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Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso...
[linux/fpc-iii.git] / fs / xfs / xfs_dir2.c
blobb26a50f9921db60e746d43946b644415ba24ca6a
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_inum.h"
23 #include "xfs_trans.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_btree.h"
28 #include "xfs_bmap_btree.h"
29 #include "xfs_alloc_btree.h"
30 #include "xfs_dinode.h"
31 #include "xfs_inode.h"
32 #include "xfs_inode_item.h"
33 #include "xfs_bmap.h"
34 #include "xfs_dir2.h"
35 #include "xfs_dir2_format.h"
36 #include "xfs_dir2_priv.h"
37 #include "xfs_error.h"
38 #include "xfs_vnodeops.h"
39 #include "xfs_trace.h"
40
41 struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2};
42
43 /*
44 * ASCII case-insensitive (ie. A-Z) support for directories that was
45 * used in IRIX.
46 */
47 STATIC xfs_dahash_t
48 xfs_ascii_ci_hashname(
49 struct xfs_name *name)
50 {
51 xfs_dahash_t hash;
52 int i;
53
54 for (i = 0, hash = 0; i < name->len; i++)
55 hash = tolower(name->name[i]) ^ rol32(hash, 7);
56
57 return hash;
58 }
59
60 STATIC enum xfs_dacmp
61 xfs_ascii_ci_compname(
62 struct xfs_da_args *args,
63 const unsigned char *name,
64 int len)
65 {
66 enum xfs_dacmp result;
67 int i;
68
69 if (args->namelen != len)
70 return XFS_CMP_DIFFERENT;
71
72 result = XFS_CMP_EXACT;
73 for (i = 0; i < len; i++) {
74 if (args->name[i] == name[i])
75 continue;
76 if (tolower(args->name[i]) != tolower(name[i]))
77 return XFS_CMP_DIFFERENT;
78 result = XFS_CMP_CASE;
79 }
80
81 return result;
82 }
83
84 static struct xfs_nameops xfs_ascii_ci_nameops = {
85 .hashname = xfs_ascii_ci_hashname,
86 .compname = xfs_ascii_ci_compname,
87 };
88
89 void
90 xfs_dir_mount(
91 xfs_mount_t *mp)
92 {
93 ASSERT(xfs_sb_version_hasdirv2(&mp->m_sb));
94 ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
95 XFS_MAX_BLOCKSIZE);
96 mp->m_dirblksize = 1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog);
97 mp->m_dirblkfsbs = 1 << mp->m_sb.sb_dirblklog;
98 mp->m_dirdatablk = xfs_dir2_db_to_da(mp, XFS_DIR2_DATA_FIRSTDB(mp));
99 mp->m_dirleafblk = xfs_dir2_db_to_da(mp, XFS_DIR2_LEAF_FIRSTDB(mp));
100 mp->m_dirfreeblk = xfs_dir2_db_to_da(mp, XFS_DIR2_FREE_FIRSTDB(mp));
101 mp->m_attr_node_ents =
102 (mp->m_sb.sb_blocksize - (uint)sizeof(xfs_da_node_hdr_t)) /
103 (uint)sizeof(xfs_da_node_entry_t);
104 mp->m_dir_node_ents =
105 (mp->m_dirblksize - (uint)sizeof(xfs_da_node_hdr_t)) /
106 (uint)sizeof(xfs_da_node_entry_t);
107 mp->m_dir_magicpct = (mp->m_dirblksize * 37) / 100;
108 if (xfs_sb_version_hasasciici(&mp->m_sb))
109 mp->m_dirnameops = &xfs_ascii_ci_nameops;
110 else
111 mp->m_dirnameops = &xfs_default_nameops;
112 }
113
114 /*
115 * Return 1 if directory contains only "." and "..".
116 */
117 int
118 xfs_dir_isempty(
119 xfs_inode_t *dp)
120 {
121 xfs_dir2_sf_hdr_t *sfp;
122
123 ASSERT(S_ISDIR(dp->i_d.di_mode));
124 if (dp->i_d.di_size == 0) /* might happen during shutdown. */
125 return 1;
126 if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
127 return 0;
128 sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
129 return !sfp->count;
130 }
131
132 /*
133 * Validate a given inode number.
