319 lines
8.9 KiB
C
319 lines
8.9 KiB
C
/* $NetBSD: null_vfsops.c,v 1.58 2005/12/11 12:24:51 christos 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
|
|
*/
|
|
|
|
/*
|
|
* Null Layer
|
|
* (See null_vnops.c for a description of what this does.)
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__KERNEL_RCSID(0, "$NetBSD: null_vfsops.c,v 1.58 2005/12/11 12:24:51 christos Exp $");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/sysctl.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 <miscfs/nullfs/null.h>
|
|
#include <miscfs/genfs/layer_extern.h>
|
|
|
|
int nullfs_mount(struct mount *, const char *, void *,
|
|
struct nameidata *, struct lwp *);
|
|
int nullfs_unmount(struct mount *, int, struct lwp *);
|
|
|
|
/*
|
|
* Mount null layer
|
|
*/
|
|
int
|
|
nullfs_mount(mp, path, data, ndp, l)
|
|
struct mount *mp;
|
|
const char *path;
|
|
void *data;
|
|
struct nameidata *ndp;
|
|
struct lwp *l;
|
|
{
|
|
struct null_args args;
|
|
struct vnode *lowerrootvp, *vp;
|
|
struct null_mount *nmp;
|
|
struct layer_mount *lmp;
|
|
int error = 0;
|
|
|
|
#ifdef NULLFS_DIAGNOSTIC
|
|
printf("nullfs_mount(mp = %p)\n", mp);
|
|
#endif
|
|
|
|
if (mp->mnt_flag & MNT_GETARGS) {
|
|
lmp = MOUNTTOLAYERMOUNT(mp);
|
|
if (lmp == NULL)
|
|
return EIO;
|
|
args.la.target = NULL;
|
|
return copyout(&args, data, sizeof(args));
|
|
}
|
|
/*
|
|
* Get argument
|
|
*/
|
|
error = copyin(data, &args, sizeof(struct null_args));
|
|
if (error)
|
|
return (error);
|
|
|
|
/*
|
|
* Update is not supported
|
|
*/
|
|
if (mp->mnt_flag & MNT_UPDATE)
|
|
return EOPNOTSUPP;
|
|
|
|
/*
|
|
* Find lower node
|
|
*/
|
|
NDINIT(ndp, LOOKUP, FOLLOW|LOCKLEAF,
|
|
UIO_USERSPACE, args.la.target, l);
|
|
if ((error = namei(ndp)) != 0)
|
|
return (error);
|
|
|
|
/*
|
|
* Sanity check on lower vnode
|
|
*/
|
|
lowerrootvp = ndp->ni_vp;
|
|
|
|
/*
|
|
* First cut at fixing up upper mount point
|
|
*/
|
|
nmp = (struct null_mount *) malloc(sizeof(struct null_mount),
|
|
M_UFSMNT, M_WAITOK); /* XXX */
|
|
memset(nmp, 0, sizeof(struct null_mount));
|
|
|
|
mp->mnt_data = nmp;
|
|
mp->mnt_leaf = lowerrootvp->v_mount->mnt_leaf;
|
|
nmp->nullm_vfs = lowerrootvp->v_mount;
|
|
if (nmp->nullm_vfs->mnt_flag & MNT_LOCAL)
|
|
mp->mnt_flag |= MNT_LOCAL;
|
|
|
|
/*
|
|
* Make sure that the mount point is sufficiently initialized
|
|
* that the node create call will work.
|
|
*/
|
|
vfs_getnewfsid(mp);
|
|
|
|
nmp->nullm_size = sizeof(struct null_node);
|
|
nmp->nullm_tag = VT_NULL;
|
|
nmp->nullm_bypass = layer_bypass;
|
|
nmp->nullm_alloc = layer_node_alloc; /* the default alloc is fine */
|
|
nmp->nullm_vnodeop_p = null_vnodeop_p;
|
|
simple_lock_init(&nmp->nullm_hashlock);
|
|
nmp->nullm_node_hashtbl = hashinit(desiredvnodes, HASH_LIST, M_CACHE,
|
|
M_WAITOK, &nmp->nullm_node_hash);
|
|
|
|
/*
|
|
* Fix up null node for root vnode
|
|
*/
|
|
error = layer_node_create(mp, lowerrootvp, &vp);
|
|
/*
|
|
* Make sure the fixup worked
|
|
*/
|
|
if (error) {
|
|
vput(lowerrootvp);
|
|
hashdone(nmp->nullm_node_hashtbl, M_CACHE);
|
|
free(nmp, M_UFSMNT); /* XXX */
|
|
return (error);
|
|
}
|
|
/*
|
|
* Unlock the node
|
|
*/
|
|
VOP_UNLOCK(vp, 0);
|
|
|
|
/*
|
|
* Keep a held reference to the root vnode.
