================================================================== BUG: KCSAN: data-race in dd_has_work / dd_insert_requests write to 0xffff8881038611a8 of 8 bytes by task 5364 on cpu 1: __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_request+0x22c/0x280 block/blk-mq-sched.c:458 blk_mq_submit_bio+0x868/0x1000 block/blk-mq.c:2216 __submit_bio_noacct_mq block/blk-core.c:1028 [inline] submit_bio_noacct+0x75d/0x910 block/blk-core.c:1061 submit_bio+0x1f3/0x350 block/blk-core.c:1131 submit_bh_wbc+0x392/0x3d0 fs/buffer.c:3054 submit_bh fs/buffer.c:3060 [inline] __sync_dirty_buffer+0x12c/0x1d0 fs/buffer.c:3155 sync_dirty_buffer+0x16/0x20 fs/buffer.c:3168 ext4_write_inode+0x28b/0x390 fs/ext4/inode.c:5241 write_inode+0x8c/0x1f0 fs/fs-writeback.c:1320 __writeback_single_inode+0x2a7/0x500 fs/fs-writeback.c:1518 writeback_single_inode+0x126/0x580 fs/fs-writeback.c:1572 sync_inode fs/fs-writeback.c:2604 [inline] sync_inode_metadata+0x52/0x70 fs/fs-writeback.c:2624 ext4_fsync_nojournal fs/ext4/fsync.c:92 [inline] ext4_sync_file+0x359/0x6e0 fs/ext4/fsync.c:170 vfs_fsync_range+0x107/0x120 fs/sync.c:200 generic_write_sync include/linux/fs.h:2737 [inline] ext4_buffered_write_iter+0x384/0x3d0 fs/ext4/file.c:278 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503 call_write_iter include/linux/fs.h:1901 [inline] do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740 do_iter_write+0x112/0x4b0 fs/read_write.c:866 vfs_iter_write+0x4c/0x70 fs/read_write.c:907 iter_file_splice_write+0x42a/0x780 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+0x5db/0xca0 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 0xffff8881038611a8 of 8 bytes by task 2198 on cpu 0: list_empty_careful include/linux/list.h:319 [inline] dd_has_work+0xfe/0x110 block/mq-deadline.c:590 __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+0x8f/0xf0 block/blk-mq-sched.c:341 __blk_mq_run_hw_queue block/blk-mq.c:1515 [inline] blk_mq_run_work_fn+0xb3/0x130 block/blk-mq.c:1793 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275 worker_thread+0x64a/0xaa0 kernel/workqueue.c:2421 kthread+0x1fd/0x220 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 2198 Comm: kworker/0:1H Not tainted 5.11.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: kblockd blk_mq_run_work_fn ==================================================================