io_uring: separate ref_list from fixed_rsrc_data

Uplevel ref_list and make it common to all resources.  This is to
allow one common ref_list to be used for both files, and buffers
in upcoming patches.
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -227,8 +227,6 @@ struct fixed_rsrc_data {
 	struct fixed_rsrc_ref_node	*node;
 	struct percpu_ref		refs;
 	struct completion		done;
-	struct list_head		ref_list;
-	spinlock_t			lock;
 };
 
 struct io_buffer {
@@ -398,6 +396,8 @@ struct io_ring_ctx {
 
 	struct delayed_work		rsrc_put_work;
 	struct llist_head		rsrc_put_llist;
+	struct list_head		rsrc_ref_list;
+	spinlock_t			rsrc_ref_lock;
 
 	struct work_struct		exit_work;
 	struct io_restriction		restrictions;
@@ -1342,6 +1342,8 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	INIT_LIST_HEAD(&ctx->timeout_list);
 	spin_lock_init(&ctx->inflight_lock);
 	INIT_LIST_HEAD(&ctx->inflight_list);
+	spin_lock_init(&ctx->rsrc_ref_lock);
+	INIT_LIST_HEAD(&ctx->rsrc_ref_list);
 	INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
 	init_llist_head(&ctx->rsrc_put_llist);
 	return ctx;
@@ -7348,13 +7350,14 @@ static void io_rsrc_ref_kill(struct percpu_ref *ref)
 	complete(&data->done);
 }
 
-static void io_sqe_rsrc_set_node(struct fixed_rsrc_data *rsrc_data,
+static void io_sqe_rsrc_set_node(struct io_ring_ctx *ctx,
+				 struct fixed_rsrc_data *rsrc_data,
 				 struct fixed_rsrc_ref_node *ref_node)
 {
-	spin_lock_bh(&rsrc_data->lock);
+	spin_lock_bh(&ctx->rsrc_ref_lock);
 	rsrc_data->node = ref_node;
-	list_add_tail(&ref_node->node, &rsrc_data->ref_list);
-	spin_unlock_bh(&rsrc_data->lock);
+	list_add_tail(&ref_node->node, &ctx->rsrc_ref_list);
+	spin_unlock_bh(&ctx->rsrc_ref_lock);
 	percpu_ref_get(&rsrc_data->refs);
 }
 
@@ -7371,9 +7374,9 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 	if (!backup_node)
 		return -ENOMEM;
 
-	spin_lock_bh(&data->lock);
+	spin_lock_bh(&ctx->rsrc_ref_lock);
 	ref_node = data->node;
-	spin_unlock_bh(&data->lock);
+	spin_unlock_bh(&ctx->rsrc_ref_lock);
 	if (ref_node)
 		percpu_ref_kill(&ref_node->refs);
 
@@ -7389,7 +7392,7 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 		if (ret < 0) {
 			percpu_ref_resurrect(&data->refs);
 			reinit_completion(&data->done);
-			io_sqe_rsrc_set_node(data, backup_node);
+			io_sqe_rsrc_set_node(ctx, data, backup_node);
 			return ret;
 		}
 	} while (1);
@@ -7763,11 +7766,11 @@ static void io_rsrc_data_ref_zero(struct percpu_ref *ref)
 	data = ref_node->rsrc_data;
 	ctx = data->ctx;
 
-	spin_lock_bh(&data->lock);
+	spin_lock_bh(&ctx->rsrc_ref_lock);
 	ref_node->done = true;
 
-	while (!list_empty(&data->ref_list)) {
-		ref_node = list_first_entry(&data->ref_list,
+	while (!list_empty(&ctx->rsrc_ref_list)) {
+		ref_node = list_first_entry(&ctx->rsrc_ref_list,
 					struct fixed_rsrc_ref_node, node);
 		/* recycle ref nodes in order */
 		if (!ref_node->done)
@@ -7775,7 +7778,7 @@ static void io_rsrc_data_ref_zero(struct percpu_ref *ref)
 		list_del(&ref_node->node);
 		first_add |= llist_add(&ref_node->llist, &ctx->rsrc_put_llist);
 	}
-	spin_unlock_bh(&data->lock);
+	spin_unlock_bh(&ctx->rsrc_ref_lock);
 
 	if (percpu_ref_is_dying(&data->refs))
 		delay = 0;
@@ -7836,8 +7839,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 		return -ENOMEM;
 	file_data->ctx = ctx;
 	init_completion(&file_data->done);
-	INIT_LIST_HEAD(&file_data->ref_list);
-	spin_lock_init(&file_data->lock);
 
 	nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
 	file_data->table = kcalloc(nr_tables, sizeof(*file_data->table),
@@ -7898,7 +7899,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
 		return -ENOMEM;
 	}
 
-	io_sqe_rsrc_set_node(file_data, ref_node);
+	io_sqe_rsrc_set_node(ctx, file_data, ref_node);
 	return ret;
 out_fput:
 	for (i = 0; i < ctx->nr_user_files; i++) {
@@ -8059,7 +8060,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 
 	if (needs_switch) {
 		percpu_ref_kill(&data->node->refs);
-		io_sqe_rsrc_set_node(data, ref_node);
+		io_sqe_rsrc_set_node(ctx, data, ref_node);
 	} else
 		destroy_fixed_rsrc_ref_node(ref_node);