agf->agf_flfirst = 0;
2365
2366 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2367 ASSERT(!pag->pagf_agflreset);
2368 be32_add_cpu(&agf->agf_flcount, -1);
2369 xfs_trans_agflist_delta(tp, -1);
2370 pag->pagf_flcount--;
2371 xfs_perag_put(pag);
2372
2373 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2374 if (btreeblk) {
2375 be32_add_cpu(&agf->agf_btreeblks, 1);
2376 pag->pagf_btreeblks++;
2377 logflags |= XFS_AGF_BTREEBLKS;
2378 }
2379
2380 xfs_alloc_log_agf(tp, agbp, logflags);
2381 *bnop = bno;
2382
2383 return 0;
2384 }
2385
2386 /*
2387 * Log the given fields from the agf structure.
2388 */
2389 void
2390 xfs_alloc_log_agf(
2391 xfs_trans_t *tp, /* transaction pointer */
2392 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2393 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2394 {
2395 int first; /* first byte offset */
2396 int last; /* last byte offset */
2397 static const short offsets[] = {
2398 offsetof(xfs_agf_t, agf_magicnum),
2399 offsetof(xfs_agf_t, agf_versionnum),
2400 offsetof(xfs_agf_t, agf_seqno),
2401 offsetof(xfs_agf_t, agf_length),
2402 offsetof(xfs_agf_t, agf_roots[0]),
2403 offsetof(xfs_agf_t, agf_levels[0]),
2404 offsetof(xfs_agf_t, agf_flfirst),
2405 offsetof(xfs_agf_t, agf_fllast),
2406 offsetof(xfs_agf_t, agf_flcount),
2407 offsetof(xfs_agf_t, agf_freeblks),
2408 offsetof(xfs_agf_t, agf_longest),
2409 offsetof(xfs_agf_t, agf_btreeblks),
2410 offsetof(xfs_agf_t, agf_uuid),
2411 offsetof(xfs_agf_t, agf_rmap_blocks),
2412 offsetof(xfs_agf_t, agf_refcount_blocks),
2413 offsetof(xfs_agf_t, agf_refcount_root),
2414 offsetof(xfs_agf_t, agf_refcount_level),
2415 /* needed so that we don't log the whole rest of the structure: */
2416 offsetof(xfs_agf_t, agf_spare64),
2417 sizeof(xfs_agf_t)
2418 };
2419
2420 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2421
2422 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
2423
2424 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2425 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2426 }
2427
2428 /*
2429 * Interface for inode allocation to force the pag data to be initialized.
2430 */
2431 int /* error */
2432 xfs_alloc_pagf_init(
2433 xfs_mount_t *mp, /* file system mount structure */
2434 xfs_trans_t *tp, /* transaction pointer */
2435 xfs_agnumber_t agno, /* allocation group number */
2436 int flags) /* XFS_ALLOC_FLAGS_... */
2437 {
2438 xfs_buf_t *bp;
2439 int error;
2440
2441 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2442 return error;
2443 if (bp)
2444 xfs_trans_brelse(tp, bp);
2445 return 0;
2446 }
2447
2448 /*
2449 * Put the block on the freelist for the allocation group.
