root/fs/befs/io.c

DEFINITIONS

1. befs_bread_iaddr
2. befs_bread

/*
 * 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/buffer_head.h>

#include "befs.h"
#include "io.h"

/*
 * Converts befs notion of disk addr to a disk offset and uses
 * linux kernel function sb_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;
        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);

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

        bh = sb_bread(sb, block);

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

        bh = sb_bread(sb, block);

        if (bh == NULL) {
                befs_error(sb, "Failed to read block %lu", block);
                goto error;
        }

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

        return bh;

      error:
        befs_debug(sb, "<--- befs_read() ERROR");
        return NULL;
}