The current implementation of the test case loop/010 assumes that the
prepared loop device is /dev/loop0, which is not always true. When other
loop devices are set up before the test case run, the assumption is
wrong and the test case fails.

To avoid the failure, use the prepared loop device name stored in
$loop_device instead of /dev/loop0. Adjust the grep string to meet the
device name. Also use "losetup --detach" instead of
"losetup --detach-all" to not detach the loop devices which existed
before the test case runs.

Fixes: 1c4ae4fed9b4 ("loop: Detect a race condition between loop detach and open")
Signed-off-by: Shin'ichiro Kawasaki <redacted>
---
 tests/loop/010 | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/tests/loop/010 b/tests/loop/010
index ea396ec..f8c6f2c 100755
--- a/tests/loop/010
+++ b/tests/loop/010

@@ -16,18 +16,26 @@ requires() {
 }
 
 create_loop() {
+	local dev
+
 	while true
 	do
-		loop_device="$(losetup --partscan --find --show "${image_file}")"
-		blkid /dev/loop0p1 >& /dev/null
+		dev="$(losetup --partscan --find --show "${image_file}")"
+		if [[ $dev != "$1" ]]; then
+			echo "Unepxected loop device set up: $dev"
+			return
+		fi
+		blkid "$dev" >& /dev/null