NetBSD/sys/miscfs/nullfs/null_vfsops.c
cgd 90688fce27 Change the second and third args to struct vfsops' (*vfs_mount)() to
'const char *', and 'void *', respectively.  The second arg is taken directly
from user arguments, and is const there, so must be const in the prototypes
and functions.  The third arg is also taken directly from user arguments.
It doesn't have to be changed, but since it's cleaner to keep the type
the same as the user arg's type, and I'm already making the 'const char *'
change...
1996-12-22 10:10:12 +00:00

384 lines
9.3 KiB
C

/* $NetBSD: null_vfsops.c,v 1.14 1996/12/22 10:10:23 cgd 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
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 8.2 (Berkeley) 1/21/94
*/
/*
* Null Layer
* (See null_vnops.c for a description of what this does.)
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <miscfs/nullfs/null.h>
int nullfs_mount __P((struct mount *, const char *, void *,
struct nameidata *, struct proc *));
int nullfs_start __P((struct mount *, int, struct proc *));
int nullfs_unmount __P((struct mount *, int, struct proc *));
int nullfs_root __P((struct mount *, struct vnode **));
int nullfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
struct proc *));
int nullfs_statfs __P((struct mount *, struct statfs *, struct proc *));
int nullfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
int nullfs_vget __P((struct mount *, ino_t, struct vnode **));
int nullfs_fhtovp __P((struct mount *, struct fid *, struct mbuf *,
struct vnode **, int *, struct ucred **));
int nullfs_vptofh __P((struct vnode *, struct fid *));
/*
* Mount null layer
*/
int
nullfs_mount(mp, path, data, ndp, p)
struct mount *mp;
const char *path;
void *data;
struct nameidata *ndp;
struct proc *p;
{
int error = 0;
struct null_args args;
struct vnode *lowerrootvp, *vp;
struct vnode *nullm_rootvp;
struct null_mount *xmp;
size_t size;
#ifdef NULLFS_DIAGNOSTIC
printf("nullfs_mount(mp = %x)\n", mp);
#endif
/*
* Update is a no-op
*/
if (mp->mnt_flag & MNT_UPDATE) {
return (EOPNOTSUPP);
/* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
}
/*
* Get argument
*/
error = copyin(data, (caddr_t)&args, sizeof(struct null_args));
if (error)
return (error);
/*
* Find lower node
*/
NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
UIO_USERSPACE, args.target, p);
if ((error = namei(ndp)) != 0)
return (error);
/*
* Sanity check on lower vnode
*/
lowerrootvp = ndp->ni_vp;
vrele(ndp->ni_dvp);
ndp->ni_dvp = NULL;
xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
M_UFSMNT, M_WAITOK); /* XXX */
/*
* Save reference to underlying FS
*/
xmp->nullm_vfs = lowerrootvp->v_mount;
/*
* Save reference. Each mount also holds
* a reference on the root vnode.
*/
error = null_node_create(mp, lowerrootvp, &vp, 1);
/*
* Unlock the node (either the lower or the alias)
*/
VOP_UNLOCK(vp);
/*
* Make sure the node alias worked
*/
if (error) {
vrele(lowerrootvp);
free(xmp, M_UFSMNT); /* XXX */
return (error);
}
/*
* Keep a held reference to the root vnode.
* It is vrele'd in nullfs_unmount.
*/
nullm_rootvp = vp;
nullm_rootvp->v_flag |= VROOT;
xmp->nullm_rootvp = nullm_rootvp;
if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_data = (qaddr_t) xmp;
getnewfsid(mp, makefstype(MOUNT_LOFS));
(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
&size);
bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
#ifdef NULLFS_DIAGNOSTIC
printf("nullfs_mount: lower %s, alias at %s\n",
mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
#endif
return (0);
}
/*
* VFS start. Nothing needed here - the start routine
* on the underlying filesystem will have been called
* when that filesystem was mounted.
*/
int
nullfs_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
return (0);
/* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
}
/*
* Free reference to null layer
*/
int
nullfs_unmount(mp, mntflags, p)
struct mount *mp;
int mntflags;
struct proc *p;
{
struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
int error;
int flags = 0;
extern int doforce;
#ifdef NULLFS_DIAGNOSTIC
printf("nullfs_unmount(mp = %x)\n", mp);
#endif
if (mntflags & MNT_FORCE) {
/* lofs can never be rootfs so don't check for it */
if (!doforce)
return (EINVAL);
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 (nullm_rootvp->v_usecount > 1)
return (EBUSY);
if ((error = vflush(mp, nullm_rootvp, flags)) != 0)
return (error);
#ifdef NULLFS_DIAGNOSTIC
vprint("alias root of lower", nullm_rootvp);
#endif
/*
* Release reference on underlying root vnode
*/
vrele(nullm_rootvp);
/*
* And blow it away for future re-use
*/
vgone(nullm_rootvp);
/*
* Finally, throw away the null_mount structure
*/
free(mp->mnt_data, M_UFSMNT); /* XXX */
mp->mnt_data = 0;
return 0;
}
int
nullfs_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct vnode *vp;
#ifdef NULLFS_DIAGNOSTIC
printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
MOUNTTONULLMOUNT(mp)->nullm_rootvp,
NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
#endif
/*
* Return locked reference to root.
*/
vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
VREF(vp);
VOP_LOCK(vp);
*vpp = vp;
return 0;
}
int
nullfs_quotactl(mp, cmd, uid, arg, p)
struct mount *mp;
int cmd;
uid_t uid;
caddr_t arg;
struct proc *p;
{
return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
}
int
nullfs_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
int error;
struct statfs mstat;
#ifdef NULLFS_DIAGNOSTIC
printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
MOUNTTONULLMOUNT(mp)->nullm_rootvp,
NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp));
#endif
bzero(&mstat, sizeof(mstat));
error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
if (error)
return (error);
/* now copy across the "interesting" information and fake the rest */
sbp->f_type = mstat.f_type;
sbp->f_flags = mstat.f_flags;
sbp->f_bsize = mstat.f_bsize;
sbp->f_iosize = mstat.f_iosize;
sbp->f_blocks = mstat.f_blocks;
sbp->f_bfree = mstat.f_bfree;
sbp->f_bavail = mstat.f_bavail;
sbp->f_files = mstat.f_files;
sbp->f_ffree = mstat.f_ffree;
if (sbp != &mp->mnt_stat) {
bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
}
strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
return (0);
}
int
nullfs_sync(mp, waitfor, cred, p)
struct mount *mp;
int waitfor;
struct ucred *cred;
struct proc *p;
{
/*
* XXX - Assumes no data cached at null layer.
*/
return (0);
}
int
nullfs_vget(mp, ino, vpp)
struct mount *mp;
ino_t ino;
struct vnode **vpp;
{
return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
}
int
nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
struct mount *mp;
struct fid *fidp;
struct mbuf *nam;
struct vnode **vpp;
int *exflagsp;
struct ucred**credanonp;
{
return (EOPNOTSUPP);
}
int
nullfs_vptofh(vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
return (EOPNOTSUPP);
}
struct vfsops null_vfsops = {
MOUNT_NULL,
nullfs_mount,
nullfs_start,
nullfs_unmount,
nullfs_root,
nullfs_quotactl,
nullfs_statfs,
nullfs_sync,
nullfs_vget,
nullfs_fhtovp,
nullfs_vptofh,
nullfs_init,
};