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BUG: KCSAN: data-race in __lru_cache_add / lru_add_drain_all

read to 0xffff88812c1299e0 of 1 bytes by task 13391 on cpu 0:
 lru_add_drain_all+0x17e/0x3d0 mm/swap.c:746
 invalidate_bdev+0x6e/0x90 fs/block_dev.c:97
 open_ctree+0x14fd/0x407c fs/btrfs/disk-io.c:2823
 btrfs_fill_super fs/btrfs/super.c:1213 [inline]
 btrfs_mount_root.cold+0x13/0x19d fs/btrfs/super.c:1561
 legacy_get_tree+0x7e/0xf0 fs/fs_context.c:647
 vfs_get_tree+0x56/0x1a0 fs/super.c:1545
 fc_mount+0x20/0x80 fs/namespace.c:962
 vfs_kern_mount.part.0+0xe6/0xf0 fs/namespace.c:992
 vfs_kern_mount+0x49/0x70 fs/namespace.c:979
 btrfs_mount+0x250/0xf37 fs/btrfs/super.c:1621
 legacy_get_tree+0x7e/0xf0 fs/fs_context.c:647
 vfs_get_tree+0x56/0x1a0 fs/super.c:1545
 do_new_mount fs/namespace.c:2822 [inline]
 do_mount+0x1004/0x14f0 fs/namespace.c:3142
 ksys_mount+0xe8/0x160 fs/namespace.c:3351
 __do_sys_mount fs/namespace.c:3365 [inline]
 __se_sys_mount fs/namespace.c:3362 [inline]
 __x64_sys_mount+0x70/0x90 fs/namespace.c:3362
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88812c1299e0 of 1 bytes by task 13400 on cpu 1:
 pagevec_add include/linux/pagevec.h:81 [inline]
 __lru_cache_add+0xbf/0x1d0 mm/swap.c:410
 lru_cache_add+0x1f/0x30 mm/swap.c:447
 add_to_page_cache_lru+0x16a/0x260 mm/filemap.c:959
 mpage_readpages+0x263/0x3c0 fs/mpage.c:399
 blkdev_readpages+0x36/0x50 fs/block_dev.c:620
 read_pages+0xa2/0x2d0 mm/readahead.c:126
 __do_page_cache_readahead+0x353/0x390 mm/readahead.c:212
 force_page_cache_readahead+0x13a/0x1f0 mm/readahead.c:243
 page_cache_sync_readahead+0x1cf/0x1e0 mm/readahead.c:522
 generic_file_buffered_read mm/filemap.c:2051 [inline]
 generic_file_read_iter+0xeb6/0x1440 mm/filemap.c:2324
 blkdev_read_iter+0xb2/0xe0 fs/block_dev.c:2039
 call_read_iter include/linux/fs.h:1896 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 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: 13400 Comm: blkid Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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