1 /*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License"). You may not use this file except in compliance with the
9 * License. Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
11 *
12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
23 /*
24 * Copyright (c) 1989, 1993
25 * The Regents of the University of California. All rights reserved.
26 * (c) UNIX System Laboratories, Inc.
27 * All or some portions of this file are derived from material licensed
28 * to the University of California by American Telephone and Telegraph
29 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
30 * the permission of UNIX System Laboratories, Inc.
31 *
32 * Redistribution and use in source and binary forms, with or without
33 * modification, are permitted provided that the following conditions
34 * are met:
35 * 1. Redistributions of source code must retain the above copyright
36 * notice, this list of conditions and the following disclaimer.
37 * 2. Redistributions in binary form must reproduce the above copyright
38 * notice, this list of conditions and the following disclaimer in the
39 * documentation and/or other materials provided with the distribution.
40 * 3. All advertising materials mentioning features or use of this software
41 * must display the following acknowledgement:
42 * This product includes software developed by the University of
43 * California, Berkeley and its contributors.
44 * 4. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)ufs_lookup.c 8.15 (Berkeley) 6/16/95
61 */
62 #include <rev_endian_fs.h>
63 #include <sys/param.h>
64 #include <sys/namei.h>
65 #include <sys/buf.h>
66 #include <sys/file.h>
67 #include <sys/mount_internal.h>
68 #include <sys/vnode_internal.h>
69 #include <sys/quota.h>
70 #include <sys/kauth.h>
71 #include <sys/uio_internal.h>
72
73 #include <ufs/ufs/quota.h>
74 #include <ufs/ufs/inode.h>
75 #include <ufs/ufs/dir.h>
76 #include <ufs/ufs/ufsmount.h>
77 #include <ufs/ufs/ufs_extern.h>
78 #include <ufs/ffs/ffs_extern.h>
79 #if REV_ENDIAN_FS
80 #include <ufs/ufs/ufs_byte_order.h>
81 #include <architecture/byte_order.h>
82 #endif /* REV_ENDIAN_FS */
83
84 extern struct nchstats nchstats;
85 #if DIAGNOSTIC
86 int dirchk = 1;
87 #else
88 int dirchk = 0;
89 #endif
90
91 #define FSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0)
92
93 /*
94 * Convert a component of a pathname into a pointer to a locked inode.
95 * This is a very central and rather complicated routine.
96 * If the file system is not maintained in a strict tree hierarchy,
97 * this can result in a deadlock situation (see comments in code below).
98 *
99 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
100 * on whether the name is to be looked up, created, renamed, or deleted.
101 * When CREATE, RENAME, or DELETE is specified, information usable in
102 * creating, renaming, or deleting a directory entry may be calculated.
103 * If flag has LOCKPARENT or'ed into it and the target of the pathname
104 * exists, lookup returns both the target and its parent directory locked.
105 * When creating or renaming and LOCKPARENT is specified, the target may
106 * not be ".". When deleting and LOCKPARENT is specified, the target may
107 * be ".".,
108 *
109 * Overall outline of ufs_lookup:
110 *
111 * check accessibility of directory
112 * look for name in cache, if found, then if at end of path
113 * and deleting or creating, drop it, else return name
114 * search for name in directory, to found or notfound
115 * notfound:
116 * if creating, return locked directory, leaving info on available slots
117 * else return error
118 * found:
119 * if at end of path and deleting, return information to allow delete
120 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
121 * inode and return info to allow rewrite
122 * if not at end, add name to cache; if at end and neither creating
123 * nor deleting, add name to cache
124 */
125 int
126 ufs_lookup(ap)
127 struct vnop_lookup_args /* {
128 struct vnode *a_dvp;
129 struct vnode **a_vpp;
130 struct componentname *a_cnp;
131 vfs_context_t a_context
132 } */ *ap;
133 {
134 register struct vnode *vdp; /* vnode for directory being searched */
135 register struct inode *dp; /* inode for directory being searched */
136 struct buf *bp; /* a buffer of directory entries */
137 register struct direct *ep; /* the current directory entry */
138 int entryoffsetinblock; /* offset of ep in bp's buffer */
139 enum {NONE, COMPACT, FOUND} slotstatus;
140 doff_t slotoffset; /* offset of area with free space */
141 int slotsize; /* size of area at slotoffset */
142 int slotfreespace; /* amount of space free in slot */
143 int slotneeded; /* size of the entry we're seeking */
144 int numdirpasses; /* strategy for directory search */
145 doff_t endsearch; /* offset to end directory search */
146 doff_t prevoff; /* prev entry dp->i_offset */
147 struct vnode *pdp; /* saved dp during symlink work */
148 struct vnode *tdp; /* returned by VFS_VGET */
149 doff_t enduseful; /* pointer past last used dir slot */
150 u_long bmask; /* block offset mask */
151 int wantparent; /* 1 => wantparent or lockparent flag */
152 int namlen, error;
153 struct vnode **vpp = ap->a_vpp;
154 struct componentname *cnp = ap->a_cnp;
155 int flags = cnp->cn_flags;
156 int nameiop = cnp->cn_nameiop;
157 vfs_context_t context = ap->a_context;
158 kauth_cred_t cred;
159 #if REV_ENDIAN_FS
160 int rev_endian=0;
161 #endif /* REV_ENDIAN_FS */
162
163
164 cred = vfs_context_ucred(context);
165 bp = NULL;
166 slotoffset = -1;
167 *vpp = NULL;
168 vdp = ap->a_dvp;
169 dp = VTOI(vdp);
170
171 wantparent = flags & (LOCKPARENT|WANTPARENT);
172
173 #if REV_ENDIAN_FS
174 rev_endian=(vdp->v_mount->mnt_flag & MNT_REVEND);
175 #endif /* REV_ENDIAN_FS */
176
177 /*
178 * Check accessiblity of directory.
