BUG: KCSAN: data-race in __lru_add_drain_all / lru_cache_add

write to 0xffff888237d42528 of 1 bytes by task 27984 on cpu 1:
 pagevec_add include/linux/pagevec.h:74 [inline]
 pagevec_add_and_need_flush mm/swap.c:244 [inline]
 lru_cache_add+0x75/0x150 mm/swap.c:474
 add_to_page_cache_lru+0x150/0x1b0 mm/filemap.c:983
 pagecache_get_page+0x6a3/0x900 mm/filemap.c:1896
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grow_dev_page fs/buffer.c:949 [inline]
 grow_buffers fs/buffer.c:1014 [inline]
 __getblk_slow fs/buffer.c:1041 [inline]
 __getblk_gfp+0x199/0x590 fs/buffer.c:1334
 sb_getblk_gfp include/linux/buffer_head.h:334 [inline]
 __ext4_sb_bread_gfp fs/ext4/super.c:220 [inline]
 ext4_sb_bread_unmovable+0x3b/0x1a0 fs/ext4/super.c:243
 ext4_fill_super+0x427/0x7ff0 fs/ext4/super.c:4085
 mount_bdev+0x1e8/0x290 fs/super.c:1368
 ext4_mount+0x2d/0x40 fs/ext4/super.c:6638
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1498
 do_new_mount fs/namespace.c:2923 [inline]
 path_mount+0x11f2/0x1d30 fs/namespace.c:3253
 do_mount fs/namespace.c:3266 [inline]
 __do_sys_mount fs/namespace.c:3474 [inline]
 __se_sys_mount+0x23d/0x2e0 fs/namespace.c:3451
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3451
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237d42528 of 1 bytes by task 27974 on cpu 0:
 pagevec_count include/linux/pagevec.h:61 [inline]
 __lru_add_drain_all+0x12c/0x3e0 mm/swap.c:828
 lru_add_drain_all+0xc/0x10 mm/swap.c:850
 invalidate_bdev+0x50/0x70 fs/block_dev.c:96
 __loop_clr_fd+0x566/0x8f0 drivers/block/loop.c:1402
 loop_clr_fd drivers/block/loop.c:1496 [inline]
 lo_ioctl+0xa48/0x1340 drivers/block/loop.c:1852
 blkdev_ioctl+0x1d0/0x3c0 block/ioctl.c:585
 block_ioctl+0x6d/0x80 fs/block_dev.c:1604
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0d -> 0x0e

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 27974 Comm: syz-executor.5 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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