1 /*-
2 * Copyright (c) 1994 Jan-Simon Pendry
3 * Copyright (c) 1994
4 * The Regents of the University of California. All rights reserved.
5 * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
6 * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Jan-Simon Pendry.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 * @(#)union_subr.c 8.20 (Berkeley) 5/20/95
36 * $FreeBSD: releng/9.0/sys/fs/unionfs/union_subr.c 211826 2010-08-25 21:32:08Z trasz $
37 */
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/malloc.h>
45 #include <sys/mount.h>
46 #include <sys/namei.h>
47 #include <sys/proc.h>
48 #include <sys/vnode.h>
49 #include <sys/dirent.h>
50 #include <sys/fcntl.h>
51 #include <sys/filedesc.h>
52 #include <sys/stat.h>
53 #include <sys/resourcevar.h>
54
55 #include <security/mac/mac_framework.h>
56
57 #include <vm/uma.h>
58
59 #include <fs/unionfs/union.h>
60
61 #define NUNIONFSNODECACHE 16
62
63 static MALLOC_DEFINE(M_UNIONFSHASH, "UNIONFS hash", "UNIONFS hash table");
64 MALLOC_DEFINE(M_UNIONFSNODE, "UNIONFS node", "UNIONFS vnode private part");
65 MALLOC_DEFINE(M_UNIONFSPATH, "UNIONFS path", "UNIONFS path private part");
66
67 /*
68 * Initialize
69 */
70 int
71 unionfs_init(struct vfsconf *vfsp)
72 {
73 UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */
74 return (0);
75 }
76
77 /*
78 * Uninitialize
79 */
80 int
81 unionfs_uninit(struct vfsconf *vfsp)
82 {
83 return (0);
84 }
85
86 static struct unionfs_node_hashhead *
87 unionfs_get_hashhead(struct vnode *dvp, char *path)
88 {
89 int count;
90 char hash;
91 struct unionfs_node *unp;
92
93 hash = 0;
94 unp = VTOUNIONFS(dvp);
95 if (path != NULL) {
96 for (count = 0; path[count]; count++)
97 hash += path[count];
98 }
99
100 return (&(unp->un_hashtbl[hash & (unp->un_hashmask)]));
101 }
102
103 /*
104 * Get the cached vnode.
105 */
106 static struct vnode *
107 unionfs_get_cached_vnode(struct vnode *uvp, struct vnode *lvp,
108 struct vnode *dvp, char *path)
109 {
110 struct unionfs_node_hashhead *hd;
111 struct unionfs_node *unp;
112 struct vnode *vp;
113
114 KASSERT((uvp == NULLVP || uvp->v_type == VDIR),
115 ("unionfs_get_cached_vnode: v_type != VDIR"));
116 KASSERT((lvp == NULLVP || lvp->v_type == VDIR),
117 ("unionfs_get_cached_vnode: v_type != VDIR"));
118
119 VI_LOCK(dvp);
120 hd = unionfs_get_hashhead(dvp, path);
121 LIST_FOREACH(unp, hd, un_hash) {
122 if (!strcmp(unp->un_path, path)) {
123 vp = UNIONFSTOV(unp);
124 VI_LOCK_FLAGS(vp, MTX_DUPOK);
125 VI_UNLOCK(dvp);
126 vp->v_iflag &= ~VI_OWEINACT;
127 if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) {
128 VI_UNLOCK(vp);
129 vp = NULLVP;
130 } else
131 VI_UNLOCK(vp);
132 return (vp);
133 }
134 }
135 VI_UNLOCK(dvp);
136
137 return (NULLVP);
138 }
139
140 /*
141 * Add the new vnode into cache.
142 */
143 static struct vnode *
144 unionfs_ins_cached_vnode(struct unionfs_node *uncp,
145 struct vnode *dvp, char *path)
146 {
147 struct unionfs_node_hashhead *hd;
148 struct unionfs_node *unp;
149 struct vnode *vp;
150
151 KASSERT((uncp->un_uppervp==NULLVP || uncp->un_uppervp->v_type==VDIR),
152 ("unionfs_ins_cached_vnode: v_type != VDIR"));
153 KASSERT((uncp->un_lowervp==NULLVP || uncp->un_lowervp->v_type==VDIR),
154 ("unionfs_ins_cached_vnode: v_type != VDIR"));
155
156 VI_LOCK(dvp);
157 hd = unionfs_get_hashhead(dvp, path);
158 LIST_FOREACH(unp, hd, un_hash) {
159 if (!strcmp(unp->un_path, path)) {
160 vp = UNIONFSTOV(unp);
161 VI_LOCK_FLAGS(vp, MTX_DUPOK);
162 vp->v_iflag &= ~VI_OWEINACT;
163 if ((vp->v_iflag & (VI_DOOMED | VI_DOINGINACT)) != 0) {
164 LIST_INSERT_HEAD(hd, uncp, un_hash);
165 VI_UNLOCK(vp);
166 vp = NULLVP;
167 } else
168 VI_UNLOCK(vp);
169 VI_UNLOCK(dvp);
170 return (vp);
171 }
172 }
173
174 LIST_INSERT_HEAD(hd, uncp, un_hash);
175 VI_UNLOCK(dvp);
176
177 return (NULLVP);
178 }
179
180 /*
181 * Remove the vnode.
