4.4BSD/usr/src/sys/miscfs/lofs/lofs_vfsops.c
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* 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.
*
* @(#)lofs_vfsops.c 8.1 (Berkeley) 6/10/93
*
* $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $
*/
/*
* Loopback Filesystem
*/
#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/lofs/lofs.h>
/*
* Mount loopback copy of existing name space
*/
lofs_mount(mp, path, data, ndp, p)
struct mount *mp;
char *path;
caddr_t data;
struct nameidata *ndp;
struct proc *p;
{
int error = 0;
struct lofs_args args;
struct vnode *vp;
struct vnode *rootvp;
struct lofsmount *amp;
u_int size;
#ifdef LOFS_DIAGNOSTIC
printf("lofs_mount(mp = %x)\n", mp);
#endif
/*
* Update is a no-op
*/
if (mp->mnt_flag & MNT_UPDATE) {
return (EOPNOTSUPP);
/* return VFS_MOUNT(VFSTOLOFS(mp)->looped_vfs, path, data, ndp, p);*/
}
/*
* Get argument
*/
if (error = copyin(data, (caddr_t)&args, sizeof(struct lofs_args)))
return (error);
/*
* Find target node
*/
NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
UIO_USERSPACE, args.target, p);
if (error = namei(ndp))
return (error);
/*
* Sanity check on target vnode
*/
vp = ndp->ni_vp;
#ifdef LOFS_DIAGNOSTIC
printf("vp = %x, check for VDIR...\n", vp);
#endif
vrele(ndp->ni_dvp);
ndp->ni_dvp = 0;
if (vp->v_type != VDIR) {
vput(vp);
return (EINVAL);
}
#ifdef LOFS_DIAGNOSTIC
printf("mp = %x\n", mp);
#endif
amp = (struct lofsmount *) malloc(sizeof(struct lofsmount),
M_UFSMNT, M_WAITOK); /* XXX */
/*
* Save reference to underlying target FS
*/
amp->looped_vfs = vp->v_mount;
/*
* Save reference. Each mount also holds
* a reference on the root vnode.
*/
error = make_lofs(mp, &vp);
/*
* Unlock the node (either the target or the alias)
*/
VOP_UNLOCK(vp);
/*
* Make sure the node alias worked
*/
if (error) {
vrele(vp);
free(amp, M_UFSMNT); /* XXX */
return (error);
}
/*
* Keep a held reference to the root vnode.
* It is vrele'd in lofs_unmount.
*/
rootvp = vp;
rootvp->v_flag |= VROOT;
amp->rootvp = rootvp;
if (LOFSVP(rootvp)->v_mount->mnt_flag & MNT_LOCAL)
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_data = (qaddr_t) amp;
getnewfsid(mp, 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 LOFS_DIAGNOSTIC
printf("lofs_mount: target %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.
*/
lofs_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
return (0);
/* return VFS_START(VFSTOLOFS(mp)->looped_vfs, flags, p); */
}
/*
* Free reference to looped FS
*/
lofs_unmount(mp, mntflags, p)
struct mount *mp;
int mntflags;
struct proc *p;
{
struct vnode *rootvp = VFSTOLOFS(mp)->rootvp;
int error;
int flags = 0;
extern int doforce;
#ifdef LOFS_DIAGNOSTIC
printf("lofs_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 (rootvp->v_usecount > 1)
return (EBUSY);
if (error = vflush(mp, rootvp, flags))
return (error);
#ifdef LOFS_DIAGNOSTIC
/*
* Flush any remaining vnode references
*/
lofs_flushmp(mp);
#endif
#ifdef LOFS_DIAGNOSTIC
vprint("alias root of target", rootvp);
#endif
/*
* Release reference on underlying root vnode
*/
vrele(rootvp);
/*
* And blow it away for future re-use
*/
vgone(rootvp);
/*
* Finally, throw away the lofsmount structure
*/
free(mp->mnt_data, M_UFSMNT); /* XXX */
mp->mnt_data = 0;
return 0;
}
lofs_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct vnode *vp;
#ifdef LOFS_DIAGNOSTIC
printf("lofs_root(mp = %x, vp = %x->%x)\n", mp,
VFSTOLOFS(mp)->rootvp,
LOFSVP(VFSTOLOFS(mp)->rootvp)
);
#endif
/*
* Return locked reference to root.
*/
vp = VFSTOLOFS(mp)->rootvp;
VREF(vp);
VOP_LOCK(vp);
*vpp = vp;
return 0;
}
lofs_quotactl(mp, cmd, uid, arg, p)
struct mount *mp;
int cmd;
uid_t uid;
caddr_t arg;
struct proc *p;
{
return VFS_QUOTACTL(VFSTOLOFS(mp)->looped_vfs, cmd, uid, arg, p);
}
lofs_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
int error;
struct statfs mstat;
#ifdef LOFS_DIAGNOSTIC
printf("lofs_statfs(mp = %x, vp = %x->%x)\n", mp,
VFSTOLOFS(mp)->rootvp,
LOFSVP(VFSTOLOFS(mp)->rootvp)
);
#endif
bzero(&mstat, sizeof(mstat));
error = VFS_STATFS(VFSTOLOFS(mp)->looped_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);
}
return (0);
}
lofs_sync(mp, waitfor)
struct mount *mp;
int waitfor;
{
return (0);
}
/*
* LOFS flat namespace lookup.
* Currently unsupported.
*/
lofs_vget(mp, ino, vpp)
struct mount *mp;
ino_t ino;
struct vnode **vpp;
{
return (EOPNOTSUPP);
}
lofs_fhtovp(mp, fhp, nam, vpp, exflagsp, credanonp)
register struct mount *mp;
struct fid *fhp;
struct mbuf *nam;
struct vnode **vpp;
int *exflagsp;
struct ucred **credanonp;
{
return VFS_FHTOVP(VFSTOLOFS(mp)->looped_vfs, fhp, nam, vpp, exflagsp, credanonp);
}
lofs_vptofh(vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
return VFS_VPTOFH(LOFSVP(vp), fhp);
}
int lofs_init __P((void));
struct vfsops lofs_vfsops = {
lofs_mount,
lofs_start,
lofs_unmount,
lofs_root,
lofs_quotactl,
lofs_statfs,
lofs_sync,
lofs_vget,
lofs_fhtovp,
lofs_vptofh,
lofs_init,
};