[apple/xnu.git] / bsd / isofs / cd9660 / cd9660_bmap.c

/*
 * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*	$NetBSD: cd9660_bmap.c,v 1.5 1994/12/13 22:33:12 mycroft Exp $	*/

/*-
 * 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_bmap.c	8.4 (Berkeley) 12/5/94
 */

#include <sys/param.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/buf.h>
#include <sys/file.h>

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

/*
 * Bmap converts the logical block number of a file to its physical block
 * number on the disk. The conversion is done by using the logical block
 * number to index into the data block (extent) for the file.
 */
int
cd9660_bmap(ap)
	struct vop_bmap_args /* {
		struct vnode *a_vp;
		daddr_t  a_bn;
		struct vnode **a_vpp;
		daddr_t *a_bnp;
		int *a_runp;
	} */ *ap;
{
	struct iso_node *ip = VTOI(ap->a_vp);
	daddr_t lblkno = ap->a_bn;
	int bshift;

	/*
	 * Check for underlying vnode requests and ensure that logical
	 * to physical mapping is requested.
	 */
	if (ap->a_vpp != NULL)
		*ap->a_vpp = ip->i_devvp;
	if (ap->a_bnp == NULL)
		return (0);

	/*
	 * Associated files have an Apple Double header
	 */
	if ((ip->i_flag & ISO_ASSOCIATED) && (lblkno > (ADH_BLKS - 1))) {
		lblkno -= ADH_BLKS;
		*ap->a_bnp = (ip->iso_start + lblkno);
		if (ap->a_runp)
			*ap->a_runp = 0;
		return (0);
	}

	/*
	 * Compute the requested block number
	 */
	bshift = ip->i_mnt->im_bshift;
	*ap->a_bnp = (ip->iso_start + lblkno);

	/*
	 * Determine maximum number of readahead blocks following the
	 * requested block.
	 */
	if (ap->a_runp) {
		int nblk;

		nblk = (ip->i_size >> bshift) - (lblkno + 1);
		if (nblk <= 0)
			*ap->a_runp = 0;
		else if (nblk >= (MAXBSIZE >> bshift))
			*ap->a_runp = (MAXBSIZE >> bshift) - 1;
		else
			*ap->a_runp = nblk;
	}

	return (0);
}

/* blktooff converts a logical block number to a file offset */
int
cd9660_blktooff(ap)
	struct vop_blktooff_args /* {
		struct vnode *a_vp;
		daddr_t a_lblkno;
		off_t *a_offset;    
	} */ *ap;
{
	register struct iso_node *ip;
	register struct iso_mnt *imp;

	if (ap->a_vp == NULL)
		return (EINVAL);

	ip = VTOI(ap->a_vp);
	imp = ip->i_mnt;

	*ap->a_offset = (off_t)lblktosize(imp, ap->a_lblkno);
	return (0);
}

/* offtoblk converts a file offset to a logical block number */
int
cd9660_offtoblk(ap)
struct vop_offtoblk_args /* {
	struct vnode *a_vp;
	off_t a_offset;    
	daddr_t *a_lblkno;
	} */ *ap;
{
	register struct iso_node *ip;
	register struct iso_mnt *imp;

	if (ap->a_vp == NULL)
		return (EINVAL);

	ip = VTOI(ap->a_vp);
	imp = ip->i_mnt;

	*ap->a_lblkno = (daddr_t)lblkno(imp, ap->a_offset);
	return (0);
}

int
cd9660_cmap(ap)
struct vop_cmap_args /* {
	struct vnode *a_vp;
	off_t a_offset;    
	size_t a_size;
	daddr_t *a_bpn;
	size_t *a_run;
	void *a_poff;
} */ *ap;
{
	struct iso_node *ip = VTOI(ap->a_vp);
	size_t cbytes;
	int devBlockSize = 0;
	off_t offset = ap->a_foffset;

	/*
	 * Check for underlying vnode requests and ensure that logical
	 * to physical mapping is requested.
	 */
	if (ap->a_bpn == NULL)
		return (0);

	VOP_DEVBLOCKSIZE(ip->i_devvp, &devBlockSize);

	/*
	 * Associated files have an Apple Double header
	 */
	if (ip->i_flag & ISO_ASSOCIATED) {
		if (offset < ADH_SIZE) {
			if (ap->a_run)
				*ap->a_run = 0;
			*ap->a_bpn = -1;
			goto out;
		} else {
			offset -= ADH_SIZE;
		}
	}

