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_types.h"
23 #include "xfs_trans.h"
26 #include "xfs_mount.h"
27 #include "xfs_bmap_btree.h"
28 #include "xfs_alloc_btree.h"
29 #include "xfs_ialloc_btree.h"
30 #include "xfs_dinode.h"
31 #include "xfs_inode.h"
32 #include "xfs_btree.h"
33 #include "xfs_alloc.h"
34 #include "xfs_extent_busy.h"
35 #include "xfs_error.h"
36 #include "xfs_cksum.h"
37 #include "xfs_trace.h"
38 #include "xfs_buf_item.h"
40 struct workqueue_struct *xfs_alloc_wq;
42 #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
44 #define XFSA_FIXUP_BNO_OK 1
45 #define XFSA_FIXUP_CNT_OK 2
47 STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
48 STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
49 STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
50 STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
51 xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
54 * Lookup the record equal to [bno, len] in the btree given by cur.
56 STATIC int /* error */
58 struct xfs_btree_cur *cur, /* btree cursor */
59 xfs_agblock_t bno, /* starting block of extent */
60 xfs_extlen_t len, /* length of extent */
61 int *stat) /* success/failure */
63 cur->bc_rec.a.ar_startblock = bno;
64 cur->bc_rec.a.ar_blockcount = len;
65 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
69 * Lookup the first record greater than or equal to [bno, len]
70 * in the btree given by cur.
74 struct xfs_btree_cur *cur, /* btree cursor */
75 xfs_agblock_t bno, /* starting block of extent */
76 xfs_extlen_t len, /* length of extent */
77 int *stat) /* success/failure */
79 cur->bc_rec.a.ar_startblock = bno;
80 cur->bc_rec.a.ar_blockcount = len;
81 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
85 * Lookup the first record less than or equal to [bno, len]
86 * in the btree given by cur.
90 struct xfs_btree_cur *cur, /* btree cursor */
91 xfs_agblock_t bno, /* starting block of extent */
92 xfs_extlen_t len, /* length of extent */
93 int *stat) /* success/failure */
95 cur->bc_rec.a.ar_startblock = bno;
96 cur->bc_rec.a.ar_blockcount = len;
97 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
101 * Update the record referred to by cur to the value given
103 * This either works (return 0) or gets an EFSCORRUPTED error.
105 STATIC int /* error */
107 struct xfs_btree_cur *cur, /* btree cursor */
108 xfs_agblock_t bno, /* starting block of extent */
109 xfs_extlen_t len) /* length of extent */
111 union xfs_btree_rec rec;
113 rec.alloc.ar_startblock = cpu_to_be32(bno);
114 rec.alloc.ar_blockcount = cpu_to_be32(len);
115 return xfs_btree_update(cur, &rec);
119 * Get the data from the pointed-to record.
123 struct xfs_btree_cur *cur, /* btree cursor */
124 xfs_agblock_t *bno, /* output: starting block of extent */
125 xfs_extlen_t *len, /* output: length of extent */
126 int *stat) /* output: success/failure */
128 union xfs_btree_rec *rec;
131 error = xfs_btree_get_rec(cur, &rec, stat);
132 if (!error && *stat == 1) {
133 *bno = be32_to_cpu(rec->alloc.ar_startblock);
134 *len = be32_to_cpu(rec->alloc.ar_blockcount);
140 * Compute aligned version of the found extent.
141 * Takes alignment and min length into account.
144 xfs_alloc_compute_aligned(
145 xfs_alloc_arg_t *args, /* allocation argument structure */
146 xfs_agblock_t foundbno, /* starting block in found extent */
147 xfs_extlen_t foundlen, /* length in found extent */
148 xfs_agblock_t *resbno, /* result block number */
149 xfs_extlen_t *reslen) /* result length */
154 /* Trim busy sections out of found extent */
155 xfs_extent_busy_trim(args, foundbno, foundlen, &bno, &len);
157 if (args->alignment > 1 && len >= args->minlen) {
158 xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
159 xfs_extlen_t diff = aligned_bno - bno;
161 *resbno = aligned_bno;
162 *reslen = diff >= len ? 0 : len - diff;
170 * Compute best start block and diff for "near" allocations.
171 * freelen >= wantlen already checked by caller.
173 STATIC xfs_extlen_t /* difference value (absolute) */
174 xfs_alloc_compute_diff(
175 xfs_agblock_t wantbno, /* target starting block */
176 xfs_extlen_t wantlen, /* target length */
177 xfs_extlen_t alignment, /* target alignment */
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;
192 if (freebno >= wantbno) {
193 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
194 newbno1 = NULLAGBLOCK;
195 } else if (freeend >= wantend && alignment > 1) {
196 newbno1 = roundup(wantbno, alignment);
197 newbno2 = newbno1 - alignment;
198 if (newbno1 >= freeend)
199 newbno1 = NULLAGBLOCK;
201 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
202 if (newbno2 < freebno)
203 newbno2 = NULLAGBLOCK;
205 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
206 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
207 if (newlen1 < newlen2 ||
208 (newlen1 == newlen2 &&
209 XFS_ABSDIFF(newbno1, wantbno) >
210 XFS_ABSDIFF(newbno2, wantbno)))
212 } else if (newbno2 != NULLAGBLOCK)
214 } else if (freeend >= wantend) {
216 } else if (alignment > 1) {
217 newbno1 = roundup(freeend - wantlen, alignment);
218 if (newbno1 > freeend - wantlen &&
219 newbno1 - alignment >= freebno)
220 newbno1 -= alignment;
221 else if (newbno1 >= freeend)
222 newbno1 = NULLAGBLOCK;
224 newbno1 = freeend - wantlen;
226 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
230 * Fix up the length, based on mod and prod.
231 * len should be k * prod + mod for some k.
232 * If len is too small it is returned unchanged.
233 * If len hits maxlen it is left alone.
237 xfs_alloc_arg_t *args) /* allocation argument structure */
242 ASSERT(args->mod < args->prod);
244 ASSERT(rlen >= args->minlen);
245 ASSERT(rlen <= args->maxlen);
246 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
247 (args->mod == 0 && rlen < args->prod))
249 k = rlen % args->prod;
253 if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
256 if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
260 ASSERT(rlen >= args->minlen);
261 ASSERT(rlen <= args->maxlen);
266 * Fix up length if there is too little space left in the a.g.
267 * Return 1 if ok, 0 if too little, should give up.
