Merge pull request #146 from fidencio/topic/release-v0.3.5

release: v0.3.5

.github/workflows/bvt.yaml

@@ -1,7 +1,7 @@
 name: BVT
 on: [pull_request]
 env:
-  RUST_VERSION: 1.52
+  RUST_VERSION: 1.69.0
 jobs:
   build:
     name: Build

.gitignore

@@ -8,7 +8,3 @@ Cargo.lock
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
-
-/target
-**/*.rs.bk
-Cargo.lock

Cargo.toml

@@ -5,7 +5,7 @@ repository = "https://github.com/kata-containers/cgroups-rs"
 keywords = ["linux", "cgroup", "containers", "isolation"]
 categories = ["os", "api-bindings", "os::unix-apis"]
 license = "MIT OR Apache-2.0"
-version = "0.2.11"
+version = "0.3.5"
 authors = ["The Kata Containers community <kata-dev@lists.katacontainers.io>", "Levente Kurusa <lkurusa@acm.org>", "Sam Wilson <tecywiz121@hotmail.com>"]
 edition = "2018"
 homepage = "https://github.com/kata-containers/cgroups-rs"

src/blkio.rs

@@ -43,7 +43,7 @@ pub struct BlkIoData {
     pub data: u64,
 }
 
-#[derive(Eq, PartialEq, Debug)]
+#[derive(Eq, PartialEq, Debug, Default)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 /// Per-device activity from the control group.
 pub struct IoService {
@@ -59,6 +59,8 @@ pub struct IoService {
     pub sync: u64,
     /// How many items were asynchronously transferred.
     pub r#async: u64,
+    /// How many items were discarded.
+    pub discard: u64,
     /// Total number of items transferred.
     pub total: u64,
 }
@@ -87,44 +89,62 @@ pub struct IoStat {
 }
 
 fn parse_io_service(s: String) -> Result<Vec<IoService>> {
-    s.lines()
+    let mut io_services = Vec::<IoService>::new();
+    let mut io_service = IoService::default();
+
+    let lines = s
+        .lines()
         .filter(|x| x.split_whitespace().count() == 3)
         .map(|x| {
             let mut spl = x.split_whitespace();
-            (spl.next().unwrap(), spl.next().unwrap(), spl.next().unwrap())
+            (
+                spl.next().unwrap(),
+                spl.next().unwrap(),
+                spl.next().unwrap(),
+            )
         })
         .map(|(a, b, c)| {
             let mut spl = a.split(':');
-            (spl.next().unwrap(), spl.next().unwrap(), b, c)
-        })
-        .collect::<Vec<_>>()
-        .chunks(5)
-        .map(|x| {
-            match x {
-                [(major, minor, "Read", read_val), (_, _, "Write", write_val),
-                   (_, _, "Sync", sync_val), (_, _, "Async", async_val),
-                   (_, _, "Total", total_val)] =>
-                    Some(IoService {
-                        major: major.parse::<i16>().unwrap(),
-                        minor: minor.parse::<i16>().unwrap(),
-                        read: read_val.parse::<u64>().unwrap(),
-                        write: write_val.parse::<u64>().unwrap(),
-                        sync: sync_val.parse::<u64>().unwrap(),
-                        r#async: async_val.parse::<u64>().unwrap(),
-                        total: total_val.parse::<u64>().unwrap(),
-                    }),
-               _ => None,
-            }
-        })
-        .fold(Ok(Vec::new()), |acc, x| {
-            if acc.is_err() || x.is_none() {
-                Err(Error::new(ParseError))
-            } else {
-                let mut acc = acc.unwrap();
-                acc.push(x.unwrap());
-                Ok(acc)
-            }
+            (
+                spl.next().unwrap().parse::<i16>(),
+                spl.next().unwrap().parse::<i16>(),
+                b,
+                c,
+            )
         })
+        .collect::<Vec<_>>();
+
+    for (major_num, minor_num, op, val) in lines.iter() {
+        let major = *major_num.as_ref().map_err(|_| Error::new(ParseError))?;
+        let minor = *minor_num.as_ref().map_err(|_| Error::new(ParseError))?;
+
+        if (major != io_service.major || minor != io_service.minor) && io_service.major != 0 {
+            // new block device
+            io_services.push(io_service);
+            io_service = IoService::default();
+        }
+
+        io_service.major = major;
+        io_service.minor = minor;
+
+        let val = val.parse::<u64>().map_err(|_| Error::new(ParseError))?;
+
+        match *op {
+            "Read" => io_service.read = val,
+            "Write" => io_service.write = val,
+            "Sync" => io_service.sync = val,
+            "Async" => io_service.r#async = val,
+            "Discard" => io_service.discard = val,
+            "Total" => io_service.total = val,
+            _ => {}
+        }
+    }
+
+    if io_service.major != 0 {
+        io_services.push(io_service);
+    }
+
+    Ok(io_services)
 }
 
 fn get_value(s: &str) -> String {
@@ -410,10 +430,10 @@ impl<'a> From<&'a Subsystem> for &'a BlkIoController {
 
 impl BlkIoController {
     /// Constructs a new `BlkIoController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             v2,
         }
     }
@@ -817,6 +837,7 @@ mod test {
 8:32 Write 0
 8:32 Sync 4280320
 8:32 Async 0
+8:32 Discard 1
 8:32 Total 4280320
 8:48 Read 5705479168
 8:48 Write 56096055296
@@ -833,28 +854,6 @@ mod test {
 8:0 Sync 7192576
 8:0 Async 0
 8:0 Total 7192576
-Total 61823067136
- ";
-
-    static TEST_WRONG_VALUE: &str = "\
-8:32 Read 4280320
-8:32 Write 0
-8:32 Async 0
-8:32 Total 4280320 8:48 Read 5705479168
-8:48 Write 56096055296
-8:48 Sync 11213923328
-8:48 Async 50587611136
-8:48 Total 61801534464
-8:16 Read 10059776
-8:16 Write 0
-8:16 Sync 10059776
-8:16 Async 0
-8:16 Total 10059776
-8:0 Read 7192576
-8:0 Write 0
-8:0 Sync 7192576
-8:0 Async 0
-8:0 Total 7192576
 Total 61823067136
  ";
 
@@ -884,6 +883,7 @@ Total 61823067136
                     write: 0,
                     sync: 4280320,
                     r#async: 0,
+                    discard: 1,
                     total: 4280320,
                 },
                 IoService {
@@ -893,6 +893,7 @@ Total 61823067136
                     write: 56096055296,
                     sync: 11213923328,
                     r#async: 50587611136,
+                    discard: 0,
                     total: 61801534464,
                 },
                 IoService {
@@ -902,6 +903,7 @@ Total 61823067136
                     write: 0,
                     sync: 10059776,
                     r#async: 0,
+                    discard: 0,
                     total: 10059776,
                 },
                 IoService {
@@ -911,12 +913,34 @@ Total 61823067136
                     write: 0,
                     sync: 7192576,
                     r#async: 0,
+                    discard: 0,
                     total: 7192576,
                 }
             ]
         );
-        let err = parse_io_service(TEST_WRONG_VALUE.to_string()).unwrap_err();
-        assert_eq!(err.kind(), &ErrorKind::ParseError,);
+
+        let invalid_values = vec![
+            "\
+8:32 Read 4280320
+8:32 Write a
+8:32 Async 1
+",
+            "\
+8:32 Read 4280320
+b:32 Write 1
+8:32 Async 1
+",
+            "\
+8:32 Read 4280320
+8:32 Write 1
+8:c Async 1
+",
+        ];
+
+        for value in invalid_values {
+            let err = parse_io_service(value.to_string()).unwrap_err();
+            assert_eq!(err.kind(), &ErrorKind::ParseError,);
+        }
     }
 
     #[test]

src/cgroup.rs

@@ -9,6 +9,7 @@
 use crate::error::ErrorKind::*;
 use crate::error::*;
 
+use crate::hierarchies::V1;
 use crate::{CgroupPid, ControllIdentifier, Controller, Hierarchy, Resources, Subsystem};
 
 use std::collections::HashMap;
@@ -16,6 +17,11 @@ use std::convert::From;
 use std::fs;
 use std::path::{Path, PathBuf};
 
+pub const CGROUP_MODE_DOMAIN: &str = "domain";
+pub const CGROUP_MODE_DOMAIN_THREADED: &str = "domain threaded";
+pub const CGROUP_MODE_DOMAIN_INVALID: &str = "domain invalid";
+pub const CGROUP_MODE_THREADED: &str = "threaded";
+
 /// A control group is the central structure to this crate.
 ///
 ///
@@ -36,14 +42,18 @@ pub struct Cgroup {
     /// The hierarchy.
     hier: Box<dyn Hierarchy>,
     path: String,
+
+    /// List of controllers specifically enabled in the control group.
+    specified_controllers: Option<Vec<String>>,
 }
 
 impl Clone for Cgroup {
     fn clone(&self) -> Self {
         Cgroup {
             subsystems: self.subsystems.clone(),
-            path: self.path.clone(),
             hier: crate::hierarchies::auto(),
+            path: self.path.clone(),
+            specified_controllers: None,
         }
     }
 }
@@ -54,48 +64,72 @@ impl Default for Cgroup {
             subsystems: Vec::new(),
             hier: crate::hierarchies::auto(),
             path: "".to_string(),
+            specified_controllers: None,
         }
     }
 }
 
 impl Cgroup {
+    pub fn v2(&self) -> bool {
+        self.hier.v2()
+    }
+
+    /// Return the path the cgroup is located at.
+    pub fn path(&self) -> &str {
+        &self.path
+    }
+
     /// Create this control group.
-    fn create(&self) {
+    pub fn create(&self) -> Result<()> {
         if self.hier.v2() {
-            let _ret = create_v2_cgroup(self.hier.root(), &self.path);
+            create_v2_cgroup(self.hier.root(), &self.path, &self.specified_controllers)
         } else {
             for subsystem in &self.subsystems {
                 subsystem.to_controller().create();
             }
+            Ok(())
         }
     }
 
