1 /*-
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
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 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)ufs_lookup.c 8.15 (Berkeley) 6/16/95
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/9.0/sys/ufs/ufs/ufs_lookup.c 222954 2011-06-10 22:18:25Z jeff $");
39
40 #include "opt_ufs.h"
41 #include "opt_quota.h"
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/namei.h>
47 #include <sys/bio.h>
48 #include <sys/buf.h>
49 #include <sys/proc.h>
50 #include <sys/stat.h>
51 #include <sys/mount.h>
52 #include <sys/vnode.h>
53 #include <sys/sysctl.h>
54
55 #include <vm/vm.h>
56 #include <vm/vm_extern.h>
57
58 #include <ufs/ufs/extattr.h>
59 #include <ufs/ufs/quota.h>
60 #include <ufs/ufs/inode.h>
61 #include <ufs/ufs/dir.h>
62 #ifdef UFS_DIRHASH
63 #include <ufs/ufs/dirhash.h>
64 #endif
65 #include <ufs/ufs/ufsmount.h>
66 #include <ufs/ufs/ufs_extern.h>
67
68 #ifdef DIAGNOSTIC
69 static int dirchk = 1;
70 #else
71 static int dirchk = 0;
72 #endif
73
74 SYSCTL_INT(_debug, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, "");
75
76 /* true if old FS format...*/
77 #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0)
78
79 #ifdef QUOTA
80 static int
81 ufs_lookup_upgrade_lock(struct vnode *vp)
82 {
83 int error;
84
85 ASSERT_VOP_LOCKED(vp, __FUNCTION__);
86 if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE)
87 return (0);
88
89 error = 0;
90
91 /*
92 * Upgrade vnode lock, since getinoquota()
93 * requires exclusive lock to modify inode.
94 */
95 vhold(vp);
96 vn_lock(vp, LK_UPGRADE | LK_RETRY);
97 VI_LOCK(vp);
98 if (vp->v_iflag & VI_DOOMED)
99 error = ENOENT;
100 vdropl(vp);
101 return (error);
102 }
103 #endif
104
105 static int
106 ufs_delete_denied(struct vnode *vdp, struct vnode *tdp, struct ucred *cred,
107 struct thread *td)
108 {
109 int error;
110
111 #ifdef UFS_ACL
112 /*
113 * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
114 *
115 * 3.16.2.1. ACE4_DELETE vs. ACE4_DELETE_CHILD
116 */
117
118 /*
119 * XXX: Is this check required?
120 */
121 error = VOP_ACCESS(vdp, VEXEC, cred, td);
122 if (error)
123 return (error);
124
125 error = VOP_ACCESSX(tdp, VDELETE, cred, td);
126 if (error == 0)
127 return (0);
128
129 error = VOP_ACCESSX(vdp, VDELETE_CHILD, cred, td);
130 if (error == 0)
131 return (0);
132
133 error = VOP_ACCESSX(vdp, VEXPLICIT_DENY | VDELETE_CHILD, cred, td);
134 if (error)
135 return (error);
136
137 #endif /* !UFS_ACL */
138
139 /*
140 * Standard Unix access control - delete access requires VWRITE.
141 */
142 error = VOP_ACCESS(vdp, VWRITE, cred, td);
143 if (error)
144 return (error);
145
146 /*
147 * If directory is "sticky", then user must own
148 * the directory, or the file in it, else she
149 * may not delete it (unless she's root). This
150 * implements append-only directories.
151 */
152 if ((VTOI(vdp)->i_mode & ISVTX) &&
153 VOP_ACCESS(vdp, VADMIN, cred, td) &&
154 VOP_ACCESS(tdp, VADMIN, cred, td))
155 return (EPERM);
156
157 return (0);
158 }
159
160 /*
161 * Convert a component of a pathname into a pointer to a locked inode.
162 * This is a very central and rather complicated routine.
163 * If the filesystem is not maintained in a strict tree hierarchy,
164 * this can result in a deadlock situation (see comments in code below).
165 *
166 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
167 * on whether the name is to be looked up, created, renamed, or deleted.
168 * When CREATE, RENAME, or DELETE is specified, information usable in
169 * creating, renaming, or deleting a directory entry may be calculated.
170 * If flag has LOCKPARENT or'ed into it and the target of the pathname
171 * exists, lookup returns both the target and its parent directory locked.
172 * When creating or renaming and LOCKPARENT is specified, the target may
173 * not be ".". When deleting and LOCKPARENT is specified, the target may
174 * be "."., but the caller must check to ensure it does an vrele and vput
175 * instead of two vputs.
176 *
177 * This routine is actually used as VOP_CACHEDLOOKUP method, and the
178 * filesystem employs the generic vfs_cache_lookup() as VOP_LOOKUP
179 * method.
180 *
181 * vfs_cache_lookup() performs the following for us:
182 * check that it is a directory
183 * check accessibility of directory
184 * check for modification attempts on read-only mounts
185 * if name found in cache
186 * if at end of path and deleting or creating
187 * drop it
188 * else
189 * return name.
190 * return VOP_CACHEDLOOKUP()
191 *
192 * Overall outline of ufs_lookup:
193 *
194 * search for name in directory, to found or notfound
195 * notfound:
196 * if creating, return locked directory, leaving info on available slots
197 * else return error
198 * found:
199 * if at end of path and deleting, return information to allow delete
200 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
201 * inode and return info to allow rewrite
202 * if not at end, add name to cache; if at end and neither creating
203 * nor deleting, add name to cache
204 */
205 int
206 ufs_lookup(ap)
207 struct vop_cachedlookup_args /* {
208 struct vnode *a_dvp;
209 struct vnode **a_vpp;
210 struct componentname *a_cnp;
211 } */ *ap;
212 {
213
214 return (ufs_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL));
215 }
216
217 int
218 ufs_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp,
219 ino_t *dd_ino)
220 {
221 struct inode *dp; /* inode for directory being searched */
222 struct buf *bp; /* a buffer of directory entries */
223 struct direct *ep; /* the current directory entry */
224 int entryoffsetinblock; /* offset of ep in bp's buffer */
225 enum {NONE, COMPACT, FOUND} slotstatus;
226 doff_t slotoffset; /* offset of area with free space */
227 doff_t i_diroff; /* cached i_diroff value. */
228 doff_t i_offset; /* cached i_offset value. */
229 int slotsize; /* size of area at slotoffset */
230 int slotfreespace; /* amount of space free in slot */
231 int slotneeded; /* size of the entry we're seeking */
232 int numdirpasses; /* strategy for directory search */
233 doff_t endsearch; /* offset to end directory search */
234 doff_t prevoff; /* prev entry dp->i_offset */
235 struct vnode *pdp; /* saved dp during symlink work */
236 struct vnode *tdp; /* returned by VFS_VGET */
237 doff_t enduseful; /* pointer past last used dir slot */
238 u_long bmask; /* block offset mask */
239 int namlen, error;
240 struct ucred *cred = cnp->cn_cred;
241 int flags = cnp->cn_flags;
242 int nameiop = cnp->cn_nameiop;
243 ino_t ino, ino1;
244 int ltype;
245
246 if (vpp != NULL)
247 *vpp = NULL;
248
249 dp = VTOI(vdp);
250 if (dp->i_effnlink == 0)
251 return (ENOENT);
252
253 /*
254 * Create a vm object if vmiodirenable is enabled.
