2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include "xfs_format.h"
21 #include "xfs_log_format.h"
22 #include "xfs_shared.h"
23 #include "xfs_trans_resv.h"
26 #include "xfs_mount.h"
27 #include "xfs_inode.h"
28 #include "xfs_btree.h"
29 #include "xfs_alloc_btree.h"
30 #include "xfs_alloc.h"
31 #include "xfs_extent_busy.h"
32 #include "xfs_error.h"
33 #include "xfs_cksum.h"
34 #include "xfs_trace.h"
35 #include "xfs_trans.h"
36 #include "xfs_buf_item.h"
39 struct workqueue_struct *xfs_alloc_wq;
41 #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
43 #define XFSA_FIXUP_BNO_OK 1
44 #define XFSA_FIXUP_CNT_OK 2
46 STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
47 STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
48 STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
49 STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
50 xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
53 * Lookup the record equal to [bno, len] in the btree given by cur.
55 STATIC int /* error */
57 struct xfs_btree_cur *cur, /* btree cursor */
58 xfs_agblock_t bno, /* starting block of extent */
59 xfs_extlen_t len, /* length of extent */
60 int *stat) /* success/failure */
62 cur->bc_rec.a.ar_startblock = bno;
63 cur->bc_rec.a.ar_blockcount = len;
64 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
68 * Lookup the first record greater than or equal to [bno, len]
69 * in the btree given by cur.
73 struct xfs_btree_cur *cur, /* btree cursor */
74 xfs_agblock_t bno, /* starting block of extent */
75 xfs_extlen_t len, /* length of extent */
76 int *stat) /* success/failure */
78 cur->bc_rec.a.ar_startblock = bno;
79 cur->bc_rec.a.ar_blockcount = len;
80 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
84 * Lookup the first record less than or equal to [bno, len]
85 * in the btree given by cur.
89 struct xfs_btree_cur *cur, /* btree cursor */
90 xfs_agblock_t bno, /* starting block of extent */
91 xfs_extlen_t len, /* length of extent */
92 int *stat) /* success/failure */
94 cur->bc_rec.a.ar_startblock = bno;
95 cur->bc_rec.a.ar_blockcount = len;
96 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
100 * Update the record referred to by cur to the value given
102 * This either works (return 0) or gets an EFSCORRUPTED error.
104 STATIC int /* error */
106 struct xfs_btree_cur *cur, /* btree cursor */
107 xfs_agblock_t bno, /* starting block of extent */
108 xfs_extlen_t len) /* length of extent */
110 union xfs_btree_rec rec;
112 rec.alloc.ar_startblock = cpu_to_be32(bno);
113 rec.alloc.ar_blockcount = cpu_to_be32(len);
114 return xfs_btree_update(cur, &rec);
118 * Get the data from the pointed-to record.
122 struct xfs_btree_cur *cur, /* btree cursor */
123 xfs_agblock_t *bno, /* output: starting block of extent */
124 xfs_extlen_t *len, /* output: length of extent */
125 int *stat) /* output: success/failure */
127 union xfs_btree_rec *rec;
130 error = xfs_btree_get_rec(cur, &rec, stat);
131 if (!error && *stat == 1) {
132 *bno = be32_to_cpu(rec->alloc.ar_startblock);
133 *len = be32_to_cpu(rec->alloc.ar_blockcount);
139 * Compute aligned version of the found extent.
140 * Takes alignment and min length into account.
143 xfs_alloc_compute_aligned(
144 xfs_alloc_arg_t *args, /* allocation argument structure */
145 xfs_agblock_t foundbno, /* starting block in found extent */
146 xfs_extlen_t foundlen, /* length in found extent */
147 xfs_agblock_t *resbno, /* result block number */
148 xfs_extlen_t *reslen) /* result length */
153 /* Trim busy sections out of found extent */
154 xfs_extent_busy_trim(args, foundbno, foundlen, &bno, &len);
156 if (args->alignment > 1 && len >= args->minlen) {
157 xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
158 xfs_extlen_t diff = aligned_bno - bno;
160 *resbno = aligned_bno;
161 *reslen = diff >= len ? 0 : len - diff;
169 * Compute best start block and diff for "near" allocations.
170 * freelen >= wantlen already checked by caller.
172 STATIC xfs_extlen_t /* difference value (absolute) */
173 xfs_alloc_compute_diff(
174 xfs_agblock_t wantbno, /* target starting block */
175 xfs_extlen_t wantlen, /* target length */
176 xfs_extlen_t alignment, /* target alignment */
177 char userdata, /* are we allocating data? */
178 xfs_agblock_t freebno, /* freespace's starting block */
179 xfs_extlen_t freelen, /* freespace's length */
180 xfs_agblock_t *newbnop) /* result: best start block from free */
182 xfs_agblock_t freeend; /* end of freespace extent */
183 xfs_agblock_t newbno1; /* return block number */
184 xfs_agblock_t newbno2; /* other new block number */
185 xfs_extlen_t newlen1=0; /* length with newbno1 */
186 xfs_extlen_t newlen2=0; /* length with newbno2 */
187 xfs_agblock_t wantend; /* end of target extent */
189 ASSERT(freelen >= wantlen);
190 freeend = freebno + freelen;
191 wantend = wantbno + wantlen;
193 * We want to allocate from the start of a free extent if it is past
194 * the desired block or if we are allocating user data and the free
195 * extent is before desired block. The second case is there to allow
196 * for contiguous allocation from the remaining free space if the file
197 * grows in the short term.
199 if (freebno >= wantbno || (userdata && freeend < wantend)) {
200 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
201 newbno1 = NULLAGBLOCK;
202 } else if (freeend >= wantend && alignment > 1) {
203 newbno1 = roundup(wantbno, alignment);
204 newbno2 = newbno1 - alignment;
205 if (newbno1 >= freeend)
206 newbno1 = NULLAGBLOCK;
208 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
209 if (newbno2 < freebno)
210 newbno2 = NULLAGBLOCK;
212 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
213 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
214 if (newlen1 < newlen2 ||
215 (newlen1 == newlen2 &&
216 XFS_ABSDIFF(newbno1, wantbno) >
217 XFS_ABSDIFF(newbno2, wantbno)))
219 } else if (newbno2 != NULLAGBLOCK)
221 } else if (freeend >= wantend) {
223 } else if (alignment > 1) {
224 newbno1 = roundup(freeend - wantlen, alignment);
225 if (newbno1 > freeend - wantlen &&
226 newbno1 - alignment >= freebno)
227 newbno1 -= alignment;
228 else if (newbno1 >= freeend)
229 newbno1 = NULLAGBLOCK;
231 newbno1 = freeend - wantlen;
233 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
237 * Fix up the length, based on mod and prod.
238 * len should be k * prod + mod for some k.
239 * If len is too small it is returned unchanged.
240 * If len hits maxlen it is left alone.
244 xfs_alloc_arg_t *args) /* allocation argument structure */
249 ASSERT(args->mod < args->prod);
251 ASSERT(rlen >= args->minlen);
252 ASSERT(rlen <= args->maxlen);
253 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
254 (args->mod == 0 && rlen < args->prod))
256 k = rlen % args->prod;
260 rlen = rlen - (k - args->mod);
262 rlen = rlen - args->prod + (args->mod - k);
263 if ((int)rlen < (int)args->minlen)
265 ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
266 ASSERT(rlen % args->prod == args->mod);
271 * Fix up length if there is too little space left in the a.g.
272 * Return 1 if ok, 0 if too little, should give up.
