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xfs: add agf freeblocks verify in xfs_agf_verify
[linux/fpc-iii.git] / fs / xfs / libxfs / xfs_alloc.c
blob0a36f532cf86c16b957de683fb6c989cb1663b1e
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_format.h"
9 #include "xfs_log_format.h"
10 #include "xfs_shared.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_bit.h"
13 #include "xfs_sb.h"
14 #include "xfs_mount.h"
15 #include "xfs_defer.h"
16 #include "xfs_btree.h"
17 #include "xfs_rmap.h"
18 #include "xfs_alloc_btree.h"
19 #include "xfs_alloc.h"
20 #include "xfs_extent_busy.h"
21 #include "xfs_errortag.h"
22 #include "xfs_error.h"
23 #include "xfs_trace.h"
24 #include "xfs_trans.h"
25 #include "xfs_buf_item.h"
26 #include "xfs_log.h"
27 #include "xfs_ag_resv.h"
28 #include "xfs_bmap.h"
29
30 extern kmem_zone_t *xfs_bmap_free_item_zone;
31
32 struct workqueue_struct *xfs_alloc_wq;
33
34 #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
35
36 #define XFSA_FIXUP_BNO_OK 1
37 #define XFSA_FIXUP_CNT_OK 2
38
39 STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
40 STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
41 STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
42
43 /*
44 * Size of the AGFL. For CRC-enabled filesystes we steal a couple of slots in
45 * the beginning of the block for a proper header with the location information
46 * and CRC.
47 */
48 unsigned int
49 xfs_agfl_size(
50 struct xfs_mount *mp)
51 {
52 unsigned int size = mp->m_sb.sb_sectsize;
53
54 if (xfs_sb_version_hascrc(&mp->m_sb))
55 size -= sizeof(struct xfs_agfl);
56
57 return size / sizeof(xfs_agblock_t);
58 }
59
60 unsigned int
61 xfs_refc_block(
62 struct xfs_mount *mp)
63 {
64 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
65 return XFS_RMAP_BLOCK(mp) + 1;
66 if (xfs_sb_version_hasfinobt(&mp->m_sb))
67 return XFS_FIBT_BLOCK(mp) + 1;
68 return XFS_IBT_BLOCK(mp) + 1;
69 }
70
71 xfs_extlen_t
72 xfs_prealloc_blocks(
73 struct xfs_mount *mp)
74 {
75 if (xfs_sb_version_hasreflink(&mp->m_sb))
76 return xfs_refc_block(mp) + 1;
77 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
78 return XFS_RMAP_BLOCK(mp) + 1;
79 if (xfs_sb_version_hasfinobt(&mp->m_sb))
80 return XFS_FIBT_BLOCK(mp) + 1;
81 return XFS_IBT_BLOCK(mp) + 1;
82 }
83
84 /*
85 * In order to avoid ENOSPC-related deadlock caused by out-of-order locking of
86 * AGF buffer (PV 947395), we place constraints on the relationship among
87 * actual allocations for data blocks, freelist blocks, and potential file data
88 * bmap btree blocks. However, these restrictions may result in no actual space
89 * allocated for a delayed extent, for example, a data block in a certain AG is
90 * allocated but there is no additional block for the additional bmap btree
91 * block due to a split of the bmap btree of the file. The result of this may
92 * lead to an infinite loop when the file gets flushed to disk and all delayed
93 * extents need to be actually allocated. To get around this, we explicitly set
94 * aside a few blocks which will not be reserved in delayed allocation.
95 *
96 * We need to reserve 4 fsbs _per AG_ for the freelist and 4 more to handle a
97 * potential split of the file's bmap btree.
98 */
99 unsigned int
100 xfs_alloc_set_aside(
101 struct xfs_mount *mp)
102 {
103 return mp->m_sb.sb_agcount * (XFS_ALLOC_AGFL_RESERVE + 4);
104 }
105
106 /*
107 * When deciding how much space to allocate out of an AG, we limit the
108 * allocation maximum size to the size the AG. However, we cannot use all the
109 * blocks in the AG - some are permanently used by metadata. These
110 * blocks are generally:
111 * - the AG superblock, AGF, AGI and AGFL
112 * - the AGF (bno and cnt) and AGI btree root blocks, and optionally
113 * the AGI free inode and rmap btree root blocks.
114 * - blocks on the AGFL according to xfs_alloc_set_aside() limits
115 * - the rmapbt root block
116 *
117 * The AG headers are sector sized, so the amount of space they take up is
118 * dependent on filesystem geometry. The others are all single blocks.
119 */
120 unsigned int
121 xfs_alloc_ag_max_usable(
122 struct xfs_mount *mp)
123 {
124 unsigned int blocks;
125
126 blocks = XFS_BB_TO_FSB(mp, XFS_FSS_TO_BB(mp, 4)); /* ag headers */
127 blocks += XFS_ALLOC_AGFL_RESERVE;
128 blocks += 3; /* AGF, AGI btree root blocks */
129 if (xfs_sb_version_hasfinobt(&mp->m_sb))
130 blocks++; /* finobt root block */
131 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
132 blocks++; /* rmap root block */
133 if (xfs_sb_version_hasreflink(&mp->m_sb))
134 blocks++; /* refcount root block */
135
136 return mp->m_sb.sb_agblocks - blocks;
137 }
138
139 /*
140 * Lookup the record equal to [bno, len] in the btree given by cur.
141 */
142 STATIC int /* error */
143 xfs_alloc_lookup_eq(
144 struct xfs_btree_cur *cur, /* btree cursor */
145 xfs_agblock_t bno, /* starting block of extent */
146 xfs_extlen_t len, /* length of extent */
147 int *stat) /* success/failure */
148 {
149 cur->bc_rec.a.ar_startblock = bno;
150 cur->bc_rec.a.ar_blockcount = len;
151 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
152 }
153
154 /*
155 * Lookup the first record greater than or equal to [bno, len]
156 * in the btree given by cur.
157 */
158 int /* error */
159 xfs_alloc_lookup_ge(
160 struct xfs_btree_cur *cur, /* btree cursor */
161 xfs_agblock_t bno, /* starting block of extent */
162 xfs_extlen_t len, /* length of extent */
163 int *stat) /* success/failure */
164 {
165 cur->bc_rec.a.ar_startblock = bno;
166 cur->bc_rec.a.ar_blockcount = len;
167 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
168 }
169
170 /*
171 * Lookup the first record less than or equal to [bno, len]
172 * in the btree given by cur.
173 */
174 int /* error */
175 xfs_alloc_lookup_le(
176 struct xfs_btree_cur *cur, /* btree cursor */
177 xfs_agblock_t bno, /* starting block of extent */
178 xfs_extlen_t len, /* length of extent */
179 int *stat) /* success/failure */
180 {
181 cur->bc_rec.a.ar_startblock = bno;
182 cur->bc_rec.a.ar_blockcount = len;
183 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
184 }
185
186 /*
187 * Update the record referred to by cur to the value given
188 * by [bno, len].
189 * This either works (return 0) or gets an EFSCORRUPTED error.
190 */
191 STATIC int /* error */
192 xfs_alloc_update(
193 struct xfs_btree_cur *cur, /* btree cursor */
194 xfs_agblock_t bno, /* starting block of extent */
195 xfs_extlen_t len) /* length of extent */
196 {
197 union xfs_btree_rec rec;
198
199 rec.alloc.ar_startblock = cpu_to_be32(bno);
200 rec.alloc.ar_blockcount = cpu_to_be32(len);
201 return xfs_btree_update(cur, &rec);
202 }
203
204 /*
205 * Get the data from the pointed-to record.
206 */
207 int /* error */
208 xfs_alloc_get_rec(
209 struct xfs_btree_cur *cur, /* btree cursor */
210 xfs_agblock_t *bno, /* output: starting block of extent */
211 xfs_extlen_t *len, /* output: length of extent */
212 int *stat) /* output: success/failure */
213 {
214 struct xfs_mount *mp = cur->bc_mp;
215 xfs_agnumber_t agno = cur->bc_private.a.agno;
216 union xfs_btree_rec *rec;
217 int error;
218
219 error = xfs_btree_get_rec(cur, &rec, stat);
220 if (error || !(*stat))
221 return error;
222
223 *bno = be32_to_cpu(rec->alloc.ar_startblock);
224 *len = be32_to_cpu(rec->alloc.ar_blockcount);
225
226 if (*len == 0)
227 goto out_bad_rec;
228
229 /* check for valid extent range, including overflow */
230 if (!xfs_verify_agbno(mp, agno, *bno))
231 goto out_bad_rec;
232 if (*bno > *bno + *len)
233 goto out_bad_rec;
234 if (!xfs_verify_agbno(mp, agno, *bno + *len - 1))
235 goto out_bad_rec;
236
237 return 0;
238
239 out_bad_rec:
240 xfs_warn(mp,
241 "%s Freespace BTree record corruption in AG %d detected!",
242 cur->bc_btnum == XFS_BTNUM_BNO ? "Block" : "Size", agno);
243 xfs_warn(mp,
244 "start block 0x%x block count 0x%x", *bno, *len);
245 return -EFSCORRUPTED;
246 }
247
248 /*
249 * Compute aligned version of the found extent.
250 * Takes alignment and min length into account.
251 */
252 STATIC bool
253 xfs_alloc_compute_aligned(
254 xfs_alloc_arg_t *args, /* allocation argument structure */
255 xfs_agblock_t foundbno, /* starting block in found extent */
256 xfs_extlen_t foundlen, /* length in found extent */
257 xfs_agblock_t *resbno, /* result block number */
258 xfs_extlen_t *reslen, /* result length */
259 unsigned *busy_gen)
260 {
261 xfs_agblock_t bno = foundbno;
262 xfs_extlen_t len = foundlen;
263 xfs_extlen_t diff;
264 bool busy;
265
266 /* Trim busy sections out of found extent */
267 busy = xfs_extent_busy_trim(args, &bno, &len, busy_gen);
268
269 /*
270 * If we have a largish extent that happens to start before min_agbno,
271 * see if we can shift it into range...
272 */
273 if (bno < args->min_agbno && bno + len > args->min_agbno) {
274 diff = args->min_agbno - bno;
275 if (len > diff) {
276 bno += diff;
277 len -= diff;
278 }
279 }
280
281 if (args->alignment > 1 && len >= args->minlen) {
282 xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
283
284 diff = aligned_bno - bno;
285
286 *resbno = aligned_bno;
287 *reslen = diff >= len ? 0 : len - diff;
288 } else {
289 *resbno = bno;
290 *reslen = len;
291 }
292
293 return busy;
294 }
295
296 /*
297 * Compute best start block and diff for "near" allocations.
298 * freelen >= wantlen already checked by caller.
299 */
300 STATIC xfs_extlen_t /* difference value (absolute) */
301 xfs_alloc_compute_diff(
302 xfs_agblock_t wantbno, /* target starting block */
303 xfs_extlen_t wantlen, /* target length */
304 xfs_extlen_t alignment, /* target alignment */
305 int datatype, /* are we allocating data? */
306 xfs_agblock_t freebno, /* freespace's starting block */
307 xfs_extlen_t freelen, /* freespace's length */
308 xfs_agblock_t *newbnop) /* result: best start block from free */
309 {
310 xfs_agblock_t freeend; /* end of freespace extent */
311 xfs_agblock_t newbno1; /* return block number */
312 xfs_agblock_t newbno2; /* other new block number */
313 xfs_extlen_t newlen1=0; /* length with newbno1 */
314 xfs_extlen_t newlen2=0; /* length with newbno2 */
315 xfs_agblock_t wantend; /* end of target extent */
316 bool userdata = xfs_alloc_is_userdata(datatype);
317
318 ASSERT(freelen >= wantlen);
319 freeend = freebno + freelen;
320 wantend = wantbno + wantlen;
321 /*
322 * We want to allocate from the start of a free extent if it is past
323 * the desired block or if we are allocating user data and the free
324 * extent is before desired block. The second case is there to allow
325 * for contiguous allocation from the remaining free space if the file
326 * grows in the short term.
327 */
328 if (freebno >= wantbno || (userdata && freeend < wantend)) {
329 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
330 newbno1 = NULLAGBLOCK;
331 } else if (freeend >= wantend && alignment > 1) {
332 newbno1 = roundup(wantbno, alignment);
333 newbno2 = newbno1 - alignment;
334 if (newbno1 >= freeend)
335 newbno1 = NULLAGBLOCK;
336 else
337 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
338 if (newbno2 < freebno)
339 newbno2 = NULLAGBLOCK;
340 else
341 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
342 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
343 if (newlen1 < newlen2 ||
344 (newlen1 == newlen2 &&
345 XFS_ABSDIFF(newbno1, wantbno) >
346 XFS_ABSDIFF(newbno2, wantbno)))
347 newbno1 = newbno2;
348 } else if (newbno2 != NULLAGBLOCK)
349 newbno1 = newbno2;
350 } else if (freeend >= wantend) {
351 newbno1 = wantbno;
352 } else if (alignment > 1) {
353 newbno1 = roundup(freeend - wantlen, alignment);
354 if (newbno1 > freeend - wantlen &&
355 newbno1 - alignment >= freebno)
356 newbno1 -= alignment;
357 else if (newbno1 >= freeend)
358 newbno1 = NULLAGBLOCK;
359 } else
360 newbno1 = freeend - wantlen;
361 *newbnop = newbno1;
362 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
363 }
364
365 /*
366 * Fix up the length, based on mod and prod.
