2 * Copyright (c) 1989, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley
6 * by Pace Willisson (pace@blitz.com). The Rock Ridge Extension
7 * Support code is derived from software contributed to Berkeley
8 * by Atsushi Murai (amurai@spec.co.jp).
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * from: @(#)ufs_lookup.c 7.33 (Berkeley) 5/19/91
40 * @(#)cd9660_lookup.c 8.2 (Berkeley) 1/23/94
41 * $FreeBSD: src/sys/isofs/cd9660/cd9660_lookup.c,v 1.23.2.2 2001/11/04 06:19:47 dillon Exp $
42 * $DragonFly: src/sys/vfs/isofs/cd9660/cd9660_lookup.c,v 1.25 2008/06/19 23:27:39 dillon Exp $
45 #include <sys/param.h>
46 #include <sys/systm.h>
48 #include <sys/namei.h>
50 #include <sys/vnode.h>
51 #include <sys/mount.h>
54 #include "cd9660_node.h"
58 * Convert a component of a pathname into a pointer to a locked inode.
59 * This is a very central and rather complicated routine.
60 * If the file system is not maintained in a strict tree hierarchy,
61 * this can result in a deadlock situation (see comments in code below).
63 * The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
64 * whether the name is to be looked up, created, renamed, or deleted.
65 * When CREATE, RENAME, or DELETE is specified, information usable in
66 * creating, renaming, or deleting a directory entry may be calculated.
67 * If flag has LOCKPARENT or'ed into it and the target of the pathname
68 * exists, lookup returns both the target and its parent directory locked.
69 * When creating or renaming and LOCKPARENT is specified, the target may
70 * not be ".". When deleting and LOCKPARENT is specified, the target may
71 * be "."., but the caller must check to ensure it does an vrele and iput
72 * instead of two iputs.
74 * Overall outline of ufs_lookup:
76 * search for name in directory, to found or notfound
78 * if creating, return locked directory, leaving info on available slots
81 * if at end of path and deleting, return information to allow delete
82 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
83 * inode and return info to allow rewrite
84 * if not at end, add name to cache; if at end and neither creating
85 * nor deleting, add name to cache
87 * NOTE: (LOOKUP | LOCKPARENT) currently returns the parent inode unlocked.
89 * cd9660_lookup(struct vnode *a_dvp, struct vnode **a_vpp,
90 * struct componentname *a_cnp)
93 cd9660_lookup(struct vop_old_lookup_args
*ap
)
95 struct vnode
*vdp
; /* vnode for directory being searched */
96 globaldata_t gd
= mycpu
;
97 struct iso_node
*dp
; /* inode for directory being searched */
98 struct iso_mnt
*imp
; /* file system that directory is in */
99 struct buf
*bp
; /* a buffer of directory entries */
100 struct iso_directory_record
*ep
= 0;/* the current directory entry */
101 int entryoffsetinblock
; /* offset of ep in bp's buffer */
102 int saveoffset
= 0; /* offset of last directory entry in dir */
103 int numdirpasses
; /* strategy for directory search */
104 doff_t endsearch
; /* offset to end directory search */
105 struct vnode
*pdp
; /* saved dp during symlink work */
106 struct vnode
*tdp
; /* returned by cd9660_vget_internal */
107 u_long bmask
; /* block offset mask */
108 int lockparent
; /* 1 => lockparent flag is set */
109 int wantparent
; /* 1 => wantparent or lockparent flag */
115 char altname
[NAME_MAX
];
119 struct vnode
**vpp
= ap
->a_vpp
;
120 struct componentname
*cnp
= ap
->a_cnp
;
121 int flags
= cnp
->cn_flags
;
122 int nameiop
= cnp
->cn_nameiop
;
129 lockparent
= flags
& CNP_LOCKPARENT
;
130 wantparent
= flags
& (CNP_LOCKPARENT
| CNP_WANTPARENT
);
131 cnp
->cn_flags
&= ~CNP_PDIRUNLOCK
;
134 * We now have a segment name to search for, and a directory to search.
137 len
= cnp
->cn_namelen
;
138 name
= cnp
->cn_nameptr
;
140 * A leading `=' means, we are looking for an associated file
142 if ((assoc
= (imp
->iso_ftype
!= ISO_FTYPE_RRIP
&& *name
== ASSOCCHAR
)))
149 * If there is cached information on a previous search of
150 * this directory, pick up where we last left off.
