?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
[wrt350n-kernel.git] / fs / xfs / xfs_alloc.c
blobe80dda3437d196345b0d19cded4cac518b4e0eda
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_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_dir2.h"
28 #include "xfs_dmapi.h"
29 #include "xfs_mount.h"
30 #include "xfs_bmap_btree.h"
31 #include "xfs_alloc_btree.h"
32 #include "xfs_ialloc_btree.h"
33 #include "xfs_dir2_sf.h"
34 #include "xfs_attr_sf.h"
35 #include "xfs_dinode.h"
36 #include "xfs_inode.h"
37 #include "xfs_btree.h"
38 #include "xfs_ialloc.h"
39 #include "xfs_alloc.h"
40 #include "xfs_error.h"
41
42
43 #define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
44
45 #define XFSA_FIXUP_BNO_OK 1
46 #define XFSA_FIXUP_CNT_OK 2
47
48 STATIC int
49 xfs_alloc_search_busy(xfs_trans_t *tp,
50 xfs_agnumber_t agno,
51 xfs_agblock_t bno,
52 xfs_extlen_t len);
53
54 #if defined(XFS_ALLOC_TRACE)
55 ktrace_t *xfs_alloc_trace_buf;
56
57 #define TRACE_ALLOC(s,a) \
58 xfs_alloc_trace_alloc(fname, s, a, __LINE__)
59 #define TRACE_FREE(s,a,b,x,f) \
60 xfs_alloc_trace_free(fname, s, mp, a, b, x, f, __LINE__)
61 #define TRACE_MODAGF(s,a,f) \
62 xfs_alloc_trace_modagf(fname, s, mp, a, f, __LINE__)
63 #define TRACE_BUSY(fname,s,ag,agb,l,sl,tp) \
64 xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSY, __LINE__)
65 #define TRACE_UNBUSY(fname,s,ag,sl,tp) \
66 xfs_alloc_trace_busy(fname, s, mp, ag, -1, -1, sl, tp, XFS_ALLOC_KTRACE_UNBUSY, __LINE__)
67 #define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp) \
68 xfs_alloc_trace_busy(fname, s, mp, ag, agb, l, sl, tp, XFS_ALLOC_KTRACE_BUSYSEARCH, __LINE__)
69 #else
70 #define TRACE_ALLOC(s,a)
71 #define TRACE_FREE(s,a,b,x,f)
72 #define TRACE_MODAGF(s,a,f)
73 #define TRACE_BUSY(s,a,ag,agb,l,sl,tp)
74 #define TRACE_UNBUSY(fname,s,ag,sl,tp)
75 #define TRACE_BUSYSEARCH(fname,s,ag,agb,l,sl,tp)
76 #endif /* XFS_ALLOC_TRACE */
77
78 /*
79 * Prototypes for per-ag allocation routines
80 */
81
82 STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
83 STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
84 STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
85 STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
86 xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
87
88 /*
89 * Internal functions.
90 */
91
92 /*
93 * Compute aligned version of the found extent.
94 * Takes alignment and min length into account.
95 */
96 STATIC int /* success (>= minlen) */
97 xfs_alloc_compute_aligned(
98 xfs_agblock_t foundbno, /* starting block in found extent */
99 xfs_extlen_t foundlen, /* length in found extent */
100 xfs_extlen_t alignment, /* alignment for allocation */
101 xfs_extlen_t minlen, /* minimum length for allocation */
102 xfs_agblock_t *resbno, /* result block number */
103 xfs_extlen_t *reslen) /* result length */
104 {
105 xfs_agblock_t bno;
106 xfs_extlen_t diff;
107 xfs_extlen_t len;
108
109 if (alignment > 1 && foundlen >= minlen) {
110 bno = roundup(foundbno, alignment);
111 diff = bno - foundbno;
112 len = diff >= foundlen ? 0 : foundlen - diff;
113 } else {
114 bno = foundbno;
115 len = foundlen;
116 }
117 *resbno = bno;
118 *reslen = len;
119 return len >= minlen;
120 }
121
122 /*
123 * Compute best start block and diff for "near" allocations.
124 * freelen >= wantlen already checked by caller.
125 */
126 STATIC xfs_extlen_t /* difference value (absolute) */
127 xfs_alloc_compute_diff(
128 xfs_agblock_t wantbno, /* target starting block */
129 xfs_extlen_t wantlen, /* target length */
130 xfs_extlen_t alignment, /* target alignment */
131 xfs_agblock_t freebno, /* freespace's starting block */
132 xfs_extlen_t freelen, /* freespace's length */
133 xfs_agblock_t *newbnop) /* result: best start block from free */
134 {
135 xfs_agblock_t freeend; /* end of freespace extent */
136 xfs_agblock_t newbno1; /* return block number */
137 xfs_agblock_t newbno2; /* other new block number */
138 xfs_extlen_t newlen1=0; /* length with newbno1 */
139 xfs_extlen_t newlen2=0; /* length with newbno2 */
140 xfs_agblock_t wantend; /* end of target extent */
141
142 ASSERT(freelen >= wantlen);
143 freeend = freebno + freelen;
144 wantend = wantbno + wantlen;
145 if (freebno >= wantbno) {
146 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
147 newbno1 = NULLAGBLOCK;
148 } else if (freeend >= wantend && alignment > 1) {
149 newbno1 = roundup(wantbno, alignment);
150 newbno2 = newbno1 - alignment;
151 if (newbno1 >= freeend)
152 newbno1 = NULLAGBLOCK;
153 else
154 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
155 if (newbno2 < freebno)
156 newbno2 = NULLAGBLOCK;
157 else
158 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
159 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
160 if (newlen1 < newlen2 ||
161 (newlen1 == newlen2 &&
162 XFS_ABSDIFF(newbno1, wantbno) >
163 XFS_ABSDIFF(newbno2, wantbno)))
164 newbno1 = newbno2;
165 } else if (newbno2 != NULLAGBLOCK)
166 newbno1 = newbno2;
167 } else if (freeend >= wantend) {
168 newbno1 = wantbno;
169 } else if (alignment > 1) {
170 newbno1 = roundup(freeend - wantlen, alignment);
171 if (newbno1 > freeend - wantlen &&
172 newbno1 - alignment >= freebno)
173 newbno1 -= alignment;
174 else if (newbno1 >= freeend)
175 newbno1 = NULLAGBLOCK;
176 } else
177 newbno1 = freeend - wantlen;
178 *newbnop = newbno1;
179 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
180 }
181
182 /*
183 * Fix up the length, based on mod and prod.
184 * len should be k * prod + mod for some k.
185 * If len is too small it is returned unchanged.
186 * If len hits maxlen it is left alone.
187 */
188 STATIC void
189 xfs_alloc_fix_len(
190 xfs_alloc_arg_t *args) /* allocation argument structure */
191 {
192 xfs_extlen_t k;
193 xfs_extlen_t rlen;
194
195 ASSERT(args->mod < args->prod);
196 rlen = args->len;
197 ASSERT(rlen >= args->minlen);
198 ASSERT(rlen <= args->maxlen);
199 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
200 (args->mod == 0 && rlen < args->prod))
201 return;
202 k = rlen % args->prod;
203 if (k == args->mod)
204 return;
205 if (k > args->mod) {
206 if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
207 return;
208 } else {
209 if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
210 (int)args->minlen)
211 return;
212 }
213 ASSERT(rlen >= args->minlen);
214 ASSERT(rlen <= args->maxlen);
215 args->len = rlen;
216 }
217
218 /*
219 * Fix up length if there is too little space left in the a.g.
220 * Return 1 if ok, 0 if too little, should give up.
221 */
222 STATIC int
223 xfs_alloc_fix_minleft(
224 xfs_alloc_arg_t *args) /* allocation argument structure */
225 {
226 xfs_agf_t *agf; /* a.g. freelist header */
227 int diff; /* free space difference */
228
229 if (args->minleft == 0)
230 return 1;
231 agf = XFS_BUF_TO_AGF(args->agbp);
232 diff = be32_to_cpu(agf->agf_freeblks)
233 + be32_to_cpu(agf->agf_flcount)
234 - args->len - args->minleft;
235 if (diff >= 0)
236 return 1;
237 args->len += diff; /* shrink the allocated space */
238 if (args->len >= args->minlen)
239 return 1;
240 args->agbno = NULLAGBLOCK;
241 return 0;
242 }
243
244 /*
245 * Update the two btrees, logically removing from freespace the extent
246 * starting at rbno, rlen blocks. The extent is contained within the
247 * actual (current) free extent fbno for flen blocks.
248 * Flags are passed in indicating whether the cursors are set to the
249 * relevant records.
250 */
251 STATIC int /* error code */
252 xfs_alloc_fixup_trees(
253 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
254 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
255 xfs_agblock_t fbno, /* starting block of free extent */
256 xfs_extlen_t flen, /* length of free extent */
257 xfs_agblock_t rbno, /* starting block of returned extent */
258 xfs_extlen_t rlen, /* length of returned extent */
259 int flags) /* flags, XFSA_FIXUP_... */
260 {
261 int error; /* error code */
262 int i; /* operation results */
263 xfs_agblock_t nfbno1; /* first new free startblock */
264 xfs_agblock_t nfbno2; /* second new free startblock */
265 xfs_extlen_t nflen1=0; /* first new free length */
266 xfs_extlen_t nflen2=0; /* second new free length */
267
268 /*
269 * Look up the record in the by-size tree if necessary.
270 */
271 if (flags & XFSA_FIXUP_CNT_OK) {
272 #ifdef DEBUG
273 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
274 return error;
275 XFS_WANT_CORRUPTED_RETURN(
276 i == 1 && nfbno1 == fbno && nflen1 == flen);
277 #endif
278 } else {
279 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
280 return error;
281 XFS_WANT_CORRUPTED_RETURN(i == 1);
282 }
283 /*
284 * Look up the record in the by-block tree if necessary.
285 */
286 if (flags & XFSA_FIXUP_BNO_OK) {
287 #ifdef DEBUG
288 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
289 return error;
290 XFS_WANT_CORRUPTED_RETURN(
291 i == 1 && nfbno1 == fbno && nflen1 == flen);
292 #endif
293 } else {
294 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
295 return error;
296 XFS_WANT_CORRUPTED_RETURN(i == 1);
297 }
298 #ifdef DEBUG
299 {
300 xfs_alloc_block_t *bnoblock;
301 xfs_alloc_block_t *cntblock;
302
303 if (bno_cur->bc_nlevels == 1 &&
304 cnt_cur->bc_nlevels == 1) {
305 bnoblock = XFS_BUF_TO_ALLOC_BLOCK(bno_cur->bc_bufs[0]);
306 cntblock = XFS_BUF_TO_ALLOC_BLOCK(cnt_cur->bc_bufs[0]);
307 XFS_WANT_CORRUPTED_RETURN(
308 be16_to_cpu(bnoblock->bb_numrecs) ==
309 be16_to_cpu(cntblock->bb_numrecs));
310 }
311 }
312 #endif
313 /*
314 * Deal with all four cases: the allocated record is contained
315 * within the freespace record, so we can have new freespace
316 * at either (or both) end, or no freespace remaining.