275 xfs_alloc_fix_minleft(
276 xfs_alloc_arg_t *args) /* allocation argument structure */
278 xfs_agf_t *agf; /* a.g. freelist header */
279 int diff; /* free space difference */
281 if (args->minleft == 0)
283 agf = XFS_BUF_TO_AGF(args->agbp);
284 diff = be32_to_cpu(agf->agf_freeblks)
285 - args->len - args->minleft;
288 args->len += diff; /* shrink the allocated space */
289 if (args->len >= args->minlen)
291 args->agbno = NULLAGBLOCK;
296 * Update the two btrees, logically removing from freespace the extent
297 * starting at rbno, rlen blocks. The extent is contained within the
298 * actual (current) free extent fbno for flen blocks.
299 * Flags are passed in indicating whether the cursors are set to the
302 STATIC int /* error code */
303 xfs_alloc_fixup_trees(
304 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
305 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
306 xfs_agblock_t fbno, /* starting block of free extent */
307 xfs_extlen_t flen, /* length of free extent */
308 xfs_agblock_t rbno, /* starting block of returned extent */
309 xfs_extlen_t rlen, /* length of returned extent */
310 int flags) /* flags, XFSA_FIXUP_... */
312 int error; /* error code */
313 int i; /* operation results */
314 xfs_agblock_t nfbno1; /* first new free startblock */
315 xfs_agblock_t nfbno2; /* second new free startblock */
316 xfs_extlen_t nflen1=0; /* first new free length */
317 xfs_extlen_t nflen2=0; /* second new free length */
320 * Look up the record in the by-size tree if necessary.
322 if (flags & XFSA_FIXUP_CNT_OK) {
324 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
326 XFS_WANT_CORRUPTED_RETURN(
327 i == 1 && nfbno1 == fbno && nflen1 == flen);
330 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
332 XFS_WANT_CORRUPTED_RETURN(i == 1);
335 * Look up the record in the by-block tree if necessary.
337 if (flags & XFSA_FIXUP_BNO_OK) {
339 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
341 XFS_WANT_CORRUPTED_RETURN(
342 i == 1 && nfbno1 == fbno && nflen1 == flen);
345 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
347 XFS_WANT_CORRUPTED_RETURN(i == 1);
351 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
352 struct xfs_btree_block *bnoblock;
353 struct xfs_btree_block *cntblock;
355 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
356 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
358 XFS_WANT_CORRUPTED_RETURN(
359 bnoblock->bb_numrecs == cntblock->bb_numrecs);
364 * Deal with all four cases: the allocated record is contained
365 * within the freespace record, so we can have new freespace
366 * at either (or both) end, or no freespace remaining.
368 if (rbno == fbno && rlen == flen)
369 nfbno1 = nfbno2 = NULLAGBLOCK;
370 else if (rbno == fbno) {
371 nfbno1 = rbno + rlen;
372 nflen1 = flen - rlen;
373 nfbno2 = NULLAGBLOCK;
374 } else if (rbno + rlen == fbno + flen) {
376 nflen1 = flen - rlen;
377 nfbno2 = NULLAGBLOCK;
380 nflen1 = rbno - fbno;
381 nfbno2 = rbno + rlen;
382 nflen2 = (fbno + flen) - nfbno2;
385 * Delete the entry from the by-size btree.
387 if ((error = xfs_btree_delete(cnt_cur, &i)))
389 XFS_WANT_CORRUPTED_RETURN(i == 1);
391 * Add new by-size btree entry(s).
393 if (nfbno1 != NULLAGBLOCK) {
394 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
396 XFS_WANT_CORRUPTED_RETURN(i == 0);
397 if ((error = xfs_btree_insert(cnt_cur, &i)))
399 XFS_WANT_CORRUPTED_RETURN(i == 1);
401 if (nfbno2 != NULLAGBLOCK) {
402 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
404 XFS_WANT_CORRUPTED_RETURN(i == 0);
405 if ((error = xfs_btree_insert(cnt_cur, &i)))
407 XFS_WANT_CORRUPTED_RETURN(i == 1);
410 * Fix up the by-block btree entry(s).
412 if (nfbno1 == NULLAGBLOCK) {
414 * No remaining freespace, just delete the by-block tree entry.
416 if ((error = xfs_btree_delete(bno_cur, &i)))
418 XFS_WANT_CORRUPTED_RETURN(i == 1);
421 * Update the by-block entry to start later|be shorter.
423 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
426 if (nfbno2 != NULLAGBLOCK) {
428 * 2 resulting free entries, need to add one.
430 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
432 XFS_WANT_CORRUPTED_RETURN(i == 0);
433 if ((error = xfs_btree_insert(bno_cur, &i)))
435 XFS_WANT_CORRUPTED_RETURN(i == 1);
444 struct xfs_mount *mp = bp->b_target->bt_mount;
445 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
448 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_uuid))
450 if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
453 * during growfs operations, the perag is not fully initialised,
454 * so we can't use it for any useful checking. growfs ensures we can't
455 * use it by using uncached buffers that don't have the perag attached
456 * so we can detect and avoid this problem.
458 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
461 for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
462 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
463 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
470 xfs_agfl_read_verify(
473 struct xfs_mount *mp = bp->b_target->bt_mount;
476 * There is no verification of non-crc AGFLs because mkfs does not
477 * initialise the AGFL to zero or NULL. Hence the only valid part of the
478 * AGFL is what the AGF says is active. We can't get to the AGF, so we
479 * can't verify just those entries are valid.
481 if (!xfs_sb_version_hascrc(&mp->m_sb))
484 if (!xfs_buf_verify_cksum(bp, XFS_AGFL_CRC_OFF))
485 xfs_buf_ioerror(bp, -EFSBADCRC);
486 else if (!xfs_agfl_verify(bp))
487 xfs_buf_ioerror(bp, -EFSCORRUPTED);
490 xfs_verifier_error(bp);
494 xfs_agfl_write_verify(
497 struct xfs_mount *mp = bp->b_target->bt_mount;
498 struct xfs_buf_log_item *bip = bp->b_fspriv;
500 /* no verification of non-crc AGFLs */
501 if (!xfs_sb_version_hascrc(&mp->m_sb))
504 if (!xfs_agfl_verify(bp)) {
505 xfs_buf_ioerror(bp, -EFSCORRUPTED);
506 xfs_verifier_error(bp);
511 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
513 xfs_buf_update_cksum(bp, XFS_AGFL_CRC_OFF);
516 const struct xfs_buf_ops xfs_agfl_buf_ops = {
517 .verify_read = xfs_agfl_read_verify,
518 .verify_write = xfs_agfl_write_verify,
522 * Read in the allocation group free block array.
524 STATIC int /* error */
526 xfs_mount_t *mp, /* mount point structure */
527 xfs_trans_t *tp, /* transaction pointer */
528 xfs_agnumber_t agno, /* allocation group number */
529 xfs_buf_t **bpp) /* buffer for the ag free block array */
531 xfs_buf_t *bp; /* return value */
534 ASSERT(agno != NULLAGNUMBER);
535 error = xfs_trans_read_buf(
536 mp, tp, mp->m_ddev_targp,
537 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
538 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
541 xfs_buf_set_ref(bp, XFS_AGFL_REF);
547 xfs_alloc_update_counters(
548 struct xfs_trans *tp,
549 struct xfs_perag *pag,
550 struct xfs_buf *agbp,
553 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
555 pag->pagf_freeblks += len;
556 be32_add_cpu(&agf->agf_freeblks, len);
558 xfs_trans_agblocks_delta(tp, len);
559 if (unlikely(be32_to_cpu(agf->agf_freeblks) >
560 be32_to_cpu(agf->agf_length)))
561 return -EFSCORRUPTED;
563 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
568 * Allocation group level functions.