151 * We cache only lookups as these are the most common
152 * and have the greatest payoff. Caching CREATE has little
153 * benefit as it usually must search the entire directory
154 * to determine that the entry does not exist. Caching the
155 * location of the last DELETE or RENAME has not reduced
156 * profiling time and hence has been removed in the interest
159 bmask
= imp
->im_bmask
;
160 if (nameiop
!= NAMEI_LOOKUP
|| dp
->i_diroff
== 0 ||
161 dp
->i_diroff
> dp
->i_size
) {
162 entryoffsetinblock
= 0;
166 dp
->i_offset
= dp
->i_diroff
;
167 if ((entryoffsetinblock
= dp
->i_offset
& bmask
) &&
168 (error
= cd9660_devblkatoff(vdp
, (off_t
)dp
->i_offset
, NULL
, &bp
)))
171 gd
->gd_nchstats
->ncs_2passes
++;
173 endsearch
= dp
->i_size
;
176 while (dp
->i_offset
< endsearch
) {
178 * If offset is on a block boundary,
179 * read the next directory block.
180 * Release previous if it exists.
182 if ((dp
->i_offset
& bmask
) == 0) {
186 cd9660_devblkatoff(vdp
, (off_t
)dp
->i_offset
, NULL
, &bp
)) != 0)
188 entryoffsetinblock
= 0;
191 * Get pointer to next entry.
193 ep
= (struct iso_directory_record
*)
194 ((char *)bp
->b_data
+ entryoffsetinblock
);
196 reclen
= isonum_711(ep
->length
);
198 /* skip to next block, if any */
200 (dp
->i_offset
& ~bmask
) + imp
->logical_block_size
;
204 if (reclen
< ISO_DIRECTORY_RECORD_SIZE
)
205 /* illegal entry, stop */
208 if (entryoffsetinblock
+ reclen
> imp
->logical_block_size
)
209 /* entries are not allowed to cross boundaries */
212 namelen
= isonum_711(ep
->name_len
);
213 isoflags
= isonum_711(imp
->iso_ftype
== ISO_FTYPE_HIGH_SIERRA
?
214 &ep
->date
[6]: ep
->flags
);
216 if (reclen
< ISO_DIRECTORY_RECORD_SIZE
+ namelen
)
217 /* illegal entry, stop */
221 * Check for a name match.
223 switch (imp
->iso_ftype
) {
225 if (!(isoflags
& 4) == !assoc
) {
228 || (flags
& CNP_ISDOTDOT
)) {
230 && ep
->name
[0] == ((flags
& CNP_ISDOTDOT
) ? 1 : 0)) {
232 * Save directory entry's inode number and
233 * release directory buffer.
235 dp
->i_ino
= isodirino(ep
, imp
);
241 } else if (!(res
= isofncmp(name
, len
,
248 ino
= isodirino(ep
, imp
);
250 ino
= bp
->b_bio1
.bio_offset
+
252 saveoffset
= dp
->i_offset
;
255 #ifdef NOSORTBUG /* On some CDs directory entries are not sorted correctly */
258 else if (res
> 0 && numdirpasses
== 2)
264 if (isonum_711(ep
->flags
)&2)
265 ino
= isodirino(ep
, imp
);
267 ino
= bp
->b_bio1
.bio_offset
+
270 cd9660_rrip_getname(ep
,altname
,&namelen
,&dp
->i_ino
,imp
);
271 if (namelen
== cnp
->cn_namelen
272 && !bcmp(name
,altname
,namelen
))
277 dp
->i_offset
+= reclen
;
278 entryoffsetinblock
+= reclen
;
283 if (saveoffset
!= dp
->i_offset
) {
284 if (lblkno(imp
, dp
->i_offset
) !=
285 lblkno(imp
, saveoffset
)) {
288 if ((error
= cd9660_devblkatoff(vdp
,
289 (off_t
)saveoffset
, NULL
, &bp
)) != 0)
292 entryoffsetinblock
= saveoffset
& bmask
;
293 ep
= (struct iso_directory_record
*)
294 ((char *)bp
->b_data
+ entryoffsetinblock
);
295 dp
->i_offset
= saveoffset
;
301 * If we started in the middle of the directory and failed
302 * to find our target, we must check the beginning as well.
304 if (numdirpasses
== 2) {
307 endsearch
= dp
->i_diroff
;
313 if (nameiop
== NAMEI_CREATE
|| nameiop
== NAMEI_RENAME
)
318 if (numdirpasses
== 2)
319 gd
->gd_nchstats
->ncs_pass2
++;
322 * Found component in pathname.
323 * If the final component of path name, save information
324 * in the cache as to where the entry was found.
