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 */
154 /* Trim busy sections out of found extent */
155 xfs_extent_busy_trim(args, foundbno, foundlen, &bno, &len);
158 * If we have a largish extent that happens to start before min_agbno,
159 * see if we can shift it into range...
161 if (bno < args->min_agbno && bno + len > args->min_agbno) {
162 diff = args->min_agbno - bno;
169 if (args->alignment > 1 && len >= args->minlen) {
170 xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
172 diff = aligned_bno - bno;
174 *resbno = aligned_bno;
175 *reslen = diff >= len ? 0 : len - diff;
183 * Compute best start block and diff for "near" allocations.
184 * freelen >= wantlen already checked by caller.
186 STATIC xfs_extlen_t /* difference value (absolute) */
187 xfs_alloc_compute_diff(
188 xfs_agblock_t wantbno, /* target starting block */
189 xfs_extlen_t wantlen, /* target length */
190 xfs_extlen_t alignment, /* target alignment */
191 char userdata, /* are we allocating data? */
192 xfs_agblock_t freebno, /* freespace's starting block */
193 xfs_extlen_t freelen, /* freespace's length */
194 xfs_agblock_t *newbnop) /* result: best start block from free */
196 xfs_agblock_t freeend; /* end of freespace extent */
197 xfs_agblock_t newbno1; /* return block number */
198 xfs_agblock_t newbno2; /* other new block number */
199 xfs_extlen_t newlen1=0; /* length with newbno1 */
200 xfs_extlen_t newlen2=0; /* length with newbno2 */
201 xfs_agblock_t wantend; /* end of target extent */
203 ASSERT(freelen >= wantlen);
204 freeend = freebno + freelen;
205 wantend = wantbno + wantlen;
207 * We want to allocate from the start of a free extent if it is past
208 * the desired block or if we are allocating user data and the free
209 * extent is before desired block. The second case is there to allow
210 * for contiguous allocation from the remaining free space if the file
211 * grows in the short term.
213 if (freebno >= wantbno || (userdata && freeend < wantend)) {
214 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
215 newbno1 = NULLAGBLOCK;
216 } else if (freeend >= wantend && alignment > 1) {
217 newbno1 = roundup(wantbno, alignment);
218 newbno2 = newbno1 - alignment;
219 if (newbno1 >= freeend)
220 newbno1 = NULLAGBLOCK;
222 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
223 if (newbno2 < freebno)
224 newbno2 = NULLAGBLOCK;
226 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
227 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
228 if (newlen1 < newlen2 ||
229 (newlen1 == newlen2 &&
230 XFS_ABSDIFF(newbno1, wantbno) >
231 XFS_ABSDIFF(newbno2, wantbno)))
233 } else if (newbno2 != NULLAGBLOCK)
235 } else if (freeend >= wantend) {
237 } else if (alignment > 1) {
238 newbno1 = roundup(freeend - wantlen, alignment);
239 if (newbno1 > freeend - wantlen &&
240 newbno1 - alignment >= freebno)
241 newbno1 -= alignment;
242 else if (newbno1 >= freeend)
243 newbno1 = NULLAGBLOCK;
245 newbno1 = freeend - wantlen;
247 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
251 * Fix up the length, based on mod and prod.
252 * len should be k * prod + mod for some k.
253 * If len is too small it is returned unchanged.
254 * If len hits maxlen it is left alone.
258 xfs_alloc_arg_t *args) /* allocation argument structure */
263 ASSERT(args->mod < args->prod);
265 ASSERT(rlen >= args->minlen);
266 ASSERT(rlen <= args->maxlen);
267 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
268 (args->mod == 0 && rlen < args->prod))
270 k = rlen % args->prod;
274 rlen = rlen - (k - args->mod);
276 rlen = rlen - args->prod + (args->mod - k);
277 /* casts to (int) catch length underflows */
278 if ((int)rlen < (int)args->minlen)
280 ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
281 ASSERT(rlen % args->prod == args->mod);
286 * Fix up length if there is too little space left in the a.g.
287 * Return 1 if ok, 0 if too little, should give up.
290 xfs_alloc_fix_minleft(
291 xfs_alloc_arg_t *args) /* allocation argument structure */
293 xfs_agf_t *agf; /* a.g. freelist header */
294 int diff; /* free space difference */
296 if (args->minleft == 0)
298 agf = XFS_BUF_TO_AGF(args->agbp);
299 diff = be32_to_cpu(agf->agf_freeblks)
300 - args->len - args->minleft;
303 args->len += diff; /* shrink the allocated space */
304 /* casts to (int) catch length underflows */
305 if ((int)args->len >= (int)args->minlen)
307 args->agbno = NULLAGBLOCK;
312 * Update the two btrees, logically removing from freespace the extent
313 * starting at rbno, rlen blocks. The extent is contained within the
314 * actual (current) free extent fbno for flen blocks.
315 * Flags are passed in indicating whether the cursors are set to the
318 STATIC int /* error code */
319 xfs_alloc_fixup_trees(
320 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
321 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
322 xfs_agblock_t fbno, /* starting block of free extent */
323 xfs_extlen_t flen, /* length of free extent */
324 xfs_agblock_t rbno, /* starting block of returned extent */
325 xfs_extlen_t rlen, /* length of returned extent */
326 int flags) /* flags, XFSA_FIXUP_... */
328 int error; /* error code */
329 int i; /* operation results */
330 xfs_agblock_t nfbno1; /* first new free startblock */
331 xfs_agblock_t nfbno2; /* second new free startblock */
332 xfs_extlen_t nflen1=0; /* first new free length */
333 xfs_extlen_t nflen2=0; /* second new free length */
334 struct xfs_mount *mp;
339 * Look up the record in the by-size tree if necessary.
341 if (flags & XFSA_FIXUP_CNT_OK) {
343 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
345 XFS_WANT_CORRUPTED_RETURN(mp,
346 i == 1 && nfbno1 == fbno && nflen1 == flen);
349 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
351 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
354 * Look up the record in the by-block tree if necessary.
356 if (flags & XFSA_FIXUP_BNO_OK) {
358 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
360 XFS_WANT_CORRUPTED_RETURN(mp,
361 i == 1 && nfbno1 == fbno && nflen1 == flen);
364 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
366 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
370 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
371 struct xfs_btree_block *bnoblock;
372 struct xfs_btree_block *cntblock;
374 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
375 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
377 XFS_WANT_CORRUPTED_RETURN(mp,
378 bnoblock->bb_numrecs == cntblock->bb_numrecs);
383 * Deal with all four cases: the allocated record is contained
384 * within the freespace record, so we can have new freespace
385 * at either (or both) end, or no freespace remaining.
387 if (rbno == fbno && rlen == flen)
388 nfbno1 = nfbno2 = NULLAGBLOCK;
389 else if (rbno == fbno) {
390 nfbno1 = rbno + rlen;
391 nflen1 = flen - rlen;
392 nfbno2 = NULLAGBLOCK;
393 } else if (rbno + rlen == fbno + flen) {
395 nflen1 = flen - rlen;
396 nfbno2 = NULLAGBLOCK;
399 nflen1 = rbno - fbno;
400 nfbno2 = rbno + rlen;
401 nflen2 = (fbno + flen) - nfbno2;
404 * Delete the entry from the by-size btree.
406 if ((error = xfs_btree_delete(cnt_cur, &i)))
408 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
410 * Add new by-size btree entry(s).
