include/linux/ext2_fs.h

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