original development tree for Linux kernel GTP module; now long in mainline.
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/*
* 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)
{
BUG_ON(infp->vsi_fshino);
infp->vsi_fshino = fshp->olt_fsino[0];
}
static inline void
vxfs_get_ilist(struct vxfs_oltilist *ilistp, struct vxfs_sb_info *infp)
{
BUG_ON(infp->vsi_iext);
infp->vsi_iext = ilistp->olt_iext[0];
}
static inline u_long
vxfs_oblock(struct super_block *sbp, daddr_t block, u_long bsize)
{
BUG_ON(sbp->s_blocksize % bsize);
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;
}