cephfs/volume: create/delete-volume idempotency checks

pkg/cephfs/util.go

@@ -17,11 +17,11 @@ limitations under the License.
 package cephfs
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io"
+	"os"
-	"io/ioutil"
 	"os/exec"
 
 	"google.golang.org/grpc/codes"
@@ -30,61 +30,41 @@ import (
 
 	"github.com/ceph/ceph-csi/pkg/util"
 	"github.com/container-storage-interface/spec/lib/go/csi"
+	"k8s.io/kubernetes/pkg/util/keymutex"
 	"k8s.io/kubernetes/pkg/util/mount"
 )
 
 type volumeID string
 
+func mustUnlock(m keymutex.KeyMutex, key string) {
+	if err := m.UnlockKey(key); err != nil {
+		klog.Fatalf("failed to unlock mutex for %s: %v", key, err)
+	}
+}
+
 func makeVolumeID(volName string) volumeID {
 	return volumeID("csi-cephfs-" + volName)
 }
 
-func closePipeOnError(pipe io.Closer, err error) {
-	if err != nil {
-		if err = pipe.Close(); err != nil {
-			klog.Warningf("failed to close pipe: %v", err)
-		}
-	}
-}
-
 func execCommand(program string, args ...string) (stdout, stderr []byte, err error) {
-	cmd := exec.Command(program, args...) // nolint: gosec
+	var (
-	stripArgs := util.StripSecretInArgs(args)
+		cmd           = exec.Command(program, args...) // nolint: gosec
-	klog.V(4).Infof("cephfs: EXEC %s %s", program, stripArgs)
+		sanitizedArgs = util.StripSecretInArgs(args)
+		stdoutBuf     bytes.Buffer
+		stderrBuf     bytes.Buffer
+	)
 
-	stdoutPipe, err := cmd.StdoutPipe()
+	cmd.Stdout = &stdoutBuf
-	if err != nil {
+	cmd.Stderr = &stderrBuf
-		return nil, nil, fmt.Errorf("cannot open stdout pipe for %s %v: %v", program, stripArgs, err)
+
+	klog.V(4).Infof("cephfs: EXEC %s %s", program, sanitizedArgs)
+
+	if err := cmd.Run(); err != nil {
+		return nil, nil, fmt.Errorf("an error occurred while running (%d) %s %v: %v: %s",
+			cmd.Process.Pid, program, sanitizedArgs, err, stderrBuf.Bytes())
 	}
 
-	defer closePipeOnError(stdoutPipe, err)
+	return stdoutBuf.Bytes(), stderrBuf.Bytes(), nil
-
-	stderrPipe, err := cmd.StderrPipe()
-	if err != nil {
-		return nil, nil, fmt.Errorf("cannot open stdout pipe for %s %v: %v", program, stripArgs, err)
-	}
-
-	defer closePipeOnError(stderrPipe, err)
-
-	if err = cmd.Start(); err != nil {
-		return nil, nil, fmt.Errorf("failed to run %s %v: %v", program, stripArgs, err)
-	}
-
-	stdout, err = ioutil.ReadAll(stdoutPipe)
-	if err != nil {
-		return nil, nil, fmt.Errorf("failed to read from stdout for %s %v: %v", program, stripArgs, err)
-	}
-
-	stderr, err = ioutil.ReadAll(stderrPipe)
-	if err != nil {
-		return nil, nil, fmt.Errorf("failed to read from stderr for %s %v: %v", program, stripArgs, err)
-	}
-
-	if waitErr := cmd.Wait(); waitErr != nil {
-		return nil, nil, fmt.Errorf("an error occurred while running %s %v: %v: %s", program, stripArgs, waitErr, stderr)
-	}
-
-	return
 }
 
 func execCommandErr(program string, args ...string) error {
@@ -117,6 +97,11 @@ func isMountPoint(p string) (bool, error) {
 	return !notMnt, nil
 }
 
+func pathExists(p string) bool {
+	_, err := os.Stat(p)
+	return err == nil
+}
+
 // Controller service request validation
 func (cs *ControllerServer) validateCreateVolumeRequest(req *csi.CreateVolumeRequest) error {
 	if err := cs.Driver.ValidateControllerServiceRequest(csi.ControllerServiceCapability_RPC_CREATE_DELETE_VOLUME); err != nil {

pkg/cephfs/volume.go

@@ -52,79 +52,66 @@ func setVolumeAttribute(root, attrName, attrValue string) error {
 }
 
 func createVolume(volOptions *volumeOptions, adminCr *credentials, volID volumeID, bytesQuota int64) error {
-	cephRoot := getCephRootPathLocal(volID)
+	if err := mountCephRoot(volID, volOptions, adminCr); err != nil {
-
-	if err := createMountPoint(cephRoot); err != nil {
 		return err
 	}
+	defer unmountCephRoot(volID)
 
-	// RootPath is not set for a dynamically provisioned volume
+	var (
-	// Access to cephfs's / is required
+		volRoot         = getCephRootVolumePathLocal(volID)
-	volOptions.RootPath = "/"
+		volRootCreating = volRoot + "-creating"
+	)
 
-	m, err := newMounter(volOptions)
+	if pathExists(volRoot) {
-	if err != nil {
+		klog.V(4).Infof("cephfs: volume %s already exists, skipping creation", volID)
-		return fmt.Errorf("failed to create mounter: %v", err)
+		return nil
 	}
 
