xref: /openbmc/linux/fs/xfs/libxfs/xfs_dir2.c (revision 1c2dd16a)
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_defer.h"
25 #include "xfs_da_format.h"
26 #include "xfs_da_btree.h"
27 #include "xfs_inode.h"
28 #include "xfs_trans.h"
29 #include "xfs_inode_item.h"
30 #include "xfs_bmap.h"
31 #include "xfs_dir2.h"
32 #include "xfs_dir2_priv.h"
33 #include "xfs_error.h"
34 #include "xfs_trace.h"
35 
36 struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2, XFS_DIR3_FT_DIR };
37 
38 /*
39  * Convert inode mode to directory entry filetype
40  */
41 unsigned char xfs_mode_to_ftype(int mode)
42 {
43 	switch (mode & S_IFMT) {
44 	case S_IFREG:
45 		return XFS_DIR3_FT_REG_FILE;
46 	case S_IFDIR:
47 		return XFS_DIR3_FT_DIR;
48 	case S_IFCHR:
49 		return XFS_DIR3_FT_CHRDEV;
50 	case S_IFBLK:
51 		return XFS_DIR3_FT_BLKDEV;
52 	case S_IFIFO:
53 		return XFS_DIR3_FT_FIFO;
54 	case S_IFSOCK:
55 		return XFS_DIR3_FT_SOCK;
56 	case S_IFLNK:
57 		return XFS_DIR3_FT_SYMLINK;
58 	default:
59 		return XFS_DIR3_FT_UNKNOWN;
60 	}
61 }
62 
63 /*
64  * ASCII case-insensitive (ie. A-Z) support for directories that was
65  * used in IRIX.
66  */
67 STATIC xfs_dahash_t
68 xfs_ascii_ci_hashname(
69 	struct xfs_name	*name)
70 {
71 	xfs_dahash_t	hash;
72 	int		i;
73 
74 	for (i = 0, hash = 0; i < name->len; i++)
75 		hash = tolower(name->name[i]) ^ rol32(hash, 7);
76 
77 	return hash;
78 }
79 
80 STATIC enum xfs_dacmp
81 xfs_ascii_ci_compname(
82 	struct xfs_da_args *args,
83 	const unsigned char *name,
84 	int		len)
85 {
86 	enum xfs_dacmp	result;
87 	int		i;
88 
89 	if (args->namelen != len)
90 		return XFS_CMP_DIFFERENT;
91 
92 	result = XFS_CMP_EXACT;
93 	for (i = 0; i < len; i++) {
94 		if (args->name[i] == name[i])
95 			continue;
96 		if (tolower(args->name[i]) != tolower(name[i]))
97 			return XFS_CMP_DIFFERENT;
98 		result = XFS_CMP_CASE;
99 	}
100 
101 	return result;
102 }
103 
104 static const struct xfs_nameops xfs_ascii_ci_nameops = {
105 	.hashname	= xfs_ascii_ci_hashname,
106 	.compname	= xfs_ascii_ci_compname,
107 };
108 
109 int
110 xfs_da_mount(
111 	struct xfs_mount	*mp)
112 {
113 	struct xfs_da_geometry	*dageo;
114 	int			nodehdr_size;
115 
116 
117 	ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
118 	ASSERT((1 << (mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog)) <=
119 	       XFS_MAX_BLOCKSIZE);
120 
121 	mp->m_dir_inode_ops = xfs_dir_get_ops(mp, NULL);
122 	mp->m_nondir_inode_ops = xfs_nondir_get_ops(mp, NULL);
123 
124 	nodehdr_size = mp->m_dir_inode_ops->node_hdr_size;
125 	mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
126 				    KM_SLEEP | KM_MAYFAIL);
127 	mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
128 				     KM_SLEEP | KM_MAYFAIL);
129 	if (!mp->m_dir_geo || !mp->m_attr_geo) {
130 		kmem_free(mp->m_dir_geo);
131 		kmem_free(mp->m_attr_geo);
132 		return -ENOMEM;
133 	}
134 
135 	/* set up directory geometry */
136 	dageo = mp->m_dir_geo;
137 	dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
138 	dageo->fsblog = mp->m_sb.sb_blocklog;
139 	dageo->blksize = 1 << dageo->blklog;
140 	dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
141 
142 	/*
143 	 * Now we've set up the block conversion variables, we can calculate the
144 	 * segment block constants using the geometry structure.
