NetBSD/sys/miscfs/genfs/genfs_vnops.c

503 lines
10 KiB
C

/* $NetBSD: genfs_vnops.c,v 1.167 2008/04/28 20:24:08 martin Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1982, 1986, 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. 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: genfs_vnops.c,v 1.167 2008/04/28 20:24:08 martin Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/fcntl.h>
#include <sys/kmem.h>
#include <sys/poll.h>
#include <sys/mman.h>
#include <sys/file.h>
#include <sys/kauth.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/genfs/genfs_node.h>
#include <miscfs/specfs/specdev.h>
#include <uvm/uvm.h>
#include <uvm/uvm_pager.h>
static void filt_genfsdetach(struct knote *);
static int filt_genfsread(struct knote *, long);
static int filt_genfsvnode(struct knote *, long);
int
genfs_poll(void *v)
{
struct vop_poll_args /* {
struct vnode *a_vp;
int a_events;
struct lwp *a_l;
} */ *ap = v;
return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
}
int
genfs_seek(void *v)
{
struct vop_seek_args /* {
struct vnode *a_vp;
off_t a_oldoff;
off_t a_newoff;
kauth_cred_t cred;
} */ *ap = v;
if (ap->a_newoff < 0)
return (EINVAL);
return (0);
}
int
genfs_abortop(void *v)
{
struct vop_abortop_args /* {
struct vnode *a_dvp;
struct componentname *a_cnp;
} */ *ap = v;
if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
PNBUF_PUT(ap->a_cnp->cn_pnbuf);
return (0);
}
int
genfs_fcntl(void *v)
{
struct vop_fcntl_args /* {
struct vnode *a_vp;
u_int a_command;
void *a_data;
int a_fflag;
kauth_cred_t a_cred;
struct lwp *a_l;
} */ *ap = v;
if (ap->a_command == F_SETFL)
return (0);
else
return (EOPNOTSUPP);
}
/*ARGSUSED*/
int
genfs_badop(void *v)
{
panic("genfs: bad op");
}
/*ARGSUSED*/
int
genfs_nullop(void *v)
{
return (0);
}
/*ARGSUSED*/
int
genfs_einval(void *v)
{
return (EINVAL);
}
/*
* Called when an fs doesn't support a particular vop.
* This takes care to vrele, vput, or vunlock passed in vnodes.
*/
int
genfs_eopnotsupp(void *v)
{
struct vop_generic_args /*
struct vnodeop_desc *a_desc;
/ * other random data follows, presumably * /
} */ *ap = v;
struct vnodeop_desc *desc = ap->a_desc;
struct vnode *vp, *vp_last = NULL;
int flags, i, j, offset;
flags = desc->vdesc_flags;
for (i = 0; i < VDESC_MAX_VPS; flags >>=1, i++) {
if ((offset = desc->vdesc_vp_offsets[i]) == VDESC_NO_OFFSET)
break; /* stop at end of list */
if ((j = flags & VDESC_VP0_WILLPUT)) {
vp = *VOPARG_OFFSETTO(struct vnode **, offset, ap);
/* Skip if NULL */
if (!vp)
continue;
switch (j) {
case VDESC_VP0_WILLPUT:
/* Check for dvp == vp cases */
if (vp == vp_last)
vrele(vp);
else {
vput(vp);
vp_last = vp;
}
break;
case VDESC_VP0_WILLUNLOCK:
VOP_UNLOCK(vp, 0);
break;
case VDESC_VP0_WILLRELE:
vrele(vp);
break;
}
}
}
return (EOPNOTSUPP);
}
/*ARGSUSED*/
int
genfs_ebadf(void *v)
{
return (EBADF);
}
/* ARGSUSED */
int
genfs_enoioctl(void *v)
{
return (EPASSTHROUGH);
}
/*
* Eliminate all activity associated with the requested vnode
* and with all vnodes aliased to the requested vnode.
*/
int
genfs_revoke(void *v)
{
struct vop_revoke_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap = v;
#ifdef DIAGNOSTIC
if ((ap->a_flags & REVOKEALL) == 0)
panic("genfs_revoke: not revokeall");
#endif
vrevoke(ap->a_vp);
return (0);
}
/*
* Lock the node.
*/
int
genfs_lock(void *v)
{
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
int flags = ap->a_flags;
if ((flags & LK_INTERLOCK) != 0) {
flags &= ~LK_INTERLOCK;
mutex_exit(&vp->v_interlock);
}
return (vlockmgr(vp->v_vnlock, flags));
}
/*
* Unlock the node.
*/
int
genfs_unlock(void *v)
{
struct vop_unlock_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
KASSERT(ap->a_flags == 0);
return (vlockmgr(vp->v_vnlock, LK_RELEASE));
}
/*
* Return whether or not the node is locked.
