freebsd-nq/sys/miscfs/deadfs/dead_vnops.c
1997-10-15 10:05:29 +00:00

364 lines
10 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)dead_vnops.c 8.1 (Berkeley) 6/10/93
* $Id: dead_vnops.c,v 1.16 1997/10/15 09:20:50 phk Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/buf.h>
static int chkvnlock __P((struct vnode *));
/*
* Prototypes for dead operations on vnodes.
*/
static int dead_badop __P((void));
static int dead_ebadf __P((void));
static int dead_lookup __P((struct vop_lookup_args *));
#define dead_create ((int (*) __P((struct vop_create_args *)))dead_badop)
#define dead_mknod ((int (*) __P((struct vop_mknod_args *)))dead_badop)
static int dead_open __P((struct vop_open_args *));
#define dead_close ((int (*) __P((struct vop_close_args *)))nullop)
#define dead_access ((int (*) __P((struct vop_access_args *)))dead_ebadf)
#define dead_getattr ((int (*) __P((struct vop_getattr_args *)))dead_ebadf)
#define dead_setattr ((int (*) __P((struct vop_setattr_args *)))dead_ebadf)
static int dead_read __P((struct vop_read_args *));
static int dead_write __P((struct vop_write_args *));
static int dead_ioctl __P((struct vop_ioctl_args *));
#define dead_poll vop_nopoll
#define dead_mmap ((int (*) __P((struct vop_mmap_args *)))dead_badop)
#define dead_fsync ((int (*) __P((struct vop_fsync_args *)))nullop)
#define dead_seek ((int (*) __P((struct vop_seek_args *)))nullop)
#define dead_remove ((int (*) __P((struct vop_remove_args *)))dead_badop)
#define dead_link ((int (*) __P((struct vop_link_args *)))dead_badop)
#define dead_rename ((int (*) __P((struct vop_rename_args *)))dead_badop)
#define dead_mkdir ((int (*) __P((struct vop_mkdir_args *)))dead_badop)
#define dead_rmdir ((int (*) __P((struct vop_rmdir_args *)))dead_badop)
#define dead_symlink ((int (*) __P((struct vop_symlink_args *)))dead_badop)
#define dead_readdir ((int (*) __P((struct vop_readdir_args *)))dead_ebadf)
#define dead_readlink ((int (*) __P((struct vop_readlink_args *)))dead_ebadf)
#define dead_abortop ((int (*) __P((struct vop_abortop_args *)))dead_badop)
#define dead_inactive ((int (*) __P((struct vop_inactive_args *)))nullop)
#define dead_reclaim ((int (*) __P((struct vop_reclaim_args *)))nullop)
static int dead_lock __P((struct vop_lock_args *));
#define dead_unlock ((int (*) __P((struct vop_unlock_args *)))vop_nounlock)
static int dead_bmap __P((struct vop_bmap_args *));
static int dead_strategy __P((struct vop_strategy_args *));
static int dead_print __P((struct vop_print_args *));
#define dead_islocked ((int(*) __P((struct vop_islocked_args *)))vop_noislocked)
#define dead_pathconf ((int (*) __P((struct vop_pathconf_args *)))dead_ebadf)
#define dead_advlock ((int (*) __P((struct vop_advlock_args *)))dead_ebadf)
#define dead_blkatoff ((int (*) __P((struct vop_blkatoff_args *)))dead_badop)
#define dead_valloc ((int (*) __P((struct vop_valloc_args *)))dead_badop)
#define dead_vfree ((int (*) __P((struct vop_vfree_args *)))dead_badop)
#define dead_truncate ((int (*) __P((struct vop_truncate_args *)))nullop)
#define dead_update ((int (*) __P((struct vop_update_args *)))nullop)
#define dead_bwrite ((int (*) __P((struct vop_bwrite_args *)))nullop)
vop_t **dead_vnodeop_p;
static struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vn_default_error },
{ &vop_abortop_desc, (vop_t *) dead_abortop },
{ &vop_access_desc, (vop_t *) dead_access },
{ &vop_advlock_desc, (vop_t *) dead_advlock },
{ &vop_blkatoff_desc, (vop_t *) dead_blkatoff },
{ &vop_bmap_desc, (vop_t *) dead_bmap },
{ &vop_bwrite_desc, (vop_t *) dead_bwrite },
{ &vop_close_desc, (vop_t *) dead_close },
{ &vop_create_desc, (vop_t *) dead_create },
{ &vop_fsync_desc, (vop_t *) dead_fsync },
{ &vop_getattr_desc, (vop_t *) dead_getattr },
{ &vop_inactive_desc, (vop_t *) dead_inactive },
{ &vop_ioctl_desc, (vop_t *) dead_ioctl },
{ &vop_islocked_desc, (vop_t *) dead_islocked },
{ &vop_link_desc, (vop_t *) dead_link },
{ &vop_lock_desc, (vop_t *) dead_lock },
{ &vop_lookup_desc, (vop_t *) dead_lookup },
{ &vop_mkdir_desc, (vop_t *) dead_mkdir },
{ &vop_mknod_desc, (vop_t *) dead_mknod },
{ &vop_mmap_desc, (vop_t *) dead_mmap },
