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Merge branch 'akpm'
[linux-2.6/next.git] / fs / xfs / xfs_dir2.c
bloba2e27010c7fb7a6bec8f8dca69204bcf7f5fbcb7
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_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_mount.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_alloc_btree.h"
31 #include "xfs_dinode.h"
32 #include "xfs_inode.h"
33 #include "xfs_inode_item.h"
34 #include "xfs_bmap.h"
35 #include "xfs_dir2.h"
36 #include "xfs_dir2_format.h"
37 #include "xfs_dir2_priv.h"
38 #include "xfs_error.h"
39 #include "xfs_vnodeops.h"
40 #include "xfs_trace.h"
41
42 struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2};
43
44 /*
45 * ASCII case-insensitive (ie. A-Z) support for directories that was
46 * used in IRIX.
47 */
48 STATIC xfs_dahash_t
49 xfs_ascii_ci_hashname(
50 struct xfs_name *name)
51 {
52 xfs_dahash_t hash;
53 int i;
54
55 for (i = 0, hash = 0; i < name->len; i++)
56 hash = tolower(name->name[i]) ^ rol32(hash, 7);
57
58 return hash;
59 }
60
61 STATIC enum xfs_dacmp
62 xfs_ascii_ci_compname(
63 struct xfs_da_args *args,
64 const unsigned char *name,
65 int len)
66 {
67 enum xfs_dacmp result;
68 int i;
69
70 if (args->namelen != len)
71 return XFS_CMP_DIFFERENT;
72
73 result = XFS_CMP_EXACT;
74 for (i = 0; i < len; i++) {
75 if (args->name[i] == name[i])
76 continue;
77 if (tolower(args->name[i]) != tolower(name[i]))
78 return XFS_CMP_DIFFERENT;
79 result = XFS_CMP_CASE;
80 }
81
82 return result;
83 }
84
85 static struct xfs_nameops xfs_ascii_ci_nameops = {
86 .hashname = xfs_ascii_ci_hashname,
87 .compname = xfs_ascii_ci_compname,
88 };
89
90 void
91 xfs_dir_mount(
92 xfs_mount_t *mp)
93 {
94 ASSERT(xfs_sb_version_hasdirv2(&mp->m_sb));
95 ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
96 XFS_MAX_BLOCKSIZE);
97 mp->m_dirblksize = 1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog);
98 mp->m_dirblkfsbs = 1 << mp->m_sb.sb_dirblklog;
99 mp->m_dirdatablk = xfs_dir2_db_to_da(mp, XFS_DIR2_DATA_FIRSTDB(mp));
100 mp->m_dirleafblk = xfs_dir2_db_to_da(mp, XFS_DIR2_LEAF_FIRSTDB(mp));
101 mp->m_dirfreeblk = xfs_dir2_db_to_da(mp, XFS_DIR2_FREE_FIRSTDB(mp));
102 mp->m_attr_node_ents =
103 (mp->m_sb.sb_blocksize - (uint)sizeof(xfs_da_node_hdr_t)) /
104 (uint)sizeof(xfs_da_node_entry_t);
105 mp->m_dir_node_ents =
106 (mp->m_dirblksize - (uint)sizeof(xfs_da_node_hdr_t)) /
107 (uint)sizeof(xfs_da_node_entry_t);
108 mp->m_dir_magicpct = (mp->m_dirblksize * 37) / 100;
109 if (xfs_sb_version_hasasciici(&mp->m_sb))
110 mp->m_dirnameops = &xfs_ascii_ci_nameops;
111 else
112 mp->m_dirnameops = &xfs_default_nameops;
113 }
114
115 /*
116 * Return 1 if directory contains only "." and "..".
117 */
118 int
119 xfs_dir_isempty(
120 xfs_inode_t *dp)
121 {
122 xfs_dir2_sf_hdr_t *sfp;
123
124 ASSERT(S_ISDIR(dp->i_d.di_mode));
125 if (dp->i_d.di_size == 0) /* might happen during shutdown. */
126 return 1;
127 if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
128 return 0;
129 sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
130 return !sfp->count;
131 }
132
133 /*
134 * Validate a given inode number.
