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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include "xfs.h"
Nathan Scotta844f452005-11-02 14:38:42 +110019#include "xfs_fs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include "xfs_types.h"
Nathan Scotta844f452005-11-02 14:38:42 +110021#include "xfs_bit.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "xfs_log.h"
23#include "xfs_trans.h"
24#include "xfs_sb.h"
25#include "xfs_ag.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include "xfs_mount.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include "xfs_bmap_btree.h"
Nathan Scotta844f452005-11-02 14:38:42 +110028#include "xfs_alloc_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include "xfs_ialloc_btree.h"
Nathan Scotta844f452005-11-02 14:38:42 +110030#include "xfs_dinode.h"
31#include "xfs_inode.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include "xfs_btree.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include "xfs_alloc.h"
Dave Chinnerefc27b52012-04-29 10:39:43 +000034#include "xfs_extent_busy.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include "xfs_error.h"
Dave Chinner4e0e6042013-04-03 16:11:13 +110036#include "xfs_cksum.h"
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000037#include "xfs_trace.h"
Dave Chinner4e0e6042013-04-03 16:11:13 +110038#include "xfs_buf_item.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Dave Chinnerc999a222012-03-22 05:15:07 +000040struct workqueue_struct *xfs_alloc_wq;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42#define XFS_ABSDIFF(a,b) (((a) <= (b)) ? ((b) - (a)) : ((a) - (b)))
43
44#define XFSA_FIXUP_BNO_OK 1
45#define XFSA_FIXUP_CNT_OK 2
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047STATIC int xfs_alloc_ag_vextent_exact(xfs_alloc_arg_t *);
48STATIC int xfs_alloc_ag_vextent_near(xfs_alloc_arg_t *);
49STATIC int xfs_alloc_ag_vextent_size(xfs_alloc_arg_t *);
50STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *,
Christoph Hellwige26f0502011-04-24 19:06:15 +000051 xfs_btree_cur_t *, xfs_agblock_t *, xfs_extlen_t *, int *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53/*
Christoph Hellwigfe033cc2008-10-30 16:56:09 +110054 * Lookup the record equal to [bno, len] in the btree given by cur.
55 */
56STATIC int /* error */
57xfs_alloc_lookup_eq(
58 struct xfs_btree_cur *cur, /* btree cursor */
59 xfs_agblock_t bno, /* starting block of extent */
60 xfs_extlen_t len, /* length of extent */
61 int *stat) /* success/failure */
62{
63 cur->bc_rec.a.ar_startblock = bno;
64 cur->bc_rec.a.ar_blockcount = len;
65 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
66}
67
68/*
69 * Lookup the first record greater than or equal to [bno, len]
70 * in the btree given by cur.
71 */
Dave Chinnera66d6362012-03-22 05:15:12 +000072int /* error */
Christoph Hellwigfe033cc2008-10-30 16:56:09 +110073xfs_alloc_lookup_ge(
74 struct xfs_btree_cur *cur, /* btree cursor */
75 xfs_agblock_t bno, /* starting block of extent */
76 xfs_extlen_t len, /* length of extent */
77 int *stat) /* success/failure */
78{
79 cur->bc_rec.a.ar_startblock = bno;
80 cur->bc_rec.a.ar_blockcount = len;
81 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
82}
83
84/*
85 * Lookup the first record less than or equal to [bno, len]
86 * in the btree given by cur.
87 */
Christoph Hellwiga46db602011-01-07 13:02:04 +000088int /* error */
Christoph Hellwigfe033cc2008-10-30 16:56:09 +110089xfs_alloc_lookup_le(
90 struct xfs_btree_cur *cur, /* btree cursor */
91 xfs_agblock_t bno, /* starting block of extent */
92 xfs_extlen_t len, /* length of extent */
93 int *stat) /* success/failure */
94{
95 cur->bc_rec.a.ar_startblock = bno;
96 cur->bc_rec.a.ar_blockcount = len;
97 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
98}
99
Christoph Hellwig278d0ca2008-10-30 16:56:32 +1100100/*
101 * Update the record referred to by cur to the value given
102 * by [bno, len].
103 * This either works (return 0) or gets an EFSCORRUPTED error.
104 */
105STATIC int /* error */
106xfs_alloc_update(
107 struct xfs_btree_cur *cur, /* btree cursor */
108 xfs_agblock_t bno, /* starting block of extent */
109 xfs_extlen_t len) /* length of extent */
110{
111 union xfs_btree_rec rec;
112
113 rec.alloc.ar_startblock = cpu_to_be32(bno);
114 rec.alloc.ar_blockcount = cpu_to_be32(len);
115 return xfs_btree_update(cur, &rec);
116}
Christoph Hellwigfe033cc2008-10-30 16:56:09 +1100117
118/*
Christoph Hellwig8cc938f2008-10-30 16:58:11 +1100119 * Get the data from the pointed-to record.
120 */
Christoph Hellwiga46db602011-01-07 13:02:04 +0000121int /* error */
Christoph Hellwig8cc938f2008-10-30 16:58:11 +1100122xfs_alloc_get_rec(
123 struct xfs_btree_cur *cur, /* btree cursor */
124 xfs_agblock_t *bno, /* output: starting block of extent */
125 xfs_extlen_t *len, /* output: length of extent */
126 int *stat) /* output: success/failure */
127{
128 union xfs_btree_rec *rec;
129 int error;
130
131 error = xfs_btree_get_rec(cur, &rec, stat);
132 if (!error && *stat == 1) {
133 *bno = be32_to_cpu(rec->alloc.ar_startblock);
134 *len = be32_to_cpu(rec->alloc.ar_blockcount);
135 }
136 return error;
137}
138
139/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 * Compute aligned version of the found extent.
141 * Takes alignment and min length into account.
142 */
David Chinner12375c82008-04-10 12:21:32 +1000143STATIC void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144xfs_alloc_compute_aligned(
Christoph Hellwig86fa8af2011-03-04 12:59:54 +0000145 xfs_alloc_arg_t *args, /* allocation argument structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 xfs_agblock_t foundbno, /* starting block in found extent */
147 xfs_extlen_t foundlen, /* length in found extent */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 xfs_agblock_t *resbno, /* result block number */
149 xfs_extlen_t *reslen) /* result length */
150{
151 xfs_agblock_t bno;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 xfs_extlen_t len;
153
Christoph Hellwige26f0502011-04-24 19:06:15 +0000154 /* Trim busy sections out of found extent */
Dave Chinner4ecbfe62012-04-29 10:41:10 +0000155 xfs_extent_busy_trim(args, foundbno, foundlen, &bno, &len);
Christoph Hellwige26f0502011-04-24 19:06:15 +0000156
157 if (args->alignment > 1 && len >= args->minlen) {
158 xfs_agblock_t aligned_bno = roundup(bno, args->alignment);
159 xfs_extlen_t diff = aligned_bno - bno;
160
161 *resbno = aligned_bno;
162 *reslen = diff >= len ? 0 : len - diff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 } else {
Christoph Hellwige26f0502011-04-24 19:06:15 +0000164 *resbno = bno;
165 *reslen = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167}
168
169/*
170 * Compute best start block and diff for "near" allocations.
171 * freelen >= wantlen already checked by caller.
172 */
173STATIC xfs_extlen_t /* difference value (absolute) */
174xfs_alloc_compute_diff(
175 xfs_agblock_t wantbno, /* target starting block */
176 xfs_extlen_t wantlen, /* target length */
177 xfs_extlen_t alignment, /* target alignment */
Jan Kara211d0222013-04-11 22:09:56 +0200178 char userdata, /* are we allocating data? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 xfs_agblock_t freebno, /* freespace's starting block */
180 xfs_extlen_t freelen, /* freespace's length */
181 xfs_agblock_t *newbnop) /* result: best start block from free */
182{
183 xfs_agblock_t freeend; /* end of freespace extent */
184 xfs_agblock_t newbno1; /* return block number */
185 xfs_agblock_t newbno2; /* other new block number */
186 xfs_extlen_t newlen1=0; /* length with newbno1 */
187 xfs_extlen_t newlen2=0; /* length with newbno2 */
188 xfs_agblock_t wantend; /* end of target extent */
189
190 ASSERT(freelen >= wantlen);
191 freeend = freebno + freelen;
192 wantend = wantbno + wantlen;
Jan Kara211d0222013-04-11 22:09:56 +0200193 /*
194 * We want to allocate from the start of a free extent if it is past
195 * the desired block or if we are allocating user data and the free
196 * extent is before desired block. The second case is there to allow
197 * for contiguous allocation from the remaining free space if the file
198 * grows in the short term.
199 */
200 if (freebno >= wantbno || (userdata && freeend < wantend)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 if ((newbno1 = roundup(freebno, alignment)) >= freeend)
202 newbno1 = NULLAGBLOCK;
203 } else if (freeend >= wantend && alignment > 1) {
204 newbno1 = roundup(wantbno, alignment);
205 newbno2 = newbno1 - alignment;
206 if (newbno1 >= freeend)
207 newbno1 = NULLAGBLOCK;
208 else
209 newlen1 = XFS_EXTLEN_MIN(wantlen, freeend - newbno1);
210 if (newbno2 < freebno)
211 newbno2 = NULLAGBLOCK;
212 else
213 newlen2 = XFS_EXTLEN_MIN(wantlen, freeend - newbno2);
214 if (newbno1 != NULLAGBLOCK && newbno2 != NULLAGBLOCK) {
215 if (newlen1 < newlen2 ||
216 (newlen1 == newlen2 &&
217 XFS_ABSDIFF(newbno1, wantbno) >
218 XFS_ABSDIFF(newbno2, wantbno)))
219 newbno1 = newbno2;
220 } else if (newbno2 != NULLAGBLOCK)
221 newbno1 = newbno2;
222 } else if (freeend >= wantend) {
223 newbno1 = wantbno;
224 } else if (alignment > 1) {
225 newbno1 = roundup(freeend - wantlen, alignment);
226 if (newbno1 > freeend - wantlen &&
227 newbno1 - alignment >= freebno)
228 newbno1 -= alignment;
229 else if (newbno1 >= freeend)
230 newbno1 = NULLAGBLOCK;
231 } else
232 newbno1 = freeend - wantlen;
233 *newbnop = newbno1;
234 return newbno1 == NULLAGBLOCK ? 0 : XFS_ABSDIFF(newbno1, wantbno);
235}
236
237/*
238 * Fix up the length, based on mod and prod.
239 * len should be k * prod + mod for some k.
240 * If len is too small it is returned unchanged.
241 * If len hits maxlen it is left alone.
242 */
243STATIC void
244xfs_alloc_fix_len(
245 xfs_alloc_arg_t *args) /* allocation argument structure */
246{
247 xfs_extlen_t k;
248 xfs_extlen_t rlen;
249
250 ASSERT(args->mod < args->prod);
251 rlen = args->len;
252 ASSERT(rlen >= args->minlen);
253 ASSERT(rlen <= args->maxlen);
254 if (args->prod <= 1 || rlen < args->mod || rlen == args->maxlen ||
255 (args->mod == 0 && rlen < args->prod))
256 return;
257 k = rlen % args->prod;
258 if (k == args->mod)
259 return;
260 if (k > args->mod) {
261 if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen)
262 return;
263 } else {
264 if ((int)(rlen = rlen - args->prod - (args->mod - k)) <
265 (int)args->minlen)
266 return;
267 }
268 ASSERT(rlen >= args->minlen);
269 ASSERT(rlen <= args->maxlen);
270 args->len = rlen;
271}
272
273/*
274 * Fix up length if there is too little space left in the a.g.
275 * Return 1 if ok, 0 if too little, should give up.
276 */
277STATIC int
278xfs_alloc_fix_minleft(
279 xfs_alloc_arg_t *args) /* allocation argument structure */
280{
281 xfs_agf_t *agf; /* a.g. freelist header */
282 int diff; /* free space difference */
283
284 if (args->minleft == 0)
285 return 1;
286 agf = XFS_BUF_TO_AGF(args->agbp);
Christoph Hellwig16259e72005-11-02 15:11:25 +1100287 diff = be32_to_cpu(agf->agf_freeblks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 - args->len - args->minleft;
289 if (diff >= 0)
290 return 1;
291 args->len += diff; /* shrink the allocated space */
292 if (args->len >= args->minlen)
293 return 1;
294 args->agbno = NULLAGBLOCK;
295 return 0;
296}
297
298/*
299 * Update the two btrees, logically removing from freespace the extent
300 * starting at rbno, rlen blocks. The extent is contained within the
301 * actual (current) free extent fbno for flen blocks.
302 * Flags are passed in indicating whether the cursors are set to the
303 * relevant records.
304 */
305STATIC int /* error code */
306xfs_alloc_fixup_trees(
307 xfs_btree_cur_t *cnt_cur, /* cursor for by-size btree */
308 xfs_btree_cur_t *bno_cur, /* cursor for by-block btree */
309 xfs_agblock_t fbno, /* starting block of free extent */
310 xfs_extlen_t flen, /* length of free extent */
311 xfs_agblock_t rbno, /* starting block of returned extent */
312 xfs_extlen_t rlen, /* length of returned extent */
313 int flags) /* flags, XFSA_FIXUP_... */
314{
315 int error; /* error code */
316 int i; /* operation results */
317 xfs_agblock_t nfbno1; /* first new free startblock */
318 xfs_agblock_t nfbno2; /* second new free startblock */
319 xfs_extlen_t nflen1=0; /* first new free length */
320 xfs_extlen_t nflen2=0; /* second new free length */
321
322 /*
323 * Look up the record in the by-size tree if necessary.
324 */
325 if (flags & XFSA_FIXUP_CNT_OK) {
326#ifdef DEBUG
327 if ((error = xfs_alloc_get_rec(cnt_cur, &nfbno1, &nflen1, &i)))
328 return error;
329 XFS_WANT_CORRUPTED_RETURN(
330 i == 1 && nfbno1 == fbno && nflen1 == flen);
331#endif
332 } else {
333 if ((error = xfs_alloc_lookup_eq(cnt_cur, fbno, flen, &i)))
334 return error;
335 XFS_WANT_CORRUPTED_RETURN(i == 1);
336 }
337 /*
338 * Look up the record in the by-block tree if necessary.
