freebsd-nq/sys/miscfs/kernfs/kernfs_vfsops.c
1997-08-02 14:33:27 +00:00

285 lines
6.9 KiB
C

/*
* 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. 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.
*
* @(#)kernfs_vfsops.c 8.10 (Berkeley) 5/14/95
* $Id: kernfs_vfsops.c,v 1.18 1997/02/22 09:40:19 peter Exp $
*/
/*
* Kernel params Filesystem
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <miscfs/kernfs/kernfs.h>
dev_t rrootdev = NODEV;
static int cdevvp __P((dev_t dev, struct vnode **vpp));
static void kernfs_get_rrootdev __P((void));
static int kernfs_init __P((struct vfsconf *vfsp));
static int kernfs_mount __P((struct mount *mp, char *path, caddr_t data,
struct nameidata *ndp, struct proc *p));
static int kernfs_start __P((struct mount *mp, int flags, struct proc *p));
static int kernfs_unmount __P((struct mount *mp, int mntflags,
struct proc *p));
static int kernfs_root __P((struct mount *mp, struct vnode **vpp));
static int kernfs_statfs __P((struct mount *mp, struct statfs *sbp,
struct proc *p));
static int
kernfs_init(vfsp)
struct vfsconf *vfsp;
{
return (0);
}
static void
kernfs_get_rrootdev()
{
static int tried = 0;
int bmaj = major(rootdev);
int cmaj;
if (tried) {
/* Already did it once. */
return;
}
tried = 1;
if (!bdevsw[bmaj]) {
panic("root dev has no bdevsw");
}
if (rootdev == NODEV)
return;
for (cmaj = 0; cmaj < nchrdev; cmaj++) {
rrootdev = makedev(cmaj, minor(rootdev));
if (chrtoblk(rrootdev) == rootdev)
return;
}
rrootdev = NODEV;
printf("kernfs_get_rrootdev: no raw root device\n");
}
/*
* Mount the Kernel params filesystem
*/
static int
kernfs_mount(mp, path, data, ndp, p)
struct mount *mp;
char *path;
caddr_t data;
struct nameidata *ndp;
struct proc *p;
{
int error = 0;
u_int size;
struct kernfs_mount *fmp;
struct vnode *rvp;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_mount(mp = %x)\n", mp);
#endif
/*
* Update is a no-op
*/
if (mp->mnt_flag & MNT_UPDATE)
return (EOPNOTSUPP);
MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
M_UFSMNT, M_WAITOK); /* XXX */
error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp); /* XXX */
if (error) {
FREE(fmp, M_UFSMNT);
return (error);
}
rvp->v_type = VDIR;
rvp->v_flag |= VROOT;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_mount: root vp = %x\n", rvp);
#endif
fmp->kf_root = rvp;
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_data = (qaddr_t) fmp;
vfs_getnewfsid(mp);
(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
bcopy("kernfs", mp->mnt_stat.f_mntfromname, sizeof("kernfs"));
(void)kernfs_statfs(mp, &mp->mnt_stat, p);
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
#endif
kernfs_get_rrootdev();
return (0);
}
static int
kernfs_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
return (0);
}
static int
kernfs_unmount(mp, mntflags, p)
struct mount *mp;
int mntflags;
struct proc *p;
{
int error;
int flags = 0;
struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_unmount(mp = %x)\n", mp);
#endif
if (mntflags & MNT_FORCE)
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);
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_unmount: calling vflush\n");
#endif
error = vflush(mp, rootvp, flags);
if (error)
return (error);
#ifdef KERNFS_DIAGNOSTIC
vprint("kernfs root", rootvp);
#endif
/*
* Release reference on underlying root vnode
*/
vrele(rootvp);
/*
* And blow it away for future re-use
*/
vgone(rootvp);
/*
* Finally, throw away the kernfs_mount structure
*/
free(mp->mnt_data, M_UFSMNT); /* XXX */
mp->mnt_data = 0;
return 0;
}
static int
kernfs_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct proc *p = curproc; /* XXX */
struct vnode *vp;
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_root(mp = %x)\n", mp);
#endif
/*
* Return locked reference to root.
*/
vp = VFSTOKERNFS(mp)->kf_root;
VREF(vp);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
*vpp = vp;
return (0);
}
static int
kernfs_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
#ifdef KERNFS_DIAGNOSTIC
printf("kernfs_statfs(mp = %x)\n", mp);
#endif
sbp->f_flags = 0;
sbp->f_bsize = DEV_BSIZE;
sbp->f_iosize = DEV_BSIZE;
sbp->f_blocks = 2; /* 1K to keep df happy */
sbp->f_bfree = 0;
sbp->f_bavail = 0;
sbp->f_files = 0;
sbp->f_ffree = 0;
if (sbp != &mp->mnt_stat) {
sbp->f_type = mp->mnt_vfc->vfc_typenum;
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);
}
static struct vfsops kernfs_vfsops = {
kernfs_mount,
kernfs_start,
kernfs_unmount,
kernfs_root,
kernfs_quotactl,
kernfs_statfs,
kernfs_sync,
kernfs_vget,
kernfs_fhtovp,
kernfs_vptofh,
kernfs_init,
};
VFS_SET(kernfs_vfsops, kernfs, MOUNT_KERNFS, VFCF_SYNTHETIC);