[v2] block: do not drain while holding the graph lock

[PATCH v2 19/24] block: mark bdrv_drained_begin() as GRAPH_UNLOCKED

Posted by Fiona Ebner 5 months, 4 weeks ago

bdrv_drained_begin() polls and is not allowed to be called with the
block graph lock held. Mark the function as such.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---

No changes in v2, but ordered differently (in particular, it avoids
the need for patch 04/11 from last time).

 include/block/block-io.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/block/block-io.h b/include/block/block-io.h
index b99cc98d26..4cf83fb367 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -431,7 +431,7 @@ bdrv_drain_poll(BlockDriverState *bs, BdrvChild *ignore_parent,
  *
  * This function can be recursive.
  */
-void bdrv_drained_begin(BlockDriverState *bs);
+void GRAPH_UNLOCKED bdrv_drained_begin(BlockDriverState *bs);
 
 /**
  * bdrv_do_drained_begin_quiesce:
-- 
2.39.5

Re: [PATCH v2 19/24] block: mark bdrv_drained_begin() as GRAPH_UNLOCKED

Posted by Andrey Drobyshev 5 months, 3 weeks ago

On 5/20/25 1:30 PM, Fiona Ebner wrote:
> bdrv_drained_begin() polls and is not allowed to be called with the
> block graph lock held. Mark the function as such.
> 
> Suggested-by: Kevin Wolf <kwolf@redhat.com>
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> ---
> 
> No changes in v2, but ordered differently (in particular, it avoids
> the need for patch 04/11 from last time).
> 
>  include/block/block-io.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/block/block-io.h b/include/block/block-io.h
> index b99cc98d26..4cf83fb367 100644
> --- a/include/block/block-io.h
> +++ b/include/block/block-io.h
> @@ -431,7 +431,7 @@ bdrv_drain_poll(BlockDriverState *bs, BdrvChild *ignore_parent,
>   *
>   * This function can be recursive.
>   */
> -void bdrv_drained_begin(BlockDriverState *bs);
> +void GRAPH_UNLOCKED bdrv_drained_begin(BlockDriverState *bs);
>  
>  /**
>   * bdrv_do_drained_begin_quiesce:

Again, for readability we might as well add the GRAPH_UNLOCKED mark to
the definition in block/io.c.

Andrey