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"
24 #include "xfs_trans.h"
27 #include "xfs_mount.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_alloc_btree.h"
30 #include "xfs_ialloc_btree.h"
31 #include "xfs_dinode.h"
32 #include "xfs_inode.h"
33 #include "xfs_btree.h"
34 #include "xfs_alloc.h"
35 #include "xfs_error.h"
36 #include "xfs_trace.h"
39 #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
41 #define XFSA_FIXUP_BNO_OK 1
42 #define XFSA_FIXUP_CNT_OK 2
45 xfs_alloc_busy_search(struct xfs_mount
*mp
, xfs_agnumber_t agno
,
46 xfs_agblock_t bno
, xfs_extlen_t len
);
49 * Prototypes for per-ag allocation routines
52 STATIC
int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t
*);
53 STATIC
int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t
*);
54 STATIC
int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t
*);
55 STATIC
int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t
*,
56 xfs_btree_cur_t
*, xfs_agblock_t
*, xfs_extlen_t
*, int *);
63 * Lookup the record equal to [bno, len] in the btree given by cur.
65 STATIC
int /* error */
67 struct xfs_btree_cur
*cur
, /* btree cursor */
68 xfs_agblock_t bno
, /* starting block of extent */
69 xfs_extlen_t len
, /* length of extent */
70 int *stat
) /* success/failure */
72 cur
->bc_rec
.a
.ar_startblock
= bno
;
73 cur
->bc_rec
.a
.ar_blockcount
= len
;
74 return xfs_btree_lookup(cur
, XFS_LOOKUP_EQ
, stat
);
78 * Lookup the first record greater than or equal to [bno, len]
79 * in the btree given by cur.
81 STATIC
int /* error */
83 struct xfs_btree_cur
*cur
, /* btree cursor */
84 xfs_agblock_t bno
, /* starting block of extent */
85 xfs_extlen_t len
, /* length of extent */
86 int *stat
) /* success/failure */
88 cur
->bc_rec
.a
.ar_startblock
= bno
;
89 cur
->bc_rec
.a
.ar_blockcount
= len
;
90 return xfs_btree_lookup(cur
, XFS_LOOKUP_GE
, stat
);
94 * Lookup the first record less than or equal to [bno, len]
95 * in the btree given by cur.
97 STATIC
int /* error */
99 struct xfs_btree_cur
*cur
, /* btree cursor */
100 xfs_agblock_t bno
, /* starting block of extent */
101 xfs_extlen_t len
, /* length of extent */
102 int *stat
) /* success/failure */
104 cur
->bc_rec
.a
.ar_startblock
= bno
;
105 cur
->bc_rec
.a
.ar_blockcount
= len
;
106 return xfs_btree_lookup(cur
, XFS_LOOKUP_LE
, stat
);
110 * Update the record referred to by cur to the value given
112 * This either works (return 0) or gets an EFSCORRUPTED error.
114 STATIC
int /* error */
116 struct xfs_btree_cur
*cur
, /* btree cursor */
117 xfs_agblock_t bno
, /* starting block of extent */
118 xfs_extlen_t len
) /* length of extent */
120 union xfs_btree_rec rec
;
122 rec
.alloc
.ar_startblock
= cpu_to_be32(bno
);
123 rec
.alloc
.ar_blockcount
= cpu_to_be32(len
);
124 return xfs_btree_update(cur
, &rec
);
128 * Get the data from the pointed-to record.
130 STATIC
int /* error */
132 struct xfs_btree_cur
*cur
, /* btree cursor */
133 xfs_agblock_t
*bno
, /* output: starting block of extent */
134 xfs_extlen_t
*len
, /* output: length of extent */
135 int *stat
) /* output: success/failure */
137 union xfs_btree_rec
*rec
;
140 error
= xfs_btree_get_rec(cur
, &rec
, stat
);
141 if (!error
&& *stat
== 1) {
142 *bno
= be32_to_cpu(rec
->alloc
.ar_startblock
);
143 *len
= be32_to_cpu(rec
->alloc
.ar_blockcount
);
149 * Compute aligned version of the found extent.
150 * Takes alignment and min length into account.
153 xfs_alloc_compute_aligned(
154 xfs_agblock_t foundbno
, /* starting block in found extent */
155 xfs_extlen_t foundlen
, /* length in found extent */
156 xfs_extlen_t alignment
, /* alignment for allocation */
157 xfs_extlen_t minlen
, /* minimum length for allocation */
158 xfs_agblock_t
*resbno
, /* result block number */
159 xfs_extlen_t
*reslen
) /* result length */
165 if (alignment
> 1 && foundlen
>= minlen
) {
166 bno
= roundup(foundbno
, alignment
);
167 diff
= bno
- foundbno
;
168 len
= diff
>= foundlen
? 0 : foundlen
- diff
;
178 * Compute best start block and diff for "near" allocations.
179 * freelen >= wantlen already checked by caller.
181 STATIC xfs_extlen_t
/* difference value (absolute) */
182 xfs_alloc_compute_diff(
183 xfs_agblock_t wantbno
, /* target starting block */
184 xfs_extlen_t wantlen
, /* target length */
185 xfs_extlen_t alignment
, /* target alignment */
186 xfs_agblock_t freebno
, /* freespace's starting block */
187 xfs_extlen_t freelen
, /* freespace's length */
188 xfs_agblock_t
*newbnop
) /* result: best start block from free */
190 xfs_agblock_t freeend
; /* end of freespace extent */
191 xfs_agblock_t newbno1
; /* return block number */
192 xfs_agblock_t newbno2
; /* other new block number */
193 xfs_extlen_t newlen1
=0; /* length with newbno1 */
194 xfs_extlen_t newlen2
=0; /* length with newbno2 */
195 xfs_agblock_t wantend
; /* end of target extent */
197 ASSERT(freelen
>= wantlen
);
198 freeend
= freebno
+ freelen
;
199 wantend
= wantbno
+ wantlen
;
200 if (freebno
>= wantbno
) {
201 if ((newbno1
= roundup(freebno
, alignment
)) >= freeend
)
202 newbno1
= NULLAGBLOCK
;
203 } else if (freeend
>= wantend
&& alignment
> 1) {
204 newbno1
= roundup(wantbno
, alignment
);
205 newbno2
= newbno1
- alignment
;
206 if (newbno1
>= freeend
)
207 newbno1
= NULLAGBLOCK
;
209 newlen1
= XFS_EXTLEN_MIN(wantlen
, freeend
- newbno1
);
210 if (newbno2
< freebno
)
211 newbno2
= NULLAGBLOCK
;
213 newlen2
= XFS_EXTLEN_MIN(wantlen
, freeend
- newbno2
);
214 if (newbno1
!= NULLAGBLOCK
&& newbno2
!= NULLAGBLOCK
) {
215 if (newlen1
< newlen2
||
216 (newlen1
== newlen2
&&
217 XFS_ABSDIFF(newbno1
, wantbno
) >
218 XFS_ABSDIFF(newbno2
, wantbno
)))
220 } else if (newbno2
!= NULLAGBLOCK
)
222 } else if (freeend
>= wantend
) {
224 } else if (alignment
> 1) {
225 newbno1
= roundup(freeend
- wantlen
, alignment
);
226 if (newbno1
> freeend
- wantlen
&&
227 newbno1
- alignment
>= freebno
)
228 newbno1
-= alignment
;
229 else if (newbno1
>= freeend
)
230 newbno1
= NULLAGBLOCK
;
232 newbno1
= freeend
- wantlen
;
234 return newbno1
== NULLAGBLOCK
? 0 : XFS_ABSDIFF(newbno1
, wantbno
);
238 * Fix up the length, based on mod and prod.
239 * len should be k * prod + mod for some k.
240 * If len is too small it is returned unchanged.
241 * If len hits maxlen it is left alone.
245 xfs_alloc_arg_t
*args
) /* allocation argument structure */
250 ASSERT(args
->mod
< args
->prod
);
252 ASSERT(rlen
>= args
->minlen
);
253 ASSERT(rlen
<= args
->maxlen
);
254 if (args
->prod
<= 1 || rlen
< args
->mod
|| rlen
== args
->maxlen
||
255 (args
->mod
== 0 && rlen
< args
->prod
))
257 k
= rlen
% args
->prod
;
261 if ((int)(rlen
= rlen
- k
- args
->mod
) < (int)args
->minlen
)
264 if ((int)(rlen
= rlen
- args
->prod
- (args
->mod
- k
)) <
268 ASSERT(rlen
>= args
->minlen
);
269 ASSERT(rlen
<= args
->maxlen
);
274 * Fix up length if there is too little space left in the a.g.
275 * Return 1 if ok, 0 if too little, should give up.
278 xfs_alloc_fix_minleft(
279 xfs_alloc_arg_t
*args
) /* allocation argument structure */
281 xfs_agf_t
*agf
; /* a.g. freelist header */
282 int diff
; /* free space difference */
284 if (args
->minleft
== 0)
286 agf
= XFS_BUF_TO_AGF(args
->agbp
);
287 diff
= be32_to_cpu(agf
->agf_freeblks
)
288 + be32_to_cpu(agf
->agf_flcount
)
289 - args
->len
- args
->minleft
;
292 args
->len
+= diff
; /* shrink the allocated space */
293 if (args
->len
>= args
->minlen
)
295 args
->agbno
= NULLAGBLOCK
;
300 * Update the two btrees, logically removing from freespace the extent
301 * starting at rbno, rlen blocks. The extent is contained within the
302 * actual (current) free extent fbno for flen blocks.
303 * Flags are passed in indicating whether the cursors are set to the
306 STATIC
int /* error code */
307 xfs_alloc_fixup_trees(
308 xfs_btree_cur_t
*cnt_cur
, /* cursor for by-size btree */
309 xfs_btree_cur_t
*bno_cur
, /* cursor for by-block btree */
310 xfs_agblock_t fbno
, /* starting block of free extent */
311 xfs_extlen_t flen
, /* length of free extent */
312 xfs_agblock_t rbno
, /* starting block of returned extent */
313 xfs_extlen_t rlen
, /* length of returned extent */
314 int flags
) /* flags, XFSA_FIXUP_... */
316 int error
; /* error code */
317 int i
; /* operation results */
318 xfs_agblock_t nfbno1
; /* first new free startblock */
319 xfs_agblock_t nfbno2
; /* second new free startblock */
320 xfs_extlen_t nflen1
=0; /* first new free length */
321 xfs_extlen_t nflen2
=0; /* second new free length */
324 * Look up the record in the by-size tree if necessary.
326 if (flags
& XFSA_FIXUP_CNT_OK
) {
328 if ((error
= xfs_alloc_get_rec(cnt_cur
, &nfbno1
, &nflen1
, &i
)))
330 XFS_WANT_CORRUPTED_RETURN(
331 i
== 1 && nfbno1
== fbno
&& nflen1
== flen
);
334 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, fbno
, flen
, &i
)))
336 XFS_WANT_CORRUPTED_RETURN(i
== 1);
339 * Look up the record in the by-block tree if necessary.
341 if (flags
& XFSA_FIXUP_BNO_OK
) {
343 if ((error
= xfs_alloc_get_rec(bno_cur
, &nfbno1
, &nflen1
, &i
)))
345 XFS_WANT_CORRUPTED_RETURN(
346 i
== 1 && nfbno1
== fbno
&& nflen1
== flen
);
349 if ((error
= xfs_alloc_lookup_eq(bno_cur
, fbno
, flen
, &i
)))
351 XFS_WANT_CORRUPTED_RETURN(i
== 1);
355 if (bno_cur
->bc_nlevels
== 1 && cnt_cur
->bc_nlevels
== 1) {
356 struct xfs_btree_block
*bnoblock
;
357 struct xfs_btree_block
*cntblock
;
359 bnoblock
= XFS_BUF_TO_BLOCK(bno_cur
->bc_bufs
[0]);
360 cntblock
= XFS_BUF_TO_BLOCK(cnt_cur
->bc_bufs
[0]);
362 XFS_WANT_CORRUPTED_RETURN(
363 bnoblock
->bb_numrecs
== cntblock
->bb_numrecs
);
368 * Deal with all four cases: the allocated record is contained
369 * within the freespace record, so we can have new freespace
370 * at either (or both) end, or no freespace remaining.
372 if (rbno
== fbno
&& rlen
== flen
)
373 nfbno1
= nfbno2
= NULLAGBLOCK
;
374 else if (rbno
== fbno
) {
375 nfbno1
= rbno
+ rlen
;
376 nflen1
= flen
- rlen
;
377 nfbno2
= NULLAGBLOCK
;
378 } else if (rbno
+ rlen
== fbno
+ flen
) {
380 nflen1
= flen
- rlen
;
381 nfbno2
= NULLAGBLOCK
;
384 nflen1
= rbno
- fbno
;
385 nfbno2
= rbno
+ rlen
;
386 nflen2
= (fbno
+ flen
) - nfbno2
;
389 * Delete the entry from the by-size btree.
391 if ((error
= xfs_btree_delete(cnt_cur
, &i
)))
393 XFS_WANT_CORRUPTED_RETURN(i
== 1);
395 * Add new by-size btree entry(s).
397 if (nfbno1
!= NULLAGBLOCK
) {
398 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, nfbno1
, nflen1
, &i
)))
400 XFS_WANT_CORRUPTED_RETURN(i
== 0);
401 if ((error
= xfs_btree_insert(cnt_cur
, &i
)))
403 XFS_WANT_CORRUPTED_RETURN(i
== 1);
405 if (nfbno2
!= NULLAGBLOCK
) {
406 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, nfbno2
, nflen2
, &i
)))
408 XFS_WANT_CORRUPTED_RETURN(i
== 0);
409 if ((error
= xfs_btree_insert(cnt_cur
, &i
)))
411 XFS_WANT_CORRUPTED_RETURN(i
== 1);
414 * Fix up the by-block btree entry(s).
416 if (nfbno1
== NULLAGBLOCK
) {
418 * No remaining freespace, just delete the by-block tree entry.
420 if ((error
= xfs_btree_delete(bno_cur
, &i
)))
422 XFS_WANT_CORRUPTED_RETURN(i
== 1);
425 * Update the by-block entry to start later|be shorter.
427 if ((error
= xfs_alloc_update(bno_cur
, nfbno1
, nflen1
)))
430 if (nfbno2
!= NULLAGBLOCK
) {
432 * 2 resulting free entries, need to add one.
434 if ((error
= xfs_alloc_lookup_eq(bno_cur
, nfbno2
, nflen2
, &i
)))
436 XFS_WANT_CORRUPTED_RETURN(i
== 0);
437 if ((error
= xfs_btree_insert(bno_cur
, &i
)))
439 XFS_WANT_CORRUPTED_RETURN(i
== 1);
445 * Read in the allocation group free block array.
447 STATIC
int /* error */
449 xfs_mount_t
*mp
, /* mount point structure */
450 xfs_trans_t
*tp
, /* transaction pointer */
451 xfs_agnumber_t agno
, /* allocation group number */
452 xfs_buf_t
**bpp
) /* buffer for the ag free block array */
454 xfs_buf_t
*bp
; /* return value */
457 ASSERT(agno
!= NULLAGNUMBER
);
458 error
= xfs_trans_read_buf(
459 mp
, tp
, mp
->m_ddev_targp
,
460 XFS_AG_DADDR(mp
, agno
, XFS_AGFL_DADDR(mp
)),
461 XFS_FSS_TO_BB(mp
, 1), 0, &bp
);
465 ASSERT(!XFS_BUF_GETERROR(bp
));
466 XFS_BUF_SET_VTYPE_REF(bp
, B_FS_AGFL
, XFS_AGFL_REF
);
472 * Allocation group level functions.
476 * Allocate a variable extent in the allocation group agno.
477 * Type and bno are used to determine where in the allocation group the
479 * Extent's length (returned in *len) will be between minlen and maxlen,
480 * and of the form k * prod + mod unless there's nothing that large.
481 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
483 STATIC
int /* error */
484 xfs_alloc_ag_vextent(
485 xfs_alloc_arg_t
*args
) /* argument structure for allocation */
489 ASSERT(args
->minlen
> 0);
490 ASSERT(args
->maxlen
> 0);
491 ASSERT(args
->minlen
<= args
->maxlen
);
492 ASSERT(args
->mod
< args
->prod
);
493 ASSERT(args
->alignment
> 0);
495 * Branch to correct routine based on the type.
498 switch (args
->type
) {
499 case XFS_ALLOCTYPE_THIS_AG
:
500 error
= xfs_alloc_ag_vextent_size(args
);
502 case XFS_ALLOCTYPE_NEAR_BNO
:
503 error
= xfs_alloc_ag_vextent_near(args
);
505 case XFS_ALLOCTYPE_THIS_BNO
:
506 error
= xfs_alloc_ag_vextent_exact(args
);
515 * If the allocation worked, need to change the agf structure
516 * (and log it), and the superblock.
518 if (args
->agbno
!= NULLAGBLOCK
) {
519 xfs_agf_t
*agf
; /* allocation group freelist header */
520 long slen
= (long)args
->len
;
522 ASSERT(args
->len
>= args
->minlen
&& args
->len
<= args
->maxlen
);
523 ASSERT(!(args
->wasfromfl
) || !args
->isfl
);
524 ASSERT(args
->agbno
% args
->alignment
== 0);
525 if (!(args
->wasfromfl
)) {
527 agf
= XFS_BUF_TO_AGF(args
->agbp
);
528 be32_add_cpu(&agf
->agf_freeblks
, -(args
->len
));
529 xfs_trans_agblocks_delta(args
->tp
,
530 -((long)(args
->len
)));
531 args
->pag
->pagf_freeblks
-= args
->len
;
532 ASSERT(be32_to_cpu(agf
->agf_freeblks
) <=
533 be32_to_cpu(agf
->agf_length
));
534 xfs_alloc_log_agf(args
->tp
, args
->agbp
,
537 * Search the busylist for these blocks and mark the
538 * transaction as synchronous if blocks are found. This
539 * avoids the need to block due to a synchronous log
540 * force to ensure correct ordering as the synchronous
541 * transaction will guarantee that for us.
543 if (xfs_alloc_busy_search(args
->mp
, args
->agno
,
544 args
->agbno
, args
->len
))
545 xfs_trans_set_sync(args
->tp
);
548 xfs_trans_mod_sb(args
->tp
,
549 args
->wasdel
? XFS_TRANS_SB_RES_FDBLOCKS
:
550 XFS_TRANS_SB_FDBLOCKS
, -slen
);
551 XFS_STATS_INC(xs_allocx
);
552 XFS_STATS_ADD(xs_allocb
, args
->len
);
558 * Allocate a variable extent at exactly agno/bno.
559 * Extent's length (returned in *len) will be between minlen and maxlen,
560 * and of the form k * prod + mod unless there's nothing that large.
561 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
563 STATIC
int /* error */
564 xfs_alloc_ag_vextent_exact(
565 xfs_alloc_arg_t
*args
) /* allocation argument structure */
567 xfs_btree_cur_t
*bno_cur
;/* by block-number btree cursor */
568 xfs_btree_cur_t
*cnt_cur
;/* by count btree cursor */
569 xfs_agblock_t end
; /* end of allocated extent */
571 xfs_agblock_t fbno
; /* start block of found extent */
572 xfs_agblock_t fend
; /* end block of found extent */
573 xfs_extlen_t flen
; /* length of found extent */
574 int i
; /* success/failure of operation */
575 xfs_agblock_t maxend
; /* end of maximal extent */
576 xfs_agblock_t minend
; /* end of minimal extent */
577 xfs_extlen_t rlen
; /* length of returned extent */
579 ASSERT(args
->alignment
== 1);
582 * Allocate/initialize a cursor for the by-number freespace btree.
584 bno_cur
= xfs_allocbt_init_cursor(args
->mp
, args
->tp
, args
->agbp
,
585 args
->agno
, XFS_BTNUM_BNO
);
588 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
589 * Look for the closest free block <= bno, it must contain bno
590 * if any free block does.
592 error
= xfs_alloc_lookup_le(bno_cur
, args
->agbno
, args
->minlen
, &i
);
599 * Grab the freespace record.
601 error
= xfs_alloc_get_rec(bno_cur
, &fbno
, &flen
, &i
);
604 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
605 ASSERT(fbno
<= args
->agbno
);
606 minend
= args
->agbno
+ args
->minlen
;
607 maxend
= args
->agbno
+ args
->maxlen
;
611 * Give up if the freespace isn't long enough for the minimum request.
617 * End of extent will be smaller of the freespace end and the
618 * maximal requested end.
620 * Fix the length according to mod and prod if given.
622 end
= XFS_AGBLOCK_MIN(fend
, maxend
);
623 args
->len
= end
- args
->agbno
;
624 xfs_alloc_fix_len(args
);
625 if (!xfs_alloc_fix_minleft(args
))
629 ASSERT(args
->agbno
+ rlen
<= fend
);
630 end
= args
->agbno
+ rlen
;
633 * We are allocating agbno for rlen [agbno .. end]
634 * Allocate/initialize a cursor for the by-size btree.
636 cnt_cur
= xfs_allocbt_init_cursor(args
->mp
, args
->tp
, args
->agbp
,
637 args
->agno
, XFS_BTNUM_CNT
);
638 ASSERT(args
->agbno
+ args
->len
<=
639 be32_to_cpu(XFS_BUF_TO_AGF(args
->agbp
)->agf_length
));
640 error
= xfs_alloc_fixup_trees(cnt_cur
, bno_cur
, fbno
, flen
, args
->agbno
,
641 args
->len
, XFSA_FIXUP_BNO_OK
);
643 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_ERROR
);
647 xfs_btree_del_cursor(bno_cur
, XFS_BTREE_NOERROR
);
648 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
651 trace_xfs_alloc_exact_done(args
);
655 /* Didn't find it, return null. */
656 xfs_btree_del_cursor(bno_cur
, XFS_BTREE_NOERROR
);
657 args
->agbno
= NULLAGBLOCK
;
658 trace_xfs_alloc_exact_notfound(args
);
662 xfs_btree_del_cursor(bno_cur
, XFS_BTREE_ERROR
);
663 trace_xfs_alloc_exact_error(args
);
668 * Search the btree in a given direction via the search cursor and compare
669 * the records found against the good extent we've already found.
672 xfs_alloc_find_best_extent(
673 struct xfs_alloc_arg
*args
, /* allocation argument structure */
674 struct xfs_btree_cur
**gcur
, /* good cursor */
675 struct xfs_btree_cur
**scur
, /* searching cursor */
676 xfs_agblock_t gdiff
, /* difference for search comparison */
677 xfs_agblock_t
*sbno
, /* extent found by search */
679 xfs_extlen_t
*slena
, /* aligned length */
680 int dir
) /* 0 = search right, 1 = search left */
688 /* The good extent is perfect, no need to search. */
693 * Look until we find a better one, run out of space or run off the end.
