xref: /linux/fs/xfs/libxfs/xfs_dir2.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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_mount.h"
24 #include "xfs_da_format.h"
25 #include "xfs_da_btree.h"
26 #include "xfs_inode.h"
27 #include "xfs_trans.h"
28 #include "xfs_inode_item.h"
29 #include "xfs_bmap.h"
30 #include "xfs_dir2.h"
31 #include "xfs_dir2_priv.h"
32 #include "xfs_error.h"
33 #include "xfs_trace.h"
34 
35 struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2, XFS_DIR3_FT_DIR };
36 
37 /*
38  * @mode, if set, indicates that the type field needs to be set up.
39  * This uses the transformation from file mode to DT_* as defined in linux/fs.h
40  * for file type specification. This will be propagated into the directory
41  * structure if appropriate for the given operation and filesystem config.
42  */
43 const unsigned char xfs_mode_to_ftype[S_IFMT >> S_SHIFT] = {
44 	[0]			= XFS_DIR3_FT_UNKNOWN,
45 	[S_IFREG >> S_SHIFT]    = XFS_DIR3_FT_REG_FILE,
46 	[S_IFDIR >> S_SHIFT]    = XFS_DIR3_FT_DIR,
47 	[S_IFCHR >> S_SHIFT]    = XFS_DIR3_FT_CHRDEV,
48 	[S_IFBLK >> S_SHIFT]    = XFS_DIR3_FT_BLKDEV,
49 	[S_IFIFO >> S_SHIFT]    = XFS_DIR3_FT_FIFO,
50 	[S_IFSOCK >> S_SHIFT]   = XFS_DIR3_FT_SOCK,
51 	[S_IFLNK >> S_SHIFT]    = XFS_DIR3_FT_SYMLINK,
52 };
53 
54 /*
55  * ASCII case-insensitive (ie. A-Z) support for directories that was
56  * used in IRIX.
57  */
58 STATIC xfs_dahash_t
59 xfs_ascii_ci_hashname(
60 	struct xfs_name	*name)
61 {
62 	xfs_dahash_t	hash;
63 	int		i;
64 
65 	for (i = 0, hash = 0; i < name->len; i++)
66 		hash = tolower(name->name[i]) ^ rol32(hash, 7);
67 
68 	return hash;
69 }
70 
71 STATIC enum xfs_dacmp
72 xfs_ascii_ci_compname(
73 	struct xfs_da_args *args,
74 	const unsigned char *name,
75 	int		len)
76 {
77 	enum xfs_dacmp	result;
78 	int		i;
79 
80 	if (args->namelen != len)
81 		return XFS_CMP_DIFFERENT;
82 
83 	result = XFS_CMP_EXACT;
84 	for (i = 0; i < len; i++) {
85 		if (args->name[i] == name[i])
86 			continue;
87 		if (tolower(args->name[i]) != tolower(name[i]))
88 			return XFS_CMP_DIFFERENT;
89 		result = XFS_CMP_CASE;
90 	}
91 
92 	return result;
93 }
94 
95 static struct xfs_nameops xfs_ascii_ci_nameops = {
96 	.hashname	= xfs_ascii_ci_hashname,
97 	.compname	= xfs_ascii_ci_compname,
98 };
99 
100 int
101 xfs_da_mount(
102 	struct xfs_mount	*mp)
103 {
104 	struct xfs_da_geometry	*dageo;
105 	int			nodehdr_size;
106 
107 
108 	ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
109 	ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
110 	       XFS_MAX_BLOCKSIZE);
111 
112 	mp->m_dir_inode_ops = xfs_dir_get_ops(mp, NULL);
113 	mp->m_nondir_inode_ops = xfs_nondir_get_ops(mp, NULL);
114 
115 	nodehdr_size = mp->m_dir_inode_ops->node_hdr_size;
116 	mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
117 				    KM_SLEEP | KM_MAYFAIL);
118 	mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
119 				     KM_SLEEP | KM_MAYFAIL);
120 	if (!mp->m_dir_geo || !mp->m_attr_geo) {
121 		kmem_free(mp->m_dir_geo);
122 		kmem_free(mp->m_attr_geo);
123 		return -ENOMEM;
124 	}
125 
126 	/* set up directory geometry */
127 	dageo = mp->m_dir_geo;
128 	dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
129 	dageo->fsblog = mp->m_sb.sb_blocklog;
130 	dageo->blksize = 1 << dageo->blklog;
131 	dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
132 
133 	/*
134 	 * Now we've set up the block conversion variables, we can calculate the
135 	 * segment block constants using the geometry structure.