255 * Alternatively we could call vnode_create_vobject
256 * in VFS_VGET but we could end up creating objects
257 * that are never used.
258 */
259 vnode_create_vobject(vdp, DIP(dp, i_size), cnp->cn_thread);
260
261 bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
262 #ifdef QUOTA
263 if ((nameiop == DELETE || nameiop == RENAME) && (flags & ISLASTCN)) {
264 error = ufs_lookup_upgrade_lock(vdp);
265 if (error != 0)
266 return (error);
267 }
268 #endif
269
270 restart:
271 bp = NULL;
272 slotoffset = -1;
273
274 /*
275 * We now have a segment name to search for, and a directory to search.
276 *
277 * Suppress search for slots unless creating
278 * file and at end of pathname, in which case
279 * we watch for a place to put the new file in
280 * case it doesn't already exist.
281 */
282 ino = 0;
283 i_diroff = dp->i_diroff;
284 slotstatus = FOUND;
285 slotfreespace = slotsize = slotneeded = 0;
286 if ((nameiop == CREATE || nameiop == RENAME) &&
287 (flags & ISLASTCN)) {
288 slotstatus = NONE;
289 slotneeded = DIRECTSIZ(cnp->cn_namelen);
290 }
291
292 #ifdef UFS_DIRHASH
293 /*
294 * Use dirhash for fast operations on large directories. The logic
295 * to determine whether to hash the directory is contained within
296 * ufsdirhash_build(); a zero return means that it decided to hash
297 * this directory and it successfully built up the hash table.
298 */
299 if (ufsdirhash_build(dp) == 0) {
300 /* Look for a free slot if needed. */
301 enduseful = dp->i_size;
302 if (slotstatus != FOUND) {
303 slotoffset = ufsdirhash_findfree(dp, slotneeded,
304 &slotsize);
305 if (slotoffset >= 0) {
306 slotstatus = COMPACT;
307 enduseful = ufsdirhash_enduseful(dp);
308 if (enduseful < 0)
309 enduseful = dp->i_size;
310 }
311 }
312 /* Look up the component. */
313 numdirpasses = 1;
314 entryoffsetinblock = 0; /* silence compiler warning */
315 switch (ufsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
316 &i_offset, &bp, nameiop == DELETE ? &prevoff : NULL)) {
317 case 0:
318 ep = (struct direct *)((char *)bp->b_data +
319 (i_offset & bmask));
320 goto foundentry;
321 case ENOENT:
322 i_offset = roundup2(dp->i_size, DIRBLKSIZ);
323 goto notfound;
324 default:
325 /* Something failed; just do a linear search. */
326 break;
327 }
328 }
329 #endif /* UFS_DIRHASH */
330 /*
331 * If there is cached information on a previous search of
332 * this directory, pick up where we last left off.
333 * We cache only lookups as these are the most common
334 * and have the greatest payoff. Caching CREATE has little
335 * benefit as it usually must search the entire directory
336 * to determine that the entry does not exist. Caching the
337 * location of the last DELETE or RENAME has not reduced
338 * profiling time and hence has been removed in the interest
339 * of simplicity.
340 */
341 if (nameiop != LOOKUP || i_diroff == 0 || i_diroff >= dp->i_size) {
342 entryoffsetinblock = 0;
343 i_offset = 0;
344 numdirpasses = 1;
345 } else {
346 i_offset = i_diroff;
347 if ((entryoffsetinblock = i_offset & bmask) &&
348 (error = UFS_BLKATOFF(vdp, (off_t)i_offset, NULL, &bp)))
349 return (error);
350 numdirpasses = 2;
351 nchstats.ncs_2passes++;
352 }
353 prevoff = i_offset;
354 endsearch = roundup2(dp->i_size, DIRBLKSIZ);
355 enduseful = 0;
356
357 searchloop:
358 while (i_offset < endsearch) {
359 /*
360 * If necessary, get the next directory block.
361 */
362 if ((i_offset & bmask) == 0) {
363 if (bp != NULL)
364 brelse(bp);
365 error =
366 UFS_BLKATOFF(vdp, (off_t)i_offset, NULL, &bp);
367 if (error)
368 return (error);
369 entryoffsetinblock = 0;
370 }
371 /*
372 * If still looking for a slot, and at a DIRBLKSIZE
373 * boundary, have to start looking for free space again.
374 */
375 if (slotstatus == NONE &&
376 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
377 slotoffset = -1;
378 slotfreespace = 0;
379 }
380 /*
381 * Get pointer to next entry.
382 * Full validation checks are slow, so we only check
383 * enough to insure forward progress through the
384 * directory. Complete checks can be run by patching
385 * "dirchk" to be true.
386 */
387 ep = (struct direct *)((char *)bp->b_data + entryoffsetinblock);
388 if (ep->d_reclen == 0 || ep->d_reclen >
389 DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
390 (dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) {
391 int i;
392
393 ufs_dirbad(dp, i_offset, "mangled entry");
394 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
395 i_offset += i;
396 entryoffsetinblock += i;
397 continue;
398 }
399
400 /*
401 * If an appropriate sized slot has not yet been found,
402 * check to see if one is available. Also accumulate space
403 * in the current block so that we can determine if
404 * compaction is viable.