182 */
183 static void
184 unionfs_rem_cached_vnode(struct unionfs_node *unp, struct vnode *dvp)
185 {
186 KASSERT((unp != NULL), ("unionfs_rem_cached_vnode: null node"));
187 KASSERT((dvp != NULLVP),
188 ("unionfs_rem_cached_vnode: null parent vnode"));
189 KASSERT((unp->un_hash.le_prev != NULL),
190 ("unionfs_rem_cached_vnode: null hash"));
191
192 VI_LOCK(dvp);
193 LIST_REMOVE(unp, un_hash);
194 unp->un_hash.le_next = NULL;
195 unp->un_hash.le_prev = NULL;
196 VI_UNLOCK(dvp);
197 }
198
199 /*
200 * Make a new or get existing unionfs node.
201 *
202 * uppervp and lowervp should be unlocked. Because if new unionfs vnode is
203 * locked, uppervp or lowervp is locked too. In order to prevent dead lock,
204 * you should not lock plurality simultaneously.
205 */
206 int
207 unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
208 struct vnode *lowervp, struct vnode *dvp,
209 struct vnode **vpp, struct componentname *cnp,
210 struct thread *td)
211 {
212 struct unionfs_mount *ump;
213 struct unionfs_node *unp;
214 struct vnode *vp;
215 int error;
216 int lkflags;
217 enum vtype vt;
218 char *path;
219
220 ump = MOUNTTOUNIONFSMOUNT(mp);
221 lkflags = (cnp ? cnp->cn_lkflags : 0);
222 path = (cnp ? cnp->cn_nameptr : NULL);
223 *vpp = NULLVP;
224
225 if (uppervp == NULLVP && lowervp == NULLVP)
226 panic("unionfs_nodeget: upper and lower is null");
227
228 vt = (uppervp != NULLVP ? uppervp->v_type : lowervp->v_type);
229
230 /* If it has no ISLASTCN flag, path check is skipped. */
231 if (cnp && !(cnp->cn_flags & ISLASTCN))
232 path = NULL;
233
234 /* check the cache */
235 if (path != NULL && dvp != NULLVP && vt == VDIR) {
236 vp = unionfs_get_cached_vnode(uppervp, lowervp, dvp, path);
237 if (vp != NULLVP) {
238 vref(vp);
239 *vpp = vp;
240 goto unionfs_nodeget_out;
241 }
242 }
243
244 if ((uppervp == NULLVP || ump->um_uppervp != uppervp) ||
245 (lowervp == NULLVP || ump->um_lowervp != lowervp)) {
246 /* dvp will be NULLVP only in case of root vnode. */
247 if (dvp == NULLVP)
248 return (EINVAL);
249 }
250
251 /*
252 * Do the MALLOC before the getnewvnode since doing so afterward
253 * might cause a bogus v_data pointer to get dereferenced elsewhere
254 * if MALLOC should block.
255 */
256 unp = malloc(sizeof(struct unionfs_node),
257 M_UNIONFSNODE, M_WAITOK | M_ZERO);
258
259 error = getnewvnode("unionfs", mp, &unionfs_vnodeops, &vp);
260 if (error != 0) {
261 free(unp, M_UNIONFSNODE);
262 return (error);
263 }
264 error = insmntque(vp, mp); /* XXX: Too early for mpsafe fs */
265 if (error != 0) {
266 free(unp, M_UNIONFSNODE);
267 return (error);
268 }
269 if (dvp != NULLVP)
270 vref(dvp);
271 if (uppervp != NULLVP)
272 vref(uppervp);
273 if (lowervp != NULLVP)
274 vref(lowervp);
275
276 if (vt == VDIR)
277 unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH,
278 &(unp->un_hashmask));
279
280 unp->un_vnode = vp;
281 unp->un_uppervp = uppervp;
282 unp->un_lowervp = lowervp;
283 unp->un_dvp = dvp;
284 if (uppervp != NULLVP)
285 vp->v_vnlock = uppervp->v_vnlock;
286 else
287 vp->v_vnlock = lowervp->v_vnlock;
288
289 if (path != NULL) {
290 unp->un_path = (char *)
291 malloc(cnp->cn_namelen +1, M_UNIONFSPATH, M_WAITOK|M_ZERO);
292 bcopy(cnp->cn_nameptr, unp->un_path, cnp->cn_namelen);
293 unp->un_path[cnp->cn_namelen] = '\0';
294 }
295 vp->v_type = vt;
296 vp->v_data = unp;
297
298 if ((uppervp != NULLVP && ump->um_uppervp == uppervp) &&
299 (lowervp != NULLVP && ump->um_lowervp == lowervp))
300 vp->v_vflag |= VV_ROOT;
301
302 if (path != NULL && dvp != NULLVP && vt == VDIR)
303 *vpp = unionfs_ins_cached_vnode(unp, dvp, path);
304 if ((*vpp) != NULLVP) {
305 if (dvp != NULLVP)
306 vrele(dvp);
307 if (uppervp != NULLVP)
308 vrele(uppervp);
309 if (lowervp != NULLVP)
310 vrele(lowervp);
311
312 unp->un_uppervp = NULLVP;
313 unp->un_lowervp = NULLVP;
314 unp->un_dvp = NULLVP;
315 vrele(vp);
316 vp = *vpp;
317 vref(vp);
318 } else
319 *vpp = vp;
320
321 unionfs_nodeget_out:
322 if (lkflags & LK_TYPE_MASK)
323 vn_lock(vp, lkflags | LK_RETRY);
324
325 return (0);
326 }
327
328 /*
329 * Clean up the unionfs node.
