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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)dead_vnops.c 8.1 (Berkeley) 6/10/93 34 * $FreeBSD: src/sys/miscfs/deadfs/dead_vnops.c,v 1.26 1999/08/28 00:46:42 peter Exp $ 35 * $DragonFly: src/sys/vfs/deadfs/dead_vnops.c,v 1.5 2003/07/26 20:05:55 rob Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/lock.h> 42 #include <sys/vnode.h> 43 #include <sys/buf.h> 44 #include <sys/poll.h> 45 46 static int chkvnlock __P((struct vnode *)); 47 /* 48 * Prototypes for dead operations on vnodes. 49 */ 50 static int dead_badop __P((void)); 51 static int dead_bmap __P((struct vop_bmap_args *)); 52 static int dead_ioctl __P((struct vop_ioctl_args *)); 53 static int dead_lock __P((struct vop_lock_args *)); 54 static int dead_lookup __P((struct vop_lookup_args *)); 55 static int dead_open __P((struct vop_open_args *)); 56 static int dead_poll __P((struct vop_poll_args *)); 57 static int dead_print __P((struct vop_print_args *)); 58 static int dead_read __P((struct vop_read_args *)); 59 static int dead_write __P((struct vop_write_args *)); 60 61 vop_t **dead_vnodeop_p; 62 static struct vnodeopv_entry_desc dead_vnodeop_entries[] = { 63 { &vop_default_desc, (vop_t *) vop_defaultop }, 64 { &vop_access_desc, (vop_t *) vop_ebadf }, 65 { &vop_advlock_desc, (vop_t *) vop_ebadf }, 66 { &vop_bmap_desc, (vop_t *) dead_bmap }, 67 { &vop_create_desc, (vop_t *) dead_badop }, 68 { &vop_getattr_desc, (vop_t *) vop_ebadf }, 69 { &vop_inactive_desc, (vop_t *) vop_null }, 70 { &vop_ioctl_desc, (vop_t *) dead_ioctl }, 71 { &vop_link_desc, (vop_t *) dead_badop }, 72 { &vop_lock_desc, (vop_t *) dead_lock }, 73 { &vop_lookup_desc, (vop_t *) dead_lookup }, 74 { &vop_mkdir_desc, (vop_t *) dead_badop }, 75 { &vop_mknod_desc, (vop_t *) dead_badop }, 76 { &vop_mmap_desc, (vop_t *) dead_badop }, 77 { &vop_open_desc, (vop_t *) dead_open }, 78 { &vop_pathconf_desc, (vop_t *) vop_ebadf }, /* per pathconf(2) */ 79 { &vop_poll_desc, (vop_t *) dead_poll }, 80 { &vop_print_desc, (vop_t *) dead_print }, 81 { &vop_read_desc, (vop_t *) dead_read }, 82 { &vop_readdir_desc, (vop_t *) vop_ebadf }, 83 { &vop_readlink_desc, (vop_t *) vop_ebadf }, 84 { &vop_reclaim_desc, (vop_t *) vop_null }, 85 { &vop_remove_desc, (vop_t *) dead_badop }, 86 { &vop_rename_desc, (vop_t *) dead_badop }, 87 { &vop_rmdir_desc, (vop_t *) dead_badop }, 88 { &vop_setattr_desc, (vop_t *) vop_ebadf }, 89 { &vop_symlink_desc, (vop_t *) dead_badop }, 90 { &vop_write_desc, (vop_t *) dead_write }, 91 { NULL, NULL } 92 }; 93 static struct vnodeopv_desc dead_vnodeop_opv_desc = 94 { &dead_vnodeop_p, dead_vnodeop_entries }; 95 96 VNODEOP_SET(dead_vnodeop_opv_desc); 97 98 /* 99 * Trivial lookup routine that always fails. 100 */ 101 /* ARGSUSED */ 102 static int 103 dead_lookup(ap) 104 struct vop_lookup_args /* { 105 struct vnode * a_dvp; 106 struct vnode ** a_vpp; 107 struct componentname * a_cnp; 108 } */ *ap; 109 { 110 111 *ap->a_vpp = NULL; 112 return (ENOTDIR); 113 } 114 115 /* 116 * Open always fails as if device did not exist. 