Tested-by: Yi Zhang <yi.zhang@xxxxxxxxxx>
# ./check zbd/001
common/null_blk: line 67: : No such file or directory
zbd/001 => nullb1 (sysfs and ioctl) [passed]
runtime ... 0.167s
With the patch
# ./check zbd/001
zbd/001 => nullb1 (sysfs and ioctl) [passed]
runtime 0.167s ... 0.174s
On Fri, Jul 4, 2025 at 6:54 PM Shin'ichiro Kawasaki
<shinichiro.kawasaki@xxxxxxx> wrote:
>
> Commit e2805c7911a4 ("common/null_blk: Log null_blk configuration
> parameters") introduced the write to the $FULL file in
> _configure_null_blk(). However, the $FULL file is not available when
> _configure_null_blk() is called in the fallback_device() context. In
> this case, the write fails with the error "No such file or directory".
> To avoid the error, confirm that $FULL is available before write to it.
>
> Fixes: e2805c7911a4 ("common/null_blk: Log null_blk configuration parameters")
> Link: https://github.com/linux-blktests/blktests/issues/187
> Reported-by: Yi Zhang <yi.zhang@xxxxxxxxxx>
> Suggested-by: Bart Van Assche <bvanassche@xxxxxxx>
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@xxxxxxx>
> ---
> common/null_blk | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/common/null_blk b/common/null_blk
> index 83f508f..7395754 100644
> --- a/common/null_blk
> +++ b/common/null_blk
> @@ -64,7 +64,7 @@ _configure_null_blk() {
> fi
> params+=("$@")
>
> - echo "$nullb_path ${params[*]}" >>"${FULL}"
> + [[ -n "${FULL}" ]] && echo "$nullb_path ${params[*]}" >>"${FULL}"
>
> for param in "${params[@]}"; do
> local key="${param%%=*}" val="${param#*=}"
> --
> 2.50.0
>
>
--
Best Regards,
Yi Zhang
