syzbot

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BUG: KCSAN: data-race in list_lru_count_one / list_lru_del

write to 0xffff88812aff0f18 of 8 bytes by task 24237 on cpu 1:
 list_lru_del+0x1d1/0x220 mm/list_lru.c:149
 workingset_update_node+0x98/0xe0 mm/workingset.c:443
 xas_update lib/xarray.c:350 [inline]
 update_node lib/xarray.c:751 [inline]
 xas_store+0x863/0xd00 lib/xarray.c:838
 __add_to_page_cache_locked+0x1f0/0x6e0 mm/filemap.c:859
 add_to_page_cache_lru+0xa0/0x1b0 mm/filemap.c:919
 page_cache_readahead_unbounded+0x234/0x440 mm/readahead.c:228
 __do_page_cache_readahead+0x96/0xb0 mm/readahead.c:273
 ra_submit mm/internal.h:64 [inline]
 do_sync_mmap_readahead mm/filemap.c:2503 [inline]
 filemap_fault+0x63d/0x11e0 mm/filemap.c:2589
 ext4_filemap_fault+0x4b/0x60 fs/ext4/inode.c:6060
 __do_fault mm/memory.c:3467 [inline]
 do_read_fault+0x41f/0x730 mm/memory.c:3860
 do_fault mm/memory.c:3988 [inline]
 handle_pte_fault mm/memory.c:4228 [inline]
 __handle_mm_fault mm/memory.c:4360 [inline]
 handle_mm_fault+0x136c/0x1950 mm/memory.c:4397
 do_user_addr_fault+0x393/0x810 arch/x86/mm/fault.c:1294
 handle_page_fault arch/x86/mm/fault.c:1364 [inline]
 exc_page_fault+0xb8/0x330 arch/x86/mm/fault.c:1417
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538

read to 0xffff88812aff0f18 of 8 bytes by task 2482 on cpu 0:
 list_lru_count_one+0xb6/0xd0 mm/list_lru.c:183
 list_lru_shrink_count include/linux/list_lru.h:123 [inline]
 count_shadow_nodes+0x45/0x3e0 mm/workingset.c:456
 do_shrink_slab+0x86/0x5c0 mm/vmscan.c:431
 shrink_slab+0xea/0x1c0 mm/vmscan.c:674
 shrink_node_memcgs+0x270/0x410 mm/vmscan.c:2646
 shrink_node+0x94e/0x1140 mm/vmscan.c:2758
 kswapd_shrink_node mm/vmscan.c:3499 [inline]
 balance_pgdat+0x675/0xbb0 mm/vmscan.c:3657
 kswapd+0x1ef/0x370 mm/vmscan.c:3914
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2482 Comm: kswapd0 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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