nilfs2: add /sys/fs/nilfs2/<device>/superblock group

This patch adds creation of /sys/fs/nilfs2/<device>/superblock
group.

The superblock group contains attributes that describe
superblock's details:
(1) sb_write_time - show previous write time of super block in
human-readable format.
(2) sb_write_time_secs - show previous write time of super block
in seconds.
(3) sb_write_count - show write count of super block.
(4) sb_update_frequency - show/set interval of periodical update
of superblock (in seconds). You can set preferable frequency of
superblock update by command:

echo <value> > /sys/fs/nilfs2/<device>/superblock/sb_update_frequency

Signed-off-by: Vyacheslav Dubeyko <[email protected]>
Cc: Vyacheslav Dubeyko <[email protected]>
Cc: Ryusuke Konishi <[email protected]>
Cc: Michael L. Semon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions