1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #pragma ident "%Z%%M% %I% %E% SMI"
27
28 #include <sys/types.h>
29 #include <sys/param.h>
30 #include <sys/sysmacros.h>
31 #include <sys/systm.h>
32 #include <sys/time.h>
33 #include <sys/vfs.h>
34 #include <sys/vnode.h>
35 #include <sys/errno.h>
36 #include <sys/cmn_err.h>
37 #include <sys/cred.h>
38 #include <sys/stat.h>
39 #include <sys/debug.h>
40 #include <sys/policy.h>
41 #include <sys/fs/tmpnode.h>
42 #include <sys/fs/tmp.h>
43 #include <sys/vtrace.h>
44
45 static int tdircheckpath(struct tmpnode *, struct tmpnode *, struct cred *);
46 static int tdirrename(struct tmpnode *, struct tmpnode *, struct tmpnode *,
47 char *, struct tmpnode *, struct tdirent *, struct cred *);
48 static void tdirfixdotdot(struct tmpnode *, struct tmpnode *, struct tmpnode *);
49 static int tdirmaketnode(struct tmpnode *, struct tmount *, struct vattr *,
50 enum de_op, struct tmpnode **, struct cred *);
51 static int tdiraddentry(struct tmpnode *, struct tmpnode *, char *,
52 enum de_op, struct tmpnode *);
53
54
55 #define T_HASH_SIZE 8192 /* must be power of 2 */
56 #define T_MUTEX_SIZE 64
57
58 static struct tdirent *t_hashtable[T_HASH_SIZE];
59 static kmutex_t t_hashmutex[T_MUTEX_SIZE];
60
61 #define T_HASH_INDEX(a) ((a) & (T_HASH_SIZE-1))
62 #define T_MUTEX_INDEX(a) ((a) & (T_MUTEX_SIZE-1))
63
64 #define TMPFS_HASH(tp, name, hash) \
65 { \
66 char Xc, *Xcp; \
67 hash = (uint_t)(uintptr_t)(tp) >> 8; \
68 for (Xcp = (name); (Xc = *Xcp) != 0; Xcp++) \
69 hash = (hash << 4) + hash + (uint_t)Xc; \
70 }
71
72 void
73 tmpfs_hash_init(void)
74 {
75 int ix;
76
77 for (ix = 0; ix < T_MUTEX_SIZE; ix++)
78 mutex_init(&t_hashmutex[ix], NULL, MUTEX_DEFAULT, NULL);
79 }
80
81 /*
82 * This routine is where the rubber meets the road for identities.
83 */
84 static void
85 tmpfs_hash_in(struct tdirent *t)
86 {
87 uint_t hash;
88 struct tdirent **prevpp;
89 kmutex_t *t_hmtx;
90
91 TMPFS_HASH(t->td_parent, t->td_name, hash);
92 t->td_hash = hash;
93 prevpp = &t_hashtable[T_HASH_INDEX(hash)];
94 t_hmtx = &t_hashmutex[T_MUTEX_INDEX(hash)];
95 mutex_enter(t_hmtx);
96 t->td_link = *prevpp;
97 *prevpp = t;
98 mutex_exit(t_hmtx);
99 }
100
101 /*
102 * Remove tdirent *t from the hash list.
103 */
104 static void
105 tmpfs_hash_out(struct tdirent *t)
106 {
107 uint_t hash;
108 struct tdirent **prevpp;
109 kmutex_t *t_hmtx;
110
111 hash = t->td_hash;
112 prevpp = &t_hashtable[T_HASH_INDEX(hash)];
113 t_hmtx = &t_hashmutex[T_MUTEX_INDEX(hash)];
114 mutex_enter(t_hmtx);
115 while (*prevpp != t)
116 prevpp = &(*prevpp)->td_link;
117 *prevpp = t->td_link;
118 mutex_exit(t_hmtx);
119 }
120
121 /*
122 * Currently called by tdirrename() only.
123 * rename operation needs to be done with lock held, to ensure that
124 * no other operations can access the tmpnode at the same instance.
