loop4: detected capacity change from 270 to 0
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BUG: KCSAN: data-race in wb_timer_fn / wbt_inflight_cb

write to 0xffff888141fb9e04 of 4 bytes by interrupt on cpu 0:
 calc_wb_limits block/blk-wbt.c:304 [inline]
 scale_up block/blk-wbt.c:313 [inline]
 wb_timer_fn+0x54a/0xa00 block/blk-wbt.c:374
 blk_stat_timer_fn+0x3f4/0x410 block/blk-stat.c:99
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1417
 expire_timers+0x116/0x260 kernel/time/timer.c:1462
 __run_timers+0x338/0x3d0 kernel/time/timer.c:1731
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1744
 __do_softirq+0x13c/0x2c3 kernel/softirq.c:343
 run_ksoftirqd+0x13/0x20 kernel/softirq.c:650
 smpboot_thread_fn+0x34f/0x520 kernel/smpboot.c:165
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff888141fb9e04 of 4 bytes by task 23507 on cpu 1:
 rwb_enabled block/blk-wbt.c:80 [inline]
 get_limit block/blk-wbt.c:458 [inline]
 wbt_inflight_cb+0x3f/0x220 block/blk-wbt.c:495
 rq_qos_wait+0xac/0x210 block/blk-rq-qos.c:266
 __wbt_wait block/blk-wbt.c:518 [inline]
 wbt_wait+0x1bb/0x2b0 block/blk-wbt.c:583
 __rq_qos_throttle+0x39/0x70 block/blk-rq-qos.c:72
 rq_qos_throttle block/blk-rq-qos.h:182 [inline]
 blk_mq_submit_bio+0x229/0x1000 block/blk-mq.c:2158
 __submit_bio_noacct_mq block/blk-core.c:1027 [inline]
 submit_bio_noacct+0x75d/0x910 block/blk-core.c:1060
 submit_bio+0x1f3/0x350 block/blk-core.c:1130
 submit_bh_wbc+0x392/0x3d0 fs/buffer.c:3054
 submit_bh fs/buffer.c:3060 [inline]
 write_dirty_buffer+0xd4/0xe0 fs/buffer.c:3128
 fat_sync_bhs+0x52/0x160 fs/fat/misc.c:357
 fat_zeroed_cluster+0x2b3/0x5e0 fs/fat/dir.c:1108
 fat_alloc_new_dir+0x43f/0x4b0 fs/fat/dir.c:1185
 vfat_mkdir+0x70/0x210 fs/fat/namei_vfat.c:860
 vfs_mkdir+0x288/0x350 fs/namei.c:3650
 do_mkdirat+0x132/0x220 fs/namei.c:3673
 __do_sys_mkdirat fs/namei.c:3684 [inline]
 __se_sys_mkdirat fs/namei.c:3682 [inline]
 __x64_sys_mkdirat+0x3e/0x50 fs/namei.c:3682
 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: 23507 Comm: syz-executor.4 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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