-	if err = m.mount(cephRoot, adminCr, volOptions, volID); err != nil {
+	if err := createMountPoint(volRootCreating); err != nil {
-		return fmt.Errorf("error mounting ceph root: %v", err)
-	}
-
-	defer unmountAndRemove(cephRoot)
-
-	volOptions.RootPath = getVolumeRootPathCeph(volID)
-	localVolRoot := getCephRootVolumePathLocal(volID)
-
-	if err := createMountPoint(localVolRoot); err != nil {
 		return err
 	}
 
 	if bytesQuota > 0 {
-		if err := setVolumeAttribute(localVolRoot, "ceph.quota.max_bytes", fmt.Sprintf("%d", bytesQuota)); err != nil {
+		if err := setVolumeAttribute(volRootCreating, "ceph.quota.max_bytes", fmt.Sprintf("%d", bytesQuota)); err != nil {
 			return err
 		}
 	}
 
-	if err := setVolumeAttribute(localVolRoot, "ceph.dir.layout.pool", volOptions.Pool); err != nil {
+	if err := setVolumeAttribute(volRootCreating, "ceph.dir.layout.pool", volOptions.Pool); err != nil {
 		return fmt.Errorf("%v\ncephfs: Does pool '%s' exist?", err, volOptions.Pool)
 	}
 
-	if err := setVolumeAttribute(localVolRoot, "ceph.dir.layout.pool_namespace", getVolumeNamespace(volID)); err != nil {
+	if err := setVolumeAttribute(volRootCreating, "ceph.dir.layout.pool_namespace", getVolumeNamespace(volID)); err != nil {
 		return err
 	}
 
+	if err := os.Rename(volRootCreating, volRoot); err != nil {
+		return fmt.Errorf("couldn't mark volume %s as created: %v", volID, err)
+	}
+
 	return nil
 }
 
 func purgeVolume(volID volumeID, adminCr *credentials, volOptions *volumeOptions) error {
+	if err := mountCephRoot(volID, volOptions, adminCr); err != nil {
+		return err
+	}
+	defer unmountCephRoot(volID)
+
 	var (
-		cephRoot        = getCephRootPathLocal(volID)
 		volRoot         = getCephRootVolumePathLocal(volID)
 		volRootDeleting = volRoot + "-deleting"
 	)
 
-	if err := createMountPoint(cephRoot); err != nil {
+	if pathExists(volRoot) {
-		return err
+		if err := os.Rename(volRoot, volRootDeleting); err != nil {
-	}
+			return fmt.Errorf("couldn't mark volume %s for deletion: %v", volID, err)
-
+		}
-	// Root path is not set for dynamically provisioned volumes
+	} else {
-	// Access to cephfs's / is required
+		if !pathExists(volRootDeleting) {
-	volOptions.RootPath = "/"
+			klog.V(4).Infof("cephfs: volume %s not found, assuming it to be already deleted", volID)
-
+			return nil
-	m, err := newMounter(volOptions)
+		}
-	if err != nil {
-		return fmt.Errorf("failed to create mounter: %v", err)
-	}
-
-	if err = m.mount(cephRoot, adminCr, volOptions, volID); err != nil {
-		return fmt.Errorf("error mounting ceph root: %v", err)
-	}
-
-	defer unmountAndRemove(cephRoot)
-
-	if err := os.Rename(volRoot, volRootDeleting); err != nil {
-		return fmt.Errorf("couldn't mark volume %s for deletion: %v", volID, err)
 	}
 
 	if err := os.RemoveAll(volRootDeleting); err != nil {
@@ -134,13 +121,37 @@ func purgeVolume(volID volumeID, adminCr *credentials, volOptions *volumeOptions
 	return nil
 }
 
-func unmountAndRemove(mountPoint string) {
+func mountCephRoot(volID volumeID, volOptions *volumeOptions, adminCr *credentials) error {
-	var err error
+	cephRoot := getCephRootPathLocal(volID)
-	if err = unmountVolume(mountPoint); err != nil {
+
-		klog.Errorf("failed to unmount %s with error %s", mountPoint, err)
+	// Root path is not set for dynamically provisioned volumes
+	// Access to cephfs's / is required
+	volOptions.RootPath = "/"
+
+	if err := createMountPoint(cephRoot); err != nil {
+		return err
 	}
 
-	if err = os.Remove(mountPoint); err != nil {
+	m, err := newMounter(volOptions)
-		klog.Errorf("failed to remove %s with error %s", mountPoint, err)
+	if err != nil {
+		return fmt.Errorf("failed to create mounter: %v", err)
+	}
+
+	if err = m.mount(cephRoot, adminCr, volOptions, volID); err != nil {
+		return fmt.Errorf("error mounting ceph root: %v", err)
+	}
+
+	return nil
+}
+
+func unmountCephRoot(volID volumeID) {
+	cephRoot := getCephRootPathLocal(volID)
+
+	if err := unmountVolume(cephRoot); err != nil {
+		klog.Errorf("failed to unmount %s with error %s", cephRoot, err)
+	}
+
+	if err := os.Remove(cephRoot); err != nil {
+		klog.Errorf("failed to remove %s with error %s", cephRoot, err)
 	}
 }