367 * len should be k * prod + mod for some k.
368 * If len is too small it is returned unchanged.
369 * If len hits maxlen it is left alone.
370 */
371 STATIC void
372 xfs_alloc_fix_len(
373 xfs_alloc_arg_t *args) /* allocation argument structure */
374 {
375 xfs_extlen_t k;
376 xfs_extlen_t rlen;
377
378 ASSERT(args->mod < args->prod);
379 rlen = args->len;
380 ASSERT(rlen >= args->minlen);
381 ASSERT(rlen <= args->maxlen);
382 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
383 (args->mod == 0 && rlen < args->prod))
384 return;
385 k = rlen % args->prod;
386 if (k == args->mod)
387 return;
388 if (k > args->mod)
389 rlen = rlen - (k - args->mod);
390 else
391 rlen = rlen - args->prod + (args->mod - k);
392 /* casts to (int) catch length underflows */
393 if ((int)rlen < (int)args->minlen)
394 return;
395 ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
396 ASSERT(rlen % args->prod == args->mod);
397 ASSERT(args->pag->pagf_freeblks + args->pag->pagf_flcount >=
398 rlen + args->minleft);
399 args->len = rlen;
400 }
401
402 /*
403 * Update the two btrees, logically removing from freespace the extent
404 * starting at rbno, rlen blocks. The extent is contained within the
405 * actual (current) free extent fbno for flen blocks.
406 * Flags are passed in indicating whether the cursors are set to the
407 * relevant records.
408 */
409 STATIC int /* error code */
410 xfs_alloc_fixup_trees(
411 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
412 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
413 xfs_agblock_t fbno, /* starting block of free extent */
414 xfs_extlen_t flen, /* length of free extent */
415 xfs_agblock_t rbno, /* starting block of returned extent */
416 xfs_extlen_t rlen, /* length of returned extent */
417 int flags) /* flags, XFSA_FIXUP_... */
418 {
419 int error; /* error code */
420 int i; /* operation results */
421 xfs_agblock_t nfbno1; /* first new free startblock */
422 xfs_agblock_t nfbno2; /* second new free startblock */
423 xfs_extlen_t nflen1=0; /* first new free length */
424 xfs_extlen_t nflen2=0; /* second new free length */
425 struct xfs_mount *mp;
426
427 mp = cnt_cur->bc_mp;
428
429 /*
430 * Look up the record in the by-size tree if necessary.
431 */
432 if (flags & XFSA_FIXUP_CNT_OK) {
433 #ifdef DEBUG
434 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
435 return error;
436 XFS_WANT_CORRUPTED_RETURN(mp,
437 i == 1 && nfbno1 == fbno && nflen1 == flen);
438 #endif
439 } else {
440 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
441 return error;
442 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
443 }
444 /*
445 * Look up the record in the by-block tree if necessary.
446 */
447 if (flags & XFSA_FIXUP_BNO_OK) {
448 #ifdef DEBUG
449 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
450 return error;
451 XFS_WANT_CORRUPTED_RETURN(mp,
452 i == 1 && nfbno1 == fbno && nflen1 == flen);
453 #endif
454 } else {
455 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
456 return error;
457 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
458 }
459
460 #ifdef DEBUG
461 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
462 struct xfs_btree_block *bnoblock;
463 struct xfs_btree_block *cntblock;
464
465 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
466 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
467
468 XFS_WANT_CORRUPTED_RETURN(mp,
469 bnoblock->bb_numrecs == cntblock->bb_numrecs);
470 }
471 #endif
472
473 /*
474 * Deal with all four cases: the allocated record is contained
475 * within the freespace record, so we can have new freespace
476 * at either (or both) end, or no freespace remaining.
477 */
478 if (rbno == fbno && rlen == flen)
479 nfbno1 = nfbno2 = NULLAGBLOCK;
480 else if (rbno == fbno) {
481 nfbno1 = rbno + rlen;
482 nflen1 = flen - rlen;
483 nfbno2 = NULLAGBLOCK;
484 } else if (rbno + rlen == fbno + flen) {
485 nfbno1 = fbno;
486 nflen1 = flen - rlen;
487 nfbno2 = NULLAGBLOCK;
488 } else {
489 nfbno1 = fbno;
490 nflen1 = rbno - fbno;
491 nfbno2 = rbno + rlen;
492 nflen2 = (fbno + flen) - nfbno2;
493 }
494 /*
495 * Delete the entry from the by-size btree.
496 */
497 if ((error = xfs_btree_delete(cnt_cur, &i)))
498 return error;
499 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
500 /*
501 * Add new by-size btree entry(s).
502 */
503 if (nfbno1 != NULLAGBLOCK) {
504 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
505 return error;
506 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
507 if ((error = xfs_btree_insert(cnt_cur, &i)))
508 return error;
509 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
510 }
511 if (nfbno2 != NULLAGBLOCK) {
512 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
513 return error;
514 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
515 if ((error = xfs_btree_insert(cnt_cur, &i)))
516 return error;
517 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
518 }
519 /*
520 * Fix up the by-block btree entry(s).
521 */
522 if (nfbno1 == NULLAGBLOCK) {
523 /*
524 * No remaining freespace, just delete the by-block tree entry.
525 */
526 if ((error = xfs_btree_delete(bno_cur, &i)))
527 return error;
528 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
529 } else {
530 /*
531 * Update the by-block entry to start later|be shorter.
532 */
533 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
534 return error;
535 }
536 if (nfbno2 != NULLAGBLOCK) {
537 /*
538 * 2 resulting free entries, need to add one.
539 */
540 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
541 return error;
542 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
543 if ((error = xfs_btree_insert(bno_cur, &i)))
544 return error;
545 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
546 }
547 return 0;
548 }
549
550 static xfs_failaddr_t
551 xfs_agfl_verify(
552 struct xfs_buf *bp)
553 {
554 struct xfs_mount *mp = bp->b_mount;
555 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
556 int i;
557
558 /*
559 * There is no verification of non-crc AGFLs because mkfs does not
560 * initialise the AGFL to zero or NULL. Hence the only valid part of the
561 * AGFL is what the AGF says is active. We can't get to the AGF, so we
562 * can't verify just those entries are valid.
563 */
564 if (!xfs_sb_version_hascrc(&mp->m_sb))
565 return NULL;
566
567 if (!xfs_verify_magic(bp, agfl->agfl_magicnum))
568 return __this_address;
569 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid))
570 return __this_address;
571 /*
572 * during growfs operations, the perag is not fully initialised,
573 * so we can't use it for any useful checking. growfs ensures we can't
574 * use it by using uncached buffers that don't have the perag attached
575 * so we can detect and avoid this problem.
576 */
577 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
578 return __this_address;
579
580 for (i = 0; i < xfs_agfl_size(mp); i++) {
581 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
582 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
583 return __this_address;
584 }
585
586 if (!xfs_log_check_lsn(mp, be64_to_cpu(XFS_BUF_TO_AGFL(bp)->agfl_lsn)))
587 return __this_address;
588 return NULL;
589 }
590
591 static void
592 xfs_agfl_read_verify(
593 struct xfs_buf *bp)
594 {
595 struct xfs_mount *mp = bp->b_mount;
596 xfs_failaddr_t fa;
597
598 /*
599 * There is no verification of non-crc AGFLs because mkfs does not
600 * initialise the AGFL to zero or NULL. Hence the only valid part of the
601 * AGFL is what the AGF says is active. We can't get to the AGF, so we
602 * can't verify just those entries are valid.
603 */
604 if (!xfs_sb_version_hascrc(&mp->m_sb))
605 return;
606
607 if (!xfs_buf_verify_cksum(bp, XFS_AGFL_CRC_OFF))
608 xfs_verifier_error(bp, -EFSBADCRC, __this_address);
609 else {
610 fa = xfs_agfl_verify(bp);
611 if (fa)
612 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
613 }
614 }
615
616 static void
617 xfs_agfl_write_verify(
618 struct xfs_buf *bp)
619 {
620 struct xfs_mount *mp = bp->b_mount;
621 struct xfs_buf_log_item *bip = bp->b_log_item;
622 xfs_failaddr_t fa;
623
624 /* no verification of non-crc AGFLs */
625 if (!xfs_sb_version_hascrc(&mp->m_sb))
626 return;
627
628 fa = xfs_agfl_verify(bp);
629 if (fa) {
630 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
631 return;
632 }
633
634 if (bip)
635 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
636
637 xfs_buf_update_cksum(bp, XFS_AGFL_CRC_OFF);
638 }
639
640 const struct xfs_buf_ops xfs_agfl_buf_ops = {
641 .name = "xfs_agfl",
642 .magic = { cpu_to_be32(XFS_AGFL_MAGIC), cpu_to_be32(XFS_AGFL_MAGIC) },
643 .verify_read = xfs_agfl_read_verify,
644 .verify_write = xfs_agfl_write_verify,
645 .verify_struct = xfs_agfl_verify,
646 };
647
648 /*
649 * Read in the allocation group free block array.
650 */
651 int /* error */
652 xfs_alloc_read_agfl(
653 xfs_mount_t *mp, /* mount point structure */
654 xfs_trans_t *tp, /* transaction pointer */
655 xfs_agnumber_t agno, /* allocation group number */
656 xfs_buf_t **bpp) /* buffer for the ag free block array */
657 {
658 xfs_buf_t *bp; /* return value */
659 int error;
660
661 ASSERT(agno != NULLAGNUMBER);
662 error = xfs_trans_read_buf(
663 mp, tp, mp->m_ddev_targp,
664 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
665 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
666 if (error)
667 return error;
668 xfs_buf_set_ref(bp, XFS_AGFL_REF);
669 *bpp = bp;
670 return 0;
671 }
672
673 STATIC int
674 xfs_alloc_update_counters(
675 struct xfs_trans *tp,
676 struct xfs_perag *pag,
677 struct xfs_buf *agbp,
678 long len)
679 {
680 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
681
682 pag->pagf_freeblks += len;
683 be32_add_cpu(&agf->agf_freeblks, len);
684
685 xfs_trans_agblocks_delta(tp, len);
686 if (unlikely(be32_to_cpu(agf->agf_freeblks) >
687 be32_to_cpu(agf->agf_length)))
688 return -EFSCORRUPTED;
689
690 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
691 return 0;
692 }
693
694 /*
695 * Allocation group level functions.
696 */
697
698 /*
699 * Deal with the case where only small freespaces remain. Either return the
700 * contents of the last freespace record, or allocate space from the freelist if
701 * there is nothing in the tree.
702 */
703 STATIC int /* error */
704 xfs_alloc_ag_vextent_small(
705 struct xfs_alloc_arg *args, /* allocation argument structure */
706 struct xfs_btree_cur *ccur, /* optional by-size cursor */
707 xfs_agblock_t *fbnop, /* result block number */
708 xfs_extlen_t *flenp, /* result length */
709 int *stat) /* status: 0-freelist, 1-normal/none */
710 {
711 int error = 0;
712 xfs_agblock_t fbno = NULLAGBLOCK;
713 xfs_extlen_t flen = 0;
714 int i = 0;
715
716 /*
717 * If a cntbt cursor is provided, try to allocate the largest record in
718 * the tree. Try the AGFL if the cntbt is empty, otherwise fail the
719 * allocation. Make sure to respect minleft even when pulling from the
720 * freelist.
721 */
722 if (ccur)
723 error = xfs_btree_decrement(ccur, 0, &i);
724 if (error)
725 goto error;
726 if (i) {
727 error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i);
728 if (error)
729 goto error;
730 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error);
731 goto out;
732 }
733
734 if (args->minlen != 1 || args->alignment != 1 ||
735 args->resv == XFS_AG_RESV_AGFL ||
736 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount) <=
737 args->minleft))
738 goto out;
739
740 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
741 if (error)
742 goto error;
743 if (fbno == NULLAGBLOCK)
744 goto out;
745
746 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
747 xfs_alloc_allow_busy_reuse(args->datatype));
748
749 if (xfs_alloc_is_userdata(args->datatype)) {
750 struct xfs_buf *bp;
751
752 bp = xfs_btree_get_bufs(args->mp, args->tp, args->agno, fbno);
753 if (!bp) {
754 error = -EFSCORRUPTED;
755 goto error;
756 }
757 xfs_trans_binval(args->tp, bp);
758 }
759 *fbnop = args->agbno = fbno;
760 *flenp = args->len = 1;
761 XFS_WANT_CORRUPTED_GOTO(args->mp,
762 fbno < be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
763 error);
764 args->wasfromfl = 1;
765 trace_xfs_alloc_small_freelist(args);
766
767 /*
768 * If we're feeding an AGFL block to something that doesn't live in the
769 * free space, we need to clear out the OWN_AG rmap.
770 */
771 error = xfs_rmap_free(args->tp, args->agbp, args->agno, fbno, 1,
772 &XFS_RMAP_OINFO_AG);
773 if (error)
774 goto error;
775
776 *stat = 0;
777 return 0;
778
779 out:
780 /*
781 * Can't do the allocation, give up.
