syzbot

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BUG: KCSAN: data-race in __delete_from_page_cache / nr_blockdev_pages

write to 0xffff888100425c00 of 8 bytes by task 12439 on cpu 0:
 page_cache_delete mm/filemap.c:146 [inline]
 __delete_from_page_cache+0x1e1/0x2c0 mm/filemap.c:231
 delete_from_page_cache+0x97/0x1e0 mm/filemap.c:266
 truncate_inode_page mm/truncate.c:229 [inline]
 truncate_inode_pages_range+0x8d7/0xa00 mm/truncate.c:407
 truncate_inode_pages+0x20/0x30 mm/truncate.c:435
 kill_bdev block/bdev.c:78 [inline]
 set_blocksize+0x24e/0x270 block/bdev.c:158
 sb_set_blocksize block/bdev.c:167 [inline]
 sb_min_blocksize+0x92/0x110 block/bdev.c:183
 fat_fill_super+0xe95/0x2af0 fs/fat/inode.c:1646
 vfat_fill_super+0x2c/0x40 fs/fat/namei_vfat.c:1051
 mount_bdev+0x1e8/0x290 fs/super.c:1370
 vfat_mount+0x2d/0x40 fs/fat/namei_vfat.c:1058
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1500
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x11cf/0x1c40 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3516
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3516
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888100425c00 of 8 bytes by task 1916 on cpu 1:
 nr_blockdev_pages+0x7f/0xd0 block/bdev.c:522
 si_meminfo+0x3a/0x60 mm/page_alloc.c:5778
 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+0x3f6/0x960 kernel/workqueue.c:2307
 worker_thread+0x616/0xa70 kernel/workqueue.c:2454
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

value changed: 0x00000000000000c7 -> 0x00000000000000c4

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1916 Comm: kworker/1:6 Not tainted 5.16.0-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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