Revert "Mount cgroups in the container"

This reverts commit b441dfa729.

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@docker.com> (github: crosbymichael)
This commit is contained in:
Michael Crosby 2014-06-17 11:41:40 -07:00
parent 2a9ff02bee
commit c7d1cb2272
1 changed files with 0 additions and 66 deletions

View File

@ -6,11 +6,9 @@ import (
"fmt" "fmt"
"os" "os"
"path/filepath" "path/filepath"
"strings"
"syscall" "syscall"
"github.com/docker/libcontainer" "github.com/docker/libcontainer"
"github.com/docker/libcontainer/cgroups"
"github.com/docker/libcontainer/label" "github.com/docker/libcontainer/label"
"github.com/docker/libcontainer/mount/nodes" "github.com/docker/libcontainer/mount/nodes"
"github.com/dotcloud/docker/pkg/symlink" "github.com/dotcloud/docker/pkg/symlink"
@ -94,69 +92,6 @@ func mountSystem(rootfs string, container *libcontainer.Container) error {
return fmt.Errorf("mounting %s into %s %s", m.source, m.path, err) return fmt.Errorf("mounting %s into %s %s", m.source, m.path, err)
} }
} }
// Mount all cgroup subsystems into the container, read-only. Create symlinks for each
// subsystem if any subsystems are merged
cgroupMounts, err := cgroups.GetCgroupMounts()
if err != nil {
return err
}
cgroupsDir := filepath.Join(rootfs, "/sys/fs/cgroup")
for _, m := range cgroupMounts {
dir := filepath.Base(m.Mountpoint)
mountpoint := filepath.Join(cgroupsDir, dir)
if err := os.MkdirAll(mountpoint, 0755); err != nil && !os.IsExist(err) {
return fmt.Errorf("mkdirall %s %s", mountpoint, err)
}
// Bind-mount the cgroup to /sys/fs/cgroup with the same name as the outer mount
if err := system.Mount(m.Mountpoint, mountpoint, "bind", uintptr(syscall.MS_BIND|defaultMountFlags), ""); err != nil {
return fmt.Errorf("mounting %s into %s %s", m.Mountpoint, mountpoint, err)
}
// Make it read-only
if err := system.Mount(mountpoint, mountpoint, "bind", uintptr(syscall.MS_BIND|syscall.MS_REMOUNT|syscall.MS_RDONLY|defaultMountFlags), ""); err != nil {
return fmt.Errorf("remounting %s into %s %s", mountpoint, mountpoint, err)
}
hasName := false
for _, subsys := range m.Subsystems {
isName := strings.HasPrefix(subsys, "name=")
canonicalName := subsys
if isName {
hasName = true
canonicalName = subsys[5:]
}
// For the merged case dir will be something like "cpu,cpuacct", so
// we make symlinks for all the pure subsystem names "cpu -> cpu,cpuacct", etc
if canonicalName != dir {
if err := os.Symlink(dir, filepath.Join(cgroupsDir, canonicalName)); err != nil {
return fmt.Errorf("creating cgroup symlink for %s: %s", dir, err)
}
}
}
// For named cgroups, such as name=systemd we mount a read-write subset at the
// current cgroup path. This lets e.g. systemd work inside a container, as it can create subcgroups inside the
// current cgroup, while not being able to do anything dangerous in the real cgroups
if hasName {
cgroupPath, _ := m.GetThisCgroupDir()
if cgroupPath != "" && cgroupPath != "/" {
if err := system.Mount(filepath.Join(m.Mountpoint, cgroupPath), filepath.Join(mountpoint, cgroupPath), "bind", uintptr(syscall.MS_BIND|defaultMountFlags), ""); err != nil {
return fmt.Errorf("mounting %s into %s %s", filepath.Join(m.Mountpoint, cgroupPath), filepath.Join(mountpoint, cgroupPath), err)
}
}
}
}
// Make /sys/fs/cgroup read-only
if err := system.Mount(cgroupsDir, cgroupsDir, "bind", uintptr(syscall.MS_REMOUNT|syscall.MS_RDONLY|defaultMountFlags), ""); err != nil {
return fmt.Errorf("remounting %s read-only %s", cgroupsDir, err)
}
return nil return nil
} }
@ -258,7 +193,6 @@ func newSystemMounts(rootfs, mountLabel string, mounts libcontainer.Mounts) []mo
{source: "proc", path: filepath.Join(rootfs, "proc"), device: "proc", flags: defaultMountFlags}, {source: "proc", path: filepath.Join(rootfs, "proc"), device: "proc", flags: defaultMountFlags},
{source: "sysfs", path: filepath.Join(rootfs, "sys"), device: "sysfs", flags: defaultMountFlags}, {source: "sysfs", path: filepath.Join(rootfs, "sys"), device: "sysfs", flags: defaultMountFlags},
{source: "tmpfs", path: filepath.Join(rootfs, "dev"), device: "tmpfs", flags: syscall.MS_NOSUID | syscall.MS_STRICTATIME, data: label.FormatMountLabel("mode=755", mountLabel)}, {source: "tmpfs", path: filepath.Join(rootfs, "dev"), device: "tmpfs", flags: syscall.MS_NOSUID | syscall.MS_STRICTATIME, data: label.FormatMountLabel("mode=755", mountLabel)},
{source: "tmpfs", path: filepath.Join(rootfs, "sys/fs/cgroup"), device: "tmpfs", flags: defaultMountFlags},
{source: "shm", path: filepath.Join(rootfs, "dev", "shm"), device: "tmpfs", flags: defaultMountFlags, data: label.FormatMountLabel("mode=1777,size=65536k", mountLabel)}, {source: "shm", path: filepath.Join(rootfs, "dev", "shm"), device: "tmpfs", flags: defaultMountFlags, data: label.FormatMountLabel("mode=1777,size=65536k", mountLabel)},
{source: "devpts", path: filepath.Join(rootfs, "dev", "pts"), device: "devpts", flags: syscall.MS_NOSUID | syscall.MS_NOEXEC, data: label.FormatMountLabel("newinstance,ptmxmode=0666,mode=620,gid=5", mountLabel)}, {source: "devpts", path: filepath.Join(rootfs, "dev", "pts"), device: "devpts", flags: syscall.MS_NOSUID | syscall.MS_NOEXEC, data: label.FormatMountLabel("newinstance,ptmxmode=0666,mode=620,gid=5", mountLabel)},
} }