270 xfs_alloc_fix_minleft(
271 xfs_alloc_arg_t *args) /* allocation argument structure */
273 xfs_agf_t *agf; /* a.g. freelist header */
274 int diff; /* free space difference */
276 if (args->minleft == 0)
278 agf = XFS_BUF_TO_AGF(args->agbp);
279 diff = be32_to_cpu(agf->agf_freeblks)
280 - args->len - args->minleft;
283 args->len += diff; /* shrink the allocated space */
284 if (args->len >= args->minlen)
286 args->agbno = NULLAGBLOCK;
291 * Update the two btrees, logically removing from freespace the extent
292 * starting at rbno, rlen blocks. The extent is contained within the
293 * actual (current) free extent fbno for flen blocks.
294 * Flags are passed in indicating whether the cursors are set to the
297 STATIC int /* error code */
298 xfs_alloc_fixup_trees(
299 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
300 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
301 xfs_agblock_t fbno, /* starting block of free extent */
302 xfs_extlen_t flen, /* length of free extent */
303 xfs_agblock_t rbno, /* starting block of returned extent */
304 xfs_extlen_t rlen, /* length of returned extent */
305 int flags) /* flags, XFSA_FIXUP_... */
307 int error; /* error code */
308 int i; /* operation results */
309 xfs_agblock_t nfbno1; /* first new free startblock */
310 xfs_agblock_t nfbno2; /* second new free startblock */
311 xfs_extlen_t nflen1=0; /* first new free length */
312 xfs_extlen_t nflen2=0; /* second new free length */
315 * Look up the record in the by-size tree if necessary.
317 if (flags & XFSA_FIXUP_CNT_OK) {
319 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
321 XFS_WANT_CORRUPTED_RETURN(
322 i == 1 && nfbno1 == fbno && nflen1 == flen);
325 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
327 XFS_WANT_CORRUPTED_RETURN(i == 1);
330 * Look up the record in the by-block tree if necessary.
332 if (flags & XFSA_FIXUP_BNO_OK) {
334 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
336 XFS_WANT_CORRUPTED_RETURN(
337 i == 1 && nfbno1 == fbno && nflen1 == flen);
340 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
342 XFS_WANT_CORRUPTED_RETURN(i == 1);
346 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
347 struct xfs_btree_block *bnoblock;
348 struct xfs_btree_block *cntblock;
350 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
351 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
353 XFS_WANT_CORRUPTED_RETURN(
354 bnoblock->bb_numrecs == cntblock->bb_numrecs);
359 * Deal with all four cases: the allocated record is contained
360 * within the freespace record, so we can have new freespace
361 * at either (or both) end, or no freespace remaining.
363 if (rbno == fbno && rlen == flen)
364 nfbno1 = nfbno2 = NULLAGBLOCK;
365 else if (rbno == fbno) {
366 nfbno1 = rbno + rlen;
367 nflen1 = flen - rlen;
368 nfbno2 = NULLAGBLOCK;
369 } else if (rbno + rlen == fbno + flen) {
371 nflen1 = flen - rlen;
372 nfbno2 = NULLAGBLOCK;
375 nflen1 = rbno - fbno;
376 nfbno2 = rbno + rlen;
377 nflen2 = (fbno + flen) - nfbno2;
380 * Delete the entry from the by-size btree.
382 if ((error = xfs_btree_delete(cnt_cur, &i)))
384 XFS_WANT_CORRUPTED_RETURN(i == 1);
386 * Add new by-size btree entry(s).
388 if (nfbno1 != NULLAGBLOCK) {
389 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
391 XFS_WANT_CORRUPTED_RETURN(i == 0);
392 if ((error = xfs_btree_insert(cnt_cur, &i)))
394 XFS_WANT_CORRUPTED_RETURN(i == 1);
396 if (nfbno2 != NULLAGBLOCK) {
397 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
399 XFS_WANT_CORRUPTED_RETURN(i == 0);
400 if ((error = xfs_btree_insert(cnt_cur, &i)))
402 XFS_WANT_CORRUPTED_RETURN(i == 1);
405 * Fix up the by-block btree entry(s).
407 if (nfbno1 == NULLAGBLOCK) {
409 * No remaining freespace, just delete the by-block tree entry.
411 if ((error = xfs_btree_delete(bno_cur, &i)))
413 XFS_WANT_CORRUPTED_RETURN(i == 1);
416 * Update the by-block entry to start later|be shorter.
418 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
421 if (nfbno2 != NULLAGBLOCK) {
423 * 2 resulting free entries, need to add one.
425 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
427 XFS_WANT_CORRUPTED_RETURN(i == 0);
428 if ((error = xfs_btree_insert(bno_cur, &i)))
430 XFS_WANT_CORRUPTED_RETURN(i == 1);
439 struct xfs_mount *mp = bp->b_target->bt_mount;
440 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
443 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_uuid))
445 if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
448 * during growfs operations, the perag is not fully initialised,
449 * so we can't use it for any useful checking. growfs ensures we can't
450 * use it by using uncached buffers that don't have the perag attached
451 * so we can detect and avoid this problem.
453 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
456 for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
457 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
458 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
465 xfs_agfl_read_verify(
468 struct xfs_mount *mp = bp->b_target->bt_mount;
472 * There is no verification of non-crc AGFLs because mkfs does not
473 * initialise the AGFL to zero or NULL. Hence the only valid part of the
474 * AGFL is what the AGF says is active. We can't get to the AGF, so we
475 * can't verify just those entries are valid.
477 if (!xfs_sb_version_hascrc(&mp->m_sb))
480 agfl_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
481 offsetof(struct xfs_agfl, agfl_crc));
483 agfl_ok = agfl_ok && xfs_agfl_verify(bp);
486 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
487 xfs_buf_ioerror(bp, EFSCORRUPTED);
492 xfs_agfl_write_verify(
495 struct xfs_mount *mp = bp->b_target->bt_mount;
496 struct xfs_buf_log_item *bip = bp->b_fspriv;
498 /* no verification of non-crc AGFLs */
499 if (!xfs_sb_version_hascrc(&mp->m_sb))
502 if (!xfs_agfl_verify(bp)) {
503 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
504 xfs_buf_ioerror(bp, EFSCORRUPTED);
509 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
511 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
512 offsetof(struct xfs_agfl, agfl_crc));
515 const struct xfs_buf_ops xfs_agfl_buf_ops = {
516 .verify_read = xfs_agfl_read_verify,
517 .verify_write = xfs_agfl_write_verify,
521 * Read in the allocation group free block array.
523 STATIC int /* error */
525 xfs_mount_t *mp, /* mount point structure */
526 xfs_trans_t *tp, /* transaction pointer */
527 xfs_agnumber_t agno, /* allocation group number */
528 xfs_buf_t **bpp) /* buffer for the ag free block array */
530 xfs_buf_t *bp; /* return value */
533 ASSERT(agno != NULLAGNUMBER);
534 error = xfs_trans_read_buf(
535 mp, tp, mp->m_ddev_targp,
536 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
537 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
540 ASSERT(!xfs_buf_geterror(bp));
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)))
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,
808 args->alignment, *sbnoa,
812 * Choose closer size and invalidate other cursor.