317 */
318 if (rbno == fbno && rlen == flen)
319 nfbno1 = nfbno2 = NULLAGBLOCK;
320 else if (rbno == fbno) {
321 nfbno1 = rbno + rlen;
322 nflen1 = flen - rlen;
323 nfbno2 = NULLAGBLOCK;
324 } else if (rbno + rlen == fbno + flen) {
325 nfbno1 = fbno;
326 nflen1 = flen - rlen;
327 nfbno2 = NULLAGBLOCK;
328 } else {
329 nfbno1 = fbno;
330 nflen1 = rbno - fbno;
331 nfbno2 = rbno + rlen;
332 nflen2 = (fbno + flen) - nfbno2;
333 }
334 /*
335 * Delete the entry from the by-size btree.
336 */
337 if ((error = xfs_alloc_delete(cnt_cur, &i)))
338 return error;
339 XFS_WANT_CORRUPTED_RETURN(i == 1);
340 /*
341 * Add new by-size btree entry(s).
342 */
343 if (nfbno1 != NULLAGBLOCK) {
344 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
345 return error;
346 XFS_WANT_CORRUPTED_RETURN(i == 0);
347 if ((error = xfs_alloc_insert(cnt_cur, &i)))
348 return error;
349 XFS_WANT_CORRUPTED_RETURN(i == 1);
350 }
351 if (nfbno2 != NULLAGBLOCK) {
352 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
353 return error;
354 XFS_WANT_CORRUPTED_RETURN(i == 0);
355 if ((error = xfs_alloc_insert(cnt_cur, &i)))
356 return error;
357 XFS_WANT_CORRUPTED_RETURN(i == 1);
358 }
359 /*
360 * Fix up the by-block btree entry(s).
361 */
362 if (nfbno1 == NULLAGBLOCK) {
363 /*
364 * No remaining freespace, just delete the by-block tree entry.
365 */
366 if ((error = xfs_alloc_delete(bno_cur, &i)))
367 return error;
368 XFS_WANT_CORRUPTED_RETURN(i == 1);
369 } else {
370 /*
371 * Update the by-block entry to start later|be shorter.
372 */
373 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
374 return error;
375 }
376 if (nfbno2 != NULLAGBLOCK) {
377 /*
378 * 2 resulting free entries, need to add one.
379 */
380 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
381 return error;
382 XFS_WANT_CORRUPTED_RETURN(i == 0);
383 if ((error = xfs_alloc_insert(bno_cur, &i)))
384 return error;
385 XFS_WANT_CORRUPTED_RETURN(i == 1);
386 }
387 return 0;
388 }
389
390 /*
391 * Read in the allocation group free block array.
392 */
393 STATIC int /* error */
394 xfs_alloc_read_agfl(
395 xfs_mount_t *mp, /* mount point structure */
396 xfs_trans_t *tp, /* transaction pointer */
397 xfs_agnumber_t agno, /* allocation group number */
398 xfs_buf_t **bpp) /* buffer for the ag free block array */
399 {
400 xfs_buf_t *bp; /* return value */
401 int error;
402
403 ASSERT(agno != NULLAGNUMBER);
404 error = xfs_trans_read_buf(
405 mp, tp, mp->m_ddev_targp,
406 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
407 XFS_FSS_TO_BB(mp, 1), 0, &bp);
408 if (error)
409 return error;
410 ASSERT(bp);
411 ASSERT(!XFS_BUF_GETERROR(bp));
412 XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGFL, XFS_AGFL_REF);
413 *bpp = bp;
414 return 0;
415 }
416
417 #if defined(XFS_ALLOC_TRACE)
418 /*
419 * Add an allocation trace entry for an alloc call.
420 */
421 STATIC void
422 xfs_alloc_trace_alloc(
423 char *name, /* function tag string */
424 char *str, /* additional string */
425 xfs_alloc_arg_t *args, /* allocation argument structure */
426 int line) /* source line number */
427 {
428 ktrace_enter(xfs_alloc_trace_buf,
429 (void *)(__psint_t)(XFS_ALLOC_KTRACE_ALLOC | (line << 16)),
430 (void *)name,
431 (void *)str,
432 (void *)args->mp,
433 (void *)(__psunsigned_t)args->agno,
434 (void *)(__psunsigned_t)args->agbno,
435 (void *)(__psunsigned_t)args->minlen,
436 (void *)(__psunsigned_t)args->maxlen,
437 (void *)(__psunsigned_t)args->mod,
438 (void *)(__psunsigned_t)args->prod,
439 (void *)(__psunsigned_t)args->minleft,
440 (void *)(__psunsigned_t)args->total,
441 (void *)(__psunsigned_t)args->alignment,
442 (void *)(__psunsigned_t)args->len,
443 (void *)((((__psint_t)args->type) << 16) |
444 (__psint_t)args->otype),
445 (void *)(__psint_t)((args->wasdel << 3) |
446 (args->wasfromfl << 2) |
447 (args->isfl << 1) |
448 (args->userdata << 0)));
449 }
450
451 /*
452 * Add an allocation trace entry for a free call.
453 */
454 STATIC void
455 xfs_alloc_trace_free(
456 char *name, /* function tag string */
457 char *str, /* additional string */
458 xfs_mount_t *mp, /* file system mount point */
459 xfs_agnumber_t agno, /* allocation group number */
460 xfs_agblock_t agbno, /* a.g. relative block number */
461 xfs_extlen_t len, /* length of extent */
462 int isfl, /* set if is freelist allocation/free */
463 int line) /* source line number */
464 {
465 ktrace_enter(xfs_alloc_trace_buf,
466 (void *)(__psint_t)(XFS_ALLOC_KTRACE_FREE | (line << 16)),
467 (void *)name,
468 (void *)str,
469 (void *)mp,
470 (void *)(__psunsigned_t)agno,
471 (void *)(__psunsigned_t)agbno,
472 (void *)(__psunsigned_t)len,
473 (void *)(__psint_t)isfl,
474 NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL);
475 }
476
477 /*
478 * Add an allocation trace entry for modifying an agf.
479 */
480 STATIC void
481 xfs_alloc_trace_modagf(
482 char *name, /* function tag string */
483 char *str, /* additional string */
484 xfs_mount_t *mp, /* file system mount point */
485 xfs_agf_t *agf, /* new agf value */
486 int flags, /* logging flags for agf */
487 int line) /* source line number */
488 {
489 ktrace_enter(xfs_alloc_trace_buf,
490 (void *)(__psint_t)(XFS_ALLOC_KTRACE_MODAGF | (line << 16)),
491 (void *)name,
492 (void *)str,
493 (void *)mp,
494 (void *)(__psint_t)flags,
495 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_seqno),
496 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_length),
497 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_roots[XFS_BTNUM_BNO]),
498 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_roots[XFS_BTNUM_CNT]),
499 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]),
500 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]),
501 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_flfirst),
502 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_fllast),
503 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_flcount),
504 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_freeblks),
505 (void *)(__psunsigned_t)be32_to_cpu(agf->agf_longest));
506 }
507
508 STATIC void
509 xfs_alloc_trace_busy(
510 char *name, /* function tag string */
511 char *str, /* additional string */
512 xfs_mount_t *mp, /* file system mount point */
513 xfs_agnumber_t agno, /* allocation group number */
514 xfs_agblock_t agbno, /* a.g. relative block number */
515 xfs_extlen_t len, /* length of extent */
516 int slot, /* perag Busy slot */
517 xfs_trans_t *tp,
518 int trtype, /* type: add, delete, search */
519 int line) /* source line number */
520 {
521 ktrace_enter(xfs_alloc_trace_buf,
522 (void *)(__psint_t)(trtype | (line << 16)),
523 (void *)name,
524 (void *)str,
525 (void *)mp,
526 (void *)(__psunsigned_t)agno,
527 (void *)(__psunsigned_t)agbno,
528 (void *)(__psunsigned_t)len,
529 (void *)(__psint_t)slot,
530 (void *)tp,
531 NULL, NULL, NULL, NULL, NULL, NULL, NULL);
532 }
533 #endif /* XFS_ALLOC_TRACE */
534
535 /*
536 * Allocation group level functions.
537 */
538
539 /*
540 * Allocate a variable extent in the allocation group agno.
541 * Type and bno are used to determine where in the allocation group the
542 * extent will start.
543 * Extent's length (returned in *len) will be between minlen and maxlen,
544 * and of the form k * prod + mod unless there's nothing that large.
545 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
546 */
547 STATIC int /* error */
548 xfs_alloc_ag_vextent(
549 xfs_alloc_arg_t *args) /* argument structure for allocation */
550 {
551 int error=0;
552 #ifdef XFS_ALLOC_TRACE
553 static char fname[] = "xfs_alloc_ag_vextent";
554 #endif
555
556 ASSERT(args->minlen > 0);
557 ASSERT(args->maxlen > 0);
558 ASSERT(args->minlen <= args->maxlen);
559 ASSERT(args->mod < args->prod);
560 ASSERT(args->alignment > 0);
561 /*
562 * Branch to correct routine based on the type.
563 */
564 args->wasfromfl = 0;
565 switch (args->type) {
566 case XFS_ALLOCTYPE_THIS_AG:
567 error = xfs_alloc_ag_vextent_size(args);
568 break;
569 case XFS_ALLOCTYPE_NEAR_BNO:
570 error = xfs_alloc_ag_vextent_near(args);
571 break;
572 case XFS_ALLOCTYPE_THIS_BNO:
573 error = xfs_alloc_ag_vextent_exact(args);
574 break;
575 default:
576 ASSERT(0);
577 /* NOTREACHED */
578 }
579 if (error)
580 return error;
581 /*
582 * If the allocation worked, need to change the agf structure
583 * (and log it), and the superblock.
584 */
585 if (args->agbno != NULLAGBLOCK) {
586 xfs_agf_t *agf; /* allocation group freelist header */
587 #ifdef XFS_ALLOC_TRACE
588 xfs_mount_t *mp = args->mp;
589 #endif
590 long slen = (long)args->len;
591
592 ASSERT(args->len >= args->minlen && args->len <= args->maxlen);
593 ASSERT(!(args->wasfromfl) || !args->isfl);
594 ASSERT(args->agbno % args->alignment == 0);
595 if (!(args->wasfromfl)) {
596
597 agf = XFS_BUF_TO_AGF(args->agbp);
598 be32_add(&agf->agf_freeblks, -(args->len));
599 xfs_trans_agblocks_delta(args->tp,
600 -((long)(args->len)));
601 args->pag->pagf_freeblks -= args->len;
602 ASSERT(be32_to_cpu(agf->agf_freeblks) <=
603 be32_to_cpu(agf->agf_length));
604 TRACE_MODAGF(NULL, agf, XFS_AGF_FREEBLKS);
605 xfs_alloc_log_agf(args->tp, args->agbp,
606 XFS_AGF_FREEBLKS);
607 /* search the busylist for these blocks */
608 xfs_alloc_search_busy(args->tp, args->agno,
609 args->agbno, args->len);
610 }
611 if (!args->isfl)
612 xfs_trans_mod_sb(args->tp,
613 args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
614 XFS_TRANS_SB_FDBLOCKS, -slen);
615 XFS_STATS_INC(xs_allocx);
616 XFS_STATS_ADD(xs_allocb, args->len);
617 }
618 return 0;
619 }
620
621 /*
622 * Allocate a variable extent at exactly agno/bno.
623 * Extent's length (returned in *len) will be between minlen and maxlen,
624 * and of the form k * prod + mod unless there's nothing that large.
625 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
626 */
627 STATIC int /* error */
628 xfs_alloc_ag_vextent_exact(
629 xfs_alloc_arg_t *args) /* allocation argument structure */
630 {
631 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
632 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
633 xfs_agblock_t end; /* end of allocated extent */
634 int error;
635 xfs_agblock_t fbno; /* start block of found extent */
636 xfs_agblock_t fend; /* end block of found extent */
637 xfs_extlen_t flen; /* length of found extent */
638 #ifdef XFS_ALLOC_TRACE
639 static char fname[] = "xfs_alloc_ag_vextent_exact";
640 #endif
641 int i; /* success/failure of operation */
642 xfs_agblock_t maxend; /* end of maximal extent */
643 xfs_agblock_t minend; /* end of minimal extent */
644 xfs_extlen_t rlen; /* length of returned extent */
645
646 ASSERT(args->alignment == 1);
647 /*
648 * Allocate/initialize a cursor for the by-number freespace btree.
649 */
650 bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
651 args->agno, XFS_BTNUM_BNO, NULL, 0);
652 /*
653 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
654 * Look for the closest free block <= bno, it must contain bno
655 * if any free block does.
656 */
657 if ((error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i)))
658 goto error0;
659 if (!i) {
660 /*
661 * Didn't find it, return null.
662 */
663 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
664 args->agbno = NULLAGBLOCK;
665 return 0;
666 }
667 /*
668 * Grab the freespace record.
669 */
670 if ((error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i)))
671 goto error0;
672 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
673 ASSERT(fbno <= args->agbno);
674 minend = args->agbno + args->minlen;
675 maxend = args->agbno + args->maxlen;
676 fend = fbno + flen;
677 /*
678 * Give up if the freespace isn't long enough for the minimum request.
679 */
680 if (fend < minend) {
681 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
682 args->agbno = NULLAGBLOCK;
683 return 0;
684 }
685 /*
686 * End of extent will be smaller of the freespace end and the
687 * maximal requested end.
688 */
689 end = XFS_AGBLOCK_MIN(fend, maxend);
690 /*
691 * Fix the length according to mod and prod if given.
692 */
693 args->len = end - args->agbno;
694 xfs_alloc_fix_len(args);
695 if (!xfs_alloc_fix_minleft(args)) {
696 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
697 return 0;
698 }
699 rlen = args->len;
700 ASSERT(args->agbno + rlen <= fend);
701 end = args->agbno + rlen;
702 /*
703 * We are allocating agbno for rlen [agbno .. end]
704 * Allocate/initialize a cursor for the by-size btree.
705 */
706 cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
707 args->agno, XFS_BTNUM_CNT, NULL, 0);
708 ASSERT(args->agbno + args->len <=
709 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
710 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
711 args->agbno, args->len, XFSA_FIXUP_BNO_OK))) {
712 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
713 goto error0;
714 }
715 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
716 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
717 TRACE_ALLOC("normal", args);
718 args->wasfromfl = 0;
719 return 0;
720
721 error0:
722 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
723 TRACE_ALLOC("error", args);
724 return error;
725 }
726
727 /*
728 * Allocate a variable extent near bno in the allocation group agno.
729 * Extent's length (returned in len) will be between minlen and maxlen,
730 * and of the form k * prod + mod unless there's nothing that large.
731 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
732 */
733 STATIC int /* error */
734 xfs_alloc_ag_vextent_near(
735 xfs_alloc_arg_t *args) /* allocation argument structure */
736 {
737 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
738 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
739 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
740 #ifdef XFS_ALLOC_TRACE
741 static char fname[] = "xfs_alloc_ag_vextent_near";
742 #endif
743 xfs_agblock_t gtbno; /* start bno of right side entry */
744 xfs_agblock_t gtbnoa; /* aligned ... */
745 xfs_extlen_t gtdiff; /* difference to right side entry */
746 xfs_extlen_t gtlen; /* length of right side entry */
747 xfs_extlen_t gtlena; /* aligned ... */
748 xfs_agblock_t gtnew; /* useful start bno of right side */
749 int error; /* error code */
750 int i; /* result code, temporary */
751 int j; /* result code, temporary */
752 xfs_agblock_t ltbno; /* start bno of left side entry */
753 xfs_agblock_t ltbnoa; /* aligned ... */
754 xfs_extlen_t ltdiff; /* difference to left side entry */
755 /*REFERENCED*/
756 xfs_agblock_t ltend; /* end bno of left side entry */
757 xfs_extlen_t ltlen; /* length of left side entry */
758 xfs_extlen_t ltlena; /* aligned ... */
759 xfs_agblock_t ltnew; /* useful start bno of left side */
760 xfs_extlen_t rlen; /* length of returned extent */
761 #if defined(DEBUG) && defined(__KERNEL__)
762 /*
763 * Randomly don't execute the first algorithm.
764 */
765 int dofirst; /* set to do first algorithm */
766
767 dofirst = random() & 1;
768 #endif
769 /*
770 * Get a cursor for the by-size btree.
771 */
772 cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
773 args->agno, XFS_BTNUM_CNT, NULL, 0);
774 ltlen = 0;
775 bno_cur_lt = bno_cur_gt = NULL;
776 /*
777 * See if there are any free extents as big as maxlen.
778 */
779 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
780 goto error0;
781 /*
782 * If none, then pick up the last entry in the tree unless the
783 * tree is empty.
784 */
785 if (!i) {
786 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
787 &ltlen, &i)))
788 goto error0;
789 if (i == 0 || ltlen == 0) {
790 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
791 return 0;
792 }
793 ASSERT(i == 1);
794 }
795 args->wasfromfl = 0;
796 /*
797 * First algorithm.
798 * If the requested extent is large wrt the freespaces available
799 * in this a.g., then the cursor will be pointing to a btree entry
800 * near the right edge of the tree. If it's in the last btree leaf
801 * block, then we just examine all the entries in that block
802 * that are big enough, and pick the best one.
803 * This is written as a while loop so we can break out of it,
804 * but we never loop back to the top.
805 */
806 while (xfs_btree_islastblock(cnt_cur, 0)) {
807 xfs_extlen_t bdiff;
808 int besti=0;
809 xfs_extlen_t blen=0;
810 xfs_agblock_t bnew=0;
811
812 #if defined(DEBUG) && defined(__KERNEL__)
813 if (!dofirst)
814 break;
815 #endif
816 /*
817 * Start from the entry that lookup found, sequence through
818 * all larger free blocks. If we're actually pointing at a
819 * record smaller than maxlen, go to the start of this block,
820 * and skip all those smaller than minlen.
821 */
822 if (ltlen || args->alignment > 1) {
823 cnt_cur->bc_ptrs[0] = 1;
824 do {
825 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
826 &ltlen, &i)))
827 goto error0;
828 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
829 if (ltlen >= args->minlen)
830 break;
831 if ((error = xfs_alloc_increment(cnt_cur, 0, &i)))
832 goto error0;
833 } while (i);
834 ASSERT(ltlen >= args->minlen);
835 if (!i)
836 break;
837 }
838 i = cnt_cur->bc_ptrs[0];
839 for (j = 1, blen = 0, bdiff = 0;
840 !error && j && (blen < args->maxlen || bdiff > 0);
841 error = xfs_alloc_increment(cnt_cur, 0, &j)) {
842 /*
843 * For each entry, decide if it's better than
844 * the previous best entry.
845 */
846 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
847 goto error0;
848 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
849 if (!xfs_alloc_compute_aligned(ltbno, ltlen,
850 args->alignment, args->minlen,
851 &ltbnoa, &ltlena))
852 continue;
853 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
854 xfs_alloc_fix_len(args);
855 ASSERT(args->len >= args->minlen);
856 if (args->len < blen)
857 continue;
858 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
859 args->alignment, ltbno, ltlen, &ltnew);
860 if (ltnew != NULLAGBLOCK &&
861 (args->len > blen || ltdiff < bdiff)) {
862 bdiff = ltdiff;
863 bnew = ltnew;
864 blen = args->len;
865 besti = cnt_cur->bc_ptrs[0];
866 }
867 }
868 /*
869 * It didn't work. We COULD be in a case where
870 * there's a good record somewhere, so try again.
871 */
872 if (blen == 0)
873 break;
874 /*
875 * Point at the best entry, and retrieve it again.
876 */
877 cnt_cur->bc_ptrs[0] = besti;
878 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
879 goto error0;
880 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
881 ltend = ltbno + ltlen;
882 ASSERT(ltend <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
883 args->len = blen;
884 if (!xfs_alloc_fix_minleft(args)) {
885 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
886 TRACE_ALLOC("nominleft", args);
887 return 0;
888 }
889 blen = args->len;
890 /*
891 * We are allocating starting at bnew for blen blocks.
892 */
893 args->agbno = bnew;
894 ASSERT(bnew >= ltbno);
895 ASSERT(bnew + blen <= ltend);
896 /*
897 * Set up a cursor for the by-bno tree.
898 */
899 bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp,
900 args->agbp, args->agno, XFS_BTNUM_BNO, NULL, 0);
901 /*
902 * Fix up the btree entries.
903 */
904 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
905 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
906 goto error0;
907 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
908 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
909 TRACE_ALLOC("first", args);
910 return 0;
911 }
912 /*
913 * Second algorithm.
914 * Search in the by-bno tree to the left and to the right
915 * simultaneously, until in each case we find a space big enough,
916 * or run into the edge of the tree. When we run into the edge,
917 * we deallocate that cursor.
918 * If both searches succeed, we compare the two spaces and pick
919 * the better one.
920 * With alignment, it's possible for both to fail; the upper
921 * level algorithm that picks allocation groups for allocations
922 * is not supposed to do this.
923 */
924 /*
925 * Allocate and initialize the cursor for the leftward search.
926 */
927 bno_cur_lt = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
928 args->agno, XFS_BTNUM_BNO, NULL, 0);
929 /*
930 * Lookup <= bno to find the leftward search's starting point.
931 */
932 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
933 goto error0;
934 if (!i) {
935 /*
936 * Didn't find anything; use this cursor for the rightward
937 * search.
938 */
939 bno_cur_gt = bno_cur_lt;
940 bno_cur_lt = NULL;
941 }
942 /*
943 * Found something. Duplicate the cursor for the rightward search.
944 */
945 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
946 goto error0;
947 /*
948 * Increment the cursor, so we will point at the entry just right
949 * of the leftward entry if any, or to the leftmost entry.
950 */
951 if ((error = xfs_alloc_increment(bno_cur_gt, 0, &i)))
952 goto error0;
953 if (!i) {
954 /*
955 * It failed, there are no rightward entries.
956 */
957 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
958 bno_cur_gt = NULL;
959 }
960 /*
961 * Loop going left with the leftward cursor, right with the
962 * rightward cursor, until either both directions give up or
963 * we find an entry at least as big as minlen.
