xref: /openbmc/linux/fs/xfs/libxfs/xfs_dir2.c (revision 4da722ca)
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_warn(mp, "Invalid inode number 0x%Lx",
223 				(unsigned long long) ino);
224 		XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
225 		return -EFSCORRUPTED;
226 	}
227 	return 0;
228 }
229 
230 /*
231  * Initialize a directory with its "." and ".." entries.
232  */
233 int
234 xfs_dir_init(
235 	xfs_trans_t	*tp,
236 	xfs_inode_t	*dp,
237 	xfs_inode_t	*pdp)
238 {
239 	struct xfs_da_args *args;
240 	int		error;
241 
242 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
243 	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
244 	if (error)
245 		return error;
246 
247 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
248 	if (!args)
249 		return -ENOMEM;
250 
251 	args->geo = dp->i_mount->m_dir_geo;
252 	args->dp = dp;
253 	args->trans = tp;
254 	error = xfs_dir2_sf_create(args, pdp->i_ino);
255 	kmem_free(args);
256 	return error;
257 }
258 
259 /*
260  * Enter a name in a directory, or check for available space.
261  * If inum is 0, only the available space test is performed.
262  */
263 int
264 xfs_dir_createname(
265 	xfs_trans_t		*tp,
266 	xfs_inode_t		*dp,
267 	struct xfs_name		*name,
268 	xfs_ino_t		inum,		/* new entry inode number */
269 	xfs_fsblock_t		*first,		/* bmap's firstblock */
270 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
271 	xfs_extlen_t		total)		/* bmap's total block count */
272 {
273 	struct xfs_da_args	*args;
274 	int			rval;
275 	int			v;		/* type-checking value */
276 
277 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
278 	if (inum) {
279 		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
280 		if (rval)
281 			return rval;
282 		XFS_STATS_INC(dp->i_mount, xs_dir_create);
283 	}
284 
285 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
286 	if (!args)
287 		return -ENOMEM;
288 
289 	args->geo = dp->i_mount->m_dir_geo;
290 	args->name = name->name;
291 	args->namelen = name->len;
292 	args->filetype = name->type;
293 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
294 	args->inumber = inum;
295 	args->dp = dp;
296 	args->firstblock = first;
297 	args->dfops = dfops;
298 	args->total = total;
299 	args->whichfork = XFS_DATA_FORK;
300 	args->trans = tp;
301 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
302 	if (!inum)
303 		args->op_flags |= XFS_DA_OP_JUSTCHECK;
304 
305 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
306 		rval = xfs_dir2_sf_addname(args);
307 		goto out_free;
308 	}
309 
310 	rval = xfs_dir2_isblock(args, &v);
311 	if (rval)
312 		goto out_free;
313 	if (v) {
314 		rval = xfs_dir2_block_addname(args);
315 		goto out_free;
316 	}
317 
318 	rval = xfs_dir2_isleaf(args, &v);
319 	if (rval)
320 		goto out_free;
321 	if (v)
322 		rval = xfs_dir2_leaf_addname(args);
323 	else
324 		rval = xfs_dir2_node_addname(args);
325 
326 out_free:
327 	kmem_free(args);
328 	return rval;
329 }
330 
331 /*
332  * If doing a CI lookup and case-insensitive match, dup actual name into
333  * args.value. Return EEXIST for success (ie. name found) or an error.
334  */
335 int
336 xfs_dir_cilookup_result(
337 	struct xfs_da_args *args,
338 	const unsigned char *name,
339 	int		len)
340 {
341 	if (args->cmpresult == XFS_CMP_DIFFERENT)
342 		return -ENOENT;
343 	if (args->cmpresult != XFS_CMP_CASE ||
344 					!(args->op_flags & XFS_DA_OP_CILOOKUP))
345 		return -EEXIST;
346 
347 	args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
348 	if (!args->value)
349 		return -ENOMEM;
350 
351 	memcpy(args->value, name, len);
352 	args->valuelen = len;
353 	return -EEXIST;
354 }
355 
356 /*
357  * Lookup a name in a directory, give back the inode number.