136 	 */
137 	dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
138 	dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
139 	dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
140 	dageo->node_ents = (dageo->blksize - nodehdr_size) /
141 				(uint)sizeof(xfs_da_node_entry_t);
142 	dageo->magicpct = (dageo->blksize * 37) / 100;
143 
144 	/* set up attribute geometry - single fsb only */
145 	dageo = mp->m_attr_geo;
146 	dageo->blklog = mp->m_sb.sb_blocklog;
147 	dageo->fsblog = mp->m_sb.sb_blocklog;
148 	dageo->blksize = 1 << dageo->blklog;
149 	dageo->fsbcount = 1;
150 	dageo->node_ents = (dageo->blksize - nodehdr_size) /
151 				(uint)sizeof(xfs_da_node_entry_t);
152 	dageo->magicpct = (dageo->blksize * 37) / 100;
153 
154 	if (xfs_sb_version_hasasciici(&mp->m_sb))
155 		mp->m_dirnameops = &xfs_ascii_ci_nameops;
156 	else
157 		mp->m_dirnameops = &xfs_default_nameops;
158 
159 	return 0;
160 }
161 
162 void
163 xfs_da_unmount(
164 	struct xfs_mount	*mp)
165 {
166 	kmem_free(mp->m_dir_geo);
167 	kmem_free(mp->m_attr_geo);
168 }
169 
170 /*
171  * Return 1 if directory contains only "." and "..".
172  */
173 int
174 xfs_dir_isempty(
175 	xfs_inode_t	*dp)
176 {
177 	xfs_dir2_sf_hdr_t	*sfp;
178 
179 	ASSERT(S_ISDIR(dp->i_d.di_mode));
180 	if (dp->i_d.di_size == 0)	/* might happen during shutdown. */
181 		return 1;
182 	if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
183 		return 0;
184 	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
185 	return !sfp->count;
186 }
187 
188 /*
189  * Validate a given inode number.
190  */
191 int
192 xfs_dir_ino_validate(
193 	xfs_mount_t	*mp,
194 	xfs_ino_t	ino)
195 {
196 	xfs_agblock_t	agblkno;
197 	xfs_agino_t	agino;
198 	xfs_agnumber_t	agno;
199 	int		ino_ok;
200 	int		ioff;
201 
202 	agno = XFS_INO_TO_AGNO(mp, ino);
203 	agblkno = XFS_INO_TO_AGBNO(mp, ino);
204 	ioff = XFS_INO_TO_OFFSET(mp, ino);
205 	agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
206 	ino_ok =
207 		agno < mp->m_sb.sb_agcount &&
208 		agblkno < mp->m_sb.sb_agblocks &&
209 		agblkno != 0 &&
210 		ioff < (1 << mp->m_sb.sb_inopblog) &&
211 		XFS_AGINO_TO_INO(mp, agno, agino) == ino;
212 	if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
213 			XFS_RANDOM_DIR_INO_VALIDATE))) {
214 		xfs_warn(mp, "Invalid inode number 0x%Lx",
215 				(unsigned long long) ino);
216 		XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
217 		return -EFSCORRUPTED;
218 	}
219 	return 0;
220 }
221 
222 /*
223  * Initialize a directory with its "." and ".." entries.