964 */
965 do {
966 if (bno_cur_lt) {
967 if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
968 goto error0;
969 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
970 if (xfs_alloc_compute_aligned(ltbno, ltlen,
971 args->alignment, args->minlen,
972 &ltbnoa, &ltlena))
973 break;
974 if ((error = xfs_alloc_decrement(bno_cur_lt, 0, &i)))
975 goto error0;
976 if (!i) {
977 xfs_btree_del_cursor(bno_cur_lt,
978 XFS_BTREE_NOERROR);
979 bno_cur_lt = NULL;
980 }
981 }
982 if (bno_cur_gt) {
983 if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
984 goto error0;
985 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
986 if (xfs_alloc_compute_aligned(gtbno, gtlen,
987 args->alignment, args->minlen,
988 &gtbnoa, &gtlena))
989 break;
990 if ((error = xfs_alloc_increment(bno_cur_gt, 0, &i)))
991 goto error0;
992 if (!i) {
993 xfs_btree_del_cursor(bno_cur_gt,
994 XFS_BTREE_NOERROR);
995 bno_cur_gt = NULL;
996 }
997 }
998 } while (bno_cur_lt || bno_cur_gt);
999 /*
1000 * Got both cursors still active, need to find better entry.
1001 */
1002 if (bno_cur_lt && bno_cur_gt) {
1003 /*
1004 * Left side is long enough, look for a right side entry.
1005 */
1006 if (ltlena >= args->minlen) {
1007 /*
1008 * Fix up the length.
1009 */
1010 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1011 xfs_alloc_fix_len(args);
1012 rlen = args->len;
1013 ltdiff = xfs_alloc_compute_diff(args->agbno, rlen,
1014 args->alignment, ltbno, ltlen, &ltnew);
1015 /*
1016 * Not perfect.
1017 */
1018 if (ltdiff) {
1019 /*
1020 * Look until we find a better one, run out of
1021 * space, or run off the end.
1022 */
1023 while (bno_cur_lt && bno_cur_gt) {
1024 if ((error = xfs_alloc_get_rec(
1025 bno_cur_gt, &gtbno,
1026 &gtlen, &i)))
1027 goto error0;
1028 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1029 xfs_alloc_compute_aligned(gtbno, gtlen,
1030 args->alignment, args->minlen,
1031 &gtbnoa, &gtlena);
1032 /*
1033 * The left one is clearly better.
1034 */
1035 if (gtbnoa >= args->agbno + ltdiff) {
1036 xfs_btree_del_cursor(
1037 bno_cur_gt,
1038 XFS_BTREE_NOERROR);
1039 bno_cur_gt = NULL;
1040 break;
1041 }
1042 /*
1043 * If we reach a big enough entry,
1044 * compare the two and pick the best.
1045 */
1046 if (gtlena >= args->minlen) {
1047 args->len =
1048 XFS_EXTLEN_MIN(gtlena,
1049 args->maxlen);
1050 xfs_alloc_fix_len(args);
1051 rlen = args->len;
1052 gtdiff = xfs_alloc_compute_diff(
1053 args->agbno, rlen,
1054 args->alignment,
1055 gtbno, gtlen, &gtnew);
1056 /*
1057 * Right side is better.
1058 */
1059 if (gtdiff < ltdiff) {
1060 xfs_btree_del_cursor(
1061 bno_cur_lt,
1062 XFS_BTREE_NOERROR);
1063 bno_cur_lt = NULL;
1064 }
1065 /*
1066 * Left side is better.
1067 */
1068 else {
1069 xfs_btree_del_cursor(
1070 bno_cur_gt,
1071 XFS_BTREE_NOERROR);
1072 bno_cur_gt = NULL;
1073 }
1074 break;
1075 }
1076 /*
1077 * Fell off the right end.
1078 */
1079 if ((error = xfs_alloc_increment(
1080 bno_cur_gt, 0, &i)))
1081 goto error0;
1082 if (!i) {
1083 xfs_btree_del_cursor(
1084 bno_cur_gt,
1085 XFS_BTREE_NOERROR);
1086 bno_cur_gt = NULL;
1087 break;
1088 }
1089 }
1090 }
1091 /*
1092 * The left side is perfect, trash the right side.
1093 */
1094 else {
1095 xfs_btree_del_cursor(bno_cur_gt,
1096 XFS_BTREE_NOERROR);
1097 bno_cur_gt = NULL;
1098 }
1099 }
1100 /*
1101 * It's the right side that was found first, look left.
1102 */
1103 else {
1104 /*
1105 * Fix up the length.
1106 */
1107 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1108 xfs_alloc_fix_len(args);
1109 rlen = args->len;
1110 gtdiff = xfs_alloc_compute_diff(args->agbno, rlen,
1111 args->alignment, gtbno, gtlen, &gtnew);
1112 /*
1113 * Right side entry isn't perfect.
1114 */
1115 if (gtdiff) {
1116 /*
1117 * Look until we find a better one, run out of
1118 * space, or run off the end.
1119 */
1120 while (bno_cur_lt && bno_cur_gt) {
1121 if ((error = xfs_alloc_get_rec(
1122 bno_cur_lt, &ltbno,
1123 &ltlen, &i)))
1124 goto error0;
1125 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1126 xfs_alloc_compute_aligned(ltbno, ltlen,
1127 args->alignment, args->minlen,
1128 &ltbnoa, &ltlena);
1129 /*
1130 * The right one is clearly better.
1131 */
1132 if (ltbnoa <= args->agbno - gtdiff) {
1133 xfs_btree_del_cursor(
1134 bno_cur_lt,
1135 XFS_BTREE_NOERROR);
1136 bno_cur_lt = NULL;
1137 break;
1138 }
1139 /*
1140 * If we reach a big enough entry,
1141 * compare the two and pick the best.
1142 */
1143 if (ltlena >= args->minlen) {
1144 args->len = XFS_EXTLEN_MIN(
1145 ltlena, args->maxlen);
1146 xfs_alloc_fix_len(args);
1147 rlen = args->len;
1148 ltdiff = xfs_alloc_compute_diff(
1149 args->agbno, rlen,
1150 args->alignment,
1151 ltbno, ltlen, &ltnew);
1152 /*
1153 * Left side is better.
1154 */
1155 if (ltdiff < gtdiff) {
1156 xfs_btree_del_cursor(
1157 bno_cur_gt,
1158 XFS_BTREE_NOERROR);
1159 bno_cur_gt = NULL;
1160 }
1161 /*
1162 * Right side is better.
1163 */
1164 else {
1165 xfs_btree_del_cursor(
1166 bno_cur_lt,
1167 XFS_BTREE_NOERROR);
1168 bno_cur_lt = NULL;
1169 }
1170 break;
1171 }
1172 /*
1173 * Fell off the left end.
1174 */
1175 if ((error = xfs_alloc_decrement(
1176 bno_cur_lt, 0, &i)))
1177 goto error0;
1178 if (!i) {
1179 xfs_btree_del_cursor(bno_cur_lt,
1180 XFS_BTREE_NOERROR);
1181 bno_cur_lt = NULL;
1182 break;
1183 }
1184 }
1185 }
1186 /*
1187 * The right side is perfect, trash the left side.
1188 */
1189 else {
1190 xfs_btree_del_cursor(bno_cur_lt,
1191 XFS_BTREE_NOERROR);
1192 bno_cur_lt = NULL;
1193 }
1194 }
1195 }
1196 /*
1197 * If we couldn't get anything, give up.
1198 */
1199 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
1200 TRACE_ALLOC("neither", args);
1201 args->agbno = NULLAGBLOCK;
1202 return 0;
1203 }
1204 /*
1205 * At this point we have selected a freespace entry, either to the
1206 * left or to the right. If it's on the right, copy all the
1207 * useful variables to the "left" set so we only have one
1208 * copy of this code.
1209 */
1210 if (bno_cur_gt) {
1211 bno_cur_lt = bno_cur_gt;
1212 bno_cur_gt = NULL;
1213 ltbno = gtbno;
1214 ltbnoa = gtbnoa;
1215 ltlen = gtlen;
1216 ltlena = gtlena;
1217 j = 1;
1218 } else
1219 j = 0;
1220 /*
1221 * Fix up the length and compute the useful address.
1222 */
1223 ltend = ltbno + ltlen;
1224 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1225 xfs_alloc_fix_len(args);
1226 if (!xfs_alloc_fix_minleft(args)) {
1227 TRACE_ALLOC("nominleft", args);
1228 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1229 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1230 return 0;
1231 }
1232 rlen = args->len;
1233 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment, ltbno,
1234 ltlen, &ltnew);
1235 ASSERT(ltnew >= ltbno);
1236 ASSERT(ltnew + rlen <= ltend);
1237 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
1238 args->agbno = ltnew;
1239 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1240 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1241 goto error0;
1242 TRACE_ALLOC(j ? "gt" : "lt", args);
1243 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1244 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1245 return 0;
1246
1247 error0:
1248 TRACE_ALLOC("error", args);
1249 if (cnt_cur != NULL)
1250 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1251 if (bno_cur_lt != NULL)
1252 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1253 if (bno_cur_gt != NULL)
1254 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1255 return error;
1256 }
1257
1258 /*
1259 * Allocate a variable extent anywhere in the allocation group agno.
1260 * Extent's length (returned in len) will be between minlen and maxlen,
1261 * and of the form k * prod + mod unless there's nothing that large.
1262 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1263 */
1264 STATIC int /* error */
1265 xfs_alloc_ag_vextent_size(
1266 xfs_alloc_arg_t *args) /* allocation argument structure */
1267 {
1268 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1269 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1270 int error; /* error result */
1271 xfs_agblock_t fbno; /* start of found freespace */
1272 xfs_extlen_t flen; /* length of found freespace */
1273 #ifdef XFS_ALLOC_TRACE
1274 static char fname[] = "xfs_alloc_ag_vextent_size";
1275 #endif
1276 int i; /* temp status variable */
1277 xfs_agblock_t rbno; /* returned block number */
1278 xfs_extlen_t rlen; /* length of returned extent */
1279
1280 /*
1281 * Allocate and initialize a cursor for the by-size btree.
1282 */
1283 cnt_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
1284 args->agno, XFS_BTNUM_CNT, NULL, 0);
1285 bno_cur = NULL;
1286 /*
1287 * Look for an entry >= maxlen+alignment-1 blocks.
1288 */
1289 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1290 args->maxlen + args->alignment - 1, &i)))
1291 goto error0;
1292 /*
1293 * If none, then pick up the last entry in the tree unless the
1294 * tree is empty.
1295 */
1296 if (!i) {
1297 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &fbno,
1298 &flen, &i)))
1299 goto error0;
1300 if (i == 0 || flen == 0) {
1301 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1302 TRACE_ALLOC("noentry", args);
1303 return 0;
1304 }
1305 ASSERT(i == 1);
1306 }
1307 /*
1308 * There's a freespace as big as maxlen+alignment-1, get it.
1309 */
1310 else {
1311 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i)))
1312 goto error0;
1313 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1314 }
1315 /*
1316 * In the first case above, we got the last entry in the
1317 * by-size btree. Now we check to see if the space hits maxlen
1318 * once aligned; if not, we search left for something better.
