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Merge tag 'arc-v3.13-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux/fpc-iii.git] / fs / xfs / xfs_alloc.c
blob9eab2dfdcbb54cc1337f4d6f248c808fcb2cc426
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
40 struct 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
47 STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
48 STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
49 STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
50 STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
51 xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
52
53 /*
54 * Lookup the record equal to [bno, len] in the btree given by cur.
55 */
56 STATIC int /* error */
57 xfs_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 */
72 int /* error */
73 xfs_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 */
88 int /* error */
89 xfs_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 */
105 STATIC int /* error */
106 xfs_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 */
121 int /* error */
122 xfs_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 */
143 STATIC void
144 xfs_alloc_compute_aligned(
145 xfs_alloc_arg_t *args, /* allocation argument structure */
146 xfs_agblock_t foundbno, /* starting block in found extent */
147 xfs_extlen_t foundlen, /* length in found extent */
148 xfs_agblock_t *resbno, /* result block number */
149 xfs_extlen_t *reslen) /* result length */
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 */
173 STATIC xfs_extlen_t /* difference value (absolute) */
174 xfs_alloc_compute_diff(
175 xfs_agblock_t wantbno, /* target starting block */
176 xfs_extlen_t wantlen, /* target length */
177 xfs_extlen_t alignment, /* target alignment */
178 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 */
243 STATIC void
244 xfs_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 if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
262 return;
263 } else {
264 if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
265 (int)args->minlen)
266 return;
267 }
268 ASSERT(rlen >= args->minlen);
269 ASSERT(rlen <= args->maxlen);
270 args->len = rlen;
271 }
272
273 /*
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.
276 */
277 STATIC int
278 xfs_alloc_fix_minleft(
279 xfs_alloc_arg_t *args) /* allocation argument structure */
280 {
281 xfs_agf_t *agf; /* a.g. freelist header */
282 int diff; /* free space difference */
283
284 if (args->minleft == 0)
285 return 1;
286 agf = XFS_BUF_TO_AGF(args->agbp);
287 diff = be32_to_cpu(agf->agf_freeblks)
288 - args->len - args->minleft;
289 if (diff >= 0)
290 return 1;
291 args->len += diff; /* shrink the allocated space */
292 if (args->len >= args->minlen)
293 return 1;
294 args->agbno = NULLAGBLOCK;
295 return 0;
296 }
297
298 /*
299 * Update the two btrees, logically removing from freespace the extent
300 * starting at rbno, rlen blocks. The extent is contained within the
301 * actual (current) free extent fbno for flen blocks.
302 * Flags are passed in indicating whether the cursors are set to the
303 * relevant records.
304 */
305 STATIC int /* error code */
306 xfs_alloc_fixup_trees(
307 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
308 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
309 xfs_agblock_t fbno, /* starting block of free extent */
310 xfs_extlen_t flen, /* length of free extent */
311 xfs_agblock_t rbno, /* starting block of returned extent */
312 xfs_extlen_t rlen, /* length of returned extent */
313 int flags) /* flags, XFSA_FIXUP_... */
314 {
315 int error; /* error code */
316 int i; /* operation results */
317 xfs_agblock_t nfbno1; /* first new free startblock */
318 xfs_agblock_t nfbno2; /* second new free startblock */
319 xfs_extlen_t nflen1=0; /* first new free length */
320 xfs_extlen_t nflen2=0; /* second new free length */
321
322 /*
323 * Look up the record in the by-size tree if necessary.
324 */
325 if (flags & XFSA_FIXUP_CNT_OK) {
326 #ifdef DEBUG
327 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
328 return error;
329 XFS_WANT_CORRUPTED_RETURN(
330 i == 1 && nfbno1 == fbno && nflen1 == flen);
331 #endif
332 } else {
333 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
334 return error;
335 XFS_WANT_CORRUPTED_RETURN(i == 1);
336 }
337 /*
338 * Look up the record in the by-block tree if necessary.
339 */
340 if (flags & XFSA_FIXUP_BNO_OK) {
341 #ifdef DEBUG
342 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
343 return error;
344 XFS_WANT_CORRUPTED_RETURN(
345 i == 1 && nfbno1 == fbno && nflen1 == flen);
346 #endif
347 } else {
348 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
349 return error;
350 XFS_WANT_CORRUPTED_RETURN(i == 1);
351 }
352
353 #ifdef DEBUG
354 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
355 struct xfs_btree_block *bnoblock;
356 struct xfs_btree_block *cntblock;
357
358 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
359 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
360
361 XFS_WANT_CORRUPTED_RETURN(
362 bnoblock->bb_numrecs == cntblock->bb_numrecs);
363 }
364 #endif
365
366 /*
367 * Deal with all four cases: the allocated record is contained
368 * within the freespace record, so we can have new freespace
369 * at either (or both) end, or no freespace remaining.
370 */
371 if (rbno == fbno && rlen == flen)
372 nfbno1 = nfbno2 = NULLAGBLOCK;
373 else if (rbno == fbno) {
374 nfbno1 = rbno + rlen;
375 nflen1 = flen - rlen;
376 nfbno2 = NULLAGBLOCK;
377 } else if (rbno + rlen == fbno + flen) {
378 nfbno1 = fbno;
379 nflen1 = flen - rlen;
380 nfbno2 = NULLAGBLOCK;
381 } else {
382 nfbno1 = fbno;
383 nflen1 = rbno - fbno;
384 nfbno2 = rbno + rlen;
385 nflen2 = (fbno + flen) - nfbno2;
386 }
387 /*
388 * Delete the entry from the by-size btree.
389 */
390 if ((error = xfs_btree_delete(cnt_cur, &i)))
391 return error;
392 XFS_WANT_CORRUPTED_RETURN(i == 1);
393 /*
394 * Add new by-size btree entry(s).
395 */
396 if (nfbno1 != NULLAGBLOCK) {
397 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
398 return error;
399 XFS_WANT_CORRUPTED_RETURN(i == 0);
400 if ((error = xfs_btree_insert(cnt_cur, &i)))
401 return error;
402 XFS_WANT_CORRUPTED_RETURN(i == 1);
403 }
404 if (nfbno2 != NULLAGBLOCK) {
405 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
406 return error;
407 XFS_WANT_CORRUPTED_RETURN(i == 0);
408 if ((error = xfs_btree_insert(cnt_cur, &i)))
409 return error;
410 XFS_WANT_CORRUPTED_RETURN(i == 1);
411 }
412 /*
413 * Fix up the by-block btree entry(s).
414 */
415 if (nfbno1 == NULLAGBLOCK) {
416 /*
417 * No remaining freespace, just delete the by-block tree entry.
418 */
419 if ((error = xfs_btree_delete(bno_cur, &i)))
420 return error;
421 XFS_WANT_CORRUPTED_RETURN(i == 1);
422 } else {
423 /*
424 * Update the by-block entry to start later|be shorter.
425 */
426 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
427 return error;
428 }
429 if (nfbno2 != NULLAGBLOCK) {
430 /*
431 * 2 resulting free entries, need to add one.
432 */
433 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
434 return error;
435 XFS_WANT_CORRUPTED_RETURN(i == 0);
436 if ((error = xfs_btree_insert(bno_cur, &i)))
437 return error;
438 XFS_WANT_CORRUPTED_RETURN(i == 1);
439 }
440 return 0;
441 }
442
443 static bool
444 xfs_agfl_verify(
445 struct xfs_buf *bp)
446 {
447 struct xfs_mount *mp = bp->b_target->bt_mount;
448 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
449 int i;
450
451 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_uuid))
452 return false;
453 if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
454 return false;
455 /*
456 * during growfs operations, the perag is not fully initialised,
457 * so we can't use it for any useful checking. growfs ensures we can't
458 * use it by using uncached buffers that don't have the perag attached
459 * so we can detect and avoid this problem.
460 */
461 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
462 return false;
463
464 for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
465 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
466 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
467 return false;
468 }
469 return true;
470 }
471
472 static void
473 xfs_agfl_read_verify(
474 struct xfs_buf *bp)
475 {
476 struct xfs_mount *mp = bp->b_target->bt_mount;
477 int agfl_ok = 1;
478
479 /*
480 * There is no verification of non-crc AGFLs because mkfs does not
481 * initialise the AGFL to zero or NULL. Hence the only valid part of the
482 * AGFL is what the AGF says is active. We can't get to the AGF, so we
483 * can't verify just those entries are valid.
484 */
485 if (!xfs_sb_version_hascrc(&mp->m_sb))
486 return;
487
488 agfl_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
489 offsetof(struct xfs_agfl, agfl_crc));
490
491 agfl_ok = agfl_ok && xfs_agfl_verify(bp);
492
493 if (!agfl_ok) {
494 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
495 xfs_buf_ioerror(bp, EFSCORRUPTED);
496 }
497 }
498
499 static void
500 xfs_agfl_write_verify(
501 struct xfs_buf *bp)
502 {
503 struct xfs_mount *mp = bp->b_target->bt_mount;
504 struct xfs_buf_log_item *bip = bp->b_fspriv;
505
506 /* no verification of non-crc AGFLs */
507 if (!xfs_sb_version_hascrc(&mp->m_sb))
508 return;
509
510 if (!xfs_agfl_verify(bp)) {
511 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
512 xfs_buf_ioerror(bp, EFSCORRUPTED);
513 return;
514 }
515
516 if (bip)
517 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
518
519 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
520 offsetof(struct xfs_agfl, agfl_crc));
521 }
522
523 const struct xfs_buf_ops xfs_agfl_buf_ops = {
524 .verify_read = xfs_agfl_read_verify,
525 .verify_write = xfs_agfl_write_verify,
526 };
527
528 /*
529 * Read in the allocation group free block array.