125 */
126 static void
127 tmpfs_hash_change(struct tdirent *tdp, struct tmpnode *fromtp)
128 {
129 uint_t hash;
130 kmutex_t *t_hmtx;
131
132 hash = tdp->td_hash;
133 t_hmtx = &t_hashmutex[T_MUTEX_INDEX(hash)];
134 mutex_enter(t_hmtx);
135 tdp->td_tmpnode = fromtp;
136 mutex_exit(t_hmtx);
137 }
138
139 static struct tdirent *
140 tmpfs_hash_lookup(char *name, struct tmpnode *parent, uint_t hold,
141 struct tmpnode **found)
142 {
143 struct tdirent *l;
144 uint_t hash;
145 kmutex_t *t_hmtx;
146 struct tmpnode *tnp;
147
148 TMPFS_HASH(parent, name, hash);
149 t_hmtx = &t_hashmutex[T_MUTEX_INDEX(hash)];
150 mutex_enter(t_hmtx);
151 l = t_hashtable[T_HASH_INDEX(hash)];
152 while (l) {
153 if ((l->td_hash == hash) &&
154 (l->td_parent == parent) &&
155 (strcmp(l->td_name, name) == 0)) {
156 /*
157 * We need to make sure that the tmpnode that
158 * we put a hold on is the same one that we pass back.
159 * Hence, temporary variable tnp is necessary.
160 */
161 tnp = l->td_tmpnode;
162 if (hold) {
163 ASSERT(tnp);
164 tmpnode_hold(tnp);
165 }
166 if (found)
167 *found = tnp;
168 mutex_exit(t_hmtx);
169 return (l);
170 } else {
171 l = l->td_link;
172 }
173 }
174 mutex_exit(t_hmtx);
175 return (NULL);
176 }
177
178 /*
179 * Search directory 'parent' for entry 'name'.
180 *
181 * The calling thread can't hold the write version
182 * of the rwlock for the directory being searched
183 *
184 * 0 is returned on success and *foundtp points
185 * to the found tmpnode with its vnode held.
186 */
187 int
188 tdirlookup(
189 struct tmpnode *parent,
190 char *name,
191 struct tmpnode **foundtp,
192 struct cred *cred)
193 {
194 int error;
195
196 *foundtp = NULL;
197 if (parent->tn_type != VDIR)
198 return (ENOTDIR);
199
200 if ((error = tmp_taccess(parent, VEXEC, cred)))
201 return (error);
202
203 if (*name == '\0') {
204 tmpnode_hold(parent);
205 *foundtp = parent;
206 return (0);
207 }
208
209 /*
210 * Search the directory for the matching name
211 * We need the lock protecting the tn_dir list
212 * so that it doesn't change out from underneath us.
213 * tmpfs_hash_lookup() will pass back the tmpnode
214 * with a hold on it.
215 */
216
217 if (tmpfs_hash_lookup(name, parent, 1, foundtp) != NULL) {
218 ASSERT(*foundtp);
219 return (0);
220 }
221
222 return (ENOENT);
223 }
224
225 /*
226 * Enter a directory entry for 'name' and 'tp' into directory 'dir'
227 *
228 * Returns 0 on success.
229 */
230 int
231 tdirenter(
232 struct tmount *tm,
233 struct tmpnode *dir, /* target directory to make entry in */
234 char *name, /* name of entry */
235 enum de_op op, /* entry operation */
236 struct tmpnode *fromparent, /* source directory if rename */
237 struct tmpnode *tp, /* source tmpnode, if link/rename */
238 struct vattr *va,
239 struct tmpnode **tpp, /* return tmpnode, if create/mkdir */
240 struct cred *cred,
241 caller_context_t *ctp)
242 {
243 struct tdirent *tdp;
244 struct tmpnode *found = NULL;
245 int error = 0;
246 char *s;
247
248 /*
249 * tn_rwlock is held to serialize direnter and dirdeletes
250 */
251 ASSERT(RW_WRITE_HELD(&dir->tn_rwlock));
252 ASSERT(dir->tn_type == VDIR);
253
254 /*
255 * Don't allow '/' characters in pathname component
256 * (thus in ufs_direnter()).
257 */
258 for (s = name; *s; s++)
259 if (*s == '/')
260 return (EACCES);
261
262 if (name[0] == '\0')
263 panic("tdirenter: NULL name");
264
265 /*
266 * For link and rename lock the source entry and check the link count
267 * to see if it has been removed while it was unlocked.
268 */
269 if (op == DE_LINK || op == DE_RENAME) {
270 if (tp != dir)
271 rw_enter(&tp->tn_rwlock, RW_WRITER);
272 mutex_enter(&tp->tn_tlock);
273 if (tp->tn_nlink == 0) {
274 mutex_exit(&tp->tn_tlock);
275 if (tp != dir)
276 rw_exit(&tp->tn_rwlock);
277 return (ENOENT);
278 }
279
280 if (tp->tn_nlink == MAXLINK) {
281 mutex_exit(&tp->tn_tlock);
282 if (tp != dir)
283 rw_exit(&tp->tn_rwlock);
284 return (EMLINK);
285 }
286 tp->tn_nlink++;
287 gethrestime(&tp->tn_ctime);
288 mutex_exit(&tp->tn_tlock);
289 if (tp != dir)
290 rw_exit(&tp->tn_rwlock);
291 }
292
293 /*
294 * This might be a "dangling detached directory".
