freebsd-dev/sys/fs/umapfs/umap_vfsops.c
Mike Smith 34bdbbd0de The intent is to get rid of WILLRELE in vnode_if.src by making
a complement to all ops that return a vpp, VFS_VRELE.  This is
initially only for file systems that implement the following ops
that do a WILLRELE:

	vop_create, vop_whiteout, vop_mknod, vop_remove, vop_link,
	vop_rename, vop_mkdir, vop_rmdir, vop_symlink

This is initial DNA that doesn't do anything yet.  VFS_VRELE is
implemented but not called.

A default vfs_vrele was created for fs implementations that use the
standard vnode management routines.

VFS_VRELE implementations were made for the following file systems:

Standard (vfs_vrele)
	ffs mfs nfs msdosfs devfs ext2fs

Custom
	union umapfs

Just EOPNOTSUPP
	fdesc procfs kernfs portal cd9660

These implementations may change as VOP changes are implemented.

In the next phase, in the vop implementations calls to vrele and the vrele
part of vput will be moved to the top layer vfs_vnops and made visible
to all layers.  vput will be replaced by unlock in these cases.  Unlocking
will still be done in the per fs layer but the refcount decrement will be
triggered at the top because it doesn't hurt to hold a vnode reference a
little longer.  This will have minimal impact on the structure of the
existing code.

This will only be done for vnode arguments that are released by the various
fs vop implementations.

Wider use of VFS_VRELE will likely require restructuring of the code.

Reviewed by:	phk, dyson, terry et. al.
Submitted by:	Michael Hancock <michaelh@cet.co.jp>
1998-03-01 22:46:53 +00:00

448 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
*
* $Id: umap_vfsops.c,v 1.20 1998/02/07 01:34:32 kato Exp $
*/
/*
* 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/proc.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 sockaddr *nam, struct vnode **vpp,
int *exflagsp, 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_vrele __P((struct mount *mp, struct vnode *vp));
static int umapfs_vptofh __P((struct vnode *vp, struct fid *fhp));
/*
* 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 UMAP_DIAGNOSTIC
int i;
#endif
#ifdef UMAPFS_DIAGNOSTIC
printf("umapfs_mount(mp = %x)\n", 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);
/*
* Sanity check on lower vnode
*/
lowerrootvp = ndp->ni_vp;
#ifdef UMAPFS_DIAGNOSTIC
printf("vp = %x, check for VDIR...\n", lowerrootvp);
#endif
vrele(ndp->ni_dvp);
ndp->ni_dvp = 0;
if (lowerrootvp->v_type != VDIR) {
vput(lowerrootvp);
return (EINVAL);
}
#ifdef UMAPFS_DIAGNOSTIC
printf("mp = %x\n", 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 UMAP_DIAGNOSTIC
printf("umap_mount:nentries %d\n",args.nentries);
for (i = 0; i < args.nentries; i++)
printf(" %d maps to %d\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 UMAP_DIAGNOSTIC
printf("umap_mount:gnentries %d\n",args.gnentries);
for (i = 0; i < args.gnentries; i++)
printf(" group %d maps to %d\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(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)umapfs_statfs(mp, &mp->mnt_stat, p);
#ifdef UMAPFS_DIAGNOSTIC
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 UMAPFS_DIAGNOSTIC
printf("umapfs_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...
*/
#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 UMAPFS_DIAGNOSTIC
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 UMAPFS_DIAGNOSTIC
printf("umapfs_root(mp = %x, vp = %x->%x)\n", mp,
MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
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 UMAPFS_DIAGNOSTIC
printf("umapfs_statfs(mp = %x, vp = %x->%x)\n", mp,
MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
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));
}
/*
* Complement to all vpp returning ops.
* XXX - initially only to get rid of WILLRELE.
*/
/* ARGSUSED */
static int
umapfs_vrele(mp, vp)
struct mount *mp;
struct vnode *vp;
{
vrele(vp);
return (0);
}
static int
umapfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
struct mount *mp;
struct fid *fidp;
struct sockaddr *nam;
struct vnode **vpp;
int *exflagsp;
struct ucred**credanonp;
{
return (VFS_FHTOVP(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, fidp, nam, vpp, exflagsp,credanonp));
}
static int
umapfs_vptofh(vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
return (VFS_VPTOFH(UMAPVPTOLOWERVP(vp), fhp));
}
static struct vfsops umap_vfsops = {
umapfs_mount,
umapfs_start,
umapfs_unmount,
umapfs_root,
umapfs_quotactl,
umapfs_statfs,
umapfs_sync,
umapfs_vget,
umapfs_vrele,
umapfs_fhtovp,
umapfs_vptofh,
umapfs_init,
};
VFS_SET(umap_vfsops, umap, MOUNT_UMAP, VFCF_LOOPBACK);