530 */
531 STATIC int /* error */
532 xfs_alloc_read_agfl(
533 xfs_mount_t *mp, /* mount point structure */
534 xfs_trans_t *tp, /* transaction pointer */
535 xfs_agnumber_t agno, /* allocation group number */
536 xfs_buf_t **bpp) /* buffer for the ag free block array */
537 {
538 xfs_buf_t *bp; /* return value */
539 int error;
540
541 ASSERT(agno != NULLAGNUMBER);
542 error = xfs_trans_read_buf(
543 mp, tp, mp->m_ddev_targp,
544 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
545 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
546 if (error)
547 return error;
548 ASSERT(!xfs_buf_geterror(bp));
549 xfs_buf_set_ref(bp, XFS_AGFL_REF);
550 *bpp = bp;
551 return 0;
552 }
553
554 STATIC int
555 xfs_alloc_update_counters(
556 struct xfs_trans *tp,
557 struct xfs_perag *pag,
558 struct xfs_buf *agbp,
559 long len)
560 {
561 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
562
563 pag->pagf_freeblks += len;
564 be32_add_cpu(&agf->agf_freeblks, len);
565
566 xfs_trans_agblocks_delta(tp, len);
567 if (unlikely(be32_to_cpu(agf->agf_freeblks) >
568 be32_to_cpu(agf->agf_length)))
569 return EFSCORRUPTED;
570
571 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
572 return 0;
573 }
574
575 /*
576 * Allocation group level functions.
577 */
578
579 /*
580 * Allocate a variable extent in the allocation group agno.
581 * Type and bno are used to determine where in the allocation group the
582 * extent will start.
583 * Extent's length (returned in *len) will be between minlen and maxlen,
584 * and of the form k * prod + mod unless there's nothing that large.
585 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
586 */
587 STATIC int /* error */
588 xfs_alloc_ag_vextent(
589 xfs_alloc_arg_t *args) /* argument structure for allocation */
590 {
591 int error=0;
592
593 ASSERT(args->minlen > 0);
594 ASSERT(args->maxlen > 0);
595 ASSERT(args->minlen <= args->maxlen);
596 ASSERT(args->mod < args->prod);
597 ASSERT(args->alignment > 0);
598 /*
599 * Branch to correct routine based on the type.
600 */
601 args->wasfromfl = 0;
602 switch (args->type) {
603 case XFS_ALLOCTYPE_THIS_AG:
604 error = xfs_alloc_ag_vextent_size(args);
605 break;
606 case XFS_ALLOCTYPE_NEAR_BNO:
607 error = xfs_alloc_ag_vextent_near(args);
608 break;
609 case XFS_ALLOCTYPE_THIS_BNO:
610 error = xfs_alloc_ag_vextent_exact(args);
611 break;
612 default:
613 ASSERT(0);
614 /* NOTREACHED */
615 }
616
617 if (error || args->agbno == NULLAGBLOCK)
618 return error;
619
620 ASSERT(args->len >= args->minlen);
621 ASSERT(args->len <= args->maxlen);
622 ASSERT(!args->wasfromfl || !args->isfl);
623 ASSERT(args->agbno % args->alignment == 0);
624
625 if (!args->wasfromfl) {
626 error = xfs_alloc_update_counters(args->tp, args->pag,
627 args->agbp,
628 -((long)(args->len)));
629 if (error)
630 return error;
631
632 ASSERT(!xfs_extent_busy_search(args->mp, args->agno,
633 args->agbno, args->len));
634 }
635
636 if (!args->isfl) {
637 xfs_trans_mod_sb(args->tp, args->wasdel ?
638 XFS_TRANS_SB_RES_FDBLOCKS :
639 XFS_TRANS_SB_FDBLOCKS,
640 -((long)(args->len)));
641 }
642
643 XFS_STATS_INC(xs_allocx);
644 XFS_STATS_ADD(xs_allocb, args->len);
645 return error;
646 }
647
648 /*
649 * Allocate a variable extent at exactly agno/bno.
650 * Extent's length (returned in *len) will be between minlen and maxlen,
651 * and of the form k * prod + mod unless there's nothing that large.
652 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
653 */
654 STATIC int /* error */
655 xfs_alloc_ag_vextent_exact(
656 xfs_alloc_arg_t *args) /* allocation argument structure */
657 {
658 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
659 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
660 int error;
661 xfs_agblock_t fbno; /* start block of found extent */
662 xfs_extlen_t flen; /* length of found extent */
663 xfs_agblock_t tbno; /* start block of trimmed extent */
664 xfs_extlen_t tlen; /* length of trimmed extent */
665 xfs_agblock_t tend; /* end block of trimmed extent */
666 int i; /* success/failure of operation */
667
668 ASSERT(args->alignment == 1);
669
670 /*
671 * Allocate/initialize a cursor for the by-number freespace btree.
672 */
673 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
674 args->agno, XFS_BTNUM_BNO);
675
676 /*
677 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
678 * Look for the closest free block <= bno, it must contain bno
679 * if any free block does.
680 */
681 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
682 if (error)
683 goto error0;
684 if (!i)
685 goto not_found;
686
687 /*
688 * Grab the freespace record.
689 */
690 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
691 if (error)
692 goto error0;
693 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
694 ASSERT(fbno <= args->agbno);
695
696 /*
697 * Check for overlapping busy extents.
698 */
699 xfs_extent_busy_trim(args, fbno, flen, &tbno, &tlen);
700
701 /*
702 * Give up if the start of the extent is busy, or the freespace isn't
703 * long enough for the minimum request.
704 */
705 if (tbno > args->agbno)
706 goto not_found;
707 if (tlen < args->minlen)
708 goto not_found;
709 tend = tbno + tlen;
710 if (tend < args->agbno + args->minlen)
711 goto not_found;
712
713 /*
714 * End of extent will be smaller of the freespace end and the
715 * maximal requested end.
716 *
717 * Fix the length according to mod and prod if given.
718 */
719 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
720 - args->agbno;
721 xfs_alloc_fix_len(args);
722 if (!xfs_alloc_fix_minleft(args))
723 goto not_found;
724
725 ASSERT(args->agbno + args->len <= tend);
726
727 /*
728 * We are allocating agbno for args->len
729 * Allocate/initialize a cursor for the by-size btree.
730 */
731 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
732 args->agno, XFS_BTNUM_CNT);
733 ASSERT(args->agbno + args->len <=
734 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
735 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
736 args->len, XFSA_FIXUP_BNO_OK);
737 if (error) {
738 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
739 goto error0;
740 }
741
742 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
743 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
744
745 args->wasfromfl = 0;
746 trace_xfs_alloc_exact_done(args);
747 return 0;
748
749 not_found:
750 /* Didn't find it, return null. */
751 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
752 args->agbno = NULLAGBLOCK;
753 trace_xfs_alloc_exact_notfound(args);
754 return 0;
755
756 error0:
757 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
758 trace_xfs_alloc_exact_error(args);
759 return error;
760 }
761
762 /*
763 * Search the btree in a given direction via the search cursor and compare
764 * the records found against the good extent we've already found.
765 */
766 STATIC int
767 xfs_alloc_find_best_extent(
768 struct xfs_alloc_arg *args, /* allocation argument structure */
769 struct xfs_btree_cur **gcur, /* good cursor */
770 struct xfs_btree_cur **scur, /* searching cursor */
771 xfs_agblock_t gdiff, /* difference for search comparison */
772 xfs_agblock_t *sbno, /* extent found by search */
773 xfs_extlen_t *slen, /* extent length */
774 xfs_agblock_t *sbnoa, /* aligned extent found by search */
775 xfs_extlen_t *slena, /* aligned extent length */
776 int dir) /* 0 = search right, 1 = search left */
777 {
778 xfs_agblock_t new;
779 xfs_agblock_t sdiff;
780 int error;
781 int i;
782
783 /* The good extent is perfect, no need to search. */
784 if (!gdiff)
785 goto out_use_good;
786
787 /*
788 * Look until we find a better one, run out of space or run off the end.
789 */
790 do {
791 error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
792 if (error)
793 goto error0;
794 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
795 xfs_alloc_compute_aligned(args, *sbno, *slen, sbnoa, slena);
796
797 /*
798 * The good extent is closer than this one.
799 */
800 if (!dir) {
801 if (*sbnoa >= args->agbno + gdiff)
802 goto out_use_good;
803 } else {
804 if (*sbnoa <= args->agbno - gdiff)
805 goto out_use_good;
806 }
807
808 /*
809 * Same distance, compare length and pick the best.
810 */
811 if (*slena >= args->minlen) {
812 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
813 xfs_alloc_fix_len(args);
814
815 sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
816 args->alignment,
817 args->userdata, *sbnoa,
818 *slena, &new);
819
820 /*
821 * Choose closer size and invalidate other cursor.
