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dead_vnops.c revision 1.32 
      1 /*	$NetBSD: dead_vnops.c,v 1.32 2001/12/06 04:27:40 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)dead_vnops.c	8.2 (Berkeley) 11/21/94
     36  */
     37 
     38 #include <sys/cdefs.h>
     39 __KERNEL_RCSID(0, "$NetBSD: dead_vnops.c,v 1.32 2001/12/06 04:27:40 chs Exp $");
     40 
     41 #include <sys/param.h>
     42 #include <sys/systm.h>
     43 #include <sys/time.h>
     44 #include <sys/vnode.h>
     45 #include <sys/errno.h>
     46 #include <sys/namei.h>
     47 #include <sys/buf.h>
     48 #include <sys/proc.h>
     49 
     50 #include <miscfs/genfs/genfs.h>
     51 
     52 /*
     53  * Prototypes for dead operations on vnodes.
     54  */
     55 int	dead_lookup	__P((void *));
     56 #define dead_create	genfs_badop
     57 #define dead_mknod	genfs_badop
     58 int	dead_open	__P((void *));
     59 #define dead_close	genfs_nullop
     60 #define dead_access	genfs_ebadf
     61 #define dead_getattr	genfs_ebadf
     62 #define dead_setattr	genfs_ebadf
     63 int	dead_read	__P((void *));
     64 int	dead_write	__P((void *));
     65 #define dead_lease_check genfs_nullop
     66 #define dead_fcntl	genfs_nullop
     67 int	dead_ioctl	__P((void *));
     68 int	dead_poll	__P((void *));
     69 #define dead_mmap	genfs_badop
     70 #define dead_fsync	genfs_nullop
     71 #define dead_seek	genfs_nullop
     72 #define dead_remove	genfs_badop
     73 #define dead_link	genfs_badop
     74 #define dead_rename	genfs_badop
     75 #define dead_mkdir	genfs_badop
     76 #define dead_rmdir	genfs_badop
     77 #define dead_symlink	genfs_badop
     78 #define dead_readdir	genfs_ebadf
     79 #define dead_readlink	genfs_ebadf
     80 #define dead_abortop	genfs_badop
     81 #define dead_inactive	genfs_nullop
     82 #define dead_reclaim	genfs_nullop
     83 int	dead_lock	__P((void *));
     84 #define dead_unlock	genfs_nullop
     85 int	dead_bmap	__P((void *));
     86 int	dead_strategy	__P((void *));
     87 int	dead_print	__P((void *));
     88 #define dead_islocked	genfs_nullop
     89 #define dead_pathconf	genfs_ebadf
     90 #define dead_advlock	genfs_ebadf
     91 #define dead_blkatoff	genfs_badop
     92 #define dead_valloc	genfs_badop
     93 #define dead_vfree	genfs_badop
     94 #define dead_truncate	genfs_nullop
     95 #define dead_update	genfs_nullop
     96 #define dead_bwrite	genfs_nullop
     97 #define dead_revoke	genfs_nullop
     98 #define dead_putpages	genfs_null_putpages
     99 
    100 int	chkvnlock __P((struct vnode *));
    101 
    102 int (**dead_vnodeop_p) __P((void *));
    103 
    104 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
    105 	{ &vop_default_desc, vn_default_error },
    106 	{ &vop_lookup_desc, dead_lookup },		/* lookup */
    107 	{ &vop_create_desc, dead_create },		/* create */
    108 	{ &vop_mknod_desc, dead_mknod },		/* mknod */
    109 	{ &vop_open_desc, dead_open },			/* open */
    110 	{ &vop_close_desc, dead_close },		/* close */
    111 	{ &vop_access_desc, dead_access },		/* access */
    112 	{ &vop_getattr_desc, dead_getattr },		/* getattr */
    113 	{ &vop_setattr_desc, dead_setattr },		/* setattr */
    114 	{ &vop_read_desc, dead_read },			/* read */
    115 	{ &vop_write_desc, dead_write },		/* write */
    116 	{ &vop_lease_desc, dead_lease_check },		/* lease */
    117 	{ &vop_fcntl_desc, dead_fcntl },		/* fcntl */
    118 	{ &vop_ioctl_desc, dead_ioctl },		/* ioctl */
    119 	{ &vop_poll_desc, dead_poll },			/* poll */
