Ceph » CephFS

Thread 19 "ms_dispatch" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffb7fff700 (LWP 1213331)]
MDCache::expire_recursive (this=this@entry=0x7fffc8065920, in=in@entry=0x7fffc8082610, expiremap=std::map with 1 element = {...}) at ../src/mds/MDCache.cc:3747
3747          if (dnl->is_primary()) {
(gdb) bt
#0  MDCache::expire_recursive (this=this@entry=0x7fffc8065920, in=in@entry=0x7fffc8082610, expiremap=std::map with 1 element = {...}) at ../src/mds/MDCache.cc:3747
#1  0x00005555558ee433 in MDCache::trim (this=this@entry=0x7fffc8065920, count=count@entry=0) at ../src/mds/MDCache.cc:6811
#2  0x00005555558f3c24 in MDCache::upkeep_main (this=0x7fffc8065920) at ../src/mds/MDCache.cc:13285
#3  0x00005555559190bd in std::__invoke_impl<void, void (MDCache::*)(), MDCache*> (__t=<optimized out>, __f=<optimized out>) at /usr/include/c++/9/bits/invoke.h:89
#4  std::__invoke<void (MDCache::*)(), MDCache*> (__fn=<optimized out>) at /usr/include/c++/9/bits/invoke.h:95
#5  std::thread::_Invoker<std::tuple<void (MDCache::*)(), MDCache*> >::_M_invoke<0ul, 1ul> (this=<optimized out>) at /usr/include/c++/9/thread:244
#6  std::thread::_Invoker<std::tuple<void (MDCache::*)(), MDCache*> >::operator() (this=<optimized out>) at /usr/include/c++/9/thread:251
#7  std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (MDCache::*)(), MDCache*> > >::_M_run (this=<optimized out>) at /usr/include/c++/9/thread:195
#8  0x00007ffff71cdde4 in ?? () from /lib/x86_64-linux-gnu/libstdc++.so.6
#9  0x00007ffff72e2609 in start_thread (arg=<optimized out>) at pthread_create.c:477
#10 0x00007ffff6ebb293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb) p dnl
$1 = (CDentry::linkage_t *) 0x1a8

Range-based for should not be used when we are altering the container.