Loading...
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
22const 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 */
31unsigned char
32xfs_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 */
59xfs_dahash_t
60xfs_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
72enum xfs_dacmp
73xfs_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
96int
97xfs_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
176void
177xfs_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 */
187int
188xfs_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 */
205int
206xfs_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 */
224int
225xfs_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 */
254int
255xfs_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
314out_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 */
323int
324xfs_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
350int
351xfs_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
409out_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 }
419out_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 */
428int
429xfs_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);
478out_free:
479 kmem_free(args);
480 return rval;
481}
482
483/*
484 * Replace the inode number of a directory entry.
485 */
486int
487xfs_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);
539out_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 */
547int
548xfs_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 */
566int
567xfs_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 */
610int
611xfs_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 */
636int
637xfs_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 */
661int
662xfs_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. */
734bool
735xfs_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
750xfs_dahash_t
751xfs_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
760enum xfs_dacmp
761xfs_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}
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
22struct xfs_name xfs_name_dotdot = { (unsigned char *)"..", 2, XFS_DIR3_FT_DIR };
23
24/*
25 * Convert inode mode to directory entry filetype
26 */
27unsigned char
28xfs_mode_to_ftype(
29 int mode)
30{
31 switch (mode & S_IFMT) {
32 case S_IFREG:
33 return XFS_DIR3_FT_REG_FILE;
34 case S_IFDIR:
35 return XFS_DIR3_FT_DIR;
36 case S_IFCHR:
37 return XFS_DIR3_FT_CHRDEV;
38 case S_IFBLK:
39 return XFS_DIR3_FT_BLKDEV;
40 case S_IFIFO:
41 return XFS_DIR3_FT_FIFO;
42 case S_IFSOCK:
43 return XFS_DIR3_FT_SOCK;
44 case S_IFLNK:
45 return XFS_DIR3_FT_SYMLINK;
46 default:
47 return XFS_DIR3_FT_UNKNOWN;
48 }
49}
50
51/*
52 * ASCII case-insensitive (ie. A-Z) support for directories that was
53 * used in IRIX.
54 */
55STATIC xfs_dahash_t
56xfs_ascii_ci_hashname(
57 struct xfs_name *name)
58{
59 xfs_dahash_t hash;
60 int i;
61
62 for (i = 0, hash = 0; i < name->len; i++)
63 hash = tolower(name->name[i]) ^ rol32(hash, 7);
64
65 return hash;
66}
67
68STATIC enum xfs_dacmp
69xfs_ascii_ci_compname(
70 struct xfs_da_args *args,
71 const unsigned char *name,
72 int len)
73{
74 enum xfs_dacmp result;
75 int i;
76
77 if (args->namelen != len)
78 return XFS_CMP_DIFFERENT;
79
80 result = XFS_CMP_EXACT;
81 for (i = 0; i < len; i++) {
82 if (args->name[i] == name[i])
83 continue;
84 if (tolower(args->name[i]) != tolower(name[i]))
85 return XFS_CMP_DIFFERENT;
86 result = XFS_CMP_CASE;
87 }
88
89 return result;
90}
91
92static const struct xfs_nameops xfs_ascii_ci_nameops = {
93 .hashname = xfs_ascii_ci_hashname,
94 .compname = xfs_ascii_ci_compname,
95};
96
97int
98xfs_da_mount(
99 struct xfs_mount *mp)
100{
101 struct xfs_da_geometry *dageo;
102 int nodehdr_size;
103
104
105 ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT);
106 ASSERT(xfs_dir2_dirblock_bytes(&mp->m_sb) <= XFS_MAX_BLOCKSIZE);
107
108 mp->m_dir_inode_ops = xfs_dir_get_ops(mp, NULL);
109 mp->m_nondir_inode_ops = xfs_nondir_get_ops(mp, NULL);
110
111 nodehdr_size = mp->m_dir_inode_ops->node_hdr_size;
112 mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
113 KM_MAYFAIL);
114 mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry),
115 KM_MAYFAIL);
116 if (!mp->m_dir_geo || !mp->m_attr_geo) {
117 kmem_free(mp->m_dir_geo);
118 kmem_free(mp->m_attr_geo);
119 return -ENOMEM;
120 }
121
122 /* set up directory geometry */
123 dageo = mp->m_dir_geo;
124 dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog;
125 dageo->fsblog = mp->m_sb.sb_blocklog;
126 dageo->blksize = xfs_dir2_dirblock_bytes(&mp->m_sb);
127 dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog;
128
129 /*
130 * Now we've set up the block conversion variables, we can calculate the
131 * segment block constants using the geometry structure.
