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 /* 60 * Mount the filesystem 61 */ 62 static int 63 devfs_mount(struct mount *mp) 64 { 65 int error; 66 struct devfs_mount *fmp; 67 struct vnode *rvp; 68 69 if (devfs_unr == NULL) 70 devfs_unr = new_unrhdr(0, INT_MAX, NULL); 71 72 error = 0; 73 74 if (mp->mnt_flag & (MNT_UPDATE | MNT_ROOTFS)) 75 return (EOPNOTSUPP); 76 77 fmp = malloc(sizeof *fmp, M_DEVFS, M_WAITOK | M_ZERO); 78 fmp->dm_idx = alloc_unr(devfs_unr); 79 sx_init(&fmp->dm_lock, "devfsmount"); 80 fmp->dm_holdcnt = 1; 81 82 MNT_ILOCK(mp); 83 mp->mnt_flag |= MNT_LOCAL; 84 mp->mnt_kern_flag |= MNTK_MPSAFE | MNTK_LOOKUP_SHARED | 85 MNTK_EXTENDED_SHARED; 86 #ifdef MAC 87 mp->mnt_flag |= MNT_MULTILABEL; 88 #endif 89 MNT_IUNLOCK(mp); 90 fmp->dm_mount = mp; 91 mp->mnt_data = (void *) fmp; 92 vfs_getnewfsid(mp); 93 94 fmp->dm_rootdir = devfs_vmkdir(fmp, NULL, 0, NULL, DEVFS_ROOTINO); 95 96 error = devfs_root(mp, LK_EXCLUSIVE, &rvp); 97 if (error) { 98 sx_destroy(&fmp->dm_lock); 99 free_unr(devfs_unr, fmp->dm_idx); 100 free(fmp, M_DEVFS); 101 return (error); 102 } 103 104 VOP_UNLOCK(rvp, 0); 105 106 vfs_mountedfrom(mp, "devfs"); 107 108 return (0); 109 } 110 111 void 112 devfs_unmount_final(struct devfs_mount *fmp) 113 { 114 sx_destroy(&fmp->dm_lock); 115 free(fmp, M_DEVFS); 116 } 117 118 static int 119 devfs_unmount(struct mount *mp, int mntflags) 120 { 121 int error; 122 int flags = 0; 123 struct devfs_mount *fmp; 124 int hold; 125 u_int idx; 126 127 fmp = VFSTODEVFS(mp); 128 KASSERT(fmp->dm_mount != NULL, 129 ("devfs_unmount unmounted devfs_mount")); 130 /* There is 1 extra root vnode reference from devfs_mount(). */ 131 error = vflush(mp, 1, flags, curthread); 132 if (error) 133 return (error); 134 sx_xlock(&fmp->dm_lock); 135 devfs_cleanup(fmp); 136 devfs_rules_cleanup(fmp); 137 fmp->dm_mount = NULL; 138 hold = --fmp->dm_holdcnt; 139 mp->mnt_data = NULL; 140 idx = fmp->dm_idx; 141 sx_xunlock(&fmp->dm_lock); 142 free_unr(devfs_unr, idx); 143 if (hold == 0) 144 devfs_unmount_final(fmp); 145 return 0; 146 } 147 148 /* Return locked reference to root. */ 149 150 static int 151 devfs_root(struct mount *mp, int flags, struct vnode **vpp) 152 { 153 int error; 154 struct vnode *vp; 155 struct devfs_mount *dmp; 156 157 dmp = VFSTODEVFS(mp); 158 sx_xlock(&dmp->dm_lock); 159 error = devfs_allocv(dmp->dm_rootdir, mp, LK_EXCLUSIVE, &vp); 160 if (error) 161 return (error); 162 vp->v_vflag |= VV_ROOT; 163 *vpp = vp; 164 return (0); 165 } 166 167 static int 168 devfs_statfs(struct mount *mp, struct statfs *sbp) 169 { 170 171 sbp->f_flags = 0; 172 sbp->f_bsize = DEV_BSIZE; 173 sbp->f_iosize = DEV_BSIZE; 174 sbp->f_blocks = 2; /* 1K to keep df happy */ 175 sbp->f_bfree = 0; 176 sbp->f_bavail = 0; 177 sbp->f_files = 0; 178 sbp->f_ffree = 0; 179 return (0); 180 } 181 182 static struct vfsops devfs_vfsops = { 183 .vfs_mount = devfs_mount, 184 .vfs_root = devfs_root, 185 .vfs_statfs = devfs_statfs, 186 .vfs_unmount = devfs_unmount, 187 }; 188 189 VFS_SET(devfs_vfsops, devfs, VFCF_SYNTHETIC); 190