405 */
406 if (slotstatus != FOUND) {
407 int size = ep->d_reclen;
408
409 if (ep->d_ino != 0)
410 size -= DIRSIZ(OFSFMT(vdp), ep);
411 if (size > 0) {
412 if (size >= slotneeded) {
413 slotstatus = FOUND;
414 slotoffset = i_offset;
415 slotsize = ep->d_reclen;
416 } else if (slotstatus == NONE) {
417 slotfreespace += size;
418 if (slotoffset == -1)
419 slotoffset = i_offset;
420 if (slotfreespace >= slotneeded) {
421 slotstatus = COMPACT;
422 slotsize = i_offset +
423 ep->d_reclen - slotoffset;
424 }
425 }
426 }
427 }
428
429 /*
430 * Check for a name match.
431 */
432 if (ep->d_ino) {
433 # if (BYTE_ORDER == LITTLE_ENDIAN)
434 if (OFSFMT(vdp))
435 namlen = ep->d_type;
436 else
437 namlen = ep->d_namlen;
438 # else
439 namlen = ep->d_namlen;
440 # endif
441 if (namlen == cnp->cn_namelen &&
442 (cnp->cn_nameptr[0] == ep->d_name[0]) &&
443 !bcmp(cnp->cn_nameptr, ep->d_name,
444 (unsigned)namlen)) {
445 #ifdef UFS_DIRHASH
446 foundentry:
447 #endif
448 /*
449 * Save directory entry's inode number and
450 * reclen in ndp->ni_ufs area, and release
451 * directory buffer.
452 */
453 if (vdp->v_mount->mnt_maxsymlinklen > 0 &&
454 ep->d_type == DT_WHT) {
455 slotstatus = FOUND;
456 slotoffset = i_offset;
457 slotsize = ep->d_reclen;
458 enduseful = dp->i_size;
459 cnp->cn_flags |= ISWHITEOUT;
460 numdirpasses--;
461 goto notfound;
462 }
463 ino = ep->d_ino;
464 goto found;
465 }
466 }
467 prevoff = i_offset;
468 i_offset += ep->d_reclen;
469 entryoffsetinblock += ep->d_reclen;
470 if (ep->d_ino)
471 enduseful = i_offset;
472 }
473 notfound:
474 /*
475 * If we started in the middle of the directory and failed
476 * to find our target, we must check the beginning as well.
477 */
478 if (numdirpasses == 2) {
479 numdirpasses--;
480 i_offset = 0;
481 endsearch = i_diroff;
482 goto searchloop;
483 }
484 if (bp != NULL)
485 brelse(bp);
486 /*
487 * If creating, and at end of pathname and current
488 * directory has not been removed, then can consider
489 * allowing file to be created.
490 */
491 if ((nameiop == CREATE || nameiop == RENAME ||
492 (nameiop == DELETE &&
493 (cnp->cn_flags & DOWHITEOUT) &&
494 (cnp->cn_flags & ISWHITEOUT))) &&
495 (flags & ISLASTCN) && dp->i_effnlink != 0) {
496 /*
497 * Access for write is interpreted as allowing
498 * creation of files in the directory.
499 *
500 * XXX: Fix the comment above.
501 */
502 if (flags & WILLBEDIR)
503 error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread);
504 else
505 error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread);
506 if (error)
507 return (error);
508 /*
509 * Return an indication of where the new directory
510 * entry should be put. If we didn't find a slot,
511 * then set dp->i_count to 0 indicating
512 * that the new slot belongs at the end of the
513 * directory. If we found a slot, then the new entry
514 * can be put in the range from dp->i_offset to
515 * dp->i_offset + dp->i_count.
516 */
517 if (slotstatus == NONE) {
518 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
519 dp->i_count = 0;
520 enduseful = dp->i_offset;
521 } else if (nameiop == DELETE) {
522 dp->i_offset = slotoffset;
523 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
524 dp->i_count = 0;
525 else
526 dp->i_count = dp->i_offset - prevoff;
527 } else {
528 dp->i_offset = slotoffset;
529 dp->i_count = slotsize;
530 if (enduseful < slotoffset + slotsize)
531 enduseful = slotoffset + slotsize;
532 }
533 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ);
534 /*
535 * We return with the directory locked, so that
536 * the parameters we set up above will still be
537 * valid if we actually decide to do a direnter().
538 * We return ni_vp == NULL to indicate that the entry
539 * does not currently exist; we leave a pointer to
540 * the (locked) directory inode in ndp->ni_dvp.
541 * The pathname buffer is saved so that the name
542 * can be obtained later.
543 *
544 * NB - if the directory is unlocked, then this
545 * information cannot be used.
546 */
547 cnp->cn_flags |= SAVENAME;
548 return (EJUSTRETURN);
549 }
550 /*
551 * Insert name into cache (as non-existent) if appropriate.
552 */
553 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE)
554 cache_enter(vdp, NULL, cnp);
555 return (ENOENT);
556
557 found:
558 if (dd_ino != NULL)
559 *dd_ino = ino;
560 if (numdirpasses == 2)
561 nchstats.ncs_pass2++;
562 /*
563 * Check that directory length properly reflects presence
564 * of this entry.
565 */
566 if (i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) {
567 ufs_dirbad(dp, i_offset, "i_size too small");
568 dp->i_size = i_offset + DIRSIZ(OFSFMT(vdp), ep);
569 DIP_SET(dp, i_size, dp->i_size);
570 dp->i_flag |= IN_CHANGE | IN_UPDATE;
571 }
572 brelse(bp);
573
574 /*
575 * Found component in pathname.
576 * If the final component of path name, save information
577 * in the cache as to where the entry was found.
578 */
579 if ((flags & ISLASTCN) && nameiop == LOOKUP)
580 dp->i_diroff = i_offset &~ (DIRBLKSIZ - 1);
581
582 /*
583 * If deleting, and at end of pathname, return
584 * parameters which can be used to remove file.
585 */
586 if (nameiop == DELETE && (flags & ISLASTCN)) {
587 if (flags & LOCKPARENT)
588 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__);
589 /*
590 * Return pointer to current entry in dp->i_offset,
591 * and distance past previous entry (if there
592 * is a previous entry in this block) in dp->i_count.
593 * Save directory inode pointer in ndp->ni_dvp for dirremove().
594 *
595 * Technically we shouldn't be setting these in the
596 * WANTPARENT case (first lookup in rename()), but any
597 * lookups that will result in directory changes will
598 * overwrite these.
