ENOSPC / no space on very large devices
Hi list, while i didn't had the problem for some month i'm now getting ENOSPC on a regular basis on one host. It would be great if someone can help me debugging this. Some basic informations: # touch /vmbackup/abc touch: cannot touch `/vmbackup/abc': No space left on device # df -h /vmbackup/ FilesystemSize Used Avail Use% Mounted on /dev/mapper/stripe0-vmbackup 37T 28T 8,5T 77% /vmbackup # btrfs filesystem df /vmbackup/ Data, single: total=27.87TiB, used=27.39TiB System, DUP: total=8.00MiB, used=4.34MiB Metadata, DUP: total=286.50GiB, used=199.91GiB GlobalReserve, single: total=512.00MiB, used=0.00B # btrfs filesystem show /vmbackup/ Label: none uuid: c8c3abf7-8280-4baa-bb51-a8c599e48002 Total devices 1 FS bytes used 27.59TiB devid1 size 36.38TiB used 28.43TiB path /dev/mapper/stripe0-vmbackup # mount | grep vmbackup /dev/mapper/stripe0-vmbackup on /vmbackup type btrfs (rw,noatime,compress-force=zlib,nossd,noacl,space_cache=v2,clear_cache,commit=300,subvolid=5,subvol=/) dmesg is empty. if i umount the volume i get traces (i already did a clear_cache 4 days ago to recalculate the space_tree): [545031.675797] [ cut here ] [545031.725166] WARNING: CPU: 1 PID: 17711 at fs/btrfs/extent-tree.c:5710 btrfs_free_block_groups+0x35a/0x400 [btrfs]() [545031.778329] Modules linked in: netconsole ipt_REJECT nf_reject_ipv4 mpt3sas raid_class scsi_transport_sas xt_multiport iptable_filter ip_tables x_tables 8021q garp bonding coretemp loop i40e(O) vxlan ip6_udp_tunnel usbhid udp_tunnel sb_edac ehci_pci edac_core ehci_hcd i2c_i801 i2c_core usbcore shpchp usb_common ipmi_si ipmi_msghandler button btrfs dm_mod raid1 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq md_mod ixgbe mdio sg sd_mod ahci ptp libahci megaraid_sas pps_core [545032.081037] CPU: 1 PID: 17711 Comm: umount Tainted: G O 4.4.15+43-ph #1 [545032.145078] Hardware name: Supermicro X10DRH/X10DRH-iT, BIOS 1.0c 02/18/2015 [545032.210238] 88010c40bcd8 bd3c712f [545032.275650] c03ec603 88010c40bd18 bd0837e7 0047a000 [545032.341525] 88105e0ea400 881054a76088 881054a76000 [545032.408500] Call Trace: [545032.475272] [] dump_stack+0x63/0x84 [545032.543620] [] warn_slowpath_common+0x97/0xe0 [545032.612900] [] warn_slowpath_null+0x1a/0x20 [545032.682026] [] btrfs_free_block_groups+0x35a/0x400 [btrfs] [545032.750297] [] close_ctree+0x15b/0x330 [btrfs] [545032.817085] [] btrfs_put_super+0x19/0x20 [btrfs] [545032.883439] [] generic_shutdown_super+0x6f/0x100 [545032.949302] [] kill_anon_super+0x16/0x30 [545033.014327] [] btrfs_kill_super+0x1a/0xb0 [btrfs] [545033.079031] [] deactivate_locked_super+0x51/0x90 [545033.143275] [] deactivate_super+0x4e/0x70 [545033.206535] [] cleanup_mnt+0x43/0x90 [545033.268842] [] __cleanup_mnt+0x12/0x20 [545033.331629] [] task_work_run+0x7e/0xa0 [545033.393350] [] exit_to_usermode_loop+0x66/0x95 [545033.454685] [] syscall_return_slowpath+0xa6/0xf0 [545033.515485] [] int_ret_from_sys_call+0x25/0x8f [545033.575890] ---[ end trace bd985b05cc90617c ]--- [545033.636708] [ cut here ] [545033.696339] WARNING: CPU: 1 PID: 17711 at fs/btrfs/extent-tree.c:5711 