block: Simplify bdrv_append_temp_snapshot() logic
Noticed while checking Coccinelle results. Naming a label 'out:'
when it is only used on error paths is weird. Also, we had some
dead stores to 'ret'. Meanwhile we know that snapshot_options
is NULL on success and that QDECREF(NULL) is safe. So merge the
two exit paths into one by careful control over bs_snapshot.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-8-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/block.c b/block.c
index aae8f7e..a45b9b5 100644
--- a/block.c
+++ b/block.c
@@ -2195,7 +2195,7 @@
char *tmp_filename = g_malloc0(PATH_MAX + 1);
int64_t total_size;
QemuOpts *opts = NULL;
- BlockDriverState *bs_snapshot;
+ BlockDriverState *bs_snapshot = NULL;
Error *local_err = NULL;
int ret;
@@ -2235,28 +2235,25 @@
bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp);
snapshot_options = NULL;
if (!bs_snapshot) {
- ret = -EINVAL;
goto out;
}
- /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
- * call bdrv_unref() on it), so in order to be able to return one, we have
- * to increase bs_snapshot's refcount here */
+ /* bdrv_append() consumes a strong reference to bs_snapshot
+ * (i.e. it will call bdrv_unref() on it) even on error, so in
+ * order to be able to return one, we have to increase
+ * bs_snapshot's refcount here */
bdrv_ref(bs_snapshot);
bdrv_append(bs_snapshot, bs, &local_err);
if (local_err) {
error_propagate(errp, local_err);
- ret = -EINVAL;
+ bs_snapshot = NULL;
goto out;
}
- g_free(tmp_filename);
- return bs_snapshot;
-
out:
QDECREF(snapshot_options);
g_free(tmp_filename);
- return NULL;
+ return bs_snapshot;
}
/*
