File:  [DragonFly] / src / sys / vfs / isofs / cd9660 / cd9660_vfsops.c
Revision 1.46: download - view: text, annotated - select for diffs
Wed Sep 17 21:44:23 2008 UTC (5 years, 11 months ago) by dillon
Branches: MAIN
CVS tags: HEAD
* Implement the ability to export NULLFS mounts via NFS.

* Enforce PFS isolation when exporting a HAMMER PFS via a NULLFS mount.

NOTE: Exporting anything other then HAMMER PFS root's via nullfs does
NOT protect the parent of the exported directory from being accessed via NFS.

Generally speaking this feature is implemented by giving each nullfs mount
a synthesized fsid based on what is being mounted and implementing the
NFS export infrastructure in the nullfs code instead of just bypassing those
functions to the underyling VFS.

/*-
 * Copyright (c) 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley
 * by Pace Willisson (pace@blitz.com).  The Rock Ridge Extension
 * Support code is derived from software contributed to Berkeley
 * by Atsushi Murai (amurai@spec.co.jp).
 *
 * 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.
 *
 *	@(#)cd9660_vfsops.c	8.18 (Berkeley) 5/22/95
 * $FreeBSD: src/sys/isofs/cd9660/cd9660_vfsops.c,v 1.74.2.7 2002/04/08 09:39:29 bde Exp $
 * $DragonFly: src/sys/vfs/isofs/cd9660/cd9660_vfsops.c,v 1.46 2008/09/17 21:44:23 dillon Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/nlookup.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/buf.h>
#include <sys/cdio.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/malloc.h>
#include <sys/stat.h>
#include <sys/syslog.h>

#include <vm/vm_zone.h>

#include "iso.h"
#include "iso_rrip.h"
#include "cd9660_node.h"
#include "cd9660_mount.h"

extern struct vop_ops cd9660_vnode_vops;
extern struct vop_ops cd9660_spec_vops;
extern struct vop_ops cd9660_fifo_vops;

MALLOC_DEFINE(M_ISOFSMNT, "ISOFS mount", "ISOFS mount structure");
MALLOC_DEFINE(M_ISOFSNODE, "ISOFS node", "ISOFS vnode private part");

static int cd9660_mount (struct mount *, char *, caddr_t, struct ucred *);
static int cd9660_unmount (struct mount *, int);
static int cd9660_root (struct mount *, struct vnode **);
static int cd9660_statfs (struct mount *, struct statfs *, struct ucred *);
static int cd9660_vget (struct mount *, ino_t, struct vnode **);
static int cd9660_fhtovp (struct mount *, struct vnode *rootvp,
				struct fid *, struct vnode **);
static int cd9660_checkexp (struct mount *, struct sockaddr *,
	    int *, struct ucred **);
static int cd9660_vptofh (struct vnode *, struct fid *);

static struct vfsops cd9660_vfsops = {
	.vfs_mount =    	cd9660_mount,
	.vfs_unmount =  	cd9660_unmount,
	.vfs_root =      	cd9660_root,
	.vfs_statfs =   	cd9660_statfs,
	.vfs_sync =     	vfs_stdsync,
	.vfs_vget =     	cd9660_vget,
	.vfs_fhtovp =   	cd9660_fhtovp,
	.vfs_checkexp =  	cd9660_checkexp,
	.vfs_vptofh =   	cd9660_vptofh,
	.vfs_init =     	cd9660_init,
	.vfs_uninit =    	cd9660_uninit,
};
VFS_SET(cd9660_vfsops, cd9660, VFCF_READONLY);
MODULE_VERSION(cd9660, 1);


/*
 * Called by vfs_mountroot when iso is going to be mounted as root.
 */

static int iso_get_ssector (cdev_t dev);
static int iso_mountfs (struct vnode *devvp, struct mount *mp,
			    struct iso_args *argp);