782 */
783 if (flen < args->minlen) {
784 args->agbno = NULLAGBLOCK;
785 trace_xfs_alloc_small_notenough(args);
786 flen = 0;
787 }
788 *fbnop = fbno;
789 *flenp = flen;
790 *stat = 1;
791 trace_xfs_alloc_small_done(args);
792 return 0;
793
794 error:
795 trace_xfs_alloc_small_error(args);
796 return error;
797 }
798
799 /*
800 * Allocate a variable extent in the allocation group agno.
801 * Type and bno are used to determine where in the allocation group the
802 * extent will start.
803 * Extent's length (returned in *len) will be between minlen and maxlen,
804 * and of the form k * prod + mod unless there's nothing that large.
805 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
806 */
807 STATIC int /* error */
808 xfs_alloc_ag_vextent(
809 xfs_alloc_arg_t *args) /* argument structure for allocation */
810 {
811 int error=0;
812
813 ASSERT(args->minlen > 0);
814 ASSERT(args->maxlen > 0);
815 ASSERT(args->minlen <= args->maxlen);
816 ASSERT(args->mod < args->prod);
817 ASSERT(args->alignment > 0);
818
819 /*
820 * Branch to correct routine based on the type.
821 */
822 args->wasfromfl = 0;
823 switch (args->type) {
824 case XFS_ALLOCTYPE_THIS_AG:
825 error = xfs_alloc_ag_vextent_size(args);
826 break;
827 case XFS_ALLOCTYPE_NEAR_BNO:
828 error = xfs_alloc_ag_vextent_near(args);
829 break;
830 case XFS_ALLOCTYPE_THIS_BNO:
831 error = xfs_alloc_ag_vextent_exact(args);
832 break;
833 default:
834 ASSERT(0);
835 /* NOTREACHED */
836 }
837
838 if (error || args->agbno == NULLAGBLOCK)
839 return error;
840
841 ASSERT(args->len >= args->minlen);
842 ASSERT(args->len <= args->maxlen);
843 ASSERT(!args->wasfromfl || args->resv != XFS_AG_RESV_AGFL);
844 ASSERT(args->agbno % args->alignment == 0);
845
846 /* if not file data, insert new block into the reverse map btree */
847 if (!xfs_rmap_should_skip_owner_update(&args->oinfo)) {
848 error = xfs_rmap_alloc(args->tp, args->agbp, args->agno,
849 args->agbno, args->len, &args->oinfo);
850 if (error)
851 return error;
852 }
853
854 if (!args->wasfromfl) {
855 error = xfs_alloc_update_counters(args->tp, args->pag,
856 args->agbp,
857 -((long)(args->len)));
858 if (error)
859 return error;
860
861 ASSERT(!xfs_extent_busy_search(args->mp, args->agno,
862 args->agbno, args->len));
863 }
864
865 xfs_ag_resv_alloc_extent(args->pag, args->resv, args);
866
867 XFS_STATS_INC(args->mp, xs_allocx);
868 XFS_STATS_ADD(args->mp, xs_allocb, args->len);
869 return error;
870 }
871
872 /*
873 * Allocate a variable extent at exactly agno/bno.
874 * Extent's length (returned in *len) will be between minlen and maxlen,
875 * and of the form k * prod + mod unless there's nothing that large.
876 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
877 */
878 STATIC int /* error */
879 xfs_alloc_ag_vextent_exact(
880 xfs_alloc_arg_t *args) /* allocation argument structure */
881 {
882 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
883 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
884 int error;
885 xfs_agblock_t fbno; /* start block of found extent */
886 xfs_extlen_t flen; /* length of found extent */
887 xfs_agblock_t tbno; /* start block of busy extent */
888 xfs_extlen_t tlen; /* length of busy extent */
889 xfs_agblock_t tend; /* end block of busy extent */
890 int i; /* success/failure of operation */
891 unsigned busy_gen;
892
893 ASSERT(args->alignment == 1);
894
895 /*
896 * Allocate/initialize a cursor for the by-number freespace btree.
897 */
898 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
899 args->agno, XFS_BTNUM_BNO);
900
901 /*
902 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
903 * Look for the closest free block <= bno, it must contain bno
904 * if any free block does.
905 */
906 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
907 if (error)
908 goto error0;
909 if (!i)
910 goto not_found;
911
912 /*
913 * Grab the freespace record.
914 */
915 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
916 if (error)
917 goto error0;
918 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
919 ASSERT(fbno <= args->agbno);
920
921 /*
922 * Check for overlapping busy extents.
923 */
924 tbno = fbno;
925 tlen = flen;
926 xfs_extent_busy_trim(args, &tbno, &tlen, &busy_gen);
927
928 /*
929 * Give up if the start of the extent is busy, or the freespace isn't
930 * long enough for the minimum request.
931 */
932 if (tbno > args->agbno)
933 goto not_found;
934 if (tlen < args->minlen)
935 goto not_found;
936 tend = tbno + tlen;
937 if (tend < args->agbno + args->minlen)
938 goto not_found;
939
940 /*
941 * End of extent will be smaller of the freespace end and the
942 * maximal requested end.
943 *
944 * Fix the length according to mod and prod if given.
945 */
946 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
947 - args->agbno;
948 xfs_alloc_fix_len(args);
949 ASSERT(args->agbno + args->len <= tend);
950
951 /*
952 * We are allocating agbno for args->len
953 * Allocate/initialize a cursor for the by-size btree.
954 */
955 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
956 args->agno, XFS_BTNUM_CNT);
957 ASSERT(args->agbno + args->len <=
958 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
959 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
960 args->len, XFSA_FIXUP_BNO_OK);
961 if (error) {
962 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
963 goto error0;
964 }
965
966 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
967 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
968
969 args->wasfromfl = 0;
970 trace_xfs_alloc_exact_done(args);
971 return 0;
972
973 not_found:
974 /* Didn't find it, return null. */
975 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
976 args->agbno = NULLAGBLOCK;
977 trace_xfs_alloc_exact_notfound(args);
978 return 0;
979
980 error0:
981 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
982 trace_xfs_alloc_exact_error(args);
983 return error;
984 }
985
986 /*
987 * Search the btree in a given direction via the search cursor and compare
988 * the records found against the good extent we've already found.
989 */
990 STATIC int
991 xfs_alloc_find_best_extent(
992 struct xfs_alloc_arg *args, /* allocation argument structure */
993 struct xfs_btree_cur **gcur, /* good cursor */
994 struct xfs_btree_cur **scur, /* searching cursor */
995 xfs_agblock_t gdiff, /* difference for search comparison */
996 xfs_agblock_t *sbno, /* extent found by search */
997 xfs_extlen_t *slen, /* extent length */
998 xfs_agblock_t *sbnoa, /* aligned extent found by search */
999 xfs_extlen_t *slena, /* aligned extent length */
1000 int dir) /* 0 = search right, 1 = search left */
1001 {
1002 xfs_agblock_t new;
1003 xfs_agblock_t sdiff;
1004 int error;
1005 int i;
1006 unsigned busy_gen;
1007
1008 /* The good extent is perfect, no need to search. */
1009 if (!gdiff)
1010 goto out_use_good;
1011
1012 /*
1013 * Look until we find a better one, run out of space or run off the end.
1014 */
1015 do {
1016 error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
1017 if (error)
1018 goto error0;
1019 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1020 xfs_alloc_compute_aligned(args, *sbno, *slen,
1021 sbnoa, slena, &busy_gen);
1022
1023 /*
1024 * The good extent is closer than this one.
1025 */
1026 if (!dir) {
1027 if (*sbnoa > args->max_agbno)
1028 goto out_use_good;
1029 if (*sbnoa >= args->agbno + gdiff)
1030 goto out_use_good;
1031 } else {
1032 if (*sbnoa < args->min_agbno)
1033 goto out_use_good;
1034 if (*sbnoa <= args->agbno - gdiff)
1035 goto out_use_good;
1036 }
1037
1038 /*
1039 * Same distance, compare length and pick the best.
1040 */
1041 if (*slena >= args->minlen) {
1042 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
1043 xfs_alloc_fix_len(args);
1044
1045 sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1046 args->alignment,
1047 args->datatype, *sbnoa,
1048 *slena, &new);
1049
1050 /*
1051 * Choose closer size and invalidate other cursor.
1052 */
1053 if (sdiff < gdiff)
1054 goto out_use_search;
1055 goto out_use_good;
1056 }
1057
1058 if (!dir)
1059 error = xfs_btree_increment(*scur, 0, &i);
1060 else
1061 error = xfs_btree_decrement(*scur, 0, &i);
1062 if (error)
1063 goto error0;
1064 } while (i);
1065
1066 out_use_good:
1067 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
1068 *scur = NULL;
1069 return 0;
1070
1071 out_use_search:
1072 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
1073 *gcur = NULL;
1074 return 0;
1075
1076 error0:
1077 /* caller invalidates cursors */
1078 return error;
1079 }
1080
1081 /*
1082 * Allocate a variable extent near bno in the allocation group agno.
1083 * Extent's length (returned in len) will be between minlen and maxlen,
1084 * and of the form k * prod + mod unless there's nothing that large.
1085 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1086 */
1087 STATIC int /* error */
1088 xfs_alloc_ag_vextent_near(
1089 xfs_alloc_arg_t *args) /* allocation argument structure */
1090 {
1091 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
1092 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
1093 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
1094 xfs_agblock_t gtbno; /* start bno of right side entry */
1095 xfs_agblock_t gtbnoa; /* aligned ... */
1096 xfs_extlen_t gtdiff; /* difference to right side entry */
1097 xfs_extlen_t gtlen; /* length of right side entry */
1098 xfs_extlen_t gtlena; /* aligned ... */
1099 xfs_agblock_t gtnew; /* useful start bno of right side */
1100 int error; /* error code */
1101 int i; /* result code, temporary */
1102 int j; /* result code, temporary */
1103 xfs_agblock_t ltbno; /* start bno of left side entry */
1104 xfs_agblock_t ltbnoa; /* aligned ... */
1105 xfs_extlen_t ltdiff; /* difference to left side entry */
1106 xfs_extlen_t ltlen; /* length of left side entry */
1107 xfs_extlen_t ltlena; /* aligned ... */
1108 xfs_agblock_t ltnew; /* useful start bno of left side */
1109 xfs_extlen_t rlen; /* length of returned extent */
1110 bool busy;
1111 unsigned busy_gen;
1112 #ifdef DEBUG
1113 /*
1114 * Randomly don't execute the first algorithm.
1115 */
1116 int dofirst; /* set to do first algorithm */
1117
1118 dofirst = prandom_u32() & 1;
1119 #endif
1120
1121 /* handle unitialized agbno range so caller doesn't have to */
1122 if (!args->min_agbno && !args->max_agbno)
1123 args->max_agbno = args->mp->m_sb.sb_agblocks - 1;
1124 ASSERT(args->min_agbno <= args->max_agbno);
1125
1126 /* clamp agbno to the range if it's outside */
1127 if (args->agbno < args->min_agbno)
1128 args->agbno = args->min_agbno;
1129 if (args->agbno > args->max_agbno)
1130 args->agbno = args->max_agbno;
1131
1132 restart:
1133 bno_cur_lt = NULL;
1134 bno_cur_gt = NULL;
1135 ltlen = 0;
1136 gtlena = 0;
1137 ltlena = 0;
1138 busy = false;
1139
1140 /*
1141 * Get a cursor for the by-size btree.
1142 */
1143 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1144 args->agno, XFS_BTNUM_CNT);
1145
1146 /*
1147 * See if there are any free extents as big as maxlen.
1148 */
1149 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
1150 goto error0;
1151 /*
1152 * If none, then pick up the last entry in the tree unless the
1153 * tree is empty.
1154 */
1155 if (!i) {
1156 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
1157 &ltlen, &i)))
1158 goto error0;
1159 if (i == 0 || ltlen == 0) {
1160 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1161 trace_xfs_alloc_near_noentry(args);
1162 return 0;
1163 }
1164 ASSERT(i == 1);
1165 }
1166 args->wasfromfl = 0;
1167
1168 /*
1169 * First algorithm.
1170 * If the requested extent is large wrt the freespaces available
1171 * in this a.g., then the cursor will be pointing to a btree entry
1172 * near the right edge of the tree. If it's in the last btree leaf
1173 * block, then we just examine all the entries in that block
1174 * that are big enough, and pick the best one.
1175 * This is written as a while loop so we can break out of it,
1176 * but we never loop back to the top.
1177 */
1178 while (xfs_btree_islastblock(cnt_cur, 0)) {
1179 xfs_extlen_t bdiff;
1180 int besti=0;
1181 xfs_extlen_t blen=0;
1182 xfs_agblock_t bnew=0;
1183
1184 #ifdef DEBUG
1185 if (dofirst)
1186 break;
1187 #endif
1188 /*
1189 * Start from the entry that lookup found, sequence through
1190 * all larger free blocks. If we're actually pointing at a
1191 * record smaller than maxlen, go to the start of this block,
1192 * and skip all those smaller than minlen.