696 error
= xfs_alloc_get_rec(*scur
, sbno
, slen
, &i
);
699 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
700 xfs_alloc_compute_aligned(*sbno
, *slen
, args
->alignment
,
701 args
->minlen
, &bno
, slena
);
704 * The good extent is closer than this one.
707 if (bno
>= args
->agbno
+ gdiff
)
710 if (bno
<= args
->agbno
- gdiff
)
715 * Same distance, compare length and pick the best.
717 if (*slena
>= args
->minlen
) {
718 args
->len
= XFS_EXTLEN_MIN(*slena
, args
->maxlen
);
719 xfs_alloc_fix_len(args
);
721 sdiff
= xfs_alloc_compute_diff(args
->agbno
, args
->len
,
722 args
->alignment
, *sbno
,
726 * Choose closer size and invalidate other cursor.
734 error
= xfs_btree_increment(*scur
, 0, &i
);
736 error
= xfs_btree_decrement(*scur
, 0, &i
);
742 xfs_btree_del_cursor(*scur
, XFS_BTREE_NOERROR
);
747 xfs_btree_del_cursor(*gcur
, XFS_BTREE_NOERROR
);
752 /* caller invalidates cursors */
757 * Allocate a variable extent near bno in the allocation group agno.
758 * Extent's length (returned in len) will be between minlen and maxlen,
759 * and of the form k * prod + mod unless there's nothing that large.
760 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
762 STATIC
int /* error */
763 xfs_alloc_ag_vextent_near(
764 xfs_alloc_arg_t
*args
) /* allocation argument structure */
766 xfs_btree_cur_t
*bno_cur_gt
; /* cursor for bno btree, right side */
767 xfs_btree_cur_t
*bno_cur_lt
; /* cursor for bno btree, left side */
768 xfs_btree_cur_t
*cnt_cur
; /* cursor for count btree */
769 xfs_agblock_t gtbno
; /* start bno of right side entry */
770 xfs_agblock_t gtbnoa
; /* aligned ... */
771 xfs_extlen_t gtdiff
; /* difference to right side entry */
772 xfs_extlen_t gtlen
; /* length of right side entry */
773 xfs_extlen_t gtlena
= 0; /* aligned ... */
774 xfs_agblock_t gtnew
; /* useful start bno of right side */
775 int error
; /* error code */
776 int i
; /* result code, temporary */
777 int j
; /* result code, temporary */
778 xfs_agblock_t ltbno
; /* start bno of left side entry */
779 xfs_agblock_t ltbnoa
; /* aligned ... */
780 xfs_extlen_t ltdiff
; /* difference to left side entry */
781 xfs_extlen_t ltlen
; /* length of left side entry */
782 xfs_extlen_t ltlena
= 0; /* aligned ... */
783 xfs_agblock_t ltnew
; /* useful start bno of left side */
784 xfs_extlen_t rlen
; /* length of returned extent */
785 #if defined(DEBUG) && defined(__KERNEL__)
787 * Randomly don't execute the first algorithm.
789 int dofirst
; /* set to do first algorithm */
791 dofirst
= random32() & 1;
794 * Get a cursor for the by-size btree.
796 cnt_cur
= xfs_allocbt_init_cursor(args
->mp
, args
->tp
, args
->agbp
,
797 args
->agno
, XFS_BTNUM_CNT
);
799 bno_cur_lt
= bno_cur_gt
= NULL
;
801 * See if there are any free extents as big as maxlen.
803 if ((error
= xfs_alloc_lookup_ge(cnt_cur
, 0, args
->maxlen
, &i
)))
806 * If none, then pick up the last entry in the tree unless the
810 if ((error
= xfs_alloc_ag_vextent_small(args
, cnt_cur
, <bno
,
813 if (i
== 0 || ltlen
== 0) {
814 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
822 * If the requested extent is large wrt the freespaces available
823 * in this a.g., then the cursor will be pointing to a btree entry
824 * near the right edge of the tree. If it's in the last btree leaf
825 * block, then we just examine all the entries in that block
826 * that are big enough, and pick the best one.
827 * This is written as a while loop so we can break out of it,
828 * but we never loop back to the top.
830 while (xfs_btree_islastblock(cnt_cur
, 0)) {
834 xfs_agblock_t bnew
=0;
836 #if defined(DEBUG) && defined(__KERNEL__)
841 * Start from the entry that lookup found, sequence through
842 * all larger free blocks. If we're actually pointing at a
843 * record smaller than maxlen, go to the start of this block,
844 * and skip all those smaller than minlen.
846 if (ltlen
|| args
->alignment
> 1) {
847 cnt_cur
->bc_ptrs
[0] = 1;
849 if ((error
= xfs_alloc_get_rec(cnt_cur
, <bno
,
852 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
853 if (ltlen
>= args
->minlen
)
855 if ((error
= xfs_btree_increment(cnt_cur
, 0, &i
)))
858 ASSERT(ltlen
>= args
->minlen
);
862 i
= cnt_cur
->bc_ptrs
[0];
863 for (j
= 1, blen
= 0, bdiff
= 0;
864 !error
&& j
&& (blen
< args
->maxlen
|| bdiff
> 0);
865 error
= xfs_btree_increment(cnt_cur
, 0, &j
)) {
867 * For each entry, decide if it's better than
868 * the previous best entry.
870 if ((error
= xfs_alloc_get_rec(cnt_cur
, <bno
, <len
, &i
)))
872 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
873 xfs_alloc_compute_aligned(ltbno
, ltlen
, args
->alignment
,
874 args
->minlen
, <bnoa
, <lena
);
875 if (ltlena
< args
->minlen
)
877 args
->len
= XFS_EXTLEN_MIN(ltlena
, args
->maxlen
);
878 xfs_alloc_fix_len(args
);
879 ASSERT(args
->len
>= args
->minlen
);
880 if (args
->len
< blen
)
882 ltdiff
= xfs_alloc_compute_diff(args
->agbno
, args
->len
,
883 args
->alignment
, ltbno
, ltlen
, <new
);
884 if (ltnew
!= NULLAGBLOCK
&&
885 (args
->len
> blen
|| ltdiff
< bdiff
)) {
889 besti
= cnt_cur
->bc_ptrs
[0];
893 * It didn't work. We COULD be in a case where
894 * there's a good record somewhere, so try again.
899 * Point at the best entry, and retrieve it again.
901 cnt_cur
->bc_ptrs
[0] = besti
;
902 if ((error
= xfs_alloc_get_rec(cnt_cur
, <bno
, <len
, &i
)))
904 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
905 ASSERT(ltbno
+ ltlen
<= be32_to_cpu(XFS_BUF_TO_AGF(args
->agbp
)->agf_length
));
907 if (!xfs_alloc_fix_minleft(args
)) {
908 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
909 trace_xfs_alloc_near_nominleft(args
);
914 * We are allocating starting at bnew for blen blocks.
917 ASSERT(bnew
>= ltbno
);
918 ASSERT(bnew
+ blen
<= ltbno
+ ltlen
);
920 * Set up a cursor for the by-bno tree.
922 bno_cur_lt
= xfs_allocbt_init_cursor(args
->mp
, args
->tp
,
923 args
->agbp
, args
->agno
, XFS_BTNUM_BNO
);
925 * Fix up the btree entries.
927 if ((error
= xfs_alloc_fixup_trees(cnt_cur
, bno_cur_lt
, ltbno
,
928 ltlen
, bnew
, blen
, XFSA_FIXUP_CNT_OK
)))
930 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
931 xfs_btree_del_cursor(bno_cur_lt
, XFS_BTREE_NOERROR
);
933 trace_xfs_alloc_near_first(args
);
938 * Search in the by-bno tree to the left and to the right
939 * simultaneously, until in each case we find a space big enough,
940 * or run into the edge of the tree. When we run into the edge,
941 * we deallocate that cursor.
942 * If both searches succeed, we compare the two spaces and pick
944 * With alignment, it's possible for both to fail; the upper
945 * level algorithm that picks allocation groups for allocations
946 * is not supposed to do this.
949 * Allocate and initialize the cursor for the leftward search.
951 bno_cur_lt
= xfs_allocbt_init_cursor(args
->mp
, args
->tp
, args
->agbp
,
952 args
->agno
, XFS_BTNUM_BNO
);
954 * Lookup <= bno to find the leftward search's starting point.
956 if ((error
= xfs_alloc_lookup_le(bno_cur_lt
, args
->agbno
, args
->maxlen
, &i
)))
960 * Didn't find anything; use this cursor for the rightward
963 bno_cur_gt
= bno_cur_lt
;
967 * Found something. Duplicate the cursor for the rightward search.
969 else if ((error
= xfs_btree_dup_cursor(bno_cur_lt
, &bno_cur_gt
)))
972 * Increment the cursor, so we will point at the entry just right
973 * of the leftward entry if any, or to the leftmost entry.
975 if ((error
= xfs_btree_increment(bno_cur_gt
, 0, &i
)))
979 * It failed, there are no rightward entries.
981 xfs_btree_del_cursor(bno_cur_gt
, XFS_BTREE_NOERROR
);
985 * Loop going left with the leftward cursor, right with the
986 * rightward cursor, until either both directions give up or
987 * we find an entry at least as big as minlen.
991 if ((error
= xfs_alloc_get_rec(bno_cur_lt
, <bno
, <len
, &i
)))
993 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
994 xfs_alloc_compute_aligned(ltbno
, ltlen
, args
->alignment
,
995 args
->minlen
, <bnoa
, <lena
);
996 if (ltlena
>= args
->minlen
)
998 if ((error
= xfs_btree_decrement(bno_cur_lt
, 0, &i
)))
1001 xfs_btree_del_cursor(bno_cur_lt
,
1007 if ((error
= xfs_alloc_get_rec(bno_cur_gt
, >bno
, >len
, &i
)))
1009 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1010 xfs_alloc_compute_aligned(gtbno
, gtlen
, args
->alignment
,
1011 args
->minlen
, >bnoa
, >lena
);
1012 if (gtlena
>= args
->minlen
)
1014 if ((error
= xfs_btree_increment(bno_cur_gt
, 0, &i
)))
1017 xfs_btree_del_cursor(bno_cur_gt
,
1022 } while (bno_cur_lt
|| bno_cur_gt
);
1025 * Got both cursors still active, need to find better entry.
1027 if (bno_cur_lt
&& bno_cur_gt
) {
1028 if (ltlena
>= args
->minlen
) {
1030 * Left side is good, look for a right side entry.
1032 args
->len
= XFS_EXTLEN_MIN(ltlena
, args
->maxlen
);
1033 xfs_alloc_fix_len(args
);
1034 ltdiff
= xfs_alloc_compute_diff(args
->agbno
, args
->len
,
1035 args
->alignment
, ltbno
, ltlen
, <new
);
1037 error
= xfs_alloc_find_best_extent(args
,
1038 &bno_cur_lt
, &bno_cur_gt
,
1039 ltdiff
, >bno
, >len
, >lena
,
1040 0 /* search right */);
1042 ASSERT(gtlena
>= args
->minlen
);
1045 * Right side is good, look for a left side entry.
1047 args
->len
= XFS_EXTLEN_MIN(gtlena
, args
->maxlen
);
1048 xfs_alloc_fix_len(args
);
1049 gtdiff
= xfs_alloc_compute_diff(args
->agbno
, args
->len
,
1050 args
->alignment
, gtbno
, gtlen
, >new
);
1052 error
= xfs_alloc_find_best_extent(args
,
1053 &bno_cur_gt
, &bno_cur_lt
,
1054 gtdiff
, <bno
, <len
, <lena
,
1055 1 /* search left */);
1063 * If we couldn't get anything, give up.