412 if (nfbno1 != NULLAGBLOCK) {
413 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
415 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
416 if ((error = xfs_btree_insert(cnt_cur, &i)))
418 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
420 if (nfbno2 != NULLAGBLOCK) {
421 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
423 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
424 if ((error = xfs_btree_insert(cnt_cur, &i)))
426 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
429 * Fix up the by-block btree entry(s).
431 if (nfbno1 == NULLAGBLOCK) {
433 * No remaining freespace, just delete the by-block tree entry.
435 if ((error = xfs_btree_delete(bno_cur, &i)))
437 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
440 * Update the by-block entry to start later|be shorter.
442 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
445 if (nfbno2 != NULLAGBLOCK) {
447 * 2 resulting free entries, need to add one.
449 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
451 XFS_WANT_CORRUPTED_RETURN(mp, i == 0);
452 if ((error = xfs_btree_insert(bno_cur, &i)))
454 XFS_WANT_CORRUPTED_RETURN(mp, i == 1);
463 struct xfs_mount *mp = bp->b_target->bt_mount;
464 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
467 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid))
469 if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
472 * during growfs operations, the perag is not fully initialised,
473 * so we can't use it for any useful checking. growfs ensures we can't
474 * use it by using uncached buffers that don't have the perag attached
475 * so we can detect and avoid this problem.
477 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
480 for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
481 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
482 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
486 return xfs_log_check_lsn(mp,
487 be64_to_cpu(XFS_BUF_TO_AGFL(bp)->agfl_lsn));
491 xfs_agfl_read_verify(
494 struct xfs_mount *mp = bp->b_target->bt_mount;
497 * There is no verification of non-crc AGFLs because mkfs does not
498 * initialise the AGFL to zero or NULL. Hence the only valid part of the
499 * AGFL is what the AGF says is active. We can't get to the AGF, so we
500 * can't verify just those entries are valid.
502 if (!xfs_sb_version_hascrc(&mp->m_sb))
505 if (!xfs_buf_verify_cksum(bp, XFS_AGFL_CRC_OFF))
506 xfs_buf_ioerror(bp, -EFSBADCRC);
507 else if (!xfs_agfl_verify(bp))
508 xfs_buf_ioerror(bp, -EFSCORRUPTED);
511 xfs_verifier_error(bp);
515 xfs_agfl_write_verify(
518 struct xfs_mount *mp = bp->b_target->bt_mount;
519 struct xfs_buf_log_item *bip = bp->b_fspriv;
521 /* no verification of non-crc AGFLs */
522 if (!xfs_sb_version_hascrc(&mp->m_sb))
525 if (!xfs_agfl_verify(bp)) {
526 xfs_buf_ioerror(bp, -EFSCORRUPTED);
527 xfs_verifier_error(bp);
532 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
534 xfs_buf_update_cksum(bp, XFS_AGFL_CRC_OFF);
537 const struct xfs_buf_ops xfs_agfl_buf_ops = {
538 .verify_read = xfs_agfl_read_verify,
539 .verify_write = xfs_agfl_write_verify,
543 * Read in the allocation group free block array.
545 STATIC int /* error */
547 xfs_mount_t *mp, /* mount point structure */
548 xfs_trans_t *tp, /* transaction pointer */
549 xfs_agnumber_t agno, /* allocation group number */
550 xfs_buf_t **bpp) /* buffer for the ag free block array */
552 xfs_buf_t *bp; /* return value */
555 ASSERT(agno != NULLAGNUMBER);
556 error = xfs_trans_read_buf(
557 mp, tp, mp->m_ddev_targp,
558 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
559 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
562 xfs_buf_set_ref(bp, XFS_AGFL_REF);
568 xfs_alloc_update_counters(
569 struct xfs_trans *tp,
570 struct xfs_perag *pag,
571 struct xfs_buf *agbp,
574 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
576 pag->pagf_freeblks += len;
577 be32_add_cpu(&agf->agf_freeblks, len);
579 xfs_trans_agblocks_delta(tp, len);
580 if (unlikely(be32_to_cpu(agf->agf_freeblks) >
581 be32_to_cpu(agf->agf_length)))
582 return -EFSCORRUPTED;
584 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
589 * Allocation group level functions.
593 * Allocate a variable extent in the allocation group agno.
594 * Type and bno are used to determine where in the allocation group the
596 * Extent's length (returned in *len) will be between minlen and maxlen,
597 * and of the form k * prod + mod unless there's nothing that large.
598 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
600 STATIC int /* error */
601 xfs_alloc_ag_vextent(
602 xfs_alloc_arg_t *args) /* argument structure for allocation */
606 ASSERT(args->minlen > 0);
607 ASSERT(args->maxlen > 0);
608 ASSERT(args->minlen <= args->maxlen);
609 ASSERT(args->mod < args->prod);
610 ASSERT(args->alignment > 0);
612 * Branch to correct routine based on the type.
615 switch (args->type) {
616 case XFS_ALLOCTYPE_THIS_AG:
617 error = xfs_alloc_ag_vextent_size(args);
619 case XFS_ALLOCTYPE_NEAR_BNO:
620 error = xfs_alloc_ag_vextent_near(args);
622 case XFS_ALLOCTYPE_THIS_BNO:
623 error = xfs_alloc_ag_vextent_exact(args);
630 if (error || args->agbno == NULLAGBLOCK)
633 ASSERT(args->len >= args->minlen);
634 ASSERT(args->len <= args->maxlen);
635 ASSERT(!args->wasfromfl || !args->isfl);
636 ASSERT(args->agbno % args->alignment == 0);
638 if (!args->wasfromfl) {
639 error = xfs_alloc_update_counters(args->tp, args->pag,
641 -((long)(args->len)));
645 ASSERT(!xfs_extent_busy_search(args->mp, args->agno,
646 args->agbno, args->len));
650 xfs_trans_mod_sb(args->tp, args->wasdel ?
651 XFS_TRANS_SB_RES_FDBLOCKS :
652 XFS_TRANS_SB_FDBLOCKS,
653 -((long)(args->len)));
656 XFS_STATS_INC(args->mp, xs_allocx);
657 XFS_STATS_ADD(args->mp, xs_allocb, args->len);
662 * Allocate a variable extent at exactly agno/bno.
663 * Extent's length (returned in *len) will be between minlen and maxlen,
664 * and of the form k * prod + mod unless there's nothing that large.
665 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
667 STATIC int /* error */
668 xfs_alloc_ag_vextent_exact(
669 xfs_alloc_arg_t *args) /* allocation argument structure */
671 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
672 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
674 xfs_agblock_t fbno; /* start block of found extent */
675 xfs_extlen_t flen; /* length of found extent */
676 xfs_agblock_t tbno; /* start block of trimmed extent */
677 xfs_extlen_t tlen; /* length of trimmed extent */
678 xfs_agblock_t tend; /* end block of trimmed extent */
679 int i; /* success/failure of operation */
681 ASSERT(args->alignment == 1);
684 * Allocate/initialize a cursor for the by-number freespace btree.
686 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
687 args->agno, XFS_BTNUM_BNO);
690 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
691 * Look for the closest free block <= bno, it must contain bno
692 * if any free block does.
694 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
701 * Grab the freespace record.
703 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
706 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
707 ASSERT(fbno <= args->agbno);
710 * Check for overlapping busy extents.
712 xfs_extent_busy_trim(args, fbno, flen, &tbno, &tlen);
715 * Give up if the start of the extent is busy, or the freespace isn't
716 * long enough for the minimum request.
718 if (tbno > args->agbno)
720 if (tlen < args->minlen)
723 if (tend < args->agbno + args->minlen)
727 * End of extent will be smaller of the freespace end and the
728 * maximal requested end.