-    pub fn v2(&self) -> bool {
-        self.hier.v2()
-    }
-
     /// Create a new control group in the hierarchy `hier`, with name `path`.
     ///
     /// Returns a handle to the control group that can be used to manipulate it.
-    pub fn new<P: AsRef<Path>>(hier: Box<dyn Hierarchy>, path: P) -> Cgroup {
+    pub fn new<P: AsRef<Path>>(hier: Box<dyn Hierarchy>, path: P) -> Result<Cgroup> {
         let cg = Cgroup::load(hier, path);
-        cg.create();
-        cg
+        cg.create()?;
+        Ok(cg)
+    }
+
+    /// Create a new control group in the hierarchy `hier`, with name `path`.
+    ///
+    /// Returns a handle to the control group that can be used to manipulate it.
+    pub fn new_with_specified_controllers<P: AsRef<Path>>(
+        hier: Box<dyn Hierarchy>,
+        path: P,
+        specified_controllers: Option<Vec<String>>,
+    ) -> Result<Cgroup> {
+        let cg = if let Some(sc) = specified_controllers {
+            Cgroup::load_with_specified_controllers(hier, path, sc)
+        } else {
+            Cgroup::load(hier, path)
+        };
+        cg.create()?;
+        Ok(cg)
     }
 
     /// Create a new control group in the hierarchy `hier`, with name `path` and `relative_paths`
     ///
     /// Returns a handle to the control group that can be used to manipulate it.
     ///
-    /// Note that this method is only meaningful for cgroup v1, call it is equivalent to call `new` in the v2 mode
+    /// Note that this method is only meaningful for cgroup v1, call it is equivalent to call `new` in the v2 mode.
     pub fn new_with_relative_paths<P: AsRef<Path>>(
         hier: Box<dyn Hierarchy>,
         path: P,
         relative_paths: HashMap<String, String>,
-    ) -> Cgroup {
+    ) -> Result<Cgroup> {
         let cg = Cgroup::load_with_relative_paths(hier, path, relative_paths);
-        cg.create();
-        cg
+        cg.create()?;
+        Ok(cg)
     }
 
     /// Create a handle for a control group in the hierarchy `hier`, with name `path`.
@@ -116,6 +150,34 @@ impl Cgroup {
             path: path.to_str().unwrap().to_string(),
             subsystems,
             hier,
+            specified_controllers: None,
+        }
+    }
+
+    /// Create a handle for a specified control group in the hierarchy `hier`, with name `path`.
+    ///
+    /// Returns a handle to the control group (that possibly does not exist until `create()` has
+    /// been called on the cgroup.
+    pub fn load_with_specified_controllers<P: AsRef<Path>>(
+        hier: Box<dyn Hierarchy>,
+        path: P,
+        specified_controllers: Vec<String>,
+    ) -> Cgroup {
+        let path = path.as_ref();
+        let mut subsystems = hier.subsystems();
+        if path.as_os_str() != "" {
+            subsystems = subsystems
+                .into_iter()
+                .filter(|x| specified_controllers.contains(&x.controller_name()))
+                .map(|x| x.enter(path))
+                .collect::<Vec<_>>();
+        }
+
+        Cgroup {
+            path: path.to_str().unwrap().to_string(),
+            subsystems,
+            hier,
+            specified_controllers: Some(specified_controllers),
         }
     }
 
@@ -159,6 +221,7 @@ impl Cgroup {
             subsystems,
             hier,
             path: path.to_str().unwrap().to_string(),
+            specified_controllers: None,
         }
     }
 
@@ -233,36 +296,137 @@ impl Cgroup {
         None
     }
 
+    /// Removes tasks from the control group by thread group id.
+    ///
+    /// Note that this means that the task will be moved back to the root control group in the
+    /// hierarchy and any rules applied to that control group will _still_ apply to the proc.
+    pub fn remove_task_by_tgid(&self, tgid: CgroupPid) -> Result<()> {
+        self.hier.root_control_group().add_task_by_tgid(tgid)
+    }
+
     /// Removes a task from the control group.
     ///
     /// Note that this means that the task will be moved back to the root control group in the
     /// hierarchy and any rules applied to that control group will _still_ apply to the task.
-    pub fn remove_task(&self, pid: CgroupPid) {
-        let _ = self.hier.root_control_group().add_task(pid);
+    pub fn remove_task(&self, tid: CgroupPid) -> Result<()> {
+        self.hier.root_control_group().add_task(tid)
+    }
+
+    /// Moves tasks to the parent control group by thread group id.
+    pub fn move_task_to_parent_by_tgid(&self, tgid: CgroupPid) -> Result<()> {
+        self.hier
+            .parent_control_group(&self.path)
+            .add_task_by_tgid(tgid)
+    }
+
+    /// Moves a task to the parent control group.
+    pub fn move_task_to_parent(&self, tid: CgroupPid) -> Result<()> {
+        self.hier.parent_control_group(&self.path).add_task(tid)
+    }
+
+    /// Return a handle to the parent control group in the hierarchy.
+    pub fn parent_control_group(&self) -> Cgroup {
+        self.hier.parent_control_group(&self.path)
+    }
+
+    /// Kill every process in the control group. Only supported for v2 cgroups and on
+    /// kernels 5.14+. This will fail with InvalidOperation if the 'cgroup.kill' file does
+    /// not exist.
+    pub fn kill(&self) -> Result<()> {
+        if !self.v2() {
+            return Err(Error::new(CgroupVersion));
+        }
+
+        let val = "1";
+        let file_name = "cgroup.kill";
+        let p = self.hier.root().join(self.path.clone()).join(file_name);
+
+        // If cgroup.kill doesn't exist they're not on 5.14+ so lets
+        // surface some error the caller can check against.
+        if !p.exists() {
+            return Err(Error::new(InvalidOperation));
+        }
+
+        fs::write(p, val)
+            .map_err(|e| Error::with_cause(WriteFailed(file_name.to_string(), val.to_string()), e))
     }
 
     /// Attach a task to the control group.
-    pub fn add_task(&self, pid: CgroupPid) -> Result<()> {
+    pub fn add_task(&self, tid: CgroupPid) -> Result<()> {
         if self.v2() {
             let subsystems = self.subsystems();
             if !subsystems.is_empty() {
                 let c = subsystems[0].to_controller();
-                c.add_task(&pid)
+                let cgroup_type = self.get_cgroup_type()?;
+                // In cgroup v2, writing to the cgroup.threads file is only supported in thread mode.
+                if cgroup_type == *CGROUP_MODE_DOMAIN_THREADED
+                    || cgroup_type == *CGROUP_MODE_THREADED
+                {
+                    // It is used to move the threads of a process into a cgroup in thread mode.
+                    c.add_task(&tid)
+                } else {
+                    // When the cgroup type is domain or domain invalid,
+                    // cgroup.threads cannot be written.
+                    Err(Error::new(CgroupMode))
+                }
             } else {
-                Ok(())
+                Err(Error::new(SubsystemsEmpty))
             }
         } else {
             self.subsystems()
                 .iter()
-                .try_for_each(|sub| sub.to_controller().add_task(&pid))
+                .try_for_each(|sub| sub.to_controller().add_task(&tid))
         }
     }
 
-    /// Attach a task to the control group by thread group id.
-    pub fn add_task_by_tgid(&self, pid: CgroupPid) -> Result<()> {
-        self.subsystems()
-            .iter()
-            .try_for_each(|sub| sub.to_controller().add_task_by_tgid(&pid))
+    /// Attach tasks to the control group by thread group id.
+    pub fn add_task_by_tgid(&self, tgid: CgroupPid) -> Result<()> {
+        if self.v2() {
+            let subsystems = self.subsystems();
+            if !subsystems.is_empty() {
+                let c = subsystems[0].to_controller();
+                // It is used to move a thread of the process to a cgroup,
+                // and other threads of the process will also move together.
+                c.add_task_by_tgid(&tgid)
+            } else {
+                Err(Error::new(SubsystemsEmpty))
+            }
+        } else {
+            self.subsystems()
+                .iter()
+                .try_for_each(|sub| sub.to_controller().add_task_by_tgid(&tgid))
+        }
+    }
+
+    /// set cgroup.type
+    pub fn set_cgroup_type(&self, cgroup_type: &str) -> Result<()> {
+        if self.v2() {
+            let subsystems = self.subsystems();
+            if !subsystems.is_empty() {
+                let c = subsystems[0].to_controller();
+                c.set_cgroup_type(cgroup_type)
+            } else {
+                Err(Error::new(SubsystemsEmpty))
+            }
+        } else {
+            Err(Error::new(CgroupVersion))
+        }
+    }
+
+    /// get cgroup.type
+    pub fn get_cgroup_type(&self) -> Result<String> {
+        if self.v2() {
+            let subsystems = self.subsystems();
+            if !subsystems.is_empty() {
+                let c = subsystems[0].to_controller();
+                let cgroup_type = c.get_cgroup_type()?;
+                Ok(cgroup_type)
+            } else {
+                Err(Error::new(SubsystemsEmpty))
+            }
+        } else {
+            Err(Error::new(CgroupVersion))
+        }
     }
 