134 */
135 int
136 xfs_dir_ino_validate(
137 xfs_mount_t *mp,
138 xfs_ino_t ino)
139 {
140 xfs_agblock_t agblkno;
141 xfs_agino_t agino;
142 xfs_agnumber_t agno;
143 int ino_ok;
144 int ioff;
145
146 agno = XFS_INO_TO_AGNO(mp, ino);
147 agblkno = XFS_INO_TO_AGBNO(mp, ino);
148 ioff = XFS_INO_TO_OFFSET(mp, ino);
149 agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
150 ino_ok =
151 agno < mp->m_sb.sb_agcount &&
152 agblkno < mp->m_sb.sb_agblocks &&
153 agblkno != 0 &&
154 ioff < (1 << mp->m_sb.sb_inopblog) &&
155 XFS_AGINO_TO_INO(mp, agno, agino) == ino;
156 if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
157 XFS_RANDOM_DIR_INO_VALIDATE))) {
158 xfs_warn(mp, "Invalid inode number 0x%Lx",
159 (unsigned long long) ino);
160 XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
161 return XFS_ERROR(EFSCORRUPTED);
162 }
163 return 0;
164 }
165
166 /*
167 * Initialize a directory with its "." and ".." entries.
168 */
169 int
170 xfs_dir_init(
171 xfs_trans_t *tp,
172 xfs_inode_t *dp,
173 xfs_inode_t *pdp)
174 {
175 xfs_da_args_t args;
176 int error;
177
178 memset((char *)&args, 0, sizeof(args));
179 args.dp = dp;
180 args.trans = tp;
181 ASSERT(S_ISDIR(dp->i_d.di_mode));
182 if ((error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino)))
183 return error;
184 return xfs_dir2_sf_create(&args, pdp->i_ino);
185 }
186
187 /*
188 Enter a name in a directory.
189 */
190 int
191 xfs_dir_createname(
192 xfs_trans_t *tp,
193 xfs_inode_t *dp,
194 struct xfs_name *name,
195 xfs_ino_t inum, /* new entry inode number */
196 xfs_fsblock_t *first, /* bmap's firstblock */
197 xfs_bmap_free_t *flist, /* bmap's freeblock list */
198 xfs_extlen_t total) /* bmap's total block count */
199 {
200 xfs_da_args_t args;
201 int rval;
202 int v; /* type-checking value */
203
204 ASSERT(S_ISDIR(dp->i_d.di_mode));
205 if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
206 return rval;
207 XFS_STATS_INC(xs_dir_create);
208
209 memset(&args, 0, sizeof(xfs_da_args_t));
210 args.name = name->name;
211 args.namelen = name->len;
212 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
213 args.inumber = inum;
214 args.dp = dp;
215 args.firstblock = first;
216 args.flist = flist;
217 args.total = total;
218 args.whichfork = XFS_DATA_FORK;
219 args.trans = tp;
220 args.op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
221
222 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
223 rval = xfs_dir2_sf_addname(&args);
224 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
225 return rval;
226 else if (v)
227 rval = xfs_dir2_block_addname(&args);
228 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
229 return rval;
230 else if (v)
231 rval = xfs_dir2_leaf_addname(&args);
232 else
233 rval = xfs_dir2_node_addname(&args);
234 return rval;
235 }
236
237 /*
238 * If doing a CI lookup and case-insensitive match, dup actual name into
239 * args.value. Return EEXIST for success (ie. name found) or an error.
240 */
241 int
242 xfs_dir_cilookup_result(
243 struct xfs_da_args *args,
244 const unsigned char *name,
245 int len)
246 {
247 if (args->cmpresult == XFS_CMP_DIFFERENT)
248 return ENOENT;
249 if (args->cmpresult != XFS_CMP_CASE ||
250 !(args->op_flags & XFS_DA_OP_CILOOKUP))
251 return EEXIST;
252
253 args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
254 if (!args->value)
255 return ENOMEM;
256
257 memcpy(args->value, name, len);
258 args->valuelen = len;
259 return EEXIST;
260 }
261
262 /*
263 * Lookup a name in a directory, give back the inode number.
264 * If ci_name is not NULL, returns the actual name in ci_name if it differs
265 * to name, or ci_name->name is set to NULL for an exact match.
