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 * $FreeBSD$ 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 48 #include <fs/devfs/devfs.h> 49 50 static struct unrhdr *devfs_unr; 51 52 MALLOC_DEFINE(M_DEVFS, "DEVFS", "DEVFS data"); 53 54 static vfs_mount_t devfs_mount; 55 static vfs_unmount_t devfs_unmount; 56 static vfs_root_t devfs_root; 57 static vfs_statfs_t devfs_statfs; 58 59 static const char *devfs_opts[] = { 60 "from", "ruleset", NULL 61 }; 62 63 /* 64 * Mount the filesystem 65 */ 66 static int 67 devfs_mount(struct mount *mp) 68 { 69 int error; 70 struct devfs_mount *fmp; 71 struct vnode *rvp; 72 int rsnum; 73 74 if (devfs_unr == NULL) 75 devfs_unr = new_unrhdr(0, INT_MAX, NULL); 76 77 error = 0; 78 79 if (mp->mnt_flag & MNT_ROOTFS) 80 return (EOPNOTSUPP); 81 82 rsnum = 0; 83 84 if (mp->mnt_optnew != NULL) { 85 if (vfs_filteropt(mp->mnt_optnew, devfs_opts)) 86 return (EINVAL); 87 88 if (vfs_getopt(mp->mnt_optnew, "ruleset", NULL, NULL) == 0 && 89 (vfs_scanopt(mp->mnt_optnew, "ruleset", "%d", 90 &rsnum) != 1 || rsnum < 0 || rsnum > 65535)) 91 error = EINVAL; 92 } 93 94 if (error) { 95 vfs_mount_error(mp, "%s", "invalid ruleset specification"); 96 return (error); 97 } 98 99 if (mp->mnt_flag & MNT_UPDATE) { 100 if (rsnum != 0) { 101 fmp = mp->mnt_data; 102 if (fmp != NULL) { 103 sx_xlock(&fmp->dm_lock); 104 devfs_ruleset_set((devfs_rsnum)rsnum, fmp); 105 devfs_ruleset_apply(fmp); 106 sx_xunlock(&fmp->dm_lock); 107 } 108 } 109 return (0); 110 } 111 112 fmp = malloc(sizeof *fmp, M_DEVFS, M_WAITOK | M_ZERO); 113 fmp->dm_idx = alloc_unr(devfs_unr); 114 sx_init(&fmp->dm_lock, "devfsmount"); 115 fmp->dm_holdcnt = 1; 116 117 MNT_ILOCK(mp); 118 mp->mnt_flag |= MNT_LOCAL; 119 mp->mnt_kern_flag |= MNTK_MPSAFE | MNTK_LOOKUP_SHARED | 120 MNTK_EXTENDED_SHARED; 121 #ifdef MAC 122 mp->mnt_flag |= MNT_MULTILABEL; 123 #endif 124 MNT_IUNLOCK(mp); 125 fmp->dm_mount = mp; 126 mp->mnt_data = (void *) fmp; 127 vfs_getnewfsid(mp); 128 129 fmp->dm_rootdir = devfs_vmkdir(fmp, NULL, 0, NULL, DEVFS_ROOTINO); 130 131 error = devfs_root(mp, LK_EXCLUSIVE, &rvp); 132 if (error) { 133 sx_destroy(&fmp->dm_lock); 134 free_unr(devfs_unr, fmp->dm_idx); 135 free(fmp, M_DEVFS); 136 return (error); 137 } 138 139 if (rsnum != 0) { 140 sx_xlock(&fmp->dm_lock); 141 devfs_ruleset_set((devfs_rsnum)rsnum, fmp); 142 sx_xunlock(&fmp->dm_lock); 143 } 144 145 VOP_UNLOCK(rvp, 0); 146 147 vfs_mountedfrom(mp, "devfs"); 148 149 return (0); 150 } 151 152 void 153 devfs_unmount_final(struct devfs_mount *fmp) 154 { 155 sx_destroy(&fmp->dm_lock); 156 free(fmp, M_DEVFS); 157 } 158 159 static int 160 devfs_unmount(struct mount *mp, int mntflags) 161 { 162 int error; 163 int flags = 0; 164 struct devfs_mount *fmp; 165 int hold; 166 u_int idx; 167 168 fmp = VFSTODEVFS(mp); 169 KASSERT(fmp->dm_mount != NULL, 170 ("devfs_unmount unmounted devfs_mount")); 171 /* There is 1 extra root vnode reference from devfs_mount(). */ 172 error = vflush(mp, 1, flags, curthread); 173 if (error) 174 return (error); 175 sx_xlock(&fmp->dm_lock); 176 devfs_cleanup(fmp); 177 devfs_rules_cleanup(fmp); 178 fmp->dm_mount = NULL; 179 hold = --fmp->dm_holdcnt; 180 mp->mnt_data = NULL; 181 idx = fmp->dm_idx; 182 sx_xunlock(&fmp->dm_lock); 183 free_unr(devfs_unr, idx); 184 if (hold == 0) 185 devfs_unmount_final(fmp); 186 return 0; 187 } 188 189 /* Return locked reference to root. */ 190 191 static int 192 devfs_root(struct mount *mp, int flags, struct vnode **vpp) 193 { 194 int error; 195 struct vnode *vp; 196 struct devfs_mount *dmp; 197 198 dmp = VFSTODEVFS(mp); 199 sx_xlock(&dmp->dm_lock); 200 error = devfs_allocv(dmp->dm_rootdir, mp, LK_EXCLUSIVE, &vp); 201 if (error) 202 return (error); 203 vp->v_vflag |= VV_ROOT; 204 *vpp = vp; 205 return (0); 206 } 207 208 static int 209 devfs_statfs(struct mount *mp, struct statfs *sbp) 210 { 211 212 sbp->f_flags = 0; 213 sbp->f_bsize = DEV_BSIZE; 214 sbp->f_iosize = DEV_BSIZE; 215 sbp->f_blocks = 2; /* 1K to keep df happy */ 216 sbp->f_bfree = 0; 217 sbp->f_bavail = 0; 218 sbp->f_files = 0; 219 sbp->f_ffree = 0; 220 return (0); 221 } 222 223 static struct vfsops devfs_vfsops = { 224 .vfs_mount = devfs_mount, 225 .vfs_root = devfs_root, 226 .vfs_statfs = devfs_statfs, 227 .vfs_unmount = devfs_unmount, 228 }; 229 230 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC); 231