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BUG: KCSAN: data-race in __filemap_remove_folio / nr_blockdev_pages

read-write to 0xffff888100631830 of 8 bytes by task 17629 on cpu 1:
 page_cache_delete mm/filemap.c:146 [inline]
 __filemap_remove_folio+0x1bc/0x2a0 mm/filemap.c:224
 __remove_mapping+0x338/0x460 mm/vmscan.c:822
 remove_mapping+0x22/0x90 mm/vmscan.c:855
 mapping_evict_folio mm/truncate.c:314 [inline]
 mapping_try_invalidate+0x26a/0x3f0 mm/truncate.c:535
 invalidate_mapping_pages+0x27/0x40 mm/truncate.c:577
 invalidate_bdev+0x58/0x70 block/bdev.c:102
 __ext4_fill_super fs/ext4/super.c:5699 [inline]
 ext4_fill_super+0x2a6e/0x34e0 fs/ext4/super.c:5724
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1679
 get_tree_bdev+0x1f/0x30 fs/super.c:1702
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5756
 vfs_get_tree+0x54/0x1d0 fs/super.c:1802
 do_new_mount+0x207/0x680 fs/namespace.c:3856
 path_mount+0x4a4/0xb20 fs/namespace.c:4180
 do_mount fs/namespace.c:4193 [inline]
 __do_sys_mount fs/namespace.c:4404 [inline]
 __se_sys_mount+0x28f/0x2e0 fs/namespace.c:4381
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4381
 x64_sys_call+0xd36/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888100631830 of 8 bytes by task 9 on cpu 0:
 nr_blockdev_pages+0x7e/0xd0 block/bdev.c:523
 si_meminfo+0x87/0xd0 mm/show_mem.c:80
 update_defense_level+0x47/0x5c0 net/netfilter/ipvs/ip_vs_ctl.c:102
 defense_work_handler+0x1f/0x80 net/netfilter/ipvs/ip_vs_ctl.c:235
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x486/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000000000006 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.15.0-syzkaller-13473-gc0c9379f235d #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_long defense_work_handler
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