822 */
823 if (sdiff < gdiff)
824 goto out_use_search;
825 goto out_use_good;
826 }
827
828 if (!dir)
829 error = xfs_btree_increment(*scur, 0, &i);
830 else
831 error = xfs_btree_decrement(*scur, 0, &i);
832 if (error)
833 goto error0;
834 } while (i);
835
836 out_use_good:
837 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
838 *scur = NULL;
839 return 0;
840
841 out_use_search:
842 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
843 *gcur = NULL;
844 return 0;
845
846 error0:
847 /* caller invalidates cursors */
848 return error;
849 }
850
851 /*
852 * Allocate a variable extent near bno in the allocation group agno.
853 * Extent's length (returned in len) will be between minlen and maxlen,
854 * and of the form k * prod + mod unless there's nothing that large.
855 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
856 */
857 STATIC int /* error */
858 xfs_alloc_ag_vextent_near(
859 xfs_alloc_arg_t *args) /* allocation argument structure */
860 {
861 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
862 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
863 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
864 xfs_agblock_t gtbno; /* start bno of right side entry */
865 xfs_agblock_t gtbnoa; /* aligned ... */
866 xfs_extlen_t gtdiff; /* difference to right side entry */
867 xfs_extlen_t gtlen; /* length of right side entry */
868 xfs_extlen_t gtlena; /* aligned ... */
869 xfs_agblock_t gtnew; /* useful start bno of right side */
870 int error; /* error code */
871 int i; /* result code, temporary */
872 int j; /* result code, temporary */
873 xfs_agblock_t ltbno; /* start bno of left side entry */
874 xfs_agblock_t ltbnoa; /* aligned ... */
875 xfs_extlen_t ltdiff; /* difference to left side entry */
876 xfs_extlen_t ltlen; /* length of left side entry */
877 xfs_extlen_t ltlena; /* aligned ... */
878 xfs_agblock_t ltnew; /* useful start bno of left side */
879 xfs_extlen_t rlen; /* length of returned extent */
880 int forced = 0;
881 #ifdef DEBUG
882 /*
883 * Randomly don't execute the first algorithm.
884 */
885 int dofirst; /* set to do first algorithm */
886
887 dofirst = prandom_u32() & 1;
888 #endif
889
890 restart:
891 bno_cur_lt = NULL;
892 bno_cur_gt = NULL;
893 ltlen = 0;
894 gtlena = 0;
895 ltlena = 0;
896
897 /*
898 * Get a cursor for the by-size btree.
899 */
900 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
901 args->agno, XFS_BTNUM_CNT);
902
903 /*
904 * See if there are any free extents as big as maxlen.
905 */
906 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
907 goto error0;
908 /*
909 * If none, then pick up the last entry in the tree unless the
910 * tree is empty.
911 */
912 if (!i) {
913 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
914 &ltlen, &i)))
915 goto error0;
916 if (i == 0 || ltlen == 0) {
917 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
918 trace_xfs_alloc_near_noentry(args);
919 return 0;
920 }
921 ASSERT(i == 1);
922 }
923 args->wasfromfl = 0;
924
925 /*
926 * First algorithm.
927 * If the requested extent is large wrt the freespaces available
928 * in this a.g., then the cursor will be pointing to a btree entry
929 * near the right edge of the tree. If it's in the last btree leaf
930 * block, then we just examine all the entries in that block
931 * that are big enough, and pick the best one.
932 * This is written as a while loop so we can break out of it,
933 * but we never loop back to the top.
934 */
935 while (xfs_btree_islastblock(cnt_cur, 0)) {
936 xfs_extlen_t bdiff;
937 int besti=0;
938 xfs_extlen_t blen=0;
939 xfs_agblock_t bnew=0;
940
941 #ifdef DEBUG
942 if (dofirst)
943 break;
944 #endif
945 /*
946 * Start from the entry that lookup found, sequence through
947 * all larger free blocks. If we're actually pointing at a
948 * record smaller than maxlen, go to the start of this block,
949 * and skip all those smaller than minlen.
950 */
951 if (ltlen || args->alignment > 1) {
952 cnt_cur->bc_ptrs[0] = 1;
953 do {
954 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
955 &ltlen, &i)))
956 goto error0;
957 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
958 if (ltlen >= args->minlen)
959 break;
960 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
961 goto error0;
962 } while (i);
963 ASSERT(ltlen >= args->minlen);
964 if (!i)
965 break;
966 }
967 i = cnt_cur->bc_ptrs[0];
968 for (j = 1, blen = 0, bdiff = 0;
969 !error && j && (blen < args->maxlen || bdiff > 0);
970 error = xfs_btree_increment(cnt_cur, 0, &j)) {
971 /*
972 * For each entry, decide if it's better than
973 * the previous best entry.
974 */
975 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
976 goto error0;
977 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
978 xfs_alloc_compute_aligned(args, ltbno, ltlen,
979 &ltbnoa, &ltlena);
980 if (ltlena < args->minlen)
981 continue;
982 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
983 xfs_alloc_fix_len(args);
984 ASSERT(args->len >= args->minlen);
985 if (args->len < blen)
986 continue;
987 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
988 args->alignment, args->userdata, ltbnoa,
989 ltlena, &ltnew);
990 if (ltnew != NULLAGBLOCK &&
991 (args->len > blen || ltdiff < bdiff)) {
992 bdiff = ltdiff;
993 bnew = ltnew;
994 blen = args->len;
995 besti = cnt_cur->bc_ptrs[0];
996 }
997 }
998 /*
999 * It didn't work. We COULD be in a case where
1000 * there's a good record somewhere, so try again.
1001 */
1002 if (blen == 0)
1003 break;
1004 /*
1005 * Point at the best entry, and retrieve it again.
1006 */
1007 cnt_cur->bc_ptrs[0] = besti;
1008 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
1009 goto error0;
1010 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1011 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1012 args->len = blen;
1013 if (!xfs_alloc_fix_minleft(args)) {
1014 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1015 trace_xfs_alloc_near_nominleft(args);
1016 return 0;
1017 }
1018 blen = args->len;
1019 /*
1020 * We are allocating starting at bnew for blen blocks.
1021 */
1022 args->agbno = bnew;
1023 ASSERT(bnew >= ltbno);
1024 ASSERT(bnew + blen <= ltbno + ltlen);
1025 /*
1026 * Set up a cursor for the by-bno tree.
1027 */
1028 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1029 args->agbp, args->agno, XFS_BTNUM_BNO);
1030 /*
1031 * Fix up the btree entries.
1032 */
1033 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1034 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1035 goto error0;
1036 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1037 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1038
1039 trace_xfs_alloc_near_first(args);
1040 return 0;
1041 }
1042 /*
1043 * Second algorithm.
1044 * Search in the by-bno tree to the left and to the right
1045 * simultaneously, until in each case we find a space big enough,
1046 * or run into the edge of the tree. When we run into the edge,
1047 * we deallocate that cursor.
1048 * If both searches succeed, we compare the two spaces and pick
1049 * the better one.
1050 * With alignment, it's possible for both to fail; the upper
1051 * level algorithm that picks allocation groups for allocations
1052 * is not supposed to do this.
1053 */
1054 /*
1055 * Allocate and initialize the cursor for the leftward search.
1056 */
1057 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1058 args->agno, XFS_BTNUM_BNO);
1059 /*
1060 * Lookup <= bno to find the leftward search's starting point.
1061 */
1062 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1063 goto error0;
1064 if (!i) {
1065 /*
1066 * Didn't find anything; use this cursor for the rightward
1067 * search.
1068 */
1069 bno_cur_gt = bno_cur_lt;
1070 bno_cur_lt = NULL;
1071 }
1072 /*
1073 * Found something. Duplicate the cursor for the rightward search.
1074 */
1075 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1076 goto error0;
1077 /*
1078 * Increment the cursor, so we will point at the entry just right
1079 * of the leftward entry if any, or to the leftmost entry.
1080 */
1081 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1082 goto error0;
1083 if (!i) {
1084 /*
1085 * It failed, there are no rightward entries.
1086 */
1087 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1088 bno_cur_gt = NULL;
1089 }
1090 /*
1091 * Loop going left with the leftward cursor, right with the
1092 * rightward cursor, until either both directions give up or
1093 * we find an entry at least as big as minlen.
1094 */
1095 do {
1096 if (bno_cur_lt) {
1097 if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
1098 goto error0;
1099 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1100 xfs_alloc_compute_aligned(args, ltbno, ltlen,
1101 &ltbnoa, &ltlena);
1102 if (ltlena >= args->minlen)
1103 break;
1104 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
1105 goto error0;
1106 if (!i) {
1107 xfs_btree_del_cursor(bno_cur_lt,
1108 XFS_BTREE_NOERROR);
1109 bno_cur_lt = NULL;
1110 }
1111 }
1112 if (bno_cur_gt) {
1113 if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
1114 goto error0;
1115 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1116 xfs_alloc_compute_aligned(args, gtbno, gtlen,
1117 &gtbnoa, &gtlena);
1118 if (gtlena >= args->minlen)
1119 break;
1120 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
1121 goto error0;
1122 if (!i) {
1123 xfs_btree_del_cursor(bno_cur_gt,
1124 XFS_BTREE_NOERROR);
1125 bno_cur_gt = NULL;
1126 }
1127 }
1128 } while (bno_cur_lt || bno_cur_gt);
1129
1130 /*
1131 * Got both cursors still active, need to find better entry.