132 */
133 dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET);
134 dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET);
135 dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET);
136 dageo->node_ents = (dageo->blksize - nodehdr_size) /
137 (uint)sizeof(xfs_da_node_entry_t);
138 dageo->magicpct = (dageo->blksize * 37) / 100;
139
140 /* set up attribute geometry - single fsb only */
141 dageo = mp->m_attr_geo;
142 dageo->blklog = mp->m_sb.sb_blocklog;
143 dageo->fsblog = mp->m_sb.sb_blocklog;
144 dageo->blksize = 1 << dageo->blklog;
145 dageo->fsbcount = 1;
146 dageo->node_ents = (dageo->blksize - nodehdr_size) /
147 (uint)sizeof(xfs_da_node_entry_t);
148 dageo->magicpct = (dageo->blksize * 37) / 100;
149
150 if (xfs_sb_version_hasasciici(&mp->m_sb))
151 mp->m_dirnameops = &xfs_ascii_ci_nameops;
152 else
153 mp->m_dirnameops = &xfs_default_nameops;
154
155 return 0;
156}
157
158void
159xfs_da_unmount(
160 struct xfs_mount *mp)
161{
162 kmem_free(mp->m_dir_geo);
163 kmem_free(mp->m_attr_geo);
164}
165
166/*
167 * Return 1 if directory contains only "." and "..".
168 */
169int
170xfs_dir_isempty(
171 xfs_inode_t *dp)
172{
173 xfs_dir2_sf_hdr_t *sfp;
174
175 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
176 if (dp->i_d.di_size == 0) /* might happen during shutdown. */
177 return 1;
178 if (dp->i_d.di_size > XFS_IFORK_DSIZE(dp))
179 return 0;
180 sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
181 return !sfp->count;
182}
183
184/*
185 * Validate a given inode number.
186 */
187int
188xfs_dir_ino_validate(
189 xfs_mount_t *mp,
190 xfs_ino_t ino)
191{
192 bool ino_ok = xfs_verify_dir_ino(mp, ino);
193
194 if (unlikely(XFS_TEST_ERROR(!ino_ok, mp, XFS_ERRTAG_DIR_INO_VALIDATE))) {
195 xfs_warn(mp, "Invalid inode number 0x%Lx",
196 (unsigned long long) ino);
197 XFS_ERROR_REPORT("xfs_dir_ino_validate", XFS_ERRLEVEL_LOW, mp);
198 return -EFSCORRUPTED;
199 }
200 return 0;
201}
202
203/*
204 * Initialize a directory with its "." and ".." entries.
205 */
206int
207xfs_dir_init(
208 xfs_trans_t *tp,
209 xfs_inode_t *dp,
210 xfs_inode_t *pdp)
211{
212 struct xfs_da_args *args;
213 int error;
214
215 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
216 error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino);
217 if (error)
218 return error;
219
220 args = kmem_zalloc(sizeof(*args), KM_NOFS);
221 if (!args)
222 return -ENOMEM;
223
224 args->geo = dp->i_mount->m_dir_geo;
225 args->dp = dp;
226 args->trans = tp;
227 error = xfs_dir2_sf_create(args, pdp->i_ino);
228 kmem_free(args);
229 return error;
230}
231
232/*
233 * Enter a name in a directory, or check for available space.
234 * If inum is 0, only the available space test is performed.