    120 	{ &vop_revoke_desc, dead_revoke },		/* revoke */
    121 	{ &vop_mmap_desc, dead_mmap },			/* mmap */
    122 	{ &vop_fsync_desc, dead_fsync },		/* fsync */
    123 	{ &vop_seek_desc, dead_seek },			/* seek */
    124 	{ &vop_remove_desc, dead_remove },		/* remove */
    125 	{ &vop_link_desc, dead_link },			/* link */
    126 	{ &vop_rename_desc, dead_rename },		/* rename */
    127 	{ &vop_mkdir_desc, dead_mkdir },		/* mkdir */
    128 	{ &vop_rmdir_desc, dead_rmdir },		/* rmdir */
    129 	{ &vop_symlink_desc, dead_symlink },		/* symlink */
    130 	{ &vop_readdir_desc, dead_readdir },		/* readdir */
    131 	{ &vop_readlink_desc, dead_readlink },		/* readlink */
    132 	{ &vop_abortop_desc, dead_abortop },		/* abortop */
    133 	{ &vop_inactive_desc, dead_inactive },		/* inactive */
    134 	{ &vop_reclaim_desc, dead_reclaim },		/* reclaim */
    135 	{ &vop_lock_desc, dead_lock },			/* lock */
    136 	{ &vop_unlock_desc, dead_unlock },		/* unlock */
    137 	{ &vop_bmap_desc, dead_bmap },			/* bmap */
    138 	{ &vop_strategy_desc, dead_strategy },		/* strategy */
    139 	{ &vop_print_desc, dead_print },		/* print */
    140 	{ &vop_islocked_desc, dead_islocked },		/* islocked */
    141 	{ &vop_pathconf_desc, dead_pathconf },		/* pathconf */
    142 	{ &vop_advlock_desc, dead_advlock },		/* advlock */
    143 	{ &vop_blkatoff_desc, dead_blkatoff },		/* blkatoff */
    144 	{ &vop_valloc_desc, dead_valloc },		/* valloc */
    145 	{ &vop_vfree_desc, dead_vfree },		/* vfree */
    146 	{ &vop_truncate_desc, dead_truncate },		/* truncate */
    147 	{ &vop_update_desc, dead_update },		/* update */
    148 	{ &vop_bwrite_desc, dead_bwrite },		/* bwrite */
    149 	{ &vop_putpages_desc, dead_putpages },		/* putpages */
    150 	{ NULL, NULL }
    151 };
    152 const struct vnodeopv_desc dead_vnodeop_opv_desc =
    153 	{ &dead_vnodeop_p, dead_vnodeop_entries };
    154 
    155 /*
    156  * Trivial lookup routine that always fails.
    157  */
    158 /* ARGSUSED */
    159 int
    160 dead_lookup(v)
    161 	void *v;
    162 {
    163 	struct vop_lookup_args /* {
    164 		struct vnode * a_dvp;
    165 		struct vnode ** a_vpp;
    166 		struct componentname * a_cnp;
    167 	} */ *ap = v;
    168 
    169 	*ap->a_vpp = NULL;
    170 	return (ENOTDIR);
    171 }
    172 
    173 /*
    174  * Open always fails as if device did not exist.
    175  */
    176 /* ARGSUSED */
    177 int
    178 dead_open(v)
    179 	void *v;
    180 {
    181 
    182 	return (ENXIO);
    183 }
    184 
    185 /*
    186  * Vnode op for read
    187  */
    188 /* ARGSUSED */
    189 int
    190 dead_read(v)
    191 	void *v;
    192 {
    193 	struct vop_read_args /* {
    194 		struct vnode *a_vp;
    195 		struct uio *a_uio;
    196 		int  a_ioflag;
    197 		struct ucred *a_cred;
    198 	} */ *ap = v;
    199 
    200 	if (chkvnlock(ap->a_vp))
    201 		panic("dead_read: lock");
    202 	/*
    203 	 * Return EOF for tty devices, EIO for others
    204 	 */
    205 	if ((ap->a_vp->v_flag & VISTTY) == 0)
    206 		return (EIO);
    207 	return (0);
    208 }
    209 
    210 /*
    211  * Vnode op for write
    212  */
    213 /* ARGSUSED */
    214 int
    215 dead_write(v)
    216 	void *v;
    217 {
    218 	struct vop_write_args /* {
    219 		struct vnode *a_vp;
    220 		struct uio *a_uio;
    221 		int  a_ioflag;
    222 		struct ucred *a_cred;
    223 	} */ *ap = v;
    224 
    225 	if (chkvnlock(ap->a_vp))
    226 		panic("dead_write: lock");
    227 	return (EIO);
    228 }
    229 
    230 /*
    231  * Device ioctl operation.