599 */
600 dp->i_offset = i_offset;
601 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
602 dp->i_count = 0;
603 else
604 dp->i_count = dp->i_offset - prevoff;
605 if (dd_ino != NULL)
606 return (0);
607 if ((error = VFS_VGET(vdp->v_mount, ino,
608 LK_EXCLUSIVE, &tdp)) != 0)
609 return (error);
610 error = ufs_delete_denied(vdp, tdp, cred, cnp->cn_thread);
611 if (error) {
612 vput(tdp);
613 return (error);
614 }
615 if (dp->i_number == ino) {
616 VREF(vdp);
617 *vpp = vdp;
618 vput(tdp);
619 return (0);
620 }
621
622 *vpp = tdp;
623 return (0);
624 }
625
626 /*
627 * If rewriting (RENAME), return the inode and the
628 * information required to rewrite the present directory
629 * Must get inode of directory entry to verify it's a
630 * regular file, or empty directory.
631 */
632 if (nameiop == RENAME && (flags & ISLASTCN)) {
633 if (flags & WILLBEDIR)
634 error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread);
635 else
636 error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread);
637 if (error)
638 return (error);
639 /*
640 * Careful about locking second inode.
641 * This can only occur if the target is ".".
642 */
643 dp->i_offset = i_offset;
644 if (dp->i_number == ino)
645 return (EISDIR);
646 if (dd_ino != NULL)
647 return (0);
648 if ((error = VFS_VGET(vdp->v_mount, ino,
649 LK_EXCLUSIVE, &tdp)) != 0)
650 return (error);
651
652 error = ufs_delete_denied(vdp, tdp, cred, cnp->cn_thread);
653 if (error) {
654 vput(tdp);
655 return (error);
656 }
657
658 #ifdef SunOS_doesnt_do_that
659 /*
660 * The only purpose of this check is to return the correct
661 * error. Assume that we want to rename directory "a"
662 * to a file "b", and that we have no ACL_WRITE_DATA on
663 * a containing directory, but we _do_ have ACL_APPEND_DATA.
664 * In that case, the VOP_ACCESS check above will return 0,
665 * and the operation will fail with ENOTDIR instead
666 * of EACCESS.
667 */
668 if (tdp->v_type == VDIR)
669 error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread);
670 else
671 error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread);
672 if (error) {
673 vput(tdp);
674 return (error);
675 }
676 #endif
677
678 *vpp = tdp;
679 cnp->cn_flags |= SAVENAME;
680 return (0);
681 }
682 if (dd_ino != NULL)
683 return (0);
684
685 /*
686 * Step through the translation in the name. We do not `vput' the
687 * directory because we may need it again if a symbolic link
688 * is relative to the current directory. Instead we save it
689 * unlocked as "pdp". We must get the target inode before unlocking
690 * the directory to insure that the inode will not be removed
691 * before we get it. We prevent deadlock by always fetching
692 * inodes from the root, moving down the directory tree. Thus
693 * when following backward pointers ".." we must unlock the
694 * parent directory before getting the requested directory.
695 * There is a potential race condition here if both the current
696 * and parent directories are removed before the VFS_VGET for the
697 * inode associated with ".." returns. We hope that this occurs
698 * infrequently since we cannot avoid this race condition without
699 * implementing a sophisticated deadlock detection algorithm.
700 * Note also that this simple deadlock detection scheme will not
701 * work if the filesystem has any hard links other than ".."
702 * that point backwards in the directory structure.
703 */
704 pdp = vdp;
705 if (flags & ISDOTDOT) {
706 error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp);
707 if (error)
708 return (error);
709
710 /*
711 * Recheck that ".." entry in the vdp directory points
712 * to the inode we looked up before vdp lock was
713 * dropped.
714 */
715 error = ufs_lookup_ino(pdp, NULL, cnp, &ino1);
716 if (error) {
717 vput(tdp);
718 return (error);
719 }
720 if (ino1 != ino) {
721 vput(tdp);
722 goto restart;
723 }
724
725 *vpp = tdp;
726 } else if (dp->i_number == ino) {
727 VREF(vdp); /* we want ourself, ie "." */
728 /*
729 * When we lookup "." we still can be asked to lock it
730 * differently.
731 */
732 ltype = cnp->cn_lkflags & LK_TYPE_MASK;
733 if (ltype != VOP_ISLOCKED(vdp)) {
734 if (ltype == LK_EXCLUSIVE)
735 vn_lock(vdp, LK_UPGRADE | LK_RETRY);
736 else /* if (ltype == LK_SHARED) */
737 vn_lock(vdp, LK_DOWNGRADE | LK_RETRY);
738 /*
739 * Relock for the "." case may left us with
740 * reclaimed vnode.
741 */
742 if (vdp->v_iflag & VI_DOOMED) {
743 vrele(vdp);
744 return (ENOENT);
745 }
746 }
747 *vpp = vdp;
748 } else {
749 error = VFS_VGET(pdp->v_mount, ino, cnp->cn_lkflags, &tdp);
750 if (error)
751 return (error);
752 *vpp = tdp;
753 }
754
755 /*
756 * Insert name into cache if appropriate.
