dead_vnops.c revision 3396
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 * $Id: dead_vnops.c,v 1.4 1994/09/21 03:46:52 wollman Exp $ 35 */ 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/time.h> 40#include <sys/kernel.h> 41#include <sys/vnode.h> 42#include <sys/errno.h> 43#include <sys/namei.h> 44#include <sys/buf.h> 45 46/* 47 * Prototypes for dead operations on vnodes. 48 */ 49int dead_badop(), 50 dead_ebadf(); 51int dead_lookup __P((struct vop_lookup_args *)); 52#define dead_create ((int (*) __P((struct vop_create_args *)))dead_badop) 53#define dead_mknod ((int (*) __P((struct vop_mknod_args *)))dead_badop) 54int dead_open __P((struct vop_open_args *)); 55#define dead_close ((int (*) __P((struct vop_close_args *)))nullop) 56#define dead_access ((int (*) __P((struct vop_access_args *)))dead_ebadf) 57#define dead_getattr ((int (*) __P((struct vop_getattr_args *)))dead_ebadf) 58#define dead_setattr ((int (*) __P((struct vop_setattr_args *)))dead_ebadf) 59int dead_read __P((struct vop_read_args *)); 60int dead_write __P((struct vop_write_args *)); 61int dead_ioctl __P((struct vop_ioctl_args *)); 62int dead_select __P((struct vop_select_args *)); 63#define dead_mmap ((int (*) __P((struct vop_mmap_args *)))dead_badop) 64#define dead_fsync ((int (*) __P((struct vop_fsync_args *)))nullop) 65#define dead_seek ((int (*) __P((struct vop_seek_args *)))nullop) 66#define dead_remove ((int (*) __P((struct vop_remove_args *)))dead_badop) 67#define dead_link ((int (*) __P((struct vop_link_args *)))dead_badop) 68#define dead_rename ((int (*) __P((struct vop_rename_args *)))dead_badop) 69#define dead_mkdir ((int (*) __P((struct vop_mkdir_args *)))dead_badop) 70#define dead_rmdir ((int (*) __P((struct vop_rmdir_args *)))dead_badop) 71#define dead_symlink ((int (*) __P((struct vop_symlink_args *)))dead_badop) 72#define dead_readdir ((int (*) __P((struct vop_readdir_args *)))dead_ebadf) 73#define dead_readlink ((int (*) __P((struct vop_readlink_args *)))dead_ebadf) 74#define dead_abortop ((int (*) __P((struct vop_abortop_args *)))dead_badop) 75#define dead_inactive ((int (*) __P((struct vop_inactive_args *)))nullop) 76#define dead_reclaim ((int (*) __P((struct vop_reclaim_args *)))nullop) 77int dead_lock __P((struct vop_lock_args *)); 78#define dead_unlock ((int (*) __P((struct vop_unlock_args *)))nullop) 79int dead_bmap __P((struct vop_bmap_args *)); 80int dead_strategy __P((struct vop_strategy_args *)); 81int dead_print __P((struct vop_print_args *)); 82#define dead_islocked ((int (*) __P((struct vop_islocked_args *)))nullop) 83#define dead_pathconf ((int (*) __P((struct vop_pathconf_args *)))dead_ebadf) 84#define dead_advlock ((int (*) __P((struct vop_advlock_args *)))dead_ebadf) 85#define dead_blkatoff ((int (*) __P((struct vop_blkatoff_args *)))dead_badop) 86#define dead_valloc ((int (*) __P((struct vop_valloc_args *)))dead_badop) 87#define dead_vfree ((int (*) __P((struct vop_vfree_args *)))dead_badop) 88#define dead_truncate ((int (*) __P((struct vop_truncate_args *)))nullop) 89#define dead_update ((int (*) __P((struct vop_update_args *)))nullop) 90#define dead_bwrite ((int (*) __P((struct vop_bwrite_args *)))nullop) 91 92int (**dead_vnodeop_p)(); 93struct vnodeopv_entry_desc dead_vnodeop_entries[] = { 94 { &vop_default_desc, vn_default_error }, 95 { &vop_lookup_desc, dead_lookup }, /* lookup */ 96 { &vop_create_desc, dead_create }, /* create */ 97 { &vop_mknod_desc, dead_mknod }, /* mknod */ 98 { &vop_open_desc, dead_open }, /* open */ 99 { &vop_close_desc, dead_close }, /* close */ 100 { &vop_access_desc, dead_access }, /* access */ 101 { &vop_getattr_desc, dead_getattr }, /* getattr */ 102 { &vop_setattr_desc, dead_setattr }, /* setattr */ 103 { &vop_read_desc, dead_read }, /* read */ 104 { &vop_write_desc, dead_write }, /* write */ 105 { &vop_ioctl_desc, dead_ioctl }, /* ioctl */ 106 { &vop_select_desc, dead_select }, /* select */ 107 { &vop_mmap_desc, dead_mmap }, /* mmap */ 108 { &vop_fsync_desc, dead_fsync }, /* fsync */ 109 { &vop_seek_desc, dead_seek }, /* seek */ 110 { &vop_remove_desc, dead_remove }, /* remove */ 111 { &vop_link_desc, dead_link }, /* link */ 112 { &vop_rename_desc, dead_rename }, /* rename */ 113 { &vop_mkdir_desc, dead_mkdir }, /* mkdir */ 114 { &vop_rmdir_desc, dead_rmdir }, /* rmdir */ 115 { &vop_symlink_desc, dead_symlink }, /* symlink */ 116 { &vop_readdir_desc, dead_readdir }, /* readdir */ 117 { &vop_readlink_desc, dead_readlink }, /* readlink */ 118 { &vop_abortop_desc, dead_abortop }, /* abortop */ 119 { &vop_inactive_desc, dead_inactive }, /* inactive */ 120 { &vop_reclaim_desc, dead_reclaim }, /* reclaim */ 121 { &vop_lock_desc, dead_lock }, /* lock */ 122 { &vop_unlock_desc, dead_unlock }, /* unlock */ 123 { &vop_bmap_desc, dead_bmap }, /* bmap */ 124 { &vop_strategy_desc, dead_strategy }, /* strategy */ 125 { &vop_print_desc, dead_print }, /* print */ 126 { &vop_islocked_desc, dead_islocked }, /* islocked */ 127 { &vop_pathconf_desc, dead_pathconf }, /* pathconf */ 128 { &vop_advlock_desc, dead_advlock }, /* advlock */ 129 { &vop_blkatoff_desc, dead_blkatoff }, /* blkatoff */ 130 { &vop_valloc_desc, dead_valloc }, /* valloc */ 131 { &vop_vfree_desc, dead_vfree }, /* vfree */ 132 { &vop_truncate_desc, dead_truncate }, /* truncate */ 133 { &vop_update_desc, dead_update }, /* update */ 134 { &vop_bwrite_desc, dead_bwrite }, /* bwrite */ 135 { (struct vnodeop_desc*)NULL, (int(*)())NULL } 136}; 137struct vnodeopv_desc dead_vnodeop_opv_desc = 138 { &dead_vnodeop_p, dead_vnodeop_entries }; 139 140VNODEOP_SET(dead_vnodeop_opv_desc); 141 142/* 143 * Trivial lookup routine that always fails. 144 */ 145/* ARGSUSED */ 146int 147dead_lookup(ap) 148 struct vop_lookup_args /* { 149 struct vnode * a_dvp; 150 struct vnode ** a_vpp; 151 struct componentname * a_cnp; 152 } */ *ap; 153{ 154 155 *ap->a_vpp = NULL; 156 return (ENOTDIR); 157} 158 159/* 160 * Open always fails as if device did not exist. 