339 */
340 if (flags & XFSA_FIXUP_BNO_OK) {
341#ifdef DEBUG
342 if ((error = xfs_alloc_get_rec(bno_cur, &nfbno1, &nflen1, &i)))
343 return error;
344 XFS_WANT_CORRUPTED_RETURN(
345 i == 1 && nfbno1 == fbno && nflen1 == flen);
346#endif
347 } else {
348 if ((error = xfs_alloc_lookup_eq(bno_cur, fbno, flen, &i)))
349 return error;
350 XFS_WANT_CORRUPTED_RETURN(i == 1);
351 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100353#ifdef DEBUG
354 if (bno_cur->bc_nlevels == 1 && cnt_cur->bc_nlevels == 1) {
355 struct xfs_btree_block *bnoblock;
356 struct xfs_btree_block *cntblock;
357
358 bnoblock = XFS_BUF_TO_BLOCK(bno_cur->bc_bufs[0]);
359 cntblock = XFS_BUF_TO_BLOCK(cnt_cur->bc_bufs[0]);
360
361 XFS_WANT_CORRUPTED_RETURN(
362 bnoblock->bb_numrecs == cntblock->bb_numrecs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 }
364#endif
Christoph Hellwig7cc95a82008-10-30 17:14:34 +1100365
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 /*
367 * Deal with all four cases: the allocated record is contained
368 * within the freespace record, so we can have new freespace
369 * at either (or both) end, or no freespace remaining.
370 */
371 if (rbno == fbno && rlen == flen)
372 nfbno1 = nfbno2 = NULLAGBLOCK;
373 else if (rbno == fbno) {
374 nfbno1 = rbno + rlen;
375 nflen1 = flen - rlen;
376 nfbno2 = NULLAGBLOCK;
377 } else if (rbno + rlen == fbno + flen) {
378 nfbno1 = fbno;
379 nflen1 = flen - rlen;
380 nfbno2 = NULLAGBLOCK;
381 } else {
382 nfbno1 = fbno;
383 nflen1 = rbno - fbno;
384 nfbno2 = rbno + rlen;
385 nflen2 = (fbno + flen) - nfbno2;
386 }
387 /*
388 * Delete the entry from the by-size btree.
389 */
Christoph Hellwig91cca5df2008-10-30 16:58:01 +1100390 if ((error = xfs_btree_delete(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 return error;
392 XFS_WANT_CORRUPTED_RETURN(i == 1);
393 /*
394 * Add new by-size btree entry(s).
395 */
396 if (nfbno1 != NULLAGBLOCK) {
397 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno1, nflen1, &i)))
398 return error;
399 XFS_WANT_CORRUPTED_RETURN(i == 0);
Christoph Hellwig4b22a572008-10-30 16:57:40 +1100400 if ((error = xfs_btree_insert(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 return error;
402 XFS_WANT_CORRUPTED_RETURN(i == 1);
403 }
404 if (nfbno2 != NULLAGBLOCK) {
405 if ((error = xfs_alloc_lookup_eq(cnt_cur, nfbno2, nflen2, &i)))
406 return error;
407 XFS_WANT_CORRUPTED_RETURN(i == 0);
Christoph Hellwig4b22a572008-10-30 16:57:40 +1100408 if ((error = xfs_btree_insert(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 return error;
410 XFS_WANT_CORRUPTED_RETURN(i == 1);
411 }
412 /*
413 * Fix up the by-block btree entry(s).
414 */
415 if (nfbno1 == NULLAGBLOCK) {
416 /*
417 * No remaining freespace, just delete the by-block tree entry.
418 */
Christoph Hellwig91cca5df2008-10-30 16:58:01 +1100419 if ((error = xfs_btree_delete(bno_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 return error;
421 XFS_WANT_CORRUPTED_RETURN(i == 1);
422 } else {
423 /*
424 * Update the by-block entry to start later|be shorter.
425 */
426 if ((error = xfs_alloc_update(bno_cur, nfbno1, nflen1)))
427 return error;
428 }
429 if (nfbno2 != NULLAGBLOCK) {
430 /*
431 * 2 resulting free entries, need to add one.
432 */
433 if ((error = xfs_alloc_lookup_eq(bno_cur, nfbno2, nflen2, &i)))
434 return error;
435 XFS_WANT_CORRUPTED_RETURN(i == 0);
Christoph Hellwig4b22a572008-10-30 16:57:40 +1100436 if ((error = xfs_btree_insert(bno_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 return error;
438 XFS_WANT_CORRUPTED_RETURN(i == 1);
439 }
440 return 0;
441}
442
Christoph Hellwig77c95bb2013-04-03 16:11:14 +1100443static bool
Dave Chinner612cfbf2012-11-14 17:52:32 +1100444xfs_agfl_verify(
Dave Chinnerbb80c6d2012-11-12 22:54:06 +1100445 struct xfs_buf *bp)
446{
Dave Chinnerbb80c6d2012-11-12 22:54:06 +1100447 struct xfs_mount *mp = bp->b_target->bt_mount;
448 struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(bp);
Dave Chinnerbb80c6d2012-11-12 22:54:06 +1100449 int i;
450
Christoph Hellwig77c95bb2013-04-03 16:11:14 +1100451 if (!uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_uuid))
452 return false;
453 if (be32_to_cpu(agfl->agfl_magicnum) != XFS_AGFL_MAGIC)
454 return false;
455 /*
456 * during growfs operations, the perag is not fully initialised,
457 * so we can't use it for any useful checking. growfs ensures we can't
458 * use it by using uncached buffers that don't have the perag attached
459 * so we can detect and avoid this problem.
460 */
461 if (bp->b_pag && be32_to_cpu(agfl->agfl_seqno) != bp->b_pag->pag_agno)
462 return false;
463
Dave Chinnerbb80c6d2012-11-12 22:54:06 +1100464 for (i = 0; i < XFS_AGFL_SIZE(mp); i++) {
Christoph Hellwig77c95bb2013-04-03 16:11:14 +1100465 if (be32_to_cpu(agfl->agfl_bno[i]) != NULLAGBLOCK &&
Dave Chinnerbb80c6d2012-11-12 22:54:06 +1100466 be32_to_cpu(agfl->agfl_bno[i]) >= mp->m_sb.sb_agblocks)
Christoph Hellwig77c95bb2013-04-03 16:11:14 +1100467 return false;
Dave Chinnerbb80c6d2012-11-12 22:54:06 +1100468 }
Christoph Hellwig77c95bb2013-04-03 16:11:14 +1100469 return true;
Dave Chinner612cfbf2012-11-14 17:52:32 +1100470}
471
Dave Chinnerb0f539d2012-11-14 17:53:49 +1100472static void
Dave Chinner612cfbf2012-11-14 17:52:32 +1100473xfs_agfl_read_verify(
474 struct xfs_buf *bp)
475{
Christoph Hellwig77c95bb2013-04-03 16:11:14 +1100476 struct xfs_mount *mp = bp->b_target->bt_mount;
477 int agfl_ok = 1;
478
479 /*
480 * There is no verification of non-crc AGFLs because mkfs does not
481 * initialise the AGFL to zero or NULL. Hence the only valid part of the
482 * AGFL is what the AGF says is active. We can't get to the AGF, so we
483 * can't verify just those entries are valid.
484 */
485 if (!xfs_sb_version_hascrc(&mp->m_sb))
486 return;
487
488 agfl_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
489 offsetof(struct xfs_agfl, agfl_crc));
490
491 agfl_ok = agfl_ok && xfs_agfl_verify(bp);
492
493 if (!agfl_ok) {
494 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
495 xfs_buf_ioerror(bp, EFSCORRUPTED);
496 }
497}
498
499static void
500xfs_agfl_write_verify(
501 struct xfs_buf *bp)
502{
503 struct xfs_mount *mp = bp->b_target->bt_mount;
504 struct xfs_buf_log_item *bip = bp->b_fspriv;
505
506 /* no verification of non-crc AGFLs */
507 if (!xfs_sb_version_hascrc(&mp->m_sb))
508 return;
509
510 if (!xfs_agfl_verify(bp)) {
511 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
512 xfs_buf_ioerror(bp, EFSCORRUPTED);
513 return;
514 }
515
516 if (bip)
517 XFS_BUF_TO_AGFL(bp)->agfl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
518
519 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
520 offsetof(struct xfs_agfl, agfl_crc));
Dave Chinnerbb80c6d2012-11-12 22:54:06 +1100521}
522
Dave Chinner1813dd62012-11-14 17:54:40 +1100523const struct xfs_buf_ops xfs_agfl_buf_ops = {
524 .verify_read = xfs_agfl_read_verify,
525 .verify_write = xfs_agfl_write_verify,
526};
527
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528/*
529 * Read in the allocation group free block array.
530 */
531STATIC int /* error */
532xfs_alloc_read_agfl(
533 xfs_mount_t *mp, /* mount point structure */
534 xfs_trans_t *tp, /* transaction pointer */
535 xfs_agnumber_t agno, /* allocation group number */
536 xfs_buf_t **bpp) /* buffer for the ag free block array */
537{
538 xfs_buf_t *bp; /* return value */
539 int error;
540
541 ASSERT(agno != NULLAGNUMBER);
542 error = xfs_trans_read_buf(
543 mp, tp, mp->m_ddev_targp,
544 XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
Dave Chinner1813dd62012-11-14 17:54:40 +1100545 XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_agfl_buf_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 if (error)
547 return error;
Chandra Seetharaman5a52c2a582011-07-22 23:39:51 +0000548 ASSERT(!xfs_buf_geterror(bp));
Christoph Hellwig38f23232011-10-10 16:52:45 +0000549 xfs_buf_set_ref(bp, XFS_AGFL_REF);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 *bpp = bp;
551 return 0;
552}
553
Christoph Hellwigecb69282011-03-04 12:59:55 +0000554STATIC int
555xfs_alloc_update_counters(
556 struct xfs_trans *tp,
557 struct xfs_perag *pag,
558 struct xfs_buf *agbp,
559 long len)
560{
561 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
562
563 pag->pagf_freeblks += len;
564 be32_add_cpu(&agf->agf_freeblks, len);
565
566 xfs_trans_agblocks_delta(tp, len);
567 if (unlikely(be32_to_cpu(agf->agf_freeblks) >
568 be32_to_cpu(agf->agf_length)))
569 return EFSCORRUPTED;
570
571 xfs_alloc_log_agf(tp, agbp, XFS_AGF_FREEBLKS);
572 return 0;
573}
574
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575/*
576 * Allocation group level functions.
577 */
578
579/*
580 * Allocate a variable extent in the allocation group agno.
581 * Type and bno are used to determine where in the allocation group the
582 * extent will start.
583 * Extent's length (returned in *len) will be between minlen and maxlen,
584 * and of the form k * prod + mod unless there's nothing that large.
585 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
586 */
587STATIC int /* error */
588xfs_alloc_ag_vextent(
589 xfs_alloc_arg_t *args) /* argument structure for allocation */
590{
591 int error=0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
593 ASSERT(args->minlen > 0);
594 ASSERT(args->maxlen > 0);
595 ASSERT(args->minlen <= args->maxlen);
596 ASSERT(args->mod < args->prod);
597 ASSERT(args->alignment > 0);
598 /*
599 * Branch to correct routine based on the type.
600 */
601 args->wasfromfl = 0;
602 switch (args->type) {
603 case XFS_ALLOCTYPE_THIS_AG:
604 error = xfs_alloc_ag_vextent_size(args);
605 break;
606 case XFS_ALLOCTYPE_NEAR_BNO:
607 error = xfs_alloc_ag_vextent_near(args);
608 break;
609 case XFS_ALLOCTYPE_THIS_BNO:
610 error = xfs_alloc_ag_vextent_exact(args);
611 break;
612 default:
613 ASSERT(0);
614 /* NOTREACHED */
615 }
Christoph Hellwigecb69282011-03-04 12:59:55 +0000616
617 if (error || args->agbno == NULLAGBLOCK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619
Christoph Hellwigecb69282011-03-04 12:59:55 +0000620 ASSERT(args->len >= args->minlen);
621 ASSERT(args->len <= args->maxlen);
622 ASSERT(!args->wasfromfl || !args->isfl);
623 ASSERT(args->agbno % args->alignment == 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
Christoph Hellwigecb69282011-03-04 12:59:55 +0000625 if (!args->wasfromfl) {
626 error = xfs_alloc_update_counters(args->tp, args->pag,
627 args->agbp,
628 -((long)(args->len)));
629 if (error)
630 return error;
631
Dave Chinner4ecbfe62012-04-29 10:41:10 +0000632 ASSERT(!xfs_extent_busy_search(args->mp, args->agno,
Christoph Hellwige26f0502011-04-24 19:06:15 +0000633 args->agbno, args->len));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 }
Christoph Hellwigecb69282011-03-04 12:59:55 +0000635
636 if (!args->isfl) {
637 xfs_trans_mod_sb(args->tp, args->wasdel ?
638 XFS_TRANS_SB_RES_FDBLOCKS :
639 XFS_TRANS_SB_FDBLOCKS,
640 -((long)(args->len)));
641 }
642
643 XFS_STATS_INC(xs_allocx);
644 XFS_STATS_ADD(xs_allocb, args->len);
645 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646}
647
648/*
649 * Allocate a variable extent at exactly agno/bno.
650 * Extent's length (returned in *len) will be between minlen and maxlen,
651 * and of the form k * prod + mod unless there's nothing that large.
652 * Return the starting a.g. block (bno), or NULLAGBLOCK if we can't do it.
653 */
654STATIC int /* error */
655xfs_alloc_ag_vextent_exact(
656 xfs_alloc_arg_t *args) /* allocation argument structure */
657{
658 xfs_btree_cur_t *bno_cur;/* by block-number btree cursor */
659 xfs_btree_cur_t *cnt_cur;/* by count btree cursor */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 int error;
661 xfs_agblock_t fbno; /* start block of found extent */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 xfs_extlen_t flen; /* length of found extent */
Christoph Hellwige26f0502011-04-24 19:06:15 +0000663 xfs_agblock_t tbno; /* start block of trimmed extent */
664 xfs_extlen_t tlen; /* length of trimmed extent */
665 xfs_agblock_t tend; /* end block of trimmed extent */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 int i; /* success/failure of operation */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
668 ASSERT(args->alignment == 1);
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 /*
671 * Allocate/initialize a cursor for the by-number freespace btree.
