Re: [PATCH 10/40] btrfs: simplify scrub_repair_page_from_good_copy

[Qu Wenruo <quwenruo.btrfs@xxxxxxx>]

On 2022/3/22 23:55, Christoph Hellwig wrote:
> The I/O in repair_io_failue is synchronous and doesn't need a btrfs_bio,
> so just use an on-stack bio.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>

Thanks,
Qu
> ---
>   fs/btrfs/scrub.c | 23 +++++++++--------------
>   1 file changed, 9 insertions(+), 14 deletions(-)
>
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 508c91e26b6e9..bb9382c02714f 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -1544,7 +1544,8 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
>   	BUG_ON(spage_good->page == NULL);
>   	if (force_write || sblock_bad->header_error ||
>   	    sblock_bad->checksum_error || spage_bad->io_error) {
> -		struct bio *bio;
> +		struct bio bio;
> +		struct bio_vec bvec;
>   		int ret;
>
>   		if (!spage_bad->dev->bdev) {
> @@ -1553,26 +1554,20 @@ static int scrub_repair_page_from_good_copy(struct scrub_block *sblock_bad,
>   			return -EIO;
>   		}
>
> -		bio = btrfs_bio_alloc(1);
> -		bio_set_dev(bio, spage_bad->dev->bdev);
> -		bio->bi_iter.bi_sector = spage_bad->physical >> 9;
> -		bio->bi_opf = REQ_OP_WRITE;
> +		bio_init(&bio, spage_bad->dev->bdev, &bvec, 1, REQ_OP_WRITE);
> +		bio.bi_iter.bi_sector = spage_bad->physical >> 9;
> +		__bio_add_page(&bio, spage_good->page, sectorsize, 0);
>
> -		ret = bio_add_page(bio, spage_good->page, sectorsize, 0);
> -		if (ret != sectorsize) {
> -			bio_put(bio);
> -			return -EIO;
> -		}
> +		btrfsic_check_bio(&bio);
> +		ret = submit_bio_wait(&bio);
> +		bio_uninit(&bio);
>
> -		btrfsic_check_bio(bio);
> -		if (submit_bio_wait(bio)) {
> +		if (ret) {
>   			btrfs_dev_stat_inc_and_print(spage_bad->dev,
>   				BTRFS_DEV_STAT_WRITE_ERRS);
>   			atomic64_inc(&fs_info->dev_replace.num_write_errors);
> -			bio_put(bio);
>   			return -EIO;
>   		}
> -		bio_put(bio);
>   	}
>
>   	return 0;