1319 * This can't happen in the second case above.
1320 */
1321 xfs_alloc_compute_aligned(fbno, flen, args->alignment, args->minlen,
1322 &rbno, &rlen);
1323 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1324 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1325 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1326 if (rlen < args->maxlen) {
1327 xfs_agblock_t bestfbno;
1328 xfs_extlen_t bestflen;
1329 xfs_agblock_t bestrbno;
1330 xfs_extlen_t bestrlen;
1331
1332 bestrlen = rlen;
1333 bestrbno = rbno;
1334 bestflen = flen;
1335 bestfbno = fbno;
1336 for (;;) {
1337 if ((error = xfs_alloc_decrement(cnt_cur, 0, &i)))
1338 goto error0;
1339 if (i == 0)
1340 break;
1341 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1342 &i)))
1343 goto error0;
1344 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1345 if (flen < bestrlen)
1346 break;
1347 xfs_alloc_compute_aligned(fbno, flen, args->alignment,
1348 args->minlen, &rbno, &rlen);
1349 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1350 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1351 (rlen <= flen && rbno + rlen <= fbno + flen),
1352 error0);
1353 if (rlen > bestrlen) {
1354 bestrlen = rlen;
1355 bestrbno = rbno;
1356 bestflen = flen;
1357 bestfbno = fbno;
1358 if (rlen == args->maxlen)
1359 break;
1360 }
1361 }
1362 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1363 &i)))
1364 goto error0;
1365 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1366 rlen = bestrlen;
1367 rbno = bestrbno;
1368 flen = bestflen;
1369 fbno = bestfbno;
1370 }
1371 args->wasfromfl = 0;
1372 /*
1373 * Fix up the length.
1374 */
1375 args->len = rlen;
1376 xfs_alloc_fix_len(args);
1377 if (rlen < args->minlen || !xfs_alloc_fix_minleft(args)) {
1378 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1379 TRACE_ALLOC("nominleft", args);
1380 args->agbno = NULLAGBLOCK;
1381 return 0;
1382 }
1383 rlen = args->len;
1384 XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
1385 /*
1386 * Allocate and initialize a cursor for the by-block tree.
1387 */
1388 bno_cur = xfs_btree_init_cursor(args->mp, args->tp, args->agbp,
1389 args->agno, XFS_BTNUM_BNO, NULL, 0);
1390 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1391 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1392 goto error0;
1393 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1394 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1395 cnt_cur = bno_cur = NULL;
1396 args->len = rlen;
1397 args->agbno = rbno;
1398 XFS_WANT_CORRUPTED_GOTO(
1399 args->agbno + args->len <=
1400 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1401 error0);
1402 TRACE_ALLOC("normal", args);
1403 return 0;
1404
1405 error0:
1406 TRACE_ALLOC("error", args);
1407 if (cnt_cur)
1408 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1409 if (bno_cur)
1410 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1411 return error;
1412 }
1413
1414 /*
1415 * Deal with the case where only small freespaces remain.
1416 * Either return the contents of the last freespace record,
1417 * or allocate space from the freelist if there is nothing in the tree.
1418 */
1419 STATIC int /* error */
1420 xfs_alloc_ag_vextent_small(
1421 xfs_alloc_arg_t *args, /* allocation argument structure */
1422 xfs_btree_cur_t *ccur, /* by-size cursor */
1423 xfs_agblock_t *fbnop, /* result block number */
1424 xfs_extlen_t *flenp, /* result length */
1425 int *stat) /* status: 0-freelist, 1-normal/none */
1426 {
1427 int error;
1428 xfs_agblock_t fbno;
1429 xfs_extlen_t flen;
1430 #ifdef XFS_ALLOC_TRACE
1431 static char fname[] = "xfs_alloc_ag_vextent_small";
1432 #endif
1433 int i;
1434
1435 if ((error = xfs_alloc_decrement(ccur, 0, &i)))
1436 goto error0;
1437 if (i) {
1438 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1439 goto error0;
1440 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1441 }
1442 /*
1443 * Nothing in the btree, try the freelist. Make sure
1444 * to respect minleft even when pulling from the
1445 * freelist.
1446 */
1447 else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
1448 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1449 > args->minleft)) {
1450 if ((error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno)))
1451 goto error0;
1452 if (fbno != NULLAGBLOCK) {
1453 if (args->userdata) {
1454 xfs_buf_t *bp;
1455
1456 bp = xfs_btree_get_bufs(args->mp, args->tp,
1457 args->agno, fbno, 0);
1458 xfs_trans_binval(args->tp, bp);
1459 }
1460 args->len = 1;
1461 args->agbno = fbno;
1462 XFS_WANT_CORRUPTED_GOTO(
1463 args->agbno + args->len <=
1464 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
1465 error0);
1466 args->wasfromfl = 1;
1467 TRACE_ALLOC("freelist", args);
1468 *stat = 0;
1469 return 0;
1470 }
1471 /*
1472 * Nothing in the freelist.
1473 */
1474 else
1475 flen = 0;
1476 }
1477 /*
1478 * Can't allocate from the freelist for some reason.
1479 */
1480 else {
1481 fbno = NULLAGBLOCK;
1482 flen = 0;
1483 }
1484 /*
1485 * Can't do the allocation, give up.
1486 */
1487 if (flen < args->minlen) {
1488 args->agbno = NULLAGBLOCK;
1489 TRACE_ALLOC("notenough", args);
1490 flen = 0;
1491 }
1492 *fbnop = fbno;
1493 *flenp = flen;
1494 *stat = 1;
1495 TRACE_ALLOC("normal", args);
1496 return 0;
1497
1498 error0:
1499 TRACE_ALLOC("error", args);
1500 return error;
1501 }
1502
1503 /*
1504 * Free the extent starting at agno/bno for length.
1505 */
1506 STATIC int /* error */
1507 xfs_free_ag_extent(
1508 xfs_trans_t *tp, /* transaction pointer */
1509 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
1510 xfs_agnumber_t agno, /* allocation group number */
1511 xfs_agblock_t bno, /* starting block number */
1512 xfs_extlen_t len, /* length of extent */
1513 int isfl) /* set if is freelist blocks - no sb acctg */
1514 {
1515 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1516 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1517 int error; /* error return value */
1518 #ifdef XFS_ALLOC_TRACE
1519 static char fname[] = "xfs_free_ag_extent";
1520 #endif
1521 xfs_agblock_t gtbno; /* start of right neighbor block */
1522 xfs_extlen_t gtlen; /* length of right neighbor block */
1523 int haveleft; /* have a left neighbor block */
1524 int haveright; /* have a right neighbor block */
1525 int i; /* temp, result code */
1526 xfs_agblock_t ltbno; /* start of left neighbor block */
1527 xfs_extlen_t ltlen; /* length of left neighbor block */
1528 xfs_mount_t *mp; /* mount point struct for filesystem */
1529 xfs_agblock_t nbno; /* new starting block of freespace */
1530 xfs_extlen_t nlen; /* new length of freespace */
1531
1532 mp = tp->t_mountp;
1533 /*
1534 * Allocate and initialize a cursor for the by-block btree.
1535 */
1536 bno_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO, NULL,
1537 0);
1538 cnt_cur = NULL;
1539 /*
1540 * Look for a neighboring block on the left (lower block numbers)
1541 * that is contiguous with this space.
1542 */
1543 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1544 goto error0;
1545 if (haveleft) {
1546 /*
1547 * There is a block to our left.
1548 */
1549 if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
1550 goto error0;
1551 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1552 /*
1553 * It's not contiguous, though.
1554 */
1555 if (ltbno + ltlen < bno)
1556 haveleft = 0;
1557 else {
1558 /*
1559 * If this failure happens the request to free this
1560 * space was invalid, it's (partly) already free.
1561 * Very bad.
1562 */
1563 XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
1564 }
1565 }
1566 /*
1567 * Look for a neighboring block on the right (higher block numbers)
1568 * that is contiguous with this space.
1569 */
1570 if ((error = xfs_alloc_increment(bno_cur, 0, &haveright)))
1571 goto error0;
1572 if (haveright) {
1573 /*
1574 * There is a block to our right.
1575 */
1576 if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
1577 goto error0;
1578 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1579 /*
1580 * It's not contiguous, though.
1581 */
1582 if (bno + len < gtbno)
1583 haveright = 0;
1584 else {
1585 /*
1586 * If this failure happens the request to free this
1587 * space was invalid, it's (partly) already free.
1588 * Very bad.
1589 */
1590 XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
1591 }
1592 }
1593 /*
1594 * Now allocate and initialize a cursor for the by-size tree.
1595 */
1596 cnt_cur = xfs_btree_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT, NULL,
1597 0);
1598 /*
1599 * Have both left and right contiguous neighbors.
1600 * Merge all three into a single free block.
1601 */
1602 if (haveleft && haveright) {
1603 /*
1604 * Delete the old by-size entry on the left.
1605 */
1606 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1607 goto error0;
1608 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1609 if ((error = xfs_alloc_delete(cnt_cur, &i)))
1610 goto error0;
1611 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1612 /*
1613 * Delete the old by-size entry on the right.
1614 */
1615 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1616 goto error0;
1617 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1618 if ((error = xfs_alloc_delete(cnt_cur, &i)))
1619 goto error0;
1620 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1621 /*
1622 * Delete the old by-block entry for the right block.
1623 */
1624 if ((error = xfs_alloc_delete(bno_cur, &i)))
1625 goto error0;
1626 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1627 /*
1628 * Move the by-block cursor back to the left neighbor.
1629 */
1630 if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
1631 goto error0;
1632 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1633 #ifdef DEBUG
1634 /*
1635 * Check that this is the right record: delete didn't
1636 * mangle the cursor.
1637 */
1638 {
1639 xfs_agblock_t xxbno;
1640 xfs_extlen_t xxlen;
1641
1642 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1643 &i)))
1644 goto error0;
1645 XFS_WANT_CORRUPTED_GOTO(
1646 i == 1 && xxbno == ltbno && xxlen == ltlen,
1647 error0);
1648 }
1649 #endif
1650 /*
1651 * Update remaining by-block entry to the new, joined block.
1652 */
1653 nbno = ltbno;
1654 nlen = len + ltlen + gtlen;
1655 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1656 goto error0;
1657 }
1658 /*
1659 * Have only a left contiguous neighbor.
1660 * Merge it together with the new freespace.
1661 */
1662 else if (haveleft) {
1663 /*
1664 * Delete the old by-size entry on the left.
1665 */
1666 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1667 goto error0;
1668 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1669 if ((error = xfs_alloc_delete(cnt_cur, &i)))
1670 goto error0;
1671 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1672 /*
1673 * Back up the by-block cursor to the left neighbor, and
1674 * update its length.
1675 */
1676 if ((error = xfs_alloc_decrement(bno_cur, 0, &i)))
1677 goto error0;
1678 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1679 nbno = ltbno;
1680 nlen = len + ltlen;
1681 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1682 goto error0;
1683 }
1684 /*
1685 * Have only a right contiguous neighbor.
1686 * Merge it together with the new freespace.
1687 */
1688 else if (haveright) {
1689 /*
1690 * Delete the old by-size entry on the right.
