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BUG: KCSAN: data-race in inode_needs_update_time / inode_set_ctime_current

write to 0xffff8881061f38e0 of 8 bytes by task 25123 on cpu 0:
 inode_set_ctime_to_ts include/linux/fs.h:1564 [inline]
 inode_set_ctime_current+0x3b3/0x4b0 fs/inode.c:2590
 inode_update_timestamps+0x68/0x3e0 fs/inode.c:1892
 generic_update_time fs/inode.c:1929 [inline]
 inode_update_time fs/inode.c:1949 [inline]
 __file_update_time fs/inode.c:2177 [inline]
 file_update_time+0xba/0x140 fs/inode.c:2207
 pipe_write+0xb0c/0xde0 fs/pipe.c:601
 call_write_iter include/linux/fs.h:1985 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x4ab/0x7d0 fs/read_write.c:584
 ksys_write+0xeb/0x1a0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:646
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff8881061f38e0 of 8 bytes by task 18177 on cpu 1:
 inode_get_ctime include/linux/fs.h:1549 [inline]
 inode_needs_update_time+0x245/0x370 fs/inode.c:2160
 file_update_time+0x2d/0x140 fs/inode.c:2203
 pipe_write+0xb0c/0xde0 fs/pipe.c:601
 __kernel_write_iter+0x162/0x3c0 fs/read_write.c:517
 __kernel_write fs/read_write.c:537 [inline]
 kernel_write+0x1f3/0x400 fs/read_write.c:558
 p9_fd_write net/9p/trans_fd.c:433 [inline]
 p9_write_work+0x32a/0x740 net/9p/trans_fd.c:484
 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

value changed: 0x000000000ca25e65 -> 0x000000000d3af4e5

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18177 Comm: kworker/1:0 Not tainted 6.6.0-rc1-syzkaller-00070-g23f108dc9ed2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
Workqueue: events p9_write_work
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