2450 */
2451 int /* error */
2452 xfs_alloc_put_freelist(
2453 xfs_trans_t *tp, /* transaction pointer */
2454 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2455 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2456 xfs_agblock_t bno, /* block being freed */
2457 int btreeblk) /* block came from a AGF btree */
2458 {
2459 xfs_agf_t *agf; /* a.g. freespace structure */
2460 __be32 *blockp;/* pointer to array entry */
2461 int error;
2462 int logflags;
2463 xfs_mount_t *mp; /* mount structure */
2464 xfs_perag_t *pag; /* per allocation group data */
2465 __be32 *agfl_bno;
2466 int startoff;
2467
2468 agf = XFS_BUF_TO_AGF(agbp);
2469 mp = tp->t_mountp;
2470
2471 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2472 be32_to_cpu(agf->agf_seqno), &agflbp)))
2473 return error;
2474 be32_add_cpu(&agf->agf_fllast, 1);
2475 if (be32_to_cpu(agf->agf_fllast) == xfs_agfl_size(mp))
2476 agf->agf_fllast = 0;
2477
2478 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2479 ASSERT(!pag->pagf_agflreset);
2480 be32_add_cpu(&agf->agf_flcount, 1);
2481 xfs_trans_agflist_delta(tp, 1);
2482 pag->pagf_flcount++;
2483
2484 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2485 if (btreeblk) {
2486 be32_add_cpu(&agf->agf_btreeblks, -1);
2487 pag->pagf_btreeblks--;
2488 logflags |= XFS_AGF_BTREEBLKS;
2489 }
2490 xfs_perag_put(pag);
2491
2492 xfs_alloc_log_agf(tp, agbp, logflags);
2493
2494 ASSERT(be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp));
2495
2496 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2497 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
2498 *blockp = cpu_to_be32(bno);
2499 startoff = (char *)blockp - (char *)agflbp->b_addr;
2500
2501 xfs_alloc_log_agf(tp, agbp, logflags);
2502
2503 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
2504 xfs_trans_log_buf(tp, agflbp, startoff,
2505 startoff + sizeof(xfs_agblock_t) - 1);
2506 return 0;
2507 }
2508
2509 static bool
2510 xfs_agf_verify(
2511 struct xfs_mount *mp,
2512 struct xfs_buf *bp)
2513 {
2514 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
2515
2516 if (xfs_sb_version_hascrc(&mp->m_sb)) {
2517 if (!uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid))
2518 return false;
2519 if (!xfs_log_check_lsn(mp,
2520 be64_to_cpu(XFS_BUF_TO_AGF(bp)->agf_lsn)))
2521 return false;
2522 }
2523
2524 if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
2525 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2526 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2527 be32_to_cpu(agf->agf_flfirst) < xfs_agfl_size(mp) &&
2528 be32_to_cpu(agf->agf_fllast) < xfs_agfl_size(mp) &&
2529 be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp)))
2530 return false;
2531
2532 if (be32_to_cpu(agf->agf_length) > mp->m_sb.sb_dblocks)
2533 return false;
2534
2535 if (be32_to_cpu(agf->agf_freeblks) < be32_to_cpu(agf->agf_longest) ||
2536 be32_to_cpu(agf->agf_freeblks) > be32_to_cpu(agf->agf_length))
2537 return false;
2538
2539 if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 ||
2540 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 ||
2541 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS ||
2542 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS)
2543 return false;
2544
2545 if (xfs_sb_version_hasrmapbt(&mp->m_sb) &&
2546 (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 ||
2547 be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS))
2548 return false;
2549
2550 if (xfs_sb_version_hasrmapbt(&mp->m_sb) &&
2551 be32_to_cpu(agf->agf_rmap_blocks) > be32_to_cpu(agf->agf_length))
2552 return false;
2553
2554 /*
2555 * during growfs operations, the perag is not fully initialised,
2556 * so we can't use it for any useful checking. growfs ensures we can't
2557 * use it by using uncached buffers that don't have the perag attached
2558 * so we can detect and avoid this problem.
