freebsd-skq/sys/miscfs/umapfs/umap_vfsops.c
adrian 4018955334 Reviewed by: jlemon
An initial tidyup of the mount() syscall and VFS mount code.

This code replaces the earlier work done by jlemon in an attempt to
make linux_mount() work.

* the guts of the mount work has been moved into vfs_mount().

* move `type', `path' and `flags' from being userland variables into being
  kernel variables in vfs_mount(). `data' remains a pointer into
  userspace.

* Attempt to verify the `type' and `path' strings passed to vfs_mount()
  aren't too long.

* rework mount() and linux_mount() to take the userland parameters
  (besides data, as mentioned) and pass kernel variables to vfs_mount().
  (linux_mount() already did this, I've just tidied it up a little more.)

* remove the copyin*() stuff for `path'. `data' still requires copyin*()
  since its a pointer into userland.

* set `mount->mnt_statf_mntonname' in vfs_mount() rather than in each
  filesystem.  This variable is generally initialised with `path', and
  each filesystem can override it if they want to.

* NOTE: f_mntonname is intiailised with "/" in the case of a root mount.
2001-03-01 21:00:17 +00:00

463 lines
11 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
* 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. 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.
*
* @(#)umap_vfsops.c 8.8 (Berkeley) 5/14/95
*
* $FreeBSD$
*/
/*
* Umap Layer
* (See mount_umap(8) for a description of this layer.)
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <miscfs/umapfs/umap.h>
static MALLOC_DEFINE(M_UMAPFSMNT, "UMAP mount", "UMAP mount structure");
static int umapfs_fhtovp __P((struct mount *mp, struct fid *fidp,
struct vnode **vpp));
static int umapfs_checkexp __P((struct mount *mp, struct sockaddr *nam,
int *extflagsp, struct ucred **credanonp));
static int umapfs_mount __P((struct mount *mp, char *path, caddr_t data,
struct nameidata *ndp, struct proc *p));
static int umapfs_quotactl __P((struct mount *mp, int cmd, uid_t uid,
caddr_t arg, struct proc *p));
static int umapfs_root __P((struct mount *mp, struct vnode **vpp));
static int umapfs_start __P((struct mount *mp, int flags, struct proc *p));
static int umapfs_statfs __P((struct mount *mp, struct statfs *sbp,
struct proc *p));
static int umapfs_sync __P((struct mount *mp, int waitfor,
struct ucred *cred, struct proc *p));
static int umapfs_unmount __P((struct mount *mp, int mntflags,
struct proc *p));
static int umapfs_vget __P((struct mount *mp, ino_t ino,
struct vnode **vpp));
static int umapfs_vptofh __P((struct vnode *vp, struct fid *fhp));
static int umapfs_extattrctl __P((struct mount *mp, int cmd,
const char *attrname, caddr_t arg,
struct proc *p));
/*
* Mount umap layer
*/
static int
umapfs_mount(mp, path, data, ndp, p)
struct mount *mp;
char *path;
caddr_t data;
struct nameidata *ndp;
struct proc *p;
{
struct umap_args args;
struct vnode *lowerrootvp, *vp;
struct vnode *umapm_rootvp;
struct umap_mount *amp;
u_int size;
int error;
#ifdef DEBUG
int i;
#endif
/*
* Only for root
*/
if ((error = suser(p)) != 0)
return (error);
#ifdef DEBUG
printf("umapfs_mount(mp = %p)\n", (void *)mp);
#endif
/*
* Update is a no-op
*/
if (mp->mnt_flag & MNT_UPDATE) {
return (EOPNOTSUPP);
/* return (VFS_MOUNT(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, path, data, ndp, p));*/
}
/*
* Get argument
*/
error = copyin(data, (caddr_t)&args, sizeof(struct umap_args));
if (error)
return (error);
/*
* Find lower node
*/
NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
UIO_USERSPACE, args.target, p);
error = namei(ndp);
if (error)
return (error);
NDFREE(ndp, NDF_ONLY_PNBUF);
/*
* Sanity check on lower vnode
*/
lowerrootvp = ndp->ni_vp;
#ifdef DEBUG
printf("vp = %p, check for VDIR...\n", (void *)lowerrootvp);
#endif
vrele(ndp->ni_dvp);
ndp->ni_dvp = 0;
if (lowerrootvp->v_type != VDIR) {
vput(lowerrootvp);
return (EINVAL);
}
#ifdef DEBUG
printf("mp = %p\n", (void *)mp);
#endif
amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
M_UMAPFSMNT, M_WAITOK); /* XXX */
/*
* Save reference to underlying FS
*/
amp->umapm_vfs = lowerrootvp->v_mount;
/*
* Now copy in the number of entries and maps for umap mapping.
*/
amp->info_nentries = args.nentries;
amp->info_gnentries = args.gnentries;
error = copyin(args.mapdata, (caddr_t)amp->info_mapdata,
2*sizeof(u_long)*args.nentries);
if (error)
return (error);
#ifdef DEBUG
printf("umap_mount:nentries %d\n",args.nentries);
for (i = 0; i < args.nentries; i++)
printf(" %lu maps to %lu\n", amp->info_mapdata[i][0],
amp->info_mapdata[i][1]);
#endif
error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata,
2*sizeof(u_long)*args.gnentries);
if (error)
return (error);
#ifdef DEBUG