179 */
180 if ((dp->i_mode & IFMT) != IFDIR)
181 return (ENOTDIR);
182
183 /*
184 * We now have a segment name to search for, and a directory to search.
185 *
186 * Before tediously performing a linear scan of the directory,
187 * check the name cache to see if the directory/name pair
188 * we are looking for is known already.
189 */
190 if (error = cache_lookup(vdp, vpp, cnp)) {
191 if (error == ENOENT)
192 return (error);
193 return (0);
194 }
195 /*
196 * Suppress search for slots unless creating
197 * file and at end of pathname, in which case
198 * we watch for a place to put the new file in
199 * case it doesn't already exist.
200 */
201 slotstatus = FOUND;
202 slotfreespace = slotsize = slotneeded = 0;
203 if ((nameiop == CREATE || nameiop == RENAME) &&
204 (flags & ISLASTCN)) {
205 slotstatus = NONE;
206 slotneeded = (sizeof(struct direct) - MAXNAMLEN +
207 cnp->cn_namelen + 3) &~ 3;
208 }
209 /*
210 * If there is cached information on a previous search of
211 * this directory, pick up where we last left off.
212 * We cache only lookups as these are the most common
213 * and have the greatest payoff. Caching CREATE has little
214 * benefit as it usually must search the entire directory
215 * to determine that the entry does not exist. Caching the
216 * location of the last DELETE or RENAME has not reduced
217 * profiling time and hence has been removed in the interest
218 * of simplicity.
219 */
220 bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_vfsstat.f_iosize - 1;
221 if (nameiop != LOOKUP || dp->i_diroff == 0 ||
222 dp->i_diroff > dp->i_size) {
223 entryoffsetinblock = 0;
224 dp->i_offset = 0;
225 numdirpasses = 1;
226 } else {
227 dp->i_offset = dp->i_diroff;
228 if ((entryoffsetinblock = dp->i_offset & bmask) &&
229 (error = ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp)))
230 goto out;
231 numdirpasses = 2;
232 nchstats.ncs_2passes++;
233 }
234 prevoff = dp->i_offset;
235 endsearch = roundup(dp->i_size, DIRBLKSIZ);
236 enduseful = 0;
237
238 searchloop:
239 while (dp->i_offset < endsearch) {
240 /*
241 * If necessary, get the next directory block.
242 */
243 if ((dp->i_offset & bmask) == 0) {
244 if (bp != NULL) {
245 #if REV_ENDIAN_FS
246 if (rev_endian)
247 byte_swap_dir_block_out(bp);
248 #endif /* REV_ENDIAN_FS */
249 buf_brelse(bp);
250 }
251 if (error = ffs_blkatoff(vdp, (off_t)dp->i_offset, NULL, &bp))
252 goto out;
253 entryoffsetinblock = 0;
254 }
255 /*
256 * If still looking for a slot, and at a DIRBLKSIZE
257 * boundary, have to start looking for free space again.
258 */
259 if (slotstatus == NONE &&
260 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
261 slotoffset = -1;
262 slotfreespace = 0;
263 }
264 /*
265 * Get pointer to next entry.
266 * Full validation checks are slow, so we only check
267 * enough to insure forward progress through the
268 * directory. Complete checks can be run by patching
269 * "dirchk" to be true.
