[Mellanox]: Improve FW upgrade: add locking mechanism.

Signed-off-by: Nazarii Hnydyn <nazariig@nvidia.com>

platform/mellanox/mlnx-fw-upgrade.j2

@@ -17,6 +17,8 @@ declare -r SCRIPT_NAME="$(basename "$0")"
 declare -r SCRIPT_PATH="$(readlink -f "$0")"
 declare -r SCRIPT_DIR="$(dirname "$SCRIPT_PATH")"
 
+declare -r LOCKFILE="/tmp/mlxfwmanager-lock"
+
 declare -r YES_PARAM="yes"
 declare -r NO_PARAM="no"
 
@@ -159,6 +161,20 @@ function ExitSuccess() {
     exit "${EXIT_SUCCESS}"
 }
 
+function LockStateChange() {
+    LogInfo "Locking ${LOCKFILE} from ${SCRIPT_NAME}"
+
+    exec {LOCKFD}>${LOCKFILE}
+    /usr/bin/flock -x ${LOCKFD}
+
+    LogInfo "Locked ${LOCKFILE} (${LOCKFD}) from ${SCRIPT_NAME}"
+}
+
+function UnlockStateChange() {
+    LogInfo "Unlocking ${LOCKFILE} (${LOCKFD}) from ${SCRIPT_NAME}"
+    /usr/bin/flock -u ${LOCKFD}
+}
+
 function WaitForDevice() {
     local -i QUERY_RETRY_COUNT_MAX="10"
     local -i QUERY_RETRY_COUNT="0"
@@ -356,10 +372,20 @@ function ExitIfQEMU() {
     fi
 }
 
+function Cleanup() {
+    if [[ -n "${LOCKFD}" ]]; then
+        UnlockStateChange
+    fi
+}
+
+trap Cleanup EXIT
+
 ParseArguments "$@"
 
 ExitIfQEMU
 
+LockStateChange
+
 WaitForDevice
 
 if [ "${IMAGE_UPGRADE}" != "${YES_PARAM}" ]; then