Re: BTRFS: error (device dm-2) in btrfs_run_delayed_refs:2960: errno=-17 Object already exists (since 3.4 / 2012)

[Marc MERLIN <marc@merlins.org>]

On Sat, Jul 15, 2017 at 04:12:45PM -0700, Marc MERLIN wrote:
> On Fri, Jul 14, 2017 at 06:22:16PM -0700, Marc MERLIN wrote:
> > Dear Chris and other developers,
> > 
> > Can you look at this bug which has been happening since 2012 on apparently all kernels between at least
> > 3.4 and 4.11.
> > I didn't look in detail at each thread (took long enough to even find them all and paste here), but they seem pretty
> > similar although the reasons how they got there may be different, or at least not as benign as a race condition
> > between snapshot creation and deletion for those who do hourly snapshot rotations like me.
> 
> I just finished 2 check repairs, one with each mode, they both come back
> clean.
> Yet my FS still remounts read only with the same
> BTRFS: error (device dm-2) in btrfs_run_delayed_refs:2967: errno=-17 Object already exists
> BTRFS info (device dm-2): forced readonly
> BTRFS warning (device dm-2): failed setting block group ro, ret=-30 

So this still happens pseudo randomly every 2 weeks maybe?

Last one is below.
It did not happen during a btrfs snapshot although I'm not entirely sure
what else was running at the time.

Any update on this problem?

------------[ cut here ]------------  
WARNING: CPU: 6 PID: 3783 at fs/btrfs/extent-tree.c:2967 btrfs_run_delayed_refs+0xbd/0x1be  
BTRFS: Transaction aborted (error -17)  
Modules linked in: asix veth ip6table_filter ip6_tables ebtable_nat ebtables ppdev lp xt_addrtype br_netfilter bridge stp llc tun autofs4 softdog binfmt_misc ftdi_sio nfsd auth_rpcgss nfs_acl nfs lockd grace fscache sunrpc ipt_REJECT nf_reject_ipv4 xt_conntrack xt_mark xt_nat xt_tcpudp nf_log_ipv4 nf_log_common xt_LOG iptable_mangle iptable_filter lm85 hwmon_vid pl2303 dm_snapshot dm_bufio iptable_nat ip_tables nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_conntrack_ftp ipt_MASQUERADE nf_nat_masquerade_ipv4 nf_nat nf_conntrack x_tables sg st snd_pcm_oss snd_mixer_oss bcache kvm_intel kvm irqbypass snd_hda_codec_realtek snd_hda_codec_generic snd_cmipci snd_mpu401_uart snd_hda_intel snd_opl3_lib snd_hda_codec snd_hda_core snd_hwdep eeepc_wmi snd_rawmidi snd_seq_device tpm_infineon tpm_tis  
 snd_pcm asus_wmi snd_timer tpm_tis_core rc_ati_x10 snd ati_remote sparse_keymap rfkill i2c_i801 usbserial hwmon usbnet libphy pcspkr wmi soundcore input_leds tpm rc_core parport_pc evdev i915 lpc_ich i2c_smbus parport battery mei_me e1000e ptp pps_core fuse raid456 multipath mmc_block mmc_core dm_crypt dm_mod async_raid6_recov async_pq async_xor async_memcpy async_tx crc32c_intel blowfish_x86_64 blowfish_common aesni_intel aes_x86_64 lrw glue_helper ablk_helper cryptd sata_sil24 fjes mvsas xhci_pci libsas xhci_hcd ehci_pci ehci_hcd thermal usbcore fan r8169 mii scsi_transport_sas [last unloaded: asix]  
CPU: 2 PID: 3783 Comm: btrfs-transacti Tainted: G     U          4.9.36-amd64-preempt-sysrq-20170406 #1  
Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013  
 ffffb7eb67affc98 ffffffffae39b00b ffffb7eb67affce8 0000000000000000  
 ffffb7eb67affcd8 ffffffffae066769 00000b9767affd58 ffff974f736da960  
 ffff9756319df000 00000000ffffffef ffff975302da7a50 ffffffffffffffff  
Call Trace:  
 [<ffffffffae39b00b>] dump_stack+0x61/0x7d  
 [<ffffffffae066769>] __warn+0xc2/0xdd  
 [<ffffffffae0667de>] warn_slowpath_fmt+0x5a/0x76  
 [<ffffffffae28dd5f>] btrfs_run_delayed_refs+0xbd/0x1be  
 [<ffffffffae29ed64>] commit_cowonly_roots+0x10d/0x2b2  
 [<ffffffffae2fb5ed>] ? btrfs_qgroup_account_extents+0x131/0x181  
 [<ffffffffae28de48>] ? btrfs_run_delayed_refs+0x1a6/0x1be  
 [<ffffffffae2a131a>] btrfs_commit_transaction+0x46b/0x8fb  
 [<ffffffffae29c560>] transaction_kthread+0xf5/0x1a1  
 [<ffffffffae29c46b>] ? btrfs_cleanup_transaction+0x436/0x436  
 [<ffffffffae081e94>] kthread+0xd1/0xd9  
 [<ffffffffae081dc3>] ? init_completion+0x24/0x24  
 [<ffffffffae003add>] ? do_fast_syscall_32+0xb7/0xfe  
 [<ffffffffae6ed4b5>] ret_from_fork+0x25/0x30  
---[ end trace 4c5fcb9daa07c11a ]---  
BTRFS: error (device dm-2) in btrfs_run_delayed_refs:2967: errno=-17 Object already exists  
BTRFS info (device dm-2): forced readonly  
BTRFS warning (device dm-2): Skipping commit of aborted transaction.  
BTRFS: error (device dm-2) in cleanup_transaction:1850: errno=-17 Object already exists  
BTRFS error (device dm-2): pending csums is 131072  

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/