xref: /linux/fs/xfs/libxfs/xfs_dir2.c (revision 46ff24efe04ac96a129dd01138640c3447a525e1)
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->max_extents = (XFS_DIR2_MAX_SPACES * XFS_DIR2_SPACE_SIZE) >>
154 					mp->m_sb.sb_blocklog;
155 	dageo->magicpct = (dageo->blksize * 37) / 100;
156 
157 	/* set up attribute geometry - single fsb only */
158 	dageo = mp->m_attr_geo;
159 	dageo->blklog = mp->m_sb.sb_blocklog;
160 	dageo->fsblog = mp->m_sb.sb_blocklog;
161 	dageo->blksize = 1 << dageo->blklog;
162 	dageo->fsbcount = 1;
163 	dageo->node_hdr_size = mp->m_dir_geo->node_hdr_size;
164 	dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) /
165 				(uint)sizeof(xfs_da_node_entry_t);
166 
167 	if (xfs_has_large_extent_counts(mp))
168 		dageo->max_extents = XFS_MAX_EXTCNT_ATTR_FORK_LARGE;
169 	else
170 		dageo->max_extents = XFS_MAX_EXTCNT_ATTR_FORK_SMALL;
171 
172 	dageo->magicpct = (dageo->blksize * 37) / 100;
173 	return 0;
174 }
175 
176 void
177 xfs_da_unmount(
178 	struct xfs_mount	*mp)
179 {
180 	kmem_free(mp->m_dir_geo);
181 	kmem_free(mp->m_attr_geo);
182 }
183 
184 /*
185  * Return 1 if directory contains only "." and "..".
186  */
187 int
188 xfs_dir_isempty(
189 	xfs_inode_t	*dp)
190 {
191 	xfs_dir2_sf_hdr_t	*sfp;
192 
193 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
194 	if (dp->i_disk_size == 0)	/* might happen during shutdown. */
195 		return 1;
196 	if (dp->i_disk_size > xfs_inode_data_fork_size(dp))
197 		return 0;
198 	sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
199 	return !sfp->count;
200 }
201 
202 /*
203  * Validate a given inode number.
204  */
205 int
206 xfs_dir_ino_validate(
207 	xfs_mount_t	*mp,
208 	xfs_ino_t	ino)
209 {
210 	bool		ino_ok = xfs_verify_dir_ino(mp, ino);
211 
212 	if (XFS_IS_CORRUPT(mp, !ino_ok) ||
213 	    XFS_TEST_ERROR(false, mp, XFS_ERRTAG_DIR_INO_VALIDATE)) {
214 		xfs_warn(mp, "Invalid inode number 0x%Lx",
215 				(unsigned long long) ino);
216 		return -EFSCORRUPTED;
217 	}
218 	return 0;
219 }
220 
221 /*
222  * Initialize a directory with its "." and ".." entries.
223  */
224 int
225 xfs_dir_init(
226 	xfs_trans_t	*tp,
227 	xfs_inode_t	*dp,
228 	xfs_inode_t	*pdp)
229 {
230 	struct xfs_da_args *args;
231 	int		error;
232 
233 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
234 	error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
235 	if (error)
236 		return error;
237 
238 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
239 	if (!args)
240 		return -ENOMEM;
241 
242 	args->geo = dp->i_mount->m_dir_geo;
243 	args->dp = dp;
244 	args->trans = tp;
245 	error = xfs_dir2_sf_create(args, pdp->i_ino);
246 	kmem_free(args);
247 	return error;
248 }
249 
250 /*
251  * Enter a name in a directory, or check for available space.
252  * If inum is 0, only the available space test is performed.
