Commit fa780334 authored by Jens Axboe's avatar Jens Axboe
Browse files

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: default avatarVincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: default avatarVincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 03b3d6be

io_uring/io_uring.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

io_uring/slist.h

+4 −1
Original line number Diff line number Diff line
@@ -3,6 +3,9 @@ 


#include <linux/io_uring_types.h>



#define __wq_list_for_each(pos, head)				\

	for (pos = (head)->first; pos; pos = (pos)->next)



#define wq_list_for_each(pos, prv, head)			\

	for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)