757 */
758 if (cnp->cn_flags & MAKEENTRY)
759 cache_enter(vdp, *vpp, cnp);
760 return (0);
761 }
762
763 void
764 ufs_dirbad(ip, offset, how)
765 struct inode *ip;
766 doff_t offset;
767 char *how;
768 {
769 struct mount *mp;
770
771 mp = ITOV(ip)->v_mount;
772 if ((mp->mnt_flag & MNT_RDONLY) == 0)
773 panic("ufs_dirbad: %s: bad dir ino %lu at offset %ld: %s",
774 mp->mnt_stat.f_mntonname, (u_long)ip->i_number, (long)offset, how);
775 else
776 (void)printf("%s: bad dir ino %lu at offset %ld: %s\n",
777 mp->mnt_stat.f_mntonname, (u_long)ip->i_number, (long)offset, how);
778 }
779
780 /*
781 * Do consistency checking on a directory entry:
782 * record length must be multiple of 4
783 * entry must fit in rest of its DIRBLKSIZ block
784 * record must be large enough to contain entry
785 * name is not longer than MAXNAMLEN
786 * name must be as long as advertised, and null terminated
787 */
788 int
789 ufs_dirbadentry(dp, ep, entryoffsetinblock)
790 struct vnode *dp;
791 struct direct *ep;
792 int entryoffsetinblock;
793 {
794 int i, namlen;
795
796 # if (BYTE_ORDER == LITTLE_ENDIAN)
797 if (OFSFMT(dp))
798 namlen = ep->d_type;
799 else
800 namlen = ep->d_namlen;
801 # else
802 namlen = ep->d_namlen;
803 # endif
804 if ((ep->d_reclen & 0x3) != 0 ||
805 ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
806 ep->d_reclen < DIRSIZ(OFSFMT(dp), ep) || namlen > MAXNAMLEN) {
807 /*return (1); */
808 printf("First bad\n");
809 goto bad;
810 }
811 if (ep->d_ino == 0)
812 return (0);
813 for (i = 0; i < namlen; i++)
814 if (ep->d_name[i] == '\0') {
815 /*return (1); */
816 printf("Second bad\n");
817 goto bad;
818 }
819 if (ep->d_name[i])
820 goto bad;
821 return (0);
822 bad:
823 return (1);
824 }
825
826 /*
827 * Construct a new directory entry after a call to namei, using the
828 * parameters that it left in the componentname argument cnp. The
829 * argument ip is the inode to which the new directory entry will refer.
830 */
831 void
832 ufs_makedirentry(ip, cnp, newdirp)
833 struct inode *ip;
834 struct componentname *cnp;
835 struct direct *newdirp;
836 {
837
838 #ifdef INVARIANTS
839 if ((cnp->cn_flags & SAVENAME) == 0)
840 panic("ufs_makedirentry: missing name");
841 #endif
842 newdirp->d_ino = ip->i_number;
843 newdirp->d_namlen = cnp->cn_namelen;
844 bcopy(cnp->cn_nameptr, newdirp->d_name, (unsigned)cnp->cn_namelen + 1);
845 if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0)
846 newdirp->d_type = IFTODT(ip->i_mode);
847 else {
848 newdirp->d_type = 0;
849 # if (BYTE_ORDER == LITTLE_ENDIAN)
850 { u_char tmp = newdirp->d_namlen;
851 newdirp->d_namlen = newdirp->d_type;
852 newdirp->d_type = tmp; }
853 # endif
854 }
855 }
856
857 /*
858 * Write a directory entry after a call to namei, using the parameters
859 * that it left in nameidata. The argument dirp is the new directory
860 * entry contents. Dvp is a pointer to the directory to be written,
861 * which was left locked by namei. Remaining parameters (dp->i_offset,
862 * dp->i_count) indicate how the space for the new entry is to be obtained.
863 * Non-null bp indicates that a directory is being created (for the
864 * soft dependency code).
865 */
866 int
867 ufs_direnter(dvp, tvp, dirp, cnp, newdirbp, isrename)
868 struct vnode *dvp;
869 struct vnode *tvp;
870 struct direct *dirp;
871 struct componentname *cnp;
872 struct buf *newdirbp;
873 int isrename;
874 {
875 struct ucred *cr;
876 struct thread *td;
877 int newentrysize;
878 struct inode *dp;
879 struct buf *bp;
880 u_int dsize;
881 struct direct *ep, *nep;
882 int error, ret, blkoff, loc, spacefree, flags, namlen;
883 char *dirbuf;
884
885 td = curthread; /* XXX */
886 cr = td->td_ucred;
887
888 dp = VTOI(dvp);
889 newentrysize = DIRSIZ(OFSFMT(dvp), dirp);
890
891 if (dp->i_count == 0) {
892 /*
893 * If dp->i_count is 0, then namei could find no
894 * space in the directory. Here, dp->i_offset will
895 * be on a directory block boundary and we will write the
896 * new entry into a fresh block.
897 */
898 if (dp->i_offset & (DIRBLKSIZ - 1))
899 panic("ufs_direnter: newblk");
900 flags = BA_CLRBUF;
901 if (!DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp))
902 flags |= IO_SYNC;
903 #ifdef QUOTA
904 if ((error = getinoquota(dp)) != 0) {
905 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
906 bdwrite(newdirbp);
907 return (error);
908 }
909 #endif
910 if ((error = UFS_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ,
911 cr, flags, &bp)) != 0) {
912 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
913 bdwrite(newdirbp);
914 return (error);
915 }
916 dp->i_size = dp->i_offset + DIRBLKSIZ;
917 DIP_SET(dp, i_size, dp->i_size);
918 dp->i_flag |= IN_CHANGE | IN_UPDATE;
919 vnode_pager_setsize(dvp, (u_long)dp->i_size);
920 dirp->d_reclen = DIRBLKSIZ;
921 blkoff = dp->i_offset &
922 (VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1);
923 bcopy((caddr_t)dirp, (caddr_t)bp->b_data + blkoff,newentrysize);
924 #ifdef UFS_DIRHASH
925 if (dp->i_dirhash != NULL) {
926 ufsdirhash_newblk(dp, dp->i_offset);
927 ufsdirhash_add(dp, dirp, dp->i_offset);
928 ufsdirhash_checkblock(dp, (char *)bp->b_data + blkoff,
929 dp->i_offset);
930 }
931 #endif
932 if (DOINGSOFTDEP(dvp)) {
933 /*
934 * Ensure that the entire newly allocated block is a
935 * valid directory so that future growth within the
936 * block does not have to ensure that the block is
937 * written before the inode.
938 */
939 blkoff += DIRBLKSIZ;
940 while (blkoff < bp->b_bcount) {
941 ((struct direct *)
942 (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
943 blkoff += DIRBLKSIZ;
944 }
945 if (softdep_setup_directory_add(bp, dp, dp->i_offset,
946 dirp->d_ino, newdirbp, 1))
947 dp->i_flag |= IN_NEEDSYNC;
948 if (newdirbp)
949 bdwrite(newdirbp);
950 bdwrite(bp);
951 if ((dp->i_flag & IN_NEEDSYNC) == 0)
952 return (UFS_UPDATE(dvp, 0));
953 /*
954 * We have just allocated a directory block in an
955 * indirect block. We must prevent holes in the
956 * directory created if directory entries are
957 * written out of order. To accomplish this we
958 * fsync when we extend a directory into indirects.
959 * During rename it's not safe to drop the tvp lock
960 * so sync must be delayed until it is.