/*
 * Try to find the start of the last data track on this CD-ROM.  This
 * is used to mount the last session of a multi-session CD.  Bail out
 * and return 0 if we fail, this is always a safe bet.
 */
static int
iso_get_ssector(cdev_t dev)
{
	struct ioc_toc_header h;
	struct ioc_read_toc_single_entry t;
	int i;

	if (dev_dioctl(dev, CDIOREADTOCHEADER, (caddr_t)&h, FREAD, proc0.p_ucred) != 0)
		return 0;

	for (i = h.ending_track; i >= 0; i--) {
		t.address_format = CD_LBA_FORMAT;
		t.track = i;
		if (dev_dioctl(dev, CDIOREADTOCENTRY, (caddr_t)&t, FREAD, proc0.p_ucred) != 0) {
			return 0;
		}
		if ((t.entry.control & 4) != 0)
			/* found a data track */
			break;
	}

	if (i < 0)
		return 0;

	return ntohl(t.entry.addr.lba);
}

static int
iso_mountroot(struct mount *mp)
{
	struct iso_args args;
	struct vnode *rootvp;
	int error;

	if ((error = bdevvp(rootdev, &rootvp))) {
		kprintf("iso_mountroot: can't find rootvp\n");
		return (error);
	}
	args.flags = ISOFSMNT_ROOT;

	vn_lock(rootvp, LK_EXCLUSIVE | LK_RETRY);
	error = VOP_OPEN(rootvp, FREAD, FSCRED, NULL);
	vn_unlock(rootvp);
	if (error)
		return (error);

	args.ssector = iso_get_ssector(rootdev);

	VOP_CLOSE(rootvp, FREAD);

	if (bootverbose)
		kprintf("iso_mountroot(): using session at block %d\n",
		       args.ssector);
	if ((error = iso_mountfs(rootvp, mp, &args)) != 0)
		return (error);

	cd9660_statfs(mp, &mp->mnt_stat, proc0.p_ucred);
	return (0);
}

/*
 * VFS Operations.
 *
 * mount system call
 */
static int
cd9660_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
{
	struct vnode *devvp;
	struct iso_args args;
	size_t size;
	int error;
	mode_t accessmode;
	struct iso_mnt *imp = 0;
	struct nlookupdata nd;

	if ((mp->mnt_flag & (MNT_ROOTFS|MNT_UPDATE)) == MNT_ROOTFS) {
		return (iso_mountroot(mp));
	}
	if ((error = copyin(data, (caddr_t)&args, sizeof (struct iso_args))))
		return (error);

	if ((mp->mnt_flag & MNT_RDONLY) == 0)
		return (EROFS);

	/*
	 * If updating, check whether changing from read-only to
	 * read/write; if there is no device name, that's all we do.
	 */
	if (mp->mnt_flag & MNT_UPDATE) {
		imp = VFSTOISOFS(mp);
		if (args.fspec == 0)
			return (vfs_export(mp, &imp->im_export, &args.export));
	}
	/*
	 * Not an update, or updating the name: look up the name
	 * and verify that it refers to a sensible block device.
	 */
	devvp = NULL;
	error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
	if (error == 0)
		error = nlookup(&nd);
	if (error == 0)
		error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
	nlookup_done(&nd);
	if (error)
		return (error);

	if (!vn_isdisk(devvp, &error)) {
		vrele(devvp);
		return (error);
	}

	/*       
	 * Verify that user has necessary permissions on the device,
	 * or has superuser abilities
	 */
	accessmode = VREAD;
	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
	error = VOP_ACCESS(devvp, accessmode, cred);
	if (error) 
		error = suser_cred(cred, 0);
	if (error) {
		vput(devvp);
		return (error);
	}
	vn_unlock(devvp);

	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
		error = iso_mountfs(devvp, mp, &args);
	} else {
		if (devvp != imp->im_devvp)
			error = EINVAL;	/* needs translation */
		else
			vrele(devvp);
	}
	if (error) {
		vrele(devvp);
		return error;
	}
	imp = VFSTOISOFS(mp);
	copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
	    &size);
	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
	cd9660_statfs(mp, &mp->mnt_stat, cred);
	return 0;
}

