Merge pull request kubernetes#6269 from ddysher/extend-mount

Abstract IsMountPoint and improve FakeMounter
duda · Apr 2, 2015 · ee98731 · ee98731
2 parents c627a35 + d62afa8
commit ee98731
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Showing 12 changed files with 70 additions and 92 deletions.
diff --git a/pkg/util/mount/fake.go b/pkg/util/mount/fake.go
@@ -39,15 +39,32 @@ func (f *FakeMounter) ResetLog() {
 }
 
 func (f *FakeMounter) Mount(source string, target string, fstype string, flags uintptr, data string) error {
+	f.MountPoints = append(f.MountPoints, MountPoint{Device: source, Path: target, Type: fstype})
 	f.Log = append(f.Log, FakeAction{Action: FakeActionMount, Target: target, Source: source, FSType: fstype})
 	return nil
 }
 
 func (f *FakeMounter) Unmount(target string, flags int) error {
+	newMountpoints := []MountPoint{}
+	for _, mp := range f.MountPoints {
+		if mp.Path != target {
+			newMountpoints = append(newMountpoints, MountPoint{Device: mp.Device, Path: mp.Path, Type: mp.Type})
+		}
+	}
+	f.MountPoints = newMountpoints
 	f.Log = append(f.Log, FakeAction{Action: FakeActionUnmount, Target: target})
 	return nil
 }
 
 func (f *FakeMounter) List() ([]MountPoint, error) {
 	return f.MountPoints, nil
 }
+
+func (f *FakeMounter) IsMountPoint(file string) (bool, error) {
+	for _, mp := range f.MountPoints {
+		if mp.Path == file {
+			return true, nil
+		}
+	}
+	return false, nil
+}
diff --git a/pkg/util/mount/mount.go b/pkg/util/mount/mount.go
@@ -24,20 +24,15 @@ package mount
 type Interface interface {
 	// Mount wraps syscall.Mount().
 	Mount(source string, target string, fstype string, flags uintptr, data string) error
-
 	// Umount wraps syscall.Mount().
 	Unmount(target string, flags int) error
-
 	// List returns a list of all mounted filesystems.  This can be large.
 	// On some platforms, reading mounts is not guaranteed consistent (i.e.
 	// it could change between chunked reads). This is guaranteed to be
 	// consistent.
 	List() ([]MountPoint, error)
-}
-
-// New returns a mount.Interface for the current system.
-func New() Interface {
-	return &Mounter{}
+	// IsMountPoint determines if a directory is a mountpoint.
+	IsMountPoint(file string) (bool, error)
 }
 
 // This represents a single line in /proc/mounts or /etc/fstab.
@@ -50,7 +45,12 @@ type MountPoint struct {
 	Pass   int
 }
 
-// Examines /proc/mounts to find all other references to the device referenced
+// New returns a mount.Interface for the current system.
+func New() Interface {
+	return &Mounter{}
+}
+
+// GetMountRefs finds all other references to the device referenced
 // by mountPath; returns a list of paths.
 func GetMountRefs(mounter Interface, mountPath string) ([]string, error) {
 	mps, err := mounter.List()

diff --git a/pkg/util/mount/mount_linux.go b/pkg/util/mount/mount_linux.go
@@ -34,22 +34,24 @@ import (
 const FlagBind = syscall.MS_BIND
 const FlagReadOnly = syscall.MS_RDONLY
 
+// Mounter implements mount.Interface for linux platform.
 type Mounter struct{}
 
-// Wraps syscall.Mount()
+// Mount wraps syscall.Mount()
 func (mounter *Mounter) Mount(source string, target string, fstype string, flags uintptr, data string) error {
 	glog.V(5).Infof("Mounting %s %s %s %d %s", source, target, fstype, flags, data)
 	return syscall.Mount(source, target, fstype, flags, data)
 }
 
-// Wraps syscall.Unmount()
+// Unmount wraps syscall.Unmount()
 func (mounter *Mounter) Unmount(target string, flags int) error {
 	return syscall.Unmount(target, flags)
 }
 
 // How many times to retry for a consistent read of /proc/mounts.
 const maxListTries = 3
 
+// List returns a list of all mounted filesystems.
 func (*Mounter) List() ([]MountPoint, error) {
 	hash1, err := readProcMounts(nil)
 	if err != nil {
@@ -71,11 +73,27 @@ func (*Mounter) List() ([]MountPoint, error) {
 	return nil, fmt.Errorf("failed to get a consistent snapshot of /proc/mounts after %d tries", maxListTries)
 }
 
