1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)ufs_lookup.c 8.15 (Berkeley) 6/16/95
37 */
38
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD: releng/12.0/sys/ufs/ufs/ufs_lookup.c 331095 2018-03-17 12:59:55Z emaste $");
41
42 #include "opt_ufs.h"
43 #include "opt_quota.h"
44
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/namei.h>
49 #include <sys/bio.h>
50 #include <sys/buf.h>
51 #include <sys/proc.h>
52 #include <sys/stat.h>
53 #include <sys/mount.h>
54 #include <sys/vnode.h>
55 #include <sys/sysctl.h>
56
57 #include <vm/vm.h>
58 #include <vm/vm_extern.h>
59
60 #include <ufs/ufs/extattr.h>
61 #include <ufs/ufs/quota.h>
62 #include <ufs/ufs/inode.h>
63 #include <ufs/ufs/dir.h>
64 #ifdef UFS_DIRHASH
65 #include <ufs/ufs/dirhash.h>
66 #endif
67 #include <ufs/ufs/ufsmount.h>
68 #include <ufs/ufs/ufs_extern.h>
69
70 #ifdef DIAGNOSTIC
71 static int dirchk = 1;
72 #else
73 static int dirchk = 0;
74 #endif
75
76 SYSCTL_INT(_debug, OID_AUTO, dircheck, CTLFLAG_RW, &dirchk, 0, "");
77
78 /* true if old FS format...*/
79 #define OFSFMT(vp) ((vp)->v_mount->mnt_maxsymlinklen <= 0)
80
81 static int
82 ufs_delete_denied(struct vnode *vdp, struct vnode *tdp, struct ucred *cred,
83 struct thread *td)
84 {
85 int error;
86
87 #ifdef UFS_ACL
88 /*
89 * NFSv4 Minor Version 1, draft-ietf-nfsv4-minorversion1-03.txt
90 *
91 * 3.16.2.1. ACE4_DELETE vs. ACE4_DELETE_CHILD
92 */
93
94 /*
95 * XXX: Is this check required?
96 */
97 error = VOP_ACCESS(vdp, VEXEC, cred, td);
98 if (error)
99 return (error);
100
101 error = VOP_ACCESSX(tdp, VDELETE, cred, td);
102 if (error == 0)
103 return (0);
104
105 error = VOP_ACCESSX(vdp, VDELETE_CHILD, cred, td);
106 if (error == 0)
107 return (0);
108
109 error = VOP_ACCESSX(vdp, VEXPLICIT_DENY | VDELETE_CHILD, cred, td);
110 if (error)
111 return (error);
112
113 #endif /* !UFS_ACL */
114
115 /*
116 * Standard Unix access control - delete access requires VWRITE.
117 */
118 error = VOP_ACCESS(vdp, VWRITE, cred, td);
119 if (error)
120 return (error);
121
122 /*
123 * If directory is "sticky", then user must own
124 * the directory, or the file in it, else she
125 * may not delete it (unless she's root). This
126 * implements append-only directories.
127 */
128 if ((VTOI(vdp)->i_mode & ISVTX) &&
129 VOP_ACCESS(vdp, VADMIN, cred, td) &&
130 VOP_ACCESS(tdp, VADMIN, cred, td))
131 return (EPERM);
132
133 return (0);
134 }
135
136 /*
137 * Convert a component of a pathname into a pointer to a locked inode.
138 * This is a very central and rather complicated routine.
139 * If the filesystem is not maintained in a strict tree hierarchy,
140 * this can result in a deadlock situation (see comments in code below).
141 *
142 * The cnp->cn_nameiop argument is LOOKUP, CREATE, RENAME, or DELETE depending
143 * on whether the name is to be looked up, created, renamed, or deleted.
144 * When CREATE, RENAME, or DELETE is specified, information usable in
145 * creating, renaming, or deleting a directory entry may be calculated.
146 * If flag has LOCKPARENT or'ed into it and the target of the pathname
147 * exists, lookup returns both the target and its parent directory locked.
148 * When creating or renaming and LOCKPARENT is specified, the target may
149 * not be ".". When deleting and LOCKPARENT is specified, the target may
150 * be "."., but the caller must check to ensure it does an vrele and vput
151 * instead of two vputs.
152 *
153 * This routine is actually used as VOP_CACHEDLOOKUP method, and the
154 * filesystem employs the generic vfs_cache_lookup() as VOP_LOOKUP
155 * method.
156 *
157 * vfs_cache_lookup() performs the following for us:
158 * check that it is a directory
159 * check accessibility of directory
160 * check for modification attempts on read-only mounts
161 * if name found in cache
162 * if at end of path and deleting or creating
163 * drop it
164 * else
165 * return name.
166 * return VOP_CACHEDLOOKUP()
167 *
168 * Overall outline of ufs_lookup:
169 *
170 * search for name in directory, to found or notfound
171 * notfound:
172 * if creating, return locked directory, leaving info on available slots
173 * else return error
174 * found:
175 * if at end of path and deleting, return information to allow delete
176 * if at end of path and rewriting (RENAME and LOCKPARENT), lock target
177 * inode and return info to allow rewrite
178 * if not at end, add name to cache; if at end and neither creating
179 * nor deleting, add name to cache
180 */
181 int
182 ufs_lookup(ap)
183 struct vop_cachedlookup_args /* {
184 struct vnode *a_dvp;
185 struct vnode **a_vpp;
186 struct componentname *a_cnp;
187 } */ *ap;
188 {
189
190 return (ufs_lookup_ino(ap->a_dvp, ap->a_vpp, ap->a_cnp, NULL));
191 }
192
193 int
194 ufs_lookup_ino(struct vnode *vdp, struct vnode **vpp, struct componentname *cnp,
195 ino_t *dd_ino)
196 {
197 struct inode *dp; /* inode for directory being searched */
198 struct buf *bp; /* a buffer of directory entries */
199 struct direct *ep; /* the current directory entry */
200 int entryoffsetinblock; /* offset of ep in bp's buffer */
201 enum {NONE, COMPACT, FOUND} slotstatus;
202 doff_t slotoffset; /* offset of area with free space */
203 doff_t i_diroff; /* cached i_diroff value. */
204 doff_t i_offset; /* cached i_offset value. */
205 int slotsize; /* size of area at slotoffset */
206 int slotfreespace; /* amount of space free in slot */
207 int slotneeded; /* size of the entry we're seeking */
208 int numdirpasses; /* strategy for directory search */
209 doff_t endsearch; /* offset to end directory search */
210 doff_t prevoff; /* prev entry dp->i_offset */
211 struct vnode *pdp; /* saved dp during symlink work */
212 struct vnode *tdp; /* returned by VFS_VGET */
213 doff_t enduseful; /* pointer past last used dir slot */
214 u_long bmask; /* block offset mask */
215 int namlen, error;
216 struct ucred *cred = cnp->cn_cred;
217 int flags = cnp->cn_flags;
218 int nameiop = cnp->cn_nameiop;
219 ino_t ino, ino1;
220 int ltype;
221
222 if (vpp != NULL)
223 *vpp = NULL;
224
225 dp = VTOI(vdp);
226 if (dp->i_effnlink == 0)
227 return (ENOENT);
228
229 /*
230 * Create a vm object if vmiodirenable is enabled.
231 * Alternatively we could call vnode_create_vobject
232 * in VFS_VGET but we could end up creating objects
233 * that are never used.
234 */
235 vnode_create_vobject(vdp, DIP(dp, i_size), cnp->cn_thread);
236
237 bmask = VFSTOUFS(vdp->v_mount)->um_mountp->mnt_stat.f_iosize - 1;
238
239 #ifdef DEBUG_VFS_LOCKS
240 /*
241 * Assert that the directory vnode is locked, and locked
242 * exclusively for the last component lookup for modifying
243 * operations.
244 *
245 * The directory-modifying operations need to save
246 * intermediate state in the inode between namei() call and
247 * actual directory manipulations. See fields in the struct
248 * inode marked as 'used during directory lookup'. We must
249 * ensure that upgrade in namei() does not happen, since
250 * upgrade might need to unlock vdp. If quotas are enabled,
251 * getinoquota() also requires exclusive lock to modify inode.
252 */
253 ASSERT_VOP_LOCKED(vdp, "ufs_lookup1");
254 if ((nameiop == CREATE || nameiop == DELETE || nameiop == RENAME) &&
255 (flags & (LOCKPARENT | ISLASTCN)) == (LOCKPARENT | ISLASTCN))
256 ASSERT_VOP_ELOCKED(vdp, "ufs_lookup2");
257 #endif
258
259 restart:
260 bp = NULL;
261 slotoffset = -1;
262
263 /*
264 * We now have a segment name to search for, and a directory to search.
265 *
266 * Suppress search for slots unless creating
267 * file and at end of pathname, in which case
268 * we watch for a place to put the new file in
269 * case it doesn't already exist.
270 */
271 ino = 0;
272 i_diroff = dp->i_diroff;
273 slotstatus = FOUND;
274 slotfreespace = slotsize = slotneeded = 0;
275 if ((nameiop == CREATE || nameiop == RENAME) &&
276 (flags & ISLASTCN)) {
277 slotstatus = NONE;
278 slotneeded = DIRECTSIZ(cnp->cn_namelen);
279 }
280
281 #ifdef UFS_DIRHASH
282 /*
283 * Use dirhash for fast operations on large directories. The logic
284 * to determine whether to hash the directory is contained within
285 * ufsdirhash_build(); a zero return means that it decided to hash
286 * this directory and it successfully built up the hash table.
287 */
288 if (ufsdirhash_build(dp) == 0) {
289 /* Look for a free slot if needed. */
290 enduseful = dp->i_size;
291 if (slotstatus != FOUND) {
292 slotoffset = ufsdirhash_findfree(dp, slotneeded,
293 &slotsize);
294 if (slotoffset >= 0) {
295 slotstatus = COMPACT;
296 enduseful = ufsdirhash_enduseful(dp);
297 if (enduseful < 0)
298 enduseful = dp->i_size;
299 }
300 }
301 /* Look up the component. */
302 numdirpasses = 1;
303 entryoffsetinblock = 0; /* silence compiler warning */
304 switch (ufsdirhash_lookup(dp, cnp->cn_nameptr, cnp->cn_namelen,
305 &i_offset, &bp, nameiop == DELETE ? &prevoff : NULL)) {
306 case 0:
307 ep = (struct direct *)((char *)bp->b_data +
308 (i_offset & bmask));
309 goto foundentry;
310 case ENOENT:
311 i_offset = roundup2(dp->i_size, DIRBLKSIZ);
312 goto notfound;
313 default:
314 /* Something failed; just do a linear search. */
315 break;
316 }
317 }
318 #endif /* UFS_DIRHASH */
319 /*
320 * If there is cached information on a previous search of
321 * this directory, pick up where we last left off.
322 * We cache only lookups as these are the most common
323 * and have the greatest payoff. Caching CREATE has little
324 * benefit as it usually must search the entire directory
325 * to determine that the entry does not exist. Caching the
326 * location of the last DELETE or RENAME has not reduced
327 * profiling time and hence has been removed in the interest
328 * of simplicity.
329 */
330 if (nameiop != LOOKUP || i_diroff == 0 || i_diroff >= dp->i_size) {
331 entryoffsetinblock = 0;
332 i_offset = 0;
333 numdirpasses = 1;
334 } else {
335 i_offset = i_diroff;
336 if ((entryoffsetinblock = i_offset & bmask) &&
337 (error = UFS_BLKATOFF(vdp, (off_t)i_offset, NULL, &bp)))
338 return (error);
339 numdirpasses = 2;
340 nchstats.ncs_2passes++;
341 }
342 prevoff = i_offset;
343 endsearch = roundup2(dp->i_size, DIRBLKSIZ);
344 enduseful = 0;
345
346 searchloop:
347 while (i_offset < endsearch) {
348 /*
349 * If necessary, get the next directory block.
350 */
351 if ((i_offset & bmask) == 0) {
352 if (bp != NULL)
353 brelse(bp);
354 error =
355 UFS_BLKATOFF(vdp, (off_t)i_offset, NULL, &bp);
356 if (error)
357 return (error);
358 entryoffsetinblock = 0;
359 }
360 /*
361 * If still looking for a slot, and at a DIRBLKSIZE
362 * boundary, have to start looking for free space again.
363 */
364 if (slotstatus == NONE &&
365 (entryoffsetinblock & (DIRBLKSIZ - 1)) == 0) {
366 slotoffset = -1;
367 slotfreespace = 0;
368 }
369 /*
370 * Get pointer to next entry.