358  * If ci_name is not NULL, returns the actual name in ci_name if it differs
359  * to name, or ci_name->name is set to NULL for an exact match.
360  */
361 
362 int
363 xfs_dir_lookup(
364 	xfs_trans_t	*tp,
365 	xfs_inode_t	*dp,
366 	struct xfs_name	*name,
367 	xfs_ino_t	*inum,		/* out: inode number */
368 	struct xfs_name *ci_name)	/* out: actual name if CI match */
369 {
370 	struct xfs_da_args *args;
371 	int		rval;
372 	int		v;		/* type-checking value */
373 	int		lock_mode;
374 
375 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
376 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
377 
378 	/*
379 	 * We need to use KM_NOFS here so that lockdep will not throw false
380 	 * positive deadlock warnings on a non-transactional lookup path. It is
381 	 * safe to recurse into inode recalim in that case, but lockdep can't
382 	 * easily be taught about it. Hence KM_NOFS avoids having to add more
383 	 * lockdep Doing this avoids having to add a bunch of lockdep class
384 	 * annotations into the reclaim path for the ilock.
385 	 */
386 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
387 	args->geo = dp->i_mount->m_dir_geo;
388 	args->name = name->name;
389 	args->namelen = name->len;
390 	args->filetype = name->type;
391 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
392 	args->dp = dp;
393 	args->whichfork = XFS_DATA_FORK;
394 	args->trans = tp;
395 	args->op_flags = XFS_DA_OP_OKNOENT;
396 	if (ci_name)
397 		args->op_flags |= XFS_DA_OP_CILOOKUP;
398 
399 	lock_mode = xfs_ilock_data_map_shared(dp);
400 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
401 		rval = xfs_dir2_sf_lookup(args);
402 		goto out_check_rval;
403 	}
404 
405 	rval = xfs_dir2_isblock(args, &v);
406 	if (rval)
407 		goto out_free;
408 	if (v) {
409 		rval = xfs_dir2_block_lookup(args);
410 		goto out_check_rval;
411 	}
412 
413 	rval = xfs_dir2_isleaf(args, &v);
414 	if (rval)
415 		goto out_free;
416 	if (v)
417 		rval = xfs_dir2_leaf_lookup(args);
418 	else
419 		rval = xfs_dir2_node_lookup(args);
420 
421 out_check_rval:
422 	if (rval == -EEXIST)
423 		rval = 0;
424 	if (!rval) {
425 		*inum = args->inumber;
426 		if (ci_name) {
427 			ci_name->name = args->value;
428 			ci_name->len = args->valuelen;
429 		}
430 	}
431 out_free:
432 	xfs_iunlock(dp, lock_mode);
433 	kmem_free(args);
434 	return rval;
435 }
436 
437 /*
438  * Remove an entry from a directory.
439  */
440 int
441 xfs_dir_removename(
442 	xfs_trans_t	*tp,
443 	xfs_inode_t	*dp,
444 	struct xfs_name	*name,
445 	xfs_ino_t	ino,
446 	xfs_fsblock_t	*first,		/* bmap's firstblock */
447 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
448 	xfs_extlen_t	total)		/* bmap's total block count */
449 {
450 	struct xfs_da_args *args;
451 	int		rval;
452 	int		v;		/* type-checking value */
453 
454 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
455 	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
456 
457 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
458 	if (!args)
459 		return -ENOMEM;
460 
461 	args->geo = dp->i_mount->m_dir_geo;
462 	args->name = name->name;
463 	args->namelen = name->len;
464 	args->filetype = name->type;
465 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
466 	args->inumber = ino;
467 	args->dp = dp;
468 	args->firstblock = first;
469 	args->dfops = dfops;
470 	args->total = total;
471 	args->whichfork = XFS_DATA_FORK;
472 	args->trans = tp;
473 
474 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
475 		rval = xfs_dir2_sf_removename(args);
476 		goto out_free;
477 	}
478 
479 	rval = xfs_dir2_isblock(args, &v);
480 	if (rval)
481 		goto out_free;
482 	if (v) {
483 		rval = xfs_dir2_block_removename(args);
484 		goto out_free;
485 	}
486 
487 	rval = xfs_dir2_isleaf(args, &v);
488 	if (rval)
489 		goto out_free;
490 	if (v)
491 		rval = xfs_dir2_leaf_removename(args);
492 	else
493 		rval = xfs_dir2_node_removename(args);
494 out_free:
495 	kmem_free(args);
496 	return rval;
497 }
498 
499 /*
500  * Replace the inode number of a directory entry.
