1 /*-
2 * Copyright (c) 1994, 1995 The Regents of the University of California.
3 * Copyright (c) 1994, 1995 Jan-Simon Pendry.
4 * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
5 * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
6 * All rights reserved.
7 *
8 * This code is derived from software donated 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_vfsops.c 8.20 (Berkeley) 5/20/95
36 * $FreeBSD$
37 */
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kdb.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.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/stat.h>
50
51 #include <fs/unionfs/union.h>
52
53 static MALLOC_DEFINE(M_UNIONFSMNT, "UNIONFS mount", "UNIONFS mount structure");
54
55 static vfs_fhtovp_t unionfs_fhtovp;
56 static vfs_checkexp_t unionfs_checkexp;
57 static vfs_mount_t unionfs_domount;
58 static vfs_quotactl_t unionfs_quotactl;
59 static vfs_root_t unionfs_root;
60 static vfs_sync_t unionfs_sync;
61 static vfs_statfs_t unionfs_statfs;
62 static vfs_unmount_t unionfs_unmount;
63 static vfs_vget_t unionfs_vget;
64 static vfs_vptofh_t unionfs_vptofh;
65 static vfs_extattrctl_t unionfs_extattrctl;
66
67 static struct vfsops unionfs_vfsops;
68
69 /*
70 * Exchange from userland file mode to vmode.
71 */
72 static u_short
73 mode2vmode(mode_t mode)
74 {
75 u_short ret;
76
77 ret = 0;
78
79 /* other */
80 if (mode & S_IXOTH)
81 ret |= VEXEC >> 6;
82 if (mode & S_IWOTH)
83 ret |= VWRITE >> 6;
84 if (mode & S_IROTH)
85 ret |= VREAD >> 6;
86
87 /* group */
88 if (mode & S_IXGRP)
89 ret |= VEXEC >> 3;
90 if (mode & S_IWGRP)
91 ret |= VWRITE >> 3;
92 if (mode & S_IRGRP)
93 ret |= VREAD >> 3;
94
95 /* owner */
96 if (mode & S_IXUSR)
97 ret |= VEXEC;
98 if (mode & S_IWUSR)
99 ret |= VWRITE;
100 if (mode & S_IRUSR)
101 ret |= VREAD;
102
103 return (ret);
104 }
105
106 /*
107 * Mount unionfs layer.
108 */
109 static int
110 unionfs_domount(struct mount *mp, struct thread *td)
111 {
112 int error;
113 struct vnode *lowerrootvp;
114 struct vnode *upperrootvp;
115 struct unionfs_mount *ump;
116 char *target;
117 char *tmp;
118 char *ep;
119 int len;
120 size_t done;
121 int below;
122 uid_t uid;
123 gid_t gid;
124 u_short udir;
125 u_short ufile;
126 unionfs_copymode copymode;
127 unionfs_whitemode whitemode;
128 struct componentname fakecn;
129 struct nameidata nd, *ndp;
130 struct vattr va;
131
132 UNIONFSDEBUG("unionfs_mount(mp = %p)\n", (void *)mp);
133
134 error = 0;
135 below = 0;
136 uid = 0;
137 gid = 0;
138 udir = 0;
139 ufile = 0;
140 copymode = UNIONFS_TRADITIONAL; /* default */
141 whitemode = UNIONFS_WHITE_ALWAYS;
142 ndp = &nd;
143
144 if (mp->mnt_flag & MNT_ROOTFS) {
145 vfs_mount_error(mp, "Cannot union mount root filesystem");
146 return (EOPNOTSUPP);
147 }
148
149 /*
150 * Update is a no operation.