371 * Full validation checks are slow, so we only check
372 * enough to insure forward progress through the
373 * directory. Complete checks can be run by patching
374 * "dirchk" to be true.
375 */
376 ep = (struct direct *)((char *)bp->b_data + entryoffsetinblock);
377 if (ep->d_reclen == 0 || ep->d_reclen >
378 DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
379 (dirchk && ufs_dirbadentry(vdp, ep, entryoffsetinblock))) {
380 int i;
381
382 ufs_dirbad(dp, i_offset, "mangled entry");
383 i = DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1));
384 i_offset += i;
385 entryoffsetinblock += i;
386 continue;
387 }
388
389 /*
390 * If an appropriate sized slot has not yet been found,
391 * check to see if one is available. Also accumulate space
392 * in the current block so that we can determine if
393 * compaction is viable.
394 */
395 if (slotstatus != FOUND) {
396 int size = ep->d_reclen;
397
398 if (ep->d_ino != 0)
399 size -= DIRSIZ(OFSFMT(vdp), ep);
400 if (size > 0) {
401 if (size >= slotneeded) {
402 slotstatus = FOUND;
403 slotoffset = i_offset;
404 slotsize = ep->d_reclen;
405 } else if (slotstatus == NONE) {
406 slotfreespace += size;
407 if (slotoffset == -1)
408 slotoffset = i_offset;
409 if (slotfreespace >= slotneeded) {
410 slotstatus = COMPACT;
411 slotsize = i_offset +
412 ep->d_reclen - slotoffset;
413 }
414 }
415 }
416 }
417
418 /*
419 * Check for a name match.
420 */
421 if (ep->d_ino) {
422 # if (BYTE_ORDER == LITTLE_ENDIAN)
423 if (OFSFMT(vdp))
424 namlen = ep->d_type;
425 else
426 namlen = ep->d_namlen;
427 # else
428 namlen = ep->d_namlen;
429 # endif
430 if (namlen == cnp->cn_namelen &&
431 (cnp->cn_nameptr[0] == ep->d_name[0]) &&
432 !bcmp(cnp->cn_nameptr, ep->d_name,
433 (unsigned)namlen)) {
434 #ifdef UFS_DIRHASH
435 foundentry:
436 #endif
437 /*
438 * Save directory entry's inode number and
439 * reclen in ndp->ni_ufs area, and release
440 * directory buffer.
441 */
442 if (vdp->v_mount->mnt_maxsymlinklen > 0 &&
443 ep->d_type == DT_WHT) {
444 slotstatus = FOUND;
445 slotoffset = i_offset;
446 slotsize = ep->d_reclen;
447 enduseful = dp->i_size;
448 cnp->cn_flags |= ISWHITEOUT;
449 numdirpasses--;
450 goto notfound;
451 }
452 ino = ep->d_ino;
453 goto found;
454 }
455 }
456 prevoff = i_offset;
457 i_offset += ep->d_reclen;
458 entryoffsetinblock += ep->d_reclen;
459 if (ep->d_ino)
460 enduseful = i_offset;
461 }
462 notfound:
463 /*
464 * If we started in the middle of the directory and failed
465 * to find our target, we must check the beginning as well.
466 */
467 if (numdirpasses == 2) {
468 numdirpasses--;
469 i_offset = 0;
470 endsearch = i_diroff;
471 goto searchloop;
472 }
473 if (bp != NULL)
474 brelse(bp);
475 /*
476 * If creating, and at end of pathname and current
477 * directory has not been removed, then can consider
478 * allowing file to be created.
479 */
480 if ((nameiop == CREATE || nameiop == RENAME ||
481 (nameiop == DELETE &&
482 (cnp->cn_flags & DOWHITEOUT) &&
483 (cnp->cn_flags & ISWHITEOUT))) &&
484 (flags & ISLASTCN) && dp->i_effnlink != 0) {
485 /*
486 * Access for write is interpreted as allowing
487 * creation of files in the directory.
488 *
489 * XXX: Fix the comment above.
490 */
491 if (flags & WILLBEDIR)
492 error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread);
493 else
494 error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread);
495 if (error)
496 return (error);
497 /*
498 * Return an indication of where the new directory
499 * entry should be put. If we didn't find a slot,
500 * then set dp->i_count to 0 indicating
501 * that the new slot belongs at the end of the
502 * directory. If we found a slot, then the new entry
503 * can be put in the range from dp->i_offset to
504 * dp->i_offset + dp->i_count.
505 */
506 if (slotstatus == NONE) {
507 dp->i_offset = roundup2(dp->i_size, DIRBLKSIZ);
508 dp->i_count = 0;
509 enduseful = dp->i_offset;
510 } else if (nameiop == DELETE) {
511 dp->i_offset = slotoffset;
512 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
513 dp->i_count = 0;
514 else
515 dp->i_count = dp->i_offset - prevoff;
516 } else {
517 dp->i_offset = slotoffset;
518 dp->i_count = slotsize;
519 if (enduseful < slotoffset + slotsize)
520 enduseful = slotoffset + slotsize;
521 }
522 dp->i_endoff = roundup2(enduseful, DIRBLKSIZ);
523 /*
524 * We return with the directory locked, so that
525 * the parameters we set up above will still be
526 * valid if we actually decide to do a direnter().
527 * We return ni_vp == NULL to indicate that the entry
528 * does not currently exist; we leave a pointer to
529 * the (locked) directory inode in ndp->ni_dvp.
530 * The pathname buffer is saved so that the name
531 * can be obtained later.
532 *
533 * NB - if the directory is unlocked, then this
534 * information cannot be used.
535 */
536 cnp->cn_flags |= SAVENAME;
537 return (EJUSTRETURN);
538 }
539 /*
540 * Insert name into cache (as non-existent) if appropriate.
541 */
542 if ((cnp->cn_flags & MAKEENTRY) != 0)
543 cache_enter(vdp, NULL, cnp);
544 return (ENOENT);
545
546 found:
547 if (dd_ino != NULL)
548 *dd_ino = ino;
549 if (numdirpasses == 2)
550 nchstats.ncs_pass2++;
551 /*
552 * Check that directory length properly reflects presence
553 * of this entry.
