diff options
| -rw-r--r-- | block/graph-lock.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/block/graph-lock.c b/block/graph-lock.c index 259a7a0bde..2490926c90 100644 --- a/block/graph-lock.c +++ b/block/graph-lock.c @@ -30,8 +30,10 @@ BdrvGraphLock graph_lock; /* Protects the list of aiocontext and orphaned_reader_count */ static QemuMutex aio_context_list_lock; +#if 0 /* Written and read with atomic operations. */ static int has_writer; +#endif /* * A reader coroutine could move from an AioContext to another. @@ -88,6 +90,7 @@ void unregister_aiocontext(AioContext *ctx) g_free(ctx->bdrv_graph); } +#if 0 static uint32_t reader_count(void) { BdrvGraphRWlock *brdv_graph; @@ -105,10 +108,17 @@ static uint32_t reader_count(void) assert((int32_t)rd >= 0); return rd; } +#endif void bdrv_graph_wrlock(void) { GLOBAL_STATE_CODE(); + /* + * TODO Some callers hold an AioContext lock when this is called, which + * causes deadlocks. Reenable once the AioContext locking is cleaned up (or + * AioContext locks are gone). + */ +#if 0 assert(!qatomic_read(&has_writer)); /* Make sure that constantly arriving new I/O doesn't cause starvation */ @@ -139,11 +149,13 @@ void bdrv_graph_wrlock(void) } while (reader_count() >= 1); bdrv_drain_all_end(); +#endif } void bdrv_graph_wrunlock(void) { GLOBAL_STATE_CODE(); +#if 0 QEMU_LOCK_GUARD(&aio_context_list_lock); assert(qatomic_read(&has_writer)); @@ -155,10 +167,13 @@ void bdrv_graph_wrunlock(void) /* Wake up all coroutine that are waiting to read the graph */ qemu_co_enter_all(&reader_queue, &aio_context_list_lock); +#endif } void coroutine_fn bdrv_graph_co_rdlock(void) { + /* TODO Reenable when wrlock is reenabled */ +#if 0 BdrvGraphRWlock *bdrv_graph; bdrv_graph = qemu_get_current_aio_context()->bdrv_graph; @@ -223,10 +238,12 @@ void coroutine_fn bdrv_graph_co_rdlock(void) qemu_co_queue_wait(&reader_queue, &aio_context_list_lock); } } +#endif } void coroutine_fn bdrv_graph_co_rdunlock(void) { +#if 0 BdrvGraphRWlock *bdrv_graph; bdrv_graph = qemu_get_current_aio_context()->bdrv_graph; @@ -249,6 +266,7 @@ void coroutine_fn bdrv_graph_co_rdunlock(void) if (qatomic_read(&has_writer)) { aio_wait_kick(); } +#endif } void bdrv_graph_rdlock_main_loop(void) @@ -266,13 +284,19 @@ void bdrv_graph_rdunlock_main_loop(void) void assert_bdrv_graph_readable(void) { /* reader_count() is slow due to aio_context_list_lock lock contention */ + /* TODO Reenable when wrlock is reenabled */ +#if 0 #ifdef CONFIG_DEBUG_GRAPH_LOCK assert(qemu_in_main_thread() || reader_count()); #endif +#endif } void assert_bdrv_graph_writable(void) { assert(qemu_in_main_thread()); + /* TODO Reenable when wrlock is reenabled */ +#if 0 assert(qatomic_read(&has_writer)); +#endif } |