135 */
136 int
137 xfs_dir_ino_validate(
138 xfs_mount_t *mp,
139 xfs_ino_t ino)
140 {
141 xfs_agblock_t agblkno;
142 xfs_agino_t agino;
143 xfs_agnumber_t agno;
144 int ino_ok;
145 int ioff;
146
147 agno = XFS_INO_TO_AGNO(mp, ino);
148 agblkno = XFS_INO_TO_AGBNO(mp, ino);
149 ioff = XFS_INO_TO_OFFSET(mp, ino);
150 agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
151 ino_ok =
152 agno < mp->m_sb.sb_agcount &&
153 agblkno < mp->m_sb.sb_agblocks &&
154 agblkno != 0 &&
155 ioff < (1 << mp->m_sb.sb_inopblog) &&
156 XFS_AGINO_TO_INO(mp, agno, agino) == ino;
157 if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
158 XFS_RANDOM_DIR_INO_VALIDATE))) {
159 xfs_warn(mp, "Invalid inode number 0x%Lx",
160 (unsigned long long) ino);
161 XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
162 return XFS_ERROR(EFSCORRUPTED);
163 }
164 return 0;
165 }
166
167 /*
168 * Initialize a directory with its "." and ".." entries.
169 */
170 int
171 xfs_dir_init(
172 xfs_trans_t *tp,
173 xfs_inode_t *dp,
174 xfs_inode_t *pdp)
175 {
176 xfs_da_args_t args;
177 int error;
178
179 memset((char *)&args, 0, sizeof(args));
180 args.dp = dp;
181 args.trans = tp;
182 ASSERT(S_ISDIR(dp->i_d.di_mode));
183 if ((error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino)))
184 return error;
185 return xfs_dir2_sf_create(&args, pdp->i_ino);
186 }
187
188 /*
189 Enter a name in a directory.
190 */
191 int
192 xfs_dir_createname(
193 xfs_trans_t *tp,
194 xfs_inode_t *dp,
195 struct xfs_name *name,
196 xfs_ino_t inum, /* new entry inode number */
197 xfs_fsblock_t *first, /* bmap's firstblock */
198 xfs_bmap_free_t *flist, /* bmap's freeblock list */
199 xfs_extlen_t total) /* bmap's total block count */
200 {
201 xfs_da_args_t args;
202 int rval;
203 int v; /* type-checking value */
204
205 ASSERT(S_ISDIR(dp->i_d.di_mode));
206 if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
207 return rval;
208 XFS_STATS_INC(xs_dir_create);
209
210 memset(&args, 0, sizeof(xfs_da_args_t));
211 args.name = name->name;
212 args.namelen = name->len;
213 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
214 args.inumber = inum;
215 args.dp = dp;
216 args.firstblock = first;
217 args.flist = flist;
218 args.total = total;
219 args.whichfork = XFS_DATA_FORK;
220 args.trans = tp;
221 args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
222
223 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
224 rval = xfs_dir2_sf_addname(&args);
225 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
226 return rval;
227 else if (v)
228 rval = xfs_dir2_block_addname(&args);
229 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
230 return rval;
231 else if (v)
232 rval = xfs_dir2_leaf_addname(&args);
233 else
234 rval = xfs_dir2_node_addname(&args);
235 return rval;
236 }
237
238 /*
239 * If doing a CI lookup and case-insensitive match, dup actual name into
240 * args.value. Return EEXIST for success (ie. name found) or an error.
241 */
242 int
243 xfs_dir_cilookup_result(
244 struct xfs_da_args *args,
245 const unsigned char *name,
246 int len)
247 {
248 if (args->cmpresult == XFS_CMP_DIFFERENT)
249 return ENOENT;
250 if (args->cmpresult != XFS_CMP_CASE ||
251 !(args->op_flags & XFS_DA_OP_CILOOKUP))
252 return EEXIST;
253
254 args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
255 if (!args->value)
256 return ENOMEM;
257
258 memcpy(args->value, name, len);
259 args->valuelen = len;
260 return EEXIST;
261 }
262
263 /*
264 * Lookup a name in a directory, give back the inode number.
