include/linux/ext2_fs.h

   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
  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 */