     /// Set notify_on_release to the control group.
@@ -281,6 +445,33 @@ impl Cgroup {
             .try_for_each(|sub| sub.to_controller().set_release_agent(path))
     }
 
+    /// Returns an Iterator that can be used to iterate over the procs that are currently in the
+    /// control group.
+    pub fn procs(&self) -> Vec<CgroupPid> {
+        // Collect the procs from all subsystems
+        let mut v = if self.v2() {
+            let subsystems = self.subsystems();
+            if !subsystems.is_empty() {
+                let c = subsystems[0].to_controller();
+                c.procs()
+            } else {
+                vec![]
+            }
+        } else {
+            self.subsystems()
+                .iter()
+                .map(|x| x.to_controller().procs())
+                .fold(vec![], |mut acc, mut x| {
+                    acc.append(&mut x);
+                    acc
+                })
+        };
+
+        v.sort();
+        v.dedup();
+        v
+    }
+
     /// Returns an Iterator that can be used to iterate over the tasks that are currently in the
     /// control group.
     pub fn tasks(&self) -> Vec<CgroupPid> {
@@ -307,6 +498,13 @@ impl Cgroup {
         v.dedup();
         v
     }
+
+    /// Checks if the cgroup exists.
+    ///
+    /// Returns true if at least one subsystem exists.
+    pub fn exists(&self) -> bool {
+        self.subsystems().iter().any(|e| e.to_controller().exists())
+    }
 }
 
 pub const UNIFIED_MOUNTPOINT: &str = "/sys/fs/cgroup";
@@ -324,13 +522,26 @@ fn supported_controllers() -> Vec<String> {
     let ret = fs::read_to_string(p.as_str());
     ret.unwrap_or_default()
         .split(' ')
-        .map(|x| x.to_string())
+        .map(|x| x.trim().to_string())
         .collect::<Vec<String>>()
 }
 
-fn create_v2_cgroup(root: PathBuf, path: &str) -> Result<()> {
+fn create_v2_cgroup(
+    root: PathBuf,
+    path: &str,
+    specified_controllers: &Option<Vec<String>>,
+) -> Result<()> {
     // controler list ["memory", "cpu"]
-    let controllers = supported_controllers();
+    let controllers = if let Some(s_controllers) = specified_controllers.clone() {
+        if verify_supported_controllers(s_controllers.as_ref()) {
+            s_controllers
+        } else {
+            return Err(Error::new(ErrorKind::SpecifiedControllers));
+        }
+    } else {
+        supported_controllers()
+    };
+
     let mut fp = root;
 
     // enable for root
@@ -358,6 +569,16 @@ fn create_v2_cgroup(root: PathBuf, path: &str) -> Result<()> {
     Ok(())
 }
 
+pub fn verify_supported_controllers(controllers: &[String]) -> bool {
+    let sc = supported_controllers();
+    for controller in controllers.iter() {
+        if !sc.contains(controller) {
+            return false;
+        }
+    }
+    true
+}
+
 pub fn get_cgroups_relative_paths() -> Result<HashMap<String, String>> {
     let path = "/proc/self/cgroup".to_string();
     get_cgroups_relative_paths_by_path(path)
@@ -368,19 +589,47 @@ pub fn get_cgroups_relative_paths_by_pid(pid: u32) -> Result<HashMap<String, Str
     get_cgroups_relative_paths_by_path(path)
 }
 
+fn get_cgroup_destination(mut mount_root: String, pidpath: String) -> String {
+    if mount_root == "/" {
+        mount_root = String::from("");
+    }
+    pidpath.trim_start_matches(&mount_root).to_string()
+}
+
+pub fn existing_path(paths: HashMap<String, String>) -> Result<HashMap<String, String>> {
+    let mount_roots_v1 = V1::new();
+    let mut mount_roots_subsystems_map = HashMap::new();
+
+    for s in mount_roots_v1.subsystems().iter() {
+        let controller_name = s.controller_name();
+        let path_from_cgroup = paths
+            .get(&controller_name)
+            .ok_or(Error::new(Common(format!(
+                "controller {} found in mountinfo, but not found in cgroup.",
+                controller_name
+            ))))?;
+        let path_from_mountinfo = s.to_controller().base().to_string_lossy().to_string();
+
+        let des_path = get_cgroup_destination(path_from_mountinfo, path_from_cgroup.to_owned());
+        mount_roots_subsystems_map.insert(controller_name, des_path);
+    }
+    Ok(mount_roots_subsystems_map)
+}
+
 fn get_cgroups_relative_paths_by_path(path: String) -> Result<HashMap<String, String>> {
     let mut m = HashMap::new();
     let content =
         fs::read_to_string(path.clone()).map_err(|e| Error::with_cause(ReadFailed(path), e))?;
-    for l in content.lines() {
-        let fl: Vec<&str> = l.split(':').collect();
-        if fl.len() != 3 {
-            continue;
-        }
-
-        let keys: Vec<&str> = fl[1].split(',').collect();
-        for key in &keys {
-            m.insert(key.to_string(), fl[2].to_string());
+    // cgroup path may have ":" , likes
+    // "2:cpu,cpuacct:/system.slice/containerd.service/test.slice:cri-containerd:96b37a2edf84351487f42039e137427f1812f678850675fac214caf597ee5e4a"
+    for line in content.lines() {
+        if let Some((first_value_part, remaining_path)) =
+            line.split_once(':').unwrap_or_default().1.split_once(':')
+        {
+            let keys: Vec<&str> = first_value_part.split(',').collect();
+            keys.iter().for_each(|key| {
+                m.insert(key.to_string(), remaining_path.to_string());
+            });
         }
     }
     Ok(m)

src/cgroup_builder.rs

@@ -57,11 +57,11 @@
 //!              .read(6, 1, 10)
 //!              .write(11, 1, 100)
 //!          .done()
-//!      .build(h);
+//!      .build(h).unwrap();
 //! ```
 
 use crate::{
-    BlkIoDeviceResource, BlkIoDeviceThrottleResource, Cgroup, DeviceResource, Hierarchy,
+    BlkIoDeviceResource, BlkIoDeviceThrottleResource, Cgroup, DeviceResource, Error, Hierarchy,
     HugePageResource, MaxValue, NetworkPriority, Resources,
 };
 
@@ -80,6 +80,8 @@ pub struct CgroupBuilder {
     name: String,
     /// Internal, unsupported field: use the associated builders instead.
     resources: Resources,
+    /// List of controllers specifically enabled in the control group.
+    specified_controllers: Option<Vec<String>>,
 }
 
 impl CgroupBuilder {
@@ -90,6 +92,7 @@ impl CgroupBuilder {
         CgroupBuilder {
             name: name.to_owned(),
             resources: Resources::default(),
+            specified_controllers: None,
         }
     }
 
@@ -134,10 +137,22 @@ impl CgroupBuilder {
     }
 
     /// Finalize the control group, consuming the builder and creating the control group.
-    pub fn build(self, hier: Box<dyn Hierarchy>) -> Cgroup {
-        let cg = Cgroup::new(hier, self.name);
-        let _ret = cg.apply(&self.resources);
-        cg
+    pub fn build(self, hier: Box<dyn Hierarchy>) -> Result<Cgroup, Error> {
+        if let Some(controllers) = self.specified_controllers {
+            let cg = Cgroup::new_with_specified_controllers(hier, self.name, Some(controllers))?;
+            cg.apply(&self.resources)?;
+            Ok(cg)
+        } else {
+            let cg = Cgroup::new(hier, self.name)?;
+            cg.apply(&self.resources)?;
+            Ok(cg)
+        }
+    }
+
+    /// Specifically enable some controllers in the control group.
+    pub fn set_specified_controllers(mut self, specified_controllers: Vec<String>) -> Self {
+        self.specified_controllers = Some(specified_controllers);
+        self
     }
 }
 

src/cpu.rs

@@ -59,7 +59,6 @@ impl ControllerInternal for CpuController {
     fn get_path(&self) -> &PathBuf {
         &self.path
     }
-
     fn get_path_mut(&mut self) -> &mut PathBuf {
         &mut self.path
     }
@@ -113,10 +112,10 @@ impl<'a> From<&'a Subsystem> for &'a CpuController {
 
 impl CpuController {
     /// Contructs a new `CpuController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             v2,
         }
     }

src/cpuacct.rs

@@ -100,10 +100,10 @@ impl<'a> From<&'a Subsystem> for &'a CpuAcctController {
 
 impl CpuAcctController {
     /// Contructs a new `CpuAcctController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
         }
     }
 

src/cpuset.rs

@@ -254,10 +254,10 @@ fn parse_range(s: String) -> Result<Vec<(u64, u64)>> {
 
 impl CpuSetController {
     /// Contructs a new `CpuSetController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             v2,
         }
     }

src/devices.rs

@@ -46,6 +46,7 @@ pub enum DeviceType {
     Block,
 }
 
+#[allow(clippy::derivable_impls)]
 impl Default for DeviceType {
     fn default() -> Self {
         DeviceType::All
@@ -170,9 +171,9 @@ impl ControllerInternal for DevicesController {
 
         for i in &res.devices {
             if i.allow {
-                let _ = self.allow_device(i.devtype, i.major, i.minor, &i.access);
+                self.allow_device(i.devtype, i.major, i.minor, &i.access)?;
             } else {
-                let _ = self.deny_device(i.devtype, i.major, i.minor, &i.access);
+                self.deny_device(i.devtype, i.major, i.minor, &i.access)?;
             }
         }
 
