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[PATCH 11/21] block: add bdrv_replace_child_safe() transaction action
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[PATCH 11/21] block: add bdrv_replace_child_safe() transaction action |
Date: |
Mon, 23 Nov 2020 23:12:23 +0300 |
To be used in the following commit.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
block.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
diff --git a/block.c b/block.c
index d799afeedd..1b10b6fb5e 100644
--- a/block.c
+++ b/block.c
@@ -82,6 +82,9 @@ static BlockDriverState *bdrv_open_inherit(const char
*filename,
BdrvChildRole child_role,
Error **errp);
+static void bdrv_replace_child_noperm(BdrvChild *child,
+ BlockDriverState *new_bs);
+
/* If non-zero, use only whitelisted block drivers */
static int use_bdrv_whitelist;
@@ -2142,6 +2145,57 @@ static int bdrv_drv_set_perm(BlockDriverState *bs,
uint64_t perm,
return 0;
}
+typedef struct BdrvReplaceChildState {
+ BdrvChild *child;
+ BlockDriverState *old_bs;
+} BdrvReplaceChildState;
+
+static void bdrv_replace_child_commit(void *opaque)
+{
+ BdrvReplaceChildState *s = opaque;
+
+ bdrv_unref(s->old_bs);
+}
+
+static void bdrv_replace_child_abort(void *opaque)
+{
+ BdrvReplaceChildState *s = opaque;
+ BlockDriverState *new_bs = s->child->bs;
+
+ /* old_bs reference is transparently moved from @s to @s->child */
+ bdrv_replace_child_noperm(s->child, s->old_bs);
+ bdrv_unref(new_bs);
+}
+
+static BdrvActionDrv bdrv_replace_child_drv = {
+ .commit = bdrv_replace_child_commit,
+ .abort = bdrv_replace_child_abort,
+ .clean = g_free,
+};
+
+/*
+ * bdrv_replace_child_safe
+ *
+ * Note: real unref of old_bs is done only on commit.
+ */
+__attribute__((unused))
+static void bdrv_replace_child_safe(BdrvChild *child, BlockDriverState *new_bs,
+ GSList **tran)
+{
+ BdrvReplaceChildState *s = g_new(BdrvReplaceChildState, 1);
+ *s = (BdrvReplaceChildState) {
+ .child = child,
+ .old_bs = child->bs,
+ };
+ tran_prepend(tran, &bdrv_replace_child_drv, s);
+
+ if (new_bs) {
+ bdrv_ref(new_bs);
+ }
+ bdrv_replace_child_noperm(child, new_bs);
+ /* old_bs reference is transparently moved from @child to @s */
+}
+
/*
* Check whether permissions on this node can be changed in a way that
* @cumulative_perms and @cumulative_shared_perms are the new cumulative
--
2.21.3
- [PATCH 02/21] tests/test-bdrv-graph-mod: add test_parallel_perm_update, (continued)
- [PATCH 02/21] tests/test-bdrv-graph-mod: add test_parallel_perm_update, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 03/21] util: add transactions.c, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 04/21] block: bdrv_refresh_perms: check parents compliance, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 06/21] block: rewrite bdrv_child_try_set_perm() using bdrv_refresh_perms(), Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 07/21] block: inline bdrv_child_*() permission functions calls, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 08/21] block: use topological sort for permission update, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 05/21] block: refactor bdrv_child* permission functions, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 09/21] block: add bdrv_drv_set_perm transaction action, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 10/21] block: add bdrv_list_* permission update functions, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 11/21] block: add bdrv_replace_child_safe() transaction action,
Vladimir Sementsov-Ogievskiy <=
- [PATCH 12/21] block: return value from bdrv_replace_node(), Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 13/21] block: fix bdrv_replace_node_common, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 15/21] block: split out bdrv_replace_node_noperm(), Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 14/21] block: add bdrv_attach_child_noperm() transaction action, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 16/21] block: bdrv_append(): don't consume reference, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 19/21] block: add bdrv_remove_backing transaction action, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 21/21] block/backup-top: drop .active, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 17/21] block: bdrv_append(): return status, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 18/21] block: adapt bdrv_append() for inserting filters, Vladimir Sementsov-Ogievskiy, 2020/11/23
- [PATCH 20/21] block: introduce bdrv_drop_filter(), Vladimir Sementsov-Ogievskiy, 2020/11/23