253  */
254 int
255 xfs_dir_createname(
256 	struct xfs_trans	*tp,
257 	struct xfs_inode	*dp,
258 	const struct xfs_name	*name,
259 	xfs_ino_t		inum,		/* new entry inode number */
260 	xfs_extlen_t		total)		/* bmap's total block count */
261 {
262 	struct xfs_da_args	*args;
263 	int			rval;
264 	bool			v;
265 
266 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
267 
268 	if (inum) {
269 		rval = xfs_dir_ino_validate(tp->t_mountp, inum);
270 		if (rval)
271 			return rval;
272 		XFS_STATS_INC(dp->i_mount, xs_dir_create);
273 	}
274 
275 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
276 	if (!args)
277 		return -ENOMEM;
278 
279 	args->geo = dp->i_mount->m_dir_geo;
280 	args->name = name->name;
281 	args->namelen = name->len;
282 	args->filetype = name->type;
283 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
284 	args->inumber = inum;
285 	args->dp = dp;
286 	args->total = total;
287 	args->whichfork = XFS_DATA_FORK;
288 	args->trans = tp;
289 	args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
290 	if (!inum)
291 		args->op_flags |= XFS_DA_OP_JUSTCHECK;
292 
293 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
294 		rval = xfs_dir2_sf_addname(args);
295 		goto out_free;
296 	}
297 
298 	rval = xfs_dir2_isblock(args, &v);
299 	if (rval)
300 		goto out_free;
301 	if (v) {
302 		rval = xfs_dir2_block_addname(args);
303 		goto out_free;
304 	}
305 
306 	rval = xfs_dir2_isleaf(args, &v);
307 	if (rval)
308 		goto out_free;
309 	if (v)
310 		rval = xfs_dir2_leaf_addname(args);
311 	else
312 		rval = xfs_dir2_node_addname(args);
313 
314 out_free:
315 	kmem_free(args);
316 	return rval;
317 }
318 
319 /*
320  * If doing a CI lookup and case-insensitive match, dup actual name into
321  * args.value. Return EEXIST for success (ie. name found) or an error.
322  */
323 int
324 xfs_dir_cilookup_result(
325 	struct xfs_da_args *args,
326 	const unsigned char *name,
327 	int		len)
328 {
329 	if (args->cmpresult == XFS_CMP_DIFFERENT)
330 		return -ENOENT;
331 	if (args->cmpresult != XFS_CMP_CASE ||
332 					!(args->op_flags & XFS_DA_OP_CILOOKUP))
333 		return -EEXIST;
334 
335 	args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
336 	if (!args->value)
337 		return -ENOMEM;
338 
339 	memcpy(args->value, name, len);
340 	args->valuelen = len;
341 	return -EEXIST;
342 }
343 
344 /*
345  * Lookup a name in a directory, give back the inode number.
346  * If ci_name is not NULL, returns the actual name in ci_name if it differs
347  * to name, or ci_name->name is set to NULL for an exact match.
348  */
349 
350 int
351 xfs_dir_lookup(
352 	struct xfs_trans	*tp,
353 	struct xfs_inode	*dp,
354 	const struct xfs_name	*name,
355 	xfs_ino_t		*inum,	  /* out: inode number */
356 	struct xfs_name		*ci_name) /* out: actual name if CI match */
357 {
358 	struct xfs_da_args	*args;
359 	int			rval;
360 	bool			v;
361 	int			lock_mode;
362 
363 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
364 	XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
365 
366 	/*
367 	 * We need to use KM_NOFS here so that lockdep will not throw false
368 	 * positive deadlock warnings on a non-transactional lookup path. It is
369 	 * safe to recurse into inode recalim in that case, but lockdep can't
370 	 * easily be taught about it. Hence KM_NOFS avoids having to add more
371 	 * lockdep Doing this avoids having to add a bunch of lockdep class
372 	 * annotations into the reclaim path for the ilock.
373 	 */
374 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
375 	args->geo = dp->i_mount->m_dir_geo;
376 	args->name = name->name;
377 	args->namelen = name->len;
378 	args->filetype = name->type;
379 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
380 	args->dp = dp;
381 	args->whichfork = XFS_DATA_FORK;
382 	args->trans = tp;
383 	args->op_flags = XFS_DA_OP_OKNOENT;
384 	if (ci_name)
385 		args->op_flags |= XFS_DA_OP_CILOOKUP;
386 
387 	lock_mode = xfs_ilock_data_map_shared(dp);
388 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
389 		rval = xfs_dir2_sf_lookup(args);
390 		goto out_check_rval;
391 	}
392 
393 	rval = xfs_dir2_isblock(args, &v);
394 	if (rval)
395 		goto out_free;
396 	if (v) {
397 		rval = xfs_dir2_block_lookup(args);
398 		goto out_check_rval;
399 	}
400 
401 	rval = xfs_dir2_isleaf(args, &v);
402 	if (rval)
403 		goto out_free;
404 	if (v)
405 		rval = xfs_dir2_leaf_lookup(args);
406 	else
407 		rval = xfs_dir2_node_lookup(args);
408 
409 out_check_rval:
410 	if (rval == -EEXIST)
411 		rval = 0;
412 	if (!rval) {
413 		*inum = args->inumber;
414 		if (ci_name) {
415 			ci_name->name = args->value;
416 			ci_name->len = args->valuelen;
417 		}
418 	}
419 out_free:
420 	xfs_iunlock(dp, lock_mode);
421 	kmem_free(args);
422 	return rval;
423 }
424 
425 /*
426  * Remove an entry from a directory.