151 */
152 if (mp->mnt_flag & MNT_UPDATE) {
153 vfs_mount_error(mp, "unionfs does not support mount update");
154 return (EOPNOTSUPP);
155 }
156
157 /*
158 * Get argument
159 */
160 error = vfs_getopt(mp->mnt_optnew, "target", (void **)&target, &len);
161 if (error)
162 error = vfs_getopt(mp->mnt_optnew, "from", (void **)&target,
163 &len);
164 if (error || target[len - 1] != '\0') {
165 vfs_mount_error(mp, "Invalid target");
166 return (EINVAL);
167 }
168 if (vfs_getopt(mp->mnt_optnew, "below", NULL, NULL) == 0)
169 below = 1;
170 if (vfs_getopt(mp->mnt_optnew, "udir", (void **)&tmp, NULL) == 0) {
171 if (tmp != NULL)
172 udir = (mode_t)strtol(tmp, &ep, 8);
173 if (tmp == NULL || *ep) {
174 vfs_mount_error(mp, "Invalid udir");
175 return (EINVAL);
176 }
177 udir = mode2vmode(udir);
178 }
179 if (vfs_getopt(mp->mnt_optnew, "ufile", (void **)&tmp, NULL) == 0) {
180 if (tmp != NULL)
181 ufile = (mode_t)strtol(tmp, &ep, 8);
182 if (tmp == NULL || *ep) {
183 vfs_mount_error(mp, "Invalid ufile");
184 return (EINVAL);
185 }
186 ufile = mode2vmode(ufile);
187 }
188 /* check umask, uid and gid */
189 if (udir == 0 && ufile != 0)
190 udir = ufile;
191 if (ufile == 0 && udir != 0)
192 ufile = udir;
193
194 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY, td);
195 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred, td);
196 if (!error) {
197 if (udir == 0)
198 udir = va.va_mode;
199 if (ufile == 0)
200 ufile = va.va_mode;
201 uid = va.va_uid;
202 gid = va.va_gid;
203 }
204 VOP_UNLOCK(mp->mnt_vnodecovered, 0, td);
205 if (error)
206 return (error);
207
208 if (mp->mnt_cred->cr_ruid == 0) { /* root only */
209 if (vfs_getopt(mp->mnt_optnew, "uid", (void **)&tmp,
210 NULL) == 0) {
211 if (tmp != NULL)
212 uid = (uid_t)strtol(tmp, &ep, 10);
213 if (tmp == NULL || *ep) {
214 vfs_mount_error(mp, "Invalid uid");
215 return (EINVAL);
216 }
217 }
218 if (vfs_getopt(mp->mnt_optnew, "gid", (void **)&tmp,
219 NULL) == 0) {
220 if (tmp != NULL)
221 gid = (gid_t)strtol(tmp, &ep, 10);
222 if (tmp == NULL || *ep) {
223 vfs_mount_error(mp, "Invalid gid");
224 return (EINVAL);
225 }
226 }
227 if (vfs_getopt(mp->mnt_optnew, "copymode", (void **)&tmp,
228 NULL) == 0) {
229 if (tmp == NULL) {
230 vfs_mount_error(mp, "Invalid copymode");
231 return (EINVAL);
232 } else if (strcasecmp(tmp, "traditional") == 0)
233 copymode = UNIONFS_TRADITIONAL;
234 else if (strcasecmp(tmp, "transparent") == 0)
235 copymode = UNIONFS_TRANSPARENT;
236 else if (strcasecmp(tmp, "masquerade") == 0)
237 copymode = UNIONFS_MASQUERADE;
238 else {
239 vfs_mount_error(mp, "Invalid copymode");
240 return (EINVAL);
241 }
242 }
243 if (vfs_getopt(mp->mnt_optnew, "whiteout", (void **)&tmp,
244 NULL) == 0) {
245 if (tmp == NULL) {
246 vfs_mount_error(mp, "Invalid whiteout mode");
247 return (EINVAL);
248 } else if (strcasecmp(tmp, "always") == 0)
249 whitemode = UNIONFS_WHITE_ALWAYS;
250 else if (strcasecmp(tmp, "whenneeded") == 0)
251 whitemode = UNIONFS_WHITE_WHENNEEDED;
252 else {
253 vfs_mount_error(mp, "Invalid whiteout mode");
254 return (EINVAL);
255 }
256 }
257 }
258 /* If copymode is UNIONFS_TRADITIONAL, uid/gid is mounted user. */
259 if (copymode == UNIONFS_TRADITIONAL) {
260 uid = mp->mnt_cred->cr_ruid;
261 gid = mp->mnt_cred->cr_rgid;
262 }
263
264 UNIONFSDEBUG("unionfs_mount: uid=%d, gid=%d\n", uid, gid);
265 UNIONFSDEBUG("unionfs_mount: udir=0%03o, ufile=0%03o\n", udir, ufile);
266 UNIONFSDEBUG("unionfs_mount: copymode=%d\n", copymode);
267
268 /*
269 * Find upper node
270 */
271 NDINIT(ndp, LOOKUP, FOLLOW | WANTPARENT | LOCKLEAF, UIO_SYSSPACE, target, td);
272 if ((error = namei(ndp)))
273 return (error);
274
275 NDFREE(ndp, NDF_ONLY_PNBUF);
276
277 /* get root vnodes */
278 lowerrootvp = mp->mnt_vnodecovered;
279 upperrootvp = ndp->ni_vp;
280
281 vrele(ndp->ni_dvp);
282 ndp->ni_dvp = NULLVP;
283
284 /* create unionfs_mount */
285 ump = (struct unionfs_mount *)malloc(sizeof(struct unionfs_mount),
286 M_UNIONFSMNT, M_WAITOK | M_ZERO);
287
288 /*
289 * Save reference
290 */
291 if (below) {
292 VOP_UNLOCK(upperrootvp, 0, td);
293 vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY, td);
294 ump->um_lowervp = upperrootvp;
295 ump->um_uppervp = lowerrootvp;
296 } else {
297 ump->um_lowervp = lowerrootvp;
298 ump->um_uppervp = upperrootvp;
299 }
300 ump->um_rootvp = NULLVP;
301 ump->um_uid = uid;
302 ump->um_gid = gid;
303 ump->um_udir = udir;
304 ump->um_ufile = ufile;
305 ump->um_copymode = copymode;
306 ump->um_whitemode = whitemode;
307
308 MNT_ILOCK(mp);
309 if ((lowerrootvp->v_mount->mnt_kern_flag & MNTK_MPSAFE) &&
310 (upperrootvp->v_mount->mnt_kern_flag & MNTK_MPSAFE))
311 mp->mnt_kern_flag |= MNTK_MPSAFE;
312 MNT_IUNLOCK(mp);
313 mp->mnt_data = (qaddr_t)ump;
314
315 /*
316 * Copy upper layer's RDONLY flag.
