Ceph » CephFS

i noticed this in dmesg:

[ 5354.344055] ------------[ cut here ]------------
[ 5354.348726] WARNING: at /srv/autobuild-ceph/gitbuilder.git/build/fs/ceph/inode.c:1000 ceph_fill_trace+0x760/0x900 [ceph]()
[ 5354.359820] Modules linked in: ceph libceph ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs reiserfs coretemp kvm_intel kvm nfsd nfs_acl exportfs auth_rpcgss ghash_clmulni_intel aesni_intel oid_registry nfs fscache ablk_helper cryptd lockd lrw sunrpc gf128mul glue_helper aes_x86_64 psmouse lpc_ich i7core_edac edac_core serio_raw mfd_core joydev microcode hed lp dcdbas parport hid_generic usbhid hid btrfs raid6_pq ixgbe dca ptp pps_core mdio mptsas mptscsih mptbase bnx2 scsi_transport_sas xor zlib_deflate crc32c_intel libcrc32c
[ 5354.408084] CPU: 5 PID: 4575 Comm: kworker/5:2 Tainted: G        W    3.10.0-ceph-00039-g77c8bf2 #1
[ 5354.417173] Hardware name: Dell Inc. PowerEdge R410/01V648, BIOS 1.6.3 02/07/2011
[ 5354.424700] Workqueue: ceph-msgr con_work [libceph]
[ 5354.429619]  ffffffffa0836290 ffff8802207f7a28 ffffffff816311b0 ffff8802207f7a68
[ 5354.437102]  ffffffff8103fae0 ffff88020cf08e00 ffff88020ad9d800 ffff880221819800
[ 5354.444573]  0000000000000000 ffff880220459800 ffff8802204cb400 ffff8802207f7a78
[ 5354.452060] Call Trace:
[ 5354.454527]  [<ffffffff816311b0>] dump_stack+0x19/0x1b
[ 5354.459697]  [<ffffffff8103fae0>] warn_slowpath_common+0x70/0xa0
[ 5354.465740]  [<ffffffff8103fb2a>] warn_slowpath_null+0x1a/0x20
[ 5354.471599]  [<ffffffffa08158f0>] ceph_fill_trace+0x760/0x900 [ceph]
[ 5354.477985]  [<ffffffff81633cfc>] ? mutex_lock_nested+0x27c/0x360
[ 5354.484112]  [<ffffffffa08314a3>] ? dispatch+0xba3/0x1740 [ceph]
[ 5354.490159]  [<ffffffffa08314b8>] dispatch+0xbb8/0x1740 [ceph]
[ 5354.496029]  [<ffffffff81511196>] ? kernel_recvmsg+0x46/0x60
[ 5354.501716]  [<ffffffffa07dbe38>] ? ceph_tcp_recvmsg+0x48/0x60 [libceph]
[ 5354.508450]  [<ffffffff810a319d>] ? trace_hardirqs_on+0xd/0x10
[ 5354.514313]  [<ffffffffa07df1f8>] con_work+0x1948/0x2d50 [libceph]
[ 5354.520530]  [<ffffffff81080c73>] ? idle_balance+0x133/0x180
[ 5354.526222]  [<ffffffff81071c08>] ? finish_task_switch+0x48/0x110
[ 5354.532336]  [<ffffffff81071c08>] ? finish_task_switch+0x48/0x110
[ 5354.538461]  [<ffffffff8105f37f>] ? process_one_work+0x16f/0x540
[ 5354.544492]  [<ffffffff8105f3ea>] process_one_work+0x1da/0x540
[ 5354.550355]  [<ffffffff8105f37f>] ? process_one_work+0x16f/0x540
[ 5354.556397]  [<ffffffff810605cc>] worker_thread+0x11c/0x370
[ 5354.561991]  [<ffffffff810604b0>] ? manage_workers.isra.20+0x2e0/0x2e0
[ 5354.568550]  [<ffffffff8106728a>] kthread+0xea/0xf0
[ 5354.573453]  [<ffffffff810671a0>] ? flush_kthread_worker+0x150/0x150
[ 5354.579841]  [<ffffffff8164071c>] ret_from_fork+0x7c/0xb0
[ 5354.585264]  [<ffffffff810671a0>] ? flush_kthread_worker+0x150/0x150
[ 5354.591648] ---[ end trace fbc981dc5d005af8 ]---

job was

kernel:
  kdb: true
  sha1: 77c8bf2f972a9d6ff446c49a41678bf931bbee44
machine_type: plana
nuke-on-error: true
overrides:
  admin_socket:
    branch: next
  ceph:
    conf:
      mds:
        debug mds: 20
        debug ms: 1
      mon:
        debug mon: 20
        debug ms: 20
        debug paxos: 20
      osd:
        osd op thread timeout: 60
    fs: btrfs
    log-whitelist:
    - slow request
    sha1: 884fa2fcb6d707b23317bab1da909586ddc27608
  ceph-deploy:
    conf:
      client:
        debug monc: 20
        debug ms: 1
        debug objecter: 20
        debug rados: 20
        log file: /var/log/ceph/ceph-..log
      mon:
        debug mon: 20
        debug ms: 20
        debug paxos: 20
  install:
    ceph:
      sha1: 884fa2fcb6d707b23317bab1da909586ddc27608
  s3tests:
    branch: next
  workunit:
    sha1: 884fa2fcb6d707b23317bab1da909586ddc27608
roles:
- - mon.a
  - mon.c
  - osd.0
  - osd.1
  - osd.2
- - mon.b
  - mds.a
  - osd.3
  - osd.4
  - osd.5
- - client.0
- - client.1
tasks:
- chef: null
- clock.check: null
- install: null
- ceph: null
- kclient:
  - client.0
- knfsd:
  - client.0
- nfs:
    client.1:
      options:
      - rw
      - hard
      - intr
      - nfsvers=3
      server: client.0
- workunit:
    clients:
      client.1:
      - suites/dbench-short.sh

and the task is hung (tho i didn't verify the warning and hang are related)