Re: [PATCH v2 RESEND] Revert "f2fs: handle dirty segments inside refresh_sit_entry"

[Chao Yu]

On 2017/10/30 9:33, Yunlong Song wrote:
> This reverts commit 5e443818fa0b2a2845561ee25bec181424fb2889
> 
> The commit should be reverted because call sequence of below two parts
> of code must be kept:
> a. update sit information, it needs to be updated before segment
> allocation since latter allocation may trigger SSR, and SSR allocation
> needs latest valid block information of all segments.
> b. update segment status, it needs to be updated after segment allocation
> since we can skip updating current opened segment status.
> 
> Fixes: 5e443818fa0b ("f2fs: handle dirty segments inside refresh_sit_entry")
> Suggested-by: Chao Yu <yuchao0@xxxxxxxxxx>
> Signed-off-by: Yunlong Song <yunlong.song@xxxxxxxxxx>

Reviewed-by: Chao Yu <yuchao0@xxxxxxxxxx>

Thanks,

> ---
>  fs/f2fs/f2fs.h    |  1 -
>  fs/f2fs/segment.c | 20 +++++++++++++-------
>  2 files changed, 13 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 13a96b8..f166112 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -2567,7 +2567,6 @@ int restore_node_summary(struct f2fs_sb_info *sbi,
>  bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr);
>  void init_discard_policy(struct discard_policy *dpolicy, int discard_type,
>  						unsigned int granularity);
> -void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new);
>  void stop_discard_thread(struct f2fs_sb_info *sbi);
>  bool f2fs_wait_discard_bios(struct f2fs_sb_info *sbi);
>  void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc);
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 46dfbca..a3509e9 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1884,14 +1884,11 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
>  		get_sec_entry(sbi, segno)->valid_blocks += del;
>  }
>  
> -void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
> +static void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
>  {
>  	update_sit_entry(sbi, new, 1);
>  	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
>  		update_sit_entry(sbi, old, -1);
> -
> -	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
> -	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
>  }
>  
>  void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
> @@ -2529,13 +2526,22 @@ void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
>  
>  	stat_inc_block_count(sbi, curseg);
>  
> +	/*
> +	 * SIT information should be updated before segment allocation,
> +	 * since SSR needs latest valid block information.
> +	 */
> +	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
> +
>  	if (!__has_curseg_space(sbi, type))
>  		sit_i->s_ops->allocate_segment(sbi, type, false);
> +
>  	/*
> -	 * SIT information should be updated after segment allocation,
> -	 * since we need to keep dirty segments precisely under SSR.
> +	 * segment dirty status should be updated after segment allocation,
> +	 * so we just need to update status only one time after previous
> +	 * segment being closed.
>  	 */
> -	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
> +	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
> +	locate_dirty_segment(sbi, GET_SEGNO(sbi, *new_blkaddr));
>  
>  	mutex_unlock(&sit_i->sentry_lock);
>  
>