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BUG: KCSAN: data-race in delete_from_page_cache_batch / nr_blockdev_pages

read-write to 0xffff8881005f1838 of 8 bytes by task 8230 on cpu 0:
 page_cache_delete_batch mm/filemap.c:317 [inline]
 delete_from_page_cache_batch+0x569/0x750 mm/filemap.c:336
 truncate_inode_pages_range+0x1fe/0x7e0 mm/truncate.c:405
 truncate_inode_pages+0x24/0x30 mm/truncate.c:485
 kill_bdev block/bdev.c:91 [inline]
 set_blocksize+0x1ed/0x270 block/bdev.c:207
 sb_set_blocksize+0x93/0x170 block/bdev.c:240
 sb_min_blocksize+0x53/0x60 block/bdev.c:255
 ext4_load_super fs/ext4/super.c:5101 [inline]
 __ext4_fill_super fs/ext4/super.c:5322 [inline]
 ext4_fill_super+0x39e/0x37c0 fs/ext4/super.c:5791
 get_tree_bdev_flags+0x291/0x300 fs/super.c:1694
 get_tree_bdev+0x1f/0x30 fs/super.c:1717
 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5823
 vfs_get_tree+0x57/0x1d0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x288/0x8d0 fs/namespace.c:3839
 path_mount+0x4d0/0xbc0 fs/namespace.c:4159
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4338
 __x64_sys_mount+0x67/0x80 fs/namespace.c:4338
 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881005f1838 of 8 bytes by task 35 on cpu 1:
 nr_blockdev_pages+0x7e/0xd0 block/bdev.c:539
 si_meminfo+0x87/0xd0 mm/show_mem.c:80
 update_defense_level+0x47/0x5d0 net/netfilter/ipvs/ip_vs_ctl.c:101
 defense_work_handler+0x1f/0x80 net/netfilter/ipvs/ip_vs_ctl.c:234
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359
 worker_thread+0x58a/0x780 kernel/workqueue.c:3440
 kthread+0x22a/0x280 kernel/kthread.c:436
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000000000000003 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 35 Comm: kworker/1:1 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_long defense_work_handler
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