io_uring: pass ctx instead of req to io_init_req_drain()

io_init_req_drain() takes a struct io_kiocb *req argument but only uses
it to get struct io_ring_ctx *ctx. The caller already knows the ctx, so
pass it instead.

Drop "req" from the function name since it operates on the ctx rather
than a specific req.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Link: https://lore.kernel.org/r/20250212164807.3681036-1-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring/io_uring.c

@@ -1997,9 +1997,8 @@ static inline bool io_check_restriction(struct io_ring_ctx *ctx,
 	return true;
 }
 
-static void io_init_req_drain(struct io_kiocb *req)
+static void io_init_drain(struct io_ring_ctx *ctx)
 {
-	struct io_ring_ctx *ctx = req->ctx;
 	struct io_kiocb *head = ctx->submit_state.link.head;
 
 	ctx->drain_active = true;
@@ -2061,7 +2060,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
 		if (sqe_flags & IOSQE_IO_DRAIN) {
 			if (ctx->drain_disabled)
 				return io_init_fail_req(req, -EOPNOTSUPP);
-			io_init_req_drain(req);
+			io_init_drain(ctx);
 		}
 	}
 	if (unlikely(ctx->restricted || ctx->drain_active || ctx->drain_next)) {