==================================================================
BUG: KCSAN: data-race in lru_add_drain_all / pagevec_lru_move_fn

write to 0xffff88812c028ac0 of 1 bytes by task 19334 on cpu 0:
 pagevec_reinit include/linux/pagevec.h:63 [inline]
 pagevec_lru_move_fn+0x175/0x190 mm/swap.c:232
 __pagevec_lru_add mm/swap.c:1031 [inline]
 lru_add_drain_cpu+0x75/0x2e0 mm/swap.c:632
 lru_add_drain+0x21/0x60 mm/swap.c:736
 free_pages_and_swap_cache+0x1d/0x1f0 mm/swap_state.c:351
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:242 [inline]
 tlb_flush_mmu+0x597/0x5f0 mm/mmu_gather.c:249
 zap_pte_range+0x12c7/0x1630 mm/memory.c:1348
 zap_pmd_range mm/memory.c:1386 [inline]
 zap_pud_range mm/memory.c:1415 [inline]
 zap_p4d_range mm/memory.c:1436 [inline]
 unmap_page_range+0x751/0x870 mm/memory.c:1457
 unmap_single_vma+0x157/0x210 mm/memory.c:1502
 unmap_vmas+0xc0/0x150 mm/memory.c:1534
 exit_mmap+0x1c7/0x3b0 mm/mmap.c:3183
 __mmput+0xa2/0x220 kernel/fork.c:1077
 mmput+0x38/0x40 kernel/fork.c:1098
 exit_mm+0x2c8/0x330 kernel/exit.c:483
 do_exit+0x40f/0x16c0 kernel/exit.c:793
 do_group_exit+0x17a/0x180 kernel/exit.c:903
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:914
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:912
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:912
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812c028ac0 of 1 bytes by task 19336 on cpu 1:
 pagevec_count include/linux/pagevec.h:68 [inline]
 lru_add_drain_all+0x118/0x3b0 mm/swap.c:796
 invalidate_bdev+0x50/0x70 fs/block_dev.c:96
 __loop_clr_fd+0x258/0x5b0 drivers/block/loop.c:1248
 loop_clr_fd drivers/block/loop.c:1345 [inline]
 lo_ioctl+0x9d1/0x1190 drivers/block/loop.c:1703
 __blkdev_driver_ioctl block/ioctl.c:224 [inline]
 blkdev_ioctl+0x1cf/0x410 block/ioctl.c:620
 block_ioctl+0x6d/0x80 fs/block_dev.c:1871
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19336 Comm: syz-executor.5 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================