Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
[sfrench/cifs-2.6.git] / fs / xfs / libxfs / xfs_alloc_btree.c
1 /*
2  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
24 #include "xfs_sb.h"
25 #include "xfs_mount.h"
26 #include "xfs_btree.h"
27 #include "xfs_alloc_btree.h"
28 #include "xfs_alloc.h"
29 #include "xfs_extent_busy.h"
30 #include "xfs_error.h"
31 #include "xfs_trace.h"
32 #include "xfs_cksum.h"
33 #include "xfs_trans.h"
34
35
36 STATIC struct xfs_btree_cur *
37 xfs_allocbt_dup_cursor(
38         struct xfs_btree_cur    *cur)
39 {
40         return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
41                         cur->bc_private.a.agbp, cur->bc_private.a.agno,
42                         cur->bc_btnum);
43 }
44
45 STATIC void
46 xfs_allocbt_set_root(
47         struct xfs_btree_cur    *cur,
48         union xfs_btree_ptr     *ptr,
49         int                     inc)
50 {
51         struct xfs_buf          *agbp = cur->bc_private.a.agbp;
52         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
53         xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
54         int                     btnum = cur->bc_btnum;
55         struct xfs_perag        *pag = xfs_perag_get(cur->bc_mp, seqno);
56
57         ASSERT(ptr->s != 0);
58
59         agf->agf_roots[btnum] = ptr->s;
60         be32_add_cpu(&agf->agf_levels[btnum], inc);
61         pag->pagf_levels[btnum] += inc;
62         xfs_perag_put(pag);
63
64         xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
65 }
66
67 STATIC int
68 xfs_allocbt_alloc_block(
69         struct xfs_btree_cur    *cur,
70         union xfs_btree_ptr     *start,
71         union xfs_btree_ptr     *new,
72         int                     *stat)
73 {
74         int                     error;
75         xfs_agblock_t           bno;
76
77         XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
78
79         /* Allocate the new block from the freelist. If we can't, give up.  */
80         error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
81                                        &bno, 1);
82         if (error) {
83                 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
84                 return error;
85         }
86
87         if (bno == NULLAGBLOCK) {
88                 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
89                 *stat = 0;
90                 return 0;
91         }
92
93         xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1, false);
94
95         xfs_trans_agbtree_delta(cur->bc_tp, 1);
96         new->s = cpu_to_be32(bno);
97
98         XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
99         *stat = 1;
100         return 0;
101 }
102
103 STATIC int
104 xfs_allocbt_free_block(
105         struct xfs_btree_cur    *cur,
106         struct xfs_buf          *bp)
107 {
108         struct xfs_buf          *agbp = cur->bc_private.a.agbp;
109         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
110         xfs_agblock_t           bno;
111         int                     error;
112
113         bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
114         error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
115         if (error)
116                 return error;
117
118         xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
119                               XFS_EXTENT_BUSY_SKIP_DISCARD);
120         xfs_trans_agbtree_delta(cur->bc_tp, -1);
121         return 0;
122 }
123
124 /*
125  * Update the longest extent in the AGF
126  */
127 STATIC void
128 xfs_allocbt_update_lastrec(
129         struct xfs_btree_cur    *cur,
130         struct xfs_btree_block  *block,
131         union xfs_btree_rec     *rec,
132         int                     ptr,
133         int                     reason)
134 {
135         struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
136         xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
137         struct xfs_perag        *pag;
138         __be32                  len;
139         int                     numrecs;
140
141         ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);
142
143         switch (reason) {
144         case LASTREC_UPDATE:
145                 /*
146                  * If this is the last leaf block and it's the last record,
147                  * then update the size of the longest extent in the AG.