@@ -203,10 +204,10 @@ impl<'a> From<&'a Subsystem> for &'a DevicesController {
 
 impl DevicesController {
     /// Constructs a new `DevicesController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
         }
     }
 
@@ -238,7 +239,13 @@ impl DevicesController {
         let final_str = format!("{} {}:{} {}", devtype.to_char(), major, minor, perms);
         self.open_path("devices.allow", true).and_then(|mut file| {
             file.write_all(final_str.as_ref()).map_err(|e| {
-                Error::with_cause(WriteFailed("devices.allow".to_string(), final_str), e)
+                Error::with_cause(
+                    WriteFailed(
+                        self.get_path().join("devices.allow").display().to_string(),
+                        final_str,
+                    ),
+                    e,
+                )
             })
         })
     }
@@ -271,7 +278,13 @@ impl DevicesController {
         let final_str = format!("{} {}:{} {}", devtype.to_char(), major, minor, perms);
         self.open_path("devices.deny", true).and_then(|mut file| {
             file.write_all(final_str.as_ref()).map_err(|e| {
-                Error::with_cause(WriteFailed("devices.deny".to_string(), final_str), e)
+                Error::with_cause(
+                    WriteFailed(
+                        self.get_path().join("devices.deny").display().to_string(),
+                        final_str,
+                    ),
+                    e,
+                )
             })
         })
     }
@@ -284,7 +297,7 @@ impl DevicesController {
             match res {
                 Ok(_) => {
                     s.lines().fold(Ok(Vec::new()), |acc, line| {
-                        let ls = line.to_string().split(|c| c == ' ' || c == ':').map(|x| x.to_string()).collect::<Vec<String>>();
+                        let ls = line.split(|c| c == ' ' || c == ':').map(|x| x.to_string()).collect::<Vec<String>>();
                         if acc.is_err() || ls.len() != 4 {
                             error!("allowed_devices: acc: {:?}, ls: {:?}", acc, ls);
                             Err(Error::new(ParseError))

src/error.rs

@@ -51,6 +51,22 @@ pub enum ErrorKind {
     #[error("invalid bytes size")]
     InvalidBytesSize,
 
+    /// The specified controller is not in the list of supported controllers.
+    #[error("specified controller is not in the list of supported controllers")]
+    SpecifiedControllers,
+
+    /// Using method in wrong cgroup version.
+    #[error("using method in wrong cgroup version")]
+    CgroupVersion,
+
+    /// Using method in wrong cgroup mode.
+    #[error("using method in wrong cgroup mode.")]
+    CgroupMode,
+
+    /// Subsystems is empty.
+    #[error("subsystems is empty")]
+    SubsystemsEmpty,
+
     /// An unknown error has occured.
     #[error("an unknown error")]
     Other,
@@ -73,7 +89,7 @@ impl fmt::Display for Error {
 }
 
 impl StdError for Error {
-    fn cause(&self) -> Option<&dyn StdError> {
+    fn source(&self) -> Option<&(dyn StdError + 'static)> {
         #[allow(clippy::manual_map)]
         match self.cause {
             Some(ref x) => Some(&**x),

src/freezer.rs

@@ -84,14 +84,13 @@ impl<'a> From<&'a Subsystem> for &'a FreezerController {
 
 impl FreezerController {
     /// Contructs a new `FreezerController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             v2,
         }
     }
-
     /// Freezes the processes in the control group.
     pub fn freeze(&self) -> Result<()> {
         let mut file_name = "freezer.state";

src/hierarchies.rs

@@ -5,14 +5,11 @@
 //
 
 //! This module represents the various control group hierarchies the Linux kernel supports.
-//!
-//! Currently, we only support the cgroupv1 hierarchy, but in the future we will add support for
-//! the Unified Hierarchy.
 
 use std::fs;
 use std::fs::File;
 use std::io::{BufRead, BufReader};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use crate::blkio::BlkIoController;
 use crate::cpu::CpuController;
@@ -37,6 +34,8 @@ use crate::cgroup::Cgroup;
 /// See `proc(5)` for format details.
 #[derive(Debug, PartialEq, Eq, Hash, Clone)]
 pub struct Mountinfo {
+    /// Mount root directory of the file system.
+    pub mount_root: PathBuf,
     /// Mount pathname relative to the process's root.
     pub mount_point: PathBuf,
     /// Filesystem type (main type with optional sub-type).
@@ -57,6 +56,7 @@ pub(crate) fn parse_mountinfo_for_line(line: &str) -> Option<Mountinfo> {
         return None;
     }
     let mount_point = PathBuf::from(s0_values[4]);
+    let mount_root = PathBuf::from(s0_values[3]);
     let fs_type_values: Vec<_> = s1_values[0].trim().split('.').collect();
     let fs_type = match fs_type_values.len() {
         1 => (fs_type_values[0].to_string(), None),
@@ -69,6 +69,7 @@ pub(crate) fn parse_mountinfo_for_line(line: &str) -> Option<Mountinfo> {
 
     let super_opts: Vec<String> = s1_values[2].trim().split(',').map(String::from).collect();
     Some(Mountinfo {
+        mount_root,
         mount_point,
         fs_type,
         super_opts,
@@ -123,47 +124,53 @@ impl Hierarchy for V1 {
         // The cgroup writeback feature requires cooperation between memcgs and blkcgs
         // To avoid exceptions, we should add_task for blkcg before memcg(push BlkIo before Mem)
         // For more Information: https://www.alibabacloud.com/help/doc-detail/155509.htm
-        if let Some(root) = self.get_mount_point(Controllers::BlkIo) {
-            subs.push(Subsystem::BlkIo(BlkIoController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::BlkIo) {
+            subs.push(Subsystem::BlkIo(BlkIoController::new(point, root, false)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::Mem) {
-            subs.push(Subsystem::Mem(MemController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::Mem) {
+            subs.push(Subsystem::Mem(MemController::new(point, root, false)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::Pids) {
-            subs.push(Subsystem::Pid(PidController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::Pids) {
+            subs.push(Subsystem::Pid(PidController::new(point, root, false)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::CpuSet) {
-            subs.push(Subsystem::CpuSet(CpuSetController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::CpuSet) {
+            subs.push(Subsystem::CpuSet(CpuSetController::new(point, root, false)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::CpuAcct) {
-            subs.push(Subsystem::CpuAcct(CpuAcctController::new(root)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::CpuAcct) {
+            subs.push(Subsystem::CpuAcct(CpuAcctController::new(point, root)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::Cpu) {
-            subs.push(Subsystem::Cpu(CpuController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::Cpu) {
+            subs.push(Subsystem::Cpu(CpuController::new(point, root, false)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::Devices) {
-            subs.push(Subsystem::Devices(DevicesController::new(root)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::Devices) {
+            subs.push(Subsystem::Devices(DevicesController::new(point, root)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::Freezer) {
-            subs.push(Subsystem::Freezer(FreezerController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::Freezer) {
+            subs.push(Subsystem::Freezer(FreezerController::new(
+                point, root, false,
+            )));
         }
-        if let Some(root) = self.get_mount_point(Controllers::NetCls) {
-            subs.push(Subsystem::NetCls(NetClsController::new(root)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::NetCls) {
+            subs.push(Subsystem::NetCls(NetClsController::new(point, root)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::PerfEvent) {
-            subs.push(Subsystem::PerfEvent(PerfEventController::new(root)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::PerfEvent) {
+            subs.push(Subsystem::PerfEvent(PerfEventController::new(point, root)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::NetPrio) {
-            subs.push(Subsystem::NetPrio(NetPrioController::new(root)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::NetPrio) {
+            subs.push(Subsystem::NetPrio(NetPrioController::new(point, root)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::HugeTlb) {
-            subs.push(Subsystem::HugeTlb(HugeTlbController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::HugeTlb) {
+            subs.push(Subsystem::HugeTlb(HugeTlbController::new(
+                point, root, false,
+            )));
         }
-        if let Some(root) = self.get_mount_point(Controllers::Rdma) {
-            subs.push(Subsystem::Rdma(RdmaController::new(root)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::Rdma) {
+            subs.push(Subsystem::Rdma(RdmaController::new(point, root)));
         }
-        if let Some(root) = self.get_mount_point(Controllers::Systemd) {
-            subs.push(Subsystem::Systemd(SystemdController::new(root, false)));
+        if let Some((point, root)) = self.get_mount_point(Controllers::Systemd) {
+            subs.push(Subsystem::Systemd(SystemdController::new(
+                point, root, false,
+            )));
         }
 
         subs
@@ -173,6 +180,12 @@ impl Hierarchy for V1 {
         Cgroup::load(auto(), "")
     }
 
