ceph-0.41 kernel-libre-3.2.3-2.fc16.x86_64

[root@freie osd0]# ls
ls: cannot access snap_8218138: No such file or directory
ceph_fsid               current   snap_8217787   whoami
clustersnap_1328380592  fsid      snap_8217891
clustersnap_1328384911  journal0  snap_8218138
clustersnap_1328488096  magic     store_version

# cannot access or remove snap_8218138 at this point, it was just snapshotted from current

[root@freie osd0]# btrfs su del current
Delete subvolume '/media/ceph/osd0/current'

# *can* access snap_8218138 at this point, but snapshotting it repeats the failure

[root@freie osd0]# btrfs su del snap_8218138
Delete subvolume '/media/ceph/osd0/snap_8218138'
[root@freie osd0]# btrfs su snap snap_8217891 current
Create a snapshot of 'snap_8217891' in './current'
[root@freie osd0]# service ceph start osd0

# all is fine now

[ 9615.792926] btrfs: unlinked 1 orphans
[10267.616701] btrfs: unlinked 1 orphans
[10425.607538] ------------[ cut here ]------------
[10425.607603] WARNING: at fs/btrfs/inode.c:2222 btrfs_orphan_cleanup+0xbd/0x450 [btrfs]()
[10425.607620] Hardware name: System Product Name
[10425.607625] Modules linked in: tcp_lp fuse tun ip6t_REJECT ipt_MASQUERADE nf_conntrack_ipv6 ipt_REDIRECT nf_defrag_ipv6 xt_state xt_owner iptable_nat nf_nat nf_conntrack_ipv4 nf_conntrack nf_defrag_ipv4 ip6table_filter iptable_mangle ip6_tables snd_hda_codec_via dm9601 usbnet mii snd_hda_intel snd_hda_codec joydev snd_hwdep snd_seq snd_seq_device snd_pcm nfsd lockd nfs_acl snd_timer snd soundcore virtio_net ppdev forcedeth k10temp i2c_nforce2 edac_core edac_mce_amd auth_rpcgss asus_atk0110 serio_raw parport_pc parport snd_page_alloc kvm_amd kvm sunrpc uinput raid1 btrfs pata_acpi hid_sunplus zlib_deflate libcrc32c ata_generic sata_nv pata_amd usb_storage nouveau ttm drm_kms_helper drm i2c_algo_bit i2c_core mxm_wmi wmi video [last unloaded: scsi_wait_scan]
[10425.607735] Pid: 2838, comm: ceph-osd Not tainted 3.2.3-libre.2.fc16.x86_64 #1
[10425.607741] Call Trace:
[10425.607768]  [<ffffffff8106dd4f>] warn_slowpath_common+0x7f/0xc0
[10425.607779]  [<ffffffff8106ddaa>] warn_slowpath_null+0x1a/0x20
[10425.607818]  [<ffffffffa01be36d>] btrfs_orphan_cleanup+0xbd/0x450 [btrfs]
[10425.607857]  [<ffffffffa01df2b5>] btrfs_mksubvol+0x2f5/0x3a0 [btrfs]
[10425.607893]  [<ffffffffa01df47b>] btrfs_ioctl_snap_create_transid+0x11b/0x150 [btrfs]
[10425.607934]  [<ffffffffa01df5d2>] btrfs_ioctl_snap_create_v2.constprop.2+0xa2/0xf0 [btrfs]
[10425.607971]  [<ffffffffa01e0e50>] btrfs_ioctl+0x5a0/0x1090 [btrfs]
[10425.607982]  [<ffffffff811785e2>] ? do_sync_write+0xd2/0x110
[10425.607993]  [<ffffffff811b4e43>] ? fsnotify+0x1e3/0x290
[10425.608002]  [<ffffffff810137da>] ? __switch_to+0x1ea/0x310
[10425.608045]  [<ffffffff8118a7f8>] do_vfs_ioctl+0x98/0x550
[10425.608061]  [<ffffffff8118ad41>] sys_ioctl+0x91/0xa0
[10425.608078]  [<ffffffff815e9802>] system_call_fastpath+0x16/0x1b
[10425.608090] ---[ end trace b0138cd7c5a1900b ]---
[10425.608111] btrfs: Error removing orphan entry, stopping orphan cleanup
[10425.608122] btrfs: could not do orphan cleanup -22
[10429.503129] ceph-osd[2838]: segfault at 0 ip 00000033b208f593 sp 00007fb2e93d7a88 error 6 in libc-2.14.90.so[33b2000000+1ab000]
[10738.203525] BTRFS: inode 9330 still on the orphan list

# the last line above was at about the time I removed one of the subvolumes

# This is the tail of osd.0.log, before restarting it:

2012-02-07 16:23:27.437270 7fb2e93dd700 filestore(/etc/ceph/osd0) async snap create 'snap_8218138' transid 0 got (22) Invalid argument
os/FileStore.cc: In function 'void FileStore::sync_entry()' thread 7fb2e93dd700 time 2012-02-07 16:23:27.437347
os/FileStore.cc: 3085: FAILED assert(0 == "async snap ioctl error")
 ceph version 0.41-2-g3bcabb5 (commit:3bcabb5ad357eecb85f08584f0f886ada67e82e8)
 1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0xae) [0x995f2e]
 2: (FileStore::sync_entry()+0xd91) [0xac6677]
 3: (FileStore::SyncThread::entry()+0x1c) [0xad1cf0]
 4: (Thread::_entry_func(void*)+0x23) [0x99087d]
 5: /lib64/libpthread.so.0() [0x33b2807d90]
 6: (clone()+0x6d) [0x33b20ef48d]
 ceph version 0.41-2-g3bcabb5 (commit:3bcabb5ad357eecb85f08584f0f886ada67e82e8)
 1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0xae) [0x995f2e]
 2: (FileStore::sync_entry()+0xd91) [0xac6677]
 3: (FileStore::SyncThread::entry()+0x1c) [0xad1cf0]
 4: (Thread::_entry_func(void*)+0x23) [0x99087d]
 5: /lib64/libpthread.so.0() [0x33b2807d90]
 6: (clone()+0x6d) [0x33b20ef48d]
*** Caught signal (Aborted) **
 in thread 7fb2e93dd700
*** Caught signal (Segmentation fault) **
 in thread 7fb2e93dd700