730 * Fix the length according to mod and prod if given.
732 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
734 xfs_alloc_fix_len(args);
735 if (!xfs_alloc_fix_minleft(args))
738 ASSERT(args->agbno + args->len <= tend);
741 * We are allocating agbno for args->len
742 * Allocate/initialize a cursor for the by-size btree.
744 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
745 args->agno, XFS_BTNUM_CNT);
746 ASSERT(args->agbno + args->len <=
747 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
748 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
749 args->len, XFSA_FIXUP_BNO_OK);
751 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
755 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
756 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
759 trace_xfs_alloc_exact_done(args);
763 /* Didn't find it, return null. */
764 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
765 args->agbno = NULLAGBLOCK;
766 trace_xfs_alloc_exact_notfound(args);
770 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
771 trace_xfs_alloc_exact_error(args);
776 * Search the btree in a given direction via the search cursor and compare
777 * the records found against the good extent we've already found.
780 xfs_alloc_find_best_extent(
781 struct xfs_alloc_arg *args, /* allocation argument structure */
782 struct xfs_btree_cur **gcur, /* good cursor */
783 struct xfs_btree_cur **scur, /* searching cursor */
784 xfs_agblock_t gdiff, /* difference for search comparison */
785 xfs_agblock_t *sbno, /* extent found by search */
786 xfs_extlen_t *slen, /* extent length */
787 xfs_agblock_t *sbnoa, /* aligned extent found by search */
788 xfs_extlen_t *slena, /* aligned extent length */
789 int dir) /* 0 = search right, 1 = search left */
796 /* The good extent is perfect, no need to search. */
801 * Look until we find a better one, run out of space or run off the end.
804 error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
807 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
808 xfs_alloc_compute_aligned(args, *sbno, *slen, sbnoa, slena);
811 * The good extent is closer than this one.
814 if (*sbnoa > args->max_agbno)
816 if (*sbnoa >= args->agbno + gdiff)
819 if (*sbnoa < args->min_agbno)
821 if (*sbnoa <= args->agbno - gdiff)
826 * Same distance, compare length and pick the best.
828 if (*slena >= args->minlen) {
829 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
830 xfs_alloc_fix_len(args);
832 sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
834 args->userdata, *sbnoa,
838 * Choose closer size and invalidate other cursor.
846 error = xfs_btree_increment(*scur, 0, &i);
848 error = xfs_btree_decrement(*scur, 0, &i);
854 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
859 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
864 /* caller invalidates cursors */
869 * Allocate a variable extent near bno in the allocation group agno.
870 * Extent's length (returned in len) will be between minlen and maxlen,
871 * and of the form k * prod + mod unless there's nothing that large.
872 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
874 STATIC int /* error */
875 xfs_alloc_ag_vextent_near(
876 xfs_alloc_arg_t *args) /* allocation argument structure */
878 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
879 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
880 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
881 xfs_agblock_t gtbno; /* start bno of right side entry */
882 xfs_agblock_t gtbnoa; /* aligned ... */
883 xfs_extlen_t gtdiff; /* difference to right side entry */
884 xfs_extlen_t gtlen; /* length of right side entry */
885 xfs_extlen_t gtlena; /* aligned ... */
886 xfs_agblock_t gtnew; /* useful start bno of right side */
887 int error; /* error code */
888 int i; /* result code, temporary */
889 int j; /* result code, temporary */
890 xfs_agblock_t ltbno; /* start bno of left side entry */
891 xfs_agblock_t ltbnoa; /* aligned ... */
892 xfs_extlen_t ltdiff; /* difference to left side entry */
893 xfs_extlen_t ltlen; /* length of left side entry */
894 xfs_extlen_t ltlena; /* aligned ... */
895 xfs_agblock_t ltnew; /* useful start bno of left side */
896 xfs_extlen_t rlen; /* length of returned extent */
900 * Randomly don't execute the first algorithm.
902 int dofirst; /* set to do first algorithm */
904 dofirst = prandom_u32() & 1;
907 /* handle unitialized agbno range so caller doesn't have to */
908 if (!args->min_agbno && !args->max_agbno)
909 args->max_agbno = args->mp->m_sb.sb_agblocks - 1;
910 ASSERT(args->min_agbno <= args->max_agbno);
912 /* clamp agbno to the range if it's outside */
913 if (args->agbno < args->min_agbno)
914 args->agbno = args->min_agbno;
915 if (args->agbno > args->max_agbno)
916 args->agbno = args->max_agbno;
926 * Get a cursor for the by-size btree.
928 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
929 args->agno, XFS_BTNUM_CNT);
932 * See if there are any free extents as big as maxlen.
934 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
937 * If none, then pick up the last entry in the tree unless the
941 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, <bno,
944 if (i == 0 || ltlen == 0) {
945 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
946 trace_xfs_alloc_near_noentry(args);
955 * If the requested extent is large wrt the freespaces available
956 * in this a.g., then the cursor will be pointing to a btree entry
957 * near the right edge of the tree. If it's in the last btree leaf
958 * block, then we just examine all the entries in that block
959 * that are big enough, and pick the best one.
960 * This is written as a while loop so we can break out of it,
961 * but we never loop back to the top.
963 while (xfs_btree_islastblock(cnt_cur, 0)) {
967 xfs_agblock_t bnew=0;
974 * Start from the entry that lookup found, sequence through
975 * all larger free blocks. If we're actually pointing at a
976 * record smaller than maxlen, go to the start of this block,
977 * and skip all those smaller than minlen.
979 if (ltlen || args->alignment > 1) {
980 cnt_cur->bc_ptrs[0] = 1;
982 if ((error = xfs_alloc_get_rec(cnt_cur, <bno,
985 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
986 if (ltlen >= args->minlen)
988 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
991 ASSERT(ltlen >= args->minlen);
995 i = cnt_cur->bc_ptrs[0];
996 for (j = 1, blen = 0, bdiff = 0;
997 !error && j && (blen < args->maxlen || bdiff > 0);
998 error = xfs_btree_increment(cnt_cur, 0, &j)) {
1000 * For each entry, decide if it's better than
1001 * the previous best entry.
1003 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
1005 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1006 xfs_alloc_compute_aligned(args, ltbno, ltlen,
1008 if (ltlena < args->minlen)
1010 if (ltbnoa < args->min_agbno || ltbnoa > args->max_agbno)
1012 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1013 xfs_alloc_fix_len(args);
1014 ASSERT(args->len >= args->minlen);
1015 if (args->len < blen)
1017 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1018 args->alignment, args->userdata, ltbnoa,
1020 if (ltnew != NULLAGBLOCK &&
1021 (args->len > blen || ltdiff < bdiff)) {
1025 besti = cnt_cur->bc_ptrs[0];
1029 * It didn't work. We COULD be in a case where
1030 * there's a good record somewhere, so try again.
1035 * Point at the best entry, and retrieve it again.
1037 cnt_cur->bc_ptrs[0] = besti;
1038 if ((error = xfs_alloc_get_rec(cnt_cur, <bno, <len, &i)))
1040 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1041 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1043 if (!xfs_alloc_fix_minleft(args)) {
1044 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1045 trace_xfs_alloc_near_nominleft(args);
1050 * We are allocating starting at bnew for blen blocks.
1053 ASSERT(bnew >= ltbno);
1054 ASSERT(bnew + blen <= ltbno + ltlen);
1056 * Set up a cursor for the by-bno tree.