672 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100673 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000674 args->agno, XFS_BTNUM_BNO);
675
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 /*
677 * Lookup bno and minlen in the btree (minlen is irrelevant, really).
678 * Look for the closest free block <= bno, it must contain bno
679 * if any free block does.
680 */
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000681 error = xfs_alloc_lookup_le(bno_cur, args->agbno, args->minlen, &i);
682 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 goto error0;
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000684 if (!i)
685 goto not_found;
686
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 /*
688 * Grab the freespace record.
689 */
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000690 error = xfs_alloc_get_rec(bno_cur, &fbno, &flen, &i);
691 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 goto error0;
693 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
694 ASSERT(fbno <= args->agbno);
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 /*
Christoph Hellwige26f0502011-04-24 19:06:15 +0000697 * Check for overlapping busy extents.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 */
Dave Chinner4ecbfe62012-04-29 10:41:10 +0000699 xfs_extent_busy_trim(args, fbno, flen, &tbno, &tlen);
Christoph Hellwige26f0502011-04-24 19:06:15 +0000700
701 /*
702 * Give up if the start of the extent is busy, or the freespace isn't
703 * long enough for the minimum request.
704 */
705 if (tbno > args->agbno)
706 goto not_found;
707 if (tlen < args->minlen)
708 goto not_found;
709 tend = tbno + tlen;
710 if (tend < args->agbno + args->minlen)
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000711 goto not_found;
712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 /*
714 * End of extent will be smaller of the freespace end and the
715 * maximal requested end.
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000716 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 * Fix the length according to mod and prod if given.
718 */
Chandra Seetharaman81463b12011-06-09 16:47:49 +0000719 args->len = XFS_AGBLOCK_MIN(tend, args->agbno + args->maxlen)
720 - args->agbno;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 xfs_alloc_fix_len(args);
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000722 if (!xfs_alloc_fix_minleft(args))
723 goto not_found;
724
Chandra Seetharaman81463b12011-06-09 16:47:49 +0000725 ASSERT(args->agbno + args->len <= tend);
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000726
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 /*
Chandra Seetharaman81463b12011-06-09 16:47:49 +0000728 * We are allocating agbno for args->len
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 * Allocate/initialize a cursor for the by-size btree.
730 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100731 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
732 args->agno, XFS_BTNUM_CNT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 ASSERT(args->agbno + args->len <=
Christoph Hellwig16259e72005-11-02 15:11:25 +1100734 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000735 error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen, args->agbno,
736 args->len, XFSA_FIXUP_BNO_OK);
737 if (error) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
739 goto error0;
740 }
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000741
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
743 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
Christoph Hellwig0b1b2132009-12-14 23:14:59 +0000744
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 args->wasfromfl = 0;
Christoph Hellwig9f9baab2010-12-10 15:03:57 +0000746 trace_xfs_alloc_exact_done(args);
747 return 0;
748
749not_found:
750 /* Didn't find it, return null. */
751 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
752 args->agbno = NULLAGBLOCK;
753 trace_xfs_alloc_exact_notfound(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 return 0;
755
756error0:
757 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
Christoph Hellwig0b1b2132009-12-14 23:14:59 +0000758 trace_xfs_alloc_exact_error(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 return error;
760}
761
762/*
Christoph Hellwig489a1502010-12-10 15:04:11 +0000763 * Search the btree in a given direction via the search cursor and compare
764 * the records found against the good extent we've already found.
765 */
766STATIC int
767xfs_alloc_find_best_extent(
768 struct xfs_alloc_arg *args, /* allocation argument structure */
769 struct xfs_btree_cur **gcur, /* good cursor */
770 struct xfs_btree_cur **scur, /* searching cursor */
771 xfs_agblock_t gdiff, /* difference for search comparison */
772 xfs_agblock_t *sbno, /* extent found by search */
Christoph Hellwige26f0502011-04-24 19:06:15 +0000773 xfs_extlen_t *slen, /* extent length */
774 xfs_agblock_t *sbnoa, /* aligned extent found by search */
775 xfs_extlen_t *slena, /* aligned extent length */
Christoph Hellwig489a1502010-12-10 15:04:11 +0000776 int dir) /* 0 = search right, 1 = search left */
777{
Christoph Hellwig489a1502010-12-10 15:04:11 +0000778 xfs_agblock_t new;
779 xfs_agblock_t sdiff;
780 int error;
781 int i;
782
783 /* The good extent is perfect, no need to search. */
784 if (!gdiff)
785 goto out_use_good;
786
787 /*
788 * Look until we find a better one, run out of space or run off the end.
789 */
790 do {
791 error = xfs_alloc_get_rec(*scur, sbno, slen, &i);
792 if (error)
793 goto error0;
794 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwige26f0502011-04-24 19:06:15 +0000795 xfs_alloc_compute_aligned(args, *sbno, *slen, sbnoa, slena);
Christoph Hellwig489a1502010-12-10 15:04:11 +0000796
797 /*
798 * The good extent is closer than this one.
799 */
800 if (!dir) {
Christoph Hellwige26f0502011-04-24 19:06:15 +0000801 if (*sbnoa >= args->agbno + gdiff)
Christoph Hellwig489a1502010-12-10 15:04:11 +0000802 goto out_use_good;
803 } else {
Christoph Hellwige26f0502011-04-24 19:06:15 +0000804 if (*sbnoa <= args->agbno - gdiff)
Christoph Hellwig489a1502010-12-10 15:04:11 +0000805 goto out_use_good;
806 }
807
808 /*
809 * Same distance, compare length and pick the best.
810 */
811 if (*slena >= args->minlen) {
812 args->len = XFS_EXTLEN_MIN(*slena, args->maxlen);
813 xfs_alloc_fix_len(args);
814
815 sdiff = xfs_alloc_compute_diff(args->agbno, args->len,
Jan Kara211d0222013-04-11 22:09:56 +0200816 args->alignment,
817 args->userdata, *sbnoa,
Christoph Hellwige26f0502011-04-24 19:06:15 +0000818 *slena, &new);
Christoph Hellwig489a1502010-12-10 15:04:11 +0000819
820 /*
821 * Choose closer size and invalidate other cursor.
822 */
823 if (sdiff < gdiff)
824 goto out_use_search;
825 goto out_use_good;
826 }
827
828 if (!dir)
829 error = xfs_btree_increment(*scur, 0, &i);
830 else
831 error = xfs_btree_decrement(*scur, 0, &i);
832 if (error)
833 goto error0;
834 } while (i);
835
836out_use_good:
837 xfs_btree_del_cursor(*scur, XFS_BTREE_NOERROR);
838 *scur = NULL;
839 return 0;
840
841out_use_search:
842 xfs_btree_del_cursor(*gcur, XFS_BTREE_NOERROR);
843 *gcur = NULL;
844 return 0;
845
846error0:
847 /* caller invalidates cursors */
848 return error;
849}
850
851/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 * Allocate a variable extent near bno in the allocation group agno.
853 * Extent's length (returned in len) will be between minlen and maxlen,
854 * and of the form k * prod + mod unless there's nothing that large.
855 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
856 */
857STATIC int /* error */
858xfs_alloc_ag_vextent_near(
859 xfs_alloc_arg_t *args) /* allocation argument structure */
860{
861 xfs_btree_cur_t *bno_cur_gt; /* cursor for bno btree, right side */
862 xfs_btree_cur_t *bno_cur_lt; /* cursor for bno btree, left side */
863 xfs_btree_cur_t *cnt_cur; /* cursor for count btree */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 xfs_agblock_t gtbno; /* start bno of right side entry */
865 xfs_agblock_t gtbnoa; /* aligned ... */
866 xfs_extlen_t gtdiff; /* difference to right side entry */
867 xfs_extlen_t gtlen; /* length of right side entry */
Christoph Hellwige26f0502011-04-24 19:06:15 +0000868 xfs_extlen_t gtlena; /* aligned ... */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 xfs_agblock_t gtnew; /* useful start bno of right side */
870 int error; /* error code */
871 int i; /* result code, temporary */
872 int j; /* result code, temporary */
873 xfs_agblock_t ltbno; /* start bno of left side entry */
874 xfs_agblock_t ltbnoa; /* aligned ... */
875 xfs_extlen_t ltdiff; /* difference to left side entry */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 xfs_extlen_t ltlen; /* length of left side entry */
Christoph Hellwige26f0502011-04-24 19:06:15 +0000877 xfs_extlen_t ltlena; /* aligned ... */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 xfs_agblock_t ltnew; /* useful start bno of left side */
879 xfs_extlen_t rlen; /* length of returned extent */
Christoph Hellwige26f0502011-04-24 19:06:15 +0000880 int forced = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881#if defined(DEBUG) && defined(__KERNEL__)
882 /*
883 * Randomly don't execute the first algorithm.
884 */
885 int dofirst; /* set to do first algorithm */
886
Akinobu Mitaecb34032013-03-04 21:58:20 +0900887 dofirst = prandom_u32() & 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888#endif
Christoph Hellwige26f0502011-04-24 19:06:15 +0000889
890restart:
891 bno_cur_lt = NULL;
892 bno_cur_gt = NULL;
893 ltlen = 0;
894 gtlena = 0;
895 ltlena = 0;
896
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 /*
898 * Get a cursor for the by-size btree.
899 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +1100900 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
901 args->agno, XFS_BTNUM_CNT);
Christoph Hellwige26f0502011-04-24 19:06:15 +0000902
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 /*
904 * See if there are any free extents as big as maxlen.
905 */
906 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0, args->maxlen, &i)))
907 goto error0;
908 /*
909 * If none, then pick up the last entry in the tree unless the
910 * tree is empty.
911 */
912 if (!i) {
913 if ((error = xfs_alloc_ag_vextent_small(args, cnt_cur, &ltbno,
914 &ltlen, &i)))
915 goto error0;
916 if (i == 0 || ltlen == 0) {
917 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
Christoph Hellwige26f0502011-04-24 19:06:15 +0000918 trace_xfs_alloc_near_noentry(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 return 0;
920 }
921 ASSERT(i == 1);
922 }
923 args->wasfromfl = 0;
Christoph Hellwige26f0502011-04-24 19:06:15 +0000924
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 /*
926 * First algorithm.
927 * If the requested extent is large wrt the freespaces available
928 * in this a.g., then the cursor will be pointing to a btree entry
929 * near the right edge of the tree. If it's in the last btree leaf
930 * block, then we just examine all the entries in that block
931 * that are big enough, and pick the best one.
932 * This is written as a while loop so we can break out of it,
933 * but we never loop back to the top.
934 */
935 while (xfs_btree_islastblock(cnt_cur, 0)) {
936 xfs_extlen_t bdiff;
937 int besti=0;
938 xfs_extlen_t blen=0;
939 xfs_agblock_t bnew=0;
940
941#if defined(DEBUG) && defined(__KERNEL__)
942 if (!dofirst)
943 break;
944#endif
945 /*
946 * Start from the entry that lookup found, sequence through
947 * all larger free blocks. If we're actually pointing at a
948 * record smaller than maxlen, go to the start of this block,
949 * and skip all those smaller than minlen.
950 */
951 if (ltlen || args->alignment > 1) {
952 cnt_cur->bc_ptrs[0] = 1;
953 do {
954 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno,
955 &ltlen, &i)))
956 goto error0;
957 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
958 if (ltlen >= args->minlen)
959 break;
Christoph Hellwig637aa502008-10-30 16:55:45 +1100960 if ((error = xfs_btree_increment(cnt_cur, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 goto error0;
962 } while (i);
963 ASSERT(ltlen >= args->minlen);
964 if (!i)
965 break;
966 }
967 i = cnt_cur->bc_ptrs[0];
968 for (j = 1, blen = 0, bdiff = 0;
969 !error && j && (blen < args->maxlen || bdiff > 0);
Christoph Hellwig637aa502008-10-30 16:55:45 +1100970 error = xfs_btree_increment(cnt_cur, 0, &j)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 /*
972 * For each entry, decide if it's better than
973 * the previous best entry.
974 */
975 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
976 goto error0;
977 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig86fa8af2011-03-04 12:59:54 +0000978 xfs_alloc_compute_aligned(args, ltbno, ltlen,
979 &ltbnoa, &ltlena);
David Chinnere6430032008-04-17 16:49:49 +1000980 if (ltlena < args->minlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 continue;
982 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
983 xfs_alloc_fix_len(args);
984 ASSERT(args->len >= args->minlen);
985 if (args->len < blen)
986 continue;
987 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
Jan Kara211d0222013-04-11 22:09:56 +0200988 args->alignment, args->userdata, ltbnoa,
989 ltlena, &ltnew);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 if (ltnew != NULLAGBLOCK &&
991 (args->len > blen || ltdiff < bdiff)) {
992 bdiff = ltdiff;
993 bnew = ltnew;
994 blen = args->len;
995 besti = cnt_cur->bc_ptrs[0];
996 }
997 }
998 /*
999 * It didn't work. We COULD be in a case where
1000 * there's a good record somewhere, so try again.
1001 */
1002 if (blen == 0)
1003 break;
1004 /*
1005 * Point at the best entry, and retrieve it again.
1006 */
1007 cnt_cur->bc_ptrs[0] = besti;
1008 if ((error = xfs_alloc_get_rec(cnt_cur, &ltbno, &ltlen, &i)))
1009 goto error0;
1010 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig73523a22010-07-20 17:54:45 +10001011 ASSERT(ltbno + ltlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 args->len = blen;
1013 if (!xfs_alloc_fix_minleft(args)) {
1014 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001015 trace_xfs_alloc_near_nominleft(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 return 0;
1017 }
1018 blen = args->len;
1019 /*
1020 * We are allocating starting at bnew for blen blocks.
