xfs: verify btree blocks as they are read from disk
[deliverable/linux.git] / fs / xfs / 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_types.h"
21 #include "xfs_log.h"
22 #include "xfs_trans.h"
23 #include "xfs_sb.h"
24 #include "xfs_ag.h"
25 #include "xfs_mount.h"
26 #include "xfs_bmap_btree.h"
27 #include "xfs_alloc_btree.h"
28 #include "xfs_ialloc_btree.h"
29 #include "xfs_dinode.h"
30 #include "xfs_inode.h"
31 #include "xfs_btree.h"
32 #include "xfs_alloc.h"
33 #include "xfs_extent_busy.h"
34 #include "xfs_error.h"
35 #include "xfs_trace.h"
36
37
38 STATIC struct xfs_btree_cur *
39 xfs_allocbt_dup_cursor(
40 struct xfs_btree_cur *cur)
41 {
42 return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
43 cur->bc_private.a.agbp, cur->bc_private.a.agno,
44 cur->bc_btnum);
45 }
46
47 STATIC void
48 xfs_allocbt_set_root(
49 struct xfs_btree_cur *cur,
50 union xfs_btree_ptr *ptr,
51 int inc)
52 {
53 struct xfs_buf *agbp = cur->bc_private.a.agbp;
54 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
55 xfs_agnumber_t seqno = be32_to_cpu(agf->agf_seqno);
56 int btnum = cur->bc_btnum;
57 struct xfs_perag *pag = xfs_perag_get(cur->bc_mp, seqno);
58
59 ASSERT(ptr->s != 0);
60
61 agf->agf_roots[btnum] = ptr->s;
62 be32_add_cpu(&agf->agf_levels[btnum], inc);
63 pag->pagf_levels[btnum] += inc;
64 xfs_perag_put(pag);
65
66 xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
67 }
68
69 STATIC int
70 xfs_allocbt_alloc_block(
71 struct xfs_btree_cur *cur,
72 union xfs_btree_ptr *start,
73 union xfs_btree_ptr *new,
74 int length,
75 int *stat)
76 {
77 int error;
78 xfs_agblock_t bno;
79
80 XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);
81
82 /* Allocate the new block from the freelist. If we can't, give up. */
83 error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_private.a.agbp,
84 &bno, 1);
85 if (error) {
86 XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
87 return error;
88 }
89
90 if (bno == NULLAGBLOCK) {
91 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
92 *stat = 0;
93 return 0;
94 }
95
96 xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1, false);
97
98 xfs_trans_agbtree_delta(cur->bc_tp, 1);
99 new->s = cpu_to_be32(bno);
100
101 XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
102 *stat = 1;
103 return 0;
104 }
105
106 STATIC int
107 xfs_allocbt_free_block(
108 struct xfs_btree_cur *cur,
109 struct xfs_buf *bp)
110 {
111 struct xfs_buf *agbp = cur->bc_private.a.agbp;
112 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
113 xfs_agblock_t bno;
114 int error;
115
116 bno = xfs_daddr_to_agbno(cur->bc_mp, XFS_BUF_ADDR(bp));
117 error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
118 if (error)
119 return error;
120
121 xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
122 XFS_EXTENT_BUSY_SKIP_DISCARD);
123 xfs_trans_agbtree_delta(cur->bc_tp, -1);
124
125 xfs_trans_binval(cur->bc_tp, bp);
126 return 0;
127 }
128
129 /*
130 * Update the longest extent in the AGF
131 */
132 STATIC void
133 xfs_allocbt_update_lastrec(
134 struct xfs_btree_cur *cur,
135 struct xfs_btree_block *block,
136 union xfs_btree_rec *rec,
137 int ptr,
138 int reason)
139 {
140 struct xfs_agf *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
141 xfs_agnumber_t seqno = be32_to_cpu(agf->agf_seqno);
142 struct xfs_perag *pag;
143 __be32 len;
144 int numrecs;
145
146 ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);
147
148 switch (reason) {
149 case LASTREC_UPDATE:
150 /*
151 * If this is the last leaf block and it's the last record,
152 * then update the size of the longest extent in the AG.
