Merge pull request #1514 from mulkieran/master-trylock

Use Result functions instead of match primitives

src/bin/stratisd.rs

@@ -105,20 +105,17 @@ fn initialize_log(debug: bool) -> buff_log::Handle<env_logger::Logger> {
 /// To ensure only one instance of stratisd runs at a time, acquire an
 /// exclusive lock. Return an error if lock attempt fails.
 fn trylock_pid_file() -> StratisResult<File> {
-    let mut f = match OpenOptions::new()
+    let mut f = OpenOptions::new()
         .read(true)
         .write(true)
         .create(true)
         .open(STRATISD_PID_PATH)
-    {
-        Ok(f) => f,
-        Err(e) => {
-            return Err(StratisError::Error(format!(
+        .map_err(|err| {
+            StratisError::Error(format!(
                 "Failed to create or open the stratisd PID file at {}: {}",
-                STRATISD_PID_PATH, e
-            )));
-        }
-    };
+                STRATISD_PID_PATH, err
+            ))
+        })?;
     match flock(f.as_raw_fd(), FlockArg::LockExclusiveNonblock) {
         Ok(_) => {
             f.write_all(format!("{}\n", getpid()).as_bytes())?;