[PATCH] io_uring/rsrc: avoid NULL check in io_put_rsrc_node()

From: Caleb Sander Mateos
Date: Sun Feb 16 2025 - 17:59:43 EST


Most callers of io_put_rsrc_node() already check that node is non-NULL:
- io_rsrc_data_free()
- io_sqe_buffer_register()
- io_reset_rsrc_node()
- io_req_put_rsrc_nodes() (REQ_F_BUF_NODE indicates non-NULL buf_node)

Only io_splice_cleanup() can call io_put_rsrc_node() with a NULL node.
So move the NULL check there.

Signed-off-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
---
io_uring/rsrc.h | 2 +-
io_uring/splice.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 190f7ee45de9..a6d883c62b22 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -81,11 +81,11 @@ static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data
}

static inline void io_put_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node)
{
lockdep_assert_held(&ctx->uring_lock);
- if (node && !--node->refs)
+ if (!--node->refs)
io_free_rsrc_node(ctx, node);
}

static inline bool io_reset_rsrc_node(struct io_ring_ctx *ctx,
struct io_rsrc_data *data, int index)
diff --git a/io_uring/splice.c b/io_uring/splice.c
index 5b84f1630611..7b89bd84d486 100644
--- a/io_uring/splice.c
+++ b/io_uring/splice.c
@@ -49,11 +49,12 @@ int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

void io_splice_cleanup(struct io_kiocb *req)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);

- io_put_rsrc_node(req->ctx, sp->rsrc_node);
+ if (sp->rsrc_node)
+ io_put_rsrc_node(req->ctx, sp->rsrc_node);
}

static struct file *io_splice_get_file(struct io_kiocb *req,
unsigned int issue_flags)
{
--
2.45.2