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, 2012 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
5 * Copyright (c) 2006, 2012 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: releng/11.0/sys/fs/unionfs/union_vfsops.c 285182 2015-07-05 22:37:33Z markj $
37 */
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kdb.h>
42 #include <sys/fcntl.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)
74 {
75 int error;
76 struct vnode *lowerrootvp;
77 struct vnode *upperrootvp;
78 struct unionfs_mount *ump;
79 struct thread *td;
80 char *target;
81 char *tmp;
82 char *ep;
83 int len;
84 size_t done;
85 int below;
86 uid_t uid;
87 gid_t gid;
88 u_short udir;
89 u_short ufile;
90 unionfs_copymode copymode;
91 unionfs_whitemode whitemode;
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 td = curthread;
107
108 if (mp->mnt_flag & MNT_ROOTFS) {
109 vfs_mount_error(mp, "Cannot union mount root filesystem");
110 return (EOPNOTSUPP);
111 }
112
113 /*
114 * Update is a no operation.
115 */
116 if (mp->mnt_flag & MNT_UPDATE) {
117 vfs_mount_error(mp, "unionfs does not support mount update");
118 return (EOPNOTSUPP);
119 }
120
121 /*
122 * Get argument
123 */
124 error = vfs_getopt(mp->mnt_optnew, "target", (void **)&target, &len);
125 if (error)
126 error = vfs_getopt(mp->mnt_optnew, "from", (void **)&target,
127 &len);
128 if (error || target[len - 1] != '\0') {
129 vfs_mount_error(mp, "Invalid target");
130 return (EINVAL);
131 }
132 if (vfs_getopt(mp->mnt_optnew, "below", NULL, NULL) == 0)
133 below = 1;
134 if (vfs_getopt(mp->mnt_optnew, "udir", (void **)&tmp, NULL) == 0) {
135 if (tmp != NULL)
136 udir = (mode_t)strtol(tmp, &ep, 8);
137 if (tmp == NULL || *ep) {
138 vfs_mount_error(mp, "Invalid udir");
139 return (EINVAL);
140 }
141 udir &= S_IRWXU | S_IRWXG | S_IRWXO;
142 }
143 if (vfs_getopt(mp->mnt_optnew, "ufile", (void **)&tmp, NULL) == 0) {
144 if (tmp != NULL)
145 ufile = (mode_t)strtol(tmp, &ep, 8);
146 if (tmp == NULL || *ep) {
147 vfs_mount_error(mp, "Invalid ufile");
148 return (EINVAL);
149 }
150 ufile &= S_IRWXU | S_IRWXG | S_IRWXO;
151 }
152 /* check umask, uid and gid */
153 if (udir == 0 && ufile != 0)
154 udir = ufile;
155 if (ufile == 0 && udir != 0)
156 ufile = udir;
157
158 vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY);
159 error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred);
160 if (!error) {
161 if (udir == 0)
162 udir = va.va_mode;
163 if (ufile == 0)
164 ufile = va.va_mode;
165 uid = va.va_uid;
166 gid = va.va_gid;
167 }
168 VOP_UNLOCK(mp->mnt_vnodecovered, LK_RELEASE);
169 if (error)
170 return (error);
171
172 if (mp->mnt_cred->cr_ruid == 0) { /* root only */
173 if (vfs_getopt(mp->mnt_optnew, "uid", (void **)&tmp,
174 NULL) == 0) {
175 if (tmp != NULL)
176 uid = (uid_t)strtol(tmp, &ep, 10);
177 if (tmp == NULL || *ep) {
178 vfs_mount_error(mp, "Invalid uid");
179 return (EINVAL);
180 }
181 }
182 if (vfs_getopt(mp->mnt_optnew, "gid", (void **)&tmp,
183 NULL) == 0) {
184 if (tmp != NULL)
185 gid = (gid_t)strtol(tmp, &ep, 10);
186 if (tmp == NULL || *ep) {
187 vfs_mount_error(mp, "Invalid gid");
188 return (EINVAL);
189 }
190 }
191 if (vfs_getopt(mp->mnt_optnew, "copymode", (void **)&tmp,
192 NULL) == 0) {
193 if (tmp == NULL) {
194 vfs_mount_error(mp, "Invalid copymode");
195 return (EINVAL);
196 } else if (strcasecmp(tmp, "traditional") == 0)
197 copymode = UNIONFS_TRADITIONAL;
198 else if (strcasecmp(tmp, "transparent") == 0)
199 copymode = UNIONFS_TRANSPARENT;
200 else if (strcasecmp(tmp, "masquerade") == 0)
201 copymode = UNIONFS_MASQUERADE;
202 else {
203 vfs_mount_error(mp, "Invalid copymode");
204 return (EINVAL);
205 }
206 }
207 if (vfs_getopt(mp->mnt_optnew, "whiteout", (void **)&tmp,
208 NULL) == 0) {
209 if (tmp == NULL) {
210 vfs_mount_error(mp, "Invalid whiteout mode");
211 return (EINVAL);
212 } else if (strcasecmp(tmp, "always") == 0)
213 whitemode = UNIONFS_WHITE_ALWAYS;
214 else if (strcasecmp(tmp, "whenneeded") == 0)
