================================================================== BUG: KCSAN: data-race in dd_has_work / dd_insert_requests write to 0xffff888101fc9818 of 8 bytes by task 8590 on cpu 0: __list_add include/linux/list.h:70 [inline] list_add_tail include/linux/list.h:100 [inline] dd_insert_request block/mq-deadline.c:521 [inline] dd_insert_requests+0x38e/0x4f0 block/mq-deadline.c:537 blk_mq_sched_insert_requests+0xc3/0x210 block/blk-mq-sched.c:486 blk_mq_flush_plug_list+0x2f5/0x400 block/blk-mq.c:1915 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1755 blk_finish_plug+0x44/0x60 block/blk-core.c:1772 read_pages+0x3aa/0x6e0 mm/readahead.c:150 page_cache_ra_unbounded+0x46c/0x4c0 mm/readahead.c:238 ondemand_readahead+0x560/0x780 mm/readahead.c:267 page_cache_sync_ra+0x18f/0x1a0 mm/readahead.c:577 page_cache_sync_readahead include/linux/pagemap.h:839 [inline] generic_file_buffered_read_get_pages+0x234/0xaf0 mm/filemap.c:2365 generic_file_buffered_read+0x26e/0x9c0 mm/filemap.c:2485 generic_file_read_iter+0x82/0x3e0 mm/filemap.c:2637 ext4_file_read_iter+0x2e0/0x430 fs/ext4/file.c:74 call_read_iter include/linux/fs.h:1895 [inline] generic_file_splice_read+0x22a/0x310 fs/splice.c:311 do_splice_to fs/splice.c:788 [inline] splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x5e0/0xcf0 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff888101fc9818 of 8 bytes by task 8582 on cpu 1: list_empty_careful include/linux/list.h:319 [inline] dd_has_work+0xc3/0x110 block/mq-deadline.c:589 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:135 [inline] blk_mq_do_dispatch_sched+0x138/0x610 block/blk-mq-sched.c:199 __blk_mq_sched_dispatch_requests+0x1fd/0x2a0 block/blk-mq-sched.c:310 blk_mq_sched_dispatch_requests+0x9f/0x110 block/blk-mq-sched.c:341 __blk_mq_run_hw_queue block/blk-mq.c:1515 [inline] __blk_mq_delay_run_hw_queue+0x207/0x420 block/blk-mq.c:1592 blk_mq_run_hw_queue+0x231/0x260 block/blk-mq.c:1645 blk_mq_sched_insert_requests+0x144/0x210 block/blk-mq-sched.c:501 blk_mq_flush_plug_list+0x2f5/0x400 block/blk-mq.c:1915 blk_flush_plug_list+0x235/0x260 block/blk-core.c:1755 blk_finish_plug+0x44/0x60 block/blk-core.c:1772 __iomap_dio_rw+0x60f/0x9b0 fs/iomap/direct-io.c:539 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:605 ext4_dio_write_iter fs/ext4/file.c:552 [inline] ext4_file_write_iter+0xe6a/0x1060 fs/ext4/file.c:662 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4c0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x41a/0x770 fs/splice.c:686 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x80/0xa0 fs/splice.c:933 splice_direct_to_actor+0x345/0x650 fs/splice.c:888 do_splice_direct+0xf5/0x170 fs/splice.c:976 do_sendfile+0x5e0/0xcf0 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 8582 Comm: syz-executor.1 Not tainted 5.11.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================