/*
 * Common code for mount and mountroot
 */
static int
iso_mountfs(struct vnode *devvp, struct mount *mp, struct iso_args *argp)
{
	struct iso_mnt *isomp = NULL;
	struct buf *bp = NULL;
	struct buf *pribp = NULL, *supbp = NULL;
	cdev_t dev;
	int error = EINVAL;
	int needclose = 0;
	int high_sierra = 0;
	int iso_bsize;
	int iso_blknum;
	int joliet_level;
	struct iso_volume_descriptor *vdp = 0;
	struct iso_primary_descriptor *pri = NULL;
	struct iso_sierra_primary_descriptor *pri_sierra = NULL;
	struct iso_supplementary_descriptor *sup = NULL;
	struct iso_directory_record *rootp;
	int logical_block_size;

	if (!(mp->mnt_flag & MNT_RDONLY))
		return EROFS;

	/*
	 * Disallow multiple mounts of the same device.
	 * Disallow mounting of a device that is currently in use
	 * Flush out any old buffers remaining from a previous use.
	 */
	if ((error = vfs_mountedon(devvp)))
		return error;
	if (count_udev(devvp->v_umajor, devvp->v_uminor) > 0)
		return EBUSY;
	if ((error = vinvalbuf(devvp, V_SAVE, 0, 0)))
		return (error);

	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
	error = VOP_OPEN(devvp, FREAD, FSCRED, NULL);
	vn_unlock(devvp);
	if (error)
		return error;
	dev = devvp->v_rdev;
	if (dev->si_iosize_max != 0)
		mp->mnt_iosize_max = dev->si_iosize_max;
	if (mp->mnt_iosize_max > MAXPHYS)
		mp->mnt_iosize_max = MAXPHYS;

	needclose = 1;

	/* This is the "logical sector size".  The standard says this
	 * should be 2048 or the physical sector size on the device,
	 * whichever is greater.  For now, we'll just use a constant.
	 */
	iso_bsize = ISO_DEFAULT_BLOCK_SIZE;

	joliet_level = 0;
	for (iso_blknum = 16 + argp->ssector;
	     iso_blknum < 100 + argp->ssector;
	     iso_blknum++) {
		if ((error = bread(devvp, (off_t)iso_blknum * iso_bsize,
				  iso_bsize, &bp)) != 0)
			goto out;
		
		vdp = (struct iso_volume_descriptor *)bp->b_data;
		if (bcmp (vdp->id, ISO_STANDARD_ID, sizeof vdp->id) != 0) {
			if (bcmp (vdp->id_sierra, ISO_SIERRA_ID,
				  sizeof vdp->id) != 0) {
				error = EINVAL;
				goto out;
			} else
				high_sierra = 1;
		}
		switch (isonum_711 (high_sierra? vdp->type_sierra: vdp->type)){
		case ISO_VD_PRIMARY:
			if (pribp == NULL) {
				pribp = bp;
				bp = NULL;
				pri = (struct iso_primary_descriptor *)vdp;
				pri_sierra =
				  (struct iso_sierra_primary_descriptor *)vdp;
			}
			break;

		case ISO_VD_SUPPLEMENTARY:
			if (supbp == NULL) {
				supbp = bp;
				bp = NULL;
				sup = (struct iso_supplementary_descriptor *)vdp;

				if (!(argp->flags & ISOFSMNT_NOJOLIET)) {
					if (bcmp(sup->escape, "%/@", 3) == 0)
						joliet_level = 1;
					if (bcmp(sup->escape, "%/C", 3) == 0)
						joliet_level = 2;
					if (bcmp(sup->escape, "%/E", 3) == 0)
						joliet_level = 3;

					if ((isonum_711 (sup->flags) & 1) &&
					    (argp->flags & ISOFSMNT_BROKENJOLIET) == 0)
						joliet_level = 0;
				}
			}
			break;

		case ISO_VD_END:
			goto vd_end;

		default:
			break;
		}
		if (bp) {
			brelse(bp);
			bp = NULL;
		}
	}
 vd_end:
	if (bp) {
		brelse(bp);
		bp = NULL;
	}

