For the upcoming async polled IO, we can't sleep allocating requests.
If we do, then we introduce a deadlock where the submitter already
has async polled IO in-flight, but can't wait for them to complete
since polled requests must be active found and reaped.

Signed-off-by: Jens Axboe <ax...@kernel.dk>
---
 include/linux/blk_types.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index c0ba1a038ff3..1d9c3da0f2a1 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -346,6 +346,7 @@ enum req_flag_bits {
 #define REQ_NOWAIT             (1ULL << __REQ_NOWAIT)
 #define REQ_NOUNMAP            (1ULL << __REQ_NOUNMAP)
 #define REQ_HIPRI              (1ULL << __REQ_HIPRI)
+#define REQ_HIPRI_ASYNC                (REQ_HIPRI | REQ_NOWAIT)
 
 #define REQ_DRV                        (1ULL << __REQ_DRV)
 #define REQ_SWAP               (1ULL << __REQ_SWAP)
-- 
2.17.1

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