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BUG: KCSAN: data-race in inode_set_ctime_to_ts / inode_update_timestamps

write to 0xffff88811c0dec80 of 4 bytes by task 27907 on cpu 0:
 inode_set_ctime_to_ts+0x85/0x180 fs/inode.c:2716
 inode_set_ctime_current+0x1b5/0x770 fs/inode.c:2779
 inode_update_timestamps+0x85/0x250 fs/inode.c:2066
 generic_update_time fs/inode.c:2105 [inline]
 inode_update_time fs/inode.c:2125 [inline]
 __file_update_time fs/inode.c:2353 [inline]
 file_update_time+0x219/0x2b0 fs/inode.c:2383
 pipe_write+0xa7b/0xd20 fs/pipe.c:608
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x77b/0x920 fs/read_write.c:679
 ksys_write+0xe8/0x1b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:739
 x64_sys_call+0x287e/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811c0dec80 of 4 bytes by task 1080 on cpu 1:
 inode_get_ctime_nsec include/linux/fs.h:1726 [inline]
 inode_get_ctime include/linux/fs.h:1732 [inline]
 inode_update_timestamps+0x50/0x250 fs/inode.c:2063
 generic_update_time fs/inode.c:2105 [inline]
 inode_update_time fs/inode.c:2125 [inline]
 __file_update_time fs/inode.c:2353 [inline]
 file_update_time+0x219/0x2b0 fs/inode.c:2383
 pipe_write+0xa7b/0xd20 fs/pipe.c:608
 __kernel_write_iter+0x247/0x4c0 fs/read_write.c:612
 __kernel_write fs/read_write.c:632 [inline]
 kernel_write+0x1ed/0x400 fs/read_write.c:653
 p9_fd_write net/9p/trans_fd.c:432 [inline]
 p9_write_work+0x32a/0x750 net/9p/trans_fd.c:483
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3317
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3398
 kthread+0x4ae/0x520 kernel/kthread.c:464
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x32d8978e -> 0x38ce8e75

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 1080 Comm: kworker/1:2 Not tainted 6.13.0-syzkaller-09793-g69b8923f5003 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: events p9_write_work
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