1058 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1059 args->agbp, args->agno, XFS_BTNUM_BNO);
1061 * Fix up the btree entries.
1063 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1064 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1066 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1067 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1069 trace_xfs_alloc_near_first(args);
1074 * Search in the by-bno tree to the left and to the right
1075 * simultaneously, until in each case we find a space big enough,
1076 * or run into the edge of the tree. When we run into the edge,
1077 * we deallocate that cursor.
1078 * If both searches succeed, we compare the two spaces and pick
1080 * With alignment, it's possible for both to fail; the upper
1081 * level algorithm that picks allocation groups for allocations
1082 * is not supposed to do this.
1085 * Allocate and initialize the cursor for the leftward search.
1087 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1088 args->agno, XFS_BTNUM_BNO);
1090 * Lookup <= bno to find the leftward search's starting point.
1092 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1096 * Didn't find anything; use this cursor for the rightward
1099 bno_cur_gt = bno_cur_lt;
1103 * Found something. Duplicate the cursor for the rightward search.
1105 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1108 * Increment the cursor, so we will point at the entry just right
1109 * of the leftward entry if any, or to the leftmost entry.
1111 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1115 * It failed, there are no rightward entries.
1117 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1121 * Loop going left with the leftward cursor, right with the
1122 * rightward cursor, until either both directions give up or
1123 * we find an entry at least as big as minlen.
1127 if ((error = xfs_alloc_get_rec(bno_cur_lt, <bno, <len, &i)))
1129 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1130 xfs_alloc_compute_aligned(args, ltbno, ltlen,
1132 if (ltlena >= args->minlen && ltbnoa >= args->min_agbno)
1134 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
1136 if (!i || ltbnoa < args->min_agbno) {
1137 xfs_btree_del_cursor(bno_cur_lt,
1143 if ((error = xfs_alloc_get_rec(bno_cur_gt, >bno, >len, &i)))
1145 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1146 xfs_alloc_compute_aligned(args, gtbno, gtlen,
1148 if (gtlena >= args->minlen && gtbnoa <= args->max_agbno)
1150 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1152 if (!i || gtbnoa > args->max_agbno) {
1153 xfs_btree_del_cursor(bno_cur_gt,
1158 } while (bno_cur_lt || bno_cur_gt);
1161 * Got both cursors still active, need to find better entry.
1163 if (bno_cur_lt && bno_cur_gt) {
1164 if (ltlena >= args->minlen) {
1166 * Left side is good, look for a right side entry.
1168 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1169 xfs_alloc_fix_len(args);
1170 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1171 args->alignment, args->userdata, ltbnoa,
1174 error = xfs_alloc_find_best_extent(args,
1175 &bno_cur_lt, &bno_cur_gt,
1176 ltdiff, >bno, >len,
1178 0 /* search right */);
1180 ASSERT(gtlena >= args->minlen);
1183 * Right side is good, look for a left side entry.
1185 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1186 xfs_alloc_fix_len(args);
1187 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1188 args->alignment, args->userdata, gtbnoa,
1191 error = xfs_alloc_find_best_extent(args,
1192 &bno_cur_gt, &bno_cur_lt,
1193 gtdiff, <bno, <len,
1195 1 /* search left */);
1203 * If we couldn't get anything, give up.
1205 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1206 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1209 trace_xfs_alloc_near_busy(args);
1210 xfs_log_force(args->mp, XFS_LOG_SYNC);
1213 trace_xfs_alloc_size_neither(args);
1214 args->agbno = NULLAGBLOCK;
1219 * At this point we have selected a freespace entry, either to the
1220 * left or to the right. If it's on the right, copy all the
1221 * useful variables to the "left" set so we only have one
1222 * copy of this code.
1225 bno_cur_lt = bno_cur_gt;
1236 * Fix up the length and compute the useful address.
1238 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1239 xfs_alloc_fix_len(args);
1240 if (!xfs_alloc_fix_minleft(args)) {
1241 trace_xfs_alloc_near_nominleft(args);
1242 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1243 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1247 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
1248 args->userdata, ltbnoa, ltlena, <new);
1249 ASSERT(ltnew >= ltbno);
1250 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
1251 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1252 ASSERT(ltnew >= args->min_agbno && ltnew <= args->max_agbno);
1253 args->agbno = ltnew;
1255 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1256 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1260 trace_xfs_alloc_near_greater(args);
1262 trace_xfs_alloc_near_lesser(args);
1264 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1265 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1269 trace_xfs_alloc_near_error(args);
1270 if (cnt_cur != NULL)
1271 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1272 if (bno_cur_lt != NULL)
1273 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1274 if (bno_cur_gt != NULL)
1275 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1280 * Allocate a variable extent anywhere in the allocation group agno.
1281 * Extent's length (returned in len) will be between minlen and maxlen,
1282 * and of the form k * prod + mod unless there's nothing that large.
1283 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1285 STATIC int /* error */
1286 xfs_alloc_ag_vextent_size(
1287 xfs_alloc_arg_t *args) /* allocation argument structure */
1289 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1290 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1291 int error; /* error result */
1292 xfs_agblock_t fbno; /* start of found freespace */
1293 xfs_extlen_t flen; /* length of found freespace */
1294 int i; /* temp status variable */
1295 xfs_agblock_t rbno; /* returned block number */
1296 xfs_extlen_t rlen; /* length of returned extent */
1301 * Allocate and initialize a cursor for the by-size btree.
1303 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1304 args->agno, XFS_BTNUM_CNT);
1308 * Look for an entry >= maxlen+alignment-1 blocks.
1310 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1311 args->maxlen + args->alignment - 1, &i)))
1315 * If none or we have busy extents that we cannot allocate from, then
1316 * we have to settle for a smaller extent. In the case that there are
1317 * no large extents, this will return the last entry in the tree unless
1318 * the tree is empty. In the case that there are only busy large
1319 * extents, this will return the largest small extent unless there
1320 * are no smaller extents available.
1322 if (!i || forced > 1) {
1323 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1327 if (i == 0 || flen == 0) {
1328 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1329 trace_xfs_alloc_size_noentry(args);
1333 xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
1336 * Search for a non-busy extent that is large enough.
1337 * If we are at low space, don't check, or if we fall of
1338 * the end of the btree, turn off the busy check and
1342 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1345 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1347 xfs_alloc_compute_aligned(args, fbno, flen,
1350 if (rlen >= args->maxlen)
1353 error = xfs_btree_increment(cnt_cur, 0, &i);
1358 * Our only valid extents must have been busy.
1359 * Make it unbusy by forcing the log out and
1360 * retrying. If we've been here before, forcing
1361 * the log isn't making the extents available,
1362 * which means they have probably been freed in
1363 * this transaction. In that case, we have to
1364 * give up on them and we'll attempt a minlen
1365 * allocation the next time around.
1367 xfs_btree_del_cursor(cnt_cur,
1369 trace_xfs_alloc_size_busy(args);
1371 xfs_log_force(args->mp, XFS_LOG_SYNC);
1378 * In the first case above, we got the last entry in the
1379 * by-size btree. Now we check to see if the space hits maxlen
1380 * once aligned; if not, we search left for something better.
1381 * This can't happen in the second case above.
1383 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1384 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 ||
1385 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1386 if (rlen < args->maxlen) {
1387 xfs_agblock_t bestfbno;
1388 xfs_extlen_t bestflen;
1389 xfs_agblock_t bestrbno;
1390 xfs_extlen_t bestrlen;
1397 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
1401 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1404 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1405 if (flen < bestrlen)
1407 xfs_alloc_compute_aligned(args, fbno, flen,
1409 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1410 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen == 0 ||
1411 (rlen <= flen && rbno + rlen <= fbno + flen),
1413 if (rlen > bestrlen) {
1418 if (rlen == args->maxlen)
1422 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1425 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1431 args->wasfromfl = 0;
1433 * Fix up the length.
