PID: 17642  TASK: ffff8800a6692220  CPU: 2   COMMAND: "umount"
 #0 [ffff88009f483748] machine_kexec at ffffffff810613ae
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/arch/x86/kernel/machine_kexec_64.c: 343
 #1 [ffff88009f4837a8] __crash_kexec at ffffffff811160a2
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/kernel/kexec_core.c: 897
 #2 [ffff88009f483878] panic at ffffffff817d8546
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/./arch/x86/include/asm/smp.h: 93
 #3 [ffff88009f4838f8] lbug_with_loc at ffffffffa02e656b [libcfs]
    /home/green/git/lustre-release/libcfs/libcfs/debug.c: 470
 #4 [ffff88009f483918] ldlm_server_completion_ast at ffffffffa0808295 [ptlrpc]
    /home/green/git/lustre-release/lustre/ptlrpc/../../lustre/ldlm/ldlm_lockd.c: 1006
 #5 [ffff88009f483988] cleanup_resource at ffffffffa07e2637 [ptlrpc]
    /home/green/git/lustre-release/lustre/ptlrpc/../../lustre/ldlm/ldlm_resource.c: 1081
 #6 [ffff88009f4839f0] ldlm_resource_clean at ffffffffa07e275f [ptlrpc]
    /home/green/git/lustre-release/lustre/ptlrpc/../../lustre/ldlm/ldlm_resource.c: 1112
 #7 [ffff88009f483a10] cfs_hash_for_each_relax at ffffffffa02eea42 [libcfs]
    /home/green/git/lustre-release/libcfs/libcfs/hash.c: 1645
 #8 [ffff88009f483a90] cfs_hash_for_each_nolock at ffffffffa02f1bd5 [libcfs]
    /home/green/git/lustre-release/libcfs/libcfs/hash.c: 1710
 #9 [ffff88009f483ac0] ldlm_namespace_cleanup at ffffffffa07e0ec0 [ptlrpc]
    /home/green/git/lustre-release/lustre/ptlrpc/../../lustre/ldlm/ldlm_resource.c: 1150
#10 [ffff88009f483ae0] __ldlm_namespace_free at ffffffffa07e1871 [ptlrpc]
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/./arch/x86/include/asm/atomic.h: 25
#11 [ffff88009f483b70] ldlm_namespace_free_prior at ffffffffa07e1e6a [ptlrpc]
    /home/green/git/lustre-release/lustre/ptlrpc/../../lustre/ldlm/ldlm_resource.c: 1237
#12 [ffff88009f483ba0] mdt_device_fini at ffffffffa1344b24 [mdt]
    /home/green/git/lustre-release/lustre/mdt/mdt_handler.c: 5867
#13 [ffff88009f483be8] class_cleanup at ffffffffa0577d1c [obdclass]
    /home/green/git/lustre-release/lustre/include/obd_class.h: 598
#14 [ffff88009f483c60] class_process_config at ffffffffa0578ba7 [obdclass]
    /home/green/git/lustre-release/libcfs/include/libcfs/libcfs_debug.h: 155
#15 [ffff88009f483d10] class_manual_cleanup at ffffffffa057af26 [obdclass]
    /home/green/git/lustre-release/lustre/obdclass/obd_config.c: 2334
#16 [ffff88009f483db8] server_put_super at ffffffffa05b5925 [obdclass]
    /home/green/git/lustre-release/libcfs/include/libcfs/libcfs_fail.h: 79
#17 [ffff88009f483e40] generic_shutdown_super at ffffffff812476ca
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/fs/super.c: 401
#18 [ffff88009f483e60] kill_anon_super at ffffffff81247ac2
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/fs/super.c: 961
#19 [ffff88009f483e78] lustre_kill_super at ffffffffa15fb29b [lustre]
    /home/green/git/lustre-release/lustre/llite/super25.c: 207
#20 [ffff88009f483e90] deactivate_locked_super at ffffffff81247ec9
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/fs/super.c: 277
#21 [ffff88009f483eb0] deactivate_super at ffffffff81248616
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/fs/super.c: 298
#22 [ffff88009f483ec8] cleanup_mnt at ffffffff81268b1f
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/fs/namespace.c: 1172
#23 [ffff88009f483ee0] __cleanup_mnt at ffffffff81268bb2
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/fs/namespace.c: 1179
#24 [ffff88009f483ef0] task_work_run at ffffffff810b69b5
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/kernel/task_work.c: 89
#25 [ffff88009f483f30] do_notify_resume at ffffffff8102ccb2
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/include/linux/tracehook.h: 196
#26 [ffff88009f483f50] int_signal at ffffffff817f4363
    /home/green/bk/linux-3.10.0-1160.59.1.el7-debug/arch/x86/kernel/entry_64.S: 701
    RIP: 00007fd255c19ba7  RSP: 00007ffd556cf8e8  RFLAGS: 00000246
    RAX: 0000000000000000  RBX: 000055d3c5725040  RCX: ffffffffffffffff
    RDX: 0000000000000001  RSI: 0000000000000000  RDI: 000055d3c5727140
    RBP: 000055d3c5727140   R8: 003173646d2d6572   R9: 0000000000000011
    R10: 00007ffd556cf360  R11: 0000000000000246  R12: 00007fd256797d78
    R13: 0000000000000000  R14: 000055d3c5725210  R15: 000055d3c5725040
    ORIG_RAX: 00000000000000a6  CS: 0033  SS: 002b