283 lines
8.5 KiB
C
283 lines
8.5 KiB
C
/* $NetBSD: null_vfsops.c,v 1.101 2023/02/06 10:32:58 hannken 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 file-system: VFS operations.
|
|
*
|
|
* See null_vnops.c for a description.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__KERNEL_RCSID(0, "$NetBSD: null_vfsops.c,v 1.101 2023/02/06 10:32:58 hannken Exp $");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/namei.h>
|
|
#include <sys/module.h>
|
|
|
|
#include <miscfs/nullfs/null.h>
|
|
#include <miscfs/genfs/layer_extern.h>
|
|
|
|
MODULE(MODULE_CLASS_VFS, null, "layerfs");
|
|
|
|
VFS_PROTOS(nullfs);
|
|
|
|
int
|
|
nullfs_mount(struct mount *mp, const char *path, void *data, size_t *data_len)
|
|
{
|
|
struct vnode *lowerrootvp, *vp;
|
|
struct null_args *args = data;
|
|
struct null_mount *nmp;
|
|
struct layer_mount *lmp;
|
|
struct pathbuf *pb;
|
|
struct nameidata nd;
|
|
int error;
|
|
|
|
if (args == NULL)
|
|
return EINVAL;
|
|
if (*data_len < sizeof(*args))
|
|
return EINVAL;
|
|
|
|
if (mp->mnt_flag & MNT_GETARGS) {
|
|
lmp = MOUNTTOLAYERMOUNT(mp);
|
|
if (lmp == NULL)
|
|
return EIO;
|
|
args->la.target = NULL;
|
|
*data_len = sizeof(*args);
|
|
return 0;
|
|
}
|
|
|
|
/* Update is not supported. */
|
|
if (mp->mnt_flag & MNT_UPDATE)
|
|
return EOPNOTSUPP;
|
|
|
|
/* Find the lower vnode and lock it. */
|
|
error = pathbuf_copyin(args->la.target, &pb);
|
|
if (error) {
|
|
return error;
|
|
}
|
|
NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF, pb);
|
|
if ((error = namei(&nd)) != 0) {
|
|
pathbuf_destroy(pb);
|
|
return error;
|
|
}
|
|
lowerrootvp = nd.ni_vp;
|
|
pathbuf_destroy(pb);
|
|
|
|
/* Create the mount point. */
|
|
nmp = kmem_zalloc(sizeof(struct null_mount), KM_SLEEP);
|
|
mp->mnt_data = nmp;
|
|
mp->mnt_iflag |= lowerrootvp->v_mount->mnt_iflag & IMNT_MPSAFE;
|
|
mp->mnt_iflag |= lowerrootvp->v_mount->mnt_iflag & IMNT_SHRLOOKUP;
|
|
|
|
/*
|
|
* Make sure that the mount point is sufficiently initialized
|
|
* that the node create call will work.
|
|
*/
|
|
vfs_getnewfsid(mp);
|
|
error = vfs_set_lowermount(mp, lowerrootvp->v_mount);
|
|
if (error) {
|
|
vput(lowerrootvp);
|
|
kmem_free(nmp, sizeof(struct null_mount));
|
|
return error;
|
|
}
|
|
|
|
nmp->nullm_size = sizeof(struct null_node);
|
|
nmp->nullm_tag = VT_NULL;
|
|
nmp->nullm_bypass = layer_bypass;
|
|
nmp->nullm_vnodeop_p = null_vnodeop_p;
|
|
|
|
/* Setup a null node for root vnode. */
|
|
VOP_UNLOCK(lowerrootvp);
|
|
error = layer_node_create(mp, lowerrootvp, &vp);
|
|
if (error) {
|
|
vrele(lowerrootvp);
|
|
kmem_free(nmp, sizeof(struct null_mount));
|
|
return error;
|
|
}
|
|
/*
|
|
* Keep a held reference to the root vnode. It will be released on
|
|
* umount. Note: nullfs is MP-safe.
