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dead_vnops.c revision 1.39
      1 /*	$NetBSD: dead_vnops.c,v 1.39 2006/05/14 21:31:52 elad 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 1.39 2006/05/14 21:31:52 elad 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_lookup(void *);
     52 #define dead_create	genfs_badop
     53 #define dead_mknod	genfs_badop
     54 int	dead_open(void *);
     55 #define dead_close	genfs_nullop
     56 #define dead_access	genfs_ebadf
     57 #define dead_getattr	genfs_ebadf
     58 #define dead_setattr	genfs_ebadf
     59 int	dead_read(void *);
     60 int	dead_write(void *);
     61 #define dead_lease_check genfs_nullop
     62 #define dead_fcntl	genfs_nullop
     63 int	dead_ioctl(void *);
     64 int	dead_poll(void *);
     65 #define dead_mmap	genfs_badop
     66 #define dead_fsync	genfs_nullop
     67 #define dead_seek	genfs_nullop
     68 #define dead_remove	genfs_badop
     69 #define dead_link	genfs_badop
     70 #define dead_rename	genfs_badop
     71 #define dead_mkdir	genfs_badop
     72 #define dead_rmdir	genfs_badop
     73 #define dead_symlink	genfs_badop
     74 #define dead_readdir	genfs_ebadf
     75 #define dead_readlink	genfs_ebadf
     76 #define dead_abortop	genfs_badop
     77 #define dead_inactive	genfs_nullop
     78 #define dead_reclaim	genfs_nullop
     79 int	dead_lock(void *);
     80 #define dead_unlock	genfs_nullop
     81 int	dead_bmap(void *);
     82 int	dead_strategy(void *);
     83 int	dead_print(void *);
     84 #define dead_islocked	genfs_nullop
     85 #define dead_pathconf	genfs_ebadf
     86 #define dead_advlock	genfs_ebadf
     87 #define dead_bwrite	genfs_nullop
     88 #define dead_revoke	genfs_nullop
     89 #define dead_putpages	genfs_null_putpages
     90 
     91 int	chkvnlock(struct vnode *);
     92 
     93 int (**dead_vnodeop_p)(void *);
     94 
     95 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
     96 	{ &vop_default_desc, vn_default_error },
     97 	{ &vop_lookup_desc, dead_lookup },		/* lookup */
     98 	{ &vop_create_desc, dead_create },		/* create */
     99 	{ &vop_mknod_desc, dead_mknod },		/* mknod */
    100 	{ &vop_open_desc, dead_open },			/* open */
    101 	{ &vop_close_desc, dead_close },		/* close */
    102 	{ &vop_access_desc, dead_access },		/* access */
    103 	{ &vop_getattr_desc, dead_getattr },		/* getattr */
    104 	{ &vop_setattr_desc, dead_setattr },		/* setattr */
    105 	{ &vop_read_desc, dead_read },			/* read */
    106 	{ &vop_write_desc, dead_write },		/* write */
    107 	{ &vop_lease_desc, dead_lease_check },		/* lease */
    108 	{ &vop_fcntl_desc, dead_fcntl },		/* fcntl */
    109 	{ &vop_ioctl_desc, dead_ioctl },		/* ioctl */
    110 	{ &vop_poll_desc, dead_poll },			/* poll */
    111 	{ &vop_revoke_desc, dead_revoke },		/* revoke */
    112 	{ &vop_mmap_desc, dead_mmap },			/* mmap */
    113 	{ &vop_fsync_desc, dead_fsync },		/* fsync */
    114 	{ &vop_seek_desc, dead_seek },			/* seek */
    115 	{ &vop_remove_desc, dead_remove },		/* remove */
    116 	{ &vop_link_desc, dead_link },			/* link */
    117 	{ &vop_rename_desc, dead_rename },		/* rename */
    118 	{ &vop_mkdir_desc, dead_mkdir },		/* mkdir */
    119 	{ &vop_rmdir_desc, dead_rmdir },		/* rmdir */
    120 	{ &vop_symlink_desc, dead_symlink },		/* symlink */
    121 	{ &vop_readdir_desc, dead_readdir },		/* readdir */
    122 	{ &vop_readlink_desc, dead_readlink },		/* readlink */
    123 	{ &vop_abortop_desc, dead_abortop },		/* abortop */
    124 	{ &vop_inactive_desc, dead_inactive },		/* inactive */
    125 	{ &vop_reclaim_desc, dead_reclaim },		/* reclaim */
    126 	{ &vop_lock_desc, dead_lock },			/* lock */
    127 	{ &vop_unlock_desc, dead_unlock },		/* unlock */
    128 	{ &vop_bmap_desc, dead_bmap },			/* bmap */
    129 	{ &vop_strategy_desc, dead_strategy },		/* strategy */
    130 	{ &vop_print_desc, dead_print },		/* print */
    131 	{ &vop_islocked_desc, dead_islocked },		/* islocked */
    132 	{ &vop_pathconf_desc, dead_pathconf },		/* pathconf */
    133 	{ &vop_advlock_desc, dead_advlock },		/* advlock */
    134 	{ &vop_bwrite_desc, dead_bwrite },		/* bwrite */
    135 	{ &vop_putpages_desc, dead_putpages },		/* putpages */
    136 	{ NULL, NULL }
    137 };
    138 const struct vnodeopv_desc dead_vnodeop_opv_desc =
    139 	{ &dead_vnodeop_p, dead_vnodeop_entries };
    140 
    141 /*
    142  * Trivial lookup routine that always fails.