820 error = xfs_btree_increment(*scur, 0, &i);
822 error = xfs_btree_decrement(*scur, 0, &i);
828 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
833 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
838 /* caller invalidates cursors */
843 * Allocate a variable extent near bno in the allocation group agno.
844 * Extent's length (returned in len) will be between minlen and maxlen,
845 * and of the form k * prod + mod unless there's nothing that large.
846 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
848 STATIC int /* error */
849 xfs_alloc_ag_vextent_near(
850 xfs_alloc_arg_t *args) /* allocation argument structure */
852 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
853 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
854 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
855 xfs_agblock_t gtbno; /* start bno of right side entry */
856 xfs_agblock_t gtbnoa; /* aligned ... */
857 xfs_extlen_t gtdiff; /* difference to right side entry */
858 xfs_extlen_t gtlen; /* length of right side entry */
859 xfs_extlen_t gtlena; /* aligned ... */
860 xfs_agblock_t gtnew; /* useful start bno of right side */
861 int error; /* error code */
862 int i; /* result code, temporary */
863 int j; /* result code, temporary */
864 xfs_agblock_t ltbno; /* start bno of left side entry */
865 xfs_agblock_t ltbnoa; /* aligned ... */
866 xfs_extlen_t ltdiff; /* difference to left side entry */
867 xfs_extlen_t ltlen; /* length of left side entry */
868 xfs_extlen_t ltlena; /* aligned ... */
869 xfs_agblock_t ltnew; /* useful start bno of left side */
870 xfs_extlen_t rlen; /* length of returned extent */
872 #if defined(DEBUG) && defined(__KERNEL__)
874 * Randomly don't execute the first algorithm.
876 int dofirst; /* set to do first algorithm */
878 dofirst = prandom_u32() & 1;
889 * Get a cursor for the by-size btree.
891 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
892 args->agno, XFS_BTNUM_CNT);
895 * See if there are any free extents as big as maxlen.
897 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
900 * If none, then pick up the last entry in the tree unless the
904 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, <bno,
907 if (i == 0 || ltlen == 0) {
908 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
909 trace_xfs_alloc_near_noentry(args);
918 * If the requested extent is large wrt the freespaces available
919 * in this a.g., then the cursor will be pointing to a btree entry
920 * near the right edge of the tree. If it's in the last btree leaf
921 * block, then we just examine all the entries in that block
922 * that are big enough, and pick the best one.
923 * This is written as a while loop so we can break out of it,
924 * but we never loop back to the top.
926 while (xfs_btree_islastblock(cnt_cur, 0)) {
930 xfs_agblock_t bnew=0;
932 #if defined(DEBUG) && defined(__KERNEL__)
937 * Start from the entry that lookup found, sequence through
938 * all larger free blocks. If we're actually pointing at a
939 * record smaller than maxlen, go to the start of this block,
940 * and skip all those smaller than minlen.
942 if (ltlen || args->alignment > 1) {
943 cnt_cur->bc_ptrs[0] = 1;
945 if ((error = xfs_alloc_get_rec(cnt_cur, <bno,
948 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
949 if (ltlen >= args->minlen)
951 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
954 ASSERT(ltlen >= args->minlen);
958 i = cnt_cur->bc_ptrs[0];
959 for (j = 1, blen = 0, bdiff = 0;
960 !error && j && (blen < args->maxlen || bdiff > 0);
961 error = xfs_btree_increment(cnt_cur, 0, &j)) {
963 * For each entry, decide if it's better than
964 * the previous best entry.
966 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
968 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
969 xfs_alloc_compute_aligned(args, ltbno, ltlen,
971 if (ltlena < args->minlen)
973 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
974 xfs_alloc_fix_len(args);
975 ASSERT(args->len >= args->minlen);
976 if (args->len < blen)
978 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
979 args->alignment, ltbnoa, ltlena, <new);
980 if (ltnew != NULLAGBLOCK &&
981 (args->len > blen || ltdiff < bdiff)) {
985 besti = cnt_cur->bc_ptrs[0];
989 * It didn't work. We COULD be in a case where
990 * there's a good record somewhere, so try again.
995 * Point at the best entry, and retrieve it again.
997 cnt_cur->bc_ptrs[0] = besti;
998 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
1000 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1001 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1003 if (!xfs_alloc_fix_minleft(args)) {
1004 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1005 trace_xfs_alloc_near_nominleft(args);
1010 * We are allocating starting at bnew for blen blocks.
1013 ASSERT(bnew >= ltbno);
1014 ASSERT(bnew + blen <= ltbno + ltlen);
1016 * Set up a cursor for the by-bno tree.
1018 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1019 args->agbp, args->agno, XFS_BTNUM_BNO);
1021 * Fix up the btree entries.
1023 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1024 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1026 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1027 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1029 trace_xfs_alloc_near_first(args);
1034 * Search in the by-bno tree to the left and to the right
1035 * simultaneously, until in each case we find a space big enough,
1036 * or run into the edge of the tree. When we run into the edge,
1037 * we deallocate that cursor.
1038 * If both searches succeed, we compare the two spaces and pick
1040 * With alignment, it's possible for both to fail; the upper
1041 * level algorithm that picks allocation groups for allocations
1042 * is not supposed to do this.
1045 * Allocate and initialize the cursor for the leftward search.
1047 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1048 args->agno, XFS_BTNUM_BNO);
1050 * Lookup <= bno to find the leftward search's starting point.
1052 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1056 * Didn't find anything; use this cursor for the rightward
1059 bno_cur_gt = bno_cur_lt;
1063 * Found something. Duplicate the cursor for the rightward search.
1065 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1068 * Increment the cursor, so we will point at the entry just right
1069 * of the leftward entry if any, or to the leftmost entry.
1071 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1075 * It failed, there are no rightward entries.
1077 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1081 * Loop going left with the leftward cursor, right with the
1082 * rightward cursor, until either both directions give up or
1083 * we find an entry at least as big as minlen.
1087 if ((error = xfs_alloc_get_rec(bno_cur_lt, <bno, <len, &i)))
1089 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1090 xfs_alloc_compute_aligned(args, ltbno, ltlen,
1092 if (ltlena >= args->minlen)
1094 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
1097 xfs_btree_del_cursor(bno_cur_lt,
1103 if ((error = xfs_alloc_get_rec(bno_cur_gt, >bno, >len, &i)))
1105 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1106 xfs_alloc_compute_aligned(args, gtbno, gtlen,
1108 if (gtlena >= args->minlen)
1110 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1113 xfs_btree_del_cursor(bno_cur_gt,
1118 } while (bno_cur_lt || bno_cur_gt);
1121 * Got both cursors still active, need to find better entry.