	if (pri == NULL) {
		error = EINVAL;
		goto out;
	}

	logical_block_size =
		isonum_723 (high_sierra?
			    pri_sierra->logical_block_size:
			    pri->logical_block_size);

	if (logical_block_size < DEV_BSIZE || logical_block_size > MAXBSIZE
	    || (logical_block_size & (logical_block_size - 1)) != 0) {
		error = EINVAL;
		goto out;
	}

	rootp = (struct iso_directory_record *)
		(high_sierra?
		 pri_sierra->root_directory_record:
		 pri->root_directory_record);

	isomp = kmalloc(sizeof *isomp, M_ISOFSMNT, M_WAITOK | M_ZERO);
	isomp->logical_block_size = logical_block_size;
	isomp->volume_space_size =
		isonum_733 (high_sierra?
			    pri_sierra->volume_space_size:
			    pri->volume_space_size);
	isomp->joliet_level = 0;
	/*
	 * Since an ISO9660 multi-session CD can also access previous
	 * sessions, we have to include them into the space consider-
	 * ations.  This doesn't yield a very accurate number since
	 * parts of the old sessions might be inaccessible now, but we
	 * can't do much better.  This is also important for the NFS
	 * filehandle validation.
	 */
	isomp->volume_space_size += argp->ssector;
	bcopy (rootp, isomp->root, sizeof isomp->root);
	isomp->root_extent = isonum_733 (rootp->extent);
	isomp->root_size = isonum_733 (rootp->size);

	isomp->im_bmask = logical_block_size - 1;
	isomp->im_bshift = ffs(logical_block_size) - 1;

	pribp->b_flags |= B_AGE;
	brelse(pribp);
	pribp = NULL;

	mp->mnt_data = (qaddr_t)isomp;
	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
	mp->mnt_maxsymlinklen = 0;
	mp->mnt_flag |= MNT_LOCAL;
	isomp->im_mountp = mp;
	isomp->im_dev = dev;
	isomp->im_devvp = devvp;

	dev->si_mountpoint = mp;

	/* Check the Rock Ridge Extention support */
	if (!(argp->flags & ISOFSMNT_NORRIP)) {
		if ((error = bread(isomp->im_devvp,
				  lblktooff(isomp, isomp->root_extent + isonum_711(rootp->ext_attr_length)),
				  isomp->logical_block_size, &bp)) != 0)
		    goto out;
		
		rootp = (struct iso_directory_record *)bp->b_data;
		
		if ((isomp->rr_skip = cd9660_rrip_offset(rootp,isomp)) < 0) {
		    argp->flags	 |= ISOFSMNT_NORRIP;
		} else {
		    argp->flags	 &= ~ISOFSMNT_GENS;
		}

		/*
		 * The contents are valid,
		 * but they will get reread as part of another vnode, so...
		 */
		bp->b_flags |= B_AGE;
		brelse(bp);
		bp = NULL;
	}
	isomp->im_flags = argp->flags & (ISOFSMNT_NORRIP | ISOFSMNT_GENS |
					 ISOFSMNT_EXTATT | ISOFSMNT_NOJOLIET);

	if (high_sierra) {
		/* this effectively ignores all the mount flags */
		log(LOG_INFO, "cd9660: High Sierra Format\n");
		isomp->iso_ftype = ISO_FTYPE_HIGH_SIERRA;
	} else {
		switch (isomp->im_flags&(ISOFSMNT_NORRIP|ISOFSMNT_GENS)) {
		  default:
			  isomp->iso_ftype = ISO_FTYPE_DEFAULT;
			  break;
		  case ISOFSMNT_GENS|ISOFSMNT_NORRIP:
			  isomp->iso_ftype = ISO_FTYPE_9660;
			  break;
		  case 0:
			  log(LOG_INFO, "cd9660: RockRidge Extension\n");
			  isomp->iso_ftype = ISO_FTYPE_RRIP;
			  break;
		}
	}

