dead_vnops.c revision 1.42
1 /* $NetBSD: dead_vnops.c,v 1.42 2006/12/09 16:11:51 chs Exp $ */ 2 3 /* 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. 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 * @(#)dead_vnops.c 8.2 (Berkeley) 11/21/94 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: dead_vnops.c,v 1.42 2006/12/09 16:11:51 chs Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/time.h> 40 #include <sys/vnode.h> 41 #include <sys/errno.h> 42 #include <sys/namei.h> 43 #include <sys/buf.h> 44 #include <sys/proc.h> 45 46 #include <miscfs/genfs/genfs.h> 47 48 /* 49 * Prototypes for dead operations on vnodes. 50 */ 51 int dead_open(void *); 52 #define dead_close genfs_nullop 53 int dead_read(void *); 54 int dead_write(void *); 55 #define dead_lease_check genfs_nullop 56 #define dead_fcntl genfs_nullop 57 int dead_ioctl(void *); 58 int dead_poll(void *); 59 #define dead_fsync genfs_nullop 60 #define dead_seek genfs_nullop 61 #define dead_inactive genfs_nullop 62 #define dead_reclaim genfs_nullop 63 int dead_lock(void *); 64 #define dead_unlock genfs_nullop 65 int dead_bmap(void *); 66 int dead_strategy(void *); 67 int dead_print(void *); 68 #define dead_islocked genfs_nullop 69 #define dead_bwrite genfs_nullop 70 #define dead_revoke genfs_nullop 71 #define dead_putpages genfs_null_putpages 72 73 int chkvnlock(struct vnode *); 74 int dead_default_error(void *); 75 76 int (**dead_vnodeop_p)(void *); 77 78 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = { 79 { &vop_default_desc, dead_default_error }, 80 { &vop_open_desc, dead_open }, /* open */ 81 { &vop_close_desc, dead_close }, /* close */ 82 { &vop_read_desc, dead_read }, /* read */ 83 { &vop_write_desc, dead_write }, /* write */ 84 { &vop_lease_desc, dead_lease_check }, /* lease */ 85 { &vop_fcntl_desc, dead_fcntl }, /* fcntl */ 86 { &vop_ioctl_desc, dead_ioctl }, /* ioctl */ 87 { &vop_poll_desc, dead_poll }, /* poll */ 88 { &vop_revoke_desc, dead_revoke }, /* revoke */ 89 { &vop_fsync_desc, dead_fsync }, /* fsync */ 90 { &vop_seek_desc, dead_seek }, /* seek */ 91 { &vop_inactive_desc, dead_inactive }, /* inactive */ 92 { &vop_reclaim_desc, dead_reclaim }, /* reclaim */ 93 { &vop_lock_desc, dead_lock }, /* lock */ 94 { &vop_unlock_desc, dead_unlock }, /* unlock */ 95 { &vop_bmap_desc, dead_bmap }, /* bmap */ 96 { &vop_strategy_desc, dead_strategy }, /* strategy */ 97 { &vop_print_desc, dead_print }, /* print */ 98 { &vop_islocked_desc, dead_islocked }, /* islocked */ 99 { &vop_bwrite_desc, dead_bwrite }, /* bwrite */ 100 { &vop_putpages_desc, dead_putpages }, /* putpages */ 101 { NULL, NULL } 102 }; 103 const struct vnodeopv_desc dead_vnodeop_opv_desc = 104 { &dead_vnodeop_p, dead_vnodeop_entries }; 105 106 int 107 dead_default_error(void *v) 108 { 109 110 return EBADF; 111 } 112 113 /* 114 * Open always fails as if device did not exist. 115 */ 116 /* ARGSUSED */ 117 int 118 dead_open(void *v) 119 { 120 121 return (ENXIO); 122 } 123 124 /* 125 * Vnode op for read 126 */ 127 /* ARGSUSED */ 128 int 129 dead_read(v) 130 void *v; 131 { 132 struct vop_read_args /* { 133 struct vnode *a_vp; 134 struct uio *a_uio; 135 int a_ioflag; 136 kauth_cred_t a_cred; 137 } */ *ap = v; 138 139 if (chkvnlock(ap->a_vp)) 140 panic("dead_read: lock"); 141 /* 142 * Return EOF for tty devices, EIO for others 143 */ 144 if ((ap->a_vp->v_flag & VISTTY) == 0) 145 return (EIO); 146 return (0); 147 } 148 149 /* 150 * Vnode op for write 151 */ 152 /* ARGSUSED */ 153 int 154 dead_write(v) 155 void *v; 156 { 157 struct vop_write_args /* { 158 struct vnode *a_vp; 159 struct uio *a_uio; 160 int a_ioflag; 161 kauth_cred_t a_cred; 162 } */ *ap = v; 163 164 if (chkvnlock(ap->a_vp)) 165 panic("dead_write: lock"); 166 return (EIO); 167 } 168 169 /* 170 * Device ioctl operation. 171 */ 172 /* ARGSUSED */ 173 int 174 dead_ioctl(v) 175 void *v; 176 { 177 struct vop_ioctl_args /* { 178 struct vnode *a_vp; 179 u_long a_command; 180 void *a_data; 181 int a_fflag; 182 kauth_cred_t a_cred; 183 struct lwp *a_l; 184 } */ *ap = v; 185 186 if (!chkvnlock(ap->a_vp)) 187 return (EBADF); 188 return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap)); 189 } 190 191 /* ARGSUSED */ 192 int 193 dead_poll(v) 194 void *v; 195 { 196 struct vop_poll_args /* { 197 struct vnode *a_vp; 198 int a_events; 199 struct lwp *a_l; 200 } */ *ap = v; 201 202 /* 203 * Let the user find out that the descriptor is gone. 204 */ 205 return (ap->a_events); 206 } 207 208 /* 209 * Just call the device strategy routine 210 */ 211 int 212 dead_strategy(v) 213 void *v; 214 { 215 216 struct vop_strategy_args /* { 217 struct vnode *a_vp; 218 struct buf *a_bp; 219 } */ *ap = v; 220 if (ap->a_vp == NULL || !chkvnlock(ap->a_vp)) { 221 ap->a_bp->b_flags |= B_ERROR; 222 biodone(ap->a_bp); 223 return (EIO); 224 } 225 return (VOP_STRATEGY(ap->a_vp, ap->a_bp)); 226 } 227 228 /* 229 * Wait until the vnode has finished changing state. 230 */ 231 int 232 dead_lock(v) 233 void *v; 234 { 235 struct vop_lock_args /* { 236 struct vnode *a_vp; 237 int a_flags; 238 struct proc *a_p; 239 } */ *ap = v; 240 241 if (ap->a_flags & LK_INTERLOCK) { 242 simple_unlock(&ap->a_vp->v_interlock); 243 ap->a_flags &= ~LK_INTERLOCK; 244 } 245 if (!chkvnlock(ap->a_vp)) 246 return (0); 247 return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap)); 248 } 249 250 /* 251 * Wait until the vnode has finished changing state. 252 */ 253 int 254 dead_bmap(v) 255 void *v; 256 { 257 struct vop_bmap_args /* { 258 struct vnode *a_vp; 259 daddr_t a_bn; 260 struct vnode **a_vpp; 261 daddr_t *a_bnp; 262 int *a_runp; 263 } */ *ap = v; 264 265 if (!chkvnlock(ap->a_vp)) 266 return (EIO); 267 return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp)); 268 } 269 270 /* 271 * Print out the contents of a dead vnode. 272 */ 273 /* ARGSUSED */ 274 int 275 dead_print(void *v) 276 { 277 printf("tag VT_NON, dead vnode\n"); 278 return 0; 279 } 280 281 /* 282 * We have to wait during times when the vnode is 283 * in a state of change. 284 */ 285 int 286 chkvnlock(vp) 287 struct vnode *vp; 288 { 289 int locked = 0; 290 291 while (vp->v_flag & VXLOCK) { 292 vp->v_flag |= VXWANT; 293 (void) tsleep(vp, PINOD, "deadchk", 0); 294 locked = 1; 295 } 296 return (locked); 297 } 298
Indexes created Thu Sep 25 02:09:54 GMT 2025