io_uring/io_uring.c:2932:40: error: variable 'prev' set but not used

From: kernel test robot
Date: Thu Mar 02 2023 - 08:47:22 EST


Hi Jens,

First bad commit (maybe != root cause):

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: ee3f96b164688dae21e2466a57f2e806b64e8a37
commit: ed29b0b4fd835b058ddd151c49d021e28d631ee6 io_uring: move to separate directory
date: 7 months ago
config: x86_64-sof-customedconfig-edison-defconfig (https://download.01.org/0day-ci/archive/20230302/202303022133.y7FMQVJo-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed29b0b4fd835b058ddd151c49d021e28d631ee6
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout ed29b0b4fd835b058ddd151c49d021e28d631ee6
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=x86_64 olddefconfig
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202303022133.y7FMQVJo-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>):

io_uring/io_uring.c: In function '__io_submit_flush_completions':
>> io_uring/io_uring.c:2932:40: error: variable 'prev' set but not used [-Werror=unused-but-set-variable]
2932 | struct io_wq_work_node *node, *prev;
| ^~~~
cc1: all warnings being treated as errors


vim +/prev +2932 io_uring/io_uring.c

7a743e225b2a9d fs/io_uring.c Pavel Begunkov 2020-03-03 2928
c450178d9be9dc fs/io_uring.c Pavel Begunkov 2021-09-08 2929 static void __io_submit_flush_completions(struct io_ring_ctx *ctx)
a141dd896f544d fs/io_uring.c Jens Axboe 2021-08-12 2930 __must_hold(&ctx->uring_lock)
905c172f32c56f fs/io_uring.c Pavel Begunkov 2021-02-10 2931 {
6f33b0bc4ea43f fs/io_uring.c Pavel Begunkov 2021-09-24 @2932 struct io_wq_work_node *node, *prev;
cd0ca2e048dc0d fs/io_uring.c Pavel Begunkov 2021-08-09 2933 struct io_submit_state *state = &ctx->submit_state;
905c172f32c56f fs/io_uring.c Pavel Begunkov 2021-02-10 2934
3d4aeb9f98058c fs/io_uring.c Pavel Begunkov 2021-11-10 2935 if (state->flush_cqes) {
79ebeaee8a21a0 fs/io_uring.c Jens Axboe 2021-08-10 2936 spin_lock(&ctx->completion_lock);
6f33b0bc4ea43f fs/io_uring.c Pavel Begunkov 2021-09-24 2937 wq_list_for_each(node, prev, &state->compl_reqs) {
6f33b0bc4ea43f fs/io_uring.c Pavel Begunkov 2021-09-24 2938 struct io_kiocb *req = container_of(node, struct io_kiocb,
6f33b0bc4ea43f fs/io_uring.c Pavel Begunkov 2021-09-24 2939 comp_list);
5182ed2e332e8e fs/io_uring.c Pavel Begunkov 2021-06-26 2940
f43de1f88841d5 fs/io_uring.c Pavel Begunkov 2022-06-15 2941 if (!(req->flags & REQ_F_CQE_SKIP))
91ef75a7db0d08 fs/io_uring.c Pavel Begunkov 2022-06-15 2942 __io_fill_cqe_req(ctx, req);
905c172f32c56f fs/io_uring.c Pavel Begunkov 2021-02-10 2943 }
3d4aeb9f98058c fs/io_uring.c Pavel Begunkov 2021-11-10 2944
905c172f32c56f fs/io_uring.c Pavel Begunkov 2021-02-10 2945 io_commit_cqring(ctx);
79ebeaee8a21a0 fs/io_uring.c Jens Axboe 2021-08-10 2946 spin_unlock(&ctx->completion_lock);
905c172f32c56f fs/io_uring.c Pavel Begunkov 2021-02-10 2947 io_cqring_ev_posted(ctx);
3d4aeb9f98058c fs/io_uring.c Pavel Begunkov 2021-11-10 2948 state->flush_cqes = false;
3d4aeb9f98058c fs/io_uring.c Pavel Begunkov 2021-11-10 2949 }
5182ed2e332e8e fs/io_uring.c Pavel Begunkov 2021-06-26 2950
1cce17aca621c3 fs/io_uring.c Pavel Begunkov 2021-09-24 2951 io_free_batch_list(ctx, state->compl_reqs.first);
6f33b0bc4ea43f fs/io_uring.c Pavel Begunkov 2021-09-24 2952 INIT_WQ_LIST(&state->compl_reqs);
7a743e225b2a9d fs/io_uring.c Pavel Begunkov 2020-03-03 2953 }
7a743e225b2a9d fs/io_uring.c Pavel Begunkov 2020-03-03 2954

:::::: The code at line 2932 was first introduced by commit
:::::: 6f33b0bc4ea43f5c5ce7b7c9ab66051f80837862 io_uring: use slist for completion batching

:::::: TO: Pavel Begunkov <asml.silence@xxxxxxxxx>
:::::: CC: Jens Axboe <axboe@xxxxxxxxx>

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