	/* Decide whether to use the Joliet descriptor */

	if (isomp->iso_ftype != ISO_FTYPE_RRIP && joliet_level) {
		log(LOG_INFO, "cd9660: Joliet Extension (Level %d)\n", joliet_level);
		rootp = (struct iso_directory_record *)
			sup->root_directory_record;
		bcopy (rootp, isomp->root, sizeof isomp->root);
		isomp->root_extent = isonum_733 (rootp->extent);
		isomp->root_size = isonum_733 (rootp->size);
		isomp->joliet_level = joliet_level;
		supbp->b_flags |= B_AGE;
	}

	if (supbp) {
		brelse(supbp);
		supbp = NULL;
	}

	vfs_add_vnodeops(mp, &cd9660_vnode_vops, &mp->mnt_vn_norm_ops);
	vfs_add_vnodeops(mp, &cd9660_spec_vops, &mp->mnt_vn_spec_ops);
	vfs_add_vnodeops(mp, &cd9660_fifo_vops, &mp->mnt_vn_fifo_ops);

	return 0;
out:
	dev->si_mountpoint = NULL;
	if (bp)
		brelse(bp);
	if (pribp)
		brelse(pribp);
	if (supbp)
		brelse(supbp);
	if (needclose)
		VOP_CLOSE(devvp, FREAD);
	if (isomp) {
		kfree((caddr_t)isomp, M_ISOFSMNT);
		mp->mnt_data = (qaddr_t)0;
	}
	return error;
}

/*
 * unmount system call
 */
static int
cd9660_unmount(struct mount *mp, int mntflags)
{
	struct iso_mnt *isomp;
	int error, flags = 0;

	if (mntflags & MNT_FORCE)
		flags |= FORCECLOSE;
#if 0
	mntflushbuf(mp, 0);
	if (mntinvalbuf(mp))
		return EBUSY;
#endif
	if ((error = vflush(mp, 0, flags)))
		return (error);

	isomp = VFSTOISOFS(mp);

	isomp->im_devvp->v_rdev->si_mountpoint = NULL;
	error = VOP_CLOSE(isomp->im_devvp, FREAD);
	vrele(isomp->im_devvp);
	kfree((caddr_t)isomp, M_ISOFSMNT);
	mp->mnt_data = (qaddr_t)0;
	mp->mnt_flag &= ~MNT_LOCAL;
	return (error);
}

/*
 * Return root of a filesystem
 */
static int
cd9660_root(struct mount *mp, struct vnode **vpp)
{
	struct iso_mnt *imp = VFSTOISOFS(mp);
	struct iso_directory_record *dp =
	    (struct iso_directory_record *)imp->root;
	ino_t ino = isodirino(dp, imp);
	
	/*
	 * With RRIP we must use the `.' entry of the root directory.
	 * Simply tell vget, that it's a relocated directory.
	 */
	return (cd9660_vget_internal(mp, ino, vpp,
	    imp->iso_ftype == ISO_FTYPE_RRIP, dp));
}

/*
 * Get file system statistics.
 */
int
cd9660_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
{
	struct iso_mnt *isomp;

	isomp = VFSTOISOFS(mp);

	sbp->f_bsize = isomp->logical_block_size;
	sbp->f_iosize = sbp->f_bsize;	/* XXX */
	sbp->f_blocks = isomp->volume_space_size;
	sbp->f_bfree = 0; /* total free blocks */
	sbp->f_bavail = 0; /* blocks free for non superuser */
	sbp->f_files =	0; /* total files */
	sbp->f_ffree = 0; /* free file nodes */
	if (sbp != &mp->mnt_stat) {
		sbp->f_type = mp->mnt_vfc->vfc_typenum;
		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
	}
	return 0;
}

/*
 * File handle to vnode
 *
 * Have to be really careful about stale file handles:
 * - check that the inode number is in range
 * - call iget() to get the locked inode
 * - check for an unallocated inode (i_mode == 0)
 * - check that the generation number matches
 */

struct ifid {
	ushort	ifid_len;
	ushort	ifid_pad;
	int	ifid_ino;
	long	ifid_start;
};

