NetBSD/sys/miscfs/deadfs/dead_vnops.c

435 lines
9.2 KiB
C

/*
* Copyright (c) 1989 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.
*
* from: @(#)dead_vnops.c 7.13 (Berkeley) 4/15/91
* $Id: dead_vnops.c,v 1.4 1993/08/01 19:25:58 mycroft Exp $
*/
#include "param.h"
#include "systm.h"
#include "time.h"
#include "vnode.h"
#include "errno.h"
#include "namei.h"
#include "buf.h"
/*
* Prototypes for dead operations on vnodes.
*/
volatile void dead_badop();
int dead_ebadf();
int dead_lookup __P((
struct vnode *vp,
struct nameidata *ndp,
struct proc *p));
#define dead_create ((int (*) __P(( \
struct nameidata *ndp, \
struct vattr *vap, \
struct proc *p))) dead_badop)
#define dead_mknod ((int (*) __P(( \
struct nameidata *ndp, \
struct vattr *vap, \
struct ucred *cred, \
struct proc *p))) dead_badop)
int dead_open __P((
struct vnode *vp,
int mode,
struct ucred *cred,
struct proc *p));
#define dead_close ((int (*) __P(( \
struct vnode *vp, \
int fflag, \
struct ucred *cred, \
struct proc *p))) nullop)
#define dead_access ((int (*) __P(( \
struct vnode *vp, \
int mode, \
struct ucred *cred, \
struct proc *p))) dead_ebadf)
#define dead_getattr ((int (*) __P(( \
struct vnode *vp, \
struct vattr *vap, \
struct ucred *cred, \
struct proc *p))) dead_ebadf)
#define dead_setattr ((int (*) __P(( \
struct vnode *vp, \
struct vattr *vap, \
struct ucred *cred, \
struct proc *p))) dead_ebadf)
int dead_read __P((
struct vnode *vp,
struct uio *uio,
int ioflag,
struct ucred *cred));
int dead_write __P((
struct vnode *vp,
struct uio *uio,
int ioflag,
struct ucred *cred));
int dead_ioctl __P((
struct vnode *vp,
int command,
caddr_t data,
int fflag,
struct ucred *cred,
struct proc *p));
int dead_select __P((
struct vnode *vp,
int which,
int fflags,
struct ucred *cred,
struct proc *p));
#define dead_mmap ((int (*) __P(( \
struct vnode *vp, \
int fflags, \
struct ucred *cred, \
struct proc *p))) dead_badop)
#define dead_fsync ((int (*) __P(( \
struct vnode *vp, \
int fflags, \
struct ucred *cred, \
int waitfor, \
struct proc *p))) nullop)
#define dead_seek ((int (*) __P(( \
struct vnode *vp, \
off_t oldoff, \
off_t newoff, \
struct ucred *cred))) nullop)
#define dead_remove ((int (*) __P(( \
struct nameidata *ndp, \
struct proc *p))) dead_badop)
#define dead_link ((int (*) __P(( \
struct vnode *vp, \
struct nameidata *ndp, \
struct proc *p))) dead_badop)
#define dead_rename ((int (*) __P(( \
struct nameidata *fndp, \
struct nameidata *tdnp, \
struct proc *p))) dead_badop)
#define dead_mkdir ((int (*) __P(( \
struct nameidata *ndp, \
struct vattr *vap, \
struct proc *p))) dead_badop)
#define dead_rmdir ((int (*) __P(( \
struct nameidata *ndp, \
struct proc *p))) dead_badop)
#define dead_symlink ((int (*) __P(( \
struct nameidata *ndp, \
struct vattr *vap, \
char *target, \
struct proc *p))) dead_badop)
#define dead_readdir ((int (*) __P(( \
struct vnode *vp, \
struct uio *uio, \
struct ucred *cred, \
int *eofflagp))) dead_ebadf)
#define dead_readlink ((int (*) __P(( \
struct vnode *vp, \
struct uio *uio, \
struct ucred *cred))) dead_ebadf)
#define dead_abortop ((int (*) __P(( \
struct nameidata *ndp))) dead_badop)
#define dead_inactive ((int (*) __P(( \
struct vnode *vp, \
struct proc *p))) nullop)
#define dead_reclaim ((int (*) __P(( \
struct vnode *vp))) nullop)
int dead_lock __P((
struct vnode *vp));
#define dead_unlock ((int (*) __P(( \
struct vnode *vp))) nullop)
int dead_bmap __P((
struct vnode *vp,
daddr_t bn,
struct vnode **vpp,
daddr_t *bnp));
int dead_strategy __P((
struct buf *bp));
void dead_print __P((
struct vnode *vp));
#define dead_islocked ((int (*) __P(( \
struct vnode *vp))) nullop)
#define dead_advlock ((int (*) __P(( \
struct vnode *vp, \
caddr_t id, \
int op, \
struct flock *fl, \
int flags))) dead_ebadf)
int chkvnlock __P((
struct vnode *vp));
struct vnodeops dead_vnodeops = {
dead_lookup, /* lookup */
dead_create, /* create */
dead_mknod, /* mknod */
dead_open, /* open */
dead_close, /* close */
dead_access, /* access */
dead_getattr, /* getattr */
dead_setattr, /* setattr */
dead_read, /* read */
dead_write, /* write */
dead_ioctl, /* ioctl */
dead_select, /* select */
dead_mmap, /* mmap */
dead_fsync, /* fsync */
dead_seek, /* seek */
dead_remove, /* remove */
dead_link, /* link */
dead_rename, /* rename */
dead_mkdir, /* mkdir */
dead_rmdir, /* rmdir */
dead_symlink, /* symlink */
dead_readdir, /* readdir */
dead_readlink, /* readlink */
dead_abortop, /* abortop */
dead_inactive, /* inactive */
dead_reclaim, /* reclaim */
dead_lock, /* lock */
dead_unlock, /* unlock */
dead_bmap, /* bmap */
dead_strategy, /* strategy */
dead_print, /* print */
dead_islocked, /* islocked */
dead_advlock, /* advlock */
};
/*
* Trivial lookup routine that always fails.
