block: Convert bdrv_is_inserted() to co_wrapper

bdrv_is_inserted() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

At the same time, add also blk_is_inserted as co_wrapper_mixed, since it
is called in both coroutine and non-coroutine contexts.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally c_w_mixed_bdrv_rdlock calls AIO_WAIT_WHILE and it expects to
release the AioContext lock. Once the rwlock is ultimated and placed in
every place it needs to be, we will poll using AIO_WAIT_WHILE_UNLOCKED
and remove the AioContext lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-5-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/block/block-backend.c b/block/block-backend.c
index e9cc7d291e..7ba436811b 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1983,12 +1983,12 @@ void blk_activate(BlockBackend *blk, Error **errp)
     bdrv_activate(bs, errp);
 }
 
-bool blk_is_inserted(BlockBackend *blk)
+bool coroutine_fn blk_co_is_inserted(BlockBackend *blk)
 {
     BlockDriverState *bs = blk_bs(blk);
     IO_CODE();
 
-    return bs && bdrv_is_inserted(bs);
+    return bs && bdrv_co_is_inserted(bs);
 }
 
 bool blk_is_available(BlockBackend *blk)