f2fs: mark inode dirty for FI_ATOMIC_COMMITTED flag

In f2fs_update_inode, i_size of the atomic file isn't updated until
FI_ATOMIC_COMMITTED flag is set. When committing atomic write right
after the writeback of the inode, i_size of the raw inode will not be
updated. It can cause the atomicity corruption due to a mismatch between
old file size and new data.

To prevent the problem, let's mark inode dirty for FI_ATOMIC_COMMITTED

Atomic write thread                   Writeback thread
                                        __writeback_single_inode
                                          write_inode
                                            f2fs_update_inode
                                              - skip i_size update
  f2fs_ioc_commit_atomic_write
    f2fs_commit_atomic_write
      set_inode_flag(inode, FI_ATOMIC_COMMITTED)
    f2fs_do_sync_file
      f2fs_fsync_node_pages
        - skip f2fs_update_inode since the inode is clean

Fixes: 3db1de0e ("f2fs: change the current atomic write way")
Cc: stable@vger.kernel.org #v5.19+
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Yeongjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Sunmin Jeong <s_min.jeong@samsung.com>
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>