295 * it could have been removed, but a reference
296 * to it kept in u_cwd. don't bother searching
297 * it, and with any luck the user will get tired
298 * of dealing with us and cd to some absolute
299 * pathway. *sigh*, thus in ufs, too.
300 */
301 if (dir->tn_nlink == 0) {
302 error = ENOENT;
303 goto out;
304 }
305
306 /*
307 * If this is a rename of a directory and the parent is
308 * different (".." must be changed), then the source
309 * directory must not be in the directory hierarchy
310 * above the target, as this would orphan everything
311 * below the source directory.
312 */
313 if (op == DE_RENAME) {
314 if (tp == dir) {
315 error = EINVAL;
316 goto out;
317 }
318 if (tp->tn_type == VDIR) {
319 if ((fromparent != dir) &&
320 (error = tdircheckpath(tp, dir, cred))) {
321 goto out;
322 }
323 }
324 }
325
326 /*
327 * Search for the entry. Return "found" if it exists.
328 */
329 tdp = tmpfs_hash_lookup(name, dir, 1, &found);
330
331 if (tdp) {
332 ASSERT(found);
333 switch (op) {
334 case DE_CREATE:
335 case DE_MKDIR:
336 if (tpp) {
337 *tpp = found;
338 error = EEXIST;
339 } else {
340 tmpnode_rele(found);
341 }
342 break;
343
344 case DE_RENAME:
345 error = tdirrename(fromparent, tp,
346 dir, name, found, tdp, cred);
347 if (error == 0) {
348 if (found != NULL) {
349 vnevent_rename_dest(TNTOV(found),
350 TNTOV(dir), name, ctp);
351 }
352 }
353
354 tmpnode_rele(found);
355 break;
356
357 case DE_LINK:
358 /*
359 * Can't link to an existing file.
360 */
361 error = EEXIST;
362 tmpnode_rele(found);
363 break;
364 }
365 } else {
366
367 /*
368 * The entry does not exist. Check write permission in
369 * directory to see if entry can be created.
370 */
371 if (error = tmp_taccess(dir, VWRITE, cred))
372 goto out;
373 if (op == DE_CREATE || op == DE_MKDIR) {
374 /*
375 * Make new tmpnode and directory entry as required.
376 */
377 error = tdirmaketnode(dir, tm, va, op, &tp, cred);
378 if (error)
379 goto out;
380 }
381 if (error = tdiraddentry(dir, tp, name, op, fromparent)) {
382 if (op == DE_CREATE || op == DE_MKDIR) {
383 /*
384 * Unmake the inode we just made.
385 */
386 rw_enter(&tp->tn_rwlock, RW_WRITER);
387 if ((tp->tn_type) == VDIR) {
388 ASSERT(tdp == NULL);
389 /*
390 * cleanup allocs made by tdirinit()
391 */
392 tdirtrunc(tp);
393 }
394 mutex_enter(&tp->tn_tlock);
395 tp->tn_nlink = 0;
396 mutex_exit(&tp->tn_tlock);
397 gethrestime(&tp->tn_ctime);
398 rw_exit(&tp->tn_rwlock);
399 tmpnode_rele(tp);
400 tp = NULL;
401 }
402 } else if (tpp) {
403 *tpp = tp;
404 } else if (op == DE_CREATE || op == DE_MKDIR) {
405 tmpnode_rele(tp);
406 }
407 }
408
409 out:
410 if (error && (op == DE_LINK || op == DE_RENAME)) {
411 /*
412 * Undo bumped link count.
413 */
414 DECR_COUNT(&tp->tn_nlink, &tp->tn_tlock);
415 gethrestime(&tp->tn_ctime);
416 }
417 return (error);
418 }
419
420 /*
421 * Delete entry tp of name "nm" from dir.
422 * Free dir entry space and decrement link count on tmpnode(s).
423 *
424 * Return 0 on success.
425 */
426 int
427 tdirdelete(
428 struct tmpnode *dir,
429 struct tmpnode *tp,
430 char *nm,
431 enum dr_op op,
432 struct cred *cred)
433 {
434 struct tdirent *tpdp;
435 int error;
436 size_t namelen;
437 struct tmpnode *tnp;
438 timestruc_t now;
439
440 ASSERT(RW_WRITE_HELD(&dir->tn_rwlock));
441 ASSERT(RW_WRITE_HELD(&tp->tn_rwlock));
442 ASSERT(dir->tn_type == VDIR);
443
444 if (nm[0] == '\0')
445 panic("tdirdelete: NULL name for %p", (void *)tp);
446
447 /*
448 * return error when removing . and ..