1193 */
1194 if (ltlen || args->alignment > 1) {
1195 cnt_cur->bc_ptrs[0] = 1;
1196 do {
1197 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
1198 &ltlen, &i)))
1199 goto error0;
1200 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1201 if (ltlen >= args->minlen)
1202 break;
1203 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
1204 goto error0;
1205 } while (i);
1206 ASSERT(ltlen >= args->minlen);
1207 if (!i)
1208 break;
1209 }
1210 i = cnt_cur->bc_ptrs[0];
1211 for (j = 1, blen = 0, bdiff = 0;
1212 !error && j && (blen < args->maxlen || bdiff > 0);
1213 error = xfs_btree_increment(cnt_cur, 0, &j)) {
1214 /*
1215 * For each entry, decide if it's better than
1216 * the previous best entry.
1217 */
1218 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
1219 goto error0;
1220 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1221 busy = xfs_alloc_compute_aligned(args, ltbno, ltlen,
1222 &ltbnoa, &ltlena, &busy_gen);
1223 if (ltlena < args->minlen)
1224 continue;
1225 if (ltbnoa < args->min_agbno || ltbnoa > args->max_agbno)
1226 continue;
1227 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1228 xfs_alloc_fix_len(args);
1229 ASSERT(args->len >= args->minlen);
1230 if (args->len < blen)
1231 continue;
1232 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1233 args->alignment, args->datatype, ltbnoa,
1234 ltlena, &ltnew);
1235 if (ltnew != NULLAGBLOCK &&
1236 (args->len > blen || ltdiff < bdiff)) {
1237 bdiff = ltdiff;
1238 bnew = ltnew;
1239 blen = args->len;
1240 besti = cnt_cur->bc_ptrs[0];
1241 }
1242 }
1243 /*
1244 * It didn't work. We COULD be in a case where
1245 * there's a good record somewhere, so try again.
1246 */
1247 if (blen == 0)
1248 break;
1249 /*
1250 * Point at the best entry, and retrieve it again.
1251 */
1252 cnt_cur->bc_ptrs[0] = besti;
1253 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
1254 goto error0;
1255 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1256 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1257 args->len = blen;
1258
1259 /*
1260 * We are allocating starting at bnew for blen blocks.
1261 */
1262 args->agbno = bnew;
1263 ASSERT(bnew >= ltbno);
1264 ASSERT(bnew + blen <= ltbno + ltlen);
1265 /*
1266 * Set up a cursor for the by-bno tree.
1267 */
1268 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1269 args->agbp, args->agno, XFS_BTNUM_BNO);
1270 /*
1271 * Fix up the btree entries.
1272 */
1273 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1274 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1275 goto error0;
1276 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1277 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1278
1279 trace_xfs_alloc_near_first(args);
1280 return 0;
1281 }
1282 /*
1283 * Second algorithm.
1284 * Search in the by-bno tree to the left and to the right
1285 * simultaneously, until in each case we find a space big enough,
1286 * or run into the edge of the tree. When we run into the edge,
1287 * we deallocate that cursor.
1288 * If both searches succeed, we compare the two spaces and pick
1289 * the better one.
1290 * With alignment, it's possible for both to fail; the upper
1291 * level algorithm that picks allocation groups for allocations
1292 * is not supposed to do this.
1293 */
1294 /*
1295 * Allocate and initialize the cursor for the leftward search.
1296 */
1297 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1298 args->agno, XFS_BTNUM_BNO);
1299 /*
1300 * Lookup <= bno to find the leftward search's starting point.
1301 */
1302 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1303 goto error0;
1304 if (!i) {
1305 /*
1306 * Didn't find anything; use this cursor for the rightward
1307 * search.
1308 */
1309 bno_cur_gt = bno_cur_lt;
1310 bno_cur_lt = NULL;
1311 }
1312 /*
1313 * Found something. Duplicate the cursor for the rightward search.
1314 */
1315 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1316 goto error0;
1317 /*
1318 * Increment the cursor, so we will point at the entry just right
1319 * of the leftward entry if any, or to the leftmost entry.
1320 */
1321 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1322 goto error0;
1323 if (!i) {
1324 /*
1325 * It failed, there are no rightward entries.
1326 */
1327 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1328 bno_cur_gt = NULL;
1329 }
1330 /*
1331 * Loop going left with the leftward cursor, right with the
1332 * rightward cursor, until either both directions give up or
1333 * we find an entry at least as big as minlen.
1334 */
1335 do {
1336 if (bno_cur_lt) {
1337 if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
1338 goto error0;
1339 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1340 busy |= xfs_alloc_compute_aligned(args, ltbno, ltlen,
1341 &ltbnoa, &ltlena, &busy_gen);
1342 if (ltlena >= args->minlen && ltbnoa >= args->min_agbno)
1343 break;
1344 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
1345 goto error0;
1346 if (!i || ltbnoa < args->min_agbno) {
1347 xfs_btree_del_cursor(bno_cur_lt,
1348 XFS_BTREE_NOERROR);
1349 bno_cur_lt = NULL;
1350 }
1351 }
1352 if (bno_cur_gt) {
1353 if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
1354 goto error0;
1355 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1356 busy |= xfs_alloc_compute_aligned(args, gtbno, gtlen,
1357 &gtbnoa, &gtlena, &busy_gen);
1358 if (gtlena >= args->minlen && gtbnoa <= args->max_agbno)
1359 break;
1360 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1361 goto error0;
1362 if (!i || gtbnoa > args->max_agbno) {
1363 xfs_btree_del_cursor(bno_cur_gt,
1364 XFS_BTREE_NOERROR);
1365 bno_cur_gt = NULL;
1366 }
1367 }
1368 } while (bno_cur_lt || bno_cur_gt);
1369
1370 /*
1371 * Got both cursors still active, need to find better entry.
1372 */
1373 if (bno_cur_lt && bno_cur_gt) {
1374 if (ltlena >= args->minlen) {
1375 /*
1376 * Left side is good, look for a right side entry.
1377 */
1378 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1379 xfs_alloc_fix_len(args);
1380 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1381 args->alignment, args->datatype, ltbnoa,
1382 ltlena, &ltnew);
1383
1384 error = xfs_alloc_find_best_extent(args,
1385 &bno_cur_lt, &bno_cur_gt,
1386 ltdiff, &gtbno, &gtlen,
1387 &gtbnoa, &gtlena,
1388 0 /* search right */);
1389 } else {
1390 ASSERT(gtlena >= args->minlen);
1391
1392 /*
1393 * Right side is good, look for a left side entry.
1394 */
1395 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1396 xfs_alloc_fix_len(args);
1397 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1398 args->alignment, args->datatype, gtbnoa,
1399 gtlena, &gtnew);
1400
1401 error = xfs_alloc_find_best_extent(args,
1402 &bno_cur_gt, &bno_cur_lt,
1403 gtdiff, &ltbno, &ltlen,
1404 &ltbnoa, &ltlena,
1405 1 /* search left */);
1406 }
1407
1408 if (error)
1409 goto error0;
1410 }
1411
1412 /*
1413 * If we couldn't get anything, give up.
1414 */
1415 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1416 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1417
1418 if (busy) {
1419 trace_xfs_alloc_near_busy(args);
1420 xfs_extent_busy_flush(args->mp, args->pag, busy_gen);
1421 goto restart;
1422 }
1423 trace_xfs_alloc_size_neither(args);
1424 args->agbno = NULLAGBLOCK;
1425 return 0;
1426 }
1427
1428 /*
1429 * At this point we have selected a freespace entry, either to the
1430 * left or to the right. If it's on the right, copy all the
1431 * useful variables to the "left" set so we only have one
1432 * copy of this code.
1433 */
1434 if (bno_cur_gt) {
1435 bno_cur_lt = bno_cur_gt;
1436 bno_cur_gt = NULL;
1437 ltbno = gtbno;
1438 ltbnoa = gtbnoa;
1439 ltlen = gtlen;
1440 ltlena = gtlena;
1441 j = 1;
1442 } else
1443 j = 0;
1444
1445 /*
1446 * Fix up the length and compute the useful address.
1447 */
1448 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1449 xfs_alloc_fix_len(args);
1450 rlen = args->len;
1451 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
1452 args->datatype, ltbnoa, ltlena, &ltnew);
1453 ASSERT(ltnew >= ltbno);
1454 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
1455 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1456 ASSERT(ltnew >= args->min_agbno && ltnew <= args->max_agbno);
1457 args->agbno = ltnew;
1458
1459 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1460 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1461 goto error0;
1462
1463 if (j)
1464 trace_xfs_alloc_near_greater(args);
1465 else
1466 trace_xfs_alloc_near_lesser(args);
1467
1468 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1469 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1470 return 0;
1471
1472 error0:
1473 trace_xfs_alloc_near_error(args);
1474 if (cnt_cur != NULL)
1475 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1476 if (bno_cur_lt != NULL)
1477 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1478 if (bno_cur_gt != NULL)
1479 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1480 return error;
1481 }
1482
1483 /*
1484 * Allocate a variable extent anywhere in the allocation group agno.
1485 * Extent's length (returned in len) will be between minlen and maxlen,
1486 * and of the form k * prod + mod unless there's nothing that large.
1487 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1488 */
1489 STATIC int /* error */
1490 xfs_alloc_ag_vextent_size(
1491 xfs_alloc_arg_t *args) /* allocation argument structure */
1492 {
1493 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1494 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1495 int error; /* error result */
1496 xfs_agblock_t fbno; /* start of found freespace */
1497 xfs_extlen_t flen; /* length of found freespace */
1498 int i; /* temp status variable */
1499 xfs_agblock_t rbno; /* returned block number */
1500 xfs_extlen_t rlen; /* length of returned extent */
1501 bool busy;
1502 unsigned busy_gen;
1503
1504 restart:
1505 /*
1506 * Allocate and initialize a cursor for the by-size btree.
1507 */
1508 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1509 args->agno, XFS_BTNUM_CNT);
1510 bno_cur = NULL;
1511 busy = false;
1512
1513 /*
1514 * Look for an entry >= maxlen+alignment-1 blocks.
1515 */
1516 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1517 args->maxlen + args->alignment - 1, &i)))
1518 goto error0;
1519
1520 /*
1521 * If none then we have to settle for a smaller extent. In the case that
1522 * there are no large extents, this will return the last entry in the
1523 * tree unless the tree is empty. In the case that there are only busy
1524 * large extents, this will return the largest small extent unless there
1525 * are no smaller extents available.
1526 */
1527 if (!i) {
1528 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1529 &fbno, &flen, &i);
1530 if (error)
1531 goto error0;
1532 if (i == 0 || flen == 0) {
1533 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1534 trace_xfs_alloc_size_noentry(args);
1535 return 0;
1536 }
1537 ASSERT(i == 1);
1538 busy = xfs_alloc_compute_aligned(args, fbno, flen, &rbno,
1539 &rlen, &busy_gen);
1540 } else {
1541 /*
1542 * Search for a non-busy extent that is large enough.
1543 */
1544 for (;;) {
1545 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1546 if (error)
1547 goto error0;
1548 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1549
1550 busy = xfs_alloc_compute_aligned(args, fbno, flen,
1551 &rbno, &rlen, &busy_gen);
1552
1553 if (rlen >= args->maxlen)
1554 break;
1555
1556 error = xfs_btree_increment(cnt_cur, 0, &i);
1557 if (error)
1558 goto error0;
1559 if (i == 0) {
1560 /*
1561 * Our only valid extents must have been busy.
1562 * Make it unbusy by forcing the log out and
1563 * retrying.
1564 */
1565 xfs_btree_del_cursor(cnt_cur,
1566 XFS_BTREE_NOERROR);
1567 trace_xfs_alloc_size_busy(args);
1568 xfs_extent_busy_flush(args->mp,
1569 args->pag, busy_gen);
1570 goto restart;
1571 }
1572 }
1573 }
1574
1575 /*
1576 * In the first case above, we got the last entry in the
1577 * by-size btree. Now we check to see if the space hits maxlen
1578 * once aligned; if not, we search left for something better.
1579 * This can't happen in the second case above.
1580 */
1581 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1582 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 ||
1583 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1584 if (rlen < args->maxlen) {
1585 xfs_agblock_t bestfbno;
1586 xfs_extlen_t bestflen;
1587 xfs_agblock_t bestrbno;
1588 xfs_extlen_t bestrlen;
1589
1590 bestrlen = rlen;
1591 bestrbno = rbno;
1592 bestflen = flen;
1593 bestfbno = fbno;
1594 for (;;) {
1595 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
1596 goto error0;
1597 if (i == 0)
1598 break;
1599 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1600 &i)))
1601 goto error0;
1602 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1603 if (flen < bestrlen)
1604 break;
1605 busy = xfs_alloc_compute_aligned(args, fbno, flen,
1606 &rbno, &rlen, &busy_gen);
1607 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1608 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 ||
1609 (rlen <= flen && rbno + rlen <= fbno + flen),
1610 error0);
1611 if (rlen > bestrlen) {
1612 bestrlen = rlen;
1613 bestrbno = rbno;
1614 bestflen = flen;
1615 bestfbno = fbno;
1616 if (rlen == args->maxlen)
1617 break;
1618 }
1619 }
1620 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1621 &i)))
1622 goto error0;
1623 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1624 rlen = bestrlen;
1625 rbno = bestrbno;
1626 flen = bestflen;
1627 fbno = bestfbno;
1628 }
1629 args->wasfromfl = 0;
1630 /*
1631 * Fix up the length.
