Re: [f2fs-dev] [PATCH v2] f2fs: replace blk_finish_plug() with blk_flush_plug()

[Chao Yu <chao@kernel.org>]

On 2023/8/31 15:10, Chunhai Guo wrote:
> The commit 344150999b7f ("f2fs: fix to avoid potential deadlock") only
> requires unplugging current->plug. Using blk_finish_plug() is unnecessary
> as it sets current->plug as NULL and prevents wb_writeback() from using
> plug in subsequent loops. Instead, use blk_flush_plug() as a replacement.
> 
> Signed-off-by: Chunhai Guo <guochunhai@vivo.com>
> ---
>   fs/f2fs/data.c | 3 +--
>   fs/f2fs/node.c | 3 +--
>   2 files changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 916e317ac925..77b4a55d6d94 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -3346,8 +3346,7 @@ static int __f2fs_write_data_pages(struct address_space *mapping,
>   		atomic_inc(&sbi->wb_sync_req[DATA]);
>   	else if (atomic_read(&sbi->wb_sync_req[DATA])) {
>   		/* to avoid potential deadlock */
> -		if (current->plug)
> -			blk_finish_plug(current->plug);

What about?

if (current->plug) {
	struct blk_plug *plug = current->plug;

	blk_finish_plug(plug);
	blk_start_plug(plug);
}

Jaegeuk, thoughts?

Thanks,

> +		blk_flush_plug(current->plug, false);
>   		goto skip_write;
>   	}
>   
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index ee2e1dd64f25..c4b5717a8c1a 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -2126,8 +2126,7 @@ static int f2fs_write_node_pages(struct address_space *mapping,
>   		atomic_inc(&sbi->wb_sync_req[NODE]);
>   	else if (atomic_read(&sbi->wb_sync_req[NODE])) {
>   		/* to avoid potential deadlock */
> -		if (current->plug)
> -			blk_finish_plug(current->plug);
> +		blk_flush_plug(current->plug, false);
>   		goto skip_write;
>   	}
>   


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel