==================================================================
BUG: KCSAN: data-race in __add_to_page_cache_locked / nr_blockdev_pages

read to 0xffff888125258468 of 8 bytes by task 12 on cpu 0:
 nr_blockdev_pages+0x73/0xc0 fs/block_dev.c:952
 si_meminfo+0x3e/0x60 mm/page_alloc.c:5151
 update_defense_level+0x40/0xb50 net/netfilter/ipvs/ip_vs_ctl.c:101
 defense_work_handler+0x3d/0xd0 net/netfilter/ipvs/ip_vs_ctl.c:224
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2264
 worker_thread+0xa0/0x800 kernel/workqueue.c:2410
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff888125258468 of 8 bytes by task 13323 on cpu 1:
 __add_to_page_cache_locked+0x298/0x780 mm/filemap.c:890
 add_to_page_cache_lru+0xc4/0x260 mm/filemap.c:943
 do_read_cache_page+0x2fd/0x8d0 mm/filemap.c:2770
 read_cache_page+0x46/0x60 mm/filemap.c:2874
 read_mapping_page include/linux/pagemap.h:396 [inline]
 read_dev_sector+0x61/0x1a0 block/partition-generic.c:592
 read_part_sector block/partitions/check.h:38 [inline]
 adfspart_check_ICS+0x8b/0x6b0 block/partitions/acorn.c:361
 check_partition+0x260/0x40f block/partitions/check.c:167
 blk_add_partitions+0xaf/0x41d block/partition-generic.c:525
 bdev_disk_changed+0xb4/0x1a0 fs/block_dev.c:1531
 loop_reread_partitions+0x36/0x70 drivers/block/loop.c:644
 loop_set_status+0xa02/0xb30 drivers/block/loop.c:1356
 loop_set_status64+0x6d/0xb0 drivers/block/loop.c:1476
 lo_ioctl+0x30b/0xc80 drivers/block/loop.c:1619
 __blkdev_driver_ioctl block/ioctl.c:277 [inline]
 blkdev_ioctl+0xbe5/0x1260 block/ioctl.c:582
 block_ioctl+0x95/0xc0 fs/block_dev.c:1983
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:545 [inline]
 do_vfs_ioctl+0x84f/0xcf0 fs/ioctl.c:732
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:749
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:754
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13323 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================