From 3f35f82e04923affb3283b451b6d66880f266a5a Mon Sep 17 00:00:00 2001 From: Emanuele Giuseppe Esposito Date: Wed, 7 Dec 2022 14:18:33 +0100 Subject: block: assert that graph read and writes are performed correctly Remove the old assert_bdrv_graph_writable, and replace it with the new version using graph-lock API. See the function documentation for more information. Signed-off-by: Emanuele Giuseppe Esposito Signed-off-by: Kevin Wolf Message-Id: <20221207131838.239125-14-kwolf@redhat.com> Reviewed-by: Emanuele Giuseppe Esposito Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- include/block/block_int-global-state.h | 17 ----------------- include/block/graph-lock.h | 15 +++++++++++++++ 2 files changed, 15 insertions(+), 17 deletions(-) (limited to 'include/block') diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h index b49f4eb35b..2f0993f6e9 100644 --- a/include/block/block_int-global-state.h +++ b/include/block/block_int-global-state.h @@ -310,21 +310,4 @@ void bdrv_remove_aio_context_notifier(BlockDriverState *bs, */ void bdrv_drain_all_end_quiesce(BlockDriverState *bs); -/** - * Make sure that the function is running under both drain and BQL. - * The latter protects from concurrent writings - * from the GS API, while the former prevents concurrent reads - * from I/O. - */ -static inline void assert_bdrv_graph_writable(BlockDriverState *bs) -{ - /* - * TODO: this function is incomplete. Because the users of this - * assert lack the necessary drains, check only for BQL. - * Once the necessary drains are added, - * assert also for qatomic_read(&bs->quiesce_counter) > 0 - */ - assert(qemu_in_main_thread()); -} - #endif /* BLOCK_INT_GLOBAL_STATE_H */ diff --git a/include/block/graph-lock.h b/include/block/graph-lock.h index b27d8a5fb1..85e8a53b73 100644 --- a/include/block/graph-lock.h +++ b/include/block/graph-lock.h @@ -135,6 +135,21 @@ void coroutine_fn bdrv_graph_co_rdunlock(void); void bdrv_graph_rdlock_main_loop(void); void bdrv_graph_rdunlock_main_loop(void); +/* + * assert_bdrv_graph_readable: + * Make sure that the reader is either the main loop, + * or there is at least a reader helding the rdlock. + * In this way an incoming writer is aware of the read and waits. + */ +void assert_bdrv_graph_readable(void); + +/* + * assert_bdrv_graph_writable: + * Make sure that the writer is the main loop and has set @has_writer, + * so that incoming readers will pause. + */ +void assert_bdrv_graph_writable(void); + typedef struct GraphLockable { } GraphLockable; /* -- cgit v1.2.3