145 	 */
146 	dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
147 	dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
148 	dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
149 	dageo->node_ents = (dageo->blksize - nodehdr_size) /
150 				(uint)sizeof(xfs_da_node_entry_t);
151 	dageo->magicpct = (dageo->blksize * 37) / 100;
152 
153 	/* set up attribute geometry - single fsb only */
154 	dageo = mp->m_attr_geo;
155 	dageo->blklog = mp->m_sb.sb_blocklog;
156 	dageo->fsblog = mp->m_sb.sb_blocklog;
157 	dageo->blksize = 1 << dageo->blklog;
158 	dageo->fsbcount = 1;
159 	dageo->node_ents = (dageo->blksize - nodehdr_size) /
160 				(uint)sizeof(xfs_da_node_entry_t);
161 	dageo->magicpct = (dageo->blksize * 37) / 100;
162 
163 	if (xfs_sb_version_hasasciici(&mp->m_sb))
164 		mp->m_dirnameops = &xfs_ascii_ci_nameops;
165 	else
166 		mp->m_dirnameops = &xfs_default_nameops;
167 
168 	return 0;
169 }
170 
171 void
172 xfs_da_unmount(
173 	struct xfs_mount	*mp)
174 {
175 	kmem_free(mp->m_dir_geo);
176 	kmem_free(mp->m_attr_geo);
177 }
178 
179 /*
180  * Return 1 if directory contains only "." and "..".
181  */
182 int
183 xfs_dir_isempty(
184 	xfs_inode_t	*dp)
185 {
186 	xfs_dir2_sf_hdr_t	*sfp;
187 
188 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
189 	if (dp->i_d.di_size == 0)	/* might happen during shutdown. */
190 		return 1;
191 	if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
192 		return 0;
193 	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
194 	return !sfp->count;
195 }
196 
197 /*
198  * Validate a given inode number.
199  */
200 int
201 xfs_dir_ino_validate(
202 	xfs_mount_t	*mp,
203 	xfs_ino_t	ino)
204 {
205 	xfs_agblock_t	agblkno;
206 	xfs_agino_t	agino;
207 	xfs_agnumber_t	agno;
208 	int		ino_ok;
209 	int		ioff;
210 
211 	agno = XFS_INO_TO_AGNO(mp, ino);
212 	agblkno = XFS_INO_TO_AGBNO(mp, ino);
213 	ioff = XFS_INO_TO_OFFSET(mp, ino);
214 	agino = XFS_OFFBNO_TO_AGINO(mp, agblkno, ioff);
215 	ino_ok =
216 		agno < mp->m_sb.sb_agcount &&
217 		agblkno < mp->m_sb.sb_agblocks &&
218 		agblkno != 0 &&
219 		ioff < (1 << mp->m_sb.sb_inopblog) &&
220 		XFS_AGINO_TO_INO(mp, agno, agino) == ino;
221 	if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE,
222 			XFS_RANDOM_DIR_INO_VALIDATE))) {
223 		xfs_warn(mp, "Invalid inode number 0x%Lx",
224 				(unsigned long long) ino);
225 		XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
226 		return -EFSCORRUPTED;
227 	}
228 	return 0;
229 }
230 
231 /*
232  * Initialize a directory with its "." and ".." entries.
233  */
234 int
235 xfs_dir_init(
236 	xfs_trans_t	*tp,
237 	xfs_inode_t	*dp,
238 	xfs_inode_t	*pdp)
239 {
240 	struct xfs_da_args *args;
241 	int		error;
242 
243 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
244 	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
245 	if (error)
246 		return error;
247 
248 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
249 	if (!args)
250 		return -ENOMEM;
251 
252 	args->geo = dp->i_mount->m_dir_geo;
253 	args->dp = dp;
254 	args->trans = tp;
255 	error = xfs_dir2_sf_create(args, pdp->i_ino);
256 	kmem_free(args);
257 	return error;
258 }
259 
260 /*
261  * Enter a name in a directory, or check for available space.
262  * If inum is 0, only the available space test is performed.