1065 if (bno_cur_lt
== NULL
&& bno_cur_gt
== NULL
) {
1066 trace_xfs_alloc_size_neither(args
);
1067 args
->agbno
= NULLAGBLOCK
;
1072 * At this point we have selected a freespace entry, either to the
1073 * left or to the right. If it's on the right, copy all the
1074 * useful variables to the "left" set so we only have one
1075 * copy of this code.
1078 bno_cur_lt
= bno_cur_gt
;
1089 * Fix up the length and compute the useful address.
1091 args
->len
= XFS_EXTLEN_MIN(ltlena
, args
->maxlen
);
1092 xfs_alloc_fix_len(args
);
1093 if (!xfs_alloc_fix_minleft(args
)) {
1094 trace_xfs_alloc_near_nominleft(args
);
1095 xfs_btree_del_cursor(bno_cur_lt
, XFS_BTREE_NOERROR
);
1096 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
1100 (void)xfs_alloc_compute_diff(args
->agbno
, rlen
, args
->alignment
, ltbno
,
1102 ASSERT(ltnew
>= ltbno
);
1103 ASSERT(ltnew
+ rlen
<= ltbno
+ ltlen
);
1104 ASSERT(ltnew
+ rlen
<= be32_to_cpu(XFS_BUF_TO_AGF(args
->agbp
)->agf_length
));
1105 args
->agbno
= ltnew
;
1106 if ((error
= xfs_alloc_fixup_trees(cnt_cur
, bno_cur_lt
, ltbno
, ltlen
,
1107 ltnew
, rlen
, XFSA_FIXUP_BNO_OK
)))
1111 trace_xfs_alloc_near_greater(args
);
1113 trace_xfs_alloc_near_lesser(args
);
1115 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
1116 xfs_btree_del_cursor(bno_cur_lt
, XFS_BTREE_NOERROR
);
1120 trace_xfs_alloc_near_error(args
);
1121 if (cnt_cur
!= NULL
)
1122 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_ERROR
);
1123 if (bno_cur_lt
!= NULL
)
1124 xfs_btree_del_cursor(bno_cur_lt
, XFS_BTREE_ERROR
);
1125 if (bno_cur_gt
!= NULL
)
1126 xfs_btree_del_cursor(bno_cur_gt
, XFS_BTREE_ERROR
);
1131 * Allocate a variable extent anywhere in the allocation group agno.
1132 * Extent's length (returned in len) will be between minlen and maxlen,
1133 * and of the form k * prod + mod unless there's nothing that large.
1134 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1136 STATIC
int /* error */
1137 xfs_alloc_ag_vextent_size(
1138 xfs_alloc_arg_t
*args
) /* allocation argument structure */
1140 xfs_btree_cur_t
*bno_cur
; /* cursor for bno btree */
1141 xfs_btree_cur_t
*cnt_cur
; /* cursor for cnt btree */
1142 int error
; /* error result */
1143 xfs_agblock_t fbno
; /* start of found freespace */
1144 xfs_extlen_t flen
; /* length of found freespace */
1145 int i
; /* temp status variable */
1146 xfs_agblock_t rbno
; /* returned block number */
1147 xfs_extlen_t rlen
; /* length of returned extent */
1150 * Allocate and initialize a cursor for the by-size btree.
1152 cnt_cur
= xfs_allocbt_init_cursor(args
->mp
, args
->tp
, args
->agbp
,
1153 args
->agno
, XFS_BTNUM_CNT
);
1156 * Look for an entry >= maxlen+alignment-1 blocks.
1158 if ((error
= xfs_alloc_lookup_ge(cnt_cur
, 0,
1159 args
->maxlen
+ args
->alignment
- 1, &i
)))
1162 * If none, then pick up the last entry in the tree unless the
1166 if ((error
= xfs_alloc_ag_vextent_small(args
, cnt_cur
, &fbno
,
1169 if (i
== 0 || flen
== 0) {
1170 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
1171 trace_xfs_alloc_size_noentry(args
);
1177 * There's a freespace as big as maxlen+alignment-1, get it.
1180 if ((error
= xfs_alloc_get_rec(cnt_cur
, &fbno
, &flen
, &i
)))
1182 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1185 * In the first case above, we got the last entry in the
1186 * by-size btree. Now we check to see if the space hits maxlen
1187 * once aligned; if not, we search left for something better.
1188 * This can't happen in the second case above.
1190 xfs_alloc_compute_aligned(fbno
, flen
, args
->alignment
, args
->minlen
,
1192 rlen
= XFS_EXTLEN_MIN(args
->maxlen
, rlen
);
1193 XFS_WANT_CORRUPTED_GOTO(rlen
== 0 ||
1194 (rlen
<= flen
&& rbno
+ rlen
<= fbno
+ flen
), error0
);
1195 if (rlen
< args
->maxlen
) {
1196 xfs_agblock_t bestfbno
;
1197 xfs_extlen_t bestflen
;
1198 xfs_agblock_t bestrbno
;
1199 xfs_extlen_t bestrlen
;
1206 if ((error
= xfs_btree_decrement(cnt_cur
, 0, &i
)))
1210 if ((error
= xfs_alloc_get_rec(cnt_cur
, &fbno
, &flen
,
1213 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1214 if (flen
< bestrlen
)
1216 xfs_alloc_compute_aligned(fbno
, flen
, args
->alignment
,
1217 args
->minlen
, &rbno
, &rlen
);
1218 rlen
= XFS_EXTLEN_MIN(args
->maxlen
, rlen
);
1219 XFS_WANT_CORRUPTED_GOTO(rlen
== 0 ||
1220 (rlen
<= flen
&& rbno
+ rlen
<= fbno
+ flen
),
1222 if (rlen
> bestrlen
) {
1227 if (rlen
== args
->maxlen
)
1231 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, bestfbno
, bestflen
,
1234 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1240 args
->wasfromfl
= 0;
1242 * Fix up the length.
1245 xfs_alloc_fix_len(args
);
1246 if (rlen
< args
->minlen
|| !xfs_alloc_fix_minleft(args
)) {
1247 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
1248 trace_xfs_alloc_size_nominleft(args
);
1249 args
->agbno
= NULLAGBLOCK
;
1253 XFS_WANT_CORRUPTED_GOTO(rlen
<= flen
, error0
);
1255 * Allocate and initialize a cursor for the by-block tree.
1257 bno_cur
= xfs_allocbt_init_cursor(args
->mp
, args
->tp
, args
->agbp
,
1258 args
->agno
, XFS_BTNUM_BNO
);
1259 if ((error
= xfs_alloc_fixup_trees(cnt_cur
, bno_cur
, fbno
, flen
,
1260 rbno
, rlen
, XFSA_FIXUP_CNT_OK
)))
1262 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
1263 xfs_btree_del_cursor(bno_cur
, XFS_BTREE_NOERROR
);
1264 cnt_cur
= bno_cur
= NULL
;
1267 XFS_WANT_CORRUPTED_GOTO(
1268 args
->agbno
+ args
->len
<=
1269 be32_to_cpu(XFS_BUF_TO_AGF(args
->agbp
)->agf_length
),
1271 trace_xfs_alloc_size_done(args
);
1275 trace_xfs_alloc_size_error(args
);
1277 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_ERROR
);
1279 xfs_btree_del_cursor(bno_cur
, XFS_BTREE_ERROR
);
1284 * Deal with the case where only small freespaces remain.
1285 * Either return the contents of the last freespace record,
1286 * or allocate space from the freelist if there is nothing in the tree.
1288 STATIC
int /* error */
1289 xfs_alloc_ag_vextent_small(
1290 xfs_alloc_arg_t
*args
, /* allocation argument structure */
1291 xfs_btree_cur_t
*ccur
, /* by-size cursor */
1292 xfs_agblock_t
*fbnop
, /* result block number */
1293 xfs_extlen_t
*flenp
, /* result length */
1294 int *stat
) /* status: 0-freelist, 1-normal/none */
1301 if ((error
= xfs_btree_decrement(ccur
, 0, &i
)))
1304 if ((error
= xfs_alloc_get_rec(ccur
, &fbno
, &flen
, &i
)))
1306 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1309 * Nothing in the btree, try the freelist. Make sure
1310 * to respect minleft even when pulling from the
1313 else if (args
->minlen
== 1 && args
->alignment
== 1 && !args
->isfl
&&
1314 (be32_to_cpu(XFS_BUF_TO_AGF(args
->agbp
)->agf_flcount
)
1316 error
= xfs_alloc_get_freelist(args
->tp
, args
->agbp
, &fbno
, 0);
1319 if (fbno
!= NULLAGBLOCK
) {
1320 if (args
->userdata
) {
1323 bp
= xfs_btree_get_bufs(args
->mp
, args
->tp
,
1324 args
->agno
, fbno
, 0);
1325 xfs_trans_binval(args
->tp
, bp
);
1329 XFS_WANT_CORRUPTED_GOTO(
1330 args
->agbno
+ args
->len
<=
1331 be32_to_cpu(XFS_BUF_TO_AGF(args
->agbp
)->agf_length
),
1333 args
->wasfromfl
= 1;
1334 trace_xfs_alloc_small_freelist(args
);
1339 * Nothing in the freelist.
1345 * Can't allocate from the freelist for some reason.
1352 * Can't do the allocation, give up.
1354 if (flen
< args
->minlen
) {
1355 args
->agbno
= NULLAGBLOCK
;
1356 trace_xfs_alloc_small_notenough(args
);
1362 trace_xfs_alloc_small_done(args
);
1366 trace_xfs_alloc_small_error(args
);
1371 * Free the extent starting at agno/bno for length.
1373 STATIC
int /* error */
1375 xfs_trans_t
*tp
, /* transaction pointer */
1376 xfs_buf_t
*agbp
, /* buffer for a.g. freelist header */
1377 xfs_agnumber_t agno
, /* allocation group number */
1378 xfs_agblock_t bno
, /* starting block number */
1379 xfs_extlen_t len
, /* length of extent */
1380 int isfl
) /* set if is freelist blocks - no sb acctg */
1382 xfs_btree_cur_t
*bno_cur
; /* cursor for by-block btree */
1383 xfs_btree_cur_t
*cnt_cur
; /* cursor for by-size btree */
1384 int error
; /* error return value */
1385 xfs_agblock_t gtbno
; /* start of right neighbor block */
1386 xfs_extlen_t gtlen
; /* length of right neighbor block */
1387 int haveleft
; /* have a left neighbor block */
1388 int haveright
; /* have a right neighbor block */
1389 int i
; /* temp, result code */
1390 xfs_agblock_t ltbno
; /* start of left neighbor block */
1391 xfs_extlen_t ltlen
; /* length of left neighbor block */
1392 xfs_mount_t
*mp
; /* mount point struct for filesystem */
1393 xfs_agblock_t nbno
; /* new starting block of freespace */
1394 xfs_extlen_t nlen
; /* new length of freespace */
1398 * Allocate and initialize a cursor for the by-block btree.
1400 bno_cur
= xfs_allocbt_init_cursor(mp
, tp
, agbp
, agno
, XFS_BTNUM_BNO
);
1403 * Look for a neighboring block on the left (lower block numbers)
1404 * that is contiguous with this space.
1406 if ((error
= xfs_alloc_lookup_le(bno_cur
, bno
, len
, &haveleft
)))
1410 * There is a block to our left.
1412 if ((error
= xfs_alloc_get_rec(bno_cur
, <bno
, <len
, &i
)))
1414 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1416 * It's not contiguous, though.
