loop5: detected capacity change from 0 to 264192
==================================================================
BUG: KCSAN: data-race in lru_add_drain_all / lru_cache_add

write to 0xffff888237c26468 of 1 bytes by task 25129 on cpu 0:
 pagevec_add include/linux/pagevec.h:74 [inline]
 lru_cache_add+0x74/0x130 mm/swap.c:461
 shmem_getpage_gfp+0xcf8/0x1410 mm/shmem.c:1934
 shmem_getpage mm/shmem.c:155 [inline]
 shmem_file_read_iter+0x1a2/0x5c0 mm/shmem.c:2607
 call_read_iter include/linux/fs.h:1971 [inline]
 do_iter_readv_writev+0x2e8/0x360 fs/read_write.c:738
 do_iter_read+0x109/0x4b0 fs/read_write.c:801
 vfs_iter_read+0x4c/0x70 fs/read_write.c:843
 lo_read_simple drivers/block/loop.c:360 [inline]
 do_req_filebacked drivers/block/loop.c:636 [inline]
 loop_handle_cmd drivers/block/loop.c:2045 [inline]
 loop_queue_work+0xdfb/0x1330 drivers/block/loop.c:2063
 kthread_worker_fn+0x280/0x4d0 kernel/kthread.c:735
 loop_kthread_worker_fn+0x3e/0x50 drivers/block/loop.c:932
 kthread+0x1d0/0x1f0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

read to 0xffff888237c26468 of 1 bytes by task 25119 on cpu 1:
 pagevec_count include/linux/pagevec.h:61 [inline]
 lru_add_drain_all+0x108/0x3c0 mm/swap.c:813
 invalidate_bdev+0x50/0x70 fs/block_dev.c:96
 blk_drop_partitions+0x5e/0x1a0 block/partitions/core.c:545
 bdev_disk_changed+0x58/0x200 fs/block_dev.c:1248
 loop_reread_partitions drivers/block/loop.c:655 [inline]
 loop_set_status+0x75f/0x7e0 drivers/block/loop.c:1418
 lo_ioctl+0x758/0x11f0 drivers/block/loop.c:1486
 blkdev_ioctl+0x1d0/0x3c0 block/ioctl.c:583
 block_ioctl+0x6d/0x80 fs/block_dev.c:1671
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25119 Comm: syz-executor.5 Not tainted 5.12.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
 loop5: p2 p4
loop5: p2 size 327680 extends beyond EOD, truncated
loop5: p4 size 2097152 extends beyond EOD, truncated