Re: [PATCH 09/11] btrfs: simplify the submit_stripe_bio calling convention

[Nikolay Borisov <nborisov@suse.com>]

On 13.07.22 г. 9:13 ч., Christoph Hellwig wrote:
> Remove the orig_bio argument as it can be derived from the bioc, and
> the clone argument as it can be calculated from bioc and dev_nr.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>   fs/btrfs/volumes.c | 14 +++++---------
>   1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index d5b6777874e3c..73e538da31bc4 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -6785,13 +6785,12 @@ static void btrfs_submit_dev_bio(struct btrfs_device *dev, struct bio *bio)
>   	submit_bio(bio);
>   }
>   
> -static void submit_stripe_bio(struct btrfs_io_context *bioc,
> -			      struct bio *orig_bio, int dev_nr, bool clone)
> +static void submit_stripe_bio(struct btrfs_io_context *bioc, int dev_nr)
>   {
> -	struct bio *bio;
> +	struct bio *orig_bio = bioc->orig_bio, *bio;
>   
>   	/* Reuse the bio embedded into the btrfs_bio for the last mirror */
> -	if (!clone) {
> +	if (dev_nr == bioc->num_stripes - 1) {

nit: I think this warrants a comment that the last bios being submitted 
is always the orig one.

>   		bio = orig_bio;
>   		btrfs_bio(bio)->device = bioc->stripes[dev_nr].dev;
>   		bio->bi_end_io = btrfs_end_bio;
> @@ -6847,11 +6846,8 @@ void btrfs_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio, int mirror
>   		BUG();
>   	}
>   
> -	for (dev_nr = 0; dev_nr < total_devs; dev_nr++) {
> -		const bool should_clone = (dev_nr < total_devs - 1);
> -
> -		submit_stripe_bio(bioc, bio, dev_nr, should_clone);
> -	}
> +	for (dev_nr = 0; dev_nr < total_devs; dev_nr++)
> +		submit_stripe_bio(bioc, dev_nr);
>   }
>   
>   static bool dev_args_match_fs_devices(const struct btrfs_dev_lookup_args *args,