572 * Allocate a variable extent in the allocation group agno.
573 * Type and bno are used to determine where in the allocation group the
575 * Extent's length (returned in *len) will be between minlen and maxlen,
576 * and of the form k * prod + mod unless there's nothing that large.
577 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
579 STATIC int /* error */
580 xfs_alloc_ag_vextent(
581 xfs_alloc_arg_t *args) /* argument structure for allocation */
585 ASSERT(args->minlen > 0);
586 ASSERT(args->maxlen > 0);
587 ASSERT(args->minlen <= args->maxlen);
588 ASSERT(args->mod < args->prod);
589 ASSERT(args->alignment > 0);
591 * Branch to correct routine based on the type.
594 switch (args->type) {
595 case XFS_ALLOCTYPE_THIS_AG:
596 error = xfs_alloc_ag_vextent_size(args);
598 case XFS_ALLOCTYPE_NEAR_BNO:
599 error = xfs_alloc_ag_vextent_near(args);
601 case XFS_ALLOCTYPE_THIS_BNO:
602 error = xfs_alloc_ag_vextent_exact(args);
609 if (error || args->agbno == NULLAGBLOCK)
612 ASSERT(args->len >= args->minlen);
613 ASSERT(args->len <= args->maxlen);
614 ASSERT(!args->wasfromfl || !args->isfl);
615 ASSERT(args->agbno % args->alignment == 0);
617 if (!args->wasfromfl) {
618 error = xfs_alloc_update_counters(args->tp, args->pag,
620 -((long)(args->len)));
624 ASSERT(!xfs_extent_busy_search(args->mp, args->agno,
625 args->agbno, args->len));
629 xfs_trans_mod_sb(args->tp, args->wasdel ?
630 XFS_TRANS_SB_RES_FDBLOCKS :
631 XFS_TRANS_SB_FDBLOCKS,
632 -((long)(args->len)));
635 XFS_STATS_INC(xs_allocx);
636 XFS_STATS_ADD(xs_allocb, args->len);
641 * Allocate a variable extent at exactly agno/bno.
642 * Extent's length (returned in *len) will be between minlen and maxlen,
643 * and of the form k * prod + mod unless there's nothing that large.
644 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
646 STATIC int /* error */
647 xfs_alloc_ag_vextent_exact(
648 xfs_alloc_arg_t *args) /* allocation argument structure */
650 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
651 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
653 xfs_agblock_t fbno; /* start block of found extent */
654 xfs_extlen_t flen; /* length of found extent */
655 xfs_agblock_t tbno; /* start block of trimmed extent */
656 xfs_extlen_t tlen; /* length of trimmed extent */
657 xfs_agblock_t tend; /* end block of trimmed extent */
658 int i; /* success/failure of operation */
660 ASSERT(args->alignment == 1);
663 * Allocate/initialize a cursor for the by-number freespace btree.
665 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
666 args->agno, XFS_BTNUM_BNO);
669 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
670 * Look for the closest free block <= bno, it must contain bno
671 * if any free block does.
673 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
680 * Grab the freespace record.
682 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
685 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
686 ASSERT(fbno <= args->agbno);
689 * Check for overlapping busy extents.
691 xfs_extent_busy_trim(args, fbno, flen, &tbno, &tlen);
694 * Give up if the start of the extent is busy, or the freespace isn't
695 * long enough for the minimum request.
697 if (tbno > args->agbno)
699 if (tlen < args->minlen)
702 if (tend < args->agbno + args->minlen)
706 * End of extent will be smaller of the freespace end and the
707 * maximal requested end.
709 * Fix the length according to mod and prod if given.
711 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
713 xfs_alloc_fix_len(args);
714 if (!xfs_alloc_fix_minleft(args))
717 ASSERT(args->agbno + args->len <= tend);
720 * We are allocating agbno for args->len
721 * Allocate/initialize a cursor for the by-size btree.
723 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
724 args->agno, XFS_BTNUM_CNT);
725 ASSERT(args->agbno + args->len <=
726 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
727 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
728 args->len, XFSA_FIXUP_BNO_OK);
730 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
734 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
735 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
738 trace_xfs_alloc_exact_done(args);
742 /* Didn't find it, return null. */
743 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
744 args->agbno = NULLAGBLOCK;
745 trace_xfs_alloc_exact_notfound(args);
749 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
750 trace_xfs_alloc_exact_error(args);
755 * Search the btree in a given direction via the search cursor and compare
756 * the records found against the good extent we've already found.
759 xfs_alloc_find_best_extent(
760 struct xfs_alloc_arg *args, /* allocation argument structure */
761 struct xfs_btree_cur **gcur, /* good cursor */
762 struct xfs_btree_cur **scur, /* searching cursor */
763 xfs_agblock_t gdiff, /* difference for search comparison */
764 xfs_agblock_t *sbno, /* extent found by search */
765 xfs_extlen_t *slen, /* extent length */
766 xfs_agblock_t *sbnoa, /* aligned extent found by search */
767 xfs_extlen_t *slena, /* aligned extent length */
768 int dir) /* 0 = search right, 1 = search left */
775 /* The good extent is perfect, no need to search. */
780 * Look until we find a better one, run out of space or run off the end.
783 error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
786 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
787 xfs_alloc_compute_aligned(args, *sbno, *slen, sbnoa, slena);
790 * The good extent is closer than this one.
793 if (*sbnoa >= args->agbno + gdiff)
796 if (*sbnoa <= args->agbno - gdiff)
801 * Same distance, compare length and pick the best.
803 if (*slena >= args->minlen) {
804 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
805 xfs_alloc_fix_len(args);
807 sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
809 args->userdata, *sbnoa,
813 * Choose closer size and invalidate other cursor.
821 error = xfs_btree_increment(*scur, 0, &i);
823 error = xfs_btree_decrement(*scur, 0, &i);
829 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
834 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
839 /* caller invalidates cursors */
844 * Allocate a variable extent near bno in the allocation group agno.
845 * Extent's length (returned in len) will be between minlen and maxlen,
846 * and of the form k * prod + mod unless there's nothing that large.
847 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
849 STATIC int /* error */
850 xfs_alloc_ag_vextent_near(
851 xfs_alloc_arg_t *args) /* allocation argument structure */
853 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
854 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
855 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
856 xfs_agblock_t gtbno; /* start bno of right side entry */
857 xfs_agblock_t gtbnoa; /* aligned ... */
858 xfs_extlen_t gtdiff; /* difference to right side entry */
859 xfs_extlen_t gtlen; /* length of right side entry */
860 xfs_extlen_t gtlena; /* aligned ... */
861 xfs_agblock_t gtnew; /* useful start bno of right side */
862 int error; /* error code */
863 int i; /* result code, temporary */
864 int j; /* result code, temporary */
865 xfs_agblock_t ltbno; /* start bno of left side entry */
866 xfs_agblock_t ltbnoa; /* aligned ... */
867 xfs_extlen_t ltdiff; /* difference to left side entry */
868 xfs_extlen_t ltlen; /* length of left side entry */
869 xfs_extlen_t ltlena; /* aligned ... */
870 xfs_agblock_t ltnew; /* useful start bno of left side */
871 xfs_extlen_t rlen; /* length of returned extent */
875 * Randomly don't execute the first algorithm.
877 int dofirst; /* set to do first algorithm */
879 dofirst = prandom_u32() & 1;
890 * Get a cursor for the by-size btree.
892 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
893 args->agno, XFS_BTNUM_CNT);
896 * See if there are any free extents as big as maxlen.
