cd9660_node.c

早期freebsd实现

/*-
 * Copyright (c) 1982, 1986, 1989, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley
 * by Pace Willisson ([e-mail]).  The Rock Ridge Extension
 * Support code is derived from software contributed to Berkeley
 * by Atsushi Murai ([e-mail]).
 *
 * 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_node.c	8.2 (Berkeley) 1/23/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/buf.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/stat.h>

#include <isofs/cd9660/iso.h>
#include <isofs/cd9660/cd9660_node.h>
#include <isofs/cd9660/iso_rrip.h>

#define	INOHSZ	512
#if	((INOHSZ&(INOHSZ-1)) == 0)
#define	INOHASH(dev,ino)	(((dev)+((ino)>>12))&(INOHSZ-1))
#else
#define	INOHASH(dev,ino)	(((unsigned)((dev)+((ino)>>12)))%INOHSZ)
#endif

union iso_ihead {
	union  iso_ihead *ih_head[2];
	struct iso_node *ih_chain[2];
} iso_ihead[INOHSZ];

#ifdef	ISODEVMAP
#define	DNOHSZ	64
#if	((DNOHSZ&(DNOHSZ-1)) == 0)
#define	DNOHASH(dev,ino)	(((dev)+((ino)>>12))&(DNOHSZ-1))
#else
#define	DNOHASH(dev,ino)	(((unsigned)((dev)+((ino)>>12)))%DNOHSZ)
#endif

union iso_dhead {
	union  iso_dhead  *dh_head[2];
	struct iso_dnode *dh_chain[2];
} iso_dhead[DNOHSZ];
#endif

int prtactive;	/* 1 => print out reclaim of active vnodes */

/*
 * Initialize hash links for inodes and dnodes.
 */
cd9660_init()
{
	register int i;
	register union iso_ihead *ih = iso_ihead;
#ifdef	ISODEVMAP
	register union iso_dhead *dh = iso_dhead;
#endif

	for (i = INOHSZ; --i >= 0; ih++) {
		ih->ih_head[0] = ih;
		ih->ih_head[1] = ih;
	}
#ifdef	ISODEVMAP
	for (i = DNOHSZ; --i >= 0; dh++) {
		dh->dh_head[0] = dh;
		dh->dh_head[1] = dh;
	}
#endif
}

#ifdef	ISODEVMAP
/*
 * Enter a new node into the device hash list
 */
struct iso_dnode *
iso_dmap(dev,ino,create)
	dev_t	dev;
	ino_t	ino;
	int	create;
{
	struct iso_dnode *dp;
	union iso_dhead *dh;
	
	dh = &iso_dhead[DNOHASH(dev, ino)];
	for (dp = dh->dh_chain[0];
	     dp != (struct iso_dnode *)dh;
	     dp = dp->d_forw)
		if (ino == dp->i_number && dev == dp->i_dev)
			return dp;

	if (!create)
		return (struct iso_dnode *)0;

	MALLOC(dp,struct iso_dnode *,sizeof(struct iso_dnode),M_CACHE,M_WAITOK);
	dp->i_dev = dev;
	dp->i_number = ino;
	insque(dp,dh);
	
	return dp;
}

void
iso_dunmap(dev)
	dev_t	dev;
{
	struct iso_dnode *dp, *dq;
	union iso_dhead *dh;
	
	for (dh = iso_dhead; dh < iso_dhead + DNOHSZ; dh++) {
		for (dp = dh->dh_chain[0];
		     dp != (struct iso_dnode *)dh;
		     dp = dq) {
			dq = dp->d_forw;
			if (dev == dp->i_dev) {
				remque(dp);
				FREE(dp,M_CACHE);
			}
		}
	}
}
#endif

/*
 * Look up a ISOFS dinode number to find its incore vnode.
 * If it is not in core, read it in from the specified device.
 * If it is in core, wait for the lock bit to clear, then
 * return the inode locked. Detection and handling of mount
 * points must be done by the calling routine.
 */
iso_iget(xp, ino, relocated, ipp, isodir)
	struct iso_node *xp;
	ino_t ino;
	struct iso_node **ipp;
	struct iso_directory_record *isodir;
{
	dev_t dev = xp->i_dev;
	struct mount *mntp = ITOV(xp)->v_mount;
	register struct iso_node *ip, *iq;
	register struct vnode *vp;
	register struct iso_dnode *dp;
	struct vnode *nvp;
	struct buf *bp = NULL, *bp2 = NULL;
	union iso_ihead *ih;
	union iso_dhead *dh;
	int i, error, result;
	struct iso_mnt *imp;
	ino_t defino;
	
