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BUG: KCSAN: data-race in __wb_update_bandwidth / percpu_counter_add_batch

read-write to 0xffff888100fb6920 of 8 bytes by task 9062 on cpu 1:
 percpu_counter_add_batch+0x120/0x140 lib/percpu_counter.c:107
 wb_stat_mod include/linux/backing-dev.h:66 [inline]
 folio_account_dirtied mm/page-writeback.c:2766 [inline]
 __folio_mark_dirty+0x27f/0x4e0 mm/page-writeback.c:2812
 mark_buffer_dirty+0x134/0x230 fs/buffer.c:1196
 __block_commit_write fs/buffer.c:2189 [inline]
 block_write_end+0x123/0x210 fs/buffer.c:2265
 ext4_da_do_write_end fs/ext4/inode.c:3011 [inline]
 ext4_da_write_end+0x20a/0x810 fs/ext4/inode.c:3086
 generic_perform_write+0x33c/0x4a0 mm/filemap.c:4070
 ext4_buffered_write_iter+0x1ea/0x370 fs/ext4/file.c:299
 ext4_file_write_iter+0x383/0xf20
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x77f/0x920 fs/read_write.c:679
 ksys_pwrite64 fs/read_write.c:786 [inline]
 __do_sys_pwrite64 fs/read_write.c:794 [inline]
 __se_sys_pwrite64 fs/read_write.c:791 [inline]
 __x64_sys_pwrite64+0xf6/0x150 fs/read_write.c:791
 x64_sys_call+0xab0/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888100fb6920 of 8 bytes by task 28 on cpu 0:
 percpu_counter_read include/linux/percpu_counter.h:110 [inline]
 __wb_update_bandwidth+0x83/0x5d0 mm/page-writeback.c:1547
 wb_update_bandwidth+0x55/0x80 mm/page-writeback.c:1575
 wb_update_bandwidth_workfn+0x1c/0x30 mm/backing-dev.c:507
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x0000000000004470 -> 0x0000000000004480

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 28 Comm: kworker/u8:1 Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: writeback wb_update_bandwidth_workfn
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