NetBSD/sys/miscfs/nullfs/null_vfsops.c

376 lines
8.7 KiB
C

/* $NetBSD: null_vfsops.c,v 1.3 1994/09/15 03:42:40 mycroft 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>
/*
* Mount null layer
*/
int
nullfs_mount(mp, path, data, ndp, p)
struct mount *mp;
char *path;
caddr_t 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;
u_int 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
*/
if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args)))
return (error);
/*
* Find lower node
*/
NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
UIO_USERSPACE, args.target, p);
if (error = namei(ndp))
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);
/*
* 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);
(void)nullfs_statfs(mp, &mp->mnt_stat, p);
#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))
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[0], mp->mnt_op->vfs_name, MFSNAMELEN);
sbp->f_fstypename[MFSNAMELEN] = '\0';
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 VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp);
}
int
nullfs_vptofh(vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
}
int nullfs_init __P((void));
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,
};