FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_mount.c
1 /*-
2 * Copyright (c) 1999-2004 Poul-Henning Kamp
3 * Copyright (c) 1999 Michael Smith
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/8.2/sys/kern/vfs_mount.c 214420 2010-10-27 15:44:49Z kib $");
39
40 #include <sys/param.h>
41 #include <sys/conf.h>
42 #include <sys/fcntl.h>
43 #include <sys/jail.h>
44 #include <sys/kernel.h>
45 #include <sys/libkern.h>
46 #include <sys/malloc.h>
47 #include <sys/mount.h>
48 #include <sys/mutex.h>
49 #include <sys/namei.h>
50 #include <sys/priv.h>
51 #include <sys/proc.h>
52 #include <sys/filedesc.h>
53 #include <sys/reboot.h>
54 #include <sys/syscallsubr.h>
55 #include <sys/sysproto.h>
56 #include <sys/sx.h>
57 #include <sys/sysctl.h>
58 #include <sys/sysent.h>
59 #include <sys/systm.h>
60 #include <sys/vnode.h>
61 #include <vm/uma.h>
62
63 #include <geom/geom.h>
64
65 #include <machine/stdarg.h>
66
67 #include <security/audit/audit.h>
68 #include <security/mac/mac_framework.h>
69
70 #include "opt_rootdevname.h"
71
72 #define ROOTNAME "root_device"
73 #define VFS_MOUNTARG_SIZE_MAX (1024 * 64)
74
75 static void set_rootvnode(void);
76 static int vfs_domount(struct thread *td, const char *fstype,
77 char *fspath, int fsflags, void *fsdata);
78 static int vfs_mountroot_ask(void);
79 static int vfs_mountroot_try(const char *mountfrom, const char *options);
80 static void free_mntarg(struct mntarg *ma);
81
82 static int usermount = 0;
83 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
84 "Unprivileged users may mount and unmount file systems");
85
86 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
87 MALLOC_DEFINE(M_VNODE_MARKER, "vnodemarker", "vnode marker");
88 static uma_zone_t mount_zone;
89
90 /* List of mounted filesystems. */
91 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist);
92
93 /* For any iteration/modification of mountlist */
94 struct mtx mountlist_mtx;
95 MTX_SYSINIT(mountlist, &mountlist_mtx, "mountlist", MTX_DEF);
96
97 /*
98 * The vnode of the system's root (/ in the filesystem, without chroot
99 * active.)
100 */
101 struct vnode *rootvnode;
102
103 /*
104 * The root filesystem is detailed in the kernel environment variable
105 * vfs.root.mountfrom, which is expected to be in the general format
106 *
107 * <vfsname>:[<path>][ <vfsname>:[<path>] ...]
108 * vfsname := the name of a VFS known to the kernel and capable
109 * of being mounted as root
110 * path := disk device name or other data used by the filesystem
111 * to locate its physical store
112 *
113 * If the environment variable vfs.root.mountfrom is a space separated list,
114 * each list element is tried in turn and the root filesystem will be mounted
115 * from the first one that suceeds.
116 *
117 * The environment variable vfs.root.mountfrom.options is a comma delimited
118 * set of string mount options. These mount options must be parseable
119 * by nmount() in the kernel.
120 */
121
122 /*
123 * Global opts, taken by all filesystems
124 */
125 static const char *global_opts[] = {
126 "errmsg",
127 "fstype",
128 "fspath",
129 "ro",
130 "rw",
131 "nosuid",
132 "noexec",
133 NULL
134 };
135
136 /*
137 * The root specifiers we will try if RB_CDROM is specified.
138 */
139 static char *cdrom_rootdevnames[] = {
140 "cd9660:cd0",
141 "cd9660:acd0",
142 NULL
143 };
144
145 /* legacy find-root code */
146 char *rootdevnames[2] = {NULL, NULL};
147 #ifndef ROOTDEVNAME
148 # define ROOTDEVNAME NULL
149 #endif
150 static const char *ctrootdevname = ROOTDEVNAME;
151
152 /*
153 * ---------------------------------------------------------------------
154 * Functions for building and sanitizing the mount options
155 */
156
157 /* Remove one mount option. */
158 static void
159 vfs_freeopt(struct vfsoptlist *opts, struct vfsopt *opt)
160 {
161
162 TAILQ_REMOVE(opts, opt, link);
163 free(opt->name, M_MOUNT);
164 if (opt->value != NULL)
165 free(opt->value, M_MOUNT);
166 free(opt, M_MOUNT);
167 }
168
169 /* Release all resources related to the mount options. */
170 void
171 vfs_freeopts(struct vfsoptlist *opts)
172 {
173 struct vfsopt *opt;
174
175 while (!TAILQ_EMPTY(opts)) {
176 opt = TAILQ_FIRST(opts);
177 vfs_freeopt(opts, opt);
178 }
179 free(opts, M_MOUNT);
180 }
181
182 void
183 vfs_deleteopt(struct vfsoptlist *opts, const char *name)
184 {
185 struct vfsopt *opt, *temp;
186
187 if (opts == NULL)
188 return;
189 TAILQ_FOREACH_SAFE(opt, opts, link, temp) {
190 if (strcmp(opt->name, name) == 0)
191 vfs_freeopt(opts, opt);
192 }
193 }
194
195 /*
196 * Check if options are equal (with or without the "no" prefix).
197 */
198 static int
199 vfs_equalopts(const char *opt1, const char *opt2)
200 {
201 char *p;
202
203 /* "opt" vs. "opt" or "noopt" vs. "noopt" */
204 if (strcmp(opt1, opt2) == 0)
205 return (1);
206 /* "noopt" vs. "opt" */
207 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
208 return (1);
209 /* "opt" vs. "noopt" */
210 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
211 return (1);
212 while ((p = strchr(opt1, '.')) != NULL &&
213 !strncmp(opt1, opt2, ++p - opt1)) {
214 opt2 += p - opt1;
215 opt1 = p;
216 /* "foo.noopt" vs. "foo.opt" */
217 if (strncmp(opt1, "no", 2) == 0 && strcmp(opt1 + 2, opt2) == 0)
218 return (1);
219 /* "foo.opt" vs. "foo.noopt" */
220 if (strncmp(opt2, "no", 2) == 0 && strcmp(opt1, opt2 + 2) == 0)
221 return (1);
222 }
223 return (0);
224 }
225
226 /*
227 * If a mount option is specified several times,
228 * (with or without the "no" prefix) only keep
229 * the last occurence of it.
230 */
231 static void
232 vfs_sanitizeopts(struct vfsoptlist *opts)
233 {
234 struct vfsopt *opt, *opt2, *tmp;
235
236 TAILQ_FOREACH_REVERSE(opt, opts, vfsoptlist, link) {
237 opt2 = TAILQ_PREV(opt, vfsoptlist, link);
238 while (opt2 != NULL) {
239 if (vfs_equalopts(opt->name, opt2->name)) {
240 tmp = TAILQ_PREV(opt2, vfsoptlist, link);
241 vfs_freeopt(opts, opt2);
242 opt2 = tmp;
243 } else {
244 opt2 = TAILQ_PREV(opt2, vfsoptlist, link);
245 }
246 }
247 }
248 }
249
250 /*
251 * Build a linked list of mount options from a struct uio.
252 */
253 int
254 vfs_buildopts(struct uio *auio, struct vfsoptlist **options)
255 {
256 struct vfsoptlist *opts;
257 struct vfsopt *opt;
258 size_t memused, namelen, optlen;
259 unsigned int i, iovcnt;
260 int error;
261
262 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
263 TAILQ_INIT(opts);
264 memused = 0;
265 iovcnt = auio->uio_iovcnt;
266 for (i = 0; i < iovcnt; i += 2) {
267 namelen = auio->uio_iov[i].iov_len;
268 optlen = auio->uio_iov[i + 1].iov_len;
269 memused += sizeof(struct vfsopt) + optlen + namelen;
270 /*
271 * Avoid consuming too much memory, and attempts to overflow
272 * memused.
273 */
274 if (memused > VFS_MOUNTARG_SIZE_MAX ||
275 optlen > VFS_MOUNTARG_SIZE_MAX ||
276 namelen > VFS_MOUNTARG_SIZE_MAX) {
277 error = EINVAL;
278 goto bad;
279 }
280
281 opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
282 opt->name = malloc(namelen, M_MOUNT, M_WAITOK);
283 opt->value = NULL;
284 opt->len = 0;
285 opt->pos = i / 2;
286 opt->seen = 0;
287
288 /*
289 * Do this early, so jumps to "bad" will free the current
290 * option.
291 */
292 TAILQ_INSERT_TAIL(opts, opt, link);
293
294 if (auio->uio_segflg == UIO_SYSSPACE) {
295 bcopy(auio->uio_iov[i].iov_base, opt->name, namelen);
296 } else {
297 error = copyin(auio->uio_iov[i].iov_base, opt->name,
298 namelen);
299 if (error)
300 goto bad;
301 }
302 /* Ensure names are null-terminated strings. */
303 if (namelen == 0 || opt->name[namelen - 1] != '\0') {
304 error = EINVAL;
305 goto bad;
306 }
307 if (optlen != 0) {
308 opt->len = optlen;
309 opt->value = malloc(optlen, M_MOUNT, M_WAITOK);
310 if (auio->uio_segflg == UIO_SYSSPACE) {
311 bcopy(auio->uio_iov[i + 1].iov_base, opt->value,
312 optlen);
313 } else {
314 error = copyin(auio->uio_iov[i + 1].iov_base,
315 opt->value, optlen);
316 if (error)
317 goto bad;
318 }
319 }
320 }
321 vfs_sanitizeopts(opts);
322 *options = opts;
323 return (0);
324 bad:
325 vfs_freeopts(opts);
326 return (error);
327 }
328
329 /*
330 * Merge the old mount options with the new ones passed
331 * in the MNT_UPDATE case.
332 *
333 * XXX This function will keep a "nofoo" option in the
334 * new options if there is no matching "foo" option
335 * to be cancelled in the old options. This is a bug
336 * if the option's canonical name is "foo". E.g., "noro"
337 * shouldn't end up in the mount point's active options,
338 * but it can.
339 */
340 static void
341 vfs_mergeopts(struct vfsoptlist *toopts, struct vfsoptlist *opts)
342 {
343 struct vfsopt *opt, *opt2, *new;
344
345 TAILQ_FOREACH(opt, opts, link) {
346 /*
347 * Check that this option hasn't been redefined
348 * nor cancelled with a "no" mount option.