449 */
450 if (nm[0] == '.') {
451 if (nm[1] == '\0')
452 return (EINVAL);
453 if (nm[1] == '.' && nm[2] == '\0')
454 return (EEXIST); /* thus in ufs */
455 }
456
457 if (error = tmp_taccess(dir, VEXEC|VWRITE, cred))
458 return (error);
459
460 /*
461 * If the parent directory is "sticky", then the user must
462 * own the parent directory or the file in it, or else must
463 * have permission to write the file. Otherwise it may not
464 * be deleted (except by privileged users).
465 * Same as ufs_dirremove.
466 */
467 if ((error = tmp_sticky_remove_access(dir, tp, cred)) != 0)
468 return (error);
469
470 if (dir->tn_dir == NULL)
471 return (ENOENT);
472
473 tpdp = tmpfs_hash_lookup(nm, dir, 0, &tnp);
474 if (tpdp == NULL) {
475 /*
476 * If it is gone, some other thread got here first!
477 * Return error ENOENT.
478 */
479 return (ENOENT);
480 }
481
482 /*
483 * If the tmpnode in the tdirent changed, we were probably
484 * the victim of a concurrent rename operation. The original
485 * is gone, so return that status (same as UFS).
486 */
487 if (tp != tnp)
488 return (ENOENT);
489
490 tmpfs_hash_out(tpdp);
491
492 /*
493 * Take tpdp out of the directory list.
494 */
495 ASSERT(tpdp->td_next != tpdp);
496 ASSERT(tpdp->td_prev != tpdp);
497 if (tpdp->td_prev) {
498 tpdp->td_prev->td_next = tpdp->td_next;
499 }
500 if (tpdp->td_next) {
501 tpdp->td_next->td_prev = tpdp->td_prev;
502 }
503
504 /*
505 * If the roving slot pointer happens to match tpdp,
506 * point it at the previous dirent.
507 */
508 if (dir->tn_dir->td_prev == tpdp) {
509 dir->tn_dir->td_prev = tpdp->td_prev;
510 }
511 ASSERT(tpdp->td_next != tpdp);
512 ASSERT(tpdp->td_prev != tpdp);
513
514 /*
515 * tpdp points to the correct directory entry
516 */
517 namelen = strlen(tpdp->td_name) + 1;
518
519 tmp_memfree(tpdp, sizeof (struct tdirent) + namelen);
520 dir->tn_size -= (sizeof (struct tdirent) + namelen);
521 dir->tn_dirents--;
522
523 gethrestime(&now);
524 dir->tn_mtime = now;
525 dir->tn_ctime = now;
526 tp->tn_ctime = now;
527
528 ASSERT(tp->tn_nlink > 0);
529 DECR_COUNT(&tp->tn_nlink, &tp->tn_tlock);
530 if (op == DR_RMDIR && tp->tn_type == VDIR) {
531 tdirtrunc(tp);
532 ASSERT(tp->tn_nlink == 0);
533 }
534 return (0);
535 }
536
537 /*
538 * tdirinit is used internally to initialize a directory (dir)
539 * with '.' and '..' entries without checking permissions and locking
540 */
541 void
542 tdirinit(
543 struct tmpnode *parent, /* parent of directory to initialize */
544 struct tmpnode *dir) /* the new directory */
545 {
546 struct tdirent *dot, *dotdot;
547 timestruc_t now;
548
549 ASSERT(RW_WRITE_HELD(&parent->tn_rwlock));
550 ASSERT(dir->tn_type == VDIR);
551
552 dot = tmp_memalloc(sizeof (struct tdirent) + 2, TMP_MUSTHAVE);
553 dotdot = tmp_memalloc(sizeof (struct tdirent) + 3, TMP_MUSTHAVE);
554
555 /*
556 * Initialize the entries
557 */
558 dot->td_tmpnode = dir;
559 dot->td_offset = 0;
560 dot->td_name = (char *)dot + sizeof (struct tdirent);
561 dot->td_name[0] = '.';
562 dot->td_parent = dir;
563 tmpfs_hash_in(dot);
564
565 dotdot->td_tmpnode = parent;
566 dotdot->td_offset = 1;
567 dotdot->td_name = (char *)dotdot + sizeof (struct tdirent);
568 dotdot->td_name[0] = '.';
569 dotdot->td_name[1] = '.';
570 dotdot->td_parent = dir;
571 tmpfs_hash_in(dotdot);
572
573 /*
574 * Initialize directory entry list.
575 */
576 dot->td_next = dotdot;
577 dot->td_prev = dotdot; /* dot's td_prev holds roving slot pointer */
578 dotdot->td_next = NULL;
579 dotdot->td_prev = dot;
580
581 gethrestime(&now);
582 dir->tn_mtime = now;
583 dir->tn_ctime = now;
584
585 /*
586 * Link counts are special for the hidden attribute directory.
