io_uring: inline struct io_comp_state

Inline struct io_comp_state into struct io_submit_state. They are
already coupled tightly, together with mixed responsibilities it
only brings confusion having them separately.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/e55bba77426b399e3a2e54e3c6c267c6a0fc4b57.1628536684.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -299,13 +299,6 @@ struct io_sq_data {
 #define IO_REQ_CACHE_SIZE		32
 #define IO_REQ_ALLOC_BATCH		8
 
-struct io_comp_state {
-	struct io_kiocb		*reqs[IO_COMPL_BATCH];
-	unsigned int		nr;
-	/* inline/task_work completion list, under ->uring_lock */
-	struct list_head	free_list;
-};
-
 struct io_submit_link {
 	struct io_kiocb		*head;
 	struct io_kiocb		*last;
@@ -326,7 +319,10 @@ struct io_submit_state {
 	/*
 	 * Batch completion logic
 	 */
-	struct io_comp_state	comp;
+	struct io_kiocb		*compl_reqs[IO_COMPL_BATCH];
+	unsigned int		compl_nr;
+	/* inline/task_work completion list, under ->uring_lock */
+	struct list_head	free_list;
 
 	/*
 	 * File reference cache
@@ -1208,7 +1204,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
 	init_llist_head(&ctx->rsrc_put_llist);
 	INIT_LIST_HEAD(&ctx->tctx_list);
-	INIT_LIST_HEAD(&ctx->submit_state.comp.free_list);
+	INIT_LIST_HEAD(&ctx->submit_state.free_list);
 	INIT_LIST_HEAD(&ctx->locked_free_list);
 	INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
 	return ctx;
@@ -1734,10 +1730,10 @@ static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
 }
 
 static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
-					struct io_comp_state *cs)
+					struct io_submit_state *state)
 {
 	spin_lock_irq(&ctx->completion_lock);
-	list_splice_init(&ctx->locked_free_list, &cs->free_list);
+	list_splice_init(&ctx->locked_free_list, &state->free_list);
 	ctx->locked_free_nr = 0;
 	spin_unlock_irq(&ctx->completion_lock);
 }
@@ -1746,7 +1742,6 @@ static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
 static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
 {
 	struct io_submit_state *state = &ctx->submit_state;
-	struct io_comp_state *cs = &state->comp;
 	int nr;
 
 	/*
@@ -1755,11 +1750,11 @@ static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
 	 * side cache.
 	 */
 	if (READ_ONCE(ctx->locked_free_nr) > IO_COMPL_BATCH)
-		io_flush_cached_locked_reqs(ctx, cs);
+		io_flush_cached_locked_reqs(ctx, state);
 
 	nr = state->free_reqs;
-	while (!list_empty(&cs->free_list)) {
-		struct io_kiocb *req = list_first_entry(&cs->free_list,
+	while (!list_empty(&state->free_list)) {
+		struct io_kiocb *req = list_first_entry(&state->free_list,
 					struct io_kiocb, inflight_entry);
 
 		list_del(&req->inflight_entry);
@@ -1946,7 +1941,7 @@ static void ctx_flush_and_put(struct io_ring_ctx *ctx)
 {
 	if (!ctx)
 		return;
-	if (ctx->submit_state.comp.nr) {
+	if (ctx->submit_state.compl_nr) {
 		mutex_lock(&ctx->uring_lock);
 		io_submit_flush_completions(ctx);
 		mutex_unlock(&ctx->uring_lock);
@@ -2143,19 +2138,19 @@ static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req,
 	if (state->free_reqs != ARRAY_SIZE(state->reqs))
 		state->reqs[state->free_reqs++] = req;
 	else
-		list_add(&req->inflight_entry, &state->comp.free_list);
+		list_add(&req->inflight_entry, &state->free_list);
 }
 
 static void io_submit_flush_completions(struct io_ring_ctx *ctx)
 	__must_hold(&req->ctx->uring_lock)
 {
-	struct io_comp_state *cs = &ctx->submit_state.comp;
-	int i, nr = cs->nr;
+	struct io_submit_state *state = &ctx->submit_state;
+	int i, nr = state->compl_nr;
 	struct req_batch rb;
 
 	spin_lock_irq(&ctx->completion_lock);
 	for (i = 0; i < nr; i++) {
-		struct io_kiocb *req = cs->reqs[i];
+		struct io_kiocb *req = state->compl_reqs[i];
 
 		__io_cqring_fill_event(ctx, req->user_data, req->result,
 					req->compl.cflags);
@@ -2166,7 +2161,7 @@ static void io_submit_flush_completions(struct io_ring_ctx *ctx)
 
 	io_init_req_batch(&rb);
 	for (i = 0; i < nr; i++) {
-		struct io_kiocb *req = cs->reqs[i];
+		struct io_kiocb *req = state->compl_reqs[i];
 
 		/* submission and completion refs */
 		if (req_ref_sub_and_test(req, 2))
@@ -2174,7 +2169,7 @@ static void io_submit_flush_completions(struct io_ring_ctx *ctx)
 	}
 
 	io_req_free_batch_finish(ctx, &rb);
-	cs->nr = 0;
+	state->compl_nr = 0;
 }
 
 /*
@@ -6484,10 +6479,10 @@ issue_sqe:
 		/* drop submission reference */
 		if (req->flags & REQ_F_COMPLETE_INLINE) {
 			struct io_ring_ctx *ctx = req->ctx;
-			struct io_comp_state *cs = &ctx->submit_state.comp;
+			struct io_submit_state *state = &ctx->submit_state;
 
-			cs->reqs[cs->nr++] = req;
-			if (cs->nr == ARRAY_SIZE(cs->reqs))
+			state->compl_reqs[state->compl_nr++] = req;
+			if (state->compl_nr == ARRAY_SIZE(state->compl_reqs))
 				io_submit_flush_completions(ctx);
 		} else {
 			io_put_req(req);
@@ -6690,7 +6685,7 @@ static void io_submit_state_end(struct io_submit_state *state,
 {
 	if (state->link.head)
 		io_queue_sqe(state->link.head);
-	if (state->comp.nr)
+	if (state->compl_nr)
 		io_submit_flush_completions(ctx);
 	if (state->plug_started)
 		blk_finish_plug(&state->plug);
@@ -8633,19 +8628,17 @@ static void io_req_cache_free(struct list_head *list)
 
 static void io_req_caches_free(struct io_ring_ctx *ctx)
 {
-	struct io_submit_state *submit_state = &ctx->submit_state;
-	struct io_comp_state *cs = &ctx->submit_state.comp;
+	struct io_submit_state *state = &ctx->submit_state;
 
 	mutex_lock(&ctx->uring_lock);
 
-	if (submit_state->free_reqs) {
-		kmem_cache_free_bulk(req_cachep, submit_state->free_reqs,
-				     submit_state->reqs);
-		submit_state->free_reqs = 0;
+	if (state->free_reqs) {
+		kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
+		state->free_reqs = 0;
 	}
 
-	io_flush_cached_locked_reqs(ctx, cs);
-	io_req_cache_free(&cs->free_list);
+	io_flush_cached_locked_reqs(ctx, state);
+	io_req_cache_free(&state->free_list);
 	mutex_unlock(&ctx->uring_lock);
 }