148                  */
149                 if (ptr != xfs_btree_get_numrecs(block))
150                         return;
151                 len = rec->alloc.ar_blockcount;
152                 break;
153         case LASTREC_INSREC:
154                 if (be32_to_cpu(rec->alloc.ar_blockcount) <=
155                     be32_to_cpu(agf->agf_longest))
156                         return;
157                 len = rec->alloc.ar_blockcount;
158                 break;
159         case LASTREC_DELREC:
160                 numrecs = xfs_btree_get_numrecs(block);
161                 if (ptr <= numrecs)
162                         return;
163                 ASSERT(ptr == numrecs + 1);
164
165                 if (numrecs) {
166                         xfs_alloc_rec_t *rrp;
167
168                         rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
169                         len = rrp->ar_blockcount;
170                 } else {
171                         len = 0;
172                 }
173
174                 break;
175         default:
176                 ASSERT(0);
177                 return;
178         }
179
180         agf->agf_longest = len;
181         pag = xfs_perag_get(cur->bc_mp, seqno);
182         pag->pagf_longest = be32_to_cpu(len);
183         xfs_perag_put(pag);
184         xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp, XFS_AGF_LONGEST);
185 }
186
187 STATIC int
188 xfs_allocbt_get_minrecs(
189         struct xfs_btree_cur    *cur,
190         int                     level)
191 {
192         return cur->bc_mp->m_alloc_mnr[level != 0];
193 }
194
195 STATIC int
196 xfs_allocbt_get_maxrecs(
197         struct xfs_btree_cur    *cur,
198         int                     level)
199 {
200         return cur->bc_mp->m_alloc_mxr[level != 0];
201 }
202
203 STATIC void
204 xfs_allocbt_init_key_from_rec(
205         union xfs_btree_key     *key,
206         union xfs_btree_rec     *rec)
207 {
208         key->alloc.ar_startblock = rec->alloc.ar_startblock;
209         key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
210 }
211
212 STATIC void
213 xfs_bnobt_init_high_key_from_rec(
214         union xfs_btree_key     *key,
215         union xfs_btree_rec     *rec)
216 {
217         __u32                   x;
218
219         x = be32_to_cpu(rec->alloc.ar_startblock);
220         x += be32_to_cpu(rec->alloc.ar_blockcount) - 1;
221         key->alloc.ar_startblock = cpu_to_be32(x);
222         key->alloc.ar_blockcount = 0;
223 }
224
225 STATIC void
226 xfs_cntbt_init_high_key_from_rec(
227         union xfs_btree_key     *key,
228         union xfs_btree_rec     *rec)
229 {
230         key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
231         key->alloc.ar_startblock = 0;
232 }
233
234 STATIC void
235 xfs_allocbt_init_rec_from_cur(
236         struct xfs_btree_cur    *cur,
237         union xfs_btree_rec     *rec)
238 {
239         rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
240         rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
241 }
242
243 STATIC void
244 xfs_allocbt_init_ptr_from_cur(
245         struct xfs_btree_cur    *cur,
246         union xfs_btree_ptr     *ptr)
247 {
248         struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
249
250         ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
251         ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
252
253         ptr->s = agf->agf_roots[cur->bc_btnum];
254 }
255
256 STATIC __int64_t
257 xfs_bnobt_key_diff(
258         struct xfs_btree_cur    *cur,
259         union xfs_btree_key     *key)
260 {
261         xfs_alloc_rec_incore_t  *rec = &cur->bc_rec.a;
262         xfs_alloc_key_t         *kp = &key->alloc;
263
264         return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
265 }
266
267 STATIC __int64_t
268 xfs_cntbt_key_diff(
269         struct xfs_btree_cur    *cur,
270         union xfs_btree_key     *key)
271 {
272         xfs_alloc_rec_incore_t  *rec = &cur->bc_rec.a;
273         xfs_alloc_key_t         *kp = &key->alloc;
274         __int64_t               diff;
275
276         diff = (__int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
277         if (diff)
278                 return diff;
279
280         return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
281 }
282
283 STATIC __int64_t
284 xfs_bnobt_diff_two_keys(
285         struct xfs_btree_cur    *cur,
286         union xfs_btree_key     *k1,
287         union xfs_btree_key     *k2)
288 {
289         return (__int64_t)be32_to_cpu(k1->alloc.ar_startblock) -
290                           be32_to_cpu(k2->alloc.ar_startblock);
291 }
292
293 STATIC __int64_t
294 xfs_cntbt_diff_two_keys(
295         struct xfs_btree_cur    *cur,
296         union xfs_btree_key     *k1,
297         union xfs_btree_key     *k2)
298 {
299         __int64_t               diff;
300
301         diff =  be32_to_cpu(k1->alloc.ar_blockcount) -
302                 be32_to_cpu(k2->alloc.ar_blockcount);
303         if (diff)
304                 return diff;
305
306         return  be32_to_cpu(k1->alloc.ar_startblock) -
307                 be32_to_cpu(k2->alloc.ar_startblock);
308 }
309
310 static bool
311 xfs_allocbt_verify(
312         struct xfs_buf          *bp)
313 {
314         struct xfs_mount        *mp = bp->b_target->bt_mount;
315         struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
316         struct xfs_perag        *pag = bp->b_pag;
317         unsigned int            level;
318
319         /*
320          * magic number and level verification
321          *
322          * During growfs operations, we can't verify the exact level or owner as
323          * the perag is not fully initialised and hence not attached to the
324          * buffer.  In this case, check against the maximum tree depth.