330 */
331 void
332 unionfs_noderem(struct vnode *vp, struct thread *td)
333 {
334 int vfslocked;
335 int count;
336 struct unionfs_node *unp, *unp_t1, *unp_t2;
337 struct unionfs_node_hashhead *hd;
338 struct unionfs_node_status *unsp, *unsp_tmp;
339 struct vnode *lvp;
340 struct vnode *uvp;
341 struct vnode *dvp;
342
343 /*
344 * Use the interlock to protect the clearing of v_data to
345 * prevent faults in unionfs_lock().
346 */
347 VI_LOCK(vp);
348 unp = VTOUNIONFS(vp);
349 lvp = unp->un_lowervp;
350 uvp = unp->un_uppervp;
351 dvp = unp->un_dvp;
352 unp->un_lowervp = unp->un_uppervp = NULLVP;
353
354 vp->v_vnlock = &(vp->v_lock);
355 vp->v_data = NULL;
356 lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_INTERLOCK, VI_MTX(vp));
357 if (lvp != NULLVP)
358 VOP_UNLOCK(lvp, 0);
359 if (uvp != NULLVP)
360 VOP_UNLOCK(uvp, 0);
361 vp->v_object = NULL;
362
363 if (dvp != NULLVP && unp->un_hash.le_prev != NULL)
364 unionfs_rem_cached_vnode(unp, dvp);
365
366 if (lvp != NULLVP) {
367 vfslocked = VFS_LOCK_GIANT(lvp->v_mount);
368 vrele(lvp);
369 VFS_UNLOCK_GIANT(vfslocked);
370 }
371 if (uvp != NULLVP) {
372 vfslocked = VFS_LOCK_GIANT(uvp->v_mount);
373 vrele(uvp);
374 VFS_UNLOCK_GIANT(vfslocked);
375 }
376 if (dvp != NULLVP) {
377 vfslocked = VFS_LOCK_GIANT(dvp->v_mount);
378 vrele(dvp);
379 VFS_UNLOCK_GIANT(vfslocked);
380 unp->un_dvp = NULLVP;
381 }
382 if (unp->un_path != NULL) {
383 free(unp->un_path, M_UNIONFSPATH);
384 unp->un_path = NULL;
385 }
386
387 if (unp->un_hashtbl != NULL) {
388 for (count = 0; count <= unp->un_hashmask; count++) {
389 hd = unp->un_hashtbl + count;
390 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) {
391 LIST_REMOVE(unp_t1, un_hash);
392 unp_t1->un_hash.le_next = NULL;
393 unp_t1->un_hash.le_prev = NULL;
394 }
395 }
396 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask);
397 }
398
399 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) {
400 LIST_REMOVE(unsp, uns_list);
401 free(unsp, M_TEMP);
402 }
403 free(unp, M_UNIONFSNODE);
404 }
405
406 /*
407 * Get the unionfs node status.
408 * You need exclusive lock this vnode.
409 */
410 void
411 unionfs_get_node_status(struct unionfs_node *unp, struct thread *td,
412 struct unionfs_node_status **unspp)
413 {
414 struct unionfs_node_status *unsp;
415 pid_t pid = td->td_proc->p_pid;
416
417 KASSERT(NULL != unspp, ("null pointer"));
418 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status");
419
420 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) {
421 if (unsp->uns_pid == pid) {
422 *unspp = unsp;
423 return;
424 }
425 }
426
427 /* create a new unionfs node status */
428 unsp = malloc(sizeof(struct unionfs_node_status),
429 M_TEMP, M_WAITOK | M_ZERO);
430
431 unsp->uns_pid = pid;
432 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list);
433
434 *unspp = unsp;
435 }
436
437 /*
438 * Remove the unionfs node status, if you can.