270 */
271 ep = (struct direct *)((char *)buf_dataptr(bp) + entryoffsetinblock);
272 if (ep->d_reclen == 0 ||
273 dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock)) {
274 int i;
275
276 ufs_dirbad(dp, dp->i_offset, "mangled entry");
277 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
278 dp->i_offset += i;
279 entryoffsetinblock += i;
280 continue;
281 }
282
283 /*
284 * If an appropriate sized slot has not yet been found,
285 * check to see if one is available. Also accumulate space
286 * in the current block so that we can determine if
287 * compaction is viable.
288 */
289 if (slotstatus != FOUND) {
290 int size = ep->d_reclen;
291
292 if (ep->d_ino != 0)
293 size -= DIRSIZ(FSFMT(vdp), ep);
294 if (size > 0) {
295 if (size >= slotneeded) {
296 slotstatus = FOUND;
297 slotoffset = dp->i_offset;
298 slotsize = ep->d_reclen;
299 } else if (slotstatus == NONE) {
300 slotfreespace += size;
301 if (slotoffset == -1)
302 slotoffset = dp->i_offset;
303 if (slotfreespace >= slotneeded) {
304 slotstatus = COMPACT;
305 slotsize = dp->i_offset +
306 ep->d_reclen - slotoffset;
307 }
308 }
309 }
310 }
311
312 /*
313 * Check for a name match.
314 */
315 if (ep->d_ino) {
316 # if (BYTE_ORDER == LITTLE_ENDIAN)
317 if (vdp->v_mount->mnt_maxsymlinklen > 0)
318 namlen = ep->d_namlen;
319 else
320 namlen = ep->d_type;
321 # else
322 namlen = ep->d_namlen;
323 # endif
324 if (namlen == cnp->cn_namelen &&
325 !bcmp(cnp->cn_nameptr, ep->d_name,
326 (unsigned)namlen)) {
327 /*
328 * Save directory entry's inode number and
329 * reclen in ndp->ni_ufs area, and release
330 * directory buffer.
331 */
332 if (vdp->v_mount->mnt_maxsymlinklen > 0 &&
333 ep->d_type == DT_WHT) {
334 slotstatus = FOUND;
335 slotoffset = dp->i_offset;
336 slotsize = ep->d_reclen;
337 dp->i_reclen = slotsize;
338 enduseful = dp->i_size;
339 ap->a_cnp->cn_flags |= ISWHITEOUT;
340 numdirpasses--;
341 goto notfound;
342 }
343 dp->i_ino = ep->d_ino;
344 dp->i_reclen = ep->d_reclen;
345 #if REV_ENDIAN_FS
346 if (rev_endian)
347 byte_swap_dir_block_out(bp);
348 #endif /* REV_ENDIAN_FS */
349 buf_brelse(bp);
350 goto found;
351 }
352 }
353 prevoff = dp->i_offset;
354 dp->i_offset += ep->d_reclen;
355 entryoffsetinblock += ep->d_reclen;
356 if (ep->d_ino)
357 enduseful = dp->i_offset;
358 }
359 notfound:
360 /*
361 * If we started in the middle of the directory and failed
362 * to find our target, we must check the beginning as well.
363 */
364 if (numdirpasses == 2) {
365 numdirpasses--;
366 dp->i_offset = 0;
367 endsearch = dp->i_diroff;
368 goto searchloop;
369 }
370 if (bp != NULL) {
371 #if REV_ENDIAN_FS
372 if (rev_endian)
373 byte_swap_dir_block_out(bp);
374 #endif /* REV_ENDIAN_FS */
375 buf_brelse(bp);
376 }
377 /*
378 * If creating, and at end of pathname and current
379 * directory has not been removed, then can consider
380 * allowing file to be created.
381 */
382 if ((nameiop == CREATE || nameiop == RENAME ||
383 (nameiop == DELETE &&
384 (ap->a_cnp->cn_flags & DOWHITEOUT) &&
385 (ap->a_cnp->cn_flags & ISWHITEOUT))) &&
386 (flags & ISLASTCN) && dp->i_nlink != 0) {
387 /*
388 * Return an indication of where the new directory
389 * entry should be put. If we didn't find a slot,
390 * then set dp->i_count to 0 indicating
391 * that the new slot belongs at the end of the
392 * directory. If we found a slot, then the new entry
393 * can be put in the range from dp->i_offset to
394 * dp->i_offset + dp->i_count.
395 */
396 if (slotstatus == NONE) {
397 dp->i_offset = roundup(dp->i_size, DIRBLKSIZ);
398 dp->i_count = 0;
399 enduseful = dp->i_offset;
400 } else if (nameiop == DELETE) {
401 dp->i_offset = slotoffset;
402 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
403 dp->i_count = 0;
404 else
405 dp->i_count = dp->i_offset - prevoff;
406 } else {
407 dp->i_offset = slotoffset;
408 dp->i_count = slotsize;
409 if (enduseful < slotoffset + slotsize)
410 enduseful = slotoffset + slotsize;
411 }
412 dp->i_endoff = roundup(enduseful, DIRBLKSIZ);
413 dp->i_flag |= IN_CHANGE | IN_UPDATE;
414 /*
415 * We return with the directory locked, so that
416 * the parameters we set up above will still be
417 * valid if we actually decide to do a direnter().
