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BUG: KCSAN: data-race in __wb_update_bandwidth / percpu_counter_add_batch

read-write to 0xffff888100fac920 of 8 bytes by task 26142 on cpu 0:
 percpu_counter_add_batch+0xc9/0x140 lib/percpu_counter.c:96
 wb_stat_mod include/linux/backing-dev.h:66 [inline]
 folio_account_dirtied mm/page-writeback.c:2700 [inline]
 __folio_mark_dirty+0x27f/0x4e0 mm/page-writeback.c:2748
 mark_buffer_dirty+0x148/0x250 fs/buffer.c:1207
 __block_commit_write fs/buffer.c:2200 [inline]
 block_write_end+0x158/0x2e0 fs/buffer.c:2276
 ext4_da_do_write_end fs/ext4/inode.c:2952 [inline]
 ext4_da_write_end+0x1ad/0x860 fs/ext4/inode.c:3025
 generic_perform_write+0x276/0x410 mm/filemap.c:4026
 ext4_buffered_write_iter+0x1f6/0x380 fs/ext4/file.c:299
 ext4_file_write_iter+0x29f/0xe30
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x78f/0x900 fs/read_write.c:590
 ksys_write+0xeb/0x1b0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:652
 x64_sys_call+0x27ef/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:2
 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 0xffff888100fac920 of 8 bytes by task 26144 on cpu 1:
 percpu_counter_read include/linux/percpu_counter.h:110 [inline]
 __wb_update_bandwidth+0x83/0x5d0 mm/page-writeback.c:1483
 wb_update_bandwidth mm/page-writeback.c:1511 [inline]
 do_writepages+0x443/0x480 mm/page-writeback.c:2660
 filemap_fdatawrite_wbc+0xdb/0x100 mm/filemap.c:397
 __filemap_fdatawrite_range mm/filemap.c:430 [inline]
 file_write_and_wait_range+0xc8/0x170 mm/filemap.c:788
 ext4_sync_file+0x134/0x6c0 fs/ext4/fsync.c:158
 vfs_fsync_range fs/sync.c:188 [inline]
 vfs_fsync fs/sync.c:202 [inline]
 do_fsync fs/sync.c:212 [inline]
 __do_sys_fdatasync fs/sync.c:225 [inline]
 __se_sys_fdatasync fs/sync.c:223 [inline]
 __x64_sys_fdatasync+0x88/0xe0 fs/sync.c:223
 x64_sys_call+0xa4d/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:76
 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

value changed: 0x0000000000090410 -> 0x0000000000090420

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26144 Comm: syz-executor.2 Tainted: G        W          6.10.0-rc2-syzkaller-00366-g771ed66105de #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
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