Re: [PATCH 1/2] common: introduce zone_capacity() to return a zone capacity

[Zorro Lang <zlang@redhat.com>]

On Thu, Sep 22, 2022 at 02:54:58PM +0900, Naohiro Aota wrote:
> Introduce _zone_capacity() to return a zone capacity of the given address
> in the given device (optional). Rewrite btrfs/237 with it.
> 
> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
> ---
>  common/zbd      | 17 +++++++++++++++++
>  tests/btrfs/237 |  8 ++------
>  2 files changed, 19 insertions(+), 6 deletions(-)
>  create mode 100644 common/zbd
> 
> diff --git a/common/zbd b/common/zbd
> new file mode 100644
> index 000000000000..329bb7be6b7b
> --- /dev/null
> +++ b/common/zbd

I don't like this abbreviation :-P If others don't open this file and read the
comment in it, they nearly no chance to guess what's this file for.

> @@ -0,0 +1,17 @@
> +#
> +# Common zoned block device specific functions
> +#
> +
> +. common/filter
> +
> +_zone_capacity() {
> +    local phy=$1
> +    local dev=$2
> +
> +    [ -z "$dev" ] && dev=$SCRATCH_DEV
> +
> +    size=$($BLKZONE_PROG report -o $phy -l 1 $dev |\
> +	       _filter_blkzone_report |\
> +	       grep -Po "cap 0x[[:xdigit:]]+" | cut -d ' ' -f 2)
> +    echo $((size << 9))
> +}

Do you have more zone related helpers are going to provide? If only this
single one helper, I think it's not worth adding a new common file. You
can put it into common/rc simply, as there're already several *zone*
related helpers in it.

We can pick up these *zone* related function into a separate include file in
one day we feel it's time (too many related helpers, and better to be maintained
individually).

Thanks,
Zorro

> diff --git a/tests/btrfs/237 b/tests/btrfs/237
> index bc6522e2200a..101094b5ce70 100755
> --- a/tests/btrfs/237
> +++ b/tests/btrfs/237
> @@ -13,7 +13,7 @@
>  _begin_fstest auto quick zone balance
>  
>  # Import common functions.
> -. ./common/filter
> +. ./common/zbd
>  
>  # real QA test starts here
>  
> @@ -56,11 +56,7 @@ fi
>  
>  start_data_bg_phy=$(get_data_bg_physical)
>  start_data_bg_phy=$((start_data_bg_phy >> 9))
> -
> -size=$($BLKZONE_PROG report -o $start_data_bg_phy -l 1 $SCRATCH_DEV |\
> -	_filter_blkzone_report |\
> -	grep -Po "cap 0x[[:xdigit:]]+" | cut -d ' ' -f 2)
> -size=$((size << 9))
> +size=$(_zone_capacity $start_data_bg_phy)
>  
>  reclaim_threshold=75
>  echo $reclaim_threshold > /sys/fs/btrfs/"$uuid"/bg_reclaim_threshold
> -- 
> 2.37.3
>