Merge pull request #149 from kata-containers/bump-rust

Bump Rust version to 1.85.1

.github/workflows/bvt.yaml

@@ -1,7 +1,7 @@
 name: BVT
 on: [pull_request]
 env:
-  RUST_VERSION: 1.69.0
+  RUST_VERSION: 1.85.1
 jobs:
   build:
     name: Build

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 = "0.3.4"
+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"
@@ -13,7 +13,6 @@ readme = "README.md"
 
 [dependencies]
 log = "0.4"
-regex = "1.1"
 nix = { version = "0.25.0", default-features = false, features = ["event", "fs", "process"] }
 libc = "0.2"
 serde = { version = "1.0", features = ["derive"], optional = true }

src/blkio.rs

@@ -181,13 +181,14 @@ fn parse_io_stat(s: String) -> Vec<IoStat> {
 
 fn parse_io_service_total(s: String) -> Result<u64> {
     s.lines()
-        .filter(|x| x.split_whitespace().count() == 2)
-        .fold(Err(Error::new(ParseError)), |_, x| {
-            match x.split_whitespace().collect::<Vec<_>>().as_slice() {
-                ["Total", val] => val.parse::<u64>().map_err(|_| Error::new(ParseError)),
-                _ => Err(Error::new(ParseError)),
+        .find_map(|line| {
+            let mut parts = line.split_whitespace();
+            match (parts.next(), parts.next(), parts.next()) {
+                (Some("Total"), Some(val), None) => val.parse::<u64>().ok(),
+                _ => None,
             }
         })
+        .ok_or_else(|| Error::new(ParseError))
 }
 
 fn parse_blkio_data(s: String) -> Result<Vec<BlkIoData>> {
@@ -430,10 +431,10 @@ 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,
         }
     }

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;
@@ -521,7 +522,7 @@ 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>>()
 }
 
@@ -588,19 +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/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,
         }
     }
@@ -602,7 +602,7 @@ mod tests {
             "1,2,3,4".to_string(),
             "1-5,6-7,8-9".to_string(),
         ];
-        let expecteds = vec![
+        let expecteds = [
             vec![(1, 1), (2, 2), (4, 6), (9, 9)],
             vec![],
             vec![(1, 1)],

src/devices.rs

@@ -204,10 +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,
         }
     }
 
@@ -295,43 +295,48 @@ impl DevicesController {
             let mut s = String::new();
             let res = file.read_to_string(&mut s);
             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>>();
-                        if acc.is_err() || ls.len() != 4 {
-                            error!("allowed_devices: acc: {:?}, ls: {:?}", acc, ls);
-                            Err(Error::new(ParseError))
-                        } else {
-                            let devtype = DeviceType::from_char(ls[0].chars().next());
-                            let mut major = ls[1].parse::<i64>();
-                            let mut minor = ls[2].parse::<i64>();
-                            if major.is_err() && ls[1] == "*" {
-                                major = Ok(-1);
-                            }
-                            if minor.is_err() && ls[2] == "*" {
-                                minor = Ok(-1);
-                            }
-                            if devtype.is_none() || major.is_err() || minor.is_err() || !DevicePermissions::is_valid(&ls[3]) {
-                                error!("allowed_devices: acc: {:?}, ls: {:?}, devtype: {:?}, major {:?} minor {:?} ls3 {:?}",
-                                         acc, ls, devtype, major, minor, &ls[3]);
-                                Err(Error::new(ParseError))
-                            } else {
-                                let access = DevicePermissions::from_str(&ls[3])?;
-                                let mut acc = acc.unwrap();
-                                acc.push(DeviceResource {
-                                    allow: true,
-                                    devtype: devtype.unwrap(),
-                                    major: major.unwrap(),
-                                    minor: minor.unwrap(),
-                                    access,
-                                });
-                                Ok(acc)
-                            }
-                        }
-                    })
-                },
+                Ok(_) => s
+                    .lines()
+                    .map(|line| parse_device_line(line, true))
+                    .collect(),
                 Err(e) => Err(Error::with_cause(ReadFailed("devices.list".to_string()), e)),
             }
         })
     }
 }
+
+fn parse_device_number(s: &str) -> Result<i64> {
+    if s == "*" {
+        Ok(-1)
+    } else {
+        s.parse::<i64>().map_err(|_| Error::new(ParseError))
+    }
+}
+
+fn parse_device_line(line: &str, allow: bool) -> Result<DeviceResource> {
+    let parts: Vec<&str> = line.split([' ', ':']).collect();
+    if parts.len() != 4 {
+        error!("allowed_devices: invalid line format: {:?}", line);
+        return Err(Error::new(ParseError));
+    }
+
+    let devtype = DeviceType::from_char(parts[0].chars().next()).ok_or_else(|| {
+        error!("allowed_devices: invalid device type: {:?}", parts[0]);
+        Error::new(ParseError)
+    })?;
+    let major = parse_device_number(parts[1]).inspect_err(|_| {
+        error!("allowed_devices: invalid major number: {:?}", parts[1]);
+    })?;
+    let minor = parse_device_number(parts[2]).inspect_err(|_| {
+        error!("allowed_devices: invalid minor number: {:?}", parts[2]);
+    })?;
+    let access = DevicePermissions::from_str(parts[3])?;
+
+    Ok(DeviceResource {
+        allow,
+        devtype,
+        major,
+        minor,
+        access,
+    })
+}

