xref: /linux/fs/xfs/libxfs/xfs_dir2.c (revision fba2689ee77e63b05e203b3f26079ef915e55660)
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 
22 const struct xfs_name xfs_name_dotdot = {
23 	.name	= (const unsigned char *)"..",
24 	.len	= 2,
25 	.type	= XFS_DIR3_FT_DIR,
26 };
27 
28 /*
29  * Convert inode mode to directory entry filetype
30  */
31 unsigned char
32 xfs_mode_to_ftype(
33 	int		mode)
34 {
35 	switch (mode & S_IFMT) {
36 	case S_IFREG:
37 		return XFS_DIR3_FT_REG_FILE;
38 	case S_IFDIR:
39 		return XFS_DIR3_FT_DIR;
40 	case S_IFCHR:
41 		return XFS_DIR3_FT_CHRDEV;
42 	case S_IFBLK:
43 		return XFS_DIR3_FT_BLKDEV;
44 	case S_IFIFO:
45 		return XFS_DIR3_FT_FIFO;
46 	case S_IFSOCK:
47 		return XFS_DIR3_FT_SOCK;
48 	case S_IFLNK:
49 		return XFS_DIR3_FT_SYMLINK;
50 	default:
51 		return XFS_DIR3_FT_UNKNOWN;
52 	}
53 }
54 
55 /*
56  * ASCII case-insensitive (ie. A-Z) support for directories that was
57  * used in IRIX.
58  */
59 xfs_dahash_t
60 xfs_ascii_ci_hashname(
61 	const struct xfs_name	*name)
62 {
63 	xfs_dahash_t		hash;
64 	int			i;
65 
66 	for (i = 0, hash = 0; i < name->len; i++)
67 		hash = tolower(name->name[i]) ^ rol32(hash, 7);
68 
69 	return hash;
70 }
71 
72 enum xfs_dacmp
73 xfs_ascii_ci_compname(
74 	struct xfs_da_args	*args,
75 	const unsigned char	*name,
76 	int			len)
77 {
78 	enum xfs_dacmp		result;
79 	int			i;
80 
81 	if (args->namelen != len)
82 		return XFS_CMP_DIFFERENT;
83 
84 	result = XFS_CMP_EXACT;
85 	for (i = 0; i < len; i++) {
86 		if (args->name[i] == name[i])
87 			continue;
88 		if (tolower(args->name[i]) != tolower(name[i]))
89 			return XFS_CMP_DIFFERENT;
90 		result = XFS_CMP_CASE;
91 	}
92 
93 	return result;
94 }
95 
96 int
97 xfs_da_mount(
98 	struct xfs_mount	*mp)
99 {
100 	struct xfs_da_geometry	*dageo;
101 
102 
103 	ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
104 	ASSERT(xfs_dir2_dirblock_bytes(&mp->m_sb) <= XFS_MAX_BLOCKSIZE);
105 
106 	mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
107 				    KM_MAYFAIL);
108 	mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
109 				     KM_MAYFAIL);
110 	if (!mp->m_dir_geo || !mp->m_attr_geo) {
111 		kmem_free(mp->m_dir_geo);
112 		kmem_free(mp->m_attr_geo);
113 		return -ENOMEM;
114 	}
115 
116 	/* set up directory geometry */
117 	dageo = mp->m_dir_geo;
118 	dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
119 	dageo->fsblog = mp->m_sb.sb_blocklog;
120 	dageo->blksize = xfs_dir2_dirblock_bytes(&mp->m_sb);
121 	dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
122 	if (xfs_has_crc(mp)) {
123 		dageo->node_hdr_size = sizeof(struct xfs_da3_node_hdr);
124 		dageo->leaf_hdr_size = sizeof(struct xfs_dir3_leaf_hdr);
125 		dageo->free_hdr_size = sizeof(struct xfs_dir3_free_hdr);
126 		dageo->data_entry_offset =
127 				sizeof(struct xfs_dir3_data_hdr);
128 	} else {
129 		dageo->node_hdr_size = sizeof(struct xfs_da_node_hdr);
130 		dageo->leaf_hdr_size = sizeof(struct xfs_dir2_leaf_hdr);
131 		dageo->free_hdr_size = sizeof(struct xfs_dir2_free_hdr);
132 		dageo->data_entry_offset =
133 				sizeof(struct xfs_dir2_data_hdr);
134 	}
135 	dageo->leaf_max_ents = (dageo->blksize - dageo->leaf_hdr_size) /
136 			sizeof(struct xfs_dir2_leaf_entry);
137 	dageo->free_max_bests = (dageo->blksize - dageo->free_hdr_size) /
138 			sizeof(xfs_dir2_data_off_t);
139 
140 	dageo->data_first_offset = dageo->data_entry_offset +
141 			xfs_dir2_data_entsize(mp, 1) +
142 			xfs_dir2_data_entsize(mp, 2);
143 
144 	/*
145 	 * Now we've set up the block conversion variables, we can calculate the
146 	 * segment block constants using the geometry structure.
