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xfs: convert m_dirblksize to xfs_da_geometry
[deliverable/linux.git] / fs / xfs / xfs_dir2.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_format.h"
21 #include "xfs_log_format.h"
22 #include "xfs_trans_resv.h"
23 #include "xfs_inum.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_format.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_inode.h"
30 #include "xfs_trans.h"
31 #include "xfs_inode_item.h"
32 #include "xfs_bmap.h"
33 #include "xfs_dir2.h"
34 #include "xfs_dir2_priv.h"
35 #include "xfs_error.h"
36 #include "xfs_trace.h"
37 #include "xfs_dinode.h"
38
39 struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2, XFS_DIR3_FT_DIR };
40
41
42 /*
43 * ASCII case-insensitive (ie. A-Z) support for directories that was
44 * used in IRIX.
45 */
46 STATIC xfs_dahash_t
47 xfs_ascii_ci_hashname(
48 struct xfs_name *name)
49 {
50 xfs_dahash_t hash;
51 int i;
52
53 for (i = 0, hash = 0; i < name->len; i++)
54 hash = tolower(name->name[i]) ^ rol32(hash, 7);
55
56 return hash;
57 }
58
59 STATIC enum xfs_dacmp
60 xfs_ascii_ci_compname(
61 struct xfs_da_args *args,
62 const unsigned char *name,
63 int len)
64 {
65 enum xfs_dacmp result;
66 int i;
67
68 if (args->namelen != len)
69 return XFS_CMP_DIFFERENT;
70
71 result = XFS_CMP_EXACT;
72 for (i = 0; i < len; i++) {
73 if (args->name[i] == name[i])
74 continue;
75 if (tolower(args->name[i]) != tolower(name[i]))
76 return XFS_CMP_DIFFERENT;
77 result = XFS_CMP_CASE;
78 }
79
80 return result;
81 }
82
83 static struct xfs_nameops xfs_ascii_ci_nameops = {
84 .hashname = xfs_ascii_ci_hashname,
85 .compname = xfs_ascii_ci_compname,
86 };
87
88 int
89 xfs_da_mount(
90 struct xfs_mount *mp)
91 {
92 struct xfs_da_geometry *dageo;
93 int nodehdr_size;
94
95
96 ASSERT(xfs_sb_version_hasdirv2(&mp->m_sb));
97 ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
98 XFS_MAX_BLOCKSIZE);
99
100 mp->m_dir_inode_ops = xfs_dir_get_ops(mp, NULL);
101 mp->m_nondir_inode_ops = xfs_nondir_get_ops(mp, NULL);
102
103 nodehdr_size = mp->m_dir_inode_ops->node_hdr_size;
104 mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
105 KM_SLEEP | KM_MAYFAIL);
106 mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
107 KM_SLEEP | KM_MAYFAIL);
108 if (!mp->m_dir_geo || !mp->m_attr_geo) {
109 kmem_free(mp->m_dir_geo);
110 kmem_free(mp->m_attr_geo);
111 return ENOMEM;
112 }
113
114 /* set up directory geometry */
115 dageo = mp->m_dir_geo;
116 dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
117 dageo->fsblog = mp->m_sb.sb_blocklog;
118 dageo->blksize = 1 << dageo->blklog;
119 dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
120
121 /*
122 * Now we've set up the block conversion variables, we can calculate the
123 * segment block constants using the geometry structure.
