xref: /linux/fs/xfs/libxfs/xfs_dir2.c (revision b1992c3772e69a6fd0e3fc81cd4d2820c8b6eca0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_mount.h"
13 #include "xfs_inode.h"
14 #include "xfs_trans.h"
15 #include "xfs_bmap.h"
16 #include "xfs_dir2.h"
17 #include "xfs_dir2_priv.h"
18 #include "xfs_errortag.h"
19 #include "xfs_error.h"
20 #include "xfs_trace.h"
21 #include "xfs_health.h"
22 
23 const struct xfs_name xfs_name_dotdot = {
24 	.name	= (const unsigned char *)"..",
25 	.len	= 2,
26 	.type	= XFS_DIR3_FT_DIR,
27 };
28 
29 const struct xfs_name xfs_name_dot = {
30 	.name	= (const unsigned char *)".",
31 	.len	= 1,
32 	.type	= XFS_DIR3_FT_DIR,
33 };
34 
35 /*
36  * Convert inode mode to directory entry filetype
37  */
38 unsigned char
39 xfs_mode_to_ftype(
40 	int		mode)
41 {
42 	switch (mode & S_IFMT) {
43 	case S_IFREG:
44 		return XFS_DIR3_FT_REG_FILE;
45 	case S_IFDIR:
46 		return XFS_DIR3_FT_DIR;
47 	case S_IFCHR:
48 		return XFS_DIR3_FT_CHRDEV;
49 	case S_IFBLK:
50 		return XFS_DIR3_FT_BLKDEV;
51 	case S_IFIFO:
52 		return XFS_DIR3_FT_FIFO;
53 	case S_IFSOCK:
54 		return XFS_DIR3_FT_SOCK;
55 	case S_IFLNK:
56 		return XFS_DIR3_FT_SYMLINK;
57 	default:
58 		return XFS_DIR3_FT_UNKNOWN;
59 	}
60 }
61 
62 /*
63  * ASCII case-insensitive (ie. A-Z) support for directories that was
64  * used in IRIX.
65  */
66 xfs_dahash_t
67 xfs_ascii_ci_hashname(
68 	const struct xfs_name	*name)
69 {
70 	xfs_dahash_t		hash;
71 	int			i;
72 
73 	for (i = 0, hash = 0; i < name->len; i++)
74 		hash = xfs_ascii_ci_xfrm(name->name[i]) ^ rol32(hash, 7);
75 
76 	return hash;
77 }
78 
79 enum xfs_dacmp
80 xfs_ascii_ci_compname(
81 	struct xfs_da_args	*args,
82 	const unsigned char	*name,
83 	int			len)
84 {
85 	enum xfs_dacmp		result;
86 	int			i;
87 
88 	if (args->namelen != len)
89 		return XFS_CMP_DIFFERENT;
90 
91 	result = XFS_CMP_EXACT;
92 	for (i = 0; i < len; i++) {
93 		if (args->name[i] == name[i])
94 			continue;
95 		if (xfs_ascii_ci_xfrm(args->name[i]) !=
96 		    xfs_ascii_ci_xfrm(name[i]))
97 			return XFS_CMP_DIFFERENT;
98 		result = XFS_CMP_CASE;
99 	}
100 
101 	return result;
102 }
103 
104 int
105 xfs_da_mount(
106 	struct xfs_mount	*mp)
107 {
108 	struct xfs_da_geometry	*dageo;
109 
110 
111 	ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
112 	ASSERT(xfs_dir2_dirblock_bytes(&mp->m_sb) <= XFS_MAX_BLOCKSIZE);
113 
114 	mp->m_dir_geo = kzalloc(sizeof(struct xfs_da_geometry),
115 				GFP_KERNEL | __GFP_RETRY_MAYFAIL);
116 	mp->m_attr_geo = kzalloc(sizeof(struct xfs_da_geometry),
117 				GFP_KERNEL | __GFP_RETRY_MAYFAIL);
118 	if (!mp->m_dir_geo || !mp->m_attr_geo) {
119 		kfree(mp->m_dir_geo);
120 		kfree(mp->m_attr_geo);
121 		return -ENOMEM;
122 	}
123 
124 	/* set up directory geometry */
125 	dageo = mp->m_dir_geo;
126 	dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
127 	dageo->fsblog = mp->m_sb.sb_blocklog;
128 	dageo->blksize = xfs_dir2_dirblock_bytes(&mp->m_sb);
129 	dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
130 	if (xfs_has_crc(mp)) {
131 		dageo->node_hdr_size = sizeof(struct xfs_da3_node_hdr);
132 		dageo->leaf_hdr_size = sizeof(struct xfs_dir3_leaf_hdr);
