Re: [f2fs-dev] [PATCH 1/2] f2fs: count writeback pages correctly

[Chao Yu]

Hi Jaegeuk,

On 2017/4/6 2:02, Jaegeuk Kim wrote:
> This patch fixes # of outstanding writeback pages by checking its original page.

Originally, we use bio_page to track encrypted page which is been writebacked,
there are two cases:
1. background flush through .writepages: encrypted_page has no mapping info,
will not be tracked.
2. synchronized GC through move_encrypted_block: encrypted_page is meta page,
will be tracked.

So there is no problem with old code?

Thanks,

> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
>  fs/f2fs/data.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 3d74c0ffa4c7..af3e849e96d2 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -94,7 +94,6 @@ static void f2fs_write_end_io(struct bio *bio)
>  
>  	bio_for_each_segment_all(bvec, bio, i) {
>  		struct page *page = bvec->bv_page;
> -		enum count_type type = WB_DATA_TYPE(page);
>  
>  		if (IS_DUMMY_WRITTEN_PAGE(page)) {
>  			set_page_private(page, (unsigned long)NULL);
> @@ -113,7 +112,7 @@ static void f2fs_write_end_io(struct bio *bio)
>  			mapping_set_error(page->mapping, -EIO);
>  			f2fs_stop_checkpoint(sbi, true);
>  		}
> -		dec_page_count(sbi, type);
> +		dec_page_count(sbi, WB_DATA_TYPE(page));
>  		clear_cold_data(page);
>  		end_page_writeback(page);
>  	}
> @@ -389,7 +388,7 @@ int f2fs_submit_page_mbio(struct f2fs_io_info *fio)
>  	fio->submitted = 1;
>  
>  	if (!is_read)
> -		inc_page_count(sbi, WB_DATA_TYPE(bio_page));
> +		inc_page_count(sbi, WB_DATA_TYPE(fio->page));
>  
>  	down_write(&io->io_rwsem);
>  
> @@ -403,7 +402,7 @@ int f2fs_submit_page_mbio(struct f2fs_io_info *fio)
>  				fio->new_blkaddr & F2FS_IO_SIZE_MASK(sbi)) {
>  			err = -EAGAIN;
>  			if (!is_read)
> -				dec_page_count(sbi, WB_DATA_TYPE(bio_page));
> +				dec_page_count(sbi, WB_DATA_TYPE(fio->page));
>  			goto out_fail;
>  		}
>  		io->bio = __bio_alloc(sbi, fio->new_blkaddr,
>