587 * The only explicit reference in the name space is "." and
588 * the reference through ".." is not counted on the parent
589 * file. The attrdir is created as a side effect to lookup,
590 * so don't change the ctime of the parent.
591 * Since tdirinit is called with both dir and parent being the
592 * same for the root vnode, we need to increment this before we set
593 * tn_nlink = 2 below.
594 */
595 if (!(dir->tn_vnode->v_flag & V_XATTRDIR)) {
596 INCR_COUNT(&parent->tn_nlink, &parent->tn_tlock);
597 parent->tn_ctime = now;
598 }
599
600 dir->tn_dir = dot;
601 dir->tn_size = 2 * sizeof (struct tdirent) + 5; /* dot and dotdot */
602 dir->tn_dirents = 2;
603 dir->tn_nlink = 2;
604 }
605
606
607 /*
608 * tdirtrunc is called to remove all directory entries under this directory.
609 */
610 void
611 tdirtrunc(struct tmpnode *dir)
612 {
613 struct tdirent *tdp;
614 struct tmpnode *tp;
615 size_t namelen;
616 timestruc_t now;
617 int isvattrdir, isdotdot, skip_decr;
618
619 ASSERT(RW_WRITE_HELD(&dir->tn_rwlock));
620 ASSERT(dir->tn_type == VDIR);
621
622 isvattrdir = (dir->tn_vnode->v_flag & V_XATTRDIR) ? 1 : 0;
623 for (tdp = dir->tn_dir; tdp; tdp = dir->tn_dir) {
624 ASSERT(tdp->td_next != tdp);
625 ASSERT(tdp->td_prev != tdp);
626 ASSERT(tdp->td_tmpnode);
627
628 dir->tn_dir = tdp->td_next;
629 namelen = strlen(tdp->td_name) + 1;
630
631 /*
632 * Adjust the link counts to account for this directory
633 * entry removal. Hidden attribute directories may
634 * not be empty as they may be truncated as a side-
635 * effect of removing the parent. We do hold/rele
636 * operations to free up these tmpnodes.
637 *
638 * Skip the link count adjustment for parents of
639 * attribute directories as those link counts
640 * do not include the ".." reference in the hidden
641 * directories.
642 */
643 tp = tdp->td_tmpnode;
644 isdotdot = (strcmp("..", tdp->td_name) == 0);
645 skip_decr = (isvattrdir && isdotdot);
646 if (!skip_decr) {
647 ASSERT(tp->tn_nlink > 0);
648 DECR_COUNT(&tp->tn_nlink, &tp->tn_tlock);
649 }
650
651 tmpfs_hash_out(tdp);
652
653 tmp_memfree(tdp, sizeof (struct tdirent) + namelen);
654 dir->tn_size -= (sizeof (struct tdirent) + namelen);
655 dir->tn_dirents--;
656 }
657
658 gethrestime(&now);
659 dir->tn_mtime = now;
660 dir->tn_ctime = now;
661
662 ASSERT(dir->tn_dir == NULL);
663 ASSERT(dir->tn_size == 0);
664 ASSERT(dir->tn_dirents == 0);
665 }
666
667 /*
668 * Check if the source directory is in the path of the target directory.
669 * The target directory is locked by the caller.
670 *
671 * XXX - The source and target's should be different upon entry.
672 */
673 static int
674 tdircheckpath(
675 struct tmpnode *fromtp,
676 struct tmpnode *toparent,
677 struct cred *cred)
678 {
679 int error = 0;
680 struct tmpnode *dir, *dotdot;
681 struct tdirent *tdp;
682
683 ASSERT(RW_WRITE_HELD(&toparent->tn_rwlock));
684
685 tdp = tmpfs_hash_lookup("..", toparent, 1, &dotdot);
686 if (tdp == NULL)
687 return (ENOENT);
688
689 ASSERT(dotdot);
690
691 if (dotdot == toparent) {
692 /* root of fs. search trivially satisfied. */
693 tmpnode_rele(dotdot);
694 return (0);
695 }
696 for (;;) {
697 /*
698 * Return error for cases like "mv c c/d",
699 * "mv c c/d/e" and so on.
700 */
701 if (dotdot == fromtp) {
702 tmpnode_rele(dotdot);
703 error = EINVAL;
704 break;
705 }
706 dir = dotdot;
707 error = tdirlookup(dir, "..", &dotdot, cred);
708 if (error) {
709 tmpnode_rele(dir);
710 break;
711 }
712 /*
713 * We're okay if we traverse the directory tree up to
714 * the root directory and don't run into the
715 * parent directory.