418 * We return ni_vp == NULL to indicate that the entry
419 * does not currently exist; we leave a pointer to
420 * the (locked) directory inode in ndp->ni_dvp.
421 *
422 * NB - if the directory is unlocked, then this
423 * information cannot be used.
424 */
425 error = EJUSTRETURN;
426 goto out;
427 }
428 /*
429 * Insert name into cache (as non-existent) if appropriate.
430 */
431 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
432 cache_enter(vdp, *vpp, cnp);
433 error = ENOENT;
434 goto out;
435
436 found:
437 if (numdirpasses == 2)
438 nchstats.ncs_pass2++;
439 /*
440 * Check that directory length properly reflects presence
441 * of this entry.
442 */
443 if (entryoffsetinblock + DIRSIZ(FSFMT(vdp), ep) > dp->i_size) {
444 ufs_dirbad(dp, dp->i_offset, "i_size too small");
445 dp->i_size = entryoffsetinblock + DIRSIZ(FSFMT(vdp), ep);
446 dp->i_flag |= IN_CHANGE | IN_UPDATE;
447 }
448
449 /*
450 * Found component in pathname.
451 * If the final component of path name, save information
452 * in the cache as to where the entry was found.
453 */
454 if ((flags & ISLASTCN) && nameiop == LOOKUP)
455 dp->i_diroff = dp->i_offset &~ (DIRBLKSIZ - 1);
456
457 /*
458 * If deleting, and at end of pathname, return
459 * parameters which can be used to remove file.
460 * If the wantparent flag isn't set, we return only
461 * the directory (in ndp->ni_dvp), otherwise we go
462 * on and lock the inode, being careful with ".".
463 */
464 if (nameiop == DELETE && (flags & ISLASTCN)) {
465 /*
466 * Return pointer to current entry in dp->i_offset,
467 * and distance past previous entry (if there
468 * is a previous entry in this block) in dp->i_count.
469 * Save directory inode pointer in ndp->ni_dvp for dirremove().
470 */
471 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
472 dp->i_count = 0;
473 else
474 dp->i_count = dp->i_offset - prevoff;
475 if (dp->i_number == dp->i_ino) {
476 vnode_get(vdp);
477 *vpp = vdp;
478 error = 0;
479 goto out;
480 }
481 if (error = ffs_vget_internal(vdp->v_mount, dp->i_ino, &tdp, vdp, cnp, 0, 0))
482 goto out;
483 *vpp = tdp;
484 goto out;
485 }
486
487 /*
488 * If rewriting (RENAME), return the inode and the
489 * information required to rewrite the present directory
490 * Must get inode of directory entry to verify it's a
491 * regular file, or empty directory.
492 */
493 if (nameiop == RENAME && wantparent && (flags & ISLASTCN)) {
494 /*
495 * Careful about locking second inode.
496 * This can only occur if the target is ".".
497 */
498 if (dp->i_number == dp->i_ino) {
499 error =EISDIR;
500 goto out;
501 }
502 if (error = ffs_vget_internal(vdp->v_mount, dp->i_ino, &tdp, vdp, cnp, 0, 0))
503 goto out;
504 *vpp = tdp;
505
506 goto out;
507 }
508
509 /*
510 * Step through the translation in the name. We do not `vnode_put' the
511 * directory because we may need it again if a symbolic link
512 * is relative to the current directory. Instead we save it
513 * unlocked as "pdp". We must get the target inode before unlocking
514 * the directory to insure that the inode will not be removed
515 * before we get it. We prevent deadlock by always fetching
516 * inodes from the root, moving down the directory tree. Thus
517 * when following backward pointers ".." we must unlock the
518 * parent directory before getting the requested directory.
519 * There is a potential race condition here if both the current
520 * and parent directories are removed before the VFS_VGET for the
521 * inode associated with ".." returns. We hope that this occurs
522 * infrequently since we cannot avoid this race condition without
523 * implementing a sophisticated deadlock detection algorithm.
524 * Note also that this simple deadlock detection scheme will not
525 * work if the file system has any hard links other than ".."
526 * that point backwards in the directory structure.
