io_uring: add allow_overflow to io_post_aux_cqe

Some use cases of io_post_aux_cqe would not want to overflow as is, but
might want to change the flags/result. For example multishot receive
requires in order CQE, and so if there is an overflow it would need to
stop receiving until the overflow is taken care of.

Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220630091231.1456789-8-dylany@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 10 insertions, 4 deletions

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 745264938a48..523b6ebad15a 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -736,7 +736,8 @@ struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx)
 }
 
 static bool io_fill_cqe_aux(struct io_ring_ctx *ctx,
-			    u64 user_data, s32 res, u32 cflags)
+			    u64 user_data, s32 res, u32 cflags,
+			    bool allow_overflow)
 {
 	struct io_uring_cqe *cqe;
 
@@ -760,16 +761,21 @@ static bool io_fill_cqe_aux(struct io_ring_ctx *ctx,
 		}
 		return true;
 	}
-	return io_cqring_event_overflow(ctx, user_data, res, cflags, 0, 0);
+
+	if (allow_overflow)
+		return io_cqring_event_overflow(ctx, user_data, res, cflags, 0, 0);
+
+	return false;
 }
 
 bool io_post_aux_cqe(struct io_ring_ctx *ctx,
-		     u64 user_data, s32 res, u32 cflags)
+		     u64 user_data, s32 res, u32 cflags,
+		     bool allow_overflow)
 {
 	bool filled;
 
 	io_cq_lock(ctx);
-	filled = io_fill_cqe_aux(ctx, user_data, res, cflags);
+	filled = io_fill_cqe_aux(ctx, user_data, res, cflags, allow_overflow);
 	io_cq_unlock_post(ctx);
 	return filled;
 }