898 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
901 * If none, then pick up the last entry in the tree unless the
905 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, <bno,
908 if (i == 0 || ltlen == 0) {
909 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
910 trace_xfs_alloc_near_noentry(args);
919 * If the requested extent is large wrt the freespaces available
920 * in this a.g., then the cursor will be pointing to a btree entry
921 * near the right edge of the tree. If it's in the last btree leaf
922 * block, then we just examine all the entries in that block
923 * that are big enough, and pick the best one.
924 * This is written as a while loop so we can break out of it,
925 * but we never loop back to the top.
927 while (xfs_btree_islastblock(cnt_cur, 0)) {
931 xfs_agblock_t bnew=0;
938 * Start from the entry that lookup found, sequence through
939 * all larger free blocks. If we're actually pointing at a
940 * record smaller than maxlen, go to the start of this block,
941 * and skip all those smaller than minlen.
943 if (ltlen || args->alignment > 1) {
944 cnt_cur->bc_ptrs[0] = 1;
946 if ((error = xfs_alloc_get_rec(cnt_cur, <bno,
949 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
950 if (ltlen >= args->minlen)
952 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
955 ASSERT(ltlen >= args->minlen);
959 i = cnt_cur->bc_ptrs[0];
960 for (j = 1, blen = 0, bdiff = 0;
961 !error && j && (blen < args->maxlen || bdiff > 0);
962 error = xfs_btree_increment(cnt_cur, 0, &j)) {
964 * For each entry, decide if it's better than
965 * the previous best entry.
967 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
969 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
970 xfs_alloc_compute_aligned(args, ltbno, ltlen,
972 if (ltlena < args->minlen)
974 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
975 xfs_alloc_fix_len(args);
976 ASSERT(args->len >= args->minlen);
977 if (args->len < blen)
979 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
980 args->alignment, args->userdata, ltbnoa,
982 if (ltnew != NULLAGBLOCK &&
983 (args->len > blen || ltdiff < bdiff)) {
987 besti = cnt_cur->bc_ptrs[0];
991 * It didn't work. We COULD be in a case where
992 * there's a good record somewhere, so try again.
997 * Point at the best entry, and retrieve it again.
999 cnt_cur->bc_ptrs[0] = besti;
1000 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
1002 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1003 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1005 if (!xfs_alloc_fix_minleft(args)) {
1006 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1007 trace_xfs_alloc_near_nominleft(args);
1012 * We are allocating starting at bnew for blen blocks.
1015 ASSERT(bnew >= ltbno);
1016 ASSERT(bnew + blen <= ltbno + ltlen);
1018 * Set up a cursor for the by-bno tree.
1020 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1021 args->agbp, args->agno, XFS_BTNUM_BNO);
1023 * Fix up the btree entries.
1025 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1026 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1028 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1029 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1031 trace_xfs_alloc_near_first(args);
1036 * Search in the by-bno tree to the left and to the right
1037 * simultaneously, until in each case we find a space big enough,
1038 * or run into the edge of the tree. When we run into the edge,
1039 * we deallocate that cursor.
1040 * If both searches succeed, we compare the two spaces and pick
1042 * With alignment, it's possible for both to fail; the upper
1043 * level algorithm that picks allocation groups for allocations
1044 * is not supposed to do this.
1047 * Allocate and initialize the cursor for the leftward search.
1049 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1050 args->agno, XFS_BTNUM_BNO);
1052 * Lookup <= bno to find the leftward search's starting point.
1054 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1058 * Didn't find anything; use this cursor for the rightward
1061 bno_cur_gt = bno_cur_lt;
1065 * Found something. Duplicate the cursor for the rightward search.
1067 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1070 * Increment the cursor, so we will point at the entry just right
1071 * of the leftward entry if any, or to the leftmost entry.
1073 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1077 * It failed, there are no rightward entries.
1079 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1083 * Loop going left with the leftward cursor, right with the
1084 * rightward cursor, until either both directions give up or
1085 * we find an entry at least as big as minlen.
1089 if ((error = xfs_alloc_get_rec(bno_cur_lt, <bno, <len, &i)))
1091 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1092 xfs_alloc_compute_aligned(args, ltbno, ltlen,
1094 if (ltlena >= args->minlen)
1096 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
1099 xfs_btree_del_cursor(bno_cur_lt,
1105 if ((error = xfs_alloc_get_rec(bno_cur_gt, >bno, >len, &i)))
1107 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1108 xfs_alloc_compute_aligned(args, gtbno, gtlen,
1110 if (gtlena >= args->minlen)
1112 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1115 xfs_btree_del_cursor(bno_cur_gt,
1120 } while (bno_cur_lt || bno_cur_gt);
1123 * Got both cursors still active, need to find better entry.
1125 if (bno_cur_lt && bno_cur_gt) {
1126 if (ltlena >= args->minlen) {
1128 * Left side is good, look for a right side entry.
1130 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1131 xfs_alloc_fix_len(args);
1132 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1133 args->alignment, args->userdata, ltbnoa,
1136 error = xfs_alloc_find_best_extent(args,
1137 &bno_cur_lt, &bno_cur_gt,
1138 ltdiff, >bno, >len,
1140 0 /* search right */);
1142 ASSERT(gtlena >= args->minlen);
1145 * Right side is good, look for a left side entry.
1147 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1148 xfs_alloc_fix_len(args);
1149 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1150 args->alignment, args->userdata, gtbnoa,
1153 error = xfs_alloc_find_best_extent(args,
1154 &bno_cur_gt, &bno_cur_lt,
1155 gtdiff, <bno, <len,
1157 1 /* search left */);
1165 * If we couldn't get anything, give up.
1167 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1168 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1171 trace_xfs_alloc_near_busy(args);
1172 xfs_log_force(args->mp, XFS_LOG_SYNC);
1175 trace_xfs_alloc_size_neither(args);
1176 args->agbno = NULLAGBLOCK;
1181 * At this point we have selected a freespace entry, either to the
1182 * left or to the right. If it's on the right, copy all the
1183 * useful variables to the "left" set so we only have one
1184 * copy of this code.
1187 bno_cur_lt = bno_cur_gt;
1198 * Fix up the length and compute the useful address.
1200 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1201 xfs_alloc_fix_len(args);
1202 if (!xfs_alloc_fix_minleft(args)) {
1203 trace_xfs_alloc_near_nominleft(args);
1204 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1205 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1209 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
1210 args->userdata, ltbnoa, ltlena, <new);
1211 ASSERT(ltnew >= ltbno);
1212 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
1213 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1214 args->agbno = ltnew;
1216 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1217 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1221 trace_xfs_alloc_near_greater(args);
1223 trace_xfs_alloc_near_lesser(args);
1225 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1226 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1230 trace_xfs_alloc_near_error(args);
1231 if (cnt_cur != NULL)
1232 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1233 if (bno_cur_lt != NULL)
1234 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1235 if (bno_cur_gt != NULL)
1236 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1241 * Allocate a variable extent anywhere in the allocation group agno.
1242 * Extent's length (returned in len) will be between minlen and maxlen,
1243 * and of the form k * prod + mod unless there's nothing that large.
1244 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1246 STATIC int /* error */
1247 xfs_alloc_ag_vextent_size(
1248 xfs_alloc_arg_t *args) /* allocation argument structure */
1250 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1251 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1252 int error; /* error result */
1253 xfs_agblock_t fbno; /* start of found freespace */
1254 xfs_extlen_t flen; /* length of found freespace */
1255 int i; /* temp status variable */
1256 xfs_agblock_t rbno; /* returned block number */
1257 xfs_extlen_t rlen; /* length of returned extent */
1262 * Allocate and initialize a cursor for the by-size btree.