	*ap->a_bpn = (daddr_t)(ip->iso_start + lblkno(ip->i_mnt, offset));

	/*
	 * Determine maximum number of contiguous bytes following the
	 * requested offset.
	 */
	if (ap->a_run) {
		if (ip->i_size > offset)
			cbytes = ip->i_size - offset;
		else
			cbytes = 0;

		cbytes = (cbytes + (devBlockSize - 1)) & ~(devBlockSize - 1);

		*ap->a_run = MIN(cbytes, ap->a_size);
	};
out:
	if (ap->a_poff)
		*(int *)ap->a_poff = (long)offset & (devBlockSize - 1);

	return (0);	
}
Commit	Line	Data
1c79356b	1	/*
55e303ae	2	* Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
1c79356b A	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
43866e37	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
1c79356b	7	*
43866e37 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
43866e37 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
1c79356b A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/* $NetBSD: cd9660_bmap.c,v 1.5 1994/12/13 22:33:12 mycroft Exp $ */
	26
	27	/*-
	28	* Copyright (c) 1994
	29	* The Regents of the University of California. All rights reserved.
	30	*
	31	* This code is derived from software contributed to Berkeley
	32	* by Pace Willisson (pace@blitz.com). The Rock Ridge Extension
	33	* Support code is derived from software contributed to Berkeley
	34	* by Atsushi Murai (amurai@spec.co.jp).
	35	*
	36	* Redistribution and use in source and binary forms, with or without
	37	* modification, are permitted provided that the following conditions
	38	* are met:
	39	* 1. Redistributions of source code must retain the above copyright
	40	* notice, this list of conditions and the following disclaimer.
	41	* 2. Redistributions in binary form must reproduce the above copyright
	42	* notice, this list of conditions and the following disclaimer in the
	43	* documentation and/or other materials provided with the distribution.
	44	* 3. All advertising materials mentioning features or use of this software
	45	* must display the following acknowledgement:
	46	* This product includes software developed by the University of
	47	* California, Berkeley and its contributors.
	48	* 4. Neither the name of the University nor the names of its contributors
	49	* may be used to endorse or promote products derived from this software
	50	* without specific prior written permission.
	51	*
	52	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	53	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	54	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	55	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	56	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	57	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	58	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	59	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	60	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	61	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	62	* SUCH DAMAGE.
	63	*
	64	* @(#)cd9660_bmap.c 8.4 (Berkeley) 12/5/94
	65	*/
	66
	67	#include <sys/param.h>
	68	#include <sys/vnode.h>
	69	#include <sys/mount.h>
	70	#include <sys/namei.h>
	71	#include <sys/buf.h>
	72	#include <sys/file.h>
	73
	74	#include <isofs/cd9660/iso.h>
	75	#include <isofs/cd9660/cd9660_node.h>
	76
	77	/*
	78	* Bmap converts the logical block number of a file to its physical block
	79	* number on the disk. The conversion is done by using the logical block
	80	* number to index into the data block (extent) for the file.
	81	*/
	82	int
	83	cd9660_bmap(ap)
	84	struct vop_bmap_args /* {
	85	struct vnode *a_vp;
86	daddr_t a_bn;
87	struct vnode **a_vpp;
88	daddr_t *a_bnp;
89	int *a_runp;
90	} / ap;
91	{
92	struct iso_node *ip = VTOI(ap->a_vp);