1123 if (bno_cur_lt && bno_cur_gt) {
1124 if (ltlena >= args->minlen) {
1126 * Left side is good, look for a right side entry.
1128 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1129 xfs_alloc_fix_len(args);
1130 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1131 args->alignment, ltbnoa, ltlena, <new);
1133 error = xfs_alloc_find_best_extent(args,
1134 &bno_cur_lt, &bno_cur_gt,
1135 ltdiff, >bno, >len,
1137 0 /* search right */);
1139 ASSERT(gtlena >= args->minlen);
1142 * Right side is good, look for a left side entry.
1144 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1145 xfs_alloc_fix_len(args);
1146 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1147 args->alignment, gtbnoa, gtlena, >new);
1149 error = xfs_alloc_find_best_extent(args,
1150 &bno_cur_gt, &bno_cur_lt,
1151 gtdiff, <bno, <len,
1153 1 /* search left */);
1161 * If we couldn't get anything, give up.
1163 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1164 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1167 trace_xfs_alloc_near_busy(args);
1168 xfs_log_force(args->mp, XFS_LOG_SYNC);
1171 trace_xfs_alloc_size_neither(args);
1172 args->agbno = NULLAGBLOCK;
1177 * At this point we have selected a freespace entry, either to the
1178 * left or to the right. If it's on the right, copy all the
1179 * useful variables to the "left" set so we only have one
1180 * copy of this code.
1183 bno_cur_lt = bno_cur_gt;
1194 * Fix up the length and compute the useful address.
1196 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1197 xfs_alloc_fix_len(args);
1198 if (!xfs_alloc_fix_minleft(args)) {
1199 trace_xfs_alloc_near_nominleft(args);
1200 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1201 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1205 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
1206 ltbnoa, ltlena, <new);
1207 ASSERT(ltnew >= ltbno);
1208 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
1209 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1210 args->agbno = ltnew;
1212 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1213 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1217 trace_xfs_alloc_near_greater(args);
1219 trace_xfs_alloc_near_lesser(args);
1221 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1222 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1226 trace_xfs_alloc_near_error(args);
1227 if (cnt_cur != NULL)
1228 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1229 if (bno_cur_lt != NULL)
1230 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1231 if (bno_cur_gt != NULL)
1232 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1237 * Allocate a variable extent anywhere in the allocation group agno.
1238 * Extent's length (returned in len) will be between minlen and maxlen,
1239 * and of the form k * prod + mod unless there's nothing that large.
1240 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1242 STATIC int /* error */
1243 xfs_alloc_ag_vextent_size(
1244 xfs_alloc_arg_t *args) /* allocation argument structure */
1246 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1247 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1248 int error; /* error result */
1249 xfs_agblock_t fbno; /* start of found freespace */
1250 xfs_extlen_t flen; /* length of found freespace */
1251 int i; /* temp status variable */
1252 xfs_agblock_t rbno; /* returned block number */
1253 xfs_extlen_t rlen; /* length of returned extent */
1258 * Allocate and initialize a cursor for the by-size btree.
1260 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1261 args->agno, XFS_BTNUM_CNT);
1265 * Look for an entry >= maxlen+alignment-1 blocks.
1267 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1268 args->maxlen + args->alignment - 1, &i)))
1272 * If none or we have busy extents that we cannot allocate from, then
1273 * we have to settle for a smaller extent. In the case that there are
1274 * no large extents, this will return the last entry in the tree unless
1275 * the tree is empty. In the case that there are only busy large
1276 * extents, this will return the largest small extent unless there
1277 * are no smaller extents available.
1279 if (!i || forced > 1) {
1280 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1284 if (i == 0 || flen == 0) {
1285 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1286 trace_xfs_alloc_size_noentry(args);
1290 xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
1293 * Search for a non-busy extent that is large enough.
1294 * If we are at low space, don't check, or if we fall of
1295 * the end of the btree, turn off the busy check and
1299 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1302 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1304 xfs_alloc_compute_aligned(args, fbno, flen,
1307 if (rlen >= args->maxlen)
1310 error = xfs_btree_increment(cnt_cur, 0, &i);
1315 * Our only valid extents must have been busy.
1316 * Make it unbusy by forcing the log out and
1317 * retrying. If we've been here before, forcing
1318 * the log isn't making the extents available,
1319 * which means they have probably been freed in
1320 * this transaction. In that case, we have to
1321 * give up on them and we'll attempt a minlen
1322 * allocation the next time around.
1324 xfs_btree_del_cursor(cnt_cur,
1326 trace_xfs_alloc_size_busy(args);
1328 xfs_log_force(args->mp, XFS_LOG_SYNC);
1335 * In the first case above, we got the last entry in the
1336 * by-size btree. Now we check to see if the space hits maxlen
1337 * once aligned; if not, we search left for something better.
1338 * This can't happen in the second case above.
1340 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1341 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1342 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1343 if (rlen < args->maxlen) {
1344 xfs_agblock_t bestfbno;
1345 xfs_extlen_t bestflen;
1346 xfs_agblock_t bestrbno;
1347 xfs_extlen_t bestrlen;
1354 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
1358 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1361 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1362 if (flen < bestrlen)
1364 xfs_alloc_compute_aligned(args, fbno, flen,
1366 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1367 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1368 (rlen <= flen && rbno + rlen <= fbno + flen),
1370 if (rlen > bestrlen) {
1375 if (rlen == args->maxlen)
1379 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1382 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1388 args->wasfromfl = 0;
1390 * Fix up the length.
1393 if (rlen < args->minlen) {
1395 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1396 trace_xfs_alloc_size_busy(args);
1397 xfs_log_force(args->mp, XFS_LOG_SYNC);
1402 xfs_alloc_fix_len(args);
1404 if (!xfs_alloc_fix_minleft(args))
1407 XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
1409 * Allocate and initialize a cursor for the by-block tree.
1411 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1412 args->agno, XFS_BTNUM_BNO);
1413 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1414 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1416 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1417 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1418 cnt_cur = bno_cur = NULL;
1421 XFS_WANT_CORRUPTED_GOTO(
1422 args->agbno + args->len <=
1423 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1425 trace_xfs_alloc_size_done(args);
1429 trace_xfs_alloc_size_error(args);
1431 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1433 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1437 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1438 trace_xfs_alloc_size_nominleft(args);
1439 args->agbno = NULLAGBLOCK;
1444 * Deal with the case where only small freespaces remain.