	ih = &iso_ihead[INOHASH(dev, ino)];
loop:
	for (ip = ih->ih_chain[0];
	     ip != (struct iso_node *)ih;
	     ip = ip->i_forw) {
		if (ino != ip->i_number || dev != ip->i_dev)
			continue;
		if ((ip->i_flag&ILOCKED) != 0) {
			ip->i_flag |= IWANT;
			sleep((caddr_t)ip, PINOD);
			goto loop;
		}
		if (vget(ITOV(ip), 1))
			goto loop;
		*ipp = ip;
		return 0;
	}
	/*
	 * Allocate a new vnode/iso_node.
	 */
	if (error = getnewvnode(VT_ISOFS, mntp, cd9660_vnodeop_p, &nvp)) {
		*ipp = 0;
		return error;
	}
	MALLOC(ip, struct iso_node *, sizeof(struct iso_node),
	       M_ISOFSNODE, M_WAITOK);
	bzero((caddr_t)ip, sizeof(struct iso_node));
	nvp->v_data = ip;
	ip->i_vnode = nvp;
	ip->i_flag = 0;
	ip->i_devvp = 0;
	ip->i_diroff = 0;
	ip->i_lockf = 0;
	
	/*
	 * Put it onto its hash chain and lock it so that other requests for
	 * this inode will block if they arrive while we are sleeping waiting
	 * for old data structures to be purged or for the contents of the
	 * disk portion of this inode to be read.
	 */
	ip->i_dev = dev;
	ip->i_number = ino;
	insque(ip, ih);
	ISO_ILOCK(ip);

	imp = VFSTOISOFS (mntp);
	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 (error = iso_blkatoff(ip,0,&bp)) {
			vrele(ip->i_devvp);
			remque(ip);
			ip->i_forw = ip;
			ip->i_back = ip;
			iso_iput(ip);
			*ipp = 0;
			return error;
		}
		isodir = (struct iso_directory_record *)bp->b_un.b_addr;
	}
	
	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;
	
	vp = ITOV(ip);
	
	/*
	 * Setup time stamp, attribute
	 */
	vp->v_type = VNON;
	switch (imp->iso_ftype) {
	default:	/* ISO_FTYPE_9660 */
		if ((imp->im_flags&ISOFSMNT_EXTATT)
		    && isonum_711(isodir->ext_attr_length))
			iso_blkatoff(ip,-isonum_711(isodir->ext_attr_length),
				     &bp2);
		cd9660_defattr(isodir,ip,bp2 );
		cd9660_deftstamp(isodir,ip,bp2 );
		break;
	case ISO_FTYPE_RRIP:
		result = cd9660_rrip_analyze(isodir,ip,imp);
		break;
	}
	if (bp2)
		brelse(bp2);
	if (bp)
		brelse(bp);
	
	/*
	 * Initialize the associated vnode
	 */
	vp->v_type = IFTOVT(ip->inode.iso_mode);
	
	if ( vp->v_type == VFIFO ) {
#ifdef	FIFO
		extern int (**cd9660_fifoop_p)();
		vp->v_op = cd9660_fifoop_p;
#else
		iso_iput(ip);
		*ipp = 0;
		return EOPNOTSUPP;
#endif	/* FIFO */
	} else if ( vp->v_type == VCHR || vp->v_type == VBLK ) {
		extern int (**cd9660_specop_p)();

		/*
		 * if device, look at device number table for translation
		 */
#ifdef	ISODEVMAP
		if (dp = iso_dmap(dev,ino,0))
			ip->inode.iso_rdev = dp->d_dev;
#endif
		vp->v_op = cd9660_specop_p;
		if (nvp = checkalias(vp, ip->inode.iso_rdev, mntp)) {
			/*
			 * Reinitialize aliased inode.
			 */
			vp = nvp;
			iq = VTOI(vp);
			iq->i_vnode = vp;
			iq->i_flag = 0;
			ISO_ILOCK(iq);
			iq->i_dev = dev;
			iq->i_number = ino;
			iq->i_mnt = ip->i_mnt;
			bcopy(&ip->iso_extent,&iq->iso_extent,
			      (char *)(ip + 1) - (char *)&ip->iso_extent);
			insque(iq, ih);
			/*
			 * Discard unneeded vnode
			 * (This introduces the need of INACTIVE modification)
			 */
			ip->inode.iso_mode = 0;