From e336fd4c4b2fa04e5d6c7f8ee524bfd2d9e9e8f1 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Mon, 5 Oct 2020 17:58:53 +0200 Subject: block: Add bdrv_co_enter()/leave() Add a pair of functions to temporarily move the current coroutine to the AioContext of a given BlockDriverState. Signed-off-by: Kevin Wolf Message-Id: <20201005155855.256490-13-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Markus Armbruster --- include/block/block.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include') diff --git a/include/block/block.h b/include/block/block.h index ce2ac39299..1027c58a41 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -640,6 +640,23 @@ bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag); */ AioContext *bdrv_get_aio_context(BlockDriverState *bs); +/** + * Move the current coroutine to the AioContext of @bs and return the old + * AioContext of the coroutine. Increase bs->in_flight so that draining @bs + * will wait for the operation to proceed until the corresponding + * bdrv_co_leave(). + * + * Consequently, you can't call drain inside a bdrv_co_enter/leave() section as + * this will deadlock. + */ +AioContext *coroutine_fn bdrv_co_enter(BlockDriverState *bs); + +/** + * Ends a section started by bdrv_co_enter(). Move the current coroutine back + * to old_ctx and decrease bs->in_flight again. + */ +void coroutine_fn bdrv_co_leave(BlockDriverState *bs, AioContext *old_ctx); + /** * Transfer control to @co in the aio context of @bs */ -- cgit v1.2.3-55-g7522