aboutsummaryrefslogtreecommitdiffstats
path: root/fs/xfs/libxfs/xfs_alloc.c
diff options
context:
space:
mode:
authorDave Chinner <dchinner@redhat.com>2014-06-25 00:57:53 -0400
committerDave Chinner <david@fromorbit.com>2014-06-25 00:57:53 -0400
commit30f712c9dd69348aa51351d5cb6d366bf4fae31d (patch)
tree9b246ca3986b784d8f9f6841466dfd4c90909e47 /fs/xfs/libxfs/xfs_alloc.c
parent84be0ffc9043f7c56044294eb775a2200452c76d (diff)
libxfs: move source files
Move all the source files that are shared with userspace into libxfs/. This is done as one big chunk simpy to get it done quickly Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/libxfs/xfs_alloc.c')
-rw-r--r--fs/xfs/libxfs/xfs_alloc.c2630
1 files changed, 2630 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
new file mode 100644
index 000000000000..d43813267a80
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -0,0 +1,2630 @@
1/*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
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.
8 *
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.
13 *
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
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_format.h"
21#include "xfs_log_format.h"
22#include "xfs_shared.h"
23#include "xfs_trans_resv.h"
24#include "xfs_bit.h"
25#include "xfs_sb.h"
26#include "xfs_ag.h"
27#include "xfs_mount.h"
28#include "xfs_inode.h"
29#include "xfs_btree.h"
30#include "xfs_alloc_btree.h"
31#include "xfs_alloc.h"
32#include "xfs_extent_busy.h"
33#include "xfs_error.h"
34#include "xfs_cksum.h"
35#include "xfs_trace.h"
36#include "xfs_trans.h"
37#include "xfs_buf_item.h"
38#include "xfs_log.h"
39
40struct workqueue_struct *xfs_alloc_wq;
41
42#define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
43
44#define XFSA_FIXUP_BNO_OK 1
45#define XFSA_FIXUP_CNT_OK 2
46
47STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
48STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
49STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
50STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
51 xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
52
53/*
54 * Lookup the record equal to [bno, len] in the btree given by cur.
55 */
56STATIC int /* error */
57xfs_alloc_lookup_eq(
58 struct xfs_btree_cur *cur, /* btree cursor */
59 xfs_agblock_t bno, /* starting block of extent */
60 xfs_extlen_t len, /* length of extent */
61 int *stat) /* success/failure */
62{
63 cur->bc_rec.a.ar_startblock = bno;
64 cur->bc_rec.a.ar_blockcount = len;
65 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
66}
67
68/*
69 * Lookup the first record greater than or equal to [bno, len]
70 * in the btree given by cur.
71 */
72int /* error */
73xfs_alloc_lookup_ge(
74 struct xfs_btree_cur *cur, /* btree cursor */
75 xfs_agblock_t bno, /* starting block of extent */
76 xfs_extlen_t len, /* length of extent */
77 int *stat) /* success/failure */
78{
79 cur->bc_rec.a.ar_startblock = bno;
80 cur->bc_rec.a.ar_blockcount = len;
81 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
82}
83
84/*
85 * Lookup the first record less than or equal to [bno, len]
86 * in the btree given by cur.
87 */
88int /* error */
89xfs_alloc_lookup_le(
90 struct xfs_btree_cur *cur, /* btree cursor */
91 xfs_agblock_t bno, /* starting block of extent */
92 xfs_extlen_t len, /* length of extent */
93 int *stat) /* success/failure */
94{
95 cur->bc_rec.a.ar_startblock = bno;
96 cur->bc_rec.a.ar_blockcount = len;
97 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
98}
99
100/*
101 * Update the record referred to by cur to the value given
102 * by [bno, len].
103 * This either works (return 0) or gets an EFSCORRUPTED error.
104 */
105STATIC int /* error */
106xfs_alloc_update(
107 struct xfs_btree_cur *cur, /* btree cursor */
108 xfs_agblock_t bno, /* starting block of extent */
109 xfs_extlen_t len) /* length of extent */
110{
111 union xfs_btree_rec rec;
112
113 rec.alloc.ar_startblock = cpu_to_be32(bno);
114 rec.alloc.ar_blockcount = cpu_to_be32(len);
115 return xfs_btree_update(cur, &rec);
116}
117
118/*
119 * Get the data from the pointed-to record.
120 */
121int /* error */
122xfs_alloc_get_rec(
123 struct xfs_btree_cur *cur, /* btree cursor */
124 xfs_agblock_t *bno, /* output: starting block of extent */
125 xfs_extlen_t *len, /* output: length of extent */
126 int *stat) /* output: success/failure */
127{
128 union xfs_btree_rec *rec;
129 int error;
130
131 error = xfs_btree_get_rec(cur, &rec, stat);
132 if (!error && *stat == 1) {
133 *bno = be32_to_cpu(rec->alloc.ar_startblock);
134 *len = be32_to_cpu(rec->alloc.ar_blockcount);
135 }
136 return error;
137}
138
139/*
140 * Compute aligned version of the found extent.
141 * Takes alignment and min length into account.
142 */
143STATIC void
144xfs_alloc_compute_aligned(
145 xfs_alloc_arg_t *args, /* allocation argument structure */
146 xfs_agblock_t foundbno, /* starting block in found extent */
147 xfs_extlen_t foundlen, /* length in found extent */
148 xfs_agblock_t *resbno, /* result block number */
149 xfs_extlen_t *reslen) /* result length */
150{
151 xfs_agblock_t bno;
152 xfs_extlen_t len;
153
154 /* Trim busy sections out of found extent */
155 xfs_extent_busy_trim(args, foundbno, foundlen, &bno, &len);
156
157 if (args->alignment > 1 && len >= args->minlen) {
158 xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
159 xfs_extlen_t diff = aligned_bno - bno;
160
161 *resbno = aligned_bno;
162 *reslen = diff >= len ? 0 : len - diff;
163 } else {
164 *resbno = bno;
165 *reslen = len;
166 }
167}
168
169/*
170 * Compute best start block and diff for "near" allocations.
171 * freelen >= wantlen already checked by caller.
172 */
173STATIC xfs_extlen_t /* difference value (absolute) */
174xfs_alloc_compute_diff(
175 xfs_agblock_t wantbno, /* target starting block */
176 xfs_extlen_t wantlen, /* target length */
177 xfs_extlen_t alignment, /* target alignment */
178 char userdata, /* are we allocating data? */
179 xfs_agblock_t freebno, /* freespace's starting block */
180 xfs_extlen_t freelen, /* freespace's length */
181 xfs_agblock_t *newbnop) /* result: best start block from free */
182{
183 xfs_agblock_t freeend; /* end of freespace extent */
184 xfs_agblock_t newbno1; /* return block number */
185 xfs_agblock_t newbno2; /* other new block number */
186 xfs_extlen_t newlen1=0; /* length with newbno1 */
187 xfs_extlen_t newlen2=0; /* length with newbno2 */
188 xfs_agblock_t wantend; /* end of target extent */
189
190 ASSERT(freelen >= wantlen);
191 freeend = freebno + freelen;
192 wantend = wantbno + wantlen;
193 /*
194 * We want to allocate from the start of a free extent if it is past
195 * the desired block or if we are allocating user data and the free
196 * extent is before desired block. The second case is there to allow
197 * for contiguous allocation from the remaining free space if the file
198 * grows in the short term.
199 */
200 if (freebno >= wantbno || (userdata && freeend < wantend)) {
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;
208 else
209 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
210 if (newbno2 < freebno)
211 newbno2 = NULLAGBLOCK;
212 else
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)))
219 newbno1 = newbno2;
220 } else if (newbno2 != NULLAGBLOCK)
221 newbno1 = newbno2;
222 } else if (freeend >= wantend) {
223 newbno1 = wantbno;
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;
231 } else
232 newbno1 = freeend - wantlen;
233 *newbnop = newbno1;
234 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
235}
236
237/*
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.
242 */
243STATIC void
244xfs_alloc_fix_len(
245 xfs_alloc_arg_t *args) /* allocation argument structure */
246{
247 xfs_extlen_t k;
248 xfs_extlen_t rlen;
249
250 ASSERT(args->mod < args->prod);
251 rlen = args->len;
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))
256 return;
257 k = rlen % args->prod;
258 if (k == args->mod)
259 return;
260 if (k > args->mod)
261 rlen = rlen - (k - args->mod);
262 else
263 rlen = rlen - args->prod + (args->mod - k);
264 if ((int)rlen < (int)args->minlen)
265 return;
266 ASSERT(rlen >= args->minlen && rlen <= args->maxlen);
267 ASSERT(rlen % args->prod == args->mod);
268 args->len = rlen;
269}
270
271/*
272 * Fix up length if there is too little space left in the a.g.
273 * Return 1 if ok, 0 if too little, should give up.
274 */
275STATIC int
276xfs_alloc_fix_minleft(
277 xfs_alloc_arg_t *args) /* allocation argument structure */
278{
279 xfs_agf_t *agf; /* a.g. freelist header */
280 int diff; /* free space difference */
281
282 if (args->minleft == 0)
283 return 1;
284 agf = XFS_BUF_TO_AGF(args->agbp);
285 diff = be32_to_cpu(agf->agf_freeblks)
286 - args->len - args->minleft;
287 if (diff >= 0)
288 return 1;
289 args->len += diff; /* shrink the allocated space */
290 if (args->len >= args->minlen)
291 return 1;
292 args->agbno = NULLAGBLOCK;
293 return 0;
294}
295
296/*
297 * Update the two btrees, logically removing from freespace the extent
298 * starting at rbno, rlen blocks. The extent is contained within the
299 * actual (current) free extent fbno for flen blocks.
300 * Flags are passed in indicating whether the cursors are set to the
301 * relevant records.