266 */
267
268 int
269 xfs_dir_lookup(
270 xfs_trans_t *tp,
271 xfs_inode_t *dp,
272 struct xfs_name *name,
273 xfs_ino_t *inum, /* out: inode number */
274 struct xfs_name *ci_name) /* out: actual name if CI match */
275 {
276 xfs_da_args_t args;
277 int rval;
278 int v; /* type-checking value */
279
280 ASSERT(S_ISDIR(dp->i_d.di_mode));
281 XFS_STATS_INC(xs_dir_lookup);
282
283 memset(&args, 0, sizeof(xfs_da_args_t));
284 args.name = name->name;
285 args.namelen = name->len;
286 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
287 args.dp = dp;
288 args.whichfork = XFS_DATA_FORK;
289 args.trans = tp;
290 args.op_flags = XFS_DA_OP_OKNOENT;
291 if (ci_name)
292 args.op_flags |= XFS_DA_OP_CILOOKUP;
293
294 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
295 rval = xfs_dir2_sf_lookup(&args);
296 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
297 return rval;
298 else if (v)
299 rval = xfs_dir2_block_lookup(&args);
300 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
301 return rval;
302 else if (v)
303 rval = xfs_dir2_leaf_lookup(&args);
304 else
305 rval = xfs_dir2_node_lookup(&args);
306 if (rval == EEXIST)
307 rval = 0;
308 if (!rval) {
309 *inum = args.inumber;
310 if (ci_name) {
311 ci_name->name = args.value;
312 ci_name->len = args.valuelen;
313 }
314 }
315 return rval;
316 }
317
318 /*
319 * Remove an entry from a directory.
320 */
321 int
322 xfs_dir_removename(
323 xfs_trans_t *tp,
324 xfs_inode_t *dp,
325 struct xfs_name *name,
326 xfs_ino_t ino,
327 xfs_fsblock_t *first, /* bmap's firstblock */
328 xfs_bmap_free_t *flist, /* bmap's freeblock list */
329 xfs_extlen_t total) /* bmap's total block count */
330 {
331 xfs_da_args_t args;
332 int rval;
333 int v; /* type-checking value */
334
335 ASSERT(S_ISDIR(dp->i_d.di_mode));
336 XFS_STATS_INC(xs_dir_remove);
337
338 memset(&args, 0, sizeof(xfs_da_args_t));
339 args.name = name->name;
340 args.namelen = name->len;
341 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
342 args.inumber = ino;
343 args.dp = dp;
344 args.firstblock = first;
345 args.flist = flist;
346 args.total = total;
347 args.whichfork = XFS_DATA_FORK;
348 args.trans = tp;
349
350 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
351 rval = xfs_dir2_sf_removename(&args);
352 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
353 return rval;
354 else if (v)
355 rval = xfs_dir2_block_removename(&args);
356 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
357 return rval;
358 else if (v)
359 rval = xfs_dir2_leaf_removename(&args);
360 else
361 rval = xfs_dir2_node_removename(&args);
362 return rval;
363 }
364
365 /*
366 * Read a directory.
367 */
368 int
369 xfs_readdir(
370 xfs_inode_t *dp,
371 void *dirent,
372 size_t bufsize,
373 xfs_off_t *offset,
374 filldir_t filldir)
375 {
376 int rval; /* return value */
377 int v; /* type-checking value */
378
379 trace_xfs_readdir(dp);
380
381 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
382 return XFS_ERROR(EIO);
383
384 ASSERT(S_ISDIR(dp->i_d.di_mode));
385 XFS_STATS_INC(xs_dir_getdents);
386
387 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
388 rval = xfs_dir2_sf_getdents(dp, dirent, offset, filldir);
389 else if ((rval = xfs_dir2_isblock(NULL, dp, &v)))
390 ;
391 else if (v)
392 rval = xfs_dir2_block_getdents(dp, dirent, offset, filldir);
393 else
394 rval = xfs_dir2_leaf_getdents(dp, dirent, bufsize, offset,
395 filldir);
396 return rval;
397 }
398
399 /*
400 * Replace the inode number of a directory entry.