    232  */
    233 /* ARGSUSED */
    234 int
    235 dead_ioctl(v)
    236 	void *v;
    237 {
    238 	struct vop_ioctl_args /* {
    239 		struct vnode *a_vp;
    240 		u_long a_command;
    241 		caddr_t  a_data;
    242 		int  a_fflag;
    243 		struct ucred *a_cred;
    244 		struct proc *a_p;
    245 	} */ *ap = v;
    246 
    247 	if (!chkvnlock(ap->a_vp))
    248 		return (EBADF);
    249 	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
    250 }
    251 
    252 /* ARGSUSED */
    253 int
    254 dead_poll(v)
    255 	void *v;
    256 {
    257 	struct vop_poll_args /* {
    258 		struct vnode *a_vp;
    259 		int a_events;
    260 		struct proc *a_p;
    261 	} */ *ap = v;
    262 
    263 	/*
    264 	 * Let the user find out that the descriptor is gone.
    265 	 */
    266 	return (ap->a_events);
    267 }
    268 
    269 /*
    270  * Just call the device strategy routine
    271  */
    272 int
    273 dead_strategy(v)
    274 	void *v;
    275 {
    276 
    277 	struct vop_strategy_args /* {
    278 		struct buf *a_bp;
    279 	} */ *ap = v;
    280 	if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
    281 		ap->a_bp->b_flags |= B_ERROR;
    282 		biodone(ap->a_bp);
    283 		return (EIO);
    284 	}
    285 	return (VOP_STRATEGY(ap->a_bp));
    286 }
    287 
    288 /*
    289  * Wait until the vnode has finished changing state.
    290  */
    291 int
    292 dead_lock(v)
    293 	void *v;
    294 {
    295 	struct vop_lock_args /* {
    296 		struct vnode *a_vp;
    297 		int a_flags;
    298 		struct proc *a_p;
    299 	} */ *ap = v;
    300 
    301 	if (ap->a_flags & LK_INTERLOCK) {
    302 		simple_unlock(&ap->a_vp->v_interlock);
    303 		ap->a_flags &= ~LK_INTERLOCK;
    304 	}
    305 	if (!chkvnlock(ap->a_vp))
    306 		return (0);
    307 	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
    308 }
    309 
    310 /*
    311  * Wait until the vnode has finished changing state.
    312  */
    313 int
    314 dead_bmap(v)
    315 	void *v;
    316 {
    317 	struct vop_bmap_args /* {
    318 		struct vnode *a_vp;
    319 		daddr_t  a_bn;
    320 		struct vnode **a_vpp;
    321 		daddr_t *a_bnp;
    322 		int *a_runp;
    323 	} */ *ap = v;
    324 
    325 	if (!chkvnlock(ap->a_vp))
    326 		return (EIO);
    327 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
    328 }
    329 
    330 /*
    331  * Print out the contents of a dead vnode.
    332  */
    333 /* ARGSUSED */
    334 int
    335 dead_print(v)
    336 	void *v;
    337 {
    338 	printf("tag VT_NON, dead vnode\n");
    339 	return 0;
    340 }
    341 
    342 /*
    343  * We have to wait during times when the vnode is
    344  * in a state of change.
    345  */
    346 int
    347 chkvnlock(vp)
    348 	struct vnode *vp;
    349 {
    350 	int locked = 0;
    351 
    352 	while (vp->v_flag & VXLOCK) {
    353 		vp->v_flag |= VXWANT;
    354 		(void) tsleep(vp, PINOD, "deadchk", 0);
    355 		locked = 1;
    356 	}
    357 	return (locked);
    358 }
    359