133 		dageo->free_hdr_size = sizeof(struct xfs_dir3_free_hdr);
134 		dageo->data_entry_offset =
135 				sizeof(struct xfs_dir3_data_hdr);
136 	} else {
137 		dageo->node_hdr_size = sizeof(struct xfs_da_node_hdr);
138 		dageo->leaf_hdr_size = sizeof(struct xfs_dir2_leaf_hdr);
139 		dageo->free_hdr_size = sizeof(struct xfs_dir2_free_hdr);
140 		dageo->data_entry_offset =
141 				sizeof(struct xfs_dir2_data_hdr);
142 	}
143 	dageo->leaf_max_ents = (dageo->blksize - dageo->leaf_hdr_size) /
144 			sizeof(struct xfs_dir2_leaf_entry);
145 	dageo->free_max_bests = (dageo->blksize - dageo->free_hdr_size) /
146 			sizeof(xfs_dir2_data_off_t);
147 
148 	dageo->data_first_offset = dageo->data_entry_offset +
149 			xfs_dir2_data_entsize(mp, 1) +
150 			xfs_dir2_data_entsize(mp, 2);
151 
152 	/*
153 	 * Now we've set up the block conversion variables, we can calculate the
154 	 * segment block constants using the geometry structure.
155 	 */
156 	dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
157 	dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
158 	dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
159 	dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
160 				(uint)sizeof(xfs_da_node_entry_t);
161 	dageo->max_extents = (XFS_DIR2_MAX_SPACES * XFS_DIR2_SPACE_SIZE) >>
162 					mp->m_sb.sb_blocklog;
163 	dageo->magicpct = (dageo->blksize * 37) / 100;
164 
165 	/* set up attribute geometry - single fsb only */
166 	dageo = mp->m_attr_geo;
167 	dageo->blklog = mp->m_sb.sb_blocklog;
168 	dageo->fsblog = mp->m_sb.sb_blocklog;
169 	dageo->blksize = 1 << dageo->blklog;
170 	dageo->fsbcount = 1;
171 	dageo->node_hdr_size = mp->m_dir_geo->node_hdr_size;
172 	dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
173 				(uint)sizeof(xfs_da_node_entry_t);
174 
175 	if (xfs_has_large_extent_counts(mp))
176 		dageo->max_extents = XFS_MAX_EXTCNT_ATTR_FORK_LARGE;
177 	else
178 		dageo->max_extents = XFS_MAX_EXTCNT_ATTR_FORK_SMALL;
179 
180 	dageo->magicpct = (dageo->blksize * 37) / 100;
181 	return 0;
182 }
183 
184 void
185 xfs_da_unmount(
186 	struct xfs_mount	*mp)
187 {
188 	kfree(mp->m_dir_geo);
189 	kfree(mp->m_attr_geo);
190 }
191 
192 /*
193  * Return 1 if directory contains only "." and "..".
194  */
195 int
196 xfs_dir_isempty(
197 	xfs_inode_t	*dp)
198 {
199 	xfs_dir2_sf_hdr_t	*sfp;
200 
201 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
202 	if (dp->i_disk_size == 0)	/* might happen during shutdown. */
203 		return 1;
204 	if (dp->i_disk_size > xfs_inode_data_fork_size(dp))
205 		return 0;
206 	sfp = dp->i_df.if_data;
207 	return !sfp->count;
208 }
209 
210 /*
211  * Validate a given inode number.
212  */
213 int
214 xfs_dir_ino_validate(
215 	xfs_mount_t	*mp,
216 	xfs_ino_t	ino)
217 {
218 	bool		ino_ok = xfs_verify_dir_ino(mp, ino);
219 
220 	if (XFS_IS_CORRUPT(mp, !ino_ok) ||
221 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_DIR_INO_VALIDATE)) {
222 		xfs_warn(mp, "Invalid inode number 0x%Lx",
223 				(unsigned long long) ino);
224 		return -EFSCORRUPTED;
225 	}
226 	return 0;
227 }
228 
229 /*
230  * Initialize a directory with its "." and ".." entries.