554 */
555 if (i_offset + DIRSIZ(OFSFMT(vdp), ep) > dp->i_size) {
556 ufs_dirbad(dp, i_offset, "i_size too small");
557 dp->i_size = i_offset + DIRSIZ(OFSFMT(vdp), ep);
558 DIP_SET(dp, i_size, dp->i_size);
559 dp->i_flag |= IN_CHANGE | IN_UPDATE;
560 }
561 brelse(bp);
562
563 /*
564 * Found component in pathname.
565 * If the final component of path name, save information
566 * in the cache as to where the entry was found.
567 */
568 if ((flags & ISLASTCN) && nameiop == LOOKUP)
569 dp->i_diroff = rounddown2(i_offset, DIRBLKSIZ);
570
571 /*
572 * If deleting, and at end of pathname, return
573 * parameters which can be used to remove file.
574 */
575 if (nameiop == DELETE && (flags & ISLASTCN)) {
576 if (flags & LOCKPARENT)
577 ASSERT_VOP_ELOCKED(vdp, __FUNCTION__);
578 /*
579 * Return pointer to current entry in dp->i_offset,
580 * and distance past previous entry (if there
581 * is a previous entry in this block) in dp->i_count.
582 * Save directory inode pointer in ndp->ni_dvp for dirremove().
583 *
584 * Technically we shouldn't be setting these in the
585 * WANTPARENT case (first lookup in rename()), but any
586 * lookups that will result in directory changes will
587 * overwrite these.
588 */
589 dp->i_offset = i_offset;
590 if ((dp->i_offset & (DIRBLKSIZ - 1)) == 0)
591 dp->i_count = 0;
592 else
593 dp->i_count = dp->i_offset - prevoff;
594 if (dd_ino != NULL)
595 return (0);
596 if ((error = VFS_VGET(vdp->v_mount, ino,
597 LK_EXCLUSIVE, &tdp)) != 0)
598 return (error);
599 error = ufs_delete_denied(vdp, tdp, cred, cnp->cn_thread);
600 if (error) {
601 vput(tdp);
602 return (error);
603 }
604 if (dp->i_number == ino) {
605 VREF(vdp);
606 *vpp = vdp;
607 vput(tdp);
608 return (0);
609 }
610
611 *vpp = tdp;
612 return (0);
613 }
614
615 /*
616 * If rewriting (RENAME), return the inode and the
617 * information required to rewrite the present directory
618 * Must get inode of directory entry to verify it's a
619 * regular file, or empty directory.
620 */
621 if (nameiop == RENAME && (flags & ISLASTCN)) {
622 if (flags & WILLBEDIR)
623 error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread);
624 else
625 error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread);
626 if (error)
627 return (error);
628 /*
629 * Careful about locking second inode.
630 * This can only occur if the target is ".".
631 */
632 dp->i_offset = i_offset;
633 if (dp->i_number == ino)
634 return (EISDIR);
635 if (dd_ino != NULL)
636 return (0);
637 if ((error = VFS_VGET(vdp->v_mount, ino,
638 LK_EXCLUSIVE, &tdp)) != 0)
639 return (error);
640
641 error = ufs_delete_denied(vdp, tdp, cred, cnp->cn_thread);
642 if (error) {
643 vput(tdp);
644 return (error);
645 }
646
647 #ifdef SunOS_doesnt_do_that
648 /*
649 * The only purpose of this check is to return the correct
650 * error. Assume that we want to rename directory "a"
651 * to a file "b", and that we have no ACL_WRITE_DATA on
652 * a containing directory, but we _do_ have ACL_APPEND_DATA.
653 * In that case, the VOP_ACCESS check above will return 0,
654 * and the operation will fail with ENOTDIR instead
655 * of EACCESS.
656 */
657 if (tdp->v_type == VDIR)
658 error = VOP_ACCESSX(vdp, VWRITE | VAPPEND, cred, cnp->cn_thread);
659 else
660 error = VOP_ACCESS(vdp, VWRITE, cred, cnp->cn_thread);
661 if (error) {
662 vput(tdp);
663 return (error);
664 }
665 #endif
666
667 *vpp = tdp;
668 cnp->cn_flags |= SAVENAME;
669 return (0);
670 }
671 if (dd_ino != NULL)
672 return (0);
673
674 /*
675 * Step through the translation in the name. We do not `vput' the
676 * directory because we may need it again if a symbolic link
677 * is relative to the current directory. Instead we save it
678 * unlocked as "pdp". We must get the target inode before unlocking
679 * the directory to insure that the inode will not be removed
680 * before we get it. We prevent deadlock by always fetching
681 * inodes from the root, moving down the directory tree. Thus
682 * when following backward pointers ".." we must unlock the
683 * parent directory before getting the requested directory.
684 * There is a potential race condition here if both the current
685 * and parent directories are removed before the VFS_VGET for the
686 * inode associated with ".." returns. We hope that this occurs
687 * infrequently since we cannot avoid this race condition without
688 * implementing a sophisticated deadlock detection algorithm.
689 * Note also that this simple deadlock detection scheme will not
690 * work if the filesystem has any hard links other than ".."
691 * that point backwards in the directory structure.
692 */
693 pdp = vdp;
694 if (flags & ISDOTDOT) {
695 error = vn_vget_ino(pdp, ino, cnp->cn_lkflags, &tdp);
696 if (error)
697 return (error);
698
699 /*
700 * Recheck that ".." entry in the vdp directory points
701 * to the inode we looked up before vdp lock was
702 * dropped.
703 */
704 error = ufs_lookup_ino(pdp, NULL, cnp, &ino1);
705 if (error) {
706 vput(tdp);
707 return (error);
708 }
709 if (ino1 != ino) {
710 vput(tdp);
711 goto restart;
712 }
713
714 *vpp = tdp;
715 } else if (dp->i_number == ino) {
716 VREF(vdp); /* we want ourself, ie "." */
717 /*
718 * When we lookup "." we still can be asked to lock it
719 * differently.
720 */
721 ltype = cnp->cn_lkflags & LK_TYPE_MASK;
722 if (ltype != VOP_ISLOCKED(vdp)) {
723 if (ltype == LK_EXCLUSIVE)
724 vn_lock(vdp, LK_UPGRADE | LK_RETRY);
725 else /* if (ltype == LK_SHARED) */
726 vn_lock(vdp, LK_DOWNGRADE | LK_RETRY);
727 /*
728 * Relock for the "." case may left us with
729 * reclaimed vnode.
