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>

docs/devel/block-coroutine-wrapper.rst

@@ -26,12 +26,12 @@ called ``bdrv_foo(<same args>)``. In this case the script can help. To
 trigger the generation:
 
 1. You need ``bdrv_foo`` declaration somewhere (for example, in
-   ``block/coroutines.h``) with the ``generated_co_wrapper`` mark,
+   ``block/coroutines.h``) with the ``co_wrapper`` mark,
    like this:
 
 .. code-block:: c
 
-    int generated_co_wrapper bdrv_foo(<some args>);
+    int co_wrapper bdrv_foo(<some args>);
 
 2. You need to feed this declaration to block-coroutine-wrapper script.
    For this, add the .h (or .c) file with the declaration to the
@@ -46,7 +46,7 @@ Links
 
 1. The script location is ``scripts/block-coroutine-wrapper.py``.
 
-2. Generic place for private ``generated_co_wrapper`` declarations is
+2. Generic place for private ``co_wrapper`` declarations is
    ``block/coroutines.h``, for public declarations:
    ``include/block/block.h``