EXT4-fs error (device loop3): ext4_group_add_blocks:5609: comm syz-executor.3: bit already cleared for block 200
EXT4-fs error (device loop3): ext4_group_add_blocks:5609: comm syz-executor.3: bit already cleared for block 201
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BUG: KCSAN: data-race in __blk_mq_sched_dispatch_requests / blk_mq_run_hw_queue

write to 0xffff8881026c2810 of 8 bytes by task 2975 on cpu 1:
 INIT_LIST_HEAD include/linux/list.h:36 [inline]
 list_splice_init include/linux/list.h:483 [inline]
 __blk_mq_sched_dispatch_requests+0x16a/0x2a0 block/blk-mq-sched.c:289
 blk_mq_sched_dispatch_requests+0x8f/0xf0 block/blk-mq-sched.c:341
 __blk_mq_run_hw_queue+0xee/0x1c0 block/blk-mq.c:1532
 __blk_mq_delay_run_hw_queue+0x17d/0x330 block/blk-mq.c:1609
 blk_mq_run_hw_queue+0x231/0x260 block/blk-mq.c:1662
 blk_mq_run_hw_queues block/blk-mq.c:1680 [inline]
 blk_mq_requeue_work+0x423/0x490 block/blk-mq.c:816
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
 worker_thread+0x635/0xb90 kernel/workqueue.c:2418
 kthread+0x1fa/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff8881026c2810 of 8 bytes by task 15902 on cpu 0:
 list_empty_careful include/linux/list.h:319 [inline]
 blk_mq_hctx_has_pending block/blk-mq.c:72 [inline]
 blk_mq_run_hw_queue+0x12e/0x260 block/blk-mq.c:1658
 blk_mq_submit_bio+0xd0d/0x1020 block/blk-mq.c:2205
 __submit_bio_noacct_mq block/blk-core.c:1026 [inline]
 submit_bio_noacct+0x77d/0x930 block/blk-core.c:1059
 submit_bio+0x1f3/0x360 block/blk-core.c:1129
 submit_bh_wbc+0x38c/0x3d0 fs/buffer.c:3054
 submit_bh fs/buffer.c:3060 [inline]
 __sync_dirty_buffer+0x12c/0x1d0 fs/buffer.c:3155
 ext4_commit_super+0x561/0x600 fs/ext4/super.c:5556
 save_error_info fs/ext4/super.c:532 [inline]
 __ext4_error+0x118/0x270 fs/ext4/super.c:736
 ext4_group_add_blocks+0x532/0xc80 fs/ext4/mballoc.c:5608
 ext4_group_extend_no_check+0x1e1/0x350 fs/ext4/resize.c:1725
 ext4_group_extend+0x30a/0x340 fs/ext4/resize.c:1818
 __ext4_ioctl fs/ext4/ioctl.c:935 [inline]
 ext4_ioctl+0x163c/0x3540 fs/ext4/ioctl.c:1319
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 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: 0 PID: 15902 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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