231  */
232 int
233 xfs_dir_init(
234 	xfs_trans_t	*tp,
235 	xfs_inode_t	*dp,
236 	xfs_inode_t	*pdp)
237 {
238 	struct xfs_da_args *args;
239 	int		error;
240 
241 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
242 	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
243 	if (error)
244 		return error;
245 
246 	args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
247 	if (!args)
248 		return -ENOMEM;
249 
250 	args->geo = dp->i_mount->m_dir_geo;
251 	args->dp = dp;
252 	args->trans = tp;
253 	error = xfs_dir2_sf_create(args, pdp->i_ino);
254 	kfree(args);
255 	return error;
256 }
257 
258 /*
259  * Enter a name in a directory, or check for available space.
260  * If inum is 0, only the available space test is performed.
261  */
262 int
263 xfs_dir_createname(
264 	struct xfs_trans	*tp,
265 	struct xfs_inode	*dp,
266 	const struct xfs_name	*name,
267 	xfs_ino_t		inum,		/* new entry inode number */
268 	xfs_extlen_t		total)		/* bmap's total block count */
269 {
270 	struct xfs_da_args	*args;
271 	int			rval;
272 	bool			v;
273 
274 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
275 
276 	if (inum) {
277 		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
278 		if (rval)
279 			return rval;
280 		XFS_STATS_INC(dp->i_mount, xs_dir_create);
281 	}
282 
283 	args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
284 	if (!args)
285 		return -ENOMEM;
286 
287 	args->geo = dp->i_mount->m_dir_geo;
288 	args->name = name->name;
289 	args->namelen = name->len;
290 	args->filetype = name->type;
291 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
292 	args->inumber = inum;
293 	args->dp = dp;
294 	args->total = total;
295 	args->whichfork = XFS_DATA_FORK;
296 	args->trans = tp;
297 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
298 	if (!inum)
299 		args->op_flags |= XFS_DA_OP_JUSTCHECK;
300 
301 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
302 		rval = xfs_dir2_sf_addname(args);
303 		goto out_free;
304 	}
305 
306 	rval = xfs_dir2_isblock(args, &v);
307 	if (rval)
308 		goto out_free;
309 	if (v) {
310 		rval = xfs_dir2_block_addname(args);
311 		goto out_free;
312 	}
313 
314 	rval = xfs_dir2_isleaf(args, &v);
315 	if (rval)
316 		goto out_free;
317 	if (v)
318 		rval = xfs_dir2_leaf_addname(args);
319 	else
320 		rval = xfs_dir2_node_addname(args);
321 
322 out_free:
323 	kfree(args);
324 	return rval;
325 }
326 
327 /*
328  * If doing a CI lookup and case-insensitive match, dup actual name into
329  * args.value. Return EEXIST for success (ie. name found) or an error.
330  */
331 int
332 xfs_dir_cilookup_result(
333 	struct xfs_da_args *args,
334 	const unsigned char *name,
335 	int		len)
336 {
337 	if (args->cmpresult == XFS_CMP_DIFFERENT)
338 		return -ENOENT;
339 	if (args->cmpresult != XFS_CMP_CASE ||
340 					!(args->op_flags & XFS_DA_OP_CILOOKUP))
341 		return -EEXIST;
342 
343 	args->value = kmalloc(len,
344 			GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_RETRY_MAYFAIL);
345 	if (!args->value)
346 		return -ENOMEM;
347 
348 	memcpy(args->value, name, len);
349 	args->valuelen = len;
350 	return -EEXIST;
351 }
352 
353 /*
354  * Lookup a name in a directory, give back the inode number.
355  * If ci_name is not NULL, returns the actual name in ci_name if it differs
356  * to name, or ci_name->name is set to NULL for an exact match.
