From 294a0973bd1e088b8106c63f0194432d5a8c951c Mon Sep 17 00:00:00 2001
From: Niels de Vos <ndevos@redhat.com>
Date: Thu, 28 Jan 2021 09:45:51 +0100
Subject: [PATCH] rbd: mark images thick-provisioned in metadata

When images get resized/expanded, the additional space needs to be
allocated if the image was initially thick-provisioned. By marking the
image with a "thick-provisioned" key in the metadata, future operations
can check the need.

A missing "thick-provisioned" key indicates that the image has not been
thick-provisioned.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
---
 internal/rbd/rbd_util.go | 41 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/internal/rbd/rbd_util.go b/internal/rbd/rbd_util.go
index 5d6df381e..89f73e3e2 100644
--- a/internal/rbd/rbd_util.go
+++ b/internal/rbd/rbd_util.go
@@ -53,6 +53,9 @@ const (
 	rbdTaskRemoveCmdInvalidString1      = "no valid command found"
 	rbdTaskRemoveCmdInvalidString2      = "Error EINVAL: invalid command"
 	rbdTaskRemoveCmdAccessDeniedMessage = "Error EACCES:"
+
+	// image metadata key for thick-provisioning
+	thickProvisionMetaKey = ".rbd.csi.ceph.com/thick-provisioned"
 )
 
 // rbdVolume represents a CSI volume and its RBD image specifics.
@@ -232,6 +235,14 @@ func createImage(ctx context.Context, pOpts *rbdVolume, cr *util.Credentials) er
 			_ = deleteImage(ctx, pOpts, cr)
 			return fmt.Errorf("failed to thick provision image: %w", err)
 		}
+
+		err = pOpts.setThickProvisioned()
+		if err != nil {
+			// nolint:errcheck // deleteImage() will log errors in
+			// case it fails, no need to log them here again
+			_ = deleteImage(ctx, pOpts, cr)
+			return fmt.Errorf("failed to mark image as thick-provisioned: %w", err)
+		}
 	}
 
 	return nil
@@ -1242,6 +1253,36 @@ func (rv *rbdVolume) SetMetadata(key, value string) error {
 	return image.SetMetadata(key, value)
 }
 
+// setThickProvisioned records in the image metadata that it has been
+// thick-provisioned.
+func (rv *rbdVolume) setThickProvisioned() error {
+	err := rv.SetMetadata(thickProvisionMetaKey, "true")
+	if err != nil {
+		return fmt.Errorf("failed to set metadata %q for %q: %w", thickProvisionMetaKey, rv.String(), err)
+	}
+
+	return nil
+}
+
+// isThickProvisioned checks in the image metadata if the image has been marked
+// as thick-provisioned. This can be used while expanding the image, so that
+// the expansion can be allocated too.
+func (rv *rbdVolume) isThickProvisioned() (bool, error) {
+	value, err := rv.GetMetadata(thickProvisionMetaKey)
+	if err != nil {
+		if err == librbd.ErrNotFound {
+			return false, nil
+		}
+		return false, fmt.Errorf("failed to get metadata %q for %q: %w", thickProvisionMetaKey, rv.String(), err)
+	}
+
+	thick, err := strconv.ParseBool(value)
+	if err != nil {
+		return false, fmt.Errorf("failed to convert %q=%q to a boolean: %w", thickProvisionMetaKey, value, err)
+	}
+	return thick, nil
+}
+
 func (rv *rbdVolume) listSnapshots() ([]librbd.SnapInfo, error) {
 	image, err := rv.open()
 	if err != nil {