1/*-
2 * Copyright (c) 1992, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
4 * Copyright (c) 2000
5 * Poul-Henning Kamp. All rights reserved.
6 *
7 * This code is derived from software donated to Berkeley by
8 * Jan-Simon Pendry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)kernfs_vfsops.c 8.10 (Berkeley) 5/14/95
32 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
33 *
34 * $FreeBSD: head/sys/fs/devfs/devfs_vfsops.c 231267 2012-02-09 10:22:08Z mm $
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/kernel.h>
40#include <sys/lock.h>
41#include <sys/malloc.h>
42#include <sys/mount.h>
43#include <sys/proc.h>
44#include <sys/sx.h>
45#include <sys/vnode.h>
46#include <sys/limits.h>
47#include <sys/jail.h>
48
49#include <fs/devfs/devfs.h>
50
51static struct unrhdr *devfs_unr;
52
53MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data");
54
55static vfs_mount_t devfs_mount;
56static vfs_unmount_t devfs_unmount;
57static vfs_root_t devfs_root;
58static vfs_statfs_t devfs_statfs;
59
60static const char *devfs_opts[] = {
61 "from", "ruleset", NULL
62};
63
64/*
65 * Mount the filesystem
66 */
67static int
68devfs_mount(struct mount *mp)
69{
70 int error;
71 struct devfs_mount *fmp;
72 struct vnode *rvp;
73 struct thread *td = curthread;
74 int rsnum;
75
76 if (devfs_unr == NULL)
77 devfs_unr = new_unrhdr(0, INT_MAX, NULL);
78
79 error = 0;
80
81 if (mp->mnt_flag & MNT_ROOTFS)
82 return (EOPNOTSUPP);
83
84 rsnum = 0;
85
86 if (mp->mnt_optnew != NULL) {
87 if (vfs_filteropt(mp->mnt_optnew, devfs_opts))
88 return (EINVAL);
89
90 if (vfs_getopt(mp->mnt_optnew, "ruleset", NULL, NULL) == 0 &&
91 (vfs_scanopt(mp->mnt_optnew, "ruleset", "%d",
92 &rsnum) != 1 || rsnum < 0 || rsnum > 65535))
93 error = EINVAL;
94 }
95
96 /* jails enforce their ruleset, prison0 has no restrictions */
97 if (td->td_ucred->cr_prison->pr_devfs_rsnum != 0) {
98 rsnum = td->td_ucred->cr_prison->pr_devfs_rsnum;
99 if (rsnum == -1)
100 return (EPERM);
101 /* check rsnum for sanity, devfs_rsnum is uint16_t */
102 if (rsnum < 0 || rsnum > 65535)
103 error = EINVAL;
104 }
105
106 if (error) {
107 vfs_mount_error(mp, "%s", "invalid ruleset specification");
108 return (error);
109 }
110
111 if (mp->mnt_flag & MNT_UPDATE) {
112 if (rsnum != 0) {
113 fmp = mp->mnt_data;
114 if (fmp != NULL) {
115 sx_xlock(&fmp->dm_lock);
116 devfs_ruleset_set((devfs_rsnum)rsnum, fmp);
117 devfs_ruleset_apply(fmp);
118 sx_xunlock(&fmp->dm_lock);
119 }
120 }
121 return (0);
122 }
123
124 fmp = malloc(sizeof *fmp, M_DEVFS, M_WAITOK | M_ZERO);
125 fmp->dm_idx = alloc_unr(devfs_unr);
126 sx_init(&fmp->dm_lock, "devfsmount");
127 fmp->dm_holdcnt = 1;
128
129 MNT_ILOCK(mp);
130 mp->mnt_flag |= MNT_LOCAL;
131 mp->mnt_kern_flag |= MNTK_MPSAFE | MNTK_LOOKUP_SHARED |
132 MNTK_EXTENDED_SHARED;
133#ifdef MAC
134 mp->mnt_flag |= MNT_MULTILABEL;
135#endif
136 MNT_IUNLOCK(mp);
137 fmp->dm_mount = mp;
138 mp->mnt_data = (void *) fmp;
139 vfs_getnewfsid(mp);
140
141 fmp->dm_rootdir = devfs_vmkdir(fmp, NULL, 0, NULL, DEVFS_ROOTINO);
142
143 error = devfs_root(mp, LK_EXCLUSIVE, &rvp);
144 if (error) {
145 sx_destroy(&fmp->dm_lock);
146 free_unr(devfs_unr, fmp->dm_idx);
147 free(fmp, M_DEVFS);
148 return (error);
149 }
150
151 if (rsnum != 0) {
152 sx_xlock(&fmp->dm_lock);
153 devfs_ruleset_set((devfs_rsnum)rsnum, fmp);
154 sx_xunlock(&fmp->dm_lock);
155 }
156
157 VOP_UNLOCK(rvp, 0);
158
159 vfs_mountedfrom(mp, "devfs");
160
161 return (0);
162}
163
164void
165devfs_unmount_final(struct devfs_mount *fmp)
166{
167 sx_destroy(&fmp->dm_lock);
168 free(fmp, M_DEVFS);
169}
170
171static int
172devfs_unmount(struct mount *mp, int mntflags)
173{
174 int error;
175 int flags = 0;
176 struct devfs_mount *fmp;
177 int hold;
178 u_int idx;
179
180 fmp = VFSTODEVFS(mp);
181 KASSERT(fmp->dm_mount != NULL,
182 ("devfs_unmount unmounted devfs_mount"));
183 /* There is 1 extra root vnode reference from devfs_mount(). */
184 error = vflush(mp, 1, flags, curthread);
185 if (error)
186 return (error);
187 sx_xlock(&fmp->dm_lock);
188 devfs_cleanup(fmp);
189 devfs_rules_cleanup(fmp);
190 fmp->dm_mount = NULL;
191 hold = --fmp->dm_holdcnt;
192 mp->mnt_data = NULL;
193 idx = fmp->dm_idx;
194 sx_xunlock(&fmp->dm_lock);
195 free_unr(devfs_unr, idx);
196 if (hold == 0)
197 devfs_unmount_final(fmp);
198 return 0;
199}
200
201/* Return locked reference to root. */
202
203static int
204devfs_root(struct mount *mp, int flags, struct vnode **vpp)
205{
206 int error;
207 struct vnode *vp;
208 struct devfs_mount *dmp;
209
210 dmp = VFSTODEVFS(mp);
211 sx_xlock(&dmp->dm_lock);
212 error = devfs_allocv(dmp->dm_rootdir, mp, LK_EXCLUSIVE, &vp);
213 if (error)
214 return (error);
215 vp->v_vflag |= VV_ROOT;
216 *vpp = vp;
217 return (0);
218}
219
220static int
221devfs_statfs(struct mount *mp, struct statfs *sbp)
222{
223
224 sbp->f_flags = 0;
225 sbp->f_bsize = DEV_BSIZE;
226 sbp->f_iosize = DEV_BSIZE;
227 sbp->f_blocks = 2; /* 1K to keep df happy */
228 sbp->f_bfree = 0;
229 sbp->f_bavail = 0;
230 sbp->f_files = 0;
231 sbp->f_ffree = 0;
232 return (0);
233}
234
235static struct vfsops devfs_vfsops = {
236 .vfs_mount = devfs_mount,
237 .vfs_root = devfs_root,
238 .vfs_statfs = devfs_statfs,
239 .vfs_unmount = devfs_unmount,
240};
241
242VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC | VFCF_JAIL);