235 */
236int
237xfs_dir_createname(
238 struct xfs_trans *tp,
239 struct xfs_inode *dp,
240 struct xfs_name *name,
241 xfs_ino_t inum, /* new entry inode number */
242 xfs_extlen_t total) /* bmap's total block count */
243{
244 struct xfs_da_args *args;
245 int rval;
246 int v; /* type-checking value */
247
248 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
249
250 if (inum) {
251 rval = xfs_dir_ino_validate(tp->t_mountp, inum);
252 if (rval)
253 return rval;
254 XFS_STATS_INC(dp->i_mount, xs_dir_create);
255 }
256
257 args = kmem_zalloc(sizeof(*args), KM_NOFS);
258 if (!args)
259 return -ENOMEM;
260
261 args->geo = dp->i_mount->m_dir_geo;
262 args->name = name->name;
263 args->namelen = name->len;
264 args->filetype = name->type;
265 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
266 args->inumber = inum;
267 args->dp = dp;
268 args->total = total;
269 args->whichfork = XFS_DATA_FORK;
270 args->trans = tp;
271 args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
272 if (!inum)
273 args->op_flags |= XFS_DA_OP_JUSTCHECK;
274
275 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
276 rval = xfs_dir2_sf_addname(args);
277 goto out_free;
278 }
279
280 rval = xfs_dir2_isblock(args, &v);
281 if (rval)
282 goto out_free;
283 if (v) {
284 rval = xfs_dir2_block_addname(args);
285 goto out_free;
286 }
287
288 rval = xfs_dir2_isleaf(args, &v);
289 if (rval)
290 goto out_free;
291 if (v)
292 rval = xfs_dir2_leaf_addname(args);
293 else
294 rval = xfs_dir2_node_addname(args);
295
296out_free:
297 kmem_free(args);
298 return rval;
299}
300
301/*
302 * If doing a CI lookup and case-insensitive match, dup actual name into
303 * args.value. Return EEXIST for success (ie. name found) or an error.
304 */
305int
306xfs_dir_cilookup_result(
307 struct xfs_da_args *args,
308 const unsigned char *name,
309 int len)
310{
311 if (args->cmpresult == XFS_CMP_DIFFERENT)
312 return -ENOENT;
313 if (args->cmpresult != XFS_CMP_CASE ||
314 !(args->op_flags & XFS_DA_OP_CILOOKUP))
315 return -EEXIST;
316
317 args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL);
318 if (!args->value)
319 return -ENOMEM;
320
321 memcpy(args->value, name, len);
322 args->valuelen = len;
323 return -EEXIST;
324}
325
326/*
327 * Lookup a name in a directory, give back the inode number.
328 * If ci_name is not NULL, returns the actual name in ci_name if it differs
329 * to name, or ci_name->name is set to NULL for an exact match.
330 */
331
332int
333xfs_dir_lookup(
334 xfs_trans_t *tp,
335 xfs_inode_t *dp,
336 struct xfs_name *name,
337 xfs_ino_t *inum, /* out: inode number */
338 struct xfs_name *ci_name) /* out: actual name if CI match */
339{
340 struct xfs_da_args *args;
341 int rval;
342 int v; /* type-checking value */
343 int lock_mode;
344
345 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
346 XFS_STATS_INC(dp->i_mount, xs_dir_lookup);
347
348 /*
349 * We need to use KM_NOFS here so that lockdep will not throw false
350 * positive deadlock warnings on a non-transactional lookup path. It is
351 * safe to recurse into inode recalim in that case, but lockdep can't
352 * easily be taught about it. Hence KM_NOFS avoids having to add more
353 * lockdep Doing this avoids having to add a bunch of lockdep class
354 * annotations into the reclaim path for the ilock.
355 */
356 args = kmem_zalloc(sizeof(*args), KM_NOFS);
357 args->geo = dp->i_mount->m_dir_geo;
358 args->name = name->name;
359 args->namelen = name->len;
360 args->filetype = name->type;
361 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
362 args->dp = dp;
363 args->whichfork = XFS_DATA_FORK;
364 args->trans = tp;
365 args->op_flags = XFS_DA_OP_OKNOENT;
366 if (ci_name)
367 args->op_flags |= XFS_DA_OP_CILOOKUP;
368
369 lock_mode = xfs_ilock_data_map_shared(dp);
370 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
371 rval = xfs_dir2_sf_lookup(args);
372 goto out_check_rval;
373 }
374
375 rval = xfs_dir2_isblock(args, &v);
376 if (rval)
377 goto out_free;
378 if (v) {
379 rval = xfs_dir2_block_lookup(args);
380 goto out_check_rval;
381 }
382
383 rval = xfs_dir2_isleaf(args, &v);
384 if (rval)
385 goto out_free;
386 if (v)
387 rval = xfs_dir2_leaf_lookup(args);
388 else
389 rval = xfs_dir2_node_lookup(args);
390
391out_check_rval:
392 if (rval == -EEXIST)
393 rval = 0;
394 if (!rval) {
395 *inum = args->inumber;
396 if (ci_name) {
397 ci_name->name = args->value;
398 ci_name->len = args->valuelen;
399 }
400 }
401out_free:
402 xfs_iunlock(dp, lock_mode);
403 kmem_free(args);
404 return rval;
405}
406
407/*
408 * Remove an entry from a directory.