1691 */
1692 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1693 goto error0;
1694 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1695 if ((error = xfs_alloc_delete(cnt_cur, &i)))
1696 goto error0;
1697 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1698 /*
1699 * Update the starting block and length of the right
1700 * neighbor in the by-block tree.
1701 */
1702 nbno = bno;
1703 nlen = len + gtlen;
1704 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1705 goto error0;
1706 }
1707 /*
1708 * No contiguous neighbors.
1709 * Insert the new freespace into the by-block tree.
1710 */
1711 else {
1712 nbno = bno;
1713 nlen = len;
1714 if ((error = xfs_alloc_insert(bno_cur, &i)))
1715 goto error0;
1716 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1717 }
1718 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1719 bno_cur = NULL;
1720 /*
1721 * In all cases we need to insert the new freespace in the by-size tree.
1722 */
1723 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1724 goto error0;
1725 XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
1726 if ((error = xfs_alloc_insert(cnt_cur, &i)))
1727 goto error0;
1728 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1729 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1730 cnt_cur = NULL;
1731 /*
1732 * Update the freespace totals in the ag and superblock.
1733 */
1734 {
1735 xfs_agf_t *agf;
1736 xfs_perag_t *pag; /* per allocation group data */
1737
1738 agf = XFS_BUF_TO_AGF(agbp);
1739 pag = &mp->m_perag[agno];
1740 be32_add(&agf->agf_freeblks, len);
1741 xfs_trans_agblocks_delta(tp, len);
1742 pag->pagf_freeblks += len;
1743 XFS_WANT_CORRUPTED_GOTO(
1744 be32_to_cpu(agf->agf_freeblks) <=
1745 be32_to_cpu(agf->agf_length),
1746 error0);
1747 TRACE_MODAGF(NULL, agf, XFS_AGF_FREEBLKS);
1748 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
1749 if (!isfl)
1750 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1751 XFS_STATS_INC(xs_freex);
1752 XFS_STATS_ADD(xs_freeb, len);
1753 }
1754 TRACE_FREE(haveleft ?
1755 (haveright ? "both" : "left") :
1756 (haveright ? "right" : "none"),
1757 agno, bno, len, isfl);
1758
1759 /*
1760 * Since blocks move to the free list without the coordination
1761 * used in xfs_bmap_finish, we can't allow block to be available
1762 * for reallocation and non-transaction writing (user data)
1763 * until we know that the transaction that moved it to the free
1764 * list is permanently on disk. We track the blocks by declaring
1765 * these blocks as "busy"; the busy list is maintained on a per-ag
1766 * basis and each transaction records which entries should be removed
1767 * when the iclog commits to disk. If a busy block is allocated,
1768 * the iclog is pushed up to the LSN that freed the block.
1769 */
1770 xfs_alloc_mark_busy(tp, agno, bno, len);
1771 return 0;
1772
1773 error0:
1774 TRACE_FREE("error", agno, bno, len, isfl);
1775 if (bno_cur)
1776 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1777 if (cnt_cur)
1778 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1779 return error;
1780 }
1781
1782 /*
1783 * Visible (exported) allocation/free functions.
1784 * Some of these are used just by xfs_alloc_btree.c and this file.
1785 */
1786
1787 /*
1788 * Compute and fill in value of m_ag_maxlevels.
1789 */
1790 void
1791 xfs_alloc_compute_maxlevels(
1792 xfs_mount_t *mp) /* file system mount structure */
1793 {
1794 int level;
1795 uint maxblocks;
1796 uint maxleafents;
1797 int minleafrecs;
1798 int minnoderecs;
1799
1800 maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1801 minleafrecs = mp->m_alloc_mnr[0];
1802 minnoderecs = mp->m_alloc_mnr[1];
1803 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1804 for (level = 1; maxblocks > 1; level++)
1805 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1806 mp->m_ag_maxlevels = level;
1807 }
1808
1809 /*
1810 * Decide whether to use this allocation group for this allocation.
1811 * If so, fix up the btree freelist's size.
1812 */
1813 STATIC int /* error */
1814 xfs_alloc_fix_freelist(
1815 xfs_alloc_arg_t *args, /* allocation argument structure */
1816 int flags) /* XFS_ALLOC_FLAG_... */
1817 {
1818 xfs_buf_t *agbp; /* agf buffer pointer */
1819 xfs_agf_t *agf; /* a.g. freespace structure pointer */
1820 xfs_buf_t *agflbp;/* agfl buffer pointer */
1821 xfs_agblock_t bno; /* freelist block */
1822 xfs_extlen_t delta; /* new blocks needed in freelist */
1823 int error; /* error result code */
1824 xfs_extlen_t longest;/* longest extent in allocation group */
1825 xfs_mount_t *mp; /* file system mount point structure */
1826 xfs_extlen_t need; /* total blocks needed in freelist */
1827 xfs_perag_t *pag; /* per-ag information structure */
1828 xfs_alloc_arg_t targs; /* local allocation arguments */
1829 xfs_trans_t *tp; /* transaction pointer */
1830
1831 mp = args->mp;
1832
1833 pag = args->pag;
1834 tp = args->tp;
1835 if (!pag->pagf_init) {
1836 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1837 &agbp)))
1838 return error;
1839 if (!pag->pagf_init) {
1840 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1841 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1842 args->agbp = NULL;
1843 return 0;
1844 }
1845 } else
1846 agbp = NULL;
1847
1848 /*
1849 * If this is a metadata preferred pag and we are user data
1850 * then try somewhere else if we are not being asked to
1851 * try harder at this point
1852 */
1853 if (pag->pagf_metadata && args->userdata &&
1854 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
1855 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1856 args->agbp = NULL;
1857 return 0;
1858 }
1859
1860 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1861 need = XFS_MIN_FREELIST_PAG(pag, mp);
1862 delta = need > pag->pagf_flcount ? need - pag->pagf_flcount : 0;
1863 /*
1864 * If it looks like there isn't a long enough extent, or enough
1865 * total blocks, reject it.
1866 */
1867 longest = (pag->pagf_longest > delta) ?
1868 (pag->pagf_longest - delta) :
1869 (pag->pagf_flcount > 0 || pag->pagf_longest > 0);
1870 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1871 longest ||
1872 ((int)(pag->pagf_freeblks + pag->pagf_flcount -
1873 need - args->total) < (int)args->minleft)) {
1874 if (agbp)
1875 xfs_trans_brelse(tp, agbp);
1876 args->agbp = NULL;
1877 return 0;
1878 }
1879 }
1880
1881 /*
1882 * Get the a.g. freespace buffer.
1883 * Can fail if we're not blocking on locks, and it's held.
1884 */
1885 if (agbp == NULL) {
1886 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1887 &agbp)))
1888 return error;
1889 if (agbp == NULL) {
1890 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1891 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
1892 args->agbp = NULL;
1893 return 0;
1894 }
1895 }
1896 /*
1897 * Figure out how many blocks we should have in the freelist.
1898 */
1899 agf = XFS_BUF_TO_AGF(agbp);
1900 need = XFS_MIN_FREELIST(agf, mp);
1901 /*
1902 * If there isn't enough total or single-extent, reject it.
1903 */
1904 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1905 delta = need > be32_to_cpu(agf->agf_flcount) ?
1906 (need - be32_to_cpu(agf->agf_flcount)) : 0;
1907 longest = be32_to_cpu(agf->agf_longest);
1908 longest = (longest > delta) ? (longest - delta) :
1909 (be32_to_cpu(agf->agf_flcount) > 0 || longest > 0);
1910 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1911 longest ||
1912 ((int)(be32_to_cpu(agf->agf_freeblks) +
1913 be32_to_cpu(agf->agf_flcount) - need - args->total) <
1914 (int)args->minleft)) {
1915 xfs_trans_brelse(tp, agbp);
1916 args->agbp = NULL;
1917 return 0;
1918 }
1919 }
1920 /*
1921 * Make the freelist shorter if it's too long.
1922 */
1923 while (be32_to_cpu(agf->agf_flcount) > need) {
1924 xfs_buf_t *bp;
1925
1926 if ((error = xfs_alloc_get_freelist(tp, agbp, &bno)))
1927 return error;
1928 if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
1929 return error;
1930 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
1931 xfs_trans_binval(tp, bp);
1932 }
1933 /*
1934 * Initialize the args structure.
1935 */
1936 targs.tp = tp;
1937 targs.mp = mp;
1938 targs.agbp = agbp;
1939 targs.agno = args->agno;
1940 targs.mod = targs.minleft = targs.wasdel = targs.userdata =
1941 targs.minalignslop = 0;
1942 targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
1943 targs.type = XFS_ALLOCTYPE_THIS_AG;
1944 targs.pag = pag;
1945 if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
1946 return error;
1947 /*
1948 * Make the freelist longer if it's too short.
1949 */
1950 while (be32_to_cpu(agf->agf_flcount) < need) {
1951 targs.agbno = 0;
1952 targs.maxlen = need - be32_to_cpu(agf->agf_flcount);
1953 /*
1954 * Allocate as many blocks as possible at once.
1955 */
1956 if ((error = xfs_alloc_ag_vextent(&targs))) {
1957 xfs_trans_brelse(tp, agflbp);
1958 return error;
1959 }
1960 /*
1961 * Stop if we run out. Won't happen if callers are obeying
1962 * the restrictions correctly. Can happen for free calls
1963 * on a completely full ag.
1964 */
1965 if (targs.agbno == NULLAGBLOCK) {
1966 if (flags & XFS_ALLOC_FLAG_FREEING)
1967 break;
1968 xfs_trans_brelse(tp, agflbp);
1969 args->agbp = NULL;
1970 return 0;
1971 }
1972 /*
1973 * Put each allocated block on the list.
1974 */
1975 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
1976 if ((error = xfs_alloc_put_freelist(tp, agbp, agflbp,
1977 bno)))
1978 return error;
1979 }
1980 }
1981 xfs_trans_brelse(tp, agflbp);
1982 args->agbp = agbp;
1983 return 0;
1984 }
1985
1986 /*
1987 * Get a block from the freelist.
1988 * Returns with the buffer for the block gotten.
1989 */
1990 int /* error */
1991 xfs_alloc_get_freelist(
1992 xfs_trans_t *tp, /* transaction pointer */
1993 xfs_buf_t *agbp, /* buffer containing the agf structure */
1994 xfs_agblock_t *bnop) /* block address retrieved from freelist */
1995 {
1996 xfs_agf_t *agf; /* a.g. freespace structure */
1997 xfs_agfl_t *agfl; /* a.g. freelist structure */
1998 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
1999 xfs_agblock_t bno; /* block number returned */
2000 int error;
2001 #ifdef XFS_ALLOC_TRACE
2002 static char fname[] = "xfs_alloc_get_freelist";
2003 #endif
2004 xfs_mount_t *mp; /* mount structure */
2005 xfs_perag_t *pag; /* per allocation group data */
2006
2007 agf = XFS_BUF_TO_AGF(agbp);
2008 /*
2009 * Freelist is empty, give up.
2010 */
2011 if (!agf->agf_flcount) {
2012 *bnop = NULLAGBLOCK;
2013 return 0;
2014 }
2015 /*
2016 * Read the array of free blocks.