716 */
717 if (dir == dotdot) {
718 tmpnode_rele(dir);
719 tmpnode_rele(dotdot);
720 break;
721 }
722 tmpnode_rele(dir);
723 }
724 return (error);
725 }
726
727 static int
728 tdirrename(
729 struct tmpnode *fromparent, /* parent directory of source */
730 struct tmpnode *fromtp, /* source tmpnode */
731 struct tmpnode *toparent, /* parent directory of target */
732 char *nm, /* entry we are trying to change */
733 struct tmpnode *to, /* target tmpnode */
734 struct tdirent *where, /* target tmpnode directory entry */
735 struct cred *cred) /* credentials */
736 {
737 int error = 0;
738 int doingdirectory;
739 timestruc_t now;
740
741 #if defined(lint)
742 nm = nm;
743 #endif
744 ASSERT(RW_WRITE_HELD(&toparent->tn_rwlock));
745
746 /*
747 * Short circuit rename of something to itself.
748 */
749 if (fromtp == to)
750 return (ESAME); /* special KLUDGE error code */
751
752 rw_enter(&fromtp->tn_rwlock, RW_READER);
753 rw_enter(&to->tn_rwlock, RW_READER);
754
755 /*
756 * Check that everything is on the same filesystem.
757 */
758 if (to->tn_vnode->v_vfsp != toparent->tn_vnode->v_vfsp ||
759 to->tn_vnode->v_vfsp != fromtp->tn_vnode->v_vfsp) {
760 error = EXDEV;
761 goto out;
762 }
763
764 /*
765 * Must have write permission to rewrite target entry.
766 * Check for stickyness.
767 */
768 if ((error = tmp_taccess(toparent, VWRITE, cred)) != 0 ||
769 (error = tmp_sticky_remove_access(toparent, to, cred)) != 0)
770 goto out;
771
772 /*
773 * Ensure source and target are compatible (both directories
774 * or both not directories). If target is a directory it must
775 * be empty and have no links to it; in addition it must not
776 * be a mount point, and both the source and target must be
777 * writable.
778 */
779 doingdirectory = (fromtp->tn_type == VDIR);
780 if (to->tn_type == VDIR) {
781 if (!doingdirectory) {
782 error = EISDIR;
783 goto out;
784 }
785 /*
786 * vn_vfswlock will prevent mounts from using the directory
787 * until we are done.
788 */
789 if (vn_vfswlock(TNTOV(to))) {
790 error = EBUSY;
791 goto out;
792 }
793 if (vn_mountedvfs(TNTOV(to)) != NULL) {
794 vn_vfsunlock(TNTOV(to));
795 error = EBUSY;
796 goto out;
797 }
798
799 mutex_enter(&to->tn_tlock);
800 if (to->tn_dirents > 2 || to->tn_nlink > 2) {
801 mutex_exit(&to->tn_tlock);
802 vn_vfsunlock(TNTOV(to));
803 error = EEXIST; /* SIGH should be ENOTEMPTY */
804 /*
805 * Update atime because checking tn_dirents is
806 * logically equivalent to reading the directory
807 */
808 gethrestime(&to->tn_atime);
809 goto out;
810 }
811 mutex_exit(&to->tn_tlock);
812 } else if (doingdirectory) {
813 error = ENOTDIR;
814 goto out;
815 }
816
817 tmpfs_hash_change(where, fromtp);
818 gethrestime(&now);
819 toparent->tn_mtime = now;
820 toparent->tn_ctime = now;
821
822 /*
823 * Upgrade to write lock on "to" (i.e., the target tmpnode).
824 */
825 rw_exit(&to->tn_rwlock);
826 rw_enter(&to->tn_rwlock, RW_WRITER);
827
828 /*
829 * Decrement the link count of the target tmpnode.
830 */
831 DECR_COUNT(&to->tn_nlink, &to->tn_tlock);
832 to->tn_ctime = now;
833
834 if (doingdirectory) {
835 /*
836 * The entry for "to" no longer exists so release the vfslock.
837 */
838 vn_vfsunlock(TNTOV(to));
839
840 /*
841 * Decrement the target link count and delete all entires.
842 */
843 tdirtrunc(to);
844 ASSERT(to->tn_nlink == 0);
845
846 /*
847 * Renaming a directory with the parent different
848 * requires that ".." be rewritten. The window is
849 * still there for ".." to be inconsistent, but this
850 * is unavoidable, and a lot shorter than when it was
851 * done in a user process.
