Block layer patches

- Code cleanups around block graph modification
 - Simplify drain
 - coroutine_fn correctness fixes, including splitting generated
   coroutine wrappers into co_wrapper (to be called only from
   non-coroutine context) and co_wrapper_mixed (both coroutine and
   non-coroutine context)
 - Introduce a block graph rwlock
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Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging

Block layer patches

- Code cleanups around block graph modification
- Simplify drain
- coroutine_fn correctness fixes, including splitting generated
  coroutine wrappers into co_wrapper (to be called only from
  non-coroutine context) and co_wrapper_mixed (both coroutine and
  non-coroutine context)
- Introduce a block graph rwlock

# gpg: Signature made Thu 15 Dec 2022 15:08:34 GMT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (50 commits)
  block: GRAPH_RDLOCK for functions only called by co_wrappers
  block: use co_wrapper_mixed_bdrv_rdlock in functions taking the rdlock
  block-coroutine-wrapper.py: introduce annotations that take the graph rdlock
  Mark assert_bdrv_graph_readable/writable() GRAPH_RD/WRLOCK
  graph-lock: TSA annotations for lock/unlock functions
  block: assert that graph read and writes are performed correctly
  block: remove unnecessary assert_bdrv_graph_writable()
  block: wrlock in bdrv_replace_child_noperm
  block: Fix locking in external_snapshot_prepare()
  test-bdrv-drain: Fix incorrrect drain assumptions
  clang-tsa: Add macros for shared locks
  clang-tsa: Add TSA_ASSERT() macro
  Import clang-tsa.h
  async: Register/unregister aiocontext in graph lock list
  graph-lock: Implement guard macros
  graph-lock: Introduce a lock to protect block graph operations
  block: Factor out bdrv_drain_all_begin_nopoll()
  block/dirty-bitmap: convert coroutine-only functions to co_wrapper
  block: convert bdrv_create to co_wrapper
  block-coroutine-wrapper.py: support also basic return types
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

util/async.c

@@ -27,6 +27,7 @@
 #include "qapi/error.h"
 #include "block/aio.h"
 #include "block/thread-pool.h"
+#include "block/graph-lock.h"
 #include "qemu/main-loop.h"
 #include "qemu/atomic.h"
 #include "qemu/rcu_queue.h"
@@ -376,6 +377,7 @@ aio_ctx_finalize(GSource     *source)
     qemu_rec_mutex_destroy(&ctx->lock);
     qemu_lockcnt_destroy(&ctx->list_lock);
     timerlistgroup_deinit(&ctx->tlg);
+    unregister_aiocontext(ctx);
     aio_context_destroy(ctx);
 }
 
@@ -574,6 +576,8 @@ AioContext *aio_context_new(Error **errp)
     ctx->thread_pool_min = 0;
     ctx->thread_pool_max = THREAD_POOL_MAX_THREADS_DEFAULT;
 
+    register_aiocontext(ctx);
+
     return ctx;
 fail:
     g_source_destroy(&ctx->source);