Bug #21573: [upgrade] buffer::list ABI broken in luminous release - RADOS - Ceph

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Bug #21573

closed

[upgrade] buffer::list ABI broken in luminous release

Added by Jason Dillaman over 6 years ago. Updated over 6 years ago.

Status:

Resolved

Priority:

Urgent

Assignee:

Sage Weil

Category:

Target version:

% Done:

Source:

Tags:

Backport:

luminous

Regression:

Severity:

3 - minor

Reviewed:

Affected Versions:

ceph-qa-suite:

Component(RADOS):

librados

Pull request ID:

Crash signature (v1):

Crash signature (v2):

Description

A client application that was compiled against a pre-Luminous librados C++ API and therefore utilizing bufferlist will now be ABI incompatible w/ the Luminous version of librados. Specifically, the addition of "_mempool" within buffer::list causes a seg fault since pre-Luminous clients would not have initialized that field.

#0  mempool::pool_t::adjust_count (this=0x8737e8a5c980, items=items@entry=1, bytes=bytes@entry=4008)
    at /home/jdillaman/ceph/src/common/mempool.cc:85
#1  0x00007ffff75dea47 in ceph::buffer::raw::reassign_to_mempool (this=<optimized out>, this=<optimized out>, pool=1879025072)
    at /home/jdillaman/ceph/src/common/buffer.cc:206
#2  ceph::buffer::list::append (this=this@entry=0x7fff6fffa5b0, data=data@entry=0x7fffee427477 "ceph v027", len=len@entry=9)
    at /home/jdillaman/ceph/src/common/buffer.cc:1912
#3  0x00007fffee0ab632 in AsyncConnection::_process_connection (this=this@entry=0x7fff64009730)
    at /home/jdillaman/ceph/src/msg/async/AsyncConnection.cc:923
#4  0x00007fffee0b1e98 in AsyncConnection::process (this=0x7fff64009730) at /home/jdillaman/ceph/src/msg/async/AsyncConnection.cc:838
#5  0x00007fffee0c4405 in EventCenter::process_events (this=this@entry=0xb09910, timeout_microseconds=<optimized out>, 
    timeout_microseconds@entry=30000000, working_dur=working_dur@entry=0x7fff6fffb2e8) at /home/jdillaman/ceph/src/msg/async/Event.cc:436
#6  0x00007fffee0c8b68 in NetworkStack::<lambda()>::operator()(void) const (__closure=0xb369c8)
    at /home/jdillaman/ceph/src/msg/async/Stack.cc:53
#7  0x00007ffff703376f in ?? () from /lib64/libstdc++.so.6
#8  0x00007ffff730773a in start_thread () from /lib64/libpthread.so.0
#9  0x00007ffff6aa2e7f in clone () from /lib64/libc.so.6

Related issues 2 (0 open — 2 closed)

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Updated by Jason Dillaman over 6 years ago

Backport set to luminous

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Updated by Jason Dillaman over 6 years ago

Subject changed from [upgrade] bufferlist ABI broken in luminous release to [upgrade] buffer::list ABI broken in luminous release
Description updated (diff)

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Updated by Jason Dillaman over 6 years ago

Description updated (diff)

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Updated by Jason Dillaman over 6 years ago

Priority changed from High to Urgent

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Updated by Yuri Weinstein over 6 years ago

Assignee set to Kefu Chai

@Kefu Chai can you pls take a look?

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Updated by Kefu Chai over 6 years ago

this would be a little bit tricky:

  class CEPH_BUFFER_API list {
    # ..
    int _mempool = -1;
    # ..
  public:
    // cons/des
    list() : _len(0), _memcopy_count(0), last_p(this) {}
    // cppcheck-suppress noExplicitConstructor
    list(unsigned prealloc) : _len(0), _memcopy_count(0), last_p(this) {
      reserve(prealloc);
    }
    // ...
  };

so the constructors are inlined, and are not defined in librados. that's why _mempool is not initialized by the old clients, which are still using their own copies of the ctors.

and we have no way to change the behavior of the inlined constructors.

so i'd suggest bump up the so version of librados. will send a mail to ceph-devel asking for more opinions.

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