Ceph - Assertion in DBObjectMap::lookup_parent

Issue

The OSD dies after startup and is logging an assertion in DBObjectMap::lookup_parent:

2017-11-30 13:33:04.512490 7f20d1a68a40 -1 os/filestore/DBObjectMap.cc: In function 'DBObjectMap::Header DBObjectMap::lookup_parent(DBObjectMap::Header)' thread 7f20d1a68a40 time 2017-11-30 13:33:04.508132
os/filestore/DBObjectMap.cc: 1148: FAILED assert(0)

 ceph version 10.2.7-48.el7cp (cf7751bcd460c757e596d3ee2991884e13c37b96)
 1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x85) [0x55c56dedee65]
 2: (DBObjectMap::lookup_parent(std::shared_ptr<DBObjectMap::_Header>)+0x7a9) [0x55c56dc10cd9]
 3: (DBObjectMap::_clear(std::shared_ptr<DBObjectMap::_Header>, std::shared_ptr<KeyValueDB::TransactionImpl>)+0x104) [0x55c56dc127d4]
 4: (DBObjectMap::clear(ghobject_t const&, SequencerPosition const*)+0x1ff) [0x55c56dc18b5f]
 5: (FileStore::lfn_unlink(coll_t const&, ghobject_t const&, SequencerPosition const&, bool)+0x241) [0x55c56db4d311]
 6: (FileStore::_remove(coll_t const&, ghobject_t const&, SequencerPosition const&)+0x8e) [0x55c56db4dcee]
 7: (FileStore::_do_transaction(ObjectStore::Transaction&, unsigned long, int, ThreadPool::TPHandle*)+0x20b3) [0x55c56db62503]
 8: (FileStore::_do_transactions(std::vector<ObjectStore::Transaction, std::allocator<ObjectStore::Transaction> >&, unsigned long, ThreadPool::TPHandle*)+0x3b) [0x55c56db6708b]
 9: (JournalingObjectStore::journal_replay(unsigned long)+0x8f7) [0x55c56db7e087]
 10: (FileStore::mount()+0x3cd6) [0x55c56db55056]
 11: (OSD::init()+0x27d) [0x55c56d80423d]
 12: (main()+0x2c55) [0x55c56d71d145]
 13: (__libc_start_main()+0xf5) [0x7f20ce971c05]
 14: (()+0x3c9837) [0x55c56d7b3837]