1632 */
1633 args->len = rlen;
1634 if (rlen < args->minlen) {
1635 if (busy) {
1636 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1637 trace_xfs_alloc_size_busy(args);
1638 xfs_extent_busy_flush(args->mp, args->pag, busy_gen);
1639 goto restart;
1640 }
1641 goto out_nominleft;
1642 }
1643 xfs_alloc_fix_len(args);
1644
1645 rlen = args->len;
1646 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen <= flen, error0);
1647 /*
1648 * Allocate and initialize a cursor for the by-block tree.
1649 */
1650 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1651 args->agno, XFS_BTNUM_BNO);
1652 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1653 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1654 goto error0;
1655 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1656 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1657 cnt_cur = bno_cur = NULL;
1658 args->len = rlen;
1659 args->agbno = rbno;
1660 XFS_WANT_CORRUPTED_GOTO(args->mp,
1661 args->agbno + args->len <=
1662 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1663 error0);
1664 trace_xfs_alloc_size_done(args);
1665 return 0;
1666
1667 error0:
1668 trace_xfs_alloc_size_error(args);
1669 if (cnt_cur)
1670 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1671 if (bno_cur)
1672 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1673 return error;
1674
1675 out_nominleft:
1676 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1677 trace_xfs_alloc_size_nominleft(args);
1678 args->agbno = NULLAGBLOCK;
1679 return 0;
1680 }
1681
1682 /*
1683 * Free the extent starting at agno/bno for length.
1684 */
1685 STATIC int
1686 xfs_free_ag_extent(
1687 struct xfs_trans *tp,
1688 struct xfs_buf *agbp,
1689 xfs_agnumber_t agno,
1690 xfs_agblock_t bno,
1691 xfs_extlen_t len,
1692 const struct xfs_owner_info *oinfo,
1693 enum xfs_ag_resv_type type)
1694 {
1695 struct xfs_mount *mp;
1696 struct xfs_perag *pag;
1697 struct xfs_btree_cur *bno_cur;
1698 struct xfs_btree_cur *cnt_cur;
1699 xfs_agblock_t gtbno; /* start of right neighbor */
1700 xfs_extlen_t gtlen; /* length of right neighbor */
1701 xfs_agblock_t ltbno; /* start of left neighbor */
1702 xfs_extlen_t ltlen; /* length of left neighbor */
1703 xfs_agblock_t nbno; /* new starting block of freesp */
1704 xfs_extlen_t nlen; /* new length of freespace */
1705 int haveleft; /* have a left neighbor */
1706 int haveright; /* have a right neighbor */
1707 int i;
1708 int error;
1709
1710 bno_cur = cnt_cur = NULL;
1711 mp = tp->t_mountp;
1712
1713 if (!xfs_rmap_should_skip_owner_update(oinfo)) {
1714 error = xfs_rmap_free(tp, agbp, agno, bno, len, oinfo);
1715 if (error)
1716 goto error0;
1717 }
1718
1719 /*
1720 * Allocate and initialize a cursor for the by-block btree.
1721 */
1722 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
1723 /*
1724 * Look for a neighboring block on the left (lower block numbers)
1725 * that is contiguous with this space.
1726 */
1727 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1728 goto error0;
1729 if (haveleft) {
1730 /*
1731 * There is a block to our left.
1732 */
1733 if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
1734 goto error0;
1735 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1736 /*
1737 * It's not contiguous, though.
1738 */
1739 if (ltbno + ltlen < bno)
1740 haveleft = 0;
1741 else {
1742 /*
1743 * If this failure happens the request to free this
1744 * space was invalid, it's (partly) already free.
1745 * Very bad.
1746 */
1747 XFS_WANT_CORRUPTED_GOTO(mp,
1748 ltbno + ltlen <= bno, error0);
1749 }
1750 }
1751 /*
1752 * Look for a neighboring block on the right (higher block numbers)
1753 * that is contiguous with this space.
1754 */
1755 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
1756 goto error0;
1757 if (haveright) {
1758 /*
1759 * There is a block to our right.
1760 */
1761 if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
1762 goto error0;
1763 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1764 /*
1765 * It's not contiguous, though.
1766 */
1767 if (bno + len < gtbno)
1768 haveright = 0;
1769 else {
1770 /*
1771 * If this failure happens the request to free this
1772 * space was invalid, it's (partly) already free.
1773 * Very bad.
1774 */
1775 XFS_WANT_CORRUPTED_GOTO(mp, gtbno >= bno + len, error0);
1776 }
1777 }
1778 /*
1779 * Now allocate and initialize a cursor for the by-size tree.
1780 */
1781 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
1782 /*
1783 * Have both left and right contiguous neighbors.
1784 * Merge all three into a single free block.
1785 */
1786 if (haveleft && haveright) {
1787 /*
1788 * Delete the old by-size entry on the left.
1789 */
1790 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1791 goto error0;
1792 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1793 if ((error = xfs_btree_delete(cnt_cur, &i)))
1794 goto error0;
1795 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1796 /*
1797 * Delete the old by-size entry on the right.
1798 */
1799 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1800 goto error0;
1801 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1802 if ((error = xfs_btree_delete(cnt_cur, &i)))
1803 goto error0;
1804 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1805 /*
1806 * Delete the old by-block entry for the right block.
1807 */
1808 if ((error = xfs_btree_delete(bno_cur, &i)))
1809 goto error0;
1810 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1811 /*
1812 * Move the by-block cursor back to the left neighbor.
1813 */
1814 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1815 goto error0;
1816 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1817 #ifdef DEBUG
1818 /*
1819 * Check that this is the right record: delete didn't
1820 * mangle the cursor.
1821 */
1822 {
1823 xfs_agblock_t xxbno;
1824 xfs_extlen_t xxlen;
1825
1826 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1827 &i)))
1828 goto error0;
1829 XFS_WANT_CORRUPTED_GOTO(mp,
1830 i == 1 && xxbno == ltbno && xxlen == ltlen,
1831 error0);
1832 }
1833 #endif
1834 /*
1835 * Update remaining by-block entry to the new, joined block.
1836 */
1837 nbno = ltbno;
1838 nlen = len + ltlen + gtlen;
1839 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1840 goto error0;
1841 }
1842 /*
1843 * Have only a left contiguous neighbor.
1844 * Merge it together with the new freespace.
1845 */
1846 else if (haveleft) {
1847 /*
1848 * Delete the old by-size entry on the left.
1849 */
1850 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1851 goto error0;
1852 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1853 if ((error = xfs_btree_delete(cnt_cur, &i)))
1854 goto error0;
1855 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1856 /*
1857 * Back up the by-block cursor to the left neighbor, and
1858 * update its length.
1859 */
1860 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1861 goto error0;
1862 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1863 nbno = ltbno;
1864 nlen = len + ltlen;
1865 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1866 goto error0;
1867 }
1868 /*
1869 * Have only a right contiguous neighbor.
1870 * Merge it together with the new freespace.
1871 */
1872 else if (haveright) {
1873 /*
1874 * Delete the old by-size entry on the right.
1875 */
1876 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1877 goto error0;
1878 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1879 if ((error = xfs_btree_delete(cnt_cur, &i)))
1880 goto error0;
1881 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1882 /*
1883 * Update the starting block and length of the right
1884 * neighbor in the by-block tree.
1885 */
1886 nbno = bno;
1887 nlen = len + gtlen;
1888 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1889 goto error0;
1890 }
1891 /*
1892 * No contiguous neighbors.
1893 * Insert the new freespace into the by-block tree.
1894 */
1895 else {
1896 nbno = bno;
1897 nlen = len;
1898 if ((error = xfs_btree_insert(bno_cur, &i)))
1899 goto error0;
1900 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1901 }
1902 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1903 bno_cur = NULL;
1904 /*
1905 * In all cases we need to insert the new freespace in the by-size tree.
1906 */
1907 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1908 goto error0;
1909 XFS_WANT_CORRUPTED_GOTO(mp, i == 0, error0);
1910 if ((error = xfs_btree_insert(cnt_cur, &i)))
1911 goto error0;
1912 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1913 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1914 cnt_cur = NULL;
1915
1916 /*
1917 * Update the freespace totals in the ag and superblock.
1918 */
1919 pag = xfs_perag_get(mp, agno);
1920 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1921 xfs_ag_resv_free_extent(pag, type, tp, len);
1922 xfs_perag_put(pag);
1923 if (error)
1924 goto error0;
1925
1926 XFS_STATS_INC(mp, xs_freex);
1927 XFS_STATS_ADD(mp, xs_freeb, len);
1928
1929 trace_xfs_free_extent(mp, agno, bno, len, type, haveleft, haveright);
1930
1931 return 0;
1932
1933 error0:
1934 trace_xfs_free_extent(mp, agno, bno, len, type, -1, -1);
1935 if (bno_cur)
1936 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1937 if (cnt_cur)
1938 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1939 return error;
1940 }
1941
1942 /*
1943 * Visible (exported) allocation/free functions.
1944 * Some of these are used just by xfs_alloc_btree.c and this file.
1945 */
1946
1947 /*
1948 * Compute and fill in value of m_ag_maxlevels.
1949 */
1950 void
1951 xfs_alloc_compute_maxlevels(
1952 xfs_mount_t *mp) /* file system mount structure */
1953 {
1954 mp->m_ag_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr,
1955 (mp->m_sb.sb_agblocks + 1) / 2);
1956 }
1957
1958 /*
1959 * Find the length of the longest extent in an AG. The 'need' parameter
1960 * specifies how much space we're going to need for the AGFL and the
1961 * 'reserved' parameter tells us how many blocks in this AG are reserved for
1962 * other callers.
1963 */
1964 xfs_extlen_t
1965 xfs_alloc_longest_free_extent(
1966 struct xfs_perag *pag,
1967 xfs_extlen_t need,
1968 xfs_extlen_t reserved)
1969 {
1970 xfs_extlen_t delta = 0;
1971
1972 /*
1973 * If the AGFL needs a recharge, we'll have to subtract that from the
1974 * longest extent.
1975 */
1976 if (need > pag->pagf_flcount)
1977 delta = need - pag->pagf_flcount;
1978
1979 /*
1980 * If we cannot maintain others' reservations with space from the
1981 * not-longest freesp extents, we'll have to subtract /that/ from
1982 * the longest extent too.
1983 */
1984 if (pag->pagf_freeblks - pag->pagf_longest < reserved)
1985 delta += reserved - (pag->pagf_freeblks - pag->pagf_longest);
1986
1987 /*
1988 * If the longest extent is long enough to satisfy all the
1989 * reservations and AGFL rules in place, we can return this extent.
1990 */
1991 if (pag->pagf_longest > delta)
1992 return pag->pagf_longest - delta;
1993
1994 /* Otherwise, let the caller try for 1 block if there's space. */
1995 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1996 }
1997
1998 unsigned int
1999 xfs_alloc_min_freelist(
2000 struct xfs_mount *mp,
2001 struct xfs_perag *pag)
2002 {
2003 unsigned int min_free;
2004
2005 /* space needed by-bno freespace btree */
2006 min_free = min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_BNOi] + 1,
2007 mp->m_ag_maxlevels);
2008 /* space needed by-size freespace btree */
2009 min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1,
2010 mp->m_ag_maxlevels);
2011 /* space needed reverse mapping used space btree */
2012 if (xfs_sb_version_hasrmapbt(&mp->m_sb))
2013 min_free += min_t(unsigned int,
2014 pag->pagf_levels[XFS_BTNUM_RMAPi] + 1,
2015 mp->m_rmap_maxlevels);
2016
2017 return min_free;
2018 }
2019
2020 /*
2021 * Check if the operation we are fixing up the freelist for should go ahead or
2022 * not. If we are freeing blocks, we always allow it, otherwise the allocation
2023 * is dependent on whether the size and shape of free space available will
2024 * permit the requested allocation to take place.
2025 */
2026 static bool
2027 xfs_alloc_space_available(
2028 struct xfs_alloc_arg *args,
2029 xfs_extlen_t min_free,
2030 int flags)
2031 {
2032 struct xfs_perag *pag = args->pag;
2033 xfs_extlen_t alloc_len, longest;
2034 xfs_extlen_t reservation; /* blocks that are still reserved */
2035 int available;
2036 xfs_extlen_t agflcount;
2037
2038 if (flags & XFS_ALLOC_FLAG_FREEING)
2039 return true;
2040
2041 reservation = xfs_ag_resv_needed(pag, args->resv);
2042
2043 /* do we have enough contiguous free space for the allocation? */
2044 alloc_len = args->minlen + (args->alignment - 1) + args->minalignslop;
2045 longest = xfs_alloc_longest_free_extent(pag, min_free, reservation);
2046 if (longest < alloc_len)
2047 return false;
2048
2049 /*
2050 * Do we have enough free space remaining for the allocation? Don't
2051 * account extra agfl blocks because we are about to defer free them,
2052 * making them unavailable until the current transaction commits.
2053 */
2054 agflcount = min_t(xfs_extlen_t, pag->pagf_flcount, min_free);
2055 available = (int)(pag->pagf_freeblks + agflcount -
2056 reservation - min_free - args->minleft);
2057 if (available < (int)max(args->total, alloc_len))
2058 return false;
2059
2060 /*
2061 * Clamp maxlen to the amount of free space available for the actual
2062 * extent allocation.