124 */
125 dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
126 dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
127 dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
128 dageo->node_ents = (dageo->blksize - nodehdr_size) /
129 (uint)sizeof(xfs_da_node_entry_t);
130 dageo->magicpct = (dageo->blksize * 37) / 100;
131
132 /* set up attribute geometry - single fsb only */
133 dageo = mp->m_attr_geo;
134 dageo->blklog = mp->m_sb.sb_blocklog;
135 dageo->fsblog = mp->m_sb.sb_blocklog;
136 dageo->blksize = 1 << dageo->blklog;
137 dageo->fsbcount = 1;
138 dageo->node_ents = (dageo->blksize - nodehdr_size) /
139 (uint)sizeof(xfs_da_node_entry_t);
140 dageo->magicpct = (dageo->blksize * 37) / 100;
141
142 if (xfs_sb_version_hasasciici(&mp->m_sb))
143 mp->m_dirnameops = &xfs_ascii_ci_nameops;
144 else
145 mp->m_dirnameops = &xfs_default_nameops;
146
147 /* XXX: these are to be removed as code is converted to use geo */
148 mp->m_dir_node_ents = mp->m_dir_geo->node_ents;
149 mp->m_dir_magicpct = mp->m_dir_geo->magicpct;
150 mp->m_attr_node_ents = mp->m_attr_geo->node_ents;
151 mp->m_attr_magicpct = mp->m_attr_geo->magicpct;
152 return 0;
153 }
154
155 void
156 xfs_da_unmount(
157 struct xfs_mount *mp)
158 {
159 kmem_free(mp->m_dir_geo);
160 kmem_free(mp->m_attr_geo);
161 }
162
163 /*
164 * Return 1 if directory contains only "." and "..".
165 */
166 int
167 xfs_dir_isempty(
168 xfs_inode_t *dp)
169 {
170 xfs_dir2_sf_hdr_t *sfp;
171
172 ASSERT(S_ISDIR(dp->i_d.di_mode));
173 if (dp->i_d.di_size == 0) /* might happen during shutdown. */
174 return 1;
175 if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
176 return 0;
177 sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
178 return !sfp->count;
179 }
180
181 /*
182 * Validate a given inode number.
183 */
184 int
185 xfs_dir_ino_validate(
186 xfs_mount_t *mp,
187 xfs_ino_t ino)
188 {
189 xfs_agblock_t agblkno;
190 xfs_agino_t agino;
191 xfs_agnumber_t agno;
192 int ino_ok;
193 int ioff;
194
195 agno = XFS_INO_TO_AGNO(mp, ino);
196 agblkno = XFS_INO_TO_AGBNO(mp, ino);
197 ioff = XFS_INO_TO_OFFSET(mp, ino);
198 agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
199 ino_ok =
200 agno < mp->m_sb.sb_agcount &&
201 agblkno < mp->m_sb.sb_agblocks &&
202 agblkno != 0 &&
203 ioff < (1 << mp->m_sb.sb_inopblog) &&
204 XFS_AGINO_TO_INO(mp, agno, agino) == ino;
205 if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
206 XFS_RANDOM_DIR_INO_VALIDATE))) {
207 xfs_warn(mp, "Invalid inode number 0x%Lx",
208 (unsigned long long) ino);
209 XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
210 return XFS_ERROR(EFSCORRUPTED);
211 }
212 return 0;
213 }
214
215 /*
216 * Initialize a directory with its "." and ".." entries.
217 */
218 int
219 xfs_dir_init(
220 xfs_trans_t *tp,
221 xfs_inode_t *dp,
222 xfs_inode_t *pdp)
223 {
224 struct xfs_da_args *args;
225 int error;
226
227 ASSERT(S_ISDIR(dp->i_d.di_mode));
228 error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
229 if (error)
230 return error;
231
232 args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
233 if (!args)
234 return ENOMEM;
235
236 args->geo = dp->i_mount->m_dir_geo;
237 args->dp = dp;
238 args->trans = tp;
239 error = xfs_dir2_sf_create(args, pdp->i_ino);
240 kmem_free(args);
241 return error;