409 */
410int
411xfs_dir_removename(
412 struct xfs_trans *tp,
413 struct xfs_inode *dp,
414 struct xfs_name *name,
415 xfs_ino_t ino,
416 xfs_extlen_t total) /* bmap's total block count */
417{
418 struct xfs_da_args *args;
419 int rval;
420 int v; /* type-checking value */
421
422 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
423 XFS_STATS_INC(dp->i_mount, xs_dir_remove);
424
425 args = kmem_zalloc(sizeof(*args), KM_NOFS);
426 if (!args)
427 return -ENOMEM;
428
429 args->geo = dp->i_mount->m_dir_geo;
430 args->name = name->name;
431 args->namelen = name->len;
432 args->filetype = name->type;
433 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
434 args->inumber = ino;
435 args->dp = dp;
436 args->total = total;
437 args->whichfork = XFS_DATA_FORK;
438 args->trans = tp;
439
440 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
441 rval = xfs_dir2_sf_removename(args);
442 goto out_free;
443 }
444
445 rval = xfs_dir2_isblock(args, &v);
446 if (rval)
447 goto out_free;
448 if (v) {
449 rval = xfs_dir2_block_removename(args);
450 goto out_free;
451 }
452
453 rval = xfs_dir2_isleaf(args, &v);
454 if (rval)
455 goto out_free;
456 if (v)
457 rval = xfs_dir2_leaf_removename(args);
458 else
459 rval = xfs_dir2_node_removename(args);
460out_free:
461 kmem_free(args);
462 return rval;
463}
464
465/*
466 * Replace the inode number of a directory entry.
467 */
468int
469xfs_dir_replace(
470 struct xfs_trans *tp,
471 struct xfs_inode *dp,
472 struct xfs_name *name, /* name of entry to replace */
473 xfs_ino_t inum, /* new inode number */
474 xfs_extlen_t total) /* bmap's total block count */
475{
476 struct xfs_da_args *args;
477 int rval;
478 int v; /* type-checking value */
479
480 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
481
482 rval = xfs_dir_ino_validate(tp->t_mountp, inum);
483 if (rval)
484 return rval;
485
486 args = kmem_zalloc(sizeof(*args), KM_NOFS);
487 if (!args)
488 return -ENOMEM;
489
490 args->geo = dp->i_mount->m_dir_geo;
491 args->name = name->name;
492 args->namelen = name->len;
493 args->filetype = name->type;
494 args->hashval = dp->i_mount->m_dirnameops->hashname(name);
495 args->inumber = inum;
496 args->dp = dp;
497 args->total = total;
498 args->whichfork = XFS_DATA_FORK;
499 args->trans = tp;
500
501 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
502 rval = xfs_dir2_sf_replace(args);
503 goto out_free;
504 }
505
506 rval = xfs_dir2_isblock(args, &v);
507 if (rval)
508 goto out_free;
509 if (v) {
510 rval = xfs_dir2_block_replace(args);
511 goto out_free;
512 }
513
514 rval = xfs_dir2_isleaf(args, &v);
515 if (rval)
516 goto out_free;
517 if (v)
518 rval = xfs_dir2_leaf_replace(args);
519 else
520 rval = xfs_dir2_node_replace(args);
521out_free:
522 kmem_free(args);
523 return rval;
524}
525
526/*
527 * See if this entry can be added to the directory without allocating space.
528 */
529int
530xfs_dir_canenter(
531 xfs_trans_t *tp,
532 xfs_inode_t *dp,
533 struct xfs_name *name) /* name of entry to add */
534{
535 return xfs_dir_createname(tp, dp, name, 0, 0);
536}
537
538/*
539 * Utility routines.
540 */
541
542/*
543 * Add a block to the directory.
544 *
545 * This routine is for data and free blocks, not leaf/node blocks which are
546 * handled by xfs_da_grow_inode.
547 */
548int
549xfs_dir2_grow_inode(
550 struct xfs_da_args *args,
551 int space, /* v2 dir's space XFS_DIR2_xxx_SPACE */
552 xfs_dir2_db_t *dbp) /* out: block number added */
553{
554 struct xfs_inode *dp = args->dp;
555 struct xfs_mount *mp = dp->i_mount;
556 xfs_fileoff_t bno; /* directory offset of new block */
557 int count; /* count of filesystem blocks */
558 int error;
559
560 trace_xfs_dir2_grow_inode(args, space);
561
562 /*
563 * Set lowest possible block in the space requested.
