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BUG: KCSAN: data-race in __wb_update_bandwidth / percpu_counter_add_batch

write to 0xffff888101c7d540 of 8 bytes by interrupt on cpu 1:
 percpu_counter_add_batch+0xb4/0x130 lib/percpu_counter.c:91
 wb_stat_mod include/linux/backing-dev.h:70 [inline]
 __wb_writeout_add mm/page-writeback.c:592 [inline]
 __folio_end_writeback+0x274/0x580 mm/page-writeback.c:2821
 folio_end_writeback+0x57/0x130 mm/filemap.c:1597
 end_page_writeback+0x37/0x50 mm/folio-compat.c:25
 ext4_finish_bio+0x3e2/0x430 fs/ext4/page-io.c:143
 ext4_end_bio+0x1bc/0x310
 bio_endio+0x31b/0x340 block/bio.c:1489
 req_bio_endio block/blk-mq.c:658 [inline]
 blk_update_request+0x48d/0x990 block/blk-mq.c:726
 scsi_end_request+0x4b/0x440 drivers/scsi/scsi_lib.c:543
 scsi_io_completion+0xd0/0x10d0 drivers/scsi/scsi_lib.c:939
 scsi_finish_command+0x1c0/0x1d0 drivers/scsi/scsi.c:199
 scsi_complete+0x1a5/0x1e0 drivers/scsi/scsi_lib.c:1442
 blk_complete_reqs block/blk-mq.c:868 [inline]
 blk_done_softirq+0x92/0xc0 block/blk-mq.c:873
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 __irq_exit_rcu kernel/softirq.c:636 [inline]
 irq_exit_rcu+0x37/0x70 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x8d/0xb0 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20
 ep_pm_stay_awake fs/eventpoll.c:577 [inline]
 ep_send_events fs/eventpoll.c:1713 [inline]
 ep_poll fs/eventpoll.c:1799 [inline]
 do_epoll_wait+0x89c/0xf40 fs/eventpoll.c:2227
 __do_sys_epoll_wait fs/eventpoll.c:2239 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2234 [inline]
 __x64_sys_epoll_wait+0x119/0x140 fs/eventpoll.c:2234
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888101c7d540 of 8 bytes by task 5595 on cpu 0:
 percpu_counter_read include/linux/percpu_counter.h:72 [inline]
 __wb_update_bandwidth+0x9f/0x420 mm/page-writeback.c:1353
 wb_update_bandwidth+0x46/0x70 mm/page-writeback.c:1380
 wb_update_bandwidth_workfn+0x18/0x20 mm/backing-dev.c:280
 process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
 worker_thread+0x616/0xa70 kernel/workqueue.c:2445
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

value changed: 0x00000000000117b0 -> 0x00000000000117c0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5595 Comm: kworker/u4:16 Tainted: G        W         5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_update_bandwidth_workfn
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