[Qemu-devel] [PULL 08/14] migration: factor our snapshottability check in load_vmstate

[Juan Quintela <quintela@redhat.com>]

From: "Denis V. Lunev" <den@openvz.org>

We should check that all inserted and not read-only images support
snapshotting. This could be made using already invented helper
bdrv_all_can_snapshot().

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
Tested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/savevm.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 254e51d..2ecc1b3 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2051,6 +2051,12 @@ int load_vmstate(const char *name)
     QEMUFile *f;
     int ret;

+    if (!bdrv_all_can_snapshot(&bs)) {
+        error_report("Device '%s' is writable but does not support snapshots.",
+                     bdrv_get_device_name(bs));
+        return -ENOTSUP;
+    }
+
     bs_vm_state = find_vmstate_bs();
     if (!bs_vm_state) {
         error_report("No block device supports snapshots");
@@ -2071,15 +2077,8 @@ int load_vmstate(const char *name)
     writable and check if the requested snapshot is available too. */
     bs = NULL;
     while ((bs = bdrv_next(bs))) {
-
-        if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) {
-            continue;
-        }
-
         if (!bdrv_can_snapshot(bs)) {
-            error_report("Device '%s' is writable but does not support snapshots.",
-                               bdrv_get_device_name(bs));
-            return -ENOTSUP;
+            continue;
         }

         ret = bdrv_snapshot_find(bs, &sn, name);
-- 
2.5.0