Re: [PATCH 3/3] xfs/547: fix problems with realtime

[Zorro Lang <zlang@redhat.com>]

On Tue, Jul 05, 2022 at 03:02:19PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> This test needs to fragment the free space on the data device so that
> each block added to the attr fork gets its own mapping.  If the test
> configuration sets up a rt device and rtinherit=1 on the root dir, the
> test will erroneously fragment space on the *realtime* volume.  When
> this happens, attr fork allocations are contiguous and get merged into
> fewer than 10 extents and the test fails.
> 
> Fix this test to force all allocations to be on the data device, and fix
> incorrect variable usage in the error messages.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  tests/xfs/547 |   14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> 
> diff --git a/tests/xfs/547 b/tests/xfs/547
> index 9d4216ca..60121eb9 100755
> --- a/tests/xfs/547
> +++ b/tests/xfs/547
> @@ -33,6 +33,10 @@ for nrext64 in 0 1; do
>  		      >> $seqres.full
>  	_scratch_mount >> $seqres.full
>  
> +	# Force data device extents so that we can fragment the free space
> +	# and force attr fork allocations to be non-contiguous
> +	_xfs_force_bdev data $SCRATCH_MNT
> +
>  	bsize=$(_get_file_block_size $SCRATCH_MNT)
>  
>  	testfile=$SCRATCH_MNT/testfile
> @@ -76,13 +80,15 @@ for nrext64 in 0 1; do
>  	acnt=$(_scratch_xfs_get_metadata_field core.naextents \
>  					       "path /$(basename $testfile)")
>  
> -	if (( $dcnt != 10 )); then
> -		echo "Invalid data fork extent count: $dextcnt"
> +	echo "nrext64: $nrext64 dcnt: $dcnt acnt: $acnt" >> $seqres.full
> +
> +	if [ -z "$dcnt" ] || (( $dcnt != 10 )); then

I'm wondering why we need to use bash ((...)) operator at here, is $dcnt
an expression? Can [ "$dcnt" != "10" ] help that?

Thanks,
Zorro

> +		echo "Invalid data fork extent count: $dcnt"
>  		exit 1
>  	fi
>  
> -	if (( $acnt < 10 )); then
> -		echo "Invalid attr fork extent count: $aextcnt"
> +	if [ -z "$acnt" ] || (( $acnt < 10 )); then
> +		echo "Invalid attr fork extent count: $acnt"
>  		exit 1
>  	fi
>  done
>