439 * You need exclusive lock this vnode.
440 */
441 void
442 unionfs_tryrem_node_status(struct unionfs_node *unp,
443 struct unionfs_node_status *unsp)
444 {
445 KASSERT(NULL != unsp, ("null pointer"));
446 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status");
447
448 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt)
449 return;
450
451 LIST_REMOVE(unsp, uns_list);
452 free(unsp, M_TEMP);
453 }
454
455 /*
456 * Create upper node attr.
457 */
458 void
459 unionfs_create_uppervattr_core(struct unionfs_mount *ump,
460 struct vattr *lva,
461 struct vattr *uva,
462 struct thread *td)
463 {
464 VATTR_NULL(uva);
465 uva->va_type = lva->va_type;
466 uva->va_atime = lva->va_atime;
467 uva->va_mtime = lva->va_mtime;
468 uva->va_ctime = lva->va_ctime;
469
470 switch (ump->um_copymode) {
471 case UNIONFS_TRANSPARENT:
472 uva->va_mode = lva->va_mode;
473 uva->va_uid = lva->va_uid;
474 uva->va_gid = lva->va_gid;
475 break;
476 case UNIONFS_MASQUERADE:
477 if (ump->um_uid == lva->va_uid) {
478 uva->va_mode = lva->va_mode & 077077;
479 uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700;
480 uva->va_uid = lva->va_uid;
481 uva->va_gid = lva->va_gid;
482 } else {
483 uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile);
484 uva->va_uid = ump->um_uid;
485 uva->va_gid = ump->um_gid;
486 }
487 break;
488 default: /* UNIONFS_TRADITIONAL */
489 uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask;
490 uva->va_uid = ump->um_uid;
491 uva->va_gid = ump->um_gid;
492 break;
493 }
494 }
495
496 /*
497 * Create upper node attr.
498 */
499 int
500 unionfs_create_uppervattr(struct unionfs_mount *ump,
501 struct vnode *lvp,
502 struct vattr *uva,
503 struct ucred *cred,
504 struct thread *td)
505 {
506 int error;
507 struct vattr lva;
508
509 if ((error = VOP_GETATTR(lvp, &lva, cred)))
510 return (error);
511
512 unionfs_create_uppervattr_core(ump, &lva, uva, td);
513
514 return (error);
515 }
516
517 /*
518 * relookup
519 *
520 * dvp should be locked on entry and will be locked on return.
521 *
522 * If an error is returned, *vpp will be invalid, otherwise it will hold a
523 * locked, referenced vnode. If *vpp == dvp then remember that only one
524 * LK_EXCLUSIVE lock is held.
525 */
526 int
527 unionfs_relookup(struct vnode *dvp, struct vnode **vpp,
528 struct componentname *cnp, struct componentname *cn,
529 struct thread *td, char *path, int pathlen, u_long nameiop)
530 {
531 int error;
532
533 cn->cn_namelen = pathlen;
534 cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK);
535 bcopy(path, cn->cn_pnbuf, pathlen);
536 cn->cn_pnbuf[pathlen] = '\0';
537
538 cn->cn_nameiop = nameiop;
539 cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN);
540 cn->cn_lkflags = LK_EXCLUSIVE;
541 cn->cn_thread = td;
542 cn->cn_cred = cnp->cn_cred;
543
544 cn->cn_nameptr = cn->cn_pnbuf;
545 cn->cn_consume = cnp->cn_consume;
546
547 if (nameiop == DELETE)
548 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART));
549 else if (RENAME == nameiop)
550 cn->cn_flags |= (cnp->cn_flags & SAVESTART);
551
552 vref(dvp);
553 VOP_UNLOCK(dvp, 0);
554
555 if ((error = relookup(dvp, vpp, cn))) {
556 uma_zfree(namei_zone, cn->cn_pnbuf);
557 cn->cn_flags &= ~HASBUF;
558 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
559 } else
560 vrele(dvp);
561
562 return (error);
563 }
564
565 /*
566 * relookup for CREATE namei operation.
567 *
568 * dvp is unionfs vnode. dvp should be locked.
569 *
570 * If it called 'unionfs_copyfile' function by unionfs_link etc,
571 * VOP_LOOKUP information is broken.
572 * So it need relookup in order to create link etc.
573 */
574 int
575 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp,
576 struct thread *td)
577 {
578 int error;
579 struct vnode *udvp;
580 struct vnode *vp;
581 struct componentname cn;
582
583 udvp = UNIONFSVPTOUPPERVP(dvp);
584 vp = NULLVP;
585
586 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr,
587 strlen(cnp->cn_nameptr), CREATE);
588 if (error)
589 return (error);
590
591 if (vp != NULLVP) {
592 if (udvp == vp)
593 vrele(vp);
594 else
595 vput(vp);
596
597 error = EEXIST;
598 }
599
600 if (cn.cn_flags & HASBUF) {
601 uma_zfree(namei_zone, cn.cn_pnbuf);
602 cn.cn_flags &= ~HASBUF;
603 }
604
605 if (!error) {
606 cn.cn_flags |= (cnp->cn_flags & HASBUF);
607 cnp->cn_flags = cn.cn_flags;
608 }
609
610 return (error);
611 }
612
613 /*
614 * relookup for DELETE namei operation.