+    fn parent_control_group(&self, path: &str) -> Cgroup {
+        let path = Path::new(path);
+        let parent_path = path.parent().unwrap().to_string_lossy().to_string();
+        Cgroup::load(auto(), parent_path)
+    }
+
     fn root(&self) -> PathBuf {
         self.mountinfo
             .iter()
@@ -212,29 +225,51 @@ impl Hierarchy for V2 {
         for s in controller_list {
             match s {
                 "cpu" => {
-                    subs.push(Subsystem::Cpu(CpuController::new(self.root(), true)));
+                    subs.push(Subsystem::Cpu(CpuController::new(
+                        self.root(),
+                        PathBuf::from(""),
+                        true,
+                    )));
                 }
                 "io" => {
-                    subs.push(Subsystem::BlkIo(BlkIoController::new(self.root(), true)));
+                    subs.push(Subsystem::BlkIo(BlkIoController::new(
+                        self.root(),
+                        PathBuf::from(""),
+                        true,
+                    )));
                 }
                 "cpuset" => {
-                    subs.push(Subsystem::CpuSet(CpuSetController::new(self.root(), true)));
+                    subs.push(Subsystem::CpuSet(CpuSetController::new(
+                        self.root(),
+                        PathBuf::from(""),
+                        true,
+                    )));
                 }
                 "memory" => {
-                    subs.push(Subsystem::Mem(MemController::new(self.root(), true)));
+                    subs.push(Subsystem::Mem(MemController::new(
+                        self.root(),
+                        PathBuf::from(""),
+                        true,
+                    )));
                 }
                 "pids" => {
-                    subs.push(Subsystem::Pid(PidController::new(self.root(), true)));
+                    subs.push(Subsystem::Pid(PidController::new(
+                        self.root(),
+                        PathBuf::from(""),
+                        true,
+                    )));
                 }
                 "freezer" => {
                     subs.push(Subsystem::Freezer(FreezerController::new(
                         self.root(),
+                        PathBuf::from(""),
                         true,
                     )));
                 }
                 "hugetlb" => {
                     subs.push(Subsystem::HugeTlb(HugeTlbController::new(
                         self.root(),
+                        PathBuf::from(""),
                         true,
                     )));
                 }
@@ -249,6 +284,12 @@ impl Hierarchy for V2 {
         Cgroup::load(auto(), "")
     }
 
+    fn parent_control_group(&self, path: &str) -> Cgroup {
+        let path = Path::new(path);
+        let parent_path = path.parent().unwrap().to_string_lossy().to_string();
+        Cgroup::load(auto(), parent_path)
+    }
+
     fn root(&self) -> PathBuf {
         PathBuf::from(self.root.clone())
     }
@@ -263,10 +304,10 @@ impl V1 {
         }
     }
 
-    pub fn get_mount_point(&self, controller: Controllers) -> Option<PathBuf> {
+    pub fn get_mount_point(&self, controller: Controllers) -> Option<(PathBuf, PathBuf)> {
         self.mountinfo.iter().find_map(|m| {
             if m.fs_type.0 == "cgroup" && m.super_opts.contains(&controller.to_string()) {
-                return Some(m.mount_point.clone());
+                return Some((m.mount_point.to_owned(), m.mount_root.to_owned()));
             }
             None
         })
@@ -297,43 +338,16 @@ impl Default for V2 {
 
 pub const UNIFIED_MOUNTPOINT: &str = "/sys/fs/cgroup";
 
-#[cfg(any(
-    all(target_os = "linux", not(target_env = "musl")),
-    target_os = "android"
-))]
 pub fn is_cgroup2_unified_mode() -> bool {
     use nix::sys::statfs;
 
     let path = std::path::Path::new(UNIFIED_MOUNTPOINT);
-    let fs_stat = statfs::statfs(path);
-    if fs_stat.is_err() {
-        return false;
-    }
+    let fs_stat = match statfs::statfs(path) {
+        Ok(fs_stat) => fs_stat,
+        Err(_) => return false,
+    };
 
-    // FIXME notwork, nix will not compile CGROUP2_SUPER_MAGIC because not(target_env = "musl")
-    fs_stat.unwrap().filesystem_type() == statfs::CGROUP2_SUPER_MAGIC
-}
-
-pub const INIT_CGROUP_PATHS: &str = "/proc/1/cgroup";
-
-#[cfg(all(target_os = "linux", target_env = "musl"))]
-pub fn is_cgroup2_unified_mode() -> bool {
-    let lines = fs::read_to_string(INIT_CGROUP_PATHS);
-    if lines.is_err() {
-        return false;
-    }
-
-    for line in lines.unwrap().lines() {
-        let fields: Vec<&str> = line.split(':').collect();
-        if fields.len() != 3 {
-            continue;
-        }
-        if fields[0] != "0" {
-            return false;
-        }
-    }
-
-    true
+    fs_stat.filesystem_type() == statfs::CGROUP2_SUPER_MAGIC
 }
 
 pub fn auto() -> Box<dyn Hierarchy> {
@@ -352,19 +366,19 @@ mod tests {
     fn test_parse_mount() {
         let mountinfo = vec![
             ("29 26 0:26 / /sys/fs/cgroup/cpuset,cpu,cpuacct rw,nosuid,nodev,noexec,relatime shared:10 - cgroup cgroup rw,cpuset,cpu,cpuacct",
-             Mountinfo{mount_point: PathBuf::from("/sys/fs/cgroup/cpuset,cpu,cpuacct"), fs_type: ("cgroup".to_string(), None), super_opts: vec![
+             Mountinfo{mount_root: PathBuf::from("/"), mount_point: PathBuf::from("/sys/fs/cgroup/cpuset,cpu,cpuacct"), fs_type: ("cgroup".to_string(), None), super_opts: vec![
                 "rw".to_string(),
                 "cpuset".to_string(),
                 "cpu".to_string(),
                 "cpuacct".to_string(),
              ]}),
             ("121 1731 0:42 / /shm rw,nosuid,nodev,noexec,relatime shared:68 master:66 - tmpfs shm rw,size=65536k",
-             Mountinfo{mount_point: PathBuf::from("/shm"), fs_type: ("tmpfs".to_string(), None), super_opts: vec![
+             Mountinfo{mount_root: PathBuf::from("/"), mount_point: PathBuf::from("/shm"), fs_type: ("tmpfs".to_string(), None), super_opts: vec![
                 "rw".to_string(),
                 "size=65536k".to_string(),
              ]}),
             ("121 1731 0:42 / /shm rw,nosuid,nodev,noexec,relatime shared:68 master:66 - tmpfs.123 shm rw,size=65536k",
-             Mountinfo{mount_point: PathBuf::from("/shm"), fs_type: ("tmpfs".to_string(), Some("123".to_string())), super_opts: vec![
+             Mountinfo{mount_root: PathBuf::from("/"), mount_point: PathBuf::from("/shm"), fs_type: ("tmpfs".to_string(), Some("123".to_string())), super_opts: vec![
                 "rw".to_string(),
                 "size=65536k".to_string(),
              ]}),

src/hugetlb.rs

@@ -88,11 +88,11 @@ impl<'a> From<&'a Subsystem> for &'a HugeTlbController {
 
 impl HugeTlbController {
     /// Constructs a new `HugeTlbController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         let sizes = get_hugepage_sizes();
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             sizes,
             v2,
         }
@@ -138,8 +138,11 @@ impl HugeTlbController {
     /// Get the limit (in bytes) of how much memory can be backed by hugepages of a certain size
     /// (`hugetlb_size`).
     pub fn limit_in_bytes(&self, hugetlb_size: &str) -> Result<u64> {
-        self.open_path(&format!("hugetlb.{}.limit_in_bytes", hugetlb_size), false)
-            .and_then(read_u64_from)
+        let mut file_name = format!("hugetlb.{}.limit_in_bytes", hugetlb_size);
+        if self.v2 {
+            file_name = format!("hugetlb.{}.max", hugetlb_size);
+        }
+        self.open_path(&file_name, false).and_then(read_u64_from)
     }
 
     /// Get the current usage of memory that is backed by hugepages of a certain size

src/lib.rs

@@ -231,6 +231,7 @@ mod sealed {
             })
         }
 
+        #[allow(dead_code)]
         fn get(&self, key: &str) -> Result<String> {
             self.open_path(key, false).and_then(|mut file: File| {
                 let mut string = String::new();
@@ -255,6 +256,9 @@ pub trait Controller {
     /// The file system path to the controller.
     fn path(&self) -> &Path;
 
+    /// Root path of the file system to the controller.
+    fn base(&self) -> &Path;
+
     /// Apply a set of resources to the Controller, invoking its internal functions to pass the
     /// kernel the information.
     fn apply(&self, res: &Resources) -> Result<()>;
@@ -280,9 +284,18 @@ pub trait Controller {
     /// Attach a task to this controller.
     fn add_task_by_tgid(&self, pid: &CgroupPid) -> Result<()>;
 
+    /// set cgroup type.
+    fn set_cgroup_type(&self, cgroup_type: &str) -> Result<()>;
+
+    /// get cgroup type.
+    fn get_cgroup_type(&self) -> Result<String>;
+
     /// Get the list of tasks that this controller has.
     fn tasks(&self) -> Vec<CgroupPid>;
 
+    /// Get the list of procs that this controller has.
+    fn procs(&self) -> Vec<CgroupPid>;
+
     fn v2(&self) -> bool;
 }
 
@@ -298,6 +311,10 @@ where
         self.get_path()
     }
 
+    fn base(&self) -> &Path {
+        self.get_base()
+    }
+
     /// Apply a set of resources to the Controller, invoking its internal functions to pass the
     /// kernel the information.
     fn apply(&self, res: &Resources) -> Result<()> {
@@ -317,6 +334,9 @@ where
 
     /// Set notify_on_release
     fn set_notify_on_release(&self, enable: bool) -> Result<()> {
+        if self.is_v2() {
+            return Err(Error::new(ErrorKind::CgroupVersion));
+        }
         self.open_path("notify_on_release", true)
             .and_then(|mut file| {
                 write!(file, "{}", enable as i32).map_err(|e| {
@@ -330,6 +350,9 @@ where
 
