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

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

From: Darrick J. Wong <djwong@kernel.org>

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: <fstests@vger.kernel.org> # 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" <djwong@kernel.org>
---
 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=$*
+
+	$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
+}
 
 _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