615 *
616 * dvp is unionfs vnode. dvp should be locked.
617 */
618 int
619 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp,
620 struct thread *td)
621 {
622 int error;
623 struct vnode *udvp;
624 struct vnode *vp;
625 struct componentname cn;
626
627 udvp = UNIONFSVPTOUPPERVP(dvp);
628 vp = NULLVP;
629
630 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr,
631 strlen(cnp->cn_nameptr), DELETE);
632 if (error)
633 return (error);
634
635 if (vp == NULLVP)
636 error = ENOENT;
637 else {
638 if (udvp == vp)
639 vrele(vp);
640 else
641 vput(vp);
642 }
643
644 if (cn.cn_flags & HASBUF) {
645 uma_zfree(namei_zone, cn.cn_pnbuf);
646 cn.cn_flags &= ~HASBUF;
647 }
648
649 if (!error) {
650 cn.cn_flags |= (cnp->cn_flags & HASBUF);
651 cnp->cn_flags = cn.cn_flags;
652 }
653
654 return (error);
655 }
656
657 /*
658 * relookup for RENAME namei operation.
659 *
660 * dvp is unionfs vnode. dvp should be locked.
661 */
662 int
663 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp,
664 struct thread *td)
665 {
666 int error;
667 struct vnode *udvp;
668 struct vnode *vp;
669 struct componentname cn;
670
671 udvp = UNIONFSVPTOUPPERVP(dvp);
672 vp = NULLVP;
673
674 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr,
675 strlen(cnp->cn_nameptr), RENAME);
676 if (error)
677 return (error);
678
679 if (vp != NULLVP) {
680 if (udvp == vp)
681 vrele(vp);
682 else
683 vput(vp);
684 }
685
686 if (cn.cn_flags & HASBUF) {
687 uma_zfree(namei_zone, cn.cn_pnbuf);
688 cn.cn_flags &= ~HASBUF;
689 }
690
691 if (!error) {
692 cn.cn_flags |= (cnp->cn_flags & HASBUF);
693 cnp->cn_flags = cn.cn_flags;
694 }
695
696 return (error);
697
698 }
699
700 /*
701 * Update the unionfs_node.
702 *
703 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the
704 * uvp's lock and lower's lock will be unlocked.
705 */
706 static void
707 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp,
708 struct thread *td)
709 {
710 unsigned count, lockrec;
711 struct vnode *vp;
712 struct vnode *lvp;
713 struct vnode *dvp;
714
715 vp = UNIONFSTOV(unp);
716 lvp = unp->un_lowervp;
717 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update");
718 dvp = unp->un_dvp;
719
720 /*
721 * lock update
722 */
723 VI_LOCK(vp);
724 unp->un_uppervp = uvp;
725 vp->v_vnlock = uvp->v_vnlock;
726 VI_UNLOCK(vp);
727 lockrec = lvp->v_vnlock->lk_recurse;
728 for (count = 0; count < lockrec; count++)
729 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY);
730
731 /*
732 * cache update
733 */
734 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) {
735 static struct unionfs_node_hashhead *hd;
736
737 VI_LOCK(dvp);
738 hd = unionfs_get_hashhead(dvp, unp->un_path);
739 LIST_REMOVE(unp, un_hash);
740 LIST_INSERT_HEAD(hd, unp, un_hash);
741 VI_UNLOCK(dvp);
742 }
743 }
744
745 /*
746 * Create a new shadow dir.
747 *
748 * udvp should be locked on entry and will be locked on return.
749 *
750 * If no error returned, unp will be updated.
751 */
752 int
753 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp,
754 struct unionfs_node *unp, struct componentname *cnp,
755 struct thread *td)
756 {
757 int error;
758 struct vnode *lvp;
759 struct vnode *uvp;
760 struct vattr va;
761 struct vattr lva;
762 struct componentname cn;
763 struct mount *mp;
764 struct ucred *cred;
765 struct ucred *credbk;
766 struct uidinfo *rootinfo;
767
768 if (unp->un_uppervp != NULLVP)
769 return (EEXIST);
770
771 lvp = unp->un_lowervp;
772 uvp = NULLVP;
773 credbk = cnp->cn_cred;
774
775 /* Authority change to root */
776 rootinfo = uifind((uid_t)0);
777 cred = crdup(cnp->cn_cred);
778 /*
779 * The calls to chgproccnt() are needed to compensate for change_ruid()
780 * calling chgproccnt().