427  */
428 int
429 xfs_dir_removename(
430 	struct xfs_trans	*tp,
431 	struct xfs_inode	*dp,
432 	struct xfs_name		*name,
433 	xfs_ino_t		ino,
434 	xfs_extlen_t		total)		/* bmap's total block count */
435 {
436 	struct xfs_da_args	*args;
437 	int			rval;
438 	bool			v;
439 
440 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
441 	XFS_STATS_INC(dp->i_mount, xs_dir_remove);
442 
443 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
444 	if (!args)
445 		return -ENOMEM;
446 
447 	args->geo = dp->i_mount->m_dir_geo;
448 	args->name = name->name;
449 	args->namelen = name->len;
450 	args->filetype = name->type;
451 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
452 	args->inumber = ino;
453 	args->dp = dp;
454 	args->total = total;
455 	args->whichfork = XFS_DATA_FORK;
456 	args->trans = tp;
457 
458 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
459 		rval = xfs_dir2_sf_removename(args);
460 		goto out_free;
461 	}
462 
463 	rval = xfs_dir2_isblock(args, &v);
464 	if (rval)
465 		goto out_free;
466 	if (v) {
467 		rval = xfs_dir2_block_removename(args);
468 		goto out_free;
469 	}
470 
471 	rval = xfs_dir2_isleaf(args, &v);
472 	if (rval)
473 		goto out_free;
474 	if (v)
475 		rval = xfs_dir2_leaf_removename(args);
476 	else
477 		rval = xfs_dir2_node_removename(args);
478 out_free:
479 	kmem_free(args);
480 	return rval;
481 }
482 
483 /*
484  * Replace the inode number of a directory entry.
485  */
486 int
487 xfs_dir_replace(
488 	struct xfs_trans	*tp,
489 	struct xfs_inode	*dp,
490 	const struct xfs_name	*name,		/* name of entry to replace */
491 	xfs_ino_t		inum,		/* new inode number */
492 	xfs_extlen_t		total)		/* bmap's total block count */
493 {
494 	struct xfs_da_args	*args;
495 	int			rval;
496 	bool			v;
497 
498 	ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
499 
500 	rval = xfs_dir_ino_validate(tp->t_mountp, inum);
501 	if (rval)
502 		return rval;
503 
504 	args = kmem_zalloc(sizeof(*args), KM_NOFS);
505 	if (!args)
506 		return -ENOMEM;
507 
508 	args->geo = dp->i_mount->m_dir_geo;
509 	args->name = name->name;
510 	args->namelen = name->len;
511 	args->filetype = name->type;
512 	args->hashval = xfs_dir2_hashname(dp->i_mount, name);
513 	args->inumber = inum;
514 	args->dp = dp;
515 	args->total = total;
516 	args->whichfork = XFS_DATA_FORK;
517 	args->trans = tp;
518 
519 	if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) {
520 		rval = xfs_dir2_sf_replace(args);
521 		goto out_free;
522 	}
523 
524 	rval = xfs_dir2_isblock(args, &v);
525 	if (rval)
526 		goto out_free;
527 	if (v) {
528 		rval = xfs_dir2_block_replace(args);
529 		goto out_free;
530 	}
531 
532 	rval = xfs_dir2_isleaf(args, &v);
533 	if (rval)
534 		goto out_free;
535 	if (v)
536 		rval = xfs_dir2_leaf_replace(args);
537 	else
538 		rval = xfs_dir2_node_replace(args);
539 out_free:
540 	kmem_free(args);
541 	return rval;
542 }
543 
544 /*
545  * See if this entry can be added to the directory without allocating space.
546  */
547 int
548 xfs_dir_canenter(
549 	xfs_trans_t	*tp,
550 	xfs_inode_t	*dp,
551 	struct xfs_name	*name)		/* name of entry to add */
552 {
553 	return xfs_dir_createname(tp, dp, name, 0, 0);
554 }
555 
556 /*
557  * Utility routines.
558  */
559 
560 /*
561  * Add a block to the directory.
562  *
563  * This routine is for data and free blocks, not leaf/node blocks which are
564  * handled by xfs_da_grow_inode.
565  */
566 int
567 xfs_dir2_grow_inode(
568 	struct xfs_da_args	*args,
569 	int			space,	/* v2 dir's space XFS_DIR2_xxx_SPACE */
570 	xfs_dir2_db_t		*dbp)	/* out: block number added */
571 {
572 	struct xfs_inode	*dp = args->dp;
573 	struct xfs_mount	*mp = dp->i_mount;
574 	xfs_fileoff_t		bno;	/* directory offset of new block */
575 	int			count;	/* count of filesystem blocks */
576 	int			error;
577 
578 	trace_xfs_dir2_grow_inode(args, space);
579 
580 	/*
581 	 * Set lowest possible block in the space requested.
