1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1992, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * Copyright (c) 2000 7 * Poul-Henning Kamp. All rights reserved. 8 * 9 * This code is derived from software donated to Berkeley by 10 * Jan-Simon Pendry. 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. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)kernfs_vfsops.c 8.10 (Berkeley) 5/14/95 34 * From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36 35 * 36 * $FreeBSD$ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/lock.h> 43 #include <sys/malloc.h> 44 #include <sys/mount.h> 45 #include <sys/proc.h> 46 #include <sys/sx.h> 47 #include <sys/vnode.h> 48 #include <sys/limits.h> 49 #include <sys/jail.h> 50 51 #include <fs/devfs/devfs.h> 52 53 static struct unrhdr *devfs_unr; 54 55 MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data"); 56 57 static vfs_mount_t devfs_mount; 58 static vfs_unmount_t devfs_unmount; 59 static vfs_root_t devfs_root; 60 static vfs_statfs_t devfs_statfs; 61 62 static const char *devfs_opts[] = { 63 "from", "export", "ruleset", NULL 64 }; 65 66 /* 67 * Mount the filesystem 68 */ 69 static int 70 devfs_mount(struct mount *mp) 71 { 72 int error; 73 struct devfs_mount *fmp; 74 struct vnode *rvp; 75 struct thread *td = curthread; 76 int injail, rsnum; 77 78 if (devfs_unr == NULL) 79 devfs_unr = new_unrhdr(0, INT_MAX, NULL); 80 81 error = 0; 82 83 if (mp->mnt_flag & MNT_ROOTFS) 84 return (EOPNOTSUPP); 85 86 rsnum = 0; 87 injail = jailed(td->td_ucred); 88 89 if (mp->mnt_optnew != NULL) { 90 if (vfs_filteropt(mp->mnt_optnew, devfs_opts)) 91 return (EINVAL); 92 93 if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0)) 94 return (EOPNOTSUPP); 95 96 if (vfs_getopt(mp->mnt_optnew, "ruleset", NULL, NULL) == 0 && 97 (vfs_scanopt(mp->mnt_optnew, "ruleset", "%d", 98 &rsnum) != 1 || rsnum < 0 || rsnum > 65535)) { 99 vfs_mount_error(mp, "%s", 100 "invalid ruleset specification"); 101 return (EINVAL); 102 } 103 104 if (injail && rsnum != 0 && 105 rsnum != td->td_ucred->cr_prison->pr_devfs_rsnum) 106 return (EPERM); 107 } 108 109 /* jails enforce their ruleset */ 110 if (injail) 111 rsnum = td->td_ucred->cr_prison->pr_devfs_rsnum; 112 113 if (mp->mnt_flag & MNT_UPDATE) { 114 if (rsnum != 0) { 115 fmp = mp->mnt_data; 116 if (fmp != NULL) { 117 sx_xlock(&fmp->dm_lock); 118 devfs_ruleset_set((devfs_rsnum)rsnum, fmp); 119 devfs_ruleset_apply(fmp); 120 sx_xunlock(&fmp->dm_lock); 121 } 122 } 123 return (0); 124 } 125 126 fmp = malloc(sizeof *fmp, M_DEVFS, M_WAITOK | M_ZERO); 127 fmp->dm_idx = alloc_unr(devfs_unr); 128 sx_init(&fmp->dm_lock, "devfsmount"); 129 fmp->dm_holdcnt = 1; 130 131 MNT_ILOCK(mp); 132 mp->mnt_flag |= MNT_LOCAL; 133 mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED | 134 MNTK_NOMSYNC; 135 #ifdef MAC 136 mp->mnt_flag |= MNT_MULTILABEL; 137 #endif 138 MNT_IUNLOCK(mp); 139 fmp->dm_mount = mp; 140 mp->mnt_data = (void *) fmp; 141 vfs_getnewfsid(mp); 142 143 fmp->dm_rootdir = devfs_vmkdir(fmp, NULL, 0, NULL, DEVFS_ROOTINO); 144 145 error = devfs_root(mp, LK_EXCLUSIVE, &rvp); 146 if (error) { 147 sx_destroy(&fmp->dm_lock); 148 free_unr(devfs_unr, fmp->dm_idx); 149 free(fmp, M_DEVFS); 150 return (error); 151 } 152 153 if (rsnum != 0) { 154 sx_xlock(&fmp->dm_lock); 155 devfs_ruleset_set((devfs_rsnum)rsnum, fmp); 156 sx_xunlock(&fmp->dm_lock); 157 } 158 159 VOP_UNLOCK(rvp); 160 vfs_cache_root_set(mp, rvp); 161 162 vfs_mountedfrom(mp, "devfs"); 163 164 return (0); 165 } 166 167 void 168 devfs_unmount_final(struct devfs_mount *fmp) 169 { 170 sx_destroy(&fmp->dm_lock); 171 free(fmp, M_DEVFS); 172 } 173 174 static int 175 devfs_unmount(struct mount *mp, int mntflags) 176 { 177 int error; 178 int flags = 0; 179 struct devfs_mount *fmp; 180 int hold; 181 u_int idx; 182 183 fmp = VFSTODEVFS(mp); 184 KASSERT(fmp->dm_mount != NULL, 185 ("devfs_unmount unmounted devfs_mount")); 186 if (mntflags & MNT_FORCE) 187 flags |= FORCECLOSE; 188 /* There is 1 extra root vnode reference from devfs_mount(). */ 189 error = vflush(mp, 1, flags, curthread); 190 if (error) 191 return (error); 192 sx_xlock(&fmp->dm_lock); 193 devfs_cleanup(fmp); 194 devfs_rules_cleanup(fmp); 195 fmp->dm_mount = NULL; 196 hold = --fmp->dm_holdcnt; 197 mp->mnt_data = NULL; 198 idx = fmp->dm_idx; 199 sx_xunlock(&fmp->dm_lock); 200 free_unr(devfs_unr, idx); 201 if (hold == 0) 202 devfs_unmount_final(fmp); 203 return 0; 204 } 205 206 /* Return locked reference to root. */ 207 208 static int 209 devfs_root(struct mount *mp, int flags, struct vnode **vpp) 210 { 211 int error; 212 struct vnode *vp; 213 struct devfs_mount *dmp; 214 215 dmp = VFSTODEVFS(mp); 216 sx_xlock(&dmp->dm_lock); 217 error = devfs_allocv(dmp->dm_rootdir, mp, LK_EXCLUSIVE, &vp); 218 if (error) 219 return (error); 220 vp->v_vflag |= VV_ROOT; 221 *vpp = vp; 222 return (0); 223 } 224 225 static int 226 devfs_statfs(struct mount *mp, struct statfs *sbp) 227 { 228 229 sbp->f_flags = 0; 230 sbp->f_bsize = DEV_BSIZE; 231 sbp->f_iosize = DEV_BSIZE; 232 sbp->f_blocks = 2; /* 1K to keep df happy */ 233 sbp->f_bfree = 0; 234 sbp->f_bavail = 0; 235 sbp->f_files = 0; 236 sbp->f_ffree = 0; 237 return (0); 238 } 239 240 static struct vfsops devfs_vfsops = { 241 .vfs_mount = devfs_mount, 242 .vfs_root = vfs_cache_root, 243 .vfs_cachedroot = devfs_root, 244 .vfs_statfs = devfs_statfs, 245 .vfs_unmount = devfs_unmount, 246 }; 247 248 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC | VFCF_JAIL); 249