302 */
303STATIC int /* error code */
304xfs_alloc_fixup_trees(
305 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
306 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
307 xfs_agblock_t fbno, /* starting block of free extent */
308 xfs_extlen_t flen, /* length of free extent */
309 xfs_agblock_t rbno, /* starting block of returned extent */
310 xfs_extlen_t rlen, /* length of returned extent */
311 int flags) /* flags, XFSA_FIXUP_... */
312{
313 int error; /* error code */
314 int i; /* operation results */
315 xfs_agblock_t nfbno1; /* first new free startblock */
316 xfs_agblock_t nfbno2; /* second new free startblock */
317 xfs_extlen_t nflen1=0; /* first new free length */
318 xfs_extlen_t nflen2=0; /* second new free length */
319
320 /*
321 * Look up the record in the by-size tree if necessary.
322 */
323 if (flags & XFSA_FIXUP_CNT_OK) {
324#ifdef DEBUG
325 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
326 return error;
327 XFS_WANT_CORRUPTED_RETURN(
328 i == 1 && nfbno1 == fbno && nflen1 == flen);
329#endif
330 } else {
331 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
332 return error;
333 XFS_WANT_CORRUPTED_RETURN(i == 1);
334 }
335 /*
336 * Look up the record in the by-block tree if necessary.
337 */
338 if (flags & XFSA_FIXUP_BNO_OK) {
339#ifdef DEBUG
340 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
341 return error;
342 XFS_WANT_CORRUPTED_RETURN(
343 i == 1 && nfbno1 == fbno && nflen1 == flen);
344#endif
345 } else {
346 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
347 return error;
348 XFS_WANT_CORRUPTED_RETURN(i == 1);
349 }
350
351#ifdef DEBUG
352 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
353 struct xfs_btree_block *bnoblock;
354 struct xfs_btree_block *cntblock;
355
356 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
357 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
358
359 XFS_WANT_CORRUPTED_RETURN(
360 bnoblock->bb_numrecs == cntblock->bb_numrecs);
361 }
362#endif
363
364 /*
365 * Deal with all four cases: the allocated record is contained
366 * within the freespace record, so we can have new freespace
367 * at either (or both) end, or no freespace remaining.
368 */
369 if (rbno == fbno && rlen == flen)
370 nfbno1 = nfbno2 = NULLAGBLOCK;
371 else if (rbno == fbno) {
372 nfbno1 = rbno + rlen;
373 nflen1 = flen - rlen;
374 nfbno2 = NULLAGBLOCK;
375 } else if (rbno + rlen == fbno + flen) {
376 nfbno1 = fbno;
377 nflen1 = flen - rlen;
378 nfbno2 = NULLAGBLOCK;
379 } else {
380 nfbno1 = fbno;
381 nflen1 = rbno - fbno;
382 nfbno2 = rbno + rlen;
383 nflen2 = (fbno + flen) - nfbno2;
384 }
385 /*
386 * Delete the entry from the by-size btree.
387 */
388 if ((error = xfs_btree_delete(cnt_cur, &i)))
389 return error;
390 XFS_WANT_CORRUPTED_RETURN(i == 1);
391 /*
392 * Add new by-size btree entry(s).
393 */
394 if (nfbno1 != NULLAGBLOCK) {
395 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
396 return error;
397 XFS_WANT_CORRUPTED_RETURN(i == 0);
398 if ((error = xfs_btree_insert(cnt_cur, &i)))
399 return error;
400 XFS_WANT_CORRUPTED_RETURN(i == 1);
401 }
402 if (nfbno2 != NULLAGBLOCK) {
403 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
404 return error;
405 XFS_WANT_CORRUPTED_RETURN(i == 0);
406 if ((error = xfs_btree_insert(cnt_cur, &i)))
407 return error;
408 XFS_WANT_CORRUPTED_RETURN(i == 1);
409 }
410 /*
411 * Fix up the by-block btree entry(s).
412 */
413 if (nfbno1 == NULLAGBLOCK) {
414 /*
415 * No remaining freespace, just delete the by-block tree entry.
416 */
417 if ((error = xfs_btree_delete(bno_cur, &i)))
418 return error;
419 XFS_WANT_CORRUPTED_RETURN(i == 1);
420 } else {
421 /*
422 * Update the by-block entry to start later|be shorter.
423 */
424 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
425 return error;
426 }
427 if (nfbno2 != NULLAGBLOCK) {
428 /*
429 * 2 resulting free entries, need to add one.
430 */
431 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
432 return error;
433 XFS_WANT_CORRUPTED_RETURN(i == 0);
434 if ((error = xfs_btree_insert(bno_cur, &i)))
435 return error;
436 XFS_WANT_CORRUPTED_RETURN(i == 1);
437 }
438 return 0;
439}
440
441static bool
442xfs_agfl_verify(
443 struct xfs_buf *bp)
444{
445 struct xfs_mount *mp = bp->b_target->bt_mount;
446 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
447 int i;
448
449 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_uuid))
450 return false;
451 if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
452 return false;
453 /*
454 * during growfs operations, the perag is not fully initialised,
455 * so we can't use it for any useful checking. growfs ensures we can't
456 * use it by using uncached buffers that don't have the perag attached
457 * so we can detect and avoid this problem.
458 */
459 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
460 return false;
461
462 for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
463 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
464 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
465 return false;
466 }
467 return true;
468}
469
470static void
471xfs_agfl_read_verify(
472 struct xfs_buf *bp)
473{
474 struct xfs_mount *mp = bp->b_target->bt_mount;
475
476 /*
477 * There is no verification of non-crc AGFLs because mkfs does not
478 * initialise the AGFL to zero or NULL. Hence the only valid part of the
479 * AGFL is what the AGF says is active. We can't get to the AGF, so we
480 * can't verify just those entries are valid.
481 */
482 if (!xfs_sb_version_hascrc(&mp->m_sb))
483 return;
484
485 if (!xfs_buf_verify_cksum(bp, XFS_AGFL_CRC_OFF))
486 xfs_buf_ioerror(bp, EFSBADCRC);
487 else if (!xfs_agfl_verify(bp))
488 xfs_buf_ioerror(bp, EFSCORRUPTED);
489
490 if (bp->b_error)
491 xfs_verifier_error(bp);
492}
493
494static void
495xfs_agfl_write_verify(
496 struct xfs_buf *bp)
497{
498 struct xfs_mount *mp = bp->b_target->bt_mount;
499 struct xfs_buf_log_item *bip = bp->b_fspriv;
500
501 /* no verification of non-crc AGFLs */
502 if (!xfs_sb_version_hascrc(&mp->m_sb))
503 return;
504
505 if (!xfs_agfl_verify(bp)) {
506 xfs_buf_ioerror(bp, EFSCORRUPTED);
507 xfs_verifier_error(bp);
508 return;
509 }
510
511 if (bip)
512 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
513
514 xfs_buf_update_cksum(bp, XFS_AGFL_CRC_OFF);
515}
516
517const struct xfs_buf_ops xfs_agfl_buf_ops = {
518 .verify_read = xfs_agfl_read_verify,
519 .verify_write = xfs_agfl_write_verify,
520};
521
522/*
523 * Read in the allocation group free block array.
524 */
525STATIC int /* error */
526xfs_alloc_read_agfl(
527 xfs_mount_t *mp, /* mount point structure */
528 xfs_trans_t *tp, /* transaction pointer */
529 xfs_agnumber_t agno, /* allocation group number */
530 xfs_buf_t **bpp) /* buffer for the ag free block array */
531{
532 xfs_buf_t *bp; /* return value */
533 int error;
534
535 ASSERT(agno != NULLAGNUMBER);
536 error = xfs_trans_read_buf(
537 mp, tp, mp->m_ddev_targp,
538 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
539 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
540 if (error)
541 return error;
542 xfs_buf_set_ref(bp, XFS_AGFL_REF);
543 *bpp = bp;
544 return 0;
545}
546
547STATIC int
548xfs_alloc_update_counters(
549 struct xfs_trans *tp,
550 struct xfs_perag *pag,
551 struct xfs_buf *agbp,
552 long len)
553{
554 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
555
556 pag->pagf_freeblks += len;
557 be32_add_cpu(&agf->agf_freeblks, len);
558
559 xfs_trans_agblocks_delta(tp, len);
560 if (unlikely(be32_to_cpu(agf->agf_freeblks) >
561 be32_to_cpu(agf->agf_length)))
562 return EFSCORRUPTED;
563
564 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
565 return 0;
566}
567
568/*
569 * Allocation group level functions.
570 */
571
572/*
573 * Allocate a variable extent in the allocation group agno.
574 * Type and bno are used to determine where in the allocation group the
575 * extent will start.
576 * Extent's length (returned in *len) will be between minlen and maxlen,
577 * and of the form k * prod + mod unless there's nothing that large.
578 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
579 */
580STATIC int /* error */
581xfs_alloc_ag_vextent(
582 xfs_alloc_arg_t *args) /* argument structure for allocation */
583{
584 int error=0;
585
586 ASSERT(args->minlen > 0);
587 ASSERT(args->maxlen > 0);
588 ASSERT(args->minlen <= args->maxlen);
589 ASSERT(args->mod < args->prod);
590 ASSERT(args->alignment > 0);
591 /*
592 * Branch to correct routine based on the type.
593 */
594 args->wasfromfl = 0;
595 switch (args->type) {
596 case XFS_ALLOCTYPE_THIS_AG:
597 error = xfs_alloc_ag_vextent_size(args);
598 break;
599 case XFS_ALLOCTYPE_NEAR_BNO:
600 error = xfs_alloc_ag_vextent_near(args);
601 break;
602 case XFS_ALLOCTYPE_THIS_BNO:
603 error = xfs_alloc_ag_vextent_exact(args);
604 break;
605 default:
606 ASSERT(0);
607 /* NOTREACHED */
608 }
609
610 if (error || args->agbno == NULLAGBLOCK)
611 return error;
612
613 ASSERT(args->len >= args->minlen);
614 ASSERT(args->len <= args->maxlen);
615 ASSERT(!args->wasfromfl || !args->isfl);
616 ASSERT(args->agbno % args->alignment == 0);
617
618 if (!args->wasfromfl) {
619 error = xfs_alloc_update_counters(args->tp, args->pag,
620 args->agbp,
621 -((long)(args->len)));
622 if (error)
623 return error;
624
625 ASSERT(!xfs_extent_busy_search(args->mp, args->agno,
626 args->agbno, args->len));
627 }
628
629 if (!args->isfl) {
630 xfs_trans_mod_sb(args->tp, args->wasdel ?
