[libvirt] [PATCH v3] qemu-migration: Disallow migration of read only disk

Corey S. McQuay csmcquay at linux.vnet.ibm.com
Mon Sep 26 17:16:00 UTC 2016


Currently Libvirt allows attempts to migrate read only disks. Qemu cannot handle this as read only
disks cannot be written to on the destination system. The end result is a cryptic error message
and a failed migration.

This patch causes migration to fail earlier and provides a meaningful error message stating that
migrating read only disks is not supported.

Signed-off-by: Corey S. McQuay <csmcquay at linux.vnet.ibm.com>
Reviewed-by: Jason J. Herne <jjherne at linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
---
 src/qemu/qemu_migration.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index e451ef6..c8fb7ec 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -1764,6 +1764,12 @@ qemuMigrationStartNBDServer(virQEMUDriverPtr driver,
         /* check whether disk should be migrated */
         if (!qemuMigrateDisk(disk, nmigrate_disks, migrate_disks))
             continue;
+            
+        if (disk->src->readonly) {
+            virReportError(VIR_ERR_OPERATION_UNSUPPORTED, 
+                        _("Cannot migrate read-only disk %s"), disk->dst);
+            goto cleanup;
+        }
 
         VIR_FREE(diskAlias);
         if (!(diskAlias = qemuAliasFromDisk(disk)))
-- 
2.7.4




More information about the libvir-list mailing list