1264 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1265 args->agno, XFS_BTNUM_CNT);
1269 * Look for an entry >= maxlen+alignment-1 blocks.
1271 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1272 args->maxlen + args->alignment - 1, &i)))
1276 * If none or we have busy extents that we cannot allocate from, then
1277 * we have to settle for a smaller extent. In the case that there are
1278 * no large extents, this will return the last entry in the tree unless
1279 * the tree is empty. In the case that there are only busy large
1280 * extents, this will return the largest small extent unless there
1281 * are no smaller extents available.
1283 if (!i || forced > 1) {
1284 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1288 if (i == 0 || flen == 0) {
1289 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1290 trace_xfs_alloc_size_noentry(args);
1294 xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
1297 * Search for a non-busy extent that is large enough.
1298 * If we are at low space, don't check, or if we fall of
1299 * the end of the btree, turn off the busy check and
1303 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1306 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1308 xfs_alloc_compute_aligned(args, fbno, flen,
1311 if (rlen >= args->maxlen)
1314 error = xfs_btree_increment(cnt_cur, 0, &i);
1319 * Our only valid extents must have been busy.
1320 * Make it unbusy by forcing the log out and
1321 * retrying. If we've been here before, forcing
1322 * the log isn't making the extents available,
1323 * which means they have probably been freed in
1324 * this transaction. In that case, we have to
1325 * give up on them and we'll attempt a minlen
1326 * allocation the next time around.
1328 xfs_btree_del_cursor(cnt_cur,
1330 trace_xfs_alloc_size_busy(args);
1332 xfs_log_force(args->mp, XFS_LOG_SYNC);
1339 * In the first case above, we got the last entry in the
1340 * by-size btree. Now we check to see if the space hits maxlen
1341 * once aligned; if not, we search left for something better.
1342 * This can't happen in the second case above.
1344 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1345 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1346 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1347 if (rlen < args->maxlen) {
1348 xfs_agblock_t bestfbno;
1349 xfs_extlen_t bestflen;
1350 xfs_agblock_t bestrbno;
1351 xfs_extlen_t bestrlen;
1358 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
1362 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1365 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1366 if (flen < bestrlen)
1368 xfs_alloc_compute_aligned(args, fbno, flen,
1370 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1371 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1372 (rlen <= flen && rbno + rlen <= fbno + flen),
1374 if (rlen > bestrlen) {
1379 if (rlen == args->maxlen)
1383 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1386 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1392 args->wasfromfl = 0;
1394 * Fix up the length.
1397 if (rlen < args->minlen) {
1399 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1400 trace_xfs_alloc_size_busy(args);
1401 xfs_log_force(args->mp, XFS_LOG_SYNC);
1406 xfs_alloc_fix_len(args);
1408 if (!xfs_alloc_fix_minleft(args))
1411 XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
1413 * Allocate and initialize a cursor for the by-block tree.
1415 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1416 args->agno, XFS_BTNUM_BNO);
1417 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1418 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1420 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1421 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1422 cnt_cur = bno_cur = NULL;
1425 XFS_WANT_CORRUPTED_GOTO(
1426 args->agbno + args->len <=
1427 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1429 trace_xfs_alloc_size_done(args);
1433 trace_xfs_alloc_size_error(args);
1435 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1437 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1441 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1442 trace_xfs_alloc_size_nominleft(args);
1443 args->agbno = NULLAGBLOCK;
1448 * Deal with the case where only small freespaces remain.
1449 * Either return the contents of the last freespace record,
1450 * or allocate space from the freelist if there is nothing in the tree.
1452 STATIC int /* error */
1453 xfs_alloc_ag_vextent_small(
1454 xfs_alloc_arg_t *args, /* allocation argument structure */
1455 xfs_btree_cur_t *ccur, /* by-size cursor */
1456 xfs_agblock_t *fbnop, /* result block number */
1457 xfs_extlen_t *flenp, /* result length */
1458 int *stat) /* status: 0-freelist, 1-normal/none */
1465 if ((error = xfs_btree_decrement(ccur, 0, &i)))
1468 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1470 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1473 * Nothing in the btree, try the freelist. Make sure
1474 * to respect minleft even when pulling from the
1477 else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
1478 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1480 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
1483 if (fbno != NULLAGBLOCK) {
1484 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
1487 if (args->userdata) {
1490 bp = xfs_btree_get_bufs(args->mp, args->tp,
1491 args->agno, fbno, 0);
1492 xfs_trans_binval(args->tp, bp);
1496 XFS_WANT_CORRUPTED_GOTO(
1497 args->agbno + args->len <=
1498 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1500 args->wasfromfl = 1;
1501 trace_xfs_alloc_small_freelist(args);
1506 * Nothing in the freelist.
1512 * Can't allocate from the freelist for some reason.
1519 * Can't do the allocation, give up.
1521 if (flen < args->minlen) {
1522 args->agbno = NULLAGBLOCK;
1523 trace_xfs_alloc_small_notenough(args);
1529 trace_xfs_alloc_small_done(args);
1533 trace_xfs_alloc_small_error(args);
1538 * Free the extent starting at agno/bno for length.
1540 STATIC int /* error */
1542 xfs_trans_t *tp, /* transaction pointer */
1543 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
1544 xfs_agnumber_t agno, /* allocation group number */
1545 xfs_agblock_t bno, /* starting block number */
1546 xfs_extlen_t len, /* length of extent */
1547 int isfl) /* set if is freelist blocks - no sb acctg */
1549 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1550 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1551 int error; /* error return value */
1552 xfs_agblock_t gtbno; /* start of right neighbor block */
1553 xfs_extlen_t gtlen; /* length of right neighbor block */
1554 int haveleft; /* have a left neighbor block */
1555 int haveright; /* have a right neighbor block */
1556 int i; /* temp, result code */
1557 xfs_agblock_t ltbno; /* start of left neighbor block */
1558 xfs_extlen_t ltlen; /* length of left neighbor block */
1559 xfs_mount_t *mp; /* mount point struct for filesystem */
1560 xfs_agblock_t nbno; /* new starting block of freespace */
1561 xfs_extlen_t nlen; /* new length of freespace */
1562 xfs_perag_t *pag; /* per allocation group data */
1566 * Allocate and initialize a cursor for the by-block btree.
1568 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
1571 * Look for a neighboring block on the left (lower block numbers)
1572 * that is contiguous with this space.
1574 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1578 * There is a block to our left.
1580 if ((error = xfs_alloc_get_rec(bno_cur, <bno, <len, &i)))
1582 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1584 * It's not contiguous, though.
1586 if (ltbno + ltlen < bno)
1590 * If this failure happens the request to free this
1591 * space was invalid, it's (partly) already free.
1594 XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
1598 * Look for a neighboring block on the right (higher block numbers)
1599 * that is contiguous with this space.
1601 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
1605 * There is a block to our right.
1607 if ((error = xfs_alloc_get_rec(bno_cur, >bno, >len, &i)))
1609 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1611 * It's not contiguous, though.
1613 if (bno + len < gtbno)
1617 * If this failure happens the request to free this
1618 * space was invalid, it's (partly) already free.
1621 XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
1625 * Now allocate and initialize a cursor for the by-size tree.
1627 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
1629 * Have both left and right contiguous neighbors.
1630 * Merge all three into a single free block.
1632 if (haveleft && haveright) {
1634 * Delete the old by-size entry on the left.
1636 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1638 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1639 if ((error = xfs_btree_delete(cnt_cur, &i)))
1641 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1643 * Delete the old by-size entry on the right.
