[PATCH 03/14] block: bdrv_refresh_perms(): allow external tran

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Allow passing external Transaction pointer, stop creating extra
Transaction objects.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/block.c b/block.c
index 378841a546..7b65c7c5c0 100644
--- a/block.c
+++ b/block.c
@@ -2475,14 +2475,23 @@ char *bdrv_perm_names(uint64_t perm)
 }
 
 
-static int bdrv_refresh_perms(BlockDriverState *bs, Error **errp)
+/* @tran is allowed to be NULL. In this case no rollback is possible */
+static int bdrv_refresh_perms(BlockDriverState *bs, Transaction *tran,
+                              Error **errp)
 {
     int ret;
-    Transaction *tran = tran_new();
+    Transaction *local_tran = NULL;
     g_autoptr(GSList) list = bdrv_topological_dfs(NULL, NULL, bs);
 
+    if (!tran) {
+        tran = local_tran = tran_new();
+    }
+
     ret = bdrv_list_refresh_perms(list, NULL, tran, errp);
-    tran_finalize(tran, ret);
+
+    if (local_tran) {
+        tran_finalize(local_tran, ret);
+    }
 
     return ret;
 }
@@ -2496,7 +2505,7 @@ int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
 
     bdrv_child_set_perm(c, perm, shared, tran);
 
-    ret = bdrv_refresh_perms(c->bs, &local_err);
+    ret = bdrv_refresh_perms(c->bs, tran, &local_err);
 
     tran_finalize(tran, ret);
 
@@ -2976,7 +2985,7 @@ BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
         goto out;
     }
 
-    ret = bdrv_refresh_perms(child_bs, errp);
+    ret = bdrv_refresh_perms(child_bs, tran, errp);
 
 out:
     tran_finalize(tran, ret);
@@ -3014,7 +3023,7 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
         goto out;
     }
 
-    ret = bdrv_refresh_perms(parent_bs, errp);
+    ret = bdrv_refresh_perms(parent_bs, tran, errp);
     if (ret < 0) {
         goto out;
     }
@@ -3041,7 +3050,7 @@ void bdrv_root_unref_child(BdrvChild *child)
          * we're loosening restrictions. Errors of permission update are not
          * fatal in this case, ignore them.
          */
-        bdrv_refresh_perms(child_bs, NULL);
+        bdrv_refresh_perms(child_bs, NULL, NULL);
 
         /*
          * When the parent requiring a non-default AioContext is removed, the
@@ -3277,7 +3286,7 @@ int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
         goto out;
     }
 
-    ret = bdrv_refresh_perms(bs, errp);
+    ret = bdrv_refresh_perms(bs, tran, errp);
 out:
     tran_finalize(tran, ret);
 
@@ -5067,7 +5076,7 @@ int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
         goto out;
     }
 
-    ret = bdrv_refresh_perms(bs_new, errp);
+    ret = bdrv_refresh_perms(bs_new, tran, errp);
 out:
     tran_finalize(tran, ret);
 
@@ -6297,7 +6306,7 @@ int coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs, Error **errp)
      */
     if (bs->open_flags & BDRV_O_INACTIVE) {
         bs->open_flags &= ~BDRV_O_INACTIVE;
-        ret = bdrv_refresh_perms(bs, errp);
+        ret = bdrv_refresh_perms(bs, NULL, errp);
         if (ret < 0) {
             bs->open_flags |= BDRV_O_INACTIVE;
             return ret;
@@ -6422,7 +6431,7 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs)
      * We only tried to loosen restrictions, so errors are not fatal, ignore
      * them.
      */
-    bdrv_refresh_perms(bs, NULL);
+    bdrv_refresh_perms(bs, NULL, NULL);
 
     /* Recursively inactivate children */
     QLIST_FOREACH(child, &bs->children, next) {
-- 
2.31.1