/* ARGSUSED */
int
cd9660_fhtovp(struct mount *mp, struct vnode *rootvp,
	      struct fid *fhp, struct vnode **vpp)
{
	struct ifid *ifhp = (struct ifid *)fhp;
	struct iso_node *ip;
	struct vnode *nvp;
	int error;
	
#ifdef	ISOFS_DBG
	kprintf("fhtovp: ino %d, start %ld\n",
	       ifhp->ifid_ino, ifhp->ifid_start);
#endif
	
	if ((error = VFS_VGET(mp, ifhp->ifid_ino, &nvp)) != 0) {
		*vpp = NULLVP;
		return (error);
	}
	ip = VTOI(nvp);
	if (ip->inode.iso_mode == 0) {
		vput(nvp);
		*vpp = NULLVP;
		return (ESTALE);
	}
	*vpp = nvp;
	return (0);
}

int
cd9660_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp,
		struct ucred **credanonp)
{
	struct netcred *np;
	struct iso_mnt *imp;

	imp = VFSTOISOFS(mp);	

	/*
	 * Get the export permission structure for this <mp, client> tuple.
	 */
	np = vfs_export_lookup(mp, &imp->im_export, nam);
	if (np == NULL)
		return (EACCES);

	*exflagsp = np->netc_exflags;
	*credanonp = &np->netc_anon;
	return (0);
}

int
cd9660_vget(struct mount *mp, ino_t ino, struct vnode **vpp)
{

	/*
	 * XXXX
	 * It would be nice if we didn't always set the `relocated' flag
	 * and force the extra read, but I don't want to think about fixing
	 * that right now.
	 */
	return (cd9660_vget_internal(mp, ino, vpp,
#if 0
	    VFSTOISOFS(mp)->iso_ftype == ISO_FTYPE_RRIP,
#else
	    0,
#endif
	    (struct iso_directory_record *)0));
}

int
cd9660_vget_internal(struct mount *mp, ino_t ino, struct vnode **vpp,
		     int relocated, struct iso_directory_record *isodir)
{
	struct iso_mnt *imp;
	struct iso_node *ip;
	struct buf *bp;
	struct vnode *vp;
	cdev_t dev;
	int error;

	imp = VFSTOISOFS(mp);
	dev = imp->im_dev;
again:
	if ((*vpp = cd9660_ihashget(dev, ino)) != NULLVP)
		return (0);

	/* Allocate a new vnode/iso_node. */
	error = getnewvnode(VT_ISOFS, mp, &vp, 0, 0);
	if (error) {
		*vpp = NULLVP;
		return (error);
	}
	MALLOC(ip, struct iso_node *, sizeof(struct iso_node), M_ISOFSNODE,
	    M_WAITOK | M_ZERO);
	ip->i_vnode = vp;
	ip->i_dev = dev;
	ip->i_number = ino;

	/*
	 * Insert it into the inode hash table and check for a collision.
	 * If a collision occurs, throw away the vnode and try again.
	 */
	if (cd9660_ihashins(ip) != 0) {
		kprintf("debug: cd9660 ihashins collision, retrying\n");
		vx_put(vp);
		kfree(ip, M_ISOFSNODE);
		goto again;
	}
	vp->v_data = ip;

	if (isodir == NULL) {
		int lbn, off;

		lbn = lblkno(imp, ino);
		if (lbn >= imp->volume_space_size) {
			vx_put(vp);
			kprintf("fhtovp: lbn exceed volume space %d\n", lbn);
			return (ESTALE);
		}
	
		off = blkoff(imp, ino);
		if (off + ISO_DIRECTORY_RECORD_SIZE > imp->logical_block_size) {
			vx_put(vp);
			kprintf("fhtovp: crosses block boundary %d\n",
			       off + ISO_DIRECTORY_RECORD_SIZE);
			return (ESTALE);
		}
	
		error = bread(imp->im_devvp,
			      lblktooff(imp, lbn),
			      imp->logical_block_size, &bp);
		if (error) {
			vx_put(vp);
			brelse(bp);
			kprintf("fhtovp: bread error %d\n",error);
			return (error);
		}
		isodir = (struct iso_directory_record *)(bp->b_data + off);

		if (off + isonum_711(isodir->length) >
		    imp->logical_block_size) {
			vx_put(vp);
			if (bp != NULL)
				brelse(bp);
			kprintf("fhtovp: directory crosses block boundary %d[off=%d/len=%d]\n",
			       off +isonum_711(isodir->length), off,
			       isonum_711(isodir->length));
			return (ESTALE);
		}
	
