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, 2012 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
6 * Copyright (c) 2006, 2012 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 * $FreeBSD$
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 vp->v_vnlock = &(vp->v_lock);
354 vp->v_data = NULL;
355 vp->v_object = NULL;
356 VI_UNLOCK(vp);
357
358 if (lvp != NULLVP)
359 VOP_UNLOCK(lvp, LK_RELEASE);
360 if (uvp != NULLVP)
361 VOP_UNLOCK(uvp, LK_RELEASE);
362
363 if (dvp != NULLVP && unp->un_hash.le_prev != NULL)
364 unionfs_rem_cached_vnode(unp, dvp);
365
366 if (lockmgr(vp->v_vnlock, LK_EXCLUSIVE, VI_MTX(vp)) != 0)
367 panic("the lock for deletion is unacquirable.");
368
369 if (lvp != NULLVP) {
370 vfslocked = VFS_LOCK_GIANT(lvp->v_mount);
371 vrele(lvp);
372 VFS_UNLOCK_GIANT(vfslocked);
373 }
374 if (uvp != NULLVP) {
375 vfslocked = VFS_LOCK_GIANT(uvp->v_mount);
376 vrele(uvp);
377 VFS_UNLOCK_GIANT(vfslocked);
378 }
379 if (dvp != NULLVP) {
380 vfslocked = VFS_LOCK_GIANT(dvp->v_mount);
381 vrele(dvp);
382 VFS_UNLOCK_GIANT(vfslocked);
383 unp->un_dvp = NULLVP;
384 }
385 if (unp->un_path != NULL) {
386 free(unp->un_path, M_UNIONFSPATH);
387 unp->un_path = NULL;
388 }
389
390 if (unp->un_hashtbl != NULL) {
391 for (count = 0; count <= unp->un_hashmask; count++) {
392 hd = unp->un_hashtbl + count;
393 LIST_FOREACH_SAFE(unp_t1, hd, un_hash, unp_t2) {
394 LIST_REMOVE(unp_t1, un_hash);
395 unp_t1->un_hash.le_next = NULL;
396 unp_t1->un_hash.le_prev = NULL;
397 }
398 }
399 hashdestroy(unp->un_hashtbl, M_UNIONFSHASH, unp->un_hashmask);
400 }
401
402 LIST_FOREACH_SAFE(unsp, &(unp->un_unshead), uns_list, unsp_tmp) {
403 LIST_REMOVE(unsp, uns_list);
404 free(unsp, M_TEMP);
405 }
406 free(unp, M_UNIONFSNODE);
407 }
408
409 /*
410 * Get the unionfs node status.
411 * You need exclusive lock this vnode.
412 */
413 void
414 unionfs_get_node_status(struct unionfs_node *unp, struct thread *td,
415 struct unionfs_node_status **unspp)
416 {
417 struct unionfs_node_status *unsp;
418 pid_t pid = td->td_proc->p_pid;
419
420 KASSERT(NULL != unspp, ("null pointer"));
421 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status");
422
423 LIST_FOREACH(unsp, &(unp->un_unshead), uns_list) {
424 if (unsp->uns_pid == pid) {
425 *unspp = unsp;
426 return;
427 }
428 }
429
430 /* create a new unionfs node status */
431 unsp = malloc(sizeof(struct unionfs_node_status),
432 M_TEMP, M_WAITOK | M_ZERO);
433
434 unsp->uns_pid = pid;
435 LIST_INSERT_HEAD(&(unp->un_unshead), unsp, uns_list);
436
437 *unspp = unsp;
438 }
439
440 /*
441 * Remove the unionfs node status, if you can.
442 * You need exclusive lock this vnode.
443 */
444 void
445 unionfs_tryrem_node_status(struct unionfs_node *unp,
446 struct unionfs_node_status *unsp)
447 {
448 KASSERT(NULL != unsp, ("null pointer"));
449 ASSERT_VOP_ELOCKED(UNIONFSTOV(unp), "unionfs_get_node_status");
450
451 if (0 < unsp->uns_lower_opencnt || 0 < unsp->uns_upper_opencnt)
452 return;
453
454 LIST_REMOVE(unsp, uns_list);
455 free(unsp, M_TEMP);
456 }
457
458 /*
459 * Create upper node attr.
