[deliverable/linux.git] / fs / freevxfs / vxfs_olt.c

/*
 * Copyright (c) 2000-2001 Christoph Hellwig.
 * All rights reserved.
 *
 * 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,
 *    without modification.
 * 2. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL").
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

/* 
 * Veritas filesystem driver - object location table support.
 */
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/kernel.h>

#include "vxfs.h"
#include "vxfs_olt.h"
#include "vxfs_extern.h"


static inline void
vxfs_get_fshead(struct vxfs_oltfshead *fshp, struct vxfs_sb_info *infp)
{
	if (infp->vsi_fshino)
		BUG();
	infp->vsi_fshino = fshp->olt_fsino[0];
}

static inline void
vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp)
{
	if (infp->vsi_iext)
		BUG();
	infp->vsi_iext = ilistp->olt_iext[0]; 
}

static inline u_long
vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize)
{
	if (sbp->s_blocksize % bsize)
		BUG();
	return (block * (sbp->s_blocksize / bsize));
}


/**
 * vxfs_read_olt - read olt
 * @sbp:	superblock of the filesystem
 * @bsize:	blocksize of the filesystem
 *
 * Description:
 *   vxfs_read_olt reads the olt of the filesystem described by @sbp
 *   into main memory and does some basic setup.
 *
 * Returns:
 *   Zero on success, else a negative error code.
 */
int
vxfs_read_olt(struct super_block *sbp, u_long bsize)
{
	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
	struct buffer_head	*bp;
	struct vxfs_olt		*op;
	char			*oaddr, *eaddr;


	bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize));
	if (!bp || !bp->b_data)
		goto fail;

	op = (struct vxfs_olt *)bp->b_data;
	if (op->olt_magic != VXFS_OLT_MAGIC) {
		printk(KERN_NOTICE "vxfs: ivalid olt magic number\n");
		goto fail;
	}

	/*
	 * It is in theory possible that vsi_oltsize is > 1.
	 * I've not seen any such filesystem yet and I'm lazy..  --hch
	 */
	if (infp->vsi_oltsize > 1) {
		printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n");
		printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n");
		goto fail;
	}

	oaddr = bp->b_data + op->olt_size;
	eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize);

	while (oaddr < eaddr) {
		struct vxfs_oltcommon	*ocp =
			(struct vxfs_oltcommon *)oaddr;
		
		switch (ocp->olt_type) {
		case VXFS_OLT_FSHEAD:
			vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp);
			break;
		case VXFS_OLT_ILIST:
			vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp);
			break;
		}

		oaddr += ocp->olt_size;
	}

	brelse(bp);
	return 0;

fail:
	brelse(bp);
	return -EINVAL;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (c) 2000-2001 Christoph Hellwig.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions, and the following disclaimer,
	10	* without modification.
	11	* 2. The name of the author may not be used to endorse or promote products
	12	* derived from this software without specific prior written permission.
	13	*
	14	* Alternatively, this software may be distributed under the terms of the
	15	* GNU General Public License ("GPL").
	16	*
	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	18	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	19	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	20	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
	21	* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	22	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	23	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	24	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	25	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	26	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	27	* SUCH DAMAGE.
	28	*/
	29
	30	/*
	31	* Veritas filesystem driver - object location table support.
	32	*/
	33	#include <linux/fs.h>
	34	#include <linux/buffer_head.h>
	35	#include <linux/kernel.h>
	36
	37	#include "vxfs.h"
	38	#include "vxfs_olt.h"
6e1e8e11	39	#include "vxfs_extern.h"
1da177e4 LT	40
1da177e4 LT	41
8cb681b9	42	static inline void
1da177e4 LT	43	vxfs_get_fshead(struct vxfs_oltfshead fshp, struct vxfs_sb_info infp)
	44	{
	45	if (infp->vsi_fshino)
	46	BUG();
	47	infp->vsi_fshino = fshp->olt_fsino[0];
	48	}
	49
8cb681b9	50	static inline void
1da177e4 LT	51	vxfs_get_ilist(struct vxfs_oltilist ilistp, struct vxfs_sb_info infp)
	52	{
	53	if (infp->vsi_iext)
	54	BUG();
	55	infp->vsi_iext = ilistp->olt_iext[0];
	56	}
	57
8cb681b9	58	static inline u_long
1da177e4 LT	59	vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize)
	60	{
	61	if (sbp->s_blocksize % bsize)
	62	BUG();
	63	return (block * (sbp->s_blocksize / bsize));
	64	}
	65
	66
	67	/**
	68	* vxfs_read_olt - read olt
	69	* @sbp: superblock of the filesystem
	70	* @bsize: blocksize of the filesystem
	71	*
	72	* Description:
	73	* vxfs_read_olt reads the olt of the filesystem described by @sbp
	74	* into main memory and does some basic setup.
	75	*
	76	* Returns:
	77	* Zero on success, else a negative error code.
	78	*/
	79	int
	80	vxfs_read_olt(struct super_block *sbp, u_long bsize)
	81	{
	82	struct vxfs_sb_info *infp = VXFS_SBI(sbp);
	83	struct buffer_head *bp;
	84	struct vxfs_olt *op;
	85	char oaddr, eaddr;
	86
	87
	88	bp = sb_bread(sbp, vxfs_oblock(sbp, infp->vsi_oltext, bsize));
	89	if (!bp \|\| !bp->b_data)
	90	goto fail;
	91
	92	op = (struct vxfs_olt *)bp->b_data;
	93	if (op->olt_magic != VXFS_OLT_MAGIC) {
	94	printk(KERN_NOTICE "vxfs: ivalid olt magic number\n");
	95	goto fail;
	96	}
	97
	98	/*
	99	* It is in theory possible that vsi_oltsize is > 1.
	100	* I've not seen any such filesystem yet and I'm lazy.. --hch
	101	*/
	102	if (infp->vsi_oltsize > 1) {
	103	printk(KERN_NOTICE "vxfs: oltsize > 1 detected.\n");
	104	printk(KERN_NOTICE "vxfs: please notify hch@infradead.org\n");
	105	goto fail;
	106	}
	107
8cb681b9 PE	108	oaddr = bp->b_data + op->olt_size;
8cb681b9 PE	109	eaddr = bp->b_data + (infp->vsi_oltsize * sbp->s_blocksize);
1da177e4 LT	110
	111	while (oaddr < eaddr) {
	112	struct vxfs_oltcommon *ocp =
	113	(struct vxfs_oltcommon *)oaddr;
	114
	115	switch (ocp->olt_type) {
	116	case VXFS_OLT_FSHEAD:
	117	vxfs_get_fshead((struct vxfs_oltfshead *)oaddr, infp);
	118	break;
	119	case VXFS_OLT_ILIST:
	120	vxfs_get_ilist((struct vxfs_oltilist *)oaddr, infp);
	121	break;
	122	}
	123
	124	oaddr += ocp->olt_size;
	125	}
	126
	127	brelse(bp);
	128	return 0;
	129
	130	fail:
	131	brelse(bp);
	132	return -EINVAL;
	133	}