349 */
350 opt2 = TAILQ_FIRST(toopts);
351 while (opt2 != NULL) {
352 if (strcmp(opt2->name, opt->name) == 0)
353 goto next;
354 if (strncmp(opt2->name, "no", 2) == 0 &&
355 strcmp(opt2->name + 2, opt->name) == 0) {
356 vfs_freeopt(toopts, opt2);
357 goto next;
358 }
359 opt2 = TAILQ_NEXT(opt2, link);
360 }
361 /* We want this option, duplicate it. */
362 new = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
363 new->name = malloc(strlen(opt->name) + 1, M_MOUNT, M_WAITOK);
364 strcpy(new->name, opt->name);
365 if (opt->len != 0) {
366 new->value = malloc(opt->len, M_MOUNT, M_WAITOK);
367 bcopy(opt->value, new->value, opt->len);
368 } else {
369 new->value = NULL;
370 }
371 new->len = opt->len;
372 new->seen = opt->seen;
373 TAILQ_INSERT_TAIL(toopts, new, link);
374 next:
375 continue;
376 }
377 }
378
379 /*
380 * Mount a filesystem.
381 */
382 int
383 nmount(td, uap)
384 struct thread *td;
385 struct nmount_args /* {
386 struct iovec *iovp;
387 unsigned int iovcnt;
388 int flags;
389 } */ *uap;
390 {
391 struct uio *auio;
392 int error;
393 u_int iovcnt;
394
395 AUDIT_ARG_FFLAGS(uap->flags);
396 CTR4(KTR_VFS, "%s: iovp %p with iovcnt %d and flags %d", __func__,
397 uap->iovp, uap->iovcnt, uap->flags);
398
399 /*
400 * Filter out MNT_ROOTFS. We do not want clients of nmount() in
401 * userspace to set this flag, but we must filter it out if we want
402 * MNT_UPDATE on the root file system to work.
403 * MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try().
404 */
405 uap->flags &= ~MNT_ROOTFS;
406
407 iovcnt = uap->iovcnt;
408 /*
409 * Check that we have an even number of iovec's
410 * and that we have at least two options.
411 */
412 if ((iovcnt & 1) || (iovcnt < 4)) {
413 CTR2(KTR_VFS, "%s: failed for invalid iovcnt %d", __func__,
414 uap->iovcnt);
415 return (EINVAL);
416 }
417
418 error = copyinuio(uap->iovp, iovcnt, &auio);
419 if (error) {
420 CTR2(KTR_VFS, "%s: failed for invalid uio op with %d errno",
421 __func__, error);
422 return (error);
423 }
424 error = vfs_donmount(td, uap->flags, auio);
425
426 free(auio, M_IOV);
427 return (error);
428 }
429
430 /*
431 * ---------------------------------------------------------------------
432 * Various utility functions
433 */
434
435 void
436 vfs_ref(struct mount *mp)
437 {
438
439 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
440 MNT_ILOCK(mp);
441 MNT_REF(mp);
442 MNT_IUNLOCK(mp);
443 }
444
445 void
446 vfs_rel(struct mount *mp)
447 {
448
449 CTR2(KTR_VFS, "%s: mp %p", __func__, mp);
450 MNT_ILOCK(mp);
451 MNT_REL(mp);
452 MNT_IUNLOCK(mp);
453 }
454
455 static int
456 mount_init(void *mem, int size, int flags)
457 {
458 struct mount *mp;
459
460 mp = (struct mount *)mem;
461 mtx_init(&mp->mnt_mtx, "struct mount mtx", NULL, MTX_DEF);
462 lockinit(&mp->mnt_explock, PVFS, "explock", 0, 0);
463 return (0);
464 }
465
466 static void
467 mount_fini(void *mem, int size)
468 {
469 struct mount *mp;
470
471 mp = (struct mount *)mem;
472 lockdestroy(&mp->mnt_explock);
473 mtx_destroy(&mp->mnt_mtx);
474 }
475
476 /*
477 * Allocate and initialize the mount point struct.
478 */
479 struct mount *
480 vfs_mount_alloc(struct vnode *vp, struct vfsconf *vfsp, const char *fspath,
481 struct ucred *cred)
482 {
483 struct mount *mp;
484
485 mp = uma_zalloc(mount_zone, M_WAITOK);
486 bzero(&mp->mnt_startzero,
487 __rangeof(struct mount, mnt_startzero, mnt_endzero));
488 TAILQ_INIT(&mp->mnt_nvnodelist);
489 mp->mnt_nvnodelistsize = 0;
490 mp->mnt_ref = 0;
491 (void) vfs_busy(mp, MBF_NOWAIT);
492 mp->mnt_op = vfsp->vfc_vfsops;
493 mp->mnt_vfc = vfsp;
494 vfsp->vfc_refcount++; /* XXX Unlocked */
495 mp->mnt_stat.f_type = vfsp->vfc_typenum;
496 mp->mnt_gen++;
497 strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
498 mp->mnt_vnodecovered = vp;
499 mp->mnt_cred = crdup(cred);
500 mp->mnt_stat.f_owner = cred->cr_uid;
501 strlcpy(mp->mnt_stat.f_mntonname, fspath, MNAMELEN);
502 mp->mnt_iosize_max = DFLTPHYS;
503 #ifdef MAC
504 mac_mount_init(mp);
505 mac_mount_create(cred, mp);
506 #endif
507 arc4rand(&mp->mnt_hashseed, sizeof mp->mnt_hashseed, 0);
508 return (mp);
509 }
510
511 /*
512 * Destroy the mount struct previously allocated by vfs_mount_alloc().
513 */
514 void
515 vfs_mount_destroy(struct mount *mp)
516 {
517
518 MNT_ILOCK(mp);
519 mp->mnt_kern_flag |= MNTK_REFEXPIRE;
520 if (mp->mnt_kern_flag & MNTK_MWAIT) {
521 mp->mnt_kern_flag &= ~MNTK_MWAIT;
522 wakeup(mp);
523 }
524 while (mp->mnt_ref)
525 msleep(mp, MNT_MTX(mp), PVFS, "mntref", 0);
526 KASSERT(mp->mnt_ref == 0,
527 ("%s: invalid refcount in the drain path @ %s:%d", __func__,
528 __FILE__, __LINE__));
529 if (mp->mnt_writeopcount != 0)
530 panic("vfs_mount_destroy: nonzero writeopcount");
531 if (mp->mnt_secondary_writes != 0)
532 panic("vfs_mount_destroy: nonzero secondary_writes");
533 mp->mnt_vfc->vfc_refcount--;
534 if (!TAILQ_EMPTY(&mp->mnt_nvnodelist)) {
535 struct vnode *vp;
536
537 TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes)
538 vprint("", vp);
539 panic("unmount: dangling vnode");
540 }
541 if (mp->mnt_nvnodelistsize != 0)
542 panic("vfs_mount_destroy: nonzero nvnodelistsize");
543 if (mp->mnt_lockref != 0)
544 panic("vfs_mount_destroy: nonzero lock refcount");
545 MNT_IUNLOCK(mp);
546 #ifdef MAC
547 mac_mount_destroy(mp);
548 #endif
549 if (mp->mnt_opt != NULL)
550 vfs_freeopts(mp->mnt_opt);
551 crfree(mp->mnt_cred);
552 uma_zfree(mount_zone, mp);
553 }
554
555 int
556 vfs_donmount(struct thread *td, int fsflags, struct uio *fsoptions)
557 {
558 struct vfsoptlist *optlist;
559 struct vfsopt *opt, *noro_opt, *tmp_opt;
560 char *fstype, *fspath, *errmsg;
561 int error, fstypelen, fspathlen, errmsg_len, errmsg_pos;
562 int has_rw, has_noro;
563
564 errmsg = fspath = NULL;
565 errmsg_len = has_noro = has_rw = fspathlen = 0;
566 errmsg_pos = -1;
567
568 error = vfs_buildopts(fsoptions, &optlist);
569 if (error)
570 return (error);
571
572 if (vfs_getopt(optlist, "errmsg", (void **)&errmsg, &errmsg_len) == 0)
573 errmsg_pos = vfs_getopt_pos(optlist, "errmsg");
574
575 /*
576 * We need these two options before the others,
577 * and they are mandatory for any filesystem.
578 * Ensure they are NUL terminated as well.
579 */
580 fstypelen = 0;
581 error = vfs_getopt(optlist, "fstype", (void **)&fstype, &fstypelen);
582 if (error || fstype[fstypelen - 1] != '\0') {
583 error = EINVAL;
584 if (errmsg != NULL)
585 strncpy(errmsg, "Invalid fstype", errmsg_len);
586 goto bail;
587 }
588 fspathlen = 0;
589 error = vfs_getopt(optlist, "fspath", (void **)&fspath, &fspathlen);
590 if (error || fspath[fspathlen - 1] != '\0') {
591 error = EINVAL;
592 if (errmsg != NULL)
593 strncpy(errmsg, "Invalid fspath", errmsg_len);
594 goto bail;
595 }
596
597 /*
598 * We need to see if we have the "update" option
599 * before we call vfs_domount(), since vfs_domount() has special
600 * logic based on MNT_UPDATE. This is very important
601 * when we want to update the root filesystem.
602 */
603 TAILQ_FOREACH_SAFE(opt, optlist, link, tmp_opt) {
604 if (strcmp(opt->name, "update") == 0) {
605 fsflags |= MNT_UPDATE;
606 vfs_freeopt(optlist, opt);
607 }
608 else if (strcmp(opt->name, "async") == 0)
609 fsflags |= MNT_ASYNC;
610 else if (strcmp(opt->name, "force") == 0) {
611 fsflags |= MNT_FORCE;
612 vfs_freeopt(optlist, opt);
613 }
614 else if (strcmp(opt->name, "reload") == 0) {
615 fsflags |= MNT_RELOAD;
616 vfs_freeopt(optlist, opt);
617 }
618 else if (strcmp(opt->name, "multilabel") == 0)
619 fsflags |= MNT_MULTILABEL;
620 else if (strcmp(opt->name, "noasync") == 0)
621 fsflags &= ~MNT_ASYNC;
622 else if (strcmp(opt->name, "noatime") == 0)
623 fsflags |= MNT_NOATIME;
624 else if (strcmp(opt->name, "atime") == 0) {
625 free(opt->name, M_MOUNT);
626 opt->name = strdup("nonoatime", M_MOUNT);
627 }
628 else if (strcmp(opt->name, "noclusterr") == 0)
629 fsflags |= MNT_NOCLUSTERR;
630 else if (strcmp(opt->name, "clusterr") == 0) {
631 free(opt->name, M_MOUNT);
632 opt->name = strdup("nonoclusterr", M_MOUNT);
633 }
634 else if (strcmp(opt->name, "noclusterw") == 0)
635 fsflags |= MNT_NOCLUSTERW;
636 else if (strcmp(opt->name, "clusterw") == 0) {
637 free(opt->name, M_MOUNT);
638 opt->name = strdup("nonoclusterw", M_MOUNT);
639 }
640 else if (strcmp(opt->name, "noexec") == 0)
641 fsflags |= MNT_NOEXEC;
642 else if (strcmp(opt->name, "exec") == 0) {
643 free(opt->name, M_MOUNT);
644 opt->name = strdup("nonoexec", M_MOUNT);
645 }
646 else if (strcmp(opt->name, "nosuid") == 0)
647 fsflags |= MNT_NOSUID;
648 else if (strcmp(opt->name, "suid") == 0) {
649 free(opt->name, M_MOUNT);
650 opt->name = strdup("nonosuid", M_MOUNT);
651 }
652 else if (strcmp(opt->name, "nosymfollow") == 0)
653 fsflags |= MNT_NOSYMFOLLOW;
654 else if (strcmp(opt->name, "symfollow") == 0) {
655 free(opt->name, M_MOUNT);
656 opt->name = strdup("nonosymfollow", M_MOUNT);
657 }
658 else if (strcmp(opt->name, "noro") == 0) {
659 fsflags &= ~MNT_RDONLY;
660 has_noro = 1;
661 }
662 else if (strcmp(opt->name, "rw") == 0) {
663 fsflags &= ~MNT_RDONLY;
664 has_rw = 1;
665 }
666 else if (strcmp(opt->name, "ro") == 0)
667 fsflags |= MNT_RDONLY;
668 else if (strcmp(opt->name, "rdonly") == 0) {
669 free(opt->name, M_MOUNT);
670 opt->name = strdup("ro", M_MOUNT);
671 fsflags |= MNT_RDONLY;
672 }
673 else if (strcmp(opt->name, "suiddir") == 0)
674 fsflags |= MNT_SUIDDIR;
675 else if (strcmp(opt->name, "sync") == 0)
676 fsflags |= MNT_SYNCHRONOUS;
677 else if (strcmp(opt->name, "union") == 0)
678 fsflags |= MNT_UNION;
679 }
680
681 /*
682 * If "rw" was specified as a mount option, and we
683 * are trying to update a mount-point from "ro" to "rw",
684 * we need a mount option "noro", since in vfs_mergeopts(),
685 * "noro" will cancel "ro", but "rw" will not do anything.