2017 */
2018 mp = tp->t_mountp;
2019 if ((error = xfs_alloc_read_agfl(mp, tp,
2020 be32_to_cpu(agf->agf_seqno), &agflbp)))
2021 return error;
2022 agfl = XFS_BUF_TO_AGFL(agflbp);
2023 /*
2024 * Get the block number and update the data structures.
2025 */
2026 bno = be32_to_cpu(agfl->agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
2027 be32_add(&agf->agf_flfirst, 1);
2028 xfs_trans_brelse(tp, agflbp);
2029 if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
2030 agf->agf_flfirst = 0;
2031 pag = &mp->m_perag[be32_to_cpu(agf->agf_seqno)];
2032 be32_add(&agf->agf_flcount, -1);
2033 xfs_trans_agflist_delta(tp, -1);
2034 pag->pagf_flcount--;
2035 TRACE_MODAGF(NULL, agf, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
2036 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT);
2037 *bnop = bno;
2038
2039 /*
2040 * As blocks are freed, they are added to the per-ag busy list
2041 * and remain there until the freeing transaction is committed to
2042 * disk. Now that we have allocated blocks, this list must be
2043 * searched to see if a block is being reused. If one is, then
2044 * the freeing transaction must be pushed to disk NOW by forcing
2045 * to disk all iclogs up that transaction's LSN.
2046 */
2047 xfs_alloc_search_busy(tp, be32_to_cpu(agf->agf_seqno), bno, 1);
2048 return 0;
2049 }
2050
2051 /*
2052 * Log the given fields from the agf structure.
2053 */
2054 void
2055 xfs_alloc_log_agf(
2056 xfs_trans_t *tp, /* transaction pointer */
2057 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2058 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2059 {
2060 int first; /* first byte offset */
2061 int last; /* last byte offset */
2062 static const short offsets[] = {
2063 offsetof(xfs_agf_t, agf_magicnum),
2064 offsetof(xfs_agf_t, agf_versionnum),
2065 offsetof(xfs_agf_t, agf_seqno),
2066 offsetof(xfs_agf_t, agf_length),
2067 offsetof(xfs_agf_t, agf_roots[0]),
2068 offsetof(xfs_agf_t, agf_levels[0]),
2069 offsetof(xfs_agf_t, agf_flfirst),
2070 offsetof(xfs_agf_t, agf_fllast),
2071 offsetof(xfs_agf_t, agf_flcount),
2072 offsetof(xfs_agf_t, agf_freeblks),
2073 offsetof(xfs_agf_t, agf_longest),
2074 sizeof(xfs_agf_t)
2075 };
2076
2077 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2078 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2079 }
2080
2081 /*
2082 * Interface for inode allocation to force the pag data to be initialized.
2083 */
2084 int /* error */
2085 xfs_alloc_pagf_init(
2086 xfs_mount_t *mp, /* file system mount structure */
2087 xfs_trans_t *tp, /* transaction pointer */
2088 xfs_agnumber_t agno, /* allocation group number */
2089 int flags) /* XFS_ALLOC_FLAGS_... */
2090 {
2091 xfs_buf_t *bp;
2092 int error;
2093
2094 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2095 return error;
2096 if (bp)
2097 xfs_trans_brelse(tp, bp);
2098 return 0;
2099 }
2100
2101 /*
2102 * Put the block on the freelist for the allocation group.
2103 */
2104 int /* error */
2105 xfs_alloc_put_freelist(
2106 xfs_trans_t *tp, /* transaction pointer */
2107 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2108 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
2109 xfs_agblock_t bno) /* block being freed */
2110 {
2111 xfs_agf_t *agf; /* a.g. freespace structure */
2112 xfs_agfl_t *agfl; /* a.g. free block array */
2113 __be32 *blockp;/* pointer to array entry */
2114 int error;
2115 #ifdef XFS_ALLOC_TRACE
2116 static char fname[] = "xfs_alloc_put_freelist";
2117 #endif
2118 xfs_mount_t *mp; /* mount structure */
2119 xfs_perag_t *pag; /* per allocation group data */
2120
2121 agf = XFS_BUF_TO_AGF(agbp);
2122 mp = tp->t_mountp;
2123
2124 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
2125 be32_to_cpu(agf->agf_seqno), &agflbp)))
2126 return error;
2127 agfl = XFS_BUF_TO_AGFL(agflbp);
2128 be32_add(&agf->agf_fllast, 1);
2129 if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
2130 agf->agf_fllast = 0;
2131 pag = &mp->m_perag[be32_to_cpu(agf->agf_seqno)];
2132 be32_add(&agf->agf_flcount, 1);
2133 xfs_trans_agflist_delta(tp, 1);
2134 pag->pagf_flcount++;
2135 ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
2136 blockp = &agfl->agfl_bno[be32_to_cpu(agf->agf_fllast)];
2137 *blockp = cpu_to_be32(bno);
2138 TRACE_MODAGF(NULL, agf, XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
2139 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
2140 xfs_trans_log_buf(tp, agflbp,
2141 (int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl),
2142 (int)((xfs_caddr_t)blockp - (xfs_caddr_t)agfl +
2143 sizeof(xfs_agblock_t) - 1));
2144 return 0;
2145 }
2146
2147 /*
2148 * Read in the allocation group header (free/alloc section).
2149 */
2150 int /* error */
2151 xfs_alloc_read_agf(
2152 xfs_mount_t *mp, /* mount point structure */
2153 xfs_trans_t *tp, /* transaction pointer */
2154 xfs_agnumber_t agno, /* allocation group number */
2155 int flags, /* XFS_ALLOC_FLAG_... */
2156 xfs_buf_t **bpp) /* buffer for the ag freelist header */
2157 {
2158 xfs_agf_t *agf; /* ag freelist header */
2159 int agf_ok; /* set if agf is consistent */
2160 xfs_buf_t *bp; /* return value */
2161 xfs_perag_t *pag; /* per allocation group data */
2162 int error;
2163
2164 ASSERT(agno != NULLAGNUMBER);
2165 error = xfs_trans_read_buf(
2166 mp, tp, mp->m_ddev_targp,
2167 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
2168 XFS_FSS_TO_BB(mp, 1),
2169 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XFS_BUF_TRYLOCK : 0U,
2170 &bp);
2171 if (error)
2172 return error;
2173 ASSERT(!bp || !XFS_BUF_GETERROR(bp));
2174 if (!bp) {
2175 *bpp = NULL;
2176 return 0;
2177 }
2178 /*
2179 * Validate the magic number of the agf block.
2180 */
2181 agf = XFS_BUF_TO_AGF(bp);
2182 agf_ok =
2183 be32_to_cpu(agf->agf_magicnum) == XFS_AGF_MAGIC &&
2184 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2185 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2186 be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
2187 be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
2188 be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp);
2189 if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
2190 XFS_RANDOM_ALLOC_READ_AGF))) {
2191 XFS_CORRUPTION_ERROR("xfs_alloc_read_agf",
2192 XFS_ERRLEVEL_LOW, mp, agf);
2193 xfs_trans_brelse(tp, bp);
2194 return XFS_ERROR(EFSCORRUPTED);
2195 }
2196 pag = &mp->m_perag[agno];
2197 if (!pag->pagf_init) {
2198 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
2199 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2200 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
2201 pag->pagf_levels[XFS_BTNUM_BNOi] =
2202 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
2203 pag->pagf_levels[XFS_BTNUM_CNTi] =
2204 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
2205 spinlock_init(&pag->pagb_lock, "xfspagb");
2206 pag->pagb_list = kmem_zalloc(XFS_PAGB_NUM_SLOTS *
2207 sizeof(xfs_perag_busy_t), KM_SLEEP);
2208 pag->pagf_init = 1;
2209 }
2210 #ifdef DEBUG
2211 else if (!XFS_FORCED_SHUTDOWN(mp)) {
2212 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
2213 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2214 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
2215 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
2216 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
2217 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
2218 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
2219 }
2220 #endif
2221 XFS_BUF_SET_VTYPE_REF(bp, B_FS_AGF, XFS_AGF_REF);
2222 *bpp = bp;
2223 return 0;
2224 }
2225
2226 /*
2227 * Allocate an extent (variable-size).
2228 * Depending on the allocation type, we either look in a single allocation
2229 * group or loop over the allocation groups to find the result.
2230 */
2231 int /* error */
2232 xfs_alloc_vextent(
2233 xfs_alloc_arg_t *args) /* allocation argument structure */
2234 {
2235 xfs_agblock_t agsize; /* allocation group size */
2236 int error;
2237 int flags; /* XFS_ALLOC_FLAG_... locking flags */
2238 #ifdef XFS_ALLOC_TRACE
2239 static char fname[] = "xfs_alloc_vextent";
2240 #endif
2241 xfs_extlen_t minleft;/* minimum left value, temp copy */
2242 xfs_mount_t *mp; /* mount structure pointer */
2243 xfs_agnumber_t sagno; /* starting allocation group number */
2244 xfs_alloctype_t type; /* input allocation type */
2245 int bump_rotor = 0;
2246 int no_min = 0;
2247 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2248
2249 mp = args->mp;
2250 type = args->otype = args->type;
2251 args->agbno = NULLAGBLOCK;
2252 /*
2253 * Just fix this up, for the case where the last a.g. is shorter
2254 * (or there's only one a.g.) and the caller couldn't easily figure
2255 * that out (xfs_bmap_alloc).
2256 */
2257 agsize = mp->m_sb.sb_agblocks;
2258 if (args->maxlen > agsize)
2259 args->maxlen = agsize;
2260 if (args->alignment == 0)
2261 args->alignment = 1;
2262 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2263 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2264 ASSERT(args->minlen <= args->maxlen);
2265 ASSERT(args->minlen <= agsize);
2266 ASSERT(args->mod < args->prod);
2267 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2268 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2269 args->minlen > args->maxlen || args->minlen > agsize ||
2270 args->mod >= args->prod) {
2271 args->fsbno = NULLFSBLOCK;
2272 TRACE_ALLOC("badargs", args);
2273 return 0;
2274 }
2275 minleft = args->minleft;
2276
2277 switch (type) {
2278 case XFS_ALLOCTYPE_THIS_AG:
2279 case XFS_ALLOCTYPE_NEAR_BNO:
2280 case XFS_ALLOCTYPE_THIS_BNO:
2281 /*
2282 * These three force us into a single a.g.
2283 */
2284 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2285 down_read(&mp->m_peraglock);
2286 args->pag = &mp->m_perag[args->agno];
2287 args->minleft = 0;
2288 error = xfs_alloc_fix_freelist(args, 0);
2289 args->minleft = minleft;
2290 if (error) {
2291 TRACE_ALLOC("nofix", args);
2292 goto error0;
2293 }
2294 if (!args->agbp) {
2295 up_read(&mp->m_peraglock);
2296 TRACE_ALLOC("noagbp", args);
2297 break;
2298 }
2299 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2300 if ((error = xfs_alloc_ag_vextent(args)))
2301 goto error0;
2302 up_read(&mp->m_peraglock);
2303 break;
2304 case XFS_ALLOCTYPE_START_BNO:
2305 /*
2306 * Try near allocation first, then anywhere-in-ag after
2307 * the first a.g. fails.