401 */
402 int
403 xfs_dir_replace(
404 xfs_trans_t *tp,
405 xfs_inode_t *dp,
406 struct xfs_name *name, /* name of entry to replace */
407 xfs_ino_t inum, /* new inode number */
408 xfs_fsblock_t *first, /* bmap's firstblock */
409 xfs_bmap_free_t *flist, /* bmap's freeblock list */
410 xfs_extlen_t total) /* bmap's total block count */
411 {
412 xfs_da_args_t args;
413 int rval;
414 int v; /* type-checking value */
415
416 ASSERT(S_ISDIR(dp->i_d.di_mode));
417
418 if ((rval = xfs_dir_ino_validate(tp->t_mountp, inum)))
419 return rval;
420
421 memset(&args, 0, sizeof(xfs_da_args_t));
422 args.name = name->name;
423 args.namelen = name->len;
424 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
425 args.inumber = inum;
426 args.dp = dp;
427 args.firstblock = first;
428 args.flist = flist;
429 args.total = total;
430 args.whichfork = XFS_DATA_FORK;
431 args.trans = tp;
432
433 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
434 rval = xfs_dir2_sf_replace(&args);
435 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
436 return rval;
437 else if (v)
438 rval = xfs_dir2_block_replace(&args);
439 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
440 return rval;
441 else if (v)
442 rval = xfs_dir2_leaf_replace(&args);
443 else
444 rval = xfs_dir2_node_replace(&args);
445 return rval;
446 }
447
448 /*
449 * See if this entry can be added to the directory without allocating space.
450 * First checks that the caller couldn't reserve enough space (resblks = 0).
451 */
452 int
453 xfs_dir_canenter(
454 xfs_trans_t *tp,
455 xfs_inode_t *dp,
456 struct xfs_name *name, /* name of entry to add */
457 uint resblks)
458 {
459 xfs_da_args_t args;
460 int rval;
461 int v; /* type-checking value */
462
463 if (resblks)
464 return 0;
465
466 ASSERT(S_ISDIR(dp->i_d.di_mode));
467
468 memset(&args, 0, sizeof(xfs_da_args_t));
469 args.name = name->name;
470 args.namelen = name->len;
471 args.hashval = dp->i_mount->m_dirnameops->hashname(name);
472 args.dp = dp;
473 args.whichfork = XFS_DATA_FORK;
474 args.trans = tp;
475 args.op_flags = XFS_DA_OP_JUSTCHECK | XFS_DA_OP_ADDNAME |
476 XFS_DA_OP_OKNOENT;
477
478 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
479 rval = xfs_dir2_sf_addname(&args);
480 else if ((rval = xfs_dir2_isblock(tp, dp, &v)))
481 return rval;
482 else if (v)
483 rval = xfs_dir2_block_addname(&args);
484 else if ((rval = xfs_dir2_isleaf(tp, dp, &v)))
485 return rval;
486 else if (v)
487 rval = xfs_dir2_leaf_addname(&args);
488 else
489 rval = xfs_dir2_node_addname(&args);
490 return rval;
491 }
492
493 /*
494 * Utility routines.
495 */
496
497 /*
498 * Add a block to the directory.
499 *
500 * This routine is for data and free blocks, not leaf/node blocks which are
501 * handled by xfs_da_grow_inode.
502 */
503 int
504 xfs_dir2_grow_inode(
505 struct xfs_da_args *args,
506 int space, /* v2 dir's space XFS_DIR2_xxx_SPACE */
507 xfs_dir2_db_t *dbp) /* out: block number added */
508 {
509 struct xfs_inode *dp = args->dp;
510 struct xfs_mount *mp = dp->i_mount;
511 xfs_fileoff_t bno; /* directory offset of new block */
512 int count; /* count of filesystem blocks */
513 int error;
514
515 trace_xfs_dir2_grow_inode(args, space);
516
517 /*
518 * Set lowest possible block in the space requested.
519 */
520 bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
521 count = mp->m_dirblkfsbs;
522
523 error = xfs_da_grow_inode_int(args, &bno, count);
524 if (error)
525 return error;
526
527 *dbp = xfs_dir2_da_to_db(mp, (xfs_dablk_t)bno);
528
529 /*
530 * Update file's size if this is the data space and it grew.
