Merge pull request dragonflyoss#539 from imeoer/jiangliu/fscache-mt

nydusd: wrap thread validator as func

src/bin/nydusd/main.rs

@@ -38,6 +38,8 @@ use crate::daemon::{DaemonError, NydusDaemon};
 use crate::fs_service::{FsBackendMountCmd, FsService};
 use crate::service_controller::create_daemon;
 
+use nydus::ensure_threads;
+
 #[cfg(feature = "fusedev")]
 mod fusedev;
 #[cfg(feature = "virtiofs")]
@@ -202,6 +204,10 @@ const SHARED_DIR_HELP_MESSAGE: &str = "Directory to share between host and guest
 const SHARED_DIR_HELP_MESSAGE: &str =
     "Directory to share by FUSE for testing, which also enables `passthroughfs` mode";
 
+pub fn thread_validator(v: String) -> std::result::Result<(), String> {
+    ensure_threads(v).map(|_| ())
+}
+
 #[cfg(any(feature = "fusedev", feature = "virtiofs"))]
 fn append_fs_options(app: App<'static, 'static>) -> App<'static, 'static> {
     app.arg(
@@ -270,17 +276,7 @@ fn append_fuse_options(app: App<'static, 'static>) -> App<'static, 'static> {
             .help("Number of worker threads to serve IO requests")
             .takes_value(true)
             .required(false)
-            .validator(|v| {
-                if let Ok(t) = v.parse::<i32>() {
-                    if t > 0 && t <= 1024 {
-                        Ok(())
-                    } else {
-                        Err("Invalid working thread number {}, valid values: [1-1024]".to_string())
-                    }
-                } else {
-                    Err("Input thread number is invalid".to_string())
-                }
-            }),
+            .validator(thread_validator),
     )
     .arg(
         Arg::with_name("writable")
@@ -351,18 +347,7 @@ fn append_services_subcmd_options(app: App<'static, 'static>) -> App<'static, 's
                 .help("Number of working threads to serve fscache requests")
                 .takes_value(true)
                 .required(false)
-                .validator(|v| {
-                    if let Ok(t) = v.parse::<i32>() {
-                        if t > 0 && t <= 1024 {
-                            Ok(())
-                        } else {
-                            Err("Invalid working thread number {}, valid values: [1-1024]"
-                                .to_string())
-                        }
-                    } else {
-                        Err("Input thread number is invalid".to_string())
-                    }
-                }),
+                .validator(thread_validator),
         );
 
     app.subcommand(subcmd)

src/bin/nydusd/service_controller.rs

@@ -19,6 +19,8 @@ use crate::daemon::{
     DaemonStateMachineSubscriber,
 };
 use crate::{FsService, NydusDaemon, SubCmdArgs, DAEMON_CONTROLLER};
+#[cfg(target_os = "linux")]
+use nydus::ensure_threads;
 
 pub struct ServiceController {
     bti: BuildTimeInfo,
@@ -120,20 +122,11 @@ impl ServiceController {
         };
         let tag = subargs.value_of("fscache-tag");
 
-        let mut threads = 1usize;
-        if let Some(threads_value) = subargs.value_of("fscache-threads") {
-            if let Ok(t) = threads_value.parse::<i32>() {
-                if t > 0 && t <= 1024 {
-                    threads = t as usize;
-                } else {
-                    return Err(einval!(
-                        "Invalid working thread number {}, valid values: [1-1024]"
-                    ));
-                }
-            } else {
-                return Err(einval!("Input thread number is invalid".to_string()));
-            }
-        }
+        let threads = if let Some(threads_value) = subargs.value_of("fscache-threads") {
+            ensure_threads(threads_value).map_err(|err| einval!(err))?
+        } else {
+            1usize
+        };
 
         info!(
             "Create fscache instance at {} with tag {}, {} working threads",

src/lib.rs

@@ -62,3 +62,15 @@ pub struct FsBackendDesc {
     pub mounted_time: DateTime<Local>,
     pub config: Option<serde_json::Value>,
 }
+
+pub fn ensure_threads<V: AsRef<str>>(v: V) -> std::result::Result<usize, String> {
+    if let Ok(t) = v.as_ref().parse::<usize>() {
+        if t > 0 && t <= 1024 {
+            Ok(t)
+        } else {
+            Err("Invalid working thread number {}, valid values: [1-1024]".to_string())
+        }
+    } else {
+        Err("Input thread number is invalid".to_string())
+    }
+}