93	daddr_t lblkno = ap->a_bn;
94	int bshift;
95
96	/*
97	* Check for underlying vnode requests and ensure that logical
98	* to physical mapping is requested.
99	*/
100	if (ap->a_vpp != NULL)
101	*ap->a_vpp = ip->i_devvp;
102	if (ap->a_bnp == NULL)
103	return (0);
104
55e303ae A	105	/*
	106	* Associated files have an Apple Double header
	107	*/
	108	if ((ip->i_flag & ISO_ASSOCIATED) && (lblkno > (ADH_BLKS - 1))) {
	109	lblkno -= ADH_BLKS;
	110	*ap->a_bnp = (ip->iso_start + lblkno);
	111	if (ap->a_runp)
	112	*ap->a_runp = 0;
	113	return (0);
	114	}
	115
1c79356b A	116	/*
	117	* Compute the requested block number
	118	*/
	119	bshift = ip->i_mnt->im_bshift;
	120	*ap->a_bnp = (ip->iso_start + lblkno);
	121
	122	/*
	123	* Determine maximum number of readahead blocks following the
	124	* requested block.
	125	*/
	126	if (ap->a_runp) {
	127	int nblk;
	128
	129	nblk = (ip->i_size >> bshift) - (lblkno + 1);
	130	if (nblk <= 0)
	131	*ap->a_runp = 0;
	132	else if (nblk >= (MAXBSIZE >> bshift))
	133	*ap->a_runp = (MAXBSIZE >> bshift) - 1;
	134	else
	135	*ap->a_runp = nblk;
	136	}
	137
	138	return (0);
	139	}
	140
	141	/* blktooff converts a logical block number to a file offset */
	142	int
	143	cd9660_blktooff(ap)
	144	struct vop_blktooff_args /* {
	145	struct vnode *a_vp;
	146	daddr_t a_lblkno;
	147	off_t *a_offset;
	148	} / ap;
	149	{
	150	register struct iso_node *ip;
55e303ae	151	register struct iso_mnt *imp;
1c79356b A	152
	153	if (ap->a_vp == NULL)
	154	return (EINVAL);
	155
	156	ip = VTOI(ap->a_vp);
	157	imp = ip->i_mnt;
	158
	159	*ap->a_offset = (off_t)lblktosize(imp, ap->a_lblkno);
	160	return (0);
	161	}
	162
	163	/* offtoblk converts a file offset to a logical block number */
	164	int
	165	cd9660_offtoblk(ap)
	166	struct vop_offtoblk_args /* {
	167	struct vnode *a_vp;
	168	off_t a_offset;
	169	daddr_t *a_lblkno;
	170	} / ap;
	171	{
	172	register struct iso_node *ip;
	173	register struct iso_mnt *imp;
	174
	175	if (ap->a_vp == NULL)
	176	return (EINVAL);
	177
	178	ip = VTOI(ap->a_vp);
	179	imp = ip->i_mnt;
	180
	181	*ap->a_lblkno = (daddr_t)lblkno(imp, ap->a_offset);
	182	return (0);
	183	}
	184
	185	int
	186	cd9660_cmap(ap)
	187	struct vop_cmap_args /* {
	188	struct vnode *a_vp;
	189	off_t a_offset;
	190	size_t a_size;
	191	daddr_t *a_bpn;
	192	size_t *a_run;
	193	void *a_poff;
	194	} / ap;
	195	{
	196	struct iso_node *ip = VTOI(ap->a_vp);
	197	size_t cbytes;
	198	int devBlockSize = 0;
55e303ae	199	off_t offset = ap->a_foffset;
1c79356b A	200
	201	/*
	202	* Check for underlying vnode requests and ensure that logical
	203	* to physical mapping is requested.
	204	*/
	205	if (ap->a_bpn == NULL)
	206	return (0);
	207
	208	VOP_DEVBLOCKSIZE(ip->i_devvp, &devBlockSize);
	209
55e303ae A	210	/*
	211	* Associated files have an Apple Double header
	212	*/
	213	if (ip->i_flag & ISO_ASSOCIATED) {
	214	if (offset < ADH_SIZE) {
	215	if (ap->a_run)
	216	*ap->a_run = 0;
	217	*ap->a_bpn = -1;
	218	goto out;
	219	} else {
	220	offset -= ADH_SIZE;
	221	}
	222	}
	223
	224	*ap->a_bpn = (daddr_t)(ip->iso_start + lblkno(ip->i_mnt, offset));
1c79356b A	225
	226	/*
	227	* Determine maximum number of contiguous bytes following the
	228	* requested offset.
	229	*/
	230	if (ap->a_run) {
55e303ae A	231	if (ip->i_size > offset)
55e303ae A	232	cbytes = ip->i_size - offset;
1c79356b A	233	else
	234	cbytes = 0;
	235
	236	cbytes = (cbytes + (devBlockSize - 1)) & ~(devBlockSize - 1);
	237
	238	*ap->a_run = MIN(cbytes, ap->a_size);
	239	};
55e303ae	240	out:
1c79356b	241	if (ap->a_poff)
55e303ae	242	(int )ap->a_poff = (long)offset & (devBlockSize - 1);
1c79356b A	243
	244	return (0);
	245	}
	246