1021 */
1022 args->agbno = bnew;
1023 ASSERT(bnew >= ltbno);
Christoph Hellwig73523a22010-07-20 17:54:45 +10001024 ASSERT(bnew + blen <= ltbno + ltlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 /*
1026 * Set up a cursor for the by-bno tree.
1027 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +11001028 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp,
1029 args->agbp, args->agno, XFS_BTNUM_BNO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 /*
1031 * Fix up the btree entries.
1032 */
1033 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno,
1034 ltlen, bnew, blen, XFSA_FIXUP_CNT_OK)))
1035 goto error0;
1036 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1037 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001038
1039 trace_xfs_alloc_near_first(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040 return 0;
1041 }
1042 /*
1043 * Second algorithm.
1044 * Search in the by-bno tree to the left and to the right
1045 * simultaneously, until in each case we find a space big enough,
1046 * or run into the edge of the tree. When we run into the edge,
1047 * we deallocate that cursor.
1048 * If both searches succeed, we compare the two spaces and pick
1049 * the better one.
1050 * With alignment, it's possible for both to fail; the upper
1051 * level algorithm that picks allocation groups for allocations
1052 * is not supposed to do this.
1053 */
1054 /*
1055 * Allocate and initialize the cursor for the leftward search.
1056 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +11001057 bno_cur_lt = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1058 args->agno, XFS_BTNUM_BNO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059 /*
1060 * Lookup <= bno to find the leftward search's starting point.
1061 */
1062 if ((error = xfs_alloc_lookup_le(bno_cur_lt, args->agbno, args->maxlen, &i)))
1063 goto error0;
1064 if (!i) {
1065 /*
1066 * Didn't find anything; use this cursor for the rightward
1067 * search.
1068 */
1069 bno_cur_gt = bno_cur_lt;
1070 bno_cur_lt = NULL;
1071 }
1072 /*
1073 * Found something. Duplicate the cursor for the rightward search.
1074 */
1075 else if ((error = xfs_btree_dup_cursor(bno_cur_lt, &bno_cur_gt)))
1076 goto error0;
1077 /*
1078 * Increment the cursor, so we will point at the entry just right
1079 * of the leftward entry if any, or to the leftmost entry.
1080 */
Christoph Hellwig637aa502008-10-30 16:55:45 +11001081 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 goto error0;
1083 if (!i) {
1084 /*
1085 * It failed, there are no rightward entries.
1086 */
1087 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_NOERROR);
1088 bno_cur_gt = NULL;
1089 }
1090 /*
1091 * Loop going left with the leftward cursor, right with the
1092 * rightward cursor, until either both directions give up or
1093 * we find an entry at least as big as minlen.
1094 */
1095 do {
1096 if (bno_cur_lt) {
1097 if ((error = xfs_alloc_get_rec(bno_cur_lt, &ltbno, &ltlen, &i)))
1098 goto error0;
1099 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig86fa8af2011-03-04 12:59:54 +00001100 xfs_alloc_compute_aligned(args, ltbno, ltlen,
1101 &ltbnoa, &ltlena);
David Chinner12375c82008-04-10 12:21:32 +10001102 if (ltlena >= args->minlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 break;
Christoph Hellwig8df4da42008-10-30 16:55:58 +11001104 if ((error = xfs_btree_decrement(bno_cur_lt, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 goto error0;
1106 if (!i) {
1107 xfs_btree_del_cursor(bno_cur_lt,
1108 XFS_BTREE_NOERROR);
1109 bno_cur_lt = NULL;
1110 }
1111 }
1112 if (bno_cur_gt) {
1113 if ((error = xfs_alloc_get_rec(bno_cur_gt, &gtbno, &gtlen, &i)))
1114 goto error0;
1115 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig86fa8af2011-03-04 12:59:54 +00001116 xfs_alloc_compute_aligned(args, gtbno, gtlen,
1117 &gtbnoa, &gtlena);
David Chinner12375c82008-04-10 12:21:32 +10001118 if (gtlena >= args->minlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 break;
Christoph Hellwig637aa502008-10-30 16:55:45 +11001120 if ((error = xfs_btree_increment(bno_cur_gt, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121 goto error0;
1122 if (!i) {
1123 xfs_btree_del_cursor(bno_cur_gt,
1124 XFS_BTREE_NOERROR);
1125 bno_cur_gt = NULL;
1126 }
1127 }
1128 } while (bno_cur_lt || bno_cur_gt);
Christoph Hellwig489a1502010-12-10 15:04:11 +00001129
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 /*
1131 * Got both cursors still active, need to find better entry.
1132 */
1133 if (bno_cur_lt && bno_cur_gt) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 if (ltlena >= args->minlen) {
1135 /*
Christoph Hellwig489a1502010-12-10 15:04:11 +00001136 * Left side is good, look for a right side entry.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 */
1138 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1139 xfs_alloc_fix_len(args);
Christoph Hellwig489a1502010-12-10 15:04:11 +00001140 ltdiff = xfs_alloc_compute_diff(args->agbno, args->len,
Jan Kara211d0222013-04-11 22:09:56 +02001141 args->alignment, args->userdata, ltbnoa,
1142 ltlena, &ltnew);
Christoph Hellwig489a1502010-12-10 15:04:11 +00001143
1144 error = xfs_alloc_find_best_extent(args,
1145 &bno_cur_lt, &bno_cur_gt,
Christoph Hellwige26f0502011-04-24 19:06:15 +00001146 ltdiff, &gtbno, &gtlen,
1147 &gtbnoa, &gtlena,
Christoph Hellwig489a1502010-12-10 15:04:11 +00001148 0 /* search right */);
1149 } else {
1150 ASSERT(gtlena >= args->minlen);
1151
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 /*
Christoph Hellwig489a1502010-12-10 15:04:11 +00001153 * Right side is good, look for a left side entry.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 */
1155 args->len = XFS_EXTLEN_MIN(gtlena, args->maxlen);
1156 xfs_alloc_fix_len(args);
Christoph Hellwig489a1502010-12-10 15:04:11 +00001157 gtdiff = xfs_alloc_compute_diff(args->agbno, args->len,
Jan Kara211d0222013-04-11 22:09:56 +02001158 args->alignment, args->userdata, gtbnoa,
1159 gtlena, &gtnew);
Christoph Hellwig489a1502010-12-10 15:04:11 +00001160
1161 error = xfs_alloc_find_best_extent(args,
1162 &bno_cur_gt, &bno_cur_lt,
Christoph Hellwige26f0502011-04-24 19:06:15 +00001163 gtdiff, &ltbno, &ltlen,
1164 &ltbnoa, &ltlena,
Christoph Hellwig489a1502010-12-10 15:04:11 +00001165 1 /* search left */);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001166 }
Christoph Hellwig489a1502010-12-10 15:04:11 +00001167
1168 if (error)
1169 goto error0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 }
Christoph Hellwig489a1502010-12-10 15:04:11 +00001171
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 /*
1173 * If we couldn't get anything, give up.
1174 */
1175 if (bno_cur_lt == NULL && bno_cur_gt == NULL) {
Dave Chinnere3a746f52012-07-12 07:40:42 +10001176 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1177
Christoph Hellwige26f0502011-04-24 19:06:15 +00001178 if (!forced++) {
1179 trace_xfs_alloc_near_busy(args);
1180 xfs_log_force(args->mp, XFS_LOG_SYNC);
1181 goto restart;
1182 }
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001183 trace_xfs_alloc_size_neither(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184 args->agbno = NULLAGBLOCK;
1185 return 0;
1186 }
Christoph Hellwig489a1502010-12-10 15:04:11 +00001187
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 /*
1189 * At this point we have selected a freespace entry, either to the
1190 * left or to the right. If it's on the right, copy all the
1191 * useful variables to the "left" set so we only have one
1192 * copy of this code.
1193 */
1194 if (bno_cur_gt) {
1195 bno_cur_lt = bno_cur_gt;
1196 bno_cur_gt = NULL;
1197 ltbno = gtbno;
1198 ltbnoa = gtbnoa;
1199 ltlen = gtlen;
1200 ltlena = gtlena;
1201 j = 1;
1202 } else
1203 j = 0;
Christoph Hellwig489a1502010-12-10 15:04:11 +00001204
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 /*
1206 * Fix up the length and compute the useful address.
1207 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 args->len = XFS_EXTLEN_MIN(ltlena, args->maxlen);
1209 xfs_alloc_fix_len(args);
1210 if (!xfs_alloc_fix_minleft(args)) {
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001211 trace_xfs_alloc_near_nominleft(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1213 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1214 return 0;
1215 }
1216 rlen = args->len;
Christoph Hellwige26f0502011-04-24 19:06:15 +00001217 (void)xfs_alloc_compute_diff(args->agbno, rlen, args->alignment,
Jan Kara211d0222013-04-11 22:09:56 +02001218 args->userdata, ltbnoa, ltlena, &ltnew);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219 ASSERT(ltnew >= ltbno);
Christoph Hellwige26f0502011-04-24 19:06:15 +00001220 ASSERT(ltnew + rlen <= ltbnoa + ltlena);
Christoph Hellwig16259e72005-11-02 15:11:25 +11001221 ASSERT(ltnew + rlen <= be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 args->agbno = ltnew;
Christoph Hellwige26f0502011-04-24 19:06:15 +00001223
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur_lt, ltbno, ltlen,
1225 ltnew, rlen, XFSA_FIXUP_BNO_OK)))
1226 goto error0;
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001227
1228 if (j)
1229 trace_xfs_alloc_near_greater(args);
1230 else
1231 trace_xfs_alloc_near_lesser(args);
1232
Linus Torvalds1da177e2005-04-16 15:20:36 -07001233 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1234 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_NOERROR);
1235 return 0;
1236
1237 error0:
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001238 trace_xfs_alloc_near_error(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239 if (cnt_cur != NULL)
1240 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1241 if (bno_cur_lt != NULL)
1242 xfs_btree_del_cursor(bno_cur_lt, XFS_BTREE_ERROR);
1243 if (bno_cur_gt != NULL)
1244 xfs_btree_del_cursor(bno_cur_gt, XFS_BTREE_ERROR);
1245 return error;
1246}
1247
1248/*
1249 * Allocate a variable extent anywhere in the allocation group agno.
1250 * Extent's length (returned in len) will be between minlen and maxlen,
1251 * and of the form k * prod + mod unless there's nothing that large.
1252 * Return the starting a.g. block, or NULLAGBLOCK if we can't do it.
1253 */
1254STATIC int /* error */
1255xfs_alloc_ag_vextent_size(
1256 xfs_alloc_arg_t *args) /* allocation argument structure */
1257{
1258 xfs_btree_cur_t *bno_cur; /* cursor for bno btree */
1259 xfs_btree_cur_t *cnt_cur; /* cursor for cnt btree */
1260 int error; /* error result */
1261 xfs_agblock_t fbno; /* start of found freespace */
1262 xfs_extlen_t flen; /* length of found freespace */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 int i; /* temp status variable */
1264 xfs_agblock_t rbno; /* returned block number */
1265 xfs_extlen_t rlen; /* length of returned extent */
Christoph Hellwige26f0502011-04-24 19:06:15 +00001266 int forced = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267
Christoph Hellwige26f0502011-04-24 19:06:15 +00001268restart:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 /*
1270 * Allocate and initialize a cursor for the by-size btree.
1271 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +11001272 cnt_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1273 args->agno, XFS_BTNUM_CNT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 bno_cur = NULL;
Christoph Hellwige26f0502011-04-24 19:06:15 +00001275
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 /*
1277 * Look for an entry >= maxlen+alignment-1 blocks.
1278 */
1279 if ((error = xfs_alloc_lookup_ge(cnt_cur, 0,
1280 args->maxlen + args->alignment - 1, &i)))
1281 goto error0;
Christoph Hellwige26f0502011-04-24 19:06:15 +00001282
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 /*
Christoph Hellwige26f0502011-04-24 19:06:15 +00001284 * If none or we have busy extents that we cannot allocate from, then
1285 * we have to settle for a smaller extent. In the case that there are
1286 * no large extents, this will return the last entry in the tree unless
1287 * the tree is empty. In the case that there are only busy large
1288 * extents, this will return the largest small extent unless there
1289 * are no smaller extents available.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 */
Christoph Hellwige26f0502011-04-24 19:06:15 +00001291 if (!i || forced > 1) {
1292 error = xfs_alloc_ag_vextent_small(args, cnt_cur,
1293 &fbno, &flen, &i);
1294 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295 goto error0;
1296 if (i == 0 || flen == 0) {
1297 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001298 trace_xfs_alloc_size_noentry(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 return 0;
1300 }
1301 ASSERT(i == 1);
Christoph Hellwige26f0502011-04-24 19:06:15 +00001302 xfs_alloc_compute_aligned(args, fbno, flen, &rbno, &rlen);
1303 } else {
1304 /*
1305 * Search for a non-busy extent that is large enough.
1306 * If we are at low space, don't check, or if we fall of
1307 * the end of the btree, turn off the busy check and
1308 * restart.
1309 */
1310 for (;;) {
1311 error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen, &i);
1312 if (error)
1313 goto error0;
1314 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1315
1316 xfs_alloc_compute_aligned(args, fbno, flen,
1317 &rbno, &rlen);
1318
1319 if (rlen >= args->maxlen)
1320 break;
1321
1322 error = xfs_btree_increment(cnt_cur, 0, &i);
1323 if (error)
1324 goto error0;
1325 if (i == 0) {
1326 /*
1327 * Our only valid extents must have been busy.
1328 * Make it unbusy by forcing the log out and
1329 * retrying. If we've been here before, forcing
1330 * the log isn't making the extents available,
1331 * which means they have probably been freed in
1332 * this transaction. In that case, we have to
1333 * give up on them and we'll attempt a minlen
1334 * allocation the next time around.
1335 */
1336 xfs_btree_del_cursor(cnt_cur,
1337 XFS_BTREE_NOERROR);
1338 trace_xfs_alloc_size_busy(args);
1339 if (!forced++)
1340 xfs_log_force(args->mp, XFS_LOG_SYNC);
1341 goto restart;
1342 }
1343 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 }
Christoph Hellwige26f0502011-04-24 19:06:15 +00001345
Linus Torvalds1da177e2005-04-16 15:20:36 -07001346 /*
1347 * In the first case above, we got the last entry in the
1348 * by-size btree. Now we check to see if the space hits maxlen
1349 * once aligned; if not, we search left for something better.
