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BUG: KCSAN: data-race in write_cache_pages / write_cache_pages

write to 0xffff888100633778 of 8 bytes by task 3094 on cpu 1:
 write_cache_pages+0x6f3/0x740 mm/page-writeback.c:2527
 do_writepages+0x20f/0x340 mm/page-writeback.c:2558
 filemap_fdatawrite_wbc+0xdb/0xf0 mm/filemap.c:387
 __filemap_fdatawrite_range mm/filemap.c:420 [inline]
 __filemap_fdatawrite mm/filemap.c:426 [inline]
 filemap_flush+0x95/0xc0 mm/filemap.c:453
 sync_blockdev_nowait+0x36/0x50 block/bdev.c:186
 sync_filesystem+0xe0/0x180 fs/sync.c:60
 ext4_quota_off+0xb4/0x280 fs/ext4/super.c:7126
 ext4_quotas_off fs/ext4/super.c:1200 [inline]
 ext4_put_super+0xad/0x7e0 fs/ext4/super.c:1315
 generic_shutdown_super+0xdb/0x210 fs/super.c:696
 kill_block_super+0x2a/0x60 fs/super.c:1667
 ext4_kill_sb+0x44/0x80 fs/ext4/super.c:7330
 deactivate_locked_super+0x7a/0x1c0 fs/super.c:484
 deactivate_super+0x9b/0xb0 fs/super.c:517
 cleanup_mnt+0x272/0x2e0 fs/namespace.c:1256
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1263
 task_work_run+0x135/0x1a0 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd6/0xe0 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+0x50/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888100633778 of 8 bytes by task 1634 on cpu 0:
 write_cache_pages+0x123/0x740 mm/page-writeback.c:2411
 do_writepages+0x20f/0x340 mm/page-writeback.c:2558
 __writeback_single_inode+0x91/0x860 fs/fs-writeback.c:1625
 writeback_sb_inodes+0x514/0xad0 fs/fs-writeback.c:1916
 __writeback_inodes_wb+0x9a/0x1a0 fs/fs-writeback.c:1987
 wb_writeback+0x264/0x6e0 fs/fs-writeback.c:2094
 wb_check_background_flush fs/fs-writeback.c:2164 [inline]
 wb_do_writeback fs/fs-writeback.c:2252 [inline]
 wb_workfn+0x67f/0x8d0 fs/fs-writeback.c:2279
 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:242

value changed: 0x0000000000000000 -> 0x000000000000000a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1634 Comm: kworker/u4:5 Not tainted 6.7.0-rc3-syzkaller-00024-g18d46e76d7c2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: writeback wb_workfn (flush-7:0)
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