781 */
782 chgproccnt(cred->cr_ruidinfo, 1, 0);
783 change_euid(cred, rootinfo);
784 change_ruid(cred, rootinfo);
785 change_svuid(cred, (uid_t)0);
786 uifree(rootinfo);
787 cnp->cn_cred = cred;
788
789 memset(&cn, 0, sizeof(cn));
790
791 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred)))
792 goto unionfs_mkshadowdir_abort;
793
794 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE)))
795 goto unionfs_mkshadowdir_abort;
796 if (uvp != NULLVP) {
797 if (udvp == uvp)
798 vrele(uvp);
799 else
800 vput(uvp);
801
802 error = EEXIST;
803 goto unionfs_mkshadowdir_free_out;
804 }
805
806 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)))
807 goto unionfs_mkshadowdir_free_out;
808 unionfs_create_uppervattr_core(ump, &lva, &va, td);
809
810 error = VOP_MKDIR(udvp, &uvp, &cn, &va);
811
812 if (!error) {
813 unionfs_node_update(unp, uvp, td);
814
815 /*
816 * XXX The bug which cannot set uid/gid was corrected.
817 * Ignore errors.
818 */
819 va.va_type = VNON;
820 VOP_SETATTR(uvp, &va, cn.cn_cred);
821 }
822 vn_finished_write(mp);
823
824 unionfs_mkshadowdir_free_out:
825 if (cn.cn_flags & HASBUF) {
826 uma_zfree(namei_zone, cn.cn_pnbuf);
827 cn.cn_flags &= ~HASBUF;
828 }
829
830 unionfs_mkshadowdir_abort:
831 cnp->cn_cred = credbk;
832 chgproccnt(cred->cr_ruidinfo, -1, 0);
833 crfree(cred);
834
835 return (error);
836 }
837
838 /*
839 * Create a new whiteout.
840 *
841 * dvp should be locked on entry and will be locked on return.
842 */
843 int
844 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp,
845 struct thread *td, char *path)
846 {
847 int error;
848 struct vnode *wvp;
849 struct componentname cn;
850 struct mount *mp;
851
852 if (path == NULL)
853 path = cnp->cn_nameptr;
854
855 wvp = NULLVP;
856 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE)))
857 return (error);
858 if (wvp != NULLVP) {
859 if (cn.cn_flags & HASBUF) {
860 uma_zfree(namei_zone, cn.cn_pnbuf);
861 cn.cn_flags &= ~HASBUF;
862 }
863 if (dvp == wvp)
864 vrele(wvp);
865 else
866 vput(wvp);
867
868 return (EEXIST);
869 }
870
871 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH)))
872 goto unionfs_mkwhiteout_free_out;
873 error = VOP_WHITEOUT(dvp, &cn, CREATE);
874
875 vn_finished_write(mp);
876
877 unionfs_mkwhiteout_free_out:
878 if (cn.cn_flags & HASBUF) {
879 uma_zfree(namei_zone, cn.cn_pnbuf);
880 cn.cn_flags &= ~HASBUF;
881 }
882
883 return (error);
884 }
885
886 /*
887 * Create a new vnode for create a new shadow file.
888 *
889 * If an error is returned, *vpp will be invalid, otherwise it will hold a
890 * locked, referenced and opened vnode.
891 *
892 * unp is never updated.
893 */
894 static int
895 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp,
896 struct unionfs_node *unp, struct vattr *uvap,
897 struct thread *td)
898 {
899 struct unionfs_mount *ump;
900 struct vnode *vp;
901 struct vnode *lvp;
902 struct ucred *cred;
903 struct vattr lva;
904 int fmode;
905 int error;
906 struct componentname cn;
907
908 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount);
909 vp = NULLVP;
910 lvp = unp->un_lowervp;
911 cred = td->td_ucred;
912 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL);
913 error = 0;
914
915 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0)
916 return (error);
917 unionfs_create_uppervattr_core(ump, &lva, uvap, td);
918
919 if (unp->un_path == NULL)
920 panic("unionfs: un_path is null");
921
922 cn.cn_namelen = strlen(unp->un_path);
923 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK);
924 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1);
925 cn.cn_nameiop = CREATE;
926 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN);
927 cn.cn_lkflags = LK_EXCLUSIVE;
928 cn.cn_thread = td;
929 cn.cn_cred = cred;
930 cn.cn_nameptr = cn.cn_pnbuf;
931 cn.cn_consume = 0;
932
933 vref(udvp);
934 if ((error = relookup(udvp, &vp, &cn)) != 0)
935 goto unionfs_vn_create_on_upper_free_out2;
936 vrele(udvp);
937
938 if (vp != NULLVP) {
939 if (vp == udvp)
940 vrele(vp);
941 else
942 vput(vp);
943 error = EEXIST;
944 goto unionfs_vn_create_on_upper_free_out1;
945 }
946
947 if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0)
948 goto unionfs_vn_create_on_upper_free_out1;
949
950 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) {
951 vput(vp);
952 goto unionfs_vn_create_on_upper_free_out1;
953 }
954 vp->v_writecount++;
955 *vpp = vp;
956
957 unionfs_vn_create_on_upper_free_out1:
958 VOP_UNLOCK(udvp, 0);
959
960 unionfs_vn_create_on_upper_free_out2:
961 if (cn.cn_flags & HASBUF) {
962 uma_zfree(namei_zone, cn.cn_pnbuf);
963 cn.cn_flags &= ~HASBUF;
964 }
965
966 return (error);
967 }
968
969 /*
970 * Copy from lvp to uvp.
