syzbot

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BUG: KCSAN: data-race in nr_blockdev_pages / page_cache_delete

read-write to 0xffff888102017648 of 8 bytes by task 27731 on cpu 0:
 page_cache_delete+0x35d/0x390 mm/filemap.c:145
 __filemap_remove_folio+0x3b/0xf0 mm/filemap.c:223
 __remove_mapping+0x42a/0x530 mm/vmscan.c:1366
 remove_mapping+0x1f/0x140 mm/vmscan.c:1399
 mapping_evict_folio mm/truncate.c:282 [inline]
 invalidate_mapping_pagevec+0x44d/0x5d0 mm/truncate.c:528
 invalidate_mapping_pages+0x23/0x30 mm/truncate.c:567
 invalidate_bdev+0x67/0x80 block/bdev.c:86
 invalidate_disk+0x25/0xb0 block/genhd.c:672
 __loop_clr_fd+0x176/0x3c0 drivers/block/loop.c:1164
 loop_clr_fd drivers/block/loop.c:1257 [inline]
 lo_ioctl+0xd8c/0x1290 drivers/block/loop.c:1563
 blkdev_ioctl+0x20e/0x440 block/ioctl.c:614
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888102017648 of 8 bytes by task 1888 on cpu 1:
 nr_blockdev_pages+0x7f/0xd0 block/bdev.c:522
 si_meminfo+0x3a/0x60 mm/page_alloc.c:5924
 update_defense_level+0x46/0x560 net/netfilter/ipvs/ip_vs_ctl.c:102
 defense_work_handler+0x1b/0x80 net/netfilter/ipvs/ip_vs_ctl.c:236
 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

value changed: 0x0000000000000001 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1888 Comm: kworker/1:3 Not tainted 6.0.0-rc6-syzkaller-00045-gdc164f4fb00a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2022
Workqueue: events_long defense_work_handler
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