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authorEmanuele Giuseppe Esposito <eesposit@redhat.com>2023-02-03 08:17:28 -0500
committerKevin Wolf <kwolf@redhat.com>2023-04-25 13:17:28 +0200
commitab50533b6946b1adeb8eef62c6b16689abcd1e70 (patch)
treef26f82f922d324d83cb181a9c1176833afd562ba /include/sysemu/block-backend-io.h
parente95200c1c524403e42e8712c7391a8acd5825656 (diff)
downloadfocaccia-qemu-ab50533b6946b1adeb8eef62c6b16689abcd1e70.tar.gz
focaccia-qemu-ab50533b6946b1adeb8eef62c6b16689abcd1e70.zip
linux-aio: use LinuxAioState from the running thread
Remove usage of aio_context_acquire by always submitting asynchronous
AIO to the current thread's LinuxAioState.

In order to prevent mistakes from the caller side, avoid passing LinuxAioState
in laio_io_{plug/unplug} and laio_co_submit, and document the functions
to make clear that they work in the current thread's AioContext.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20230203131731.851116-2-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'include/sysemu/block-backend-io.h')
-rw-r--r--include/sysemu/block-backend-io.h5
1 files changed, 5 insertions, 0 deletions
diff --git a/include/sysemu/block-backend-io.h b/include/sysemu/block-backend-io.h
index bb25493ba1..851a44de96 100644
--- a/include/sysemu/block-backend-io.h
+++ b/include/sysemu/block-backend-io.h
@@ -90,6 +90,11 @@ void blk_iostatus_set_err(BlockBackend *blk, int error);
 int blk_get_max_iov(BlockBackend *blk);
 int blk_get_max_hw_iov(BlockBackend *blk);
 
+/*
+ * blk_io_plug/unplug are thread-local operations. This means that multiple
+ * IOThreads can simultaneously call plug/unplug, but the caller must ensure
+ * that each unplug() is called in the same IOThread of the matching plug().
+ */
 void coroutine_fn blk_co_io_plug(BlockBackend *blk);
 void co_wrapper blk_io_plug(BlockBackend *blk);