686 */
687 if (has_rw && !has_noro) {
688 noro_opt = malloc(sizeof(struct vfsopt), M_MOUNT, M_WAITOK);
689 noro_opt->name = strdup("noro", M_MOUNT);
690 noro_opt->value = NULL;
691 noro_opt->len = 0;
692 noro_opt->pos = -1;
693 noro_opt->seen = 1;
694 TAILQ_INSERT_TAIL(optlist, noro_opt, link);
695 }
696
697 /*
698 * Be ultra-paranoid about making sure the type and fspath
699 * variables will fit in our mp buffers, including the
700 * terminating NUL.
701 */
702 if (fstypelen >= MFSNAMELEN - 1 || fspathlen >= MNAMELEN - 1) {
703 error = ENAMETOOLONG;
704 goto bail;
705 }
706
707 mtx_lock(&Giant);
708 error = vfs_domount(td, fstype, fspath, fsflags, optlist);
709 mtx_unlock(&Giant);
710 bail:
711 /* copyout the errmsg */
712 if (errmsg_pos != -1 && ((2 * errmsg_pos + 1) < fsoptions->uio_iovcnt)
713 && errmsg_len > 0 && errmsg != NULL) {
714 if (fsoptions->uio_segflg == UIO_SYSSPACE) {
715 bcopy(errmsg,
716 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
717 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
718 } else {
719 copyout(errmsg,
720 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_base,
721 fsoptions->uio_iov[2 * errmsg_pos + 1].iov_len);
722 }
723 }
724
725 if (error != 0)
726 vfs_freeopts(optlist);
727 return (error);
728 }
729
730 /*
731 * Old mount API.
732 */
733 #ifndef _SYS_SYSPROTO_H_
734 struct mount_args {
735 char *type;
736 char *path;
737 int flags;
738 caddr_t data;
739 };
740 #endif
741 /* ARGSUSED */
742 int
743 mount(td, uap)
744 struct thread *td;
745 struct mount_args /* {
746 char *type;
747 char *path;
748 int flags;
749 caddr_t data;
750 } */ *uap;
751 {
752 char *fstype;
753 struct vfsconf *vfsp = NULL;
754 struct mntarg *ma = NULL;
755 int error;
756
757 AUDIT_ARG_FFLAGS(uap->flags);
758
759 /*
760 * Filter out MNT_ROOTFS. We do not want clients of mount() in
761 * userspace to set this flag, but we must filter it out if we want
762 * MNT_UPDATE on the root file system to work.
763 * MNT_ROOTFS should only be set in the kernel in vfs_mountroot_try().
764 */
765 uap->flags &= ~MNT_ROOTFS;
766
767 fstype = malloc(MFSNAMELEN, M_TEMP, M_WAITOK);
768 error = copyinstr(uap->type, fstype, MFSNAMELEN, NULL);
769 if (error) {
770 free(fstype, M_TEMP);
771 return (error);
772 }
773
774 AUDIT_ARG_TEXT(fstype);
775 mtx_lock(&Giant);
776 vfsp = vfs_byname_kld(fstype, td, &error);
777 free(fstype, M_TEMP);
778 if (vfsp == NULL) {
779 mtx_unlock(&Giant);
780 return (ENOENT);
781 }
782 if (vfsp->vfc_vfsops->vfs_cmount == NULL) {
783 mtx_unlock(&Giant);
784 return (EOPNOTSUPP);
785 }
786
787 ma = mount_argsu(ma, "fstype", uap->type, MNAMELEN);
788 ma = mount_argsu(ma, "fspath", uap->path, MNAMELEN);
789 ma = mount_argb(ma, uap->flags & MNT_RDONLY, "noro");
790 ma = mount_argb(ma, !(uap->flags & MNT_NOSUID), "nosuid");
791 ma = mount_argb(ma, !(uap->flags & MNT_NOEXEC), "noexec");
792
793 error = vfsp->vfc_vfsops->vfs_cmount(ma, uap->data, uap->flags);
794 mtx_unlock(&Giant);
795 return (error);
796 }
797
798
799 /*
800 * vfs_domount(): actually attempt a filesystem mount.
801 */
802 static int
803 vfs_domount(
804 struct thread *td, /* Calling thread. */
805 const char *fstype, /* Filesystem type. */
806 char *fspath, /* Mount path. */
807 int fsflags, /* Flags common to all filesystems. */
808 void *fsdata /* Options local to the filesystem. */
809 )
810 {
811 struct vnode *vp;
812 struct mount *mp;
813 struct vfsconf *vfsp;
814 struct oexport_args oexport;
815 struct export_args export;
816 int error, flag = 0;
817 struct vattr va;
818 struct nameidata nd;
819
820 mtx_assert(&Giant, MA_OWNED);
821 /*
822 * Be ultra-paranoid about making sure the type and fspath
823 * variables will fit in our mp buffers, including the
824 * terminating NUL.
825 */
826 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
827 return (ENAMETOOLONG);
828
829 if (jailed(td->td_ucred) || usermount == 0) {
830 if ((error = priv_check(td, PRIV_VFS_MOUNT)) != 0)
831 return (error);
832 }
833
834 /*
835 * Do not allow NFS export or MNT_SUIDDIR by unprivileged users.
836 */
837 if (fsflags & MNT_EXPORTED) {
838 error = priv_check(td, PRIV_VFS_MOUNT_EXPORTED);
839 if (error)
840 return (error);
841 }
842 if (fsflags & MNT_SUIDDIR) {
843 error = priv_check(td, PRIV_VFS_MOUNT_SUIDDIR);
844 if (error)
845 return (error);
846 }
847 /*
848 * Silently enforce MNT_NOSUID and MNT_USER for unprivileged users.
849 */
850 if ((fsflags & (MNT_NOSUID | MNT_USER)) != (MNT_NOSUID | MNT_USER)) {
851 if (priv_check(td, PRIV_VFS_MOUNT_NONUSER) != 0)
852 fsflags |= MNT_NOSUID | MNT_USER;
853 }
854
855 /* Load KLDs before we lock the covered vnode to avoid reversals. */
856 vfsp = NULL;
857 if ((fsflags & MNT_UPDATE) == 0) {
858 /* Don't try to load KLDs if we're mounting the root. */
859 if (fsflags & MNT_ROOTFS)
860 vfsp = vfs_byname(fstype);
861 else
862 vfsp = vfs_byname_kld(fstype, td, &error);
863 if (vfsp == NULL)
864 return (ENODEV);
865 if (jailed(td->td_ucred) && !(vfsp->vfc_flags & VFCF_JAIL))
866 return (EPERM);
867 }
868 /*
869 * Get vnode to be covered
870 */
871 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_SYSSPACE,
872 fspath, td);
873 if ((error = namei(&nd)) != 0)
874 return (error);
875 NDFREE(&nd, NDF_ONLY_PNBUF);
876 vp = nd.ni_vp;
877 if (fsflags & MNT_UPDATE) {
878 if ((vp->v_vflag & VV_ROOT) == 0) {
879 vput(vp);
880 return (EINVAL);
881 }
882 mp = vp->v_mount;
883 MNT_ILOCK(mp);
884 flag = mp->mnt_flag;
885 /*
886 * We only allow the filesystem to be reloaded if it
887 * is currently mounted read-only.
888 */
889 if ((fsflags & MNT_RELOAD) &&
890 ((mp->mnt_flag & MNT_RDONLY) == 0)) {
891 MNT_IUNLOCK(mp);
892 vput(vp);
893 return (EOPNOTSUPP); /* Needs translation */
894 }
895 MNT_IUNLOCK(mp);
896 /*
897 * Only privileged root, or (if MNT_USER is set) the user that
898 * did the original mount is permitted to update it.
899 */
900 error = vfs_suser(mp, td);
901 if (error) {
902 vput(vp);
903 return (error);
904 }
905 if (vfs_busy(mp, MBF_NOWAIT)) {
906 vput(vp);
907 return (EBUSY);
908 }
909 VI_LOCK(vp);
910 if ((vp->v_iflag & VI_MOUNT) != 0 ||
911 vp->v_mountedhere != NULL) {
912 VI_UNLOCK(vp);
913 vfs_unbusy(mp);
914 vput(vp);
915 return (EBUSY);
916 }
917 vp->v_iflag |= VI_MOUNT;
918 VI_UNLOCK(vp);
919 MNT_ILOCK(mp);
920 mp->mnt_flag |= fsflags &
921 (MNT_RELOAD | MNT_FORCE | MNT_UPDATE | MNT_SNAPSHOT | MNT_ROOTFS);
922 MNT_IUNLOCK(mp);
923 VOP_UNLOCK(vp, 0);
924 mp->mnt_optnew = fsdata;
925 vfs_mergeopts(mp->mnt_optnew, mp->mnt_opt);
926 } else {
927 /*
928 * If the user is not root, ensure that they own the directory
929 * onto which we are attempting to mount.
