github.com/rhatdan/docker@v0.7.7-0.20180119204836-47a0dcbcd20a/daemon/graphdriver/driver_linux.go (about)

     1  package graphdriver
     2  
     3  import (
     4  	"github.com/docker/docker/pkg/mount"
     5  	"golang.org/x/sys/unix"
     6  )
     7  
     8  const (
     9  	// FsMagicAufs filesystem id for Aufs
    10  	FsMagicAufs = FsMagic(0x61756673)
    11  	// FsMagicBtrfs filesystem id for Btrfs
    12  	FsMagicBtrfs = FsMagic(0x9123683E)
    13  	// FsMagicCramfs filesystem id for Cramfs
    14  	FsMagicCramfs = FsMagic(0x28cd3d45)
    15  	// FsMagicEcryptfs filesystem id for eCryptfs
    16  	FsMagicEcryptfs = FsMagic(0xf15f)
    17  	// FsMagicExtfs filesystem id for Extfs
    18  	FsMagicExtfs = FsMagic(0x0000EF53)
    19  	// FsMagicF2fs filesystem id for F2fs
    20  	FsMagicF2fs = FsMagic(0xF2F52010)
    21  	// FsMagicGPFS filesystem id for GPFS
    22  	FsMagicGPFS = FsMagic(0x47504653)
    23  	// FsMagicJffs2Fs filesystem if for Jffs2Fs
    24  	FsMagicJffs2Fs = FsMagic(0x000072b6)
    25  	// FsMagicJfs filesystem id for Jfs
    26  	FsMagicJfs = FsMagic(0x3153464a)
    27  	// FsMagicNfsFs filesystem id for NfsFs
    28  	FsMagicNfsFs = FsMagic(0x00006969)
    29  	// FsMagicRAMFs filesystem id for RamFs
    30  	FsMagicRAMFs = FsMagic(0x858458f6)
    31  	// FsMagicReiserFs filesystem id for ReiserFs
    32  	FsMagicReiserFs = FsMagic(0x52654973)
    33  	// FsMagicSmbFs filesystem id for SmbFs
    34  	FsMagicSmbFs = FsMagic(0x0000517B)
    35  	// FsMagicSquashFs filesystem id for SquashFs
    36  	FsMagicSquashFs = FsMagic(0x73717368)
    37  	// FsMagicTmpFs filesystem id for TmpFs
    38  	FsMagicTmpFs = FsMagic(0x01021994)
    39  	// FsMagicVxFS filesystem id for VxFs
    40  	FsMagicVxFS = FsMagic(0xa501fcf5)
    41  	// FsMagicXfs filesystem id for Xfs
    42  	FsMagicXfs = FsMagic(0x58465342)
    43  	// FsMagicZfs filesystem id for Zfs
    44  	FsMagicZfs = FsMagic(0x2fc12fc1)
    45  	// FsMagicOverlay filesystem id for overlay
    46  	FsMagicOverlay = FsMagic(0x794C7630)
    47  )
    48  
    49  var (
    50  	// List of drivers that should be used in an order
    51  	priority = "btrfs,zfs,overlay2,aufs,overlay,devicemapper,vfs"
    52  
    53  	// FsNames maps filesystem id to name of the filesystem.
    54  	FsNames = map[FsMagic]string{
    55  		FsMagicAufs:        "aufs",
    56  		FsMagicBtrfs:       "btrfs",
    57  		FsMagicCramfs:      "cramfs",
    58  		FsMagicEcryptfs:    "ecryptfs",
    59  		FsMagicExtfs:       "extfs",
    60  		FsMagicF2fs:        "f2fs",
    61  		FsMagicGPFS:        "gpfs",
    62  		FsMagicJffs2Fs:     "jffs2",
    63  		FsMagicJfs:         "jfs",
    64  		FsMagicNfsFs:       "nfs",
    65  		FsMagicOverlay:     "overlayfs",
    66  		FsMagicRAMFs:       "ramfs",
    67  		FsMagicReiserFs:    "reiserfs",
    68  		FsMagicSmbFs:       "smb",
    69  		FsMagicSquashFs:    "squashfs",
    70  		FsMagicTmpFs:       "tmpfs",
    71  		FsMagicUnsupported: "unsupported",
    72  		FsMagicVxFS:        "vxfs",
    73  		FsMagicXfs:         "xfs",
    74  		FsMagicZfs:         "zfs",
    75  	}
    76  )
    77  
    78  // GetFSMagic returns the filesystem id given the path.
    79  func GetFSMagic(rootpath string) (FsMagic, error) {
    80  	var buf unix.Statfs_t
    81  	if err := unix.Statfs(rootpath, &buf); err != nil {
    82  		return 0, err
    83  	}
    84  	return FsMagic(buf.Type), nil
    85  }
    86  
    87  // NewFsChecker returns a checker configured for the provided FsMagic
    88  func NewFsChecker(t FsMagic) Checker {
    89  	return &fsChecker{
    90  		t: t,
    91  	}
    92  }
    93  
    94  type fsChecker struct {
    95  	t FsMagic
    96  }
    97  
    98  func (c *fsChecker) IsMounted(path string) bool {
    99  	m, _ := Mounted(c.t, path)
   100  	return m
   101  }
   102  
   103  // NewDefaultChecker returns a check that parses /proc/mountinfo to check
   104  // if the specified path is mounted.
   105  func NewDefaultChecker() Checker {
   106  	return &defaultChecker{}
   107  }
   108  
   109  type defaultChecker struct {
   110  }
   111  
   112  func (c *defaultChecker) IsMounted(path string) bool {
   113  	m, _ := mount.Mounted(path)
   114  	return m
   115  }
   116  
   117  // Mounted checks if the given path is mounted as the fs type
   118  func Mounted(fsType FsMagic, mountPath string) (bool, error) {
   119  	var buf unix.Statfs_t
   120  	if err := unix.Statfs(mountPath, &buf); err != nil {
   121  		return false, err
   122  	}
   123  	return FsMagic(buf.Type) == fsType, nil
   124  }