LXR linux/fs/befs/io.c

   1/*
   2 * linux/fs/befs/io.c
   3 *
   4 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
   5 *
   6 * Based on portions of file.c and inode.c 
   7 * by Makoto Kato (m_kato@ga2.so-net.ne.jp)
   8 *
   9 * Many thanks to Dominic Giampaolo, author of Practical File System
  10 * Design with the Be File System, for such a helpful book.
  11 *
  12 */
  13
  14#include <linux/buffer_head.h>
  15
  16#include "befs.h"
  17#include "io.h"
  18
  19/*
  20 * Converts befs notion of disk addr to a disk offset and uses
  21 * linux kernel function sb_bread() to get the buffer containing
  22 * the offset. -Will Dyson
  23 *
  24 */
  25
  26struct buffer_head *
  27befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr)
  28{
  29        struct buffer_head *bh = NULL;
  30        befs_blocknr_t block = 0;
  31        struct befs_sb_info *befs_sb = BEFS_SB(sb);
  32
  33        befs_debug(sb, "---> Enter %s "
  34                   "[%u, %hu, %hu]", __func__, iaddr.allocation_group,
  35                   iaddr.start, iaddr.len);
  36
  37        if (iaddr.allocation_group > befs_sb->num_ags) {
  38                befs_error(sb, "BEFS: Invalid allocation group %u, max is %u",
  39                           iaddr.allocation_group, befs_sb->num_ags);
  40                goto error;
  41        }
  42
  43        block = iaddr2blockno(sb, &iaddr);
  44
  45        befs_debug(sb, "%s: offset = %lu", __func__, (unsigned long)block);
  46
  47        bh = sb_bread(sb, block);
  48
  49        if (bh == NULL) {
  50                befs_error(sb, "Failed to read block %lu",
  51                           (unsigned long)block);
  52                goto error;
  53        }
  54
  55        befs_debug(sb, "<--- %s", __func__);
  56        return bh;
  57
  58      error:
  59        befs_debug(sb, "<--- %s ERROR", __func__);
  60        return NULL;
  61}
  62
  63struct buffer_head *
  64befs_bread(struct super_block *sb, befs_blocknr_t block)
  65{
  66        struct buffer_head *bh = NULL;
  67
  68        befs_debug(sb, "---> Enter %s %lu", __func__, (unsigned long)block);
  69
  70        bh = sb_bread(sb, block);
  71
  72        if (bh == NULL) {
  73                befs_error(sb, "Failed to read block %lu",
  74                           (unsigned long)block);
  75                goto error;
  76        }
  77
  78        befs_debug(sb, "<--- %s", __func__);
  79
  80        return bh;
  81
  82      error:
  83        befs_debug(sb, "<--- %s ERROR", __func__);
  84        return NULL;
  85}
  86