1 /*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)dead_vnops.c 8.1 (Berkeley) 6/10/93 30 * $FreeBSD$ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/poll.h> 39 #include <sys/vnode.h> 40 41 static int chkvnlock(struct vnode *); 42 /* 43 * Prototypes for dead operations on vnodes. 44 */ 45 static vop_bmap_t dead_bmap; 46 static vop_ioctl_t dead_ioctl; 47 static vop_lock_t dead_lock; 48 static vop_lookup_t dead_lookup; 49 static vop_open_t dead_open; 50 static vop_poll_t dead_poll; 51 static vop_read_t dead_read; 52 static vop_write_t dead_write; 53 54 struct vop_vector dead_vnodeops = { 55 .vop_default = &default_vnodeops, 56 57 .vop_access = VOP_EBADF, 58 .vop_advlock = VOP_EBADF, 59 .vop_bmap = dead_bmap, 60 .vop_create = VOP_PANIC, 61 .vop_getattr = VOP_EBADF, 62 .vop_inactive = VOP_NULL, 63 .vop_ioctl = dead_ioctl, 64 .vop_link = VOP_PANIC, 65 .vop_lock = dead_lock, 66 .vop_lookup = dead_lookup, 67 .vop_mkdir = VOP_PANIC, 68 .vop_mknod = VOP_PANIC, 69 .vop_open = dead_open, 70 .vop_pathconf = VOP_EBADF, /* per pathconf(2) */ 71 .vop_poll = dead_poll, 72 .vop_read = dead_read, 73 .vop_readdir = VOP_EBADF, 74 .vop_readlink = VOP_EBADF, 75 .vop_reclaim = VOP_NULL, 76 .vop_remove = VOP_PANIC, 77 .vop_rename = VOP_PANIC, 78 .vop_rmdir = VOP_PANIC, 79 .vop_setattr = VOP_EBADF, 80 .vop_symlink = VOP_PANIC, 81 .vop_write = dead_write, 82 }; 83 84 /* 85 * Trivial lookup routine that always fails. 86 */ 87 /* ARGSUSED */ 88 static int 89 dead_lookup(ap) 90 struct vop_lookup_args /* { 91 struct vnode * a_dvp; 92 struct vnode ** a_vpp; 93 struct componentname * a_cnp; 94 } */ *ap; 95 { 96 97 *ap->a_vpp = NULL; 98 return (ENOTDIR); 99 } 100 101 /* 102 * Open always fails as if device did not exist. 103 */ 104 /* ARGSUSED */ 105 static int 106 dead_open(ap) 107 struct vop_open_args /* { 108 struct vnode *a_vp; 109 int a_mode; 110 struct ucred *a_cred; 111 struct proc *a_p; 112 } */ *ap; 113 { 114 115 return (ENXIO); 116 } 117 118 /* 119 * Vnode op for read 120 */ 121 /* ARGSUSED */ 122 static int 123 dead_read(ap) 124 struct vop_read_args /* { 125 struct vnode *a_vp; 126 struct uio *a_uio; 127 int a_ioflag; 128 struct ucred *a_cred; 129 } */ *ap; 130 { 131 132 if (chkvnlock(ap->a_vp)) 133 panic("dead_read: lock"); 134 /* 135 * Return EOF for tty devices, EIO for others 136 */ 137 if ((ap->a_vp->v_vflag & VV_ISTTY) == 0) 138 return (EIO); 139 return (0); 140 } 141 142 /* 143 * Vnode op for write 144 */ 145 /* ARGSUSED */ 146 static int 147 dead_write(ap) 148 struct vop_write_args /* { 149 struct vnode *a_vp; 150 struct uio *a_uio; 151 int a_ioflag; 152 struct ucred *a_cred; 153 } */ *ap; 154 { 155 156 if (chkvnlock(ap->a_vp)) 157 panic("dead_write: lock"); 158 return (EIO); 159 } 160 161 /* 162 * Device ioctl operation. 163 */ 164 /* ARGSUSED */ 165 static int 166 dead_ioctl(ap) 167 struct vop_ioctl_args /* { 168 struct vnode *a_vp; 169 u_long a_command; 170 caddr_t a_data; 171 int a_fflag; 172 struct ucred *a_cred; 173 struct proc *a_p; 174 } */ *ap; 175 { 176 177 if (!chkvnlock(ap->a_vp)) 178 return (ENOTTY); 179 /* XXX: Doesn't this just recurse back here ? */ 180 return (VOP_IOCTL_AP(ap)); 181 } 182 183 184 /* 185 * Wait until the vnode has finished changing state. 186 */ 187 static int 188 dead_lock(ap) 189 struct vop_lock_args /* { 190 struct vnode *a_vp; 191 int a_flags; 192 struct proc *a_p; 193 } */ *ap; 194 { 195 struct vnode *vp = ap->a_vp; 196 197 /* 198 * Since we are not using the lock manager, we must clear 199 * the interlock here. 200 */ 201 if (ap->a_flags & LK_INTERLOCK) { 202 mtx_unlock(&vp->v_interlock); 203 ap->a_flags &= ~LK_INTERLOCK; 204 } 205 if (!chkvnlock(vp)) 206 return (0); 207 return (VOP_LOCK_AP(ap)); 208 } 209 210 /* 211 * Wait until the vnode has finished changing state. 212 */ 213 static int 214 dead_bmap(ap) 215 struct vop_bmap_args /* { 216 struct vnode *a_vp; 217 daddr_t a_bn; 218 struct bufobj **a_bop; 219 daddr_t *a_bnp; 220 int *a_runp; 221 int *a_runb; 222 } */ *ap; 223 { 224 225 if (!chkvnlock(ap->a_vp)) 226 return (EIO); 227 return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_bop, ap->a_bnp, ap->a_runp, ap->a_runb)); 228 } 229 230 /* 231 * We have to wait during times when the vnode is 232 * in a state of change. 233 */ 234 static int 235 chkvnlock(vp) 236 register struct vnode *vp; 237 { 238 int locked = 0; 239 240 VI_LOCK(vp); 241 while (vp->v_iflag & VI_XLOCK) { 242 vp->v_iflag |= VI_XWANT; 243 (void) msleep((caddr_t)vp, VI_MTX(vp), PINOD, "ckvnlk", 0); 244 locked = 1; 245 } 246 VI_UNLOCK(vp); 247 return (locked); 248 } 249 250 /* 251 * Trivial poll routine that always returns POLLHUP. 252 * This is necessary so that a process which is polling a file 253 * gets notified when that file is revoke()d. 254 */ 255 static int 256 dead_poll(ap) 257 struct vop_poll_args *ap; 258 { 259 return (POLLHUP); 260 } 261