virDomainBlockStats(Flags): Produce saner error message on empty disk path

As of 0bd2ccdec an empty disk path for virDomainBlockStats (or the one
with Flags) is allowed meaning "get me overall summarized statistics".
However, running 'virsh domblkstat $dom' throws a misleading error:

  # ./tools/virsh domblkstat dom
  error: Failed to get block stats dom
  error: invalid argument: invalid path:

while after this commit

  # virsh domblkstat dom
  error: Operation not supported: summary statistics are not supported yet

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index c9a865ebcf7bd06107c7cde9048a965305d86ce9..e04a32841807851fd1386ab8a7fd91672f114dce 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -9434,6 +9434,12 @@ qemuDomainBlockStats(virDomainPtr dom,
     virDomainDiskDefPtr disk = NULL;
     qemuDomainObjPrivatePtr priv;
 
+    if (!*path) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("summary statistics are not supported yet"));
+        return ret;
+    }
+
     if (!(vm = qemuDomObjFromDomain(dom)))
         goto cleanup;
 
@@ -9507,6 +9513,12 @@ qemuDomainBlockStatsFlags(virDomainPtr dom,
 
     virCheckFlags(VIR_TYPED_PARAM_STRING_OKAY, -1);
 
+    if (!*path) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("summary statistics are not supported yet"));
+        return ret;
+    }
+
     /* We don't return strings, and thus trivially support this flag.  */
     flags &= ~VIR_TYPED_PARAM_STRING_OKAY;
 

diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index b724f82b05abbc1007b1fc5ef21c798226c0a828..6806ffdf12250d32de8038b6ca28cba6a95559aa 100644 (file)
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -3362,6 +3362,12 @@ static int testDomainBlockStats(virDomainPtr domain,
     unsigned long long statbase;
     int ret = -1;
 
+    if (!*path) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("summary statistics are not supported yet"));
+        return ret;
+    }
+
     testDriverLock(privconn);
     privdom = virDomainObjListFindByName(privconn->domains,
                                          domain->name);