#if 0
		if (isonum_733(isodir->extent) +
		    isonum_711(isodir->ext_attr_length) != ifhp->ifid_start) {
			if (bp != NULL)
				brelse(bp);
			kprintf("fhtovp: file start miss %d vs %d\n",
			       isonum_733(isodir->extent) + isonum_711(isodir->ext_attr_length),
			       ifhp->ifid_start);
			return (ESTALE);
		}
#endif
	} else
		bp = 0;

	ip->i_mnt = imp;
	ip->i_devvp = imp->im_devvp;
	vref(ip->i_devvp);

	if (relocated) {
		/*
		 * On relocated directories we must
		 * read the `.' entry out of a dir.
		 */
		ip->iso_start = ino >> imp->im_bshift;
		if (bp != NULL)
			brelse(bp);
		if ((error = cd9660_devblkatoff(vp, (off_t)0, NULL, &bp)) != 0) {
			vx_put(vp);
			return (error);
		}
		isodir = (struct iso_directory_record *)bp->b_data;
	}

	ip->iso_extent = isonum_733(isodir->extent);
	ip->i_size = isonum_733(isodir->size);
	ip->iso_start = isonum_711(isodir->ext_attr_length) + ip->iso_extent;

	/*
	 * Setup time stamp, attribute
	 */
	vp->v_type = VNON;
	switch (imp->iso_ftype) {
	default:	/* ISO_FTYPE_9660 */
	    {
		struct buf *bp2;
		int off;
		if ((imp->im_flags & ISOFSMNT_EXTATT)
		    && (off = isonum_711(isodir->ext_attr_length)))
			cd9660_devblkatoff(vp, (off_t)-(off << imp->im_bshift), NULL,
				     &bp2);
		else
			bp2 = NULL;
		cd9660_defattr(isodir, ip, bp2, ISO_FTYPE_9660);
		cd9660_deftstamp(isodir, ip, bp2, ISO_FTYPE_9660);
		if (bp2)
			brelse(bp2);
		break;
	    }
	case ISO_FTYPE_RRIP:
		cd9660_rrip_analyze(isodir, ip, imp);
		break;
	}

	if (bp != NULL)
		brelse(bp);

	/*
	 * Initialize the associated vnode
	 */
	vp->v_type = IFTOVT(ip->inode.iso_mode);

	switch (vp->v_type) {
	case VFIFO:
		vp->v_ops = &mp->mnt_vn_fifo_ops;
		break;
	case VCHR:
	case VBLK:
		vp->v_ops = &mp->mnt_vn_spec_ops;
		addaliasu(vp, umajor(ip->inode.iso_rdev),
			  uminor(ip->inode.iso_rdev));
		break;
	case VREG:
	case VDIR:
		vinitvmio(vp, ip->i_size);
		break;
	default:
		break;
	}
	
	if (ip->iso_extent == imp->root_extent)
		vp->v_flag |= VROOT;

	/*
	 * Return the locked and refd vp
	 */
	*vpp = vp;
	return (0);
}

/*
 * Vnode pointer to File handle
 */
/* ARGSUSED */
int
cd9660_vptofh(struct vnode *vp, struct fid *fhp)
{
	struct iso_node *ip = VTOI(vp);
	struct ifid *ifhp;

	ifhp = (struct ifid *)fhp;
	ifhp->ifid_len = sizeof(struct ifid);

	ifhp->ifid_ino = ip->i_number;
	ifhp->ifid_start = ip->iso_start;

#ifdef	ISOFS_DBG
	kprintf("vptofh: ino %d, start %ld\n",
	       ifhp->ifid_ino,ifhp->ifid_start);
#endif
	return 0;
}