1418 if (ltbno
+ ltlen
< bno
)
1422 * If this failure happens the request to free this
1423 * space was invalid, it's (partly) already free.
1426 XFS_WANT_CORRUPTED_GOTO(ltbno
+ ltlen
<= bno
, error0
);
1430 * Look for a neighboring block on the right (higher block numbers)
1431 * that is contiguous with this space.
1433 if ((error
= xfs_btree_increment(bno_cur
, 0, &haveright
)))
1437 * There is a block to our right.
1439 if ((error
= xfs_alloc_get_rec(bno_cur
, >bno
, >len
, &i
)))
1441 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1443 * It's not contiguous, though.
1445 if (bno
+ len
< gtbno
)
1449 * If this failure happens the request to free this
1450 * space was invalid, it's (partly) already free.
1453 XFS_WANT_CORRUPTED_GOTO(gtbno
>= bno
+ len
, error0
);
1457 * Now allocate and initialize a cursor for the by-size tree.
1459 cnt_cur
= xfs_allocbt_init_cursor(mp
, tp
, agbp
, agno
, XFS_BTNUM_CNT
);
1461 * Have both left and right contiguous neighbors.
1462 * Merge all three into a single free block.
1464 if (haveleft
&& haveright
) {
1466 * Delete the old by-size entry on the left.
1468 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, ltbno
, ltlen
, &i
)))
1470 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1471 if ((error
= xfs_btree_delete(cnt_cur
, &i
)))
1473 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1475 * Delete the old by-size entry on the right.
1477 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, gtbno
, gtlen
, &i
)))
1479 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1480 if ((error
= xfs_btree_delete(cnt_cur
, &i
)))
1482 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1484 * Delete the old by-block entry for the right block.
1486 if ((error
= xfs_btree_delete(bno_cur
, &i
)))
1488 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1490 * Move the by-block cursor back to the left neighbor.
1492 if ((error
= xfs_btree_decrement(bno_cur
, 0, &i
)))
1494 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1497 * Check that this is the right record: delete didn't
1498 * mangle the cursor.
1501 xfs_agblock_t xxbno
;
1504 if ((error
= xfs_alloc_get_rec(bno_cur
, &xxbno
, &xxlen
,
1507 XFS_WANT_CORRUPTED_GOTO(
1508 i
== 1 && xxbno
== ltbno
&& xxlen
== ltlen
,
1513 * Update remaining by-block entry to the new, joined block.
1516 nlen
= len
+ ltlen
+ gtlen
;
1517 if ((error
= xfs_alloc_update(bno_cur
, nbno
, nlen
)))
1521 * Have only a left contiguous neighbor.
1522 * Merge it together with the new freespace.
1524 else if (haveleft
) {
1526 * Delete the old by-size entry on the left.
1528 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, ltbno
, ltlen
, &i
)))
1530 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1531 if ((error
= xfs_btree_delete(cnt_cur
, &i
)))
1533 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1535 * Back up the by-block cursor to the left neighbor, and
1536 * update its length.
1538 if ((error
= xfs_btree_decrement(bno_cur
, 0, &i
)))
1540 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1543 if ((error
= xfs_alloc_update(bno_cur
, nbno
, nlen
)))
1547 * Have only a right contiguous neighbor.
1548 * Merge it together with the new freespace.
1550 else if (haveright
) {
1552 * Delete the old by-size entry on the right.
1554 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, gtbno
, gtlen
, &i
)))
1556 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1557 if ((error
= xfs_btree_delete(cnt_cur
, &i
)))
1559 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1561 * Update the starting block and length of the right
1562 * neighbor in the by-block tree.
1566 if ((error
= xfs_alloc_update(bno_cur
, nbno
, nlen
)))
1570 * No contiguous neighbors.
1571 * Insert the new freespace into the by-block tree.
1576 if ((error
= xfs_btree_insert(bno_cur
, &i
)))
1578 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1580 xfs_btree_del_cursor(bno_cur
, XFS_BTREE_NOERROR
);
1583 * In all cases we need to insert the new freespace in the by-size tree.
1585 if ((error
= xfs_alloc_lookup_eq(cnt_cur
, nbno
, nlen
, &i
)))
1587 XFS_WANT_CORRUPTED_GOTO(i
== 0, error0
);
1588 if ((error
= xfs_btree_insert(cnt_cur
, &i
)))
1590 XFS_WANT_CORRUPTED_GOTO(i
== 1, error0
);
1591 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_NOERROR
);
1594 * Update the freespace totals in the ag and superblock.
1598 xfs_perag_t
*pag
; /* per allocation group data */
1600 pag
= xfs_perag_get(mp
, agno
);
1601 pag
->pagf_freeblks
+= len
;
1604 agf
= XFS_BUF_TO_AGF(agbp
);
1605 be32_add_cpu(&agf
->agf_freeblks
, len
);
1606 xfs_trans_agblocks_delta(tp
, len
);
1607 XFS_WANT_CORRUPTED_GOTO(
1608 be32_to_cpu(agf
->agf_freeblks
) <=
1609 be32_to_cpu(agf
->agf_length
),
1611 xfs_alloc_log_agf(tp
, agbp
, XFS_AGF_FREEBLKS
);
1613 xfs_trans_mod_sb(tp
, XFS_TRANS_SB_FDBLOCKS
, (long)len
);
1614 XFS_STATS_INC(xs_freex
);
1615 XFS_STATS_ADD(xs_freeb
, len
);
1618 trace_xfs_free_extent(mp
, agno
, bno
, len
, isfl
, haveleft
, haveright
);
1621 * Since blocks move to the free list without the coordination
1622 * used in xfs_bmap_finish, we can't allow block to be available
1623 * for reallocation and non-transaction writing (user data)
1624 * until we know that the transaction that moved it to the free
1625 * list is permanently on disk. We track the blocks by declaring
1626 * these blocks as "busy"; the busy list is maintained on a per-ag
1627 * basis and each transaction records which entries should be removed
1628 * when the iclog commits to disk. If a busy block is allocated,
1629 * the iclog is pushed up to the LSN that freed the block.
1631 xfs_alloc_busy_insert(tp
, agno
, bno
, len
);
1635 trace_xfs_free_extent(mp
, agno
, bno
, len
, isfl
, -1, -1);
1637 xfs_btree_del_cursor(bno_cur
, XFS_BTREE_ERROR
);
1639 xfs_btree_del_cursor(cnt_cur
, XFS_BTREE_ERROR
);
1644 * Visible (exported) allocation/free functions.
1645 * Some of these are used just by xfs_alloc_btree.c and this file.
1649 * Compute and fill in value of m_ag_maxlevels.
1652 xfs_alloc_compute_maxlevels(
1653 xfs_mount_t
*mp
) /* file system mount structure */
1661 maxleafents
= (mp
->m_sb
.sb_agblocks
+ 1) / 2;
1662 minleafrecs
= mp
->m_alloc_mnr
[0];
1663 minnoderecs
= mp
->m_alloc_mnr
[1];
1664 maxblocks
= (maxleafents
+ minleafrecs
- 1) / minleafrecs
;
1665 for (level
= 1; maxblocks
> 1; level
++)
1666 maxblocks
= (maxblocks
+ minnoderecs
- 1) / minnoderecs
;
1667 mp
->m_ag_maxlevels
= level
;
1671 * Find the length of the longest extent in an AG.
1674 xfs_alloc_longest_free_extent(
1675 struct xfs_mount
*mp
,
1676 struct xfs_perag
*pag
)
1678 xfs_extlen_t need
, delta
= 0;
1680 need
= XFS_MIN_FREELIST_PAG(pag
, mp
);
1681 if (need
> pag
->pagf_flcount
)
1682 delta
= need
- pag
->pagf_flcount
;
1684 if (pag
->pagf_longest
> delta
)
1685 return pag
->pagf_longest
- delta
;
1686 return pag
->pagf_flcount
> 0 || pag
->pagf_longest
> 0;
1690 * Decide whether to use this allocation group for this allocation.
1691 * If so, fix up the btree freelist's size.
1693 STATIC
int /* error */
1694 xfs_alloc_fix_freelist(
1695 xfs_alloc_arg_t
*args
, /* allocation argument structure */
1696 int flags
) /* XFS_ALLOC_FLAG_... */
1698 xfs_buf_t
*agbp
; /* agf buffer pointer */
1699 xfs_agf_t
*agf
; /* a.g. freespace structure pointer */
1700 xfs_buf_t
*agflbp
;/* agfl buffer pointer */
1701 xfs_agblock_t bno
; /* freelist block */
1702 xfs_extlen_t delta
; /* new blocks needed in freelist */
1703 int error
; /* error result code */
1704 xfs_extlen_t longest
;/* longest extent in allocation group */
1705 xfs_mount_t
*mp
; /* file system mount point structure */
1706 xfs_extlen_t need
; /* total blocks needed in freelist */
1707 xfs_perag_t
*pag
; /* per-ag information structure */
1708 xfs_alloc_arg_t targs
; /* local allocation arguments */
1709 xfs_trans_t
*tp
; /* transaction pointer */
1715 if (!pag
->pagf_init
) {
1716 if ((error
= xfs_alloc_read_agf(mp
, tp
, args
->agno
, flags
,
1719 if (!pag
->pagf_init
) {
1720 ASSERT(flags
& XFS_ALLOC_FLAG_TRYLOCK
);
1721 ASSERT(!(flags
& XFS_ALLOC_FLAG_FREEING
));
1729 * If this is a metadata preferred pag and we are user data
1730 * then try somewhere else if we are not being asked to
1731 * try harder at this point
1733 if (pag
->pagf_metadata
&& args
->userdata
&&
1734 (flags
& XFS_ALLOC_FLAG_TRYLOCK
)) {
1735 ASSERT(!(flags
& XFS_ALLOC_FLAG_FREEING
));
1740 if (!(flags
& XFS_ALLOC_FLAG_FREEING
)) {
1742 * If it looks like there isn't a long enough extent, or enough
1743 * total blocks, reject it.
1745 need
= XFS_MIN_FREELIST_PAG(pag
, mp
);
1746 longest
= xfs_alloc_longest_free_extent(mp
, pag
);
1747 if ((args
->minlen
+ args
->alignment
+ args
->minalignslop
- 1) >
1749 ((int)(pag
->pagf_freeblks
+ pag
->pagf_flcount
-
1750 need
- args
->total
) < (int)args
->minleft
)) {
1752 xfs_trans_brelse(tp
, agbp
);
1759 * Get the a.g. freespace buffer.
1760 * Can fail if we're not blocking on locks, and it's held.
1763 if ((error
= xfs_alloc_read_agf(mp
, tp
, args
->agno
, flags
,
1767 ASSERT(flags
& XFS_ALLOC_FLAG_TRYLOCK
);
1768 ASSERT(!(flags
& XFS_ALLOC_FLAG_FREEING
));
1774 * Figure out how many blocks we should have in the freelist.
1776 agf
= XFS_BUF_TO_AGF(agbp
);
1777 need
= XFS_MIN_FREELIST(agf
, mp
);
1779 * If there isn't enough total or single-extent, reject it.
1781 if (!(flags
& XFS_ALLOC_FLAG_FREEING
)) {
1782 delta
= need
> be32_to_cpu(agf
->agf_flcount
) ?