317 */
318 mp->mnt_flag |= ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY;
319
320 /*
321 * Check whiteout
322 */
323 if ((mp->mnt_flag & MNT_RDONLY) == 0) {
324 memset(&fakecn, 0, sizeof(fakecn));
325 fakecn.cn_nameiop = LOOKUP;
326 fakecn.cn_thread = td;
327 error = VOP_WHITEOUT(ump->um_uppervp, &fakecn, LOOKUP);
328 if (error) {
329 if (below) {
330 VOP_UNLOCK(ump->um_uppervp, 0, td);
331 vrele(upperrootvp);
332 } else
333 vput(ump->um_uppervp);
334 free(ump, M_UNIONFSMNT);
335 mp->mnt_data = NULL;
336 return (error);
337 }
338 }
339
340 /*
341 * Unlock the node
342 */
343 VOP_UNLOCK(ump->um_uppervp, 0, td);
344
345 /*
346 * Get the unionfs root vnode.
347 */
348 error = unionfs_nodeget(mp, ump->um_uppervp, ump->um_lowervp,
349 NULLVP, &(ump->um_rootvp), NULL, td);
350 vrele(upperrootvp);
351 if (error) {
352 free(ump, M_UNIONFSMNT);
353 mp->mnt_data = NULL;
354 return (error);
355 }
356
357 /*
358 * Check mnt_flag
359 */
360 if ((ump->um_lowervp->v_mount->mnt_flag & MNT_LOCAL) &&
361 (ump->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))
362 mp->mnt_flag |= MNT_LOCAL;
363
364 /*
365 * Get new fsid
366 */
367 vfs_getnewfsid(mp);
368
369 len = MNAMELEN - 1;
370 tmp = mp->mnt_stat.f_mntfromname;
371 copystr((below ? "<below>:" : "<above>:"), tmp, len, &done);
372 len -= done - 1;
373 tmp += done - 1;
374 copystr(target, tmp, len, NULL);
375
376 UNIONFSDEBUG("unionfs_mount: from %s, on %s\n",
377 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
378
379 return (0);
380 }
381
382 /*
383 * Free reference to unionfs layer
384 */
385 static int
386 unionfs_unmount(struct mount *mp, int mntflags, struct thread *td)
387 {
388 struct unionfs_mount *ump;
389 int error;
390 int num;
391 int freeing;
392 int flags;
393
394 UNIONFSDEBUG("unionfs_unmount: mp = %p\n", (void *)mp);
395
396 ump = MOUNTTOUNIONFSMOUNT(mp);
397 flags = 0;
398
399 if (mntflags & MNT_FORCE)
400 flags |= FORCECLOSE;
401
402 /* vflush (no need to call vrele) */
403 for (freeing = 0; (error = vflush(mp, 1, flags, td)) != 0;) {
404 num = mp->mnt_nvnodelistsize;
405 if (num == freeing)
406 break;
407 freeing = num;
408 }
409
410 if (error)
411 return (error);
412
413 free(ump, M_UNIONFSMNT);
414 mp->mnt_data = 0;
415
416 return (0);
417 }
418
419 static int
420 unionfs_root(struct mount *mp, int flags, struct vnode **vpp, struct thread *td)
421 {
422 struct unionfs_mount *ump;
423 struct vnode *vp;
424
425 ump = MOUNTTOUNIONFSMOUNT(mp);
426 vp = ump->um_rootvp;
427
428 UNIONFSDEBUG("unionfs_root: rootvp=%p locked=%x\n",
429 vp, VOP_ISLOCKED(vp, td));
430
431 vref(vp);
432 if (flags & LK_TYPE_MASK)
433 vn_lock(vp, flags, td);
434
435 *vpp = vp;
436
437 return (0);
438 }
439
440 static int
441 unionfs_quotactl(struct mount *mp, int cmd, uid_t uid, caddr_t arg,
442 struct thread *td)
443 {
444 struct unionfs_mount *ump;
445
446 ump = MOUNTTOUNIONFSMOUNT(mp);
447
448 /*
449 * Writing is always performed to upper vnode.