1445 * Either return the contents of the last freespace record,
1446 * or allocate space from the freelist if there is nothing in the tree.
1448 STATIC int /* error */
1449 xfs_alloc_ag_vextent_small(
1450 xfs_alloc_arg_t *args, /* allocation argument structure */
1451 xfs_btree_cur_t *ccur, /* by-size cursor */
1452 xfs_agblock_t *fbnop, /* result block number */
1453 xfs_extlen_t *flenp, /* result length */
1454 int *stat) /* status: 0-freelist, 1-normal/none */
1461 if ((error = xfs_btree_decrement(ccur, 0, &i)))
1464 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1466 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1469 * Nothing in the btree, try the freelist. Make sure
1470 * to respect minleft even when pulling from the
1473 else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
1474 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1476 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
1479 if (fbno != NULLAGBLOCK) {
1480 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
1483 if (args->userdata) {
1486 bp = xfs_btree_get_bufs(args->mp, args->tp,
1487 args->agno, fbno, 0);
1488 xfs_trans_binval(args->tp, bp);
1492 XFS_WANT_CORRUPTED_GOTO(
1493 args->agbno + args->len <=
1494 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1496 args->wasfromfl = 1;
1497 trace_xfs_alloc_small_freelist(args);
1502 * Nothing in the freelist.
1508 * Can't allocate from the freelist for some reason.
1515 * Can't do the allocation, give up.
1517 if (flen < args->minlen) {
1518 args->agbno = NULLAGBLOCK;
1519 trace_xfs_alloc_small_notenough(args);
1525 trace_xfs_alloc_small_done(args);
1529 trace_xfs_alloc_small_error(args);
1534 * Free the extent starting at agno/bno for length.
1536 STATIC int /* error */
1538 xfs_trans_t *tp, /* transaction pointer */
1539 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
1540 xfs_agnumber_t agno, /* allocation group number */
1541 xfs_agblock_t bno, /* starting block number */
1542 xfs_extlen_t len, /* length of extent */
1543 int isfl) /* set if is freelist blocks - no sb acctg */
1545 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1546 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1547 int error; /* error return value */
1548 xfs_agblock_t gtbno; /* start of right neighbor block */
1549 xfs_extlen_t gtlen; /* length of right neighbor block */
1550 int haveleft; /* have a left neighbor block */
1551 int haveright; /* have a right neighbor block */
1552 int i; /* temp, result code */
1553 xfs_agblock_t ltbno; /* start of left neighbor block */
1554 xfs_extlen_t ltlen; /* length of left neighbor block */
1555 xfs_mount_t *mp; /* mount point struct for filesystem */
1556 xfs_agblock_t nbno; /* new starting block of freespace */
1557 xfs_extlen_t nlen; /* new length of freespace */
1558 xfs_perag_t *pag; /* per allocation group data */
1562 * Allocate and initialize a cursor for the by-block btree.
1564 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
1567 * Look for a neighboring block on the left (lower block numbers)
1568 * that is contiguous with this space.
1570 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1574 * There is a block to our left.
1576 if ((error = xfs_alloc_get_rec(bno_cur, <bno, <len, &i)))
1578 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1580 * It's not contiguous, though.
1582 if (ltbno + ltlen < bno)
1586 * If this failure happens the request to free this
1587 * space was invalid, it's (partly) already free.
1590 XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
1594 * Look for a neighboring block on the right (higher block numbers)
1595 * that is contiguous with this space.
1597 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
1601 * There is a block to our right.
1603 if ((error = xfs_alloc_get_rec(bno_cur, >bno, >len, &i)))
1605 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1607 * It's not contiguous, though.
1609 if (bno + len < gtbno)
1613 * If this failure happens the request to free this
1614 * space was invalid, it's (partly) already free.
1617 XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
1621 * Now allocate and initialize a cursor for the by-size tree.
1623 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
1625 * Have both left and right contiguous neighbors.
1626 * Merge all three into a single free block.
1628 if (haveleft && haveright) {
1630 * Delete the old by-size entry on the left.
1632 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1634 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1635 if ((error = xfs_btree_delete(cnt_cur, &i)))
1637 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1639 * Delete the old by-size entry on the right.
1641 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1643 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1644 if ((error = xfs_btree_delete(cnt_cur, &i)))
1646 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1648 * Delete the old by-block entry for the right block.
1650 if ((error = xfs_btree_delete(bno_cur, &i)))
1652 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1654 * Move the by-block cursor back to the left neighbor.
1656 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1658 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1661 * Check that this is the right record: delete didn't
1662 * mangle the cursor.
1665 xfs_agblock_t xxbno;
1668 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1671 XFS_WANT_CORRUPTED_GOTO(
1672 i == 1 && xxbno == ltbno && xxlen == ltlen,
1677 * Update remaining by-block entry to the new, joined block.
1680 nlen = len + ltlen + gtlen;
1681 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1685 * Have only a left contiguous neighbor.
1686 * Merge it together with the new freespace.
1688 else if (haveleft) {
1690 * Delete the old by-size entry on the left.
1692 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1694 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1695 if ((error = xfs_btree_delete(cnt_cur, &i)))
1697 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1699 * Back up the by-block cursor to the left neighbor, and
1700 * update its length.
1702 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1704 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1707 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1711 * Have only a right contiguous neighbor.
1712 * Merge it together with the new freespace.
1714 else if (haveright) {
1716 * Delete the old by-size entry on the right.
1718 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1720 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1721 if ((error = xfs_btree_delete(cnt_cur, &i)))
1723 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1725 * Update the starting block and length of the right
1726 * neighbor in the by-block tree.
1730 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1734 * No contiguous neighbors.
1735 * Insert the new freespace into the by-block tree.
1740 if ((error = xfs_btree_insert(bno_cur, &i)))
1742 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1744 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1747 * In all cases we need to insert the new freespace in the by-size tree.
1749 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1751 XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
1752 if ((error = xfs_btree_insert(cnt_cur, &i)))
1754 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1755 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1759 * Update the freespace totals in the ag and superblock.
1761 pag = xfs_perag_get(mp, agno);
1762 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1768 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1769 XFS_STATS_INC(xs_freex);
1770 XFS_STATS_ADD(xs_freeb, len);
1772 trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
1777 trace_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
1779 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1781 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1786 * Visible (exported) allocation/free functions.
1787 * Some of these are used just by xfs_alloc_btree.c and this file.
1791 * Compute and fill in value of m_ag_maxlevels.