1132 */
1133 if (bno_cur_lt && bno_cur_gt) {
1134 if (ltlena >= args->minlen) {
1135 /*
1136 * Left side is good, look for a right side entry.
1137 */
1138 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1139 xfs_alloc_fix_len(args);
1140 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1141 args->alignment, args->userdata, ltbnoa,
1142 ltlena, &ltnew);
1143
1144 error = xfs_alloc_find_best_extent(args,
1145 &bno_cur_lt, &bno_cur_gt,
1146 ltdiff, &gtbno, &gtlen,
1147 &gtbnoa, &gtlena,
1148 0 /* search right */);
1149 } else {
1150 ASSERT(gtlena >= args->minlen);
1151
1152 /*
1153 * Right side is good, look for a left side entry.
1154 */
1155 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1156 xfs_alloc_fix_len(args);
1157 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
1158 args->alignment, args->userdata, gtbnoa,
1159 gtlena, &gtnew);
1160
1161 error = xfs_alloc_find_best_extent(args,
1162 &bno_cur_gt, &bno_cur_lt,
1163 gtdiff, &ltbno, &ltlen,
1164 &ltbnoa, &ltlena,
1165 1 /* search left */);
1166 }
1167
1168 if (error)
1169 goto error0;
1170 }
1171
1172 /*
1173 * If we couldn't get anything, give up.
1174 */
1175 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1176 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1177
1178 if (!forced++) {
1179 trace_xfs_alloc_near_busy(args);
1180 xfs_log_force(args->mp, XFS_LOG_SYNC);
1181 goto restart;
1182 }
1183 trace_xfs_alloc_size_neither(args);
1184 args->agbno = NULLAGBLOCK;
1185 return 0;
1186 }
1187
1188 /*
1189 * At this point we have selected a freespace entry, either to the
1190 * left or to the right. If it's on the right, copy all the
1191 * useful variables to the "left" set so we only have one
1192 * copy of this code.
1193 */
1194 if (bno_cur_gt) {
1195 bno_cur_lt = bno_cur_gt;
1196 bno_cur_gt = NULL;
1197 ltbno = gtbno;
1198 ltbnoa = gtbnoa;
1199 ltlen = gtlen;
1200 ltlena = gtlena;
1201 j = 1;
1202 } else
1203 j = 0;
1204
1205 /*
1206 * Fix up the length and compute the useful address.
1207 */
1208 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1209 xfs_alloc_fix_len(args);
1210 if (!xfs_alloc_fix_minleft(args)) {
1211 trace_xfs_alloc_near_nominleft(args);
1212 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1213 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1214 return 0;
1215 }
1216 rlen = args->len;
1217 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
1218 args->userdata, ltbnoa, ltlena, &ltnew);
1219 ASSERT(ltnew >= ltbno);
1220 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
1221 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1222 args->agbno = ltnew;
1223
1224 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1225 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1226 goto error0;
1227
1228 if (j)
1229 trace_xfs_alloc_near_greater(args);
1230 else
1231 trace_xfs_alloc_near_lesser(args);
1232
1233 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1234 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1235 return 0;
1236
1237 error0:
1238 trace_xfs_alloc_near_error(args);
1239 if (cnt_cur != NULL)
1240 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1241 if (bno_cur_lt != NULL)
1242 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1243 if (bno_cur_gt != NULL)
1244 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1245 return error;
1246 }
1247
1248 /*
1249 * Allocate a variable extent anywhere in the allocation group agno.
1250 * Extent's length (returned in len) will be between minlen and maxlen,
1251 * and of the form k * prod + mod unless there's nothing that large.
1252 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1253 */
1254 STATIC int /* error */
1255 xfs_alloc_ag_vextent_size(
1256 xfs_alloc_arg_t *args) /* allocation argument structure */
1257 {
1258 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1259 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1260 int error; /* error result */
1261 xfs_agblock_t fbno; /* start of found freespace */
1262 xfs_extlen_t flen; /* length of found freespace */
1263 int i; /* temp status variable */
1264 xfs_agblock_t rbno; /* returned block number */
1265 xfs_extlen_t rlen; /* length of returned extent */
1266 int forced = 0;
1267
1268 restart:
1269 /*
1270 * Allocate and initialize a cursor for the by-size btree.
1271 */
1272 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1273 args->agno, XFS_BTNUM_CNT);
1274 bno_cur = NULL;
1275
1276 /*
1277 * Look for an entry >= maxlen+alignment-1 blocks.
1278 */
1279 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1280 args->maxlen + args->alignment - 1, &i)))
1281 goto error0;
1282
1283 /*
1284 * If none or we have busy extents that we cannot allocate from, then
1285 * we have to settle for a smaller extent. In the case that there are
1286 * no large extents, this will return the last entry in the tree unless
1287 * the tree is empty. In the case that there are only busy large
1288 * extents, this will return the largest small extent unless there
1289 * are no smaller extents available.
1290 */
1291 if (!i || forced > 1) {
1292 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1293 &fbno, &flen, &i);
1294 if (error)
1295 goto error0;
1296 if (i == 0 || flen == 0) {
1297 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1298 trace_xfs_alloc_size_noentry(args);
1299 return 0;
1300 }
1301 ASSERT(i == 1);
1302 xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
1303 } else {
1304 /*
1305 * Search for a non-busy extent that is large enough.
1306 * If we are at low space, don't check, or if we fall of
1307 * the end of the btree, turn off the busy check and
1308 * restart.
1309 */
1310 for (;;) {
1311 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1312 if (error)
1313 goto error0;
1314 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1315
1316 xfs_alloc_compute_aligned(args, fbno, flen,
1317 &rbno, &rlen);
1318
1319 if (rlen >= args->maxlen)
1320 break;
1321
1322 error = xfs_btree_increment(cnt_cur, 0, &i);
1323 if (error)
1324 goto error0;
1325 if (i == 0) {
1326 /*
1327 * Our only valid extents must have been busy.
1328 * Make it unbusy by forcing the log out and
1329 * retrying. If we've been here before, forcing
1330 * the log isn't making the extents available,
1331 * which means they have probably been freed in
1332 * this transaction. In that case, we have to
1333 * give up on them and we'll attempt a minlen
1334 * allocation the next time around.
1335 */
1336 xfs_btree_del_cursor(cnt_cur,
1337 XFS_BTREE_NOERROR);
1338 trace_xfs_alloc_size_busy(args);
1339 if (!forced++)
1340 xfs_log_force(args->mp, XFS_LOG_SYNC);
1341 goto restart;
1342 }
1343 }
1344 }
1345
1346 /*
1347 * In the first case above, we got the last entry in the
1348 * by-size btree. Now we check to see if the space hits maxlen
1349 * once aligned; if not, we search left for something better.
1350 * This can't happen in the second case above.
1351 */
1352 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1353 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1354 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1355 if (rlen < args->maxlen) {
1356 xfs_agblock_t bestfbno;
1357 xfs_extlen_t bestflen;
1358 xfs_agblock_t bestrbno;
1359 xfs_extlen_t bestrlen;
1360
1361 bestrlen = rlen;
1362 bestrbno = rbno;
1363 bestflen = flen;
1364 bestfbno = fbno;
1365 for (;;) {
1366 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
1367 goto error0;
1368 if (i == 0)
1369 break;
1370 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1371 &i)))
1372 goto error0;
1373 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1374 if (flen < bestrlen)
1375 break;
1376 xfs_alloc_compute_aligned(args, fbno, flen,
1377 &rbno, &rlen);
1378 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1379 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1380 (rlen <= flen && rbno + rlen <= fbno + flen),
1381 error0);
1382 if (rlen > bestrlen) {
1383 bestrlen = rlen;
1384 bestrbno = rbno;
1385 bestflen = flen;
1386 bestfbno = fbno;
1387 if (rlen == args->maxlen)
1388 break;
1389 }
1390 }
1391 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1392 &i)))
1393 goto error0;
1394 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1395 rlen = bestrlen;
1396 rbno = bestrbno;
1397 flen = bestflen;
1398 fbno = bestfbno;
1399 }
1400 args->wasfromfl = 0;
1401 /*
1402 * Fix up the length.
1403 */
1404 args->len = rlen;
1405 if (rlen < args->minlen) {
1406 if (!forced++) {
1407 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1408 trace_xfs_alloc_size_busy(args);
1409 xfs_log_force(args->mp, XFS_LOG_SYNC);
1410 goto restart;
1411 }
1412 goto out_nominleft;
1413 }
1414 xfs_alloc_fix_len(args);
1415
1416 if (!xfs_alloc_fix_minleft(args))
1417 goto out_nominleft;
1418 rlen = args->len;
1419 XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
1420 /*
1421 * Allocate and initialize a cursor for the by-block tree.
1422 */
1423 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1424 args->agno, XFS_BTNUM_BNO);
1425 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1426 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1427 goto error0;
1428 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1429 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1430 cnt_cur = bno_cur = NULL;
1431 args->len = rlen;
1432 args->agbno = rbno;
1433 XFS_WANT_CORRUPTED_GOTO(
1434 args->agbno + args->len <=
1435 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1436 error0);
1437 trace_xfs_alloc_size_done(args);
1438 return 0;
1439
1440 error0:
1441 trace_xfs_alloc_size_error(args);
1442 if (cnt_cur)
1443 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1444 if (bno_cur)
1445 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1446 return error;
1447
1448 out_nominleft:
1449 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1450 trace_xfs_alloc_size_nominleft(args);
1451 args->agbno = NULLAGBLOCK;
1452 return 0;
1453 }
1454
1455 /*
1456 * Deal with the case where only small freespaces remain.