631 XFS_TRANS_SB_RES_FDBLOCKS :
632 XFS_TRANS_SB_FDBLOCKS,
633 -((long)(args->len)));
634 }
635
636 XFS_STATS_INC(xs_allocx);
637 XFS_STATS_ADD(xs_allocb, args->len);
638 return error;
639}
640
641/*
642 * Allocate a variable extent at exactly agno/bno.
643 * Extent's length (returned in *len) will be between minlen and maxlen,
644 * and of the form k * prod + mod unless there's nothing that large.
645 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
646 */
647STATIC int /* error */
648xfs_alloc_ag_vextent_exact(
649 xfs_alloc_arg_t *args) /* allocation argument structure */
650{
651 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
652 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
653 int error;
654 xfs_agblock_t fbno; /* start block of found extent */
655 xfs_extlen_t flen; /* length of found extent */
656 xfs_agblock_t tbno; /* start block of trimmed extent */
657 xfs_extlen_t tlen; /* length of trimmed extent */
658 xfs_agblock_t tend; /* end block of trimmed extent */
659 int i; /* success/failure of operation */
660
661 ASSERT(args->alignment == 1);
662
663 /*
664 * Allocate/initialize a cursor for the by-number freespace btree.
665 */
666 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
667 args->agno, XFS_BTNUM_BNO);
668
669 /*
670 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
671 * Look for the closest free block <= bno, it must contain bno
672 * if any free block does.
673 */
674 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
675 if (error)
676 goto error0;
677 if (!i)
678 goto not_found;
679
680 /*
681 * Grab the freespace record.
682 */
683 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
684 if (error)
685 goto error0;
686 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
687 ASSERT(fbno <= args->agbno);
688
689 /*
690 * Check for overlapping busy extents.
691 */
692 xfs_extent_busy_trim(args, fbno, flen, &tbno, &tlen);
693
694 /*
695 * Give up if the start of the extent is busy, or the freespace isn't
696 * long enough for the minimum request.
697 */
698 if (tbno > args->agbno)
699 goto not_found;
700 if (tlen < args->minlen)
701 goto not_found;
702 tend = tbno + tlen;
703 if (tend < args->agbno + args->minlen)
704 goto not_found;
705
706 /*
707 * End of extent will be smaller of the freespace end and the
708 * maximal requested end.
709 *
710 * Fix the length according to mod and prod if given.
711 */
712 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
713 - args->agbno;
714 xfs_alloc_fix_len(args);
715 if (!xfs_alloc_fix_minleft(args))
716 goto not_found;
717
718 ASSERT(args->agbno + args->len <= tend);
719
720 /*
721 * We are allocating agbno for args->len
722 * Allocate/initialize a cursor for the by-size btree.
723 */
724 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
725 args->agno, XFS_BTNUM_CNT);
726 ASSERT(args->agbno + args->len <=
727 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
728 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
729 args->len, XFSA_FIXUP_BNO_OK);
730 if (error) {
731 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
732 goto error0;
733 }
734
735 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
736 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
737
738 args->wasfromfl = 0;
739 trace_xfs_alloc_exact_done(args);
740 return 0;
741
742not_found:
743 /* Didn't find it, return null. */
744 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
745 args->agbno = NULLAGBLOCK;
746 trace_xfs_alloc_exact_notfound(args);
747 return 0;
748
749error0:
750 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
751 trace_xfs_alloc_exact_error(args);
752 return error;
753}
754
755/*
756 * Search the btree in a given direction via the search cursor and compare
757 * the records found against the good extent we've already found.
758 */
759STATIC int
760xfs_alloc_find_best_extent(
761 struct xfs_alloc_arg *args, /* allocation argument structure */
762 struct xfs_btree_cur **gcur, /* good cursor */
763 struct xfs_btree_cur **scur, /* searching cursor */
764 xfs_agblock_t gdiff, /* difference for search comparison */
765 xfs_agblock_t *sbno, /* extent found by search */
766 xfs_extlen_t *slen, /* extent length */
767 xfs_agblock_t *sbnoa, /* aligned extent found by search */
768 xfs_extlen_t *slena, /* aligned extent length */
769 int dir) /* 0 = search right, 1 = search left */
770{
771 xfs_agblock_t new;
772 xfs_agblock_t sdiff;
773 int error;
774 int i;
775
776 /* The good extent is perfect, no need to search. */
777 if (!gdiff)
778 goto out_use_good;
779
780 /*
781 * Look until we find a better one, run out of space or run off the end.
782 */
783 do {
784 error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
785 if (error)
786 goto error0;
787 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
788 xfs_alloc_compute_aligned(args, *sbno, *slen, sbnoa, slena);
789
790 /*
791 * The good extent is closer than this one.
792 */
793 if (!dir) {
794 if (*sbnoa >= args->agbno + gdiff)
795 goto out_use_good;
796 } else {
797 if (*sbnoa <= args->agbno - gdiff)
798 goto out_use_good;
799 }
800
801 /*
802 * Same distance, compare length and pick the best.
803 */
804 if (*slena >= args->minlen) {
805 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
806 xfs_alloc_fix_len(args);
807
808 sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
809 args->alignment,
810 args->userdata, *sbnoa,
811 *slena, &new);
812
813 /*
814 * Choose closer size and invalidate other cursor.
815 */
816 if (sdiff < gdiff)
817 goto out_use_search;
818 goto out_use_good;
819 }
820
821 if (!dir)
822 error = xfs_btree_increment(*scur, 0, &i);
823 else
824 error = xfs_btree_decrement(*scur, 0, &i);
825 if (error)
826 goto error0;
827 } while (i);
828
829out_use_good:
830 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
831 *scur = NULL;
832 return 0;
833
834out_use_search:
835 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
836 *gcur = NULL;
837 return 0;
838
839error0:
840 /* caller invalidates cursors */
841 return error;
842}
843
844/*
845 * Allocate a variable extent near bno in the allocation group agno.
846 * Extent's length (returned in len) will be between minlen and maxlen,
847 * and of the form k * prod + mod unless there's nothing that large.
848 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
849 */
850STATIC int /* error */
851xfs_alloc_ag_vextent_near(
852 xfs_alloc_arg_t *args) /* allocation argument structure */
853{
854 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
855 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
856 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
857 xfs_agblock_t gtbno; /* start bno of right side entry */
858 xfs_agblock_t gtbnoa; /* aligned ... */
859 xfs_extlen_t gtdiff; /* difference to right side entry */
860 xfs_extlen_t gtlen; /* length of right side entry */
861 xfs_extlen_t gtlena; /* aligned ... */
862 xfs_agblock_t gtnew; /* useful start bno of right side */
863 int error; /* error code */
864 int i; /* result code, temporary */
865 int j; /* result code, temporary */
866 xfs_agblock_t ltbno; /* start bno of left side entry */
867 xfs_agblock_t ltbnoa; /* aligned ... */
868 xfs_extlen_t ltdiff; /* difference to left side entry */
869 xfs_extlen_t ltlen; /* length of left side entry */
870 xfs_extlen_t ltlena; /* aligned ... */
871 xfs_agblock_t ltnew; /* useful start bno of left side */
872 xfs_extlen_t rlen; /* length of returned extent */
873 int forced = 0;
874#ifdef DEBUG
875 /*
876 * Randomly don't execute the first algorithm.
877 */
878 int dofirst; /* set to do first algorithm */
879
880 dofirst = prandom_u32() & 1;
881#endif
882
883restart:
884 bno_cur_lt = NULL;
885 bno_cur_gt = NULL;
886 ltlen = 0;
887 gtlena = 0;
888 ltlena = 0;
889
890 /*
891 * Get a cursor for the by-size btree.
892 */
893 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
894 args->agno, XFS_BTNUM_CNT);
895
896 /*
897 * See if there are any free extents as big as maxlen.
898 */
899 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
900 goto error0;
901 /*
902 * If none, then pick up the last entry in the tree unless the
903 * tree is empty.
904 */
905 if (!i) {
906 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
907 &ltlen, &i)))
908 goto error0;
909 if (i == 0 || ltlen == 0) {
910 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
911 trace_xfs_alloc_near_noentry(args);
912 return 0;
913 }
914 ASSERT(i == 1);
915 }
916 args->wasfromfl = 0;
917
918 /*
919 * First algorithm.
920 * If the requested extent is large wrt the freespaces available
921 * in this a.g., then the cursor will be pointing to a btree entry
922 * near the right edge of the tree. If it's in the last btree leaf
923 * block, then we just examine all the entries in that block
924 * that are big enough, and pick the best one.
925 * This is written as a while loop so we can break out of it,
926 * but we never loop back to the top.
927 */
928 while (xfs_btree_islastblock(cnt_cur, 0)) {
929 xfs_extlen_t bdiff;
930 int besti=0;
931 xfs_extlen_t blen=0;
932 xfs_agblock_t bnew=0;
933
934#ifdef DEBUG
935 if (dofirst)
936 break;
937#endif
938 /*
939 * Start from the entry that lookup found, sequence through
940 * all larger free blocks. If we're actually pointing at a
941 * record smaller than maxlen, go to the start of this block,
942 * and skip all those smaller than minlen.
943 */
944 if (ltlen || args->alignment > 1) {
945 cnt_cur->bc_ptrs[0] = 1;
946 do {
947 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
948 &ltlen, &i)))
949 goto error0;
950 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
951 if (ltlen >= args->minlen)
952 break;
953 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
954 goto error0;
955 } while (i);
956 ASSERT(ltlen >= args->minlen);
957 if (!i)
958 break;
959 }
960 i = cnt_cur->bc_ptrs[0];
961 for (j = 1, blen = 0, bdiff = 0;
962 !error && j && (blen < args->maxlen || bdiff > 0);
963 error = xfs_btree_increment(cnt_cur, 0, &j)) {
964 /*
965 * For each entry, decide if it's better than
966 * the previous best entry.
