EXT2_DESC_PER_BLOCK  150 include/linux/ext2_fs.h # define EXT2_DESC_PER_BLOCK(s)		(EXT2_SB(s)->s_desc_per_block)
EXT2_DESC_PER_BLOCK  155 include/linux/ext2_fs.h # define EXT2_DESC_PER_BLOCK(s)		(EXT2_BLOCK_SIZE(s) / sizeof (struct ext2_group_desc))