[PATCH 1/3] io_uring: add hash_index and its logic to track req in cancel_hash

[Hao Xu <haoxu.linux@icloud.com>]

From: Hao Xu <howeyxu@tencent.com>

Add a new member hash_index in struct io_kiocb to track the req index
in cancel_hash array. This is needed in later patches.

Signed-off-by: Hao Xu <howeyxu@tencent.com>
---
 io_uring/io_uring_types.h | 1 +
 io_uring/poll.c           | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/io_uring/io_uring_types.h b/io_uring/io_uring_types.h
index 7c22cf35a7e2..2041ee83467d 100644
--- a/io_uring/io_uring_types.h
+++ b/io_uring/io_uring_types.h
@@ -474,6 +474,7 @@ struct io_kiocb {
 			u64		extra2;
 		};
 	};
+	unsigned int			hash_index;
 	/* internal polling, see IORING_FEAT_FAST_POLL */
 	struct async_poll		*apoll;
 	/* opcode allocated if it needs to store data for async defer */
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 0df5eca93b16..95e28f32b49c 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -74,8 +74,10 @@ static void io_poll_req_insert(struct io_kiocb *req)
 {
 	struct io_ring_ctx *ctx = req->ctx;
 	struct hlist_head *list;
+	u32 index = hash_long(req->cqe.user_data, ctx->cancel_hash_bits);
 
-	list = &ctx->cancel_hash[hash_long(req->cqe.user_data, ctx->cancel_hash_bits)];
+	req->hash_index = index;
+	list = &ctx->cancel_hash[index];
 	hlist_add_head(&req->hash_node, list);
 }
 
-- 
2.25.1