930 */
931 error = VOP_GETATTR(vp, &va, td->td_ucred);
932 if (error) {
933 vput(vp);
934 return (error);
935 }
936 if (va.va_uid != td->td_ucred->cr_uid) {
937 error = priv_check_cred(td->td_ucred, PRIV_VFS_ADMIN,
938 0);
939 if (error) {
940 vput(vp);
941 return (error);
942 }
943 }
944 error = vinvalbuf(vp, V_SAVE, 0, 0);
945 if (error != 0) {
946 vput(vp);
947 return (error);
948 }
949 if (vp->v_type != VDIR) {
950 vput(vp);
951 return (ENOTDIR);
952 }
953 VI_LOCK(vp);
954 if ((vp->v_iflag & VI_MOUNT) != 0 ||
955 vp->v_mountedhere != NULL) {
956 VI_UNLOCK(vp);
957 vput(vp);
958 return (EBUSY);
959 }
960 vp->v_iflag |= VI_MOUNT;
961 VI_UNLOCK(vp);
962
963 /*
964 * Allocate and initialize the filesystem.
965 */
966 mp = vfs_mount_alloc(vp, vfsp, fspath, td->td_ucred);
967 VOP_UNLOCK(vp, 0);
968
969 /* XXXMAC: pass to vfs_mount_alloc? */
970 mp->mnt_optnew = fsdata;
971 }
972
973 /*
974 * Set the mount level flags.
975 */
976 MNT_ILOCK(mp);
977 mp->mnt_flag = (mp->mnt_flag & ~MNT_UPDATEMASK) |
978 (fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS |
979 MNT_RDONLY));
980 if ((mp->mnt_flag & MNT_ASYNC) == 0)
981 mp->mnt_kern_flag &= ~MNTK_ASYNC;
982 MNT_IUNLOCK(mp);
983 /*
984 * Mount the filesystem.
985 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
986 * get. No freeing of cn_pnbuf.
987 */
988 error = VFS_MOUNT(mp);
989
990 /*
991 * Process the export option only if we are
992 * updating mount options.
993 */
994 if (!error && (fsflags & MNT_UPDATE)) {
995 if (vfs_copyopt(mp->mnt_optnew, "export", &export,
996 sizeof(export)) == 0)
997 error = vfs_export(mp, &export);
998 else if (vfs_copyopt(mp->mnt_optnew, "export", &oexport,
999 sizeof(oexport)) == 0) {
1000 export.ex_flags = oexport.ex_flags;
1001 export.ex_root = oexport.ex_root;
1002 export.ex_anon = oexport.ex_anon;
1003 export.ex_addr = oexport.ex_addr;
1004 export.ex_addrlen = oexport.ex_addrlen;
1005 export.ex_mask = oexport.ex_mask;
1006 export.ex_masklen = oexport.ex_masklen;
1007 export.ex_indexfile = oexport.ex_indexfile;
1008 export.ex_numsecflavors = 0;
1009 error = vfs_export(mp, &export);
1010 }
1011 }
1012
1013 if (!error) {
1014 if (mp->mnt_opt != NULL)
1015 vfs_freeopts(mp->mnt_opt);
1016 mp->mnt_opt = mp->mnt_optnew;
1017 (void)VFS_STATFS(mp, &mp->mnt_stat);
1018 }
1019 /*
1020 * Prevent external consumers of mount options from reading
1021 * mnt_optnew.
1022 */
1023 mp->mnt_optnew = NULL;
1024 if (mp->mnt_flag & MNT_UPDATE) {
1025 MNT_ILOCK(mp);
1026 if (error)
1027 mp->mnt_flag = (mp->mnt_flag & MNT_QUOTA) |
1028 (flag & ~MNT_QUOTA);
1029 else
1030 mp->mnt_flag &= ~(MNT_UPDATE | MNT_RELOAD |
1031 MNT_FORCE | MNT_SNAPSHOT);
1032 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
1033 mp->mnt_kern_flag |= MNTK_ASYNC;
1034 else
1035 mp->mnt_kern_flag &= ~MNTK_ASYNC;
1036 MNT_IUNLOCK(mp);
1037 if ((mp->mnt_flag & MNT_RDONLY) == 0) {
1038 if (mp->mnt_syncer == NULL)
1039 error = vfs_allocate_syncvnode(mp);
1040 } else {
1041 if (mp->mnt_syncer != NULL)
1042 vrele(mp->mnt_syncer);
1043 mp->mnt_syncer = NULL;
1044 }
1045 vfs_unbusy(mp);
1046 VI_LOCK(vp);
1047 vp->v_iflag &= ~VI_MOUNT;
1048 VI_UNLOCK(vp);
1049 vrele(vp);
1050 return (error);
1051 }
1052 MNT_ILOCK(mp);
1053 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
1054 mp->mnt_kern_flag |= MNTK_ASYNC;
1055 else
1056 mp->mnt_kern_flag &= ~MNTK_ASYNC;
1057 MNT_IUNLOCK(mp);
1058 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1059 /*
1060 * Put the new filesystem on the mount list after root.
1061 */
1062 cache_purge(vp);
1063 if (!error) {
1064 struct vnode *newdp;
1065
1066 VI_LOCK(vp);
1067 vp->v_iflag &= ~VI_MOUNT;
1068 VI_UNLOCK(vp);
1069 vp->v_mountedhere = mp;
1070 mtx_lock(&mountlist_mtx);
1071 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
1072 mtx_unlock(&mountlist_mtx);
1073 vfs_event_signal(NULL, VQ_MOUNT, 0);
1074 if (VFS_ROOT(mp, LK_EXCLUSIVE, &newdp))
1075 panic("mount: lost mount");
1076 VOP_UNLOCK(newdp, 0);
1077 VOP_UNLOCK(vp, 0);
1078 mountcheckdirs(vp, newdp);
1079 vrele(newdp);
1080 if ((mp->mnt_flag & MNT_RDONLY) == 0)
1081 error = vfs_allocate_syncvnode(mp);
1082 vfs_unbusy(mp);
1083 if (error)
1084 vrele(vp);
1085 } else {
1086 VI_LOCK(vp);
1087 vp->v_iflag &= ~VI_MOUNT;
1088 VI_UNLOCK(vp);
1089 vfs_unbusy(mp);
1090 vfs_mount_destroy(mp);
1091 vput(vp);
1092 }
1093 return (error);
1094 }
1095
1096 /*
1097 * Unmount a filesystem.
1098 *
1099 * Note: unmount takes a path to the vnode mounted on as argument, not
1100 * special file (as before).
1101 */
1102 #ifndef _SYS_SYSPROTO_H_
1103 struct unmount_args {
1104 char *path;
1105 int flags;
1106 };
1107 #endif
1108 /* ARGSUSED */
1109 int
1110 unmount(td, uap)
1111 struct thread *td;
1112 register struct unmount_args /* {
1113 char *path;
1114 int flags;
1115 } */ *uap;
1116 {
1117 struct mount *mp;
1118 char *pathbuf;
1119 int error, id0, id1;
1120
1121 AUDIT_ARG_VALUE(uap->flags);
1122 if (jailed(td->td_ucred) || usermount == 0) {
1123 error = priv_check(td, PRIV_VFS_UNMOUNT);
1124 if (error)
1125 return (error);
1126 }
1127
1128 pathbuf = malloc(MNAMELEN, M_TEMP, M_WAITOK);
1129 error = copyinstr(uap->path, pathbuf, MNAMELEN, NULL);
1130 if (error) {
1131 free(pathbuf, M_TEMP);
1132 return (error);
1133 }
1134 mtx_lock(&Giant);
1135 if (uap->flags & MNT_BYFSID) {
1136 AUDIT_ARG_TEXT(pathbuf);
1137 /* Decode the filesystem ID. */
1138 if (sscanf(pathbuf, "FSID:%d:%d", &id0, &id1) != 2) {
1139 mtx_unlock(&Giant);
1140 free(pathbuf, M_TEMP);
1141 return (EINVAL);
1142 }
1143
1144 mtx_lock(&mountlist_mtx);
1145 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1146 if (mp->mnt_stat.f_fsid.val[0] == id0 &&
1147 mp->mnt_stat.f_fsid.val[1] == id1)
1148 break;
1149 }
1150 mtx_unlock(&mountlist_mtx);
1151 } else {
1152 AUDIT_ARG_UPATH1(td, pathbuf);
1153 mtx_lock(&mountlist_mtx);
1154 TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
1155 if (strcmp(mp->mnt_stat.f_mntonname, pathbuf) == 0)
1156 break;
1157 }
1158 mtx_unlock(&mountlist_mtx);
1159 }
1160 free(pathbuf, M_TEMP);
1161 if (mp == NULL) {
1162 /*
1163 * Previously we returned ENOENT for a nonexistent path and
1164 * EINVAL for a non-mountpoint. We cannot tell these apart
1165 * now, so in the !MNT_BYFSID case return the more likely
1166 * EINVAL for compatibility.
1167 */
1168 mtx_unlock(&Giant);
1169 return ((uap->flags & MNT_BYFSID) ? ENOENT : EINVAL);
1170 }
1171
1172 /*
1173 * Don't allow unmounting the root filesystem.
1174 */
1175 if (mp->mnt_flag & MNT_ROOTFS) {
1176 mtx_unlock(&Giant);
1177 return (EINVAL);
1178 }
1179 error = dounmount(mp, uap->flags, td);
1180 mtx_unlock(&Giant);
1181 return (error);
1182 }
1183
1184 /*
1185 * Do the actual filesystem unmount.
1186 */
1187 int
1188 dounmount(mp, flags, td)
1189 struct mount *mp;
1190 int flags;
1191 struct thread *td;
1192 {
1193 struct vnode *coveredvp, *fsrootvp;
1194 int error;
1195 int async_flag;
1196 int mnt_gen_r;
1197
1198 mtx_assert(&Giant, MA_OWNED);
1199
1200 if ((coveredvp = mp->mnt_vnodecovered) != NULL) {
1201 mnt_gen_r = mp->mnt_gen;
1202 VI_LOCK(coveredvp);
1203 vholdl(coveredvp);
1204 vn_lock(coveredvp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY);
1205 vdrop(coveredvp);
1206 /*
1207 * Check for mp being unmounted while waiting for the
1208 * covered vnode lock.
1209 */
1210 if (coveredvp->v_mountedhere != mp ||
1211 coveredvp->v_mountedhere->mnt_gen != mnt_gen_r) {
1212 VOP_UNLOCK(coveredvp, 0);
1213 return (EBUSY);
1214 }
1215 }
1216 /*
1217 * Only privileged root, or (if MNT_USER is set) the user that did the
1218 * original mount is permitted to unmount this filesystem.