730 */
731 if (vdp->v_iflag & VI_DOOMED) {
732 vrele(vdp);
733 return (ENOENT);
734 }
735 }
736 *vpp = vdp;
737 } else {
738 error = VFS_VGET(pdp->v_mount, ino, cnp->cn_lkflags, &tdp);
739 if (error)
740 return (error);
741 *vpp = tdp;
742 }
743
744 /*
745 * Insert name into cache if appropriate.
746 */
747 if (cnp->cn_flags & MAKEENTRY)
748 cache_enter(vdp, *vpp, cnp);
749 return (0);
750 }
751
752 void
753 ufs_dirbad(ip, offset, how)
754 struct inode *ip;
755 doff_t offset;
756 char *how;
757 {
758 struct mount *mp;
759
760 mp = ITOV(ip)->v_mount;
761 if ((mp->mnt_flag & MNT_RDONLY) == 0)
762 panic("ufs_dirbad: %s: bad dir ino %ju at offset %ld: %s",
763 mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number,
764 (long)offset, how);
765 else
766 (void)printf("%s: bad dir ino %ju at offset %ld: %s\n",
767 mp->mnt_stat.f_mntonname, (uintmax_t)ip->i_number,
768 (long)offset, how);
769 }
770
771 /*
772 * Do consistency checking on a directory entry:
773 * record length must be multiple of 4
774 * entry must fit in rest of its DIRBLKSIZ block
775 * record must be large enough to contain entry
776 * name is not longer than UFS_MAXNAMLEN
777 * name must be as long as advertised, and null terminated
778 */
779 int
780 ufs_dirbadentry(dp, ep, entryoffsetinblock)
781 struct vnode *dp;
782 struct direct *ep;
783 int entryoffsetinblock;
784 {
785 int i, namlen;
786
787 # if (BYTE_ORDER == LITTLE_ENDIAN)
788 if (OFSFMT(dp))
789 namlen = ep->d_type;
790 else
791 namlen = ep->d_namlen;
792 # else
793 namlen = ep->d_namlen;
794 # endif
795 if ((ep->d_reclen & 0x3) != 0 ||
796 ep->d_reclen > DIRBLKSIZ - (entryoffsetinblock & (DIRBLKSIZ - 1)) ||
797 ep->d_reclen < DIRSIZ(OFSFMT(dp), ep) || namlen > UFS_MAXNAMLEN) {
798 /*return (1); */
799 printf("First bad\n");
800 goto bad;
801 }
802 if (ep->d_ino == 0)
803 return (0);
804 for (i = 0; i < namlen; i++)
805 if (ep->d_name[i] == '\0') {
806 /*return (1); */
807 printf("Second bad\n");
808 goto bad;
809 }
810 if (ep->d_name[i])
811 goto bad;
812 return (0);
813 bad:
814 return (1);
815 }
816
817 /*
818 * Construct a new directory entry after a call to namei, using the
819 * parameters that it left in the componentname argument cnp. The
820 * argument ip is the inode to which the new directory entry will refer.
821 */
822 void
823 ufs_makedirentry(ip, cnp, newdirp)
824 struct inode *ip;
825 struct componentname *cnp;
826 struct direct *newdirp;
827 {
828
829 #ifdef INVARIANTS
830 if ((cnp->cn_flags & SAVENAME) == 0)
831 panic("ufs_makedirentry: missing name");
832 #endif
833 newdirp->d_ino = ip->i_number;
834 newdirp->d_namlen = cnp->cn_namelen;
835 bcopy(cnp->cn_nameptr, newdirp->d_name, (unsigned)cnp->cn_namelen + 1);
836 if (ITOV(ip)->v_mount->mnt_maxsymlinklen > 0)
837 newdirp->d_type = IFTODT(ip->i_mode);
838 else {
839 newdirp->d_type = 0;
840 # if (BYTE_ORDER == LITTLE_ENDIAN)
841 { u_char tmp = newdirp->d_namlen;
842 newdirp->d_namlen = newdirp->d_type;
843 newdirp->d_type = tmp; }
844 # endif
845 }
846 }
847
848 /*
849 * Write a directory entry after a call to namei, using the parameters
850 * that it left in nameidata. The argument dirp is the new directory
851 * entry contents. Dvp is a pointer to the directory to be written,
852 * which was left locked by namei. Remaining parameters (dp->i_offset,
853 * dp->i_count) indicate how the space for the new entry is to be obtained.
854 * Non-null bp indicates that a directory is being created (for the
855 * soft dependency code).
856 */
857 int
858 ufs_direnter(dvp, tvp, dirp, cnp, newdirbp, isrename)
859 struct vnode *dvp;
860 struct vnode *tvp;
861 struct direct *dirp;
862 struct componentname *cnp;
863 struct buf *newdirbp;
864 int isrename;
865 {
866 struct ucred *cr;
867 struct thread *td;
868 int newentrysize;
869 struct inode *dp;
870 struct buf *bp;
871 u_int dsize;
872 struct direct *ep, *nep;
873 u_int64_t old_isize;
874 int error, ret, blkoff, loc, spacefree, flags, namlen;
875 char *dirbuf;
876
877 td = curthread; /* XXX */
878 cr = td->td_ucred;
879
880 dp = VTOI(dvp);
881 newentrysize = DIRSIZ(OFSFMT(dvp), dirp);
882
883 if (dp->i_count == 0) {
884 /*
885 * If dp->i_count is 0, then namei could find no
886 * space in the directory. Here, dp->i_offset will
887 * be on a directory block boundary and we will write the
888 * new entry into a fresh block.