357  */
358 
359 int
360 xfs_dir_lookup(
361 	struct xfs_trans	*tp,
362 	struct xfs_inode	*dp,
363 	const struct xfs_name	*name,
364 	xfs_ino_t		*inum,	  /* out: inode number */
365 	struct xfs_name		*ci_name) /* out: actual name if CI match */
366 {
367 	struct xfs_da_args	*args;
368 	int			rval;
369 	bool			v;
370 	int			lock_mode;
371 
372 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
373 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
374 
375 	args = kzalloc(sizeof(*args),
376 			GFP_KERNEL | __GFP_NOLOCKDEP | __GFP_NOFAIL);
377 	args->geo = dp->i_mount->m_dir_geo;
378 	args->name = name->name;
379 	args->namelen = name->len;
380 	args->filetype = name->type;
381 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
382 	args->dp = dp;
383 	args->whichfork = XFS_DATA_FORK;
384 	args->trans = tp;
385 	args->op_flags = XFS_DA_OP_OKNOENT;
386 	if (ci_name)
387 		args->op_flags |= XFS_DA_OP_CILOOKUP;
388 
389 	lock_mode = xfs_ilock_data_map_shared(dp);
390 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
391 		rval = xfs_dir2_sf_lookup(args);
392 		goto out_check_rval;
393 	}
394 
395 	rval = xfs_dir2_isblock(args, &v);
396 	if (rval)
397 		goto out_free;
398 	if (v) {
399 		rval = xfs_dir2_block_lookup(args);
400 		goto out_check_rval;
401 	}
402 
403 	rval = xfs_dir2_isleaf(args, &v);
404 	if (rval)
405 		goto out_free;
406 	if (v)
407 		rval = xfs_dir2_leaf_lookup(args);
408 	else
409 		rval = xfs_dir2_node_lookup(args);
410 
411 out_check_rval:
412 	if (rval == -EEXIST)
413 		rval = 0;
414 	if (!rval) {
415 		*inum = args->inumber;
416 		if (ci_name) {
417 			ci_name->name = args->value;
418 			ci_name->len = args->valuelen;
419 		}
420 	}
421 out_free:
422 	xfs_iunlock(dp, lock_mode);
423 	kfree(args);
424 	return rval;
425 }
426 
427 /*
428  * Remove an entry from a directory.
429  */
430 int
431 xfs_dir_removename(
432 	struct xfs_trans	*tp,
433 	struct xfs_inode	*dp,
434 	struct xfs_name		*name,
435 	xfs_ino_t		ino,
436 	xfs_extlen_t		total)		/* bmap's total block count */
437 {
438 	struct xfs_da_args	*args;
439 	int			rval;
440 	bool			v;
441 
442 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
443 	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
444 
445 	args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
446 	if (!args)
447 		return -ENOMEM;
448 
449 	args->geo = dp->i_mount->m_dir_geo;
450 	args->name = name->name;
451 	args->namelen = name->len;
452 	args->filetype = name->type;
453 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
454 	args->inumber = ino;
455 	args->dp = dp;
456 	args->total = total;
457 	args->whichfork = XFS_DATA_FORK;
458 	args->trans = tp;
459 
460 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
461 		rval = xfs_dir2_sf_removename(args);
462 		goto out_free;
463 	}
464 
465 	rval = xfs_dir2_isblock(args, &v);
466 	if (rval)
467 		goto out_free;
468 	if (v) {
469 		rval = xfs_dir2_block_removename(args);
470 		goto out_free;
471 	}
472 
473 	rval = xfs_dir2_isleaf(args, &v);
474 	if (rval)
475 		goto out_free;
476 	if (v)
477 		rval = xfs_dir2_leaf_removename(args);
478 	else
479 		rval = xfs_dir2_node_removename(args);
480 out_free:
481 	kfree(args);
482 	return rval;
483 }
484 
485 /*
486  * Replace the inode number of a directory entry.