265 * If ci_name is not NULL, returns the actual name in ci_name if it differs
266 * to name, or ci_name->name is set to NULL for an exact match.
267 */
268
269 int
270 xfs_dir_lookup(
271 xfs_trans_t *tp,
272 xfs_inode_t *dp,
273 struct xfs_name *name,
274 xfs_ino_t *inum, /* out: inode number */
275 struct xfs_name *ci_name) /* out: actual name if CI match */
276 {
277 xfs_da_args_t args;
278 int rval;
279 int v; /* type-checking value */
280
281 ASSERT(S_ISDIR(dp->i_d.di_mode));
282 XFS_STATS_INC(xs_dir_lookup);
283
284 memset(&args, 0, sizeof(xfs_da_args_t));
285 args.name = name->name;
286 args.namelen = name->len;
287 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
288 args.dp = dp;
289 args.whichfork = XFS_DATA_FORK;
290 args.trans = tp;
291 args.op_flags = XFS_DA_OP_OKNOENT;
292 if (ci_name)
293 args.op_flags |= XFS_DA_OP_CILOOKUP;
294
295 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
296 rval = xfs_dir2_sf_lookup(&args);
297 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
298 return rval;
299 else if (v)
300 rval = xfs_dir2_block_lookup(&args);
301 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
302 return rval;
303 else if (v)
304 rval = xfs_dir2_leaf_lookup(&args);
305 else
306 rval = xfs_dir2_node_lookup(&args);
307 if (rval == EEXIST)
308 rval = 0;
309 if (!rval) {
310 *inum = args.inumber;
311 if (ci_name) {
312 ci_name->name = args.value;
313 ci_name->len = args.valuelen;
314 }
315 }
316 return rval;
317 }
318
319 /*
320 * Remove an entry from a directory.
321 */
322 int
323 xfs_dir_removename(
324 xfs_trans_t *tp,
325 xfs_inode_t *dp,
326 struct xfs_name *name,
327 xfs_ino_t ino,
328 xfs_fsblock_t *first, /* bmap's firstblock */
329 xfs_bmap_free_t *flist, /* bmap's freeblock list */
330 xfs_extlen_t total) /* bmap's total block count */
331 {
332 xfs_da_args_t args;
333 int rval;
334 int v; /* type-checking value */
335
336 ASSERT(S_ISDIR(dp->i_d.di_mode));
337 XFS_STATS_INC(xs_dir_remove);
338
339 memset(&args, 0, sizeof(xfs_da_args_t));
340 args.name = name->name;
341 args.namelen = name->len;
342 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
343 args.inumber = ino;
344 args.dp = dp;
345 args.firstblock = first;
346 args.flist = flist;
347 args.total = total;
348 args.whichfork = XFS_DATA_FORK;
349 args.trans = tp;
350
351 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
352 rval = xfs_dir2_sf_removename(&args);
353 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
354 return rval;
355 else if (v)
356 rval = xfs_dir2_block_removename(&args);
357 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
358 return rval;
359 else if (v)
360 rval = xfs_dir2_leaf_removename(&args);
361 else
362 rval = xfs_dir2_node_removename(&args);
363 return rval;
364 }
365
366 /*
367 * Read a directory.
368 */
369 int
370 xfs_readdir(
371 xfs_inode_t *dp,
372 void *dirent,
373 size_t bufsize,
374 xfs_off_t *offset,
375 filldir_t filldir)
376 {
377 int rval; /* return value */
378 int v; /* type-checking value */
379
380 trace_xfs_readdir(dp);
381
382 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
383 return XFS_ERROR(EIO);
384
385 ASSERT(S_ISDIR(dp->i_d.di_mode));
386 XFS_STATS_INC(xs_dir_getdents);
387
388 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
389 rval = xfs_dir2_sf_getdents(dp, dirent, offset, filldir);
390 else if ((rval = xfs_dir2_isblock(NULL, dp, &v)))
391 ;
392 else if (v)
393 rval = xfs_dir2_block_getdents(dp, dirent, offset, filldir);
394 else
395 rval = xfs_dir2_leaf_getdents(dp, dirent, bufsize, offset,
396 filldir);
397 return rval;
398 }
399
400 /*
401 * Replace the inode number of a directory entry.