889 */
890 if (dp->i_offset & (DIRBLKSIZ - 1))
891 panic("ufs_direnter: newblk");
892 flags = BA_CLRBUF;
893 if (!DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp))
894 flags |= IO_SYNC;
895 #ifdef QUOTA
896 if ((error = getinoquota(dp)) != 0) {
897 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
898 bdwrite(newdirbp);
899 return (error);
900 }
901 #endif
902 old_isize = dp->i_size;
903 vnode_pager_setsize(dvp, (u_long)dp->i_offset + DIRBLKSIZ);
904 if ((error = UFS_BALLOC(dvp, (off_t)dp->i_offset, DIRBLKSIZ,
905 cr, flags, &bp)) != 0) {
906 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
907 bdwrite(newdirbp);
908 vnode_pager_setsize(dvp, (u_long)old_isize);
909 return (error);
910 }
911 dp->i_size = dp->i_offset + DIRBLKSIZ;
912 DIP_SET(dp, i_size, dp->i_size);
913 dp->i_endoff = dp->i_size;
914 dp->i_flag |= IN_CHANGE | IN_UPDATE;
915 dirp->d_reclen = DIRBLKSIZ;
916 blkoff = dp->i_offset &
917 (VFSTOUFS(dvp->v_mount)->um_mountp->mnt_stat.f_iosize - 1);
918 bcopy((caddr_t)dirp, (caddr_t)bp->b_data + blkoff,newentrysize);
919 #ifdef UFS_DIRHASH
920 if (dp->i_dirhash != NULL) {
921 ufsdirhash_newblk(dp, dp->i_offset);
922 ufsdirhash_add(dp, dirp, dp->i_offset);
923 ufsdirhash_checkblock(dp, (char *)bp->b_data + blkoff,
924 dp->i_offset);
925 }
926 #endif
927 if (DOINGSOFTDEP(dvp)) {
928 /*
929 * Ensure that the entire newly allocated block is a
930 * valid directory so that future growth within the
931 * block does not have to ensure that the block is
932 * written before the inode.
933 */
934 blkoff += DIRBLKSIZ;
935 while (blkoff < bp->b_bcount) {
936 ((struct direct *)
937 (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
938 blkoff += DIRBLKSIZ;
939 }
940 if (softdep_setup_directory_add(bp, dp, dp->i_offset,
941 dirp->d_ino, newdirbp, 1))
942 dp->i_flag |= IN_NEEDSYNC;
943 if (newdirbp)
944 bdwrite(newdirbp);
945 bdwrite(bp);
946 if ((dp->i_flag & IN_NEEDSYNC) == 0)
947 return (UFS_UPDATE(dvp, 0));
948 /*
949 * We have just allocated a directory block in an
950 * indirect block. We must prevent holes in the
951 * directory created if directory entries are
952 * written out of order. To accomplish this we
953 * fsync when we extend a directory into indirects.
954 * During rename it's not safe to drop the tvp lock
955 * so sync must be delayed until it is.
956 *
957 * This synchronous step could be removed if fsck and
958 * the kernel were taught to fill in sparse
959 * directories rather than panic.
960 */
961 if (isrename)
962 return (0);
963 if (tvp != NULL)
964 VOP_UNLOCK(tvp, 0);
965 (void) VOP_FSYNC(dvp, MNT_WAIT, td);
966 if (tvp != NULL)
967 vn_lock(tvp, LK_EXCLUSIVE | LK_RETRY);
968 return (error);
969 }
970 if (DOINGASYNC(dvp)) {
971 bdwrite(bp);
972 return (UFS_UPDATE(dvp, 0));
973 }
974 error = bwrite(bp);
975 ret = UFS_UPDATE(dvp, 1);
976 if (error == 0)
977 return (ret);
978 return (error);
979 }
980
981 /*
982 * If dp->i_count is non-zero, then namei found space for the new
983 * entry in the range dp->i_offset to dp->i_offset + dp->i_count
984 * in the directory. To use this space, we may have to compact
985 * the entries located there, by copying them together towards the
986 * beginning of the block, leaving the free space in one usable
987 * chunk at the end.
988 */
989
990 /*
991 * Increase size of directory if entry eats into new space.
992 * This should never push the size past a new multiple of
993 * DIRBLKSIZE.
994 *
995 * N.B. - THIS IS AN ARTIFACT OF 4.2 AND SHOULD NEVER HAPPEN.
996 */
997 if (dp->i_offset + dp->i_count > dp->i_size) {
998 dp->i_size = dp->i_offset + dp->i_count;
999 DIP_SET(dp, i_size, dp->i_size);
1000 }
1001 /*
1002 * Get the block containing the space for the new directory entry.
1003 */
1004 error = UFS_BLKATOFF(dvp, (off_t)dp->i_offset, &dirbuf, &bp);
1005 if (error) {
1006 if (DOINGSOFTDEP(dvp) && newdirbp != NULL)
1007 bdwrite(newdirbp);
1008 return (error);
1009 }
1010 /*
1011 * Find space for the new entry. In the simple case, the entry at
1012 * offset base will have the space. If it does not, then namei
1013 * arranged that compacting the region dp->i_offset to
1014 * dp->i_offset + dp->i_count would yield the space.
1015 */
1016 ep = (struct direct *)dirbuf;
1017 dsize = ep->d_ino ? DIRSIZ(OFSFMT(dvp), ep) : 0;
1018 spacefree = ep->d_reclen - dsize;
1019 for (loc = ep->d_reclen; loc < dp->i_count; ) {
1020 nep = (struct direct *)(dirbuf + loc);
1021
1022 /* Trim the existing slot (NB: dsize may be zero). */
1023 ep->d_reclen = dsize;
1024 ep = (struct direct *)((char *)ep + dsize);
1025
1026 /* Read nep->d_reclen now as the bcopy() may clobber it. */
1027 loc += nep->d_reclen;
1028 if (nep->d_ino == 0) {
1029 /*
1030 * A mid-block unused entry. Such entries are
1031 * never created by the kernel, but fsck_ffs
1032 * can create them (and it doesn't fix them).
1033 *
1034 * Add up the free space, and initialise the
1035 * relocated entry since we don't bcopy it.
1036 */
1037 spacefree += nep->d_reclen;
1038 ep->d_ino = 0;
1039 dsize = 0;
1040 continue;
1041 }
1042 dsize = DIRSIZ(OFSFMT(dvp), nep);
1043 spacefree += nep->d_reclen - dsize;
1044 #ifdef UFS_DIRHASH
1045 if (dp->i_dirhash != NULL)
1046 ufsdirhash_move(dp, nep,
1047 dp->i_offset + ((char *)nep - dirbuf),
1048 dp->i_offset + ((char *)ep - dirbuf));
1049 #endif
1050 if (DOINGSOFTDEP(dvp))
1051 softdep_change_directoryentry_offset(bp, dp, dirbuf,
1052 (caddr_t)nep, (caddr_t)ep, dsize);
1053 else
1054 bcopy((caddr_t)nep, (caddr_t)ep, dsize);
1055 }
1056 /*
1057 * Here, `ep' points to a directory entry containing `dsize' in-use
1058 * bytes followed by `spacefree' unused bytes. If ep->d_ino == 0,
1059 * then the entry is completely unused (dsize == 0). The value
1060 * of ep->d_reclen is always indeterminate.
