BUG: KCSAN: data-race in delete_from_page_cache_batch / nr_blockdev_pages

read-write to 0xffff888102254d90 of 8 bytes by task 25118 on cpu 1:
 page_cache_delete_batch mm/filemap.c:340 [inline]
 delete_from_page_cache_batch+0x58b/0x810 mm/filemap.c:358
 truncate_inode_pages_range+0x482/0x10c0 mm/truncate.c:366
 truncate_inode_pages+0x20/0x30 mm/truncate.c:476
 kill_bdev fs/block_dev.c:86 [inline]
 set_blocksize+0x286/0x2a0 fs/block_dev.c:150
 sb_set_blocksize fs/block_dev.c:159 [inline]
 sb_min_blocksize+0x9d/0x120 fs/block_dev.c:175
 squashfs_fill_super+0x6a/0xc90 fs/squashfs/super.c:88
 get_tree_bdev+0x2b4/0x3b0 fs/super.c:1291
 squashfs_get_tree+0x18/0x20 fs/squashfs/super.c:348
 vfs_get_tree+0x4a/0x190 fs/super.c:1496
 do_new_mount fs/namespace.c:2878 [inline]
 path_mount+0x119d/0x1c10 fs/namespace.c:3208
 do_mount fs/namespace.c:3221 [inline]
 __do_sys_mount fs/namespace.c:3429 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3406
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3406
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888102254d90 of 8 bytes by task 9349 on cpu 0:
 nr_blockdev_pages+0x7c/0xd0 fs/block_dev.c:934
 si_meminfo+0x3a/0x60 mm/page_alloc.c:5401
 update_defense_level+0x34/0x550 net/netfilter/ipvs/ip_vs_ctl.c:101
 defense_work_handler+0x1b/0x80 net/netfilter/ipvs/ip_vs_ctl.c:235
 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275
 worker_thread+0x635/0xb90 kernel/workqueue.c:2421
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 9349 Comm: kworker/0:3 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_long defense_work_handler
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