1783 (need
- be32_to_cpu(agf
->agf_flcount
)) : 0;
1784 longest
= be32_to_cpu(agf
->agf_longest
);
1785 longest
= (longest
> delta
) ? (longest
- delta
) :
1786 (be32_to_cpu(agf
->agf_flcount
) > 0 || longest
> 0);
1787 if ((args
->minlen
+ args
->alignment
+ args
->minalignslop
- 1) >
1789 ((int)(be32_to_cpu(agf
->agf_freeblks
) +
1790 be32_to_cpu(agf
->agf_flcount
) - need
- args
->total
) <
1791 (int)args
->minleft
)) {
1792 xfs_trans_brelse(tp
, agbp
);
1798 * Make the freelist shorter if it's too long.
1800 while (be32_to_cpu(agf
->agf_flcount
) > need
) {
1803 error
= xfs_alloc_get_freelist(tp
, agbp
, &bno
, 0);
1806 if ((error
= xfs_free_ag_extent(tp
, agbp
, args
->agno
, bno
, 1, 1)))
1808 bp
= xfs_btree_get_bufs(mp
, tp
, args
->agno
, bno
, 0);
1809 xfs_trans_binval(tp
, bp
);
1812 * Initialize the args structure.
1817 targs
.agno
= args
->agno
;
1818 targs
.mod
= targs
.minleft
= targs
.wasdel
= targs
.userdata
=
1819 targs
.minalignslop
= 0;
1820 targs
.alignment
= targs
.minlen
= targs
.prod
= targs
.isfl
= 1;
1821 targs
.type
= XFS_ALLOCTYPE_THIS_AG
;
1823 if ((error
= xfs_alloc_read_agfl(mp
, tp
, targs
.agno
, &agflbp
)))
1826 * Make the freelist longer if it's too short.
1828 while (be32_to_cpu(agf
->agf_flcount
) < need
) {
1830 targs
.maxlen
= need
- be32_to_cpu(agf
->agf_flcount
);
1832 * Allocate as many blocks as possible at once.
1834 if ((error
= xfs_alloc_ag_vextent(&targs
))) {
1835 xfs_trans_brelse(tp
, agflbp
);
1839 * Stop if we run out. Won't happen if callers are obeying
1840 * the restrictions correctly. Can happen for free calls
1841 * on a completely full ag.
1843 if (targs
.agbno
== NULLAGBLOCK
) {
1844 if (flags
& XFS_ALLOC_FLAG_FREEING
)
1846 xfs_trans_brelse(tp
, agflbp
);
1851 * Put each allocated block on the list.
1853 for (bno
= targs
.agbno
; bno
< targs
.agbno
+ targs
.len
; bno
++) {
1854 error
= xfs_alloc_put_freelist(tp
, agbp
,
1860 xfs_trans_brelse(tp
, agflbp
);
1866 * Get a block from the freelist.
1867 * Returns with the buffer for the block gotten.
1870 xfs_alloc_get_freelist(
1871 xfs_trans_t
*tp
, /* transaction pointer */
1872 xfs_buf_t
*agbp
, /* buffer containing the agf structure */
1873 xfs_agblock_t
*bnop
, /* block address retrieved from freelist */
1874 int btreeblk
) /* destination is a AGF btree */
1876 xfs_agf_t
*agf
; /* a.g. freespace structure */
1877 xfs_agfl_t
*agfl
; /* a.g. freelist structure */
1878 xfs_buf_t
*agflbp
;/* buffer for a.g. freelist structure */
1879 xfs_agblock_t bno
; /* block number returned */
1882 xfs_mount_t
*mp
; /* mount structure */
1883 xfs_perag_t
*pag
; /* per allocation group data */
1885 agf
= XFS_BUF_TO_AGF(agbp
);
1887 * Freelist is empty, give up.
1889 if (!agf
->agf_flcount
) {
1890 *bnop
= NULLAGBLOCK
;
1894 * Read the array of free blocks.
1897 if ((error
= xfs_alloc_read_agfl(mp
, tp
,
1898 be32_to_cpu(agf
->agf_seqno
), &agflbp
)))
1900 agfl
= XFS_BUF_TO_AGFL(agflbp
);
1902 * Get the block number and update the data structures.
1904 bno
= be32_to_cpu(agfl
->agfl_bno
[be32_to_cpu(agf
->agf_flfirst
)]);
1905 be32_add_cpu(&agf
->agf_flfirst
, 1);
1906 xfs_trans_brelse(tp
, agflbp
);
1907 if (be32_to_cpu(agf
->agf_flfirst
) == XFS_AGFL_SIZE(mp
))
1908 agf
->agf_flfirst
= 0;
1910 pag
= xfs_perag_get(mp
, be32_to_cpu(agf
->agf_seqno
));
1911 be32_add_cpu(&agf
->agf_flcount
, -1);
1912 xfs_trans_agflist_delta(tp
, -1);
1913 pag
->pagf_flcount
--;
1916 logflags
= XFS_AGF_FLFIRST
| XFS_AGF_FLCOUNT
;
1918 be32_add_cpu(&agf
->agf_btreeblks
, 1);
1919 pag
->pagf_btreeblks
++;
1920 logflags
|= XFS_AGF_BTREEBLKS
;
1923 xfs_alloc_log_agf(tp
, agbp
, logflags
);
1927 * As blocks are freed, they are added to the per-ag busy list and
1928 * remain there until the freeing transaction is committed to disk.
1929 * Now that we have allocated blocks, this list must be searched to see
1930 * if a block is being reused. If one is, then the freeing transaction
1931 * must be pushed to disk before this transaction.
1933 * We do this by setting the current transaction to a sync transaction
1934 * which guarantees that the freeing transaction is on disk before this
1935 * transaction. This is done instead of a synchronous log force here so
1936 * that we don't sit and wait with the AGF locked in the transaction
1937 * during the log force.
1939 if (xfs_alloc_busy_search(mp
, be32_to_cpu(agf
->agf_seqno
), bno
, 1))
1940 xfs_trans_set_sync(tp
);
1945 * Log the given fields from the agf structure.
1949 xfs_trans_t
*tp
, /* transaction pointer */
1950 xfs_buf_t
*bp
, /* buffer for a.g. freelist header */
1951 int fields
) /* mask of fields to be logged (XFS_AGF_...) */
1953 int first
; /* first byte offset */
1954 int last
; /* last byte offset */
1955 static const short offsets
[] = {
1956 offsetof(xfs_agf_t
, agf_magicnum
),
1957 offsetof(xfs_agf_t
, agf_versionnum
),
1958 offsetof(xfs_agf_t
, agf_seqno
),
1959 offsetof(xfs_agf_t
, agf_length
),
1960 offsetof(xfs_agf_t
, agf_roots
[0]),
1961 offsetof(xfs_agf_t
, agf_levels
[0]),
1962 offsetof(xfs_agf_t
, agf_flfirst
),
1963 offsetof(xfs_agf_t
, agf_fllast
),
1964 offsetof(xfs_agf_t
, agf_flcount
),
1965 offsetof(xfs_agf_t
, agf_freeblks
),
1966 offsetof(xfs_agf_t
, agf_longest
),
1967 offsetof(xfs_agf_t
, agf_btreeblks
),
1971 trace_xfs_agf(tp
->t_mountp
, XFS_BUF_TO_AGF(bp
), fields
, _RET_IP_
);
1973 xfs_btree_offsets(fields
, offsets
, XFS_AGF_NUM_BITS
, &first
, &last
);
1974 xfs_trans_log_buf(tp
, bp
, (uint
)first
, (uint
)last
);
1978 * Interface for inode allocation to force the pag data to be initialized.
1981 xfs_alloc_pagf_init(
1982 xfs_mount_t
*mp
, /* file system mount structure */
1983 xfs_trans_t
*tp
, /* transaction pointer */
1984 xfs_agnumber_t agno
, /* allocation group number */
1985 int flags
) /* XFS_ALLOC_FLAGS_... */
1990 if ((error
= xfs_alloc_read_agf(mp
, tp
, agno
, flags
, &bp
)))
1993 xfs_trans_brelse(tp
, bp
);
1998 * Put the block on the freelist for the allocation group.
2001 xfs_alloc_put_freelist(
2002 xfs_trans_t
*tp
, /* transaction pointer */
2003 xfs_buf_t
*agbp
, /* buffer for a.g. freelist header */
2004 xfs_buf_t
*agflbp
,/* buffer for a.g. free block array */
2005 xfs_agblock_t bno
, /* block being freed */
2006 int btreeblk
) /* block came from a AGF btree */
2008 xfs_agf_t
*agf
; /* a.g. freespace structure */
2009 xfs_agfl_t
*agfl
; /* a.g. free block array */
2010 __be32
*blockp
;/* pointer to array entry */
2013 xfs_mount_t
*mp
; /* mount structure */
2014 xfs_perag_t
*pag
; /* per allocation group data */
2016 agf
= XFS_BUF_TO_AGF(agbp
);
2019 if (!agflbp
&& (error
= xfs_alloc_read_agfl(mp
, tp
,
2020 be32_to_cpu(agf
->agf_seqno
), &agflbp
)))
2022 agfl
= XFS_BUF_TO_AGFL(agflbp
);
2023 be32_add_cpu(&agf
->agf_fllast
, 1);
2024 if (be32_to_cpu(agf
->agf_fllast
) == XFS_AGFL_SIZE(mp
))
2025 agf
->agf_fllast
= 0;
2027 pag
= xfs_perag_get(mp
, be32_to_cpu(agf
->agf_seqno
));
2028 be32_add_cpu(&agf
->agf_flcount
, 1);
2029 xfs_trans_agflist_delta(tp
, 1);
2030 pag
->pagf_flcount
++;
2032 logflags
= XFS_AGF_FLLAST
| XFS_AGF_FLCOUNT
;
2034 be32_add_cpu(&agf
->agf_btreeblks
, -1);
2035 pag
->pagf_btreeblks
--;
2036 logflags
|= XFS_AGF_BTREEBLKS
;
2040 xfs_alloc_log_agf(tp
, agbp
, logflags
);
2042 ASSERT(be32_to_cpu(agf
->agf_flcount
) <= XFS_AGFL_SIZE(mp
));
2043 blockp
= &agfl
->agfl_bno
[be32_to_cpu(agf
->agf_fllast
)];
2044 *blockp
= cpu_to_be32(bno
);
2045 xfs_alloc_log_agf(tp
, agbp
, logflags
);
2046 xfs_trans_log_buf(tp
, agflbp
,
2047 (int)((xfs_caddr_t
)blockp
- (xfs_caddr_t
)agfl
),
2048 (int)((xfs_caddr_t
)blockp
- (xfs_caddr_t
)agfl
+
2049 sizeof(xfs_agblock_t
) - 1));
2054 * Read in the allocation group header (free/alloc section).
2058 struct xfs_mount
*mp
, /* mount point structure */
2059 struct xfs_trans
*tp
, /* transaction pointer */
2060 xfs_agnumber_t agno
, /* allocation group number */
2061 int flags
, /* XFS_BUF_ */
2062 struct xfs_buf
**bpp
) /* buffer for the ag freelist header */
2064 struct xfs_agf
*agf
; /* ag freelist header */
2065 int agf_ok
; /* set if agf is consistent */
2068 ASSERT(agno
!= NULLAGNUMBER
);
2069 error
= xfs_trans_read_buf(
2070 mp
, tp
, mp
->m_ddev_targp
,
2071 XFS_AG_DADDR(mp
, agno
, XFS_AGF_DADDR(mp
)),
2072 XFS_FSS_TO_BB(mp
, 1), flags
, bpp
);
2078 ASSERT(!XFS_BUF_GETERROR(*bpp
));
2079 agf
= XFS_BUF_TO_AGF(*bpp
);
2082 * Validate the magic number of the agf block.