527 */
528 pdp = vdp;
529 if (flags & ISDOTDOT) {
530 if (error = ffs_vget_internal(vdp->v_mount, dp->i_ino, &tdp, vdp, cnp, 0, 0)) {
531 goto out;
532 }
533 *vpp = tdp;
534 } else if (dp->i_number == dp->i_ino) {
535 vnode_get(vdp); /* we want ourself, ie "." */
536 *vpp = vdp;
537 } else {
538 if (error = ffs_vget_internal(vdp->v_mount, dp->i_ino, &tdp, vdp, cnp, 0, 0))
539 goto out;
540 *vpp = tdp;
541 }
542
543 error = 0;
544 out:
545 return (error);
546 }
547
548 void
549 ufs_dirbad(ip, offset, how)
550 struct inode *ip;
551 doff_t offset;
552 const char *how;
553 {
554 struct mount *mp;
555
556 mp = ITOV(ip)->v_mount;
557 (void)printf("%s: bad dir ino %d at offset %d: %s\n",
558 mp->mnt_vfsstat.f_mntonname, ip->i_number, offset, how);
559 if ((mp->mnt_vfsstat.f_flags & MNT_RDONLY) == 0)
560 panic("bad dir");
561 }
562
563 /*
564 * Do consistency checking on a directory entry:
565 * record length must be multiple of 4
566 * entry must fit in rest of its DIRBLKSIZ block
567 * record must be large enough to contain entry
568 * name is not longer than MAXNAMLEN
569 * name must be as long as advertised, and null terminated
570 */
571 int
572 ufs_dirbadentry(dp, ep, entryoffsetinblock)
573 struct vnode *dp;
574 register struct direct *ep;
575 int entryoffsetinblock;
576 {
577 register int i;
578 int namlen;
579
580 # if (BYTE_ORDER == LITTLE_ENDIAN)
581 if (dp->v_mount->mnt_maxsymlinklen > 0)
582 namlen = ep->d_namlen;
583 else
584 namlen = ep->d_type;
585 # else
586 namlen = ep->d_namlen;
587 # endif
588 if ((ep->d_reclen & 0x3) != 0 ||
589 ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
590 ep->d_reclen < DIRSIZ(FSFMT(dp), ep) || namlen > MAXNAMLEN) {
591 /*return (1); */
592 printf("First bad\n");
593 goto bad;
594 }
595 if (ep->d_ino == 0)
596 return (0);
597 for (i = 0; i < namlen; i++)
598 if (ep->d_name[i] == '\0') {
599 /*return (1); */
600 printf("Second bad\n");
601 goto bad;
602 }
603 if (ep->d_name[i])
604 goto bad;
605 return (0);
606 bad:
607 return (1);
608 }
609
610 /*
611 * Write a directory entry after a call to namei, using the parameters
612 * that it left in nameidata. The argument ip is the inode which the new
613 * directory entry will refer to. Dvp is a pointer to the directory to
614 * be written, which was left locked by namei. Remaining parameters
615 * (dp->i_offset, dp->i_count) indicate how the space for the new
616 * entry is to be obtained.
617 */
618 int
619 ufs_direnter(ip, dvp, cnp)
620 struct inode *ip;
621 struct vnode *dvp;
622 register struct componentname *cnp;
623 {
624 register struct inode *dp;
625 struct direct newdir;
626
627 dp = VTOI(dvp);
628 newdir.d_ino = ip->i_number;
629 newdir.d_namlen = cnp->cn_namelen;
630 bcopy(cnp->cn_nameptr, newdir.d_name, (unsigned)cnp->cn_namelen + 1);
631 if (dvp->v_mount->mnt_maxsymlinklen > 0)
632 newdir.d_type = IFTODT(ip->i_mode);
633 else {
634 newdir.d_type = 0;
635 # if (BYTE_ORDER == LITTLE_ENDIAN)
636 { u_char tmp = newdir.d_namlen;
637 newdir.d_namlen = newdir.d_type;
638 newdir.d_type = tmp; }
639 # endif
640 }
641 return (ufs_direnter2(dvp, &newdir, cnp->cn_context));
642 }
643
644 /*
645 * Common entry point for directory entry removal used by ufs_direnter
646 * and ufs_whiteout
647 */
648 int
649 ufs_direnter2(struct vnode *dvp, struct direct *dirp, vfs_context_t ctx)
650 {
651 int newentrysize;
652 struct inode *dp;
653 struct buf *bp;
654 uio_t auio;
655 u_int dsize;
656 struct direct *ep, *nep;
657 int error, loc, spacefree;
658 char *dirbuf;
659 char uio_buf[ UIO_SIZEOF(1) ];
660 #if REV_ENDIAN_FS
661 struct mount *mp=dvp->v_mount;
662 int rev_endian=(mp->mnt_flag & MNT_REVEND);
663 #endif /* REV_ENDIAN_FS */
664
665 dp = VTOI(dvp);
666 newentrysize = DIRSIZ(FSFMT(dvp), dirp);
667
668 if (dp->i_count == 0) {
669 /*
670 * If dp->i_count is 0, then namei could find no
671 * space in the directory. Here, dp->i_offset will
672 * be on a directory block boundary and we will write the
673 * new entry into a fresh block.
