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BUG: KCSAN: data-race in __wb_writeout_add / writeout_period

write to 0xffffffff86efbd90 of 8 bytes by interrupt on cpu 0:
 writeout_period+0xa6/0xe0 mm/page-writeback.c:614
 call_timer_fn+0x37/0x2f0 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x46c/0x650 kernel/time/timer.c:2022
 run_timer_softirq+0x31/0x40 kernel/time/timer.c:2037
 __do_softirq+0xc4/0x279 kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0x3b/0x90 kernel/softirq.c:644
 sysvec_apic_timer_interrupt+0x6d/0x80 arch/x86/kernel/apic/apic.c:1076
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
 check_access kernel/kcsan/core.c:752 [inline]
 __tsan_read8+0x118/0x180 kernel/kcsan/core.c:1025
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:406 [inline]
 batadv_nc_worker+0x80/0xac0 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
 worker_thread+0x525/0x730 kernel/workqueue.c:2784
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

read to 0xffffffff86efbd90 of 8 bytes by task 8164 on cpu 1:
 wb_domain_writeout_add mm/page-writeback.c:563 [inline]
 __wb_writeout_add+0x8a/0x1d0 mm/page-writeback.c:584
 __folio_end_writeback+0x21b/0x4a0 mm/page-writeback.c:2963
 folio_end_writeback+0x74/0x1f0 mm/filemap.c:1598
 __block_write_full_folio+0x5c9/0x8a0 fs/buffer.c:1921
 block_write_full_page+0x2d3/0x390
 blkdev_writepage+0x24/0x30 block/fops.c:415
 writepage_cb+0x36/0xc0 mm/page-writeback.c:2537
 write_cache_pages+0x38d/0x740 mm/page-writeback.c:2474
 do_writepages+0x20f/0x340 mm/page-writeback.c:2558
 __writeback_single_inode+0x91/0x860 fs/fs-writeback.c:1625
 writeback_sb_inodes+0x514/0xad0 fs/fs-writeback.c:1916
 __writeback_inodes_wb+0x9a/0x1a0 fs/fs-writeback.c:1987
 wb_writeback+0x264/0x6e0 fs/fs-writeback.c:2094
 wb_check_background_flush fs/fs-writeback.c:2164 [inline]
 wb_do_writeback fs/fs-writeback.c:2252 [inline]
 wb_workfn+0x67f/0x8d0 fs/fs-writeback.c:2279
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
 worker_thread+0x525/0x730 kernel/workqueue.c:2784
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

value changed: 0x000000010003ca30 -> 0x000000010003cb5c

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8164 Comm: kworker/u4:27 Tainted: G        W          6.7.0-rc1-syzkaller-00213-g791c8ab095f7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: writeback wb_workfn (flush-8:0)
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