215 whitemode = UNIONFS_WHITE_WHENNEEDED;
216 else {
217 vfs_mount_error(mp, "Invalid whiteout mode");
218 return (EINVAL);
219 }
220 }
221 }
222 /* If copymode is UNIONFS_TRADITIONAL, uid/gid is mounted user. */
223 if (copymode == UNIONFS_TRADITIONAL) {
224 uid = mp->mnt_cred->cr_ruid;
225 gid = mp->mnt_cred->cr_rgid;
226 }
227
228 UNIONFSDEBUG("unionfs_mount: uid=%d, gid=%d\n", uid, gid);
229 UNIONFSDEBUG("unionfs_mount: udir=0%03o, ufile=0%03o\n", udir, ufile);
230 UNIONFSDEBUG("unionfs_mount: copymode=%d\n", copymode);
231
232 /*
233 * Find upper node
234 */
235 NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, target, td);
236 if ((error = namei(ndp)))
237 return (error);
238
239 NDFREE(ndp, NDF_ONLY_PNBUF);
240
241 /* get root vnodes */
242 lowerrootvp = mp->mnt_vnodecovered;
243 upperrootvp = ndp->ni_vp;
244
245 /* create unionfs_mount */
246 ump = (struct unionfs_mount *)malloc(sizeof(struct unionfs_mount),
247 M_UNIONFSMNT, M_WAITOK | M_ZERO);
248
249 /*
250 * Save reference
251 */
252 if (below) {
253 VOP_UNLOCK(upperrootvp, LK_RELEASE);
254 vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY);
255 ump->um_lowervp = upperrootvp;
256 ump->um_uppervp = lowerrootvp;
257 } else {
258 ump->um_lowervp = lowerrootvp;
259 ump->um_uppervp = upperrootvp;
260 }
261 ump->um_rootvp = NULLVP;
262 ump->um_uid = uid;
263 ump->um_gid = gid;
264 ump->um_udir = udir;
265 ump->um_ufile = ufile;
266 ump->um_copymode = copymode;
267 ump->um_whitemode = whitemode;
268
269 mp->mnt_data = ump;
270
271 /*
272 * Copy upper layer's RDONLY flag.
273 */
274 mp->mnt_flag |= ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY;
275
276 /*
277 * Unlock the node
278 */
279 VOP_UNLOCK(ump->um_uppervp, LK_RELEASE);
280
281 /*
282 * Get the unionfs root vnode.
283 */
284 error = unionfs_nodeget(mp, ump->um_uppervp, ump->um_lowervp,
285 NULLVP, &(ump->um_rootvp), NULL, td);
286 vrele(upperrootvp);
287 if (error) {
288 free(ump, M_UNIONFSMNT);
289 mp->mnt_data = NULL;
290 return (error);
291 }
292
293 MNT_ILOCK(mp);
294 if ((ump->um_lowervp->v_mount->mnt_flag & MNT_LOCAL) &&
295 (ump->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))
296 mp->mnt_flag |= MNT_LOCAL;
297 MNT_IUNLOCK(mp);
298
299 /*
300 * Get new fsid
301 */
302 vfs_getnewfsid(mp);
303
304 len = MNAMELEN - 1;
305 tmp = mp->mnt_stat.f_mntfromname;
306 copystr((below ? "<below>:" : "<above>:"), tmp, len, &done);
307 len -= done - 1;
308 tmp += done - 1;
309 copystr(target, tmp, len, NULL);
310
311 UNIONFSDEBUG("unionfs_mount: from %s, on %s\n",
312 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
313
314 return (0);
315 }
316
317 /*
318 * Free reference to unionfs layer
319 */
320 static int
321 unionfs_unmount(struct mount *mp, int mntflags)
322 {
323 struct unionfs_mount *ump;
324 int error;
325 int num;
326 int freeing;
327 int flags;
328
329 UNIONFSDEBUG("unionfs_unmount: mp = %p\n", (void *)mp);
330
331 ump = MOUNTTOUNIONFSMOUNT(mp);
332 flags = 0;
333
334 if (mntflags & MNT_FORCE)
335 flags |= FORCECLOSE;
336
337 /* vflush (no need to call vrele) */
338 for (freeing = 0; (error = vflush(mp, 1, flags, curthread)) != 0;) {
339 num = mp->mnt_nvnodelistsize;
340 if (num == freeing)
341 break;
342 freeing = num;
343 }
344
345 if (error)
346 return (error);
347
348 free(ump, M_UNIONFSMNT);
349 mp->mnt_data = NULL;
350
351 return (0);
352 }
353
354 static int
355 unionfs_root(struct mount *mp, int flags, struct vnode **vpp)
356 {
357 struct unionfs_mount *ump;
358 struct vnode *vp;
359
360 ump = MOUNTTOUNIONFSMOUNT(mp);
361 vp = ump->um_rootvp;
362
363 UNIONFSDEBUG("unionfs_root: rootvp=%p locked=%x\n",
364 vp, VOP_ISLOCKED(vp));
365
366 vref(vp);
367 if (flags & LK_TYPE_MASK)
368 vn_lock(vp, flags);
369
370 *vpp = vp;
371
372 return (0);
373 }
374
375 static int
376 unionfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg)
377 {
378 struct unionfs_mount *ump;
379
380 ump = MOUNTTOUNIONFSMOUNT(mp);
381
382 /*
383 * Writing is always performed to upper vnode.
