syzbot

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BUG: KCSAN: data-race in nr_blockdev_pages / page_cache_delete_batch

read-write to 0xffff888101b9e600 of 8 bytes by task 19237 on cpu 0:
 page_cache_delete_batch+0x445/0x470 mm/filemap.c:315
 delete_from_page_cache_batch+0x18f/0x2a0 mm/filemap.c:334
 truncate_inode_pages_range+0x3ca/0xae0 mm/truncate.c:370
 truncate_inode_pages+0x20/0x30 mm/truncate.c:452
 kill_bdev block/bdev.c:77 [inline]
 blkdev_flush_mapping+0xde/0x230 block/bdev.c:656
 blkdev_put_whole block/bdev.c:687 [inline]
 blkdev_put+0x34a/0x440 block/bdev.c:947
 kill_block_super+0x7b/0x90 fs/super.c:1397
 deactivate_locked_super+0x6a/0xb0 fs/super.c:332
 mount_bdev+0x1fe/0x280 fs/super.c:1369
 isofs_mount+0x2d/0x40 fs/isofs/inode.c:1567
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x49/0x190 fs/super.c:1497
 do_new_mount+0x200/0x650 fs/namespace.c:3040
 path_mount+0x4b1/0xb60 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x281/0x2d0 fs/namespace.c:3568
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3568
 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+0x44/0xae

read to 0xffff888101b9e600 of 8 bytes by task 4124 on cpu 1:
 nr_blockdev_pages+0x7f/0xd0 block/bdev.c:517
 si_meminfo+0x3a/0x60 mm/page_alloc.c:5817
 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: 0x0000000000001027 -> 0x0000000000001018

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4124 Comm: kworker/1:3 Not tainted 5.18.0-rc3-syzkaller-dirty #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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