     /// Set release_agent
     fn set_release_agent(&self, path: &str) -> Result<()> {
+        if self.is_v2() {
+            return Err(Error::new(ErrorKind::CgroupVersion));
+        }
         self.open_path("release_agent", true).and_then(|mut file| {
             file.write_all(path.as_bytes()).map_err(|e| {
                 Error::with_cause(
@@ -373,7 +396,7 @@ where
     fn add_task(&self, pid: &CgroupPid) -> Result<()> {
         let mut file_name = "tasks";
         if self.is_v2() {
-            file_name = "cgroup.procs";
+            file_name = "cgroup.threads";
         }
         self.open_path(file_name, true).and_then(|mut file| {
             file.write_all(pid.pid.to_string().as_ref()).map_err(|e| {
@@ -387,23 +410,21 @@ where
 
     /// Attach a task to this controller by thread group id.
     fn add_task_by_tgid(&self, pid: &CgroupPid) -> Result<()> {
-        self.open_path("cgroup.procs", true).and_then(|mut file| {
+        let file_name = "cgroup.procs";
+        self.open_path(file_name, true).and_then(|mut file| {
             file.write_all(pid.pid.to_string().as_ref()).map_err(|e| {
                 Error::with_cause(
-                    ErrorKind::WriteFailed("cgroup.procs".to_string(), pid.pid.to_string()),
+                    ErrorKind::WriteFailed(file_name.to_string(), pid.pid.to_string()),
                     e,
                 )
             })
         })
     }
 
-    /// Get the list of tasks that this controller has.
-    fn tasks(&self) -> Vec<CgroupPid> {
-        let mut file = "tasks";
-        if self.is_v2() {
-            file = "cgroup.procs";
-        }
-        self.open_path(file, false)
+    /// Get the list of procs that this controller has.
+    fn procs(&self) -> Vec<CgroupPid> {
+        let file_name = "cgroup.procs";
+        self.open_path(file_name, false)
             .map(|file| {
                 let bf = BufReader::new(file);
                 let mut v = Vec::new();
@@ -421,6 +442,64 @@ where
             .unwrap_or_default()
     }
 
+    /// Get the list of tasks that this controller has.
+    fn tasks(&self) -> Vec<CgroupPid> {
+        let mut file_name = "tasks";
+        if self.is_v2() {
+            file_name = "cgroup.threads";
+        }
+        self.open_path(file_name, false)
+            .map(|file| {
+                let bf = BufReader::new(file);
+                let mut v = Vec::new();
+                for line in bf.lines() {
+                    match line {
+                        Ok(line) => {
+                            let n = line.trim().parse().unwrap_or(0u64);
+                            v.push(n);
+                        }
+                        Err(_) => break,
+                    }
+                }
+                v.into_iter().map(CgroupPid::from).collect()
+            })
+            .unwrap_or_default()
+    }
+
+    /// set cgroup.type
+    fn set_cgroup_type(&self, cgroup_type: &str) -> Result<()> {
+        if !self.is_v2() {
+            return Err(Error::new(ErrorKind::CgroupVersion));
+        }
+        let file_name = "cgroup.type";
+        self.open_path(file_name, true).and_then(|mut file| {
+            file.write_all(cgroup_type.as_bytes()).map_err(|e| {
+                Error::with_cause(
+                    ErrorKind::WriteFailed(file_name.to_string(), cgroup_type.to_string()),
+                    e,
+                )
+            })
+        })
+    }
+
+    /// get cgroup.type
+    fn get_cgroup_type(&self) -> Result<String> {
+        if !self.is_v2() {
+            return Err(Error::new(ErrorKind::CgroupVersion));
+        }
+        let file_name = "cgroup.type";
+        self.open_path(file_name, false).and_then(|mut file: File| {
+            let mut string = String::new();
+            match file.read_to_string(&mut string) {
+                Ok(_) => Ok(string.trim().to_owned()),
+                Err(e) => Err(Error::with_cause(
+                    ErrorKind::ReadFailed(file_name.to_string()),
+                    e,
+                )),
+            }
+        })
+    }
+
     fn v2(&self) -> bool {
         self.is_v2()
     }
@@ -468,6 +547,9 @@ pub trait Hierarchy: std::fmt::Debug + Send + Sync {
     /// Return a handle to the root control group in the hierarchy.
     fn root_control_group(&self) -> Cgroup;
 
+    /// Return a handle to the parent control group in the hierarchy.
+    fn parent_control_group(&self, path: &str) -> Cgroup;
+
     fn v2(&self) -> bool;
 }
 
@@ -530,9 +612,9 @@ pub struct CpuResources {
     /// Weight of how much of the total CPU time should this control group get. Note that this is
     /// hierarchical, so this is weighted against the siblings of this control group.
     pub shares: Option<u64>,
-    /// In one `period`, how much can the tasks run in nanoseconds.
+    /// In one `period`, how much can the tasks run in microseconds.
     pub quota: Option<i64>,
-    /// Period of time in nanoseconds.
+    /// Period of time in microseconds.
     pub period: Option<u64>,
     /// This is currently a no-operation.
     pub realtime_runtime: Option<i64>,
@@ -805,6 +887,7 @@ pub enum MaxValue {
     Value(i64),
 }
 
+#[allow(clippy::derivable_impls)]
 impl Default for MaxValue {
     fn default() -> Self {
         MaxValue::Max

src/memory.rs

@@ -540,10 +540,10 @@ impl ControllerInternal for MemController {
 
 impl MemController {
     /// Contructs a new `MemController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             v2,
         }
     }
@@ -573,18 +573,33 @@ impl MemController {
 
     // for v2
     pub fn get_mem(&self) -> Result<SetMemory> {
-        let mut m: SetMemory = Default::default();
-        self.get_max_value("memory.high")
-            .map(|x| m.high = Some(x))?;
-        self.get_max_value("memory.low").map(|x| m.low = Some(x))?;
-        self.get_max_value("memory.max").map(|x| m.max = Some(x))?;
-        self.get_max_value("memory.min").map(|x| m.min = Some(x))?;
+        let m = SetMemory {
+            high: self
+                .get_max_value("memory.high")
+                .map_or(Some(MaxValue::default()), Some),
+            low: self
+                .get_max_value("memory.low")
+                .map_or(Some(MaxValue::Value(0)), Some),
+            max: self
+                .get_max_value("memory.max")
+                .map_or(Some(MaxValue::default()), Some),
+            min: self
+                .get_max_value("memory.min")
+                .map_or(Some(MaxValue::Value(0)), Some),
+        };
 
         Ok(m)
     }
 
     fn memory_stat_v2(&self) -> Memory {
-        let set = self.get_mem().unwrap();
+        // NOTE: get_mem() always returns T, but let's
+        // still do `unwrap_or` for safety.
+        let set = self.get_mem().unwrap_or(SetMemory {
+            low: Some(MaxValue::Value(0)),
+            high: Some(MaxValue::default()),
+            max: Some(MaxValue::default()),
+            min: Some(MaxValue::Value(0)),
+        });
 
         Memory {
             fail_cnt: 0,
@@ -593,7 +608,10 @@ impl MemController {
                 .open_path("memory.current", false)
                 .and_then(read_u64_from)
                 .unwrap_or(0),
-            max_usage_in_bytes: 0,
+            max_usage_in_bytes: self
+                .open_path("memory.peak", false)
+                .and_then(read_u64_from)
+                .unwrap_or(0),
             move_charge_at_immigrate: 0,
             numa_stat: NumaStat::default(),
             oom_control: OomControl::default(),
@@ -727,7 +745,7 @@ impl MemController {
                 .open_path("memory.swap.events", false)
                 .and_then(flat_keyed_to_hashmap)
                 .map(|x| *x.get("fail").unwrap_or(&0) as u64)
-                .unwrap(),
+                .unwrap_or(0),
             limit_in_bytes: self
                 .open_path("memory.swap.max", false)
                 .and_then(read_i64_from)
@@ -736,7 +754,10 @@ impl MemController {
                 .open_path("memory.swap.current", false)
                 .and_then(read_u64_from)
                 .unwrap_or(0),
-            max_usage_in_bytes: 0,
+            max_usage_in_bytes: self
+                .open_path("memory.swap.peak", false)
+                .and_then(read_u64_from)
+                .unwrap_or(0),
         }
     }
 
@@ -844,13 +865,16 @@ impl MemController {
     /// Set the memory usage limit of the control group, in bytes.
     pub fn set_limit(&self, limit: i64) -> Result<()> {
         let mut file_name = "memory.limit_in_bytes";
+        let mut limit_str = limit.to_string();
         if self.v2 {
             file_name = "memory.max";
+            if limit == -1 {
+                limit_str = "max".to_string();
+            }
         }
         self.open_path(file_name, true).and_then(|mut file| {
-            file.write_all(limit.to_string().as_ref()).map_err(|e| {
-                Error::with_cause(WriteFailed(file_name.to_string(), limit.to_string()), e)
-            })
+            file.write_all(limit_str.as_ref())
+                .map_err(|e| Error::with_cause(WriteFailed(file_name.to_string(), limit_str), e))
         })
     }
 