2063 */
2064 if (available < (int)args->maxlen && !(flags & XFS_ALLOC_FLAG_CHECK)) {
2065 args->maxlen = available;
2066 ASSERT(args->maxlen > 0);
2067 ASSERT(args->maxlen >= args->minlen);
2068 }
2069
2070 return true;
2071 }
2072
2073 int
2074 xfs_free_agfl_block(
2075 struct xfs_trans *tp,
2076 xfs_agnumber_t agno,
2077 xfs_agblock_t agbno,
2078 struct xfs_buf *agbp,
2079 struct xfs_owner_info *oinfo)
2080 {
2081 int error;
2082 struct xfs_buf *bp;
2083
2084 error = xfs_free_ag_extent(tp, agbp, agno, agbno, 1, oinfo,
2085 XFS_AG_RESV_AGFL);
2086 if (error)
2087 return error;
2088
2089 bp = xfs_btree_get_bufs(tp->t_mountp, tp, agno, agbno);
2090 if (!bp)
2091 return -EFSCORRUPTED;
2092 xfs_trans_binval(tp, bp);
2093
2094 return 0;
2095 }
2096
2097 /*
2098 * Check the agfl fields of the agf for inconsistency or corruption. The purpose
2099 * is to detect an agfl header padding mismatch between current and early v5
2100 * kernels. This problem manifests as a 1-slot size difference between the
2101 * on-disk flcount and the active [first, last] range of a wrapped agfl. This
2102 * may also catch variants of agfl count corruption unrelated to padding. Either
2103 * way, we'll reset the agfl and warn the user.
2104 *
2105 * Return true if a reset is required before the agfl can be used, false
2106 * otherwise.
2107 */
2108 static bool
2109 xfs_agfl_needs_reset(
2110 struct xfs_mount *mp,
2111 struct xfs_agf *agf)
2112 {
2113 uint32_t f = be32_to_cpu(agf->agf_flfirst);
2114 uint32_t l = be32_to_cpu(agf->agf_fllast);
2115 uint32_t c = be32_to_cpu(agf->agf_flcount);
2116 int agfl_size = xfs_agfl_size(mp);
2117 int active;
2118
2119 /* no agfl header on v4 supers */
2120 if (!xfs_sb_version_hascrc(&mp->m_sb))
2121 return false;
2122
2123 /*
2124 * The agf read verifier catches severe corruption of these fields.
2125 * Repeat some sanity checks to cover a packed -> unpacked mismatch if
2126 * the verifier allows it.
2127 */
2128 if (f >= agfl_size || l >= agfl_size)
2129 return true;
2130 if (c > agfl_size)
2131 return true;
2132
2133 /*
2134 * Check consistency between the on-disk count and the active range. An
2135 * agfl padding mismatch manifests as an inconsistent flcount.
2136 */
2137 if (c && l >= f)
2138 active = l - f + 1;
2139 else if (c)
2140 active = agfl_size - f + l + 1;
2141 else
2142 active = 0;
2143
2144 return active != c;
2145 }
2146
2147 /*
2148 * Reset the agfl to an empty state. Ignore/drop any existing blocks since the
2149 * agfl content cannot be trusted. Warn the user that a repair is required to
2150 * recover leaked blocks.
2151 *
2152 * The purpose of this mechanism is to handle filesystems affected by the agfl
2153 * header padding mismatch problem. A reset keeps the filesystem online with a
2154 * relatively minor free space accounting inconsistency rather than suffer the
2155 * inevitable crash from use of an invalid agfl block.
2156 */
2157 static void
2158 xfs_agfl_reset(
2159 struct xfs_trans *tp,
2160 struct xfs_buf *agbp,
2161 struct xfs_perag *pag)
2162 {
2163 struct xfs_mount *mp = tp->t_mountp;
2164 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
2165
2166 ASSERT(pag->pagf_agflreset);
2167 trace_xfs_agfl_reset(mp, agf, 0, _RET_IP_);
2168
2169 xfs_warn(mp,
2170 "WARNING: Reset corrupted AGFL on AG %u. %d blocks leaked. "
2171 "Please unmount and run xfs_repair.",
2172 pag->pag_agno, pag->pagf_flcount);
2173
2174 agf->agf_flfirst = 0;
2175 agf->agf_fllast = cpu_to_be32(xfs_agfl_size(mp) - 1);
2176 agf->agf_flcount = 0;
2177 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLLAST |
2178 XFS_AGF_FLCOUNT);
2179
2180 pag->pagf_flcount = 0;
2181 pag->pagf_agflreset = false;
2182 }
2183
2184 /*
2185 * Defer an AGFL block free. This is effectively equivalent to
2186 * xfs_bmap_add_free() with some special handling particular to AGFL blocks.
2187 *
2188 * Deferring AGFL frees helps prevent log reservation overruns due to too many
2189 * allocation operations in a transaction. AGFL frees are prone to this problem
2190 * because for one they are always freed one at a time. Further, an immediate
2191 * AGFL block free can cause a btree join and require another block free before
2192 * the real allocation can proceed. Deferring the free disconnects freeing up
2193 * the AGFL slot from freeing the block.
2194 */
2195 STATIC void
2196 xfs_defer_agfl_block(
2197 struct xfs_trans *tp,
2198 xfs_agnumber_t agno,
2199 xfs_fsblock_t agbno,
2200 struct xfs_owner_info *oinfo)
2201 {
2202 struct xfs_mount *mp = tp->t_mountp;
2203 struct xfs_extent_free_item *new; /* new element */
2204
2205 ASSERT(xfs_bmap_free_item_zone != NULL);
2206 ASSERT(oinfo != NULL);
2207
2208 new = kmem_zone_alloc(xfs_bmap_free_item_zone, 0);
2209 new->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno);
2210 new->xefi_blockcount = 1;
2211 new->xefi_oinfo = *oinfo;
2212
2213 trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1);
2214
2215 xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_AGFL_FREE, &new->xefi_list);
2216 }
2217
2218 /*
2219 * Decide whether to use this allocation group for this allocation.
2220 * If so, fix up the btree freelist's size.
2221 */
2222 int /* error */
2223 xfs_alloc_fix_freelist(
2224 struct xfs_alloc_arg *args, /* allocation argument structure */
2225 int flags) /* XFS_ALLOC_FLAG_... */
2226 {
2227 struct xfs_mount *mp = args->mp;
2228 struct xfs_perag *pag = args->pag;
2229 struct xfs_trans *tp = args->tp;
2230 struct xfs_buf *agbp = NULL;
2231 struct xfs_buf *agflbp = NULL;
2232 struct xfs_alloc_arg targs; /* local allocation arguments */
2233 xfs_agblock_t bno; /* freelist block */
2234 xfs_extlen_t need; /* total blocks needed in freelist */
2235 int error = 0;
2236
2237 /* deferred ops (AGFL block frees) require permanent transactions */
2238 ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
2239
2240 if (!pag->pagf_init) {
2241 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
2242 if (error)
2243 goto out_no_agbp;
2244 if (!pag->pagf_init) {
2245 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
2246 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
2247 goto out_agbp_relse;
2248 }
2249 }
2250
2251 /*
2252 * If this is a metadata preferred pag and we are user data then try
2253 * somewhere else if we are not being asked to try harder at this
2254 * point
2255 */
2256 if (pag->pagf_metadata && xfs_alloc_is_userdata(args->datatype) &&
2257 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
2258 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
2259 goto out_agbp_relse;
2260 }
2261
2262 need = xfs_alloc_min_freelist(mp, pag);
2263 if (!xfs_alloc_space_available(args, need, flags |
2264 XFS_ALLOC_FLAG_CHECK))
2265 goto out_agbp_relse;
2266
2267 /*
2268 * Get the a.g. freespace buffer.
2269 * Can fail if we're not blocking on locks, and it's held.
2270 */
2271 if (!agbp) {
2272 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
2273 if (error)
2274 goto out_no_agbp;
2275 if (!agbp) {
2276 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
2277 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
2278 goto out_no_agbp;
2279 }
2280 }
2281
2282 /* reset a padding mismatched agfl before final free space check */
2283 if (pag->pagf_agflreset)
2284 xfs_agfl_reset(tp, agbp, pag);
2285
2286 /* If there isn't enough total space or single-extent, reject it. */
2287 need = xfs_alloc_min_freelist(mp, pag);
2288 if (!xfs_alloc_space_available(args, need, flags))
2289 goto out_agbp_relse;
2290
2291 /*
2292 * Make the freelist shorter if it's too long.
2293 *
2294 * Note that from this point onwards, we will always release the agf and
2295 * agfl buffers on error. This handles the case where we error out and
2296 * the buffers are clean or may not have been joined to the transaction
2297 * and hence need to be released manually. If they have been joined to
2298 * the transaction, then xfs_trans_brelse() will handle them
2299 * appropriately based on the recursion count and dirty state of the
2300 * buffer.
2301 *
2302 * XXX (dgc): When we have lots of free space, does this buy us
2303 * anything other than extra overhead when we need to put more blocks
2304 * back on the free list? Maybe we should only do this when space is
2305 * getting low or the AGFL is more than half full?
2306 *
2307 * The NOSHRINK flag prevents the AGFL from being shrunk if it's too
2308 * big; the NORMAP flag prevents AGFL expand/shrink operations from
2309 * updating the rmapbt. Both flags are used in xfs_repair while we're
2310 * rebuilding the rmapbt, and neither are used by the kernel. They're
2311 * both required to ensure that rmaps are correctly recorded for the
2312 * regenerated AGFL, bnobt, and cntbt. See repair/phase5.c and
2313 * repair/rmap.c in xfsprogs for details.
2314 */
2315 memset(&targs, 0, sizeof(targs));
2316 /* struct copy below */
2317 if (flags & XFS_ALLOC_FLAG_NORMAP)
2318 targs.oinfo = XFS_RMAP_OINFO_SKIP_UPDATE;
2319 else
2320 targs.oinfo = XFS_RMAP_OINFO_AG;
2321 while (!(flags & XFS_ALLOC_FLAG_NOSHRINK) && pag->pagf_flcount > need) {
2322 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
2323 if (error)
2324 goto out_agbp_relse;
2325
2326 /* defer agfl frees */
2327 xfs_defer_agfl_block(tp, args->agno, bno, &targs.oinfo);
2328 }
2329
2330 targs.tp = tp;
2331 targs.mp = mp;
2332 targs.agbp = agbp;
2333 targs.agno = args->agno;
2334 targs.alignment = targs.minlen = targs.prod = 1;
2335 targs.type = XFS_ALLOCTYPE_THIS_AG;
2336 targs.pag = pag;
2337 error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);
2338 if (error)
2339 goto out_agbp_relse;
2340
2341 /* Make the freelist longer if it's too short. */
2342 while (pag->pagf_flcount < need) {
2343 targs.agbno = 0;
2344 targs.maxlen = need - pag->pagf_flcount;
2345 targs.resv = XFS_AG_RESV_AGFL;
2346
2347 /* Allocate as many blocks as possible at once. */
2348 error = xfs_alloc_ag_vextent(&targs);
2349 if (error)
2350 goto out_agflbp_relse;
2351
2352 /*
2353 * Stop if we run out. Won't happen if callers are obeying
2354 * the restrictions correctly. Can happen for free calls
2355 * on a completely full ag.
2356 */
2357 if (targs.agbno == NULLAGBLOCK) {
2358 if (flags & XFS_ALLOC_FLAG_FREEING)
2359 break;
2360 goto out_agflbp_relse;
2361 }
2362 /*
2363 * Put each allocated block on the list.
2364 */
2365 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
2366 error = xfs_alloc_put_freelist(tp, agbp,
2367 agflbp, bno, 0);
2368 if (error)
2369 goto out_agflbp_relse;
2370 }
2371 }
2372 xfs_trans_brelse(tp, agflbp);
2373 args->agbp = agbp;
2374 return 0;
2375
2376 out_agflbp_relse:
2377 xfs_trans_brelse(tp, agflbp);
2378 out_agbp_relse:
2379 if (agbp)
2380 xfs_trans_brelse(tp, agbp);
2381 out_no_agbp:
2382 args->agbp = NULL;
2383 return error;
2384 }
2385
2386 /*
2387 * Get a block from the freelist.
2388 * Returns with the buffer for the block gotten.
2389 */
2390 int /* error */
2391 xfs_alloc_get_freelist(
2392 xfs_trans_t *tp, /* transaction pointer */
2393 xfs_buf_t *agbp, /* buffer containing the agf structure */
2394 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2395 int btreeblk) /* destination is a AGF btree */
2396 {
2397 xfs_agf_t *agf; /* a.g. freespace structure */
2398 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2399 xfs_agblock_t bno; /* block number returned */
2400 __be32 *agfl_bno;
2401 int error;
2402 int logflags;
2403 xfs_mount_t *mp = tp->t_mountp;
2404 xfs_perag_t *pag; /* per allocation group data */
2405
2406 /*
2407 * Freelist is empty, give up.
2408 */
2409 agf = XFS_BUF_TO_AGF(agbp);
2410 if (!agf->agf_flcount) {
2411 *bnop = NULLAGBLOCK;
2412 return 0;
2413 }
2414 /*
2415 * Read the array of free blocks.
2416 */
2417 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2418 &agflbp);
2419 if (error)
2420 return error;
2421
2422
2423 /*
2424 * Get the block number and update the data structures.