1219 */
1220 error = vfs_suser(mp, td);
1221 if (error) {
1222 if (coveredvp)
1223 VOP_UNLOCK(coveredvp, 0);
1224 return (error);
1225 }
1226
1227 MNT_ILOCK(mp);
1228 if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
1229 MNT_IUNLOCK(mp);
1230 if (coveredvp)
1231 VOP_UNLOCK(coveredvp, 0);
1232 return (EBUSY);
1233 }
1234 mp->mnt_kern_flag |= MNTK_UNMOUNT | MNTK_NOINSMNTQ;
1235 /* Allow filesystems to detect that a forced unmount is in progress. */
1236 if (flags & MNT_FORCE)
1237 mp->mnt_kern_flag |= MNTK_UNMOUNTF;
1238 error = 0;
1239 if (mp->mnt_lockref) {
1240 if ((flags & MNT_FORCE) == 0) {
1241 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_NOINSMNTQ |
1242 MNTK_UNMOUNTF);
1243 if (mp->mnt_kern_flag & MNTK_MWAIT) {
1244 mp->mnt_kern_flag &= ~MNTK_MWAIT;
1245 wakeup(mp);
1246 }
1247 MNT_IUNLOCK(mp);
1248 if (coveredvp)
1249 VOP_UNLOCK(coveredvp, 0);
1250 return (EBUSY);
1251 }
1252 mp->mnt_kern_flag |= MNTK_DRAINING;
1253 error = msleep(&mp->mnt_lockref, MNT_MTX(mp), PVFS,
1254 "mount drain", 0);
1255 }
1256 MNT_IUNLOCK(mp);
1257 KASSERT(mp->mnt_lockref == 0,
1258 ("%s: invalid lock refcount in the drain path @ %s:%d",
1259 __func__, __FILE__, __LINE__));
1260 KASSERT(error == 0,
1261 ("%s: invalid return value for msleep in the drain path @ %s:%d",
1262 __func__, __FILE__, __LINE__));
1263 vn_start_write(NULL, &mp, V_WAIT);
1264
1265 if (mp->mnt_flag & MNT_EXPUBLIC)
1266 vfs_setpublicfs(NULL, NULL, NULL);
1267
1268 vfs_msync(mp, MNT_WAIT);
1269 MNT_ILOCK(mp);
1270 async_flag = mp->mnt_flag & MNT_ASYNC;
1271 mp->mnt_flag &= ~MNT_ASYNC;
1272 mp->mnt_kern_flag &= ~MNTK_ASYNC;
1273 MNT_IUNLOCK(mp);
1274 cache_purgevfs(mp); /* remove cache entries for this file sys */
1275 if (mp->mnt_syncer != NULL)
1276 vrele(mp->mnt_syncer);
1277 /*
1278 * For forced unmounts, move process cdir/rdir refs on the fs root
1279 * vnode to the covered vnode. For non-forced unmounts we want
1280 * such references to cause an EBUSY error.
1281 */
1282 if ((flags & MNT_FORCE) &&
1283 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
1284 if (mp->mnt_vnodecovered != NULL)
1285 mountcheckdirs(fsrootvp, mp->mnt_vnodecovered);
1286 if (fsrootvp == rootvnode) {
1287 vrele(rootvnode);
1288 rootvnode = NULL;
1289 }
1290 vput(fsrootvp);
1291 }
1292 if (((mp->mnt_flag & MNT_RDONLY) ||
1293 (error = VFS_SYNC(mp, MNT_WAIT)) == 0) || (flags & MNT_FORCE) != 0)
1294 error = VFS_UNMOUNT(mp, flags);
1295 vn_finished_write(mp);
1296 /*
1297 * If we failed to flush the dirty blocks for this mount point,
1298 * undo all the cdir/rdir and rootvnode changes we made above.
1299 * Unless we failed to do so because the device is reporting that
1300 * it doesn't exist anymore.
1301 */
1302 if (error && error != ENXIO) {
1303 if ((flags & MNT_FORCE) &&
1304 VFS_ROOT(mp, LK_EXCLUSIVE, &fsrootvp) == 0) {
1305 if (mp->mnt_vnodecovered != NULL)
1306 mountcheckdirs(mp->mnt_vnodecovered, fsrootvp);
1307 if (rootvnode == NULL) {
1308 rootvnode = fsrootvp;
1309 vref(rootvnode);
1310 }
1311 vput(fsrootvp);
1312 }
1313 MNT_ILOCK(mp);
1314 mp->mnt_kern_flag &= ~MNTK_NOINSMNTQ;
1315 if ((mp->mnt_flag & MNT_RDONLY) == 0 && mp->mnt_syncer == NULL) {
1316 MNT_IUNLOCK(mp);
1317 (void) vfs_allocate_syncvnode(mp);
1318 MNT_ILOCK(mp);
1319 }
1320 mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
1321 mp->mnt_flag |= async_flag;
1322 if ((mp->mnt_flag & MNT_ASYNC) != 0 && mp->mnt_noasync == 0)
1323 mp->mnt_kern_flag |= MNTK_ASYNC;
1324 if (mp->mnt_kern_flag & MNTK_MWAIT) {
1325 mp->mnt_kern_flag &= ~MNTK_MWAIT;
1326 wakeup(mp);
1327 }
1328 MNT_IUNLOCK(mp);
1329 if (coveredvp)
1330 VOP_UNLOCK(coveredvp, 0);
1331 return (error);
1332 }
1333 mtx_lock(&mountlist_mtx);
1334 TAILQ_REMOVE(&mountlist, mp, mnt_list);
1335 mtx_unlock(&mountlist_mtx);
1336 if (coveredvp != NULL) {
1337 coveredvp->v_mountedhere = NULL;
1338 vput(coveredvp);
1339 }
1340 vfs_event_signal(NULL, VQ_UNMOUNT, 0);
1341 vfs_mount_destroy(mp);
1342 return (0);
1343 }
1344
1345 /*
1346 * ---------------------------------------------------------------------
1347 * Mounting of root filesystem
1348 *
1349 */
1350
1351 struct root_hold_token {
1352 const char *who;
1353 LIST_ENTRY(root_hold_token) list;
1354 };
1355
1356 static LIST_HEAD(, root_hold_token) root_holds =
1357 LIST_HEAD_INITIALIZER(root_holds);
1358
1359 static int root_mount_complete;
1360
1361 /*
1362 * Hold root mount.
1363 */
1364 struct root_hold_token *
1365 root_mount_hold(const char *identifier)
1366 {
1367 struct root_hold_token *h;
1368
1369 if (root_mounted())
1370 return (NULL);
1371
1372 h = malloc(sizeof *h, M_DEVBUF, M_ZERO | M_WAITOK);
1373 h->who = identifier;
1374 mtx_lock(&mountlist_mtx);
1375 LIST_INSERT_HEAD(&root_holds, h, list);
1376 mtx_unlock(&mountlist_mtx);
1377 return (h);
1378 }
1379
1380 /*
1381 * Release root mount.
1382 */
1383 void
1384 root_mount_rel(struct root_hold_token *h)
1385 {
1386
1387 if (h == NULL)
1388 return;
1389 mtx_lock(&mountlist_mtx);
1390 LIST_REMOVE(h, list);
1391 wakeup(&root_holds);
1392 mtx_unlock(&mountlist_mtx);
1393 free(h, M_DEVBUF);
1394 }
1395
1396 /*
1397 * Wait for all subsystems to release root mount.
1398 */
1399 static void
1400 root_mount_prepare(void)
1401 {
1402 struct root_hold_token *h;
1403 struct timeval lastfail;
1404 int curfail = 0;
1405
1406 for (;;) {
1407 DROP_GIANT();
1408 g_waitidle();
1409 PICKUP_GIANT();
1410 mtx_lock(&mountlist_mtx);
1411 if (LIST_EMPTY(&root_holds)) {
1412 mtx_unlock(&mountlist_mtx);
1413 break;
1414 }
1415 if (ppsratecheck(&lastfail, &curfail, 1)) {
1416 printf("Root mount waiting for:");
1417 LIST_FOREACH(h, &root_holds, list)
1418 printf(" %s", h->who);
1419 printf("\n");
1420 }
1421 msleep(&root_holds, &mountlist_mtx, PZERO | PDROP, "roothold",
1422 hz);
1423 }
1424 }
1425
1426 /*
1427 * Root was mounted, share the good news.
1428 */
1429 static void
1430 root_mount_done(void)
1431 {
1432
1433 /* Keep prison0's root in sync with the global rootvnode. */
1434 mtx_lock(&prison0.pr_mtx);
1435 prison0.pr_root = rootvnode;
1436 vref(prison0.pr_root);
1437 mtx_unlock(&prison0.pr_mtx);
1438 /*
1439 * Use a mutex to prevent the wakeup being missed and waiting for
1440 * an extra 1 second sleep.
1441 */
1442 mtx_lock(&mountlist_mtx);
1443 root_mount_complete = 1;
1444 wakeup(&root_mount_complete);
1445 mtx_unlock(&mountlist_mtx);
1446 }
1447
1448 /*
1449 * Return true if root is already mounted.
1450 */
1451 int
1452 root_mounted(void)
1453 {
1454
1455 /* No mutex is acquired here because int stores are atomic. */
1456 return (root_mount_complete);
1457 }
1458
1459 /*
1460 * Wait until root is mounted.
1461 */
1462 void
1463 root_mount_wait(void)
1464 {
1465
1466 /*
1467 * Panic on an obvious deadlock - the function can't be called from
1468 * a thread which is doing the whole SYSINIT stuff.
1469 */
1470 KASSERT(curthread->td_proc->p_pid != 0,
1471 ("root_mount_wait: cannot be called from the swapper thread"));
1472 mtx_lock(&mountlist_mtx);
1473 while (!root_mount_complete) {
1474 msleep(&root_mount_complete, &mountlist_mtx, PZERO, "rootwait",
1475 hz);
1476 }
1477 mtx_unlock(&mountlist_mtx);
1478 }
1479
1480 static void
1481 set_rootvnode()
1482 {
1483 struct proc *p;
1484
1485 if (VFS_ROOT(TAILQ_FIRST(&mountlist), LK_EXCLUSIVE, &rootvnode))
1486 panic("Cannot find root vnode");
1487
1488 VOP_UNLOCK(rootvnode, 0);
1489
1490 p = curthread->td_proc;
1491 FILEDESC_XLOCK(p->p_fd);
1492
1493 if (p->p_fd->fd_cdir != NULL)
1494 vrele(p->p_fd->fd_cdir);
1495 p->p_fd->fd_cdir = rootvnode;
1496 VREF(rootvnode);
1497
1498 if (p->p_fd->fd_rdir != NULL)
1499 vrele(p->p_fd->fd_rdir);
1500 p->p_fd->fd_rdir = rootvnode;
1501 VREF(rootvnode);
1502
1503 FILEDESC_XUNLOCK(p->p_fd);
1504
1505 EVENTHANDLER_INVOKE(mountroot);
1506 }
1507
1508 /*
1509 * Mount /devfs as our root filesystem, but do not put it on the mountlist
1510 * yet. Create a /dev -> / symlink so that absolute pathnames will lookup.