1350 * This can't happen in the second case above.
1351 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1353 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1354 (rlen <= flen && rbno + rlen <= fbno + flen), error0);
1355 if (rlen < args->maxlen) {
1356 xfs_agblock_t bestfbno;
1357 xfs_extlen_t bestflen;
1358 xfs_agblock_t bestrbno;
1359 xfs_extlen_t bestrlen;
1360
1361 bestrlen = rlen;
1362 bestrbno = rbno;
1363 bestflen = flen;
1364 bestfbno = fbno;
1365 for (;;) {
Christoph Hellwig8df4da42008-10-30 16:55:58 +11001366 if ((error = xfs_btree_decrement(cnt_cur, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367 goto error0;
1368 if (i == 0)
1369 break;
1370 if ((error = xfs_alloc_get_rec(cnt_cur, &fbno, &flen,
1371 &i)))
1372 goto error0;
1373 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1374 if (flen < bestrlen)
1375 break;
Christoph Hellwig86fa8af2011-03-04 12:59:54 +00001376 xfs_alloc_compute_aligned(args, fbno, flen,
1377 &rbno, &rlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378 rlen = XFS_EXTLEN_MIN(args->maxlen, rlen);
1379 XFS_WANT_CORRUPTED_GOTO(rlen == 0 ||
1380 (rlen <= flen && rbno + rlen <= fbno + flen),
1381 error0);
1382 if (rlen > bestrlen) {
1383 bestrlen = rlen;
1384 bestrbno = rbno;
1385 bestflen = flen;
1386 bestfbno = fbno;
1387 if (rlen == args->maxlen)
1388 break;
1389 }
1390 }
1391 if ((error = xfs_alloc_lookup_eq(cnt_cur, bestfbno, bestflen,
1392 &i)))
1393 goto error0;
1394 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1395 rlen = bestrlen;
1396 rbno = bestrbno;
1397 flen = bestflen;
1398 fbno = bestfbno;
1399 }
1400 args->wasfromfl = 0;
1401 /*
1402 * Fix up the length.
1403 */
1404 args->len = rlen;
Christoph Hellwige26f0502011-04-24 19:06:15 +00001405 if (rlen < args->minlen) {
1406 if (!forced++) {
1407 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1408 trace_xfs_alloc_size_busy(args);
1409 xfs_log_force(args->mp, XFS_LOG_SYNC);
1410 goto restart;
1411 }
1412 goto out_nominleft;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 }
Christoph Hellwige26f0502011-04-24 19:06:15 +00001414 xfs_alloc_fix_len(args);
1415
1416 if (!xfs_alloc_fix_minleft(args))
1417 goto out_nominleft;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418 rlen = args->len;
1419 XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0);
1420 /*
1421 * Allocate and initialize a cursor for the by-block tree.
1422 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +11001423 bno_cur = xfs_allocbt_init_cursor(args->mp, args->tp, args->agbp,
1424 args->agno, XFS_BTNUM_BNO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425 if ((error = xfs_alloc_fixup_trees(cnt_cur, bno_cur, fbno, flen,
1426 rbno, rlen, XFSA_FIXUP_CNT_OK)))
1427 goto error0;
1428 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1429 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1430 cnt_cur = bno_cur = NULL;
1431 args->len = rlen;
1432 args->agbno = rbno;
1433 XFS_WANT_CORRUPTED_GOTO(
1434 args->agbno + args->len <=
Christoph Hellwig16259e72005-11-02 15:11:25 +11001435 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 error0);
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001437 trace_xfs_alloc_size_done(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 return 0;
1439
1440error0:
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001441 trace_xfs_alloc_size_error(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 if (cnt_cur)
1443 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1444 if (bno_cur)
1445 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1446 return error;
Christoph Hellwige26f0502011-04-24 19:06:15 +00001447
1448out_nominleft:
1449 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1450 trace_xfs_alloc_size_nominleft(args);
1451 args->agbno = NULLAGBLOCK;
1452 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453}
1454
1455/*
1456 * Deal with the case where only small freespaces remain.
1457 * Either return the contents of the last freespace record,
1458 * or allocate space from the freelist if there is nothing in the tree.
1459 */
1460STATIC int /* error */
1461xfs_alloc_ag_vextent_small(
1462 xfs_alloc_arg_t *args, /* allocation argument structure */
1463 xfs_btree_cur_t *ccur, /* by-size cursor */
1464 xfs_agblock_t *fbnop, /* result block number */
1465 xfs_extlen_t *flenp, /* result length */
1466 int *stat) /* status: 0-freelist, 1-normal/none */
1467{
1468 int error;
1469 xfs_agblock_t fbno;
1470 xfs_extlen_t flen;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471 int i;
1472
Christoph Hellwig8df4da42008-10-30 16:55:58 +11001473 if ((error = xfs_btree_decrement(ccur, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001474 goto error0;
1475 if (i) {
1476 if ((error = xfs_alloc_get_rec(ccur, &fbno, &flen, &i)))
1477 goto error0;
1478 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1479 }
1480 /*
1481 * Nothing in the btree, try the freelist. Make sure
1482 * to respect minleft even when pulling from the
1483 * freelist.
1484 */
1485 else if (args->minlen == 1 && args->alignment == 1 && !args->isfl &&
Christoph Hellwig16259e72005-11-02 15:11:25 +11001486 (be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_flcount)
1487 > args->minleft)) {
David Chinner92821e22007-05-24 15:26:31 +10001488 error = xfs_alloc_get_freelist(args->tp, args->agbp, &fbno, 0);
1489 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001490 goto error0;
1491 if (fbno != NULLAGBLOCK) {
Dave Chinner4ecbfe62012-04-29 10:41:10 +00001492 xfs_extent_busy_reuse(args->mp, args->agno, fbno, 1,
Christoph Hellwig97d3ac72011-04-24 19:06:16 +00001493 args->userdata);
1494
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495 if (args->userdata) {
1496 xfs_buf_t *bp;
1497
1498 bp = xfs_btree_get_bufs(args->mp, args->tp,
1499 args->agno, fbno, 0);
1500 xfs_trans_binval(args->tp, bp);
1501 }
1502 args->len = 1;
1503 args->agbno = fbno;
1504 XFS_WANT_CORRUPTED_GOTO(
1505 args->agbno + args->len <=
Christoph Hellwig16259e72005-11-02 15:11:25 +11001506 be32_to_cpu(XFS_BUF_TO_AGF(args->agbp)->agf_length),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507 error0);
1508 args->wasfromfl = 1;
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001509 trace_xfs_alloc_small_freelist(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001510 *stat = 0;
1511 return 0;
1512 }
1513 /*
1514 * Nothing in the freelist.
1515 */
1516 else
1517 flen = 0;
1518 }
1519 /*
1520 * Can't allocate from the freelist for some reason.
1521 */
Nathan Scottd432c802006-09-28 11:03:44 +10001522 else {
1523 fbno = NULLAGBLOCK;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524 flen = 0;
Nathan Scottd432c802006-09-28 11:03:44 +10001525 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 /*
1527 * Can't do the allocation, give up.
1528 */
1529 if (flen < args->minlen) {
1530 args->agbno = NULLAGBLOCK;
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001531 trace_xfs_alloc_small_notenough(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001532 flen = 0;
1533 }
1534 *fbnop = fbno;
1535 *flenp = flen;
1536 *stat = 1;
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001537 trace_xfs_alloc_small_done(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001538 return 0;
1539
1540error0:
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001541 trace_xfs_alloc_small_error(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 return error;
1543}
1544
1545/*
1546 * Free the extent starting at agno/bno for length.
1547 */
1548STATIC int /* error */
1549xfs_free_ag_extent(
1550 xfs_trans_t *tp, /* transaction pointer */
1551 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
1552 xfs_agnumber_t agno, /* allocation group number */
1553 xfs_agblock_t bno, /* starting block number */
1554 xfs_extlen_t len, /* length of extent */
1555 int isfl) /* set if is freelist blocks - no sb acctg */
1556{
1557 xfs_btree_cur_t *bno_cur; /* cursor for by-block btree */
1558 xfs_btree_cur_t *cnt_cur; /* cursor for by-size btree */
1559 int error; /* error return value */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001560 xfs_agblock_t gtbno; /* start of right neighbor block */
1561 xfs_extlen_t gtlen; /* length of right neighbor block */
1562 int haveleft; /* have a left neighbor block */
1563 int haveright; /* have a right neighbor block */
1564 int i; /* temp, result code */
1565 xfs_agblock_t ltbno; /* start of left neighbor block */
1566 xfs_extlen_t ltlen; /* length of left neighbor block */
1567 xfs_mount_t *mp; /* mount point struct for filesystem */
1568 xfs_agblock_t nbno; /* new starting block of freespace */
1569 xfs_extlen_t nlen; /* new length of freespace */
Christoph Hellwigecb69282011-03-04 12:59:55 +00001570 xfs_perag_t *pag; /* per allocation group data */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571
1572 mp = tp->t_mountp;
1573 /*
1574 * Allocate and initialize a cursor for the by-block btree.
1575 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +11001576 bno_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_BNO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001577 cnt_cur = NULL;
1578 /*
1579 * Look for a neighboring block on the left (lower block numbers)
1580 * that is contiguous with this space.
1581 */
1582 if ((error = xfs_alloc_lookup_le(bno_cur, bno, len, &haveleft)))
1583 goto error0;
1584 if (haveleft) {
1585 /*
1586 * There is a block to our left.
1587 */
1588 if ((error = xfs_alloc_get_rec(bno_cur, &ltbno, &ltlen, &i)))
1589 goto error0;
1590 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1591 /*
1592 * It's not contiguous, though.
1593 */
1594 if (ltbno + ltlen < bno)
1595 haveleft = 0;
1596 else {
1597 /*
1598 * If this failure happens the request to free this
1599 * space was invalid, it's (partly) already free.
1600 * Very bad.
1601 */
1602 XFS_WANT_CORRUPTED_GOTO(ltbno + ltlen <= bno, error0);
1603 }
1604 }
1605 /*
1606 * Look for a neighboring block on the right (higher block numbers)
1607 * that is contiguous with this space.
1608 */
Christoph Hellwig637aa502008-10-30 16:55:45 +11001609 if ((error = xfs_btree_increment(bno_cur, 0, &haveright)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 goto error0;
1611 if (haveright) {
1612 /*
1613 * There is a block to our right.
1614 */
1615 if ((error = xfs_alloc_get_rec(bno_cur, &gtbno, &gtlen, &i)))
1616 goto error0;
1617 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1618 /*
1619 * It's not contiguous, though.
1620 */
1621 if (bno + len < gtbno)
1622 haveright = 0;
1623 else {
1624 /*
1625 * If this failure happens the request to free this
1626 * space was invalid, it's (partly) already free.
1627 * Very bad.
1628 */
1629 XFS_WANT_CORRUPTED_GOTO(gtbno >= bno + len, error0);
1630 }
1631 }
1632 /*
1633 * Now allocate and initialize a cursor for the by-size tree.
1634 */
Christoph Hellwig561f7d12008-10-30 16:53:59 +11001635 cnt_cur = xfs_allocbt_init_cursor(mp, tp, agbp, agno, XFS_BTNUM_CNT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636 /*
1637 * Have both left and right contiguous neighbors.
1638 * Merge all three into a single free block.
1639 */
1640 if (haveleft && haveright) {
1641 /*
1642 * Delete the old by-size entry on the left.
1643 */
1644 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1645 goto error0;
1646 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11001647 if ((error = xfs_btree_delete(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001648 goto error0;
1649 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1650 /*
1651 * Delete the old by-size entry on the right.
1652 */
1653 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1654 goto error0;
1655 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11001656 if ((error = xfs_btree_delete(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657 goto error0;
1658 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1659 /*
1660 * Delete the old by-block entry for the right block.
1661 */
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11001662 if ((error = xfs_btree_delete(bno_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663 goto error0;
1664 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1665 /*
1666 * Move the by-block cursor back to the left neighbor.
1667 */
Christoph Hellwig8df4da42008-10-30 16:55:58 +11001668 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001669 goto error0;
1670 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1671#ifdef DEBUG
1672 /*
1673 * Check that this is the right record: delete didn't
1674 * mangle the cursor.
1675 */
1676 {
1677 xfs_agblock_t xxbno;
1678 xfs_extlen_t xxlen;
1679
1680 if ((error = xfs_alloc_get_rec(bno_cur, &xxbno, &xxlen,
1681 &i)))
1682 goto error0;
1683 XFS_WANT_CORRUPTED_GOTO(
1684 i == 1 && xxbno == ltbno && xxlen == ltlen,
1685 error0);
1686 }
1687#endif
1688 /*
1689 * Update remaining by-block entry to the new, joined block.
1690 */
1691 nbno = ltbno;
1692 nlen = len + ltlen + gtlen;
1693 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1694 goto error0;
1695 }
1696 /*
1697 * Have only a left contiguous neighbor.
1698 * Merge it together with the new freespace.
1699 */
1700 else if (haveleft) {
1701 /*
1702 * Delete the old by-size entry on the left.
1703 */
1704 if ((error = xfs_alloc_lookup_eq(cnt_cur, ltbno, ltlen, &i)))
1705 goto error0;
1706 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11001707 if ((error = xfs_btree_delete(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708 goto error0;
1709 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1710 /*
1711 * Back up the by-block cursor to the left neighbor, and
1712 * update its length.
1713 */
Christoph Hellwig8df4da42008-10-30 16:55:58 +11001714 if ((error = xfs_btree_decrement(bno_cur, 0, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715 goto error0;
1716 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1717 nbno = ltbno;
1718 nlen = len + ltlen;
1719 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1720 goto error0;
1721 }
1722 /*
1723 * Have only a right contiguous neighbor.
1724 * Merge it together with the new freespace.
1725 */
1726 else if (haveright) {
1727 /*
1728 * Delete the old by-size entry on the right.
