[PATCH v3 06/13] io_uring: generalize fixed_file_ref_node functionality

[Bijan Mottahedeh <bijan.mottahedeh@xxxxxxxxxx>]

Split alloc_fixed_file_ref_node into resource generic/specific parts,
rename destroy_fixed_file_ref_node, and factor out fixed_file_ref_node
switching, to be be leveraged by fixed buffers.

Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@xxxxxxxxxx>
---
 fs/io_uring.c | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 28e178b..e23f67f 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7672,7 +7672,7 @@ static void io_rsrc_data_ref_zero(struct percpu_ref *ref)
 		queue_delayed_work(system_wq, &ctx->rsrc_put_work, delay);
 }
 
-static struct fixed_rsrc_ref_node *alloc_fixed_file_ref_node(
+static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node(
 			struct io_ring_ctx *ctx)
 {
 	struct fixed_rsrc_ref_node *ref_node;
@@ -7688,9 +7688,21 @@ static struct fixed_rsrc_ref_node *alloc_fixed_file_ref_node(
 	}
 	INIT_LIST_HEAD(&ref_node->node);
 	INIT_LIST_HEAD(&ref_node->rsrc_list);
+	ref_node->done = false;
+	return ref_node;
+}
+
+static struct fixed_rsrc_ref_node *alloc_fixed_file_ref_node(
+			struct io_ring_ctx *ctx)
+{
+	struct fixed_rsrc_ref_node *ref_node;
+
+	ref_node = alloc_fixed_rsrc_ref_node(ctx);
+	if (!ref_node)
+		return NULL;
+
 	ref_node->rsrc_data = ctx->file_data;
 	ref_node->rsrc_put = io_ring_file_put;
-	ref_node->done = false;
 	return ref_node;
 }
 
@@ -7870,6 +7882,17 @@ static inline int io_queue_file_removal(struct fixed_rsrc_data *data,
 	return io_queue_rsrc_removal(data, (void *)file);
 }
 
+static void switch_fixed_rsrc_ref_node(struct fixed_rsrc_ref_node *ref_node,
+				       struct fixed_rsrc_data *data,
+				       struct io_ring_ctx *ctx)
+{
+	percpu_ref_kill(&data->node->refs);
+	spin_lock_bh(&ctx->rsrc_ref_lock);
+	list_add_tail(&ref_node->node, &ctx->rsrc_ref_list);
+	data->node = ref_node;
+	spin_unlock_bh(&ctx->rsrc_ref_lock);
+}
+
 static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 				 struct io_uring_rsrc_update *up,
 				 unsigned nr_args)
@@ -7946,11 +7969,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
 	}
 
 	if (needs_switch) {
-		percpu_ref_kill(&data->node->refs);
-		spin_lock_bh(&ctx->rsrc_ref_lock);
-		list_add_tail(&ref_node->node, &ctx->rsrc_ref_list);
-		data->node = ref_node;
-		spin_unlock_bh(&ctx->rsrc_ref_lock);
+		switch_fixed_rsrc_ref_node(ref_node, data, ctx);
 		percpu_ref_get(&ctx->file_data->refs);
 	} else
 		destroy_fixed_rsrc_ref_node(ref_node);
-- 
1.8.3.1