501  */
502 int
503 xfs_dir_replace(
504 	xfs_trans_t	*tp,
505 	xfs_inode_t	*dp,
506 	struct xfs_name	*name,		/* name of entry to replace */
507 	xfs_ino_t	inum,		/* new inode number */
508 	xfs_fsblock_t	*first,		/* bmap's firstblock */
509 	struct xfs_defer_ops	*dfops,		/* bmap's freeblock list */
510 	xfs_extlen_t	total)		/* bmap's total block count */
511 {
512 	struct xfs_da_args *args;
513 	int		rval;
514 	int		v;		/* type-checking value */
515 
516 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
517 
518 	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
519 	if (rval)
520 		return rval;
521 
522 	args = kmem_zalloc(sizeof(*args), KM_SLEEP | KM_NOFS);
523 	if (!args)
524 		return -ENOMEM;
525 
526 	args->geo = dp->i_mount->m_dir_geo;
527 	args->name = name->name;
528 	args->namelen = name->len;
529 	args->filetype = name->type;
530 	args->hashval = dp->i_mount->m_dirnameops->hashname(name);
531 	args->inumber = inum;
532 	args->dp = dp;
533 	args->firstblock = first;
534 	args->dfops = dfops;
535 	args->total = total;
536 	args->whichfork = XFS_DATA_FORK;
537 	args->trans = tp;
538 
539 	if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
540 		rval = xfs_dir2_sf_replace(args);
541 		goto out_free;
542 	}
543 
544 	rval = xfs_dir2_isblock(args, &v);
545 	if (rval)
546 		goto out_free;
547 	if (v) {
548 		rval = xfs_dir2_block_replace(args);
549 		goto out_free;
550 	}
551 
552 	rval = xfs_dir2_isleaf(args, &v);
553 	if (rval)
554 		goto out_free;
555 	if (v)
556 		rval = xfs_dir2_leaf_replace(args);
557 	else
558 		rval = xfs_dir2_node_replace(args);
559 out_free:
560 	kmem_free(args);
561 	return rval;
562 }
563 
564 /*
565  * See if this entry can be added to the directory without allocating space.
566  */
567 int
568 xfs_dir_canenter(
569 	xfs_trans_t	*tp,
570 	xfs_inode_t	*dp,
571 	struct xfs_name	*name)		/* name of entry to add */
572 {
573 	return xfs_dir_createname(tp, dp, name, 0, NULL, NULL, 0);
574 }
575 
576 /*
577  * Utility routines.
578  */
579 
580 /*
581  * Add a block to the directory.
582  *
583  * This routine is for data and free blocks, not leaf/node blocks which are
584  * handled by xfs_da_grow_inode.
585  */
586 int
587 xfs_dir2_grow_inode(
588 	struct xfs_da_args	*args,
589 	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
590 	xfs_dir2_db_t		*dbp)	/* out: block number added */
591 {
592 	struct xfs_inode	*dp = args->dp;
593 	struct xfs_mount	*mp = dp->i_mount;
594 	xfs_fileoff_t		bno;	/* directory offset of new block */
595 	int			count;	/* count of filesystem blocks */
596 	int			error;
597 
598 	trace_xfs_dir2_grow_inode(args, space);
599 
600 	/*
601 	 * Set lowest possible block in the space requested.
602 	 */
603 	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
604 	count = args->geo->fsbcount;
605 
606 	error = xfs_da_grow_inode_int(args, &bno, count);
607 	if (error)
608 		return error;
609 
610 	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
611 
612 	/*
613 	 * Update file's size if this is the data space and it grew.
