Re: [PATCH] f2fs: avoid unneeded preflush during checkpoint()

Jaegeuk Kim
2022-02-07T19:22:20Z

On 02/07, Chao Yu wrote:
> During checkpoint, we have committed preflush command via f2fs_flush_device_cache()

787 int f2fs_flush_device_cache(struct f2fs_sb_info *sbi)
788 {
789 int ret = 0, i;
790
791 if (!f2fs_is_multi_device(sbi))
792 return 0;

Seems a wrong assumption.

> to persist all metadata pages except last #2 CP pack page, so we don't need to
> commit another preflush command in commit_checkpoint(), remove it to avoid unneeded
> write cache overhead.
>
> Signed-off-by: Chao Yu <chao@kernel.org>
> ---
> fs/f2fs/data.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 8c417864c66a..15ac18bbbc8e 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -598,7 +598,7 @@ static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
> io->fio.op = REQ_OP_WRITE;
> io->fio.op_flags = REQ_META | REQ_PRIO | REQ_SYNC;
> if (!test_opt(sbi, NOBARRIER))
> - io->fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
> + io->fio.op_flags |= REQ_FUA;
> }
> __submit_merged_bio(io);
> up_write(&io->io_rwsem);
> --
> 2.32.0