967 */
968 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
969 goto error0;
970 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
971 xfs_alloc_compute_aligned(args, ltbno, ltlen,
972 &ltbnoa, &ltlena);
973 if (ltlena < args->minlen)
974 continue;
975 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
976 xfs_alloc_fix_len(args);
977 ASSERT(args->len >= args->minlen);
978 if (args->len < blen)
979 continue;
980 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
981 args->alignment, args->userdata, ltbnoa,
982 ltlena, &ltnew);
983 if (ltnew != NULLAGBLOCK &&
984 (args->len > blen || ltdiff < bdiff)) {
985 bdiff = ltdiff;
986 bnew = ltnew;
987 blen = args->len;
988 besti = cnt_cur->bc_ptrs[0];
989 }
990 }
991 /*
992 * It didn't work. We COULD be in a case where
993 * there's a good record somewhere, so try again.
994 */
995 if (blen == 0)
996 break;
997 /*
998 * Point at the best entry, and retrieve it again.
999 */
1000 cnt_cur->bc_ptrs[0] = besti;
1001 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
1002 goto error0;
1003 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1004 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1005 args->len = blen;
1006 if (!xfs_alloc_fix_minleft(args)) {
1007 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1008 trace_xfs_alloc_near_nominleft(args);
1009 return 0;
1010 }
1011 blen = args->len;
1012 /*
1013 * We are allocating starting at bnew for blen blocks.
1014 */
1015 args->agbno = bnew;
1016 ASSERT(bnew >= ltbno);
1017 ASSERT(bnew + blen <= ltbno + ltlen);
1018 /*
1019 * Set up a cursor for the by-bno tree.
1020 */
1021 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1022 args->agbp, args->agno, XFS_BTNUM_BNO);
1023 /*
1024 * Fix up the btree entries.
1025 */
1026 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1027 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1028 goto error0;
1029 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1030 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1031
1032 trace_xfs_alloc_near_first(args);
1033 return 0;
1034 }
1035 /*
1036 * Second algorithm.
1037 * Search in the by-bno tree to the left and to the right
1038 * simultaneously, until in each case we find a space big enough,
1039 * or run into the edge of the tree. When we run into the edge,
1040 * we deallocate that cursor.
1041 * If both searches succeed, we compare the two spaces and pick
1042 * the better one.
1043 * With alignment, it's possible for both to fail; the upper
1044 * level algorithm that picks allocation groups for allocations
1045 * is not supposed to do this.
1046 */
1047 /*
1048 * Allocate and initialize the cursor for the leftward search.
1049 */
1050 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1051 args->agno, XFS_BTNUM_BNO);
1052 /*
1053 * Lookup <= bno to find the leftward search's starting point.
1054 */
1055 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1056 goto error0;
1057 if (!i) {
1058 /*
1059 * Didn't find anything; use this cursor for the rightward
1060 * search.
1061 */
1062 bno_cur_gt = bno_cur_lt;
1063 bno_cur_lt = NULL;
1064 }
1065 /*
1066 * Found something. Duplicate the cursor for the rightward search.
1067 */
1068 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1069 goto error0;
1070 /*
1071 * Increment the cursor, so we will point at the entry just right
1072 * of the leftward entry if any, or to the leftmost entry.
1073 */
1074 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1075 goto error0;
1076 if (!i) {
1077 /*
1078 * It failed, there are no rightward entries.
1079 */
1080 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1081 bno_cur_gt = NULL;
1082 }
1083 /*
1084 * Loop going left with the leftward cursor, right with the
1085 * rightward cursor, until either both directions give up or
1086 * we find an entry at least as big as minlen.
1087 */
1088 do {
1089 if (bno_cur_lt) {
1090 if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
1091 goto error0;
1092 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1093 xfs_alloc_compute_aligned(args, ltbno, ltlen,
1094 &ltbnoa, &ltlena);
1095 if (ltlena >= args->minlen)
1096 break;
1097 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
1098 goto error0;
1099 if (!i) {
1100 xfs_btree_del_cursor(bno_cur_lt,
1101 XFS_BTREE_NOERROR);
1102 bno_cur_lt = NULL;
1103 }
1104 }
1105 if (bno_cur_gt) {
1106 if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
1107 goto error0;
1108 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1109 xfs_alloc_compute_aligned(args, gtbno, gtlen,
1110 &gtbnoa, &gtlena);
1111 if (gtlena >= args->minlen)
1112 break;
1113 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1114 goto error0;
1115 if (!i) {
1116 xfs_btree_del_cursor(bno_cur_gt,
1117 XFS_BTREE_NOERROR);
1118 bno_cur_gt = NULL;
1119 }
1120 }
1121 } while (bno_cur_lt || bno_cur_gt);
1122
1123 /*
1124 * Got both cursors still active, need to find better entry.
1125 */
1126 if (bno_cur_lt && bno_cur_gt) {
1127 if (ltlena >= args->minlen) {
1128 /*
1129 * Left side is good, look for a right side entry.
1130 */
1131 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1132 xfs_alloc_fix_len(args);
1133 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1134 args->alignment, args->userdata, ltbnoa,
1135 ltlena, &ltnew);
1136
1137 error = xfs_alloc_find_best_extent(args,
1138 &bno_cur_lt, &bno_cur_gt,
1139 ltdiff, &gtbno, &gtlen,
1140 &gtbnoa, &gtlena,
1141 0 /* search right */);
1142 } else {
1143 ASSERT(gtlena >= args->minlen);
1144
1145 /*
1146 * Right side is good, look for a left side entry.
1147 */
1148 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1149 xfs_alloc_fix_len(args);
1150 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1151 args->alignment, args->userdata, gtbnoa,
1152 gtlena, &gtnew);
1153
1154 error = xfs_alloc_find_best_extent(args,
1155 &bno_cur_gt, &bno_cur_lt,
1156 gtdiff, &ltbno, &ltlen,
1157 &ltbnoa, &ltlena,
1158 1 /* search left */);
1159 }
1160
1161 if (error)
1162 goto error0;
1163 }
1164
1165 /*
1166 * If we couldn't get anything, give up.
1167 */
1168 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1169 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1170
1171 if (!forced++) {
1172 trace_xfs_alloc_near_busy(args);
1173 xfs_log_force(args->mp, XFS_LOG_SYNC);
1174 goto restart;
1175 }
1176 trace_xfs_alloc_size_neither(args);
1177 args->agbno = NULLAGBLOCK;
1178 return 0;
1179 }
1180
1181 /*
1182 * At this point we have selected a freespace entry, either to the
1183 * left or to the right. If it's on the right, copy all the
1184 * useful variables to the "left" set so we only have one
1185 * copy of this code.
1186 */
1187 if (bno_cur_gt) {
1188 bno_cur_lt = bno_cur_gt;
1189 bno_cur_gt = NULL;
1190 ltbno = gtbno;
1191 ltbnoa = gtbnoa;
1192 ltlen = gtlen;
1193 ltlena = gtlena;
1194 j = 1;
1195 } else
1196 j = 0;
1197
1198 /*
1199 * Fix up the length and compute the useful address.
1200 */
1201 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1202 xfs_alloc_fix_len(args);
1203 if (!xfs_alloc_fix_minleft(args)) {
1204 trace_xfs_alloc_near_nominleft(args);
1205 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1206 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1207 return 0;
1208 }
1209 rlen = args->len;
1210 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
1211 args->userdata, ltbnoa, ltlena, &ltnew);
1212 ASSERT(ltnew >= ltbno);
1213 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
1214 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1215 args->agbno = ltnew;
1216
1217 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1218 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1219 goto error0;
1220
1221 if (j)
1222 trace_xfs_alloc_near_greater(args);
1223 else
1224 trace_xfs_alloc_near_lesser(args);
1225
1226 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1227 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1228 return 0;
1229
1230 error0:
1231 trace_xfs_alloc_near_error(args);
1232 if (cnt_cur != NULL)
1233 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1234 if (bno_cur_lt != NULL)
1235 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1236 if (bno_cur_gt != NULL)
1237 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1238 return error;
1239}
1240
1241/*
1242 * Allocate a variable extent anywhere in the allocation group agno.
1243 * Extent's length (returned in len) will be between minlen and maxlen,
1244 * and of the form k * prod + mod unless there's nothing that large.
1245 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1246 */
1247STATIC int /* error */
1248xfs_alloc_ag_vextent_size(
1249 xfs_alloc_arg_t *args) /* allocation argument structure */
1250{
1251 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1252 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1253 int error; /* error result */
1254 xfs_agblock_t fbno; /* start of found freespace */
1255 xfs_extlen_t flen; /* length of found freespace */
1256 int i; /* temp status variable */
1257 xfs_agblock_t rbno; /* returned block number */
1258 xfs_extlen_t rlen; /* length of returned extent */
1259 int forced = 0;
1260
1261restart:
1262 /*
1263 * Allocate and initialize a cursor for the by-size btree.
1264 */
1265 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1266 args->agno, XFS_BTNUM_CNT);
1267 bno_cur = NULL;
1268
1269 /*
1270 * Look for an entry >= maxlen+alignment-1 blocks.
1271 */
1272 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1273 args->maxlen + args->alignment - 1, &i)))
1274 goto error0;
1275
1276 /*
1277 * If none or we have busy extents that we cannot allocate from, then
1278 * we have to settle for a smaller extent. In the case that there are
1279 * no large extents, this will return the last entry in the tree unless
1280 * the tree is empty. In the case that there are only busy large
1281 * extents, this will return the largest small extent unless there
1282 * are no smaller extents available.
1283 */
1284 if (!i || forced > 1) {
1285 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1286 &fbno, &flen, &i);
1287 if (error)
1288 goto error0;
1289 if (i == 0 || flen == 0) {
1290 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1291 trace_xfs_alloc_size_noentry(args);
1292 return 0;
1293 }
1294 ASSERT(i == 1);
1295 xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
1296 } else {
1297 /*
1298 * Search for a non-busy extent that is large enough.
1299 * If we are at low space, don't check, or if we fall of
1300 * the end of the btree, turn off the busy check and
1301 * restart.
1302 */
1303 for (;;) {
1304 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1305 if (error)
1306 goto error0;
1307 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1308
1309 xfs_alloc_compute_aligned(args, fbno, flen,
1310 &rbno, &rlen);
1311
1312 if (rlen >= args->maxlen)
1313 break;
1314
1315 error = xfs_btree_increment(cnt_cur, 0, &i);
1316 if (error)
1317 goto error0;
1318 if (i == 0) {
1319 /*
1320 * Our only valid extents must have been busy.