674 */
675 if (dp->i_offset & (DIRBLKSIZ - 1))
676 panic("ufs_direnter2: newblk");
677 dirp->d_reclen = DIRBLKSIZ;
678 auio = uio_createwithbuffer(1, dp->i_offset, UIO_SYSSPACE, UIO_WRITE,
679 &uio_buf[0], sizeof(uio_buf));
680 uio_addiov(auio, CAST_USER_ADDR_T(dirp), newentrysize);
681
682 error = ffs_write_internal(dvp, auio, IO_SYNC, vfs_context_ucred(ctx));
683 if (DIRBLKSIZ >
684 VFSTOUFS(dvp->v_mount)->um_mountp->mnt_vfsstat.f_bsize)
685 /* XXX should grow with balloc() */
686 panic("ufs_direnter2: frag size");
687 else if (!error) {
688 dp->i_size = roundup(dp->i_size, DIRBLKSIZ);
689 dp->i_flag |= IN_CHANGE;
690 }
691 return (error);
692 }
693
694 /*
695 * If dp->i_count is non-zero, then namei found space
696 * for the new entry in the range dp->i_offset to
697 * dp->i_offset + dp->i_count in the directory.
698 * To use this space, we may have to compact the entries located
699 * there, by copying them together towards the beginning of the
700 * block, leaving the free space in one usable chunk at the end.
701 */
702
703 /*
704 * Increase size of directory if entry eats into new space.
705 * This should never push the size past a new multiple of
706 * DIRBLKSIZE.
707 *
708 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
709 */
710 if (dp->i_offset + dp->i_count > dp->i_size)
711 dp->i_size = dp->i_offset + dp->i_count;
712 /*
713 * Get the block containing the space for the new directory entry.
714 */
715 if (error = ffs_blkatoff(dvp, (off_t)dp->i_offset, &dirbuf, &bp))
716 return (error);
717 /*
718 * Find space for the new entry. In the simple case, the entry at
719 * offset base will have the space. If it does not, then namei
720 * arranged that compacting the region dp->i_offset to
721 * dp->i_offset + dp->i_count would yield the
722 * space.
723 */
724 ep = (struct direct *)dirbuf;
725 dsize = DIRSIZ(FSFMT(dvp), ep);
726 spacefree = ep->d_reclen - dsize;
727 for (loc = ep->d_reclen; loc < dp->i_count; ) {
728 nep = (struct direct *)(dirbuf + loc);
729 if (ep->d_ino) {
730 /* trim the existing slot */
731 ep->d_reclen = dsize;
732 ep = (struct direct *)((char *)ep + dsize);
733 } else {
734 /* overwrite; nothing there; header is ours */
735 spacefree += dsize;
736 }
737 dsize = DIRSIZ(FSFMT(dvp), nep);
738 spacefree += nep->d_reclen - dsize;
739 loc += nep->d_reclen;
740 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
741 }
742 /*
743 * Update the pointer fields in the previous entry (if any),
744 * copy in the new entry, and write out the block.
745 */
746 if (ep->d_ino == 0 ||
747 (ep->d_ino == WINO &&
748 bcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
749 if (spacefree + dsize < newentrysize)
750 panic("ufs_direnter2: compact1");
751 dirp->d_reclen = spacefree + dsize;
752 } else {
753 if (spacefree < newentrysize)
754 panic("ufs_direnter2: compact2");
755 dirp->d_reclen = spacefree;
756 ep->d_reclen = dsize;
757 ep = (struct direct *)((char *)ep + dsize);
758 }
759 bcopy((caddr_t)dirp, (caddr_t)ep, (u_int)newentrysize);
760 #if REV_ENDIAN_FS
761 if (rev_endian)
762 byte_swap_dir_block_out(bp);
763 #endif /* REV_ENDIAN_FS */
764 if (mp->mnt_flag & MNT_ASYNC) {
765 error = 0;
766 buf_bdwrite(bp);
767 } else {
768 error = VNOP_BWRITE(bp);
769 }
770 dp->i_flag |= IN_CHANGE | IN_UPDATE;
771 if (!error && dp->i_endoff && dp->i_endoff < dp->i_size)
772 error = ffs_truncate_internal(dvp, (off_t)dp->i_endoff, IO_SYNC, vfs_context_ucred(ctx));
773
774 return (error);
775 }
776
777 /*
778 * Remove a directory entry after a call to namei, using
779 * the parameters which it left in nameidata. The entry
780 * dp->i_offset contains the offset into the directory of the
781 * entry to be eliminated. The dp->i_count field contains the
782 * size of the previous record in the directory. If this
783 * is 0, the first entry is being deleted, so we need only
784 * zero the inode number to mark the entry as free. If the
785 * entry is not the first in the directory, we must reclaim
786 * the space of the now empty record by adding the record size
787 * to the size of the previous entry.