1794 xfs_alloc_compute_maxlevels(
1795 xfs_mount_t *mp) /* file system mount structure */
1803 maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1804 minleafrecs = mp->m_alloc_mnr[0];
1805 minnoderecs = mp->m_alloc_mnr[1];
1806 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1807 for (level = 1; maxblocks > 1; level++)
1808 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1809 mp->m_ag_maxlevels = level;
1813 * Find the length of the longest extent in an AG.
1816 xfs_alloc_longest_free_extent(
1817 struct xfs_mount *mp,
1818 struct xfs_perag *pag)
1820 xfs_extlen_t need, delta = 0;
1822 need = XFS_MIN_FREELIST_PAG(pag, mp);
1823 if (need > pag->pagf_flcount)
1824 delta = need - pag->pagf_flcount;
1826 if (pag->pagf_longest > delta)
1827 return pag->pagf_longest - delta;
1828 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1832 * Decide whether to use this allocation group for this allocation.
1833 * If so, fix up the btree freelist's size.
1835 STATIC int /* error */
1836 xfs_alloc_fix_freelist(
1837 xfs_alloc_arg_t *args, /* allocation argument structure */
1838 int flags) /* XFS_ALLOC_FLAG_... */
1840 xfs_buf_t *agbp; /* agf buffer pointer */
1841 xfs_agf_t *agf; /* a.g. freespace structure pointer */
1842 xfs_buf_t *agflbp;/* agfl buffer pointer */
1843 xfs_agblock_t bno; /* freelist block */
1844 xfs_extlen_t delta; /* new blocks needed in freelist */
1845 int error; /* error result code */
1846 xfs_extlen_t longest;/* longest extent in allocation group */
1847 xfs_mount_t *mp; /* file system mount point structure */
1848 xfs_extlen_t need; /* total blocks needed in freelist */
1849 xfs_perag_t *pag; /* per-ag information structure */
1850 xfs_alloc_arg_t targs; /* local allocation arguments */
1851 xfs_trans_t *tp; /* transaction pointer */
1857 if (!pag->pagf_init) {
1858 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1861 if (!pag->pagf_init) {
1862 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1863 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1871 * If this is a metadata preferred pag and we are user data
1872 * then try somewhere else if we are not being asked to
1873 * try harder at this point
1875 if (pag->pagf_metadata && args->userdata &&
1876 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
1877 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1882 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1884 * If it looks like there isn't a long enough extent, or enough
1885 * total blocks, reject it.
1887 need = XFS_MIN_FREELIST_PAG(pag, mp);
1888 longest = xfs_alloc_longest_free_extent(mp, pag);
1889 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1891 ((int)(pag->pagf_freeblks + pag->pagf_flcount -
1892 need - args->total) < (int)args->minleft)) {
1894 xfs_trans_brelse(tp, agbp);
1901 * Get the a.g. freespace buffer.
1902 * Can fail if we're not blocking on locks, and it's held.
1905 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1909 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1910 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1916 * Figure out how many blocks we should have in the freelist.
1918 agf = XFS_BUF_TO_AGF(agbp);
1919 need = XFS_MIN_FREELIST(agf, mp);
1921 * If there isn't enough total or single-extent, reject it.
1923 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1924 delta = need > be32_to_cpu(agf->agf_flcount) ?
1925 (need - be32_to_cpu(agf->agf_flcount)) : 0;
1926 longest = be32_to_cpu(agf->agf_longest);
1927 longest = (longest > delta) ? (longest - delta) :
1928 (be32_to_cpu(agf->agf_flcount) > 0 || longest > 0);
1929 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1931 ((int)(be32_to_cpu(agf->agf_freeblks) +
1932 be32_to_cpu(agf->agf_flcount) - need - args->total) <
1933 (int)args->minleft)) {
1934 xfs_trans_brelse(tp, agbp);
1940 * Make the freelist shorter if it's too long.
1942 while (be32_to_cpu(agf->agf_flcount) > need) {
1945 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
1948 if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
1950 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
1951 xfs_trans_binval(tp, bp);
1954 * Initialize the args structure.
1956 memset(&targs, 0, sizeof(targs));
1960 targs.agno = args->agno;
1961 targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
1962 targs.type = XFS_ALLOCTYPE_THIS_AG;
1964 if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
1967 * Make the freelist longer if it's too short.
1969 while (be32_to_cpu(agf->agf_flcount) < need) {
1971 targs.maxlen = need - be32_to_cpu(agf->agf_flcount);
1973 * Allocate as many blocks as possible at once.
1975 if ((error = xfs_alloc_ag_vextent(&targs))) {
1976 xfs_trans_brelse(tp, agflbp);
1980 * Stop if we run out. Won't happen if callers are obeying
1981 * the restrictions correctly. Can happen for free calls
1982 * on a completely full ag.
1984 if (targs.agbno == NULLAGBLOCK) {
1985 if (flags & XFS_ALLOC_FLAG_FREEING)
1987 xfs_trans_brelse(tp, agflbp);
1992 * Put each allocated block on the list.
1994 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
1995 error = xfs_alloc_put_freelist(tp, agbp,
2001 xfs_trans_brelse(tp, agflbp);
2007 * Get a block from the freelist.
2008 * Returns with the buffer for the block gotten.
2011 xfs_alloc_get_freelist(
2012 xfs_trans_t *tp, /* transaction pointer */
2013 xfs_buf_t *agbp, /* buffer containing the agf structure */
2014 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2015 int btreeblk) /* destination is a AGF btree */
2017 xfs_agf_t *agf; /* a.g. freespace structure */
2018 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2019 xfs_agblock_t bno; /* block number returned */
2023 xfs_mount_t *mp = tp->t_mountp;
2024 xfs_perag_t *pag; /* per allocation group data */
2027 * Freelist is empty, give up.
2029 agf = XFS_BUF_TO_AGF(agbp);
2030 if (!agf->agf_flcount) {
2031 *bnop = NULLAGBLOCK;
2035 * Read the array of free blocks.
2037 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2044 * Get the block number and update the data structures.
2046 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2047 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2048 be32_add_cpu(&agf->agf_flfirst, 1);
2049 xfs_trans_brelse(tp, agflbp);
2050 if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
2051 agf->agf_flfirst = 0;
2053 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2054 be32_add_cpu(&agf->agf_flcount, -1);
2055 xfs_trans_agflist_delta(tp, -1);
2056 pag->pagf_flcount--;
2059 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2061 be32_add_cpu(&agf->agf_btreeblks, 1);
2062 pag->pagf_btreeblks++;
2063 logflags |= XFS_AGF_BTREEBLKS;
2066 xfs_alloc_log_agf(tp, agbp, logflags);
2073 * Log the given fields from the agf structure.