1436 if (rlen < args->minlen) {
1438 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1439 trace_xfs_alloc_size_busy(args);
1440 xfs_log_force(args->mp, XFS_LOG_SYNC);
1445 xfs_alloc_fix_len(args);
1447 if (!xfs_alloc_fix_minleft(args))
1450 XFS_WANT_CORRUPTED_GOTO(args->mp, rlen <= flen, error0);
1452 * Allocate and initialize a cursor for the by-block tree.
1454 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1455 args->agno, XFS_BTNUM_BNO);
1456 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1457 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1459 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1460 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1461 cnt_cur = bno_cur = NULL;
1464 XFS_WANT_CORRUPTED_GOTO(args->mp,
1465 args->agbno + args->len <=
1466 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1468 trace_xfs_alloc_size_done(args);
1472 trace_xfs_alloc_size_error(args);
1474 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1476 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1480 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1481 trace_xfs_alloc_size_nominleft(args);
1482 args->agbno = NULLAGBLOCK;
1487 * Deal with the case where only small freespaces remain.
1488 * Either return the contents of the last freespace record,
1489 * or allocate space from the freelist if there is nothing in the tree.
1491 STATIC int /* error */
1492 xfs_alloc_ag_vextent_small(
1493 xfs_alloc_arg_t *args, /* allocation argument structure */
1494 xfs_btree_cur_t *ccur, /* by-size cursor */
1495 xfs_agblock_t *fbnop, /* result block number */
1496 xfs_extlen_t *flenp, /* result length */
1497 int *stat) /* status: 0-freelist, 1-normal/none */
1504 if ((error = xfs_btree_decrement(ccur, 0, &i)))
1507 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1509 XFS_WANT_CORRUPTED_GOTO(args->mp, i == 1, error0);
1512 * Nothing in the btree, try the freelist. Make sure
1513 * to respect minleft even when pulling from the
1516 else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
1517 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1519 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
1522 if (fbno != NULLAGBLOCK) {
1523 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
1526 if (args->userdata) {
1529 bp = xfs_btree_get_bufs(args->mp, args->tp,
1530 args->agno, fbno, 0);
1531 xfs_trans_binval(args->tp, bp);
1535 XFS_WANT_CORRUPTED_GOTO(args->mp,
1536 args->agbno + args->len <=
1537 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1539 args->wasfromfl = 1;
1540 trace_xfs_alloc_small_freelist(args);
1545 * Nothing in the freelist.
1551 * Can't allocate from the freelist for some reason.
1558 * Can't do the allocation, give up.
1560 if (flen < args->minlen) {
1561 args->agbno = NULLAGBLOCK;
1562 trace_xfs_alloc_small_notenough(args);
1568 trace_xfs_alloc_small_done(args);
1572 trace_xfs_alloc_small_error(args);
1577 * Free the extent starting at agno/bno for length.
1579 STATIC int /* error */
1581 xfs_trans_t *tp, /* transaction pointer */
1582 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
1583 xfs_agnumber_t agno, /* allocation group number */
1584 xfs_agblock_t bno, /* starting block number */
1585 xfs_extlen_t len, /* length of extent */
1586 int isfl) /* set if is freelist blocks - no sb acctg */
1588 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1589 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1590 int error; /* error return value */
1591 xfs_agblock_t gtbno; /* start of right neighbor block */
1592 xfs_extlen_t gtlen; /* length of right neighbor block */
1593 int haveleft; /* have a left neighbor block */
1594 int haveright; /* have a right neighbor block */
1595 int i; /* temp, result code */
1596 xfs_agblock_t ltbno; /* start of left neighbor block */
1597 xfs_extlen_t ltlen; /* length of left neighbor block */
1598 xfs_mount_t *mp; /* mount point struct for filesystem */
1599 xfs_agblock_t nbno; /* new starting block of freespace */
1600 xfs_extlen_t nlen; /* new length of freespace */
1601 xfs_perag_t *pag; /* per allocation group data */
1605 * Allocate and initialize a cursor for the by-block btree.
1607 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
1610 * Look for a neighboring block on the left (lower block numbers)
1611 * that is contiguous with this space.
1613 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1617 * There is a block to our left.
1619 if ((error = xfs_alloc_get_rec(bno_cur, <bno, <len, &i)))
1621 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1623 * It's not contiguous, though.
1625 if (ltbno + ltlen < bno)
1629 * If this failure happens the request to free this
1630 * space was invalid, it's (partly) already free.
1633 XFS_WANT_CORRUPTED_GOTO(mp,
1634 ltbno + ltlen <= bno, error0);
1638 * Look for a neighboring block on the right (higher block numbers)
1639 * that is contiguous with this space.
1641 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
1645 * There is a block to our right.
1647 if ((error = xfs_alloc_get_rec(bno_cur, >bno, >len, &i)))
1649 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1651 * It's not contiguous, though.
1653 if (bno + len < gtbno)
1657 * If this failure happens the request to free this
1658 * space was invalid, it's (partly) already free.
1661 XFS_WANT_CORRUPTED_GOTO(mp, gtbno >= bno + len, error0);
1665 * Now allocate and initialize a cursor for the by-size tree.
1667 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
1669 * Have both left and right contiguous neighbors.
1670 * Merge all three into a single free block.
1672 if (haveleft && haveright) {
1674 * Delete the old by-size entry on the left.
1676 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1678 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1679 if ((error = xfs_btree_delete(cnt_cur, &i)))
1681 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1683 * Delete the old by-size entry on the right.
1685 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1687 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1688 if ((error = xfs_btree_delete(cnt_cur, &i)))
1690 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1692 * Delete the old by-block entry for the right block.
1694 if ((error = xfs_btree_delete(bno_cur, &i)))
1696 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1698 * Move the by-block cursor back to the left neighbor.
1700 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1702 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1705 * Check that this is the right record: delete didn't
1706 * mangle the cursor.
1709 xfs_agblock_t xxbno;
1712 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1715 XFS_WANT_CORRUPTED_GOTO(mp,
1716 i == 1 && xxbno == ltbno && xxlen == ltlen,
1721 * Update remaining by-block entry to the new, joined block.
1724 nlen = len + ltlen + gtlen;
1725 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1729 * Have only a left contiguous neighbor.
1730 * Merge it together with the new freespace.
1732 else if (haveleft) {
1734 * Delete the old by-size entry on the left.
1736 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1738 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1739 if ((error = xfs_btree_delete(cnt_cur, &i)))
1741 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1743 * Back up the by-block cursor to the left neighbor, and
1744 * update its length.
1746 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1748 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1751 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1755 * Have only a right contiguous neighbor.
1756 * Merge it together with the new freespace.
1758 else if (haveright) {
1760 * Delete the old by-size entry on the right.
1762 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1764 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1765 if ((error = xfs_btree_delete(cnt_cur, &i)))
1767 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1769 * Update the starting block and length of the right
1770 * neighbor in the by-block tree.
1774 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1778 * No contiguous neighbors.
1779 * Insert the new freespace into the by-block tree.
1784 if ((error = xfs_btree_insert(bno_cur, &i)))
1786 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1788 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1791 * In all cases we need to insert the new freespace in the by-size tree.
