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