2077 xfs_trans_t *tp, /* transaction pointer */
2078 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2079 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2081 int first; /* first byte offset */
2082 int last; /* last byte offset */
2083 static const short offsets[] = {
2084 offsetof(xfs_agf_t, agf_magicnum),
2085 offsetof(xfs_agf_t, agf_versionnum),
2086 offsetof(xfs_agf_t, agf_seqno),
2087 offsetof(xfs_agf_t, agf_length),
2088 offsetof(xfs_agf_t, agf_roots[0]),
2089 offsetof(xfs_agf_t, agf_levels[0]),
2090 offsetof(xfs_agf_t, agf_flfirst),
2091 offsetof(xfs_agf_t, agf_fllast),
2092 offsetof(xfs_agf_t, agf_flcount),
2093 offsetof(xfs_agf_t, agf_freeblks),
2094 offsetof(xfs_agf_t, agf_longest),
2095 offsetof(xfs_agf_t, agf_btreeblks),
2096 offsetof(xfs_agf_t, agf_uuid),
2100 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2102 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
2104 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2105 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2109 * Interface for inode allocation to force the pag data to be initialized.
2112 xfs_alloc_pagf_init(
2113 xfs_mount_t *mp, /* file system mount structure */
2114 xfs_trans_t *tp, /* transaction pointer */
2115 xfs_agnumber_t agno, /* allocation group number */
2116 int flags) /* XFS_ALLOC_FLAGS_... */
2121 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2124 xfs_trans_brelse(tp, bp);
2129 * Put the block on the freelist for the allocation group.
2132 xfs_alloc_put_freelist(
2133 xfs_trans_t *tp, /* transaction pointer */
2134 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2135 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2136 xfs_agblock_t bno, /* block being freed */
2137 int btreeblk) /* block came from a AGF btree */
2139 xfs_agf_t *agf; /* a.g. freespace structure */
2140 __be32 *blockp;/* pointer to array entry */
2143 xfs_mount_t *mp; /* mount structure */
2144 xfs_perag_t *pag; /* per allocation group data */
2148 agf = XFS_BUF_TO_AGF(agbp);
2151 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2152 be32_to_cpu(agf->agf_seqno), &agflbp)))
2154 be32_add_cpu(&agf->agf_fllast, 1);
2155 if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
2156 agf->agf_fllast = 0;
2158 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2159 be32_add_cpu(&agf->agf_flcount, 1);
2160 xfs_trans_agflist_delta(tp, 1);
2161 pag->pagf_flcount++;
2163 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2165 be32_add_cpu(&agf->agf_btreeblks, -1);
2166 pag->pagf_btreeblks--;
2167 logflags |= XFS_AGF_BTREEBLKS;
2171 xfs_alloc_log_agf(tp, agbp, logflags);
2173 ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
2175 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2176 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
2177 *blockp = cpu_to_be32(bno);
2178 startoff = (char *)blockp - (char *)agflbp->b_addr;
2180 xfs_alloc_log_agf(tp, agbp, logflags);
2182 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
2183 xfs_trans_log_buf(tp, agflbp, startoff,
2184 startoff + sizeof(xfs_agblock_t) - 1);
2190 struct xfs_mount *mp,
2193 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
2195 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2196 !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
2199 if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
2200 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2201 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2202 be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
2203 be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
2204 be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
2208 * during growfs operations, the perag is not fully initialised,
2209 * so we can't use it for any useful checking. growfs ensures we can't
2210 * use it by using uncached buffers that don't have the perag attached
2211 * so we can detect and avoid this problem.
2213 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2216 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2217 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2225 xfs_agf_read_verify(
2228 struct xfs_mount *mp = bp->b_target->bt_mount;
2231 if (xfs_sb_version_hascrc(&mp->m_sb))
2232 agf_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
2233 offsetof(struct xfs_agf, agf_crc));
2235 agf_ok = agf_ok && xfs_agf_verify(mp, bp);
2237 if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
2238 XFS_RANDOM_ALLOC_READ_AGF))) {
2239 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
2240 xfs_buf_ioerror(bp, EFSCORRUPTED);
2245 xfs_agf_write_verify(
2248 struct xfs_mount *mp = bp->b_target->bt_mount;
2249 struct xfs_buf_log_item *bip = bp->b_fspriv;
2251 if (!xfs_agf_verify(mp, bp)) {
2252 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
2253 xfs_buf_ioerror(bp, EFSCORRUPTED);
2257 if (!xfs_sb_version_hascrc(&mp->m_sb))
2261 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2263 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
2264 offsetof(struct xfs_agf, agf_crc));
2267 const struct xfs_buf_ops xfs_agf_buf_ops = {
2268 .verify_read = xfs_agf_read_verify,
2269 .verify_write = xfs_agf_write_verify,
2273 * Read in the allocation group header (free/alloc section).
2277 struct xfs_mount *mp, /* mount point structure */
2278 struct xfs_trans *tp, /* transaction pointer */
2279 xfs_agnumber_t agno, /* allocation group number */
2280 int flags, /* XFS_BUF_ */
2281 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2285 ASSERT(agno != NULLAGNUMBER);
2286 error = xfs_trans_read_buf(
2287 mp, tp, mp->m_ddev_targp,
2288 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2289 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
2295 ASSERT(!(*bpp)->b_error);
2296 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
2301 * Read in the allocation group header (free/alloc section).
2305 struct xfs_mount *mp, /* mount point structure */
2306 struct xfs_trans *tp, /* transaction pointer */
2307 xfs_agnumber_t agno, /* allocation group number */
2308 int flags, /* XFS_ALLOC_FLAG_... */
2309 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2311 struct xfs_agf *agf; /* ag freelist header */
2312 struct xfs_perag *pag; /* per allocation group data */
2315 ASSERT(agno != NULLAGNUMBER);
2317 error = xfs_read_agf(mp, tp, agno,
2318 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
2324 ASSERT(!(*bpp)->b_error);
2326 agf = XFS_BUF_TO_AGF(*bpp);
2327 pag = xfs_perag_get(mp, agno);
2328 if (!pag->pagf_init) {
2329 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2330 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
2331 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2332 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2333 pag->pagf_levels[XFS_BTNUM_BNOi] =
2334 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2335 pag->pagf_levels[XFS_BTNUM_CNTi] =
2336 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2337 spin_lock_init(&pag->pagb_lock);
2338 pag->pagb_count = 0;
2339 pag->pagb_tree = RB_ROOT;
2343 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2344 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2345 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
2346 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2347 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2348 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2349 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2350 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2351 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2359 * Allocate an extent (variable-size).
2360 * Depending on the allocation type, we either look in a single allocation
2361 * group or loop over the allocation groups to find the result.