+// IsMountPoint determines if a directory is a mountpoint, by comparing the device for the
+// directory with the device for it's parent.  If they are the same, it's not a mountpoint,
+// if they're different, it is.
+func (mounter *Mounter) IsMountPoint(file string) (bool, error) {
+	stat, err := os.Stat(file)
+	if err != nil {
+		return false, err
+	}
+	rootStat, err := os.Lstat(file + "/..")
+	if err != nil {
+		return false, err
+	}
+	// If the directory has the same device as parent, then it's not a mountpoint.
+	return stat.Sys().(*syscall.Stat_t).Dev != rootStat.Sys().(*syscall.Stat_t).Dev, nil
+}
+
 // As per the fstab man page.
 const expectedNumFieldsPerLine = 6
 
-// Read /proc/mounts and produces a hash of the contents.  If the out argument
-// is not nil, this fills it with MountPoint structs.
+// readProcMounts reads /proc/mounts and produces a hash of the contents.  If the out
+// argument is not nil, this fills it with MountPoint structs.
 func readProcMounts(out *[]MountPoint) (uint32, error) {
 	file, err := os.Open("/proc/mounts")
 	if err != nil {

diff --git a/pkg/util/mount/mount_unsupported.go b/pkg/util/mount/mount_unsupported.go
@@ -34,3 +34,7 @@ func (mounter *Mounter) Unmount(target string, flags int) error {
 func (mounter *Mounter) List() ([]MountPoint, error) {
 	return []MountPoint{}, nil
 }
+
+func (mounter *Mounter) IsMountPoint(file string) (bool, error) {
+	return false, nil
+}
diff --git a/pkg/util/mount/mountpoint_unix.go b/pkg/util/mount/mountpoint_unix.go
diff --git a/pkg/util/mount/mountpoint_unsupported.go b/pkg/util/mount/mountpoint_unsupported.go
diff --git a/pkg/volume/empty_dir/empty_dir.go b/pkg/volume/empty_dir/empty_dir.go
@@ -82,7 +82,7 @@ func (plugin *emptyDirPlugin) CanSupport(spec *api.Volume) bool {
 
 func (plugin *emptyDirPlugin) NewBuilder(spec *api.Volume, podRef *api.ObjectReference) (volume.Builder, error) {
 	// Inject real implementations here, test through the internal function.
-	return plugin.newBuilderInternal(spec, podRef, plugin.mounter, &realMountDetector{})
+	return plugin.newBuilderInternal(spec, podRef, plugin.mounter, &realMountDetector{plugin.mounter})
 }
 
 func (plugin *emptyDirPlugin) newBuilderInternal(spec *api.Volume, podRef *api.ObjectReference, mounter mount.Interface, mountDetector mountDetector) (volume.Builder, error) {
@@ -107,7 +107,7 @@ func (plugin *emptyDirPlugin) newBuilderInternal(spec *api.Volume, podRef *api.O
 
 func (plugin *emptyDirPlugin) NewCleaner(volName string, podUID types.UID) (volume.Cleaner, error) {
 	// Inject real implementations here, test through the internal function.
-	return plugin.newCleanerInternal(volName, podUID, plugin.mounter, &realMountDetector{})
+	return plugin.newCleanerInternal(volName, podUID, plugin.mounter, &realMountDetector{plugin.mounter})
 }
 
 func (plugin *emptyDirPlugin) newCleanerInternal(volName string, podUID types.UID, mounter mount.Interface, mountDetector mountDetector) (volume.Cleaner, error) {

diff --git a/pkg/volume/empty_dir/empty_dir_linux.go b/pkg/volume/empty_dir/empty_dir_linux.go
@@ -27,10 +27,12 @@ import (
 const linuxTmpfsMagic = 0x01021994
 
 // realMountDetector implements mountDetector in terms of syscalls.
-type realMountDetector struct{}
+type realMountDetector struct {
+	mounter mount.Interface
+}
 
 func (m *realMountDetector) GetMountMedium(path string) (storageMedium, bool, error) {
-	isMnt, err := mount.IsMountPoint(path)
+	isMnt, err := m.mounter.IsMountPoint(path)
 	if err != nil {
 		return 0, false, fmt.Errorf("IsMountPoint(%q): %v", path, err)
 	}

diff --git a/pkg/volume/empty_dir/empty_dir_unsupported.go b/pkg/volume/empty_dir/empty_dir_unsupported.go
@@ -18,8 +18,12 @@ limitations under the License.
 