1457 * Either return the contents of the last freespace record,
1458 * or allocate space from the freelist if there is nothing in the tree.
1459 */
1460 STATIC int /* error */
1461 xfs_alloc_ag_vextent_small(
1462 xfs_alloc_arg_t *args, /* allocation argument structure */
1463 xfs_btree_cur_t *ccur, /* by-size cursor */
1464 xfs_agblock_t *fbnop, /* result block number */
1465 xfs_extlen_t *flenp, /* result length */
1466 int *stat) /* status: 0-freelist, 1-normal/none */
1467 {
1468 int error;
1469 xfs_agblock_t fbno;
1470 xfs_extlen_t flen;
1471 int i;
1472
1473 if ((error = xfs_btree_decrement(ccur, 0, &i)))
1474 goto error0;
1475 if (i) {
1476 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1477 goto error0;
1478 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1479 }
1480 /*
1481 * Nothing in the btree, try the freelist. Make sure
1482 * to respect minleft even when pulling from the
1483 * freelist.
1484 */
1485 else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
1486 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1487 > args->minleft)) {
1488 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
1489 if (error)
1490 goto error0;
1491 if (fbno != NULLAGBLOCK) {
1492 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
1493 args->userdata);
1494
1495 if (args->userdata) {
1496 xfs_buf_t *bp;
1497
1498 bp = xfs_btree_get_bufs(args->mp, args->tp,
1499 args->agno, fbno, 0);
1500 xfs_trans_binval(args->tp, bp);
1501 }
1502 args->len = 1;
1503 args->agbno = fbno;
1504 XFS_WANT_CORRUPTED_GOTO(
1505 args->agbno + args->len <=
1506 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1507 error0);
1508 args->wasfromfl = 1;
1509 trace_xfs_alloc_small_freelist(args);
1510 *stat = 0;
1511 return 0;
1512 }
1513 /*
1514 * Nothing in the freelist.
1515 */
1516 else
1517 flen = 0;
1518 }
1519 /*
1520 * Can't allocate from the freelist for some reason.
1521 */
1522 else {
1523 fbno = NULLAGBLOCK;
1524 flen = 0;
1525 }
1526 /*
1527 * Can't do the allocation, give up.
1528 */
1529 if (flen < args->minlen) {
1530 args->agbno = NULLAGBLOCK;
1531 trace_xfs_alloc_small_notenough(args);
1532 flen = 0;
1533 }
1534 *fbnop = fbno;
1535 *flenp = flen;
1536 *stat = 1;
1537 trace_xfs_alloc_small_done(args);
1538 return 0;
1539
1540 error0:
1541 trace_xfs_alloc_small_error(args);
1542 return error;
1543 }
1544
1545 /*
1546 * Free the extent starting at agno/bno for length.
1547 */
1548 STATIC int /* error */
1549 xfs_free_ag_extent(
1550 xfs_trans_t *tp, /* transaction pointer */
1551 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
1552 xfs_agnumber_t agno, /* allocation group number */
1553 xfs_agblock_t bno, /* starting block number */
1554 xfs_extlen_t len, /* length of extent */
1555 int isfl) /* set if is freelist blocks - no sb acctg */
1556 {
1557 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1558 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1559 int error; /* error return value */
1560 xfs_agblock_t gtbno; /* start of right neighbor block */
1561 xfs_extlen_t gtlen; /* length of right neighbor block */
1562 int haveleft; /* have a left neighbor block */
1563 int haveright; /* have a right neighbor block */
1564 int i; /* temp, result code */
1565 xfs_agblock_t ltbno; /* start of left neighbor block */
1566 xfs_extlen_t ltlen; /* length of left neighbor block */
1567 xfs_mount_t *mp; /* mount point struct for filesystem */
1568 xfs_agblock_t nbno; /* new starting block of freespace */
1569 xfs_extlen_t nlen; /* new length of freespace */
1570 xfs_perag_t *pag; /* per allocation group data */
1571
1572 mp = tp->t_mountp;
1573 /*
1574 * Allocate and initialize a cursor for the by-block btree.
1575 */
1576 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
1577 cnt_cur = NULL;
1578 /*
1579 * Look for a neighboring block on the left (lower block numbers)
1580 * that is contiguous with this space.
1581 */
1582 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1583 goto error0;
1584 if (haveleft) {
1585 /*
1586 * There is a block to our left.
1587 */
1588 if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
1589 goto error0;
1590 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1591 /*
1592 * It's not contiguous, though.
1593 */
1594 if (ltbno + ltlen < bno)
1595 haveleft = 0;
1596 else {
1597 /*
1598 * If this failure happens the request to free this
1599 * space was invalid, it's (partly) already free.
1600 * Very bad.
1601 */
1602 XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
1603 }
1604 }
1605 /*
1606 * Look for a neighboring block on the right (higher block numbers)
1607 * that is contiguous with this space.
1608 */
1609 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
1610 goto error0;
1611 if (haveright) {
1612 /*
1613 * There is a block to our right.
1614 */
1615 if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
1616 goto error0;
1617 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1618 /*
1619 * It's not contiguous, though.
1620 */
1621 if (bno + len < gtbno)
1622 haveright = 0;
1623 else {
1624 /*
1625 * If this failure happens the request to free this
1626 * space was invalid, it's (partly) already free.
1627 * Very bad.
1628 */
1629 XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
1630 }
1631 }
1632 /*
1633 * Now allocate and initialize a cursor for the by-size tree.
1634 */
1635 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
1636 /*
1637 * Have both left and right contiguous neighbors.
1638 * Merge all three into a single free block.
1639 */
1640 if (haveleft && haveright) {
1641 /*
1642 * Delete the old by-size entry on the left.
1643 */
1644 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1645 goto error0;
1646 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1647 if ((error = xfs_btree_delete(cnt_cur, &i)))
1648 goto error0;
1649 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1650 /*
1651 * Delete the old by-size entry on the right.
1652 */
1653 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1654 goto error0;
1655 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1656 if ((error = xfs_btree_delete(cnt_cur, &i)))
1657 goto error0;
1658 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1659 /*
1660 * Delete the old by-block entry for the right block.
1661 */
1662 if ((error = xfs_btree_delete(bno_cur, &i)))
1663 goto error0;
1664 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1665 /*
1666 * Move the by-block cursor back to the left neighbor.
1667 */
1668 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1669 goto error0;
1670 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1671 #ifdef DEBUG
1672 /*
1673 * Check that this is the right record: delete didn't
1674 * mangle the cursor.
1675 */
1676 {
1677 xfs_agblock_t xxbno;
1678 xfs_extlen_t xxlen;
1679
1680 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1681 &i)))
1682 goto error0;
1683 XFS_WANT_CORRUPTED_GOTO(
1684 i == 1 && xxbno == ltbno && xxlen == ltlen,
1685 error0);
1686 }
1687 #endif
1688 /*
1689 * Update remaining by-block entry to the new, joined block.
1690 */
1691 nbno = ltbno;
1692 nlen = len + ltlen + gtlen;
1693 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1694 goto error0;
1695 }
1696 /*
1697 * Have only a left contiguous neighbor.
1698 * Merge it together with the new freespace.
1699 */
1700 else if (haveleft) {
1701 /*
1702 * Delete the old by-size entry on the left.
1703 */
1704 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1705 goto error0;
1706 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1707 if ((error = xfs_btree_delete(cnt_cur, &i)))
1708 goto error0;
1709 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1710 /*
1711 * Back up the by-block cursor to the left neighbor, and
1712 * update its length.
1713 */
1714 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
1715 goto error0;
1716 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1717 nbno = ltbno;
1718 nlen = len + ltlen;
1719 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1720 goto error0;
1721 }
1722 /*
1723 * Have only a right contiguous neighbor.
1724 * Merge it together with the new freespace.
1725 */
1726 else if (haveright) {
1727 /*
1728 * Delete the old by-size entry on the right.
1729 */
1730 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1731 goto error0;
1732 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1733 if ((error = xfs_btree_delete(cnt_cur, &i)))
1734 goto error0;
1735 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1736 /*
1737 * Update the starting block and length of the right
1738 * neighbor in the by-block tree.
1739 */
1740 nbno = bno;
1741 nlen = len + gtlen;
1742 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1743 goto error0;
1744 }
1745 /*
1746 * No contiguous neighbors.
1747 * Insert the new freespace into the by-block tree.
1748 */
1749 else {
1750 nbno = bno;
1751 nlen = len;
1752 if ((error = xfs_btree_insert(bno_cur, &i)))
1753 goto error0;
1754 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1755 }
1756 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1757 bno_cur = NULL;
1758 /*
1759 * In all cases we need to insert the new freespace in the by-size tree.
1760 */
1761 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1762 goto error0;
1763 XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
1764 if ((error = xfs_btree_insert(cnt_cur, &i)))
1765 goto error0;
1766 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1767 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1768 cnt_cur = NULL;
1769
1770 /*
1771 * Update the freespace totals in the ag and superblock.
