Re: [PATCH 2/2] fstests: add configuration option for executing post mkfs commands

[Anand Jain <anand.jain@oracle.com>]

>>>>> @@ -690,17 +690,48 @@ _require_btrfs_scratch_logical_resolve_v2()
>>>>>        _scratch_unmount
>>>>>    }
>>>>>
>>>>> +post_scratch_mkfs_cmd()
>>>>> +{
>>>>> +    if [[ -v POST_SCRATCH_MKFS_CMD ]]; then
>>>>> +        echo "$POST_SCRATCH_MKFS_CMD $SCRATCH_DEV"
>>>>> +        $POST_SCRATCH_MKFS_CMD $SCRATCH_DEV
>>>>> +        return $?
>>>>> +    fi
> 
> Ideally this should be something like:
> 
> export SCRATCH_BTRFS_UUID='<uuid spec>'
> 
> btrfs_tune_dev() {
> 	local dev="$1"
> 
> 	if [ -n "$SCRATCH_BTRFS_UUID" ]; then
> 		btrfstune -m $SCRATCH_BTRFS_UUID $dev
> 		return $?
> 	fi
> 	return 0;
> }
> 
> _scratch_pool_mkfs_btrfs()
> {
> 	.....
> 	btrfs_tune_dev $SCRATCH_DEV_POOL
> 	.....
> }	
> 
> _scratch_mkfs_btrfs()
> {
> 	.....
> 	btrfs_tune_dev $SCRATCH_DEV
> 	.....
> }	
> 
> See how different it becomes when you stop thinking about filesystem
> configuration as a generic post-mkfs command and instead think of it
> as just another configuration option?


There's a possibility that mkfs.btrfs might include an option similar
to btrfstune -m, but its main purpose would likely be for running
fstests as there isn't any other use-case for it. If this addition
happens, I can withdraw this patch.

However, to clarify your approach mentioned above, if we want to set
SCRATCH_BTRFS_UUID to the UUID of TEST_DEV, then the config file
should contain something like this:

    SCRATCH_BTRFS_UUID=$(blkid /dev/sda1 | awk '{print $2}' | cut -d"=" 
-f2 | sed s/\"//g)


This should go in the config file. Right?

Thanks, Anand