Re: [PATCH 2/2] xfs/21[67]: fix mkfs log concurrency detection

On Wed, May 20, 2026 at 12:01:12PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <[email protected]>
> 
> Both of these tests use _scratch_mkfs_xfs_supports_concurrency to detect
> if they should be adding -lconcurrency=0 to the mkfs options that are
> used to format a loop device.
> 
> However, this doesn't work in practice because of three factors: 1) the
> scratch device could have an external log set up; 2) the loop device
> does /not/ have an external log device; and 3) -lconcurrency isn't
> compatible with -llogdev.
> 
> Fix this by creating a more general mkfs option detection helper and use
> that once we have the loop device set up.
> 
> Cc: <[email protected]> # v2026.05.17
> Fixes: ffc8bad17e5b2f ("xfs/21{6,7} Use default -l concurrency=0 on mkfs.xfs that supports it")
> Signed-off-by: "Darrick J. Wong" <[email protected]>
> ---
>  common/xfs    |   15 +++++++++++++++
>  tests/xfs/216 |    9 ++++-----
>  tests/xfs/217 |    9 ++++-----
>  3 files changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/common/xfs b/common/xfs
> index 88299acdd086be..232d40fd5e01b1 100644
> --- a/common/xfs
> +++ b/common/xfs
> @@ -64,6 +64,21 @@ _scratch_mkfs_xfs_opts()
>  	echo "$MKFS_XFS_PROG $SCRATCH_OPTIONS $mkfs_opts"
>  }
>  
> +_mkfs_xfs_supported()
> +{
> +	local mkfs_opts=$*

While it seems mkfs.xfs doesn't currently receive arguments with spaces, or
using "$@" might be safer, e.g.

  local -a mkfs_opts=("$@")
  $MKFS_XFS_PROG -f -N $MKFS_OPTIONS "${mkfs_opts[@]}"

> +
> +	$MKFS_XFS_PROG -f -N $MKFS_OPTIONS $mkfs_opts
> +	local mkfs_status=$?
> +
> +	# a mkfs failure may be caused by conflicts between $MKFS_OPTIONS and
> +	# $mkfs_opts, try again without $MKFS_OPTIONS
> +	if [ $mkfs_status -ne 0 -a -n "$mkfs_opts" ]; then
> +		$MKFS_XFS_PROG -f -N $mkfs_opts
> +		mkfs_status=$?
> +	fi
> +	return $mkfs_status
> +}

Since we now have _mkfs_xfs_supported, should we call it inside
_scratch_mkfs_xfs_supported ?

Thanks,
Zorro

>  
>  _scratch_mkfs_xfs_supported()
>  {
> diff --git a/tests/xfs/216 b/tests/xfs/216
> index e3be9f3fe39ee0..bd98ee4dbfe960 100755
> --- a/tests/xfs/216
> +++ b/tests/xfs/216
> @@ -22,11 +22,6 @@ _cleanup()
>  
>  _require_scratch
>  _scratch_mkfs_xfs >/dev/null 2>&1
> -if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
> -	loop_mkfs_opts="-l concurrency=0"
> -else
> -	loop_mkfs_opts=""
> -fi
>  _scratch_mount
>  
>  _require_loop
> @@ -76,6 +71,10 @@ mkdir $LOOP_MNT
>  
>  loop_dev=$(_create_loop_device $LOOP_IMG)
>  
> +if _mkfs_xfs_supported $loop_mkfs_opts -l concurrency=0 $loop_dev &>> $seqres.full; then
> +	loop_mkfs_opts="$loop_mkfs_opts -l concurrency=0"
> +fi
> +
>  # walk over standard sizes (up to 256GB)
>  _do_mkfs 1 2 4 8 16 32 64 128 256
>  
> diff --git a/tests/xfs/217 b/tests/xfs/217
> index 5b210627b5ed18..5ba0b2198eb84f 100755
> --- a/tests/xfs/217
> +++ b/tests/xfs/217
> @@ -21,11 +21,6 @@ _cleanup()
>  
>  _require_scratch
>  _scratch_mkfs_xfs >/dev/null 2>&1
> -if _scratch_mkfs_xfs_supports_concurrency -l >> $seqres.full 2>&1; then
> -	loop_mkfs_opts="-l concurrency=0 -d concurrency=0"
> -else
> -	loop_mkfs_opts=""
> -fi
>  _scratch_mount
>  # 16T mkfs requires a bit over 2G free
>  _require_fs_space $SCRATCH_MNT 2202000
> @@ -63,6 +58,10 @@ fi
>  
>  loop_dev=$(_create_loop_device $LOOP_IMG)
>  
> +if _mkfs_xfs_supported $loop_mkfs_opts -l concurrency=0 -d concurrency=0 $loop_dev &>> $seqres.full; then
> +	loop_mkfs_opts="$loop_mkfs_opts -l concurrency=0 -d concurrency=0"
> +fi
> +
>  #
>  # walk over "new" sizes supported by recent xfsprogs.
>  # Note that the last test is for 16TB-1GB as 32bit platforms only support