syzbot

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BUG: KCSAN: data-race in __es_shrink / __es_shrink

write to 0xffff888217e7cc78 of 8 bytes by task 2484 on cpu 0:
 __es_shrink+0x395/0x580 fs/ext4/extents_status.c:1515
 ext4_es_scan+0x88/0x270 fs/ext4/extents_status.c:1559
 do_shrink_slab+0x286/0x5c0 mm/vmscan.c:513
 shrink_slab+0xea/0x1c0 mm/vmscan.c:674
 shrink_node_memcgs+0x270/0x410 mm/vmscan.c:2645
 shrink_node+0x9ed/0x1230 mm/vmscan.c:2760
 kswapd_shrink_node mm/vmscan.c:3503 [inline]
 balance_pgdat+0x675/0xc20 mm/vmscan.c:3661
 kswapd+0x1ef/0x370 mm/vmscan.c:3918
 kthread+0x20d/0x230 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888217e7cc78 of 8 bytes by task 8694 on cpu 1:
 __es_shrink+0x367/0x580 fs/ext4/extents_status.c:1515
 ext4_es_scan+0x88/0x270 fs/ext4/extents_status.c:1559
 do_shrink_slab+0x286/0x5c0 mm/vmscan.c:513
 shrink_slab+0xea/0x1c0 mm/vmscan.c:674
 shrink_node_memcgs+0x270/0x410 mm/vmscan.c:2645
 shrink_node+0x9ed/0x1230 mm/vmscan.c:2760
 shrink_zones+0x2af/0x490 mm/vmscan.c:2963
 do_try_to_free_pages+0x193/0x6e0 mm/vmscan.c:3018
 try_to_free_pages+0x38e/0x8b0 mm/vmscan.c:3257
 __perform_reclaim mm/page_alloc.c:4255 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:4276 [inline]
 __alloc_pages_slowpath+0x55f/0x9e0 mm/page_alloc.c:4680
 __alloc_pages_nodemask+0x266/0x380 mm/page_alloc.c:4896
 alloc_pages_current+0x21d/0x310 mm/mempolicy.c:2275
 alloc_pages include/linux/gfp.h:545 [inline]
 __page_cache_alloc+0x4f/0x120 mm/filemap.c:957
 pagecache_get_page+0x4ba/0x970 mm/filemap.c:1710
 filemap_fault+0xb7a/0x1270 mm/filemap.c:2595
 ext4_filemap_fault+0x4b/0x60 fs/ext4/inode.c:6060
 __do_fault mm/memory.c:3463 [inline]
 do_read_fault+0x41f/0x760 mm/memory.c:3856
 do_fault mm/memory.c:3984 [inline]
 handle_pte_fault mm/memory.c:4224 [inline]
 __handle_mm_fault mm/memory.c:4359 [inline]
 handle_mm_fault+0x14e9/0x1af0 mm/memory.c:4457
 do_user_addr_fault+0x380/0x770 arch/x86/mm/fault.c:1294
 handle_page_fault arch/x86/mm/fault.c:1351 [inline]
 exc_page_fault+0xb8/0x330 arch/x86/mm/fault.c:1404
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8694 Comm: syz-fuzzer Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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