[PATCHv2 blktests] nvme/058: detach loop device after test finish

[Nilay Shroff <nilay@linux.ibm.com>]

The nvme/058 creates three (temp file backed) namespaces and
attach each namespace to a loop device while starting the test.
However it never detach those namespaces from the loop device
once test finishes. Ideally, we should detach loop device from
namespace so that the associated loop device is later destroyed
and its resources are released. This patch helps detach each
namespace from its associated loop device after test finishes.

Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
---
Changes from v1:
    - keep blkdevs, which are used for setting up ns, in an array
      and then later access the array to free/detach each blkdev
      (Shinichiro Kawasaki)
    - use longer option name instead of short name for readability
      (Shinichiro Kawasaki)
---
 tests/nvme/058 | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tests/nvme/058 b/tests/nvme/058
index d230a21..815503f 100755
--- a/tests/nvme/058
+++ b/tests/nvme/058
@@ -65,11 +65,13 @@ test() {
 	for ((d = 1; d <= num_namespaces; d++)); do
 		local file_path
 		local blkdev
+		local -a blkdevs
 		local uuid
 
 		file_path="${TMPDIR}/img${d}"
 		truncate -s "${NVME_IMG_SIZE}" "${file_path}"
 		blkdev="$(losetup -f --show "${file_path}")"
+		blkdevs+=("$blkdev")
 		uuid="$(uuidgen)"
 		_create_nvmet_ns --nsid "${d}" --blkdev "${blkdev}" \
 				 --uuid "${uuid}" --grpid "${d}" > /dev/null
@@ -99,6 +101,11 @@ test() {
 	done
 
 	_nvme_disconnect_subsys
+
+	for blkdev in "${blkdevs[@]}"; do
+		losetup --detach "$blkdev"
+	done
+
 	_nvmet_target_cleanup
 
 	echo "Test complete"
-- 
2.47.1