961 *
962 * This synchronous step could be removed if fsck and
963 * the kernel were taught to fill in sparse
964 * directories rather than panic.
965 */
966 if (isrename)
967 return (0);
968 if (tvp != NULL)
969 VOP_UNLOCK(tvp, 0);
970 (void) VOP_FSYNC(dvp, MNT_WAIT, td);
971 if (tvp != NULL)
972 vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
973 return (error);
974 }
975 if (DOINGASYNC(dvp)) {
976 bdwrite(bp);
977 return (UFS_UPDATE(dvp, 0));
978 }
979 error = bwrite(bp);
980 ret = UFS_UPDATE(dvp, 1);
981 if (error == 0)
982 return (ret);
983 return (error);
984 }
985
986 /*
987 * If dp->i_count is non-zero, then namei found space for the new
988 * entry in the range dp->i_offset to dp->i_offset + dp->i_count
989 * in the directory. To use this space, we may have to compact
990 * the entries located there, by copying them together towards the
991 * beginning of the block, leaving the free space in one usable
992 * chunk at the end.
993 */
994
995 /*
996 * Increase size of directory if entry eats into new space.
997 * This should never push the size past a new multiple of
998 * DIRBLKSIZE.
999 *
1000 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
1001 */
1002 if (dp->i_offset + dp->i_count > dp->i_size) {
1003 dp->i_size = dp->i_offset + dp->i_count;
1004 DIP_SET(dp, i_size, dp->i_size);
1005 }
1006 /*
1007 * Get the block containing the space for the new directory entry.
1008 */
1009 error = UFS_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp);
1010 if (error) {
1011 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
1012 bdwrite(newdirbp);
1013 return (error);
1014 }
1015 /*
1016 * Find space for the new entry. In the simple case, the entry at
1017 * offset base will have the space. If it does not, then namei
1018 * arranged that compacting the region dp->i_offset to
1019 * dp->i_offset + dp->i_count would yield the space.
1020 */
1021 ep = (struct direct *)dirbuf;
1022 dsize = ep->d_ino ? DIRSIZ(OFSFMT(dvp), ep) : 0;
1023 spacefree = ep->d_reclen - dsize;
1024 for (loc = ep->d_reclen; loc < dp->i_count; ) {
1025 nep = (struct direct *)(dirbuf + loc);
1026
1027 /* Trim the existing slot (NB: dsize may be zero). */
1028 ep->d_reclen = dsize;
1029 ep = (struct direct *)((char *)ep + dsize);
1030
1031 /* Read nep->d_reclen now as the bcopy() may clobber it. */
1032 loc += nep->d_reclen;
1033 if (nep->d_ino == 0) {
1034 /*
1035 * A mid-block unused entry. Such entries are
1036 * never created by the kernel, but fsck_ffs
1037 * can create them (and it doesn't fix them).
1038 *
1039 * Add up the free space, and initialise the
1040 * relocated entry since we don't bcopy it.
1041 */
1042 spacefree += nep->d_reclen;
1043 ep->d_ino = 0;
1044 dsize = 0;
1045 continue;
1046 }
1047 dsize = DIRSIZ(OFSFMT(dvp), nep);
1048 spacefree += nep->d_reclen - dsize;
1049 #ifdef UFS_DIRHASH
1050 if (dp->i_dirhash != NULL)
1051 ufsdirhash_move(dp, nep,
1052 dp->i_offset + ((char *)nep - dirbuf),
1053 dp->i_offset + ((char *)ep - dirbuf));
1054 #endif
1055 if (DOINGSOFTDEP(dvp))
1056 softdep_change_directoryentry_offset(bp, dp, dirbuf,
1057 (caddr_t)nep, (caddr_t)ep, dsize);
1058 else
1059 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
1060 }
1061 /*
1062 * Here, `ep' points to a directory entry containing `dsize' in-use
1063 * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0,
1064 * then the entry is completely unused (dsize == 0). The value
1065 * of ep->d_reclen is always indeterminate.
1066 *
1067 * Update the pointer fields in the previous entry (if any),
1068 * copy in the new entry, and write out the block.
1069 */
1070 # if (BYTE_ORDER == LITTLE_ENDIAN)
1071 if (OFSFMT(dvp))
1072 namlen = ep->d_type;
1073 else
1074 namlen = ep->d_namlen;
1075 # else
1076 namlen = ep->d_namlen;
1077 # endif
1078 if (ep->d_ino == 0 ||
1079 (ep->d_ino == WINO && namlen == dirp->d_namlen &&
1080 bcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
1081 if (spacefree + dsize < newentrysize)
1082 panic("ufs_direnter: compact1");
1083 dirp->d_reclen = spacefree + dsize;
1084 } else {
1085 if (spacefree < newentrysize)
1086 panic("ufs_direnter: compact2");
1087 dirp->d_reclen = spacefree;
1088 ep->d_reclen = dsize;
1089 ep = (struct direct *)((char *)ep + dsize);
1090 }
1091 #ifdef UFS_DIRHASH
1092 if (dp->i_dirhash != NULL && (ep->d_ino == 0 ||
1093 dirp->d_reclen == spacefree))
1094 ufsdirhash_add(dp, dirp, dp->i_offset + ((char *)ep - dirbuf));
1095 #endif
1096 bcopy((caddr_t)dirp, (caddr_t)ep, (u_int)newentrysize);
1097 #ifdef UFS_DIRHASH
1098 if (dp->i_dirhash != NULL)
1099 ufsdirhash_checkblock(dp, dirbuf -
1100 (dp->i_offset & (DIRBLKSIZ - 1)),
1101 dp->i_offset & ~(DIRBLKSIZ - 1));
1102 #endif
1103
1104 if (DOINGSOFTDEP(dvp)) {
1105 (void) softdep_setup_directory_add(bp, dp,
1106 dp->i_offset + (caddr_t)ep - dirbuf,
1107 dirp->d_ino, newdirbp, 0);
1108 if (newdirbp != NULL)
1109 bdwrite(newdirbp);
1110 bdwrite(bp);
1111 } else {
1112 if (DOINGASYNC(dvp)) {
1113 bdwrite(bp);
1114 error = 0;
1115 } else {
1116 error = bwrite(bp);
1117 }
1118 }
1119 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1120 /*
1121 * If all went well, and the directory can be shortened, proceed
1122 * with the truncation. Note that we have to unlock the inode for
1123 * the entry that we just entered, as the truncation may need to
1124 * lock other inodes which can lead to deadlock if we also hold a
1125 * lock on the newly entered node.