242 }
243
244 /*
245 Enter a name in a directory.
246 */
247 int
248 xfs_dir_createname(
249 xfs_trans_t *tp,
250 xfs_inode_t *dp,
251 struct xfs_name *name,
252 xfs_ino_t inum, /* new entry inode number */
253 xfs_fsblock_t *first, /* bmap's firstblock */
254 xfs_bmap_free_t *flist, /* bmap's freeblock list */
255 xfs_extlen_t total) /* bmap's total block count */
256 {
257 struct xfs_da_args *args;
258 int rval;
259 int v; /* type-checking value */
260
261 ASSERT(S_ISDIR(dp->i_d.di_mode));
262 rval = xfs_dir_ino_validate(tp->t_mountp, inum);
263 if (rval)
264 return rval;
265 XFS_STATS_INC(xs_dir_create);
266
267 args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
268 if (!args)
269 return ENOMEM;
270
271 args->geo = dp->i_mount->m_dir_geo;
272 args->name = name->name;
273 args->namelen = name->len;
274 args->filetype = name->type;
275 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
276 args->inumber = inum;
277 args->dp = dp;
278 args->firstblock = first;
279 args->flist = flist;
280 args->total = total;
281 args->whichfork = XFS_DATA_FORK;
282 args->trans = tp;
283 args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
284
285 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
286 rval = xfs_dir2_sf_addname(args);
287 goto out_free;
288 }
289
290 rval = xfs_dir2_isblock(dp, &v);
291 if (rval)
292 goto out_free;
293 if (v) {
294 rval = xfs_dir2_block_addname(args);
295 goto out_free;
296 }
297
298 rval = xfs_dir2_isleaf(dp, &v);
299 if (rval)
300 goto out_free;
301 if (v)
302 rval = xfs_dir2_leaf_addname(args);
303 else
304 rval = xfs_dir2_node_addname(args);
305
306 out_free:
307 kmem_free(args);
308 return rval;
309 }
310
311 /*
312 * If doing a CI lookup and case-insensitive match, dup actual name into
313 * args.value. Return EEXIST for success (ie. name found) or an error.
314 */
315 int
316 xfs_dir_cilookup_result(
317 struct xfs_da_args *args,
318 const unsigned char *name,
319 int len)
320 {
321 if (args->cmpresult == XFS_CMP_DIFFERENT)
322 return ENOENT;
323 if (args->cmpresult != XFS_CMP_CASE ||
324 !(args->op_flags & XFS_DA_OP_CILOOKUP))
325 return EEXIST;
326
327 args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
328 if (!args->value)
329 return ENOMEM;
330
331 memcpy(args->value, name, len);
332 args->valuelen = len;
333 return EEXIST;
334 }
335
336 /*
337 * Lookup a name in a directory, give back the inode number.
338 * If ci_name is not NULL, returns the actual name in ci_name if it differs
339 * to name, or ci_name->name is set to NULL for an exact match.
340 */
341
342 int
343 xfs_dir_lookup(
344 xfs_trans_t *tp,
345 xfs_inode_t *dp,
346 struct xfs_name *name,
347 xfs_ino_t *inum, /* out: inode number */
348 struct xfs_name *ci_name) /* out: actual name if CI match */
349 {
350 struct xfs_da_args *args;
351 int rval;
352 int v; /* type-checking value */
353
354 ASSERT(S_ISDIR(dp->i_d.di_mode));
355 XFS_STATS_INC(xs_dir_lookup);
356
357 /*
358 * We need to use KM_NOFS here so that lockdep will not throw false
359 * positive deadlock warnings on a non-transactional lookup path. It is
360 * safe to recurse into inode recalim in that case, but lockdep can't
361 * easily be taught about it. Hence KM_NOFS avoids having to add more
362 * lockdep Doing this avoids having to add a bunch of lockdep class
363 * annotations into the reclaim path for the ilock.