460 */
461 void
462 unionfs_create_uppervattr_core(struct unionfs_mount *ump,
463 struct vattr *lva,
464 struct vattr *uva,
465 struct thread *td)
466 {
467 VATTR_NULL(uva);
468 uva->va_type = lva->va_type;
469 uva->va_atime = lva->va_atime;
470 uva->va_mtime = lva->va_mtime;
471 uva->va_ctime = lva->va_ctime;
472
473 switch (ump->um_copymode) {
474 case UNIONFS_TRANSPARENT:
475 uva->va_mode = lva->va_mode;
476 uva->va_uid = lva->va_uid;
477 uva->va_gid = lva->va_gid;
478 break;
479 case UNIONFS_MASQUERADE:
480 if (ump->um_uid == lva->va_uid) {
481 uva->va_mode = lva->va_mode & 077077;
482 uva->va_mode |= (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile) & 0700;
483 uva->va_uid = lva->va_uid;
484 uva->va_gid = lva->va_gid;
485 } else {
486 uva->va_mode = (lva->va_type == VDIR ? ump->um_udir : ump->um_ufile);
487 uva->va_uid = ump->um_uid;
488 uva->va_gid = ump->um_gid;
489 }
490 break;
491 default: /* UNIONFS_TRADITIONAL */
492 uva->va_mode = 0777 & ~td->td_proc->p_fd->fd_cmask;
493 uva->va_uid = ump->um_uid;
494 uva->va_gid = ump->um_gid;
495 break;
496 }
497 }
498
499 /*
500 * Create upper node attr.
501 */
502 int
503 unionfs_create_uppervattr(struct unionfs_mount *ump,
504 struct vnode *lvp,
505 struct vattr *uva,
506 struct ucred *cred,
507 struct thread *td)
508 {
509 int error;
510 struct vattr lva;
511
512 if ((error = VOP_GETATTR(lvp, &lva, cred)))
513 return (error);
514
515 unionfs_create_uppervattr_core(ump, &lva, uva, td);
516
517 return (error);
518 }
519
520 /*
521 * relookup
522 *
523 * dvp should be locked on entry and will be locked on return.
524 *
525 * If an error is returned, *vpp will be invalid, otherwise it will hold a
526 * locked, referenced vnode. If *vpp == dvp then remember that only one
527 * LK_EXCLUSIVE lock is held.
528 */
529 int
530 unionfs_relookup(struct vnode *dvp, struct vnode **vpp,
531 struct componentname *cnp, struct componentname *cn,
532 struct thread *td, char *path, int pathlen, u_long nameiop)
533 {
534 int error;
535
536 cn->cn_namelen = pathlen;
537 cn->cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK);
538 bcopy(path, cn->cn_pnbuf, pathlen);
539 cn->cn_pnbuf[pathlen] = '\0';
540
541 cn->cn_nameiop = nameiop;
542 cn->cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN);
543 cn->cn_lkflags = LK_EXCLUSIVE;
544 cn->cn_thread = td;
545 cn->cn_cred = cnp->cn_cred;
546
547 cn->cn_nameptr = cn->cn_pnbuf;
548 cn->cn_consume = cnp->cn_consume;
549
550 if (nameiop == DELETE)
551 cn->cn_flags |= (cnp->cn_flags & (DOWHITEOUT | SAVESTART));
552 else if (RENAME == nameiop)
553 cn->cn_flags |= (cnp->cn_flags & SAVESTART);
554
555 vref(dvp);
556 VOP_UNLOCK(dvp, LK_RELEASE);
557
558 if ((error = relookup(dvp, vpp, cn))) {
559 uma_zfree(namei_zone, cn->cn_pnbuf);
560 cn->cn_flags &= ~HASBUF;
561 vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
562 } else
563 vrele(dvp);
564
565 return (error);
566 }
567
568 /*
569 * relookup for CREATE namei operation.
