io_uring: add a helper for putting rsrc nodes

Add a simple helper to encapsulating dropping rsrc nodes references,
it's cleaner and will help if we'd change rsrc refcounting or play with
percpu_ref_put() [no]inlining.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/63fdd953ac75898734cd50e8f69e95e6664f46fe.1650311386.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -1326,6 +1326,11 @@ static inline void io_req_set_refcount(struct io_kiocb *req)
 
 #define IO_RSRC_REF_BATCH	100
 
+static void io_rsrc_put_node(struct io_rsrc_node *node, int nr)
+{
+	percpu_ref_put_many(&node->refs, nr);
+}
+
 static inline void io_req_put_rsrc_locked(struct io_kiocb *req,
 					  struct io_ring_ctx *ctx)
 	__must_hold(&ctx->uring_lock)
@@ -1336,21 +1341,21 @@ static inline void io_req_put_rsrc_locked(struct io_kiocb *req,
 		if (node == ctx->rsrc_node)
 			ctx->rsrc_cached_refs++;
 		else
-			percpu_ref_put(&node->refs);
+			io_rsrc_put_node(node, 1);
 	}
 }
 
 static inline void io_req_put_rsrc(struct io_kiocb *req, struct io_ring_ctx *ctx)
 {
 	if (req->rsrc_node)
-		percpu_ref_put(&req->rsrc_node->refs);
+		io_rsrc_put_node(req->rsrc_node, 1);
 }
 
 static __cold void io_rsrc_refs_drop(struct io_ring_ctx *ctx)
 	__must_hold(&ctx->uring_lock)
 {
 	if (ctx->rsrc_cached_refs) {
-		percpu_ref_put_many(&ctx->rsrc_node->refs, ctx->rsrc_cached_refs);
+		io_rsrc_put_node(ctx->rsrc_node, ctx->rsrc_cached_refs);
 		ctx->rsrc_cached_refs = 0;
 	}
 }