2425 */
2426 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2427 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2428 be32_add_cpu(&agf->agf_flfirst, 1);
2429 xfs_trans_brelse(tp, agflbp);
2430 if (be32_to_cpu(agf->agf_flfirst) == xfs_agfl_size(mp))
2431 agf->agf_flfirst = 0;
2432
2433 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2434 ASSERT(!pag->pagf_agflreset);
2435 be32_add_cpu(&agf->agf_flcount, -1);
2436 xfs_trans_agflist_delta(tp, -1);
2437 pag->pagf_flcount--;
2438
2439 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2440 if (btreeblk) {
2441 be32_add_cpu(&agf->agf_btreeblks, 1);
2442 pag->pagf_btreeblks++;
2443 logflags |= XFS_AGF_BTREEBLKS;
2444 }
2445 xfs_perag_put(pag);
2446
2447 xfs_alloc_log_agf(tp, agbp, logflags);
2448 *bnop = bno;
2449
2450 return 0;
2451 }
2452
2453 /*
2454 * Log the given fields from the agf structure.
2455 */
2456 void
2457 xfs_alloc_log_agf(
2458 xfs_trans_t *tp, /* transaction pointer */
2459 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2460 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2461 {
2462 int first; /* first byte offset */
2463 int last; /* last byte offset */
2464 static const short offsets[] = {
2465 offsetof(xfs_agf_t, agf_magicnum),
2466 offsetof(xfs_agf_t, agf_versionnum),
2467 offsetof(xfs_agf_t, agf_seqno),
2468 offsetof(xfs_agf_t, agf_length),
2469 offsetof(xfs_agf_t, agf_roots[0]),
2470 offsetof(xfs_agf_t, agf_levels[0]),
2471 offsetof(xfs_agf_t, agf_flfirst),
2472 offsetof(xfs_agf_t, agf_fllast),
2473 offsetof(xfs_agf_t, agf_flcount),
2474 offsetof(xfs_agf_t, agf_freeblks),
2475 offsetof(xfs_agf_t, agf_longest),
2476 offsetof(xfs_agf_t, agf_btreeblks),
2477 offsetof(xfs_agf_t, agf_uuid),
2478 offsetof(xfs_agf_t, agf_rmap_blocks),
2479 offsetof(xfs_agf_t, agf_refcount_blocks),
2480 offsetof(xfs_agf_t, agf_refcount_root),
2481 offsetof(xfs_agf_t, agf_refcount_level),
2482 /* needed so that we don't log the whole rest of the structure: */
2483 offsetof(xfs_agf_t, agf_spare64),
2484 sizeof(xfs_agf_t)
2485 };
2486
2487 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2488
2489 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
2490
2491 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2492 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2493 }
2494
2495 /*
2496 * Interface for inode allocation to force the pag data to be initialized.
2497 */
2498 int /* error */
2499 xfs_alloc_pagf_init(
2500 xfs_mount_t *mp, /* file system mount structure */
2501 xfs_trans_t *tp, /* transaction pointer */
2502 xfs_agnumber_t agno, /* allocation group number */
2503 int flags) /* XFS_ALLOC_FLAGS_... */
2504 {
2505 xfs_buf_t *bp;
2506 int error;
2507
2508 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2509 return error;
2510 if (bp)
2511 xfs_trans_brelse(tp, bp);
2512 return 0;
2513 }
2514
2515 /*
2516 * Put the block on the freelist for the allocation group.
2517 */
2518 int /* error */
2519 xfs_alloc_put_freelist(
2520 xfs_trans_t *tp, /* transaction pointer */
2521 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2522 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2523 xfs_agblock_t bno, /* block being freed */
2524 int btreeblk) /* block came from a AGF btree */
2525 {
2526 xfs_agf_t *agf; /* a.g. freespace structure */
2527 __be32 *blockp;/* pointer to array entry */
2528 int error;
2529 int logflags;
2530 xfs_mount_t *mp; /* mount structure */
2531 xfs_perag_t *pag; /* per allocation group data */
2532 __be32 *agfl_bno;
2533 int startoff;
2534
2535 agf = XFS_BUF_TO_AGF(agbp);
2536 mp = tp->t_mountp;
2537
2538 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2539 be32_to_cpu(agf->agf_seqno), &agflbp)))
2540 return error;
2541 be32_add_cpu(&agf->agf_fllast, 1);
2542 if (be32_to_cpu(agf->agf_fllast) == xfs_agfl_size(mp))
2543 agf->agf_fllast = 0;
2544
2545 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2546 ASSERT(!pag->pagf_agflreset);
2547 be32_add_cpu(&agf->agf_flcount, 1);
2548 xfs_trans_agflist_delta(tp, 1);
2549 pag->pagf_flcount++;
2550
2551 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2552 if (btreeblk) {
2553 be32_add_cpu(&agf->agf_btreeblks, -1);
2554 pag->pagf_btreeblks--;
2555 logflags |= XFS_AGF_BTREEBLKS;
2556 }
2557 xfs_perag_put(pag);
2558
2559 xfs_alloc_log_agf(tp, agbp, logflags);
2560
2561 ASSERT(be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp));
2562
2563 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2564 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
2565 *blockp = cpu_to_be32(bno);
2566 startoff = (char *)blockp - (char *)agflbp->b_addr;
2567
2568 xfs_alloc_log_agf(tp, agbp, logflags);
2569
2570 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
2571 xfs_trans_log_buf(tp, agflbp, startoff,
2572 startoff + sizeof(xfs_agblock_t) - 1);
2573 return 0;
2574 }
2575
2576 static xfs_failaddr_t
2577 xfs_agf_verify(
2578 struct xfs_buf *bp)
2579 {
2580 struct xfs_mount *mp = bp->b_mount;
2581 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
2582
2583 if (xfs_sb_version_hascrc(&mp->m_sb)) {
2584 if (!uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid))
2585 return __this_address;
2586 if (!xfs_log_check_lsn(mp,
2587 be64_to_cpu(XFS_BUF_TO_AGF(bp)->agf_lsn)))
2588 return __this_address;
2589 }
2590
2591 if (!xfs_verify_magic(bp, agf->agf_magicnum))
2592 return __this_address;
2593
2594 if (!(XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2595 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2596 be32_to_cpu(agf->agf_flfirst) < xfs_agfl_size(mp) &&
2597 be32_to_cpu(agf->agf_fllast) < xfs_agfl_size(mp) &&
2598 be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp)))
2599 return __this_address;
2600
2601 if (be32_to_cpu(agf->agf_length) > mp->m_sb.sb_dblocks)
2602 return __this_address;
2603
2604 if (be32_to_cpu(agf->agf_freeblks) < be32_to_cpu(agf->agf_longest) ||
2605 be32_to_cpu(agf->agf_freeblks) > be32_to_cpu(agf->agf_length))
2606 return __this_address;
2607
2608 if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 ||
2609 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 ||
2610 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS ||
2611 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS)
2612 return __this_address;
2613
2614 if (xfs_sb_version_hasrmapbt(&mp->m_sb) &&
2615 (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 ||
2616 be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS))
2617 return __this_address;
2618
2619 if (xfs_sb_version_hasrmapbt(&mp->m_sb) &&
2620 be32_to_cpu(agf->agf_rmap_blocks) > be32_to_cpu(agf->agf_length))
2621 return __this_address;
2622
2623 /*
2624 * during growfs operations, the perag is not fully initialised,
2625 * so we can't use it for any useful checking. growfs ensures we can't
2626 * use it by using uncached buffers that don't have the perag attached
2627 * so we can detect and avoid this problem.
2628 */
2629 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2630 return __this_address;
2631
2632 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2633 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2634 return __this_address;
2635
2636 if (xfs_sb_version_hasreflink(&mp->m_sb) &&
2637 be32_to_cpu(agf->agf_refcount_blocks) >
2638 be32_to_cpu(agf->agf_length))
2639 return __this_address;
2640
2641 if (xfs_sb_version_hasreflink(&mp->m_sb) &&
2642 (be32_to_cpu(agf->agf_refcount_level) < 1 ||
2643 be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS))
2644 return __this_address;
2645
2646 return NULL;
2647
2648 }
2649
2650 static void
2651 xfs_agf_read_verify(
2652 struct xfs_buf *bp)
2653 {
2654 struct xfs_mount *mp = bp->b_mount;
2655 xfs_failaddr_t fa;
2656
2657 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2658 !xfs_buf_verify_cksum(bp, XFS_AGF_CRC_OFF))
2659 xfs_verifier_error(bp, -EFSBADCRC, __this_address);
2660 else {
2661 fa = xfs_agf_verify(bp);
2662 if (XFS_TEST_ERROR(fa, mp, XFS_ERRTAG_ALLOC_READ_AGF))
2663 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
2664 }
2665 }
2666
2667 static void
2668 xfs_agf_write_verify(
2669 struct xfs_buf *bp)
2670 {
2671 struct xfs_mount *mp = bp->b_mount;
2672 struct xfs_buf_log_item *bip = bp->b_log_item;
2673 xfs_failaddr_t fa;
2674
2675 fa = xfs_agf_verify(bp);
2676 if (fa) {
2677 xfs_verifier_error(bp, -EFSCORRUPTED, fa);
2678 return;
2679 }
2680
2681 if (!xfs_sb_version_hascrc(&mp->m_sb))
2682 return;
2683
2684 if (bip)
2685 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2686
2687 xfs_buf_update_cksum(bp, XFS_AGF_CRC_OFF);
2688 }
2689
2690 const struct xfs_buf_ops xfs_agf_buf_ops = {
2691 .name = "xfs_agf",
2692 .magic = { cpu_to_be32(XFS_AGF_MAGIC), cpu_to_be32(XFS_AGF_MAGIC) },
2693 .verify_read = xfs_agf_read_verify,
2694 .verify_write = xfs_agf_write_verify,
2695 .verify_struct = xfs_agf_verify,
2696 };
2697
2698 /*
2699 * Read in the allocation group header (free/alloc section).
2700 */
2701 int /* error */
2702 xfs_read_agf(
2703 struct xfs_mount *mp, /* mount point structure */
2704 struct xfs_trans *tp, /* transaction pointer */
2705 xfs_agnumber_t agno, /* allocation group number */
2706 int flags, /* XFS_BUF_ */
2707 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2708 {
2709 int error;
2710
2711 trace_xfs_read_agf(mp, agno);
2712
2713 ASSERT(agno != NULLAGNUMBER);
2714 error = xfs_trans_read_buf(
2715 mp, tp, mp->m_ddev_targp,
2716 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2717 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
2718 if (error)
2719 return error;
2720 if (!*bpp)
2721 return 0;
2722
2723 ASSERT(!(*bpp)->b_error);
2724 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
2725 return 0;
2726 }
2727
2728 /*
2729 * Read in the allocation group header (free/alloc section).
2730 */
2731 int /* error */
2732 xfs_alloc_read_agf(
2733 struct xfs_mount *mp, /* mount point structure */
2734 struct xfs_trans *tp, /* transaction pointer */
2735 xfs_agnumber_t agno, /* allocation group number */
2736 int flags, /* XFS_ALLOC_FLAG_... */
2737 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2738 {
2739 struct xfs_agf *agf; /* ag freelist header */
2740 struct xfs_perag *pag; /* per allocation group data */
2741 int error;
2742
2743 trace_xfs_alloc_read_agf(mp, agno);
2744
2745 ASSERT(agno != NULLAGNUMBER);
2746 error = xfs_read_agf(mp, tp, agno,
2747 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
2748 bpp);
2749 if (error)
2750 return error;
2751 if (!*bpp)
2752 return 0;
2753 ASSERT(!(*bpp)->b_error);
2754
2755 agf = XFS_BUF_TO_AGF(*bpp);
2756 pag = xfs_perag_get(mp, agno);
2757 if (!pag->pagf_init) {
2758 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2759 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
2760 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2761 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2762 pag->pagf_levels[XFS_BTNUM_BNOi] =
2763 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2764 pag->pagf_levels[XFS_BTNUM_CNTi] =
2765 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2766 pag->pagf_levels[XFS_BTNUM_RMAPi] =
2767 be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
2768 pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);
2769 pag->pagf_init = 1;
2770 pag->pagf_agflreset = xfs_agfl_needs_reset(mp, agf);
2771 }
2772 #ifdef DEBUG
2773 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2774 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2775 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
2776 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2777 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2778 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2779 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2780 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2781 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2782 }
2783 #endif
2784 xfs_perag_put(pag);
2785 return 0;
2786 }
2787
2788 /*
2789 * Allocate an extent (variable-size).
2790 * Depending on the allocation type, we either look in a single allocation
2791 * group or loop over the allocation groups to find the result.
2792 */
2793 int /* error */
2794 xfs_alloc_vextent(
2795 struct xfs_alloc_arg *args) /* allocation argument structure */
2796 {
2797 xfs_agblock_t agsize; /* allocation group size */
2798 int error;
2799 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2800 struct xfs_mount *mp; /* mount structure pointer */
2801 xfs_agnumber_t sagno; /* starting allocation group number */
2802 xfs_alloctype_t type; /* input allocation type */
2803 int bump_rotor = 0;
2804 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2805
2806 mp = args->mp;
2807 type = args->otype = args->type;
2808 args->agbno = NULLAGBLOCK;
2809 /*
2810 * Just fix this up, for the case where the last a.g. is shorter
2811 * (or there's only one a.g.) and the caller couldn't easily figure
2812 * that out (xfs_bmap_alloc).