printf("umap_mount:gnentries %d\n",args.gnentries);
for (i = 0; i < args.gnentries; i++)
printf(" group %lu maps to %lu\n",
amp->info_gmapdata[i][0],
amp->info_gmapdata[i][1]);
#endif
/*
* Save reference. Each mount also holds
* a reference on the root vnode.
*/
error = umap_node_create(mp, lowerrootvp, &vp);
/*
* Unlock the node (either the lower or the alias)
*/
VOP_UNLOCK(vp, 0, p);
/*
* Make sure the node alias worked
*/
if (error) {
vrele(lowerrootvp);
free(amp, M_UMAPFSMNT); /* XXX */
return (error);
}
/*
* Keep a held reference to the root vnode.
* It is vrele'd in umapfs_unmount.
*/
umapm_rootvp = vp;
umapm_rootvp->v_flag |= VROOT;
amp->umapm_rootvp = umapm_rootvp;
if (UMAPVPTOLOWERVP(umapm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_data = (qaddr_t) amp;
vfs_getnewfsid(mp);
(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
&size);
bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
(void)umapfs_statfs(mp, &mp->mnt_stat, p);
#ifdef DEBUG
printf("umapfs_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.
*/
static int
umapfs_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
return (0);
/* return (VFS_START(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, flags, p)); */
}
/*
* Free reference to umap layer
*/
static int
umapfs_unmount(mp, mntflags, p)
struct mount *mp;
int mntflags;
struct proc *p;
{
struct vnode *umapm_rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
int error;
int flags = 0;
#ifdef DEBUG
printf("umapfs_unmount(mp = %p)\n", (void *)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...
*/
#ifdef notyet
mntflushbuf(mp, 0);
if (mntinvalbuf(mp, 1))
return (EBUSY);
#endif
if (umapm_rootvp->v_usecount > 1)
return (EBUSY);
error = vflush(mp, umapm_rootvp, flags);
if (error)
return (error);
#ifdef DEBUG
vprint("alias root of lower", umapm_rootvp);
#endif
/*
* Release reference on underlying root vnode
*/
vrele(umapm_rootvp);
/*
* And blow it away for future re-use
*/
vgone(umapm_rootvp);
/*
* Finally, throw away the umap_mount structure
*/
free(mp->mnt_data, M_UMAPFSMNT); /* XXX */
mp->mnt_data = 0;
return (0);
}
static int
umapfs_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct proc *p = curproc; /* XXX */
struct vnode *vp;
#ifdef DEBUG
printf("umapfs_root(mp = %p, vp = %p->%p)\n",
(void *)mp, (void *)MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
(void *)UMAPVPTOLOWERVP(MOUNTTOUMAPMOUNT(mp)->umapm_rootvp));
#endif
/*
* Return locked reference to root.
*/
vp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
VREF(vp);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
*vpp = vp;
return (0);
}
static int
umapfs_quotactl(mp, cmd, uid, arg, p)
struct mount *mp;
int cmd;
uid_t uid;
caddr_t arg;
struct proc *p;
{
return (VFS_QUOTACTL(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, cmd, uid, arg, p));
}
static int
umapfs_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
int error;
struct statfs mstat;
#ifdef DEBUG
printf("umapfs_statfs(mp = %p, vp = %p->%p)\n",
(void *)mp, (void *)MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
(void *)UMAPVPTOLOWERVP(MOUNTTOUMAPMOUNT(mp)->umapm_rootvp));
#endif
bzero(&mstat, sizeof(mstat));
error = VFS_STATFS(MOUNTTOUMAPMOUNT(mp)->umapm_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);
}
static int
umapfs_sync(mp, waitfor, cred, p)
struct mount *mp;
int waitfor;
struct ucred *cred;
struct proc *p;
{
/*
* XXX - Assumes no data cached at umap layer.
*/
return (0);
}
static int
umapfs_vget(mp, ino, vpp)
struct mount *mp;
ino_t ino;
struct vnode **vpp;
{
return (VFS_VGET(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, ino, vpp));
}
static int
umapfs_fhtovp(mp, fidp, vpp)
struct mount *mp;
struct fid *fidp;
struct vnode **vpp;
{
return (VFS_FHTOVP(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, fidp, vpp));
}
static int
umapfs_checkexp(mp, nam, exflagsp, credanonp)
struct mount *mp;
struct sockaddr *nam;
int *exflagsp;
struct ucred **credanonp;
{
return (VFS_CHECKEXP(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, nam,
exflagsp, credanonp));
}
static int
umapfs_vptofh(vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
return (VFS_VPTOFH(UMAPVPTOLOWERVP(vp), fhp));
}
static int
umapfs_extattrctl(mp, cmd, attrname, arg, p)
struct mount *mp;
int cmd;
const char *attrname;
caddr_t arg;
struct proc *p;
{
return (VFS_EXTATTRCTL(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, cmd, attrname,
arg, p));
}
static struct vfsops umap_vfsops = {
umapfs_mount,
umapfs_start,
umapfs_unmount,
umapfs_root,
umapfs_quotactl,
umapfs_statfs,
umapfs_sync,
umapfs_vget,
umapfs_fhtovp,
umapfs_checkexp,
umapfs_vptofh,
umapfs_init,
vfs_stduninit,
umapfs_extattrctl,
};
VFS_SET(umap_vfsops, umap, VFCF_LOOPBACK);