224  */
225 int
226 xfs_dir_init(
227 	xfs_trans_t	*tp,
228 	xfs_inode_t	*dp,
229 	xfs_inode_t	*pdp)
230 {
231 	struct xfs_da_args *args;
232 	int		error;
233 
234 	ASSERT(S_ISDIR(dp->i_d.di_mode));
235 	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
236 	if (error)
237 		return error;
238 
239 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
240 	if (!args)
241 		return -ENOMEM;
242 
243 	args->geo = dp->i_mount->m_dir_geo;
244 	args->dp = dp;
245 	args->trans = tp;
246 	error = xfs_dir2_sf_create(args, pdp->i_ino);
247 	kmem_free(args);
248 	return error;
249 }
250 
251 /*
252  * Enter a name in a directory, or check for available space.
253  * If inum is 0, only the available space test is performed.
254  */
255 int
256 xfs_dir_createname(
257 	xfs_trans_t		*tp,
258 	xfs_inode_t		*dp,
259 	struct xfs_name		*name,
260 	xfs_ino_t		inum,		/* new entry inode number */
261 	xfs_fsblock_t		*first,		/* bmap's firstblock */
262 	xfs_bmap_free_t		*flist,		/* bmap's freeblock list */
263 	xfs_extlen_t		total)		/* bmap's total block count */
264 {
265 	struct xfs_da_args	*args;
266 	int			rval;
267 	int			v;		/* type-checking value */
268 
269 	ASSERT(S_ISDIR(dp->i_d.di_mode));
270 	if (inum) {
271 		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
272 		if (rval)
273 			return rval;
274 		XFS_STATS_INC(dp->i_mount, xs_dir_create);
275 	}
276 
277 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
278 	if (!args)
279 		return -ENOMEM;
280 
281 	args->geo = dp->i_mount->m_dir_geo;
282 	args->name = name->name;
283 	args->namelen = name->len;
284 	args->filetype = name->type;
285 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
286 	args->inumber = inum;
287 	args->dp = dp;
288 	args->firstblock = first;
289 	args->flist = flist;
290 	args->total = total;
291 	args->whichfork = XFS_DATA_FORK;
292 	args->trans = tp;
293 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
294 	if (!inum)
295 		args->op_flags |= XFS_DA_OP_JUSTCHECK;
296 
297 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
298 		rval = xfs_dir2_sf_addname(args);
299 		goto out_free;
300 	}
301 
302 	rval = xfs_dir2_isblock(args, &v);
303 	if (rval)
304 		goto out_free;
305 	if (v) {
306 		rval = xfs_dir2_block_addname(args);
307 		goto out_free;
308 	}
309 
310 	rval = xfs_dir2_isleaf(args, &v);
311 	if (rval)
312 		goto out_free;
313 	if (v)
314 		rval = xfs_dir2_leaf_addname(args);
315 	else
316 		rval = xfs_dir2_node_addname(args);
317 
318 out_free:
319 	kmem_free(args);
320 	return rval;
321 }
322 
323 /*
324  * If doing a CI lookup and case-insensitive match, dup actual name into
325  * args.value. Return EEXIST for success (ie. name found) or an error.
326  */
327 int
328 xfs_dir_cilookup_result(
329 	struct xfs_da_args *args,
330 	const unsigned char *name,
331 	int		len)
332 {
333 	if (args->cmpresult == XFS_CMP_DIFFERENT)
334 		return -ENOENT;
335 	if (args->cmpresult != XFS_CMP_CASE ||
336 					!(args->op_flags & XFS_DA_OP_CILOOKUP))
337 		return -EEXIST;
338 
339 	args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
340 	if (!args->value)
341 		return -ENOMEM;
342 
343 	memcpy(args->value, name, len);
344 	args->valuelen = len;
345 	return -EEXIST;
346 }
347 
348 /*
349  * Lookup a name in a directory, give back the inode number.
350  * If ci_name is not NULL, returns the actual name in ci_name if it differs
351  * to name, or ci_name->name is set to NULL for an exact match.