1729 */
1730 if ((error = xfs_alloc_lookup_eq(cnt_cur, gtbno, gtlen, &i)))
1731 goto error0;
1732 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
Christoph Hellwig91cca5df2008-10-30 16:58:01 +11001733 if ((error = xfs_btree_delete(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001734 goto error0;
1735 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1736 /*
1737 * Update the starting block and length of the right
1738 * neighbor in the by-block tree.
1739 */
1740 nbno = bno;
1741 nlen = len + gtlen;
1742 if ((error = xfs_alloc_update(bno_cur, nbno, nlen)))
1743 goto error0;
1744 }
1745 /*
1746 * No contiguous neighbors.
1747 * Insert the new freespace into the by-block tree.
1748 */
1749 else {
1750 nbno = bno;
1751 nlen = len;
Christoph Hellwig4b22a572008-10-30 16:57:40 +11001752 if ((error = xfs_btree_insert(bno_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 goto error0;
1754 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1755 }
1756 xfs_btree_del_cursor(bno_cur, XFS_BTREE_NOERROR);
1757 bno_cur = NULL;
1758 /*
1759 * In all cases we need to insert the new freespace in the by-size tree.
1760 */
1761 if ((error = xfs_alloc_lookup_eq(cnt_cur, nbno, nlen, &i)))
1762 goto error0;
1763 XFS_WANT_CORRUPTED_GOTO(i == 0, error0);
Christoph Hellwig4b22a572008-10-30 16:57:40 +11001764 if ((error = xfs_btree_insert(cnt_cur, &i)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765 goto error0;
1766 XFS_WANT_CORRUPTED_GOTO(i == 1, error0);
1767 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_NOERROR);
1768 cnt_cur = NULL;
Christoph Hellwigecb69282011-03-04 12:59:55 +00001769
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770 /*
1771 * Update the freespace totals in the ag and superblock.
1772 */
Christoph Hellwigecb69282011-03-04 12:59:55 +00001773 pag = xfs_perag_get(mp, agno);
1774 error = xfs_alloc_update_counters(tp, pag, agbp, len);
1775 xfs_perag_put(pag);
1776 if (error)
1777 goto error0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778
Christoph Hellwigecb69282011-03-04 12:59:55 +00001779 if (!isfl)
1780 xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (long)len);
1781 XFS_STATS_INC(xs_freex);
1782 XFS_STATS_ADD(xs_freeb, len);
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001783
1784 trace_xfs_free_extent(mp, agno, bno, len, isfl, haveleft, haveright);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 return 0;
1787
1788 error0:
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00001789 trace_xfs_free_extent(mp, agno, bno, len, isfl, -1, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790 if (bno_cur)
1791 xfs_btree_del_cursor(bno_cur, XFS_BTREE_ERROR);
1792 if (cnt_cur)
1793 xfs_btree_del_cursor(cnt_cur, XFS_BTREE_ERROR);
1794 return error;
1795}
1796
1797/*
1798 * Visible (exported) allocation/free functions.
1799 * Some of these are used just by xfs_alloc_btree.c and this file.
1800 */
1801
1802/*
1803 * Compute and fill in value of m_ag_maxlevels.
1804 */
1805void
1806xfs_alloc_compute_maxlevels(
1807 xfs_mount_t *mp) /* file system mount structure */
1808{
1809 int level;
1810 uint maxblocks;
1811 uint maxleafents;
1812 int minleafrecs;
1813 int minnoderecs;
1814
1815 maxleafents = (mp->m_sb.sb_agblocks + 1) / 2;
1816 minleafrecs = mp->m_alloc_mnr[0];
1817 minnoderecs = mp->m_alloc_mnr[1];
1818 maxblocks = (maxleafents + minleafrecs - 1) / minleafrecs;
1819 for (level = 1; maxblocks > 1; level++)
1820 maxblocks = (maxblocks + minnoderecs - 1) / minnoderecs;
1821 mp->m_ag_maxlevels = level;
1822}
1823
1824/*
Dave Chinner6cc87642009-03-16 08:29:46 +01001825 * Find the length of the longest extent in an AG.
1826 */
1827xfs_extlen_t
1828xfs_alloc_longest_free_extent(
1829 struct xfs_mount *mp,
1830 struct xfs_perag *pag)
1831{
1832 xfs_extlen_t need, delta = 0;
1833
1834 need = XFS_MIN_FREELIST_PAG(pag, mp);
1835 if (need > pag->pagf_flcount)
1836 delta = need - pag->pagf_flcount;
1837
1838 if (pag->pagf_longest > delta)
1839 return pag->pagf_longest - delta;
1840 return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
1841}
1842
1843/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001844 * Decide whether to use this allocation group for this allocation.
1845 * If so, fix up the btree freelist's size.
1846 */
1847STATIC int /* error */
1848xfs_alloc_fix_freelist(
1849 xfs_alloc_arg_t *args, /* allocation argument structure */
1850 int flags) /* XFS_ALLOC_FLAG_... */
1851{
1852 xfs_buf_t *agbp; /* agf buffer pointer */
1853 xfs_agf_t *agf; /* a.g. freespace structure pointer */
1854 xfs_buf_t *agflbp;/* agfl buffer pointer */
1855 xfs_agblock_t bno; /* freelist block */
1856 xfs_extlen_t delta; /* new blocks needed in freelist */
1857 int error; /* error result code */
1858 xfs_extlen_t longest;/* longest extent in allocation group */
1859 xfs_mount_t *mp; /* file system mount point structure */
1860 xfs_extlen_t need; /* total blocks needed in freelist */
1861 xfs_perag_t *pag; /* per-ag information structure */
1862 xfs_alloc_arg_t targs; /* local allocation arguments */
1863 xfs_trans_t *tp; /* transaction pointer */
1864
1865 mp = args->mp;
1866
1867 pag = args->pag;
1868 tp = args->tp;
1869 if (!pag->pagf_init) {
1870 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1871 &agbp)))
1872 return error;
1873 if (!pag->pagf_init) {
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001874 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1875 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876 args->agbp = NULL;
1877 return 0;
1878 }
1879 } else
1880 agbp = NULL;
1881
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001882 /*
1883 * If this is a metadata preferred pag and we are user data
Linus Torvalds1da177e2005-04-16 15:20:36 -07001884 * then try somewhere else if we are not being asked to
1885 * try harder at this point
1886 */
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001887 if (pag->pagf_metadata && args->userdata &&
1888 (flags & XFS_ALLOC_FLAG_TRYLOCK)) {
1889 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001890 args->agbp = NULL;
1891 return 0;
1892 }
1893
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001894 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001895 /*
1896 * If it looks like there isn't a long enough extent, or enough
1897 * total blocks, reject it.
1898 */
Dave Chinner6cc87642009-03-16 08:29:46 +01001899 need = XFS_MIN_FREELIST_PAG(pag, mp);
1900 longest = xfs_alloc_longest_free_extent(mp, pag);
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001901 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1902 longest ||
1903 ((int)(pag->pagf_freeblks + pag->pagf_flcount -
1904 need - args->total) < (int)args->minleft)) {
1905 if (agbp)
1906 xfs_trans_brelse(tp, agbp);
1907 args->agbp = NULL;
1908 return 0;
1909 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001910 }
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001911
Linus Torvalds1da177e2005-04-16 15:20:36 -07001912 /*
1913 * Get the a.g. freespace buffer.
1914 * Can fail if we're not blocking on locks, and it's held.
1915 */
1916 if (agbp == NULL) {
1917 if ((error = xfs_alloc_read_agf(mp, tp, args->agno, flags,
1918 &agbp)))
1919 return error;
1920 if (agbp == NULL) {
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001921 ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
1922 ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001923 args->agbp = NULL;
1924 return 0;
1925 }
1926 }
1927 /*
1928 * Figure out how many blocks we should have in the freelist.
1929 */
1930 agf = XFS_BUF_TO_AGF(agbp);
1931 need = XFS_MIN_FREELIST(agf, mp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001932 /*
1933 * If there isn't enough total or single-extent, reject it.
1934 */
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001935 if (!(flags & XFS_ALLOC_FLAG_FREEING)) {
1936 delta = need > be32_to_cpu(agf->agf_flcount) ?
1937 (need - be32_to_cpu(agf->agf_flcount)) : 0;
1938 longest = be32_to_cpu(agf->agf_longest);
1939 longest = (longest > delta) ? (longest - delta) :
1940 (be32_to_cpu(agf->agf_flcount) > 0 || longest > 0);
1941 if ((args->minlen + args->alignment + args->minalignslop - 1) >
1942 longest ||
1943 ((int)(be32_to_cpu(agf->agf_freeblks) +
1944 be32_to_cpu(agf->agf_flcount) - need - args->total) <
1945 (int)args->minleft)) {
1946 xfs_trans_brelse(tp, agbp);
1947 args->agbp = NULL;
1948 return 0;
1949 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001950 }
1951 /*
1952 * Make the freelist shorter if it's too long.
1953 */
Christoph Hellwig16259e72005-11-02 15:11:25 +11001954 while (be32_to_cpu(agf->agf_flcount) > need) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001955 xfs_buf_t *bp;
1956
David Chinner92821e22007-05-24 15:26:31 +10001957 error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
1958 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959 return error;
1960 if ((error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1, 1)))
1961 return error;
1962 bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
1963 xfs_trans_binval(tp, bp);
1964 }
1965 /*
1966 * Initialize the args structure.
1967 */
Mark Tinguelya0041682012-09-20 13:16:45 -05001968 memset(&targs, 0, sizeof(targs));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001969 targs.tp = tp;
1970 targs.mp = mp;
1971 targs.agbp = agbp;
1972 targs.agno = args->agno;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001973 targs.alignment = targs.minlen = targs.prod = targs.isfl = 1;
1974 targs.type = XFS_ALLOCTYPE_THIS_AG;
1975 targs.pag = pag;
1976 if ((error = xfs_alloc_read_agfl(mp, tp, targs.agno, &agflbp)))
1977 return error;
1978 /*
1979 * Make the freelist longer if it's too short.
1980 */
Christoph Hellwig16259e72005-11-02 15:11:25 +11001981 while (be32_to_cpu(agf->agf_flcount) < need) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982 targs.agbno = 0;
Christoph Hellwig16259e72005-11-02 15:11:25 +11001983 targs.maxlen = need - be32_to_cpu(agf->agf_flcount);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001984 /*
1985 * Allocate as many blocks as possible at once.
1986 */
Nathan Scotte63a3692006-05-08 19:51:58 +10001987 if ((error = xfs_alloc_ag_vextent(&targs))) {
1988 xfs_trans_brelse(tp, agflbp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001989 return error;
Nathan Scotte63a3692006-05-08 19:51:58 +10001990 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001991 /*
1992 * Stop if we run out. Won't happen if callers are obeying
1993 * the restrictions correctly. Can happen for free calls
1994 * on a completely full ag.
1995 */
Yingping Lud210a282006-06-09 14:55:18 +10001996 if (targs.agbno == NULLAGBLOCK) {
Nathan Scott0e1edbd2006-08-10 14:40:41 +10001997 if (flags & XFS_ALLOC_FLAG_FREEING)
1998 break;
1999 xfs_trans_brelse(tp, agflbp);
2000 args->agbp = NULL;
2001 return 0;
Yingping Lud210a282006-06-09 14:55:18 +10002002 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002003 /*
2004 * Put each allocated block on the list.
2005 */
2006 for (bno = targs.agbno; bno < targs.agbno + targs.len; bno++) {
David Chinner92821e22007-05-24 15:26:31 +10002007 error = xfs_alloc_put_freelist(tp, agbp,
2008 agflbp, bno, 0);
2009 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002010 return error;
2011 }
2012 }
Nathan Scotte63a3692006-05-08 19:51:58 +10002013 xfs_trans_brelse(tp, agflbp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002014 args->agbp = agbp;
2015 return 0;
2016}
2017
2018/*
2019 * Get a block from the freelist.
2020 * Returns with the buffer for the block gotten.
2021 */
2022int /* error */
2023xfs_alloc_get_freelist(
2024 xfs_trans_t *tp, /* transaction pointer */
2025 xfs_buf_t *agbp, /* buffer containing the agf structure */
David Chinner92821e22007-05-24 15:26:31 +10002026 xfs_agblock_t *bnop, /* block address retrieved from freelist */
2027 int btreeblk) /* destination is a AGF btree */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002028{
2029 xfs_agf_t *agf; /* a.g. freespace structure */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002030 xfs_buf_t *agflbp;/* buffer for a.g. freelist structure */
2031 xfs_agblock_t bno; /* block number returned */
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002032 __be32 *agfl_bno;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033 int error;
David Chinner92821e22007-05-24 15:26:31 +10002034 int logflags;
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002035 xfs_mount_t *mp = tp->t_mountp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002036 xfs_perag_t *pag; /* per allocation group data */
2037
Linus Torvalds1da177e2005-04-16 15:20:36 -07002038 /*
2039 * Freelist is empty, give up.
2040 */
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002041 agf = XFS_BUF_TO_AGF(agbp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042 if (!agf->agf_flcount) {
2043 *bnop = NULLAGBLOCK;
2044 return 0;
2045 }
2046 /*
2047 * Read the array of free blocks.
2048 */
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002049 error = xfs_alloc_read_agfl(mp, tp, be32_to_cpu(agf->agf_seqno),
2050 &agflbp);
2051 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002052 return error;
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002053
2054
Linus Torvalds1da177e2005-04-16 15:20:36 -07002055 /*
2056 * Get the block number and update the data structures.
