==================================================================
BUG: KCSAN: data-race in __lru_cache_add / lru_add_drain_all

write to 0xffff88812c129c40 of 1 bytes by task 22117 on cpu 1:
 pagevec_add include/linux/pagevec.h:81 [inline]
 __lru_cache_add+0xb8/0x1c0 mm/swap.c:410
 lru_cache_add+0x1b/0x30 mm/swap.c:447
 add_to_page_cache_lru+0x16b/0x260 mm/filemap.c:937
 pagecache_get_page+0x2b0/0x8c0 mm/filemap.c:1656
 grab_cache_page_write_begin+0x56/0x80 mm/filemap.c:3252
 ext4_da_write_begin+0x1b4/0xa10 fs/ext4/inode.c:2964
 generic_perform_write+0x13a/0x320 mm/filemap.c:3302
 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270
 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write+0x303/0x400 fs/read_write.c:484
 __vfs_write+0x9e/0xb0 fs/read_write.c:497
 vfs_write fs/read_write.c:559 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:543
 ksys_write+0xc5/0x1a0 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write fs/read_write.c:621 [inline]
 __x64_sys_write+0x49/0x60 fs/read_write.c:621
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812c129c40 of 1 bytes by task 22106 on cpu 0:
 lru_add_drain_all+0x169/0x3a0 mm/swap.c:746
 invalidate_bdev+0x65/0x90 fs/block_dev.c:98
 __loop_clr_fd+0x24e/0x710 drivers/block/loop.c:1162
 loop_clr_fd drivers/block/loop.c:1259 [inline]
 lo_ioctl+0x24a/0xc50 drivers/block/loop.c:1628
 __blkdev_driver_ioctl block/ioctl.c:322 [inline]
 blkdev_ioctl+0x1a1/0x420 block/ioctl.c:718
 block_ioctl+0x91/0xb0 fs/block_dev.c:1996
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x101/0x150 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 22106 Comm: syz-executor.0 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================