Ceph

     0> 2016-11-11 15:42:48.371262 7f2731ac4980 -1 /tmp/buildd/ceph-11.0.2-1428-g164de97/src/os/filestore/FileStore.cc: In function 'int FileStore::_do_copy_range(int, int, uint64_t, uint64_t, uint64_t, bool)' thread 7f2731ac4980 time 2016-11-11 15:42:48.368633
/tmp/buildd/ceph-11.0.2-1428-g164de97/src/os/filestore/FileStore.cc: 3731: FAILED assert(pos == end)

 ceph version 11.0.2-1428-g164de97 (164de97dfdce69d5387624fc19d64e8b219fdeed)
 1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x8b) [0x7f27314236ab]
 2: (FileStore::_do_copy_range(int, int, unsigned long, unsigned long, unsigned long, bool)+0x18ec) [0x7f273108e00c]
 3: (GenericFileStoreBackend::clone_range(int, int, unsigned long, unsigned long, unsigned long)+0x7b) [0x7f27310db71b]
 4: (FileStore::_do_clone_range(int, int, unsigned long, unsigned long, unsigned long)+0x80) [0x7f273108c520]
 5: (FileStore::_clone_range(coll_t const&, ghobject_t const&, coll_t const&, ghobject_t const&, unsigned long, unsigned long, unsigned long, SequencerPosition const&)+0x1a6) [0x7f27310be1c6]
 6: (FileStore::_do_transaction(ObjectStore::Transaction&, unsigned long, int, ThreadPool::TPHandle*)+0x2d09) [0x7f27310c72a9]
 7: (FileStore::_do_transactions(std::vector<ObjectStore::Transaction, std::allocator<ObjectStore::Transaction> >&, unsigned long, ThreadPool::TPHandle*)+0x3b) [0x7f27310cb3fb]
 8: (JournalingObjectStore::journal_replay(unsigned long)+0x767) [0x7f27310ddc97]
 9: (FileStore::mount()+0x33a6) [0x7f27310b7fd6]
 10: (main()+0x23cf) [0x7f2730ce350f]
 11: (__libc_start_main()+0xf5) [0x7f272e05dec5]
 12: (()+0x427ba6) [0x7f2730d5dba6]
 NOTE: a copy of the executable, or `objdump -rdS <executable>` is needed to interpret this.

/a/sage-2016-11-11_15:15:48-rados-wip-sage-testing---basic-smithi/540725
./remote/smithi065/log/objectstore_tool.22765.log.gz

Looks like a journal replay guard ordering thing perhaps? I think the source file wasn't the right size.