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BUG: KCSAN: data-race in __wb_writeout_add / writeout_period

write to 0xffffffff870d0440 of 8 bytes by interrupt on cpu 1:
 writeout_period+0xa6/0xe0 mm/page-writeback.c:613
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1474
 expire_timers+0x116/0x240 kernel/time/timer.c:1519
 __run_timers+0x350/0x400 kernel/time/timer.c:1790
 run_timer_softirq+0x56/0x60 kernel/time/timer.c:1805
 __do_softirq+0xf2/0x2c7 kernel/softirq.c:571
 __irq_exit_rcu kernel/softirq.c:650 [inline]
 irq_exit_rcu+0x41/0x70 kernel/softirq.c:662
 sysvec_apic_timer_interrupt+0x8d/0xb0 arch/x86/kernel/apic/apic.c:1107
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
 rcu_preempt_read_enter kernel/rcu/tree_plugin.h:377 [inline]
 __rcu_read_lock+0x2a/0x40 kernel/rcu/tree_plugin.h:400
 rcu_read_lock include/linux/rcupdate.h:736 [inline]
 inet_twsk_purge+0x3bb/0x400 net/ipv4/inet_timewait_sock.c:268
 dccp_v4_exit_batch+0x16/0x20 net/dccp/ipv4.c:1055
 ops_exit_list net/core/net_namespace.c:167 [inline]
 cleanup_net+0x4dc/0x8d0 net/core/net_namespace.c:594
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

read to 0xffffffff870d0440 of 8 bytes by task 2222 on cpu 0:
 wb_domain_writeout_add mm/page-writeback.c:562 [inline]
 __wb_writeout_add+0x8a/0x1d0 mm/page-writeback.c:583
 __folio_end_writeback+0x2f4/0x580 mm/page-writeback.c:2932
 folio_end_writeback+0x57/0x130 mm/filemap.c:1620
 end_page_writeback+0x3b/0xe0 mm/folio-compat.c:26
 ext4_finish_bio+0x421/0x520 fs/ext4/page-io.c:145
 ext4_release_io_end+0x98/0x200 fs/ext4/page-io.c:160
 ext4_end_io_end fs/ext4/page-io.c:194 [inline]
 ext4_do_flush_completed_IO fs/ext4/page-io.c:259 [inline]
 ext4_end_io_rsv_work+0x319/0x3a0 fs/ext4/page-io.c:273
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

value changed: 0x0000000100011176 -> 0x00000001000112a2

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2222 Comm: kworker/u4:9 Not tainted 6.0.0-syzkaller-09039-ga6afa4199d3d-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
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