block: Add errp to bdrv_all_goto_snapshot()

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NDenis V. Lunev <den@openvz.org>
Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>

block/snapshot.c

@@ -467,9 +467,10 @@ fail:
 }
 
 
-int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs)
+int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs,
+                           Error **errp)
 {
-    int err = 0;
+    int ret = 0;
     BlockDriverState *bs;
     BdrvNextIterator it;
 
@@ -478,10 +479,10 @@ int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs)
 
         aio_context_acquire(ctx);
         if (bdrv_can_snapshot(bs)) {
-            err = bdrv_snapshot_goto(bs, name, NULL);
+            ret = bdrv_snapshot_goto(bs, name, errp);
         }
         aio_context_release(ctx);
-        if (err < 0) {
+        if (ret < 0) {
             bdrv_next_cleanup(&it);
             goto fail;
         }
@@ -489,7 +490,7 @@ int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs)
 
 fail:
     *first_bad_bs = bs;
-    return err;
+    return ret;
 }
 
 int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs)

include/block/snapshot.h

@@ -84,7 +84,8 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs,
 bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs);
 int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bsd_bs,
                              Error **err);
-int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bsd_bs);
+int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs,
+                           Error **errp);
 int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs);
 int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn,
                              BlockDriverState *vm_state_bs,

migration/savevm.c

@@ -2346,10 +2346,10 @@ int load_snapshot(const char *name, Error **errp)
     /* Flush all IO requests so they don't interfere with the new state.  */
     bdrv_drain_all_begin();
 
-    ret = bdrv_all_goto_snapshot(name, &bs);
+    ret = bdrv_all_goto_snapshot(name, &bs, errp);
     if (ret < 0) {
-        error_setg(errp, "Error %d while activating snapshot '%s' on '%s'",
-                     ret, name, bdrv_get_device_name(bs));
+        error_prepend(errp, "Could not load snapshot '%s' on '%s': ",
+                      name, bdrv_get_device_name(bs));
         goto err_drain;
     }