Re: [PATCH 3/3] xfs/530: Bail out if either of reflink or rmapbt is enabled

["Darrick J. Wong" <djwong@kernel.org>]

On Mon, Jul 26, 2021 at 12:13:13PM +0530, Chandan Babu R wrote:
> _scratch_do_mkfs constructs a mkfs command line by concatenating the values of
> 1. $mkfs_cmd
> 2. $MKFS_OPTIONS
> 3. $extra_mkfs_options
> 
> The corresponding mkfs command line fails if $MKFS_OPTIONS enables either
> reflink or rmapbt feature. The failure occurs because the test tries to create
> a filesystem with realtime device enabled. In such a case, _scratch_do_mkfs()
> will construct and invoke an mkfs command line without including the value of
> $MKFS_OPTIONS.
> 
> To prevent such silent failures, this commit causes the test to exit if it
> detects either reflink or rmapbt feature being enabled.

Er, what combinations of mkfs.xfs and MKFS_OPTIONS cause this result?
What kind of fs configuration comes out of that?

Eventually, the plan is to support rmap[1] and reflink[2] on the
realtime device, at which point this will have to be torn out and a
better solution found.

--D

[1] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=realtime-rmap
[2] https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/log/?h=realtime-reflink

> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> ---
>  tests/xfs/530 | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/tests/xfs/530 b/tests/xfs/530
> index 16dc426c..669b061d 100755
> --- a/tests/xfs/530
> +++ b/tests/xfs/530
> @@ -39,6 +39,12 @@ _require_scratch_nocheck
>  echo "* Test extending rt inodes"
>  
>  _scratch_mkfs | _filter_mkfs >> $seqres.full 2> $tmp.mkfs
> +
> +_xfs_is_reflink_enabled $SCRATCH_DEV && \
> +	_notrun "Realtime device cannot be used when reflink feature is enabled"
> +_xfs_is_rmapbt_enabled $SCRATCH_DEV && \
> +	_notrun "Realtime device cannot be used when rmapbt feature is enabled"
> +
>  . $tmp.mkfs
>  
>  echo "Create fake rt volume"
> -- 
> 2.30.2
>