147 	 */
148 	dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
149 	dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
150 	dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
151 	dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
152 				(uint)sizeof(xfs_da_node_entry_t);
153 	dageo->magicpct = (dageo->blksize * 37) / 100;
154 
155 	/* set up attribute geometry - single fsb only */
156 	dageo = mp->m_attr_geo;
157 	dageo->blklog = mp->m_sb.sb_blocklog;
158 	dageo->fsblog = mp->m_sb.sb_blocklog;
159 	dageo->blksize = 1 << dageo->blklog;
160 	dageo->fsbcount = 1;
161 	dageo->node_hdr_size = mp->m_dir_geo->node_hdr_size;
162 	dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
163 				(uint)sizeof(xfs_da_node_entry_t);
164 	dageo->magicpct = (dageo->blksize * 37) / 100;
165 	return 0;
166 }
167 
168 void
169 xfs_da_unmount(
170 	struct xfs_mount	*mp)
171 {
172 	kmem_free(mp->m_dir_geo);
173 	kmem_free(mp->m_attr_geo);
174 }
175 
176 /*
177  * Return 1 if directory contains only "." and "..".
178  */
179 int
180 xfs_dir_isempty(
181 	xfs_inode_t	*dp)
182 {
183 	xfs_dir2_sf_hdr_t	*sfp;
184 
185 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
186 	if (dp->i_disk_size == 0)	/* might happen during shutdown. */
187 		return 1;
188 	if (dp->i_disk_size > XFS_IFORK_DSIZE(dp))
189 		return 0;
190 	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
191 	return !sfp->count;
192 }
193 
194 /*
195  * Validate a given inode number.
196  */
197 int
198 xfs_dir_ino_validate(
199 	xfs_mount_t	*mp,
200 	xfs_ino_t	ino)
201 {
202 	bool		ino_ok = xfs_verify_dir_ino(mp, ino);
203 
204 	if (XFS_IS_CORRUPT(mp, !ino_ok) ||
205 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_DIR_INO_VALIDATE)) {
206 		xfs_warn(mp, "Invalid inode number 0x%Lx",
207 				(unsigned long long) ino);
208 		return -EFSCORRUPTED;
209 	}
210 	return 0;
211 }
212 
213 /*
214  * Initialize a directory with its "." and ".." entries.
215  */
216 int
217 xfs_dir_init(
218 	xfs_trans_t	*tp,
219 	xfs_inode_t	*dp,
220 	xfs_inode_t	*pdp)
221 {
222 	struct xfs_da_args *args;
223 	int		error;
224 
225 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
226 	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
227 	if (error)
228 		return error;
229 
230 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
231 	if (!args)
232 		return -ENOMEM;
233 
234 	args->geo = dp->i_mount->m_dir_geo;
235 	args->dp = dp;
236 	args->trans = tp;
237 	error = xfs_dir2_sf_create(args, pdp->i_ino);
238 	kmem_free(args);
239 	return error;
240 }
241 
242 /*
243  * Enter a name in a directory, or check for available space.
244  * If inum is 0, only the available space test is performed.