|
|
*/
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
|
|
vp->v_vflag |= VV_ROOT;
|
|
nmp->nullm_rootvp = vp;
|
|
VOP_UNLOCK(vp);
|
|
|
|
error = set_statvfs_info(path, UIO_USERSPACE, args->la.target,
|
|
UIO_USERSPACE, mp->mnt_op->vfs_name, mp, curlwp);
|
|
if (error)
|
|
return error;
|
|
|
|
if (mp->mnt_lower->mnt_flag & MNT_LOCAL)
|
|
mp->mnt_flag |= MNT_LOCAL;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
nullfs_unmount(struct mount *mp, int mntflags)
|
|
{
|
|
struct null_mount *nmp = MOUNTTONULLMOUNT(mp);
|
|
struct vnode *null_rootvp = nmp->nullm_rootvp;
|
|
int error, flags = 0;
|
|
|
|
if (mntflags & MNT_FORCE)
|
|
flags |= FORCECLOSE;
|
|
|
|
if (vrefcnt(null_rootvp) > 1 && (mntflags & MNT_FORCE) == 0)
|
|
return EBUSY;
|
|
|
|
if ((error = vflush(mp, null_rootvp, flags)) != 0)
|
|
return error;
|
|
|
|
/* Eliminate all activity and release the vnode. */
|
|
vgone(null_rootvp);
|
|
|
|
/* Finally, destroy the mount point structures. */
|
|
kmem_free(mp->mnt_data, sizeof(struct null_mount));
|
|
mp->mnt_data = NULL;
|
|
return 0;
|
|
}
|
|
|
|
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 = {
|
|
.vfs_name = MOUNT_NULL,
|
|
.vfs_min_mount_data = sizeof (struct null_args),
|
|
.vfs_mount = nullfs_mount,
|
|
.vfs_start = layerfs_start,
|
|
.vfs_unmount = nullfs_unmount,
|
|
.vfs_root = layerfs_root,
|
|
.vfs_quotactl = layerfs_quotactl,
|
|
.vfs_statvfs = layerfs_statvfs,
|
|
.vfs_sync = layerfs_sync,
|
|
.vfs_loadvnode = layerfs_loadvnode,
|
|
.vfs_vget = layerfs_vget,
|
|
.vfs_fhtovp = layerfs_fhtovp,
|
|
.vfs_vptofh = layerfs_vptofh,
|
|
.vfs_init = layerfs_init,
|
|
.vfs_done = layerfs_done,
|
|
.vfs_snapshot = layerfs_snapshot,
|
|
.vfs_extattrctl = vfs_stdextattrctl,
|
|
.vfs_suspendctl = layerfs_suspendctl,
|
|
.vfs_renamelock_enter = layerfs_renamelock_enter,
|
|
.vfs_renamelock_exit = layerfs_renamelock_exit,
|
|
.vfs_fsync = (void *)eopnotsupp,
|
|
.vfs_opv_descs = nullfs_vnodeopv_descs
|
|
};
|
|
|
|
SYSCTL_SETUP(nullfs_sysctl_setup, "nullfs sysctl")
|
|
{
|
|
|
|
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
|
|
*/
|
|
}
|
|
|
|
static int
|
|
null_modcmd(modcmd_t cmd, void *arg)
|
|
{
|
|
int error;
|
|
|
|
switch (cmd) {
|
|
case MODULE_CMD_INIT:
|
|
error = vfs_attach(&nullfs_vfsops);
|
|
if (error != 0)
|
|
break;
|
|
break;
|
|
case MODULE_CMD_FINI:
|
|
error = vfs_detach(&nullfs_vfsops);
|
|
if (error != 0)
|
|
break;
|
|
break;
|
|
default:
|
|
error = ENOTTY;
|
|
break;
|
|
}
|
|
return error;
|
|
}
|