btrfs_free_block_groups+0x3f4/0x400 [btrfs]() [545033.758031] Modules linked in: netconsole ipt_REJECT nf_reject_ipv4 mpt3sas raid_class scsi_transport_sas xt_multiport iptable_filter ip_tables x_tables 8021q garp bonding coretemp loop i40e(O) vxlan ip6_udp_tunnel usbhid udp_tunnel sb_edac ehci_pci edac_core ehci_hcd i2c_i801 i2c_core usbcore shpchp usb_common ipmi_si ipmi_msghandler button btrfs dm_mod raid1 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq md_mod ixgbe mdio sg sd_mod ahci ptp libahci megaraid_sas pps_core [545034.095188] CPU: 1 PID: 17711 Comm: umount Tainted: GW O 4.4.15+43-ph #1 [545034.166070] Hardware name: Supermicro X10DRH/X10DRH-iT, BIOS 1.0c 02/18/2015 [545034.236259] 88010c40bcd8 bd3c712f [545034.307690] c03ec603 88010c40bd18 bd0837e7 0047a000 [545034.379596] 88105e0ea400 881054a76088 881054a76000 [545034.452542] Call Trace: [545034.525286] [] dump_stack+0x63/0x84 [545034.599643] [] warn_slowpath_common+0x97/0xe0 [545034.674894] [] warn_slowpath_null+0x1a/0x20 [545034.750338] [] btrfs_free_block_groups+0x3f4/0x400 [btrfs] [545034.826354] [] close_ctree+0x15b/0x330 [btrfs] [545034.900758] [] btrfs_put_super+0x19/0x20 [btrfs] [545034.973612] [] generic_shutdown_super+0x6f/0x100 [545035.044589] [] kill_anon_super+0x16/0x30 [545035.113505] [] btrfs_kill_super+0x1a/0xb0 [btrfs] [545035.180769] [] deactivate_locked_super+0x51/0x90 [545035.246451] [] deactivate_super+0x4e/0x70 [545035.311231] [] cleanup_mnt+0x43/0x90 [545035.374958] [] __cleanup_mnt+0x12/0
Re: ENOSPC / no space on very large devices
hello, On 07/20/2016 01:31 PM, Stefan Priebe - Profihost AG wrote: Hi list, while i didn't had the problem for some month i'm now getting ENOSPC on a regular basis on one host. It would be great if someone can help me debugging this. Some basic informations: # touch /vmbackup/abc touch: cannot touch `/vmbackup/abc': No space left on device When touch operation failed, would you please change dir to /sys/fs/btrfs/UUID/allocation/data/ and show me these files' value. And also files in /sys/fs/btrfs/UUID/allocation/metadata. thanks. Here UUID is your real uuid :) Regards, Xiaoguang Wang # df -h /vmbackup/ FilesystemSize Used Avail Use% Mounted on /dev/mapper/stripe0-vmbackup 37T 28T 8,5T 77% /vmbackup # btrfs filesystem df /vmbackup/ Data, single: total=27.87TiB, used=27.39TiB System, DUP: total=8.00MiB, used=4.34MiB Metadata, DUP: total=286.50GiB, used=199.91GiB GlobalReserve, single: total=512.00MiB, used=0.00B # btrfs filesystem show /vmbackup/ Label: none uuid: c8c3abf7-8280-4baa-bb51-a8c599e48002 Total devices 1 FS bytes used 27.59TiB devid1 size 36.38TiB used 28.43TiB path /dev/mapper/stripe0-vmbackup # mount | grep vmbackup /dev/mapper/stripe0-vmbackup on /vmbackup type btrfs (rw,noatime,compress-force=zlib,nossd,noacl,space_cache=v2,clear_cache,commit=300,subvolid=5,subvol=/) dmesg is empty. if i umount the volume i get traces (i already did a clear_cache 4 days ago to recalculate the space_tree): [545031.675797] [ cut here ] [545031.725166] WARNING: CPU: 1 PID: 17711 at fs/btrfs/extent-tree.c:5710 btrfs_free_block_groups+0x35a/0x400 [btrfs]() [545031.778329] Modules linked in: netconsole ipt_REJECT nf_reject_ipv4 mpt3sas raid_class scsi_transport_sas xt_multiport iptable_filter ip_tables x_tables 8021q garp bonding coretemp loop i40e(O) vxlan ip6_udp_tunnel usbhid udp_tunnel sb_edac ehci_pci edac_core ehci_hcd i2c_i801 i2c_core usbcore shpchp usb_common ipmi_si ipmi_msghandler button btrfs dm_mod raid1 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq md_mod ixgbe mdio sg sd_mod ahci ptp libahci megaraid_sas pps_core [545032.081037] CPU: 1 PID: 17711 Comm: umount Tainted: G O 4.4.15+43-ph #1 [545032.145078] Hardware name: Supermicro X10DRH/X10DRH-iT, BIOS 1.0c 02/18/2015 [545032.210238] 88010c40bcd8 bd3c712f [545032.275650] c03ec603 88010c40bd18 bd0837e7 0047a000 [545032.341525] 88105e0ea400 881054a76088 881054a76000 [545032.408500] Call Trace: [545032.475272] [] dump_stack+0x63/0x84 [545032.543620] [] warn_slowpath_common+0x97/0xe0 [545032.612900] [] warn_slowpath_null+0x1a/0x20 [545032.682026] [] btrfs_free_block_groups+0x35a/0x400 [btrfs] [545032.750297] [] close_ctree+0x15b/0x330 [btrfs] [545032.817085] [] btrfs_put_super+0x19/0x20 [btrfs] [545032.883439] [] generic_shutdown_super+0x6f/0x100 [545032.949302] [] kill_anon_super+0x16/0x30 [545033.014327] [] btrfs_kill_super+0x1a/0xb0 [btrfs] [545033.079031] [] deactivate_locked_super+0x51/0x90 [545033.143275] [] deactivate_super+0x4e/0x70 [545033.206535] [] cleanup_mnt+0x43/0x90 [545033.268842] [] __cleanup_mnt+0x12/0x20 [545033.331629] [] task_work_run+0x7e/0xa0 [545033.393350] [] exit_to_usermode_loop+0x66/0x95 [545033.454685] [] syscall_return_slowpath+0xa6/0xf0 [545033.515485] [] int_ret_from_sys_call+0x25/0x8f [545033.575890] ---[ end trace bd985b05cc90617c ]--- [545033.636708] [ cut here ] [545033.696339] WARNING: CPU: 1 PID: 17711 at fs/btrfs/extent-tree.c:5711 btrfs_free_block_groups+0x3f4/0x400 [btrfs]() [545033.758031] Modules linked in: netconsole ipt_REJECT nf_reject_ipv4 mpt3sas raid_class scsi_transport_sas xt_multiport iptable_filter ip_tables x_tables 8021q garp bonding coretemp loop i40e(O) vxlan ip6_udp_tunnel usbhid udp_tunnel sb_edac ehci_pci edac_core ehci_hcd i2c_i801 i2c_core usbcore shpchp usb_common ipmi_si ipmi_msghandler button btrfs dm_mod raid1 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq md_mod ixgbe mdio sg sd_mod ahci ptp libahci megaraid_sas pps_core [545034.095188] CPU: 1 PID: 17711 Comm: umount Tainted: GW O 4.4.15+43-ph #1 [545034.166070] Hardware name: Supermicro X10DRH/X10DRH-iT, BIOS 1.0c 02/18/2015 [545034.236259] 88010c40bcd8 bd3c712f [545034.307690] c03ec603 88010c40bd18 bd0837e7 0047a000 [545034.379596] 88105e0ea400 881054a76088 881054a76000 [545034.452542] Call Trace: [545034.525286] [] dump_stack+0x63/0x84 [545034.599643] [] warn_slowpath_common+0x97/0xe0 [545034.674894] [] warn_slowpath_null+0x1a/0x20 [545034.750338] [] btrfs_free_block_groups+0x3f4/0x400 [btrfs] [545034.826354] [] close_ctree+0x15b/0x330 [btrfs] [545034.900758] [] btrfs_put_super+0x19/0x20 [btrfs] [545034.973612
Re: ENOSPC / no space on very large devices
