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[PULL 28/39] block: add bdrv_set_backing_noperm() transaction action
From: |
Kevin Wolf |
Subject: |
[PULL 28/39] block: add bdrv_set_backing_noperm() transaction action |
Date: |
Fri, 30 Apr 2021 12:51:36 +0200 |
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Split out no-perm part of bdrv_set_backing_hd() as a separate
transaction action. Note the in case of existing BdrvChild we reuse it,
not recreate, just to do less actions.
We don't need to create extra reference to backing_hd as we don't lose
it in bdrv_attach_child().
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210428151804.439460-29-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block.c | 54 +++++++++++++++++++++++++++++++++++++-----------------
1 file changed, 37 insertions(+), 17 deletions(-)
diff --git a/block.c b/block.c
index 9922943793..bdfe59d94d 100644
--- a/block.c
+++ b/block.c
@@ -92,6 +92,8 @@ static int bdrv_attach_child_noperm(BlockDriverState
*parent_bs,
BdrvChild **child,
Transaction *tran,
Error **errp);
+static void bdrv_remove_filter_or_cow_child(BlockDriverState *bs,
+ Transaction *tran);
static int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue
*queue, Error **errp);
@@ -3322,8 +3324,9 @@ static BdrvChildRole bdrv_backing_role(BlockDriverState
*bs)
* Sets the bs->backing link of a BDS. A new reference is created; callers
* which don't need their own reference any more must call bdrv_unref().
*/
-int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
- Error **errp)
+static int bdrv_set_backing_noperm(BlockDriverState *bs,
+ BlockDriverState *backing_hd,
+ Transaction *tran, Error **errp)
{
int ret = 0;
bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
@@ -3333,36 +3336,53 @@ int bdrv_set_backing_hd(BlockDriverState *bs,
BlockDriverState *backing_hd,
return -EPERM;
}
- if (backing_hd) {
- bdrv_ref(backing_hd);
- }
-
if (bs->backing) {
/* Cannot be frozen, we checked that above */
- bdrv_unref_child(bs, bs->backing);
- bs->backing = NULL;
+ bdrv_unset_inherits_from(bs, bs->backing, tran);
+ bdrv_remove_filter_or_cow_child(bs, tran);
}
if (!backing_hd) {
goto out;
}
- bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_of_bds,
- bdrv_backing_role(bs), errp);
- if (!bs->backing) {
- ret = -EPERM;
- goto out;
+ ret = bdrv_attach_child_noperm(bs, backing_hd, "backing",
+ &child_of_bds, bdrv_backing_role(bs),
+ &bs->backing, tran, errp);
+ if (ret < 0) {
+ return ret;
}
- /* If backing_hd was already part of bs's backing chain, and
+
+ /*
+ * If backing_hd was already part of bs's backing chain, and
* inherits_from pointed recursively to bs then let's update it to
- * point directly to bs (else it will become NULL). */
+ * point directly to bs (else it will become NULL).
+ */
if (update_inherits_from) {
- backing_hd->inherits_from = bs;
+ bdrv_set_inherits_from(backing_hd, bs, tran);
}
out:
- bdrv_refresh_limits(bs, NULL, NULL);
+ bdrv_refresh_limits(bs, tran, NULL);
+
+ return 0;
+}
+
+int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
+ Error **errp)
+{
+ int ret;
+ Transaction *tran = tran_new();
+
+ ret = bdrv_set_backing_noperm(bs, backing_hd, tran, errp);
+ if (ret < 0) {
+ goto out;
+ }
+
+ ret = bdrv_refresh_perms(bs, errp);
+out:
+ tran_finalize(tran, ret);
return ret;
}
--
2.30.2
- [PULL 18/39] block: add bdrv_attach_child_common() transaction action, (continued)
- [PULL 18/39] block: add bdrv_attach_child_common() transaction action, Kevin Wolf, 2021/04/30
- [PULL 20/39] block: split out bdrv_replace_node_noperm(), Kevin Wolf, 2021/04/30
- [PULL 16/39] block: add bdrv_replace_child_safe() transaction action, Kevin Wolf, 2021/04/30
- [PULL 23/39] block: introduce bdrv_drop_filter(), Kevin Wolf, 2021/04/30
- [PULL 22/39] block: add bdrv_remove_filter_or_cow transaction action, Kevin Wolf, 2021/04/30
- [PULL 21/39] block: adapt bdrv_append() for inserting filters, Kevin Wolf, 2021/04/30
- [PULL 24/39] block/backup-top: drop .active, Kevin Wolf, 2021/04/30
- [PULL 25/39] block: drop ignore_children for permission update functions, Kevin Wolf, 2021/04/30
- [PULL 26/39] block: make bdrv_unset_inherits_from to be a transaction action, Kevin Wolf, 2021/04/30
- [PULL 28/39] block: add bdrv_set_backing_noperm() transaction action,
Kevin Wolf <=
- [PULL 29/39] block: bdrv_reopen_multiple(): move bdrv_flush to separate pre-prepare, Kevin Wolf, 2021/04/30
- [PULL 34/39] block: refactor bdrv_child_set_perm_safe() transaction action, Kevin Wolf, 2021/04/30
- [PULL 33/39] block: inline bdrv_replace_child(), Kevin Wolf, 2021/04/30
- [PULL 27/39] block: make bdrv_refresh_limits() to be a transaction action, Kevin Wolf, 2021/04/30
- [PULL 36/39] block: refactor bdrv_node_check_perm(), Kevin Wolf, 2021/04/30
- [PULL 30/39] block: bdrv_reopen_multiple: refresh permissions on updated graph, Kevin Wolf, 2021/04/30
- [PULL 31/39] block: drop unused permission update functions, Kevin Wolf, 2021/04/30
- [PULL 39/39] vhost-user-blk: Fail gracefully on too large queue size, Kevin Wolf, 2021/04/30
- [PULL 32/39] block: inline bdrv_check_perm_common(), Kevin Wolf, 2021/04/30