971 *
972 * lvp and uvp should be locked and opened on entry and will be locked and
973 * opened on return.
974 */
975 static int
976 unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp,
977 struct ucred *cred, struct thread *td)
978 {
979 int error;
980 off_t offset;
981 int count;
982 int bufoffset;
983 char *buf;
984 struct uio uio;
985 struct iovec iov;
986
987 error = 0;
988 memset(&uio, 0, sizeof(uio));
989
990 uio.uio_td = td;
991 uio.uio_segflg = UIO_SYSSPACE;
992 uio.uio_offset = 0;
993
994 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK);
995
996 while (error == 0) {
997 offset = uio.uio_offset;
998
999 uio.uio_iov = &iov;
1000 uio.uio_iovcnt = 1;
1001 iov.iov_base = buf;
1002 iov.iov_len = MAXBSIZE;
1003 uio.uio_resid = iov.iov_len;
1004 uio.uio_rw = UIO_READ;
1005
1006 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0)
1007 break;
1008 if ((count = MAXBSIZE - uio.uio_resid) == 0)
1009 break;
1010
1011 bufoffset = 0;
1012 while (bufoffset < count) {
1013 uio.uio_iov = &iov;
1014 uio.uio_iovcnt = 1;
1015 iov.iov_base = buf + bufoffset;
1016 iov.iov_len = count - bufoffset;
1017 uio.uio_offset = offset + bufoffset;
1018 uio.uio_resid = iov.iov_len;
1019 uio.uio_rw = UIO_WRITE;
1020
1021 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0)
1022 break;
1023
1024 bufoffset += (count - bufoffset) - uio.uio_resid;
1025 }
1026
1027 uio.uio_offset = offset + bufoffset;
1028 }
1029
1030 free(buf, M_TEMP);
1031
1032 return (error);
1033 }
1034
1035 /*
1036 * Copy file from lower to upper.
1037 *
1038 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to
1039 * docopy.
1040 *
1041 * If no error returned, unp will be updated.
1042 */
1043 int
1044 unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred,
1045 struct thread *td)
1046 {
1047 int error;
1048 struct mount *mp;
1049 struct vnode *udvp;
1050 struct vnode *lvp;
1051 struct vnode *uvp;
1052 struct vattr uva;
1053
1054 lvp = unp->un_lowervp;
1055 uvp = NULLVP;
1056
1057 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY))
1058 return (EROFS);
1059 if (unp->un_dvp == NULLVP)
1060 return (EINVAL);
1061 if (unp->un_uppervp != NULLVP)
1062 return (EEXIST);
1063 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp;
1064 if (udvp == NULLVP)
1065 return (EROFS);
1066 if ((udvp->v_mount->mnt_flag & MNT_RDONLY))
1067 return (EROFS);
1068
1069 error = VOP_ACCESS(lvp, VREAD, cred, td);
1070 if (error != 0)
1071 return (error);
1072
1073 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0)
1074 return (error);
1075 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td);
1076 if (error != 0) {
1077 vn_finished_write(mp);
1078 return (error);
1079 }
1080
1081 if (docopy != 0) {
1082 error = VOP_OPEN(lvp, FREAD, cred, td, NULL);
1083 if (error == 0) {
1084 error = unionfs_copyfile_core(lvp, uvp, cred, td);
1085 VOP_CLOSE(lvp, FREAD, cred, td);
1086 }
1087 }
1088 VOP_CLOSE(uvp, FWRITE, cred, td);
1089 uvp->v_writecount--;
1090
1091 vn_finished_write(mp);
1092
1093 if (error == 0) {
1094 /* Reset the attributes. Ignore errors. */
1095 uva.va_type = VNON;
1096 VOP_SETATTR(uvp, &uva, cred);
1097 }
1098
1099 unionfs_node_update(unp, uvp, td);
1100
1101 return (error);
1102 }
1103
1104 /*
1105 * It checks whether vp can rmdir. (check empty)
1106 *
1107 * vp is unionfs vnode.
1108 * vp should be locked.
1109 */
1110 int
1111 unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td)
1112 {
1113 int error;
1114 int eofflag;
1115 int lookuperr;
1116 struct vnode *uvp;
1117 struct vnode *lvp;
1118 struct vnode *tvp;
1119 struct vattr va;
1120 struct componentname cn;
1121 /*
1122 * The size of buf needs to be larger than DIRBLKSIZ.
1123 */
1124 char buf[256 * 6];
1125 struct dirent *dp;
1126 struct dirent *edp;
1127 struct uio uio;
1128 struct iovec iov;
1129
1130 ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir");
1131
1132 eofflag = 0;
1133 uvp = UNIONFSVPTOUPPERVP(vp);
1134 lvp = UNIONFSVPTOLOWERVP(vp);
1135
1136 /* check opaque */
1137 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0)
1138 return (error);
1139 if (va.va_flags & OPAQUE)
1140 return (0);
1141
1142 /* open vnode */
1143 #ifdef MAC
1144 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0)
1145 return (error);
1146 #endif
1147 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0)
1148 return (error);
1149 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0)
1150 return (error);
1151
1152 uio.uio_rw = UIO_READ;
1153 uio.uio_segflg = UIO_SYSSPACE;
1154 uio.uio_td = td;
1155 uio.uio_offset = 0;
1156
1157 #ifdef MAC
1158 error = mac_vnode_check_readdir(td->td_ucred, lvp);
1159 #endif
1160 while (!error && !eofflag) {
1161 iov.iov_base = buf;
1162 iov.iov_len = sizeof(buf);
1163 uio.uio_iov = &iov;
1164 uio.uio_iovcnt = 1;
1165 uio.uio_resid = iov.iov_len;
1166
1167 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL);
1168 if (error != 0)
1169 break;
1170 if (eofflag == 0 && uio.uio_resid == sizeof(buf)) {
1171 #ifdef DIAGNOSTIC
1172 panic("bad readdir response from lower FS.");
1173 #endif
1174 break;
1175 }
1176
1177 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid];
1178 for (dp = (struct dirent*)buf; !error && dp < edp;
1179 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) {
1180 if (dp->d_type == DT_WHT ||
1181 (dp->d_namlen == 1 && dp->d_name[0] == '.') ||
1182 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2)))
1183 continue;
1184
1185 cn.cn_namelen = dp->d_namlen;
1186 cn.cn_pnbuf = NULL;
1187 cn.cn_nameptr = dp->d_name;
1188 cn.cn_nameiop = LOOKUP;
1189 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN);
1190 cn.cn_lkflags = LK_EXCLUSIVE;
1191 cn.cn_thread = td;
1192 cn.cn_cred = cred;
1193 cn.cn_consume = 0;
1194
1195 /*
1196 * check entry in lower.
1197 * Sometimes, readdir function returns
1198 * wrong entry.
1199 */
1200 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn);
1201
1202 if (!lookuperr)
1203 vput(tvp);
1204 else
1205 continue; /* skip entry */
1206
1207 /*
1208 * check entry
1209 * If it has no exist/whiteout entry in upper,
1210 * directory is not empty.
1211 */
1212 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN);
1213 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn);
1214
1215 if (!lookuperr)
1216 vput(tvp);
1217
1218 /* ignore exist or whiteout entry */
1219 if (!lookuperr ||
1220 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT)))
1221 continue;
1222
1223 error = ENOTEMPTY;
1224 }
1225 }
1226
1227 /* close vnode */
1228 VOP_CLOSE(vp, FREAD, cred, td);
1229
1230 return (error);
1231 }
1232
1233 #ifdef DIAGNOSTIC
1234
1235 struct vnode *
1236 unionfs_checkuppervp(struct vnode *vp, char *fil, int lno)
1237 {
1238 struct unionfs_node *unp;
1239
1240 unp = VTOUNIONFS(vp);
1241
1242 #ifdef notyet
1243 if (vp->v_op != unionfs_vnodeop_p) {
1244 printf("unionfs_checkuppervp: on non-unionfs-node.\n");
1245 #ifdef KDB
1246 kdb_enter(KDB_WHY_UNIONFS,
1247 "unionfs_checkuppervp: on non-unionfs-node.\n");
1248 #endif
1249 panic("unionfs_checkuppervp");
1250 };
1251 #endif
1252 return (unp->un_uppervp);
1253 }
1254
1255 struct vnode *
1256 unionfs_checklowervp(struct vnode *vp, char *fil, int lno)
1257 {
1258 struct unionfs_node *unp;
1259
1260 unp = VTOUNIONFS(vp);
1261
1262 #ifdef notyet
1263 if (vp->v_op != unionfs_vnodeop_p) {
1264 printf("unionfs_checklowervp: on non-unionfs-node.\n");
1265 #ifdef KDB
1266 kdb_enter(KDB_WHY_UNIONFS,
1267 "unionfs_checklowervp: on non-unionfs-node.\n");
1268 #endif
1269 panic("unionfs_checklowervp");
1270 };
1271 #endif
1272 return (unp->un_lowervp);
1273 }
1274 #endif
Cache object: 485d53635a17d19f6c4dba83a8a10eac
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