Re: [PATCH for-4.19] hotplug: Restore block-tap phy compatibility (again)

[Jan Beulich <jbeulich@xxxxxxxx>]

On 16.07.2024 01:46, Jason Andryuk wrote:
> From: Jason Andryuk <jason.andryuk@xxxxxxx>
> 
> "$dev" needs to be set correctly for backendtype=phy as well as
> backendtype=tap.  Move the setting into the conditional, so it can be
> handled properly for each.
> 
> (dev could be captured during tap-ctl allocate for blktap module, but it
> would not be set properly for the find_device case.  The backendtype=tap
> case would need to be handled regardless.)
> 
> Fixes: 6fcdc84927 ("hotplug: Restore block-tap phy compatibility")
> Fixes: 76a484193d ("hotplug: Update block-tap")
> 
> Signed-off-by: Jason Andryuk <jason.andryuk@xxxxxxx>

Please don't forget to Cc Oleksii for anything you still want to go into
4.19 at this point.

Jan

> ---
> Tested with backendtype=tap & tapback and backendtype=phy & blktap
> module.
> ---
>  tools/hotplug/Linux/block-tap | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/hotplug/Linux/block-tap b/tools/hotplug/Linux/block-tap
> index 5165f459c8..a0b3924370 100755
> --- a/tools/hotplug/Linux/block-tap
> +++ b/tools/hotplug/Linux/block-tap
> @@ -204,13 +204,13 @@ add()
>          tap_create
>      fi
>  
> -    # Create nbd unix path.  find_device/tap_create set pid & minor
> -    dev=$( printf "/run/blktap-control/nbd%ld.%d" "$pid" "$minor" )
> -
>      xenstore_write "$XENBUS_PATH/pid" "$pid"
>      xenstore_write "$XENBUS_PATH/minor" "$minor"
>  
>      if [ "$XENBUS_TYPE" = "vbd3" ] ; then
> +        # Create nbd unix path.  find_device/tap_create set pid & minor
> +        dev=$( printf "/run/blktap-control/nbd%ld.%d" "$pid" "$minor" )
> +
>          # $dev, as a unix socket, has major:minor 0:0.  If write_dev writes
>          # physical-device, tapback would use that incorrect minor 0.  So 
> don't
>          # write physical-device.
> @@ -218,6 +218,9 @@ add()
>  
>          success
>      else
> +        # Construct dev path from minor
> +        dev="/dev/xen/blktap-2/tapdev$minor"
> +        [ -b "$dev" ] || fatal "blktap \"$dev\" is not a block dev"
>          write_dev "$dev"
>      fi
>