614 	 */
615 	if (space == XFS_DIR2_DATA_SPACE) {
616 		xfs_fsize_t	size;		/* directory file (data) size */
617 
618 		size = XFS_FSB_TO_B(mp, bno + count);
619 		if (size > dp->i_d.di_size) {
620 			dp->i_d.di_size = size;
621 			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
622 		}
623 	}
624 	return 0;
625 }
626 
627 /*
628  * See if the directory is a single-block form directory.
629  */
630 int
631 xfs_dir2_isblock(
632 	struct xfs_da_args	*args,
633 	int			*vp)	/* out: 1 is block, 0 is not block */
634 {
635 	xfs_fileoff_t		last;	/* last file offset */
636 	int			rval;
637 
638 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
639 		return rval;
640 	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
641 	if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize)
642 		return -EFSCORRUPTED;
643 	*vp = rval;
644 	return 0;
645 }
646 
647 /*
648  * See if the directory is a single-leaf form directory.
649  */
650 int
651 xfs_dir2_isleaf(
652 	struct xfs_da_args	*args,
653 	int			*vp)	/* out: 1 is block, 0 is not block */
654 {
655 	xfs_fileoff_t		last;	/* last file offset */
656 	int			rval;
657 
658 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
659 		return rval;
660 	*vp = last == args->geo->leafblk + args->geo->fsbcount;
661 	return 0;
662 }
663 
664 /*
665  * Remove the given block from the directory.
666  * This routine is used for data and free blocks, leaf/node are done
667  * by xfs_da_shrink_inode.
668  */
669 int
670 xfs_dir2_shrink_inode(
671 	xfs_da_args_t	*args,
672 	xfs_dir2_db_t	db,
673 	struct xfs_buf	*bp)
674 {
675 	xfs_fileoff_t	bno;		/* directory file offset */
676 	xfs_dablk_t	da;		/* directory file offset */
677 	int		done;		/* bunmap is finished */
678 	xfs_inode_t	*dp;
679 	int		error;
680 	xfs_mount_t	*mp;
681 	xfs_trans_t	*tp;
682 
683 	trace_xfs_dir2_shrink_inode(args, db);
684 
685 	dp = args->dp;
686 	mp = dp->i_mount;
687 	tp = args->trans;
688 	da = xfs_dir2_db_to_da(args->geo, db);
689 
690 	/* Unmap the fsblock(s). */
691 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0,
692 			    args->firstblock, args->dfops, &done);
693 	if (error) {
694 		/*
695 		 * ENOSPC actually can happen if we're in a removename with no
696 		 * space reservation, and the resulting block removal would
697 		 * cause a bmap btree split or conversion from extents to btree.
698 		 * This can only happen for un-fragmented directory blocks,
699 		 * since you need to be punching out the middle of an extent.
700 		 * In this case we need to leave the block in the file, and not
701 		 * binval it.  So the block has to be in a consistent empty
702 		 * state and appropriately logged.  We don't free up the buffer,
703 		 * the caller can tell it hasn't happened since it got an error
704 		 * back.
705 		 */
706 		return error;
707 	}
708 	ASSERT(done);
709 	/*
710 	 * Invalidate the buffer from the transaction.
711 	 */
712 	xfs_trans_binval(tp, bp);
713 	/*
714 	 * If it's not a data block, we're done.
715 	 */
716 	if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
717 		return 0;
718 	/*
719 	 * If the block isn't the last one in the directory, we're done.
720 	 */
721 	if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
722 		return 0;
723 	bno = da;
724 	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
725 		/*
726 		 * This can't really happen unless there's kernel corruption.
727 		 */
728 		return error;
729 	}
730 	if (db == args->geo->datablk)
731 		ASSERT(bno == 0);
732 	else
733 		ASSERT(bno > 0);
734 	/*
735 	 * Set the size to the new last block.
736 	 */
737 	dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
738 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
739 	return 0;
740 }
741