531 */
532 if (space == XFS_DIR2_DATA_SPACE) {
533 xfs_fsize_t size; /* directory file (data) size */
534
535 size = XFS_FSB_TO_B(mp, bno + count);
536 if (size > dp->i_d.di_size) {
537 dp->i_d.di_size = size;
538 xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
539 }
540 }
541 return 0;
542 }
543
544 /*
545 * See if the directory is a single-block form directory.
546 */
547 int
548 xfs_dir2_isblock(
549 xfs_trans_t *tp,
550 xfs_inode_t *dp,
551 int *vp) /* out: 1 is block, 0 is not block */
552 {
553 xfs_fileoff_t last; /* last file offset */
554 xfs_mount_t *mp;
555 int rval;
556
557 mp = dp->i_mount;
558 if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
559 return rval;
560 rval = XFS_FSB_TO_B(mp, last) == mp->m_dirblksize;
561 ASSERT(rval == 0 || dp->i_d.di_size == mp->m_dirblksize);
562 *vp = rval;
563 return 0;
564 }
565
566 /*
567 * See if the directory is a single-leaf form directory.
568 */
569 int
570 xfs_dir2_isleaf(
571 xfs_trans_t *tp,
572 xfs_inode_t *dp,
573 int *vp) /* out: 1 is leaf, 0 is not leaf */
574 {
575 xfs_fileoff_t last; /* last file offset */
576 xfs_mount_t *mp;
577 int rval;
578
579 mp = dp->i_mount;
580 if ((rval = xfs_bmap_last_offset(tp, dp, &last, XFS_DATA_FORK)))
581 return rval;
582 *vp = last == mp->m_dirleafblk + (1 << mp->m_sb.sb_dirblklog);
583 return 0;
584 }
585
586 /*
587 * Remove the given block from the directory.
588 * This routine is used for data and free blocks, leaf/node are done
589 * by xfs_da_shrink_inode.
590 */
591 int
592 xfs_dir2_shrink_inode(
593 xfs_da_args_t *args,
594 xfs_dir2_db_t db,
595 struct xfs_buf *bp)
596 {
597 xfs_fileoff_t bno; /* directory file offset */
598 xfs_dablk_t da; /* directory file offset */
599 int done; /* bunmap is finished */
600 xfs_inode_t *dp;
601 int error;
602 xfs_mount_t *mp;
603 xfs_trans_t *tp;
604
605 trace_xfs_dir2_shrink_inode(args, db);
606
607 dp = args->dp;
608 mp = dp->i_mount;
609 tp = args->trans;
610 da = xfs_dir2_db_to_da(mp, db);
611 /*
612 * Unmap the fsblock(s).
613 */
614 if ((error = xfs_bunmapi(tp, dp, da, mp->m_dirblkfsbs,
615 XFS_BMAPI_METADATA, 0, args->firstblock, args->flist,
616 &done))) {
617 /*
618 * ENOSPC actually can happen if we're in a removename with
619 * no space reservation, and the resulting block removal
620 * would cause a bmap btree split or conversion from extents
621 * to btree. This can only happen for un-fragmented
622 * directory blocks, since you need to be punching out
623 * the middle of an extent.
624 * In this case we need to leave the block in the file,
625 * and not binval it.
626 * So the block has to be in a consistent empty state
627 * and appropriately logged.
628 * We don't free up the buffer, the caller can tell it
629 * hasn't happened since it got an error back.
630 */
631 return error;
632 }
633 ASSERT(done);
634 /*
635 * Invalidate the buffer from the transaction.
636 */
637 xfs_trans_binval(tp, bp);
638 /*
639 * If it's not a data block, we're done.
640 */
641 if (db >= XFS_DIR2_LEAF_FIRSTDB(mp))
642 return 0;
643 /*
644 * If the block isn't the last one in the directory, we're done.
645 */
646 if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(mp, db + 1, 0))
647 return 0;
648 bno = da;
649 if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
650 /*
651 * This can't really happen unless there's kernel corruption.
652 */
653 return error;
654 }
655 if (db == mp->m_dirdatablk)
656 ASSERT(bno == 0);
657 else
658 ASSERT(bno > 0);
659 /*
660 * Set the size to the new last block.
661 */
662 dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
663 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
664 return 0;
665 }
Linux with added FPC-III support