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 1.20 2007/08/13 17:31:56 dillon 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/fcntl.h> 44 #include <sys/buf.h> 45 #include <sys/poll.h> 46 47 /* 48 * Prototypes for dead operations on vnodes. 49 */ 50 static int dead_badop (void); 51 static int dead_bmap (struct vop_bmap_args *); 52 static int dead_ioctl (struct vop_ioctl_args *); 53 static int dead_lookup (struct vop_old_lookup_args *); 54 static int dead_open (struct vop_open_args *); 55 static int dead_close (struct vop_close_args *); 56 static int dead_poll (struct vop_poll_args *); 57 static int dead_print (struct vop_print_args *); 58 static int dead_read (struct vop_read_args *); 59 static int dead_write (struct vop_write_args *); 60 61 struct vop_ops dead_vnode_vops = { 62 .vop_default = vop_defaultop, 63 .vop_access = (void *)vop_ebadf, 64 .vop_advlock = (void *)vop_ebadf, 65 .vop_bmap = dead_bmap, 66 .vop_old_create = (void *)dead_badop, 67 .vop_getattr = (void *)vop_ebadf, 68 .vop_inactive = (void *)vop_null, 69 .vop_ioctl = dead_ioctl, 70 .vop_old_link = (void *)dead_badop, 71 .vop_old_lookup = dead_lookup, 72 .vop_old_mkdir = (void *)dead_badop, 73 .vop_old_mknod = (void *)dead_badop, 74 .vop_mmap = (void *)dead_badop, 75 .vop_open = dead_open, 76 .vop_close = dead_close, 77 .vop_pathconf = (void *)vop_ebadf, /* per pathconf(2) */ 78 .vop_poll = dead_poll, 79 .vop_print = dead_print, 80 .vop_read = dead_read, 81 .vop_readdir = (void *)vop_ebadf, 82 .vop_readlink = (void *)vop_ebadf, 83 .vop_reclaim = (void *)vop_null, 84 .vop_old_remove = (void *)dead_badop, 85 .vop_old_rename = (void *)dead_badop, 86 .vop_old_rmdir = (void *)dead_badop, 87 .vop_setattr = (void *)vop_ebadf, 88 .vop_old_symlink = (void *)dead_badop, 89 .vop_write = dead_write 90 }; 91 92 struct vop_ops *dead_vnode_vops_p = &dead_vnode_vops; 93 94 VNODEOP_SET(dead_vnode_vops); 95 96 /* 97 * Trivial lookup routine that always fails. 98 * 99 * dead_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 100 * struct componentname *a_cnp) 101 */ 102 /* ARGSUSED */ 103 static int 104 dead_lookup(struct vop_old_lookup_args *ap) 105 { 106 *ap->a_vpp = NULL; 107 return (ENOTDIR); 108 } 109 110 /* 111 * Open always fails as if device did not exist. 112 * 113 * dead_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 114 * struct proc *a_p) 115 */ 116 /* ARGSUSED */ 117 static int 118 dead_open(struct vop_open_args *ap) 119 { 120 return (ENXIO); 121 } 122 123 /* 124 * Close always succeeds, and does not warn or panic if v_opencount or 125 * v_writecount is incorrect, because a forced unmount or revocation 126 * might have closed the file out from under the descriptor. 127 */ 128 static int 129 dead_close(struct vop_close_args *ap) 130 { 131 struct vnode *vp = ap->a_vp; 132 133 if (vp->v_opencount > 0) { 134 if ((ap->a_fflag & FWRITE) && vp->v_writecount > 0) 135 --vp->v_writecount; 136 --vp->v_opencount; 137 } 138 return (0); 139 } 140 141 /* 142 * Vnode op for read 143 * 144 * dead_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 145 * struct ucred *a_cred) 146 */ 147 /* ARGSUSED */ 148 static int 149 dead_read(struct vop_read_args *ap) 150 { 151 /* 152 * Return EOF for tty devices, EIO for others 153 */ 154 if ((ap->a_vp->v_flag & VISTTY) == 0) 155 return (EIO); 156 return (0); 157 } 158 159 /* 160 * Vnode op for write 161 * 162 * dead_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 163 * struct ucred *a_cred) 164 */ 165 /* ARGSUSED */ 166 static int 167 dead_write(struct vop_write_args *ap) 168 { 169 return (EIO); 170 } 171 172 /* 173 * Device ioctl operation. 174 * 175 * dead_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, int a_fflag, 176 * struct ucred *a_cred, struct proc *a_p) 177 */ 178 /* ARGSUSED */ 179 static int 180 dead_ioctl(struct vop_ioctl_args *ap) 181 { 182 return (ENOTTY); 183 } 184 185 /* 186 * Wait until the vnode has finished changing state. 187 * 188 * dead_bmap(struct vnode *a_vp, off_t a_loffset, 189 * off_t *a_doffsetp, int *a_runp, int *a_runb) 190 */ 191 static int 192 dead_bmap(struct vop_bmap_args *ap) 193 { 194 return (EIO); 195 } 196 197 /* 198 * Print out the contents of a dead vnode. 199 * 200 * dead_print(struct vnode *a_vp) 201 */ 202 /* ARGSUSED */ 203 static int 204 dead_print(struct vop_print_args *ap) 205 { 206 kprintf("tag VT_NON, dead vnode\n"); 207 return (0); 208 } 209 210 /* 211 * Empty vnode bad operation 212 */ 213 static int 214 dead_badop(void) 215 { 216 panic("dead_badop called"); 217 /* NOTREACHED */ 218 } 219 220 /* 221 * Trivial poll routine that always returns POLLHUP. 222 * This is necessary so that a process which is polling a file 223 * gets notified when that file is revoke()d. 224 */ 225 static int 226 dead_poll(struct vop_poll_args *ap) 227 { 228 return (POLLHUP); 229 } 230