Merge pull request moby#48092 from thaJeztah/fsmagic_internal

daemon/graphdriver: split, internalize packages to separate snapshotters and graphdrivers

daemon/graphdriver/btrfs/btrfs.go

@@ -37,6 +37,7 @@ import (
 	"github.com/containerd/containerd/pkg/userns"
 	"github.com/containerd/log"
 	"github.com/docker/docker/daemon/graphdriver"
+	"github.com/docker/docker/daemon/internal/fstype"
 	"github.com/docker/docker/internal/containerfs"
 	"github.com/docker/docker/pkg/idtools"
 	"github.com/docker/docker/pkg/parsers"
@@ -68,12 +69,12 @@ func Init(home string, options []string, idMap idtools.IdentityMapping) (graphdr
 		testdir = filepath.Dir(testdir)
 	}
 
-	fsMagic, err := graphdriver.GetFSMagic(testdir)
+	fsMagic, err := fstype.GetFSMagic(testdir)
 	if err != nil {
 		return nil, err
 	}
 
-	if fsMagic != graphdriver.FsMagicBtrfs {
+	if fsMagic != fstype.FsMagicBtrfs {
 		return nil, graphdriver.ErrPrerequisites
 	}
 

daemon/graphdriver/driver.go

@@ -15,14 +15,6 @@ import (
 	"github.com/vbatts/tar-split/tar/storage"
 )
 
-// FsMagic unsigned id of the filesystem in use.
-type FsMagic uint32
-
-const (
-	// FsMagicUnsupported is a predefined constant value other than a valid filesystem id.
-	FsMagicUnsupported = FsMagic(0x00000000)
-)
-
 // All registered drivers
 var drivers map[string]InitFunc
 
@@ -136,12 +128,6 @@ type FileGetCloser interface {
 	Close() error
 }
 
-// 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
-}
-
 func init() {
 	drivers = make(map[string]InitFunc)
 }

daemon/graphdriver/driver_linux.go

@@ -1,117 +1,4 @@
 package graphdriver // import "github.com/docker/docker/daemon/graphdriver"
 
-import (
-	"github.com/moby/sys/mountinfo"
-	"golang.org/x/sys/unix"
-)
-
-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)
-	// FsMagicFUSE filesystem id for FUSE
-	FsMagicFUSE = FsMagic(0x65735546)
-)
-
-var (
-	// List of drivers that should be used in an order
-	priority = "overlay2,fuse-overlayfs,btrfs,zfs,vfs"
-
-	// FsNames maps filesystem id to name of the filesystem.
-	FsNames = map[FsMagic]string{
-		FsMagicAufs:        "aufs",
-		FsMagicBtrfs:       "btrfs",
-		FsMagicCramfs:      "cramfs",
-		FsMagicEcryptfs:    "ecryptfs",
-		FsMagicExtfs:       "extfs",
-		FsMagicF2fs:        "f2fs",
-		FsMagicFUSE:        "fuse",
-		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 unix.Statfs_t
-	if err := unix.Statfs(rootpath, &buf); err != nil {
-		return 0, err
-	}
-	return FsMagic(buf.Type), nil
-}
-
-// NewFsChecker returns a checker configured for the provided FsMagic
-func NewFsChecker(t FsMagic) Checker {
-	return &fsChecker{
-		t: t,
-	}
-}
-
-type fsChecker struct {
-	t FsMagic
-}
-
-func (c *fsChecker) IsMounted(path string) bool {
-	fsType, _ := GetFSMagic(path)
-	return fsType == c.t
-}
-
-// 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, _ := mountinfo.Mounted(path)
-	return m
-}
+// List of drivers that should be used in an order
+var priority = "overlay2,fuse-overlayfs,btrfs,zfs,vfs"

daemon/graphdriver/driver_unsupported.go

@@ -4,8 +4,3 @@ package graphdriver // import "github.com/docker/docker/daemon/graphdriver"
 
 // List of drivers that should be used in an order
 var priority = "unsupported"
-
-// GetFSMagic returns the filesystem id given the path.
-func GetFSMagic(rootpath string) (FsMagic, error) {
-	return FsMagicUnsupported, nil
-}

daemon/graphdriver/driver_windows.go

@@ -2,9 +2,3 @@ package graphdriver // import "github.com/docker/docker/daemon/graphdriver"
 