352  */
353 
354 int
355 xfs_dir_lookup(
356 	xfs_trans_t	*tp,
357 	xfs_inode_t	*dp,
358 	struct xfs_name	*name,
359 	xfs_ino_t	*inum,		/* out: inode number */
360 	struct xfs_name *ci_name)	/* out: actual name if CI match */
361 {
362 	struct xfs_da_args *args;
363 	int		rval;
364 	int		v;		/* type-checking value */
365 	int		lock_mode;
366 
367 	ASSERT(S_ISDIR(dp->i_d.di_mode));
368 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
369 
370 	/*
371 	 * We need to use KM_NOFS here so that lockdep will not throw false
372 	 * positive deadlock warnings on a non-transactional lookup path. It is
373 	 * safe to recurse into inode recalim in that case, but lockdep can't
374 	 * easily be taught about it. Hence KM_NOFS avoids having to add more
375 	 * lockdep Doing this avoids having to add a bunch of lockdep class
376 	 * annotations into the reclaim path for the ilock.
377 	 */
378 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
379 	args->geo = dp->i_mount->m_dir_geo;
380 	args->name = name->name;
381 	args->namelen = name->len;
382 	args->filetype = name->type;
383 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
384 	args->dp = dp;
385 	args->whichfork = XFS_DATA_FORK;
386 	args->trans = tp;
387 	args->op_flags = XFS_DA_OP_OKNOENT;
388 	if (ci_name)
389 		args->op_flags |= XFS_DA_OP_CILOOKUP;
390 
391 	lock_mode = xfs_ilock_data_map_shared(dp);
392 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
393 		rval = xfs_dir2_sf_lookup(args);
394 		goto out_check_rval;
395 	}
396 
397 	rval = xfs_dir2_isblock(args, &v);
398 	if (rval)
399 		goto out_free;
400 	if (v) {
401 		rval = xfs_dir2_block_lookup(args);
402 		goto out_check_rval;
403 	}
404 
405 	rval = xfs_dir2_isleaf(args, &v);
406 	if (rval)
407 		goto out_free;
408 	if (v)
409 		rval = xfs_dir2_leaf_lookup(args);
410 	else
411 		rval = xfs_dir2_node_lookup(args);
412 
413 out_check_rval:
414 	if (rval == -EEXIST)
415 		rval = 0;
416 	if (!rval) {
417 		*inum = args->inumber;
418 		if (ci_name) {
419 			ci_name->name = args->value;
420 			ci_name->len = args->valuelen;
421 		}
422 	}
423 out_free:
424 	xfs_iunlock(dp, lock_mode);
425 	kmem_free(args);
426 	return rval;
427 }
428 
429 /*
430  * Remove an entry from a directory.
431  */
432 int
433 xfs_dir_removename(
434 	xfs_trans_t	*tp,
435 	xfs_inode_t	*dp,
436 	struct xfs_name	*name,
437 	xfs_ino_t	ino,
438 	xfs_fsblock_t	*first,		/* bmap's firstblock */
439 	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
440 	xfs_extlen_t	total)		/* bmap's total block count */
441 {
442 	struct xfs_da_args *args;
443 	int		rval;
444 	int		v;		/* type-checking value */
445 
446 	ASSERT(S_ISDIR(dp->i_d.di_mode));
447 	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
448 
449 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
450 	if (!args)
451 		return -ENOMEM;
452 
453 	args->geo = dp->i_mount->m_dir_geo;
454 	args->name = name->name;
455 	args->namelen = name->len;
456 	args->filetype = name->type;
457 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
458 	args->inumber = ino;
459 	args->dp = dp;
460 	args->firstblock = first;
461 	args->flist = flist;
462 	args->total = total;
463 	args->whichfork = XFS_DATA_FORK;
464 	args->trans = tp;
465 
466 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
467 		rval = xfs_dir2_sf_removename(args);
468 		goto out_free;
469 	}
470 
471 	rval = xfs_dir2_isblock(args, &v);
472 	if (rval)
473 		goto out_free;
474 	if (v) {
475 		rval = xfs_dir2_block_removename(args);
476 		goto out_free;
477 	}
478 
479 	rval = xfs_dir2_isleaf(args, &v);
480 	if (rval)
481 		goto out_free;
482 	if (v)
483 		rval = xfs_dir2_leaf_removename(args);
484 	else
485 		rval = xfs_dir2_node_removename(args);
486 out_free:
487 	kmem_free(args);
488 	return rval;
489 }
490 
491 /*
492  * Replace the inode number of a directory entry.
