block: mark mixed functions that can suspend

The marking should be extended transitively to all functions that call
these ones, so that static analysis can be done much more efficiently.
However, this is a start and makes it possible to use vrc's path-based
searches to find potential bugs where coroutine_fns call blocking functions.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

block/io.c

@@ -387,7 +387,8 @@ void bdrv_do_drained_begin_quiesce(BlockDriverState *bs, BdrvChild *parent)
     bdrv_do_drained_begin(bs, parent, false);
 }
 
-void bdrv_drained_begin(BlockDriverState *bs)
+void coroutine_mixed_fn
+bdrv_drained_begin(BlockDriverState *bs)
 {
     IO_OR_GS_CODE();
     bdrv_do_drained_begin(bs, NULL, true);
@@ -506,7 +507,7 @@ void bdrv_drain_all_begin_nopoll(void)
     }
 }
 
-void bdrv_drain_all_begin(void)
+void coroutine_mixed_fn bdrv_drain_all_begin(void)
 {
     BlockDriverState *bs = NULL;
 

block/qcow2.c

@@ -5288,7 +5288,7 @@ static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs,
     return spec_info;
 }
 
-static int qcow2_has_zero_init(BlockDriverState *bs)
+static int coroutine_mixed_fn qcow2_has_zero_init(BlockDriverState *bs)
 {
     BDRVQcow2State *s = bs->opaque;
     bool preallocated;

block/qed.c

@@ -570,8 +570,8 @@ static void coroutine_fn bdrv_qed_open_entry(void *opaque)
     qemu_co_mutex_unlock(&s->table_lock);
 }
 
-static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags,
-                         Error **errp)
+static int coroutine_mixed_fn bdrv_qed_open(BlockDriverState *bs, QDict *options,
+                                            int flags, Error **errp)
 {
     QEDOpenCo qoc = {
         .bs = bs,

block/throttle-groups.c

@@ -317,8 +317,8 @@ static bool coroutine_fn throttle_group_co_restart_queue(ThrottleGroupMember *tg
  * @tgm:       the current ThrottleGroupMember
  * @direction: the ThrottleDirection
  */
-static void schedule_next_request(ThrottleGroupMember *tgm,
-                                  ThrottleDirection direction)
+static void coroutine_mixed_fn schedule_next_request(ThrottleGroupMember *tgm,
+                                                     ThrottleDirection direction)
 {
     ThrottleState *ts = tgm->throttle_state;
     ThrottleGroup *tg = container_of(ts, ThrottleGroup, ts);