*/
int
genfs_islocked(void *v)
{
struct vop_islocked_args /* {
struct vnode *a_vp;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
return (vlockstatus(vp->v_vnlock));
}
/*
* Stubs to use when there is no locking to be done on the underlying object.
*/
int
genfs_nolock(void *v)
{
struct vop_lock_args /* {
struct vnode *a_vp;
int a_flags;
struct lwp *a_l;
} */ *ap = v;
/*
* Since we are not using the lock manager, we must clear
* the interlock here.
*/
if (ap->a_flags & LK_INTERLOCK)
mutex_exit(&ap->a_vp->v_interlock);
return (0);
}
int
genfs_nounlock(void *v)
{
return (0);
}
int
genfs_noislocked(void *v)
{
return (0);
}
int
genfs_mmap(void *v)
{
return (0);
}
void
genfs_node_init(struct vnode *vp, const struct genfs_ops *ops)
{
struct genfs_node *gp = VTOG(vp);
rw_init(&gp->g_glock);
gp->g_op = ops;
}
void
genfs_node_destroy(struct vnode *vp)
{
struct genfs_node *gp = VTOG(vp);
rw_destroy(&gp->g_glock);
}
void
genfs_size(struct vnode *vp, off_t size, off_t *eobp, int flags)
{
int bsize;
bsize = 1 << vp->v_mount->mnt_fs_bshift;
*eobp = (size + bsize - 1) & ~(bsize - 1);
}
static void
filt_genfsdetach(struct knote *kn)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
mutex_enter(&vp->v_interlock);
SLIST_REMOVE(&vp->v_klist, kn, knote, kn_selnext);
mutex_exit(&vp->v_interlock);
}
static int
filt_genfsread(struct knote *kn, long hint)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
int rv;
/*
* filesystem is gone, so set the EOF flag and schedule
* the knote for deletion.
*/
switch (hint) {
case NOTE_REVOKE:
KASSERT(mutex_owned(&vp->v_interlock));
kn->kn_flags |= (EV_EOF | EV_ONESHOT);
return (1);
case 0:
mutex_enter(&vp->v_interlock);
kn->kn_data = vp->v_size - ((file_t *)kn->kn_obj)->f_offset;
rv = (kn->kn_data != 0);
mutex_exit(&vp->v_interlock);
return rv;
default:
KASSERT(mutex_owned(&vp->v_interlock));
kn->kn_data = vp->v_size - ((file_t *)kn->kn_obj)->f_offset;
return (kn->kn_data != 0);
}
}
static int
filt_genfsvnode(struct knote *kn, long hint)
{
struct vnode *vp = (struct vnode *)kn->kn_hook;
int fflags;
switch (hint) {
case NOTE_REVOKE:
KASSERT(mutex_owned(&vp->v_interlock));
kn->kn_flags |= EV_EOF;
if ((kn->kn_sfflags & hint) != 0)
kn->kn_fflags |= hint;
return (1);
case 0:
mutex_enter(&vp->v_interlock);
fflags = kn->kn_fflags;
mutex_exit(&vp->v_interlock);
break;
default:
KASSERT(mutex_owned(&vp->v_interlock));
if ((kn->kn_sfflags & hint) != 0)
kn->kn_fflags |= hint;
fflags = kn->kn_fflags;
break;
}
return (fflags != 0);
}
static const struct filterops genfsread_filtops =
{ 1, NULL, filt_genfsdetach, filt_genfsread };
static const struct filterops genfsvnode_filtops =
{ 1, NULL, filt_genfsdetach, filt_genfsvnode };
int
genfs_kqfilter(void *v)
{
struct vop_kqfilter_args /* {
struct vnode *a_vp;
struct knote *a_kn;
} */ *ap = v;
struct vnode *vp;
struct knote *kn;
vp = ap->a_vp;
kn = ap->a_kn;
switch (kn->kn_filter) {
case EVFILT_READ:
kn->kn_fop = &genfsread_filtops;
break;
case EVFILT_VNODE:
kn->kn_fop = &genfsvnode_filtops;
break;
default:
return (EINVAL);
}
kn->kn_hook = vp;
mutex_enter(&vp->v_interlock);
SLIST_INSERT_HEAD(&vp->v_klist, kn, kn_selnext);
mutex_exit(&vp->v_interlock);
return (0);
}
void
genfs_node_wrlock(struct vnode *vp)
{
struct genfs_node *gp = VTOG(vp);
rw_enter(&gp->g_glock, RW_WRITER);
}
void
genfs_node_rdlock(struct vnode *vp)
{
struct genfs_node *gp = VTOG(vp);
rw_enter(&gp->g_glock, RW_READER);
}
void
genfs_node_unlock(struct vnode *vp)
{
struct genfs_node *gp = VTOG(vp);
rw_exit(&gp->g_glock);
}