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