@@ -881,13 +905,16 @@ impl MemController {
     /// Set the memory+swap limit of the control group, in bytes.
     pub fn set_memswap_limit(&self, limit: i64) -> Result<()> {
         let mut file_name = "memory.memsw.limit_in_bytes";
+        let mut limit_str = limit.to_string();
         if self.v2 {
             file_name = "memory.swap.max";
+            if limit == -1 {
+                limit_str = "max".to_string();
+            }
         }
         self.open_path(file_name, true).and_then(|mut file| {
-            file.write_all(limit.to_string().as_ref()).map_err(|e| {
-                Error::with_cause(WriteFailed(file_name.to_string(), limit.to_string()), e)
-            })
+            file.write_all(limit_str.as_ref())
+                .map_err(|e| Error::with_cause(WriteFailed(file_name.to_string(), limit_str), e))
         })
     }
 

src/net_cls.rs

@@ -76,10 +76,10 @@ impl<'a> From<&'a Subsystem> for &'a NetClsController {
 
 impl NetClsController {
     /// Constructs a new `NetClsController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
         }
     }
 

src/net_prio.rs

@@ -79,10 +79,10 @@ impl<'a> From<&'a Subsystem> for &'a NetPrioController {
 
 impl NetPrioController {
     /// Constructs a new `NetPrioController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
         }
     }
 

src/perf_event.rs

@@ -65,10 +65,10 @@ impl<'a> From<&'a Subsystem> for &'a PerfEventController {
 
 impl PerfEventController {
     /// Constructs a new `PerfEventController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
         }
     }
 }

src/pid.rs

@@ -92,10 +92,10 @@ impl<'a> From<&'a Subsystem> for &'a PidController {
 impl PidController {
     /// Constructors a new `PidController` instance, with `root` serving as the controller's root
     /// directory.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             v2,
         }
     }

src/rdma.rs

@@ -68,10 +68,10 @@ impl<'a> From<&'a Subsystem> for &'a RdmaController {
 
 impl RdmaController {
     /// Constructs a new `RdmaController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
         }
     }
 
@@ -81,6 +81,11 @@ impl RdmaController {
             .and_then(read_string_from)
     }
 
+    /// Returns the max usage of RDMA/IB specific resources.
+    pub fn max(&self) -> Result<String> {
+        self.open_path("rdma.max", false).and_then(read_string_from)
+    }
+
     /// Set a maximum usage for each RDMA/IB resource.
     pub fn set_max(&self, max: &str) -> Result<()> {
         self.open_path("rdma.max", true).and_then(|mut file| {

src/systemd.rs

@@ -62,10 +62,10 @@ impl<'a> From<&'a Subsystem> for &'a SystemdController {
 
 impl SystemdController {
     /// Constructs a new `SystemdController` with `root` serving as the root of the control group.
-    pub fn new(root: PathBuf, v2: bool) -> Self {
+    pub fn new(point: PathBuf, root: PathBuf, v2: bool) -> Self {
         Self {
-            base: root.clone(),
-            path: root,
+            base: root,
+            path: point,
             _v2: v2,
         }
     }

tests/builder.rs

@@ -22,7 +22,8 @@ pub fn test_cpu_res_build() {
         .cpu()
         .shares(85)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let cpu: &CpuController = cg.controller_of().unwrap();
@@ -42,7 +43,8 @@ pub fn test_memory_res_build() {
         .swappiness(70)
         .memory_hard_limit(1024 * 1024 * 1024)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &MemController = cg.controller_of().unwrap();
@@ -64,7 +66,8 @@ pub fn test_pid_res_build() {
         .pid()
         .maximum_number_of_processes(MaxValue::Value(123))
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &PidController = cg.controller_of().unwrap();
@@ -83,7 +86,8 @@ pub fn test_devices_res_build() {
         .devices()
         .device(1, 6, DeviceType::Char, true, vec![DevicePermissions::Read])
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &DevicesController = cg.controller_of().unwrap();
@@ -113,7 +117,8 @@ pub fn test_network_res_build() {
         .network()
         .class_id(1337)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &NetClsController = cg.controller_of().unwrap();
@@ -134,7 +139,8 @@ pub fn test_hugepages_res_build() {
         .hugepages()
         .limit("2MB".to_string(), 4 * 2 * 1024 * 1024)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &HugeTlbController = cg.controller_of().unwrap();
@@ -152,7 +158,8 @@ pub fn test_blkio_res_build() {
         .blkio()
         .weight(100)
         .done()
-        .build(h);
+        .build(h)
+        .unwrap();
 
     {
         let c: &BlkIoController = cg.controller_of().unwrap();

tests/cgroup.rs

@@ -5,29 +5,60 @@
 //
 
 //! Simple unit tests about the control groups system.
+use cgroups_rs::cgroup::{
+    CGROUP_MODE_DOMAIN, CGROUP_MODE_DOMAIN_INVALID, CGROUP_MODE_DOMAIN_THREADED,
+    CGROUP_MODE_THREADED,
+};
 use cgroups_rs::memory::MemController;
 use cgroups_rs::Controller;
 use cgroups_rs::{Cgroup, CgroupPid, Subsystem};
+use std::process::Command;
+use std::thread::sleep;
+use std::time::Duration;
 
 #[test]
-fn test_tasks_iterator() {
+fn test_procs_iterator_cgroup() {
     let h = cgroups_rs::hierarchies::auto();
     let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
-    let cg = Cgroup::new(h, String::from("test_tasks_iterator"));
+    let cg = Cgroup::new(h, String::from("test_procs_iterator_cgroup")).unwrap();
+    {
+        // Add a task to the control group.
+        cg.add_task_by_tgid(CgroupPid::from(pid)).unwrap();
+
+        let mut procs = cg.procs().into_iter();
+        // Verify that the task is indeed in the xcontrol group
+        assert_eq!(procs.next(), Some(CgroupPid::from(pid)));
+        assert_eq!(procs.next(), None);
+
+        // Now, try removing it.
+        cg.remove_task_by_tgid(CgroupPid::from(pid)).unwrap();
+        procs = cg.procs().into_iter();
+
+        // Verify that it was indeed removed.
+        assert_eq!(procs.next(), None);
+    }
+    cg.delete().unwrap();
+}
+
+#[test]
+fn test_tasks_iterator_cgroup_v1() {
+    if cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
+        return;
+    }
+    let h = cgroups_rs::hierarchies::auto();
+    let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
+    let cg = Cgroup::new(h, String::from("test_tasks_iterator_cgroup_v1")).unwrap();
     {
         // Add a task to the control group.
         cg.add_task(CgroupPid::from(pid)).unwrap();
 
-        use std::{thread, time};
-        thread::sleep(time::Duration::from_millis(100));
-
         let mut tasks = cg.tasks().into_iter();
-        // Verify that the task is indeed in the control group
+        // Verify that the task is indeed in the xcontrol group
         assert_eq!(tasks.next(), Some(CgroupPid::from(pid)));
         assert_eq!(tasks.next(), None);
 
         // Now, try removing it.
-        cg.remove_task(CgroupPid::from(pid));
+        cg.remove_task(CgroupPid::from(pid)).unwrap();
         tasks = cg.tasks().into_iter();
 
         // Verify that it was indeed removed.
@@ -36,6 +67,143 @@ fn test_tasks_iterator() {
     cg.delete().unwrap();
 }
 