570 *
571 * dvp is unionfs vnode. dvp should be locked.
572 *
573 * If it called 'unionfs_copyfile' function by unionfs_link etc,
574 * VOP_LOOKUP information is broken.
575 * So it need relookup in order to create link etc.
576 */
577 int
578 unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp,
579 struct thread *td)
580 {
581 int error;
582 struct vnode *udvp;
583 struct vnode *vp;
584 struct componentname cn;
585
586 udvp = UNIONFSVPTOUPPERVP(dvp);
587 vp = NULLVP;
588
589 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr,
590 strlen(cnp->cn_nameptr), CREATE);
591 if (error)
592 return (error);
593
594 if (vp != NULLVP) {
595 if (udvp == vp)
596 vrele(vp);
597 else
598 vput(vp);
599
600 error = EEXIST;
601 }
602
603 if (cn.cn_flags & HASBUF) {
604 uma_zfree(namei_zone, cn.cn_pnbuf);
605 cn.cn_flags &= ~HASBUF;
606 }
607
608 if (!error) {
609 cn.cn_flags |= (cnp->cn_flags & HASBUF);
610 cnp->cn_flags = cn.cn_flags;
611 }
612
613 return (error);
614 }
615
616 /*
617 * relookup for DELETE namei operation.
618 *
619 * dvp is unionfs vnode. dvp should be locked.
620 */
621 int
622 unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp,
623 struct thread *td)
624 {
625 int error;
626 struct vnode *udvp;
627 struct vnode *vp;
628 struct componentname cn;
629
630 udvp = UNIONFSVPTOUPPERVP(dvp);
631 vp = NULLVP;
632
633 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr,
634 strlen(cnp->cn_nameptr), DELETE);
635 if (error)
636 return (error);
637
638 if (vp == NULLVP)
639 error = ENOENT;
640 else {
641 if (udvp == vp)
642 vrele(vp);
643 else
644 vput(vp);
645 }
646
647 if (cn.cn_flags & HASBUF) {
648 uma_zfree(namei_zone, cn.cn_pnbuf);
649 cn.cn_flags &= ~HASBUF;
650 }
651
652 if (!error) {
653 cn.cn_flags |= (cnp->cn_flags & HASBUF);
654 cnp->cn_flags = cn.cn_flags;
655 }
656
657 return (error);
658 }
659
660 /*
661 * relookup for RENAME namei operation.
662 *
663 * dvp is unionfs vnode. dvp should be locked.
664 */
665 int
666 unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp,
667 struct thread *td)
668 {
669 int error;
670 struct vnode *udvp;
671 struct vnode *vp;
672 struct componentname cn;
673
674 udvp = UNIONFSVPTOUPPERVP(dvp);
675 vp = NULLVP;
676
677 error = unionfs_relookup(udvp, &vp, cnp, &cn, td, cnp->cn_nameptr,
678 strlen(cnp->cn_nameptr), RENAME);
679 if (error)
680 return (error);
681
682 if (vp != NULLVP) {
683 if (udvp == vp)
684 vrele(vp);
685 else
686 vput(vp);
687 }
688
689 if (cn.cn_flags & HASBUF) {
690 uma_zfree(namei_zone, cn.cn_pnbuf);
691 cn.cn_flags &= ~HASBUF;
692 }
693
694 if (!error) {
695 cn.cn_flags |= (cnp->cn_flags & HASBUF);
696 cnp->cn_flags = cn.cn_flags;
697 }
698
699 return (error);
700
701 }
702
703 /*
704 * Update the unionfs_node.
705 *
706 * uvp is new locked upper vnode. unionfs vnode's lock will be exchanged to the
707 * uvp's lock and lower's lock will be unlocked.
