NetBSD-5.0.2/sys/miscfs/umapfs/umap_vfsops.c
/* $NetBSD: umap_vfsops.c,v 1.80 2008/06/28 01:34:06 rumble Exp $ */
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* the UCLA Ficus project.
*
* 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: @(#)null_vfsops.c 1.5 (Berkeley) 7/10/92
* @(#)umap_vfsops.c 8.8 (Berkeley) 5/14/95
*/
/*
* Umap Layer
* (See mount_umap(8) for a description of this layer.)
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: umap_vfsops.c,v 1.80 2008/06/28 01:34:06 rumble Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <sys/module.h>
#include <miscfs/umapfs/umap.h>
#include <miscfs/genfs/layer_extern.h>
MODULE(MODULE_CLASS_VFS, umapfs, NULL);
VFS_PROTOS(umapfs);
static struct sysctllog *umapfs_sysctl_log;
/*
* Mount umap layer
*/
int
umapfs_mount(mp, path, data, data_len)
struct mount *mp;
const char *path;
void *data;
size_t *data_len;
{
struct lwp *l = curlwp;
struct nameidata nd;
struct umap_args *args = data;
struct vnode *lowerrootvp, *vp;
struct umap_mount *amp;
int error;
#ifdef UMAPFS_DIAGNOSTIC
int i;
#endif
if (*data_len < sizeof *args)
return EINVAL;
if (mp->mnt_flag & MNT_GETARGS) {
amp = MOUNTTOUMAPMOUNT(mp);
if (amp == NULL)
return EIO;
args->la.target = NULL;
args->nentries = amp->info_nentries;
args->gnentries = amp->info_gnentries;
*data_len = sizeof *args;
return 0;
}
/* only for root */
if ((error = kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER,
NULL)) != 0)
return error;
#ifdef UMAPFS_DIAGNOSTIC
printf("umapfs_mount(mp = %p)\n", mp);
#endif
/*
* Update is not supported
*/
if (mp->mnt_flag & MNT_UPDATE)
return EOPNOTSUPP;
/*
* Find lower node
*/
NDINIT(&nd, LOOKUP, FOLLOW|LOCKLEAF,
UIO_USERSPACE, args->umap_target);
if ((error = namei(&nd)) != 0)
return (error);
/*
* Sanity check on lower vnode
*/
lowerrootvp = nd.ni_vp;
#ifdef UMAPFS_DIAGNOSTIC
printf("vp = %p, check for VDIR...\n", lowerrootvp);
#endif
if (lowerrootvp->v_type != VDIR) {
vput(lowerrootvp);
return (EINVAL);
}
#ifdef UMAPFS_DIAGNOSTIC
printf("mp = %p\n", mp);
#endif
amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
M_UFSMNT, M_WAITOK); /* XXX */
memset(amp, 0, sizeof(struct umap_mount));
mp->mnt_data = amp;
amp->umapm_vfs = lowerrootvp->v_mount;
if (amp->umapm_vfs->mnt_flag & MNT_LOCAL)
mp->mnt_flag |= MNT_LOCAL;
/*
* Now copy in the number of entries and maps for umap mapping.
*/
if (args->nentries > MAPFILEENTRIES || args->gnentries > GMAPFILEENTRIES) {
vput(lowerrootvp);
return (error);
}
amp->info_nentries = args->nentries;
amp->info_gnentries = args->gnentries;
error = copyin(args->mapdata, amp->info_mapdata,
2*sizeof(u_long)*args->nentries);
if (error) {
vput(lowerrootvp);
return (error);
}
#ifdef UMAPFS_DIAGNOSTIC
printf("umap_mount:nentries %d\n",args->nentries);
for (i = 0; i < args->nentries; i++)
printf(" %ld maps to %ld\n", amp->info_mapdata[i][0],
amp->info_mapdata[i][1]);
#endif
error = copyin(args->gmapdata, amp->info_gmapdata,
2*sizeof(u_long)*args->gnentries);
if (error) {
vput(lowerrootvp);
return (error);
}
#ifdef UMAPFS_DIAGNOSTIC
printf("umap_mount:gnentries %d\n",args->gnentries);
for (i = 0; i < args->gnentries; i++)
printf("\tgroup %ld maps to %ld\n",
amp->info_gmapdata[i][0],
amp->info_gmapdata[i][1]);
#endif
/*
* Make sure the mount point's sufficiently initialized
* that the node create call will work.