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

@@ -5,9 +5,6 @@
 //
 
 //! 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;
@@ -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
@@ -218,29 +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,
                     )));
                 }
@@ -275,10 +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
         })
@@ -337,19 +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,
         }
@@ -181,7 +181,6 @@ impl HugeTlbController {
 }
 
 pub const HUGEPAGESIZE_DIR: &str = "/sys/kernel/mm/hugepages";
-use regex::Regex;
 use std::collections::HashMap;
 use std::fs;
 
@@ -263,37 +262,46 @@ pub fn get_decimal_abbrs() -> Vec<String> {
 }
 
 fn parse_size(s: &str, m: &HashMap<String, u128>) -> Result<u128> {
-    let re = Regex::new(r"(?P<num>\d+)(?P<mul>[kKmMgGtTpP]?)[bB]?$");
+    // Remove leading/trailing whitespace.
+    let s = s.trim();
 
-    if re.is_err() {
+    // Remove an optional trailing 'b' or 'B'
+    let s = if let Some(stripped) = s.strip_suffix('b').or_else(|| s.strip_suffix('B')) {
+        stripped
+    } else {
+        s
+    };
+
+    // Ensure that the string is not empty after stripping.
+    if s.is_empty() {
         return Err(Error::new(InvalidBytesSize));
     }
-    let caps = re.unwrap().captures(s).unwrap();
 
-    let num = caps.name("num");
-    let size: u128 = if let Some(num) = num {
-        let n = num.as_str().trim().parse::<u128>();
-        if n.is_err() {
-            return Err(Error::new(InvalidBytesSize));
-        }
-        n.unwrap()
-    } else {
+    // The last character should be the multiplier letter.
+    let last_char = s.chars().last().unwrap();
+    if !"kKmMgGtTpP".contains(last_char) {
         return Err(Error::new(InvalidBytesSize));
-    };
+    }
 
-    let q = caps.name("mul");
-    let mul: u128 = if let Some(q) = q {
-        let t = m.get(q.as_str());
-        if let Some(t) = t {
-            *t
-        } else {
-            return Err(Error::new(InvalidBytesSize));
-        }
-    } else {
+    // The numeric part is everything before the multiplier letter.
+    let num_part = &s[..s.len() - last_char.len_utf8()];
+    if num_part.trim().is_empty() {
         return Err(Error::new(InvalidBytesSize));
-    };
+    }
 