 // List of drivers that should be used in order
 var priority = "windowsfilter"
-
-// GetFSMagic returns the filesystem id given the path.
-func GetFSMagic(rootpath string) (FsMagic, error) {
-	// Note it is OK to return FsMagicUnsupported on Windows.
-	return FsMagicUnsupported, nil
-}

daemon/graphdriver/fuse-overlayfs/fuseoverlayfs.go

@@ -17,6 +17,8 @@ import (
 	"github.com/containerd/log"
 	"github.com/docker/docker/daemon/graphdriver"
 	"github.com/docker/docker/daemon/graphdriver/overlayutils"
+	"github.com/docker/docker/daemon/internal/fstype"
+	"github.com/docker/docker/daemon/internal/mountref"
 	"github.com/docker/docker/internal/containerfs"
 	"github.com/docker/docker/internal/directory"
 	"github.com/docker/docker/pkg/archive"
@@ -58,7 +60,7 @@ const (
 type Driver struct {
 	home      string
 	idMap     idtools.IdentityMapping
-	ctr       *graphdriver.RefCounter
+	ctr       *mountref.Counter
 	naiveDiff graphdriver.DiffDriver
 	locker    *locker.Locker
 }
@@ -97,7 +99,7 @@ func Init(home string, options []string, idMap idtools.IdentityMapping) (graphdr
 	d := &Driver{
 		home:   home,
 		idMap:  idMap,
-		ctr:    graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicFUSE)),
+		ctr:    mountref.NewCounter(isMounted),
 		locker: locker.New(),
 	}
 
@@ -106,6 +108,12 @@ func Init(home string, options []string, idMap idtools.IdentityMapping) (graphdr
 	return d, nil
 }
 
+// isMounted checks whether the given path is a [fstype.FsMagicFUSE] mount.
+func isMounted(path string) bool {
+	fsType, _ := fstype.GetFSMagic(path)
+	return fsType == fstype.FsMagicFUSE
+}
+
 func (d *Driver) String() string {
 	return driverName
 }

daemon/graphdriver/overlay2/overlay.go

@@ -19,6 +19,8 @@ import (
 	"github.com/containerd/log"
 	"github.com/docker/docker/daemon/graphdriver"
 	"github.com/docker/docker/daemon/graphdriver/overlayutils"
+	"github.com/docker/docker/daemon/internal/fstype"
+	"github.com/docker/docker/daemon/internal/mountref"
 	"github.com/docker/docker/internal/containerfs"
 	"github.com/docker/docker/internal/directory"
 	"github.com/docker/docker/pkg/archive"
@@ -92,7 +94,7 @@ type overlayOptions struct {
 type Driver struct {
 	home          string
 	idMap         idtools.IdentityMapping
-	ctr           *graphdriver.RefCounter
+	ctr           *mountref.Counter
 	quotaCtl      *quota.Control
 	options       overlayOptions
 	naiveDiff     graphdriver.DiffDriver
@@ -142,11 +144,11 @@ func Init(home string, options []string, idMap idtools.IdentityMapping) (graphdr
 		return nil, graphdriver.ErrNotSupported
 	}
 
-	fsMagic, err := graphdriver.GetFSMagic(testdir)
+	fsMagic, err := fstype.GetFSMagic(testdir)
 	if err != nil {
 		return nil, err
 	}
-	if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
+	if fsName, ok := fstype.FsNames[fsMagic]; ok {
 		backingFs = fsName
 	}
 
@@ -178,7 +180,7 @@ func Init(home string, options []string, idMap idtools.IdentityMapping) (graphdr
 	d := &Driver{
 		home:          home,
 		idMap:         idMap,
-		ctr:           graphdriver.NewRefCounter(graphdriver.NewFsChecker(graphdriver.FsMagicOverlay)),
+		ctr:           mountref.NewCounter(isMounted),
 		supportsDType: supportsDType,
 		usingMetacopy: usingMetacopy,
 		locker:        locker.New(),
@@ -224,6 +226,12 @@ func Init(home string, options []string, idMap idtools.IdentityMapping) (graphdr
 	return d, nil
 }
 