2559 */
2560 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2561 return false;
2562
2563 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2564 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2565 return false;
2566
2567 if (xfs_sb_version_hasreflink(&mp->m_sb) &&
2568 be32_to_cpu(agf->agf_refcount_blocks) >
2569 be32_to_cpu(agf->agf_length))
2570 return false;
2571
2572 if (xfs_sb_version_hasreflink(&mp->m_sb) &&
2573 (be32_to_cpu(agf->agf_refcount_level) < 1 ||
2574 be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS))
2575 return false;
2576
2577 return true;;
2578
2579 }
2580
2581 static void
2582 xfs_agf_read_verify(
2583 struct xfs_buf *bp)
2584 {
2585 struct xfs_mount *mp = bp->b_target->bt_mount;
2586
2587 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2588 !xfs_buf_verify_cksum(bp, XFS_AGF_CRC_OFF))
2589 xfs_buf_ioerror(bp, -EFSBADCRC);
2590 else if (XFS_TEST_ERROR(!xfs_agf_verify(mp, bp), mp,
2591 XFS_ERRTAG_ALLOC_READ_AGF))
2592 xfs_buf_ioerror(bp, -EFSCORRUPTED);
2593
2594 if (bp->b_error)
2595 xfs_verifier_error(bp);
2596 }
2597
2598 static void
2599 xfs_agf_write_verify(
2600 struct xfs_buf *bp)
2601 {
2602 struct xfs_mount *mp = bp->b_target->bt_mount;
2603 struct xfs_buf_log_item *bip = bp->b_fspriv;
2604
2605 if (!xfs_agf_verify(mp, bp)) {
2606 xfs_buf_ioerror(bp, -EFSCORRUPTED);
2607 xfs_verifier_error(bp);
2608 return;
2609 }
2610
2611 if (!xfs_sb_version_hascrc(&mp->m_sb))
2612 return;
2613
2614 if (bip)
2615 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2616
2617 xfs_buf_update_cksum(bp, XFS_AGF_CRC_OFF);
2618 }
2619
2620 const struct xfs_buf_ops xfs_agf_buf_ops = {
2621 .name = "xfs_agf",
2622 .verify_read = xfs_agf_read_verify,
2623 .verify_write = xfs_agf_write_verify,
2624 };
2625
2626 /*
2627 * Read in the allocation group header (free/alloc section).
2628 */
2629 int /* error */
2630 xfs_read_agf(
2631 struct xfs_mount *mp, /* mount point structure */
2632 struct xfs_trans *tp, /* transaction pointer */
2633 xfs_agnumber_t agno, /* allocation group number */
2634 int flags, /* XFS_BUF_ */
2635 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2636 {
2637 int error;
2638
2639 trace_xfs_read_agf(mp, agno);
2640
2641 ASSERT(agno != NULLAGNUMBER);
2642 error = xfs_trans_read_buf(
2643 mp, tp, mp->m_ddev_targp,
2644 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2645 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
2646 if (error)
2647 return error;
2648 if (!*bpp)
2649 return 0;
2650
2651 ASSERT(!(*bpp)->b_error);
2652 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
2653 return 0;
2654 }
2655
2656 /*
2657 * Read in the allocation group header (free/alloc section).
2658 */
2659 int /* error */
2660 xfs_alloc_read_agf(
2661 struct xfs_mount *mp, /* mount point structure */
2662 struct xfs_trans *tp, /* transaction pointer */
2663 xfs_agnumber_t agno, /* allocation group number */
2664 int flags, /* XFS_ALLOC_FLAG_... */
2665 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2666 {
2667 struct xfs_agf *agf; /* ag freelist header */
2668 struct xfs_perag *pag; /* per allocation group data */
2669 int error;
2670
2671 trace_xfs_alloc_read_agf(mp, agno);
2672
2673 ASSERT(agno != NULLAGNUMBER);
2674 error = xfs_read_agf(mp, tp, agno,
2675 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
2676 bpp);
2677 if (error)
2678 return error;
2679 if (!*bpp)
2680 return 0;
2681 ASSERT(!(*bpp)->b_error);
2682
2683 agf = XFS_BUF_TO_AGF(*bpp);
2684 pag = xfs_perag_get(mp, agno);
2685 if (!pag->pagf_init) {
2686 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2687 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
2688 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2689 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2690 pag->pagf_levels[XFS_BTNUM_BNOi] =
2691 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2692 pag->pagf_levels[XFS_BTNUM_CNTi] =
2693 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2694 pag->pagf_levels[XFS_BTNUM_RMAPi] =
2695 be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
2696 pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);
2697 spin_lock_init(&pag->pagb_lock);
2698 pag->pagb_count = 0;
2699 pag->pagb_tree = RB_ROOT;
2700 pag->pagf_init = 1;
2701 pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf);
2702 }
2703 #ifdef DEBUG
2704 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2705 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2706 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
2707 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2708 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2709 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2710 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2711 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2712 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2713 }
2714 #endif
2715 xfs_perag_put(pag);
2716 return 0;
2717 }
2718
2719 /*
2720 * Allocate an extent (variable-size).