788 */
789 int
790 ufs_dirremove(dvp, cnp)
791 struct vnode *dvp;
792 struct componentname *cnp;
793 {
794 register struct inode *dp;
795 struct direct *ep;
796 struct buf *bp;
797 int error;
798 #if REV_ENDIAN_FS
799 struct mount *mp=dvp->v_mount;
800 int rev_endian=(mp->mnt_flag & MNT_REVEND);
801 #endif /* REV_ENDIAN_FS */
802
803 dp = VTOI(dvp);
804
805 if (cnp->cn_flags & DOWHITEOUT) {
806 /*
807 * Whiteout entry: set d_ino to WINO.
808 */
809 if (error = ffs_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, &bp))
810 return (error);
811 ep->d_ino = WINO;
812 ep->d_type = DT_WHT;
813 #if REV_ENDIAN_FS
814 if (rev_endian)
815 byte_swap_dir_block_out(bp);
816 #endif /* REV_ENDIAN_FS */
817 if (mp->mnt_flag & MNT_ASYNC) {
818 error = 0;
819 buf_bdwrite(bp);
820 } else {
821 error = VNOP_BWRITE(bp);
822 }
823 dp->i_flag |= IN_CHANGE | IN_UPDATE;
824 return (error);
825 }
826
827 if (dp->i_count == 0) {
828 /*
829 * First entry in block: set d_ino to zero.
830 */
831 if (error = ffs_blkatoff(dvp, (off_t)dp->i_offset, (char **)&ep, &bp))
832 return (error);
833 ep->d_ino = 0;
834 #if REV_ENDIAN_FS
835 if (rev_endian)
836 byte_swap_dir_block_out(bp);
837 #endif /* REV_ENDIAN_FS */
838 if (mp->mnt_flag & MNT_ASYNC) {
839 error = 0;
840 buf_bdwrite(bp);
841 } else {
842 error = VNOP_BWRITE(bp);
843 }
844 dp->i_flag |= IN_CHANGE | IN_UPDATE;
845 return (error);
846 }
847 /*
848 * Collapse new free space into previous entry.
849 */
850 if (error = ffs_blkatoff(dvp, (off_t)(dp->i_offset - dp->i_count),
851 (char **)&ep, &bp))
852 return (error);
853 ep->d_reclen += dp->i_reclen;
854 #if REV_ENDIAN_FS
855 if (rev_endian)
856 byte_swap_dir_block_out(bp);
857 #endif /* REV_ENDIAN_FS */
858 if (mp->mnt_flag & MNT_ASYNC) {
859 error = 0;
860 buf_bdwrite(bp);
861 } else {
862 error = VNOP_BWRITE(bp);
863 }
864 dp->i_flag |= IN_CHANGE | IN_UPDATE;
865
866 return (error);
867 }
868
869 /*
870 * Rewrite an existing directory entry to point at the inode
871 * supplied. The parameters describing the directory entry are
872 * set up by a call to namei.
873 */
874 int
875 ufs_dirrewrite(dp, ip, cnp)
876 struct inode *dp, *ip;
877 struct componentname *cnp;
878 {
879 struct buf *bp;
880 struct direct *ep;
881 struct vnode *vdp = ITOV(dp);
882 int error;
883
884 if (error = ffs_blkatoff(vdp, (off_t)dp->i_offset, (char **)&ep, &bp))
885 return (error);
886 ep->d_ino = ip->i_number;
887 if (vdp->v_mount->mnt_maxsymlinklen > 0)
888 ep->d_type = IFTODT(ip->i_mode);
889 #if REV_ENDIAN_FS
890 if (vdp->v_mount->mnt_flag & MNT_REVEND)
891 byte_swap_dir_block_out(bp);
892 #endif /* REV_ENDIAN_FS */
893 if (vdp->v_mount->mnt_flag & MNT_ASYNC) {
894 error = 0;
895 buf_bdwrite(bp);
896 } else {
897 error = VNOP_BWRITE(bp);
898 }
899 dp->i_flag |= IN_CHANGE | IN_UPDATE;
900 return (error);
901 }
902
903 /*
904 * Check if a directory is empty or not.
