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