    143  */
    144 /* ARGSUSED */
    145 int
    146 dead_lookup(v)
    147 	void *v;
    148 {
    149 	struct vop_lookup_args /* {
    150 		struct vnode * a_dvp;
    151 		struct vnode ** a_vpp;
    152 		struct componentname * a_cnp;
    153 	} */ *ap = v;
    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 */
    163 int
    164 dead_open(v)
    165 	void *v;
    166 {
    167 
    168 	return (ENXIO);
    169 }
    170 
    171 /*
    172  * Vnode op for read
    173  */
    174 /* ARGSUSED */
    175 int
    176 dead_read(v)
    177 	void *v;
    178 {
    179 	struct vop_read_args /* {
    180 		struct vnode *a_vp;
    181 		struct uio *a_uio;
    182 		int  a_ioflag;
    183 		kauth_cred_t a_cred;
    184 	} */ *ap = v;
    185 
    186 	if (chkvnlock(ap->a_vp))
    187 		panic("dead_read: lock");
    188 	/*
    189 	 * Return EOF for tty devices, EIO for others
    190 	 */
    191 	if ((ap->a_vp->v_flag & VISTTY) == 0)
    192 		return (EIO);
    193 	return (0);
    194 }
    195 
    196 /*
    197  * Vnode op for write
    198  */
    199 /* ARGSUSED */
    200 int
    201 dead_write(v)
    202 	void *v;
    203 {
    204 	struct vop_write_args /* {
    205 		struct vnode *a_vp;
    206 		struct uio *a_uio;
    207 		int  a_ioflag;
    208 		kauth_cred_t a_cred;
    209 	} */ *ap = v;
    210 
    211 	if (chkvnlock(ap->a_vp))
    212 		panic("dead_write: lock");
    213 	return (EIO);
    214 }
    215 
    216 /*
    217  * Device ioctl operation.
    218  */
    219 /* ARGSUSED */
    220 int
    221 dead_ioctl(v)
    222 	void *v;
    223 {
    224 	struct vop_ioctl_args /* {
    225 		struct vnode *a_vp;
    226 		u_long a_command;
    227 		void *a_data;
    228 		int  a_fflag;
    229 		kauth_cred_t a_cred;
    230 		struct lwp *a_l;
    231 	} */ *ap = v;
    232 
    233 	if (!chkvnlock(ap->a_vp))
    234 		return (EBADF);
    235 	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
    236 }
    237 
    238 /* ARGSUSED */
    239 int
    240 dead_poll(v)
    241 	void *v;
    242 {
    243 	struct vop_poll_args /* {
    244 		struct vnode *a_vp;
    245 		int a_events;
    246 		struct lwp *a_l;
    247 	} */ *ap = v;
    248 
    249 	/*
    250 	 * Let the user find out that the descriptor is gone.
    251 	 */
    252 	return (ap->a_events);
    253 }
    254 
    255 /*
    256  * Just call the device strategy routine
    257  */
    258 int
    259 dead_strategy(v)
    260 	void *v;
    261 {
    262 
    263 	struct vop_strategy_args /* {
    264 		struct vnode *a_vp;
    265 		struct buf *a_bp;
    266 	} */ *ap = v;
    267 	if (ap->a_vp == NULL || !chkvnlock(ap->a_vp)) {
    268 		ap->a_bp->b_flags |= B_ERROR;
    269 		biodone(ap->a_bp);
    270 		return (EIO);
    271 	}
    272 	return (VOP_STRATEGY(ap->a_vp, ap->a_bp));
    273 }
    274 
    275 /*
    276  * Wait until the vnode has finished changing state.
    277  */
    278 int
    279 dead_lock(v)
    280 	void *v;
    281 {
    282 	struct vop_lock_args /* {
    283 		struct vnode *a_vp;
    284 		int a_flags;
    285 		struct proc *a_p;
    286 	} */ *ap = v;
    287 
    288 	if (ap->a_flags & LK_INTERLOCK) {
    289 		simple_unlock(&ap->a_vp->v_interlock);
    290 		ap->a_flags &= ~LK_INTERLOCK;
    291 	}
    292 	if (!chkvnlock(ap->a_vp))
    293 		return (0);
    294 	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
    295 }
    296 
    297 /*
    298  * Wait until the vnode has finished changing state.
    299  */
    300 int
    301 dead_bmap(v)
    302 	void *v;
    303 {
    304 	struct vop_bmap_args /* {
    305 		struct vnode *a_vp;
    306 		daddr_t  a_bn;
    307 		struct vnode **a_vpp;
    308 		daddr_t *a_bnp;
    309 		int *a_runp;
    310 	} */ *ap = v;
    311 
    312 	if (!chkvnlock(ap->a_vp))
    313 		return (EIO);
    314 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
    315 }
    316 
    317 /*
    318  * Print out the contents of a dead vnode.
    319  */
    320 /* ARGSUSED */
    321 int
    322 dead_print(v)
    323 	void *v;
    324 {
    325 	printf("tag VT_NON, dead vnode\n");
    326 	return 0;
    327 }
    328 
    329 /*
    330  * We have to wait during times when the vnode is
    331  * in a state of change.
    332  */
    333 int
    334 chkvnlock(vp)
    335 	struct vnode *vp;
    336 {
    337 	int locked = 0;
    338 
    339 	while (vp->v_flag & VXLOCK) {
    340 		vp->v_flag |= VXWANT;
    341 		(void) tsleep(vp, PINOD, "deadchk", 0);
    342 		locked = 1;
    343 	}
    344 	return (locked);
    345 }
    346