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. 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: src/sys/miscfs/deadfs/dead_vnops.c,v 1.26 1999/08/28 00:46:42 peter Exp $ 31 * $DragonFly: src/sys/vfs/deadfs/dead_vnops.c,v 1.20 2007/08/13 17:31:56 dillon Exp $ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/lock.h> 38 #include <sys/vnode.h> 39 #include <sys/fcntl.h> 40 #include <sys/buf.h> 41 42 /* 43 * Prototypes for dead operations on vnodes. 44 */ 45 static int dead_badop (void); 46 static int dead_bmap (struct vop_bmap_args *); 47 static int dead_ioctl (struct vop_ioctl_args *); 48 static int dead_lookup (struct vop_old_lookup_args *); 49 static int dead_open (struct vop_open_args *); 50 static int dead_close (struct vop_close_args *); 51 static int dead_print (struct vop_print_args *); 52 static int dead_read (struct vop_read_args *); 53 static int dead_write (struct vop_write_args *); 54 55 struct vop_ops dead_vnode_vops = { 56 .vop_default = vop_defaultop, 57 .vop_access = (void *)vop_ebadf, 58 .vop_advlock = (void *)vop_ebadf, 59 .vop_bmap = dead_bmap, 60 .vop_old_create = (void *)dead_badop, 61 .vop_getattr = (void *)vop_ebadf, 62 .vop_inactive = (void *)vop_null, 63 .vop_ioctl = dead_ioctl, 64 .vop_old_link = (void *)dead_badop, 65 .vop_old_lookup = dead_lookup, 66 .vop_old_mkdir = (void *)dead_badop, 67 .vop_old_mknod = (void *)dead_badop, 68 .vop_open = dead_open, 69 .vop_close = dead_close, 70 .vop_pathconf = (void *)vop_ebadf, /* per pathconf(2) */ 71 .vop_print = dead_print, 72 .vop_read = dead_read, 73 .vop_readdir = (void *)vop_ebadf, 74 .vop_readlink = (void *)vop_ebadf, 75 .vop_reclaim = (void *)vop_null, 76 .vop_old_remove = (void *)dead_badop, 77 .vop_old_rename = (void *)dead_badop, 78 .vop_old_rmdir = (void *)dead_badop, 79 .vop_setattr = (void *)vop_ebadf, 80 .vop_old_symlink = (void *)dead_badop, 81 .vop_write = dead_write 82 }; 83 84 struct vop_ops *dead_vnode_vops_p = &dead_vnode_vops; 85 86 VNODEOP_SET(dead_vnode_vops); 87 88 /* 89 * Trivial lookup routine that always fails. 90 * 91 * dead_lookup(struct vnode *a_dvp, struct vnode **a_vpp, 92 * struct componentname *a_cnp) 93 */ 94 /* ARGSUSED */ 95 static int 96 dead_lookup(struct vop_old_lookup_args *ap) 97 { 98 *ap->a_vpp = NULL; 99 return (ENOTDIR); 100 } 101 102 /* 103 * Open always fails as if device did not exist. 104 * 105 * dead_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred, 106 * struct proc *a_p) 107 */ 108 /* ARGSUSED */ 109 static int 110 dead_open(struct vop_open_args *ap) 111 { 112 return (ENXIO); 113 } 114 115 /* 116 * Close always succeeds, and does not warn or panic if v_opencount or 117 * v_writecount is incorrect, because a forced unmount or revocation 118 * might have closed the file out from under the descriptor. 119 */ 120 static int 121 dead_close(struct vop_close_args *ap) 122 { 123 struct vnode *vp = ap->a_vp; 124 125 vn_lock(vp, LK_UPGRADE | LK_RETRY); /* safety */ 126 if (vp->v_opencount > 0) { 127 if ((ap->a_fflag & FWRITE) && vp->v_writecount > 0) 128 atomic_add_int(&vp->v_writecount, -1); 129 atomic_add_int(&vp->v_opencount, -1); 130 } 131 return (0); 132 } 133 134 /* 135 * Vnode op for read 136 * 137 * dead_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 138 * struct ucred *a_cred) 139 */ 140 /* ARGSUSED */ 141 static int 142 dead_read(struct vop_read_args *ap) 143 { 144 /* 145 * Return EOF for tty devices, EIO for others 146 */ 147 if ((ap->a_vp->v_flag & VISTTY) == 0) 148 return (EIO); 149 return (0); 150 } 151 152 /* 153 * Vnode op for write 154 * 155 * dead_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, 156 * struct ucred *a_cred) 157 */ 158 /* ARGSUSED */ 159 static int 160 dead_write(struct vop_write_args *ap) 161 { 162 return (EIO); 163 } 164 165 /* 166 * Device ioctl operation. 167 * 168 * dead_ioctl(struct vnode *a_vp, int a_command, caddr_t a_data, int a_fflag, 169 * struct ucred *a_cred, struct proc *a_p) 170 */ 171 /* ARGSUSED */ 172 static int 173 dead_ioctl(struct vop_ioctl_args *ap) 174 { 175 return (ENOTTY); 176 } 177 178 /* 179 * Wait until the vnode has finished changing state. 180 * 181 * dead_bmap(struct vnode *a_vp, off_t a_loffset, 182 * off_t *a_doffsetp, int *a_runp, int *a_runb) 183 */ 184 static int 185 dead_bmap(struct vop_bmap_args *ap) 186 { 187 return (EIO); 188 } 189 190 /* 191 * Print out the contents of a dead vnode. 192 * 193 * dead_print(struct vnode *a_vp) 194 */ 195 /* ARGSUSED */ 196 static int 197 dead_print(struct vop_print_args *ap) 198 { 199 kprintf("tag VT_NON, dead vnode\n"); 200 return (0); 201 } 202 203 /* 204 * Empty vnode bad operation 205 */ 206 static int 207 dead_badop(void) 208 { 209 panic("dead_badop called"); 210 /* NOTREACHED */ 211 } 212