F2FS-fs (loop4): Small segment_count (24 < 2 * 14)
F2FS-fs (loop4): Can't find valid F2FS filesystem in 2th superblock
==================================================================
BUG: KCSAN: data-race in __lru_cache_add / lru_add_drain_all

write to 0xffff88812c0299e0 of 1 bytes by task 29377 on cpu 0:
 pagevec_add include/linux/pagevec.h:81 [inline]
 __lru_cache_add+0xbf/0x1d0 mm/swap.c:410
 lru_cache_add_anon+0x9e/0x130 mm/swap.c:423
 shmem_getpage_gfp+0x470/0x1390 mm/shmem.c:1885
 shmem_getpage mm/shmem.c:154 [inline]
 shmem_write_begin+0x9f/0x140 mm/shmem.c:2487
 generic_perform_write+0x136/0x320 mm/filemap.c:3309
 __generic_file_write_iter+0x251/0x380 mm/filemap.c:3438
 generic_file_write_iter+0x28c/0x38c mm/filemap.c:3470
 call_write_iter include/linux/fs.h:1902 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483
 __vfs_write+0xb1/0xc0 fs/read_write.c:496
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_pwrite64+0xee/0x120 fs/read_write.c:665
 __do_sys_pwrite64 fs/read_write.c:675 [inline]
 __se_sys_pwrite64 fs/read_write.c:672 [inline]
 __x64_sys_pwrite64+0x5e/0x80 fs/read_write.c:672
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812c0299e0 of 1 bytes by task 29364 on cpu 1:
 lru_add_drain_all+0x17e/0x3d0 mm/swap.c:746
 invalidate_bdev+0x6e/0x90 fs/block_dev.c:97
 __loop_clr_fd+0x250/0x740 drivers/block/loop.c:1140
 loop_clr_fd drivers/block/loop.c:1237 [inline]
 lo_ioctl+0x24c/0xc80 drivers/block/loop.c:1606
 __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: 29364 Comm: syz-executor.4 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================