364 */
365 args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
366 args->geo = dp->i_mount->m_dir_geo;
367 args->name = name->name;
368 args->namelen = name->len;
369 args->filetype = name->type;
370 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
371 args->dp = dp;
372 args->whichfork = XFS_DATA_FORK;
373 args->trans = tp;
374 args->op_flags = XFS_DA_OP_OKNOENT;
375 if (ci_name)
376 args->op_flags |= XFS_DA_OP_CILOOKUP;
377
378 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
379 rval = xfs_dir2_sf_lookup(args);
380 goto out_check_rval;
381 }
382
383 rval = xfs_dir2_isblock(dp, &v);
384 if (rval)
385 goto out_free;
386 if (v) {
387 rval = xfs_dir2_block_lookup(args);
388 goto out_check_rval;
389 }
390
391 rval = xfs_dir2_isleaf(dp, &v);
392 if (rval)
393 goto out_free;
394 if (v)
395 rval = xfs_dir2_leaf_lookup(args);
396 else
397 rval = xfs_dir2_node_lookup(args);
398
399 out_check_rval:
400 if (rval == EEXIST)
401 rval = 0;
402 if (!rval) {
403 *inum = args->inumber;
404 if (ci_name) {
405 ci_name->name = args->value;
406 ci_name->len = args->valuelen;
407 }
408 }
409 out_free:
410 kmem_free(args);
411 return rval;
412 }
413
414 /*
415 * Remove an entry from a directory.
416 */
417 int
418 xfs_dir_removename(
419 xfs_trans_t *tp,
420 xfs_inode_t *dp,
421 struct xfs_name *name,
422 xfs_ino_t ino,
423 xfs_fsblock_t *first, /* bmap's firstblock */
424 xfs_bmap_free_t *flist, /* bmap's freeblock list */
425 xfs_extlen_t total) /* bmap's total block count */
426 {
427 struct xfs_da_args *args;
428 int rval;
429 int v; /* type-checking value */
430
431 ASSERT(S_ISDIR(dp->i_d.di_mode));
432 XFS_STATS_INC(xs_dir_remove);
433
434 args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
435 if (!args)
436 return ENOMEM;
437
438 args->geo = dp->i_mount->m_dir_geo;
439 args->name = name->name;
440 args->namelen = name->len;
441 args->filetype = name->type;
442 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
443 args->inumber = ino;
444 args->dp = dp;
445 args->firstblock = first;
446 args->flist = flist;
447 args->total = total;
448 args->whichfork = XFS_DATA_FORK;
449 args->trans = tp;
450
451 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
452 rval = xfs_dir2_sf_removename(args);
453 goto out_free;
454 }
455
456 rval = xfs_dir2_isblock(dp, &v);
457 if (rval)
458 goto out_free;
459 if (v) {
460 rval = xfs_dir2_block_removename(args);
461 goto out_free;
462 }
463
464 rval = xfs_dir2_isleaf(dp, &v);
465 if (rval)
466 goto out_free;
467 if (v)
468 rval = xfs_dir2_leaf_removename(args);
469 else
470 rval = xfs_dir2_node_removename(args);
471 out_free:
472 kmem_free(args);
473 return rval;
474 }
475
476 /*
477 * Replace the inode number of a directory entry.
478 */
479 int
480 xfs_dir_replace(
481 xfs_trans_t *tp,
482 xfs_inode_t *dp,
483 struct xfs_name *name, /* name of entry to replace */
484 xfs_ino_t inum, /* new inode number */
485 xfs_fsblock_t *first, /* bmap's firstblock */
486 xfs_bmap_free_t *flist, /* bmap's freeblock list */
487 xfs_extlen_t total) /* bmap's total block count */
488 {
489 struct xfs_da_args *args;
490 int rval;
491 int v; /* type-checking value */
492
493 ASSERT(S_ISDIR(dp->i_d.di_mode));
494
495 rval = xfs_dir_ino_validate(tp->t_mountp, inum);
496 if (rval)
497 return rval;
498
499 args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
500 if (!args)
501 return ENOMEM;
502
503 args->geo = dp->i_mount->m_dir_geo;
504 args->name = name->name;
505 args->namelen = name->len;
506 args->filetype = name->type;
507 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
508 args->inumber = inum;
509 args->dp = dp;
510 args->firstblock = first;
511 args->flist = flist;
512 args->total = total;
513 args->whichfork = XFS_DATA_FORK;
514 args->trans = tp;
515
516 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
517 rval = xfs_dir2_sf_replace(args);
518 goto out_free;
519 }
520
521 rval = xfs_dir2_isblock(dp, &v);
522 if (rval)
523 goto out_free;
524 if (v) {
525 rval = xfs_dir2_block_replace(args);
526 goto out_free;
527 }
528
529 rval = xfs_dir2_isleaf(dp, &v);
530 if (rval)
531 goto out_free;
532 if (v)
533 rval = xfs_dir2_leaf_replace(args);
534 else
535 rval = xfs_dir2_node_replace(args);
536 out_free:
537 kmem_free(args);
538 return rval;
539 }
540
541 /*
542 * See if this entry can be added to the directory without allocating space.