2721 * Depending on the allocation type, we either look in a single allocation
2722 * group or loop over the allocation groups to find the result.
2723 */
2724 int /* error */
2725 xfs_alloc_vextent(
2726 xfs_alloc_arg_t *args) /* allocation argument structure */
2727 {
2728 xfs_agblock_t agsize; /* allocation group size */
2729 int error;
2730 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2731 xfs_mount_t *mp; /* mount structure pointer */
2732 xfs_agnumber_t sagno; /* starting allocation group number */
2733 xfs_alloctype_t type; /* input allocation type */
2734 int bump_rotor = 0;
2735 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2736
2737 mp = args->mp;
2738 type = args->otype = args->type;
2739 args->agbno = NULLAGBLOCK;
2740 /*
2741 * Just fix this up, for the case where the last a.g. is shorter
2742 * (or there's only one a.g.) and the caller couldn't easily figure
2743 * that out (xfs_bmap_alloc).
2744 */
2745 agsize = mp->m_sb.sb_agblocks;
2746 if (args->maxlen > agsize)
2747 args->maxlen = agsize;
2748 if (args->alignment == 0)
2749 args->alignment = 1;
2750 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2751 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2752 ASSERT(args->minlen <= args->maxlen);
2753 ASSERT(args->minlen <= agsize);
2754 ASSERT(args->mod < args->prod);
2755 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2756 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2757 args->minlen > args->maxlen || args->minlen > agsize ||
2758 args->mod >= args->prod) {
2759 args->fsbno = NULLFSBLOCK;
2760 trace_xfs_alloc_vextent_badargs(args);
2761 return 0;
2762 }
2763
2764 switch (type) {
2765 case XFS_ALLOCTYPE_THIS_AG:
2766 case XFS_ALLOCTYPE_NEAR_BNO:
2767 case XFS_ALLOCTYPE_THIS_BNO:
2768 /*
2769 * These three force us into a single a.g.
2770 */
2771 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2772 args->pag = xfs_perag_get(mp, args->agno);
2773 error = xfs_alloc_fix_freelist(args, 0);
2774 if (error) {
2775 trace_xfs_alloc_vextent_nofix(args);
2776 goto error0;
2777 }
2778 if (!args->agbp) {
2779 trace_xfs_alloc_vextent_noagbp(args);
2780 break;
2781 }
2782 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2783 if ((error = xfs_alloc_ag_vextent(args)))
2784 goto error0;
2785 break;
2786 case XFS_ALLOCTYPE_START_BNO:
2787 /*
2788 * Try near allocation first, then anywhere-in-ag after
2789 * the first a.g. fails.
2790 */
2791 if ((args->datatype & XFS_ALLOC_INITIAL_USER_DATA) &&
2792 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2793 args->fsbno = XFS_AGB_TO_FSB(mp,
2794 ((mp->m_agfrotor / rotorstep) %
2795 mp->m_sb.sb_agcount), 0);
2796 bump_rotor = 1;
2797 }
2798 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2799 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2800 /* FALLTHROUGH */
2801 case XFS_ALLOCTYPE_FIRST_AG:
2802 /*
2803 * Rotate through the allocation groups looking for a winner.
2804 */
2805 if (type == XFS_ALLOCTYPE_FIRST_AG) {
2806 /*
2807 * Start with allocation group given by bno.
2808 */
2809 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2810 args->type = XFS_ALLOCTYPE_THIS_AG;
2811 sagno = 0;
2812 flags = 0;
2813 } else {
2814 /*
2815 * Start with the given allocation group.
2816 */
2817 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2818 flags = XFS_ALLOC_FLAG_TRYLOCK;
2819 }
2820 /*
2821 * Loop over allocation groups twice; first time with
2822 * trylock set, second time without.
2823 */
2824 for (;;) {
2825 args->pag = xfs_perag_get(mp, args->agno);
2826 error = xfs_alloc_fix_freelist(args, flags);
2827 if (error) {
2828 trace_xfs_alloc_vextent_nofix(args);
2829 goto error0;
2830 }
2831 /*
2832 * If we get a buffer back then the allocation will fly.