263  */
264 int
265 xfs_dir_createname(
266 	xfs_trans_t		*tp,
267 	xfs_inode_t		*dp,
268 	struct xfs_name		*name,
269 	xfs_ino_t		inum,		/* new entry inode number */
270 	xfs_fsblock_t		*first,		/* bmap's firstblock */
271 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
272 	xfs_extlen_t		total)		/* bmap's total block count */
273 {
274 	struct xfs_da_args	*args;
275 	int			rval;
276 	int			v;		/* type-checking value */
277 
278 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
279 	if (inum) {
280 		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
281 		if (rval)
282 			return rval;
283 		XFS_STATS_INC(dp->i_mount, xs_dir_create);
284 	}
285 
286 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
287 	if (!args)
288 		return -ENOMEM;
289 
290 	args->geo = dp->i_mount->m_dir_geo;
291 	args->name = name->name;
292 	args->namelen = name->len;
293 	args->filetype = name->type;
294 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
295 	args->inumber = inum;
296 	args->dp = dp;
297 	args->firstblock = first;
298 	args->dfops = dfops;
299 	args->total = total;
300 	args->whichfork = XFS_DATA_FORK;
301 	args->trans = tp;
302 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
303 	if (!inum)
304 		args->op_flags |= XFS_DA_OP_JUSTCHECK;
305 
306 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
307 		rval = xfs_dir2_sf_addname(args);
308 		goto out_free;
309 	}
310 
311 	rval = xfs_dir2_isblock(args, &v);
312 	if (rval)
313 		goto out_free;
314 	if (v) {
315 		rval = xfs_dir2_block_addname(args);
316 		goto out_free;
317 	}
318 
319 	rval = xfs_dir2_isleaf(args, &v);
320 	if (rval)
321 		goto out_free;
322 	if (v)
323 		rval = xfs_dir2_leaf_addname(args);
324 	else
325 		rval = xfs_dir2_node_addname(args);
326 
327 out_free:
328 	kmem_free(args);
329 	return rval;
330 }
331 
332 /*
333  * If doing a CI lookup and case-insensitive match, dup actual name into
334  * args.value. Return EEXIST for success (ie. name found) or an error.
335  */
336 int
337 xfs_dir_cilookup_result(
338 	struct xfs_da_args *args,
339 	const unsigned char *name,
340 	int		len)
341 {
342 	if (args->cmpresult == XFS_CMP_DIFFERENT)
343 		return -ENOENT;
344 	if (args->cmpresult != XFS_CMP_CASE ||
345 					!(args->op_flags & XFS_DA_OP_CILOOKUP))
346 		return -EEXIST;
347 
348 	args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
349 	if (!args->value)
350 		return -ENOMEM;
351 
352 	memcpy(args->value, name, len);
353 	args->valuelen = len;
354 	return -EEXIST;
355 }
356 
357 /*
358  * Lookup a name in a directory, give back the inode number.
359  * If ci_name is not NULL, returns the actual name in ci_name if it differs
360  * to name, or ci_name->name is set to NULL for an exact match.
361  */
362 
363 int
364 xfs_dir_lookup(
365 	xfs_trans_t	*tp,
366 	xfs_inode_t	*dp,
367 	struct xfs_name	*name,
368 	xfs_ino_t	*inum,		/* out: inode number */
369 	struct xfs_name *ci_name)	/* out: actual name if CI match */
370 {
371 	struct xfs_da_args *args;
372 	int		rval;
373 	int		v;		/* type-checking value */
374 	int		lock_mode;
375 
376 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
377 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
378 
379 	/*
380 	 * We need to use KM_NOFS here so that lockdep will not throw false
381 	 * positive deadlock warnings on a non-transactional lookup path. It is
382 	 * safe to recurse into inode recalim in that case, but lockdep can't
383 	 * easily be taught about it. Hence KM_NOFS avoids having to add more
384 	 * lockdep Doing this avoids having to add a bunch of lockdep class
385 	 * annotations into the reclaim path for the ilock.
386 	 */
387 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
388 	args->geo = dp->i_mount->m_dir_geo;
389 	args->name = name->name;
390 	args->namelen = name->len;
391 	args->filetype = name->type;
392 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
393 	args->dp = dp;
394 	args->whichfork = XFS_DATA_FORK;
395 	args->trans = tp;
396 	args->op_flags = XFS_DA_OP_OKNOENT;
397 	if (ci_name)
398 		args->op_flags |= XFS_DA_OP_CILOOKUP;
399 
400 	lock_mode = xfs_ilock_data_map_shared(dp);
401 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
402 		rval = xfs_dir2_sf_lookup(args);
403 		goto out_check_rval;
404 	}
405 
406 	rval = xfs_dir2_isblock(args, &v);
407 	if (rval)
408 		goto out_free;
409 	if (v) {
410 		rval = xfs_dir2_block_lookup(args);
411 		goto out_check_rval;
412 	}
413 
414 	rval = xfs_dir2_isleaf(args, &v);
415 	if (rval)
416 		goto out_free;
417 	if (v)
418 		rval = xfs_dir2_leaf_lookup(args);
419 	else
420 		rval = xfs_dir2_node_lookup(args);
421 
422 out_check_rval:
423 	if (rval == -EEXIST)
424 		rval = 0;
425 	if (!rval) {
426 		*inum = args->inumber;
427 		if (ci_name) {
428 			ci_name->name = args->value;
429 			ci_name->len = args->valuelen;
430 		}
431 	}
432 out_free:
433 	xfs_iunlock(dp, lock_mode);
434 	kmem_free(args);
435 	return rval;
436 }
437 
438 /*
439  * Remove an entry from a directory.
