nilfs2: clarify byte offset in super block format
This inserts comments indicating hexadecimal offset in declaration of
nilfs_super_block structure so that people can know offset of its
fields without counting from the head.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 8c2c611..cc3465e 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -160,7 +160,7 @@
* struct nilfs_super_block - structure of super block on disk
*/
struct nilfs_super_block {
- __le32 s_rev_level; /* Revision level */
+/*00*/ __le32 s_rev_level; /* Revision level */
__le16 s_minor_rev_level; /* minor revision level */
__le16 s_magic; /* Magic signature */
@@ -169,47 +169,47 @@
is excluded. */
__le16 s_flags; /* flags */
__le32 s_crc_seed; /* Seed value of CRC calculation */
- __le32 s_sum; /* Check sum of super block */
+/*10*/ __le32 s_sum; /* Check sum of super block */
__le32 s_log_block_size; /* Block size represented as follows
blocksize =
1 << (s_log_block_size + 10) */
__le64 s_nsegments; /* Number of segments in filesystem */
- __le64 s_dev_size; /* block device size in bytes */
+/*20*/ __le64 s_dev_size; /* block device size in bytes */
__le64 s_first_data_block; /* 1st seg disk block number */
- __le32 s_blocks_per_segment; /* number of blocks per full segment */
+/*30*/ __le32 s_blocks_per_segment; /* number of blocks per full segment */
__le32 s_r_segments_percentage; /* Reserved segments percentage */
__le64 s_last_cno; /* Last checkpoint number */
- __le64 s_last_pseg; /* disk block addr pseg written last */
+/*40*/ __le64 s_last_pseg; /* disk block addr pseg written last */
__le64 s_last_seq; /* seq. number of seg written last */
- __le64 s_free_blocks_count; /* Free blocks count */
+/*50*/ __le64 s_free_blocks_count; /* Free blocks count */
__le64 s_ctime; /* Creation time (execution time of
newfs) */
- __le64 s_mtime; /* Mount time */
+/*60*/ __le64 s_mtime; /* Mount time */
__le64 s_wtime; /* Write time */
- __le16 s_mnt_count; /* Mount count */
+/*70*/ __le16 s_mnt_count; /* Mount count */
__le16 s_max_mnt_count; /* Maximal mount count */
__le16 s_state; /* File system state */
__le16 s_errors; /* Behaviour when detecting errors */
__le64 s_lastcheck; /* time of last check */
- __le32 s_checkinterval; /* max. time between checks */
+/*80*/ __le32 s_checkinterval; /* max. time between checks */
__le32 s_creator_os; /* OS */
__le16 s_def_resuid; /* Default uid for reserved blocks */
__le16 s_def_resgid; /* Default gid for reserved blocks */
__le32 s_first_ino; /* First non-reserved inode */
- __le16 s_inode_size; /* Size of an inode */
+/*90*/ __le16 s_inode_size; /* Size of an inode */
__le16 s_dat_entry_size; /* Size of a dat entry */
__le16 s_checkpoint_size; /* Size of a checkpoint */
__le16 s_segment_usage_size; /* Size of a segment usage */
- __u8 s_uuid[16]; /* 128-bit uuid for volume */
- char s_volume_name[80]; /* volume name */
+/*98*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */
+/*A8*/ char s_volume_name[80]; /* volume name */
- __le32 s_c_interval; /* Commit interval of segment */
+/*F8*/ __le32 s_c_interval; /* Commit interval of segment */
__le32 s_c_block_max; /* Threshold of data amount for
the segment construction */
__u32 s_reserved[192]; /* padding to the end of the block */