493  */
494 int
495 xfs_dir_replace(
496 	xfs_trans_t	*tp,
497 	xfs_inode_t	*dp,
498 	struct xfs_name	*name,		/* name of entry to replace */
499 	xfs_ino_t	inum,		/* new inode number */
500 	xfs_fsblock_t	*first,		/* bmap's firstblock */
501 	xfs_bmap_free_t	*flist,		/* bmap's freeblock list */
502 	xfs_extlen_t	total)		/* bmap's total block count */
503 {
504 	struct xfs_da_args *args;
505 	int		rval;
506 	int		v;		/* type-checking value */
507 
508 	ASSERT(S_ISDIR(dp->i_d.di_mode));
509 
510 	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
511 	if (rval)
512 		return rval;
513 
514 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
515 	if (!args)
516 		return -ENOMEM;
517 
518 	args->geo = dp->i_mount->m_dir_geo;
519 	args->name = name->name;
520 	args->namelen = name->len;
521 	args->filetype = name->type;
522 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
523 	args->inumber = inum;
524 	args->dp = dp;
525 	args->firstblock = first;
526 	args->flist = flist;
527 	args->total = total;
528 	args->whichfork = XFS_DATA_FORK;
529 	args->trans = tp;
530 
531 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
532 		rval = xfs_dir2_sf_replace(args);
533 		goto out_free;
534 	}
535 
536 	rval = xfs_dir2_isblock(args, &v);
537 	if (rval)
538 		goto out_free;
539 	if (v) {
540 		rval = xfs_dir2_block_replace(args);
541 		goto out_free;
542 	}
543 
544 	rval = xfs_dir2_isleaf(args, &v);
545 	if (rval)
546 		goto out_free;
547 	if (v)
548 		rval = xfs_dir2_leaf_replace(args);
549 	else
550 		rval = xfs_dir2_node_replace(args);
551 out_free:
552 	kmem_free(args);
553 	return rval;
554 }
555 
556 /*
557  * See if this entry can be added to the directory without allocating space.
558  */
559 int
560 xfs_dir_canenter(
561 	xfs_trans_t	*tp,
562 	xfs_inode_t	*dp,
563 	struct xfs_name	*name)		/* name of entry to add */
564 {
565 	return xfs_dir_createname(tp, dp, name, 0, NULL, NULL, 0);
566 }
567 
568 /*
569  * Utility routines.
570  */
571 
572 /*
573  * Add a block to the directory.
574  *
575  * This routine is for data and free blocks, not leaf/node blocks which are
576  * handled by xfs_da_grow_inode.
577  */
578 int
579 xfs_dir2_grow_inode(
580 	struct xfs_da_args	*args,
581 	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
582 	xfs_dir2_db_t		*dbp)	/* out: block number added */
583 {
584 	struct xfs_inode	*dp = args->dp;
585 	struct xfs_mount	*mp = dp->i_mount;
586 	xfs_fileoff_t		bno;	/* directory offset of new block */
587 	int			count;	/* count of filesystem blocks */
588 	int			error;
589 
590 	trace_xfs_dir2_grow_inode(args, space);
591 
592 	/*
593 	 * Set lowest possible block in the space requested.
594 	 */
595 	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
596 	count = args->geo->fsbcount;
597 
598 	error = xfs_da_grow_inode_int(args, &bno, count);
599 	if (error)
600 		return error;
601 
602 	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
603 
604 	/*
605 	 * Update file's size if this is the data space and it grew.