245  */
246 int
247 xfs_dir_createname(
248 	struct xfs_trans	*tp,
249 	struct xfs_inode	*dp,
250 	const struct xfs_name	*name,
251 	xfs_ino_t		inum,		/* new entry inode number */
252 	xfs_extlen_t		total)		/* bmap's total block count */
253 {
254 	struct xfs_da_args	*args;
255 	int			rval;
256 	int			v;		/* type-checking value */
257 
258 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
259 
260 	if (inum) {
261 		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
262 		if (rval)
263 			return rval;
264 		XFS_STATS_INC(dp->i_mount, xs_dir_create);
265 	}
266 
267 	args = kmem_zalloc(sizeof(*args), 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 = xfs_dir2_hashname(dp->i_mount, name);
276 	args->inumber = inum;
277 	args->dp = dp;
278 	args->total = total;
279 	args->whichfork = XFS_DATA_FORK;
280 	args->trans = tp;
281 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
282 	if (!inum)
283 		args->op_flags |= XFS_DA_OP_JUSTCHECK;
284 
285 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
286 		rval = xfs_dir2_sf_addname(args);
287 		goto out_free;
288 	}
289 
290 	rval = xfs_dir2_isblock(args, &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(args, &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 	struct xfs_trans	*tp,
345 	struct xfs_inode	*dp,
346 	const 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 	int			lock_mode;
354 
355 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
356 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
357 
358 	/*
359 	 * We need to use KM_NOFS here so that lockdep will not throw false
360 	 * positive deadlock warnings on a non-transactional lookup path. It is
361 	 * safe to recurse into inode recalim in that case, but lockdep can't
362 	 * easily be taught about it. Hence KM_NOFS avoids having to add more
363 	 * lockdep Doing this avoids having to add a bunch of lockdep class
364 	 * annotations into the reclaim path for the ilock.
365 	 */
366 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
367 	args->geo = dp->i_mount->m_dir_geo;
368 	args->name = name->name;
369 	args->namelen = name->len;
370 	args->filetype = name->type;
371 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
372 	args->dp = dp;
373 	args->whichfork = XFS_DATA_FORK;
374 	args->trans = tp;
375 	args->op_flags = XFS_DA_OP_OKNOENT;
376 	if (ci_name)
377 		args->op_flags |= XFS_DA_OP_CILOOKUP;
378 
379 	lock_mode = xfs_ilock_data_map_shared(dp);
380 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
381 		rval = xfs_dir2_sf_lookup(args);
382 		goto out_check_rval;
383 	}
384 
385 	rval = xfs_dir2_isblock(args, &v);
386 	if (rval)
387 		goto out_free;
388 	if (v) {
389 		rval = xfs_dir2_block_lookup(args);
390 		goto out_check_rval;
391 	}
392 
393 	rval = xfs_dir2_isleaf(args, &v);
394 	if (rval)
395 		goto out_free;
396 	if (v)
397 		rval = xfs_dir2_leaf_lookup(args);
398 	else
399 		rval = xfs_dir2_node_lookup(args);
400 
401 out_check_rval:
402 	if (rval == -EEXIST)
403 		rval = 0;
404 	if (!rval) {
405 		*inum = args->inumber;
406 		if (ci_name) {
407 			ci_name->name = args->value;
408 			ci_name->len = args->valuelen;
409 		}
410 	}
411 out_free:
412 	xfs_iunlock(dp, lock_mode);
413 	kmem_free(args);
414 	return rval;
415 }
416 
417 /*
418  * Remove an entry from a directory.
419  */
420 int
421 xfs_dir_removename(
422 	struct xfs_trans	*tp,
423 	struct xfs_inode	*dp,
424 	struct xfs_name		*name,
425 	xfs_ino_t		ino,
426 	xfs_extlen_t		total)		/* bmap's total block count */
427 {
428 	struct xfs_da_args	*args;
429 	int			rval;
430 	int			v;		/* type-checking value */
431 
432 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
433 	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
434 
435 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
436 	if (!args)
437 		return -ENOMEM;
438 
439 	args->geo = dp->i_mount->m_dir_geo;
440 	args->name = name->name;
441 	args->namelen = name->len;
442 	args->filetype = name->type;
443 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
444 	args->inumber = ino;
445 	args->dp = dp;
446 	args->total = total;
447 	args->whichfork = XFS_DATA_FORK;
448 	args->trans = tp;
449 
450 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
451 		rval = xfs_dir2_sf_removename(args);
452 		goto out_free;
453 	}
454 
455 	rval = xfs_dir2_isblock(args, &v);
456 	if (rval)
457 		goto out_free;
458 	if (v) {
459 		rval = xfs_dir2_block_removename(args);
460 		goto out_free;
461 	}
462 
463 	rval = xfs_dir2_isleaf(args, &v);
464 	if (rval)
465 		goto out_free;
466 	if (v)
467 		rval = xfs_dir2_leaf_removename(args);
468 	else
469 		rval = xfs_dir2_node_removename(args);
470 out_free:
471 	kmem_free(args);
472 	return rval;
473 }
474 
475 /*
476  * Replace the inode number of a directory entry.