1511 */
1512
1513 static void
1514 devfs_first(void)
1515 {
1516 struct thread *td = curthread;
1517 struct vfsoptlist *opts;
1518 struct vfsconf *vfsp;
1519 struct mount *mp = NULL;
1520 int error;
1521
1522 vfsp = vfs_byname("devfs");
1523 KASSERT(vfsp != NULL, ("Could not find devfs by name"));
1524 if (vfsp == NULL)
1525 return;
1526
1527 mp = vfs_mount_alloc(NULLVP, vfsp, "/dev", td->td_ucred);
1528
1529 error = VFS_MOUNT(mp);
1530 KASSERT(error == 0, ("VFS_MOUNT(devfs) failed %d", error));
1531 if (error)
1532 return;
1533
1534 opts = malloc(sizeof(struct vfsoptlist), M_MOUNT, M_WAITOK);
1535 TAILQ_INIT(opts);
1536 mp->mnt_opt = opts;
1537
1538 mtx_lock(&mountlist_mtx);
1539 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
1540 mtx_unlock(&mountlist_mtx);
1541
1542 set_rootvnode();
1543
1544 error = kern_symlink(td, "/", "dev", UIO_SYSSPACE);
1545 if (error)
1546 printf("kern_symlink /dev -> / returns %d\n", error);
1547 }
1548
1549 /*
1550 * Surgically move our devfs to be mounted on /dev.
1551 */
1552
1553 static void
1554 devfs_fixup(struct thread *td)
1555 {
1556 struct nameidata nd;
1557 int error;
1558 struct vnode *vp, *dvp;
1559 struct mount *mp;
1560
1561 /* Remove our devfs mount from the mountlist and purge the cache */
1562 mtx_lock(&mountlist_mtx);
1563 mp = TAILQ_FIRST(&mountlist);
1564 TAILQ_REMOVE(&mountlist, mp, mnt_list);
1565 mtx_unlock(&mountlist_mtx);
1566 cache_purgevfs(mp);
1567
1568 VFS_ROOT(mp, LK_EXCLUSIVE, &dvp);
1569 VI_LOCK(dvp);
1570 dvp->v_iflag &= ~VI_MOUNT;
1571 VI_UNLOCK(dvp);
1572 dvp->v_mountedhere = NULL;
1573
1574 /* Set up the real rootvnode, and purge the cache */
1575 TAILQ_FIRST(&mountlist)->mnt_vnodecovered = NULL;
1576 set_rootvnode();
1577 cache_purgevfs(rootvnode->v_mount);
1578
1579 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, "/dev", td);
1580 error = namei(&nd);
1581 if (error) {
1582 printf("Lookup of /dev for devfs, error: %d\n", error);
1583 return;
1584 }
1585 NDFREE(&nd, NDF_ONLY_PNBUF);
1586 vp = nd.ni_vp;
1587 if (vp->v_type != VDIR) {
1588 vput(vp);
1589 }
1590 error = vinvalbuf(vp, V_SAVE, 0, 0);
1591 if (error) {
1592 vput(vp);
1593 }
1594 cache_purge(vp);
1595 mp->mnt_vnodecovered = vp;
1596 vp->v_mountedhere = mp;
1597 mtx_lock(&mountlist_mtx);
1598 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
1599 mtx_unlock(&mountlist_mtx);
1600 VOP_UNLOCK(vp, 0);
1601 vput(dvp);
1602 vfs_unbusy(mp);
1603
1604 /* Unlink the no longer needed /dev/dev -> / symlink */
1605 kern_unlink(td, "/dev/dev", UIO_SYSSPACE);
1606 }
1607
1608 /*
1609 * Report errors during filesystem mounting.
1610 */
1611 void
1612 vfs_mount_error(struct mount *mp, const char *fmt, ...)
1613 {
1614 struct vfsoptlist *moptlist = mp->mnt_optnew;
1615 va_list ap;
1616 int error, len;
1617 char *errmsg;
1618
1619 error = vfs_getopt(moptlist, "errmsg", (void **)&errmsg, &len);
1620 if (error || errmsg == NULL || len <= 0)
1621 return;
1622
1623 va_start(ap, fmt);
1624 vsnprintf(errmsg, (size_t)len, fmt, ap);
1625 va_end(ap);
1626 }
1627
1628 void
1629 vfs_opterror(struct vfsoptlist *opts, const char *fmt, ...)
1630 {
1631 va_list ap;
1632 int error, len;
1633 char *errmsg;
1634
1635 error = vfs_getopt(opts, "errmsg", (void **)&errmsg, &len);
1636 if (error || errmsg == NULL || len <= 0)
1637 return;
1638
1639 va_start(ap, fmt);
1640 vsnprintf(errmsg, (size_t)len, fmt, ap);
1641 va_end(ap);
1642 }
1643
1644 /*
1645 * Find and mount the root filesystem
1646 */
1647 void
1648 vfs_mountroot(void)
1649 {
1650 char *cp, *cpt, *options, *tmpdev;
1651 int error, i, asked = 0;
1652
1653 options = NULL;
1654
1655 root_mount_prepare();
1656
1657 mount_zone = uma_zcreate("Mountpoints", sizeof(struct mount),
1658 NULL, NULL, mount_init, mount_fini,
1659 UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
1660 devfs_first();
1661
1662 /*
1663 * We are booted with instructions to prompt for the root filesystem.
1664 */
1665 if (boothowto & RB_ASKNAME) {
1666 if (!vfs_mountroot_ask())
1667 goto mounted;
1668 asked = 1;
1669 }
1670
1671 options = getenv("vfs.root.mountfrom.options");
1672
1673 /*
1674 * The root filesystem information is compiled in, and we are
1675 * booted with instructions to use it.
1676 */
1677 if (ctrootdevname != NULL && (boothowto & RB_DFLTROOT)) {
1678 if (!vfs_mountroot_try(ctrootdevname, options))
1679 goto mounted;
1680 ctrootdevname = NULL;
1681 }
1682
1683 /*
1684 * We've been given the generic "use CDROM as root" flag. This is
1685 * necessary because one media may be used in many different
1686 * devices, so we need to search for them.
1687 */
1688 if (boothowto & RB_CDROM) {
1689 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
1690 if (!vfs_mountroot_try(cdrom_rootdevnames[i], options))
1691 goto mounted;
1692 }
1693 }
1694
1695 /*
1696 * Try to use the value read by the loader from /etc/fstab, or
1697 * supplied via some other means. This is the preferred
1698 * mechanism.
1699 */
1700 cp = getenv("vfs.root.mountfrom");
1701 if (cp != NULL) {
1702 cpt = cp;
1703 while ((tmpdev = strsep(&cpt, " \t")) != NULL) {
1704 error = vfs_mountroot_try(tmpdev, options);
1705 if (error == 0) {
1706 freeenv(cp);
1707 goto mounted;
1708 }
1709 }
1710 freeenv(cp);
1711 }
1712
1713 /*
1714 * Try values that may have been computed by code during boot
1715 */
1716 if (!vfs_mountroot_try(rootdevnames[0], options))
1717 goto mounted;
1718 if (!vfs_mountroot_try(rootdevnames[1], options))
1719 goto mounted;
1720
1721 /*
1722 * If we (still) have a compiled-in default, try it.
1723 */
1724 if (ctrootdevname != NULL)
1725 if (!vfs_mountroot_try(ctrootdevname, options))
1726 goto mounted;
1727 /*
1728 * Everything so far has failed, prompt on the console if we haven't
1729 * already tried that.
1730 */
1731 if (!asked)
1732 if (!vfs_mountroot_ask())
1733 goto mounted;
1734
1735 panic("Root mount failed, startup aborted.");
1736
1737 mounted:
1738 root_mount_done();
1739 freeenv(options);
1740 }
1741
1742 static struct mntarg *
1743 parse_mountroot_options(struct mntarg *ma, const char *options)
1744 {
1745 char *p;
1746 char *name, *name_arg;
1747 char *val, *val_arg;
1748 char *opts;
1749
1750 if (options == NULL || options[0] == '\0')
1751 return (ma);
1752
1753 p = opts = strdup(options, M_MOUNT);
1754 if (opts == NULL) {
1755 return (ma);
1756 }
1757
1758 while((name = strsep(&p, ",")) != NULL) {
1759 if (name[0] == '\0')
1760 break;
1761
1762 val = strchr(name, '=');
1763 if (val != NULL) {
1764 *val = '\0';
1765 ++val;
1766 }
1767 if( strcmp(name, "rw") == 0 ||
1768 strcmp(name, "noro") == 0) {
1769 /*
1770 * The first time we mount the root file system,
1771 * we need to mount 'ro', so We need to ignore
1772 * 'rw' and 'noro' mount options.
1773 */
1774 continue;
1775 }
1776 name_arg = strdup(name, M_MOUNT);
1777 val_arg = NULL;
1778 if (val != NULL)
1779 val_arg = strdup(val, M_MOUNT);
1780
1781 ma = mount_arg(ma, name_arg, val_arg,
1782 (val_arg != NULL ? -1 : 0));
1783 }
1784 free(opts, M_MOUNT);
1785 return (ma);
1786 }
1787
1788 /*
1789 * Mount (mountfrom) as the root filesystem.
1790 */
1791 static int
1792 vfs_mountroot_try(const char *mountfrom, const char *options)
1793 {
1794 struct mount *mp;
1795 struct mntarg *ma;
1796 char *vfsname, *path;
1797 time_t timebase;
1798 int error;
1799 char patt[32];
1800 char errmsg[255];
1801
1802 vfsname = NULL;
1803 path = NULL;
1804 mp = NULL;
1805 ma = NULL;
1806 error = EINVAL;
1807 bzero(errmsg, sizeof(errmsg));
1808
1809 if (mountfrom == NULL)
1810 return (error); /* don't complain */
1811 printf("Trying to mount root from %s\n", mountfrom);
1812
1813 /* parse vfs name and path */
1814 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
1815 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
1816 vfsname[0] = path[0] = 0;
1817 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
1818 if (sscanf(mountfrom, patt, vfsname, path) < 1)
1819 goto out;
1820
1821 if (path[0] == '\0')
1822 strcpy(path, ROOTNAME);
1823
1824 ma = mount_arg(ma, "fstype", vfsname, -1);
1825 ma = mount_arg(ma, "fspath", "/", -1);
1826 ma = mount_arg(ma, "from", path, -1);
1827 ma = mount_arg(ma, "errmsg", errmsg, sizeof(errmsg));
1828 ma = mount_arg(ma, "ro", NULL, 0);
1829 ma = parse_mountroot_options(ma, options);
1830 error = kernel_mount(ma, MNT_ROOTFS);
1831
1832 if (error == 0) {
1833 /*
1834 * We mount devfs prior to mounting the / FS, so the first
1835 * entry will typically be devfs.
1836 */
1837 mp = TAILQ_FIRST(&mountlist);
1838 KASSERT(mp != NULL, ("%s: mountlist is empty", __func__));
1839
1840 /*
1841 * Iterate over all currently mounted file systems and use
1842 * the time stamp found to check and/or initialize the RTC.