487  */
488 int
489 xfs_dir_replace(
490 	struct xfs_trans	*tp,
491 	struct xfs_inode	*dp,
492 	const struct xfs_name	*name,		/* name of entry to replace */
493 	xfs_ino_t		inum,		/* new inode number */
494 	xfs_extlen_t		total)		/* bmap's total block count */
495 {
496 	struct xfs_da_args	*args;
497 	int			rval;
498 	bool			v;
499 
500 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
501 
502 	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
503 	if (rval)
504 		return rval;
505 
506 	args = kzalloc(sizeof(*args), GFP_KERNEL | __GFP_NOFAIL);
507 	if (!args)
508 		return -ENOMEM;
509 
510 	args->geo = dp->i_mount->m_dir_geo;
511 	args->name = name->name;
512 	args->namelen = name->len;
513 	args->filetype = name->type;
514 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
515 	args->inumber = inum;
516 	args->dp = dp;
517 	args->total = total;
518 	args->whichfork = XFS_DATA_FORK;
519 	args->trans = tp;
520 
521 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
522 		rval = xfs_dir2_sf_replace(args);
523 		goto out_free;
524 	}
525 
526 	rval = xfs_dir2_isblock(args, &v);
527 	if (rval)
528 		goto out_free;
529 	if (v) {
530 		rval = xfs_dir2_block_replace(args);
531 		goto out_free;
532 	}
533 
534 	rval = xfs_dir2_isleaf(args, &v);
535 	if (rval)
536 		goto out_free;
537 	if (v)
538 		rval = xfs_dir2_leaf_replace(args);
539 	else
540 		rval = xfs_dir2_node_replace(args);
541 out_free:
542 	kfree(args);
543 	return rval;
544 }
545 
546 /*
547  * See if this entry can be added to the directory without allocating space.
548  */
549 int
550 xfs_dir_canenter(
551 	xfs_trans_t	*tp,
552 	xfs_inode_t	*dp,
553 	struct xfs_name	*name)		/* name of entry to add */
554 {
555 	return xfs_dir_createname(tp, dp, name, 0, 0);
556 }
557 
558 /*
559  * Utility routines.
560  */
561 
562 /*
563  * Add a block to the directory.
564  *
565  * This routine is for data and free blocks, not leaf/node blocks which are
566  * handled by xfs_da_grow_inode.
567  */
568 int
569 xfs_dir2_grow_inode(
570 	struct xfs_da_args	*args,
571 	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
572 	xfs_dir2_db_t		*dbp)	/* out: block number added */
573 {
574 	struct xfs_inode	*dp = args->dp;
575 	struct xfs_mount	*mp = dp->i_mount;
576 	xfs_fileoff_t		bno;	/* directory offset of new block */
577 	int			count;	/* count of filesystem blocks */
578 	int			error;
579 
580 	trace_xfs_dir2_grow_inode(args, space);
581 
582 	/*
583 	 * Set lowest possible block in the space requested.
584 	 */
585 	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
586 	count = args->geo->fsbcount;
587 
588 	error = xfs_da_grow_inode_int(args, &bno, count);
589 	if (error)
590 		return error;
591 
592 	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
593 
594 	/*
595 	 * Update file's size if this is the data space and it grew.
596 	 */
597 	if (space == XFS_DIR2_DATA_SPACE) {
598 		xfs_fsize_t	size;		/* directory file (data) size */
599 
600 		size = XFS_FSB_TO_B(mp, bno + count);
601 		if (size > dp->i_disk_size) {
602 			dp->i_disk_size = size;
603 			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
604 		}
605 	}
606 	return 0;
607 }
608 
609 /*
610  * See if the directory is a single-block form directory.
611  */
612 int
613 xfs_dir2_isblock(
614 	struct xfs_da_args	*args,
615 	bool			*isblock)
616 {
617 	struct xfs_mount	*mp = args->dp->i_mount;
618 	xfs_fileoff_t		eof;
619 	int			error;
620 
621 	error = xfs_bmap_last_offset(args->dp, &eof, XFS_DATA_FORK);
622 	if (error)
623 		return error;
624 
625 	*isblock = false;
626 	if (XFS_FSB_TO_B(mp, eof) != args->geo->blksize)
627 		return 0;
628 
629 	*isblock = true;
630 	if (XFS_IS_CORRUPT(mp, args->dp->i_disk_size != args->geo->blksize)) {
631 		xfs_da_mark_sick(args);
632 		return -EFSCORRUPTED;
633 	}
634 	return 0;
635 }
636 
637 /*
638  * See if the directory is a single-leaf form directory.
