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BUG: KCSAN: data-race in __wb_update_bandwidth / percpu_counter_add_batch

write to 0xffff88810283cd18 of 8 bytes by task 15270 on cpu 0:
 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]
 account_page_dirtied+0x1fe/0x2e0 mm/page-writeback.c:2458
 __set_page_dirty+0xbc/0x1a0 mm/page-writeback.c:2500
 mark_buffer_dirty+0x126/0x200 fs/buffer.c:1108
 __block_commit_write fs/buffer.c:2083 [inline]
 block_write_end+0x13d/0x260 fs/buffer.c:2162
 generic_write_end+0x5e/0x180 fs/buffer.c:2176
 ext4_da_write_end+0x59b/0x730 fs/ext4/inode.c:3116
 generic_perform_write+0x251/0x3e0 mm/filemap.c:3781
 ext4_buffered_write_iter+0x305/0x400 fs/ext4/file.c:269
 ext4_file_write_iter+0x2e7/0x11f0
 call_write_iter include/linux/fs.h:2163 [inline]
 aio_write+0x2b4/0x390 fs/aio.c:1578
 io_submit_one+0x86f/0x13b0 fs/aio.c:1880
 __do_sys_io_submit fs/aio.c:1939 [inline]
 __se_sys_io_submit+0x105/0x270 fs/aio.c:1909
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:1909
 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 0xffff88810283cd18 of 8 bytes by task 15276 on cpu 1:
 percpu_counter_read include/linux/percpu_counter.h:72 [inline]
 __wb_update_bandwidth+0x87/0x470 mm/page-writeback.c:1352
 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: 0x0000000000031db0 -> 0x0000000000031dc0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15276 Comm: syz-executor.3 Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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