Re: [PATCH v2] f2fs: restrict write IO alignment condition

From: Jaegeuk Kim
Date: Mon Mar 13 2017 - 16:06:10 EST


On 03/13, Chao Yu wrote:
> We should only align start offset of bio with defined IO_SIZE for below
> conditions:
> a. mode=lfs mount option
> b. write IOs
> c. Out-place-update
> d. non-meta pages
>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> ---
> fs/f2fs/data.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 1375fef11146..53fe79c70406 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -190,6 +190,9 @@ static inline void __submit_bio(struct f2fs_sb_info *sbi,
> current->plug && (type == DATA || type == NODE))
> blk_finish_plug(current->plug);
>
> + if (!test_opt(sbi, LFS))
> + goto submit_io;

The parse_options in fill_super checks this.

> +
> if (type != DATA && type != NODE)
> goto submit_io;
>
> @@ -395,11 +398,12 @@ int f2fs_submit_page_mbio(struct f2fs_io_info *fio)
> __submit_merged_bio(io);
> alloc_new:
> if (io->bio == NULL) {
> - if ((fio->type == DATA || fio->type == NODE) &&
> + if (test_opt(sbi, LFS) &&
> + !is_read && (fio->type == DATA || fio->type == NODE) &&

The missing case is !is_read, here?
But, actually, DATA and NODE don't issue any read commands at all.

Thanks,

> fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
> err = -EAGAIN;
> - if (!is_read)
> - dec_page_count(sbi, WB_DATA_TYPE(bio_page));
> + f2fs_bug_on(sbi, fio->new_blkaddr == fio->old_blkaddr);
> + dec_page_count(sbi, WB_DATA_TYPE(bio_page));
> goto out_fail;
> }
> io->bio = __bio_alloc(sbi, fio->new_blkaddr,
> --
> 2.8.2.295.g3f1c1d0