1772 */
1773 pag = xfs_perag_get(mp, agno);
1774 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1775 xfs_perag_put(pag);
1776 if (error)
1777 goto error0;
1778
1779 if (!isfl)
1780 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1781 XFS_STATS_INC(xs_freex);
1782 XFS_STATS_ADD(xs_freeb, len);
1783
1784 trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
1785
1786 return 0;
1787
1788 error0:
1789 trace_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
1790 if (bno_cur)
1791 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1792 if (cnt_cur)
1793 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1794 return error;
1795 }
1796
1797 /*
1798 * Visible (exported) allocation/free functions.
1799 * Some of these are used just by xfs_alloc_btree.c and this file.
1800 */
1801
1802 /*
1803 * Compute and fill in value of m_ag_maxlevels.
1804 */
1805 void
1806 xfs_alloc_compute_maxlevels(
1807 xfs_mount_t *mp) /* file system mount structure */
1808 {
1809 int level;
1810 uint maxblocks;
1811 uint maxleafents;
1812 int minleafrecs;
1813 int minnoderecs;
1814
1815 maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1816 minleafrecs = mp->m_alloc_mnr[0];
1817 minnoderecs = mp->m_alloc_mnr[1];
1818 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1819 for (level = 1; maxblocks > 1; level++)
1820 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1821 mp->m_ag_maxlevels = level;
1822 }
1823
1824 /*
1825 * Find the length of the longest extent in an AG.
1826 */
1827 xfs_extlen_t
1828 xfs_alloc_longest_free_extent(
1829 struct xfs_mount *mp,
1830 struct xfs_perag *pag)
1831 {
1832 xfs_extlen_t need, delta = 0;
1833
1834 need = XFS_MIN_FREELIST_PAG(pag, mp);
1835 if (need > pag->pagf_flcount)
1836 delta = need - pag->pagf_flcount;
1837
1838 if (pag->pagf_longest > delta)
1839 return pag->pagf_longest - delta;
1840 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1841 }
1842
1843 /*
1844 * Decide whether to use this allocation group for this allocation.
1845 * If so, fix up the btree freelist's size.
1846 */
1847 STATIC int /* error */
1848 xfs_alloc_fix_freelist(
1849 xfs_alloc_arg_t *args, /* allocation argument structure */
1850 int flags) /* XFS_ALLOC_FLAG_... */
1851 {
1852 xfs_buf_t *agbp; /* agf buffer pointer */
1853 xfs_agf_t *agf; /* a.g. freespace structure pointer */
1854 xfs_buf_t *agflbp;/* agfl buffer pointer */
1855 xfs_agblock_t bno; /* freelist block */
1856 xfs_extlen_t delta; /* new blocks needed in freelist */
1857 int error; /* error result code */
1858 xfs_extlen_t longest;/* longest extent in allocation group */
1859 xfs_mount_t *mp; /* file system mount point structure */
1860 xfs_extlen_t need; /* total blocks needed in freelist */
1861 xfs_perag_t *pag; /* per-ag information structure */
1862 xfs_alloc_arg_t targs; /* local allocation arguments */
1863 xfs_trans_t *tp; /* transaction pointer */
1864
1865 mp = args->mp;
1866
1867 pag = args->pag;
1868 tp = args->tp;
1869 if (!pag->pagf_init) {
1870 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1871 &agbp)))
1872 return error;
1873 if (!pag->pagf_init) {
1874 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1875 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1876 args->agbp = NULL;
1877 return 0;
1878 }
1879 } else
1880 agbp = NULL;
1881
1882 /*
1883 * If this is a metadata preferred pag and we are user data
1884 * then try somewhere else if we are not being asked to
1885 * try harder at this point
1886 */
1887 if (pag->pagf_metadata && args->userdata &&
1888 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
1889 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1890 args->agbp = NULL;
1891 return 0;
1892 }
1893
1894 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1895 /*
1896 * If it looks like there isn't a long enough extent, or enough
1897 * total blocks, reject it.
1898 */
1899 need = XFS_MIN_FREELIST_PAG(pag, mp);
1900 longest = xfs_alloc_longest_free_extent(mp, pag);
1901 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1902 longest ||
1903 ((int)(pag->pagf_freeblks + pag->pagf_flcount -
1904 need - args->total) < (int)args->minleft)) {
1905 if (agbp)
1906 xfs_trans_brelse(tp, agbp);
1907 args->agbp = NULL;
1908 return 0;
1909 }
1910 }
1911
1912 /*
1913 * Get the a.g. freespace buffer.
1914 * Can fail if we're not blocking on locks, and it's held.
1915 */
1916 if (agbp == NULL) {
1917 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1918 &agbp)))
1919 return error;
1920 if (agbp == NULL) {
1921 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1922 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1923 args->agbp = NULL;
1924 return 0;
1925 }
1926 }
1927 /*
1928 * Figure out how many blocks we should have in the freelist.
1929 */
1930 agf = XFS_BUF_TO_AGF(agbp);
1931 need = XFS_MIN_FREELIST(agf, mp);
1932 /*
1933 * If there isn't enough total or single-extent, reject it.
1934 */
1935 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1936 delta = need > be32_to_cpu(agf->agf_flcount) ?
1937 (need - be32_to_cpu(agf->agf_flcount)) : 0;
1938 longest = be32_to_cpu(agf->agf_longest);
1939 longest = (longest > delta) ? (longest - delta) :
1940 (be32_to_cpu(agf->agf_flcount) > 0 || longest > 0);
1941 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1942 longest ||
1943 ((int)(be32_to_cpu(agf->agf_freeblks) +
1944 be32_to_cpu(agf->agf_flcount) - need - args->total) <
1945 (int)args->minleft)) {
1946 xfs_trans_brelse(tp, agbp);
1947 args->agbp = NULL;
1948 return 0;
1949 }
1950 }
1951 /*
1952 * Make the freelist shorter if it's too long.
1953 */
1954 while (be32_to_cpu(agf->agf_flcount) > need) {
1955 xfs_buf_t *bp;
1956
1957 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
1958 if (error)
1959 return error;
1960 if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
1961 return error;
1962 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
1963 xfs_trans_binval(tp, bp);
1964 }
1965 /*
1966 * Initialize the args structure.
1967 */
1968 memset(&targs, 0, sizeof(targs));
1969 targs.tp = tp;
1970 targs.mp = mp;
1971 targs.agbp = agbp;
1972 targs.agno = args->agno;
1973 targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
1974 targs.type = XFS_ALLOCTYPE_THIS_AG;
1975 targs.pag = pag;
1976 if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
1977 return error;
1978 /*
1979 * Make the freelist longer if it's too short.
1980 */
1981 while (be32_to_cpu(agf->agf_flcount) < need) {
1982 targs.agbno = 0;
1983 targs.maxlen = need - be32_to_cpu(agf->agf_flcount);
1984 /*
1985 * Allocate as many blocks as possible at once.
1986 */
1987 if ((error = xfs_alloc_ag_vextent(&targs))) {
1988 xfs_trans_brelse(tp, agflbp);
1989 return error;
1990 }
1991 /*
1992 * Stop if we run out. Won't happen if callers are obeying
1993 * the restrictions correctly. Can happen for free calls
1994 * on a completely full ag.
1995 */
1996 if (targs.agbno == NULLAGBLOCK) {
1997 if (flags & XFS_ALLOC_FLAG_FREEING)
1998 break;
1999 xfs_trans_brelse(tp, agflbp);
2000 args->agbp = NULL;
2001 return 0;
2002 }
2003 /*
2004 * Put each allocated block on the list.
2005 */
2006 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
2007 error = xfs_alloc_put_freelist(tp, agbp,
2008 agflbp, bno, 0);
2009 if (error)
2010 return error;
2011 }
2012 }
2013 xfs_trans_brelse(tp, agflbp);
2014 args->agbp = agbp;
2015 return 0;
2016 }
2017
2018 /*
2019 * Get a block from the freelist.
2020 * Returns with the buffer for the block gotten.
2021 */
2022 int /* error */
2023 xfs_alloc_get_freelist(
2024 xfs_trans_t *tp, /* transaction pointer */
2025 xfs_buf_t *agbp, /* buffer containing the agf structure */
2026 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2027 int btreeblk) /* destination is a AGF btree */
2028 {
2029 xfs_agf_t *agf; /* a.g. freespace structure */
2030 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2031 xfs_agblock_t bno; /* block number returned */
2032 __be32 *agfl_bno;
2033 int error;
2034 int logflags;
2035 xfs_mount_t *mp = tp->t_mountp;
2036 xfs_perag_t *pag; /* per allocation group data */
2037
2038 /*
2039 * Freelist is empty, give up.
2040 */
2041 agf = XFS_BUF_TO_AGF(agbp);
2042 if (!agf->agf_flcount) {
2043 *bnop = NULLAGBLOCK;
2044 return 0;
2045 }
2046 /*
2047 * Read the array of free blocks.
2048 */
2049 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2050 &agflbp);
2051 if (error)
2052 return error;
2053
2054
2055 /*
2056 * Get the block number and update the data structures.
2057 */
2058 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2059 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2060 be32_add_cpu(&agf->agf_flfirst, 1);
2061 xfs_trans_brelse(tp, agflbp);
2062 if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
2063 agf->agf_flfirst = 0;
2064
2065 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2066 be32_add_cpu(&agf->agf_flcount, -1);
2067 xfs_trans_agflist_delta(tp, -1);
2068 pag->pagf_flcount--;
2069 xfs_perag_put(pag);
2070
2071 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2072 if (btreeblk) {
2073 be32_add_cpu(&agf->agf_btreeblks, 1);
2074 pag->pagf_btreeblks++;
2075 logflags |= XFS_AGF_BTREEBLKS;
2076 }
2077
2078 xfs_alloc_log_agf(tp, agbp, logflags);
2079 *bnop = bno;
2080
2081 return 0;
2082 }
2083
2084 /*
2085 * Log the given fields from the agf structure.
2086 */
2087 void
2088 xfs_alloc_log_agf(
2089 xfs_trans_t *tp, /* transaction pointer */
2090 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2091 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2092 {
2093 int first; /* first byte offset */
2094 int last; /* last byte offset */
2095 static const short offsets[] = {
2096 offsetof(xfs_agf_t, agf_magicnum),
2097 offsetof(xfs_agf_t, agf_versionnum),
2098 offsetof(xfs_agf_t, agf_seqno),
2099 offsetof(xfs_agf_t, agf_length),
2100 offsetof(xfs_agf_t, agf_roots[0]),
2101 offsetof(xfs_agf_t, agf_levels[0]),
2102 offsetof(xfs_agf_t, agf_flfirst),
2103 offsetof(xfs_agf_t, agf_fllast),
2104 offsetof(xfs_agf_t, agf_flcount),
2105 offsetof(xfs_agf_t, agf_freeblks),
2106 offsetof(xfs_agf_t, agf_longest),
2107 offsetof(xfs_agf_t, agf_btreeblks),
2108 offsetof(xfs_agf_t, agf_uuid),
2109 sizeof(xfs_agf_t)
2110 };
2111
2112 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2113
2114 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
2115
2116 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2117 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2118 }
2119
2120 /*
2121 * Interface for inode allocation to force the pag data to be initialized.
2122 */
2123 int /* error */
2124 xfs_alloc_pagf_init(
2125 xfs_mount_t *mp, /* file system mount structure */
2126 xfs_trans_t *tp, /* transaction pointer */
2127 xfs_agnumber_t agno, /* allocation group number */
2128 int flags) /* XFS_ALLOC_FLAGS_... */
2129 {
2130 xfs_buf_t *bp;
2131 int error;
2132
2133 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2134 return error;
2135 if (bp)
2136 xfs_trans_brelse(tp, bp);
2137 return 0;
2138 }
2139
2140 /*
2141 * Put the block on the freelist for the allocation group.
2142 */
2143 int /* error */
2144 xfs_alloc_put_freelist(
2145 xfs_trans_t *tp, /* transaction pointer */
2146 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2147 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2148 xfs_agblock_t bno, /* block being freed */
2149 int btreeblk) /* block came from a AGF btree */
2150 {
2151 xfs_agf_t *agf; /* a.g. freespace structure */
2152 __be32 *blockp;/* pointer to array entry */
2153 int error;
2154 int logflags;
2155 xfs_mount_t *mp; /* mount structure */
2156 xfs_perag_t *pag; /* per allocation group data */
2157 __be32 *agfl_bno;
2158 int startoff;
2159
2160 agf = XFS_BUF_TO_AGF(agbp);
2161 mp = tp->t_mountp;
2162
2163 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2164 be32_to_cpu(agf->agf_seqno), &agflbp)))
2165 return error;
2166 be32_add_cpu(&agf->agf_fllast, 1);
2167 if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
2168 agf->agf_fllast = 0;
2169
2170 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
2171 be32_add_cpu(&agf->agf_flcount, 1);
2172 xfs_trans_agflist_delta(tp, 1);
2173 pag->pagf_flcount++;
2174
2175 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2176 if (btreeblk) {
2177 be32_add_cpu(&agf->agf_btreeblks, -1);
2178 pag->pagf_btreeblks--;
2179 logflags |= XFS_AGF_BTREEBLKS;
2180 }
2181 xfs_perag_put(pag);
2182
2183 xfs_alloc_log_agf(tp, agbp, logflags);
2184
2185 ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
2186
2187 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2188 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
2189 *blockp = cpu_to_be32(bno);
2190 startoff = (char *)blockp - (char *)agflbp->b_addr;
2191
2192 xfs_alloc_log_agf(tp, agbp, logflags);
2193
2194 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
2195 xfs_trans_log_buf(tp, agflbp, startoff,
2196 startoff + sizeof(xfs_agblock_t) - 1);
2197 return 0;
2198 }
2199
2200 static bool
2201 xfs_agf_verify(
2202 struct xfs_mount *mp,
2203 struct xfs_buf *bp)
2204 {
2205 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
2206
2207 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2208 !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
2209 return false;
2210
2211 if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
2212 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2213 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2214 be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
2215 be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
2216 be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
2217 return false;
2218
2219 /*
2220 * during growfs operations, the perag is not fully initialised,
2221 * so we can't use it for any useful checking. growfs ensures we can't
2222 * use it by using uncached buffers that don't have the perag attached
2223 * so we can detect and avoid this problem.
2224 */
2225 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2226 return false;
2227
2228 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2229 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2230 return false;
2231
2232 return true;;
2233
2234 }
2235
2236 static void
2237 xfs_agf_read_verify(
2238 struct xfs_buf *bp)
2239 {
2240 struct xfs_mount *mp = bp->b_target->bt_mount;
2241 int agf_ok = 1;
2242
2243 if (xfs_sb_version_hascrc(&mp->m_sb))
2244 agf_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
2245 offsetof(struct xfs_agf, agf_crc));
2246
2247 agf_ok = agf_ok && xfs_agf_verify(mp, bp);
2248
2249 if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
2250 XFS_RANDOM_ALLOC_READ_AGF))) {
2251 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
2252 xfs_buf_ioerror(bp, EFSCORRUPTED);
2253 }
2254 }
2255
2256 static void
2257 xfs_agf_write_verify(
2258 struct xfs_buf *bp)
2259 {
2260 struct xfs_mount *mp = bp->b_target->bt_mount;
2261 struct xfs_buf_log_item *bip = bp->b_fspriv;
2262
2263 if (!xfs_agf_verify(mp, bp)) {
2264 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
2265 xfs_buf_ioerror(bp, EFSCORRUPTED);
2266 return;
2267 }
2268
2269 if (!xfs_sb_version_hascrc(&mp->m_sb))
2270 return;
2271
2272 if (bip)
2273 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2274
2275 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
2276 offsetof(struct xfs_agf, agf_crc));
2277 }
2278
2279 const struct xfs_buf_ops xfs_agf_buf_ops = {
2280 .verify_read = xfs_agf_read_verify,
2281 .verify_write = xfs_agf_write_verify,
2282 };
2283
2284 /*
2285 * Read in the allocation group header (free/alloc section).
2286 */
2287 int /* error */
2288 xfs_read_agf(
2289 struct xfs_mount *mp, /* mount point structure */
2290 struct xfs_trans *tp, /* transaction pointer */
2291 xfs_agnumber_t agno, /* allocation group number */
2292 int flags, /* XFS_BUF_ */
2293 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2294 {
2295 int error;
2296
2297 trace_xfs_read_agf(mp, agno);
2298
2299 ASSERT(agno != NULLAGNUMBER);
2300 error = xfs_trans_read_buf(
2301 mp, tp, mp->m_ddev_targp,
2302 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2303 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
2304 if (error)
2305 return error;
2306 if (!*bpp)
2307 return 0;
2308
2309 ASSERT(!(*bpp)->b_error);
2310 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
2311 return 0;
2312 }
2313
2314 /*
2315 * Read in the allocation group header (free/alloc section).
2316 */
2317 int /* error */
2318 xfs_alloc_read_agf(
2319 struct xfs_mount *mp, /* mount point structure */
2320 struct xfs_trans *tp, /* transaction pointer */
2321 xfs_agnumber_t agno, /* allocation group number */
2322 int flags, /* XFS_ALLOC_FLAG_... */
2323 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2324 {
2325 struct xfs_agf *agf; /* ag freelist header */
2326 struct xfs_perag *pag; /* per allocation group data */
2327 int error;
2328
2329 trace_xfs_alloc_read_agf(mp, agno);
2330
2331 ASSERT(agno != NULLAGNUMBER);
2332 error = xfs_read_agf(mp, tp, agno,
2333 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
2334 bpp);
2335 if (error)
2336 return error;
2337 if (!*bpp)
2338 return 0;
2339 ASSERT(!(*bpp)->b_error);
2340
2341 agf = XFS_BUF_TO_AGF(*bpp);
2342 pag = xfs_perag_get(mp, agno);
2343 if (!pag->pagf_init) {
2344 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2345 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
2346 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2347 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2348 pag->pagf_levels[XFS_BTNUM_BNOi] =
2349 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2350 pag->pagf_levels[XFS_BTNUM_CNTi] =
2351 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2352 spin_lock_init(&pag->pagb_lock);
2353 pag->pagb_count = 0;
2354 pag->pagb_tree = RB_ROOT;
2355 pag->pagf_init = 1;
2356 }
2357 #ifdef DEBUG
2358 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2359 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2360 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
2361 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2362 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2363 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2364 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2365 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2366 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2367 }
2368 #endif
2369 xfs_perag_put(pag);
2370 return 0;
2371 }
2372
2373 /*
2374 * Allocate an extent (variable-size).