1321 * Make it unbusy by forcing the log out and
1322 * retrying. If we've been here before, forcing
1323 * the log isn't making the extents available,
1324 * which means they have probably been freed in
1325 * this transaction. In that case, we have to
1326 * give up on them and we'll attempt a minlen
1327 * allocation the next time around.
1328 */
1329 xfs_btree_del_cursor(cnt_cur,
1330 XFS_BTREE_NOERROR);
1331 trace_xfs_alloc_size_busy(args);
1332 if (!forced++)
1333 xfs_log_force(args->mp, XFS_LOG_SYNC);
1334 goto restart;
1335 }
1336 }
1337 }
1338
1339 /*
1340 * In the first case above, we got the last entry in the
1341 * by-size btree. Now we check to see if the space hits maxlen
1342 * once aligned; if not, we search left for something better.
1343 * This can't happen in the second case above.
1344 */
1345 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1346 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1347 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1348 if (rlen < args->maxlen) {
1349 xfs_agblock_t bestfbno;
1350 xfs_extlen_t bestflen;
1351 xfs_agblock_t bestrbno;
1352 xfs_extlen_t bestrlen;
1353
1354 bestrlen = rlen;
1355 bestrbno = rbno;
1356 bestflen = flen;
1357 bestfbno = fbno;
1358 for (;;) {
1359 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
1360 goto error0;
1361 if (i == 0)
1362 break;
1363 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1364 &i)))
1365 goto error0;
1366 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1367 if (flen < bestrlen)
1368 break;
1369 xfs_alloc_compute_aligned(args, fbno, flen,
1370 &rbno, &rlen);
1371 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1372 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1373 (rlen <= flen && rbno + rlen <= fbno + flen),
1374 error0);
1375 if (rlen > bestrlen) {
1376 bestrlen = rlen;
1377 bestrbno = rbno;
1378 bestflen = flen;
1379 bestfbno = fbno;
1380 if (rlen == args->maxlen)
1381 break;
1382 }
1383 }
1384 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1385 &i)))
1386 goto error0;
1387 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1388 rlen = bestrlen;
1389 rbno = bestrbno;
1390 flen = bestflen;
1391 fbno = bestfbno;
1392 }
1393 args->wasfromfl = 0;
1394 /*
1395 * Fix up the length.
1396 */
1397 args->len = rlen;
1398 if (rlen < args->minlen) {
1399 if (!forced++) {
1400 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1401 trace_xfs_alloc_size_busy(args);
1402 xfs_log_force(args->mp, XFS_LOG_SYNC);
1403 goto restart;
1404 }
1405 goto out_nominleft;
1406 }
1407 xfs_alloc_fix_len(args);
1408
1409 if (!xfs_alloc_fix_minleft(args))
1410 goto out_nominleft;
1411 rlen = args->len;
1412 XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
1413 /*
1414 * Allocate and initialize a cursor for the by-block tree.
1415 */
1416 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1417 args->agno, XFS_BTNUM_BNO);
1418 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1419 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1420 goto error0;
1421 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1422 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1423 cnt_cur = bno_cur = NULL;
1424 args->len = rlen;
1425 args->agbno = rbno;
1426 XFS_WANT_CORRUPTED_GOTO(
1427 args->agbno + args->len <=
1428 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1429 error0);
1430 trace_xfs_alloc_size_done(args);
1431 return 0;
1432
1433error0:
1434 trace_xfs_alloc_size_error(args);
1435 if (cnt_cur)
1436 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1437 if (bno_cur)
1438 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1439 return error;
1440
1441out_nominleft:
1442 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1443 trace_xfs_alloc_size_nominleft(args);
1444 args->agbno = NULLAGBLOCK;
1445 return 0;
1446}
1447
1448/*
1449 * Deal with the case where only small freespaces remain.
1450 * Either return the contents of the last freespace record,
1451 * or allocate space from the freelist if there is nothing in the tree.
1452 */
1453STATIC int /* error */
1454xfs_alloc_ag_vextent_small(
1455 xfs_alloc_arg_t *args, /* allocation argument structure */
1456 xfs_btree_cur_t *ccur, /* by-size cursor */
1457 xfs_agblock_t *fbnop, /* result block number */
1458 xfs_extlen_t *flenp, /* result length */
1459 int *stat) /* status: 0-freelist, 1-normal/none */
1460{
1461 int error;
1462 xfs_agblock_t fbno;
1463 xfs_extlen_t flen;
1464 int i;
1465
1466 if ((error = xfs_btree_decrement(ccur, 0, &i)))
1467 goto error0;
1468 if (i) {
1469 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1470 goto error0;
1471 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1472 }
1473 /*
1474 * Nothing in the btree, try the freelist. Make sure
1475 * to respect minleft even when pulling from the
1476 * freelist.
1477 */
1478 else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
1479 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1480 > args->minleft)) {
1481 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
1482 if (error)
1483 goto error0;
1484 if (fbno != NULLAGBLOCK) {
1485 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
1486 args->userdata);
1487
1488 if (args->userdata) {
1489 xfs_buf_t *bp;
1490
1491 bp = xfs_btree_get_bufs(args->mp, args->tp,
1492 args->agno, fbno, 0);
1493 xfs_trans_binval(args->tp, bp);
1494 }
1495 args->len = 1;
1496 args->agbno = fbno;
1497 XFS_WANT_CORRUPTED_GOTO(
1498 args->agbno + args->len <=
1499 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1500 error0);
1501 args->wasfromfl = 1;
1502 trace_xfs_alloc_small_freelist(args);
1503 *stat = 0;
1504 return 0;
1505 }
1506 /*
1507 * Nothing in the freelist.
1508 */
1509 else
1510 flen = 0;
1511 }
1512 /*
1513 * Can't allocate from the freelist for some reason.
1514 */
1515 else {
1516 fbno = NULLAGBLOCK;
1517 flen = 0;
1518 }
1519 /*
1520 * Can't do the allocation, give up.
1521 */
1522 if (flen < args->minlen) {
1523 args->agbno = NULLAGBLOCK;
1524 trace_xfs_alloc_small_notenough(args);
1525 flen = 0;
1526 }
1527 *fbnop = fbno;
1528 *flenp = flen;
1529 *stat = 1;
1530 trace_xfs_alloc_small_done(args);
1531 return 0;
1532
1533error0:
1534 trace_xfs_alloc_small_error(args);
1535 return error;
1536}
1537
1538/*
1539 * Free the extent starting at agno/bno for length.
1540 */
1541STATIC int /* error */
1542xfs_free_ag_extent(
1543 xfs_trans_t *tp, /* transaction pointer */
1544 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
1545 xfs_agnumber_t agno, /* allocation group number */
1546 xfs_agblock_t bno, /* starting block number */
1547 xfs_extlen_t len, /* length of extent */
1548 int isfl) /* set if is freelist blocks - no sb acctg */
1549{
1550 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1551 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1552 int error; /* error return value */
1553 xfs_agblock_t gtbno; /* start of right neighbor block */
1554 xfs_extlen_t gtlen; /* length of right neighbor block */
1555 int haveleft; /* have a left neighbor block */
1556 int haveright; /* have a right neighbor block */
1557 int i; /* temp, result code */
1558 xfs_agblock_t ltbno; /* start of left neighbor block */
1559 xfs_extlen_t ltlen; /* length of left neighbor block */
1560 xfs_mount_t *mp; /* mount point struct for filesystem */
1561 xfs_agblock_t nbno; /* new starting block of freespace */
1562 xfs_extlen_t nlen; /* new length of freespace */
1563 xfs_perag_t *pag; /* per allocation group data */
1564
1565 mp = tp->t_mountp;
1566 /*
1567 * Allocate and initialize a cursor for the by-block btree.
1568 */
1569 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
1570 cnt_cur = NULL;
1571 /*
1572 * Look for a neighboring block on the left (lower block numbers)
1573 * that is contiguous with this space.
1574 */
1575 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1576 goto error0;
1577 if (haveleft) {
1578 /*
1579 * There is a block to our left.
1580 */
1581 if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
1582 goto error0;
1583 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1584 /*
1585 * It's not contiguous, though.
1586 */
1587 if (ltbno + ltlen < bno)
1588 haveleft = 0;
1589 else {
1590 /*
1591 * If this failure happens the request to free this
1592 * space was invalid, it's (partly) already free.
1593 * Very bad.
1594 */
1595 XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
1596 }
1597 }
1598 /*
1599 * Look for a neighboring block on the right (higher block numbers)
1600 * that is contiguous with this space.
1601 */
1602 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
1603 goto error0;
1604 if (haveright) {
1605 /*
1606 * There is a block to our right.
1607 */
1608 if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
1609 goto error0;
1610 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1611 /*
1612 * It's not contiguous, though.
1613 */
1614 if (bno + len < gtbno)
1615 haveright = 0;
1616 else {
1617 /*
1618 * If this failure happens the request to free this
1619 * space was invalid, it's (partly) already free.
1620 * Very bad.
1621 */
1622 XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
1623 }
1624 }
1625 /*
1626 * Now allocate and initialize a cursor for the by-size tree.
1627 */
1628 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
1629 /*
1630 * Have both left and right contiguous neighbors.
1631 * Merge all three into a single free block.
1632 */
1633 if (haveleft && haveright) {
1634 /*
1635 * Delete the old by-size entry on the left.
1636 */
1637 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1638 goto error0;
1639 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1640 if ((error = xfs_btree_delete(cnt_cur, &i)))
1641 goto error0;
1642 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1643 /*
1644 * Delete the old by-size entry on the right.
1645 */
1646 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1647 goto error0;
1648 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1649 if ((error = xfs_btree_delete(cnt_cur, &i)))
1650 goto error0;
1651 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1652 /*
1653 * Delete the old by-block entry for the right block.
1654 */
1655 if ((error = xfs_btree_delete(bno_cur, &i)))
1656 goto error0;
1657 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1658 /*
1659 * Move the by-block cursor back to the left neighbor.