1843 * Typically devfs has no time stamp and the only other FS
1844 * is the actual / FS.
1845 * Call inittodr() only once and pass it the largest of the
1846 * timestamps we encounter.
1847 */
1848 timebase = 0;
1849 do {
1850 if (mp->mnt_time > timebase)
1851 timebase = mp->mnt_time;
1852 mp = TAILQ_NEXT(mp, mnt_list);
1853 } while (mp != NULL);
1854 inittodr(timebase);
1855
1856 devfs_fixup(curthread);
1857 }
1858
1859 if (error != 0 ) {
1860 printf("ROOT MOUNT ERROR: %s\n", errmsg);
1861 printf("If you have invalid mount options, reboot, and ");
1862 printf("first try the following from\n");
1863 printf("the loader prompt:\n\n");
1864 printf(" set vfs.root.mountfrom.options=rw\n\n");
1865 printf("and then remove invalid mount options from ");
1866 printf("/etc/fstab.\n\n");
1867 }
1868 out:
1869 free(path, M_MOUNT);
1870 free(vfsname, M_MOUNT);
1871 return (error);
1872 }
1873
1874 /*
1875 * ---------------------------------------------------------------------
1876 * Interactive root filesystem selection code.
1877 */
1878
1879 static int
1880 vfs_mountroot_ask(void)
1881 {
1882 char name[128];
1883 char *mountfrom;
1884 char *options;
1885
1886 for(;;) {
1887 printf("Loader variables:\n");
1888 printf("vfs.root.mountfrom=");
1889 mountfrom = getenv("vfs.root.mountfrom");
1890 if (mountfrom != NULL) {
1891 printf("%s", mountfrom);
1892 }
1893 printf("\n");
1894 printf("vfs.root.mountfrom.options=");
1895 options = getenv("vfs.root.mountfrom.options");
1896 if (options != NULL) {
1897 printf("%s", options);
1898 }
1899 printf("\n");
1900 freeenv(mountfrom);
1901 freeenv(options);
1902 printf("\nManual root filesystem specification:\n");
1903 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n");
1904 printf(" eg. ufs:/dev/da0s1a\n");
1905 printf(" eg. cd9660:/dev/acd0\n");
1906 printf(" This is equivalent to: ");
1907 printf("mount -t cd9660 /dev/acd0 /\n");
1908 printf("\n");
1909 printf(" ? List valid disk boot devices\n");
1910 printf(" <empty line> Abort manual input\n");
1911 printf("\nmountroot> ");
1912 gets(name, sizeof(name), 1);
1913 if (name[0] == '\0')
1914 return (1);
1915 if (name[0] == '?') {
1916 printf("\nList of GEOM managed disk devices:\n ");
1917 g_dev_print();
1918 continue;
1919 }
1920 if (!vfs_mountroot_try(name, NULL))
1921 return (0);
1922 }
1923 }
1924
1925 /*
1926 * ---------------------------------------------------------------------
1927 * Functions for querying mount options/arguments from filesystems.
1928 */
1929
1930 /*
1931 * Check that no unknown options are given
1932 */
1933 int
1934 vfs_filteropt(struct vfsoptlist *opts, const char **legal)
1935 {
1936 struct vfsopt *opt;
1937 char errmsg[255];
1938 const char **t, *p, *q;
1939 int ret = 0;
1940
1941 TAILQ_FOREACH(opt, opts, link) {
1942 p = opt->name;
1943 q = NULL;
1944 if (p[0] == 'n' && p[1] == 'o')
1945 q = p + 2;
1946 for(t = global_opts; *t != NULL; t++) {
1947 if (strcmp(*t, p) == 0)
1948 break;
1949 if (q != NULL) {
1950 if (strcmp(*t, q) == 0)
1951 break;
1952 }
1953 }
1954 if (*t != NULL)
1955 continue;
1956 for(t = legal; *t != NULL; t++) {
1957 if (strcmp(*t, p) == 0)
1958 break;
1959 if (q != NULL) {
1960 if (strcmp(*t, q) == 0)
1961 break;
1962 }
1963 }
1964 if (*t != NULL)
1965 continue;
1966 snprintf(errmsg, sizeof(errmsg),
1967 "mount option <%s> is unknown", p);
1968 printf("%s\n", errmsg);
1969 ret = EINVAL;
1970 }
1971 if (ret != 0) {
1972 TAILQ_FOREACH(opt, opts, link) {
1973 if (strcmp(opt->name, "errmsg") == 0) {
1974 strncpy((char *)opt->value, errmsg, opt->len);
1975 }
1976 }
1977 }
1978 return (ret);
1979 }
1980
1981 /*
1982 * Get a mount option by its name.
1983 *
1984 * Return 0 if the option was found, ENOENT otherwise.
1985 * If len is non-NULL it will be filled with the length
1986 * of the option. If buf is non-NULL, it will be filled
1987 * with the address of the option.
1988 */
1989 int
1990 vfs_getopt(opts, name, buf, len)
1991 struct vfsoptlist *opts;
1992 const char *name;
1993 void **buf;
1994 int *len;
1995 {
1996 struct vfsopt *opt;
1997
1998 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
1999
2000 TAILQ_FOREACH(opt, opts, link) {
2001 if (strcmp(name, opt->name) == 0) {
2002 opt->seen = 1;
2003 if (len != NULL)
2004 *len = opt->len;
2005 if (buf != NULL)
2006 *buf = opt->value;
2007 return (0);
2008 }
2009 }
2010 return (ENOENT);
2011 }
2012
2013 int
2014 vfs_getopt_pos(struct vfsoptlist *opts, const char *name)
2015 {
2016 struct vfsopt *opt;
2017
2018 if (opts == NULL)
2019 return (-1);
2020
2021 TAILQ_FOREACH(opt, opts, link) {
2022 if (strcmp(name, opt->name) == 0) {
2023 opt->seen = 1;
2024 return (opt->pos);
2025 }
2026 }
2027 return (-1);
2028 }
2029
2030 char *
2031 vfs_getopts(struct vfsoptlist *opts, const char *name, int *error)
2032 {
2033 struct vfsopt *opt;
2034
2035 *error = 0;
2036 TAILQ_FOREACH(opt, opts, link) {
2037 if (strcmp(name, opt->name) != 0)
2038 continue;
2039 opt->seen = 1;
2040 if (opt->len == 0 ||
2041 ((char *)opt->value)[opt->len - 1] != '\0') {
2042 *error = EINVAL;
2043 return (NULL);
2044 }
2045 return (opt->value);
2046 }
2047 *error = ENOENT;
2048 return (NULL);
2049 }
2050
2051 int
2052 vfs_flagopt(struct vfsoptlist *opts, const char *name, u_int *w, u_int val)
2053 {
2054 struct vfsopt *opt;
2055
2056 TAILQ_FOREACH(opt, opts, link) {
2057 if (strcmp(name, opt->name) == 0) {
2058 opt->seen = 1;
2059 if (w != NULL)
2060 *w |= val;
2061 return (1);
2062 }
2063 }
2064 if (w != NULL)
2065 *w &= ~val;
2066 return (0);
2067 }
2068
2069 int
2070 vfs_scanopt(struct vfsoptlist *opts, const char *name, const char *fmt, ...)
2071 {
2072 va_list ap;
2073 struct vfsopt *opt;
2074 int ret;
2075
2076 KASSERT(opts != NULL, ("vfs_getopt: caller passed 'opts' as NULL"));
2077
2078 TAILQ_FOREACH(opt, opts, link) {
2079 if (strcmp(name, opt->name) != 0)
2080 continue;
2081 opt->seen = 1;
2082 if (opt->len == 0 || opt->value == NULL)
2083 return (0);
2084 if (((char *)opt->value)[opt->len - 1] != '\0')
2085 return (0);
2086 va_start(ap, fmt);
2087 ret = vsscanf(opt->value, fmt, ap);
2088 va_end(ap);
2089 return (ret);
2090 }
2091 return (0);
2092 }
2093
2094 int
2095 vfs_setopt(struct vfsoptlist *opts, const char *name, void *value, int len)
2096 {
2097 struct vfsopt *opt;
2098
2099 TAILQ_FOREACH(opt, opts, link) {
2100 if (strcmp(name, opt->name) != 0)
2101 continue;
2102 opt->seen = 1;
2103 if (opt->value == NULL)
2104 opt->len = len;
2105 else {
2106 if (opt->len != len)
2107 return (EINVAL);
2108 bcopy(value, opt->value, len);
2109 }
2110 return (0);
2111 }
2112 return (ENOENT);
2113 }
2114
2115 int
2116 vfs_setopt_part(struct vfsoptlist *opts, const char *name, void *value, int len)
2117 {
2118 struct vfsopt *opt;
2119
2120 TAILQ_FOREACH(opt, opts, link) {
2121 if (strcmp(name, opt->name) != 0)
2122 continue;
2123 opt->seen = 1;
2124 if (opt->value == NULL)
2125 opt->len = len;
2126 else {
2127 if (opt->len < len)
2128 return (EINVAL);
2129 opt->len = len;
2130 bcopy(value, opt->value, len);
2131 }
2132 return (0);
2133 }
2134 return (ENOENT);
2135 }
2136
2137 int
2138 vfs_setopts(struct vfsoptlist *opts, const char *name, const char *value)
2139 {
2140 struct vfsopt *opt;
2141
2142 TAILQ_FOREACH(opt, opts, link) {
2143 if (strcmp(name, opt->name) != 0)
2144 continue;
2145 opt->seen = 1;
2146 if (opt->value == NULL)
2147 opt->len = strlen(value) + 1;
2148 else if (strlcpy(opt->value, value, opt->len) >= opt->len)
2149 return (EINVAL);
2150 return (0);
2151 }
2152 return (ENOENT);
2153 }
2154
2155 /*
2156 * Find and copy a mount option.
2157 *
2158 * The size of the buffer has to be specified
2159 * in len, if it is not the same length as the
2160 * mount option, EINVAL is returned.
2161 * Returns ENOENT if the option is not found.