708 */
709 static void
710 unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp,
711 struct thread *td)
712 {
713 unsigned count, lockrec;
714 struct vnode *vp;
715 struct vnode *lvp;
716 struct vnode *dvp;
717
718 vp = UNIONFSTOV(unp);
719 lvp = unp->un_lowervp;
720 ASSERT_VOP_ELOCKED(lvp, "unionfs_node_update");
721 dvp = unp->un_dvp;
722
723 /*
724 * lock update
725 */
726 VI_LOCK(vp);
727 unp->un_uppervp = uvp;
728 vp->v_vnlock = uvp->v_vnlock;
729 VI_UNLOCK(vp);
730 lockrec = lvp->v_vnlock->lk_recurse;
731 for (count = 0; count < lockrec; count++)
732 vn_lock(uvp, LK_EXCLUSIVE | LK_CANRECURSE | LK_RETRY);
733
734 /*
735 * cache update
736 */
737 if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) {
738 static struct unionfs_node_hashhead *hd;
739
740 VI_LOCK(dvp);
741 hd = unionfs_get_hashhead(dvp, unp->un_path);
742 LIST_REMOVE(unp, un_hash);
743 LIST_INSERT_HEAD(hd, unp, un_hash);
744 VI_UNLOCK(dvp);
745 }
746 }
747
748 /*
749 * Create a new shadow dir.
750 *
751 * udvp should be locked on entry and will be locked on return.
752 *
753 * If no error returned, unp will be updated.
754 */
755 int
756 unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *udvp,
757 struct unionfs_node *unp, struct componentname *cnp,
758 struct thread *td)
759 {
760 int error;
761 struct vnode *lvp;
762 struct vnode *uvp;
763 struct vattr va;
764 struct vattr lva;
765 struct componentname cn;
766 struct mount *mp;
767 struct ucred *cred;
768 struct ucred *credbk;
769 struct uidinfo *rootinfo;
770
771 if (unp->un_uppervp != NULLVP)
772 return (EEXIST);
773
774 lvp = unp->un_lowervp;
775 uvp = NULLVP;
776 credbk = cnp->cn_cred;
777
778 /* Authority change to root */
779 rootinfo = uifind((uid_t)0);
780 cred = crdup(cnp->cn_cred);
781 /*
782 * The calls to chgproccnt() are needed to compensate for change_ruid()
783 * calling chgproccnt().
784 */
785 chgproccnt(cred->cr_ruidinfo, 1, 0);
786 change_euid(cred, rootinfo);
787 change_ruid(cred, rootinfo);
788 change_svuid(cred, (uid_t)0);
789 uifree(rootinfo);
790 cnp->cn_cred = cred;
791
792 memset(&cn, 0, sizeof(cn));
793
794 if ((error = VOP_GETATTR(lvp, &lva, cnp->cn_cred)))
795 goto unionfs_mkshadowdir_abort;
796
797 if ((error = unionfs_relookup(udvp, &uvp, cnp, &cn, td, cnp->cn_nameptr, cnp->cn_namelen, CREATE)))
798 goto unionfs_mkshadowdir_abort;
799 if (uvp != NULLVP) {
800 if (udvp == uvp)
801 vrele(uvp);
802 else
803 vput(uvp);
804
805 error = EEXIST;
806 goto unionfs_mkshadowdir_free_out;
807 }
808
809 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)))
810 goto unionfs_mkshadowdir_free_out;
811 unionfs_create_uppervattr_core(ump, &lva, &va, td);
812
813 error = VOP_MKDIR(udvp, &uvp, &cn, &va);
814
815 if (!error) {
816 unionfs_node_update(unp, uvp, td);
817
818 /*
819 * XXX The bug which cannot set uid/gid was corrected.
820 * Ignore errors.
821 */
822 va.va_type = VNON;
823 VOP_SETATTR(uvp, &va, cn.cn_cred);
824 }
825 vn_finished_write(mp);
826
827 unionfs_mkshadowdir_free_out:
828 if (cn.cn_flags & HASBUF) {
829 uma_zfree(namei_zone, cn.cn_pnbuf);
830 cn.cn_flags &= ~HASBUF;
831 }
832
833 unionfs_mkshadowdir_abort:
834 cnp->cn_cred = credbk;
835 chgproccnt(cred->cr_ruidinfo, -1, 0);
836 crfree(cred);
837
838 return (error);
839 }
840
841 /*
842 * Create a new whiteout.
