io_uring: silence variable ‘prev’ set but not used warning

If io_uring.o is built with W=1, it triggers a warning:

io_uring/io_uring.c: In function ‘__io_submit_flush_completions’:
io_uring/io_uring.c:1502:40: warning: variable ‘prev’ set but not used [-Wunused-but-set-variable]
 1502 |         struct io_wq_work_node *node, *prev;
      |                                        ^~~~

which is due to the wq_list_for_each() iterator always keeping a 'prev'
variable. Most users need this to remove an entry from a list, for
example, but __io_submit_flush_completions() never does that.

Add a basic helper that doesn't track prev instead, and use that in
that function.

Reported-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 2 insertions, 2 deletions

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index fd1cc35a1c00..722624b6d0dc 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1499,14 +1499,14 @@ void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node)
 static void __io_submit_flush_completions(struct io_ring_ctx *ctx)
 	__must_hold(&ctx->uring_lock)
 {
-	struct io_wq_work_node *node, *prev;
 	struct io_submit_state *state = &ctx->submit_state;
+	struct io_wq_work_node *node;
 
 	__io_cq_lock(ctx);
 	/* must come first to preserve CQE ordering in failure cases */
 	if (state->cqes_count)
 		__io_flush_post_cqes(ctx);
-	wq_list_for_each(node, prev, &state->compl_reqs) {
+	__wq_list_for_each(node, &state->compl_reqs) {
 		struct io_kiocb *req = container_of(node, struct io_kiocb,
 					    comp_list);