2375 * Depending on the allocation type, we either look in a single allocation
2376 * group or loop over the allocation groups to find the result.
2377 */
2378 int /* error */
2379 xfs_alloc_vextent(
2380 xfs_alloc_arg_t *args) /* allocation argument structure */
2381 {
2382 xfs_agblock_t agsize; /* allocation group size */
2383 int error;
2384 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2385 xfs_extlen_t minleft;/* minimum left value, temp copy */
2386 xfs_mount_t *mp; /* mount structure pointer */
2387 xfs_agnumber_t sagno; /* starting allocation group number */
2388 xfs_alloctype_t type; /* input allocation type */
2389 int bump_rotor = 0;
2390 int no_min = 0;
2391 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2392
2393 mp = args->mp;
2394 type = args->otype = args->type;
2395 args->agbno = NULLAGBLOCK;
2396 /*
2397 * Just fix this up, for the case where the last a.g. is shorter
2398 * (or there's only one a.g.) and the caller couldn't easily figure
2399 * that out (xfs_bmap_alloc).
2400 */
2401 agsize = mp->m_sb.sb_agblocks;
2402 if (args->maxlen > agsize)
2403 args->maxlen = agsize;
2404 if (args->alignment == 0)
2405 args->alignment = 1;
2406 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2407 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2408 ASSERT(args->minlen <= args->maxlen);
2409 ASSERT(args->minlen <= agsize);
2410 ASSERT(args->mod < args->prod);
2411 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2412 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2413 args->minlen > args->maxlen || args->minlen > agsize ||
2414 args->mod >= args->prod) {
2415 args->fsbno = NULLFSBLOCK;
2416 trace_xfs_alloc_vextent_badargs(args);
2417 return 0;
2418 }
2419 minleft = args->minleft;
2420
2421 switch (type) {
2422 case XFS_ALLOCTYPE_THIS_AG:
2423 case XFS_ALLOCTYPE_NEAR_BNO:
2424 case XFS_ALLOCTYPE_THIS_BNO:
2425 /*
2426 * These three force us into a single a.g.
2427 */
2428 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2429 args->pag = xfs_perag_get(mp, args->agno);
2430 args->minleft = 0;
2431 error = xfs_alloc_fix_freelist(args, 0);
2432 args->minleft = minleft;
2433 if (error) {
2434 trace_xfs_alloc_vextent_nofix(args);
2435 goto error0;
2436 }
2437 if (!args->agbp) {
2438 trace_xfs_alloc_vextent_noagbp(args);
2439 break;
2440 }
2441 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2442 if ((error = xfs_alloc_ag_vextent(args)))
2443 goto error0;
2444 break;
2445 case XFS_ALLOCTYPE_START_BNO:
2446 /*
2447 * Try near allocation first, then anywhere-in-ag after
2448 * the first a.g. fails.
2449 */
2450 if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
2451 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2452 args->fsbno = XFS_AGB_TO_FSB(mp,
2453 ((mp->m_agfrotor / rotorstep) %
2454 mp->m_sb.sb_agcount), 0);
2455 bump_rotor = 1;
2456 }
2457 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2458 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2459 /* FALLTHROUGH */
2460 case XFS_ALLOCTYPE_ANY_AG:
2461 case XFS_ALLOCTYPE_START_AG:
2462 case XFS_ALLOCTYPE_FIRST_AG:
2463 /*
2464 * Rotate through the allocation groups looking for a winner.
2465 */
2466 if (type == XFS_ALLOCTYPE_ANY_AG) {
2467 /*
2468 * Start with the last place we left off.
2469 */
2470 args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2471 mp->m_sb.sb_agcount;
2472 args->type = XFS_ALLOCTYPE_THIS_AG;
2473 flags = XFS_ALLOC_FLAG_TRYLOCK;
2474 } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2475 /*
2476 * Start with allocation group given by bno.
2477 */
2478 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2479 args->type = XFS_ALLOCTYPE_THIS_AG;
2480 sagno = 0;
2481 flags = 0;
2482 } else {
2483 if (type == XFS_ALLOCTYPE_START_AG)
2484 args->type = XFS_ALLOCTYPE_THIS_AG;
2485 /*
2486 * Start with the given allocation group.
2487 */
2488 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2489 flags = XFS_ALLOC_FLAG_TRYLOCK;
2490 }
2491 /*
2492 * Loop over allocation groups twice; first time with
2493 * trylock set, second time without.
2494 */
2495 for (;;) {
2496 args->pag = xfs_perag_get(mp, args->agno);
2497 if (no_min) args->minleft = 0;
2498 error = xfs_alloc_fix_freelist(args, flags);
2499 args->minleft = minleft;
2500 if (error) {
2501 trace_xfs_alloc_vextent_nofix(args);
2502 goto error0;
2503 }
2504 /*
2505 * If we get a buffer back then the allocation will fly.
2506 */
2507 if (args->agbp) {
2508 if ((error = xfs_alloc_ag_vextent(args)))
2509 goto error0;
2510 break;
2511 }
2512
2513 trace_xfs_alloc_vextent_loopfailed(args);
2514
2515 /*
2516 * Didn't work, figure out the next iteration.
2517 */
2518 if (args->agno == sagno &&
2519 type == XFS_ALLOCTYPE_START_BNO)
2520 args->type = XFS_ALLOCTYPE_THIS_AG;
2521 /*
2522 * For the first allocation, we can try any AG to get
2523 * space. However, if we already have allocated a
2524 * block, we don't want to try AGs whose number is below
2525 * sagno. Otherwise, we may end up with out-of-order
2526 * locking of AGF, which might cause deadlock.
2527 */
2528 if (++(args->agno) == mp->m_sb.sb_agcount) {
2529 if (args->firstblock != NULLFSBLOCK)
2530 args->agno = sagno;
2531 else
2532 args->agno = 0;
2533 }
2534 /*
2535 * Reached the starting a.g., must either be done
2536 * or switch to non-trylock mode.
2537 */
2538 if (args->agno == sagno) {
2539 if (no_min == 1) {
2540 args->agbno = NULLAGBLOCK;
2541 trace_xfs_alloc_vextent_allfailed(args);
2542 break;
2543 }
2544 if (flags == 0) {
2545 no_min = 1;
2546 } else {
2547 flags = 0;
2548 if (type == XFS_ALLOCTYPE_START_BNO) {
2549 args->agbno = XFS_FSB_TO_AGBNO(mp,
2550 args->fsbno);
2551 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2552 }
2553 }
2554 }
2555 xfs_perag_put(args->pag);
2556 }
2557 if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2558 if (args->agno == sagno)
2559 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2560 (mp->m_sb.sb_agcount * rotorstep);
2561 else
2562 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2563 (mp->m_sb.sb_agcount * rotorstep);
2564 }
2565 break;
2566 default:
2567 ASSERT(0);
2568 /* NOTREACHED */
2569 }
2570 if (args->agbno == NULLAGBLOCK)
2571 args->fsbno = NULLFSBLOCK;
2572 else {
2573 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2574 #ifdef DEBUG
2575 ASSERT(args->len >= args->minlen);
2576 ASSERT(args->len <= args->maxlen);
2577 ASSERT(args->agbno % args->alignment == 0);
2578 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2579 args->len);
2580 #endif
2581 }
2582 xfs_perag_put(args->pag);
2583 return 0;
2584 error0:
2585 xfs_perag_put(args->pag);
2586 return error;
2587 }
2588
2589 /*
2590 * Free an extent.
2591 * Just break up the extent address and hand off to xfs_free_ag_extent
2592 * after fixing up the freelist.
2593 */
2594 int /* error */
2595 xfs_free_extent(
2596 xfs_trans_t *tp, /* transaction pointer */
2597 xfs_fsblock_t bno, /* starting block number of extent */
2598 xfs_extlen_t len) /* length of extent */
2599 {
2600 xfs_alloc_arg_t args;
2601 int error;
2602
2603 ASSERT(len != 0);
2604 memset(&args, 0, sizeof(xfs_alloc_arg_t));
2605 args.tp = tp;
2606 args.mp = tp->t_mountp;
2607
2608 /*
2609 * validate that the block number is legal - the enables us to detect
2610 * and handle a silent filesystem corruption rather than crashing.
2611 */
2612 args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
2613 if (args.agno >= args.mp->m_sb.sb_agcount)
2614 return EFSCORRUPTED;
2615
2616 args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
2617 if (args.agbno >= args.mp->m_sb.sb_agblocks)
2618 return EFSCORRUPTED;
2619
2620 args.pag = xfs_perag_get(args.mp, args.agno);
2621 ASSERT(args.pag);
2622
2623 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
2624 if (error)
2625 goto error0;
2626
2627 /* validate the extent size is legal now we have the agf locked */
2628 if (args.agbno + len >
2629 be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
2630 error = EFSCORRUPTED;
2631 goto error0;
2632 }
2633
2634 error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
2635 if (!error)
2636 xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
2637 error0:
2638 xfs_perag_put(args.pag);
2639 return error;
2640 }
Linux with added FPC-III support