[PATCH v4 1/2] block/nbd: extract the common cleanup code

[<pannengyuan@huawei.com>]

From: Pan Nengyuan <pannengyuan@huawei.com>

The BDRVNBDState cleanup code is common in two places, add
nbd_clear_bdrvstate() function to do these cleanups.

Signed-off-by: Stefano Garzarella <Stefano Garzarella>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v3:
- new patch, split form 2/2 patch (suggested by Stefano Garzarella)
Changes v4 to v3:
- replace function name from nbd_free_bdrvstate_prop to
  nbd_clear_bdrvstate and set cleared fields to NULL (suggested by Eric
  Blake)
- remove static function prototype. (suggested by Eric Blake)
---
 block/nbd.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/block/nbd.c b/block/nbd.c
index 1239761..8b4a65a 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -94,6 +94,19 @@ typedef struct BDRVNBDState {
 
 static int nbd_client_connect(BlockDriverState *bs, Error **errp);
 
+void nbd_clear_bdrvstate(BDRVNBDState *s)
+{
+    object_unref(OBJECT(s->tlscreds));
+    qapi_free_SocketAddress(s->saddr);
+    s->saddr = NULL;
+    g_free(s->export);
+    s->export = NULL;
+    g_free(s->tlscredsid);
+    s->tlscredsid = NULL;
+    g_free(s->x_dirty_bitmap);
+    s->x_dirty_bitmap = NULL;
+}
+
 static void nbd_channel_error(BDRVNBDState *s, int ret)
 {
     if (ret == -EIO) {
@@ -1855,10 +1868,7 @@ static int nbd_process_options(BlockDriverState *bs, QDict *options,
 
  error:
     if (ret < 0) {
-        object_unref(OBJECT(s->tlscreds));
-        qapi_free_SocketAddress(s->saddr);
-        g_free(s->export);
-        g_free(s->tlscredsid);
+        nbd_clear_bdrvstate(s);
     }
     qemu_opts_del(opts);
     return ret;
@@ -1937,12 +1947,7 @@ static void nbd_close(BlockDriverState *bs)
     BDRVNBDState *s = bs->opaque;
 
     nbd_client_close(bs);
-
-    object_unref(OBJECT(s->tlscreds));
-    qapi_free_SocketAddress(s->saddr);
-    g_free(s->export);
-    g_free(s->tlscredsid);
-    g_free(s->x_dirty_bitmap);
+    nbd_clear_bdrvstate(s);
 }
 
 static int64_t nbd_getlength(BlockDriverState *bs)
-- 
2.7.2.windows.1