84 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			84 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * linux/fs/befs/io.c | ||
|  |  * | ||
|  |  * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com | ||
|  |  * | ||
|  |  * Based on portions of file.c and inode.c  | ||
|  |  * by Makoto Kato (m_kato@ga2.so-net.ne.jp) | ||
|  |  * | ||
|  |  * Many thanks to Dominic Giampaolo, author of Practical File System | ||
|  |  * Design with the Be File System, for such a helpful book. | ||
|  |  * | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <linux/buffer_head.h>
 | ||
|  | 
 | ||
|  | #include "befs.h"
 | ||
|  | #include "io.h"
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * Converts befs notion of disk addr to a disk offset and uses | ||
|  |  * linux kernel function sb_bread() to get the buffer containing | ||
|  |  * the offset. -Will Dyson | ||
|  |  * | ||
|  |  */ | ||
|  | 
 | ||
|  | struct buffer_head * | ||
|  | befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr) | ||
|  | { | ||
|  | 	struct buffer_head *bh = NULL; | ||
|  | 	befs_blocknr_t block = 0; | ||
|  | 	befs_sb_info *befs_sb = BEFS_SB(sb); | ||
|  | 
 | ||
|  | 	befs_debug(sb, "---> Enter befs_read_iaddr() " | ||
|  | 		   "[%u, %hu, %hu]", | ||
|  | 		   iaddr.allocation_group, iaddr.start, iaddr.len); | ||
|  | 
 | ||
|  | 	if (iaddr.allocation_group > befs_sb->num_ags) { | ||
|  | 		befs_error(sb, "BEFS: Invalid allocation group %u, max is %u", | ||
|  | 			   iaddr.allocation_group, befs_sb->num_ags); | ||
|  | 		goto error; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	block = iaddr2blockno(sb, &iaddr); | ||
|  | 
 | ||
|  | 	befs_debug(sb, "befs_read_iaddr: offset = %lu", block); | ||
|  | 
 | ||
|  | 	bh = sb_bread(sb, block); | ||
|  | 
 | ||
|  | 	if (bh == NULL) { | ||
|  | 		befs_error(sb, "Failed to read block %lu", block); | ||
|  | 		goto error; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	befs_debug(sb, "<--- befs_read_iaddr()"); | ||
|  | 	return bh; | ||
|  | 
 | ||
|  |       error: | ||
|  | 	befs_debug(sb, "<--- befs_read_iaddr() ERROR"); | ||
|  | 	return NULL; | ||
|  | } | ||
|  | 
 | ||
|  | struct buffer_head * | ||
|  | befs_bread(struct super_block *sb, befs_blocknr_t block) | ||
|  | { | ||
|  | 	struct buffer_head *bh = NULL; | ||
|  | 
 | ||
|  | 	befs_debug(sb, "---> Enter befs_read() %Lu", block); | ||
|  | 
 | ||
|  | 	bh = sb_bread(sb, block); | ||
|  | 
 | ||
|  | 	if (bh == NULL) { | ||
|  | 		befs_error(sb, "Failed to read block %lu", block); | ||
|  | 		goto error; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	befs_debug(sb, "<--- befs_read()"); | ||
|  | 
 | ||
|  | 	return bh; | ||
|  | 
 | ||
|  |       error: | ||
|  | 	befs_debug(sb, "<--- befs_read() ERROR"); | ||
|  | 	return NULL; | ||
|  | } |