NetBSD-5.0.2/sys/miscfs/genfs/layer_vfsops.c
/* $NetBSD: layer_vfsops.c,v 1.29 2008/01/28 14:31:18 dholland Exp $ */
/*
* Copyright (c) 1999 National Aeronautics & Space Administration
* All rights reserved.
*
* This software was written by William Studenmund of the
* Numerical Aerospace Simulation Facility, NASA Ames Research Center.
*
* 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 National Aeronautics & Space Administration
* 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 NATIONAL AERONAUTICS & SPACE ADMINISTRATION
* ``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 ADMINISTRATION OR CONTRIB-
* UTORS 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) 1992, 1993, 1995
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* 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.
*
* from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp
* from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92
* @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95
*/
/*
* generic layer vfs ops.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: layer_vfsops.c,v 1.29 2008/01/28 14:31:18 dholland Exp $");
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <miscfs/genfs/layer.h>
#include <miscfs/genfs/layer_extern.h>
/*
* VFS start. Nothing needed here - the start routine
* on the underlying filesystem will have been called
* when that filesystem was mounted.
*/
int
layerfs_start(struct mount *mp, int flags)
{
#ifdef notyet
return VFS_START(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, flags);
#else
return 0;
#endif
}
int
layerfs_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct vnode *vp;
#ifdef LAYERFS_DIAGNOSTIC
if (layerfs_debug)
printf("layerfs_root(mp = %p, vp = %p->%p)\n", mp,
MOUNTTOLAYERMOUNT(mp)->layerm_rootvp,
LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp));
#endif
/*
* Return locked reference to root.
*/
vp = MOUNTTOLAYERMOUNT(mp)->layerm_rootvp;
if (vp == NULL) {
*vpp = NULL;
return (EINVAL);
}
VREF(vp);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
*vpp = vp;
return 0;
}
int
layerfs_quotactl(mp, cmd, uid, arg)
struct mount *mp;
int cmd;
uid_t uid;
void *arg;
{
return VFS_QUOTACTL(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, cmd, uid, arg);
}
int
layerfs_statvfs(mp, sbp)
struct mount *mp;
struct statvfs *sbp;
{
int error;
struct statvfs *sbuf;
sbuf = kmem_alloc(sizeof(*sbuf), KM_SLEEP);
if (sbuf == NULL)
return ENOMEM;
#ifdef LAYERFS_DIAGNOSTIC
if (layerfs_debug)
printf("layerfs_statvfs(mp = %p, vp = %p->%p)\n", mp,
MOUNTTOLAYERMOUNT(mp)->layerm_rootvp,
LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp));
#endif
(void)memset(sbuf, 0, sizeof(*sbuf));
error = VFS_STATVFS(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, sbuf);
if (error)
goto done;
/* now copy across the "interesting" information and fake the rest */
sbp->f_flag = sbuf->f_flag;
sbp->f_bsize = sbuf->f_bsize;
sbp->f_frsize = sbuf->f_frsize;
sbp->f_iosize = sbuf->f_iosize;
sbp->f_blocks = sbuf->f_blocks;
sbp->f_bfree = sbuf->f_bfree;
sbp->f_bavail = sbuf->f_bavail;
sbp->f_bresvd = sbuf->f_bresvd;
sbp->f_files = sbuf->f_files;
sbp->f_ffree = sbuf->f_ffree;
sbp->f_favail = sbuf->f_favail;
sbp->f_fresvd = sbuf->f_fresvd;
sbp->f_namemax = sbuf->f_namemax;
copy_statvfs_info(sbp, mp);
done:
kmem_free(sbuf, sizeof(*sbuf));
return error;
}
int
layerfs_sync(struct mount *mp, int waitfor,
kauth_cred_t cred)
{
/*
* XXX - Assumes no data cached at layer.
*/
return (0);
}
int
layerfs_vget(mp, ino, vpp)
struct mount *mp;
ino_t ino;
struct vnode **vpp;
{
int error;
struct vnode *vp;
if ((error = VFS_VGET(MOUNTTOLAYERMOUNT(mp)->layerm_vfs,
ino, &vp))) {
*vpp = NULL;
return (error);
}
if ((error = layer_node_create(mp, vp, vpp))) {
vput(vp);
*vpp = NULL;
return (error);
}
return (0);
}
int
layerfs_fhtovp(mp, fidp, vpp)
struct mount *mp;
struct fid *fidp;
struct vnode **vpp;
{
int error;
struct vnode *vp;
if ((error = VFS_FHTOVP(MOUNTTOLAYERMOUNT(mp)->layerm_vfs,
fidp, &vp)))
return (error);
if ((error = layer_node_create(mp, vp, vpp))) {
vput(vp);
*vpp = NULL;
return (error);
}
return (0);
}
int
layerfs_vptofh(vp, fhp, fh_size)
struct vnode *vp;
struct fid *fhp;
size_t *fh_size;
{
return (VFS_VPTOFH(LAYERVPTOLOWERVP(vp), fhp, fh_size));
}
/*
* layerfs_snapshot - handle a snapshot through a layered file system
*
* At present, we do NOT support snapshotting through a layered file
* system as the ffs implementation changes v_vnlock of the snapshot
* vnodes to point to one common lock. As there is no way for us to
* absolutely pass this change up the stack, a layered file system
* would end up referencing the wrong lock.
*
* This routine serves as a central resource for this behavior; all
* layered file systems don't need to worry about the above. Also, if
* things get fixed, all layers get the benefit.
*/
int
layerfs_snapshot(struct mount *mp, struct vnode *vp,
struct timespec *ts)
{
return (EOPNOTSUPP);
}
SYSCTL_SETUP(sysctl_vfs_layerfs_setup, "sysctl vfs.layerfs subtree setup")
{
const struct sysctlnode *layerfs_node = NULL;
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "vfs", NULL,
NULL, 0, NULL, 0,
CTL_VFS, CTL_EOL);
sysctl_createv(clog, 0, NULL, &layerfs_node,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "layerfs",
SYSCTL_DESCR("Generic layered file system"),
NULL, 0, NULL, 0,
CTL_VFS, CTL_CREATE);
#ifdef LAYERFS_DIAGNOSTIC
sysctl_createv(clog, 0, &layerfs_node, NULL,
CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
CTLTYPE_INT,
"debug",
SYSCTL_DESCR("Verbose debugging messages"),
NULL, 0, &layerfs_debug, 0,
CTL_CREATE, CTL_EOL);
#endif
/*
* other subtrees should really be aliases to this, but since
* they can't tell if layerfs has been instantiated yet, they
* can't do that...not easily. not yet. :-)
*/
}
int
layerfs_renamelock_enter(struct mount *mp)
{
return VFS_RENAMELOCK_ENTER(MOUNTTOLAYERMOUNT(mp)->layerm_vfs);
}
void
layerfs_renamelock_exit(struct mount *mp)
{
VFS_RENAMELOCK_EXIT(MOUNTTOLAYERMOUNT(mp)->layerm_vfs);
}