[PATCH 1/4] io_uring: add a helper for setting a ref node

Pavel Begunkov
2020-12-30T21:38:49Z

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>
---
fs/io_uring.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index eb4620ff638e..6372aba8d0c2 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7231,6 +7231,16 @@ 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;
@@ -7758,11 +7768,7 @@ 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++) {
@@ -7918,11 +7924,7 @@ 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);

--
2.24.0