{ &vop_open_desc, (vop_t *) dead_open },
{ &vop_pathconf_desc, (vop_t *) dead_pathconf },
{ &vop_poll_desc, (vop_t *) dead_poll },
{ &vop_print_desc, (vop_t *) dead_print },
{ &vop_read_desc, (vop_t *) dead_read },
{ &vop_readdir_desc, (vop_t *) dead_readdir },
{ &vop_readlink_desc, (vop_t *) dead_readlink },
{ &vop_reclaim_desc, (vop_t *) dead_reclaim },
{ &vop_remove_desc, (vop_t *) dead_remove },
{ &vop_rename_desc, (vop_t *) dead_rename },
{ &vop_rmdir_desc, (vop_t *) dead_rmdir },
{ &vop_seek_desc, (vop_t *) dead_seek },
{ &vop_setattr_desc, (vop_t *) dead_setattr },
{ &vop_strategy_desc, (vop_t *) dead_strategy },
{ &vop_symlink_desc, (vop_t *) dead_symlink },
{ &vop_truncate_desc, (vop_t *) dead_truncate },
{ &vop_unlock_desc, (vop_t *) dead_unlock },
{ &vop_update_desc, (vop_t *) dead_update },
{ &vop_valloc_desc, (vop_t *) dead_valloc },
{ &vop_vfree_desc, (vop_t *) dead_vfree },
{ &vop_write_desc, (vop_t *) dead_write },
{ NULL, NULL }
};
static struct vnodeopv_desc dead_vnodeop_opv_desc =
{ &dead_vnodeop_p, dead_vnodeop_entries };
VNODEOP_SET(dead_vnodeop_opv_desc);
/*
* Trivial lookup routine that always fails.
*/
/* ARGSUSED */
static int
dead_lookup(ap)
struct vop_lookup_args /* {
struct vnode * a_dvp;
struct vnode ** a_vpp;
struct componentname * a_cnp;
} */ *ap;
{
*ap->a_vpp = NULL;
return (ENOTDIR);
}
/*
* Open always fails as if device did not exist.
*/
/* ARGSUSED */
static int
dead_open(ap)
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
return (ENXIO);
}
/*
* Vnode op for read
*/
/* ARGSUSED */
static int
dead_read(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
if (chkvnlock(ap->a_vp))
panic("dead_read: lock");
#if 0
/* Lite2 behaviour */
/*
* Return EOF for tty devices, EIO for others
*/
if ((ap->a_vp->v_flag & VISTTY) == 0)
return (EIO);
#else
/*
* Return EOF for character devices, EIO for others
*/
if (ap->a_vp->v_type != VCHR)
return (EIO);
#endif
return (0);
}
/*
* Vnode op for write
*/
/* ARGSUSED */
static int
dead_write(ap)
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
if (chkvnlock(ap->a_vp))
panic("dead_write: lock");
return (EIO);
}
/*
* Device ioctl operation.
*/
/* ARGSUSED */
static int
dead_ioctl(ap)
struct vop_ioctl_args /* {
struct vnode *a_vp;
int a_command;
caddr_t a_data;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
if (!chkvnlock(ap->a_vp))
return (EBADF);
return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
}
/*
* Just call the device strategy routine
*/
static int
dead_strategy(ap)
struct vop_strategy_args /* {
struct buf *a_bp;
} */ *ap;
{
if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
ap->a_bp->b_flags |= B_ERROR;
biodone(ap->a_bp);
return (EIO);
}
return (VOP_STRATEGY(ap->a_bp));
}
/*
* Wait until the vnode has finished changing state.
*/
static int
dead_lock(ap)
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
/*
* Since we are not using the lock manager, we must clear
* the interlock here.
*/
if (ap->a_flags & LK_INTERLOCK) {
simple_unlock(&vp->v_interlock);
ap->a_flags &= ~LK_INTERLOCK;
}
if (!chkvnlock(vp))
return (0);
return (VCALL(vp, VOFFSET(vop_lock), ap));
}
/*
* Wait until the vnode has finished changing state.
*/
static int
dead_bmap(ap)
struct vop_bmap_args /* {
struct vnode *a_vp;
daddr_t a_bn;
struct vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
int *a_runb;
} */ *ap;
{
if (!chkvnlock(ap->a_vp))
return (EIO);
return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp, ap->a_runb));
}
/*
* Print out the contents of a dead vnode.
*/
/* ARGSUSED */
static int
dead_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
printf("tag VT_NON, dead vnode\n");
return (0);
}
/*
* Empty vnode failed operation
*/
static int
dead_ebadf()
{
return (EBADF);
}
/*
* Empty vnode bad operation
*/
static int
dead_badop()
{
panic("dead_badop called");
/* NOTREACHED */
}
/*
* We have to wait during times when the vnode is
* in a state of change.
*/
int
chkvnlock(vp)
register struct vnode *vp;
{
int locked = 0;
while (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
(void) tsleep((caddr_t)vp, PINOD, "ckvnlk", 0);
locked = 1;
}
return (locked);
}