xref: /openbmc/linux/fs/befs/io.c (revision 4f205687)
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 
26 struct buffer_head *
27 befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr)
28 {
29 	struct buffer_head *bh;
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 
63 struct buffer_head *
64 befs_bread(struct super_block *sb, befs_blocknr_t block)
65 {
66 	struct buffer_head *bh;
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