543 * First checks that the caller couldn't reserve enough space (resblks = 0).
544 */
545 int
546 xfs_dir_canenter(
547 xfs_trans_t *tp,
548 xfs_inode_t *dp,
549 struct xfs_name *name, /* name of entry to add */
550 uint resblks)
551 {
552 struct xfs_da_args *args;
553 int rval;
554 int v; /* type-checking value */
555
556 if (resblks)
557 return 0;
558
559 ASSERT(S_ISDIR(dp->i_d.di_mode));
560
561 args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
562 if (!args)
563 return ENOMEM;
564
565 args->geo = dp->i_mount->m_dir_geo;
566 args->name = name->name;
567 args->namelen = name->len;
568 args->filetype = name->type;
569 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
570 args->dp = dp;
571 args->whichfork = XFS_DATA_FORK;
572 args->trans = tp;
573 args->op_flags = XFS_DA_OP_JUSTCHECK | XFS_DA_OP_ADDNAME |
574 XFS_DA_OP_OKNOENT;
575
576 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
577 rval = xfs_dir2_sf_addname(args);
578 goto out_free;
579 }
580
581 rval = xfs_dir2_isblock(dp, &v);
582 if (rval)
583 goto out_free;
584 if (v) {
585 rval = xfs_dir2_block_addname(args);
586 goto out_free;
587 }
588
589 rval = xfs_dir2_isleaf(dp, &v);
590 if (rval)
591 goto out_free;
592 if (v)
593 rval = xfs_dir2_leaf_addname(args);
594 else
595 rval = xfs_dir2_node_addname(args);
596 out_free:
597 kmem_free(args);
598 return rval;
599 }
600
601 /*
602 * Utility routines.
603 */
604
605 /*
606 * Add a block to the directory.
607 *
608 * This routine is for data and free blocks, not leaf/node blocks which are
609 * handled by xfs_da_grow_inode.
610 */
611 int
612 xfs_dir2_grow_inode(
613 struct xfs_da_args *args,
614 int space, /* v2 dir's space XFS_DIR2_xxx_SPACE */
615 xfs_dir2_db_t *dbp) /* out: block number added */
616 {
617 struct xfs_inode *dp = args->dp;
618 struct xfs_mount *mp = dp->i_mount;
619 xfs_fileoff_t bno; /* directory offset of new block */
620 int count; /* count of filesystem blocks */
621 int error;
622
623 trace_xfs_dir2_grow_inode(args, space);
624
625 /*
626 * Set lowest possible block in the space requested.
627 */
628 bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
629 count = args->geo->fsbcount;
630
631 error = xfs_da_grow_inode_int(args, &bno, count);
632 if (error)
633 return error;
634
635 *dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
636
637 /*
638 * Update file's size if this is the data space and it grew.
639 */
640 if (space == XFS_DIR2_DATA_SPACE) {
641 xfs_fsize_t size; /* directory file (data) size */
642
643 size = XFS_FSB_TO_B(mp, bno + count);
644 if (size > dp->i_d.di_size) {
645 dp->i_d.di_size = size;
646 xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
647 }
648 }
649 return 0;
650 }
651
652 /*
653 * See if the directory is a single-block form directory.