2085 be32_to_cpu(agf
->agf_magicnum
) == XFS_AGF_MAGIC
&&
2086 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf
->agf_versionnum
)) &&
2087 be32_to_cpu(agf
->agf_freeblks
) <= be32_to_cpu(agf
->agf_length
) &&
2088 be32_to_cpu(agf
->agf_flfirst
) < XFS_AGFL_SIZE(mp
) &&
2089 be32_to_cpu(agf
->agf_fllast
) < XFS_AGFL_SIZE(mp
) &&
2090 be32_to_cpu(agf
->agf_flcount
) <= XFS_AGFL_SIZE(mp
) &&
2091 be32_to_cpu(agf
->agf_seqno
) == agno
;
2092 if (xfs_sb_version_haslazysbcount(&mp
->m_sb
))
2093 agf_ok
= agf_ok
&& be32_to_cpu(agf
->agf_btreeblks
) <=
2094 be32_to_cpu(agf
->agf_length
);
2095 if (unlikely(XFS_TEST_ERROR(!agf_ok
, mp
, XFS_ERRTAG_ALLOC_READ_AGF
,
2096 XFS_RANDOM_ALLOC_READ_AGF
))) {
2097 XFS_CORRUPTION_ERROR("xfs_alloc_read_agf",
2098 XFS_ERRLEVEL_LOW
, mp
, agf
);
2099 xfs_trans_brelse(tp
, *bpp
);
2100 return XFS_ERROR(EFSCORRUPTED
);
2102 XFS_BUF_SET_VTYPE_REF(*bpp
, B_FS_AGF
, XFS_AGF_REF
);
2107 * Read in the allocation group header (free/alloc section).
2111 struct xfs_mount
*mp
, /* mount point structure */
2112 struct xfs_trans
*tp
, /* transaction pointer */
2113 xfs_agnumber_t agno
, /* allocation group number */
2114 int flags
, /* XFS_ALLOC_FLAG_... */
2115 struct xfs_buf
**bpp
) /* buffer for the ag freelist header */
2117 struct xfs_agf
*agf
; /* ag freelist header */
2118 struct xfs_perag
*pag
; /* per allocation group data */
2121 ASSERT(agno
!= NULLAGNUMBER
);
2123 error
= xfs_read_agf(mp
, tp
, agno
,
2124 (flags
& XFS_ALLOC_FLAG_TRYLOCK
) ? XBF_TRYLOCK
: 0,
2130 ASSERT(!XFS_BUF_GETERROR(*bpp
));
2132 agf
= XFS_BUF_TO_AGF(*bpp
);
2133 pag
= xfs_perag_get(mp
, agno
);
2134 if (!pag
->pagf_init
) {
2135 pag
->pagf_freeblks
= be32_to_cpu(agf
->agf_freeblks
);
2136 pag
->pagf_btreeblks
= be32_to_cpu(agf
->agf_btreeblks
);
2137 pag
->pagf_flcount
= be32_to_cpu(agf
->agf_flcount
);
2138 pag
->pagf_longest
= be32_to_cpu(agf
->agf_longest
);
2139 pag
->pagf_levels
[XFS_BTNUM_BNOi
] =
2140 be32_to_cpu(agf
->agf_levels
[XFS_BTNUM_BNOi
]);
2141 pag
->pagf_levels
[XFS_BTNUM_CNTi
] =
2142 be32_to_cpu(agf
->agf_levels
[XFS_BTNUM_CNTi
]);
2143 spin_lock_init(&pag
->pagb_lock
);
2144 pag
->pagb_count
= 0;
2145 pag
->pagb_tree
= RB_ROOT
;
2149 else if (!XFS_FORCED_SHUTDOWN(mp
)) {
2150 ASSERT(pag
->pagf_freeblks
== be32_to_cpu(agf
->agf_freeblks
));
2151 ASSERT(pag
->pagf_btreeblks
== be32_to_cpu(agf
->agf_btreeblks
));
2152 ASSERT(pag
->pagf_flcount
== be32_to_cpu(agf
->agf_flcount
));
2153 ASSERT(pag
->pagf_longest
== be32_to_cpu(agf
->agf_longest
));
2154 ASSERT(pag
->pagf_levels
[XFS_BTNUM_BNOi
] ==
2155 be32_to_cpu(agf
->agf_levels
[XFS_BTNUM_BNOi
]));
2156 ASSERT(pag
->pagf_levels
[XFS_BTNUM_CNTi
] ==
2157 be32_to_cpu(agf
->agf_levels
[XFS_BTNUM_CNTi
]));
2165 * Allocate an extent (variable-size).
2166 * Depending on the allocation type, we either look in a single allocation
2167 * group or loop over the allocation groups to find the result.
2171 xfs_alloc_arg_t
*args
) /* allocation argument structure */
2173 xfs_agblock_t agsize
; /* allocation group size */
2175 int flags
; /* XFS_ALLOC_FLAG_... locking flags */
2176 xfs_extlen_t minleft
;/* minimum left value, temp copy */
2177 xfs_mount_t
*mp
; /* mount structure pointer */
2178 xfs_agnumber_t sagno
; /* starting allocation group number */
2179 xfs_alloctype_t type
; /* input allocation type */
2182 xfs_agnumber_t rotorstep
= xfs_rotorstep
; /* inode32 agf stepper */
2185 type
= args
->otype
= args
->type
;
2186 args
->agbno
= NULLAGBLOCK
;
2188 * Just fix this up, for the case where the last a.g. is shorter
2189 * (or there's only one a.g.) and the caller couldn't easily figure
2190 * that out (xfs_bmap_alloc).
2192 agsize
= mp
->m_sb
.sb_agblocks
;
2193 if (args
->maxlen
> agsize
)
2194 args
->maxlen
= agsize
;
2195 if (args
->alignment
== 0)
2196 args
->alignment
= 1;
2197 ASSERT(XFS_FSB_TO_AGNO(mp
, args
->fsbno
) < mp
->m_sb
.sb_agcount
);
2198 ASSERT(XFS_FSB_TO_AGBNO(mp
, args
->fsbno
) < agsize
);
2199 ASSERT(args
->minlen
<= args
->maxlen
);
2200 ASSERT(args
->minlen
<= agsize
);
2201 ASSERT(args
->mod
< args
->prod
);
2202 if (XFS_FSB_TO_AGNO(mp
, args
->fsbno
) >= mp
->m_sb
.sb_agcount
||
2203 XFS_FSB_TO_AGBNO(mp
, args
->fsbno
) >= agsize
||
2204 args
->minlen
> args
->maxlen
|| args
->minlen
> agsize
||
2205 args
->mod
>= args
->prod
) {
2206 args
->fsbno
= NULLFSBLOCK
;
2207 trace_xfs_alloc_vextent_badargs(args
);
2210 minleft
= args
->minleft
;
2213 case XFS_ALLOCTYPE_THIS_AG
:
2214 case XFS_ALLOCTYPE_NEAR_BNO
:
2215 case XFS_ALLOCTYPE_THIS_BNO
:
2217 * These three force us into a single a.g.
2219 args
->agno
= XFS_FSB_TO_AGNO(mp
, args
->fsbno
);
2220 args
->pag
= xfs_perag_get(mp
, args
->agno
);
2222 error
= xfs_alloc_fix_freelist(args
, 0);
2223 args
->minleft
= minleft
;
2225 trace_xfs_alloc_vextent_nofix(args
);
2229 trace_xfs_alloc_vextent_noagbp(args
);
2232 args
->agbno
= XFS_FSB_TO_AGBNO(mp
, args
->fsbno
);
2233 if ((error
= xfs_alloc_ag_vextent(args
)))
2236 case XFS_ALLOCTYPE_START_BNO
:
2238 * Try near allocation first, then anywhere-in-ag after
2239 * the first a.g. fails.
2241 if ((args
->userdata
== XFS_ALLOC_INITIAL_USER_DATA
) &&
2242 (mp
->m_flags
& XFS_MOUNT_32BITINODES
)) {
2243 args
->fsbno
= XFS_AGB_TO_FSB(mp
,
2244 ((mp
->m_agfrotor
/ rotorstep
) %
2245 mp
->m_sb
.sb_agcount
), 0);
2248 args
->agbno
= XFS_FSB_TO_AGBNO(mp
, args
->fsbno
);
2249 args
->type
= XFS_ALLOCTYPE_NEAR_BNO
;
2251 case XFS_ALLOCTYPE_ANY_AG
:
2252 case XFS_ALLOCTYPE_START_AG
:
2253 case XFS_ALLOCTYPE_FIRST_AG
:
2255 * Rotate through the allocation groups looking for a winner.
2257 if (type
== XFS_ALLOCTYPE_ANY_AG
) {
2259 * Start with the last place we left off.
2261 args
->agno
= sagno
= (mp
->m_agfrotor
/ rotorstep
) %
2262 mp
->m_sb
.sb_agcount
;
2263 args
->type
= XFS_ALLOCTYPE_THIS_AG
;
2264 flags
= XFS_ALLOC_FLAG_TRYLOCK
;
2265 } else if (type
== XFS_ALLOCTYPE_FIRST_AG
) {
2267 * Start with allocation group given by bno.
2269 args
->agno
= XFS_FSB_TO_AGNO(mp
, args
->fsbno
);
2270 args
->type
= XFS_ALLOCTYPE_THIS_AG
;
2274 if (type
== XFS_ALLOCTYPE_START_AG
)
2275 args
->type
= XFS_ALLOCTYPE_THIS_AG
;
2277 * Start with the given allocation group.
2279 args
->agno
= sagno
= XFS_FSB_TO_AGNO(mp
, args
->fsbno
);
2280 flags
= XFS_ALLOC_FLAG_TRYLOCK
;
2283 * Loop over allocation groups twice; first time with
2284 * trylock set, second time without.
2287 args
->pag
= xfs_perag_get(mp
, args
->agno
);
2288 if (no_min
) args
->minleft
= 0;
2289 error
= xfs_alloc_fix_freelist(args
, flags
);
2290 args
->minleft
= minleft
;
2292 trace_xfs_alloc_vextent_nofix(args
);
2296 * If we get a buffer back then the allocation will fly.
2299 if ((error
= xfs_alloc_ag_vextent(args
)))
2304 trace_xfs_alloc_vextent_loopfailed(args
);
2307 * Didn't work, figure out the next iteration.
2309 if (args
->agno
== sagno
&&
2310 type
== XFS_ALLOCTYPE_START_BNO
)
2311 args
->type
= XFS_ALLOCTYPE_THIS_AG
;
2313 * For the first allocation, we can try any AG to get
2314 * space. However, if we already have allocated a
2315 * block, we don't want to try AGs whose number is below
2316 * sagno. Otherwise, we may end up with out-of-order
2317 * locking of AGF, which might cause deadlock.
2319 if (++(args
->agno
) == mp
->m_sb
.sb_agcount
) {
2320 if (args
->firstblock
!= NULLFSBLOCK
)
2326 * Reached the starting a.g., must either be done
2327 * or switch to non-trylock mode.