1660 */
1661 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1662 goto error0;
1663 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1664#ifdef DEBUG
1665 /*
1666 * Check that this is the right record: delete didn't
1667 * mangle the cursor.
1668 */
1669 {
1670 xfs_agblock_t xxbno;
1671 xfs_extlen_t xxlen;
1672
1673 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1674 &i)))
1675 goto error0;
1676 XFS_WANT_CORRUPTED_GOTO(
1677 i == 1 && xxbno == ltbno && xxlen == ltlen,
1678 error0);
1679 }
1680#endif
1681 /*
1682 * Update remaining by-block entry to the new, joined block.
1683 */
1684 nbno = ltbno;
1685 nlen = len + ltlen + gtlen;
1686 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1687 goto error0;
1688 }
1689 /*
1690 * Have only a left contiguous neighbor.
1691 * Merge it together with the new freespace.
1692 */
1693 else if (haveleft) {
1694 /*
1695 * Delete the old by-size entry on the left.
1696 */
1697 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1698 goto error0;
1699 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1700 if ((error = xfs_btree_delete(cnt_cur, &i)))
1701 goto error0;
1702 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1703 /*
1704 * Back up the by-block cursor to the left neighbor, and
1705 * update its length.
1706 */
1707 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1708 goto error0;
1709 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1710 nbno = ltbno;
1711 nlen = len + ltlen;
1712 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1713 goto error0;
1714 }
1715 /*
1716 * Have only a right contiguous neighbor.
1717 * Merge it together with the new freespace.
1718 */
1719 else if (haveright) {
1720 /*
1721 * Delete the old by-size entry on the right.
1722 */
1723 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1724 goto error0;
1725 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1726 if ((error = xfs_btree_delete(cnt_cur, &i)))
1727 goto error0;
1728 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1729 /*
1730 * Update the starting block and length of the right
1731 * neighbor in the by-block tree.
1732 */
1733 nbno = bno;
1734 nlen = len + gtlen;
1735 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1736 goto error0;
1737 }
1738 /*
1739 * No contiguous neighbors.
1740 * Insert the new freespace into the by-block tree.
1741 */
1742 else {
1743 nbno = bno;
1744 nlen = len;
1745 if ((error = xfs_btree_insert(bno_cur, &i)))
1746 goto error0;
1747 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1748 }
1749 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1750 bno_cur = NULL;
1751 /*
1752 * In all cases we need to insert the new freespace in the by-size tree.
1753 */
1754 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1755 goto error0;
1756 XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
1757 if ((error = xfs_btree_insert(cnt_cur, &i)))
1758 goto error0;
1759 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1760 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1761 cnt_cur = NULL;
1762
1763 /*
1764 * Update the freespace totals in the ag and superblock.
1765 */
1766 pag = xfs_perag_get(mp, agno);
1767 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1768 xfs_perag_put(pag);
1769 if (error)
1770 goto error0;
1771
1772 if (!isfl)
1773 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1774 XFS_STATS_INC(xs_freex);
1775 XFS_STATS_ADD(xs_freeb, len);
1776
1777 trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
1778
1779 return 0;
1780
1781 error0:
1782 trace_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
1783 if (bno_cur)
1784 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1785 if (cnt_cur)
1786 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1787 return error;
1788}
1789
1790/*
1791 * Visible (exported) allocation/free functions.
1792 * Some of these are used just by xfs_alloc_btree.c and this file.
1793 */
1794
1795/*
1796 * Compute and fill in value of m_ag_maxlevels.
1797 */
1798void
1799xfs_alloc_compute_maxlevels(
1800 xfs_mount_t *mp) /* file system mount structure */
1801{
1802 int level;
1803 uint maxblocks;
1804 uint maxleafents;
1805 int minleafrecs;
1806 int minnoderecs;
1807
1808 maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1809 minleafrecs = mp->m_alloc_mnr[0];
1810 minnoderecs = mp->m_alloc_mnr[1];
1811 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1812 for (level = 1; maxblocks > 1; level++)
1813 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1814 mp->m_ag_maxlevels = level;
1815}
1816
1817/*
1818 * Find the length of the longest extent in an AG.
1819 */
1820xfs_extlen_t
1821xfs_alloc_longest_free_extent(
1822 struct xfs_mount *mp,
1823 struct xfs_perag *pag)
1824{
1825 xfs_extlen_t need, delta = 0;
1826
1827 need = XFS_MIN_FREELIST_PAG(pag, mp);
1828 if (need > pag->pagf_flcount)
1829 delta = need - pag->pagf_flcount;
1830
1831 if (pag->pagf_longest > delta)
1832 return pag->pagf_longest - delta;
1833 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1834}
1835
1836/*
1837 * Decide whether to use this allocation group for this allocation.
1838 * If so, fix up the btree freelist's size.
1839 */
1840STATIC int /* error */
1841xfs_alloc_fix_freelist(
1842 xfs_alloc_arg_t *args, /* allocation argument structure */
1843 int flags) /* XFS_ALLOC_FLAG_... */
1844{
1845 xfs_buf_t *agbp; /* agf buffer pointer */
1846 xfs_agf_t *agf; /* a.g. freespace structure pointer */
1847 xfs_buf_t *agflbp;/* agfl buffer pointer */
1848 xfs_agblock_t bno; /* freelist block */
1849 xfs_extlen_t delta; /* new blocks needed in freelist */
1850 int error; /* error result code */
1851 xfs_extlen_t longest;/* longest extent in allocation group */
1852 xfs_mount_t *mp; /* file system mount point structure */
1853 xfs_extlen_t need; /* total blocks needed in freelist */
1854 xfs_perag_t *pag; /* per-ag information structure */
1855 xfs_alloc_arg_t targs; /* local allocation arguments */
1856 xfs_trans_t *tp; /* transaction pointer */
1857
1858 mp = args->mp;
1859
1860 pag = args->pag;
1861 tp = args->tp;
1862 if (!pag->pagf_init) {
1863 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1864 &agbp)))
1865 return error;
1866 if (!pag->pagf_init) {
1867 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1868 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1869 args->agbp = NULL;
1870 return 0;
1871 }
1872 } else
1873 agbp = NULL;
1874
1875 /*
1876 * If this is a metadata preferred pag and we are user data
1877 * then try somewhere else if we are not being asked to
1878 * try harder at this point
1879 */
1880 if (pag->pagf_metadata && args->userdata &&
1881 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
1882 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1883 args->agbp = NULL;
1884 return 0;
1885 }
1886
1887 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1888 /*
1889 * If it looks like there isn't a long enough extent, or enough
1890 * total blocks, reject it.
1891 */
1892 need = XFS_MIN_FREELIST_PAG(pag, mp);
1893 longest = xfs_alloc_longest_free_extent(mp, pag);
1894 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1895 longest ||
1896 ((int)(pag->pagf_freeblks + pag->pagf_flcount -
1897 need - args->total) < (int)args->minleft)) {
1898 if (agbp)
1899 xfs_trans_brelse(tp, agbp);
1900 args->agbp = NULL;
1901 return 0;
1902 }
1903 }
1904
1905 /*
1906 * Get the a.g. freespace buffer.
1907 * Can fail if we're not blocking on locks, and it's held.
1908 */
1909 if (agbp == NULL) {
1910 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1911 &agbp)))
1912 return error;
1913 if (agbp == NULL) {
1914 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1915 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1916 args->agbp = NULL;
1917 return 0;
1918 }
1919 }
1920 /*
1921 * Figure out how many blocks we should have in the freelist.
1922 */
1923 agf = XFS_BUF_TO_AGF(agbp);
1924 need = XFS_MIN_FREELIST(agf, mp);
1925 /*
1926 * If there isn't enough total or single-extent, reject it.
1927 */
1928 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1929 delta = need > be32_to_cpu(agf->agf_flcount) ?
1930 (need - be32_to_cpu(agf->agf_flcount)) : 0;
1931 longest = be32_to_cpu(agf->agf_longest);
1932 longest = (longest > delta) ? (longest - delta) :
1933 (be32_to_cpu(agf->agf_flcount) > 0 || longest > 0);
1934 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1935 longest ||
1936 ((int)(be32_to_cpu(agf->agf_freeblks) +
1937 be32_to_cpu(agf->agf_flcount) - need - args->total) <
1938 (int)args->minleft)) {
1939 xfs_trans_brelse(tp, agbp);
1940 args->agbp = NULL;
1941 return 0;
1942 }
1943 }
1944 /*
1945 * Make the freelist shorter if it's too long.
1946 */
1947 while (be32_to_cpu(agf->agf_flcount) > need) {
1948 xfs_buf_t *bp;
1949
1950 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
1951 if (error)
1952 return error;
1953 if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
1954 return error;
1955 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
1956 xfs_trans_binval(tp, bp);
1957 }
1958 /*
1959 * Initialize the args structure.
1960 */
1961 memset(&targs, 0, sizeof(targs));
1962 targs.tp = tp;
1963 targs.mp = mp;
1964 targs.agbp = agbp;
1965 targs.agno = args->agno;
1966 targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
1967 targs.type = XFS_ALLOCTYPE_THIS_AG;
1968 targs.pag = pag;
1969 if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
1970 return error;
1971 /*
1972 * Make the freelist longer if it's too short.
1973 */
1974 while (be32_to_cpu(agf->agf_flcount) < need) {
1975 targs.agbno = 0;
1976 targs.maxlen = need - be32_to_cpu(agf->agf_flcount);
1977 /*
1978 * Allocate as many blocks as possible at once.
1979 */
1980 if ((error = xfs_alloc_ag_vextent(&targs))) {
1981 xfs_trans_brelse(tp, agflbp);
1982 return error;
1983 }
1984 /*
1985 * Stop if we run out. Won't happen if callers are obeying
1986 * the restrictions correctly. Can happen for free calls
1987 * on a completely full ag.
1988 */
1989 if (targs.agbno == NULLAGBLOCK) {
1990 if (flags & XFS_ALLOC_FLAG_FREEING)
1991 break;
1992 xfs_trans_brelse(tp, agflbp);
1993 args->agbp = NULL;
1994 return 0;
1995 }
1996 /*
1997 * Put each allocated block on the list.
