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. 23 */ 24 25 struct buffer_head * 26 befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr) 27 { 28 struct buffer_head *bh; 29 befs_blocknr_t block; 30 struct befs_sb_info *befs_sb = BEFS_SB(sb); 31 32 befs_debug(sb, "---> Enter %s " 33 "[%u, %hu, %hu]", __func__, iaddr.allocation_group, 34 iaddr.start, iaddr.len); 35 36 if (iaddr.allocation_group > befs_sb->num_ags) { 37 befs_error(sb, "BEFS: Invalid allocation group %u, max is %u", 38 iaddr.allocation_group, befs_sb->num_ags); 39 goto error; 40 } 41 42 block = iaddr2blockno(sb, &iaddr); 43 44 befs_debug(sb, "%s: offset = %lu", __func__, (unsigned long)block); 45 46 bh = sb_bread(sb, block); 47 48 if (bh == NULL) { 49 befs_error(sb, "Failed to read block %lu", 50 (unsigned long)block); 51 goto error; 52 } 53 54 befs_debug(sb, "<--- %s", __func__); 55 return bh; 56 57 error: 58 befs_debug(sb, "<--- %s ERROR", __func__); 59 return NULL; 60 } 61