*/
vfs_getnewfsid(mp);
amp->umapm_size = sizeof(struct umap_node);
amp->umapm_tag = VT_UMAP;
amp->umapm_bypass = umap_bypass;
amp->umapm_alloc = layer_node_alloc; /* the default alloc is fine */
amp->umapm_vnodeop_p = umap_vnodeop_p;
mutex_init(&->umapm_hashlock, MUTEX_DEFAULT, IPL_NONE);
amp->umapm_node_hashtbl = hashinit(NUMAPNODECACHE, HASH_LIST, true,
&->umapm_node_hash);
/*
* fix up umap node for root vnode.
*/
error = layer_node_create(mp, lowerrootvp, &vp);
/*
* Make sure the node alias worked
*/
if (error) {
vput(lowerrootvp);
hashdone(amp->umapm_node_hashtbl, HASH_LIST,
amp->umapm_node_hash);
free(amp, M_UFSMNT); /* XXX */
return (error);
}
/*
* Unlock the node (either the lower or the alias)
*/
vp->v_vflag |= VV_ROOT;
VOP_UNLOCK(vp, 0);
/*
* Keep a held reference to the root vnode.
* It is vrele'd in umapfs_unmount.
*/
amp->umapm_rootvp = vp;
error = set_statvfs_info(path, UIO_USERSPACE, args->umap_target,
UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);
#ifdef UMAPFS_DIAGNOSTIC
printf("umapfs_mount: lower %s, alias at %s\n",
mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
#endif
return error;
}
/*
* Free reference to umap layer
*/
int
umapfs_unmount(struct mount *mp, int mntflags)
{
struct umap_mount *amp = MOUNTTOUMAPMOUNT(mp);
struct vnode *rtvp = amp->umapm_rootvp;
int error;
int flags = 0;
#ifdef UMAPFS_DIAGNOSTIC
printf("umapfs_unmount(mp = %p)\n", mp);
#endif
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0)
return (EBUSY);
if ((error = vflush(mp, rtvp, flags)) != 0)
return (error);
#ifdef UMAPFS_DIAGNOSTIC
vprint("alias root of lower", rtvp);
#endif
/*
* Blow it away for future re-use
*/
vgone(rtvp);
/*
* Finally, throw away the umap_mount structure
*/
mutex_destroy(&->umapm_hashlock);
hashdone(amp->umapm_node_hashtbl, HASH_LIST, amp->umapm_node_hash);
free(amp, M_UFSMNT); /* XXX */
mp->mnt_data = NULL;
return (0);
}
extern const struct vnodeopv_desc umapfs_vnodeop_opv_desc;
const struct vnodeopv_desc * const umapfs_vnodeopv_descs[] = {
&umapfs_vnodeop_opv_desc,
NULL,
};
struct vfsops umapfs_vfsops = {
MOUNT_UMAP,
sizeof (struct umap_args),
umapfs_mount,
layerfs_start,
umapfs_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,
(void *)eopnotsupp, /* vfs_suspendctl */
layerfs_renamelock_enter,
layerfs_renamelock_exit,
(void *)eopnotsupp,
umapfs_vnodeopv_descs,
0, /* vfs_refcount */
{ NULL, NULL },
};
static int
umapfs_modcmd(modcmd_t cmd, void *arg)
{
int error;
switch (cmd) {
case MODULE_CMD_INIT:
error = vfs_attach(&umapfs_vfsops);
if (error != 0)
break;
sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "vfs", NULL,
NULL, 0, NULL, 0,
CTL_VFS, CTL_EOL);
sysctl_createv(&umapfs_sysctl_log, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "umap",
SYSCTL_DESCR("UID/GID remapping file system"),
NULL, 0, NULL, 0,
CTL_VFS, 10, CTL_EOL);
/*
* XXX the "10" above could be dynamic, thereby eliminating
* one more instance of the "number to vfs" mapping problem,
* but "10" is the order as taken from sys/mount.h
*/
break;
case MODULE_CMD_FINI:
error = vfs_detach(&umapfs_vfsops);
if (error != 0)
break;
sysctl_teardown(&umapfs_sysctl_log);
break;
default:
error = ENOTTY;
break;
}
return (error);
}