477  */
478 int
479 xfs_dir_replace(
480 	struct xfs_trans	*tp,
481 	struct xfs_inode	*dp,
482 	const struct xfs_name	*name,		/* name of entry to replace */
483 	xfs_ino_t		inum,		/* new inode number */
484 	xfs_extlen_t		total)		/* bmap's total block count */
485 {
486 	struct xfs_da_args	*args;
487 	int			rval;
488 	int			v;		/* type-checking value */
489 
490 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
491 
492 	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
493 	if (rval)
494 		return rval;
495 
496 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
497 	if (!args)
498 		return -ENOMEM;
499 
500 	args->geo = dp->i_mount->m_dir_geo;
501 	args->name = name->name;
502 	args->namelen = name->len;
503 	args->filetype = name->type;
504 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
505 	args->inumber = inum;
506 	args->dp = dp;
507 	args->total = total;
508 	args->whichfork = XFS_DATA_FORK;
509 	args->trans = tp;
510 
511 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
512 		rval = xfs_dir2_sf_replace(args);
513 		goto out_free;
514 	}
515 
516 	rval = xfs_dir2_isblock(args, &v);
517 	if (rval)
518 		goto out_free;
519 	if (v) {
520 		rval = xfs_dir2_block_replace(args);
521 		goto out_free;
522 	}
523 
524 	rval = xfs_dir2_isleaf(args, &v);
525 	if (rval)
526 		goto out_free;
527 	if (v)
528 		rval = xfs_dir2_leaf_replace(args);
529 	else
530 		rval = xfs_dir2_node_replace(args);
531 out_free:
532 	kmem_free(args);
533 	return rval;
534 }
535 
536 /*
537  * See if this entry can be added to the directory without allocating space.
538  */
539 int
540 xfs_dir_canenter(
541 	xfs_trans_t	*tp,
542 	xfs_inode_t	*dp,
543 	struct xfs_name	*name)		/* name of entry to add */
544 {
545 	return xfs_dir_createname(tp, dp, name, 0, 0);
546 }
547 
548 /*
549  * Utility routines.
550  */
551 
552 /*
553  * Add a block to the directory.
554  *
555  * This routine is for data and free blocks, not leaf/node blocks which are
556  * handled by xfs_da_grow_inode.
557  */
558 int
559 xfs_dir2_grow_inode(
560 	struct xfs_da_args	*args,
561 	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
562 	xfs_dir2_db_t		*dbp)	/* out: block number added */
563 {
564 	struct xfs_inode	*dp = args->dp;
565 	struct xfs_mount	*mp = dp->i_mount;
566 	xfs_fileoff_t		bno;	/* directory offset of new block */
567 	int			count;	/* count of filesystem blocks */
568 	int			error;
569 
570 	trace_xfs_dir2_grow_inode(args, space);
571 
572 	/*
573 	 * Set lowest possible block in the space requested.
574 	 */
575 	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
576 	count = args->geo->fsbcount;
577 
578 	error = xfs_da_grow_inode_int(args, &bno, count);
579 	if (error)
580 		return error;
581 
582 	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
583 
584 	/*
585 	 * Update file's size if this is the data space and it grew.
586 	 */
587 	if (space == XFS_DIR2_DATA_SPACE) {
588 		xfs_fsize_t	size;		/* directory file (data) size */
589 
590 		size = XFS_FSB_TO_B(mp, bno + count);
591 		if (size > dp->i_disk_size) {
592 			dp->i_disk_size = size;
593 			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
594 		}
595 	}
596 	return 0;
597 }
598 
599 /*
600  * See if the directory is a single-block form directory.
601  */
602 int
603 xfs_dir2_isblock(
604 	struct xfs_da_args	*args,
605 	int			*vp)	/* out: 1 is block, 0 is not block */
606 {
607 	xfs_fileoff_t		last;	/* last file offset */
608 	int			rval;
609 
610 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
611 		return rval;
612 	rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
613 	if (XFS_IS_CORRUPT(args->dp->i_mount,
614 			   rval != 0 &&
615 			   args->dp->i_disk_size != args->geo->blksize))
616 		return -EFSCORRUPTED;
617 	*vp = rval;
618 	return 0;
619 }
620 
621 /*
622  * See if the directory is a single-leaf form directory.