 package empty_dir
 
+import "github.com/GoogleCloudPlatform/kubernetes/pkg/util/mount"
+
 // realMountDetector pretends to implement mediumer.
-type realMountDetector struct{}
+type realMountDetector struct {
+	mounter mount.Interface
+}
 
 func (m *realMountDetector) GetMountMedium(path string) (storageMedium, bool, error) {
 	return mediumUnknown, false, nil

diff --git a/pkg/volume/gce_pd/gce_pd.go b/pkg/volume/gce_pd/gce_pd.go
@@ -183,7 +183,7 @@ func (pd *gcePersistentDisk) SetUpAt(dir string) error {
 	}
 
 	// TODO: handle failed mounts here.
-	mountpoint, err := mount.IsMountPoint(dir)
+	mountpoint, err := pd.mounter.IsMountPoint(dir)
 	glog.V(4).Infof("PersistentDisk set up: %s %v %v", dir, mountpoint, err)
 	if err != nil && !os.IsNotExist(err) {
 		return err
@@ -211,7 +211,7 @@ func (pd *gcePersistentDisk) SetUpAt(dir string) error {
 	// Perform a bind mount to the full path to allow duplicate mounts of the same PD.
 	err = pd.mounter.Mount(globalPDPath, dir, "", mount.FlagBind|flags, "")
 	if err != nil {
-		mountpoint, mntErr := mount.IsMountPoint(dir)
+		mountpoint, mntErr := pd.mounter.IsMountPoint(dir)
 		if mntErr != nil {
 			glog.Errorf("isMountpoint check failed: %v", mntErr)
 			return err
@@ -221,7 +221,7 @@ func (pd *gcePersistentDisk) SetUpAt(dir string) error {
 				glog.Errorf("Failed to unmount: %v", mntErr)
 				return err
 			}
-			mountpoint, mntErr := mount.IsMountPoint(dir)
+			mountpoint, mntErr := pd.mounter.IsMountPoint(dir)
 			if mntErr != nil {
 				glog.Errorf("isMountpoint check failed: %v", mntErr)
 				return err
@@ -262,7 +262,7 @@ func (pd *gcePersistentDisk) TearDown() error {
 // Unmounts the bind mount, and detaches the disk only if the PD
 // resource was the last reference to that disk on the kubelet.
 func (pd *gcePersistentDisk) TearDownAt(dir string) error {
-	mountpoint, err := mount.IsMountPoint(dir)
+	mountpoint, err := pd.mounter.IsMountPoint(dir)
 	if err != nil {
 		return err
 	}
@@ -287,7 +287,7 @@ func (pd *gcePersistentDisk) TearDownAt(dir string) error {
 			return err
 		}
 	}
-	mountpoint, mntErr := mount.IsMountPoint(dir)
+	mountpoint, mntErr := pd.mounter.IsMountPoint(dir)
 	if mntErr != nil {
 		glog.Errorf("isMountpoint check failed: %v", mntErr)
 		return err

diff --git a/pkg/volume/gce_pd/gce_util.go b/pkg/volume/gce_pd/gce_util.go
@@ -68,7 +68,7 @@ func (util *GCEDiskUtil) AttachAndMountDisk(pd *gcePersistentDisk, globalPDPath
 	}
 
 	// Only mount the PD globally once.
-	mountpoint, err := mount.IsMountPoint(globalPDPath)
+	mountpoint, err := pd.mounter.IsMountPoint(globalPDPath)
 	if err != nil {
 		if os.IsNotExist(err) {
 			if err := os.MkdirAll(globalPDPath, 0750); err != nil {

diff --git a/pkg/volume/nfs/nfs_mount.go b/pkg/volume/nfs/nfs_mount.go
@@ -67,5 +67,6 @@ func (mounter *nfsMounter) List() ([]mount.MountPoint, error) {
 }
 
 func (mounter *nfsMounter) IsMountPoint(dir string) (bool, error) {
-	return mount.IsMountPoint(dir)
+	isMounter := mount.New()
+	return isMounter.IsMountPoint(dir)
 }