+#[test]
+fn test_tasks_iterator_cgroup_threaded_mode() {
+    if !cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
+        return;
+    }
+    let pid = libc::pid_t::from(nix::unistd::getpid()) as u64;
+    let cg = Cgroup::new(
+        cgroups_rs::hierarchies::auto(),
+        String::from("test_tasks_iterator_cgroup_threaded_mode"),
+    )
+    .unwrap();
+    let cg_threaded_sub1 = Cgroup::new_with_specified_controllers(
+        cgroups_rs::hierarchies::auto(),
+        String::from("test_tasks_iterator_cgroup_threaded_mode/threaded_sub1"),
+        Some(vec![String::from("cpuset"), String::from("cpu")]),
+    )
+    .unwrap();
+    let cg_threaded_sub2 = Cgroup::new_with_specified_controllers(
+        cgroups_rs::hierarchies::auto(),
+        String::from("test_tasks_iterator_cgroup_threaded_mode/threaded_sub2"),
+        Some(vec![String::from("cpuset"), String::from("cpu")]),
+    )
+    .unwrap();
+    {
+        // Verify that cgroup type of the control group is domain mode.
+        assert_eq!(cg.get_cgroup_type().unwrap(), CGROUP_MODE_DOMAIN);
+
+        // Set cgroup type of the sub-control group is thread mode.
+        cg_threaded_sub1
+            .set_cgroup_type(CGROUP_MODE_THREADED)
+            .unwrap();
+        // Verify that cgroup type of the sub-control group is thread mode.
+        assert_eq!(
+            cg_threaded_sub1.get_cgroup_type().unwrap(),
+            CGROUP_MODE_THREADED
+        );
+        // Verify that the cgroup type of the sub-control group that does
+        // not set the cgroup type is domain invalid mode.
+        assert_eq!(
+            cg_threaded_sub2.get_cgroup_type().unwrap(),
+            CGROUP_MODE_DOMAIN_INVALID
+        );
+        // Verify whether the cgroup type of the parent control group of
+        // the control group whose cgroup type is set to thread mode is
+        // domain thread mode.
+        assert_eq!(cg.get_cgroup_type().unwrap(), CGROUP_MODE_DOMAIN_THREADED);
+
+        // Set cgroup type of the sub-control group is thread mode.
+        cg_threaded_sub2
+            .set_cgroup_type(CGROUP_MODE_THREADED)
+            .unwrap();
+        // Verify that cgroup type of the sub-control group is thread mode.
+        assert_eq!(
+            cg_threaded_sub2.get_cgroup_type().unwrap(),
+            CGROUP_MODE_THREADED
+        );
+
+        // Add a proc to the control group.
+        cg.add_task_by_tgid(CgroupPid::from(pid)).unwrap();
+
+        let mut procs = cg.procs().into_iter();
+        // Verify that the task is indeed in the x control group
+        assert_eq!(procs.next(), Some(CgroupPid::from(pid)));
+        assert_eq!(procs.next(), None);
+
+        // Add a task to the sub control group.
+        cg_threaded_sub1.add_task(CgroupPid::from(pid)).unwrap();
+
+        let mut tasks = cg_threaded_sub1.tasks().into_iter();
+        // Verify that the task is indeed in the xcontrol group
+        assert_eq!(tasks.next(), Some(CgroupPid::from(pid)));
+        assert_eq!(tasks.next(), None);
+
+        // Now, try move it to parent.
+        cg_threaded_sub1
+            .move_task_to_parent(CgroupPid::from(pid))
+            .unwrap();
+        tasks = cg_threaded_sub1.tasks().into_iter();
+
+        // Verify that it was indeed removed.
+        assert_eq!(tasks.next(), None);
+
+        // Now, try removing it.
+        cg.remove_task_by_tgid(CgroupPid::from(pid)).unwrap();
+        procs = cg.procs().into_iter();
+
+        // Verify that it was indeed removed.
+        assert_eq!(procs.next(), None);
+    }
+    cg_threaded_sub1.delete().unwrap();
+    cg_threaded_sub2.delete().unwrap();
+    cg.delete().unwrap();
+}
+
+#[test]
+fn test_kill_cgroup() {
+    if !cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
+        return;
+    }
+    let h = cgroups_rs::hierarchies::auto();
+    let cg = Cgroup::new(h, String::from("test_kill_cgroup")).unwrap();
+    {
+        // Spawn a proc, don't want to getpid(2) here.
+        let mut child = Command::new("sleep").arg("infinity").spawn().unwrap();
+        cg.add_task_by_tgid(CgroupPid::from(child.id() as u64))
+            .unwrap();
+
+        let cg_procs = cg.procs();
+        assert_eq!(cg_procs.len(), 1_usize);
+
+        // Now kill and wait on the proc.
+        cg.kill().unwrap();
+
+        let mut tries = 0;
+        let status: Option<std::process::ExitStatus> = loop {
+            match child.try_wait() {
+                Ok(Some(status)) => {
+                    break Some(status);
+                }
+                Ok(None) => {
+                    if tries > 3 {
+                        break None;
+                    }
+                    sleep(Duration::from_millis(100));
+                    tries += 1;
+                }
+                Err(e) => {
+                    child.kill().unwrap();
+                    panic!("error attempting to wait: {}", e);
+                }
+            }
+        };
+        assert!(status.is_some());
+    }
+    cg.delete().unwrap();
+}
+
 #[test]
 fn test_cgroup_with_relative_paths() {
     if cgroups_rs::hierarchies::is_cgroup2_unified_mode() {
@@ -83,7 +251,7 @@ fn test_cgroup_v2() {
         return;
     }
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_v2"));
+    let cg = Cgroup::new(h, String::from("test_v2")).unwrap();
 
     let mem_controller: &MemController = cg.controller_of().unwrap();
     let (mem, swp, rev) = (4 * 1024 * 1000, 2 * 1024 * 1000, 1024 * 1000);

tests/cpu.rs

@@ -10,7 +10,7 @@ use cgroups_rs::Cgroup;
 #[test]
 fn test_cfs_quota_and_periods() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cfs_quota_and_periods"));
+    let cg = Cgroup::new(h, String::from("test_cfs_quota_and_periods")).unwrap();
 
     let cpu_controller: &CpuController = cg.controller_of().unwrap();
 

tests/cpuset.rs

@@ -13,7 +13,7 @@ use std::fs;
 #[test]
 fn test_cpuset_memory_pressure_root_cg() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cpuset_memory_pressure_root_cg"));
+    let cg = Cgroup::new(h, String::from("test_cpuset_memory_pressure_root_cg")).unwrap();
     {
         let cpuset: &CpuSetController = cg.controller_of().unwrap();
 
@@ -27,7 +27,7 @@ fn test_cpuset_memory_pressure_root_cg() {
 #[test]
 fn test_cpuset_set_cpus() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus"));
+    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus")).unwrap();
     {
         let cpuset: &CpuSetController = cg.controller_of().unwrap();
 
@@ -64,7 +64,7 @@ fn test_cpuset_set_cpus() {
 #[test]
 fn test_cpuset_set_cpus_add_task() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus_add_task/sub-dir"));
+    let cg = Cgroup::new(h, String::from("test_cpuset_set_cpus_add_task/sub-dir")).unwrap();
 
     let cpuset: &CpuSetController = cg.controller_of().unwrap();
     let set = cpuset.cpuset();
@@ -77,13 +77,13 @@ fn test_cpuset_set_cpus_add_task() {
 
     // Add a task to the control group.
     let pid_i = libc::pid_t::from(nix::unistd::getpid()) as u64;
-    let _ = cg.add_task(CgroupPid::from(pid_i));
+    let _ = cg.add_task_by_tgid(CgroupPid::from(pid_i));
     let tasks = cg.tasks();
     assert!(!tasks.is_empty());
     println!("tasks after added: {:?}", tasks);
 
     // remove task
-    cg.remove_task(CgroupPid::from(pid_i));
+    cg.remove_task_by_tgid(CgroupPid::from(pid_i)).unwrap();
     let tasks = cg.tasks();
     println!("tasks after deleted: {:?}", tasks);
     assert_eq!(0, tasks.len());

tests/devices.rs

@@ -17,7 +17,7 @@ fn test_devices_parsing() {
     }
 
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_devices_parsing"));
+    let cg = Cgroup::new(h, String::from("test_devices_parsing")).unwrap();
     {
         let devices: &DevicesController = cg.controller_of().unwrap();
 

tests/hugetlb.rs

@@ -17,7 +17,7 @@ fn test_hugetlb_sizes() {
     }
 
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_hugetlb_sizes"));
+    let cg = Cgroup::new(h, String::from("test_hugetlb_sizes")).unwrap();
     {
         let hugetlb_controller: &HugeTlbController = cg.controller_of().unwrap();
         let _ = hugetlb_controller.get_sizes();

tests/memory.rs

@@ -11,7 +11,7 @@ use cgroups_rs::{Cgroup, MaxValue};
 #[test]
 fn test_disable_oom_killer() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_disable_oom_killer"));
+    let cg = Cgroup::new(h, String::from("test_disable_oom_killer")).unwrap();
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
 
@@ -40,7 +40,7 @@ fn set_kmem_limit_v1() {
         return;
     }
 
-    let cg = Cgroup::new(h, String::from("set_kmem_limit_v1"));
+    let cg = Cgroup::new(h, String::from("set_kmem_limit_v1")).unwrap();
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
         mem_controller.set_kmem_limit(1).unwrap();
@@ -55,7 +55,7 @@ fn set_mem_v2() {
         return;
     }
 
-    let cg = Cgroup::new(h, String::from("set_mem_v2"));
+    let cg = Cgroup::new(h, String::from("set_mem_v2")).unwrap();
     {
         let mem_controller: &MemController = cg.controller_of().unwrap();
 

tests/pids.rs

@@ -17,7 +17,7 @@ use libc::pid_t;
 #[test]
 fn create_and_delete_cgroup() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("create_and_delete_cgroup"));
+    let cg = Cgroup::new(h, String::from("create_and_delete_cgroup")).unwrap();
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
         pidcontroller.set_pid_max(MaxValue::Value(1337)).unwrap();
@@ -31,7 +31,7 @@ fn create_and_delete_cgroup() {
 #[test]
 fn test_pids_current_is_zero() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_pids_current_is_zero"));
+    let cg = Cgroup::new(h, String::from("test_pids_current_is_zero")).unwrap();
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
         let current = pidcontroller.get_pid_current();
@@ -43,7 +43,7 @@ fn test_pids_current_is_zero() {
 #[test]
 fn test_pids_events_is_zero() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_pids_events_is_zero"));
+    let cg = Cgroup::new(h, String::from("test_pids_events_is_zero")).unwrap();
     {
         let pidcontroller: &PidController = cg.controller_of().unwrap();
         let events = pidcontroller.get_pid_events();
@@ -56,7 +56,7 @@ fn test_pids_events_is_zero() {
 #[test]
 fn test_pid_events_is_not_zero() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("test_pid_events_is_not_zero"));
+    let cg = Cgroup::new(h, String::from("test_pid_events_is_not_zero")).unwrap();
     {
         let pids: &PidController = cg.controller_of().unwrap();
         let before = pids.get_pid_events();
@@ -65,7 +65,7 @@ fn test_pid_events_is_not_zero() {
         match unsafe { fork() } {
             Ok(ForkResult::Parent { child, .. }) => {
                 // move the process into the control group
-                let _ = pids.add_task(&(pid_t::from(child) as u64).into());
+                let _ = pids.add_task_by_tgid(&(pid_t::from(child) as u64).into());
 
                 println!("added task to cg: {:?}", child);
 

tests/resources.rs

@@ -11,7 +11,7 @@ use cgroups_rs::{Cgroup, MaxValue, PidResources, Resources};
 #[test]
 fn pid_resources() {
     let h = cgroups_rs::hierarchies::auto();
-    let cg = Cgroup::new(h, String::from("pid_resources"));
+    let cg = Cgroup::new(h, String::from("pid_resources")).unwrap();
     {
         let res = Resources {
             pid: PidResources {