1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/befs/io.c
4 *
5 * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
6 *
7 * Based on portions of file.c and inode.c
8 * by Makoto Kato (m_kato@ga2.so-net.ne.jp)
9 *
10 * Many thanks to Dominic Giampaolo, author of Practical File System
11 * Design with the Be File System, for such a helpful book.
12 *
13 */
14
15#include <linux/buffer_head.h>
16
17#include "befs.h"
18#include "io.h"
19
20/*
21 * Converts befs notion of disk addr to a disk offset and uses
22 * linux kernel function sb_bread() to get the buffer containing
23 * the offset.
24 */
25
26struct buffer_head *
27befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr)
28{
29	struct buffer_head *bh;
30	befs_blocknr_t block;
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
58error:
59	befs_debug(sb, "<--- %s ERROR", __func__);
60	return NULL;
61}
62