moby/daemon/graphdriver/driver_linux.go
Sebastiaan van Stijn 299beff1c4
promote overlay(2) graphdriver
Now that overlay has matured, using
overlay is a better choice than devicemapper
on loopback devices.

This change promotes overlay in the
priority list. It also adds the
overlay2 graphdriver to the list
because overlay2 (if supported)
should be preferred over overlay.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2016-10-31 23:32:10 -07:00

135 lines
3.5 KiB
Go

// +build linux
package graphdriver
import (
"path/filepath"
"syscall"
"github.com/docker/docker/pkg/mount"
)
const (
// FsMagicAufs filesystem id for Aufs
FsMagicAufs = FsMagic(0x61756673)
// FsMagicBtrfs filesystem id for Btrfs
FsMagicBtrfs = FsMagic(0x9123683E)
// FsMagicCramfs filesystem id for Cramfs
FsMagicCramfs = FsMagic(0x28cd3d45)
// FsMagicEcryptfs filesystem id for eCryptfs
FsMagicEcryptfs = FsMagic(0xf15f)
// FsMagicExtfs filesystem id for Extfs
FsMagicExtfs = FsMagic(0x0000EF53)
// FsMagicF2fs filesystem id for F2fs
FsMagicF2fs = FsMagic(0xF2F52010)
// FsMagicGPFS filesystem id for GPFS
FsMagicGPFS = FsMagic(0x47504653)
// FsMagicJffs2Fs filesystem if for Jffs2Fs
FsMagicJffs2Fs = FsMagic(0x000072b6)
// FsMagicJfs filesystem id for Jfs
FsMagicJfs = FsMagic(0x3153464a)
// FsMagicNfsFs filesystem id for NfsFs
FsMagicNfsFs = FsMagic(0x00006969)
// FsMagicRAMFs filesystem id for RamFs
FsMagicRAMFs = FsMagic(0x858458f6)
// FsMagicReiserFs filesystem id for ReiserFs
FsMagicReiserFs = FsMagic(0x52654973)
// FsMagicSmbFs filesystem id for SmbFs
FsMagicSmbFs = FsMagic(0x0000517B)
// FsMagicSquashFs filesystem id for SquashFs
FsMagicSquashFs = FsMagic(0x73717368)
// FsMagicTmpFs filesystem id for TmpFs
FsMagicTmpFs = FsMagic(0x01021994)
// FsMagicVxFS filesystem id for VxFs
FsMagicVxFS = FsMagic(0xa501fcf5)
// FsMagicXfs filesystem id for Xfs
FsMagicXfs = FsMagic(0x58465342)
// FsMagicZfs filesystem id for Zfs
FsMagicZfs = FsMagic(0x2fc12fc1)
// FsMagicOverlay filesystem id for overlay
FsMagicOverlay = FsMagic(0x794C7630)
)
var (
// Slice of drivers that should be used in an order
priority = []string{
"aufs",
"btrfs",
"zfs",
"overlay2",
"overlay",
"devicemapper",
"vfs",
}
// FsNames maps filesystem id to name of the filesystem.
FsNames = map[FsMagic]string{
FsMagicAufs: "aufs",
FsMagicBtrfs: "btrfs",
FsMagicCramfs: "cramfs",
FsMagicExtfs: "extfs",
FsMagicF2fs: "f2fs",
FsMagicGPFS: "gpfs",
FsMagicJffs2Fs: "jffs2",
FsMagicJfs: "jfs",
FsMagicNfsFs: "nfs",
FsMagicOverlay: "overlayfs",
FsMagicRAMFs: "ramfs",
FsMagicReiserFs: "reiserfs",
FsMagicSmbFs: "smb",
FsMagicSquashFs: "squashfs",
FsMagicTmpFs: "tmpfs",
FsMagicUnsupported: "unsupported",
FsMagicVxFS: "vxfs",
FsMagicXfs: "xfs",
FsMagicZfs: "zfs",
}
)
// GetFSMagic returns the filesystem id given the path.
func GetFSMagic(rootpath string) (FsMagic, error) {
var buf syscall.Statfs_t
if err := syscall.Statfs(filepath.Dir(rootpath), &buf); err != nil {
return 0, err
}
return FsMagic(buf.Type), nil
}
// NewFsChecker returns a checker configured for the provied FsMagic
func NewFsChecker(t FsMagic) Checker {
return &fsChecker{
t: t,
}
}
type fsChecker struct {
t FsMagic
}
func (c *fsChecker) IsMounted(path string) bool {
m, _ := Mounted(c.t, path)
return m
}
// NewDefaultChecker returns a check that parses /proc/mountinfo to check
// if the specified path is mounted.
func NewDefaultChecker() Checker {
return &defaultChecker{}
}
type defaultChecker struct {
}
func (c *defaultChecker) IsMounted(path string) bool {
m, _ := mount.Mounted(path)
return m
}
// Mounted checks if the given path is mounted as the fs type
func Mounted(fsType FsMagic, mountPath string) (bool, error) {
var buf syscall.Statfs_t
if err := syscall.Statfs(mountPath, &buf); err != nil {
return false, err
}
return FsMagic(buf.Type) == fsType, nil
}