852 */
853 if (fromparent != toparent)
854 tdirfixdotdot(fromtp, fromparent, toparent);
855 }
856 out:
857 rw_exit(&to->tn_rwlock);
858 rw_exit(&fromtp->tn_rwlock);
859 return (error);
860 }
861
862 static void
863 tdirfixdotdot(
864 struct tmpnode *fromtp, /* child directory */
865 struct tmpnode *fromparent, /* old parent directory */
866 struct tmpnode *toparent) /* new parent directory */
867 {
868 struct tdirent *dotdot;
869
870 ASSERT(RW_LOCK_HELD(&toparent->tn_rwlock));
871
872 /*
873 * Increment the link count in the new parent tmpnode
874 */
875 INCR_COUNT(&toparent->tn_nlink, &toparent->tn_tlock);
876 gethrestime(&toparent->tn_ctime);
877
878 dotdot = tmpfs_hash_lookup("..", fromtp, 0, NULL);
879
880 ASSERT(dotdot->td_tmpnode == fromparent);
881 dotdot->td_tmpnode = toparent;
882
883 /*
884 * Decrement the link count of the old parent tmpnode.
885 * If fromparent is NULL, then this is a new directory link;
886 * it has no parent, so we need not do anything.
887 */
888 if (fromparent != NULL) {
889 mutex_enter(&fromparent->tn_tlock);
890 if (fromparent->tn_nlink != 0) {
891 fromparent->tn_nlink--;
892 gethrestime(&fromparent->tn_ctime);
893 }
894 mutex_exit(&fromparent->tn_tlock);
895 }
896 }
897
898 static int
899 tdiraddentry(
900 struct tmpnode *dir, /* target directory to make entry in */
901 struct tmpnode *tp, /* new tmpnode */
902 char *name,
903 enum de_op op,
904 struct tmpnode *fromtp)
905 {
906 struct tdirent *tdp, *tpdp;
907 size_t namelen, alloc_size;
908 timestruc_t now;
909
910 /*
911 * Make sure the parent directory wasn't removed from
912 * underneath the caller.
913 */
914 if (dir->tn_dir == NULL)
915 return (ENOENT);
916
917 /*
918 * Check that everything is on the same filesystem.
919 */
920 if (tp->tn_vnode->v_vfsp != dir->tn_vnode->v_vfsp)
921 return (EXDEV);
922
923 /*
924 * Allocate and initialize directory entry
925 */
926 namelen = strlen(name) + 1;
927 alloc_size = namelen + sizeof (struct tdirent);
928 tdp = tmp_memalloc(alloc_size, 0);
929 if (tdp == NULL)
930 return (ENOSPC);
931
932 if ((op == DE_RENAME) && (tp->tn_type == VDIR))
933 tdirfixdotdot(tp, fromtp, dir);
934
935 dir->tn_size += alloc_size;
936 dir->tn_dirents++;
937 tdp->td_tmpnode = tp;
938 tdp->td_parent = dir;
939
940 /*
941 * The directory entry and its name were allocated sequentially.
942 */
943 tdp->td_name = (char *)tdp + sizeof (struct tdirent);
944 (void) strcpy(tdp->td_name, name);
945
946 tmpfs_hash_in(tdp);
947
948 /*
949 * Some utilities expect the size of a directory to remain
950 * somewhat static. For example, a routine which unlinks
951 * files between calls to readdir(); the size of the
952 * directory changes from underneath it and so the real
953 * directory offset in bytes is invalid. To circumvent
954 * this problem, we initialize a directory entry with an
955 * phony offset, and use this offset to determine end of
956 * file in tmp_readdir.
957 */
958 tpdp = dir->tn_dir->td_prev;
959 /*
960 * Install at first empty "slot" in directory list.
961 */
962 while (tpdp->td_next != NULL && (tpdp->td_next->td_offset -
963 tpdp->td_offset) <= 1) {
964 ASSERT(tpdp->td_next != tpdp);
965 ASSERT(tpdp->td_prev != tpdp);
966 ASSERT(tpdp->td_next->td_offset > tpdp->td_offset);
967 tpdp = tpdp->td_next;
968 }
969 tdp->td_offset = tpdp->td_offset + 1;
970
971 /*
972 * If we're at the end of the dirent list and the offset (which
973 * is necessarily the largest offset in this directory) is more
974 * than twice the number of dirents, that means the directory is
975 * 50% holes. At this point we reset the slot pointer back to
976 * the beginning of the directory so we start using the holes.
977 * The idea is that if there are N dirents, there must also be
978 * N holes, so we can satisfy the next N creates by walking at
979 * most 2N entries; thus the average cost of a create is constant.
980 * Note that we use the first dirent's td_prev as the roving
981 * slot pointer; it's ugly, but it saves a word in every dirent.