1998 */
1999 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
2000 error = xfs_alloc_put_freelist(tp, agbp,
2001 agflbp, bno, 0);
2002 if (error)
2003 return error;
2004 }
2005 }
2006 xfs_trans_brelse(tp, agflbp);
2007 args->agbp = agbp;
2008 return 0;
2009}
2010
2011/*
2012 * Get a block from the freelist.
2013 * Returns with the buffer for the block gotten.
2014 */
2015int /* error */
2016xfs_alloc_get_freelist(
2017 xfs_trans_t *tp, /* transaction pointer */
2018 xfs_buf_t *agbp, /* buffer containing the agf structure */
2019 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2020 int btreeblk) /* destination is a AGF btree */
2021{
2022 xfs_agf_t *agf; /* a.g. freespace structure */
2023 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2024 xfs_agblock_t bno; /* block number returned */
2025 __be32 *agfl_bno;
2026 int error;
2027 int logflags;
2028 xfs_mount_t *mp = tp->t_mountp;
2029 xfs_perag_t *pag; /* per allocation group data */
2030
2031 /*
2032 * Freelist is empty, give up.
2033 */
2034 agf = XFS_BUF_TO_AGF(agbp);
2035 if (!agf->agf_flcount) {
2036 *bnop = NULLAGBLOCK;
2037 return 0;
2038 }
2039 /*
2040 * Read the array of free blocks.
2041 */
2042 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2043 &agflbp);
2044 if (error)
2045 return error;
2046
2047
2048 /*
2049 * Get the block number and update the data structures.
2050 */
2051 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2052 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2053 be32_add_cpu(&agf->agf_flfirst, 1);
2054 xfs_trans_brelse(tp, agflbp);
2055 if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
2056 agf->agf_flfirst = 0;
2057
2058 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2059 be32_add_cpu(&agf->agf_flcount, -1);
2060 xfs_trans_agflist_delta(tp, -1);
2061 pag->pagf_flcount--;
2062 xfs_perag_put(pag);
2063
2064 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2065 if (btreeblk) {
2066 be32_add_cpu(&agf->agf_btreeblks, 1);
2067 pag->pagf_btreeblks++;
2068 logflags |= XFS_AGF_BTREEBLKS;
2069 }
2070
2071 xfs_alloc_log_agf(tp, agbp, logflags);
2072 *bnop = bno;
2073
2074 return 0;
2075}
2076
2077/*
2078 * Log the given fields from the agf structure.
2079 */
2080void
2081xfs_alloc_log_agf(
2082 xfs_trans_t *tp, /* transaction pointer */
2083 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2084 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2085{
2086 int first; /* first byte offset */
2087 int last; /* last byte offset */
2088 static const short offsets[] = {
2089 offsetof(xfs_agf_t, agf_magicnum),
2090 offsetof(xfs_agf_t, agf_versionnum),
2091 offsetof(xfs_agf_t, agf_seqno),
2092 offsetof(xfs_agf_t, agf_length),
2093 offsetof(xfs_agf_t, agf_roots[0]),
2094 offsetof(xfs_agf_t, agf_levels[0]),
2095 offsetof(xfs_agf_t, agf_flfirst),
2096 offsetof(xfs_agf_t, agf_fllast),
2097 offsetof(xfs_agf_t, agf_flcount),
2098 offsetof(xfs_agf_t, agf_freeblks),
2099 offsetof(xfs_agf_t, agf_longest),
2100 offsetof(xfs_agf_t, agf_btreeblks),
2101 offsetof(xfs_agf_t, agf_uuid),
2102 sizeof(xfs_agf_t)
2103 };
2104
2105 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2106
2107 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
2108
2109 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2110 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2111}
2112
2113/*
2114 * Interface for inode allocation to force the pag data to be initialized.
2115 */
2116int /* error */
2117xfs_alloc_pagf_init(
2118 xfs_mount_t *mp, /* file system mount structure */
2119 xfs_trans_t *tp, /* transaction pointer */
2120 xfs_agnumber_t agno, /* allocation group number */
2121 int flags) /* XFS_ALLOC_FLAGS_... */
2122{
2123 xfs_buf_t *bp;
2124 int error;
2125
2126 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2127 return error;
2128 if (bp)
2129 xfs_trans_brelse(tp, bp);
2130 return 0;
2131}
2132
2133/*
2134 * Put the block on the freelist for the allocation group.
2135 */
2136int /* error */
2137xfs_alloc_put_freelist(
2138 xfs_trans_t *tp, /* transaction pointer */
2139 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2140 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2141 xfs_agblock_t bno, /* block being freed */
2142 int btreeblk) /* block came from a AGF btree */
2143{
2144 xfs_agf_t *agf; /* a.g. freespace structure */
2145 __be32 *blockp;/* pointer to array entry */
2146 int error;
2147 int logflags;
2148 xfs_mount_t *mp; /* mount structure */
2149 xfs_perag_t *pag; /* per allocation group data */
2150 __be32 *agfl_bno;
2151 int startoff;
2152
2153 agf = XFS_BUF_TO_AGF(agbp);
2154 mp = tp->t_mountp;
2155
2156 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2157 be32_to_cpu(agf->agf_seqno), &agflbp)))
2158 return error;
2159 be32_add_cpu(&agf->agf_fllast, 1);
2160 if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
2161 agf->agf_fllast = 0;
2162
2163 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2164 be32_add_cpu(&agf->agf_flcount, 1);
2165 xfs_trans_agflist_delta(tp, 1);
2166 pag->pagf_flcount++;
2167
2168 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2169 if (btreeblk) {
2170 be32_add_cpu(&agf->agf_btreeblks, -1);
2171 pag->pagf_btreeblks--;
2172 logflags |= XFS_AGF_BTREEBLKS;
2173 }
2174 xfs_perag_put(pag);
2175
2176 xfs_alloc_log_agf(tp, agbp, logflags);
2177
2178 ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
2179
2180 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2181 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
2182 *blockp = cpu_to_be32(bno);
2183 startoff = (char *)blockp - (char *)agflbp->b_addr;
2184
2185 xfs_alloc_log_agf(tp, agbp, logflags);
2186
2187 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
2188 xfs_trans_log_buf(tp, agflbp, startoff,
2189 startoff + sizeof(xfs_agblock_t) - 1);
2190 return 0;
2191}
2192
2193static bool
2194xfs_agf_verify(
2195 struct xfs_mount *mp,
2196 struct xfs_buf *bp)
2197 {
2198 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
2199
2200 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2201 !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
2202 return false;
2203
2204 if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
2205 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2206 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2207 be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
2208 be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
2209 be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
2210 return false;
2211
2212 /*
2213 * during growfs operations, the perag is not fully initialised,
2214 * so we can't use it for any useful checking. growfs ensures we can't
2215 * use it by using uncached buffers that don't have the perag attached
2216 * so we can detect and avoid this problem.
2217 */
2218 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2219 return false;
2220
2221 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2222 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2223 return false;
2224
2225 return true;;
2226
2227}
2228
2229static void
2230xfs_agf_read_verify(
2231 struct xfs_buf *bp)
2232{
2233 struct xfs_mount *mp = bp->b_target->bt_mount;
2234
2235 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2236 !xfs_buf_verify_cksum(bp, XFS_AGF_CRC_OFF))
2237 xfs_buf_ioerror(bp, EFSBADCRC);
2238 else if (XFS_TEST_ERROR(!xfs_agf_verify(mp, bp), mp,
2239 XFS_ERRTAG_ALLOC_READ_AGF,
2240 XFS_RANDOM_ALLOC_READ_AGF))
2241 xfs_buf_ioerror(bp, EFSCORRUPTED);
2242
2243 if (bp->b_error)
2244 xfs_verifier_error(bp);
2245}
2246
2247static void
2248xfs_agf_write_verify(
2249 struct xfs_buf *bp)
2250{
2251 struct xfs_mount *mp = bp->b_target->bt_mount;
2252 struct xfs_buf_log_item *bip = bp->b_fspriv;
2253
2254 if (!xfs_agf_verify(mp, bp)) {
2255 xfs_buf_ioerror(bp, EFSCORRUPTED);
2256 xfs_verifier_error(bp);
2257 return;
2258 }
2259
2260 if (!xfs_sb_version_hascrc(&mp->m_sb))
2261 return;
2262
2263 if (bip)
2264 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2265
2266 xfs_buf_update_cksum(bp, XFS_AGF_CRC_OFF);
2267}
2268
2269const struct xfs_buf_ops xfs_agf_buf_ops = {
2270 .verify_read = xfs_agf_read_verify,
2271 .verify_write = xfs_agf_write_verify,
2272};
2273
2274/*
2275 * Read in the allocation group header (free/alloc section).
2276 */
2277int /* error */
2278xfs_read_agf(
2279 struct xfs_mount *mp, /* mount point structure */
2280 struct xfs_trans *tp, /* transaction pointer */
2281 xfs_agnumber_t agno, /* allocation group number */
2282 int flags, /* XFS_BUF_ */
2283 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2284{
2285 int error;
2286
2287 trace_xfs_read_agf(mp, agno);
2288
2289 ASSERT(agno != NULLAGNUMBER);
2290 error = xfs_trans_read_buf(
2291 mp, tp, mp->m_ddev_targp,
2292 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2293 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
2294 if (error)
2295 return error;
2296 if (!*bpp)
2297 return 0;
2298
2299 ASSERT(!(*bpp)->b_error);
2300 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
2301 return 0;
2302}
2303
2304/*
2305 * Read in the allocation group header (free/alloc section).
