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BUG: KCSAN: data-race in fprop_new_period / fprop_reflect_period_percpu

read-write to 0xffffffff86eff0c0 of 4 bytes by interrupt on cpu 0:
 fprop_new_period+0xa6/0xd0 lib/flex_proportions.c:79
 writeout_period+0x55/0xe0 mm/page-writeback.c:613
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1700
 expire_timers+0x11f/0x260 kernel/time/timer.c:1751
 __run_timers+0x350/0x400 kernel/time/timer.c:2022
 run_timer_softirq+0x56/0x60 kernel/time/timer.c:2037
 __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_exit kernel/rcu/tree_plugin.h:384 [inline]
 __rcu_read_unlock+0x30/0x70 kernel/rcu/tree_plugin.h:421
 rcu_read_unlock include/linux/rcupdate.h:796 [inline]
 percpu_ref_tryget_many include/linux/percpu-refcount.h:250 [inline]
 percpu_ref_tryget include/linux/percpu-refcount.h:266 [inline]
 blkg_tryget block/blk-cgroup.h:334 [inline]
 blkg_tryget_closest block/blk-cgroup.c:1904 [inline]
 bio_associate_blkg_from_css+0x62f/0x6f0 block/blk-cgroup.c:1936
 bio_associate_blkg+0x91/0xa0 block/blk-cgroup.c:1964
 bio_init block/bio.c:266 [inline]
 bio_alloc_bioset+0x6e3/0xb20 block/bio.c:572
 bio_alloc_clone block/bio.c:850 [inline]
 bio_split+0xab/0x460 block/bio.c:1638
 __bio_split_to_limits+0x885/0xa80
 blk_mq_submit_bio+0x190/0xed0 block/blk-mq.c:2955
 __submit_bio block/blk-core.c:604 [inline]
 __submit_bio_noacct_mq block/blk-core.c:681 [inline]
 submit_bio_noacct_nocheck+0x83d/0xaa0 block/blk-core.c:698
 submit_bio_noacct+0x6a5/0x810 block/blk-core.c:804
 submit_bio+0xfb/0x110 block/blk-core.c:840
 ext4_io_submit fs/ext4/page-io.c:378 [inline]
 io_submit_add_bh fs/ext4/page-io.c:420 [inline]
 ext4_bio_write_page+0x6dd/0xc20 fs/ext4/page-io.c:564
 mpage_submit_page fs/ext4/inode.c:2129 [inline]
 mpage_map_and_submit_buffers fs/ext4/inode.c:2374 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2513 [inline]
 ext4_do_writepages+0x11a8/0x1e70 fs/ext4/inode.c:2877
 ext4_writepages+0x11b/0x240 fs/ext4/inode.c:2965
 do_writepages+0x1db/0x350 mm/page-writeback.c:2581
 filemap_fdatawrite_wbc+0xd6/0xf0 mm/filemap.c:388
 __filemap_fdatawrite_range mm/filemap.c:421 [inline]
 __filemap_fdatawrite mm/filemap.c:427 [inline]
 filemap_flush+0x93/0xc0 mm/filemap.c:454
 ext4_alloc_da_blocks+0x47/0x100 fs/ext4/inode.c:3219
 ext4_release_file+0x5b/0x1d0 fs/ext4/file.c:158
 __fput+0x245/0x570 fs/file_table.c:320
 ____fput+0x11/0x20 fs/file_table.c:348
 task_work_run+0xde/0x110 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0x5a0/0x16e0 kernel/exit.c:867
 do_group_exit+0xfe/0x140 kernel/exit.c:1010
 get_signal+0xb4b/0xc70 kernel/signal.c:2859
 arch_do_signal_or_restart+0x85/0x290 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop+0x78/0x130 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0x69/0x90 kernel/entry/common.c:203
 irqentry_exit_to_user_mode+0x5/0x10 kernel/entry/common.c:309
 irqentry_exit+0xe/0x40 kernel/entry/common.c:412
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

read to 0xffffffff86eff0c0 of 4 bytes by task 25 on cpu 1:
 fprop_reflect_period_percpu+0x22/0x1a0 lib/flex_proportions.c:188
 __fprop_add_percpu lib/flex_proportions.c:219 [inline]
 __fprop_add_percpu_max+0x54/0x180 lib/flex_proportions.c:277
 wb_domain_writeout_add mm/page-writeback.c:560 [inline]
 __wb_writeout_add+0x7e/0x1d0 mm/page-writeback.c:584
 __folio_end_writeback+0x246/0x4d0 mm/page-writeback.c:3044
 folio_end_writeback+0x57/0x130 mm/filemap.c:1614
 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:308

value changed: 0x00000023 -> 0x00000024

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25 Comm: kworker/u4:1 Not tainted 6.1.0-syzkaller-14321-g0a924817d2ed-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work
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