lxd/storage/connectors: Add WaitDiskDeviceResize func

Signed-off-by: Julian Pelizäus <[email protected]>

lxd/storage/connectors/utils.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/canonical/lxd/lxd/locking"
 	"github.com/canonical/lxd/lxd/resources"
+	"github.com/canonical/lxd/lxd/storage/block"
 	"github.com/canonical/lxd/shared"
 	"github.com/canonical/lxd/shared/logger"
 	"github.com/canonical/lxd/shared/revert"
@@ -132,6 +133,29 @@ func WaitDiskDeviceGone(ctx context.Context, diskPath string) bool {
 	}
 }
 
+// WaitDiskDeviceResize waits until the disk device reflects the new size.
+func WaitDiskDeviceResize(ctx context.Context, diskPath string, newSizeBytes int64) error {
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+
+	for {
+		sizeBytes, err := block.DiskSizeBytes(diskPath)
+		if err != nil {
+			return fmt.Errorf("Error getting disk size: %w", err)
+		}
+
+		if sizeBytes == newSizeBytes {
+			return nil
+		}
+
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+
+		time.Sleep(500 * time.Millisecond)
+	}
+}
+
 // connectFunc is invoked by "connect" for each provided address.
 // It receives a session and a target address. A non-nil session indicates
 // an existing session for the target.