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[PATCH v3 16/36] block: add bdrv_replace_child_safe() transaction action
From: |
Vladimir Sementsov-Ogievskiy |
Subject: |
[PATCH v3 16/36] block: add bdrv_replace_child_safe() transaction action |
Date: |
Wed, 17 Mar 2021 17:35:09 +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 31a4e4fa5c..4f9d67a6a2 100644
--- a/block.c
+++ b/block.c
@@ -83,6 +83,9 @@ static BlockDriverState *bdrv_open_inherit(const char
*filename,
BdrvChildRole child_role,
Error **errp);
+static void bdrv_replace_child_noperm(BdrvChild *child,
+ BlockDriverState *new_bs);
+
static int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue
*queue, Error **errp);
static void bdrv_reopen_commit(BDRVReopenState *reopen_state);
@@ -2203,6 +2206,57 @@ 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 TransactionActionDrv 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,
+ Transaction *tran)
+{
+ BdrvReplaceChildState *s = g_new(BdrvReplaceChildState, 1);
+ *s = (BdrvReplaceChildState) {
+ .child = child,
+ .old_bs = child->bs,
+ };
+ tran_add(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
--
2.29.2
- [PATCH v3 14/36] block: add bdrv_drv_set_perm transaction action, (continued)
- [PATCH v3 14/36] block: add bdrv_drv_set_perm transaction action, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 25/36] block: drop ignore_children for permission update functions, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 23/36] block: introduce bdrv_drop_filter(), Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 22/36] block: add bdrv_remove_filter_or_cow transaction action, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 27/36] block: make bdrv_refresh_limits() to be a transaction action, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 32/36] block: inline bdrv_check_perm_common(), Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 26/36] block: make bdrv_unset_inherits_from to be a transaction action, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 24/36] block/backup-top: drop .active, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 28/36] block: add bdrv_set_backing_noperm() transaction action, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 15/36] block: add bdrv_list_* permission update functions, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 16/36] block: add bdrv_replace_child_safe() transaction action,
Vladimir Sementsov-Ogievskiy <=
- [PATCH v3 29/36] block: bdrv_reopen_multiple(): move bdrv_flush to separate pre-prepare, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 30/36] block: bdrv_reopen_multiple: refresh permissions on updated graph, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 31/36] block: drop unused permission update functions, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 33/36] block: inline bdrv_replace_child(), Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 34/36] block: refactor bdrv_child_set_perm_safe() transaction action, Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 35/36] block: rename bdrv_replace_child_safe() to bdrv_replace_child(), Vladimir Sementsov-Ogievskiy, 2021/03/17
- [PATCH v3 36/36] block: refactor bdrv_node_check_perm(), Vladimir Sementsov-Ogievskiy, 2021/03/17
- Re: [PATCH v3 00/36] block: update graph permissions update, no-reply, 2021/03/17