block: Don't try to set *errp directly

Assigning directly to *errp is not valid, as errp may be NULL,
&error_fatal, or &error_abort.  Use error_propagate() instead.

With this, there's no need to check if errp is NULL anymore, as
error_propagate() and error_prepend() are able to handle that.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170608133906.12737-3-ehabkost@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 3 insertions, 5 deletions

diff --git a/block.c b/block.c
index 6943962..b1599d2 100644
--- a/block.c
+++ b/block.c
@@ -4267,11 +4267,9 @@ bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
     assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
     if (!QLIST_EMPTY(&bs->op_blockers[op])) {
         blocker = QLIST_FIRST(&bs->op_blockers[op]);
-        if (errp) {
-            *errp = error_copy(blocker->reason);
-            error_prepend(errp, "Node '%s' is busy: ",
-                          bdrv_get_device_or_node_name(bs));
-        }
+        error_propagate(errp, error_copy(blocker->reason));
+        error_prepend(errp, "Node '%s' is busy: ",
+                      bdrv_get_device_or_node_name(bs));
         return true;
     }
     return false;