*/
/* ARGSUSED */
int
dead_lookup(vp, ndp, p)
struct vnode *vp;
struct nameidata *ndp;
struct proc *p;
{
ndp->ni_dvp = vp;
ndp->ni_vp = NULL;
return (ENOTDIR);
}
/*
* Open always fails as if device did not exist.
*/
/* ARGSUSED */
int
dead_open(vp, mode, cred, p)
struct vnode *vp;
int mode;
struct ucred *cred;
struct proc *p;
{
return (ENXIO);
}
/*
* Vnode op for read
*/
/* ARGSUSED */
int
dead_read(vp, uio, ioflag, cred)
struct vnode *vp;
struct uio *uio;
int ioflag;
struct ucred *cred;
{
if (chkvnlock(vp))
panic("dead_read: lock");
/*
* Return EOF for character devices, EIO for others
*/
if (vp->v_type != VCHR)
return (EIO);
return (0);
}
/*
* Vnode op for write
*/
/* ARGSUSED */
int
dead_write(vp, uio, ioflag, cred)
register struct vnode *vp;
struct uio *uio;
int ioflag;
struct ucred *cred;
{
if (chkvnlock(vp))
panic("dead_write: lock");
return (EIO);
}
/*
* Device ioctl operation.
*/
/* ARGSUSED */
int
dead_ioctl(vp, com, data, fflag, cred, p)
struct vnode *vp;
register int com;
caddr_t data;
int fflag;
struct ucred *cred;
struct proc *p;
{
if (!chkvnlock(vp))
return (EBADF);
return (VOP_IOCTL(vp, com, data, fflag, cred, p));
}
/* ARGSUSED */
int
dead_select(vp, which, fflags, cred, p)
struct vnode *vp;
int which, fflags;
struct ucred *cred;
struct proc *p;
{
/*
* Let the user find out that the descriptor is gone.
*/
return (1);
}
/*
* Just call the device strategy routine
*/
int
dead_strategy(bp)
register struct buf *bp;
{
if (bp->b_vp == NULL || !chkvnlock(bp->b_vp)) {
bp->b_flags |= B_ERROR;
biodone(bp);
return (EIO);
}
return (VOP_STRATEGY(bp));
}
/*
* Wait until the vnode has finished changing state.
*/
int
dead_lock(vp)
struct vnode *vp;
{
if (!chkvnlock(vp))
return (0);
return (VOP_LOCK(vp));
}
/*
* Wait until the vnode has finished changing state.
*/
int
dead_bmap(vp, bn, vpp, bnp)
struct vnode *vp;
daddr_t bn;
struct vnode **vpp;
daddr_t *bnp;
{
if (!chkvnlock(vp))
return (EIO);
return (VOP_BMAP(vp, bn, vpp, bnp));
}
/*
* Print out the contents of a dead vnode.
*/
/* ARGSUSED */
void
dead_print(vp)
struct vnode *vp;
{
printf("tag VT_NON, dead vnode\n");
}
/*
* Empty vnode failed operation
*/
int
dead_ebadf()
{
return (EBADF);
}
/*
* Empty vnode bad operation
*/
volatile void
dead_badop()
{
panic("dead_badop called");
/* NOTREACHED */
}
/*
* Empty vnode null operation
*/
int
dead_nullop()
{
return (0);
}
/*
* 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;
tsleep((caddr_t)vp, PINOD, "chkvunlock", 0);
locked = 1;
}
return (locked);
}