440  */
441 int
442 xfs_dir_removename(
443 	xfs_trans_t	*tp,
444 	xfs_inode_t	*dp,
445 	struct xfs_name	*name,
446 	xfs_ino_t	ino,
447 	xfs_fsblock_t	*first,		/* bmap's firstblock */
448 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
449 	xfs_extlen_t	total)		/* bmap's total block count */
450 {
451 	struct xfs_da_args *args;
452 	int		rval;
453 	int		v;		/* type-checking value */
454 
455 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
456 	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
457 
458 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
459 	if (!args)
460 		return -ENOMEM;
461 
462 	args->geo = dp->i_mount->m_dir_geo;
463 	args->name = name->name;
464 	args->namelen = name->len;
465 	args->filetype = name->type;
466 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
467 	args->inumber = ino;
468 	args->dp = dp;
469 	args->firstblock = first;
470 	args->dfops = dfops;
471 	args->total = total;
472 	args->whichfork = XFS_DATA_FORK;
473 	args->trans = tp;
474 
475 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
476 		rval = xfs_dir2_sf_removename(args);
477 		goto out_free;
478 	}
479 
480 	rval = xfs_dir2_isblock(args, &v);
481 	if (rval)
482 		goto out_free;
483 	if (v) {
484 		rval = xfs_dir2_block_removename(args);
485 		goto out_free;
486 	}
487 
488 	rval = xfs_dir2_isleaf(args, &v);
489 	if (rval)
490 		goto out_free;
491 	if (v)
492 		rval = xfs_dir2_leaf_removename(args);
493 	else
494 		rval = xfs_dir2_node_removename(args);
495 out_free:
496 	kmem_free(args);
497 	return rval;
498 }
499 
500 /*
501  * Replace the inode number of a directory entry.
502  */
503 int
504 xfs_dir_replace(
505 	xfs_trans_t	*tp,
506 	xfs_inode_t	*dp,
507 	struct xfs_name	*name,		/* name of entry to replace */
508 	xfs_ino_t	inum,		/* new inode number */
509 	xfs_fsblock_t	*first,		/* bmap's firstblock */
510 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
511 	xfs_extlen_t	total)		/* bmap's total block count */
512 {
513 	struct xfs_da_args *args;
514 	int		rval;
515 	int		v;		/* type-checking value */
516 
517 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
518 
519 	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
520 	if (rval)
521 		return rval;
522 
523 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
524 	if (!args)
525 		return -ENOMEM;
526 
527 	args->geo = dp->i_mount->m_dir_geo;
528 	args->name = name->name;
529 	args->namelen = name->len;
530 	args->filetype = name->type;
531 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
532 	args->inumber = inum;
533 	args->dp = dp;
534 	args->firstblock = first;
535 	args->dfops = dfops;
536 	args->total = total;
537 	args->whichfork = XFS_DATA_FORK;
538 	args->trans = tp;
539 
540 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
541 		rval = xfs_dir2_sf_replace(args);
542 		goto out_free;
543 	}
544 
545 	rval = xfs_dir2_isblock(args, &v);
546 	if (rval)
547 		goto out_free;
548 	if (v) {
549 		rval = xfs_dir2_block_replace(args);
550 		goto out_free;
551 	}
552 
553 	rval = xfs_dir2_isleaf(args, &v);
554 	if (rval)
555 		goto out_free;
556 	if (v)
557 		rval = xfs_dir2_leaf_replace(args);
558 	else
559 		rval = xfs_dir2_node_replace(args);
560 out_free:
561 	kmem_free(args);
562 	return rval;
563 }
564 
565 /*
566  * See if this entry can be added to the directory without allocating space.
567  */
568 int
569 xfs_dir_canenter(
570 	xfs_trans_t	*tp,
571 	xfs_inode_t	*dp,
572 	struct xfs_name	*name)		/* name of entry to add */
573 {
574 	return xfs_dir_createname(tp, dp, name, 0, NULL, NULL, 0);
575 }
576 
577 /*
578  * Utility routines.
579  */
580 
581 /*
582  * Add a block to the directory.
583  *
584  * This routine is for data and free blocks, not leaf/node blocks which are
585  * handled by xfs_da_grow_inode.
