==================================================================
BUG: KCSAN: data-race in dd_has_work / dd_insert_request

write to 0xffff8881026ca688 of 8 bytes by task 3289 on cpu 1:
 __list_add include/linux/list.h:72 [inline]
 list_add_tail include/linux/list.h:102 [inline]
 dd_insert_request+0x415/0x550 block/mq-deadline.c:758
 dd_insert_requests+0xfc/0x140 block/mq-deadline.c:777
 blk_mq_sched_insert_requests+0xc0/0x2a0 block/blk-mq-sched.c:477
 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2597
 blk_mq_flush_plug_list+0x2ea/0x340 block/blk-mq.c:2639
 __blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1240
 blk_finish_plug+0x44/0x60 block/blk-core.c:1264
 __iomap_dio_rw+0xc50/0xf80 fs/iomap/direct-io.c:599
 iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:681
 ext4_dio_read_iter fs/ext4/file.c:79 [inline]
 ext4_file_read_iter+0x22b/0x2a0 fs/ext4/file.c:130
 call_read_iter include/linux/fs.h:2044 [inline]
 generic_file_splice_read+0x1de/0x2c0 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2ac/0x660 fs/splice.c:870
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881026ca688 of 8 bytes by task 3278 on cpu 0:
 list_empty_careful include/linux/list.h:329 [inline]
 dd_has_work_for_prio block/mq-deadline.c:836 [inline]
 dd_has_work+0x144/0x260 block/mq-deadline.c:846
 blk_mq_sched_has_work block/blk-mq-sched.h:82 [inline]
 blk_mq_hctx_has_pending block/blk-mq.c:103 [inline]
 blk_mq_run_hw_queue+0x255/0x310 block/blk-mq.c:2097
 blk_mq_sched_insert_requests+0x1cb/0x2a0 block/blk-mq-sched.c:493
 blk_mq_dispatch_plug_list+0x1e9/0x2c0 block/blk-mq.c:2597
 blk_mq_flush_plug_list+0x2ea/0x340 block/blk-mq.c:2639
 __blk_flush_plug+0x25a/0x2b0 block/blk-core.c:1240
 blk_finish_plug+0x44/0x60 block/blk-core.c:1264
 ext4_writepages+0x172d/0x1d00 fs/ext4/inode.c:2855
 do_writepages+0x1db/0x350 mm/page-writeback.c:2352
 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 filemap_write_and_wait_range+0xbf/0x2e0 mm/filemap.c:673
 __iomap_dio_rw+0x514/0xf80 fs/iomap/direct-io.c:562
 iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:681
 ext4_dio_read_iter fs/ext4/file.c:79 [inline]
 ext4_file_read_iter+0x22b/0x2a0 fs/ext4/file.c:130
 call_read_iter include/linux/fs.h:2044 [inline]
 generic_file_splice_read+0x1de/0x2c0 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2ac/0x660 fs/splice.c:870
 do_splice_direct+0xfb/0x180 fs/splice.c:979
 do_sendfile+0x3ad/0x900 fs/read_write.c:1246
 __do_sys_sendfile64 fs/read_write.c:1311 [inline]
 __se_sys_sendfile64 fs/read_write.c:1297 [inline]
 __x64_sys_sendfile64+0x10c/0x150 fs/read_write.c:1297
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffff8881026ca680 -> 0xffff888101150388

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3278 Comm: syz-executor.5 Not tainted 5.18.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
syz-executor.5 (3278) used greatest stack depth: 10568 bytes left