moby/daemon/graphdriver/driver_linux.go
Michael Crosby 1ba05cdb6a Add fast path for fsmagic supported drivers
For things that we can check if they are mounted by using their fsmagic
we should use that and for others do it the slow way.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
2016-05-23 15:57:23 -07:00

131 lines
3.4 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)
// 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",
"devicemapper",
"overlay",
"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",
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
}
// Checker makes checks on specified filesystems.
type Checker interface {
// IsMounted returns true if the provided path is mounted for the specific checker
IsMounted(path string) bool
}
// 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
}
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
}