1061 *
1062 * Update the pointer fields in the previous entry (if any),
1063 * copy in the new entry, and write out the block.
1064 */
1065 # if (BYTE_ORDER == LITTLE_ENDIAN)
1066 if (OFSFMT(dvp))
1067 namlen = ep->d_type;
1068 else
1069 namlen = ep->d_namlen;
1070 # else
1071 namlen = ep->d_namlen;
1072 # endif
1073 if (ep->d_ino == 0 ||
1074 (ep->d_ino == UFS_WINO && namlen == dirp->d_namlen &&
1075 bcmp(ep->d_name, dirp->d_name, dirp->d_namlen) == 0)) {
1076 if (spacefree + dsize < newentrysize)
1077 panic("ufs_direnter: compact1");
1078 dirp->d_reclen = spacefree + dsize;
1079 } else {
1080 if (spacefree < newentrysize)
1081 panic("ufs_direnter: compact2");
1082 dirp->d_reclen = spacefree;
1083 ep->d_reclen = dsize;
1084 ep = (struct direct *)((char *)ep + dsize);
1085 }
1086 #ifdef UFS_DIRHASH
1087 if (dp->i_dirhash != NULL && (ep->d_ino == 0 ||
1088 dirp->d_reclen == spacefree))
1089 ufsdirhash_add(dp, dirp, dp->i_offset + ((char *)ep - dirbuf));
1090 #endif
1091 bcopy((caddr_t)dirp, (caddr_t)ep, (u_int)newentrysize);
1092 #ifdef UFS_DIRHASH
1093 if (dp->i_dirhash != NULL)
1094 ufsdirhash_checkblock(dp, dirbuf -
1095 (dp->i_offset & (DIRBLKSIZ - 1)),
1096 rounddown2(dp->i_offset, DIRBLKSIZ));
1097 #endif
1098
1099 if (DOINGSOFTDEP(dvp)) {
1100 (void) softdep_setup_directory_add(bp, dp,
1101 dp->i_offset + (caddr_t)ep - dirbuf,
1102 dirp->d_ino, newdirbp, 0);
1103 if (newdirbp != NULL)
1104 bdwrite(newdirbp);
1105 bdwrite(bp);
1106 } else {
1107 if (DOINGASYNC(dvp)) {
1108 bdwrite(bp);
1109 error = 0;
1110 } else {
1111 error = bwrite(bp);
1112 }
1113 }
1114 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1115 /*
1116 * If all went well, and the directory can be shortened, proceed
1117 * with the truncation. Note that we have to unlock the inode for
1118 * the entry that we just entered, as the truncation may need to
1119 * lock other inodes which can lead to deadlock if we also hold a
1120 * lock on the newly entered node.
1121 */
1122 if (isrename == 0 && error == 0 &&
1123 dp->i_endoff && dp->i_endoff < dp->i_size) {
1124 if (tvp != NULL)
1125 VOP_UNLOCK(tvp, 0);
1126 error = UFS_TRUNCATE(dvp, (off_t)dp->i_endoff,
1127 IO_NORMAL | (DOINGASYNC(dvp) ? 0 : IO_SYNC), cr);
1128 if (error != 0)
1129 vn_printf(dvp,
1130 "ufs_direnter: failed to truncate, error %d\n",
1131 error);
1132 #ifdef UFS_DIRHASH
1133 if (error == 0 && dp->i_dirhash != NULL)
1134 ufsdirhash_dirtrunc(dp, dp->i_endoff);
1135 #endif
1136 error = 0;
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 UFS_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 = UFS_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 %ju does not match dirent ino %ju\n",
1213 (uintmax_t)ip->i_number, (uintmax_t)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 rounddown2(dp->i_offset, DIRBLKSIZ));
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))
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 != NULL && (ip->i_flags & SF_SNAPSHOT) != 0 &&
1255 ip->i_effnlink == 0)
1256 UFS_SNAPGONE(ip);
1257 return (error);
1258 }
1259
1260 /*
1261 * Rewrite an existing directory entry to point at the inode
1262 * supplied. The parameters describing the directory entry are
1263 * set up by a call to namei.
1264 */
1265 int
1266 ufs_dirrewrite(dp, oip, newinum, newtype, isrmdir)
1267 struct inode *dp, *oip;
1268 ino_t newinum;
1269 int newtype;
1270 int isrmdir;
1271 {
1272 struct buf *bp;
1273 struct direct *ep;
1274 struct vnode *vdp = ITOV(dp);
1275 int error;
1276
1277 /*
1278 * Drop the link before we lock the buf so softdep can block if
1279 * necessary.
1280 */
1281 oip->i_effnlink--;
1282 if (DOINGSOFTDEP(vdp)) {
1283 softdep_setup_unlink(dp, oip);
1284 } else {
1285 oip->i_nlink--;
1286 DIP_SET(oip, i_nlink, oip->i_nlink);
1287 oip->i_flag |= IN_CHANGE;
1288 }
1289
1290 error = UFS_BLKATOFF(vdp, (off_t)dp->i_offset, (char **)&ep, &bp);
1291 if (error)
1292 return (error);
1293 if (ep->d_namlen == 2 && ep->d_name[1] == '.' && ep->d_name[0] == '.' &&
1294 ep->d_ino != oip->i_number) {
1295 brelse(bp);
1296 return (EIDRM);
1297 }
1298 ep->d_ino = newinum;
1299 if (!OFSFMT(vdp))
1300 ep->d_type = newtype;
1301 if (DOINGSOFTDEP(vdp)) {
1302 softdep_setup_directory_change(bp, dp, oip, newinum, isrmdir);
1303 bdwrite(bp);
1304 } else {
1305 if (DOINGASYNC(vdp)) {
1306 bdwrite(bp);
1307 error = 0;
1308 } else {
1309 error = bwrite(bp);
1310 }
1311 }
1312 dp->i_flag |= IN_CHANGE | IN_UPDATE;
1313 /*
1314 * If the last named reference to a snapshot goes away,
1315 * drop its snapshot reference so that it will be reclaimed
1316 * when last open reference goes away.
1317 */
1318 if ((oip->i_flags & SF_SNAPSHOT) != 0 && oip->i_effnlink == 0)
1319 UFS_SNAPGONE(oip);
1320 return (error);
1321 }
1322
1323 /*
1324 * Check if a directory is empty or not.