2833 */
2834 if (args->agbp) {
2835 if ((error = xfs_alloc_ag_vextent(args)))
2836 goto error0;
2837 break;
2838 }
2839
2840 trace_xfs_alloc_vextent_loopfailed(args);
2841
2842 /*
2843 * Didn't work, figure out the next iteration.
2844 */
2845 if (args->agno == sagno &&
2846 type == XFS_ALLOCTYPE_START_BNO)
2847 args->type = XFS_ALLOCTYPE_THIS_AG;
2848 /*
2849 * For the first allocation, we can try any AG to get
2850 * space. However, if we already have allocated a
2851 * block, we don't want to try AGs whose number is below
2852 * sagno. Otherwise, we may end up with out-of-order
2853 * locking of AGF, which might cause deadlock.
2854 */
2855 if (++(args->agno) == mp->m_sb.sb_agcount) {
2856 if (args->firstblock != NULLFSBLOCK)
2857 args->agno = sagno;
2858 else
2859 args->agno = 0;
2860 }
2861 /*
2862 * Reached the starting a.g., must either be done
2863 * or switch to non-trylock mode.
2864 */
2865 if (args->agno == sagno) {
2866 if (flags == 0) {
2867 args->agbno = NULLAGBLOCK;
2868 trace_xfs_alloc_vextent_allfailed(args);
2869 break;
2870 }
2871
2872 flags = 0;
2873 if (type == XFS_ALLOCTYPE_START_BNO) {
2874 args->agbno = XFS_FSB_TO_AGBNO(mp,
2875 args->fsbno);
2876 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2877 }
2878 }
2879 xfs_perag_put(args->pag);
2880 }
2881 if (bump_rotor) {
2882 if (args->agno == sagno)
2883 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2884 (mp->m_sb.sb_agcount * rotorstep);
2885 else
2886 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2887 (mp->m_sb.sb_agcount * rotorstep);
2888 }
2889 break;
2890 default:
2891 ASSERT(0);
2892 /* NOTREACHED */
2893 }
2894 if (args->agbno == NULLAGBLOCK)
2895 args->fsbno = NULLFSBLOCK;
2896 else {
2897 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2898 #ifdef DEBUG
2899 ASSERT(args->len >= args->minlen);
2900 ASSERT(args->len <= args->maxlen);
2901 ASSERT(args->agbno % args->alignment == 0);
2902 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2903 args->len);
2904 #endif
2905
2906 /* Zero the extent if we were asked to do so */
2907 if (args->datatype & XFS_ALLOC_USERDATA_ZERO) {
2908 error = xfs_zero_extent(args->ip, args->fsbno, args->len);
2909 if (error)
2910 goto error0;
2911 }
2912
2913 }
2914 xfs_perag_put(args->pag);
2915 return 0;
2916 error0:
2917 xfs_perag_put(args->pag);
2918 return error;
2919 }
2920
2921 /* Ensure that the freelist is at full capacity. */
2922 int
2923 xfs_free_extent_fix_freelist(
2924 struct xfs_trans *tp,
2925 xfs_agnumber_t agno,
2926 struct xfs_buf **agbp)
2927 {
2928 struct xfs_alloc_arg args;
2929 int error;
2930
2931 memset(&args, 0, sizeof(struct xfs_alloc_arg));
2932 args.tp = tp;
2933 args.mp = tp->t_mountp;
2934 args.agno = agno;
2935
2936 /*
2937 * validate that the block number is legal - the enables us to detect
2938 * and handle a silent filesystem corruption rather than crashing.
2939 */
2940 if (args.agno >= args.mp->m_sb.sb_agcount)
2941 return -EFSCORRUPTED;
2942
2943 args.pag = xfs_perag_get(args.mp, args.agno);
2944 ASSERT(args.pag);
2945
2946 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
2947 if (error)
2948 goto out;
2949
2950 *agbp = args.agbp;
2951 out:
2952 xfs_perag_put(args.pag);
2953 return error;
2954 }
2955
2956 /*
2957 * Free an extent.