2162 */
2163 int
2164 vfs_copyopt(opts, name, dest, len)
2165 struct vfsoptlist *opts;
2166 const char *name;
2167 void *dest;
2168 int len;
2169 {
2170 struct vfsopt *opt;
2171
2172 KASSERT(opts != NULL, ("vfs_copyopt: caller passed 'opts' as NULL"));
2173
2174 TAILQ_FOREACH(opt, opts, link) {
2175 if (strcmp(name, opt->name) == 0) {
2176 opt->seen = 1;
2177 if (len != opt->len)
2178 return (EINVAL);
2179 bcopy(opt->value, dest, opt->len);
2180 return (0);
2181 }
2182 }
2183 return (ENOENT);
2184 }
2185
2186 /*
2187 * This is a helper function for filesystems to traverse their
2188 * vnodes. See MNT_VNODE_FOREACH() in sys/mount.h
2189 */
2190
2191 struct vnode *
2192 __mnt_vnode_next(struct vnode **mvp, struct mount *mp)
2193 {
2194 struct vnode *vp;
2195
2196 mtx_assert(MNT_MTX(mp), MA_OWNED);
2197
2198 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
2199 if ((*mvp)->v_yield++ == 500) {
2200 MNT_IUNLOCK(mp);
2201 (*mvp)->v_yield = 0;
2202 uio_yield();
2203 MNT_ILOCK(mp);
2204 }
2205 vp = TAILQ_NEXT(*mvp, v_nmntvnodes);
2206 while (vp != NULL && vp->v_type == VMARKER)
2207 vp = TAILQ_NEXT(vp, v_nmntvnodes);
2208
2209 /* Check if we are done */
2210 if (vp == NULL) {
2211 __mnt_vnode_markerfree(mvp, mp);
2212 return (NULL);
2213 }
2214 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
2215 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
2216 return (vp);
2217 }
2218
2219 struct vnode *
2220 __mnt_vnode_first(struct vnode **mvp, struct mount *mp)
2221 {
2222 struct vnode *vp;
2223
2224 mtx_assert(MNT_MTX(mp), MA_OWNED);
2225
2226 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
2227 while (vp != NULL && vp->v_type == VMARKER)
2228 vp = TAILQ_NEXT(vp, v_nmntvnodes);
2229
2230 /* Check if we are done */
2231 if (vp == NULL) {
2232 *mvp = NULL;
2233 return (NULL);
2234 }
2235 MNT_REF(mp);
2236 MNT_IUNLOCK(mp);
2237 *mvp = (struct vnode *) malloc(sizeof(struct vnode),
2238 M_VNODE_MARKER,
2239 M_WAITOK | M_ZERO);
2240 MNT_ILOCK(mp);
2241 (*mvp)->v_type = VMARKER;
2242
2243 vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
2244 while (vp != NULL && vp->v_type == VMARKER)
2245 vp = TAILQ_NEXT(vp, v_nmntvnodes);
2246
2247 /* Check if we are done */
2248 if (vp == NULL) {
2249 MNT_IUNLOCK(mp);
2250 free(*mvp, M_VNODE_MARKER);
2251 MNT_ILOCK(mp);
2252 *mvp = NULL;
2253 MNT_REL(mp);
2254 return (NULL);
2255 }
2256 (*mvp)->v_mount = mp;
2257 TAILQ_INSERT_AFTER(&mp->mnt_nvnodelist, vp, *mvp, v_nmntvnodes);
2258 return (vp);
2259 }
2260
2261
2262 void
2263 __mnt_vnode_markerfree(struct vnode **mvp, struct mount *mp)
2264 {
2265
2266 if (*mvp == NULL)
2267 return;
2268
2269 mtx_assert(MNT_MTX(mp), MA_OWNED);
2270
2271 KASSERT((*mvp)->v_mount == mp, ("marker vnode mount list mismatch"));
2272 TAILQ_REMOVE(&mp->mnt_nvnodelist, *mvp, v_nmntvnodes);
2273 MNT_IUNLOCK(mp);
2274 free(*mvp, M_VNODE_MARKER);
2275 MNT_ILOCK(mp);
2276 *mvp = NULL;
2277 MNT_REL(mp);
2278 }
2279
2280
2281 int
2282 __vfs_statfs(struct mount *mp, struct statfs *sbp)
2283 {
2284 int error;
2285
2286 error = mp->mnt_op->vfs_statfs(mp, &mp->mnt_stat);
2287 if (sbp != &mp->mnt_stat)
2288 *sbp = mp->mnt_stat;
2289 return (error);
2290 }
2291
2292 void
2293 vfs_mountedfrom(struct mount *mp, const char *from)
2294 {
2295
2296 bzero(mp->mnt_stat.f_mntfromname, sizeof mp->mnt_stat.f_mntfromname);
2297 strlcpy(mp->mnt_stat.f_mntfromname, from,
2298 sizeof mp->mnt_stat.f_mntfromname);
2299 }
2300
2301 /*
2302 * ---------------------------------------------------------------------
2303 * This is the api for building mount args and mounting filesystems from
2304 * inside the kernel.
2305 *
2306 * The API works by accumulation of individual args. First error is
2307 * latched.
2308 *
2309 * XXX: should be documented in new manpage kernel_mount(9)
2310 */
2311
2312 /* A memory allocation which must be freed when we are done */
2313 struct mntaarg {
2314 SLIST_ENTRY(mntaarg) next;
2315 };
2316
2317 /* The header for the mount arguments */
2318 struct mntarg {
2319 struct iovec *v;
2320 int len;
2321 int error;
2322 SLIST_HEAD(, mntaarg) list;
2323 };
2324
2325 /*
2326 * Add a boolean argument.
2327 *
2328 * flag is the boolean value.
2329 * name must start with "no".
2330 */
2331 struct mntarg *
2332 mount_argb(struct mntarg *ma, int flag, const char *name)
2333 {
2334
2335 KASSERT(name[0] == 'n' && name[1] == 'o',
2336 ("mount_argb(...,%s): name must start with 'no'", name));
2337
2338 return (mount_arg(ma, name + (flag ? 2 : 0), NULL, 0));
2339 }
2340
2341 /*
2342 * Add an argument printf style
2343 */
2344 struct mntarg *
2345 mount_argf(struct mntarg *ma, const char *name, const char *fmt, ...)
2346 {
2347 va_list ap;
2348 struct mntaarg *maa;
2349 struct sbuf *sb;
2350 int len;
2351
2352 if (ma == NULL) {
2353 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
2354 SLIST_INIT(&ma->list);
2355 }
2356 if (ma->error)
2357 return (ma);
2358
2359 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
2360 M_MOUNT, M_WAITOK);
2361 ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
2362 ma->v[ma->len].iov_len = strlen(name) + 1;
2363 ma->len++;
2364
2365 sb = sbuf_new_auto();
2366 va_start(ap, fmt);
2367 sbuf_vprintf(sb, fmt, ap);
2368 va_end(ap);
2369 sbuf_finish(sb);
2370 len = sbuf_len(sb) + 1;
2371 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
2372 SLIST_INSERT_HEAD(&ma->list, maa, next);
2373 bcopy(sbuf_data(sb), maa + 1, len);
2374 sbuf_delete(sb);
2375
2376 ma->v[ma->len].iov_base = maa + 1;
2377 ma->v[ma->len].iov_len = len;
2378 ma->len++;
2379
2380 return (ma);
2381 }
2382
2383 /*
2384 * Add an argument which is a userland string.
2385 */
2386 struct mntarg *
2387 mount_argsu(struct mntarg *ma, const char *name, const void *val, int len)
2388 {
2389 struct mntaarg *maa;
2390 char *tbuf;
2391
2392 if (val == NULL)
2393 return (ma);
2394 if (ma == NULL) {
2395 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
2396 SLIST_INIT(&ma->list);
2397 }
2398 if (ma->error)
2399 return (ma);
2400 maa = malloc(sizeof *maa + len, M_MOUNT, M_WAITOK | M_ZERO);
2401 SLIST_INSERT_HEAD(&ma->list, maa, next);
2402 tbuf = (void *)(maa + 1);
2403 ma->error = copyinstr(val, tbuf, len, NULL);
2404 return (mount_arg(ma, name, tbuf, -1));
2405 }
2406
2407 /*
2408 * Plain argument.
2409 *
2410 * If length is -1, treat value as a C string.
2411 */
2412 struct mntarg *
2413 mount_arg(struct mntarg *ma, const char *name, const void *val, int len)
2414 {
2415
2416 if (ma == NULL) {
2417 ma = malloc(sizeof *ma, M_MOUNT, M_WAITOK | M_ZERO);
2418 SLIST_INIT(&ma->list);
2419 }
2420 if (ma->error)
2421 return (ma);
2422
2423 ma->v = realloc(ma->v, sizeof *ma->v * (ma->len + 2),
2424 M_MOUNT, M_WAITOK);
2425 ma->v[ma->len].iov_base = (void *)(uintptr_t)name;
2426 ma->v[ma->len].iov_len = strlen(name) + 1;
2427 ma->len++;
2428
2429 ma->v[ma->len].iov_base = (void *)(uintptr_t)val;
2430 if (len < 0)
2431 ma->v[ma->len].iov_len = strlen(val) + 1;
2432 else
2433 ma->v[ma->len].iov_len = len;
2434 ma->len++;
2435 return (ma);
2436 }
2437
2438 /*
2439 * Free a mntarg structure
2440 */
2441 static void
2442 free_mntarg(struct mntarg *ma)
2443 {
2444 struct mntaarg *maa;
2445
2446 while (!SLIST_EMPTY(&ma->list)) {
2447 maa = SLIST_FIRST(&ma->list);
2448 SLIST_REMOVE_HEAD(&ma->list, next);
2449 free(maa, M_MOUNT);
2450 }
2451 free(ma->v, M_MOUNT);
2452 free(ma, M_MOUNT);
2453 }
2454
2455 /*
2456 * Mount a filesystem
2457 */
2458 int
2459 kernel_mount(struct mntarg *ma, int flags)
2460 {
2461 struct uio auio;
2462 int error;
2463
2464 KASSERT(ma != NULL, ("kernel_mount NULL ma"));
2465 KASSERT(ma->v != NULL, ("kernel_mount NULL ma->v"));
2466 KASSERT(!(ma->len & 1), ("kernel_mount odd ma->len (%d)", ma->len));
2467
2468 auio.uio_iov = ma->v;
2469 auio.uio_iovcnt = ma->len;
2470 auio.uio_segflg = UIO_SYSSPACE;
2471
2472 error = ma->error;
2473 if (!error)
2474 error = vfs_donmount(curthread, flags, &auio);
2475 free_mntarg(ma);
2476 return (error);
2477 }
2478
2479 /*
2480 * A printflike function to mount a filesystem.
2481 */
2482 int
2483 kernel_vmount(int flags, ...)
2484 {
2485 struct mntarg *ma = NULL;
2486 va_list ap;
2487 const char *cp;
2488 const void *vp;
2489 int error;
2490
2491 va_start(ap, flags);
2492 for (;;) {
2493 cp = va_arg(ap, const char *);
2494 if (cp == NULL)
2495 break;
2496 vp = va_arg(ap, const void *);
2497 ma = mount_arg(ma, cp, vp, (vp != NULL ? -1 : 0));
2498 }
2499 va_end(ap);
2500
2501 error = kernel_mount(ma, flags);
2502 return (error);
2503 }
2504
2505 void
2506 vfs_oexport_conv(const struct oexport_args *oexp, struct export_args *exp)
2507 {
2508
2509 bcopy(oexp, exp, sizeof(*oexp));
2510 exp->ex_numsecflavors = 0;
2511 }
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