586  */
587 int
588 xfs_dir2_grow_inode(
589 	struct xfs_da_args	*args,
590 	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
591 	xfs_dir2_db_t		*dbp)	/* out: block number added */
592 {
593 	struct xfs_inode	*dp = args->dp;
594 	struct xfs_mount	*mp = dp->i_mount;
595 	xfs_fileoff_t		bno;	/* directory offset of new block */
596 	int			count;	/* count of filesystem blocks */
597 	int			error;
598 
599 	trace_xfs_dir2_grow_inode(args, space);
600 
601 	/*
602 	 * Set lowest possible block in the space requested.
603 	 */
604 	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
605 	count = args->geo->fsbcount;
606 
607 	error = xfs_da_grow_inode_int(args, &bno, count);
608 	if (error)
609 		return error;
610 
611 	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
612 
613 	/*
614 	 * Update file's size if this is the data space and it grew.
615 	 */
616 	if (space == XFS_DIR2_DATA_SPACE) {
617 		xfs_fsize_t	size;		/* directory file (data) size */
618 
619 		size = XFS_FSB_TO_B(mp, bno + count);
620 		if (size > dp->i_d.di_size) {
621 			dp->i_d.di_size = size;
622 			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
623 		}
624 	}
625 	return 0;
626 }
627 
628 /*
629  * See if the directory is a single-block form directory.
630  */
631 int
632 xfs_dir2_isblock(
633 	struct xfs_da_args	*args,
634 	int			*vp)	/* out: 1 is block, 0 is not block */
635 {
636 	xfs_fileoff_t		last;	/* last file offset */
637 	int			rval;
638 
639 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
640 		return rval;
641 	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
642 	if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize)
643 		return -EFSCORRUPTED;
644 	*vp = rval;
645 	return 0;
646 }
647 
648 /*
649  * See if the directory is a single-leaf form directory.
650  */
651 int
652 xfs_dir2_isleaf(
653 	struct xfs_da_args	*args,
654 	int			*vp)	/* out: 1 is block, 0 is not block */
655 {
656 	xfs_fileoff_t		last;	/* last file offset */
657 	int			rval;
658 
659 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
660 		return rval;
661 	*vp = last == args->geo->leafblk + args->geo->fsbcount;
662 	return 0;
663 }
664 
665 /*
666  * Remove the given block from the directory.
667  * This routine is used for data and free blocks, leaf/node are done
668  * by xfs_da_shrink_inode.
669  */
670 int
671 xfs_dir2_shrink_inode(
672 	xfs_da_args_t	*args,
673 	xfs_dir2_db_t	db,
674 	struct xfs_buf	*bp)
675 {
676 	xfs_fileoff_t	bno;		/* directory file offset */
677 	xfs_dablk_t	da;		/* directory file offset */
678 	int		done;		/* bunmap is finished */
679 	xfs_inode_t	*dp;
680 	int		error;
681 	xfs_mount_t	*mp;
682 	xfs_trans_t	*tp;
683 
684 	trace_xfs_dir2_shrink_inode(args, db);
685 
686 	dp = args->dp;
687 	mp = dp->i_mount;
688 	tp = args->trans;
689 	da = xfs_dir2_db_to_da(args->geo, db);
690 
691 	/* Unmap the fsblock(s). */
692 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0,
693 			    args->firstblock, args->dfops, &done);
694 	if (error) {
695 		/*
696 		 * ENOSPC actually can happen if we're in a removename with no
697 		 * space reservation, and the resulting block removal would
698 		 * cause a bmap btree split or conversion from extents to btree.
699 		 * This can only happen for un-fragmented directory blocks,
700 		 * since you need to be punching out the middle of an extent.
701 		 * In this case we need to leave the block in the file, and not
702 		 * binval it.  So the block has to be in a consistent empty
703 		 * state and appropriately logged.  We don't free up the buffer,
704 		 * the caller can tell it hasn't happened since it got an error
705 		 * back.
706 		 */
707 		return error;
708 	}
709 	ASSERT(done);
710 	/*
711 	 * Invalidate the buffer from the transaction.
712 	 */
713 	xfs_trans_binval(tp, bp);
714 	/*
715 	 * If it's not a data block, we're done.
716 	 */
717 	if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
718 		return 0;
719 	/*
720 	 * If the block isn't the last one in the directory, we're done.
721 	 */
722 	if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
723 		return 0;
724 	bno = da;
725 	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
726 		/*
727 		 * This can't really happen unless there's kernel corruption.
728 		 */
729 		return error;
730 	}
731 	if (db == args->geo->datablk)
732 		ASSERT(bno == 0);
733 	else
734 		ASSERT(bno > 0);
735 	/*
736 	 * Set the size to the new last block.
737 	 */
738 	dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
739 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
740 	return 0;
741 }
742