582 	 */
583 	bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
584 	count = args->geo->fsbcount;
585 
586 	error = xfs_da_grow_inode_int(args, &bno, count);
587 	if (error)
588 		return error;
589 
590 	*dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
591 
592 	/*
593 	 * Update file's size if this is the data space and it grew.
594 	 */
595 	if (space == XFS_DIR2_DATA_SPACE) {
596 		xfs_fsize_t	size;		/* directory file (data) size */
597 
598 		size = XFS_FSB_TO_B(mp, bno + count);
599 		if (size > dp->i_disk_size) {
600 			dp->i_disk_size = size;
601 			xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
602 		}
603 	}
604 	return 0;
605 }
606 
607 /*
608  * See if the directory is a single-block form directory.
609  */
610 int
611 xfs_dir2_isblock(
612 	struct xfs_da_args	*args,
613 	bool			*isblock)
614 {
615 	struct xfs_mount	*mp = args->dp->i_mount;
616 	xfs_fileoff_t		eof;
617 	int			error;
618 
619 	error = xfs_bmap_last_offset(args->dp, &eof, XFS_DATA_FORK);
620 	if (error)
621 		return error;
622 
623 	*isblock = false;
624 	if (XFS_FSB_TO_B(mp, eof) != args->geo->blksize)
625 		return 0;
626 
627 	*isblock = true;
628 	if (XFS_IS_CORRUPT(mp, args->dp->i_disk_size != args->geo->blksize))
629 		return -EFSCORRUPTED;
630 	return 0;
631 }
632 
633 /*
634  * See if the directory is a single-leaf form directory.
635  */
636 int
637 xfs_dir2_isleaf(
638 	struct xfs_da_args	*args,
639 	bool			*isleaf)
640 {
641 	xfs_fileoff_t		eof;
642 	int			error;
643 
644 	error = xfs_bmap_last_offset(args->dp, &eof, XFS_DATA_FORK);
645 	if (error)
646 		return error;
647 
648 	*isleaf = false;
649 	if (eof != args->geo->leafblk + args->geo->fsbcount)
650 		return 0;
651 
652 	*isleaf = true;
653 	return 0;
654 }
655 
656 /*
657  * Remove the given block from the directory.
658  * This routine is used for data and free blocks, leaf/node are done
659  * by xfs_da_shrink_inode.
660  */
661 int
662 xfs_dir2_shrink_inode(
663 	struct xfs_da_args	*args,
664 	xfs_dir2_db_t		db,
665 	struct xfs_buf		*bp)
666 {
667 	xfs_fileoff_t		bno;		/* directory file offset */
668 	xfs_dablk_t		da;		/* directory file offset */
669 	int			done;		/* bunmap is finished */
670 	struct xfs_inode	*dp;
671 	int			error;
672 	struct xfs_mount	*mp;
673 	struct xfs_trans	*tp;
674 
675 	trace_xfs_dir2_shrink_inode(args, db);
676 
677 	dp = args->dp;
678 	mp = dp->i_mount;
679 	tp = args->trans;
680 	da = xfs_dir2_db_to_da(args->geo, db);
681 
682 	/* Unmap the fsblock(s). */
683 	error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0, &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_disk_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_disk_size = XFS_FSB_TO_B(mp, bno);
729 	xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
730 	return 0;
731 }
732 
733 /* Returns true if the directory entry name is valid. */
734 bool
735 xfs_dir2_namecheck(
736 	const void	*name,
737 	size_t		length)
738 {
739 	/*
740 	 * MAXNAMELEN includes the trailing null, but (name/length) leave it
741 	 * out, so use >= for the length check.
742 	 */
743 	if (length >= MAXNAMELEN)
744 		return false;
745 
746 	/* There shouldn't be any slashes or nulls here */
747 	return !memchr(name, '/', length) && !memchr(name, 0, length);
748 }
749 
750 xfs_dahash_t
751 xfs_dir2_hashname(
752 	struct xfs_mount	*mp,
753 	const struct xfs_name	*name)
754 {
755 	if (unlikely(xfs_has_asciici(mp)))
756 		return xfs_ascii_ci_hashname(name);
757 	return xfs_da_hashname(name->name, name->len);
758 }
759 
760 enum xfs_dacmp
761 xfs_dir2_compname(
762 	struct xfs_da_args	*args,
763 	const unsigned char	*name,
764 	int			len)
765 {
766 	if (unlikely(xfs_has_asciici(args->dp->i_mount)))
767 		return xfs_ascii_ci_compname(args, name, len);
768 	return xfs_da_compname(args, name, len);
769 }
770