Re: [PATCH 13/17] btrfs: use bdev_rw_virt in scrub_one_super

在 2025/4/22 23:56, Christoph Hellwig 写道:
> Replace the code building a bio from a kernel direct map address and
> submitting it synchronously with the bdev_rw_virt helper.
> 
> Signed-off-by: Christoph Hellwig <[email protected]>

Reviewed-by: Qu Wenruo <[email protected]>

In fact I'm waiting for this helper to refactor how we do super block 
read/write, to get rid of any page cache usage of the block device.

Thanks,
Qu

> ---
>   fs/btrfs/scrub.c | 10 ++--------
>   1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 2c5edcee9450..7bdb2bc0a212 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -2770,17 +2770,11 @@ static int scrub_one_super(struct scrub_ctx *sctx, struct btrfs_device *dev,
>   			   struct page *page, u64 physical, u64 generation)
>   {
>   	struct btrfs_fs_info *fs_info = sctx->fs_info;
> -	struct bio_vec bvec;
> -	struct bio bio;
>   	struct btrfs_super_block *sb = page_address(page);
>   	int ret;
>   
> -	bio_init(&bio, dev->bdev, &bvec, 1, REQ_OP_READ);
> -	bio.bi_iter.bi_sector = physical >> SECTOR_SHIFT;
> -	__bio_add_page(&bio, page, BTRFS_SUPER_INFO_SIZE, 0);
> -	ret = submit_bio_wait(&bio);
> -	bio_uninit(&bio);
> -
> +	ret = bdev_rw_virt(dev->bdev, physical >> SECTOR_SHIFT, sb,
> +			BTRFS_SUPER_INFO_SIZE, REQ_OP_READ);
>   	if (ret < 0)
>   		return ret;
>   	ret = btrfs_check_super_csum(fs_info, sb);