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BUG: KCSAN: data-race in __lru_add_drain_all / lru_cache_add

write to 0xffff888237c42528 of 1 bytes by task 22807 on cpu 0:
 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
 page_cache_ra_unbounded+0x262/0x410 mm/readahead.c:221
 do_page_cache_ra mm/readahead.c:267 [inline]
 force_page_cache_ra+0x246/0x280 mm/readahead.c:299
 page_cache_sync_ra+0xcc/0xe0 mm/readahead.c:573
 page_cache_sync_readahead include/linux/pagemap.h:884 [inline]
 filemap_get_pages mm/filemap.c:2467 [inline]
 filemap_read+0x388/0x1220 mm/filemap.c:2550
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
 blkdev_read_iter+0xb9/0xf0 fs/block_dev.c:1671
 call_read_iter include/linux/fs.h:2108 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x565/0x5d0 fs/read_write.c:496
 ksys_read+0xce/0x180 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:642
 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 0xffff888237c42528 of 1 bytes by task 22798 on cpu 1:
 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
 ext4_put_super+0x5d0/0x8c0 fs/ext4/super.c:1240
 generic_shutdown_super+0xe1/0x230 fs/super.c:465
 kill_block_super+0x4a/0x90 fs/super.c:1395
 deactivate_locked_super+0x65/0xd0 fs/super.c:335
 deactivate_super+0x85/0x90 fs/super.c:366
 cleanup_mnt+0x267/0x2d0 fs/namespace.c:1136
 __cleanup_mnt+0x15/0x20 fs/namespace.c:1143
 task_work_run+0xae/0x130 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x156/0x190 kernel/entry/common.c:209
 __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+0x49/0x90 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x05 -> 0x06

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22798 Comm: syz-executor.3 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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