+// isMounted checks whether the given path is a [fstype.FsMagicOverlay] mount.
+func isMounted(path string) bool {
+	fsType, _ := fstype.GetFSMagic(path)
+	return fsType == fstype.FsMagicOverlay
+}
+
 func parseOptions(options []string) (*overlayOptions, error) {
 	o := &overlayOptions{}
 	for _, option := range options {

daemon/graphdriver/windows/windows.go

@@ -26,6 +26,7 @@ import (
 	"github.com/Microsoft/hcsshim/osversion"
 	"github.com/containerd/log"
 	"github.com/docker/docker/daemon/graphdriver"
+	"github.com/docker/docker/daemon/internal/mountref"
 	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/idtools"
 	"github.com/docker/docker/pkg/ioutils"
@@ -72,12 +73,6 @@ func init() {
 	}
 }
 
-type checker struct{}
-
-func (c *checker) IsMounted(path string) bool {
-	return false
-}
-
 type storageOptions struct {
 	size uint64
 }
@@ -86,7 +81,7 @@ type storageOptions struct {
 type Driver struct {
 	// info stores the shim driver information
 	info hcsshim.DriverInfo
-	ctr  *graphdriver.RefCounter
+	ctr  *mountref.Counter
 	// it is safe for windows to use a cache here because it does not support
 	// restoring containers when the daemon dies.
 	cacheMu            sync.Mutex
@@ -132,12 +127,18 @@ func InitFilter(home string, options []string, _ idtools.IdentityMapping) (graph
 			Flavour: filterDriver,
 		},
 		cache:              make(map[string]string),
-		ctr:                graphdriver.NewRefCounter(&checker{}),
+		ctr:                mountref.NewCounter(isMounted),
 		defaultStorageOpts: opts,
 	}
 	return d, nil
 }
 
+// isMounted checks whether the given path is mounted. It always returns
+// false for the WindowsFilter graphdriver.
+func isMounted(string) bool {
+	return false
+}
+
 // String returns the string representation of a driver. This should match
 // the name the graph driver has been registered with.
 func (d *Driver) String() string {

daemon/graphdriver/zfs/zfs.go

@@ -15,6 +15,7 @@ import (
 
 	"github.com/containerd/log"
 	"github.com/docker/docker/daemon/graphdriver"
+	"github.com/docker/docker/daemon/internal/mountref"
 	"github.com/docker/docker/pkg/idtools"
 	"github.com/docker/docker/pkg/parsers"
 	zfs "github.com/mistifyio/go-zfs/v3"
@@ -118,12 +119,19 @@ func Init(base string, opt []string, idMap idtools.IdentityMapping) (graphdriver
 		options:          options,
 		filesystemsCache: filesystemsCache,
 		idMap:            idMap,
-		ctr:              graphdriver.NewRefCounter(graphdriver.NewDefaultChecker()),
+		ctr:              mountref.NewCounter(isMounted),
 		locker:           locker.New(),
 	}
 	return graphdriver.NewNaiveDiffDriver(d, idMap), nil
 }
 
+// isMounted parses /proc/mountinfo to check whether the specified path
+// is mounted.
+func isMounted(path string) bool {
+	m, _ := mountinfo.Mounted(path)
+	return m
+}
+
 func parseOptions(opt []string) (zfsOptions, error) {
 	var options zfsOptions
 	options.fsName = ""
@@ -175,7 +183,7 @@ type Driver struct {
 	sync.Mutex       // protects filesystem cache against concurrent access
 	filesystemsCache map[string]bool
 	idMap            idtools.IdentityMapping
-	ctr              *graphdriver.RefCounter
+	ctr              *mountref.Counter
 	locker           *locker.Locker
 }
 

daemon/graphdriver/zfs/zfs_linux.go

@@ -5,19 +5,20 @@ import (
 
 	"github.com/containerd/log"
 	"github.com/docker/docker/daemon/graphdriver"
+	"github.com/docker/docker/daemon/internal/fstype"
 )
 
 func checkRootdirFs(rootDir string) error {
-	fsMagic, err := graphdriver.GetFSMagic(rootDir)
+	fsMagic, err := fstype.GetFSMagic(rootDir)
 	if err != nil {
 		return err
 	}
 	backingFS := "unknown"
-	if fsName, ok := graphdriver.FsNames[fsMagic]; ok {
+	if fsName, ok := fstype.FsNames[fsMagic]; ok {
 		backingFS = fsName
 	}
 
-	if fsMagic != graphdriver.FsMagicZfs {
+	if fsMagic != fstype.FsMagicZfs {
 		log.G(context.TODO()).WithField("root", rootDir).WithField("backingFS", backingFS).WithField("storage-driver", "zfs").Error("No zfs dataset found for root")
 		return graphdriver.ErrPrerequisites
 	}