402 */
403 int
404 xfs_dir_replace(
405 xfs_trans_t *tp,
406 xfs_inode_t *dp,
407 struct xfs_name *name, /* name of entry to replace */
408 xfs_ino_t inum, /* new inode number */
409 xfs_fsblock_t *first, /* bmap's firstblock */
410 xfs_bmap_free_t *flist, /* bmap's freeblock list */
411 xfs_extlen_t total) /* bmap's total block count */
412 {
413 xfs_da_args_t args;
414 int rval;
415 int v; /* type-checking value */
416
417 ASSERT(S_ISDIR(dp->i_d.di_mode));
418
419 if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
420 return rval;
421
422 memset(&args, 0, sizeof(xfs_da_args_t));
423 args.name = name->name;
424 args.namelen = name->len;
425 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
426 args.inumber = inum;
427 args.dp = dp;
428 args.firstblock = first;
429 args.flist = flist;
430 args.total = total;
431 args.whichfork = XFS_DATA_FORK;
432 args.trans = tp;
433
434 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
435 rval = xfs_dir2_sf_replace(&args);
436 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
437 return rval;
438 else if (v)
439 rval = xfs_dir2_block_replace(&args);
440 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
441 return rval;
442 else if (v)
443 rval = xfs_dir2_leaf_replace(&args);
444 else
445 rval = xfs_dir2_node_replace(&args);
446 return rval;
447 }
448
449 /*
450 * See if this entry can be added to the directory without allocating space.
451 * First checks that the caller couldn't reserve enough space (resblks = 0).
452 */
453 int
454 xfs_dir_canenter(
455 xfs_trans_t *tp,
456 xfs_inode_t *dp,
457 struct xfs_name *name, /* name of entry to add */
458 uint resblks)
459 {
460 xfs_da_args_t args;
461 int rval;
462 int v; /* type-checking value */
463
464 if (resblks)
465 return 0;
466
467 ASSERT(S_ISDIR(dp->i_d.di_mode));
468
469 memset(&args, 0, sizeof(xfs_da_args_t));
470 args.name = name->name;
471 args.namelen = name->len;
472 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
473 args.dp = dp;
474 args.whichfork = XFS_DATA_FORK;
475 args.trans = tp;
476 args.op_flags = XFS_DA_OP_JUSTCHECK | XFS_DA_OP_ADDNAME |
477 XFS_DA_OP_OKNOENT;
478
479 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
480 rval = xfs_dir2_sf_addname(&args);
481 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
482 return rval;
483 else if (v)
484 rval = xfs_dir2_block_addname(&args);
485 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
486 return rval;
487 else if (v)
488 rval = xfs_dir2_leaf_addname(&args);
489 else
490 rval = xfs_dir2_node_addname(&args);
491 return rval;
492 }
493
494 /*
495 * Utility routines.
496 */
497
498 /*
499 * Add a block to the directory.
500 *
501 * This routine is for data and free blocks, not leaf/node blocks which are
502 * handled by xfs_da_grow_inode.
503 */
504 int
505 xfs_dir2_grow_inode(
506 struct xfs_da_args *args,
507 int space, /* v2 dir's space XFS_DIR2_xxx_SPACE */
508 xfs_dir2_db_t *dbp) /* out: block number added */
509 {
510 struct xfs_inode *dp = args->dp;
511 struct xfs_mount *mp = dp->i_mount;
512 xfs_fileoff_t bno; /* directory offset of new block */
513 int count; /* count of filesystem blocks */
514 int error;
515
516 trace_xfs_dir2_grow_inode(args, space);
517
518 /*
519 * Set lowest possible block in the space requested.
520 */
521 bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
522 count = mp->m_dirblkfsbs;
523
524 error = xfs_da_grow_inode_int(args, &bno, count);
525 if (error)
526 return error;
527
528 *dbp = xfs_dir2_da_to_db(mp, (xfs_dablk_t)bno);
529
530 /*
531 * Update file's size if this is the data space and it grew.