1325 * Inode supplied must be locked.
1326 *
1327 * Using a struct dirtemplate here is not precisely
1328 * what we want, but better than using a struct direct.
1329 *
1330 * NB: does not handle corrupted directories.
1331 */
1332 int
1333 ufs_dirempty(ip, parentino, cred)
1334 struct inode *ip;
1335 ino_t parentino;
1336 struct ucred *cred;
1337 {
1338 doff_t off;
1339 struct dirtemplate dbuf;
1340 struct direct *dp = (struct direct *)&dbuf;
1341 int error, namlen;
1342 ssize_t count;
1343 #define MINDIRSIZ (sizeof (struct dirtemplate) / 2)
1344
1345 for (off = 0; off < ip->i_size; off += dp->d_reclen) {
1346 error = vn_rdwr(UIO_READ, ITOV(ip), (caddr_t)dp, MINDIRSIZ,
1347 off, UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK, cred,
1348 NOCRED, &count, (struct thread *)0);
1349 /*
1350 * Since we read MINDIRSIZ, residual must
1351 * be 0 unless we're at end of file.
1352 */
1353 if (error || count != 0)
1354 return (0);
1355 /* avoid infinite loops */
1356 if (dp->d_reclen == 0)
1357 return (0);
1358 /* skip empty entries */
1359 if (dp->d_ino == 0 || dp->d_ino == UFS_WINO)
1360 continue;
1361 /* accept only "." and ".." */
1362 # if (BYTE_ORDER == LITTLE_ENDIAN)
1363 if (OFSFMT(ITOV(ip)))
1364 namlen = dp->d_type;
1365 else
1366 namlen = dp->d_namlen;
1367 # else
1368 namlen = dp->d_namlen;
1369 # endif
1370 if (namlen > 2)
1371 return (0);
1372 if (dp->d_name[0] != '.')
1373 return (0);
1374 /*
1375 * At this point namlen must be 1 or 2.
1376 * 1 implies ".", 2 implies ".." if second
1377 * char is also "."
1378 */
1379 if (namlen == 1 && dp->d_ino == ip->i_number)
1380 continue;
1381 if (dp->d_name[1] == '.' && dp->d_ino == parentino)
1382 continue;
1383 return (0);
1384 }
1385 return (1);
1386 }
1387
1388 static int
1389 ufs_dir_dd_ino(struct vnode *vp, struct ucred *cred, ino_t *dd_ino,
1390 struct vnode **dd_vp)
1391 {
1392 struct dirtemplate dirbuf;
1393 struct vnode *ddvp;
1394 int error, namlen;
1395
1396 ASSERT_VOP_LOCKED(vp, "ufs_dir_dd_ino");
1397 if (vp->v_type != VDIR)
1398 return (ENOTDIR);
1399 /*
1400 * First check to see if we have it in the name cache.
1401 */
1402 if ((ddvp = vn_dir_dd_ino(vp)) != NULL) {
1403 KASSERT(ddvp->v_mount == vp->v_mount,
1404 ("ufs_dir_dd_ino: Unexpected mount point crossing"));
1405 *dd_ino = VTOI(ddvp)->i_number;
1406 *dd_vp = ddvp;
1407 return (0);
1408 }
1409 /*
1410 * Have to read the directory.
1411 */
1412 error = vn_rdwr(UIO_READ, vp, (caddr_t)&dirbuf,
1413 sizeof (struct dirtemplate), (off_t)0, UIO_SYSSPACE,
1414 IO_NODELOCKED | IO_NOMACCHECK, cred, NOCRED, NULL, NULL);
1415 if (error != 0)
1416 return (error);
1417 #if (BYTE_ORDER == LITTLE_ENDIAN)
1418 if (OFSFMT(vp))
1419 namlen = dirbuf.dotdot_type;
1420 else
1421 namlen = dirbuf.dotdot_namlen;
1422 #else
1423 namlen = dirbuf.dotdot_namlen;
1424 #endif
1425 if (namlen != 2 || dirbuf.dotdot_name[0] != '.' ||
1426 dirbuf.dotdot_name[1] != '.')
1427 return (ENOTDIR);
1428 *dd_ino = dirbuf.dotdot_ino;
1429 *dd_vp = NULL;
1430 return (0);
1431 }
1432
1433 /*
1434 * Check if source directory is in the path of the target directory.
1435 */
1436 int
1437 ufs_checkpath(ino_t source_ino, ino_t parent_ino, struct inode *target, struct ucred *cred, ino_t *wait_ino)
1438 {
1439 struct mount *mp;
1440 struct vnode *tvp, *vp, *vp1;
1441 int error;
1442 ino_t dd_ino;
1443
1444 vp = tvp = ITOV(target);
1445 mp = vp->v_mount;
1446 *wait_ino = 0;
1447 if (target->i_number == source_ino)
1448 return (EEXIST);
1449 if (target->i_number == parent_ino)
1450 return (0);
1451 if (target->i_number == UFS_ROOTINO)
1452 return (0);
1453 for (;;) {
1454 error = ufs_dir_dd_ino(vp, cred, &dd_ino, &vp1);
1455 if (error != 0)
1456 break;
1457 if (dd_ino == source_ino) {
1458 error = EINVAL;
1459 break;
1460 }
1461 if (dd_ino == UFS_ROOTINO)
1462 break;
1463 if (dd_ino == parent_ino)
1464 break;
1465 if (vp1 == NULL) {
1466 error = VFS_VGET(mp, dd_ino, LK_SHARED | LK_NOWAIT,
1467 &vp1);
1468 if (error != 0) {
1469 *wait_ino = dd_ino;
1470 break;
1471 }
1472 }
1473 KASSERT(dd_ino == VTOI(vp1)->i_number,
1474 ("directory %ju reparented\n",
1475 (uintmax_t)VTOI(vp1)->i_number));
1476 if (vp != tvp)
1477 vput(vp);
1478 vp = vp1;
1479 }
1480
1481 if (error == ENOTDIR)
1482 panic("checkpath: .. not a directory\n");
1483 if (vp1 != NULL)
1484 vput(vp1);
1485 if (vp != tvp)
1486 vput(vp);
1487 return (error);
1488 }
Cache object: ee5605b5c4f9a65a9db8bdad729a5b78
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