1126 */
1127 if (isrename == 0 && error == 0 &&
1128 dp->i_endoff && dp->i_endoff < dp->i_size) {
1129 if (tvp != NULL)
1130 VOP_UNLOCK(tvp, 0);
1131 #ifdef UFS_DIRHASH
1132 if (dp->i_dirhash != NULL)
1133 ufsdirhash_dirtrunc(dp, dp->i_endoff);
1134 #endif
1135 (void) UFS_TRUNCATE(dvp, (off_t)dp->i_endoff,
1136 IO_NORMAL | IO_SYNC, cr, td);
1137 if (tvp != NULL)
1138 vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
1139 }
1140 return (error);
1141 }
1142
1143 /*
1144 * Remove a directory entry after a call to namei, using
1145 * the parameters which it left in nameidata. The entry
1146 * dp->i_offset contains the offset into the directory of the
1147 * entry to be eliminated. The dp->i_count field contains the
1148 * size of the previous record in the directory. If this
1149 * is 0, the first entry is being deleted, so we need only
1150 * zero the inode number to mark the entry as free. If the
1151 * entry is not the first in the directory, we must reclaim
1152 * the space of the now empty record by adding the record size
1153 * to the size of the previous entry.
1154 */
1155 int
1156 ufs_dirremove(dvp, ip, flags, isrmdir)
1157 struct vnode *dvp;
1158 struct inode *ip;
1159 int flags;
1160 int isrmdir;
1161 {
1162 struct inode *dp;
1163 struct direct *ep, *rep;
1164 struct buf *bp;
1165 int error;
1166
1167 dp = VTOI(dvp);
1168
1169 /*
1170 * Adjust the link count early so softdep can block if necessary.
1171 */
1172 if (ip) {
1173 ip->i_effnlink--;
1174 if (DOINGSOFTDEP(dvp)) {
1175 softdep_setup_unlink(dp, ip);
1176 } else {
1177 ip->i_nlink--;
1178 DIP_SET(ip, i_nlink, ip->i_nlink);
1179 ip->i_flag |= IN_CHANGE;
1180 }
1181 }
1182 if (flags & DOWHITEOUT) {
1183 /*
1184 * Whiteout entry: set d_ino to WINO.
1185 */
1186 if ((error =
1187 UFS_BLKATOFF(dvp, (off_t)dp->i_offset, (char **)&ep, &bp)) != 0)
1188 return (error);
1189 ep->d_ino = WINO;
1190 ep->d_type = DT_WHT;
1191 goto out;
1192 }
1193
1194 if ((error = UFS_BLKATOFF(dvp,
1195 (off_t)(dp->i_offset - dp->i_count), (char **)&ep, &bp)) != 0)
1196 return (error);
1197
1198 /* Set 'rep' to the entry being removed. */
1199 if (dp->i_count == 0)
1200 rep = ep;
1201 else
1202 rep = (struct direct *)((char *)ep + ep->d_reclen);
1203 #ifdef UFS_DIRHASH
1204 /*
1205 * Remove the dirhash entry. This is complicated by the fact
1206 * that `ep' is the previous entry when dp->i_count != 0.
1207 */
1208 if (dp->i_dirhash != NULL)
1209 ufsdirhash_remove(dp, rep, dp->i_offset);
1210 #endif
1211 if (ip && rep->d_ino != ip->i_number)
1212 panic("ufs_dirremove: ip %d does not match dirent ino %d\n",
1213 ip->i_number, rep->d_ino);
1214 if (dp->i_count == 0) {
1215 /*
1216 * First entry in block: set d_ino to zero.
1217 */
1218 ep->d_ino = 0;
1219 } else {
1220 /*
1221 * Collapse new free space into previous entry.
1222 */
1223 ep->d_reclen += rep->d_reclen;
1224 }
1225 #ifdef UFS_DIRHASH
1226 if (dp->i_dirhash != NULL)
1227 ufsdirhash_checkblock(dp, (char *)ep -
1228 ((dp->i_offset - dp->i_count) & (DIRBLKSIZ - 1)),
1229 dp->i_offset & ~(DIRBLKSIZ - 1));
1230 #endif
1231 out:
1232 error = 0;
1233 if (DOINGSOFTDEP(dvp)) {
1234 if (ip)
1235 softdep_setup_remove(bp, dp, ip, isrmdir);
1236 if (softdep_slowdown(dvp))
1237 error = bwrite(bp);
1238 else
1239 bdwrite(bp);
1240 } else {
1241 if (flags & DOWHITEOUT)
1242 error = bwrite(bp);
1243 else if (DOINGASYNC(dvp) && dp->i_count != 0)
1244 bdwrite(bp);
1245 else
1246 error = bwrite(bp);
1247 }
1248 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1249 /*
1250 * If the last named reference to a snapshot goes away,
1251 * drop its snapshot reference so that it will be reclaimed
1252 * when last open reference goes away.
1253 */
1254 if (ip != 0 && (ip->i_flags & SF_SNAPSHOT) != 0 && ip->i_effnlink == 0)
1255 UFS_SNAPGONE(ip);
1256 return (error);
1257 }
1258
1259 /*
1260 * Rewrite an existing directory entry to point at the inode
1261 * supplied. The parameters describing the directory entry are
1262 * set up by a call to namei.
1263 */
1264 int
1265 ufs_dirrewrite(dp, oip, newinum, newtype, isrmdir)
1266 struct inode *dp, *oip;
1267 ino_t newinum;
1268 int newtype;
1269 int isrmdir;
1270 {
1271 struct buf *bp;
1272 struct direct *ep;
1273 struct vnode *vdp = ITOV(dp);
1274 int error;
1275
1276 /*
1277 * Drop the link before we lock the buf so softdep can block if
1278 * necessary.
