tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 84196390620ac0e5070ae36af84c137c6216a7dc commit: a1ab7b35db8f262cd74edff62b47b4d90f84f997 io_uring: move req link into submit_state date: 5 weeks ago config: mips-randconfig-r023-20210322 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 14696baaf4c43fe53f738bc292bbe169eed93d5d) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout a1ab7b35db8f262cd74edff62b47b4d90f84f997 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) ^ 1 warning generated. vim +/io_submit_sqes +6897 fs/io_uring.c 709b302faddfac Pavel Begunkov 2020-04-08 6896 0f2122045b9462 Jens Axboe 2020-09-13 @6897 static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) 6c271ce2f1d572 Jens Axboe 2019-01-10 6898 { 46c4e16a8625f7 Pavel Begunkov 2021-02-18 6899 int submitted = 0; 6c271ce2f1d572 Jens Axboe 2019-01-10 6900 c4a2ed72c9a615 Jens Axboe 2019-11-21 6901 /* if we have a backlog and couldn't flush it all, return BUSY */ ad3eb2c89fb24d Jens Axboe 2019-12-18 6902 if (test_bit(0, &ctx->sq_check_overflow)) { 6c503150ae33ee Pavel Begunkov 2021-01-04 6903 if (!__io_cqring_overflow_flush(ctx, false, NULL, NULL)) 1d7bb1d50fb4dc Jens Axboe 2019-11-06 6904 return -EBUSY; ad3eb2c89fb24d Jens Axboe 2019-12-18 6905 } 6c271ce2f1d572 Jens Axboe 2019-01-10 6906 ee7d46d9db19de Pavel Begunkov 2019-12-30 6907 /* make sure SQ entry isn't read before tail */ ee7d46d9db19de Pavel Begunkov 2019-12-30 6908 nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx)); 9ef4f124894b7b Pavel Begunkov 2019-12-30 6909 2b85edfc0c90ef Pavel Begunkov 2019-12-28 6910 if (!percpu_ref_tryget_many(&ctx->refs, nr)) 2b85edfc0c90ef Pavel Begunkov 2019-12-28 6911 return -EAGAIN; 6c271ce2f1d572 Jens Axboe 2019-01-10 6912 d8a6df10aac9f2 Jens Axboe 2020-10-15 6913 percpu_counter_add(&current->io_uring->inflight, nr); faf7b51c06973f Jens Axboe 2020-10-07 6914 refcount_add(nr, &current->usage); ba88ff112bdfde Pavel Begunkov 2021-02-10 6915 io_submit_state_start(&ctx->submit_state, nr); b14cca0c84c760 Pavel Begunkov 2020-01-17 6916 46c4e16a8625f7 Pavel Begunkov 2021-02-18 6917 while (submitted < nr) { 3529d8c2b353e6 Jens Axboe 2019-12-19 6918 const struct io_uring_sqe *sqe; 196be95cd55720 Pavel Begunkov 2019-11-07 6919 struct io_kiocb *req; fb5ccc98782f65 Pavel Begunkov 2019-10-25 6920 258b29a93bfe74 Pavel Begunkov 2021-02-10 6921 req = io_alloc_req(ctx); 196be95cd55720 Pavel Begunkov 2019-11-07 6922 if (unlikely(!req)) { 196be95cd55720 Pavel Begunkov 2019-11-07 6923 if (!submitted) 196be95cd55720 Pavel Begunkov 2019-11-07 6924 submitted = -EAGAIN; fb5ccc98782f65 Pavel Begunkov 2019-10-25 6925 break; 196be95cd55720 Pavel Begunkov 2019-11-07 6926 } 4fccfcbb733794 Pavel Begunkov 2021-02-12 6927 sqe = io_get_sqe(ctx); 4fccfcbb733794 Pavel Begunkov 2021-02-12 6928 if (unlikely(!sqe)) { 4fccfcbb733794 Pavel Begunkov 2021-02-12 6929 kmem_cache_free(req_cachep, req); 4fccfcbb733794 Pavel Begunkov 2021-02-12 6930 break; 4fccfcbb733794 Pavel Begunkov 2021-02-12 6931 } d3656344fea033 Jens Axboe 2019-12-18 6932 /* will complete beyond this point, count as submitted */ d3656344fea033 Jens Axboe 2019-12-18 6933 submitted++; a1ab7b35db8f26 Pavel Begunkov 2021-02-18 6934 if (io_submit_sqe(ctx, req, sqe)) fb5ccc98782f65 Pavel Begunkov 2019-10-25 6935 break; 196be95cd55720 Pavel Begunkov 2019-11-07 6936 } fb5ccc98782f65 Pavel Begunkov 2019-10-25 6937 9466f43741bc08 Pavel Begunkov 2020-01-25 6938 if (unlikely(submitted != nr)) { 9466f43741bc08 Pavel Begunkov 2020-01-25 6939 int ref_used = (submitted == -EAGAIN) ? 0 : submitted; d8a6df10aac9f2 Jens Axboe 2020-10-15 6940 struct io_uring_task *tctx = current->io_uring; d8a6df10aac9f2 Jens Axboe 2020-10-15 6941 int unused = nr - ref_used; 9466f43741bc08 Pavel Begunkov 2020-01-25 6942 d8a6df10aac9f2 Jens Axboe 2020-10-15 6943 percpu_ref_put_many(&ctx->refs, unused); d8a6df10aac9f2 Jens Axboe 2020-10-15 6944 percpu_counter_sub(&tctx->inflight, unused); d8a6df10aac9f2 Jens Axboe 2020-10-15 6945 put_task_struct_many(current, unused); 9466f43741bc08 Pavel Begunkov 2020-01-25 6946 } 6c271ce2f1d572 Jens Axboe 2019-01-10 6947 a1ab7b35db8f26 Pavel Begunkov 2021-02-18 6948 io_submit_state_end(&ctx->submit_state, ctx); ae9428ca61271b Pavel Begunkov 2019-11-06 6949 /* Commit SQ ring head once we've consumed and submitted all SQEs */ ae9428ca61271b Pavel Begunkov 2019-11-06 6950 io_commit_sqring(ctx); ae9428ca61271b Pavel Begunkov 2019-11-06 6951 6c271ce2f1d572 Jens Axboe 2019-01-10 6952 return submitted; 6c271ce2f1d572 Jens Axboe 2019-01-10 6953 } 6c271ce2f1d572 Jens Axboe 2019-01-10 6954 :::::: The code at line 6897 was first introduced by commit :::::: 0f2122045b946241a9e549c2a76cea54fa58a7ff io_uring: don't rely on weak ->files references :::::: TO: Jens Axboe <axboe(a)kernel.dk&gt; :::::: CC: Jens Axboe <axboe(a)kernel.dk&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org