tree cbb3ec5b29719457cd45f72624d03d7e31af4a4c
parent c6e071884aca360a14c21757d760e76ec34b4894
author Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> 1283671055 +0900
committer Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> 1287793478 +0900

nilfs2: get rid of back pointer to writable sb instance

Nilfs object holds a back pointer to a writable super block instance
in nilfs->ns_writer, and this became eliminable since sb is now made
per device and all inodes have a valid pointer to it.

This deletes the ns_writer pointer and a reader/writer semaphore
protecting it.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>