1793 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1795 XFS_WANT_CORRUPTED_GOTO(mp, i == 0, error0);
1796 if ((error = xfs_btree_insert(cnt_cur, &i)))
1798 XFS_WANT_CORRUPTED_GOTO(mp, i == 1, error0);
1799 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1803 * Update the freespace totals in the ag and superblock.
1805 pag = xfs_perag_get(mp, agno);
1806 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1812 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1813 XFS_STATS_INC(mp, xs_freex);
1814 XFS_STATS_ADD(mp, xs_freeb, len);
1816 trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
1821 trace_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
1823 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1825 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1830 * Visible (exported) allocation/free functions.
1831 * Some of these are used just by xfs_alloc_btree.c and this file.
1835 * Compute and fill in value of m_ag_maxlevels.
1838 xfs_alloc_compute_maxlevels(
1839 xfs_mount_t *mp) /* file system mount structure */
1847 maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1848 minleafrecs = mp->m_alloc_mnr[0];
1849 minnoderecs = mp->m_alloc_mnr[1];
1850 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1851 for (level = 1; maxblocks > 1; level++)
1852 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1853 mp->m_ag_maxlevels = level;
1857 * Find the length of the longest extent in an AG.
1860 xfs_alloc_longest_free_extent(
1861 struct xfs_mount *mp,
1862 struct xfs_perag *pag,
1865 xfs_extlen_t delta = 0;
1867 if (need > pag->pagf_flcount)
1868 delta = need - pag->pagf_flcount;
1870 if (pag->pagf_longest > delta)
1871 return pag->pagf_longest - delta;
1872 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1876 xfs_alloc_min_freelist(
1877 struct xfs_mount *mp,
1878 struct xfs_perag *pag)
1880 unsigned int min_free;
1882 /* space needed by-bno freespace btree */
1883 min_free = min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_BNOi] + 1,
1884 mp->m_ag_maxlevels);
1885 /* space needed by-size freespace btree */
1886 min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1,
1887 mp->m_ag_maxlevels);
1893 * Check if the operation we are fixing up the freelist for should go ahead or
1894 * not. If we are freeing blocks, we always allow it, otherwise the allocation
1895 * is dependent on whether the size and shape of free space available will
1896 * permit the requested allocation to take place.
1899 xfs_alloc_space_available(
1900 struct xfs_alloc_arg *args,
1901 xfs_extlen_t min_free,
1904 struct xfs_perag *pag = args->pag;
1905 xfs_extlen_t longest;
1908 if (flags & XFS_ALLOC_FLAG_FREEING)
1911 /* do we have enough contiguous free space for the allocation? */
1912 longest = xfs_alloc_longest_free_extent(args->mp, pag, min_free);
1913 if ((args->minlen + args->alignment + args->minalignslop - 1) > longest)
1916 /* do have enough free space remaining for the allocation? */
1917 available = (int)(pag->pagf_freeblks + pag->pagf_flcount -
1918 min_free - args->total);
1919 if (available < (int)args->minleft)
1926 * Decide whether to use this allocation group for this allocation.
1927 * If so, fix up the btree freelist's size.
1929 STATIC int /* error */
1930 xfs_alloc_fix_freelist(
1931 struct xfs_alloc_arg *args, /* allocation argument structure */
1932 int flags) /* XFS_ALLOC_FLAG_... */
1934 struct xfs_mount *mp = args->mp;
1935 struct xfs_perag *pag = args->pag;
1936 struct xfs_trans *tp = args->tp;
1937 struct xfs_buf *agbp = NULL;
1938 struct xfs_buf *agflbp = NULL;
1939 struct xfs_alloc_arg targs; /* local allocation arguments */
1940 xfs_agblock_t bno; /* freelist block */
1941 xfs_extlen_t need; /* total blocks needed in freelist */
1944 if (!pag->pagf_init) {
1945 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
1948 if (!pag->pagf_init) {
1949 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1950 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1951 goto out_agbp_relse;
1956 * If this is a metadata preferred pag and we are user data then try
1957 * somewhere else if we are not being asked to try harder at this
1960 if (pag->pagf_metadata && args->userdata &&
1961 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
1962 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1963 goto out_agbp_relse;
1966 need = xfs_alloc_min_freelist(mp, pag);
1967 if (!xfs_alloc_space_available(args, need, flags))
1968 goto out_agbp_relse;
1971 * Get the a.g. freespace buffer.
1972 * Can fail if we're not blocking on locks, and it's held.
1975 error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
1979 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1980 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1985 /* If there isn't enough total space or single-extent, reject it. */
1986 need = xfs_alloc_min_freelist(mp, pag);
1987 if (!xfs_alloc_space_available(args, need, flags))
1988 goto out_agbp_relse;
1991 * Make the freelist shorter if it's too long.
1993 * Note that from this point onwards, we will always release the agf and
1994 * agfl buffers on error. This handles the case where we error out and
1995 * the buffers are clean or may not have been joined to the transaction
1996 * and hence need to be released manually. If they have been joined to
1997 * the transaction, then xfs_trans_brelse() will handle them
1998 * appropriately based on the recursion count and dirty state of the
2001 * XXX (dgc): When we have lots of free space, does this buy us
2002 * anything other than extra overhead when we need to put more blocks
2003 * back on the free list? Maybe we should only do this when space is
2004 * getting low or the AGFL is more than half full?
2006 while (pag->pagf_flcount > need) {
2009 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
2011 goto out_agbp_relse;
2012 error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1);
2014 goto out_agbp_relse;
2015 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
2016 xfs_trans_binval(tp, bp);
2019 memset(&targs, 0, sizeof(targs));
2023 targs.agno = args->agno;
2024 targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
2025 targs.type = XFS_ALLOCTYPE_THIS_AG;
2027 error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp);
2029 goto out_agbp_relse;
2031 /* Make the freelist longer if it's too short. */
2032 while (pag->pagf_flcount < need) {
2034 targs.maxlen = need - pag->pagf_flcount;
2036 /* Allocate as many blocks as possible at once. */
2037 error = xfs_alloc_ag_vextent(&targs);
2039 goto out_agflbp_relse;
2042 * Stop if we run out. Won't happen if callers are obeying
2043 * the restrictions correctly. Can happen for free calls
2044 * on a completely full ag.
2046 if (targs.agbno == NULLAGBLOCK) {
2047 if (flags & XFS_ALLOC_FLAG_FREEING)
2049 goto out_agflbp_relse;
2052 * Put each allocated block on the list.
2054 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
2055 error = xfs_alloc_put_freelist(tp, agbp,
2058 goto out_agflbp_relse;
2061 xfs_trans_brelse(tp, agflbp);
2066 xfs_trans_brelse(tp, agflbp);
2069 xfs_trans_brelse(tp, agbp);
2076 * Get a block from the freelist.
2077 * Returns with the buffer for the block gotten.
2080 xfs_alloc_get_freelist(
2081 xfs_trans_t *tp, /* transaction pointer */
2082 xfs_buf_t *agbp, /* buffer containing the agf structure */
2083 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2084 int btreeblk) /* destination is a AGF btree */
2086 xfs_agf_t *agf; /* a.g. freespace structure */
2087 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2088 xfs_agblock_t bno; /* block number returned */
2092 xfs_mount_t *mp = tp->t_mountp;
2093 xfs_perag_t *pag; /* per allocation group data */
2096 * Freelist is empty, give up.
2098 agf = XFS_BUF_TO_AGF(agbp);
2099 if (!agf->agf_flcount) {
2100 *bnop = NULLAGBLOCK;
2104 * Read the array of free blocks.
2106 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2113 * Get the block number and update the data structures.
2115 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2116 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2117 be32_add_cpu(&agf->agf_flfirst, 1);
2118 xfs_trans_brelse(tp, agflbp);
2119 if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
2120 agf->agf_flfirst = 0;
2122 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2123 be32_add_cpu(&agf->agf_flcount, -1);
2124 xfs_trans_agflist_delta(tp, -1);
2125 pag->pagf_flcount--;
2128 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2130 be32_add_cpu(&agf->agf_btreeblks, 1);
2131 pag->pagf_btreeblks++;
2132 logflags |= XFS_AGF_BTREEBLKS;
2135 xfs_alloc_log_agf(tp, agbp, logflags);
2142 * Log the given fields from the agf structure.
2146 xfs_trans_t *tp, /* transaction pointer */
2147 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2148 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2150 int first; /* first byte offset */
2151 int last; /* last byte offset */
2152 static const short offsets[] = {
2153 offsetof(xfs_agf_t, agf_magicnum),
2154 offsetof(xfs_agf_t, agf_versionnum),
2155 offsetof(xfs_agf_t, agf_seqno),
2156 offsetof(xfs_agf_t, agf_length),
2157 offsetof(xfs_agf_t, agf_roots[0]),
2158 offsetof(xfs_agf_t, agf_levels[0]),
2159 offsetof(xfs_agf_t, agf_flfirst),
2160 offsetof(xfs_agf_t, agf_fllast),
2161 offsetof(xfs_agf_t, agf_flcount),
2162 offsetof(xfs_agf_t, agf_freeblks),
2163 offsetof(xfs_agf_t, agf_longest),
2164 offsetof(xfs_agf_t, agf_btreeblks),
2165 offsetof(xfs_agf_t, agf_uuid),
2169 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2171 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
2173 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2174 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2178 * Interface for inode allocation to force the pag data to be initialized.
2181 xfs_alloc_pagf_init(
2182 xfs_mount_t *mp, /* file system mount structure */
2183 xfs_trans_t *tp, /* transaction pointer */
2184 xfs_agnumber_t agno, /* allocation group number */
2185 int flags) /* XFS_ALLOC_FLAGS_... */
2190 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2193 xfs_trans_brelse(tp, bp);
2198 * Put the block on the freelist for the allocation group.
2201 xfs_alloc_put_freelist(
2202 xfs_trans_t *tp, /* transaction pointer */
2203 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2204 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2205 xfs_agblock_t bno, /* block being freed */
2206 int btreeblk) /* block came from a AGF btree */
2208 xfs_agf_t *agf; /* a.g. freespace structure */
2209 __be32 *blockp;/* pointer to array entry */
2212 xfs_mount_t *mp; /* mount structure */
2213 xfs_perag_t *pag; /* per allocation group data */
2217 agf = XFS_BUF_TO_AGF(agbp);
2220 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2221 be32_to_cpu(agf->agf_seqno), &agflbp)))
2223 be32_add_cpu(&agf->agf_fllast, 1);
2224 if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
2225 agf->agf_fllast = 0;
2227 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2228 be32_add_cpu(&agf->agf_flcount, 1);
2229 xfs_trans_agflist_delta(tp, 1);
2230 pag->pagf_flcount++;
2232 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2234 be32_add_cpu(&agf->agf_btreeblks, -1);
2235 pag->pagf_btreeblks--;
2236 logflags |= XFS_AGF_BTREEBLKS;
2240 xfs_alloc_log_agf(tp, agbp, logflags);
2242 ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
2244 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2245 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
2246 *blockp = cpu_to_be32(bno);
2247 startoff = (char *)blockp - (char *)agflbp->b_addr;
2249 xfs_alloc_log_agf(tp, agbp, logflags);
2251 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
2252 xfs_trans_log_buf(tp, agflbp, startoff,
2253 startoff + sizeof(xfs_agblock_t) - 1);
2259 struct xfs_mount *mp,
2262 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
2264 if (xfs_sb_version_hascrc(&mp->m_sb)) {
2265 if (!uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid))
2267 if (!xfs_log_check_lsn(mp,
2268 be64_to_cpu(XFS_BUF_TO_AGF(bp)->agf_lsn)))
2272 if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
2273 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2274 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2275 be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
2276 be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
2277 be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
2280 if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS ||
2281 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > XFS_BTREE_MAXLEVELS)
2285 * during growfs operations, the perag is not fully initialised,
2286 * so we can't use it for any useful checking. growfs ensures we can't
2287 * use it by using uncached buffers that don't have the perag attached
2288 * so we can detect and avoid this problem.
2290 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2293 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2294 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2302 xfs_agf_read_verify(
2305 struct xfs_mount *mp = bp->b_target->bt_mount;
2307 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2308 !xfs_buf_verify_cksum(bp, XFS_AGF_CRC_OFF))
2309 xfs_buf_ioerror(bp, -EFSBADCRC);
2310 else if (XFS_TEST_ERROR(!xfs_agf_verify(mp, bp), mp,
2311 XFS_ERRTAG_ALLOC_READ_AGF,
2312 XFS_RANDOM_ALLOC_READ_AGF))
2313 xfs_buf_ioerror(bp, -EFSCORRUPTED);
2316 xfs_verifier_error(bp);
2320 xfs_agf_write_verify(
2323 struct xfs_mount *mp = bp->b_target->bt_mount;
2324 struct xfs_buf_log_item *bip = bp->b_fspriv;
2326 if (!xfs_agf_verify(mp, bp)) {
2327 xfs_buf_ioerror(bp, -EFSCORRUPTED);
2328 xfs_verifier_error(bp);
2332 if (!xfs_sb_version_hascrc(&mp->m_sb))
2336 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2338 xfs_buf_update_cksum(bp, XFS_AGF_CRC_OFF);
2341 const struct xfs_buf_ops xfs_agf_buf_ops = {
2342 .verify_read = xfs_agf_read_verify,
2343 .verify_write = xfs_agf_write_verify,
2347 * Read in the allocation group header (free/alloc section).
2351 struct xfs_mount *mp, /* mount point structure */
2352 struct xfs_trans *tp, /* transaction pointer */
2353 xfs_agnumber_t agno, /* allocation group number */
2354 int flags, /* XFS_BUF_ */
2355 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2359 trace_xfs_read_agf(mp, agno);
2361 ASSERT(agno != NULLAGNUMBER);
2362 error = xfs_trans_read_buf(
2363 mp, tp, mp->m_ddev_targp,
2364 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2365 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
2371 ASSERT(!(*bpp)->b_error);
2372 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
2377 * Read in the allocation group header (free/alloc section).
2381 struct xfs_mount *mp, /* mount point structure */
2382 struct xfs_trans *tp, /* transaction pointer */
2383 xfs_agnumber_t agno, /* allocation group number */
2384 int flags, /* XFS_ALLOC_FLAG_... */
2385 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2387 struct xfs_agf *agf; /* ag freelist header */
2388 struct xfs_perag *pag; /* per allocation group data */
2391 trace_xfs_alloc_read_agf(mp, agno);
2393 ASSERT(agno != NULLAGNUMBER);
2394 error = xfs_read_agf(mp, tp, agno,
2395 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
2401 ASSERT(!(*bpp)->b_error);
2403 agf = XFS_BUF_TO_AGF(*bpp);
2404 pag = xfs_perag_get(mp, agno);
2405 if (!pag->pagf_init) {
2406 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2407 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
2408 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2409 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2410 pag->pagf_levels[XFS_BTNUM_BNOi] =
2411 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2412 pag->pagf_levels[XFS_BTNUM_CNTi] =
2413 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2414 spin_lock_init(&pag->pagb_lock);
2415 pag->pagb_count = 0;
2416 pag->pagb_tree = RB_ROOT;
2420 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2421 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2422 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
2423 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2424 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2425 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2426 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2427 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2428 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2436 * Allocate an extent (variable-size).
