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[Qemu-devel] [PULL 13/31] block: Fix reconfiguring graph with drained no
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 13/31] block: Fix reconfiguring graph with drained nodes |
Date: |
Wed, 25 May 2016 19:39:38 +0200 |
When changing the BlockDriverState that a BdrvChild points to while the
node is currently drained, we must call the .drained_end() parent
callback. Conversely, when this means attaching a new node that is
already drained, we need to call .drained_begin().
bdrv_root_attach_child() takes now an opaque parameter, which is needed
because the callbacks must also be called if we're attaching a new child
to the BlockBackend when the root node is already drained, and they need
a way to identify the BlockBackend. Previously, child->opaque was set
too late and the callbacks would still see it as NULL.
Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Fam Zheng <address@hidden>
---
block.c | 18 ++++++++++++++----
block/block-backend.c | 9 +++++----
include/block/block_int.h | 3 ++-
3 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/block.c b/block.c
index 351344e..598624f 100644
--- a/block.c
+++ b/block.c
@@ -1155,24 +1155,33 @@ static void bdrv_replace_child(BdrvChild *child,
BlockDriverState *new_bs)
BlockDriverState *old_bs = child->bs;
if (old_bs) {
+ if (old_bs->quiesce_counter && child->role->drained_end) {
+ child->role->drained_end(child);
+ }
QLIST_REMOVE(child, next_parent);
}
+
+ child->bs = new_bs;
+
if (new_bs) {
QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
+ if (new_bs->quiesce_counter && child->role->drained_begin) {
+ child->role->drained_begin(child);
+ }
}
-
- child->bs = new_bs;
}
BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
const char *child_name,
- const BdrvChildRole *child_role)
+ const BdrvChildRole *child_role,
+ void *opaque)
{
BdrvChild *child = g_new(BdrvChild, 1);
*child = (BdrvChild) {
.bs = NULL,
.name = g_strdup(child_name),
.role = child_role,
+ .opaque = opaque,
};
bdrv_replace_child(child, child_bs);
@@ -1185,7 +1194,8 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
const char *child_name,
const BdrvChildRole *child_role)
{
- BdrvChild *child = bdrv_root_attach_child(child_bs, child_name,
child_role);
+ BdrvChild *child = bdrv_root_attach_child(child_bs, child_name, child_role,
+ NULL);
QLIST_INSERT_HEAD(&parent_bs->children, child, next);
return child;
}
diff --git a/block/block-backend.c b/block/block-backend.c
index 4e8298b..14e528e 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -161,8 +161,7 @@ BlockBackend *blk_new_open(const char *filename, const char
*reference,
}
blk_set_enable_write_cache(blk, true);
- blk->root = bdrv_root_attach_child(bs, "root", &child_root);
- blk->root->opaque = blk;
+ blk->root = bdrv_root_attach_child(bs, "root", &child_root, blk);
return blk;
}
@@ -481,8 +480,7 @@ void blk_remove_bs(BlockBackend *blk)
void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs)
{
bdrv_ref(bs);
- blk->root = bdrv_root_attach_child(bs, "root", &child_root);
- blk->root->opaque = blk;
+ blk->root = bdrv_root_attach_child(bs, "root", &child_root, blk);
notifier_list_notify(&blk->insert_bs_notifiers, blk);
if (blk->public.throttle_state) {
@@ -1676,6 +1674,9 @@ static void blk_root_drained_begin(BdrvChild *child)
{
BlockBackend *blk = child->opaque;
+ /* Note that blk->root may not be accessible here yet if we are just
+ * attaching to a BlockDriverState that is drained. Use child instead. */
+
if (blk->public.io_limits_disabled++ == 0) {
throttle_group_restart_blk(blk);
}
diff --git a/include/block/block_int.h b/include/block/block_int.h
index b6f4755..30a9717 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -719,7 +719,8 @@ void hmp_drive_add_node(Monitor *mon, const char *optstr);
BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
const char *child_name,
- const BdrvChildRole *child_role);
+ const BdrvChildRole *child_role,
+ void *opaque);
void bdrv_root_unref_child(BdrvChild *child);
const char *bdrv_get_parent_name(const BlockDriverState *bs);
--
1.8.3.1
- [Qemu-devel] [PULL 00/31] Block layer patches, (continued)
- [Qemu-devel] [PULL 00/31] Block layer patches, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 02/31] block: Drop useless bdrv_new() call, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 01/31] block: Fix bdrv_next() memory leak, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 03/31] block: Let bdrv_open_inherit() return the snapshot, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 06/31] block: Drop bdrv_new_root(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 08/31] block: Assert !bs->refcnt in bdrv_close(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 05/31] block: Drop blk_new_with_bs(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 09/31] block: Drop bdrv_parent_cb_...() from bdrv_close(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 04/31] tests: Drop BDS from test-throttle.c, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 10/31] block: Drop errp parameter from blk_new(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 13/31] block: Fix reconfiguring graph with drained nodes,
Kevin Wolf <=
- [Qemu-devel] [PULL 11/31] block: Introduce bdrv_replace_child(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 20/31] block: Default to enabled write cache in blk_new(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 07/31] block: Make bdrv_open() return a BDS, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 14/31] block: Propagate .drained_begin/end callbacks, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 12/31] block: Make bdrv_drain() use bdrv_drained_begin/end(), Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 15/31] dma-helpers: change interface to byte-based, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 18/31] block: keep a list of block jobs, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 22/31] block: Make blk_co_preadv/pwritev() public, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 16/31] dma-helpers: change BlockBackend to opaque value in DMAIOFunc, Kevin Wolf, 2016/05/25
- [Qemu-devel] [PULL 19/31] block: Cancel jobs first in bdrv_close_all(), Kevin Wolf, 2016/05/25