450 */
451 return (VFS_QUOTACTL(ump->um_uppervp->v_mount, cmd, uid, arg, td));
452 }
453
454 static int
455 unionfs_statfs(struct mount *mp, struct statfs *sbp, struct thread *td)
456 {
457 struct unionfs_mount *ump;
458 int error;
459 struct statfs mstat;
460 uint64_t lbsize;
461
462 ump = MOUNTTOUNIONFSMOUNT(mp);
463
464 UNIONFSDEBUG("unionfs_statfs(mp = %p, lvp = %p, uvp = %p)\n",
465 (void *)mp, (void *)ump->um_lowervp, (void *)ump->um_uppervp);
466
467 bzero(&mstat, sizeof(mstat));
468
469 error = VFS_STATFS(ump->um_lowervp->v_mount, &mstat, td);
470 if (error)
471 return (error);
472
473 /* now copy across the "interesting" information and fake the rest */
474 sbp->f_blocks = mstat.f_blocks;
475 sbp->f_files = mstat.f_files;
476
477 lbsize = mstat.f_bsize;
478
479 error = VFS_STATFS(ump->um_uppervp->v_mount, &mstat, td);
480 if (error)
481 return (error);
482
483 /*
484 * The FS type etc is copy from upper vfs.
485 * (write able vfs have priority)
486 */
487 sbp->f_type = mstat.f_type;
488 sbp->f_flags = mstat.f_flags;
489 sbp->f_bsize = mstat.f_bsize;
490 sbp->f_iosize = mstat.f_iosize;
491
492 if (mstat.f_bsize != lbsize)
493 sbp->f_blocks = ((off_t)sbp->f_blocks * lbsize) / mstat.f_bsize;
494
495 sbp->f_blocks += mstat.f_blocks;
496 sbp->f_bfree = mstat.f_bfree;
497 sbp->f_bavail = mstat.f_bavail;
498 sbp->f_files += mstat.f_files;
499 sbp->f_ffree = mstat.f_ffree;
500 return (0);
501 }
502
503 static int
504 unionfs_sync(struct mount *mp, int waitfor, struct thread *td)
505 {
506 /* nothing to do */
507 return (0);
508 }
509
510 static int
511 unionfs_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
512 {
513 return (EOPNOTSUPP);
514 }
515
516 static int
517 unionfs_fhtovp(struct mount *mp, struct fid *fidp, struct vnode **vpp)
518 {
519 return (EOPNOTSUPP);
520 }
521
522 static int
523 unionfs_checkexp(struct mount *mp, struct sockaddr *nam, int *extflagsp,
524 struct ucred **credanonp)
525 {
526 return (EOPNOTSUPP);
527 }
528
529 static int
530 unionfs_vptofh(struct vnode *vp, struct fid *fhp)
531 {
532 return (EOPNOTSUPP);
533 }
534
535 static int
536 unionfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp,
537 int namespace, const char *attrname, struct thread *td)
538 {
539 struct unionfs_mount *ump;
540 struct unionfs_node *unp;
541
542 ump = MOUNTTOUNIONFSMOUNT(mp);
543 unp = VTOUNIONFS(filename_vp);
544
545 if (unp->un_uppervp != NULLVP) {
546 return (VFS_EXTATTRCTL(ump->um_uppervp->v_mount, cmd,
547 unp->un_uppervp, namespace, attrname, td));
548 } else {
549 return (VFS_EXTATTRCTL(ump->um_lowervp->v_mount, cmd,
550 unp->un_lowervp, namespace, attrname, td));
551 }
552 }
553
554 static struct vfsops unionfs_vfsops = {
555 .vfs_checkexp = unionfs_checkexp,
556 .vfs_extattrctl = unionfs_extattrctl,
557 .vfs_fhtovp = unionfs_fhtovp,
558 .vfs_init = unionfs_init,
559 .vfs_mount = unionfs_domount,
560 .vfs_quotactl = unionfs_quotactl,
561 .vfs_root = unionfs_root,
562 .vfs_statfs = unionfs_statfs,
563 .vfs_sync = unionfs_sync,
564 .vfs_uninit = unionfs_uninit,
565 .vfs_unmount = unionfs_unmount,
566 .vfs_vget = unionfs_vget,
567 .vfs_vptofh = unionfs_vptofh,
568 };
569
570 VFS_SET(unionfs_vfsops, unionfs, VFCF_LOOPBACK);
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