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/* $OpenBSD: vfs_default.c,v 1.47 2020/02/20 16:56:52 visa Exp $ */
/*
* Portions of this code are:
*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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. 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.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/pool.h>
#include <sys/event.h>
#include <sys/specdev.h>
int filt_generic_readwrite(struct knote *, long);
void filt_generic_detach(struct knote *);
/*
* Eliminate all activity associated with the requested vnode
* and with all vnodes aliased to the requested vnode.
*/
int
vop_generic_revoke(void *v)
{
struct vop_revoke_args *ap = v;
struct vnode *vp, *vq;
struct proc *p = curproc;
#ifdef DIAGNOSTIC
if ((ap->a_flags & REVOKEALL) == 0)
panic("vop_generic_revoke");
#endif
vp = ap->a_vp;
while (vp->v_type == VBLK && vp->v_specinfo != NULL &&
vp->v_specmountpoint != NULL) {
struct mount *mp = vp->v_specmountpoint;
/*
* If we have a mount point associated with the vnode, we must
* flush it out now, as to not leave a dangling zombie mount
* point laying around in VFS.
*/
if (!vfs_busy(mp, VB_WRITE|VB_WAIT)) {
dounmount(mp, MNT_FORCE | MNT_DOOMED, p);
break;
}
}
if (vp->v_flag & VALIASED) {
/*
* If a vgone (or vclean) is already in progress,
* wait until it is done and return.
*/
if (vp->v_flag & VXLOCK) {
vp->v_flag |= VXWANT;
tsleep_nsec(vp, PINOD, "vop_generic_revokeall", INFSLP);
return(0);
}
/*
* Ensure that vp will not be vgone'd while we
* are eliminating its aliases.
*/
vp->v_flag |= VXLOCK;
while (vp->v_flag & VALIASED) {
SLIST_FOREACH(vq, vp->v_hashchain, v_specnext) {
if (vq->v_rdev != vp->v_rdev ||
vq->v_type != vp->v_type || vp == vq)
continue;
vgone(vq);
break;
}
}
/*
* Remove the lock so that vgone below will
* really eliminate the vnode after which time
* vgone will awaken any sleepers.
*/
vp->v_flag &= ~VXLOCK;
}
vgonel(vp, p);
return (0);
}
int
vop_generic_bmap(void *v)
{
struct vop_bmap_args *ap = v;
if (ap->a_vpp)
*ap->a_vpp = ap->a_vp;
if (ap->a_bnp)
*ap->a_bnp = ap->a_bn;
if (ap->a_runp)
*ap->a_runp = 0;
return (0);
}
int
vop_generic_bwrite(void *v)
{
struct vop_bwrite_args *ap = v;
return (bwrite(ap->a_bp));
}
int
vop_generic_abortop(void *v)
{
struct vop_abortop_args *ap = v;
if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
pool_put(&namei_pool, ap->a_cnp->cn_pnbuf);
return (0);
}
/*
* Stubs to use when there is no locking to be done on the underlying object.
* A minimal shared lock is necessary to ensure that the underlying object
* is not revoked while an operation is in progress. So, an active shared
* count should be maintained in an auxiliary vnode lock structure. However,
* that's not done now.
*/
int
vop_generic_lock(void *v)
{
return (0);
}
/*
* Decrement the active use count. (Not done currently)
*/
int
vop_generic_unlock(void *v)
{
return (0);
}
/*
* Return whether or not the node is in use. (Not done currently)
*/
int
vop_generic_islocked(void *v)
{
return (0);
}
const struct filterops generic_filtops = {
.f_flags = FILTEROP_ISFD,
.f_attach = NULL,
.f_detach = filt_generic_detach,
.f_event = filt_generic_readwrite,
};
int
vop_generic_kqfilter(void *v)
{
struct vop_kqfilter_args *ap = v;
struct knote *kn = ap->a_kn;
switch (kn->kn_filter) {
case EVFILT_READ:
case EVFILT_WRITE:
kn->kn_fop = &generic_filtops;
break;
default:
return (EINVAL);
}
return (0);
}
/* Trivial lookup routine that always fails. */
int
vop_generic_lookup(void *v)
{
struct vop_lookup_args *ap = v;
*ap->a_vpp = NULL;
return (ENOTDIR);
}
void
filt_generic_detach(struct knote *kn)
{
}
int
filt_generic_readwrite(struct knote *kn, long hint)
{
/*
* filesystem is gone, so set the EOF flag and schedule
* the knote for deletion.
*/
if (hint == NOTE_REVOKE) {
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
return (1);
}
kn->kn_data = 0;
return (1);
}
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