|
|
* It is vrele'd in nullfs_unmount.
|
|
*/
|
|
vp->v_flag |= VROOT;
|
|
nmp->nullm_rootvp = vp;
|
|
|
|
error = set_statvfs_info(path, UIO_USERSPACE, args.la.target,
|
|
UIO_USERSPACE, mp, l);
|
|
#ifdef NULLFS_DIAGNOSTIC
|
|
printf("nullfs_mount: lower %s, alias at %s\n",
|
|
mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
|
|
#endif
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Free reference to null layer
|
|
*/
|
|
int
|
|
nullfs_unmount(mp, mntflags, l)
|
|
struct mount *mp;
|
|
int mntflags;
|
|
struct lwp *l;
|
|
{
|
|
struct null_mount *nmp = MOUNTTONULLMOUNT(mp);
|
|
struct vnode *null_rootvp = nmp->nullm_rootvp;
|
|
int error;
|
|
int flags = 0;
|
|
|
|
#ifdef NULLFS_DIAGNOSTIC
|
|
printf("nullfs_unmount(mp = %p)\n", mp);
|
|
#endif
|
|
|
|
if (mntflags & MNT_FORCE)
|
|
flags |= FORCECLOSE;
|
|
|
|
/*
|
|
* Clear out buffer cache. I don't think we
|
|
* ever get anything cached at this level at the
|
|
* moment, but who knows...
|
|
*/
|
|
#if 0
|
|
mntflushbuf(mp, 0);
|
|
if (mntinvalbuf(mp, 1))
|
|
return (EBUSY);
|
|
#endif
|
|
if (null_rootvp->v_usecount > 1)
|
|
return (EBUSY);
|
|
if ((error = vflush(mp, null_rootvp, flags)) != 0)
|
|
return (error);
|
|
|
|
#ifdef NULLFS_DIAGNOSTIC
|
|
vprint("alias root of lower", null_rootvp);
|
|
#endif
|
|
/*
|
|
* Release reference on underlying root vnode
|
|
*/
|
|
vrele(null_rootvp);
|
|
|
|
/*
|
|
* And blow it away for future re-use
|
|
*/
|
|
vgone(null_rootvp);
|
|
|
|
/*
|
|
* Finally, throw away the null_mount structure
|
|
*/
|
|
hashdone(nmp->nullm_node_hashtbl, M_CACHE);
|
|
free(mp->mnt_data, M_UFSMNT); /* XXX */
|
|
mp->mnt_data = NULL;
|
|
return (0);
|
|
}
|
|
|
|
SYSCTL_SETUP(sysctl_vfs_null_setup, "sysctl vfs.null subtree setup")
|
|
{
|
|
|
|
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, NULL,
|
|
CTLFLAG_PERMANENT,
|
|
CTLTYPE_NODE, "null",
|
|
SYSCTL_DESCR("Loopback file system"),
|
|
NULL, 0, NULL, 0,
|
|
CTL_VFS, 9, CTL_EOL);
|
|
/*
|
|
* XXX the "9" above could be dynamic, thereby eliminating one
|
|
* more instance of the "number to vfs" mapping problem, but
|
|
* "9" is the order as taken from sys/mount.h
|
|
*/
|
|
}
|
|
|
|
extern const struct vnodeopv_desc null_vnodeop_opv_desc;
|
|
|
|
const struct vnodeopv_desc * const nullfs_vnodeopv_descs[] = {
|
|
&null_vnodeop_opv_desc,
|
|
NULL,
|
|
};
|
|
|
|
struct vfsops nullfs_vfsops = {
|
|
MOUNT_NULL,
|
|
nullfs_mount,
|
|
layerfs_start,
|
|
nullfs_unmount,
|
|
layerfs_root,
|
|
layerfs_quotactl,
|
|
layerfs_statvfs,
|
|
layerfs_sync,
|
|
layerfs_vget,
|
|
layerfs_fhtovp,
|
|
layerfs_vptofh,
|
|
layerfs_init,
|
|
NULL,
|
|
layerfs_done,
|
|
NULL, /* vfs_mountroot */
|
|
layerfs_snapshot,
|
|
vfs_stdextattrctl,
|
|
nullfs_vnodeopv_descs,
|
|
};
|
|
VFS_ATTACH(nullfs_vfsops);
|