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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 *
befs_bread_iaddr(struct super_block * sb,befs_inode_addr iaddr)27  befs_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  
63  struct buffer_head *
befs_bread(struct super_block * sb,befs_blocknr_t block)64  befs_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