fix(Controller): Errors are hidden by defaul

Fixed an error hidden during the creation of cgroup,
which resulted in subsequent error propagation

Signed-off-by: jokemanfire <hu.dingyang@zte.com.cn>

Author: jokemanfire

src/fs/cgroup.rs

@@ -6,6 +6,8 @@
 
 //! This module handles cgroup operations. Start here!
 
+use log::warn;
+
 use crate::fs::error::ErrorKind::*;
 use crate::fs::error::*;
 
@@ -84,9 +86,9 @@ impl Cgroup {
         if self.hier.v2() {
             create_v2_cgroup(self.hier.root(), &self.path, &self.specified_controllers)
         } else {
-            for subsystem in &self.subsystems {
-                subsystem.to_controller().create();
-            }
+            self.subsystems
+                .iter()
+                .try_for_each(|subsystem| subsystem.to_controller().create())?;
             Ok(())
         }
     }
@@ -556,6 +558,7 @@ fn create_v2_cgroup(
         // create dir, need not check if is a file or directory
         if !fp.exists() {
             if let Err(e) = std::fs::create_dir(fp.clone()) {
+                warn!("Failed to create cgroup directory {}: {}", fp.display(), e);
                 return Err(Error::with_cause(ErrorKind::FsError, e));
             }
         }

src/fs/mod.rs

@@ -265,7 +265,7 @@ pub trait Controller {
     fn apply(&self, res: &Resources) -> Result<()>;
 
     /// Create this controller
-    fn create(&self);
+    fn create(&self) -> Result<()>;
 
     /// Does this controller already exist?
     fn exists(&self) -> bool;
@@ -323,13 +323,20 @@ where
     }
 
     /// Create this controller
-    fn create(&self) {
+    fn create(&self) -> Result<()> {
         self.verify_path()
             .unwrap_or_else(|_| panic!("path should be valid: {:?}", self.path()));
 
         match ::std::fs::create_dir_all(self.get_path()) {
-            Ok(_) => self.post_create(),
-            Err(e) => warn!("error create_dir: {:?} error: {:?}", self.get_path(), e),
+            Ok(_) => {
+                self.post_create();
+                Ok(())
+            }
+            Err(e) => {
+                let err_msg = format!("error create_dir: {:?}, because :{:?}", self.get_path(), e);
+                warn!("{}", err_msg);
+                Err(Error::with_cause(ErrorKind::Common(err_msg), e))
+            }
         }
     }