2308 */
2309 if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
2310 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2311 args->fsbno = XFS_AGB_TO_FSB(mp,
2312 ((mp->m_agfrotor / rotorstep) %
2313 mp->m_sb.sb_agcount), 0);
2314 bump_rotor = 1;
2315 }
2316 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2317 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2318 /* FALLTHROUGH */
2319 case XFS_ALLOCTYPE_ANY_AG:
2320 case XFS_ALLOCTYPE_START_AG:
2321 case XFS_ALLOCTYPE_FIRST_AG:
2322 /*
2323 * Rotate through the allocation groups looking for a winner.
2324 */
2325 if (type == XFS_ALLOCTYPE_ANY_AG) {
2326 /*
2327 * Start with the last place we left off.
2328 */
2329 args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2330 mp->m_sb.sb_agcount;
2331 args->type = XFS_ALLOCTYPE_THIS_AG;
2332 flags = XFS_ALLOC_FLAG_TRYLOCK;
2333 } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2334 /*
2335 * Start with allocation group given by bno.
2336 */
2337 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2338 args->type = XFS_ALLOCTYPE_THIS_AG;
2339 sagno = 0;
2340 flags = 0;
2341 } else {
2342 if (type == XFS_ALLOCTYPE_START_AG)
2343 args->type = XFS_ALLOCTYPE_THIS_AG;
2344 /*
2345 * Start with the given allocation group.
2346 */
2347 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2348 flags = XFS_ALLOC_FLAG_TRYLOCK;
2349 }
2350 /*
2351 * Loop over allocation groups twice; first time with
2352 * trylock set, second time without.
2353 */
2354 down_read(&mp->m_peraglock);
2355 for (;;) {
2356 args->pag = &mp->m_perag[args->agno];
2357 if (no_min) args->minleft = 0;
2358 error = xfs_alloc_fix_freelist(args, flags);
2359 args->minleft = minleft;
2360 if (error) {
2361 TRACE_ALLOC("nofix", args);
2362 goto error0;
2363 }
2364 /*
2365 * If we get a buffer back then the allocation will fly.
2366 */
2367 if (args->agbp) {
2368 if ((error = xfs_alloc_ag_vextent(args)))
2369 goto error0;
2370 break;
2371 }
2372 TRACE_ALLOC("loopfailed", args);
2373 /*
2374 * Didn't work, figure out the next iteration.
2375 */
2376 if (args->agno == sagno &&
2377 type == XFS_ALLOCTYPE_START_BNO)
2378 args->type = XFS_ALLOCTYPE_THIS_AG;
2379 /*
2380 * For the first allocation, we can try any AG to get
2381 * space. However, if we already have allocated a
2382 * block, we don't want to try AGs whose number is below
2383 * sagno. Otherwise, we may end up with out-of-order
2384 * locking of AGF, which might cause deadlock.
2385 */
2386 if (++(args->agno) == mp->m_sb.sb_agcount) {
2387 if (args->firstblock != NULLFSBLOCK)
2388 args->agno = sagno;
2389 else
2390 args->agno = 0;
2391 }
2392 /*
2393 * Reached the starting a.g., must either be done
2394 * or switch to non-trylock mode.
2395 */
2396 if (args->agno == sagno) {
2397 if (no_min == 1) {
2398 args->agbno = NULLAGBLOCK;
2399 TRACE_ALLOC("allfailed", args);
2400 break;
2401 }
2402 if (flags == 0) {
2403 no_min = 1;
2404 } else {
2405 flags = 0;
2406 if (type == XFS_ALLOCTYPE_START_BNO) {
2407 args->agbno = XFS_FSB_TO_AGBNO(mp,
2408 args->fsbno);
2409 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2410 }
2411 }
2412 }
2413 }
2414 up_read(&mp->m_peraglock);
2415 if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2416 if (args->agno == sagno)
2417 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2418 (mp->m_sb.sb_agcount * rotorstep);
2419 else
2420 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2421 (mp->m_sb.sb_agcount * rotorstep);
2422 }
2423 break;
2424 default:
2425 ASSERT(0);
2426 /* NOTREACHED */
2427 }
2428 if (args->agbno == NULLAGBLOCK)
2429 args->fsbno = NULLFSBLOCK;
2430 else {
2431 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2432 #ifdef DEBUG
2433 ASSERT(args->len >= args->minlen);
2434 ASSERT(args->len <= args->maxlen);
2435 ASSERT(args->agbno % args->alignment == 0);
2436 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2437 args->len);
2438 #endif
2439 }
2440 return 0;
2441 error0:
2442 up_read(&mp->m_peraglock);
2443 return error;
2444 }
2445
2446 /*
2447 * Free an extent.
2448 * Just break up the extent address and hand off to xfs_free_ag_extent
2449 * after fixing up the freelist.
2450 */
2451 int /* error */
2452 xfs_free_extent(
2453 xfs_trans_t *tp, /* transaction pointer */
2454 xfs_fsblock_t bno, /* starting block number of extent */
2455 xfs_extlen_t len) /* length of extent */
2456 {
2457 xfs_alloc_arg_t args;
2458 int error;
2459
2460 ASSERT(len != 0);
2461 memset(&args, 0, sizeof(xfs_alloc_arg_t));
2462 args.tp = tp;
2463 args.mp = tp->t_mountp;
2464 args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
2465 ASSERT(args.agno < args.mp->m_sb.sb_agcount);
2466 args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
2467 down_read(&args.mp->m_peraglock);
2468 args.pag = &args.mp->m_perag[args.agno];
2469 if ((error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING)))
2470 goto error0;
2471 #ifdef DEBUG
2472 ASSERT(args.agbp != NULL);
2473 ASSERT((args.agbno + len) <=
2474 be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length));
2475 #endif
2476 error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
2477 error0:
2478 up_read(&args.mp->m_peraglock);
2479 return error;
2480 }
2481
2482
2483 /*
2484 * AG Busy list management
2485 * The busy list contains block ranges that have been freed but whose
2486 * transactions have not yet hit disk. If any block listed in a busy
2487 * list is reused, the transaction that freed it must be forced to disk
2488 * before continuing to use the block.
2489 *
2490 * xfs_alloc_mark_busy - add to the per-ag busy list
2491 * xfs_alloc_clear_busy - remove an item from the per-ag busy list
2492 */
2493 void
2494 xfs_alloc_mark_busy(xfs_trans_t *tp,
2495 xfs_agnumber_t agno,
2496 xfs_agblock_t bno,
2497 xfs_extlen_t len)
2498 {
2499 xfs_mount_t *mp;
2500 xfs_perag_busy_t *bsy;
2501 int n;
2502 SPLDECL(s);
2503
2504 mp = tp->t_mountp;
2505 s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
2506
2507 /* search pagb_list for an open slot */
2508 for (bsy = mp->m_perag[agno].pagb_list, n = 0;
2509 n < XFS_PAGB_NUM_SLOTS;
2510 bsy++, n++) {
2511 if (bsy->busy_tp == NULL) {
2512 break;
2513 }
2514 }
2515
2516 if (n < XFS_PAGB_NUM_SLOTS) {
2517 bsy = &mp->m_perag[agno].pagb_list[n];
2518 mp->m_perag[agno].pagb_count++;
2519 TRACE_BUSY("xfs_alloc_mark_busy", "got", agno, bno, len, n, tp);
2520 bsy->busy_start = bno;
2521 bsy->busy_length = len;
2522 bsy->busy_tp = tp;
2523 xfs_trans_add_busy(tp, agno, n);
2524 } else {
2525 TRACE_BUSY("xfs_alloc_mark_busy", "FULL", agno, bno, len, -1, tp);
2526 /*
2527 * The busy list is full! Since it is now not possible to
2528 * track the free block, make this a synchronous transaction
2529 * to insure that the block is not reused before this
2530 * transaction commits.
2531 */
2532 xfs_trans_set_sync(tp);
2533 }
2534
2535 mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2536 }
2537
2538 void
2539 xfs_alloc_clear_busy(xfs_trans_t *tp,
2540 xfs_agnumber_t agno,
2541 int idx)
2542 {
2543 xfs_mount_t *mp;
2544 xfs_perag_busy_t *list;
2545 SPLDECL(s);
2546
2547 mp = tp->t_mountp;
2548
2549 s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
2550 list = mp->m_perag[agno].pagb_list;
2551
2552 ASSERT(idx < XFS_PAGB_NUM_SLOTS);
2553 if (list[idx].busy_tp == tp) {
2554 TRACE_UNBUSY("xfs_alloc_clear_busy", "found", agno, idx, tp);
2555 list[idx].busy_tp = NULL;
2556 mp->m_perag[agno].pagb_count--;
2557 } else {
2558 TRACE_UNBUSY("xfs_alloc_clear_busy", "missing", agno, idx, tp);
2559 }
2560
2561 mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2562 }
2563
2564
2565 /*
2566 * returns non-zero if any of (agno,bno):len is in a busy list
2567 */
2568 STATIC int
2569 xfs_alloc_search_busy(xfs_trans_t *tp,
2570 xfs_agnumber_t agno,
2571 xfs_agblock_t bno,
2572 xfs_extlen_t len)
2573 {
2574 xfs_mount_t *mp;
2575 xfs_perag_busy_t *bsy;
2576 int n;
2577 xfs_agblock_t uend, bend;
2578 xfs_lsn_t lsn;
2579 int cnt;
2580 SPLDECL(s);
2581
2582 mp = tp->t_mountp;
2583
2584 s = mutex_spinlock(&mp->m_perag[agno].pagb_lock);
2585 cnt = mp->m_perag[agno].pagb_count;
2586
2587 uend = bno + len - 1;
2588
2589 /* search pagb_list for this slot, skipping open slots */
2590 for (bsy = mp->m_perag[agno].pagb_list, n = 0;
2591 cnt; bsy++, n++) {
2592
2593 /*
2594 * (start1,length1) within (start2, length2)
2595 */
2596 if (bsy->busy_tp != NULL) {
2597 bend = bsy->busy_start + bsy->busy_length - 1;
2598 if ((bno > bend) ||
2599 (uend < bsy->busy_start)) {
2600 cnt--;
2601 } else {
2602 TRACE_BUSYSEARCH("xfs_alloc_search_busy",
2603 "found1", agno, bno, len, n,
2604 tp);
2605 break;
2606 }
2607 }
2608 }
2609
2610 /*
2611 * If a block was found, force the log through the LSN of the
2612 * transaction that freed the block
2613 */
2614 if (cnt) {
2615 TRACE_BUSYSEARCH("xfs_alloc_search_busy", "found", agno, bno, len, n, tp);
2616 lsn = bsy->busy_tp->t_commit_lsn;
2617 mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2618 xfs_log_force(mp, lsn, XFS_LOG_FORCE|XFS_LOG_SYNC);
2619 } else {
2620 TRACE_BUSYSEARCH("xfs_alloc_search_busy", "not-found", agno, bno, len, n, tp);
2621 n = -1;
2622 mutex_spinunlock(&mp->m_perag[agno].pagb_lock, s);
2623 }
2624
2625 return n;
2626 }
WRT350N Kernel Patches