2 * Copyright (c) 2006-2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/mount.h>
37 #include <sys/libkern.h>
39 MALLOC_DECLARE(M_MOUNT);
41 TAILQ_HEAD(vfsoptlist, vfsopt);
43 TAILQ_ENTRY(vfsopt) link;
50 vfs_setmntopt(vfs_t *vfsp, const char *name, const char *arg,
56 if (vfsp->mnt_opt == NULL) {
57 vfsp->mnt_opt = malloc(sizeof(*vfsp->mnt_opt), M_MOUNT, M_WAITOK);
58 TAILQ_INIT(vfsp->mnt_opt);
61 opt = malloc(sizeof(*opt), M_MOUNT, M_WAITOK);
63 namesize = strlen(name) + 1;
64 opt->name = malloc(namesize, M_MOUNT, M_WAITOK);
65 strlcpy(opt->name, name, namesize);
71 opt->len = strlen(arg) + 1;
72 opt->value = malloc(opt->len, M_MOUNT, M_WAITOK);
73 bcopy(arg, opt->value, opt->len);
76 TAILQ_INSERT_TAIL(vfsp->mnt_opt, opt, link);
80 vfs_clearmntopt(vfs_t *vfsp, const char *name)
84 if (vfsp->mnt_opt == NULL)
87 TAILQ_FOREACH(opt, vfsp->mnt_opt, link) {
88 if (strcmp(opt->name, name) == 0)
92 TAILQ_REMOVE(vfsp->mnt_opt, opt, link);
93 free(opt->name, M_MOUNT);
94 if (opt->value != NULL)
95 free(opt->value, M_MOUNT);
101 vfs_optionisset(const vfs_t *vfsp, const char *opt, char **argp)
103 struct vfsoptlist *opts = vfsp->mnt_opt;
108 error = vfs_getopt(opts, opt, (void **)argp, NULL);
109 return (error != 0 ? 0 : 1);
113 traverse(vnode_t **cvpp)
115 kthread_t *td = curthread;
125 * If this vnode is mounted on, then we transparently indirect
126 * to the vnode which is the root of the mounted file system.
127 * Before we do this we must check that an unmount is not in
128 * progress on this vnode.
133 * Reached the end of the mount chain?
135 vfsp = vn_mountedvfs(cvp);
141 * The read lock must be held across the call to VFS_ROOT() to
142 * prevent a concurrent unmount from destroying the vfs.
144 error = VFS_ROOT(vfsp, 0, &tvp, td);
147 VOP_UNLOCK(tvp, 0, td);
157 domount(kthread_t *td, vnode_t *vp, const char *fstype, char *fspath,
158 char *fspec, int fsflags)
161 struct vfsconf *vfsp;
165 * Be ultra-paranoid about making sure the type and fspath
166 * variables will fit in our mp buffers, including the
169 if (strlen(fstype) >= MFSNAMELEN || strlen(fspath) >= MNAMELEN)
170 return (ENAMETOOLONG);
172 vfsp = vfs_byname_kld(fstype, td, &error);
176 if (vp->v_type != VDIR)
179 if ((vp->v_iflag & VI_MOUNT) != 0 ||
180 vp->v_mountedhere != NULL) {
184 vp->v_iflag |= VI_MOUNT;
188 * Allocate and initialize the filesystem.
190 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
191 mp = vfs_mount_alloc(vp, vfsp, fspath, td);
192 VOP_UNLOCK(vp, 0, td);
194 mp->mnt_optnew = NULL;
195 vfs_setmntopt(mp, "from", fspec, 0);
196 mp->mnt_optnew = mp->mnt_opt;
200 * Set the mount level flags.
203 if (fsflags & MNT_RDONLY)
204 mp->mnt_flag |= MNT_RDONLY;
205 mp->mnt_flag &=~ MNT_UPDATEMASK;
206 mp->mnt_flag |= fsflags & (MNT_UPDATEMASK | MNT_FORCE | MNT_ROOTFS);
208 * Unprivileged user can trigger mounting a snapshot, but we don't want
209 * him to unmount it, so we switch to privileged credentials.
211 crfree(mp->mnt_cred);
212 mp->mnt_cred = crdup(kcred);
213 mp->mnt_stat.f_owner = mp->mnt_cred->cr_uid;
216 * Mount the filesystem.
217 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
218 * get. No freeing of cn_pnbuf.
220 error = VFS_MOUNT(mp, td);
223 if (mp->mnt_opt != NULL)
224 vfs_freeopts(mp->mnt_opt);
225 mp->mnt_opt = mp->mnt_optnew;
226 (void)VFS_STATFS(mp, &mp->mnt_stat, td);
229 * Prevent external consumers of mount options from reading
232 mp->mnt_optnew = NULL;
233 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
235 * Put the new filesystem on the mount list after root.
237 #ifdef FREEBSD_NAMECACHE
244 vp->v_iflag &= ~VI_MOUNT;
246 vp->v_mountedhere = mp;
247 mtx_lock(&mountlist_mtx);
248 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
249 mtx_unlock(&mountlist_mtx);
250 vfs_event_signal(NULL, VQ_MOUNT, 0);
251 if (VFS_ROOT(mp, LK_EXCLUSIVE, &mvp, td))
252 panic("mount: lost mount");
253 mountcheckdirs(vp, mvp);
255 VOP_UNLOCK(vp, 0, td);
256 if ((mp->mnt_flag & MNT_RDONLY) == 0)
257 error = vfs_allocate_syncvnode(mp);
262 vfs_mountedfrom(mp, fspec);
265 vp->v_iflag &= ~VI_MOUNT;
267 VOP_UNLOCK(vp, 0, td);
269 vfs_mount_destroy(mp);