2057 */
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002058 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2059 bno = be32_to_cpu(agfl_bno[be32_to_cpu(agf->agf_flfirst)]);
Marcin Slusarz413d57c2008-02-13 15:03:29 -08002060 be32_add_cpu(&agf->agf_flfirst, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002061 xfs_trans_brelse(tp, agflbp);
Christoph Hellwig16259e72005-11-02 15:11:25 +11002062 if (be32_to_cpu(agf->agf_flfirst) == XFS_AGFL_SIZE(mp))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002063 agf->agf_flfirst = 0;
Dave Chinnera862e0f2010-01-11 11:47:41 +00002064
2065 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
Marcin Slusarz413d57c2008-02-13 15:03:29 -08002066 be32_add_cpu(&agf->agf_flcount, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002067 xfs_trans_agflist_delta(tp, -1);
2068 pag->pagf_flcount--;
Dave Chinnera862e0f2010-01-11 11:47:41 +00002069 xfs_perag_put(pag);
David Chinner92821e22007-05-24 15:26:31 +10002070
2071 logflags = XFS_AGF_FLFIRST | XFS_AGF_FLCOUNT;
2072 if (btreeblk) {
Marcin Slusarz413d57c2008-02-13 15:03:29 -08002073 be32_add_cpu(&agf->agf_btreeblks, 1);
David Chinner92821e22007-05-24 15:26:31 +10002074 pag->pagf_btreeblks++;
2075 logflags |= XFS_AGF_BTREEBLKS;
2076 }
2077
David Chinner92821e22007-05-24 15:26:31 +10002078 xfs_alloc_log_agf(tp, agbp, logflags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002079 *bnop = bno;
2080
Linus Torvalds1da177e2005-04-16 15:20:36 -07002081 return 0;
2082}
2083
2084/*
2085 * Log the given fields from the agf structure.
2086 */
2087void
2088xfs_alloc_log_agf(
2089 xfs_trans_t *tp, /* transaction pointer */
2090 xfs_buf_t *bp, /* buffer for a.g. freelist header */
2091 int fields) /* mask of fields to be logged (XFS_AGF_...) */
2092{
2093 int first; /* first byte offset */
2094 int last; /* last byte offset */
2095 static const short offsets[] = {
2096 offsetof(xfs_agf_t, agf_magicnum),
2097 offsetof(xfs_agf_t, agf_versionnum),
2098 offsetof(xfs_agf_t, agf_seqno),
2099 offsetof(xfs_agf_t, agf_length),
2100 offsetof(xfs_agf_t, agf_roots[0]),
2101 offsetof(xfs_agf_t, agf_levels[0]),
2102 offsetof(xfs_agf_t, agf_flfirst),
2103 offsetof(xfs_agf_t, agf_fllast),
2104 offsetof(xfs_agf_t, agf_flcount),
2105 offsetof(xfs_agf_t, agf_freeblks),
2106 offsetof(xfs_agf_t, agf_longest),
David Chinner92821e22007-05-24 15:26:31 +10002107 offsetof(xfs_agf_t, agf_btreeblks),
Dave Chinner4e0e6042013-04-03 16:11:13 +11002108 offsetof(xfs_agf_t, agf_uuid),
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109 sizeof(xfs_agf_t)
2110 };
2111
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00002112 trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
2113
Dave Chinner61fe1352013-04-03 16:11:30 +11002114 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGF_BUF);
Dave Chinner4e0e6042013-04-03 16:11:13 +11002115
Linus Torvalds1da177e2005-04-16 15:20:36 -07002116 xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
2117 xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
2118}
2119
2120/*
2121 * Interface for inode allocation to force the pag data to be initialized.
2122 */
2123int /* error */
2124xfs_alloc_pagf_init(
2125 xfs_mount_t *mp, /* file system mount structure */
2126 xfs_trans_t *tp, /* transaction pointer */
2127 xfs_agnumber_t agno, /* allocation group number */
2128 int flags) /* XFS_ALLOC_FLAGS_... */
2129{
2130 xfs_buf_t *bp;
2131 int error;
2132
2133 if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
2134 return error;
2135 if (bp)
2136 xfs_trans_brelse(tp, bp);
2137 return 0;
2138}
2139
2140/*
2141 * Put the block on the freelist for the allocation group.
2142 */
2143int /* error */
2144xfs_alloc_put_freelist(
2145 xfs_trans_t *tp, /* transaction pointer */
2146 xfs_buf_t *agbp, /* buffer for a.g. freelist header */
2147 xfs_buf_t *agflbp,/* buffer for a.g. free block array */
David Chinner92821e22007-05-24 15:26:31 +10002148 xfs_agblock_t bno, /* block being freed */
2149 int btreeblk) /* block came from a AGF btree */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002150{
2151 xfs_agf_t *agf; /* a.g. freespace structure */
Christoph Hellwige2101002006-09-28 10:56:51 +10002152 __be32 *blockp;/* pointer to array entry */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002153 int error;
David Chinner92821e22007-05-24 15:26:31 +10002154 int logflags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155 xfs_mount_t *mp; /* mount structure */
2156 xfs_perag_t *pag; /* per allocation group data */
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002157 __be32 *agfl_bno;
2158 int startoff;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002159
2160 agf = XFS_BUF_TO_AGF(agbp);
2161 mp = tp->t_mountp;
2162
2163 if (!agflbp && (error = xfs_alloc_read_agfl(mp, tp,
Christoph Hellwig16259e72005-11-02 15:11:25 +11002164 be32_to_cpu(agf->agf_seqno), &agflbp)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002165 return error;
Marcin Slusarz413d57c2008-02-13 15:03:29 -08002166 be32_add_cpu(&agf->agf_fllast, 1);
Christoph Hellwig16259e72005-11-02 15:11:25 +11002167 if (be32_to_cpu(agf->agf_fllast) == XFS_AGFL_SIZE(mp))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002168 agf->agf_fllast = 0;
Dave Chinnera862e0f2010-01-11 11:47:41 +00002169
2170 pag = xfs_perag_get(mp, be32_to_cpu(agf->agf_seqno));
Marcin Slusarz413d57c2008-02-13 15:03:29 -08002171 be32_add_cpu(&agf->agf_flcount, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002172 xfs_trans_agflist_delta(tp, 1);
2173 pag->pagf_flcount++;
David Chinner92821e22007-05-24 15:26:31 +10002174
2175 logflags = XFS_AGF_FLLAST | XFS_AGF_FLCOUNT;
2176 if (btreeblk) {
Marcin Slusarz413d57c2008-02-13 15:03:29 -08002177 be32_add_cpu(&agf->agf_btreeblks, -1);
David Chinner92821e22007-05-24 15:26:31 +10002178 pag->pagf_btreeblks--;
2179 logflags |= XFS_AGF_BTREEBLKS;
2180 }
Dave Chinnera862e0f2010-01-11 11:47:41 +00002181 xfs_perag_put(pag);
David Chinner92821e22007-05-24 15:26:31 +10002182
David Chinner92821e22007-05-24 15:26:31 +10002183 xfs_alloc_log_agf(tp, agbp, logflags);
2184
Christoph Hellwig16259e72005-11-02 15:11:25 +11002185 ASSERT(be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp));
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002186
2187 agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
2188 blockp = &agfl_bno[be32_to_cpu(agf->agf_fllast)];
Christoph Hellwige2101002006-09-28 10:56:51 +10002189 *blockp = cpu_to_be32(bno);
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002190 startoff = (char *)blockp - (char *)agflbp->b_addr;
2191
David Chinner92821e22007-05-24 15:26:31 +10002192 xfs_alloc_log_agf(tp, agbp, logflags);
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002193
Dave Chinner61fe1352013-04-03 16:11:30 +11002194 xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF);
Christoph Hellwig77c95bb2013-04-03 16:11:14 +11002195 xfs_trans_log_buf(tp, agflbp, startoff,
2196 startoff + sizeof(xfs_agblock_t) - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002197 return 0;
2198}
2199
Dave Chinner4e0e6042013-04-03 16:11:13 +11002200static bool
Dave Chinner612cfbf2012-11-14 17:52:32 +11002201xfs_agf_verify(
Dave Chinner4e0e6042013-04-03 16:11:13 +11002202 struct xfs_mount *mp,
Dave Chinner5d5f5272012-11-14 17:44:56 +11002203 struct xfs_buf *bp)
2204 {
Dave Chinner4e0e6042013-04-03 16:11:13 +11002205 struct xfs_agf *agf = XFS_BUF_TO_AGF(bp);
Dave Chinner5d5f5272012-11-14 17:44:56 +11002206
Dave Chinner4e0e6042013-04-03 16:11:13 +11002207 if (xfs_sb_version_hascrc(&mp->m_sb) &&
2208 !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
2209 return false;
Dave Chinner5d5f5272012-11-14 17:44:56 +11002210
Dave Chinner4e0e6042013-04-03 16:11:13 +11002211 if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
2212 XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
2213 be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
2214 be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
2215 be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
2216 be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
2217 return false;
Dave Chinner5d5f5272012-11-14 17:44:56 +11002218
2219 /*
2220 * during growfs operations, the perag is not fully initialised,
2221 * so we can't use it for any useful checking. growfs ensures we can't
2222 * use it by using uncached buffers that don't have the perag attached
2223 * so we can detect and avoid this problem.
2224 */
Dave Chinner4e0e6042013-04-03 16:11:13 +11002225 if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
2226 return false;
Dave Chinner5d5f5272012-11-14 17:44:56 +11002227
Dave Chinner4e0e6042013-04-03 16:11:13 +11002228 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
2229 be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
2230 return false;
Dave Chinner5d5f5272012-11-14 17:44:56 +11002231
Dave Chinner4e0e6042013-04-03 16:11:13 +11002232 return true;;
2233
Dave Chinner612cfbf2012-11-14 17:52:32 +11002234}
Dave Chinner5d5f5272012-11-14 17:44:56 +11002235
Dave Chinner1813dd62012-11-14 17:54:40 +11002236static void
2237xfs_agf_read_verify(
Dave Chinner612cfbf2012-11-14 17:52:32 +11002238 struct xfs_buf *bp)
2239{
Dave Chinner4e0e6042013-04-03 16:11:13 +11002240 struct xfs_mount *mp = bp->b_target->bt_mount;
2241 int agf_ok = 1;
2242
2243 if (xfs_sb_version_hascrc(&mp->m_sb))
2244 agf_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
2245 offsetof(struct xfs_agf, agf_crc));
2246
2247 agf_ok = agf_ok && xfs_agf_verify(mp, bp);
2248
2249 if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
2250 XFS_RANDOM_ALLOC_READ_AGF))) {
2251 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
2252 xfs_buf_ioerror(bp, EFSCORRUPTED);
2253 }
Dave Chinner612cfbf2012-11-14 17:52:32 +11002254}
2255
Dave Chinnerb0f539d2012-11-14 17:53:49 +11002256static void
Dave Chinner1813dd62012-11-14 17:54:40 +11002257xfs_agf_write_verify(
Dave Chinner612cfbf2012-11-14 17:52:32 +11002258 struct xfs_buf *bp)
2259{
Dave Chinner4e0e6042013-04-03 16:11:13 +11002260 struct xfs_mount *mp = bp->b_target->bt_mount;
2261 struct xfs_buf_log_item *bip = bp->b_fspriv;
2262
2263 if (!xfs_agf_verify(mp, bp)) {
2264 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
2265 xfs_buf_ioerror(bp, EFSCORRUPTED);
2266 return;
2267 }
2268
2269 if (!xfs_sb_version_hascrc(&mp->m_sb))
2270 return;
2271
2272 if (bip)
2273 XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
2274
2275 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
2276 offsetof(struct xfs_agf, agf_crc));
Dave Chinner5d5f5272012-11-14 17:44:56 +11002277}
2278
Dave Chinner1813dd62012-11-14 17:54:40 +11002279const struct xfs_buf_ops xfs_agf_buf_ops = {
2280 .verify_read = xfs_agf_read_verify,
2281 .verify_write = xfs_agf_write_verify,
2282};
2283
Linus Torvalds1da177e2005-04-16 15:20:36 -07002284/*
2285 * Read in the allocation group header (free/alloc section).
2286 */
2287int /* error */
From: Christoph Hellwig48056212008-11-28 14:23:38 +11002288xfs_read_agf(
2289 struct xfs_mount *mp, /* mount point structure */
2290 struct xfs_trans *tp, /* transaction pointer */
2291 xfs_agnumber_t agno, /* allocation group number */
2292 int flags, /* XFS_BUF_ */
2293 struct xfs_buf **bpp) /* buffer for the ag freelist header */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002294{
Linus Torvalds1da177e2005-04-16 15:20:36 -07002295 int error;
2296
2297 ASSERT(agno != NULLAGNUMBER);
2298 error = xfs_trans_read_buf(
2299 mp, tp, mp->m_ddev_targp,
2300 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
Dave Chinner1813dd62012-11-14 17:54:40 +11002301 XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002302 if (error)
2303 return error;
From: Christoph Hellwig48056212008-11-28 14:23:38 +11002304 if (!*bpp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002305 return 0;
From: Christoph Hellwig48056212008-11-28 14:23:38 +11002306
Chandra Seetharaman5a52c2a582011-07-22 23:39:51 +00002307 ASSERT(!(*bpp)->b_error);
Christoph Hellwig38f23232011-10-10 16:52:45 +00002308 xfs_buf_set_ref(*bpp, XFS_AGF_REF);
From: Christoph Hellwig48056212008-11-28 14:23:38 +11002309 return 0;
2310}
2311
2312/*
2313 * Read in the allocation group header (free/alloc section).