843 *
844 * dvp should be locked on entry and will be locked on return.
845 */
846 int
847 unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp,
848 struct thread *td, char *path)
849 {
850 int error;
851 struct vnode *wvp;
852 struct componentname cn;
853 struct mount *mp;
854
855 if (path == NULL)
856 path = cnp->cn_nameptr;
857
858 wvp = NULLVP;
859 if ((error = unionfs_relookup(dvp, &wvp, cnp, &cn, td, path, strlen(path), CREATE)))
860 return (error);
861 if (wvp != NULLVP) {
862 if (cn.cn_flags & HASBUF) {
863 uma_zfree(namei_zone, cn.cn_pnbuf);
864 cn.cn_flags &= ~HASBUF;
865 }
866 if (dvp == wvp)
867 vrele(wvp);
868 else
869 vput(wvp);
870
871 return (EEXIST);
872 }
873
874 if ((error = vn_start_write(dvp, &mp, V_WAIT | PCATCH)))
875 goto unionfs_mkwhiteout_free_out;
876 error = VOP_WHITEOUT(dvp, &cn, CREATE);
877
878 vn_finished_write(mp);
879
880 unionfs_mkwhiteout_free_out:
881 if (cn.cn_flags & HASBUF) {
882 uma_zfree(namei_zone, cn.cn_pnbuf);
883 cn.cn_flags &= ~HASBUF;
884 }
885
886 return (error);
887 }
888
889 /*
890 * Create a new vnode for create a new shadow file.
891 *
892 * If an error is returned, *vpp will be invalid, otherwise it will hold a
893 * locked, referenced and opened vnode.
894 *
895 * unp is never updated.
896 */
897 static int
898 unionfs_vn_create_on_upper(struct vnode **vpp, struct vnode *udvp,
899 struct unionfs_node *unp, struct vattr *uvap,
900 struct thread *td)
901 {
902 struct unionfs_mount *ump;
903 struct vnode *vp;
904 struct vnode *lvp;
905 struct ucred *cred;
906 struct vattr lva;
907 int fmode;
908 int error;
909 struct componentname cn;
910
911 ump = MOUNTTOUNIONFSMOUNT(UNIONFSTOV(unp)->v_mount);
912 vp = NULLVP;
913 lvp = unp->un_lowervp;
914 cred = td->td_ucred;
915 fmode = FFLAGS(O_WRONLY | O_CREAT | O_TRUNC | O_EXCL);
916 error = 0;
917
918 if ((error = VOP_GETATTR(lvp, &lva, cred)) != 0)
919 return (error);
920 unionfs_create_uppervattr_core(ump, &lva, uvap, td);
921
922 if (unp->un_path == NULL)
923 panic("unionfs: un_path is null");
924
925 cn.cn_namelen = strlen(unp->un_path);
926 cn.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK);
927 bcopy(unp->un_path, cn.cn_pnbuf, cn.cn_namelen + 1);
928 cn.cn_nameiop = CREATE;
929 cn.cn_flags = (LOCKPARENT | LOCKLEAF | HASBUF | SAVENAME | ISLASTCN);
930 cn.cn_lkflags = LK_EXCLUSIVE;
931 cn.cn_thread = td;
932 cn.cn_cred = cred;
933 cn.cn_nameptr = cn.cn_pnbuf;
934 cn.cn_consume = 0;
935
936 vref(udvp);
937 if ((error = relookup(udvp, &vp, &cn)) != 0)
938 goto unionfs_vn_create_on_upper_free_out2;
939 vrele(udvp);
940
941 if (vp != NULLVP) {
942 if (vp == udvp)
943 vrele(vp);
944 else
945 vput(vp);
946 error = EEXIST;
947 goto unionfs_vn_create_on_upper_free_out1;
948 }
949
950 if ((error = VOP_CREATE(udvp, &vp, &cn, uvap)) != 0)
951 goto unionfs_vn_create_on_upper_free_out1;
952
953 if ((error = VOP_OPEN(vp, fmode, cred, td, NULL)) != 0) {
954 vput(vp);
955 goto unionfs_vn_create_on_upper_free_out1;
956 }
957 VOP_ADD_WRITECOUNT(vp, 1);
958 *vpp = vp;
959
960 unionfs_vn_create_on_upper_free_out1:
961 VOP_UNLOCK(udvp, LK_RELEASE);
962
963 unionfs_vn_create_on_upper_free_out2:
964 if (cn.cn_flags & HASBUF) {
965 uma_zfree(namei_zone, cn.cn_pnbuf);
966 cn.cn_flags &= ~HASBUF;
967 }
968
969 return (error);
970 }
971
972 /*
973 * Copy from lvp to uvp.
