Re: [PATCH] f2fs: fix wrong sum_page pointer in f2fs_gc

From: Chao Yu
Date: Thu Oct 13 2016 - 06:36:02 EST


Hi Jaegeuk,

On 2016/10/13 7:23, Jaegeuk Kim wrote:
> This patch fixes using a wrong pointer for sum_page in f2fs_gc.
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> fs/f2fs/gc.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index e48142f..9c18917 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -854,16 +854,16 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
>
> for (segno = start_segno; segno < end_segno; segno++) {
>
> - if (get_valid_blocks(sbi, segno, 1) == 0 ||
> - unlikely(f2fs_cp_error(sbi)))
> - goto next;
> -
> /* find segment summary of victim */
> sum_page = find_get_page(META_MAPPING(sbi),
> GET_SUM_BLOCK(sbi, segno));
> - f2fs_bug_on(sbi, !PageUptodate(sum_page));
> f2fs_put_page(sum_page, 0);
>
> + if (get_valid_blocks(sbi, segno, 1) == 0 ||
> + !PageUptodate(sum_page) ||

Why uptodate flag of summary page can be cleared? someone truncates it?

Thanks,

> + unlikely(f2fs_cp_error(sbi)))
> + goto next;
> +
> sum = page_address(sum_page);
> f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer)));
>
>