1645 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1647 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1648 if ((error = xfs_btree_delete(cnt_cur, &i)))
1650 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1652 * Delete the old by-block entry for the right block.
1654 if ((error = xfs_btree_delete(bno_cur, &i)))
1656 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1658 * Move the by-block cursor back to the left neighbor.
1660 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1662 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1665 * Check that this is the right record: delete didn't
1666 * mangle the cursor.
1669 xfs_agblock_t xxbno;
1672 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1675 XFS_WANT_CORRUPTED_GOTO(
1676 i == 1 && xxbno == ltbno && xxlen == ltlen,
1681 * Update remaining by-block entry to the new, joined block.
1684 nlen = len + ltlen + gtlen;
1685 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1689 * Have only a left contiguous neighbor.
1690 * Merge it together with the new freespace.
1692 else if (haveleft) {
1694 * Delete the old by-size entry on the left.
1696 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1698 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1699 if ((error = xfs_btree_delete(cnt_cur, &i)))
1701 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1703 * Back up the by-block cursor to the left neighbor, and
1704 * update its length.
1706 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1708 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1711 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1715 * Have only a right contiguous neighbor.
1716 * Merge it together with the new freespace.
1718 else if (haveright) {
1720 * Delete the old by-size entry on the right.
1722 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1724 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1725 if ((error = xfs_btree_delete(cnt_cur, &i)))
1727 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1729 * Update the starting block and length of the right
1730 * neighbor in the by-block tree.
1734 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1738 * No contiguous neighbors.
1739 * Insert the new freespace into the by-block tree.
1744 if ((error = xfs_btree_insert(bno_cur, &i)))
1746 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1748 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1751 * In all cases we need to insert the new freespace in the by-size tree.
1753 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1755 XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
1756 if ((error = xfs_btree_insert(cnt_cur, &i)))
1758 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1759 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1763 * Update the freespace totals in the ag and superblock.
1765 pag = xfs_perag_get(mp, agno);
1766 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1772 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1773 XFS_STATS_INC(xs_freex);
1774 XFS_STATS_ADD(xs_freeb, len);
1776 trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
1781 trace_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
1783 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1785 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1790 * Visible (exported) allocation/free functions.
1791 * Some of these are used just by xfs_alloc_btree.c and this file.
1795 * Compute and fill in value of m_ag_maxlevels.
1798 xfs_alloc_compute_maxlevels(
1799 xfs_mount_t *mp) /* file system mount structure */
1807 maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1808 minleafrecs = mp->m_alloc_mnr[0];
1809 minnoderecs = mp->m_alloc_mnr[1];
1810 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1811 for (level = 1; maxblocks > 1; level++)
1812 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1813 mp->m_ag_maxlevels = level;
1817 * Find the length of the longest extent in an AG.
1820 xfs_alloc_longest_free_extent(
1821 struct xfs_mount *mp,
1822 struct xfs_perag *pag)
1824 xfs_extlen_t need, delta = 0;
1826 need = XFS_MIN_FREELIST_PAG(pag, mp);
1827 if (need > pag->pagf_flcount)
1828 delta = need - pag->pagf_flcount;
1830 if (pag->pagf_longest > delta)
1831 return pag->pagf_longest - delta;
1832 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1836 * Decide whether to use this allocation group for this allocation.
1837 * If so, fix up the btree freelist's size.
1839 STATIC int /* error */
1840 xfs_alloc_fix_freelist(
1841 xfs_alloc_arg_t *args, /* allocation argument structure */
1842 int flags) /* XFS_ALLOC_FLAG_... */
1844 xfs_buf_t *agbp; /* agf buffer pointer */
1845 xfs_agf_t *agf; /* a.g. freespace structure pointer */
1846 xfs_buf_t *agflbp;/* agfl buffer pointer */
1847 xfs_agblock_t bno; /* freelist block */
1848 xfs_extlen_t delta; /* new blocks needed in freelist */
1849 int error; /* error result code */
1850 xfs_extlen_t longest;/* longest extent in allocation group */
1851 xfs_mount_t *mp; /* file system mount point structure */
1852 xfs_extlen_t need; /* total blocks needed in freelist */
1853 xfs_perag_t *pag; /* per-ag information structure */
1854 xfs_alloc_arg_t targs; /* local allocation arguments */
1855 xfs_trans_t *tp; /* transaction pointer */
1861 if (!pag->pagf_init) {
1862 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1865 if (!pag->pagf_init) {
1866 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1867 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1875 * If this is a metadata preferred pag and we are user data
1876 * then try somewhere else if we are not being asked to
1877 * try harder at this point
1879 if (pag->pagf_metadata && args->userdata &&
1880 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
1881 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1886 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1888 * If it looks like there isn't a long enough extent, or enough
1889 * total blocks, reject it.
1891 need = XFS_MIN_FREELIST_PAG(pag, mp);
1892 longest = xfs_alloc_longest_free_extent(mp, pag);
1893 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1895 ((int)(pag->pagf_freeblks + pag->pagf_flcount -
1896 need - args->total) < (int)args->minleft)) {
1898 xfs_trans_brelse(tp, agbp);
1905 * Get the a.g. freespace buffer.
1906 * Can fail if we're not blocking on locks, and it's held.
1909 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1913 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1914 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1920 * Figure out how many blocks we should have in the freelist.
1922 agf = XFS_BUF_TO_AGF(agbp);
1923 need = XFS_MIN_FREELIST(agf, mp);
1925 * If there isn't enough total or single-extent, reject it.
1927 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1928 delta = need > be32_to_cpu(agf->agf_flcount) ?
1929 (need - be32_to_cpu(agf->agf_flcount)) : 0;
1930 longest = be32_to_cpu(agf->agf_longest);
1931 longest = (longest > delta) ? (longest - delta) :
1932 (be32_to_cpu(agf->agf_flcount) > 0 || longest > 0);
1933 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1935 ((int)(be32_to_cpu(agf->agf_freeblks) +
1936 be32_to_cpu(agf->agf_flcount) - need - args->total) <
1937 (int)args->minleft)) {
1938 xfs_trans_brelse(tp, agbp);
1944 * Make the freelist shorter if it's too long.
1946 while (be32_to_cpu(agf->agf_flcount) > need) {
1949 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
1952 if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
1954 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
1955 xfs_trans_binval(tp, bp);
1958 * Initialize the args structure.
1960 memset(&targs, 0, sizeof(targs));
1964 targs.agno = args->agno;
1965 targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
1966 targs.type = XFS_ALLOCTYPE_THIS_AG;
1968 if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
1971 * Make the freelist longer if it's too short.
1973 while (be32_to_cpu(agf->agf_flcount) < need) {
1975 targs.maxlen = need - be32_to_cpu(agf->agf_flcount);
1977 * Allocate as many blocks as possible at once.
1979 if ((error = xfs_alloc_ag_vextent(&targs))) {
1980 xfs_trans_brelse(tp, agflbp);
1984 * Stop if we run out. Won't happen if callers are obeying
1985 * the restrictions correctly. Can happen for free calls
1986 * on a completely full ag.
1988 if (targs.agbno == NULLAGBLOCK) {
1989 if (flags & XFS_ALLOC_FLAG_FREEING)
1991 xfs_trans_brelse(tp, agflbp);
1996 * Put each allocated block on the list.
1998 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
1999 error = xfs_alloc_put_freelist(tp, agbp,
2005 xfs_trans_brelse(tp, agflbp);
2011 * Get a block from the freelist.
2012 * Returns with the buffer for the block gotten.
2015 xfs_alloc_get_freelist(
2016 xfs_trans_t *tp, /* transaction pointer */
2017 xfs_buf_t *agbp, /* buffer containing the agf structure */
2018 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2019 int btreeblk) /* destination is a AGF btree */
2021 xfs_agf_t *agf; /* a.g. freespace structure */
2022 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2023 xfs_agblock_t bno; /* block number returned */
2027 xfs_mount_t *mp = tp->t_mountp;
2028 xfs_perag_t *pag; /* per allocation group data */
2031 * Freelist is empty, give up.
2033 agf = XFS_BUF_TO_AGF(agbp);
2034 if (!agf->agf_flcount) {
2035 *bnop = NULLAGBLOCK;
2039 * Read the array of free blocks.
2041 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2048 * Get the block number and update the data structures.
2050 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2051 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2052 be32_add_cpu(&agf->agf_flfirst, 1);
2053 xfs_trans_brelse(tp, agflbp);
2054 if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
2055 agf->agf_flfirst = 0;
2057 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2058 be32_add_cpu(&agf->agf_flcount, -1);
2059 xfs_trans_agflist_delta(tp, -1);
2060 pag->pagf_flcount--;
2063 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2065 be32_add_cpu(&agf->agf_btreeblks, 1);
2066 pag->pagf_btreeblks++;
2067 logflags |= XFS_AGF_BTREEBLKS;
2070 xfs_alloc_log_agf(tp, agbp, logflags);
2077 * Log the given fields from the agf structure.
2081 xfs_trans_t *tp, /* transaction pointer */
2082 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2083 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2085 int first; /* first byte offset */
2086 int last; /* last byte offset */
2087 static const short offsets[] = {
2088 offsetof(xfs_agf_t, agf_magicnum),
2089 offsetof(xfs_agf_t, agf_versionnum),
2090 offsetof(xfs_agf_t, agf_seqno),
2091 offsetof(xfs_agf_t, agf_length),
2092 offsetof(xfs_agf_t, agf_roots[0]),
2093 offsetof(xfs_agf_t, agf_levels[0]),
2094 offsetof(xfs_agf_t, agf_flfirst),
2095 offsetof(xfs_agf_t, agf_fllast),
2096 offsetof(xfs_agf_t, agf_flcount),
2097 offsetof(xfs_agf_t, agf_freeblks),
2098 offsetof(xfs_agf_t, agf_longest),
2099 offsetof(xfs_agf_t, agf_btreeblks),
2100 offsetof(xfs_agf_t, agf_uuid),
2104 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2106 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
2108 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2109 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2113 * Interface for inode allocation to force the pag data to be initialized.
2116 xfs_alloc_pagf_init(
2117 xfs_mount_t *mp, /* file system mount structure */
2118 xfs_trans_t *tp, /* transaction pointer */
2119 xfs_agnumber_t agno, /* allocation group number */
2120 int flags) /* XFS_ALLOC_FLAGS_... */
2125 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2128 xfs_trans_brelse(tp, bp);
2133 * Put the block on the freelist for the allocation group.
2136 xfs_alloc_put_freelist(
2137 xfs_trans_t *tp, /* transaction pointer */
2138 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2139 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2140 xfs_agblock_t bno, /* block being freed */
2141 int btreeblk) /* block came from a AGF btree */
2143 xfs_agf_t *agf; /* a.g. freespace structure */
2144 __be32 *blockp;/* pointer to array entry */
2147 xfs_mount_t *mp; /* mount structure */
2148 xfs_perag_t *pag; /* per allocation group data */
2152 agf = XFS_BUF_TO_AGF(agbp);
2155 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2156 be32_to_cpu(agf->agf_seqno), &agflbp)))
2158 be32_add_cpu(&agf->agf_fllast, 1);
2159 if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
2160 agf->agf_fllast = 0;
2162 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2163 be32_add_cpu(&agf->agf_flcount, 1);
2164 xfs_trans_agflist_delta(tp, 1);
2165 pag->pagf_flcount++;
2167 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2169 be32_add_cpu(&agf->agf_btreeblks, -1);
2170 pag->pagf_btreeblks--;
2171 logflags |= XFS_AGF_BTREEBLKS;
2175 xfs_alloc_log_agf(tp, agbp, logflags);
2177 ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
2179 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2180 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
2181 *blockp = cpu_to_be32(bno);
2182 startoff = (char *)blockp - (char *)agflbp->b_addr;
2184 xfs_alloc_log_agf(tp, agbp, logflags);
2186 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
2187 xfs_trans_log_buf(tp, agflbp, startoff,
2188 startoff + sizeof(xfs_agblock_t) - 1);
2194 struct xfs_mount *mp,
2197 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
2199 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2200 !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
2203 if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
2204 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2205 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2206 be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
2207 be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
2208 be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
2211 if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS ||
2212 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS)
2216 * during growfs operations, the perag is not fully initialised,
2217 * so we can't use it for any useful checking. growfs ensures we can't
2218 * use it by using uncached buffers that don't have the perag attached
2219 * so we can detect and avoid this problem.
2221 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2224 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2225 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2233 xfs_agf_read_verify(
2236 struct xfs_mount *mp = bp->b_target->bt_mount;
2238 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2239 !xfs_buf_verify_cksum(bp, XFS_AGF_CRC_OFF))
2240 xfs_buf_ioerror(bp, -EFSBADCRC);
2241 else if (XFS_TEST_ERROR(!xfs_agf_verify(mp, bp), mp,
2242 XFS_ERRTAG_ALLOC_READ_AGF,
2243 XFS_RANDOM_ALLOC_READ_AGF))
2244 xfs_buf_ioerror(bp, -EFSCORRUPTED);
2247 xfs_verifier_error(bp);
2251 xfs_agf_write_verify(
2254 struct xfs_mount *mp = bp->b_target->bt_mount;
2255 struct xfs_buf_log_item *bip = bp->b_fspriv;
2257 if (!xfs_agf_verify(mp, bp)) {
2258 xfs_buf_ioerror(bp, -EFSCORRUPTED);
2259 xfs_verifier_error(bp);
2263 if (!xfs_sb_version_hascrc(&mp->m_sb))
2267 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2269 xfs_buf_update_cksum(bp, XFS_AGF_CRC_OFF);
2272 const struct xfs_buf_ops xfs_agf_buf_ops = {
2273 .verify_read = xfs_agf_read_verify,
2274 .verify_write = xfs_agf_write_verify,
2278 * Read in the allocation group header (free/alloc section).
2282 struct xfs_mount *mp, /* mount point structure */
2283 struct xfs_trans *tp, /* transaction pointer */
2284 xfs_agnumber_t agno, /* allocation group number */
2285 int flags, /* XFS_BUF_ */
2286 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2290 trace_xfs_read_agf(mp, agno);
2292 ASSERT(agno != NULLAGNUMBER);
2293 error = xfs_trans_read_buf(
2294 mp, tp, mp->m_ddev_targp,
2295 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2296 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
2302 ASSERT(!(*bpp)->b_error);
2303 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
2308 * Read in the allocation group header (free/alloc section).