2813 */
2814 agsize = mp->m_sb.sb_agblocks;
2815 if (args->maxlen > agsize)
2816 args->maxlen = agsize;
2817 if (args->alignment == 0)
2818 args->alignment = 1;
2819 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2820 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2821 ASSERT(args->minlen <= args->maxlen);
2822 ASSERT(args->minlen <= agsize);
2823 ASSERT(args->mod < args->prod);
2824 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2825 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2826 args->minlen > args->maxlen || args->minlen > agsize ||
2827 args->mod >= args->prod) {
2828 args->fsbno = NULLFSBLOCK;
2829 trace_xfs_alloc_vextent_badargs(args);
2830 return 0;
2831 }
2832
2833 switch (type) {
2834 case XFS_ALLOCTYPE_THIS_AG:
2835 case XFS_ALLOCTYPE_NEAR_BNO:
2836 case XFS_ALLOCTYPE_THIS_BNO:
2837 /*
2838 * These three force us into a single a.g.
2839 */
2840 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2841 args->pag = xfs_perag_get(mp, args->agno);
2842 error = xfs_alloc_fix_freelist(args, 0);
2843 if (error) {
2844 trace_xfs_alloc_vextent_nofix(args);
2845 goto error0;
2846 }
2847 if (!args->agbp) {
2848 trace_xfs_alloc_vextent_noagbp(args);
2849 break;
2850 }
2851 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2852 if ((error = xfs_alloc_ag_vextent(args)))
2853 goto error0;
2854 break;
2855 case XFS_ALLOCTYPE_START_BNO:
2856 /*
2857 * Try near allocation first, then anywhere-in-ag after
2858 * the first a.g. fails.
2859 */
2860 if ((args->datatype & XFS_ALLOC_INITIAL_USER_DATA) &&
2861 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2862 args->fsbno = XFS_AGB_TO_FSB(mp,
2863 ((mp->m_agfrotor / rotorstep) %
2864 mp->m_sb.sb_agcount), 0);
2865 bump_rotor = 1;
2866 }
2867 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2868 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2869 /* FALLTHROUGH */
2870 case XFS_ALLOCTYPE_FIRST_AG:
2871 /*
2872 * Rotate through the allocation groups looking for a winner.
2873 */
2874 if (type == XFS_ALLOCTYPE_FIRST_AG) {
2875 /*
2876 * Start with allocation group given by bno.
2877 */
2878 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2879 args->type = XFS_ALLOCTYPE_THIS_AG;
2880 sagno = 0;
2881 flags = 0;
2882 } else {
2883 /*
2884 * Start with the given allocation group.
2885 */
2886 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2887 flags = XFS_ALLOC_FLAG_TRYLOCK;
2888 }
2889 /*
2890 * Loop over allocation groups twice; first time with
2891 * trylock set, second time without.
2892 */
2893 for (;;) {
2894 args->pag = xfs_perag_get(mp, args->agno);
2895 error = xfs_alloc_fix_freelist(args, flags);
2896 if (error) {
2897 trace_xfs_alloc_vextent_nofix(args);
2898 goto error0;
2899 }
2900 /*
2901 * If we get a buffer back then the allocation will fly.
2902 */
2903 if (args->agbp) {
2904 if ((error = xfs_alloc_ag_vextent(args)))
2905 goto error0;
2906 break;
2907 }
2908
2909 trace_xfs_alloc_vextent_loopfailed(args);
2910
2911 /*
2912 * Didn't work, figure out the next iteration.
2913 */
2914 if (args->agno == sagno &&
2915 type == XFS_ALLOCTYPE_START_BNO)
2916 args->type = XFS_ALLOCTYPE_THIS_AG;
2917 /*
2918 * For the first allocation, we can try any AG to get
2919 * space. However, if we already have allocated a
2920 * block, we don't want to try AGs whose number is below
2921 * sagno. Otherwise, we may end up with out-of-order
2922 * locking of AGF, which might cause deadlock.
2923 */
2924 if (++(args->agno) == mp->m_sb.sb_agcount) {
2925 if (args->tp->t_firstblock != NULLFSBLOCK)
2926 args->agno = sagno;
2927 else
2928 args->agno = 0;
2929 }
2930 /*
2931 * Reached the starting a.g., must either be done
2932 * or switch to non-trylock mode.
2933 */
2934 if (args->agno == sagno) {
2935 if (flags == 0) {
2936 args->agbno = NULLAGBLOCK;
2937 trace_xfs_alloc_vextent_allfailed(args);
2938 break;
2939 }
2940
2941 flags = 0;
2942 if (type == XFS_ALLOCTYPE_START_BNO) {
2943 args->agbno = XFS_FSB_TO_AGBNO(mp,
2944 args->fsbno);
2945 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2946 }
2947 }
2948 xfs_perag_put(args->pag);
2949 }
2950 if (bump_rotor) {
2951 if (args->agno == sagno)
2952 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2953 (mp->m_sb.sb_agcount * rotorstep);
2954 else
2955 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2956 (mp->m_sb.sb_agcount * rotorstep);
2957 }
2958 break;
2959 default:
2960 ASSERT(0);
2961 /* NOTREACHED */
2962 }
2963 if (args->agbno == NULLAGBLOCK)
2964 args->fsbno = NULLFSBLOCK;
2965 else {
2966 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2967 #ifdef DEBUG
2968 ASSERT(args->len >= args->minlen);
2969 ASSERT(args->len <= args->maxlen);
2970 ASSERT(args->agbno % args->alignment == 0);
2971 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2972 args->len);
2973 #endif
2974
2975 /* Zero the extent if we were asked to do so */
2976 if (args->datatype & XFS_ALLOC_USERDATA_ZERO) {
2977 error = xfs_zero_extent(args->ip, args->fsbno, args->len);
2978 if (error)
2979 goto error0;
2980 }
2981
2982 }
2983 xfs_perag_put(args->pag);
2984 return 0;
2985 error0:
2986 xfs_perag_put(args->pag);
2987 return error;
2988 }
2989
2990 /* Ensure that the freelist is at full capacity. */
2991 int
2992 xfs_free_extent_fix_freelist(
2993 struct xfs_trans *tp,
2994 xfs_agnumber_t agno,
2995 struct xfs_buf **agbp)
2996 {
2997 struct xfs_alloc_arg args;
2998 int error;
2999
3000 memset(&args, 0, sizeof(struct xfs_alloc_arg));
3001 args.tp = tp;
3002 args.mp = tp->t_mountp;
3003 args.agno = agno;
3004
3005 /*
3006 * validate that the block number is legal - the enables us to detect
3007 * and handle a silent filesystem corruption rather than crashing.
3008 */
3009 if (args.agno >= args.mp->m_sb.sb_agcount)
3010 return -EFSCORRUPTED;
3011
3012 args.pag = xfs_perag_get(args.mp, args.agno);
3013 ASSERT(args.pag);
3014
3015 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
3016 if (error)
3017 goto out;
3018
3019 *agbp = args.agbp;
3020 out:
3021 xfs_perag_put(args.pag);
3022 return error;
3023 }
3024
3025 /*
3026 * Free an extent.
3027 * Just break up the extent address and hand off to xfs_free_ag_extent
3028 * after fixing up the freelist.
3029 */
3030 int
3031 __xfs_free_extent(
3032 struct xfs_trans *tp,
3033 xfs_fsblock_t bno,
3034 xfs_extlen_t len,
3035 const struct xfs_owner_info *oinfo,
3036 enum xfs_ag_resv_type type,
3037 bool skip_discard)
3038 {
3039 struct xfs_mount *mp = tp->t_mountp;
3040 struct xfs_buf *agbp;
3041 xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, bno);
3042 xfs_agblock_t agbno = XFS_FSB_TO_AGBNO(mp, bno);
3043 int error;
3044 unsigned int busy_flags = 0;
3045
3046 ASSERT(len != 0);
3047 ASSERT(type != XFS_AG_RESV_AGFL);
3048
3049 if (XFS_TEST_ERROR(false, mp,
3050 XFS_ERRTAG_FREE_EXTENT))
3051 return -EIO;
3052
3053 error = xfs_free_extent_fix_freelist(tp, agno, &agbp);
3054 if (error)
3055 return error;
3056
3057 XFS_WANT_CORRUPTED_GOTO(mp, agbno < mp->m_sb.sb_agblocks, err);
3058
3059 /* validate the extent size is legal now we have the agf locked */
3060 XFS_WANT_CORRUPTED_GOTO(mp,
3061 agbno + len <= be32_to_cpu(XFS_BUF_TO_AGF(agbp)->agf_length),
3062 err);
3063
3064 error = xfs_free_ag_extent(tp, agbp, agno, agbno, len, oinfo, type);
3065 if (error)
3066 goto err;
3067
3068 if (skip_discard)
3069 busy_flags |= XFS_EXTENT_BUSY_SKIP_DISCARD;
3070 xfs_extent_busy_insert(tp, agno, agbno, len, busy_flags);
3071 return 0;
3072
3073 err:
3074 xfs_trans_brelse(tp, agbp);
3075 return error;
3076 }
3077
3078 struct xfs_alloc_query_range_info {
3079 xfs_alloc_query_range_fn fn;
3080 void *priv;
3081 };
3082
3083 /* Format btree record and pass to our callback. */
3084 STATIC int
3085 xfs_alloc_query_range_helper(
3086 struct xfs_btree_cur *cur,
3087 union xfs_btree_rec *rec,
3088 void *priv)
3089 {
3090 struct xfs_alloc_query_range_info *query = priv;
3091 struct xfs_alloc_rec_incore irec;
3092
3093 irec.ar_startblock = be32_to_cpu(rec->alloc.ar_startblock);
3094 irec.ar_blockcount = be32_to_cpu(rec->alloc.ar_blockcount);
3095 return query->fn(cur, &irec, query->priv);
3096 }
3097
3098 /* Find all free space within a given range of blocks. */
3099 int
3100 xfs_alloc_query_range(
3101 struct xfs_btree_cur *cur,
3102 struct xfs_alloc_rec_incore *low_rec,
3103 struct xfs_alloc_rec_incore *high_rec,
3104 xfs_alloc_query_range_fn fn,
3105 void *priv)
3106 {
3107 union xfs_btree_irec low_brec;
3108 union xfs_btree_irec high_brec;
3109 struct xfs_alloc_query_range_info query;
3110
3111 ASSERT(cur->bc_btnum == XFS_BTNUM_BNO);
3112 low_brec.a = *low_rec;
3113 high_brec.a = *high_rec;
3114 query.priv = priv;
3115 query.fn = fn;
3116 return xfs_btree_query_range(cur, &low_brec, &high_brec,
3117 xfs_alloc_query_range_helper, &query);
3118 }
3119
3120 /* Find all free space records. */
3121 int
3122 xfs_alloc_query_all(
3123 struct xfs_btree_cur *cur,
3124 xfs_alloc_query_range_fn fn,
3125 void *priv)
3126 {
3127 struct xfs_alloc_query_range_info query;
3128
3129 ASSERT(cur->bc_btnum == XFS_BTNUM_BNO);
3130 query.priv = priv;
3131 query.fn = fn;
3132 return xfs_btree_query_all(cur, xfs_alloc_query_range_helper, &query);
3133 }
3134
3135 /* Is there a record covering a given extent? */
3136 int
3137 xfs_alloc_has_record(
3138 struct xfs_btree_cur *cur,
3139 xfs_agblock_t bno,
3140 xfs_extlen_t len,
3141 bool *exists)
3142 {
3143 union xfs_btree_irec low;
3144 union xfs_btree_irec high;
3145
3146 memset(&low, 0, sizeof(low));
3147 low.a.ar_startblock = bno;
3148 memset(&high, 0xFF, sizeof(high));
3149 high.a.ar_startblock = bno + len - 1;
3150
3151 return xfs_btree_has_record(cur, &low, &high, exists);
3152 }
3153
3154 /*
3155 * Walk all the blocks in the AGFL. The @walk_fn can return any negative
3156 * error code or XFS_ITER_*.
3157 */
3158 int
3159 xfs_agfl_walk(
3160 struct xfs_mount *mp,
3161 struct xfs_agf *agf,
3162 struct xfs_buf *agflbp,
3163 xfs_agfl_walk_fn walk_fn,
3164 void *priv)
3165 {
3166 __be32 *agfl_bno;
3167 unsigned int i;
3168 int error;
3169
3170 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
3171 i = be32_to_cpu(agf->agf_flfirst);
3172
3173 /* Nothing to walk in an empty AGFL. */
3174 if (agf->agf_flcount == cpu_to_be32(0))
3175 return 0;
3176
3177 /* Otherwise, walk from first to last, wrapping as needed. */
3178 for (;;) {
3179 error = walk_fn(mp, be32_to_cpu(agfl_bno[i]), priv);
3180 if (error)
3181 return error;
3182 if (i == be32_to_cpu(agf->agf_fllast))
3183 break;
3184 if (++i == xfs_agfl_size(mp))
3185 i = 0;
3186 }
3187
3188 return 0;
3189 }
Linux with added FPC-III support