2437 * Depending on the allocation type, we either look in a single allocation
2438 * group or loop over the allocation groups to find the result.
2442 xfs_alloc_arg_t *args) /* allocation argument structure */
2444 xfs_agblock_t agsize; /* allocation group size */
2446 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2447 xfs_extlen_t minleft;/* minimum left value, temp copy */
2448 xfs_mount_t *mp; /* mount structure pointer */
2449 xfs_agnumber_t sagno; /* starting allocation group number */
2450 xfs_alloctype_t type; /* input allocation type */
2453 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2456 type = args->otype = args->type;
2457 args->agbno = NULLAGBLOCK;
2459 * Just fix this up, for the case where the last a.g. is shorter
2460 * (or there's only one a.g.) and the caller couldn't easily figure
2461 * that out (xfs_bmap_alloc).
2463 agsize = mp->m_sb.sb_agblocks;
2464 if (args->maxlen > agsize)
2465 args->maxlen = agsize;
2466 if (args->alignment == 0)
2467 args->alignment = 1;
2468 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2469 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2470 ASSERT(args->minlen <= args->maxlen);
2471 ASSERT(args->minlen <= agsize);
2472 ASSERT(args->mod < args->prod);
2473 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2474 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2475 args->minlen > args->maxlen || args->minlen > agsize ||
2476 args->mod >= args->prod) {
2477 args->fsbno = NULLFSBLOCK;
2478 trace_xfs_alloc_vextent_badargs(args);
2481 minleft = args->minleft;
2484 case XFS_ALLOCTYPE_THIS_AG:
2485 case XFS_ALLOCTYPE_NEAR_BNO:
2486 case XFS_ALLOCTYPE_THIS_BNO:
2488 * These three force us into a single a.g.
2490 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2491 args->pag = xfs_perag_get(mp, args->agno);
2493 error = xfs_alloc_fix_freelist(args, 0);
2494 args->minleft = minleft;
2496 trace_xfs_alloc_vextent_nofix(args);
2500 trace_xfs_alloc_vextent_noagbp(args);
2503 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2504 if ((error = xfs_alloc_ag_vextent(args)))
2507 case XFS_ALLOCTYPE_START_BNO:
2509 * Try near allocation first, then anywhere-in-ag after
2510 * the first a.g. fails.
2512 if ((args->userdata & XFS_ALLOC_INITIAL_USER_DATA) &&
2513 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2514 args->fsbno = XFS_AGB_TO_FSB(mp,
2515 ((mp->m_agfrotor / rotorstep) %
2516 mp->m_sb.sb_agcount), 0);
2519 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2520 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2522 case XFS_ALLOCTYPE_ANY_AG:
2523 case XFS_ALLOCTYPE_START_AG:
2524 case XFS_ALLOCTYPE_FIRST_AG:
2526 * Rotate through the allocation groups looking for a winner.
2528 if (type == XFS_ALLOCTYPE_ANY_AG) {
2530 * Start with the last place we left off.
2532 args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2533 mp->m_sb.sb_agcount;
2534 args->type = XFS_ALLOCTYPE_THIS_AG;
2535 flags = XFS_ALLOC_FLAG_TRYLOCK;
2536 } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2538 * Start with allocation group given by bno.
2540 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2541 args->type = XFS_ALLOCTYPE_THIS_AG;
2545 if (type == XFS_ALLOCTYPE_START_AG)
2546 args->type = XFS_ALLOCTYPE_THIS_AG;
2548 * Start with the given allocation group.
2550 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2551 flags = XFS_ALLOC_FLAG_TRYLOCK;
2554 * Loop over allocation groups twice; first time with
2555 * trylock set, second time without.
2558 args->pag = xfs_perag_get(mp, args->agno);
2559 if (no_min) args->minleft = 0;
2560 error = xfs_alloc_fix_freelist(args, flags);
2561 args->minleft = minleft;
2563 trace_xfs_alloc_vextent_nofix(args);
2567 * If we get a buffer back then the allocation will fly.
2570 if ((error = xfs_alloc_ag_vextent(args)))
2575 trace_xfs_alloc_vextent_loopfailed(args);
2578 * Didn't work, figure out the next iteration.
2580 if (args->agno == sagno &&
2581 type == XFS_ALLOCTYPE_START_BNO)
2582 args->type = XFS_ALLOCTYPE_THIS_AG;
2584 * For the first allocation, we can try any AG to get
2585 * space. However, if we already have allocated a
2586 * block, we don't want to try AGs whose number is below
2587 * sagno. Otherwise, we may end up with out-of-order
2588 * locking of AGF, which might cause deadlock.
2590 if (++(args->agno) == mp->m_sb.sb_agcount) {
2591 if (args->firstblock != NULLFSBLOCK)
2597 * Reached the starting a.g., must either be done
2598 * or switch to non-trylock mode.
2600 if (args->agno == sagno) {
2602 args->agbno = NULLAGBLOCK;
2603 trace_xfs_alloc_vextent_allfailed(args);
2610 if (type == XFS_ALLOCTYPE_START_BNO) {
2611 args->agbno = XFS_FSB_TO_AGBNO(mp,
2613 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2617 xfs_perag_put(args->pag);
2619 if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2620 if (args->agno == sagno)
2621 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2622 (mp->m_sb.sb_agcount * rotorstep);
2624 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2625 (mp->m_sb.sb_agcount * rotorstep);
2632 if (args->agbno == NULLAGBLOCK)
2633 args->fsbno = NULLFSBLOCK;
2635 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2637 ASSERT(args->len >= args->minlen);
2638 ASSERT(args->len <= args->maxlen);
2639 ASSERT(args->agbno % args->alignment == 0);
2640 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2644 /* Zero the extent if we were asked to do so */
2645 if (args->userdata & XFS_ALLOC_USERDATA_ZERO) {
2646 error = xfs_zero_extent(args->ip, args->fsbno, args->len);
2652 xfs_perag_put(args->pag);
2655 xfs_perag_put(args->pag);
2661 * Just break up the extent address and hand off to xfs_free_ag_extent
2662 * after fixing up the freelist.
2666 xfs_trans_t *tp, /* transaction pointer */
2667 xfs_fsblock_t bno, /* starting block number of extent */
2668 xfs_extlen_t len) /* length of extent */
2670 xfs_alloc_arg_t args;
2674 memset(&args, 0, sizeof(xfs_alloc_arg_t));
2676 args.mp = tp->t_mountp;
2679 * validate that the block number is legal - the enables us to detect
2680 * and handle a silent filesystem corruption rather than crashing.
2682 args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
2683 if (args.agno >= args.mp->m_sb.sb_agcount)
2684 return -EFSCORRUPTED;
2686 args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
2687 if (args.agbno >= args.mp->m_sb.sb_agblocks)
2688 return -EFSCORRUPTED;
2690 args.pag = xfs_perag_get(args.mp, args.agno);
2693 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
2697 /* validate the extent size is legal now we have the agf locked */
2698 if (args.agbno + len >
2699 be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
2700 error = -EFSCORRUPTED;
2704 error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
2706 xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
2708 xfs_perag_put(args.pag);