2365 xfs_alloc_arg_t *args) /* allocation argument structure */
2367 xfs_agblock_t agsize; /* allocation group size */
2369 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2370 xfs_extlen_t minleft;/* minimum left value, temp copy */
2371 xfs_mount_t *mp; /* mount structure pointer */
2372 xfs_agnumber_t sagno; /* starting allocation group number */
2373 xfs_alloctype_t type; /* input allocation type */
2376 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2379 type = args->otype = args->type;
2380 args->agbno = NULLAGBLOCK;
2382 * Just fix this up, for the case where the last a.g. is shorter
2383 * (or there's only one a.g.) and the caller couldn't easily figure
2384 * that out (xfs_bmap_alloc).
2386 agsize = mp->m_sb.sb_agblocks;
2387 if (args->maxlen > agsize)
2388 args->maxlen = agsize;
2389 if (args->alignment == 0)
2390 args->alignment = 1;
2391 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2392 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2393 ASSERT(args->minlen <= args->maxlen);
2394 ASSERT(args->minlen <= agsize);
2395 ASSERT(args->mod < args->prod);
2396 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2397 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2398 args->minlen > args->maxlen || args->minlen > agsize ||
2399 args->mod >= args->prod) {
2400 args->fsbno = NULLFSBLOCK;
2401 trace_xfs_alloc_vextent_badargs(args);
2404 minleft = args->minleft;
2407 case XFS_ALLOCTYPE_THIS_AG:
2408 case XFS_ALLOCTYPE_NEAR_BNO:
2409 case XFS_ALLOCTYPE_THIS_BNO:
2411 * These three force us into a single a.g.
2413 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2414 args->pag = xfs_perag_get(mp, args->agno);
2416 error = xfs_alloc_fix_freelist(args, 0);
2417 args->minleft = minleft;
2419 trace_xfs_alloc_vextent_nofix(args);
2423 trace_xfs_alloc_vextent_noagbp(args);
2426 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2427 if ((error = xfs_alloc_ag_vextent(args)))
2430 case XFS_ALLOCTYPE_START_BNO:
2432 * Try near allocation first, then anywhere-in-ag after
2433 * the first a.g. fails.
2435 if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
2436 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2437 args->fsbno = XFS_AGB_TO_FSB(mp,
2438 ((mp->m_agfrotor / rotorstep) %
2439 mp->m_sb.sb_agcount), 0);
2442 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2443 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2445 case XFS_ALLOCTYPE_ANY_AG:
2446 case XFS_ALLOCTYPE_START_AG:
2447 case XFS_ALLOCTYPE_FIRST_AG:
2449 * Rotate through the allocation groups looking for a winner.
2451 if (type == XFS_ALLOCTYPE_ANY_AG) {
2453 * Start with the last place we left off.
2455 args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2456 mp->m_sb.sb_agcount;
2457 args->type = XFS_ALLOCTYPE_THIS_AG;
2458 flags = XFS_ALLOC_FLAG_TRYLOCK;
2459 } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2461 * Start with allocation group given by bno.
2463 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2464 args->type = XFS_ALLOCTYPE_THIS_AG;
2468 if (type == XFS_ALLOCTYPE_START_AG)
2469 args->type = XFS_ALLOCTYPE_THIS_AG;
2471 * Start with the given allocation group.
2473 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2474 flags = XFS_ALLOC_FLAG_TRYLOCK;
2477 * Loop over allocation groups twice; first time with
2478 * trylock set, second time without.
2481 args->pag = xfs_perag_get(mp, args->agno);
2482 if (no_min) args->minleft = 0;
2483 error = xfs_alloc_fix_freelist(args, flags);
2484 args->minleft = minleft;
2486 trace_xfs_alloc_vextent_nofix(args);
2490 * If we get a buffer back then the allocation will fly.
2493 if ((error = xfs_alloc_ag_vextent(args)))
2498 trace_xfs_alloc_vextent_loopfailed(args);
2501 * Didn't work, figure out the next iteration.
2503 if (args->agno == sagno &&
2504 type == XFS_ALLOCTYPE_START_BNO)
2505 args->type = XFS_ALLOCTYPE_THIS_AG;
2507 * For the first allocation, we can try any AG to get
2508 * space. However, if we already have allocated a
2509 * block, we don't want to try AGs whose number is below
2510 * sagno. Otherwise, we may end up with out-of-order
2511 * locking of AGF, which might cause deadlock.
2513 if (++(args->agno) == mp->m_sb.sb_agcount) {
2514 if (args->firstblock != NULLFSBLOCK)
2520 * Reached the starting a.g., must either be done
2521 * or switch to non-trylock mode.
2523 if (args->agno == sagno) {
2525 args->agbno = NULLAGBLOCK;
2526 trace_xfs_alloc_vextent_allfailed(args);
2533 if (type == XFS_ALLOCTYPE_START_BNO) {
2534 args->agbno = XFS_FSB_TO_AGBNO(mp,
2536 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2540 xfs_perag_put(args->pag);
2542 if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2543 if (args->agno == sagno)
2544 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2545 (mp->m_sb.sb_agcount * rotorstep);
2547 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2548 (mp->m_sb.sb_agcount * rotorstep);
2555 if (args->agbno == NULLAGBLOCK)
2556 args->fsbno = NULLFSBLOCK;
2558 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2560 ASSERT(args->len >= args->minlen);
2561 ASSERT(args->len <= args->maxlen);
2562 ASSERT(args->agbno % args->alignment == 0);
2563 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2567 xfs_perag_put(args->pag);
2570 xfs_perag_put(args->pag);
2576 * Just break up the extent address and hand off to xfs_free_ag_extent
2577 * after fixing up the freelist.
2581 xfs_trans_t *tp, /* transaction pointer */
2582 xfs_fsblock_t bno, /* starting block number of extent */
2583 xfs_extlen_t len) /* length of extent */
2585 xfs_alloc_arg_t args;
2589 memset(&args, 0, sizeof(xfs_alloc_arg_t));
2591 args.mp = tp->t_mountp;
2594 * validate that the block number is legal - the enables us to detect
2595 * and handle a silent filesystem corruption rather than crashing.
2597 args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
2598 if (args.agno >= args.mp->m_sb.sb_agcount)
2599 return EFSCORRUPTED;
2601 args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
2602 if (args.agbno >= args.mp->m_sb.sb_agblocks)
2603 return EFSCORRUPTED;
2605 args.pag = xfs_perag_get(args.mp, args.agno);
2608 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
2612 /* validate the extent size is legal now we have the agf locked */
2613 if (args.agbno + len >
2614 be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
2615 error = EFSCORRUPTED;
2619 error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
2621 xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
2623 xfs_perag_put(args.pag);