2306 */
2307int /* error */
2308xfs_alloc_read_agf(
2309 struct xfs_mount *mp, /* mount point structure */
2310 struct xfs_trans *tp, /* transaction pointer */
2311 xfs_agnumber_t agno, /* allocation group number */
2312 int flags, /* XFS_ALLOC_FLAG_... */
2313 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2314{
2315 struct xfs_agf *agf; /* ag freelist header */
2316 struct xfs_perag *pag; /* per allocation group data */
2317 int error;
2318
2319 trace_xfs_alloc_read_agf(mp, agno);
2320
2321 ASSERT(agno != NULLAGNUMBER);
2322 error = xfs_read_agf(mp, tp, agno,
2323 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
2324 bpp);
2325 if (error)
2326 return error;
2327 if (!*bpp)
2328 return 0;
2329 ASSERT(!(*bpp)->b_error);
2330
2331 agf = XFS_BUF_TO_AGF(*bpp);
2332 pag = xfs_perag_get(mp, agno);
2333 if (!pag->pagf_init) {
2334 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2335 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
2336 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2337 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2338 pag->pagf_levels[XFS_BTNUM_BNOi] =
2339 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2340 pag->pagf_levels[XFS_BTNUM_CNTi] =
2341 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2342 spin_lock_init(&pag->pagb_lock);
2343 pag->pagb_count = 0;
2344 pag->pagb_tree = RB_ROOT;
2345 pag->pagf_init = 1;
2346 }
2347#ifdef DEBUG
2348 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2349 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2350 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
2351 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2352 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2353 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2354 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2355 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2356 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2357 }
2358#endif
2359 xfs_perag_put(pag);
2360 return 0;
2361}
2362
2363/*
2364 * Allocate an extent (variable-size).
2365 * Depending on the allocation type, we either look in a single allocation
2366 * group or loop over the allocation groups to find the result.
2367 */
2368int /* error */
2369xfs_alloc_vextent(
2370 xfs_alloc_arg_t *args) /* allocation argument structure */
2371{
2372 xfs_agblock_t agsize; /* allocation group size */
2373 int error;
2374 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2375 xfs_extlen_t minleft;/* minimum left value, temp copy */
2376 xfs_mount_t *mp; /* mount structure pointer */
2377 xfs_agnumber_t sagno; /* starting allocation group number */
2378 xfs_alloctype_t type; /* input allocation type */
2379 int bump_rotor = 0;
2380 int no_min = 0;
2381 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2382
2383 mp = args->mp;
2384 type = args->otype = args->type;
2385 args->agbno = NULLAGBLOCK;
2386 /*
2387 * Just fix this up, for the case where the last a.g. is shorter
2388 * (or there's only one a.g.) and the caller couldn't easily figure
2389 * that out (xfs_bmap_alloc).
2390 */
2391 agsize = mp->m_sb.sb_agblocks;
2392 if (args->maxlen > agsize)
2393 args->maxlen = agsize;
2394 if (args->alignment == 0)
2395 args->alignment = 1;
2396 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2397 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2398 ASSERT(args->minlen <= args->maxlen);
2399 ASSERT(args->minlen <= agsize);
2400 ASSERT(args->mod < args->prod);
2401 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2402 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2403 args->minlen > args->maxlen || args->minlen > agsize ||
2404 args->mod >= args->prod) {
2405 args->fsbno = NULLFSBLOCK;
2406 trace_xfs_alloc_vextent_badargs(args);
2407 return 0;
2408 }
2409 minleft = args->minleft;
2410
2411 switch (type) {
2412 case XFS_ALLOCTYPE_THIS_AG:
2413 case XFS_ALLOCTYPE_NEAR_BNO:
2414 case XFS_ALLOCTYPE_THIS_BNO:
2415 /*
2416 * These three force us into a single a.g.
2417 */
2418 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2419 args->pag = xfs_perag_get(mp, args->agno);
2420 args->minleft = 0;
2421 error = xfs_alloc_fix_freelist(args, 0);
2422 args->minleft = minleft;
2423 if (error) {
2424 trace_xfs_alloc_vextent_nofix(args);
2425 goto error0;
2426 }
2427 if (!args->agbp) {
2428 trace_xfs_alloc_vextent_noagbp(args);
2429 break;
2430 }
2431 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2432 if ((error = xfs_alloc_ag_vextent(args)))
2433 goto error0;
2434 break;
2435 case XFS_ALLOCTYPE_START_BNO:
2436 /*
2437 * Try near allocation first, then anywhere-in-ag after
2438 * the first a.g. fails.
2439 */
2440 if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
2441 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2442 args->fsbno = XFS_AGB_TO_FSB(mp,
2443 ((mp->m_agfrotor / rotorstep) %
2444 mp->m_sb.sb_agcount), 0);
2445 bump_rotor = 1;
2446 }
2447 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2448 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2449 /* FALLTHROUGH */
2450 case XFS_ALLOCTYPE_ANY_AG:
2451 case XFS_ALLOCTYPE_START_AG:
2452 case XFS_ALLOCTYPE_FIRST_AG:
2453 /*
2454 * Rotate through the allocation groups looking for a winner.
2455 */
2456 if (type == XFS_ALLOCTYPE_ANY_AG) {
2457 /*
2458 * Start with the last place we left off.
2459 */
2460 args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2461 mp->m_sb.sb_agcount;
2462 args->type = XFS_ALLOCTYPE_THIS_AG;
2463 flags = XFS_ALLOC_FLAG_TRYLOCK;
2464 } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2465 /*
2466 * Start with allocation group given by bno.
2467 */
2468 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2469 args->type = XFS_ALLOCTYPE_THIS_AG;
2470 sagno = 0;
2471 flags = 0;
2472 } else {
2473 if (type == XFS_ALLOCTYPE_START_AG)
2474 args->type = XFS_ALLOCTYPE_THIS_AG;
2475 /*
2476 * Start with the given allocation group.
2477 */
2478 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2479 flags = XFS_ALLOC_FLAG_TRYLOCK;
2480 }
2481 /*
2482 * Loop over allocation groups twice; first time with
2483 * trylock set, second time without.
2484 */
2485 for (;;) {
2486 args->pag = xfs_perag_get(mp, args->agno);
2487 if (no_min) args->minleft = 0;
2488 error = xfs_alloc_fix_freelist(args, flags);
2489 args->minleft = minleft;
2490 if (error) {
2491 trace_xfs_alloc_vextent_nofix(args);
2492 goto error0;
2493 }
2494 /*
2495 * If we get a buffer back then the allocation will fly.
2496 */
2497 if (args->agbp) {
2498 if ((error = xfs_alloc_ag_vextent(args)))
2499 goto error0;
2500 break;
2501 }
2502
2503 trace_xfs_alloc_vextent_loopfailed(args);
2504
2505 /*
2506 * Didn't work, figure out the next iteration.
2507 */
2508 if (args->agno == sagno &&
2509 type == XFS_ALLOCTYPE_START_BNO)
2510 args->type = XFS_ALLOCTYPE_THIS_AG;
2511 /*
2512 * For the first allocation, we can try any AG to get
2513 * space. However, if we already have allocated a
2514 * block, we don't want to try AGs whose number is below
2515 * sagno. Otherwise, we may end up with out-of-order
2516 * locking of AGF, which might cause deadlock.
2517 */
2518 if (++(args->agno) == mp->m_sb.sb_agcount) {
2519 if (args->firstblock != NULLFSBLOCK)
2520 args->agno = sagno;
2521 else
2522 args->agno = 0;
2523 }
2524 /*
2525 * Reached the starting a.g., must either be done
2526 * or switch to non-trylock mode.
2527 */
2528 if (args->agno == sagno) {
2529 if (no_min == 1) {
2530 args->agbno = NULLAGBLOCK;
2531 trace_xfs_alloc_vextent_allfailed(args);
2532 break;
2533 }
2534 if (flags == 0) {
2535 no_min = 1;
2536 } else {
2537 flags = 0;
2538 if (type == XFS_ALLOCTYPE_START_BNO) {
2539 args->agbno = XFS_FSB_TO_AGBNO(mp,
2540 args->fsbno);
2541 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2542 }
2543 }
2544 }
2545 xfs_perag_put(args->pag);
2546 }
2547 if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2548 if (args->agno == sagno)
2549 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2550 (mp->m_sb.sb_agcount * rotorstep);
2551 else
2552 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2553 (mp->m_sb.sb_agcount * rotorstep);
2554 }
2555 break;
2556 default:
2557 ASSERT(0);
2558 /* NOTREACHED */
2559 }
2560 if (args->agbno == NULLAGBLOCK)
2561 args->fsbno = NULLFSBLOCK;
2562 else {
2563 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2564#ifdef DEBUG
2565 ASSERT(args->len >= args->minlen);
2566 ASSERT(args->len <= args->maxlen);
2567 ASSERT(args->agbno % args->alignment == 0);
2568 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2569 args->len);
2570#endif
2571 }
2572 xfs_perag_put(args->pag);
2573 return 0;
2574error0:
2575 xfs_perag_put(args->pag);
2576 return error;
2577}
2578
2579/*
2580 * Free an extent.
2581 * Just break up the extent address and hand off to xfs_free_ag_extent
2582 * after fixing up the freelist.
2583 */
2584int /* error */
2585xfs_free_extent(
2586 xfs_trans_t *tp, /* transaction pointer */
2587 xfs_fsblock_t bno, /* starting block number of extent */
2588 xfs_extlen_t len) /* length of extent */
2589{
2590 xfs_alloc_arg_t args;
2591 int error;
2592
2593 ASSERT(len != 0);
2594 memset(&args, 0, sizeof(xfs_alloc_arg_t));
2595 args.tp = tp;
2596 args.mp = tp->t_mountp;
2597
2598 /*
2599 * validate that the block number is legal - the enables us to detect
2600 * and handle a silent filesystem corruption rather than crashing.
2601 */
2602 args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
2603 if (args.agno >= args.mp->m_sb.sb_agcount)
2604 return EFSCORRUPTED;
2605
2606 args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
2607 if (args.agbno >= args.mp->m_sb.sb_agblocks)
2608 return EFSCORRUPTED;
2609
2610 args.pag = xfs_perag_get(args.mp, args.agno);
2611 ASSERT(args.pag);
2612
2613 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
2614 if (error)
2615 goto error0;
2616
2617 /* validate the extent size is legal now we have the agf locked */
2618 if (args.agbno + len >
2619 be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
2620 error = EFSCORRUPTED;
2621 goto error0;
2622 }
2623
2624 error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
2625 if (!error)
2626 xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
2627error0:
2628 xfs_perag_put(args.pag);
2629 return error;
2630}
generated by cgit v1.2.2 (git 2.25.0) at 2025-04-26 05:19:54 -0400