564 */
565 bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE);
566 count = args->geo->fsbcount;
567
568 error = xfs_da_grow_inode_int(args, &bno, count);
569 if (error)
570 return error;
571
572 *dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno);
573
574 /*
575 * Update file's size if this is the data space and it grew.
576 */
577 if (space == XFS_DIR2_DATA_SPACE) {
578 xfs_fsize_t size; /* directory file (data) size */
579
580 size = XFS_FSB_TO_B(mp, bno + count);
581 if (size > dp->i_d.di_size) {
582 dp->i_d.di_size = size;
583 xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE);
584 }
585 }
586 return 0;
587}
588
589/*
590 * See if the directory is a single-block form directory.
591 */
592int
593xfs_dir2_isblock(
594 struct xfs_da_args *args,
595 int *vp) /* out: 1 is block, 0 is not block */
596{
597 xfs_fileoff_t last; /* last file offset */
598 int rval;
599
600 if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
601 return rval;
602 rval = XFS_FSB_TO_B(args->dp->i_mount, last) == args->geo->blksize;
603 if (rval != 0 && args->dp->i_d.di_size != args->geo->blksize)
604 return -EFSCORRUPTED;
605 *vp = rval;
606 return 0;
607}
608
609/*
610 * See if the directory is a single-leaf form directory.
611 */
612int
613xfs_dir2_isleaf(
614 struct xfs_da_args *args,
615 int *vp) /* out: 1 is block, 0 is not block */
616{
617 xfs_fileoff_t last; /* last file offset */
618 int rval;
619
620 if ((rval = xfs_bmap_last_offset(args->dp, &last, XFS_DATA_FORK)))
621 return rval;
622 *vp = last == args->geo->leafblk + args->geo->fsbcount;
623 return 0;
624}
625
626/*
627 * Remove the given block from the directory.
628 * This routine is used for data and free blocks, leaf/node are done
629 * by xfs_da_shrink_inode.
630 */
631int
632xfs_dir2_shrink_inode(
633 struct xfs_da_args *args,
634 xfs_dir2_db_t db,
635 struct xfs_buf *bp)
636{
637 xfs_fileoff_t bno; /* directory file offset */
638 xfs_dablk_t da; /* directory file offset */
639 int done; /* bunmap is finished */
640 struct xfs_inode *dp;
641 int error;
642 struct xfs_mount *mp;
643 struct xfs_trans *tp;
644
645 trace_xfs_dir2_shrink_inode(args, db);
646
647 dp = args->dp;
648 mp = dp->i_mount;
649 tp = args->trans;
650 da = xfs_dir2_db_to_da(args->geo, db);
651
652 /* Unmap the fsblock(s). */
653 error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0, &done);
654 if (error) {
655 /*
656 * ENOSPC actually can happen if we're in a removename with no
657 * space reservation, and the resulting block removal would
658 * cause a bmap btree split or conversion from extents to btree.
659 * This can only happen for un-fragmented directory blocks,
660 * since you need to be punching out the middle of an extent.
661 * In this case we need to leave the block in the file, and not
662 * binval it. So the block has to be in a consistent empty
663 * state and appropriately logged. We don't free up the buffer,
664 * the caller can tell it hasn't happened since it got an error
665 * back.
666 */
667 return error;
668 }
669 ASSERT(done);
670 /*
671 * Invalidate the buffer from the transaction.
672 */
673 xfs_trans_binval(tp, bp);
674 /*
675 * If it's not a data block, we're done.
676 */
677 if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET))
678 return 0;
679 /*
680 * If the block isn't the last one in the directory, we're done.
681 */
682 if (dp->i_d.di_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0))
683 return 0;
684 bno = da;
685 if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) {
686 /*
687 * This can't really happen unless there's kernel corruption.
688 */
689 return error;
690 }
691 if (db == args->geo->datablk)
692 ASSERT(bno == 0);
693 else
694 ASSERT(bno > 0);
695 /*
696 * Set the size to the new last block.
697 */
698 dp->i_d.di_size = XFS_FSB_TO_B(mp, bno);
699 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
700 return 0;
701}
702
703/* Returns true if the directory entry name is valid. */
704bool
705xfs_dir2_namecheck(
706 const void *name,
707 size_t length)
708{
709 /*
710 * MAXNAMELEN includes the trailing null, but (name/length) leave it
711 * out, so use >= for the length check.
712 */
713 if (length >= MAXNAMELEN)
714 return false;
715
716 /* There shouldn't be any slashes or nulls here */
717 return !memchr(name, '/', length) && !memchr(name, 0, length);
718}