filesystems

Links

• configfs
• ext4
  • Ext4 Disk Layout

ext4

• direct block の数, 12
• indirect block の数, 1
• double indirect block の数, 1
• triple indirect block の数, 1

refs. linux/fs/ext4.h

/*
 * Constants relative to the data blocks
 */
#define	EXT4_NDIR_BLOCKS		12
#define	EXT4_IND_BLOCK			EXT4_NDIR_BLOCKS
#define	EXT4_DIND_BLOCK			(EXT4_IND_BLOCK + 1)
#define	EXT4_TIND_BLOCK			(EXT4_DIND_BLOCK + 1)
#define	EXT4_N_BLOCKS			(EXT4_TIND_BLOCK + 1)

super block の調べ方

nvme0 の コントローラ 1 の パーティション 2 （ext4 ）を調べる例

$ sudo dumpe2fs -h /dev/nvme0n1p2