inits/cmd/dkl-system-init/runlevel-sysinit.go
2018-07-06 19:07:37 +11:00

112 lines
2.4 KiB
Go

package main
import (
"bufio"
"io"
"io/ioutil"
"os"
"strings"
"syscall"
)
const (
msSysfs = syscall.MS_NODEV | syscall.MS_NOEXEC | syscall.MS_NOSUID
)
func init() {
services.Register(
&CommandService{
Name: "kmod-static-nodes",
PreExec: func() error {
mkdir("/run/tmpfiles.d", 0755)
return nil
},
Command: []string{"kmod", "static-nodes", "--format=tmpfiles",
"--output=/run/tmpfiles.d/kmod.conf"},
},
&Oneshot{
Name: "devfs",
Func: func() error {
for _, mount := range []struct {
fstype string
target string
mode os.FileMode
flags uintptr
data string
source string
}{
{"mqueue", "/dev/mqueue", 01777, syscall.MS_NODEV, "", "mqueue"},
{"devpts", "/dev/pts", 0755, 0, "gid=5", "devpts"},
{"tmpfs", "/dev/shm", 01777, syscall.MS_NODEV, "mode=1777", "shm"},
{"tmpfs", "/sys/fs/cgroup", 0755, 0, "mode=755,size=10m", "cgroup"},
} {
initLog.Print("mounting ", mount.target)
flags := syscall.MS_NOEXEC | syscall.MS_NOSUID | mount.flags
mkdir(mount.target, mount.mode)
err := syscall.Mount(mount.source, mount.target, mount.fstype, flags, mount.data)
if err != nil {
fatalf("mount failed: %v", err)
}
}
// mount cgroup controllers
for line := range readLines("/proc/cgroups") {
parts := strings.Split(line, "\t")
name, enabled := parts[0], parts[3]
if enabled != "1" {
continue
}
initLog.Print("mounting cgroup fs for controller ", name)
mp := "/sys/fs/cgroup/" + name
mkdir(mp, 0755)
mount(name, mp, "cgroup", msSysfs, name)
}
if err := ioutil.WriteFile("/sys/fs/cgroup/memory/memory.use_hierarchy",
[]byte{'1'}, 0644); err != nil {
initLog.Print("failed to enable use_hierarchy in memory cgroup: ", err)
}
return nil
},
},
&CommandService{
Name: "dmesg",
Command: []string{"dmesg", "-n", "warn"},
},
)
}
func readLines(path string) chan string {
f, err := os.Open(path)
if err != nil {
fatalf("failed to open %s: %v", path, err)
}
bf := bufio.NewReader(f)
ch := make(chan string, 1)
go func() {
defer f.Close()
defer close(ch)
for {
line, err := bf.ReadString('\n')
if err == io.EOF {
break
} else if err != nil {
fatalf("error while reading %s: %v", path, err)
}
ch <- line[:len(line)-1]
}
}()
return ch
}