654 */
655 int
656 xfs_dir2_isblock(
657 xfs_inode_t *dp,
658 int *vp) /* out: 1 is block, 0 is not block */
659 {
660 xfs_fileoff_t last; /* last file offset */
661 xfs_mount_t *mp;
662 int rval;
663
664 mp = dp->i_mount;
665 if ((rval = xfs_bmap_last_offset(dp, &last, XFS_DATA_FORK)))
666 return rval;
667 rval = XFS_FSB_TO_B(mp, last) == mp->m_dir_geo->blksize;
668 ASSERT(rval == 0 || dp->i_d.di_size == mp->m_dir_geo->blksize);
669 *vp = rval;
670 return 0;
671 }
672
673 /*
674 * See if the directory is a single-leaf form directory.
675 */
676 int
677 xfs_dir2_isleaf(
678 xfs_inode_t *dp,
679 int *vp) /* out: 1 is leaf, 0 is not leaf */
680 {
681 xfs_fileoff_t last; /* last file offset */
682 xfs_mount_t *mp;
683 int rval;
684
685 mp = dp->i_mount;
686 if ((rval = xfs_bmap_last_offset(dp, &last, XFS_DATA_FORK)))
687 return rval;
688 *vp = last == mp->m_dir_geo->leafblk + (1 << mp->m_sb.sb_dirblklog);
689 return 0;
690 }
691
692 /*
693 * Remove the given block from the directory.
694 * This routine is used for data and free blocks, leaf/node are done
695 * by xfs_da_shrink_inode.
696 */
697 int
698 xfs_dir2_shrink_inode(
699 xfs_da_args_t *args,
700 xfs_dir2_db_t db,
701 struct xfs_buf *bp)
702 {
703 xfs_fileoff_t bno; /* directory file offset */
704 xfs_dablk_t da; /* directory file offset */
705 int done; /* bunmap is finished */
706 xfs_inode_t *dp;
707 int error;
708 xfs_mount_t *mp;
709 xfs_trans_t *tp;
710
711 trace_xfs_dir2_shrink_inode(args, db);
712
713 dp = args->dp;
714 mp = dp->i_mount;
715 tp = args->trans;
716 da = xfs_dir2_db_to_da(args->geo, db);
717 /*
718 * Unmap the fsblock(s).
719 */
720 if ((error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount,
721 XFS_BMAPI_METADATA, 0, args->firstblock, args->flist,
722 &done))) {
723 /*
724 * ENOSPC actually can happen if we're in a removename with
725 * no space reservation, and the resulting block removal
726 * would cause a bmap btree split or conversion from extents
727 * to btree. This can only happen for un-fragmented
728 * directory blocks, since you need to be punching out
729 * the middle of an extent.
730 * In this case we need to leave the block in the file,
731 * and not binval it.
732 * So the block has to be in a consistent empty state
733 * and appropriately logged.
734 * We don't free up the buffer, the caller can tell it
735 * hasn't happened since it got an error back.
736 */
737 return error;
738 }
739 ASSERT(done);
740 /*
741 * Invalidate the buffer from the transaction.
742 */
743 xfs_trans_binval(tp, bp);
744 /*
745 * If it's not a data block, we're done.
746 */
747 if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
748 return 0;
749 /*
750 * If the block isn't the last one in the directory, we're done.
751 */
752 if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
753 return 0;
754 bno = da;
755 if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
756 /*
757 * This can't really happen unless there's kernel corruption.
758 */
759 return error;
760 }
761 if (db == args->geo->datablk)
762 ASSERT(bno == 0);
763 else
764 ASSERT(bno > 0);
765 /*
766 * Set the size to the new last block.
767 */
768 dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
769 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
770 return 0;
771 }
Linux kernel - Deliverables
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