-    Ok(size * mul)
+    // Parse the numeric part into a u128.
+    let number: u128 = num_part
+        .trim()
+        .parse()
+        .map_err(|_| Error::new(InvalidBytesSize))?;
+
+    // Look up the multiplier in the provided HashMap.
+    let multiplier_key = last_char.to_string();
+    let multiplier = m
+        .get(&multiplier_key)
+        .ok_or_else(|| Error::new(InvalidBytesSize))?;
+
+    Ok(number * multiplier)
 }
 
 fn custom_size(mut size: f64, base: f64, m: &[String]) -> String {
@@ -305,3 +313,60 @@ fn custom_size(mut size: f64, base: f64, m: &[String]) -> String {
 
     format!("{}{}", size, m[i].as_str())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_binary_size_valid() {
+        let m = get_binary_size_map();
+        // Valid inputs must include a multiplier letter.
+        assert_eq!(parse_size("1k", &m).unwrap(), KiB);
+        assert_eq!(parse_size("2m", &m).unwrap(), 2 * MiB);
+        assert_eq!(parse_size("3g", &m).unwrap(), 3 * GiB);
+        assert_eq!(parse_size("4t", &m).unwrap(), 4 * TiB);
+        assert_eq!(parse_size("5p", &m).unwrap(), 5 * PiB);
+    }
+
+    #[test]
+    fn test_decimal_size_valid() {
+        let m = get_decimal_size_map();
+        assert_eq!(parse_size("1k", &m).unwrap(), KB);
+        assert_eq!(parse_size("2m", &m).unwrap(), 2 * MB);
+        assert_eq!(parse_size("3g", &m).unwrap(), 3 * GB);
+        assert_eq!(parse_size("4t", &m).unwrap(), 4 * TB);
+        assert_eq!(parse_size("5p", &m).unwrap(), 5 * PB);
+    }
+
+    #[test]
+    fn test_trailing_b_suffix() {
+        let m = get_binary_size_map();
+        // Trailing 'b' or 'B' should be accepted.
+        assert_eq!(parse_size("1kb", &m).unwrap(), KiB);
+        assert_eq!(parse_size("2mB", &m).unwrap(), 2 * MiB);
+    }
+
+    #[test]
+    fn test_invalid_inputs() {
+        let m = get_binary_size_map();
+        // Missing multiplier letter results in error.
+        assert!(parse_size("1", &m).is_err());
+        // Invalid multiplier letter.
+        assert!(parse_size("10x", &m).is_err());
+        // Non-numeric input.
+        assert!(parse_size("abc", &m).is_err());
+        // Only multiplier letter with no number.
+        assert!(parse_size("k", &m).is_err());
+        // Number with an invalid trailing character.
+        assert!(parse_size("123z", &m).is_err());
+    }
+
+    #[test]
+    fn test_uppercase_multiplier_fails() {
+        let m = get_binary_size_map();
+        // Although the regex matches uppercase letters, the provided map only contains lowercase keys.
+        // Therefore, "1K" does not match any key and should produce an error.
+        assert!(parse_size("1K", &m).is_err());
+    }
+}

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<()>;
@@ -307,6 +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<()> {
@@ -777,7 +785,7 @@ impl From<u64> for CgroupPid {
     }
 }
 
-impl<'a> From<&'a std::process::Child> for CgroupPid {
+impl From<&std::process::Child> for CgroupPid {
     fn from(u: &std::process::Child) -> CgroupPid {
         CgroupPid { pid: u.id() as u64 }
     }

src/memory.rs

@@ -142,9 +142,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
     let hier_unevict_line = ls.next().unwrap_or_default();
 