325          *
326          * Similarly, during log recovery we will have a perag structure
327          * attached, but the agf information will not yet have been initialised
328          * from the on disk AGF. Again, we can only check against maximum limits
329          * in this case.
330          */
331         level = be16_to_cpu(block->bb_level);
332         switch (block->bb_magic) {
333         case cpu_to_be32(XFS_ABTB_CRC_MAGIC):
334                 if (!xfs_btree_sblock_v5hdr_verify(bp))
335                         return false;
336                 /* fall through */
337         case cpu_to_be32(XFS_ABTB_MAGIC):
338                 if (pag && pag->pagf_init) {
339                         if (level >= pag->pagf_levels[XFS_BTNUM_BNOi])
340                                 return false;
341                 } else if (level >= mp->m_ag_maxlevels)
342                         return false;
343                 break;
344         case cpu_to_be32(XFS_ABTC_CRC_MAGIC):
345                 if (!xfs_btree_sblock_v5hdr_verify(bp))
346                         return false;
347                 /* fall through */
348         case cpu_to_be32(XFS_ABTC_MAGIC):
349                 if (pag && pag->pagf_init) {
350                         if (level >= pag->pagf_levels[XFS_BTNUM_CNTi])
351                                 return false;
352                 } else if (level >= mp->m_ag_maxlevels)
353                         return false;
354                 break;
355         default:
356                 return false;
357         }
358
359         return xfs_btree_sblock_verify(bp, mp->m_alloc_mxr[level != 0]);
360 }
361
362 static void
363 xfs_allocbt_read_verify(
364         struct xfs_buf  *bp)
365 {
366         if (!xfs_btree_sblock_verify_crc(bp))
367                 xfs_buf_ioerror(bp, -EFSBADCRC);
368         else if (!xfs_allocbt_verify(bp))
369                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
370
371         if (bp->b_error) {
372                 trace_xfs_btree_corrupt(bp, _RET_IP_);
373                 xfs_verifier_error(bp);
374         }
375 }
376
377 static void
378 xfs_allocbt_write_verify(
379         struct xfs_buf  *bp)
380 {
381         if (!xfs_allocbt_verify(bp)) {
382                 trace_xfs_btree_corrupt(bp, _RET_IP_);
383                 xfs_buf_ioerror(bp, -EFSCORRUPTED);
384                 xfs_verifier_error(bp);
385                 return;
386         }
387         xfs_btree_sblock_calc_crc(bp);
388
389 }
390
391 const struct xfs_buf_ops xfs_allocbt_buf_ops = {
392         .name = "xfs_allocbt",
393         .verify_read = xfs_allocbt_read_verify,
394         .verify_write = xfs_allocbt_write_verify,
395 };
396
397
398 #if defined(DEBUG) || defined(XFS_WARN)
399 STATIC int
400 xfs_bnobt_keys_inorder(
401         struct xfs_btree_cur    *cur,
402         union xfs_btree_key     *k1,
403         union xfs_btree_key     *k2)
404 {
405         return be32_to_cpu(k1->alloc.ar_startblock) <
406                be32_to_cpu(k2->alloc.ar_startblock);
407 }
408
409 STATIC int
410 xfs_bnobt_recs_inorder(
411         struct xfs_btree_cur    *cur,
412         union xfs_btree_rec     *r1,
413         union xfs_btree_rec     *r2)
414 {
415         return be32_to_cpu(r1->alloc.ar_startblock) +
416                 be32_to_cpu(r1->alloc.ar_blockcount) <=
417                 be32_to_cpu(r2->alloc.ar_startblock);
418 }
419
420 STATIC int
421 xfs_cntbt_keys_inorder(
422         struct xfs_btree_cur    *cur,
423         union xfs_btree_key     *k1,
424         union xfs_btree_key     *k2)
425 {
426         return be32_to_cpu(k1->alloc.ar_blockcount) <
427                 be32_to_cpu(k2->alloc.ar_blockcount) ||
428                 (k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
429                  be32_to_cpu(k1->alloc.ar_startblock) <
430                  be32_to_cpu(k2->alloc.ar_startblock));
431 }
432
433 STATIC int
434 xfs_cntbt_recs_inorder(
435         struct xfs_btree_cur    *cur,
436         union xfs_btree_rec     *r1,
437         union xfs_btree_rec     *r2)
438 {
439         return be32_to_cpu(r1->alloc.ar_blockcount) <
440                 be32_to_cpu(r2->alloc.ar_blockcount) ||
441                 (r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
442                  be32_to_cpu(r1->alloc.ar_startblock) <
443                  be32_to_cpu(r2->alloc.ar_startblock));
444 }
445 #endif /* DEBUG */
446
447 static const struct xfs_btree_ops xfs_bnobt_ops = {
448         .rec_len                = sizeof(xfs_alloc_rec_t),
449         .key_len                = sizeof(xfs_alloc_key_t),
450
