[PATCHv2 blktests] nvme: add test for creating/deleting file-ns

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

This is regression test for commit be647e2c76b2 (nvme: use srcu for
iterating namespace list)[1]. It is fixed in commit ff0ffe5b7c3c(nvme:
fix namespace removal list)[2].

This test uses a regular file backed loop device for creating and then
deleting an NVMe namespace in a loop.

[1] https://lore.kernel.org/all/2312e6c3-a069-4388-a863-df7e261b9d70@linux.vnet.ibm.com/
[2] https://lore.kernel.org/all/20240613164246.75205-1-kbusch@meta.com/

Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
---
Changes from v1:
    - Add nvme prefix in the subject line instead of loop (Chaitanya)
    - Enrich the commit log with details including link to regression 
      discussion and fix commit (Chaitanya)
    - Few other formatting cleanup (Chaitanya)
    - Add fix commit information in the test header (Shinichiro)
    - Instead of using default 1000 iteration for test,
      set the test iteration count to 20 (Shinichiro)
    - Update test case no. to nvme/052 (Shinichiro)
---
 tests/nvme/052     | 69 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/nvme/052.out |  2 ++
 2 files changed, 71 insertions(+)
 create mode 100755 tests/nvme/052
 create mode 100644 tests/nvme/052.out

diff --git a/tests/nvme/052 b/tests/nvme/052
new file mode 100755
index 0000000..9daed8f
--- /dev/null
+++ b/tests/nvme/052
@@ -0,0 +1,69 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-3.0+
+# Copyright (C) 2024 Nilay Shroff
+#
+# Regression test for commit be647e2c76b2(nvme: use srcu for iterating
+# namespace list). This regression is resolved with commit ff0ffe5b7c3c
+# (nvme: fix namespace removal list)
+
+. tests/nvme/rc
+
+DESCRIPTION="Test file-ns creation/deletion under one subsystem"
+
+requires() {
+	_nvme_requires
+	_have_loop
+	_require_nvme_trtype_is_loop
+}
+
+set_conditions() {
+	_set_nvme_trtype "$@"
+}
+
+test() {
+	echo "Running ${TEST_NAME}"
+
+	_setup_nvmet
+
+	local subsys="blktests-subsystem-1"
+	local iterations=20
+	local loop_dev
+	local port
+
+	truncate -s "${NVME_IMG_SIZE}" "$(_nvme_def_file_path)"
+
+	loop_dev="$(losetup -f --show "$(_nvme_def_file_path)")"
+
+	port="$(_create_nvmet_port "${nvme_trtype}")"
+
+	_nvmet_target_setup --subsysnqn "${subsys}" --blkdev "${loop_dev}"
+
+	_nvme_connect_subsys --subsysnqn "${subsys}"
+
+	# start iteration from ns-id 2 because ns-id 1 is created
+	# by default when nvme target is setup. Also ns-id 1 is
+	# deleted when nvme target is cleaned up.
+	for ((i = 2; i <= iterations; i++)); do {
+		truncate -s "${NVME_IMG_SIZE}" "$(_nvme_def_file_path).$i"
+		_create_nvmet_ns "${subsys}" "${i}" "$(_nvme_def_file_path).$i"
+
+		# allow async request to be processed
+		sleep 1
+
+		_remove_nvmet_ns "${subsys}" "${i}"
+		rm "$(_nvme_def_file_path).$i"
+	}
+	done
+
+	_nvme_disconnect_subsys --subsysnqn "${subsys}" >> "${FULL}" 2>&1
+
+	_nvmet_target_cleanup --subsysnqn "${subsys}" --blkdev "${loop_dev}"
+
+	_remove_nvmet_port "${port}"
+
+	losetup -d "$loop_dev"
+
+	rm "$(_nvme_def_file_path)"
+
+	echo "Test complete"
+}
diff --git a/tests/nvme/052.out b/tests/nvme/052.out
new file mode 100644
index 0000000..f2d186d
--- /dev/null
+++ b/tests/nvme/052.out
@@ -0,0 +1,2 @@
+Running nvme/052
+Test complete
-- 
2.45.1