Linux 4.0.0-rc5 - [ 1851.858652] BTRFS: error (device sda1) in cleanup_transaction:1686: errno=-17 Object already exists

[Torbjørn <lists@skagestad.org>]

Hi,

After upgrading to 4.0.0-rc5 from 4.0.0-rc4 I see "Object already 
exists" after reboot.
The fs is forced read only.
The error does not disappear after additional reboots.

mount|grep sda1
/dev/sda1 on / type btrfs (rw,noatime,compress=lzo,space_cache,subvol=@)
/dev/sda1 on /home type btrfs 
(rw,noatime,compress=lzo,space_cache,subvol=@home)
/dev/sda1 on /mnt/volumes type btrfs (rw,noatime,compress=lzo,space_cache)

Label: 'root'  uuid: 6a681300-faef-4195-a1b3-6699c7a5aa5e
     Total devices 2 FS bytes used 66.87GiB
     devid    1 size 298.09GiB used 124.03GiB path /dev/sda1
     devid    2 size 298.09GiB used 124.03GiB path /dev/sdd1

btrfs-progs v3.19

Any additional info I can provide? Tests you want me to run?

--
Torbjørn


[ 1851.856097] ------------[ cut here ]------------
[ 1851.856166] WARNING: CPU: 4 PID: 350 at fs/btrfs/super.c:260 
__btrfs_abort_transaction+0x54/0x130 [btrfs]()
[ 1851.856255] BTRFS: Transaction aborted (error -17)
[ 1851.856256] Modules linked in: vhost_net vhost macvtap macvlan 
ipmi_devintf ipt_REJECT nf_reject_ipv4 xt_CHECKSUM ip6table_filter 
ip6_tables ebtable_nat ebtables sch_prio bridge stp llc xt_state 
iptable_filter xt_CLASSIFY xt_tcpudp xt_DSCP iptable_mangle iptable_nat 
nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack 
ip_tables x_tables dm_crypt netconsole configfs ppdev coretemp kvm_intel 
mac_hid lpc_ich video kvm serio_raw parport_pc ipmi_si tpm_infineon 
ipmi_msghandler aesni_intel aes_x86_64 glue_helper lrw gf128mul 
ablk_helper cryptd nfsd lp auth_rpcgss nfs_acl nfs lockd parport grace 
sunrpc fscache btrfs raid10 raid456 async_raid6_recov async_memcpy 
async_pq async_xor async_tx xor raid6_pq raid0 multipath linear raid1 
hid_generic usbhid hid psmouse ahci e1000e libahci ptp mpt2sas 
raid_class pps_core scsi_transport_sas
[ 1851.856977] CPU: 4 PID: 350 Comm: btrfs-transacti Not tainted 
4.0.0-rc5 #97
[ 1851.857057] Hardware name: To be filled by O.E.M. To be filled by 
O.E.M./P8B-X series, BIOS 2107 05/04/2012
[ 1851.857151]  ffffffffc02ad832 ffff88041795fbf8 ffffffff8176aaed 
0000000000000000
[ 1851.857248]  ffff88041795fc48 ffff88041795fc38 ffffffff8107a0ea 
0000000000000000
[ 1851.857336]  ffff88041a3d49a0 ffff880417cc4000 00000000ffffffef 
ffffffffc02ac0d0
[ 1851.857423] Call Trace:
[ 1851.857466]  [<ffffffff8176aaed>] dump_stack+0x45/0x57
[ 1851.857514]  [<ffffffff8107a0ea>] warn_slowpath_common+0x8a/0xc0
[ 1851.857565]  [<ffffffff8107a166>] warn_slowpath_fmt+0x46/0x50
[ 1851.857618]  [<ffffffffc01ffc84>] 
__btrfs_abort_transaction+0x54/0x130 [btrfs]
[ 1851.857704]  [<ffffffffc021d05c>] 
btrfs_run_delayed_refs.part.65+0x12c/0x2a0 [btrfs]
[ 1851.857792]  [<ffffffffc021f4d1>] ? btrfs_update_root+0xe1/0x270 [btrfs]
[ 1851.857849]  [<ffffffffc021d1e7>] btrfs_run_delayed_refs+0x17/0x20 
[btrfs]
[ 1851.857908]  [<ffffffffc02a51c6>] commit_cowonly_roots+0x27d/0x294 
[btrfs]
[ 1851.857967]  [<ffffffffc022dde1>] 
btrfs_commit_transaction+0x4c1/0xa50 [btrfs]
[ 1851.858053]  [<ffffffffc0229585>] transaction_kthread+0x1b5/0x240 [btrfs]
[ 1851.858110]  [<ffffffffc02293d0>] ? 
btrfs_cleanup_transaction+0x570/0x570 [btrfs]
[ 1851.858192]  [<ffffffff81098ea2>] kthread+0xd2/0xf0
[ 1851.858238]  [<ffffffff81098dd0>] ? kthread_create_on_node+0x180/0x180
[ 1851.858291]  [<ffffffff81772518>] ret_from_fork+0x58/0x90
[ 1851.858340]  [<ffffffff81098dd0>] ? kthread_create_on_node+0x180/0x180
[ 1851.858391] ---[ end trace 7c2776e855cf008f ]---
[ 1851.858437] BTRFS: error (device sda1) in 
btrfs_run_delayed_refs:2790: errno=-17 Object already exists
[ 1851.858524] BTRFS info (device sda1): forced readonly
[ 1851.858571] BTRFS warning (device sda1): Skipping commit of aborted 
transaction.
[ 1851.858652] BTRFS: error (device sda1) in cleanup_transaction:1686: 
errno=-17 Object already exists