982 */
983 if (tpdp->td_next == NULL && tpdp->td_offset > 2 * dir->tn_dirents)
984 dir->tn_dir->td_prev = dir->tn_dir->td_next;
985 else
986 dir->tn_dir->td_prev = tdp;
987
988 ASSERT(tpdp->td_next != tpdp);
989 ASSERT(tpdp->td_prev != tpdp);
990
991 tdp->td_next = tpdp->td_next;
992 if (tdp->td_next) {
993 tdp->td_next->td_prev = tdp;
994 }
995 tdp->td_prev = tpdp;
996 tpdp->td_next = tdp;
997
998 ASSERT(tdp->td_next != tdp);
999 ASSERT(tdp->td_prev != tdp);
1000 ASSERT(tpdp->td_next != tpdp);
1001 ASSERT(tpdp->td_prev != tpdp);
1002
1003 gethrestime(&now);
1004 dir->tn_mtime = now;
1005 dir->tn_ctime = now;
1006
1007 return (0);
1008 }
1009
1010 static int
1011 tdirmaketnode(
1012 struct tmpnode *dir,
1013 struct tmount *tm,
1014 struct vattr *va,
1015 enum de_op op,
1016 struct tmpnode **newnode,
1017 struct cred *cred)
1018 {
1019 struct tmpnode *tp;
1020 enum vtype type;
1021
1022 ASSERT(va != NULL);
1023 ASSERT(op == DE_CREATE || op == DE_MKDIR);
1024 if (((va->va_mask & AT_ATIME) && TIMESPEC_OVERFLOW(&va->va_atime)) ||
1025 ((va->va_mask & AT_MTIME) && TIMESPEC_OVERFLOW(&va->va_mtime)))
1026 return (EOVERFLOW);
1027 type = va->va_type;
1028 tp = tmp_memalloc(sizeof (struct tmpnode), TMP_MUSTHAVE);
1029 tmpnode_init(tm, tp, va, cred);
1030
1031 /* setup normal file/dir's extended attribute directory */
1032 if (dir->tn_flags & ISXATTR) {
1033 /* parent dir is , mark file as xattr */
1034 tp->tn_flags |= ISXATTR;
1035 }
1036
1037
1038 if (type == VBLK || type == VCHR) {
1039 tp->tn_vnode->v_rdev = tp->tn_rdev = va->va_rdev;
1040 } else {
1041 tp->tn_vnode->v_rdev = tp->tn_rdev = NODEV;
1042 }
1043 tp->tn_vnode->v_type = type;
1044 tp->tn_uid = crgetuid(cred);
1045
1046 /*
1047 * To determine the group-id of the created file:
1048 * 1) If the gid is set in the attribute list (non-Sun & pre-4.0
1049 * clients are not likely to set the gid), then use it if
1050 * the process is privileged, belongs to the target group,
1051 * or the group is the same as the parent directory.
1052 * 2) If the filesystem was not mounted with the Old-BSD-compatible
1053 * GRPID option, and the directory's set-gid bit is clear,
1054 * then use the process's gid.
1055 * 3) Otherwise, set the group-id to the gid of the parent directory.
1056 */
1057 if ((va->va_mask & AT_GID) &&
1058 ((va->va_gid == dir->tn_gid) || groupmember(va->va_gid, cred) ||
1059 secpolicy_vnode_create_gid(cred) == 0)) {
1060 /*
1061 * XXX - is this only the case when a 4.0 NFS client, or a
1062 * client derived from that code, makes a call over the wire?
1063 */
1064 tp->tn_gid = va->va_gid;
1065 } else {
1066 if (dir->tn_mode & VSGID)
1067 tp->tn_gid = dir->tn_gid;
1068 else
1069 tp->tn_gid = crgetgid(cred);
1070 }
1071 /*
1072 * If we're creating a directory, and the parent directory has the
1073 * set-GID bit set, set it on the new directory.
1074 * Otherwise, if the user is neither privileged nor a member of the
1075 * file's new group, clear the file's set-GID bit.
1076 */
1077 if (dir->tn_mode & VSGID && type == VDIR)
1078 tp->tn_mode |= VSGID;
1079 else {
1080 if ((tp->tn_mode & VSGID) &&
1081 secpolicy_vnode_setids_setgids(cred, tp->tn_gid) != 0)
1082 tp->tn_mode &= ~VSGID;
1083 }
1084
1085 if (va->va_mask & AT_ATIME)
1086 tp->tn_atime = va->va_atime;
1087 if (va->va_mask & AT_MTIME)
1088 tp->tn_mtime = va->va_mtime;
1089
1090 if (op == DE_MKDIR)
1091 tdirinit(dir, tp);
1092
1093 *newnode = tp;
1094 return (0);
1095 }