[PATCH 6/7] io_uring: only initialize io_kiocb rsrc_nodes when needed

[Jens Axboe <axboe@kernel.dk>]

Add the empty node initializing to the preinit part of the io_kiocb
allocation, and reset them if they have been used.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c |  4 ++--
 io_uring/rsrc.h     | 10 ++++++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 603fd51d170f..0956401acd26 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -947,6 +947,8 @@ void io_req_defer_failed(struct io_kiocb *req, s32 res)
 static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
 {
 	req->ctx = ctx;
+	req->rsrc_nodes[IORING_RSRC_FILE] = rsrc_empty_node;
+	req->rsrc_nodes[IORING_RSRC_BUFFER] = rsrc_empty_node;
 	req->link = NULL;
 	req->async_data = NULL;
 	/* not necessary, but safer to zero */
@@ -2032,8 +2034,6 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
 	req->flags = (__force io_req_flags_t) sqe_flags;
 	req->cqe.user_data = READ_ONCE(sqe->user_data);
 	req->file = NULL;
-	req->rsrc_nodes[IORING_RSRC_FILE] = rsrc_empty_node;
-	req->rsrc_nodes[IORING_RSRC_BUFFER] = rsrc_empty_node;
 	req->task = current;
 	req->cancel_seq_set = false;
 
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 69d4111d5f07..d62d086331d2 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -86,8 +86,14 @@ static inline void io_put_rsrc_node(struct io_rsrc_node *node)
 
 static inline void io_req_put_rsrc_nodes(struct io_kiocb *req)
 {
-	io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_FILE]);
-	io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_BUFFER]);
+	if (req->rsrc_nodes[IORING_RSRC_FILE] != rsrc_empty_node) {
+		io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_FILE]);
+		req->rsrc_nodes[IORING_RSRC_FILE] = rsrc_empty_node;
+	}
+	if (req->rsrc_nodes[IORING_RSRC_BUFFER] != rsrc_empty_node) {
+		io_put_rsrc_node(req->rsrc_nodes[IORING_RSRC_BUFFER]);
+		req->rsrc_nodes[IORING_RSRC_BUFFER] = rsrc_empty_node;
+	}
 }
 
 static inline void io_req_assign_rsrc_node(struct io_kiocb *req,
-- 
2.45.2