--- libvirt-0.9.7.orig/src/qemu/qemu_driver.c	2011-11-03 23:48:23.000000000 +0900
+++ libvirt-0.9.7/src/qemu/qemu_driver.c	2011-11-14 12:56:51.870453885 +0900
@@ -9025,6 +9025,7 @@ qemuDomainSnapshotCreateSingleDiskActive
     char *origsrc = NULL;
     char *origdriver = NULL;
     bool need_unlink = false;
+    struct stat sb;
 
     if (snap->snapshot != VIR_DOMAIN_DISK_SNAPSHOT_EXTERNAL) {
         qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -9032,6 +9033,17 @@ qemuDomainSnapshotCreateSingleDiskActive
         return -1;
     }
 
+    if (stat(disk->src, &sb) < 0) {
+        virReportSystemError(errno,
+                             _("unable to stat for disk %s"),
+                             disk->src);
+    }
+    if (S_ISBLK(sb.st_mode)) {
+        qemuReportError(VIR_ERR_INTERNAL_ERROR,
+                        "%s", _("src image is Block Device"));
+        return -1;
+    }
+
     if (virAsprintf(&device, "drive-%s", disk->info.alias) < 0 ||
         !(source = strdup(snap->file)) ||
         (STRNEQ_NULLABLE(disk->driverType, "qcow2") &&