326 if (nameiop
== NAMEI_LOOKUP
)
327 dp
->i_diroff
= dp
->i_offset
;
330 * Step through the translation in the name. We do not `iput' the
331 * directory because we may need it again if a symbolic link
332 * is relative to the current directory. Instead we save it
333 * unlocked as "pdp". We must get the target inode before unlocking
334 * the directory to insure that the inode will not be removed
335 * before we get it. We prevent deadlock by always fetching
336 * inodes from the root, moving down the directory tree. Thus
337 * when following backward pointers ".." we must unlock the
338 * parent directory before getting the requested directory.
339 * There is a potential race condition here if both the current
340 * and parent directories are removed before the `iget' for the
341 * inode associated with ".." returns. We hope that this occurs
342 * infrequently since we cannot avoid this race condition without
343 * implementing a sophisticated deadlock detection algorithm.
344 * Note also that this simple deadlock detection scheme will not
345 * work if the file system has any hard links other than ".."
346 * that point backwards in the directory structure.
350 * If ino is different from dp->i_ino,
351 * it's a relocated directory.
353 if (flags
& CNP_ISDOTDOT
) {
354 vn_unlock(pdp
); /* race to get the inode */
355 error
= cd9660_vget_internal(vdp
->v_mount
, dp
->i_ino
, &tdp
,
356 dp
->i_ino
!= ino
, ep
);
359 vn_lock(pdp
, LK_EXCLUSIVE
| LK_RETRY
);
363 if ((error
= vn_lock(pdp
, LK_EXCLUSIVE
)) != 0) {
364 cnp
->cn_flags
|= CNP_PDIRUNLOCK
;
369 cnp
->cn_flags
|= CNP_PDIRUNLOCK
;
371 } else if (dp
->i_number
== dp
->i_ino
) {
373 vref(vdp
); /* we want ourself, ie "." */
376 error
= cd9660_vget_internal(vdp
->v_mount
, dp
->i_ino
, &tdp
,
377 dp
->i_ino
!= ino
, ep
);
382 cnp
->cn_flags
|= CNP_PDIRUNLOCK
;
391 * Return a buffer with the contents of block "offset" from the beginning of
392 * directory "ip". If "res" is non-zero, fill it in with a pointer to the
393 * remaining space in the directory.
396 cd9660_blkatoff(struct vnode
*vp
, off_t offset
, char **res
, struct buf
**bpp
)
406 lbn
= lblkno(imp
, offset
);
407 bsize
= blksize(imp
, ip
, lbn
);
409 if ((error
= bread(vp
, lblktooff(imp
, lbn
), bsize
, &bp
)) != 0) {
416 * We must BMAP the buffer because the directory code may use
417 * bio_offset to calculate the inode for certain types of directory
418 * entries. We could get away with not doing it before we
419 * VMIO-backed the directories because the buffers would get freed
420 * atomically with the invalidation of their data. But with
421 * VMIO-backed buffers the buffers may be freed and then later
422 * reconstituted - and the reconstituted buffer will have no
423 * knowledge of bio_offset.
425 if (bp
->b_bio2
.bio_offset
== NOOFFSET
) {
426 error
= VOP_BMAP(vp
, bp
->b_bio1
.bio_offset
,
427 &bp
->b_bio2
.bio_offset
, NULL
, NULL
,
431 bp
->b_flags
|= B_ERROR
;
439 *res
= (char *)bp
->b_data
+ blkoff(imp
, offset
);
446 * Return a buffer with the contents of block "offset" from the beginning of
447 * directory "ip". If "res" is non-zero, fill it in with a pointer to the
448 * remaining space in the directory.
450 * Use the underlying device vnode rather then the passed vnode for the
451 * buffer cache operation. This allows us to access meta-data conveniently
452 * without having to instantiate a VM object for the vnode.
454 * WARNING! Callers of this routine need to be careful when accessing
455 * the bio_offset. Since this is a device buffer, the device offset will
456 * be in bio1.bio_offset, not bio2.bio_offset.
459 cd9660_devblkatoff(struct vnode
*vp
, off_t offset
, char **res
, struct buf
**bpp
)
470 lbn
= lblkno(imp
, offset
);
471 bsize
= blksize(imp
, ip
, lbn
);
473 error
= VOP_BMAP(vp
, lblktooff(imp
, lbn
), &doffset
, NULL
, NULL
,
478 if ((error
= bread(imp
->im_devvp
, doffset
, bsize
, &bp
)) != 0) {
484 *res
= (char *)bp
->b_data
+ blkoff(imp
, offset
);