161 */ 162/* ARGSUSED */ 163int 164dead_open(ap) 165 struct vop_open_args /* { 166 struct vnode *a_vp; 167 int a_mode; 168 struct ucred *a_cred; 169 struct proc *a_p; 170 } */ *ap; 171{ 172 173 return (ENXIO); 174} 175 176/* 177 * Vnode op for read 178 */ 179/* ARGSUSED */ 180int 181dead_read(ap) 182 struct vop_read_args /* { 183 struct vnode *a_vp; 184 struct uio *a_uio; 185 int a_ioflag; 186 struct ucred *a_cred; 187 } */ *ap; 188{ 189 190 if (chkvnlock(ap->a_vp)) 191 panic("dead_read: lock"); 192 /* 193 * Return EOF for character devices, EIO for others 194 */ 195 if (ap->a_vp->v_type != VCHR) 196 return (EIO); 197 return (0); 198} 199 200/* 201 * Vnode op for write 202 */ 203/* ARGSUSED */ 204int 205dead_write(ap) 206 struct vop_write_args /* { 207 struct vnode *a_vp; 208 struct uio *a_uio; 209 int a_ioflag; 210 struct ucred *a_cred; 211 } */ *ap; 212{ 213 214 if (chkvnlock(ap->a_vp)) 215 panic("dead_write: lock"); 216 return (EIO); 217} 218 219/* 220 * Device ioctl operation. 221 */ 222/* ARGSUSED */ 223int 224dead_ioctl(ap) 225 struct vop_ioctl_args /* { 226 struct vnode *a_vp; 227 int a_command; 228 caddr_t a_data; 229 int a_fflag; 230 struct ucred *a_cred; 231 struct proc *a_p; 232 } */ *ap; 233{ 234 235 if (!chkvnlock(ap->a_vp)) 236 return (EBADF); 237 return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap)); 238} 239 240/* ARGSUSED */ 241int 242dead_select(ap) 243 struct vop_select_args /* { 244 struct vnode *a_vp; 245 int a_which; 246 int a_fflags; 247 struct ucred *a_cred; 248 struct proc *a_p; 249 } */ *ap; 250{ 251 252 /* 253 * Let the user find out that the descriptor is gone. 254 */ 255 return (1); 256} 257 258/* 259 * Just call the device strategy routine 260 */ 261int 262dead_strategy(ap) 263 struct vop_strategy_args /* { 264 struct buf *a_bp; 265 } */ *ap; 266{ 267 268 if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) { 269 ap->a_bp->b_flags |= B_ERROR; 270 biodone(ap->a_bp); 271 return (EIO); 272 } 273 return (VOP_STRATEGY(ap->a_bp)); 274} 275 276/* 277 * Wait until the vnode has finished changing state. 278 */ 279int 280dead_lock(ap) 281 struct vop_lock_args /* { 282 struct vnode *a_vp; 283 } */ *ap; 284{ 285 286 if (!chkvnlock(ap->a_vp)) 287 return (0); 288 return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap)); 289} 290 291/* 292 * Wait until the vnode has finished changing state. 293 */ 294int 295dead_bmap(ap) 296 struct vop_bmap_args /* { 297 struct vnode *a_vp; 298 daddr_t a_bn; 299 struct vnode **a_vpp; 300 daddr_t *a_bnp; 301 int *a_runp; 302 } */ *ap; 303{ 304 305 if (!chkvnlock(ap->a_vp)) 306 return (EIO); 307 return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp)); 308} 309 310/* 311 * Print out the contents of a dead vnode. 312 */ 313/* ARGSUSED */ 314int 315dead_print(ap) 316 struct vop_print_args /* { 317 struct vnode *a_vp; 318 } */ *ap; 319{ 320 321 printf("tag VT_NON, dead vnode\n"); 322 return (0); 323} 324 325/* 326 * Empty vnode failed operation 327 */ 328int 329dead_ebadf() 330{ 331 332 return (EBADF); 333} 334 335/* 336 * Empty vnode bad operation 337 */ 338int 339dead_badop() 340{ 341 342 panic("dead_badop called"); 343 /* NOTREACHED */ 344} 345 346/* 347 * Empty vnode null operation 348 */ 349int 350dead_nullop() 351{ 352 353 return (0); 354} 355 356/* 357 * We have to wait during times when the vnode is 358 * in a state of change. 359 */ 360int 361chkvnlock(vp) 362 register struct vnode *vp; 363{ 364 int locked = 0; 365 366 while (vp->v_flag & VXLOCK) { 367 vp->v_flag |= VXWANT; 368 (void) tsleep((caddr_t)vp, PINOD, "ckvnlk", 0); 369 locked = 1; 370 } 371 return (locked); 372} 373