NetBSD-5.0.2/sys/miscfs/syncfs/sync_vnops.c
/* $NetBSD: sync_vnops.c,v 1.25.10.1 2009/02/24 04:13:35 snj Exp $ */
/*-
* Copyright (c) 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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 1997 Marshall Kirk McKusick. All Rights Reserved.
*
* This code is derived from work done by Greg Ganger at the
* University of Michigan.
*
* 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. None of the names of McKusick, Ganger, or the University of Michigan
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY MARSHALL KIRK MCKUSICK ``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 MARSHALL KIRK MCKUSICK 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: sync_vnops.c,v 1.25.10.1 2009/02/24 04:13:35 snj Exp $");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/errno.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/syncfs/syncfs.h>
int (**sync_vnodeop_p)(void *);
const struct vnodeopv_entry_desc sync_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_close_desc, sync_close }, /* close */
{ &vop_fsync_desc, sync_fsync }, /* fsync */
{ &vop_inactive_desc, sync_inactive }, /* inactive */
{ &vop_reclaim_desc, sync_reclaim }, /* reclaim */
{ &vop_lock_desc, sync_lock }, /* lock */
{ &vop_unlock_desc, sync_unlock }, /* unlock */
{ &vop_print_desc, sync_print }, /* print */
{ &vop_islocked_desc, sync_islocked }, /* islocked */
{ &vop_putpages_desc, sync_putpages }, /* islocked */
{ NULL, NULL }
};
const struct vnodeopv_desc sync_vnodeop_opv_desc =
{ &sync_vnodeop_p, sync_vnodeop_entries };
/*
* Return delay factor appropriate for the given file system. For
* WAPBL we use the sync vnode to burst out metadata updates: sync
* those file systems more frequently.
*/
static inline int
sync_delay(struct mount *mp)
{
return mp->mnt_wapbl != NULL ? metadelay : syncdelay;
}
/*
* Create a new filesystem syncer vnode for the specified mount point.
*/
int
vfs_allocate_syncvnode(mp)
struct mount *mp;
{
struct vnode *vp;
static int start, incr, next;
int error, vdelay;
/* Allocate a new vnode */
if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0)
return (error);
vp->v_writecount = 1;
vp->v_type = VNON;
/*
* Place the vnode onto the syncer worklist. We attempt to
* scatter them about on the list so that they will go off
* at evenly distributed times even if all the filesystems
* are mounted at once.
*/
next += incr;
if (next == 0 || next > syncer_maxdelay) {
start /= 2;
incr /= 2;
if (start == 0) {
start = syncer_maxdelay / 2;
incr = syncer_maxdelay;
}
next = start;
}
mutex_enter(&vp->v_interlock);
vdelay = sync_delay(mp);
vn_syncer_add_to_worklist(vp, vdelay > 0 ? next % vdelay : 0);
mutex_exit(&vp->v_interlock);
mp->mnt_syncer = vp;
return (0);
}
/*
* Destroy the filesystem syncer vnode for the specified mount point.
*/
void
vfs_deallocate_syncvnode(mp)
struct mount *mp;
{
struct vnode *vp;
vp = mp->mnt_syncer;
mp->mnt_syncer = NULL;
mutex_enter(&vp->v_interlock);
vn_syncer_remove_from_worklist(vp);
vp->v_writecount = 0;
mutex_exit(&vp->v_interlock);
vgone(vp);
}
/*
* Do a lazy sync of the filesystem.
*/
int
sync_fsync(v)
void *v;
{
struct vop_fsync_args /* {
struct vnode *a_vp;
kauth_cred_t a_cred;
int a_flags;
off_t offlo;
off_t offhi;
} */ *ap = v;
struct vnode *syncvp = ap->a_vp;
struct mount *mp = syncvp->v_mount;
/*
* We only need to do something if this is a lazy evaluation.
*/
if (!(ap->a_flags & FSYNC_LAZY))
return (0);
/*
* Move ourselves to the back of the sync list.
*/
mutex_enter(&syncvp->v_interlock);
vn_syncer_add_to_worklist(syncvp, sync_delay(mp));
mutex_exit(&syncvp->v_interlock);
/*
* Walk the list of vnodes pushing all that are dirty and
* not already on the sync list.
*/
if (vfs_busy(mp, NULL) == 0) {
VFS_SYNC(mp, MNT_LAZY, ap->a_cred);
vfs_unbusy(mp, false, NULL);
}
return (0);
}
/*
* The syncer vnode is no longer needed and is being decommissioned.
*/
int
sync_inactive(v)
void *v;
{
struct vop_inactive_args /* {
struct vnode *a_vp;
struct proc *a_p;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
VOP_UNLOCK(vp, 0);
return (0);
}
int
sync_reclaim(void *v)
{
return (0);
}
/*
* Print out a syncer vnode.
*/
int
sync_print(v)
void *v;
{
printf("syncer vnode\n");
return (0);
}