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BUG: KCSAN: data-race in lru_add_drain_all / lru_cache_add

read-write to 0xffff88813bc27970 of 1 bytes by task 13790 on cpu 0:
 pagevec_add include/linux/pagevec.h:78 [inline]
 lru_cache_add+0x75/0x160 mm/swap.c:464
 add_to_page_cache_lru+0x150/0x1b0 mm/filemap.c:955
 pagecache_get_page+0x60f/0x980 mm/filemap.c:1848
 grab_cache_page_write_begin+0x3f/0x70 mm/filemap.c:3358
 ext4_da_write_begin+0x34d/0xaf0 fs/ext4/inode.c:2985
 generic_perform_write+0x196/0x3a0 mm/filemap.c:3408
 ext4_buffered_write_iter+0x2e5/0x3d0 fs/ext4/file.c:270
 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1901 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4b0 fs/read_write.c:866
 vfs_writev fs/read_write.c:939 [inline]
 do_pwritev+0x20d/0x400 fs/read_write.c:1036
 __do_sys_pwritev fs/read_write.c:1083 [inline]
 __se_sys_pwritev fs/read_write.c:1078 [inline]
 __x64_sys_pwritev+0x54/0x60 fs/read_write.c:1078
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88813bc27970 of 1 bytes by task 8454 on cpu 1:
 pagevec_count include/linux/pagevec.h:65 [inline]
 lru_add_drain_all+0x108/0x3c0 mm/swap.c:823
 invalidate_bdev+0x50/0x70 fs/block_dev.c:96
 ext4_put_super+0x5b9/0x930 fs/ext4/super.c:1228
 generic_shutdown_super+0xcd/0x1f0 fs/super.c:464
 kill_block_super+0x4a/0x90 fs/super.c:1393
 deactivate_locked_super+0x6a/0xb0 fs/super.c:335
 deactivate_super+0x85/0x90 fs/super.c:366
 cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118
 __cleanup_mnt+0x15/0x20 fs/namespace.c:1125
 task_work_run+0x8e/0x110 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x16b/0x1a0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:302
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8454 Comm: syz-executor.4 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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