kdebug> bt
stack trace for thread 322 "mount_server"
    kernel stack: 0xffffffff8189e000 to 0xffffffff818a3000
      user stack: 0x00007fd85b65b000 to 0x00007fd85c65b000
frame                       caller             <image>:function + offset
 0 ffffffff818a2878 (+  32) ffffffff800afdc9   <kernel_x86_64> invoke_command_trampoline(void*) + 0x19
 1 ffffffff818a2898 (+  24) ffffffff8014ceac   <kernel_x86_64> arch_debug_call_with_fault_handler + 0x16
 2 ffffffff818a28b0 (+  80) ffffffff800ace98   <kernel_x86_64> debug_call_with_fault_handler + 0x88
 3 ffffffff818a2900 (+  96) ffffffff800b004f   <kernel_x86_64> invoke_debugger_command + 0xef
 4 ffffffff818a2960 (+  64) ffffffff800b01c9   <kernel_x86_64> invoke_pipe_segment(debugger_command_pipe*, int, char*) + 0xf9
 5 ffffffff818a29a0 (+  80) ffffffff800b02dc   <kernel_x86_64> invoke_debugger_command_pipe + 0xac
 6 ffffffff818a29f0 (+  96) ffffffff800b4f68   <kernel_x86_64> ExpressionParser::_ParseCommandPipe(int&) + 0x118
 7 ffffffff818a2a50 (+  96) ffffffff800bbc23   <kernel_x86_64> ExpressionParser::EvaluateCommand(char const*, int&) + 0xd83
 8 ffffffff818a2ab0 (+ 240) ffffffff800be1cc   <kernel_x86_64> evaluate_debug_command + 0x11c
 9 ffffffff818a2ba0 (+  96) ffffffff800ae8e0   <kernel_x86_64> kernel_debugger_loop(char const*, char const*, __va_list_tag*, int) + 0x1b0
10 ffffffff818a2c00 (+  80) ffffffff800aeb1e   <kernel_x86_64> kernel_debugger_internal(char const*, char const*, __va_list_tag*, int) + 0x6e
11 ffffffff818a2c50 (+ 240) ffffffff800aee87   <kernel_x86_64> panic + 0xb7
12 ffffffff818a2d40 (+  80) ffffffff80124d46   <kernel_x86_64> delete_object_cache_internal(ObjectCache*) + 0x66
13 ffffffff818a2d90 (+  32) ffffffff80048842   <kernel_x86_64> _GLOBAL__N_1::block_cache::~block_cache() + 0x62
14 ffffffff818a2db0 (+ 112) ffffffff8004f356   <kernel_x86_64> block_cache_delete + 0x306
15 ffffffff818a2e20 (+  32) ffffffff816b79dc   <bfs> Volume::Unmount() + 0x8e
16 ffffffff818a2e40 (+  32) ffffffff816ba1b8   <bfs> bfs_unmount(fs_volume*) + 0x13
17 ffffffff818a2e60 (+ 112) ffffffff80105fe9   <kernel_x86_64> fs_unmount(char*, int, unsigned int, bool) + 0x339
18 ffffffff818a2ed0 (+  80) ffffffff8010b3b6   <kernel_x86_64> _user_unmount + 0x86
19 ffffffff818a2f20 (+  16) ffffffff8014e8a8   <kernel_x86_64> x86_64_syscall_entry + 0xfb
user iframe at 0xffffffff818a2f30 (end = 0xffffffff818a2ff8)
 rax 0x63                  rbx 0x7fd85c65a060        rcx 0x229a07f2214
 rdx 0x18aa6114980         rsi 0x0                   rdi 0x1681bc0
 rbp 0x7fd85c65a120         r8 0x7fd                  r9 0x229a0b3f300
 r10 0x229a07f2551         r11 0x3246                r12 0x0
 r13 0x7fd85c65a150        r14 0x0                   r15 0x7fd85c65a150
 rip 0x229a07f2214         rsp 0x7fd85c65a058     rflags 0x3246
 vector: 0x63, error code: 0x0
20 ffffffff818a2f30 (+140569361478128) 00000229a07f2214   <libroot.so> _kern_unmount + 0x0c
21 00007fd85c65a120 (+ 144) 000001c19b88e134   <_APP_> AutoMounter::_UnmountAndEjectVolume(BPartition*, BPath&, char const*) + 0x54
22 00007fd85c65a1b0 (+ 528) 000001c19b88e472   <_APP_> AutoMounter::_UnmountAndEjectVolume(BMessage*) + 0x1b2
23 00007fd85c65a3c0 (+ 176) 000001c19b88eae5   <_APP_> AutoMounter::MessageReceived(BMessage*) + 0x165
24 00007fd85c65a470 (+ 592) 0000018aa5d3f6a3   <libbe.so> BApplication::DispatchMessage(BMessage*, BHandler*) + 0x1b3
25 00007fd85c65a6c0 (+  80) 0000018aa5d4692c   <libbe.so> BLooper::task_looper() + 0x26c
26 00007fd85c65a710 (+  32) 0000018aa5d3c801   <libbe.so> BApplication::Run() + 0x21
27 00007fd85c65a730 (+ 640) 000001c19b88c995   <_APP_> main + 0x25
28 00007fd85c65a9b0 (+  48) 000001c19b88cace   <_APP_> _start + 0x3e
29 00007fd85c65a9e0 (+  48) 000000c48589f575   </boot/system/runtime_loader@0x000000c48588b000> <unknown> + 0x14575
30 00007fd85c65aa10 (+   0) 00007f66a81fe260   <commpage> commpage_thread_exit + 0x00