153 */
154 if (ptr != xfs_btree_get_numrecs(block))
155 return;
156 len = rec->alloc.ar_blockcount;
157 break;
158 case LASTREC_INSREC:
159 if (be32_to_cpu(rec->alloc.ar_blockcount) <=
160 be32_to_cpu(agf->agf_longest))
161 return;
162 len = rec->alloc.ar_blockcount;
163 break;
164 case LASTREC_DELREC:
165 numrecs = xfs_btree_get_numrecs(block);
166 if (ptr <= numrecs)
167 return;
168 ASSERT(ptr == numrecs + 1);
169
170 if (numrecs) {
171 xfs_alloc_rec_t *rrp;
172
173 rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
174 len = rrp->ar_blockcount;
175 } else {
176 len = 0;
177 }
178
179 break;
180 default:
181 ASSERT(0);
182 return;
183 }
184
185 agf->agf_longest = len;
186 pag = xfs_perag_get(cur->bc_mp, seqno);
187 pag->pagf_longest = be32_to_cpu(len);
188 xfs_perag_put(pag);
189 xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.agbp, XFS_AGF_LONGEST);
190 }
191
192 STATIC int
193 xfs_allocbt_get_minrecs(
194 struct xfs_btree_cur *cur,
195 int level)
196 {
197 return cur->bc_mp->m_alloc_mnr[level != 0];
198 }
199
200 STATIC int
201 xfs_allocbt_get_maxrecs(
202 struct xfs_btree_cur *cur,
203 int level)
204 {
205 return cur->bc_mp->m_alloc_mxr[level != 0];
206 }
207
208 STATIC void
209 xfs_allocbt_init_key_from_rec(
210 union xfs_btree_key *key,
211 union xfs_btree_rec *rec)
212 {
213 ASSERT(rec->alloc.ar_startblock != 0);
214
215 key->alloc.ar_startblock = rec->alloc.ar_startblock;
216 key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
217 }
218
219 STATIC void
220 xfs_allocbt_init_rec_from_key(
221 union xfs_btree_key *key,
222 union xfs_btree_rec *rec)
223 {
224 ASSERT(key->alloc.ar_startblock != 0);
225
226 rec->alloc.ar_startblock = key->alloc.ar_startblock;
227 rec->alloc.ar_blockcount = key->alloc.ar_blockcount;
228 }
229
230 STATIC void
231 xfs_allocbt_init_rec_from_cur(
232 struct xfs_btree_cur *cur,
233 union xfs_btree_rec *rec)
234 {
235 ASSERT(cur->bc_rec.a.ar_startblock != 0);
236
237 rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
238 rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
239 }
240
241 STATIC void
242 xfs_allocbt_init_ptr_from_cur(
243 struct xfs_btree_cur *cur,
244 union xfs_btree_ptr *ptr)
245 {
246 struct xfs_agf *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
247
248 ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
249 ASSERT(agf->agf_roots[cur->bc_btnum] != 0);
250
251 ptr->s = agf->agf_roots[cur->bc_btnum];
252 }
253
254 STATIC __int64_t
255 xfs_allocbt_key_diff(
256 struct xfs_btree_cur *cur,
257 union xfs_btree_key *key)
258 {
259 xfs_alloc_rec_incore_t *rec = &cur->bc_rec.a;
260 xfs_alloc_key_t *kp = &key->alloc;
261 __int64_t diff;
262
263 if (cur->bc_btnum == XFS_BTNUM_BNO) {
264 return (__int64_t)be32_to_cpu(kp->ar_startblock) -
265 rec->ar_startblock;
266 }
267
268 diff = (__int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
269 if (diff)
270 return diff;
271
272 return (__int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
273 }
274
275 void
276 xfs_allocbt_read_verify(
277 struct xfs_buf *bp)
278 {
279 struct xfs_mount *mp = bp->b_target->bt_mount;
280 struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
281 struct xfs_perag *pag = bp->b_pag;
282 unsigned int level;
283 int sblock_ok; /* block passes checks */
284
285 /*
286 * magic number and level verification
287 *
288 * During growfs operations, we can't verify the exact level as the
289 * perag is not fully initialised and hence not attached to the buffer.
290 * In this case, check against the maximum tree depth.
