btrfs mount failure

[14244.232307] Call Trace:
[14244.232314]  [<ffffffff8171bcb4>] dump_stack+0x45/0x56
[14244.232317]  [<ffffffff810676cd>] warn_slowpath_common+0x7d/0xa0
[14244.232319]  [<ffffffff810677aa>] warn_slowpath_null+0x1a/0x20
[14244.232328]  [<ffffffffa00ad759>] btrfs_put_block_group+0x69/0x70 [btrfs]
[14244.232339]  [<ffffffffa00b6a60>] btrfs_free_block_groups+0xb0/0x390 [btrfs]
[14244.232350]  [<ffffffffa00c53b8>] open_ctree+0x1848/0x1f80 [btrfs]
[14244.232358]  [<ffffffffa009c56e>] btrfs_mount+0x63e/0x800 [btrfs]
[14244.232363]  [<ffffffff8116f02a>] ? pcpu_alloc+0x7da/0xa00
[14244.232367]  [<ffffffff811c0a29>] mount_fs+0x39/0x1b0
[14244.232369]  [<ffffffff8116f260>] ? __alloc_percpu+0x10/0x20
[14244.232373]  [<ffffffff811dbcd7>] vfs_kern_mount+0x67/0x110
[14244.232375]  [<ffffffff811de4ee>] do_mount+0x23e/0xad0
[14244.232378]  [<ffffffff8116a28b>] ? strndup_user+0x4b/0xf0
[14244.232380]  [<ffffffff811df073>] SyS_mount+0x83/0xc0
[14244.232383]  [<ffffffff8172c87f>] tracesys+0xe1/0xe6
[14244.232385] ---[ end trace fb65a2c6b18c9bc9 ]---

ubuntu 14.04 with kernel 3.13.0-32-generic