451         .dup_cursor             = xfs_allocbt_dup_cursor,
452         .set_root               = xfs_allocbt_set_root,
453         .alloc_block            = xfs_allocbt_alloc_block,
454         .free_block             = xfs_allocbt_free_block,
455         .update_lastrec         = xfs_allocbt_update_lastrec,
456         .get_minrecs            = xfs_allocbt_get_minrecs,
457         .get_maxrecs            = xfs_allocbt_get_maxrecs,
458         .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
459         .init_high_key_from_rec = xfs_bnobt_init_high_key_from_rec,
460         .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
461         .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
462         .key_diff               = xfs_bnobt_key_diff,
463         .buf_ops                = &xfs_allocbt_buf_ops,
464         .diff_two_keys          = xfs_bnobt_diff_two_keys,
465 #if defined(DEBUG) || defined(XFS_WARN)
466         .keys_inorder           = xfs_bnobt_keys_inorder,
467         .recs_inorder           = xfs_bnobt_recs_inorder,
468 #endif
469 };
470
471 static const struct xfs_btree_ops xfs_cntbt_ops = {
472         .rec_len                = sizeof(xfs_alloc_rec_t),
473         .key_len                = sizeof(xfs_alloc_key_t),
474
475         .dup_cursor             = xfs_allocbt_dup_cursor,
476         .set_root               = xfs_allocbt_set_root,
477         .alloc_block            = xfs_allocbt_alloc_block,
478         .free_block             = xfs_allocbt_free_block,
479         .update_lastrec         = xfs_allocbt_update_lastrec,
480         .get_minrecs            = xfs_allocbt_get_minrecs,
481         .get_maxrecs            = xfs_allocbt_get_maxrecs,
482         .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
483         .init_high_key_from_rec = xfs_cntbt_init_high_key_from_rec,
484         .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
485         .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
486         .key_diff               = xfs_cntbt_key_diff,
487         .buf_ops                = &xfs_allocbt_buf_ops,
488         .diff_two_keys          = xfs_cntbt_diff_two_keys,
489 #if defined(DEBUG) || defined(XFS_WARN)
490         .keys_inorder           = xfs_cntbt_keys_inorder,
491         .recs_inorder           = xfs_cntbt_recs_inorder,
492 #endif
493 };
494
495 /*
496  * Allocate a new allocation btree cursor.
497  */
498 struct xfs_btree_cur *                  /* new alloc btree cursor */
499 xfs_allocbt_init_cursor(
500         struct xfs_mount        *mp,            /* file system mount point */
501         struct xfs_trans        *tp,            /* transaction pointer */
502         struct xfs_buf          *agbp,          /* buffer for agf structure */
503         xfs_agnumber_t          agno,           /* allocation group number */
504         xfs_btnum_t             btnum)          /* btree identifier */
505 {
506         struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
507         struct xfs_btree_cur    *cur;
508
509         ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
510
511         cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_NOFS);
512
513         cur->bc_tp = tp;
514         cur->bc_mp = mp;
515         cur->bc_btnum = btnum;
516         cur->bc_blocklog = mp->m_sb.sb_blocklog;
517
518         if (btnum == XFS_BTNUM_CNT) {
519                 cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_abtc_2);
520                 cur->bc_ops = &xfs_cntbt_ops;
521                 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
522                 cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
523         } else {
524                 cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_abtb_2);
525                 cur->bc_ops = &xfs_bnobt_ops;
526                 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
527         }
528
529         cur->bc_private.a.agbp = agbp;
530         cur->bc_private.a.agno = agno;
531
532         if (xfs_sb_version_hascrc(&mp->m_sb))
533                 cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
534
535         return cur;
536 }
537
538 /*
539  * Calculate number of records in an alloc btree block.
540  */
541 int
542 xfs_allocbt_maxrecs(
543         struct xfs_mount        *mp,
544         int                     blocklen,
545         int                     leaf)
546 {
547         blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
548
549         if (leaf)
550                 return blocklen / sizeof(xfs_alloc_rec_t);
551         return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
552 }