532 */
533 if (space == XFS_DIR2_DATA_SPACE) {
534 xfs_fsize_t size; /* directory file (data) size */
535
536 size = XFS_FSB_TO_B(mp, bno + count);
537 if (size > dp->i_d.di_size) {
538 dp->i_d.di_size = size;
539 xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
540 }
541 }
542 return 0;
543 }
544
545 /*
546 * See if the directory is a single-block form directory.
547 */
548 int
549 xfs_dir2_isblock(
550 xfs_trans_t *tp,
551 xfs_inode_t *dp,
552 int *vp) /* out: 1 is block, 0 is not block */
553 {
554 xfs_fileoff_t last; /* last file offset */
555 xfs_mount_t *mp;
556 int rval;
557
558 mp = dp->i_mount;
559 if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
560 return rval;
561 rval = XFS_FSB_TO_B(mp, last) == mp->m_dirblksize;
562 ASSERT(rval == 0 || dp->i_d.di_size == mp->m_dirblksize);
563 *vp = rval;
564 return 0;
565 }
566
567 /*
568 * See if the directory is a single-leaf form directory.
569 */
570 int
571 xfs_dir2_isleaf(
572 xfs_trans_t *tp,
573 xfs_inode_t *dp,
574 int *vp) /* out: 1 is leaf, 0 is not leaf */
575 {
576 xfs_fileoff_t last; /* last file offset */
577 xfs_mount_t *mp;
578 int rval;
579
580 mp = dp->i_mount;
581 if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
582 return rval;
583 *vp = last == mp->m_dirleafblk + (1 << mp->m_sb.sb_dirblklog);
584 return 0;
585 }
586
587 /*
588 * Remove the given block from the directory.
589 * This routine is used for data and free blocks, leaf/node are done
590 * by xfs_da_shrink_inode.
591 */
592 int
593 xfs_dir2_shrink_inode(
594 xfs_da_args_t *args,
595 xfs_dir2_db_t db,
596 xfs_dabuf_t *bp)
597 {
598 xfs_fileoff_t bno; /* directory file offset */
599 xfs_dablk_t da; /* directory file offset */
600 int done; /* bunmap is finished */
601 xfs_inode_t *dp;
602 int error;
603 xfs_mount_t *mp;
604 xfs_trans_t *tp;
605
606 trace_xfs_dir2_shrink_inode(args, db);
607
608 dp = args->dp;
609 mp = dp->i_mount;
610 tp = args->trans;
611 da = xfs_dir2_db_to_da(mp, db);
612 /*
613 * Unmap the fsblock(s).
614 */
615 if ((error = xfs_bunmapi(tp, dp, da, mp->m_dirblkfsbs,
616 XFS_BMAPI_METADATA, 0, args->firstblock, args->flist,
617 &done))) {
618 /*
619 * ENOSPC actually can happen if we're in a removename with
620 * no space reservation, and the resulting block removal
621 * would cause a bmap btree split or conversion from extents
622 * to btree. This can only happen for un-fragmented
623 * directory blocks, since you need to be punching out
624 * the middle of an extent.
625 * In this case we need to leave the block in the file,
626 * and not binval it.
627 * So the block has to be in a consistent empty state
628 * and appropriately logged.
629 * We don't free up the buffer, the caller can tell it
630 * hasn't happened since it got an error back.
631 */
632 return error;
633 }
634 ASSERT(done);
635 /*
636 * Invalidate the buffer from the transaction.
637 */
638 xfs_da_binval(tp, bp);
639 /*
640 * If it's not a data block, we're done.
641 */
642 if (db >= XFS_DIR2_LEAF_FIRSTDB(mp))
643 return 0;
644 /*
645 * If the block isn't the last one in the directory, we're done.
646 */
647 if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(mp, db + 1, 0))
648 return 0;
649 bno = da;
650 if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
651 /*
652 * This can't really happen unless there's kernel corruption.
653 */
654 return error;
655 }
656 if (db == mp->m_dirdatablk)
657 ASSERT(bno == 0);
658 else
659 ASSERT(bno > 0);
660 /*
661 * Set the size to the new last block.
662 */
663 dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
664 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
665 return 0;
666 }
linux-next