291 */
292 level = be16_to_cpu(block->bb_level);
293 switch (block->bb_magic) {
294 case cpu_to_be32(XFS_ABTB_MAGIC):
295 if (pag)
296 sblock_ok = level < pag->pagf_levels[XFS_BTNUM_BNOi];
297 else
298 sblock_ok = level < mp->m_ag_maxlevels;
299 break;
300 case cpu_to_be32(XFS_ABTC_MAGIC):
301 if (pag)
302 sblock_ok = level < pag->pagf_levels[XFS_BTNUM_CNTi];
303 else
304 sblock_ok = level < mp->m_ag_maxlevels;
305 break;
306 default:
307 sblock_ok = 0;
308 break;
309 }
310
311 /* numrecs verification */
312 sblock_ok = sblock_ok &&
313 be16_to_cpu(block->bb_numrecs) <= mp->m_alloc_mxr[level != 0];
314
315 /* sibling pointer verification */
316 sblock_ok = sblock_ok &&
317 (block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
318 be32_to_cpu(block->bb_u.s.bb_leftsib) < mp->m_sb.sb_agblocks) &&
319 block->bb_u.s.bb_leftsib &&
320 (block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
321 be32_to_cpu(block->bb_u.s.bb_rightsib) < mp->m_sb.sb_agblocks) &&
322 block->bb_u.s.bb_rightsib;
323
324 if (!sblock_ok) {
325 trace_xfs_btree_corrupt(bp, _RET_IP_);
326 XFS_CORRUPTION_ERROR("xfs_allocbt_read_verify",
327 XFS_ERRLEVEL_LOW, mp, block);
328 xfs_buf_ioerror(bp, EFSCORRUPTED);
329 }
330
331 bp->b_iodone = NULL;
332 xfs_buf_ioend(bp, 0);
333 }
334
335 #ifdef DEBUG
336 STATIC int
337 xfs_allocbt_keys_inorder(
338 struct xfs_btree_cur *cur,
339 union xfs_btree_key *k1,
340 union xfs_btree_key *k2)
341 {
342 if (cur->bc_btnum == XFS_BTNUM_BNO) {
343 return be32_to_cpu(k1->alloc.ar_startblock) <
344 be32_to_cpu(k2->alloc.ar_startblock);
345 } else {
346 return be32_to_cpu(k1->alloc.ar_blockcount) <
347 be32_to_cpu(k2->alloc.ar_blockcount) ||
348 (k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
349 be32_to_cpu(k1->alloc.ar_startblock) <
350 be32_to_cpu(k2->alloc.ar_startblock));
351 }
352 }
353
354 STATIC int
355 xfs_allocbt_recs_inorder(
356 struct xfs_btree_cur *cur,
357 union xfs_btree_rec *r1,
358 union xfs_btree_rec *r2)
359 {
360 if (cur->bc_btnum == XFS_BTNUM_BNO) {
361 return be32_to_cpu(r1->alloc.ar_startblock) +
362 be32_to_cpu(r1->alloc.ar_blockcount) <=
363 be32_to_cpu(r2->alloc.ar_startblock);
364 } else {
365 return be32_to_cpu(r1->alloc.ar_blockcount) <
366 be32_to_cpu(r2->alloc.ar_blockcount) ||
367 (r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
368 be32_to_cpu(r1->alloc.ar_startblock) <
369 be32_to_cpu(r2->alloc.ar_startblock));
370 }
371 }
372 #endif /* DEBUG */
373
374 static const struct xfs_btree_ops xfs_allocbt_ops = {
375 .rec_len = sizeof(xfs_alloc_rec_t),
376 .key_len = sizeof(xfs_alloc_key_t),
377
378 .dup_cursor = xfs_allocbt_dup_cursor,
379 .set_root = xfs_allocbt_set_root,
380 .alloc_block = xfs_allocbt_alloc_block,
381 .free_block = xfs_allocbt_free_block,
382 .update_lastrec = xfs_allocbt_update_lastrec,
383 .get_minrecs = xfs_allocbt_get_minrecs,
384 .get_maxrecs = xfs_allocbt_get_maxrecs,
385 .init_key_from_rec = xfs_allocbt_init_key_from_rec,
386 .init_rec_from_key = xfs_allocbt_init_rec_from_key,
387 .init_rec_from_cur = xfs_allocbt_init_rec_from_cur,
388 .init_ptr_from_cur = xfs_allocbt_init_ptr_from_cur,
389 .key_diff = xfs_allocbt_key_diff,
390 .read_verify = xfs_allocbt_read_verify,
391 #ifdef DEBUG
392 .keys_inorder = xfs_allocbt_keys_inorder,
393 .recs_inorder = xfs_allocbt_recs_inorder,
394 #endif
395 };
396
397 /*
398 * Allocate a new allocation btree cursor.
399 */
400 struct xfs_btree_cur * /* new alloc btree cursor */
401 xfs_allocbt_init_cursor(
402 struct xfs_mount *mp, /* file system mount point */
403 struct xfs_trans *tp, /* transaction pointer */
404 struct xfs_buf *agbp, /* buffer for agf structure */
405 xfs_agnumber_t agno, /* allocation group number */
406 xfs_btnum_t btnum) /* btree identifier */
407 {
408 struct xfs_agf *agf = XFS_BUF_TO_AGF(agbp);
409 struct xfs_btree_cur *cur;
410
411 ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
412
413 cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);
414
415 cur->bc_tp = tp;
416 cur->bc_mp = mp;
417 cur->bc_btnum = btnum;
418 cur->bc_blocklog = mp->m_sb.sb_blocklog;
419 cur->bc_ops = &xfs_allocbt_ops;
420
421 if (btnum == XFS_BTNUM_CNT) {
422 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
423 cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
424 } else {
425 cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
426 }
427
428 cur->bc_private.a.agbp = agbp;
429 cur->bc_private.a.agno = agno;
430
431 return cur;
432 }
433
434 /*
435 * Calculate number of records in an alloc btree block.
436 */
437 int
438 xfs_allocbt_maxrecs(
439 struct xfs_mount *mp,
440 int blocklen,
441 int leaf)
442 {
443 blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
444
445 if (leaf)
446 return blocklen / sizeof(xfs_alloc_rec_t);
447 return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
448 }
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