1279 */
1280 oip->i_effnlink--;
1281 if (DOINGSOFTDEP(vdp)) {
1282 softdep_setup_unlink(dp, oip);
1283 } else {
1284 oip->i_nlink--;
1285 DIP_SET(oip, i_nlink, oip->i_nlink);
1286 oip->i_flag |= IN_CHANGE;
1287 }
1288
1289 error = UFS_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp);
1290 if (error)
1291 return (error);
1292 if (ep->d_namlen == 2 && ep->d_name[1] == '.' && ep->d_name[0] == '.' &&
1293 ep->d_ino != oip->i_number) {
1294 brelse(bp);
1295 return (EIDRM);
1296 }
1297 ep->d_ino = newinum;
1298 if (!OFSFMT(vdp))
1299 ep->d_type = newtype;
1300 if (DOINGSOFTDEP(vdp)) {
1301 softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir);
1302 bdwrite(bp);
1303 } else {
1304 if (DOINGASYNC(vdp)) {
1305 bdwrite(bp);
1306 error = 0;
1307 } else {
1308 error = bwrite(bp);
1309 }
1310 }
1311 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1312 /*
1313 * If the last named reference to a snapshot goes away,
1314 * drop its snapshot reference so that it will be reclaimed
1315 * when last open reference goes away.
1316 */
1317 if ((oip->i_flags & SF_SNAPSHOT) != 0 && oip->i_effnlink == 0)
1318 UFS_SNAPGONE(oip);
1319 return (error);
1320 }
1321
1322 /*
1323 * Check if a directory is empty or not.
1324 * Inode supplied must be locked.
1325 *
1326 * Using a struct dirtemplate here is not precisely
1327 * what we want, but better than using a struct direct.
1328 *
1329 * NB: does not handle corrupted directories.
1330 */
1331 int
1332 ufs_dirempty(ip, parentino, cred)
1333 struct inode *ip;
1334 ino_t parentino;
1335 struct ucred *cred;
1336 {
1337 doff_t off;
1338 struct dirtemplate dbuf;
1339 struct direct *dp = (struct direct *)&dbuf;
1340 int error, count, namlen;
1341 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
1342
1343 for (off = 0; off < ip->i_size; off += dp->d_reclen) {
1344 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ,
1345 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred,
1346 NOCRED, &count, (struct thread *)0);
1347 /*
1348 * Since we read MINDIRSIZ, residual must
1349 * be 0 unless we're at end of file.
1350 */
1351 if (error || count != 0)
1352 return (0);
1353 /* avoid infinite loops */
1354 if (dp->d_reclen == 0)
1355 return (0);
1356 /* skip empty entries */
1357 if (dp->d_ino == 0 || dp->d_ino == WINO)
1358 continue;
1359 /* accept only "." and ".." */
1360 # if (BYTE_ORDER == LITTLE_ENDIAN)
1361 if (OFSFMT(ITOV(ip)))
1362 namlen = dp->d_type;
1363 else
1364 namlen = dp->d_namlen;
1365 # else
1366 namlen = dp->d_namlen;
1367 # endif
1368 if (namlen > 2)
1369 return (0);
1370 if (dp->d_name[0] != '.')
1371 return (0);
1372 /*
1373 * At this point namlen must be 1 or 2.
1374 * 1 implies ".", 2 implies ".." if second
1375 * char is also "."
1376 */
1377 if (namlen == 1 && dp->d_ino == ip->i_number)
1378 continue;
1379 if (dp->d_name[1] == '.' && dp->d_ino == parentino)
1380 continue;
1381 return (0);
1382 }
1383 return (1);
1384 }
1385
1386 static int
1387 ufs_dir_dd_ino(struct vnode *vp, struct ucred *cred, ino_t *dd_ino)
1388 {
1389 struct dirtemplate dirbuf;
1390 int error, namlen;
1391
1392 if (vp->v_type != VDIR)
1393 return (ENOTDIR);
1394 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1395 sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE,
1396 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL, NULL);
1397 if (error != 0)
1398 return (error);
1399 #if (BYTE_ORDER == LITTLE_ENDIAN)
1400 if (OFSFMT(vp))
1401 namlen = dirbuf.dotdot_type;
1402 else
1403 namlen = dirbuf.dotdot_namlen;
1404 #else
1405 namlen = dirbuf.dotdot_namlen;
1406 #endif
1407 if (namlen != 2 || dirbuf.dotdot_name[0] != '.' ||
1408 dirbuf.dotdot_name[1] != '.')
1409 return (ENOTDIR);
1410 *dd_ino = dirbuf.dotdot_ino;
1411 return (0);
1412 }
1413
1414 /*
1415 * Check if source directory is in the path of the target directory.
1416 */
1417 int
1418 ufs_checkpath(ino_t source_ino, ino_t parent_ino, struct inode *target, struct ucred *cred, ino_t *wait_ino)
1419 {
1420 struct mount *mp;
1421 struct vnode *tvp, *vp, *vp1;
1422 int error;
1423 ino_t dd_ino;
1424
1425 vp = tvp = ITOV(target);
1426 mp = vp->v_mount;
1427 *wait_ino = 0;
1428 if (target->i_number == source_ino)
1429 return (EEXIST);
1430 if (target->i_number == parent_ino)
1431 return (0);
1432 if (target->i_number == ROOTINO)
1433 return (0);
1434 error = 0;
1435 for (;;) {
1436 error = ufs_dir_dd_ino(vp, cred, &dd_ino);
1437 if (error != 0)
1438 break;
1439 if (dd_ino == source_ino) {
1440 error = EINVAL;
1441 break;
1442 }
1443 if (dd_ino == ROOTINO)
1444 break;
1445 if (dd_ino == parent_ino)
1446 break;
1447 error = VFS_VGET(mp, dd_ino, LK_SHARED | LK_NOWAIT, &vp1);
1448 if (error != 0) {
1449 *wait_ino = dd_ino;
1450 break;
1451 }
1452 /* Recheck that ".." still points to vp1 after relock of vp */
1453 error = ufs_dir_dd_ino(vp, cred, &dd_ino);
1454 if (error != 0) {
1455 vput(vp1);
1456 break;
1457 }
1458 /* Redo the check of ".." if directory was reparented */
1459 if (dd_ino != VTOI(vp1)->i_number) {
1460 vput(vp1);
1461 continue;
1462 }
1463 if (vp != tvp)
1464 vput(vp);
1465 vp = vp1;
1466 }
1467
1468 if (error == ENOTDIR)
1469 panic("checkpath: .. not a directory\n");
1470 if (vp != tvp)
1471 vput(vp);
1472 return (error);
1473 }
Cache object: 80de2b191aadf4cd2693c8d333585c1f
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