Root/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    befs_sb_info *befs_sb = BEFS_SB(sb);
32
33    befs_debug(sb, "---> Enter befs_read_iaddr() "
34           "[%u, %hu, %hu]",
35           iaddr.allocation_group, 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, "befs_read_iaddr: offset = %lu", block);
46
47    bh = sb_bread(sb, block);
48
49    if (bh == NULL) {
50        befs_error(sb, "Failed to read block %lu", block);
51        goto error;
52    }
53
54    befs_debug(sb, "<--- befs_read_iaddr()");
55    return bh;
56
57      error:
58    befs_debug(sb, "<--- befs_read_iaddr() ERROR");
59    return NULL;
60}
61
62struct buffer_head *
63befs_bread(struct super_block *sb, befs_blocknr_t block)
64{
65    struct buffer_head *bh = NULL;
66
67    befs_debug(sb, "---> Enter befs_read() %Lu", block);
68
69    bh = sb_bread(sb, block);
70
71    if (bh == NULL) {
72        befs_error(sb, "Failed to read block %lu", block);
73        goto error;
74    }
75
76    befs_debug(sb, "<--- befs_read()");
77
78    return bh;
79
80      error:
81    befs_debug(sb, "<--- befs_read() ERROR");
82    return NULL;
83}
84

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