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