1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  linux/include/linux/ext2_fs.h
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  from
11  *
12  *  linux/include/linux/minix_fs.h
13  *
14  *  Copyright (C) 1991, 1992  Linus Torvalds
15  */
16 
17 #ifndef _LINUX_EXT2_FS_H
18 #define _LINUX_EXT2_FS_H
19 
20 #include <linux/types.h>
21 #include <linux/magic.h>
22 
23 #define EXT2_NAME_LEN 255
24 
25 /*
26  * Maximal count of links to a file
27  */
28 #define EXT2_LINK_MAX		32000
29 
30 #define EXT2_SB_MAGIC_OFFSET	0x38
31 #define EXT2_SB_BLOCKS_OFFSET	0x04
32 #define EXT2_SB_BSIZE_OFFSET	0x18
33 
ext2_image_size(void * ext2_sb)34 static inline u64 ext2_image_size(void *ext2_sb)
35 {
36 	__u8 *p = ext2_sb;
37 	if (*(__le16 *)(p + EXT2_SB_MAGIC_OFFSET) != cpu_to_le16(EXT2_SUPER_MAGIC))
38 		return 0;
39 	return (u64)le32_to_cpup((__le32 *)(p + EXT2_SB_BLOCKS_OFFSET)) <<
40 		le32_to_cpup((__le32 *)(p + EXT2_SB_BSIZE_OFFSET));
41 }
42 
43 #endif	/* _LINUX_EXT2_FS_H */
44