[PATCH v2 1/2] io_uring: Extract io_file_get_fixed_node helper

[Daniele Di Proietto <daniele.di.proietto@gmail.com>]

This has two users and it's about to have a third in a future commit.

Reading io_slot_flags() and io_slot_file() outside of
io_ring_submit_lock() should be fine after a reference has been
acquired, as those are immutable.

Signed-off-by: Daniele Di Proietto <daniele.di.proietto@gmail.com>
---
 io_uring/io_uring.c | 20 ++++++++++++++++----
 io_uring/io_uring.h |  2 ++
 io_uring/splice.c   |  6 +-----
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 9a37035e76c0..726245a28b87 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1553,22 +1553,34 @@ void io_wq_submit_work(struct io_wq_work *work)
 		io_req_task_queue_fail(req, ret);
 }
 
-inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
-				      unsigned int issue_flags)
+inline struct io_rsrc_node *io_file_get_fixed_node(struct io_kiocb *req, int fd,
+						   unsigned int issue_flags)
 {
 	struct io_ring_ctx *ctx = req->ctx;
 	struct io_rsrc_node *node;
-	struct file *file = NULL;
 
 	io_ring_submit_lock(ctx, issue_flags);
 	node = io_rsrc_node_lookup(&ctx->file_table.data, fd);
 	if (node) {
 		node->refs++;
+	}
+	io_ring_submit_unlock(ctx, issue_flags);
+
+	return node;
+}
+
+inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
+				      unsigned int issue_flags)
+{
+	struct io_rsrc_node *node;
+	struct file *file = NULL;
+
+	node = io_file_get_fixed_node(req, fd, issue_flags);
+	if (node) {
 		req->file_node = node;
 		req->flags |= io_slot_flags(node);
 		file = io_slot_file(node);
 	}
-	io_ring_submit_unlock(ctx, issue_flags);
 	return file;
 }
 
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 0fa844faf287..1ed44201fa77 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -170,6 +170,8 @@ void __io_commit_cqring_flush(struct io_ring_ctx *ctx);
 
 unsigned io_linked_nr(struct io_kiocb *req);
 void io_req_track_inflight(struct io_kiocb *req);
+struct io_rsrc_node *io_file_get_fixed_node(struct io_kiocb *req, int fd,
+					    unsigned int issue_flags);
 struct file *io_file_get_normal(struct io_kiocb *req, int fd);
 struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
 			       unsigned issue_flags);
diff --git a/io_uring/splice.c b/io_uring/splice.c
index e81ebbb91925..3c5021a46e79 100644
--- a/io_uring/splice.c
+++ b/io_uring/splice.c
@@ -60,22 +60,18 @@ static struct file *io_splice_get_file(struct io_kiocb *req,
 				       unsigned int issue_flags)
 {
 	struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
-	struct io_ring_ctx *ctx = req->ctx;
 	struct io_rsrc_node *node;
 	struct file *file = NULL;
 
 	if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
 		return io_file_get_normal(req, sp->splice_fd_in);
 
-	io_ring_submit_lock(ctx, issue_flags);
-	node = io_rsrc_node_lookup(&ctx->file_table.data, sp->splice_fd_in);
+	node = io_file_get_fixed_node(req, sp->splice_fd_in, issue_flags);
 	if (node) {
-		node->refs++;
 		sp->rsrc_node = node;
 		file = io_slot_file(node);
 		req->flags |= REQ_F_NEED_CLEANUP;
 	}
-	io_ring_submit_unlock(ctx, issue_flags);
 	return file;
 }
 
-- 
2.43.0