2312 struct xfs_mount *mp, /* mount point structure */
2313 struct xfs_trans *tp, /* transaction pointer */
2314 xfs_agnumber_t agno, /* allocation group number */
2315 int flags, /* XFS_ALLOC_FLAG_... */
2316 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2318 struct xfs_agf *agf; /* ag freelist header */
2319 struct xfs_perag *pag; /* per allocation group data */
2322 trace_xfs_alloc_read_agf(mp, agno);
2324 ASSERT(agno != NULLAGNUMBER);
2325 error = xfs_read_agf(mp, tp, agno,
2326 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
2332 ASSERT(!(*bpp)->b_error);
2334 agf = XFS_BUF_TO_AGF(*bpp);
2335 pag = xfs_perag_get(mp, agno);
2336 if (!pag->pagf_init) {
2337 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2338 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
2339 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2340 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2341 pag->pagf_levels[XFS_BTNUM_BNOi] =
2342 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2343 pag->pagf_levels[XFS_BTNUM_CNTi] =
2344 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2345 spin_lock_init(&pag->pagb_lock);
2346 pag->pagb_count = 0;
2347 pag->pagb_tree = RB_ROOT;
2351 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2352 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2353 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
2354 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2355 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2356 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2357 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2358 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2359 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2367 * Allocate an extent (variable-size).
2368 * Depending on the allocation type, we either look in a single allocation
2369 * group or loop over the allocation groups to find the result.
2373 xfs_alloc_arg_t *args) /* allocation argument structure */
2375 xfs_agblock_t agsize; /* allocation group size */
2377 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2378 xfs_extlen_t minleft;/* minimum left value, temp copy */
2379 xfs_mount_t *mp; /* mount structure pointer */
2380 xfs_agnumber_t sagno; /* starting allocation group number */
2381 xfs_alloctype_t type; /* input allocation type */
2384 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2387 type = args->otype = args->type;
2388 args->agbno = NULLAGBLOCK;
2390 * Just fix this up, for the case where the last a.g. is shorter
2391 * (or there's only one a.g.) and the caller couldn't easily figure
2392 * that out (xfs_bmap_alloc).
2394 agsize = mp->m_sb.sb_agblocks;
2395 if (args->maxlen > agsize)
2396 args->maxlen = agsize;
2397 if (args->alignment == 0)
2398 args->alignment = 1;
2399 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2400 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2401 ASSERT(args->minlen <= args->maxlen);
2402 ASSERT(args->minlen <= agsize);
2403 ASSERT(args->mod < args->prod);
2404 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2405 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2406 args->minlen > args->maxlen || args->minlen > agsize ||
2407 args->mod >= args->prod) {
2408 args->fsbno = NULLFSBLOCK;
2409 trace_xfs_alloc_vextent_badargs(args);
2412 minleft = args->minleft;
2415 case XFS_ALLOCTYPE_THIS_AG:
2416 case XFS_ALLOCTYPE_NEAR_BNO:
2417 case XFS_ALLOCTYPE_THIS_BNO:
2419 * These three force us into a single a.g.
2421 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2422 args->pag = xfs_perag_get(mp, args->agno);
2424 error = xfs_alloc_fix_freelist(args, 0);
2425 args->minleft = minleft;
2427 trace_xfs_alloc_vextent_nofix(args);
2431 trace_xfs_alloc_vextent_noagbp(args);
2434 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2435 if ((error = xfs_alloc_ag_vextent(args)))
2438 case XFS_ALLOCTYPE_START_BNO:
2440 * Try near allocation first, then anywhere-in-ag after
2441 * the first a.g. fails.
2443 if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
2444 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2445 args->fsbno = XFS_AGB_TO_FSB(mp,
2446 ((mp->m_agfrotor / rotorstep) %
2447 mp->m_sb.sb_agcount), 0);
2450 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2451 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2453 case XFS_ALLOCTYPE_ANY_AG:
2454 case XFS_ALLOCTYPE_START_AG:
2455 case XFS_ALLOCTYPE_FIRST_AG:
2457 * Rotate through the allocation groups looking for a winner.
2459 if (type == XFS_ALLOCTYPE_ANY_AG) {
2461 * Start with the last place we left off.
2463 args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2464 mp->m_sb.sb_agcount;
2465 args->type = XFS_ALLOCTYPE_THIS_AG;
2466 flags = XFS_ALLOC_FLAG_TRYLOCK;
2467 } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2469 * Start with allocation group given by bno.
2471 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2472 args->type = XFS_ALLOCTYPE_THIS_AG;
2476 if (type == XFS_ALLOCTYPE_START_AG)
2477 args->type = XFS_ALLOCTYPE_THIS_AG;
2479 * Start with the given allocation group.
2481 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2482 flags = XFS_ALLOC_FLAG_TRYLOCK;
2485 * Loop over allocation groups twice; first time with
2486 * trylock set, second time without.
2489 args->pag = xfs_perag_get(mp, args->agno);
2490 if (no_min) args->minleft = 0;
2491 error = xfs_alloc_fix_freelist(args, flags);
2492 args->minleft = minleft;
2494 trace_xfs_alloc_vextent_nofix(args);
2498 * If we get a buffer back then the allocation will fly.
2501 if ((error = xfs_alloc_ag_vextent(args)))
2506 trace_xfs_alloc_vextent_loopfailed(args);
2509 * Didn't work, figure out the next iteration.
2511 if (args->agno == sagno &&
2512 type == XFS_ALLOCTYPE_START_BNO)
2513 args->type = XFS_ALLOCTYPE_THIS_AG;
2515 * For the first allocation, we can try any AG to get
2516 * space. However, if we already have allocated a
2517 * block, we don't want to try AGs whose number is below
2518 * sagno. Otherwise, we may end up with out-of-order
2519 * locking of AGF, which might cause deadlock.
2521 if (++(args->agno) == mp->m_sb.sb_agcount) {
2522 if (args->firstblock != NULLFSBLOCK)
2528 * Reached the starting a.g., must either be done
2529 * or switch to non-trylock mode.
2531 if (args->agno == sagno) {
2533 args->agbno = NULLAGBLOCK;
2534 trace_xfs_alloc_vextent_allfailed(args);
2541 if (type == XFS_ALLOCTYPE_START_BNO) {
2542 args->agbno = XFS_FSB_TO_AGBNO(mp,
2544 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2548 xfs_perag_put(args->pag);
2550 if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2551 if (args->agno == sagno)
2552 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2553 (mp->m_sb.sb_agcount * rotorstep);
2555 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2556 (mp->m_sb.sb_agcount * rotorstep);
2563 if (args->agbno == NULLAGBLOCK)
2564 args->fsbno = NULLFSBLOCK;
2566 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2568 ASSERT(args->len >= args->minlen);
2569 ASSERT(args->len <= args->maxlen);
2570 ASSERT(args->agbno % args->alignment == 0);
2571 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2575 xfs_perag_put(args->pag);
2578 xfs_perag_put(args->pag);
2584 * Just break up the extent address and hand off to xfs_free_ag_extent
2585 * after fixing up the freelist.
2589 xfs_trans_t *tp, /* transaction pointer */
2590 xfs_fsblock_t bno, /* starting block number of extent */
2591 xfs_extlen_t len) /* length of extent */
2593 xfs_alloc_arg_t args;
2597 memset(&args, 0, sizeof(xfs_alloc_arg_t));
2599 args.mp = tp->t_mountp;
2602 * validate that the block number is legal - the enables us to detect
2603 * and handle a silent filesystem corruption rather than crashing.
2605 args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
2606 if (args.agno >= args.mp->m_sb.sb_agcount)
2607 return -EFSCORRUPTED;
2609 args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
2610 if (args.agbno >= args.mp->m_sb.sb_agblocks)
2611 return -EFSCORRUPTED;
2613 args.pag = xfs_perag_get(args.mp, args.agno);
2616 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
2620 /* validate the extent size is legal now we have the agf locked */
2621 if (args.agbno + len >
2622 be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
2623 error = -EFSCORRUPTED;
2627 error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
2629 xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
2631 xfs_perag_put(args.pag);