117 */ 118 /* ARGSUSED */ 119 static int 120 dead_open(ap) 121 struct vop_open_args /* { 122 struct vnode *a_vp; 123 int a_mode; 124 struct ucred *a_cred; 125 struct proc *a_p; 126 } */ *ap; 127 { 128 129 return (ENXIO); 130 } 131 132 /* 133 * Vnode op for read 134 */ 135 /* ARGSUSED */ 136 static int 137 dead_read(ap) 138 struct vop_read_args /* { 139 struct vnode *a_vp; 140 struct uio *a_uio; 141 int a_ioflag; 142 struct ucred *a_cred; 143 } */ *ap; 144 { 145 146 if (chkvnlock(ap->a_vp)) 147 panic("dead_read: lock"); 148 /* 149 * Return EOF for tty devices, EIO for others 150 */ 151 if ((ap->a_vp->v_flag & VISTTY) == 0) 152 return (EIO); 153 return (0); 154 } 155 156 /* 157 * Vnode op for write 158 */ 159 /* ARGSUSED */ 160 static int 161 dead_write(ap) 162 struct vop_write_args /* { 163 struct vnode *a_vp; 164 struct uio *a_uio; 165 int a_ioflag; 166 struct ucred *a_cred; 167 } */ *ap; 168 { 169 170 if (chkvnlock(ap->a_vp)) 171 panic("dead_write: lock"); 172 return (EIO); 173 } 174 175 /* 176 * Device ioctl operation. 177 */ 178 /* ARGSUSED */ 179 static int 180 dead_ioctl(ap) 181 struct vop_ioctl_args /* { 182 struct vnode *a_vp; 183 int a_command; 184 caddr_t a_data; 185 int a_fflag; 186 struct ucred *a_cred; 187 struct proc *a_p; 188 } */ *ap; 189 { 190 191 if (!chkvnlock(ap->a_vp)) 192 return (ENOTTY); 193 return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap)); 194 } 195 196 197 /* 198 * Wait until the vnode has finished changing state. 199 */ 200 static int 201 dead_lock(ap) 202 struct vop_lock_args /* { 203 struct vnode *a_vp; 204 int a_flags; 205 struct proc *a_p; 206 } */ *ap; 207 { 208 struct vnode *vp = ap->a_vp; 209 210 /* 211 * Since we are not using the lock manager, we must clear 212 * the interlock here. 213 */ 214 if (ap->a_flags & LK_INTERLOCK) { 215 lwkt_reltoken(&vp->v_interlock); 216 ap->a_flags &= ~LK_INTERLOCK; 217 } 218 if (!chkvnlock(vp)) 219 return (0); 220 return (VCALL(vp, VOFFSET(vop_lock), ap)); 221 } 222 223 /* 224 * Wait until the vnode has finished changing state. 225 */ 226 static int 227 dead_bmap(ap) 228 struct vop_bmap_args /* { 229 struct vnode *a_vp; 230 daddr_t a_bn; 231 struct vnode **a_vpp; 232 daddr_t *a_bnp; 233 int *a_runp; 234 int *a_runb; 235 } */ *ap; 236 { 237 238 if (!chkvnlock(ap->a_vp)) 239 return (EIO); 240 return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp, ap->a_runb)); 241 } 242 243 /* 244 * Print out the contents of a dead vnode. 245 */ 246 /* ARGSUSED */ 247 static int 248 dead_print(ap) 249 struct vop_print_args /* { 250 struct vnode *a_vp; 251 } */ *ap; 252 { 253 254 printf("tag VT_NON, dead vnode\n"); 255 return (0); 256 } 257 258 /* 259 * Empty vnode bad operation 260 */ 261 static int 262 dead_badop() 263 { 264 265 panic("dead_badop called"); 266 /* NOTREACHED */ 267 } 268 269 /* 270 * We have to wait during times when the vnode is 271 * in a state of change. 272 */ 273 int 274 chkvnlock(vp) 275 struct vnode *vp; 276 { 277 int locked = 0; 278 279 while (vp->v_flag & VXLOCK) { 280 vp->v_flag |= VXWANT; 281 (void) tsleep((caddr_t)vp, 0, "ckvnlk", 0); 282 locked = 1; 283 } 284 return (locked); 285 } 286 287 /* 288 * Trivial poll routine that always returns POLLHUP. 289 * This is necessary so that a process which is polling a file 290 * gets notified when that file is revoke()d. 291 */ 292 static int 293 dead_poll(ap) 294 struct vop_poll_args *ap; 295 { 296 return (POLLHUP); 297 } 298