Ceph

The bug is highly reproducible by running 'ceph -w', and presents itself in the form of:

2013-02-26 17:43:55.447660 7f2fe6ffd700 10 mon.a@0(leader) e1 handle_subscribe mon_subscribe({log-info=19+,monmap=2+}) v2
2013-02-26 17:43:55.447668 7f2fe6ffd700 10 mon.a@0(leader).log v19 check_sub client wants log-info ver 19
2013-02-26 17:43:55.447694 7f2fe6ffd700 10 mon.a@0(leader).log v19 _create_sub_incremental level 1 ver 19 cur summary ver 19
2013-02-26 17:43:55.448894 7f2fe6ffd700 -1 mon/LogMonitor.cc: In function 'void LogMonitor::_create_sub_incremental(MLog*, int, version_t)' thread 7f2fe6ffd700 time 2013-02-26 17:43:55.447740
mon/LogMonitor.cc: 495: FAILED assert(success)

 ceph version 0.57-571-g85f2783 (85f2783a23b787685101d415fdfe64bdcdd00984)
 1: (LogMonitor::_create_sub_incremental(MLog*, int, unsigned long)+0x663) [0x54f5e3]
 2: (LogMonitor::check_sub(Subscription*)+0x59d) [0x55065d]
 3: (Monitor::handle_subscribe(MMonSubscribe*)+0xdbe) [0x49cd3e]
 4: (Monitor::_ms_dispatch(Message*)+0xfdb) [0x4b695b]
 5: (Monitor::ms_dispatch(Message*)+0x32) [0x4cd592]
 6: (DispatchQueue::entry()+0x341) [0x6b0a51]
 7: (DispatchQueue::DispatchThread::entry()+0xd) [0x63fbfd]
 8: (()+0x7e9a) [0x7f2ff78f6e9a]
 9: (clone()+0x6d) [0x7f2ff631c4bd]
 NOTE: a copy of the executable, or `objdump -rdS <executable>` is needed to interpret this.