384 */
385 return (VFS_QUOTACTL(ump->um_uppervp->v_mount, cmd, uid, arg));
386 }
387
388 static int
389 unionfs_statfs(struct mount *mp, struct statfs *sbp)
390 {
391 struct unionfs_mount *ump;
392 int error;
393 struct statfs mstat;
394 uint64_t lbsize;
395
396 ump = MOUNTTOUNIONFSMOUNT(mp);
397
398 UNIONFSDEBUG("unionfs_statfs(mp = %p, lvp = %p, uvp = %p)\n",
399 (void *)mp, (void *)ump->um_lowervp, (void *)ump->um_uppervp);
400
401 bzero(&mstat, sizeof(mstat));
402
403 error = VFS_STATFS(ump->um_lowervp->v_mount, &mstat);
404 if (error)
405 return (error);
406
407 /* now copy across the "interesting" information and fake the rest */
408 sbp->f_blocks = mstat.f_blocks;
409 sbp->f_files = mstat.f_files;
410
411 lbsize = mstat.f_bsize;
412
413 error = VFS_STATFS(ump->um_uppervp->v_mount, &mstat);
414 if (error)
415 return (error);
416
417 /*
418 * The FS type etc is copy from upper vfs.
419 * (write able vfs have priority)
420 */
421 sbp->f_type = mstat.f_type;
422 sbp->f_flags = mstat.f_flags;
423 sbp->f_bsize = mstat.f_bsize;
424 sbp->f_iosize = mstat.f_iosize;
425
426 if (mstat.f_bsize != lbsize)
427 sbp->f_blocks = ((off_t)sbp->f_blocks * lbsize) / mstat.f_bsize;
428
429 sbp->f_blocks += mstat.f_blocks;
430 sbp->f_bfree = mstat.f_bfree;
431 sbp->f_bavail = mstat.f_bavail;
432 sbp->f_files += mstat.f_files;
433 sbp->f_ffree = mstat.f_ffree;
434 return (0);
435 }
436
437 static int
438 unionfs_sync(struct mount *mp, int waitfor)
439 {
440 /* nothing to do */
441 return (0);
442 }
443
444 static int
445 unionfs_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
446 {
447 return (EOPNOTSUPP);
448 }
449
450 static int
451 unionfs_fhtovp(struct mount *mp, struct fid *fidp, int flags,
452 struct vnode **vpp)
453 {
454 return (EOPNOTSUPP);
455 }
456
457 static int
458 unionfs_checkexp(struct mount *mp, struct sockaddr *nam, int *extflagsp,
459 struct ucred **credanonp, int *numsecflavors, int **secflavors)
460 {
461 return (EOPNOTSUPP);
462 }
463
464 static int
465 unionfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp,
466 int namespace, const char *attrname)
467 {
468 struct unionfs_mount *ump;
469 struct unionfs_node *unp;
470
471 ump = MOUNTTOUNIONFSMOUNT(mp);
472 unp = VTOUNIONFS(filename_vp);
473
474 if (unp->un_uppervp != NULLVP) {
475 return (VFS_EXTATTRCTL(ump->um_uppervp->v_mount, cmd,
476 unp->un_uppervp, namespace, attrname));
477 } else {
478 return (VFS_EXTATTRCTL(ump->um_lowervp->v_mount, cmd,
479 unp->un_lowervp, namespace, attrname));
480 }
481 }
482
483 static struct vfsops unionfs_vfsops = {
484 .vfs_checkexp = unionfs_checkexp,
485 .vfs_extattrctl = unionfs_extattrctl,
486 .vfs_fhtovp = unionfs_fhtovp,
487 .vfs_init = unionfs_init,
488 .vfs_mount = unionfs_domount,
489 .vfs_quotactl = unionfs_quotactl,
490 .vfs_root = unionfs_root,
491 .vfs_statfs = unionfs_statfs,
492 .vfs_sync = unionfs_sync,
493 .vfs_uninit = unionfs_uninit,
494 .vfs_unmount = unionfs_unmount,
495 .vfs_vget = unionfs_vget,
496 };
497
498 VFS_SET(unionfs_vfsops, unionfs, VFCF_LOOPBACK);
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