974 *
975 * lvp and uvp should be locked and opened on entry and will be locked and
976 * opened on return.
977 */
978 static int
979 unionfs_copyfile_core(struct vnode *lvp, struct vnode *uvp,
980 struct ucred *cred, struct thread *td)
981 {
982 int error;
983 off_t offset;
984 int count;
985 int bufoffset;
986 char *buf;
987 struct uio uio;
988 struct iovec iov;
989
990 error = 0;
991 memset(&uio, 0, sizeof(uio));
992
993 uio.uio_td = td;
994 uio.uio_segflg = UIO_SYSSPACE;
995 uio.uio_offset = 0;
996
997 buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK);
998
999 while (error == 0) {
1000 offset = uio.uio_offset;
1001
1002 uio.uio_iov = &iov;
1003 uio.uio_iovcnt = 1;
1004 iov.iov_base = buf;
1005 iov.iov_len = MAXBSIZE;
1006 uio.uio_resid = iov.iov_len;
1007 uio.uio_rw = UIO_READ;
1008
1009 if ((error = VOP_READ(lvp, &uio, 0, cred)) != 0)
1010 break;
1011 if ((count = MAXBSIZE - uio.uio_resid) == 0)
1012 break;
1013
1014 bufoffset = 0;
1015 while (bufoffset < count) {
1016 uio.uio_iov = &iov;
1017 uio.uio_iovcnt = 1;
1018 iov.iov_base = buf + bufoffset;
1019 iov.iov_len = count - bufoffset;
1020 uio.uio_offset = offset + bufoffset;
1021 uio.uio_resid = iov.iov_len;
1022 uio.uio_rw = UIO_WRITE;
1023
1024 if ((error = VOP_WRITE(uvp, &uio, 0, cred)) != 0)
1025 break;
1026
1027 bufoffset += (count - bufoffset) - uio.uio_resid;
1028 }
1029
1030 uio.uio_offset = offset + bufoffset;
1031 }
1032
1033 free(buf, M_TEMP);
1034
1035 return (error);
1036 }
1037
1038 /*
1039 * Copy file from lower to upper.
1040 *
1041 * If you need copy of the contents, set 1 to docopy. Otherwise, set 0 to
1042 * docopy.
1043 *
1044 * If no error returned, unp will be updated.