606 	 */
607 	if (space == XFS_DIR2_DATA_SPACE) {
608 		xfs_fsize_t	size;		/* directory file (data) size */
609 
610 		size = XFS_FSB_TO_B(mp, bno + count);
611 		if (size > dp->i_d.di_size) {
612 			dp->i_d.di_size = size;
613 			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
614 		}
615 	}
616 	return 0;
617 }
618 
619 /*
620  * See if the directory is a single-block form directory.
621  */
622 int
623 xfs_dir2_isblock(
624 	struct xfs_da_args	*args,
625 	int			*vp)	/* out: 1 is block, 0 is not block */
626 {
627 	xfs_fileoff_t		last;	/* last file offset */
628 	int			rval;
629 
630 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
631 		return rval;
632 	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
633 	ASSERT(rval == 0 || args->dp->i_d.di_size == args->geo->blksize);
634 	*vp = rval;
635 	return 0;
636 }
637 
638 /*
639  * See if the directory is a single-leaf form directory.
640  */
641 int
642 xfs_dir2_isleaf(
643 	struct xfs_da_args	*args,
644 	int			*vp)	/* out: 1 is block, 0 is not block */
645 {
646 	xfs_fileoff_t		last;	/* last file offset */
647 	int			rval;
648 
649 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
650 		return rval;
651 	*vp = last == args->geo->leafblk + args->geo->fsbcount;
652 	return 0;
653 }
654 
655 /*
656  * Remove the given block from the directory.
657  * This routine is used for data and free blocks, leaf/node are done
658  * by xfs_da_shrink_inode.
659  */
660 int
661 xfs_dir2_shrink_inode(
662 	xfs_da_args_t	*args,
663 	xfs_dir2_db_t	db,
664 	struct xfs_buf	*bp)
665 {
666 	xfs_fileoff_t	bno;		/* directory file offset */
667 	xfs_dablk_t	da;		/* directory file offset */
668 	int		done;		/* bunmap is finished */
669 	xfs_inode_t	*dp;
670 	int		error;
671 	xfs_mount_t	*mp;
672 	xfs_trans_t	*tp;
673 
674 	trace_xfs_dir2_shrink_inode(args, db);
675 
676 	dp = args->dp;
677 	mp = dp->i_mount;
678 	tp = args->trans;
679 	da = xfs_dir2_db_to_da(args->geo, db);
680 
681 	/* Unmap the fsblock(s). */
682 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0,
683 			    args->firstblock, args->flist, &done);
684 	if (error) {
685 		/*
686 		 * ENOSPC actually can happen if we're in a removename with no
687 		 * space reservation, and the resulting block removal would
688 		 * cause a bmap btree split or conversion from extents to btree.
689 		 * This can only happen for un-fragmented directory blocks,
690 		 * since you need to be punching out the middle of an extent.
691 		 * In this case we need to leave the block in the file, and not
692 		 * binval it.  So the block has to be in a consistent empty
693 		 * state and appropriately logged.  We don't free up the buffer,
694 		 * the caller can tell it hasn't happened since it got an error
695 		 * back.
696 		 */
697 		return error;
698 	}
699 	ASSERT(done);
700 	/*
701 	 * Invalidate the buffer from the transaction.
702 	 */
703 	xfs_trans_binval(tp, bp);
704 	/*
705 	 * If it's not a data block, we're done.
706 	 */
707 	if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
708 		return 0;
709 	/*
710 	 * If the block isn't the last one in the directory, we're done.
711 	 */
712 	if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
713 		return 0;
714 	bno = da;
715 	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
716 		/*
717 		 * This can't really happen unless there's kernel corruption.
718 		 */
719 		return error;
720 	}
721 	if (db == args->geo->datablk)
722 		ASSERT(bno == 0);
723 	else
724 		ASSERT(bno > 0);
725 	/*
726 	 * Set the size to the new last block.
727 	 */
728 	dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
729 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
730 	return 0;
731 }
732