tree 49f395d6e8bea5123a734e7d75953f694d90fd05
parent aff063e266cbf4754021d8e5d16ee418560906fd
author Jaegeuk Kim <jaegeuk.kim@samsung.com> 1351843698 +0900
committer Jaegeuk Kim <jaegeuk.kim@samsung.com> 1355201020 +0900

f2fs: add checkpoint operations

This adds functions required by the checkpoint operations.

Basically, f2fs adopts a roll-back model with checkpoint blocks written in the
CP area. The checkpoint procedure includes as follows.

- write_checkpoint()
1. block_operations() freezes VFS calls.
2. submit cached bios.
3. flush_nat_entries() writes NAT pages updated by dirty NAT entries.
4. flush_sit_entries() writes SIT pages updated by dirty SIT entries.
5. do_checkpoint() writes,
  - checkpoint block (#0)
  - orphan inode blocks
  - summary blocks made by active logs
  - checkpoint block (copy of #0)
6. unblock_opeations()

In order to provide an address space for meta pages, f2fs_sb_info has a special
inode, namely meta_inode. This patch also adds the address space operations for
meta_inode.

Signed-off-by: Chul Lee <chur.lee@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>