1045 */
1046 int
1047 unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred,
1048 struct thread *td)
1049 {
1050 int error;
1051 struct mount *mp;
1052 struct vnode *udvp;
1053 struct vnode *lvp;
1054 struct vnode *uvp;
1055 struct vattr uva;
1056
1057 lvp = unp->un_lowervp;
1058 uvp = NULLVP;
1059
1060 if ((UNIONFSTOV(unp)->v_mount->mnt_flag & MNT_RDONLY))
1061 return (EROFS);
1062 if (unp->un_dvp == NULLVP)
1063 return (EINVAL);
1064 if (unp->un_uppervp != NULLVP)
1065 return (EEXIST);
1066 udvp = VTOUNIONFS(unp->un_dvp)->un_uppervp;
1067 if (udvp == NULLVP)
1068 return (EROFS);
1069 if ((udvp->v_mount->mnt_flag & MNT_RDONLY))
1070 return (EROFS);
1071
1072 error = VOP_ACCESS(lvp, VREAD, cred, td);
1073 if (error != 0)
1074 return (error);
1075
1076 if ((error = vn_start_write(udvp, &mp, V_WAIT | PCATCH)) != 0)
1077 return (error);
1078 error = unionfs_vn_create_on_upper(&uvp, udvp, unp, &uva, td);
1079 if (error != 0) {
1080 vn_finished_write(mp);
1081 return (error);
1082 }
1083
1084 if (docopy != 0) {
1085 error = VOP_OPEN(lvp, FREAD, cred, td, NULL);
1086 if (error == 0) {
1087 error = unionfs_copyfile_core(lvp, uvp, cred, td);
1088 VOP_CLOSE(lvp, FREAD, cred, td);
1089 }
1090 }
1091 VOP_CLOSE(uvp, FWRITE, cred, td);
1092 VOP_ADD_WRITECOUNT(uvp, -1);
1093
1094 vn_finished_write(mp);
1095
1096 if (error == 0) {
1097 /* Reset the attributes. Ignore errors. */
1098 uva.va_type = VNON;
1099 VOP_SETATTR(uvp, &uva, cred);
1100 }
1101
1102 unionfs_node_update(unp, uvp, td);
1103
1104 return (error);
1105 }
1106
1107 /*
1108 * It checks whether vp can rmdir. (check empty)
1109 *
1110 * vp is unionfs vnode.
1111 * vp should be locked.
1112 */
1113 int
1114 unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td)
1115 {
1116 int error;
1117 int eofflag;
1118 int lookuperr;
1119 struct vnode *uvp;
1120 struct vnode *lvp;
1121 struct vnode *tvp;
1122 struct vattr va;
1123 struct componentname cn;
1124 /*
1125 * The size of buf needs to be larger than DIRBLKSIZ.
1126 */
1127 char buf[256 * 6];
1128 struct dirent *dp;
1129 struct dirent *edp;
1130 struct uio uio;
1131 struct iovec iov;
1132
1133 ASSERT_VOP_ELOCKED(vp, "unionfs_check_rmdir");
1134
1135 eofflag = 0;
1136 uvp = UNIONFSVPTOUPPERVP(vp);
1137 lvp = UNIONFSVPTOLOWERVP(vp);
1138
1139 /* check opaque */
1140 if ((error = VOP_GETATTR(uvp, &va, cred)) != 0)
1141 return (error);
1142 if (va.va_flags & OPAQUE)
1143 return (0);
1144
1145 /* open vnode */
1146 #ifdef MAC
1147 if ((error = mac_vnode_check_open(cred, vp, VEXEC|VREAD)) != 0)
1148 return (error);
1149 #endif
1150 if ((error = VOP_ACCESS(vp, VEXEC|VREAD, cred, td)) != 0)
1151 return (error);
1152 if ((error = VOP_OPEN(vp, FREAD, cred, td, NULL)) != 0)
1153 return (error);
1154
1155 uio.uio_rw = UIO_READ;
1156 uio.uio_segflg = UIO_SYSSPACE;
1157 uio.uio_td = td;
1158 uio.uio_offset = 0;
1159
1160 #ifdef MAC
1161 error = mac_vnode_check_readdir(td->td_ucred, lvp);
1162 #endif
