test/lvol: Add function to handle output from simple jq queries

This function exposes assoc array which consits of fields extracted
out of the parsed jq output.

Change-Id: I189c5c01e6efd60d6f2010df90093920a5d37690
Signed-off-by: Michal Berger <michalx.berger@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/778
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>

test/common/autotest_common.sh

@@ -323,6 +323,45 @@ function rpc_cmd() {
 	[[ $rc == 0 ]]
 }
 
+function rpc_cmd_simple_data_json() {
+
+	local elems="$1[@]" elem
+	local -gA jq_out=()
+	local jq val
+
+	local lvs=(
+		"uuid"
+		"name"
+		"base_bdev"
+		"total_data_clusters"
+		"free_clusters"
+		"block_size"
+		"cluster_size"
+	)
+
+	local bdev=(
+		"name"
+		"aliases[0]"
+		"block_size"
+		"num_blocks"
+		"uuid"
+		"product_name"
+	)
+
+	[[ -v $elems ]] || return 1
+
+	for elem in "${!elems}"; do
+		jq="${jq:+$jq,\"\\n\",}\"$elem\",\" \",.[0].$elem"
+	done
+	jq+=',"\n"'
+
+	shift
+	while read -r elem val; do
+		jq_out["$elem"]=$val
+	done < <(rpc_cmd "$@" | jq -jr "$jq")
+	(( ${#jq_out[@]} > 0 )) || return 1
+}
+
 function timing() {
 	direction="$1"
 	testname="$2"

test/lvol/common.sh

@@ -8,6 +8,14 @@ LVS_DEFAULT_CLUSTER_SIZE=$(( LVS_DEFAULT_CLUSTER_SIZE_MB * 1024 * 1024 ))
 LVS_DEFAULT_CAPACITY_MB=$(( MALLOC_SIZE_MB - LVS_DEFAULT_CLUSTER_SIZE_MB ))
 LVS_DEFAULT_CAPACITY=$(( LVS_DEFAULT_CAPACITY_MB * 1024 * 1024 ))
 
+function get_bdev_jq() {
+	rpc_cmd_simple_data_json bdev "$@"
+}
+
+function get_lvs_jq() {
+	rpc_cmd_simple_data_json lvs "$@"
+}
+
 function check_leftover_devices() {
 	leftover_bdevs=$(rpc_cmd bdev_get_bdevs)
 	[ "$(jq length <<< "$leftover_bdevs")" == "0" ]