     Ok(NumaStat {
-        total_pages: total_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
+        total_pages: total_line.split([' ', '=']).collect::<Vec<_>>()[1]
             .parse::<u64>()
             .unwrap_or(0),
         total_pages_per_node: {
@@ -157,9 +155,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
                 })
                 .collect()
         },
-        file_pages: file_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
+        file_pages: file_line.split([' ', '=']).collect::<Vec<_>>()[1]
             .parse::<u64>()
             .unwrap_or(0),
         file_pages_per_node: {
@@ -172,9 +168,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
                 })
                 .collect()
         },
-        anon_pages: anon_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
+        anon_pages: anon_line.split([' ', '=']).collect::<Vec<_>>()[1]
             .parse::<u64>()
             .unwrap_or(0),
         anon_pages_per_node: {
@@ -187,9 +181,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
                 })
                 .collect()
         },
-        unevictable_pages: unevict_line
-            .split(|x| x == ' ' || x == '=')
-            .collect::<Vec<_>>()[1]
+        unevictable_pages: unevict_line.split([' ', '=']).collect::<Vec<_>>()[1]
             .parse::<u64>()
             .unwrap_or(0),
         unevictable_pages_per_node: {
@@ -204,9 +196,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
         },
         hierarchical_total_pages: {
             if !hier_total_line.is_empty() {
-                hier_total_line
-                    .split(|x| x == ' ' || x == '=')
-                    .collect::<Vec<_>>()[1]
+                hier_total_line.split([' ', '=']).collect::<Vec<_>>()[1]
                     .parse::<u64>()
                     .unwrap_or(0)
             } else {
@@ -229,9 +219,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
         },
         hierarchical_file_pages: {
             if !hier_file_line.is_empty() {
-                hier_file_line
-                    .split(|x| x == ' ' || x == '=')
-                    .collect::<Vec<_>>()[1]
+                hier_file_line.split([' ', '=']).collect::<Vec<_>>()[1]
                     .parse::<u64>()
                     .unwrap_or(0)
             } else {
@@ -254,9 +242,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
         },
         hierarchical_anon_pages: {
             if !hier_anon_line.is_empty() {
-                hier_anon_line
-                    .split(|x| x == ' ' || x == '=')
-                    .collect::<Vec<_>>()[1]
+                hier_anon_line.split([' ', '=']).collect::<Vec<_>>()[1]
                     .parse::<u64>()
                     .unwrap_or(0)
             } else {
@@ -279,9 +265,7 @@ fn parse_numa_stat(s: String) -> Result<NumaStat> {
         },
         hierarchical_unevictable_pages: {
             if !hier_unevict_line.is_empty() {
-                hier_unevict_line
-                    .split(|x| x == ' ' || x == '=')
-                    .collect::<Vec<_>>()[1]
+                hier_unevict_line.split([' ', '=']).collect::<Vec<_>>()[1]
                     .parse::<u64>()
                     .unwrap_or(0)
             } else {
@@ -540,10 +524,10 @@ 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 +557,33 @@ 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,
@@ -730,7 +729,7 @@ 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)

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,
         }
     }
 
@@ -94,36 +94,26 @@ impl NetPrioController {
     }
 
     /// A map of priorities for each network interface.
-    #[allow(clippy::iter_nth_zero, clippy::unnecessary_unwrap)]
     pub fn ifpriomap(&self) -> Result<HashMap<String, u64>> {
         self.open_path("net_prio.ifpriomap", false)
             .and_then(|file| {
                 let bf = BufReader::new(file);
-                bf.lines().fold(Ok(HashMap::new()), |acc, line| {
-                    if acc.is_err() {
-                        acc
-                    } else {
-                        let mut acc = acc.unwrap();
-                        let l = line.unwrap();
-                        let mut sp = l.split_whitespace();
+                bf.lines()
+                    .map(|line| {
+                        let line = line.map_err(|_| Error::new(ParseError))?;
+                        let mut parts = line.split_whitespace();
 
-                        let ifname = sp.nth(0);
-                        let ifprio = sp.nth(1);
-                        if ifname.is_none() || ifprio.is_none() {
-                            Err(Error::new(ParseError))
-                        } else {
-                            let ifname = ifname.unwrap();
-                            let ifprio = ifprio.unwrap().trim().parse();
-                            match ifprio {
-                                Err(e) => Err(Error::with_cause(ParseError, e)),
-                                Ok(_) => {
-                                    acc.insert(ifname.to_string(), ifprio.unwrap());
-                                    Ok(acc)
-                                }
-                            }
-                        }
-                    }
-                })
+                        let ifname = parts.next().ok_or(Error::new(ParseError))?;
+                        let ifprio_str = parts.next().ok_or(Error::new(ParseError))?;
+
+                        let ifprio = ifprio_str
+                            .trim()
+                            .parse()
+                            .map_err(|e| Error::with_cause(ParseError, e))?;
+
+                        Ok((ifname.to_string(), ifprio))
+                    })
+                    .collect::<Result<HashMap<String, _>>>()
             })
     }
 

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,
         }
     }