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BUG: KCSAN: data-race in __wb_update_bandwidth / percpu_counter_add_batch

write to 0xffff888101df8540 of 8 bytes by interrupt on cpu 1:
 percpu_counter_add_batch+0x9c/0xd0 lib/percpu_counter.c:91
 __add_wb_stat include/linux/backing-dev.h:70 [inline]
 inc_wb_stat include/linux/backing-dev.h:75 [inline]
 __wb_writeout_inc mm/page-writeback.c:592 [inline]
 test_clear_page_writeback+0x37c/0x600 mm/page-writeback.c:2789
 end_page_writeback+0xd7/0x1b0 mm/filemap.c:1603
 ext4_finish_bio+0x3e2/0x430 fs/ext4/page-io.c:143
 ext4_end_bio+0x1bc/0x310
 bio_endio+0x2d4/0x300 block/bio.c:1494
 req_bio_endio block/blk-core.c:261 [inline]
 blk_update_request+0x435/0xa40 block/blk-core.c:1425
 scsi_end_request+0x4b/0x440 drivers/scsi/scsi_lib.c:542
 scsi_io_completion+0xd0/0x10c0 drivers/scsi/scsi_lib.c:938
 scsi_finish_command+0x1ba/0x1d0 drivers/scsi/scsi.c:207
 scsi_complete+0x1aa/0x1e0 drivers/scsi/scsi_lib.c:1432
 blk_complete_reqs block/blk-mq.c:577 [inline]
 blk_done_softirq+0x69/0x90 block/blk-mq.c:582
 __do_softirq+0x12c/0x26e kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu kernel/softirq.c:636 [inline]
 irq_exit_rcu+0x4e/0xa0 kernel/softirq.c:648
 common_interrupt+0x3e/0x90 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40

read to 0xffff888101df8540 of 8 bytes by task 4089 on cpu 0:
 percpu_counter_read include/linux/percpu_counter.h:72 [inline]
 __wb_update_bandwidth+0x9f/0x470 mm/page-writeback.c:1353
 wb_update_bandwidth mm/page-writeback.c:1380 [inline]
 do_writepages+0x391/0x3c0 mm/page-writeback.c:2379
 filemap_fdatawrite_wbc mm/filemap.c:400 [inline]
 __filemap_fdatawrite_range mm/filemap.c:433 [inline]
 filemap_write_and_wait_range+0x238/0x3c0 mm/filemap.c:704
 ext4_punch_hole+0x14c/0x9d0 fs/ext4/inode.c:4026
 ext4_fallocate+0xea/0x4d0 fs/ext4/extents.c:4668
 vfs_fallocate+0x459/0x6a0 fs/open.c:307
 ksys_fallocate fs/open.c:330 [inline]
 __do_sys_fallocate fs/open.c:338 [inline]
 __se_sys_fallocate fs/open.c:336 [inline]
 __x64_sys_fallocate+0x75/0xc0 fs/open.c:336
 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

value changed: 0x0000000000001a30 -> 0x0000000000001a50

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4089 Comm: syz-executor.3 Not tainted 5.15.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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