639  */
640 int
641 xfs_dir2_isleaf(
642 	struct xfs_da_args	*args,
643 	bool			*isleaf)
644 {
645 	xfs_fileoff_t		eof;
646 	int			error;
647 
648 	error = xfs_bmap_last_offset(args->dp, &eof, XFS_DATA_FORK);
649 	if (error)
650 		return error;
651 
652 	*isleaf = false;
653 	if (eof != args->geo->leafblk + args->geo->fsbcount)
654 		return 0;
655 
656 	*isleaf = true;
657 	return 0;
658 }
659 
660 /*
661  * Remove the given block from the directory.
662  * This routine is used for data and free blocks, leaf/node are done
663  * by xfs_da_shrink_inode.
664  */
665 int
666 xfs_dir2_shrink_inode(
667 	struct xfs_da_args	*args,
668 	xfs_dir2_db_t		db,
669 	struct xfs_buf		*bp)
670 {
671 	xfs_fileoff_t		bno;		/* directory file offset */
672 	xfs_dablk_t		da;		/* directory file offset */
673 	int			done;		/* bunmap is finished */
674 	struct xfs_inode	*dp;
675 	int			error;
676 	struct xfs_mount	*mp;
677 	struct xfs_trans	*tp;
678 
679 	trace_xfs_dir2_shrink_inode(args, db);
680 
681 	dp = args->dp;
682 	mp = dp->i_mount;
683 	tp = args->trans;
684 	da = xfs_dir2_db_to_da(args->geo, db);
685 
686 	/* Unmap the fsblock(s). */
687 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0, &done);
688 	if (error) {
689 		/*
690 		 * ENOSPC actually can happen if we're in a removename with no
691 		 * space reservation, and the resulting block removal would
692 		 * cause a bmap btree split or conversion from extents to btree.
693 		 * This can only happen for un-fragmented directory blocks,
694 		 * since you need to be punching out the middle of an extent.
695 		 * In this case we need to leave the block in the file, and not
696 		 * binval it.  So the block has to be in a consistent empty
697 		 * state and appropriately logged.  We don't free up the buffer,
698 		 * the caller can tell it hasn't happened since it got an error
699 		 * back.
700 		 */
701 		return error;
702 	}
703 	ASSERT(done);
704 	/*
705 	 * Invalidate the buffer from the transaction.
706 	 */
707 	xfs_trans_binval(tp, bp);
708 	/*
709 	 * If it's not a data block, we're done.
710 	 */
711 	if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
712 		return 0;
713 	/*
714 	 * If the block isn't the last one in the directory, we're done.
715 	 */
716 	if (dp->i_disk_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
717 		return 0;
718 	bno = da;
719 	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
720 		/*
721 		 * This can't really happen unless there's kernel corruption.
722 		 */
723 		return error;
724 	}
725 	if (db == args->geo->datablk)
726 		ASSERT(bno == 0);
727 	else
728 		ASSERT(bno > 0);
729 	/*
730 	 * Set the size to the new last block.
731 	 */
732 	dp->i_disk_size = XFS_FSB_TO_B(mp, bno);
733 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
734 	return 0;
735 }
736 
737 /* Returns true if the directory entry name is valid. */
738 bool
739 xfs_dir2_namecheck(
740 	const void	*name,
741 	size_t		length)
742 {
743 	/*
744 	 * MAXNAMELEN includes the trailing null, but (name/length) leave it
745 	 * out, so use >= for the length check.
746 	 */
747 	if (length >= MAXNAMELEN)
748 		return false;
749 
750 	/* There shouldn't be any slashes or nulls here */
751 	return !memchr(name, '/', length) && !memchr(name, 0, length);
752 }
753 
754 xfs_dahash_t
755 xfs_dir2_hashname(
756 	struct xfs_mount	*mp,
757 	const struct xfs_name	*name)
758 {
759 	if (unlikely(xfs_has_asciici(mp)))
760 		return xfs_ascii_ci_hashname(name);
761 	return xfs_da_hashname(name->name, name->len);
762 }
763 
764 enum xfs_dacmp
765 xfs_dir2_compname(
766 	struct xfs_da_args	*args,
767 	const unsigned char	*name,
768 	int			len)
769 {
770 	if (unlikely(xfs_has_asciici(args->dp->i_mount)))
771 		return xfs_ascii_ci_compname(args, name, len);
772 	return xfs_da_compname(args, name, len);
773 }
774