905 * Inode supplied must be locked.
906 *
907 * Using a struct dirtemplate here is not precisely
908 * what we want, but better than using a struct direct.
909 *
910 * NB: does not handle corrupted directories.
911 */
912 int
913 ufs_dirempty(struct inode *ip, ino_t parentino, kauth_cred_t cred)
914 {
915 register off_t off;
916 struct dirtemplate dbuf;
917 register struct direct *dp = (struct direct *)&dbuf;
918 int error, count, namlen;
919 #if REV_ENDIAN_FS
920 struct vnode *vp=ITOV(ip);
921 struct mount *mp=vp->v_mount;
922 int rev_endian=(mp->mnt_flag & MNT_REVEND);
923 #endif /* REV_ENDIAN_FS */
924
925 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
926
927 for (off = 0; off < ip->i_size; off += dp->d_reclen) {
928 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ, off,
929 UIO_SYSSPACE32, IO_NODELOCKED, cred, &count, (struct proc *)0);
930 /*
931 * Since we read MINDIRSIZ, residual must
932 * be 0 unless we're at end of file.
933 */
934 if (error || count != 0)
935 return (0);
936 #if 0 /*REV_ENDIAN_FS */
937 if (rev_endian)
938 byte_swap_minidir_in(dp);
939 #endif /* REV_ENDIAN_FS */
940 /* avoid infinite loops */
941 if (dp->d_reclen == 0)
942 return (0);
943 /* skip empty entries */
944 if (dp->d_ino == 0 || dp->d_ino == WINO)
945 continue;
946 /* accept only "." and ".." */
947 # if (BYTE_ORDER == LITTLE_ENDIAN)
948 if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0)
949 namlen = dp->d_namlen;
950 else
951 namlen = dp->d_type;
952 # else
953 namlen = dp->d_namlen;
954 # endif
955 if (namlen > 2)
956 return (0);
957 if (dp->d_name[0] != '.')
958 return (0);
959 /*
960 * At this point namlen must be 1 or 2.
961 * 1 implies ".", 2 implies ".." if second
962 * char is also "."
963 */
964 if (namlen == 1)
965 continue;
966 if (dp->d_name[1] == '.' && dp->d_ino == parentino)
967 continue;
968 return (0);
969 }
970 return (1);
971 }
972
973 /*
974 * Check if source directory is in the path of the target directory.
975 * Target is supplied locked, source is unlocked.
976 */
977 int
978 ufs_checkpath(source, target, cred)
979 struct inode *source, *target;
980 kauth_cred_t cred;
981 {
982 struct vnode *vp;
983 int error, rootino, namlen;
984 int need_put = 0;
985 struct dirtemplate dirbuf;
986
987 vp = ITOV(target);
988 if (target->i_number == source->i_number) {
989 error = EEXIST;
990 goto out;
991 }
992 rootino = ROOTINO;
993 error = 0;
994 if (target->i_number == rootino)
995 goto out;
996
997 for (;;) {
998 if (vp->v_type != VDIR) {
999 error = ENOTDIR;
1000 break;
1001 }
1002 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1003 sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE32,
1004 IO_NODELOCKED, cred, (int *)0, (struct proc *)0);
1005 if (error != 0)
1006 break;
1007 # if (BYTE_ORDER == LITTLE_ENDIAN)
1008 if (vp->v_mount->mnt_maxsymlinklen > 0)
1009 namlen = dirbuf.dotdot_namlen;
1010 else
1011 namlen = dirbuf.dotdot_type;
1012 # else
1013 namlen = dirbuf.dotdot_namlen;
1014 # endif
1015 if (namlen != 2 ||
1016 dirbuf.dotdot_name[0] != '.' ||
1017 dirbuf.dotdot_name[1] != '.') {
1018 error = ENOTDIR;
1019 break;
1020 }
1021 if (dirbuf.dotdot_ino == source->i_number) {
1022 error = EINVAL;
1023 break;
1024 }
1025 if (dirbuf.dotdot_ino == rootino)
1026 break;
1027
1028 if (need_put)
1029 vnode_put(vp);
1030
1031 if (error = VFS_VGET(vp->v_mount, (ino64_t)dirbuf.dotdot_ino, &vp, NULL)) { /* XXX need context */
1032 vp = NULL;
1033 break;
1034 }
1035 need_put = 1;
1036 }
1037
1038 out:
1039 if (error == ENOTDIR)
1040 printf("checkpath: .. not a directory\n");
1041 if (need_put && vp)
1042 vnode_put(vp);
1043
1044 return (error);
1045 }
Cache object: cb253cadba9b9d37a2a132d281d1e8d2
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