btrfs stack trace in dmesg 3.8.4

[    5.321758] Btrfs loaded
[    5.383144] device fsid 9d7a8466-7279-4ea7-b057-8d340dbf0215 devid 1 transid 24076 /dev/sda3
[    5.496840] device fsid 9d7a8466-7279-4ea7-b057-8d340dbf0215 devid 2 transid 24076 /dev/sdb3
[    5.613914] device fsid 9d7a8466-7279-4ea7-b057-8d340dbf0215 devid 3 transid 24076 /dev/sdc3
[    5.714075] device fsid 9d7a8466-7279-4ea7-b057-8d340dbf0215 devid 4 transid 24076 /dev/sdd3
[    5.815334] device fsid 9d7a8466-7279-4ea7-b057-8d340dbf0215 devid 2 transid 24076 /dev/sdb3
[    5.845717] btrfs: enabling auto defrag
[    5.851893] btrfs: enabling auto recovery
[    5.858011] btrfs: disk space caching is enabled
[    6.588389] ------------[ cut here ]------------
[    6.594511] WARNING: at fs/inode.c:336 inc_nlink+0x31/0x50()
[    6.600612] Hardware name: GA-990FXA-UD5
[    6.606655] Modules linked in: btrfs zlib_deflate libcrc32c radeon ttm crc32c_intel drm_kms_helper drm xhci_hcd i2c_algo_bit processor thermal_sys scsi_dh_rdac scsi_dh_hp_sw scsi_dh_emc scsi_dh_alua scsi_dh
[    6.613297] Pid: 302, comm: mount Not tainted 3.8.4-peter #9
[    6.619839] Call Trace:
[    6.626269]  [<ffffffff81058b8a>] warn_slowpath_common+0x7a/0xb0
[    6.632850]  [<ffffffff81058bd5>] warn_slowpath_null+0x15/0x20
[    6.639285]  [<ffffffff81192371>] inc_nlink+0x31/0x50
[    6.645671]  [<ffffffffa0281d68>] link_to_fixup_dir+0xb8/0xe0 [btrfs]
[    6.652090]  [<ffffffffa0285ccf>] replay_one_buffer+0x1ef/0x3b0 [btrfs]
[    6.658497]  [<ffffffffa0281450>] walk_up_log_tree+0xf0/0x270 [btrfs]
[    6.664936]  [<ffffffffa0281ac1>] walk_log_tree+0xc1/0x200 [btrfs]
[    6.671259]  [<ffffffffa0287d3b>] btrfs_recover_log_trees+0x20b/0x390 [btrfs]
[    6.677467]  [<ffffffffa0285ae0>] ? fixup_inode_link_counts+0x150/0x150 [btrfs]
[    6.683540]  [<ffffffffa024c592>] open_ctree+0x1632/0x1cc0 [btrfs]
[    6.689456]  [<ffffffff812e51ec>] ? disk_name+0x5c/0xb0
[    6.695217]  [<ffffffffa0224ab3>] btrfs_mount+0x593/0x6c0 [btrfs]
[    6.700992]  [<ffffffff81163f87>] ? alloc_pages_current+0xb7/0x190
[    6.706844]  [<ffffffff8117dbfe>] mount_fs+0x3e/0x1b0
[    6.712671]  [<ffffffff811978cf>] vfs_kern_mount+0x6f/0x110
[    6.718525]  [<ffffffff81199bb7>] do_mount+0x217/0xa90
[    6.724390]  [<ffffffff81124829>] ? __get_free_pages+0x9/0x50
[    6.730314]  [<ffffffff81199815>] ? copy_mount_options+0x35/0x180
[    6.736208]  [<ffffffff8119a4b9>] sys_mount+0x89/0xd0
[    6.742048]  [<ffffffff8161b6ed>] system_call_fastpath+0x1a/0x1f
[    6.747927] ---[ end trace f2697af8c6d36668 ]---
[   17.758929] btrfs: enabling auto defrag
[   17.764855] btrfs: enabling auto recovery
[   17.770772] btrfs: disk space caching is enabled
[   18.762227] systemd[1]: systemd 44 running in system mode. (+PAM +LIBWRAP +AUDIT +SELINUX +SYSVINIT +LIBCRYPTSETUP; suse)
[   19.113686] systemd[1]: Inserted module 'autofs4'
[   19.127177] systemd[1]: Set hostname to <peter.site>.
[   22.140769] btrfs: enabling auto defrag
[   22.144817] udevd[423]: starting version 182
[   22.150383] btrfs: enabling auto recovery
[   22.155191] btrfs: disk space caching is enabled
[   22.321857] btrfs: unlinked 5 orphans
[   22.326800] btrfs: truncated 8 orphans