1163 while (!error && !eofflag) {
1164 iov.iov_base = buf;
1165 iov.iov_len = sizeof(buf);
1166 uio.uio_iov = &iov;
1167 uio.uio_iovcnt = 1;
1168 uio.uio_resid = iov.iov_len;
1169
1170 error = VOP_READDIR(lvp, &uio, cred, &eofflag, NULL, NULL);
1171 if (error != 0)
1172 break;
1173 if (eofflag == 0 && uio.uio_resid == sizeof(buf)) {
1174 #ifdef DIAGNOSTIC
1175 panic("bad readdir response from lower FS.");
1176 #endif
1177 break;
1178 }
1179
1180 edp = (struct dirent*)&buf[sizeof(buf) - uio.uio_resid];
1181 for (dp = (struct dirent*)buf; !error && dp < edp;
1182 dp = (struct dirent*)((caddr_t)dp + dp->d_reclen)) {
1183 if (dp->d_type == DT_WHT ||
1184 (dp->d_namlen == 1 && dp->d_name[0] == '.') ||
1185 (dp->d_namlen == 2 && !bcmp(dp->d_name, "..", 2)))
1186 continue;
1187
1188 cn.cn_namelen = dp->d_namlen;
1189 cn.cn_pnbuf = NULL;
1190 cn.cn_nameptr = dp->d_name;
1191 cn.cn_nameiop = LOOKUP;
1192 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN);
1193 cn.cn_lkflags = LK_EXCLUSIVE;
1194 cn.cn_thread = td;
1195 cn.cn_cred = cred;
1196 cn.cn_consume = 0;
1197
1198 /*
1199 * check entry in lower.
1200 * Sometimes, readdir function returns
1201 * wrong entry.
1202 */
1203 lookuperr = VOP_LOOKUP(lvp, &tvp, &cn);
1204
1205 if (!lookuperr)
1206 vput(tvp);
1207 else
1208 continue; /* skip entry */
1209
1210 /*
1211 * check entry
1212 * If it has no exist/whiteout entry in upper,
1213 * directory is not empty.
1214 */
1215 cn.cn_flags = (LOCKPARENT | LOCKLEAF | SAVENAME | RDONLY | ISLASTCN);
1216 lookuperr = VOP_LOOKUP(uvp, &tvp, &cn);
1217
1218 if (!lookuperr)
1219 vput(tvp);
1220
1221 /* ignore exist or whiteout entry */
1222 if (!lookuperr ||
1223 (lookuperr == ENOENT && (cn.cn_flags & ISWHITEOUT)))
1224 continue;
1225
1226 error = ENOTEMPTY;
1227 }
1228 }
1229
1230 /* close vnode */
1231 VOP_CLOSE(vp, FREAD, cred, td);
1232
1233 return (error);
1234 }
1235
1236 #ifdef DIAGNOSTIC
1237
1238 struct vnode *
1239 unionfs_checkuppervp(struct vnode *vp, char *fil, int lno)
1240 {
1241 struct unionfs_node *unp;
1242
1243 unp = VTOUNIONFS(vp);
1244
1245 #ifdef notyet
1246 if (vp->v_op != unionfs_vnodeop_p) {
1247 printf("unionfs_checkuppervp: on non-unionfs-node.\n");
1248 #ifdef KDB
1249 kdb_enter(KDB_WHY_UNIONFS,
1250 "unionfs_checkuppervp: on non-unionfs-node.\n");
1251 #endif
1252 panic("unionfs_checkuppervp");
1253 };
1254 #endif
1255 return (unp->un_uppervp);
1256 }
1257
1258 struct vnode *
1259 unionfs_checklowervp(struct vnode *vp, char *fil, int lno)
1260 {
1261 struct unionfs_node *unp;
1262
1263 unp = VTOUNIONFS(vp);
1264
1265 #ifdef notyet
1266 if (vp->v_op != unionfs_vnodeop_p) {
1267 printf("unionfs_checklowervp: on non-unionfs-node.\n");
1268 #ifdef KDB
1269 kdb_enter(KDB_WHY_UNIONFS,
1270 "unionfs_checklowervp: on non-unionfs-node.\n");
1271 #endif
1272 panic("unionfs_checklowervp");
1273 };
1274 #endif
1275 return (unp->un_lowervp);
1276 }
1277 #endif
Cache object: 39af5579ee19cb759c3980d56b5d5d1f
|