io_uring: add a helper for setting a ref node

commit 1642b4450d20e31439c80c28256c8eee08684698 upstream.

Setting a new reference node to a file data is not trivial, don't repeat
it, add and use a helper.

Cc: stable@vger.kernel.org # 5.6+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 523bcc2..96fcc1b 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6991,6 +6991,16 @@ static void io_file_ref_kill(struct percpu_ref *ref)
        complete(&data->done);
 }
 
+static void io_sqe_files_set_node(struct fixed_file_data *file_data,
+                                 struct fixed_file_ref_node *ref_node)
+{
+       spin_lock_bh(&file_data->lock);
+       file_data->node = ref_node;
+       list_add_tail(&ref_node->node, &file_data->ref_list);
+       spin_unlock_bh(&file_data->lock);
+       percpu_ref_get(&file_data->refs);
+}
+
 static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
 {
        struct fixed_file_data *data = ctx->file_data;
@@ -7519,11 +7529,7 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
                return PTR_ERR(ref_node);
        }
 
-       file_data->node = ref_node;
-       spin_lock_bh(&file_data->lock);
-       list_add_tail(&ref_node->node, &file_data->ref_list);
-       spin_unlock_bh(&file_data->lock);
-       percpu_ref_get(&file_data->refs);
+       io_sqe_files_set_node(file_data, ref_node);
        return ret;
 out_fput:
        for (i = 0; i < ctx->nr_user_files; i++) {
@@ -7679,11 +7685,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 
        if (needs_switch) {
                percpu_ref_kill(&data->node->refs);
-               spin_lock_bh(&data->lock);
-               list_add_tail(&ref_node->node, &data->ref_list);
-               data->node = ref_node;
-               spin_unlock_bh(&data->lock);
-               percpu_ref_get(&ctx->file_data->refs);
+               io_sqe_files_set_node(data, ref_node);
        } else
                destroy_fixed_file_ref_node(ref_node);