2314 */
2315int /* error */
2316xfs_alloc_read_agf(
2317 struct xfs_mount *mp, /* mount point structure */
2318 struct xfs_trans *tp, /* transaction pointer */
2319 xfs_agnumber_t agno, /* allocation group number */
2320 int flags, /* XFS_ALLOC_FLAG_... */
2321 struct xfs_buf **bpp) /* buffer for the ag freelist header */
2322{
2323 struct xfs_agf *agf; /* ag freelist header */
2324 struct xfs_perag *pag; /* per allocation group data */
2325 int error;
2326
2327 ASSERT(agno != NULLAGNUMBER);
2328
2329 error = xfs_read_agf(mp, tp, agno,
Christoph Hellwig0cadda12010-01-19 09:56:44 +00002330 (flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
From: Christoph Hellwig48056212008-11-28 14:23:38 +11002331 bpp);
2332 if (error)
2333 return error;
2334 if (!*bpp)
2335 return 0;
Chandra Seetharaman5a52c2a582011-07-22 23:39:51 +00002336 ASSERT(!(*bpp)->b_error);
From: Christoph Hellwig48056212008-11-28 14:23:38 +11002337
2338 agf = XFS_BUF_TO_AGF(*bpp);
Dave Chinnera862e0f2010-01-11 11:47:41 +00002339 pag = xfs_perag_get(mp, agno);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002340 if (!pag->pagf_init) {
Christoph Hellwig16259e72005-11-02 15:11:25 +11002341 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
David Chinner92821e22007-05-24 15:26:31 +10002342 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
Christoph Hellwig16259e72005-11-02 15:11:25 +11002343 pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
2344 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002345 pag->pagf_levels[XFS_BTNUM_BNOi] =
Christoph Hellwig16259e72005-11-02 15:11:25 +11002346 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002347 pag->pagf_levels[XFS_BTNUM_CNTi] =
Christoph Hellwig16259e72005-11-02 15:11:25 +11002348 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
Eric Sandeen007c61c2007-10-11 17:43:56 +10002349 spin_lock_init(&pag->pagb_lock);
Dave Chinnere57336f2010-01-11 11:47:49 +00002350 pag->pagb_count = 0;
Dave Chinnered3b4d62010-05-21 12:07:08 +10002351 pag->pagb_tree = RB_ROOT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002352 pag->pagf_init = 1;
2353 }
2354#ifdef DEBUG
2355 else if (!XFS_FORCED_SHUTDOWN(mp)) {
Christoph Hellwig16259e72005-11-02 15:11:25 +11002356 ASSERT(pag->pagf_freeblks == be32_to_cpu(agf->agf_freeblks));
Barry Naujok89b28392008-10-30 17:05:49 +11002357 ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
Christoph Hellwig16259e72005-11-02 15:11:25 +11002358 ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
2359 ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002360 ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
Christoph Hellwig16259e72005-11-02 15:11:25 +11002361 be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002362 ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
Christoph Hellwig16259e72005-11-02 15:11:25 +11002363 be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002364 }
2365#endif
Dave Chinnera862e0f2010-01-11 11:47:41 +00002366 xfs_perag_put(pag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002367 return 0;
2368}
2369
2370/*
2371 * Allocate an extent (variable-size).
2372 * Depending on the allocation type, we either look in a single allocation
2373 * group or loop over the allocation groups to find the result.
2374 */
2375int /* error */
Dave Chinnere04426b2012-10-05 11:06:59 +10002376xfs_alloc_vextent(
Linus Torvalds1da177e2005-04-16 15:20:36 -07002377 xfs_alloc_arg_t *args) /* allocation argument structure */
2378{
2379 xfs_agblock_t agsize; /* allocation group size */
2380 int error;
2381 int flags; /* XFS_ALLOC_FLAG_... locking flags */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002382 xfs_extlen_t minleft;/* minimum left value, temp copy */
2383 xfs_mount_t *mp; /* mount structure pointer */
2384 xfs_agnumber_t sagno; /* starting allocation group number */
2385 xfs_alloctype_t type; /* input allocation type */
2386 int bump_rotor = 0;
2387 int no_min = 0;
2388 xfs_agnumber_t rotorstep = xfs_rotorstep; /* inode32 agf stepper */
2389
2390 mp = args->mp;
2391 type = args->otype = args->type;
2392 args->agbno = NULLAGBLOCK;
2393 /*
2394 * Just fix this up, for the case where the last a.g. is shorter
2395 * (or there's only one a.g.) and the caller couldn't easily figure
2396 * that out (xfs_bmap_alloc).
2397 */
2398 agsize = mp->m_sb.sb_agblocks;
2399 if (args->maxlen > agsize)
2400 args->maxlen = agsize;
2401 if (args->alignment == 0)
2402 args->alignment = 1;
2403 ASSERT(XFS_FSB_TO_AGNO(mp, args->fsbno) < mp->m_sb.sb_agcount);
2404 ASSERT(XFS_FSB_TO_AGBNO(mp, args->fsbno) < agsize);
2405 ASSERT(args->minlen <= args->maxlen);
2406 ASSERT(args->minlen <= agsize);
2407 ASSERT(args->mod < args->prod);
2408 if (XFS_FSB_TO_AGNO(mp, args->fsbno) >= mp->m_sb.sb_agcount ||
2409 XFS_FSB_TO_AGBNO(mp, args->fsbno) >= agsize ||
2410 args->minlen > args->maxlen || args->minlen > agsize ||
2411 args->mod >= args->prod) {
2412 args->fsbno = NULLFSBLOCK;
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00002413 trace_xfs_alloc_vextent_badargs(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002414 return 0;
2415 }
2416 minleft = args->minleft;
2417
2418 switch (type) {
2419 case XFS_ALLOCTYPE_THIS_AG:
2420 case XFS_ALLOCTYPE_NEAR_BNO:
2421 case XFS_ALLOCTYPE_THIS_BNO:
2422 /*
2423 * These three force us into a single a.g.
2424 */
2425 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
Dave Chinnera862e0f2010-01-11 11:47:41 +00002426 args->pag = xfs_perag_get(mp, args->agno);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002427 args->minleft = 0;
2428 error = xfs_alloc_fix_freelist(args, 0);
2429 args->minleft = minleft;
2430 if (error) {
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00002431 trace_xfs_alloc_vextent_nofix(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002432 goto error0;
2433 }
2434 if (!args->agbp) {
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00002435 trace_xfs_alloc_vextent_noagbp(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002436 break;
2437 }
2438 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2439 if ((error = xfs_alloc_ag_vextent(args)))
2440 goto error0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002441 break;
2442 case XFS_ALLOCTYPE_START_BNO:
2443 /*
2444 * Try near allocation first, then anywhere-in-ag after
2445 * the first a.g. fails.
2446 */
2447 if ((args->userdata == XFS_ALLOC_INITIAL_USER_DATA) &&
2448 (mp->m_flags & XFS_MOUNT_32BITINODES)) {
2449 args->fsbno = XFS_AGB_TO_FSB(mp,
2450 ((mp->m_agfrotor / rotorstep) %
2451 mp->m_sb.sb_agcount), 0);
2452 bump_rotor = 1;
2453 }
2454 args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
2455 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2456 /* FALLTHROUGH */
2457 case XFS_ALLOCTYPE_ANY_AG:
2458 case XFS_ALLOCTYPE_START_AG:
2459 case XFS_ALLOCTYPE_FIRST_AG:
2460 /*
2461 * Rotate through the allocation groups looking for a winner.
2462 */
2463 if (type == XFS_ALLOCTYPE_ANY_AG) {
2464 /*
2465 * Start with the last place we left off.
2466 */
2467 args->agno = sagno = (mp->m_agfrotor / rotorstep) %
2468 mp->m_sb.sb_agcount;
2469 args->type = XFS_ALLOCTYPE_THIS_AG;
2470 flags = XFS_ALLOC_FLAG_TRYLOCK;
2471 } else if (type == XFS_ALLOCTYPE_FIRST_AG) {
2472 /*
2473 * Start with allocation group given by bno.
2474 */
2475 args->agno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2476 args->type = XFS_ALLOCTYPE_THIS_AG;
2477 sagno = 0;
2478 flags = 0;
2479 } else {
2480 if (type == XFS_ALLOCTYPE_START_AG)
2481 args->type = XFS_ALLOCTYPE_THIS_AG;
2482 /*
2483 * Start with the given allocation group.
2484 */
2485 args->agno = sagno = XFS_FSB_TO_AGNO(mp, args->fsbno);
2486 flags = XFS_ALLOC_FLAG_TRYLOCK;
2487 }
2488 /*
2489 * Loop over allocation groups twice; first time with
2490 * trylock set, second time without.
2491 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002492 for (;;) {
Dave Chinnera862e0f2010-01-11 11:47:41 +00002493 args->pag = xfs_perag_get(mp, args->agno);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002494 if (no_min) args->minleft = 0;
2495 error = xfs_alloc_fix_freelist(args, flags);
2496 args->minleft = minleft;
2497 if (error) {
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00002498 trace_xfs_alloc_vextent_nofix(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002499 goto error0;
2500 }
2501 /*
2502 * If we get a buffer back then the allocation will fly.
2503 */
2504 if (args->agbp) {
2505 if ((error = xfs_alloc_ag_vextent(args)))
2506 goto error0;
2507 break;
2508 }
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00002509
2510 trace_xfs_alloc_vextent_loopfailed(args);
2511
Linus Torvalds1da177e2005-04-16 15:20:36 -07002512 /*
2513 * Didn't work, figure out the next iteration.
2514 */
2515 if (args->agno == sagno &&
2516 type == XFS_ALLOCTYPE_START_BNO)
2517 args->type = XFS_ALLOCTYPE_THIS_AG;
Yingping Lud210a282006-06-09 14:55:18 +10002518 /*
2519 * For the first allocation, we can try any AG to get
2520 * space. However, if we already have allocated a
2521 * block, we don't want to try AGs whose number is below
2522 * sagno. Otherwise, we may end up with out-of-order
2523 * locking of AGF, which might cause deadlock.
2524 */
2525 if (++(args->agno) == mp->m_sb.sb_agcount) {
2526 if (args->firstblock != NULLFSBLOCK)
2527 args->agno = sagno;
2528 else
2529 args->agno = 0;
2530 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002531 /*
2532 * Reached the starting a.g., must either be done
2533 * or switch to non-trylock mode.
2534 */
2535 if (args->agno == sagno) {
2536 if (no_min == 1) {
2537 args->agbno = NULLAGBLOCK;
Christoph Hellwig0b1b2132009-12-14 23:14:59 +00002538 trace_xfs_alloc_vextent_allfailed(args);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002539 break;
2540 }
2541 if (flags == 0) {
2542 no_min = 1;
2543 } else {
2544 flags = 0;
2545 if (type == XFS_ALLOCTYPE_START_BNO) {
2546 args->agbno = XFS_FSB_TO_AGBNO(mp,
2547 args->fsbno);
2548 args->type = XFS_ALLOCTYPE_NEAR_BNO;
2549 }
2550 }
2551 }
Dave Chinnera862e0f2010-01-11 11:47:41 +00002552 xfs_perag_put(args->pag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002553 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002554 if (bump_rotor || (type == XFS_ALLOCTYPE_ANY_AG)) {
2555 if (args->agno == sagno)
2556 mp->m_agfrotor = (mp->m_agfrotor + 1) %
2557 (mp->m_sb.sb_agcount * rotorstep);
2558 else
2559 mp->m_agfrotor = (args->agno * rotorstep + 1) %
2560 (mp->m_sb.sb_agcount * rotorstep);
2561 }
2562 break;
2563 default:
2564 ASSERT(0);
2565 /* NOTREACHED */
2566 }
2567 if (args->agbno == NULLAGBLOCK)
2568 args->fsbno = NULLFSBLOCK;
2569 else {
2570 args->fsbno = XFS_AGB_TO_FSB(mp, args->agno, args->agbno);
2571#ifdef DEBUG
2572 ASSERT(args->len >= args->minlen);
2573 ASSERT(args->len <= args->maxlen);
2574 ASSERT(args->agbno % args->alignment == 0);
2575 XFS_AG_CHECK_DADDR(mp, XFS_FSB_TO_DADDR(mp, args->fsbno),
2576 args->len);
2577#endif
2578 }
Dave Chinnera862e0f2010-01-11 11:47:41 +00002579 xfs_perag_put(args->pag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002580 return 0;
2581error0:
Dave Chinnera862e0f2010-01-11 11:47:41 +00002582 xfs_perag_put(args->pag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002583 return error;
2584}
2585
2586/*
2587 * Free an extent.
2588 * Just break up the extent address and hand off to xfs_free_ag_extent
2589 * after fixing up the freelist.
2590 */
2591int /* error */
2592xfs_free_extent(
2593 xfs_trans_t *tp, /* transaction pointer */
2594 xfs_fsblock_t bno, /* starting block number of extent */
2595 xfs_extlen_t len) /* length of extent */
2596{
Nathan Scott0e1edbd2006-08-10 14:40:41 +10002597 xfs_alloc_arg_t args;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002598 int error;
2599
2600 ASSERT(len != 0);
Nathan Scott0e1edbd2006-08-10 14:40:41 +10002601 memset(&args, 0, sizeof(xfs_alloc_arg_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002602 args.tp = tp;
2603 args.mp = tp->t_mountp;
Dave Chinnerbe65b182011-04-08 12:45:07 +10002604
2605 /*
2606 * validate that the block number is legal - the enables us to detect
2607 * and handle a silent filesystem corruption rather than crashing.
2608 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002609 args.agno = XFS_FSB_TO_AGNO(args.mp, bno);
Dave Chinnerbe65b182011-04-08 12:45:07 +10002610 if (args.agno >= args.mp->m_sb.sb_agcount)
2611 return EFSCORRUPTED;
2612
Linus Torvalds1da177e2005-04-16 15:20:36 -07002613 args.agbno = XFS_FSB_TO_AGBNO(args.mp, bno);
Dave Chinnerbe65b182011-04-08 12:45:07 +10002614 if (args.agbno >= args.mp->m_sb.sb_agblocks)
2615 return EFSCORRUPTED;
2616
Dave Chinnera862e0f2010-01-11 11:47:41 +00002617 args.pag = xfs_perag_get(args.mp, args.agno);
Dave Chinnerbe65b182011-04-08 12:45:07 +10002618 ASSERT(args.pag);
2619
2620 error = xfs_alloc_fix_freelist(&args, XFS_ALLOC_FLAG_FREEING);
2621 if (error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002622 goto error0;
Dave Chinnerbe65b182011-04-08 12:45:07 +10002623
2624 /* validate the extent size is legal now we have the agf locked */
2625 if (args.agbno + len >
2626 be32_to_cpu(XFS_BUF_TO_AGF(args.agbp)->agf_length)) {
2627 error = EFSCORRUPTED;
2628 goto error0;
2629 }
2630
Nathan Scott0e1edbd2006-08-10 14:40:41 +10002631 error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
Christoph Hellwiga870acd2011-04-24 19:06:14 +00002632 if (!error)
Dave Chinner4ecbfe62012-04-29 10:41:10 +00002633 xfs_extent_busy_insert(tp, args.agno, args.agbno, len, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002634error0:
Dave Chinnera862e0f2010-01-11 11:47:41 +00002635 xfs_perag_put(args.pag);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002636 return error;
2637}