2958 * Just break up the extent address and hand off to xfs_free_ag_extent
2959 * after fixing up the freelist.
2960 */
2961 int /* error */
2962 xfs_free_extent(
2963 struct xfs_trans *tp, /* transaction pointer */
2964 xfs_fsblock_t bno, /* starting block number of extent */
2965 xfs_extlen_t len, /* length of extent */
2966 struct xfs_owner_info *oinfo, /* extent owner */
2967 enum xfs_ag_resv_type type) /* block reservation type */
2968 {
2969 struct xfs_mount *mp = tp->t_mountp;
2970 struct xfs_buf *agbp;
2971 xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, bno);
2972 xfs_agblock_t agbno = XFS_FSB_TO_AGBNO(mp, bno);
2973 int error;
2974
2975 ASSERT(len != 0);
2976 ASSERT(type != XFS_AG_RESV_AGFL);
2977
2978 if (XFS_TEST_ERROR(false, mp,
2979 XFS_ERRTAG_FREE_EXTENT))
2980 return -EIO;
2981
2982 error = xfs_free_extent_fix_freelist(tp, agno, &agbp);
2983 if (error)
2984 return error;
2985
2986 XFS_WANT_CORRUPTED_GOTO(mp, agbno < mp->m_sb.sb_agblocks, err);
2987
2988 /* validate the extent size is legal now we have the agf locked */
2989 XFS_WANT_CORRUPTED_GOTO(mp,
2990 agbno + len <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_length),
2991 err);
2992
2993 error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, oinfo, type);
2994 if (error)
2995 goto err;
2996
2997 xfs_extent_busy_insert(tp, agno, agbno, len, 0);
2998 return 0;
2999
3000 err:
3001 xfs_trans_brelse(tp, agbp);
3002 return error;
3003 }
3004
3005 struct xfs_alloc_query_range_info {
3006 xfs_alloc_query_range_fn fn;
3007 void *priv;
3008 };
3009
3010 /* Format btree record and pass to our callback. */
3011 STATIC int
3012 xfs_alloc_query_range_helper(
3013 struct xfs_btree_cur *cur,
3014 union xfs_btree_rec *rec,
3015 void *priv)
3016 {
3017 struct xfs_alloc_query_range_info *query = priv;
3018 struct xfs_alloc_rec_incore irec;
3019
3020 irec.ar_startblock = be32_to_cpu(rec->alloc.ar_startblock);
3021 irec.ar_blockcount = be32_to_cpu(rec->alloc.ar_blockcount);
3022 return query->fn(cur, &irec, query->priv);
3023 }
3024
3025 /* Find all free space within a given range of blocks. */
3026 int
3027 xfs_alloc_query_range(
3028 struct xfs_btree_cur *cur,
3029 struct xfs_alloc_rec_incore *low_rec,
3030 struct xfs_alloc_rec_incore *high_rec,
3031 xfs_alloc_query_range_fn fn,
3032 void *priv)
3033 {
3034 union xfs_btree_irec low_brec;
3035 union xfs_btree_irec high_brec;
3036 struct xfs_alloc_query_range_info query;
3037
3038 ASSERT(cur->bc_btnum == XFS_BTNUM_BNO);
3039 low_brec.a = *low_rec;
3040 high_brec.a = *high_rec;
3041 query.priv = priv;
3042 query.fn = fn;
3043 return xfs_btree_query_range(cur, &low_brec, &high_brec,
3044 xfs_alloc_query_range_helper, &query);
3045 }
3046
3047 /* Find all free space records. */
3048 int
3049 xfs_alloc_query_all(
3050 struct xfs_btree_cur *cur,
3051 xfs_alloc_query_range_fn fn,
3052 void *priv)
3053 {
3054 struct xfs_alloc_query_range_info query;
3055
3056 ASSERT(cur->bc_btnum == XFS_BTNUM_BNO);
3057 query.priv = priv;
3058 query.fn = fn;
3059 return xfs_btree_query_all(cur, xfs_alloc_query_range_helper, &query);
3060 }
Linux with added FPC-III support