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/*

 * linux/fs/befs/io.c

 *

 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com

 *

 * Based on portions of file.c and inode.c

 * by Makoto Kato (m_kato@ga2.so-net.ne.jp)

 *

 * Many thanks to Dominic Giampaolo, author of Practical File System

 * Design with the Be File System, for such a helpful book.

 *

 */

#include <linux/fs.h>

#include "befs.h"

#include "io.h"

/*

 * Converts befs notion of disk addr to a disk offset and uses

 * linux kernel function bread() to get the buffer containing

 * the offset. -Will Dyson

 *

 */

struct buffer_head *

befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr)

{

        struct buffer_head *bh = NULL;

        befs_blocknr_t block = 0;

        vfs_blocknr_t vfs_block = 0;

        befs_sb_info *befs_sb = BEFS_SB(sb);

        befs_debug(sb, "---> Enter befs_read_iaddr() "

                   "[%u, %hu, %hu]",

                   iaddr.allocation_group, iaddr.start, iaddr.len);

        if (iaddr.allocation_group > befs_sb->num_ags) {

                befs_error(sb, "BEFS: Invalid allocation group %u, max is %u",

                           iaddr.allocation_group, befs_sb->num_ags);

                goto error;

        }

        block = iaddr2blockno(sb, &iaddr);

        vfs_block = (vfs_blocknr_t) block;

        if (vfs_block != block) {

                befs_error(sb, "Error converting to host blocknr_t. %Lu "

                           "is larger than the host can use", block);

                goto error;

        }

        befs_debug(sb, "befs_read_iaddr: offset = %lu", block);

        bh = bread(sb->s_dev, vfs_block, befs_sb->block_size);

        if (bh == NULL) {

                befs_error(sb, "Failed to read block %lu", block);

                goto error;

        }

        befs_debug(sb, "<--- befs_read_iaddr()");

        return bh;

      error:

        befs_debug(sb, "<--- befs_read_iaddr() ERROR");

        return NULL;

}

struct buffer_head *

befs_bread(struct super_block *sb, befs_blocknr_t block)

{

        struct buffer_head *bh = NULL;

        befs_sb_info *befs_sb = BEFS_SB(sb);

        vfs_blocknr_t vfs_block = (vfs_blocknr_t) block;

        befs_debug(sb, "---> Enter befs_read() %Lu", block);

        if (vfs_block != block) {

                befs_error(sb, "Error converting to host blocknr_t. %Lu "

                           "is larger than the host can use", block);

                goto error;

        }

        bh = bread(sb->s_dev, vfs_block, befs_sb->block_size);

        if (bh == NULL) {

                befs_error(sb, "Failed to read block %lu", vfs_block);

                goto error;

        }

        befs_debug(sb, "<--- befs_read()");

        return bh;

      error:

        befs_debug(sb, "<--- befs_read() ERROR");

        return NULL;

}