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BUG: KCSAN: data-race in __lru_add_drain_all / folio_activate

read-write to 0xffff888237c29b88 of 1 bytes by task 1814 on cpu 0:
 folio_batch_add include/linux/pagevec.h:74 [inline]
 folio_batch_add_and_move mm/swap.c:231 [inline]
 folio_activate+0xc0/0x1c0 mm/swap.c:361
 folio_mark_accessed+0x119/0x190 mm/swap.c:481
 shmem_get_folio_gfp+0xb22/0xc30 mm/shmem.c:1982
 shmem_get_folio mm/shmem.c:2143 [inline]
 shmem_write_begin+0xa6/0x210 mm/shmem.c:2688
 generic_perform_write+0x1c9/0x410 mm/filemap.c:3942
 shmem_file_write_iter+0xc8/0xe0 mm/shmem.c:2865
 do_iter_write+0x4b4/0x7b0 fs/read_write.c:860
 vfs_iter_write+0x56/0x70 fs/read_write.c:901
 lo_write_bvec drivers/block/loop.c:249 [inline]
 lo_write_simple drivers/block/loop.c:271 [inline]
 do_req_filebacked drivers/block/loop.c:495 [inline]
 loop_handle_cmd drivers/block/loop.c:1915 [inline]
 loop_process_work+0xd85/0x12e0 drivers/block/loop.c:1950
 loop_workfn+0x31/0x40 drivers/block/loop.c:1974
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703
 worker_thread+0x525/0x730 kernel/workqueue.c:2784
 kthread+0x1d7/0x210 kernel/kthread.c:388
 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304

read to 0xffff888237c29b88 of 1 bytes by task 3127 on cpu 1:
 folio_batch_count include/linux/pagevec.h:53 [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+0x54/0x70 block/bdev.c:86
 ext4_put_super+0x51b/0x7d0 fs/ext4/super.c:1353
 generic_shutdown_super+0xdb/0x210 fs/super.c:693
 kill_block_super+0x2a/0x60 fs/super.c:1646
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7305
 deactivate_locked_super+0x73/0x1c0 fs/super.c:481
 deactivate_super+0x9b/0xb0 fs/super.c:514
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1254
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1261
 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:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3127 Comm: syz-executor.4 Not tainted 6.6.0-rc1-syzkaller-00240-gf0b0d403eabb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
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