623  */
624 int
625 xfs_dir2_isleaf(
626 	struct xfs_da_args	*args,
627 	int			*vp)	/* out: 1 is block, 0 is not block */
628 {
629 	xfs_fileoff_t		last;	/* last file offset */
630 	int			rval;
631 
632 	if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
633 		return rval;
634 	*vp = last == args->geo->leafblk + args->geo->fsbcount;
635 	return 0;
636 }
637 
638 /*
639  * Remove the given block from the directory.
640  * This routine is used for data and free blocks, leaf/node are done
641  * by xfs_da_shrink_inode.
642  */
643 int
644 xfs_dir2_shrink_inode(
645 	struct xfs_da_args	*args,
646 	xfs_dir2_db_t		db,
647 	struct xfs_buf		*bp)
648 {
649 	xfs_fileoff_t		bno;		/* directory file offset */
650 	xfs_dablk_t		da;		/* directory file offset */
651 	int			done;		/* bunmap is finished */
652 	struct xfs_inode	*dp;
653 	int			error;
654 	struct xfs_mount	*mp;
655 	struct xfs_trans	*tp;
656 
657 	trace_xfs_dir2_shrink_inode(args, db);
658 
659 	dp = args->dp;
660 	mp = dp->i_mount;
661 	tp = args->trans;
662 	da = xfs_dir2_db_to_da(args->geo, db);
663 
664 	/* Unmap the fsblock(s). */
665 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0, &done);
666 	if (error) {
667 		/*
668 		 * ENOSPC actually can happen if we're in a removename with no
669 		 * space reservation, and the resulting block removal would
670 		 * cause a bmap btree split or conversion from extents to btree.
671 		 * This can only happen for un-fragmented directory blocks,
672 		 * since you need to be punching out the middle of an extent.
673 		 * In this case we need to leave the block in the file, and not
674 		 * binval it.  So the block has to be in a consistent empty
675 		 * state and appropriately logged.  We don't free up the buffer,
676 		 * the caller can tell it hasn't happened since it got an error
677 		 * back.
678 		 */
679 		return error;
680 	}
681 	ASSERT(done);
682 	/*
683 	 * Invalidate the buffer from the transaction.
684 	 */
685 	xfs_trans_binval(tp, bp);
686 	/*
687 	 * If it's not a data block, we're done.
688 	 */
689 	if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
690 		return 0;
691 	/*
692 	 * If the block isn't the last one in the directory, we're done.
693 	 */
694 	if (dp->i_disk_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
695 		return 0;
696 	bno = da;
697 	if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
698 		/*
699 		 * This can't really happen unless there's kernel corruption.
700 		 */
701 		return error;
702 	}
703 	if (db == args->geo->datablk)
704 		ASSERT(bno == 0);
705 	else
706 		ASSERT(bno > 0);
707 	/*
708 	 * Set the size to the new last block.
709 	 */
710 	dp->i_disk_size = XFS_FSB_TO_B(mp, bno);
711 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
712 	return 0;
713 }
714 
715 /* Returns true if the directory entry name is valid. */
716 bool
717 xfs_dir2_namecheck(
718 	const void	*name,
719 	size_t		length)
720 {
721 	/*
722 	 * MAXNAMELEN includes the trailing null, but (name/length) leave it
723 	 * out, so use >= for the length check.
724 	 */
725 	if (length >= MAXNAMELEN)
726 		return false;
727 
728 	/* There shouldn't be any slashes or nulls here */
729 	return !memchr(name, '/', length) && !memchr(name, 0, length);
730 }
731 
732 xfs_dahash_t
733 xfs_dir2_hashname(
734 	struct xfs_mount	*mp,
735 	const struct xfs_name	*name)
736 {
737 	if (unlikely(xfs_has_asciici(mp)))
738 		return xfs_ascii_ci_hashname(name);
739 	return xfs_da_hashname(name->name, name->len);
740 }
741 
742 enum xfs_dacmp
743 xfs_dir2_compname(
744 	struct xfs_da_args	*args,
745 	const unsigned char	*name,
746 	int			len)
747 {
748 	if (unlikely(xfs_has_asciici(args->dp->i_mount)))
749 		return xfs_ascii_ci_compname(args, name, len);
750 	return xfs_da_compname(args, name, len);
751 }
752