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BUG: KCSAN: data-race in __lru_add_drain_all / folio_activate

read-write to 0xffff888237c29ac8 of 1 bytes by task 3214 on cpu 0:
 folio_batch_add include/linux/pagevec.h:126 [inline]
 folio_batch_add_and_move mm/swap.c:231 [inline]
 folio_activate+0xbb/0x1c0 mm/swap.c:361
 folio_mark_accessed+0x114/0x190 mm/swap.c:481
 shmem_file_read_iter+0x2e8/0x560 mm/shmem.c:2691
 do_iter_read+0x4b1/0x760 fs/read_write.c:795
 vfs_iter_read+0x50/0x70 fs/read_write.c:837
 lo_read_simple drivers/block/loop.c:290 [inline]
 do_req_filebacked drivers/block/loop.c:500 [inline]
 loop_handle_cmd drivers/block/loop.c:1888 [inline]
 loop_process_work+0x9ac/0x1300 drivers/block/loop.c:1923
 loop_workfn+0x31/0x40 drivers/block/loop.c:1947
 process_one_work+0x3e6/0x750 kernel/workqueue.c:2408
 worker_thread+0x5f2/0xa10 kernel/workqueue.c:2555
 kthread+0x1d7/0x210 kernel/kthread.c:379
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff888237c29ac8 of 1 bytes by task 3059 on cpu 1:
 folio_batch_count include/linux/pagevec.h:105 [inline]
 cpu_needs_drain mm/swap.c:800 [inline]
 __lru_add_drain_all+0x21d/0x420 mm/swap.c:889
 lru_add_drain_all+0x10/0x20 mm/swap.c:905
 invalidate_bdev+0x5a/0x80 block/bdev.c:86
 ext4_put_super+0x502/0x800 fs/ext4/super.c:1329
 generic_shutdown_super+0xd9/0x260 fs/super.c:500
 kill_block_super+0x4e/0xa0 fs/super.c:1407
 deactivate_locked_super+0x6b/0xd0 fs/super.c:331
 deactivate_super+0x9b/0xb0 fs/super.c:362
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1177
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1184
 task_work_run+0x135/0x1a0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd1/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x01 -> 0x02

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3059 Comm: syz-executor.0 Not tainted 6.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
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EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.
EXT4-fs (loop0): unmounting filesystem 00000000-0000-0000-0000-000000000000.