2329 if (args
->agno
== sagno
) {
2331 args
->agbno
= NULLAGBLOCK
;
2332 trace_xfs_alloc_vextent_allfailed(args
);
2339 if (type
== XFS_ALLOCTYPE_START_BNO
) {
2340 args
->agbno
= XFS_FSB_TO_AGBNO(mp
,
2342 args
->type
= XFS_ALLOCTYPE_NEAR_BNO
;
2346 xfs_perag_put(args
->pag
);
2348 if (bump_rotor
|| (type
== XFS_ALLOCTYPE_ANY_AG
)) {
2349 if (args
->agno
== sagno
)
2350 mp
->m_agfrotor
= (mp
->m_agfrotor
+ 1) %
2351 (mp
->m_sb
.sb_agcount
* rotorstep
);
2353 mp
->m_agfrotor
= (args
->agno
* rotorstep
+ 1) %
2354 (mp
->m_sb
.sb_agcount
* rotorstep
);
2361 if (args
->agbno
== NULLAGBLOCK
)
2362 args
->fsbno
= NULLFSBLOCK
;
2364 args
->fsbno
= XFS_AGB_TO_FSB(mp
, args
->agno
, args
->agbno
);
2366 ASSERT(args
->len
>= args
->minlen
);
2367 ASSERT(args
->len
<= args
->maxlen
);
2368 ASSERT(args
->agbno
% args
->alignment
== 0);
2369 XFS_AG_CHECK_DADDR(mp
, XFS_FSB_TO_DADDR(mp
, args
->fsbno
),
2373 xfs_perag_put(args
->pag
);
2376 xfs_perag_put(args
->pag
);
2382 * Just break up the extent address and hand off to xfs_free_ag_extent
2383 * after fixing up the freelist.
2387 xfs_trans_t
*tp
, /* transaction pointer */
2388 xfs_fsblock_t bno
, /* starting block number of extent */
2389 xfs_extlen_t len
) /* length of extent */
2391 xfs_alloc_arg_t args
;
2395 memset(&args
, 0, sizeof(xfs_alloc_arg_t
));
2397 args
.mp
= tp
->t_mountp
;
2398 args
.agno
= XFS_FSB_TO_AGNO(args
.mp
, bno
);
2399 ASSERT(args
.agno
< args
.mp
->m_sb
.sb_agcount
);
2400 args
.agbno
= XFS_FSB_TO_AGBNO(args
.mp
, bno
);
2401 args
.pag
= xfs_perag_get(args
.mp
, args
.agno
);
2402 if ((error
= xfs_alloc_fix_freelist(&args
, XFS_ALLOC_FLAG_FREEING
)))
2405 ASSERT(args
.agbp
!= NULL
);
2406 ASSERT((args
.agbno
+ len
) <=
2407 be32_to_cpu(XFS_BUF_TO_AGF(args
.agbp
)->agf_length
));
2409 error
= xfs_free_ag_extent(tp
, args
.agbp
, args
.agno
, args
.agbno
, len
, 0);
2411 xfs_perag_put(args
.pag
);
2417 * AG Busy list management
2418 * The busy list contains block ranges that have been freed but whose
2419 * transactions have not yet hit disk. If any block listed in a busy
2420 * list is reused, the transaction that freed it must be forced to disk
2421 * before continuing to use the block.
2423 * xfs_alloc_busy_insert - add to the per-ag busy list
2424 * xfs_alloc_busy_clear - remove an item from the per-ag busy list
2425 * xfs_alloc_busy_search - search for a busy extent
2429 * Insert a new extent into the busy tree.
2431 * The busy extent tree is indexed by the start block of the busy extent.
2432 * there can be multiple overlapping ranges in the busy extent tree but only
2433 * ever one entry at a given start block. The reason for this is that
2434 * multi-block extents can be freed, then smaller chunks of that extent
2435 * allocated and freed again before the first transaction commit is on disk.
2436 * If the exact same start block is freed a second time, we have to wait for
2437 * that busy extent to pass out of the tree before the new extent is inserted.
2438 * There are two main cases we have to handle here.
2440 * The first case is a transaction that triggers a "free - allocate - free"
2441 * cycle. This can occur during btree manipulations as a btree block is freed
2442 * to the freelist, then allocated from the free list, then freed again. In
2443 * this case, the second extxpnet free is what triggers the duplicate and as
2444 * such the transaction IDs should match. Because the extent was allocated in
2445 * this transaction, the transaction must be marked as synchronous. This is
2446 * true for all cases where the free/alloc/free occurs in the one transaction,
2447 * hence the addition of the ASSERT(tp->t_flags & XFS_TRANS_SYNC) to this case.
2448 * This serves to catch violations of the second case quite effectively.
2450 * The second case is where the free/alloc/free occur in different
2451 * transactions. In this case, the thread freeing the extent the second time
2452 * can't mark the extent busy immediately because it is already tracked in a
2453 * transaction that may be committing. When the log commit for the existing
2454 * busy extent completes, the busy extent will be removed from the tree. If we
2455 * allow the second busy insert to continue using that busy extent structure,
2456 * it can be freed before this transaction is safely in the log. Hence our
2457 * only option in this case is to force the log to remove the existing busy
2458 * extent from the list before we insert the new one with the current
2461 * The problem we are trying to avoid in the free-alloc-free in separate
2462 * transactions is most easily described with a timeline:
2464 * Thread 1 Thread 2 Thread 3 xfslogd
2487 * checkpoint completes
2489 * By issuing a log force in thread 3 @ "KABOOM", the thread will block until
2490 * the checkpoint completes, and the busy extent it matched will have been
2491 * removed from the tree when it is woken. Hence it can then continue safely.
2493 * However, to ensure this matching process is robust, we need to use the
2494 * transaction ID for identifying transaction, as delayed logging results in
2495 * the busy extent and transaction lifecycles being different. i.e. the busy
2496 * extent is active for a lot longer than the transaction. Hence the
2497 * transaction structure can be freed and reallocated, then mark the same
2498 * extent busy again in the new transaction. In this case the new transaction
2499 * will have a different tid but can have the same address, and hence we need
2500 * to check against the tid.
2502 * Future: for delayed logging, we could avoid the log force if the extent was
2503 * first freed in the current checkpoint sequence. This, however, requires the
2504 * ability to pin the current checkpoint in memory until this transaction
2505 * commits to ensure that both the original free and the current one combine
2506 * logically into the one checkpoint. If the checkpoint sequences are
2507 * different, however, we still need to wait on a log force.
2510 xfs_alloc_busy_insert(
2511 struct xfs_trans
*tp
,
2512 xfs_agnumber_t agno
,
2516 struct xfs_busy_extent
*new;
2517 struct xfs_busy_extent
*busyp
;
2518 struct xfs_perag
*pag
;
2519 struct rb_node
**rbp
;
2520 struct rb_node
*parent
;
2524 new = kmem_zalloc(sizeof(struct xfs_busy_extent
), KM_MAYFAIL
);
2527 * No Memory! Since it is now not possible to track the free
2528 * block, make this a synchronous transaction to insure that
2529 * the block is not reused before this transaction commits.
2531 trace_xfs_alloc_busy(tp
, agno
, bno
, len
, 1);
2532 xfs_trans_set_sync(tp
);
2539 new->tid
= xfs_log_get_trans_ident(tp
);
2541 INIT_LIST_HEAD(&new->list
);
2543 /* trace before insert to be able to see failed inserts */
2544 trace_xfs_alloc_busy(tp
, agno
, bno
, len
, 0);
2546 pag
= xfs_perag_get(tp
->t_mountp
, new->agno
);
2548 spin_lock(&pag
->pagb_lock
);
2549 rbp
= &pag
->pagb_tree
.rb_node
;
2553 while (*rbp
&& match
>= 0) {
2555 busyp
= rb_entry(parent
, struct xfs_busy_extent
, rb_node
);
2557 if (new->bno
< busyp
->bno
) {
2558 /* may overlap, but exact start block is lower */
2559 rbp
= &(*rbp
)->rb_left
;
2560 if (new->bno
+ new->length
> busyp
->bno
)
2561 match
= busyp
->tid
== new->tid
? 1 : -1;
2562 } else if (new->bno
> busyp
->bno
) {
2563 /* may overlap, but exact start block is higher */
2564 rbp
= &(*rbp
)->rb_right
;
2565 if (bno
< busyp
->bno
+ busyp
->length
)
2566 match
= busyp
->tid
== new->tid
? 1 : -1;
2568 match
= busyp
->tid
== new->tid
? 1 : -1;
2573 /* overlap marked busy in different transaction */
2574 spin_unlock(&pag
->pagb_lock
);
2575 xfs_log_force(tp
->t_mountp
, XFS_LOG_SYNC
);
2580 * overlap marked busy in same transaction. Update if exact
2581 * start block match, otherwise combine the busy extents into
2584 if (busyp
->bno
== new->bno
) {
2585 busyp
->length
= max(busyp
->length
, new->length
);
2586 spin_unlock(&pag
->pagb_lock
);
2587 ASSERT(tp
->t_flags
& XFS_TRANS_SYNC
);
2592 rb_erase(&busyp
->rb_node
, &pag
->pagb_tree
);
2593 new->length
= max(busyp
->bno
+ busyp
->length
,
2594 new->bno
+ new->length
) -
2595 min(busyp
->bno
, new->bno
);
2596 new->bno
= min(busyp
->bno
, new->bno
);
2600 rb_link_node(&new->rb_node
, parent
, rbp
);
2601 rb_insert_color(&new->rb_node
, &pag
->pagb_tree
);
2603 list_add(&new->list
, &tp
->t_busy
);
2604 spin_unlock(&pag
->pagb_lock
);
2610 * Search for a busy extent within the range of the extent we are about to
2611 * allocate. You need to be holding the busy extent tree lock when calling
2612 * xfs_alloc_busy_search(). This function returns 0 for no overlapping busy
2613 * extent, -1 for an overlapping but not exact busy extent, and 1 for an exact
2614 * match. This is done so that a non-zero return indicates an overlap that
2615 * will require a synchronous transaction, but it can still be
2616 * used to distinguish between a partial or exact match.
2619 xfs_alloc_busy_search(
2620 struct xfs_mount
*mp
,
2621 xfs_agnumber_t agno
,
2625 struct xfs_perag
*pag
;
2626 struct rb_node
*rbp
;
2627 struct xfs_busy_extent
*busyp
;
2630 pag
= xfs_perag_get(mp
, agno
);
2631 spin_lock(&pag
->pagb_lock
);
2633 rbp
= pag
->pagb_tree
.rb_node
;
2635 /* find closest start bno overlap */
2637 busyp
= rb_entry(rbp
, struct xfs_busy_extent
, rb_node
);
2638 if (bno
< busyp
->bno
) {
2639 /* may overlap, but exact start block is lower */
2640 if (bno
+ len
> busyp
->bno
)
2643 } else if (bno
> busyp
->bno
) {
2644 /* may overlap, but exact start block is higher */
2645 if (bno
< busyp
->bno
+ busyp
->length
)
2647 rbp
= rbp
->rb_right
;
2649 /* bno matches busyp, length determines exact match */
2650 match
= (busyp
->length
== len
) ? 1 : -1;
2654 spin_unlock(&pag
->pagb_lock
);
2655 trace_xfs_alloc_busysearch(mp
, agno
, bno
, len
, !!match
);
2661 xfs_alloc_busy_clear(
2662 struct xfs_mount
*mp
,
2663 struct xfs_busy_extent
*busyp
)
2665 struct xfs_perag
*pag
;
2667 trace_xfs_alloc_unbusy(mp
, busyp
->agno
, busyp
->bno
,
2670 ASSERT(xfs_alloc_busy_search(mp
, busyp
->agno
, busyp
->bno
,
2671 busyp
->length
) == 1);
2673 list_del_init(&busyp
->list
);
2675 pag
= xfs_perag_get(mp
, busyp
->agno
);
2676 spin_lock(&pag
->pagb_lock
);
2677 rb_erase(&busyp
->rb_node
, &pag
->pagb_tree
);
2678 spin_unlock(&pag
->pagb_lock
);