On 07/20/16 07:31, Stefan Priebe - Profihost AG wrote: > Hi list, > > while i didn't had the problem for some month i'm now getting ENOSPC on > a regular basis on one host. Well, it's getting better. :) > if i umount the volume i get traces (i already did a clear_cache 4 days > ago to recalculate the space_tree): > > [545031.675797] [ cut here ] > [545031.725166] WARNING: CPU: 1 PID: 17711 at > fs/btrfs/extent-tree.c:5710 btrfs_free_block_groups+0x35a/0x400 [btrfs]() This is "only" a warning, but as we can see below it indicates a real problem. The warning was added only recently to for-next by the patch called "Btrfs: warn_on for unaccounted spaces" [1], but I've had it in my tree forever. Never seen the warning myself. (snip) > [545037.909700] BTRFS: space_info 4 has 18446743523026157568 free, is > not full Wow, ~18.4 exabytes really is a lot of free space. :) So it looks like something underflowed the space_info and now things are confused for about ~550 GB. Unfortunately I have no good idea how to fix that. :( > The kernel is something special - i'm using this one from holger: > https://github.com/hhoffstaette/kernel-patches > > which is basically a 4.4.15 + several patches especially a lot of btrfs > patches up to 4.8 i think. More like for-next with all the pagesize/sectorsize stuff carefully avoided. I'm really looking forward to 4.8, this is becoming unwieldy.. -h [1] https://git.kernel.org/cgit/linux/kernel/git/kdave/linux.git/commit/?h=for-next&id=d555b6c380c644af63dbdaa7cc14bba041a4e4dd -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: ENOSPC / no space on very large devices
here we go... Am 20.07.2016 um 08:31 schrieb Wang Xiaoguang: > hello, > > On 07/20/2016 01:31 PM, Stefan Priebe - Profihost AG wrote: >> Hi list, >> >> while i didn't had the problem for some month i'm now getting ENOSPC on >> a regular basis on one host. >> >> It would be great if someone can help me debugging this. >> >> Some basic informations: >> # touch /vmbackup/abc >> touch: cannot touch `/vmbackup/abc': No space left on device > When touch operation failed, would you please change dir to > /sys/fs/btrfs/UUID/allocation/data/ and show me these files' value. > And also files in /sys/fs/btrfs/UUID/allocation/metadata. thanks. > Here UUID is your real uuid :) /sys/fs/btrfs/ebcb9a5e-d784-4e17-9cd0-bc67fe7b1ed6/allocation/data]# grep -H '' * bytes_may_use:0 bytes_pinned:0 bytes_reserved:0 bytes_used:6175380234240 disk_total:6641093181440 disk_used:6175380234240 flags:1 grep: single: Is a directory total_bytes:6641093181440 total_bytes_pinned:726104035328 /sys/fs/btrfs/ebcb9a5e-d784-4e17-9cd0-bc67fe7b1ed6/allocation/metadata]# grep -H '' * bytes_may_use:2089625649152 bytes_pinned:0 bytes_reserved:0 bytes_used:36823187456 disk_total:95563022336 disk_used:73646374912 grep: dup: Is a directory flags:4 total_bytes:47781511168 total_bytes_pinned:-16792829952 Greets, Stefan > > Regards, > Xiaoguang Wang > >> # df -h /vmbackup/ >> FilesystemSize Used Avail Use% Mounted on >> /dev/mapper/stripe0-vmbackup 37T 28T 8,5T 77% /vmbackup >> >> # btrfs filesystem df /vmbackup/ >> Data, single: total=27.87TiB, used=27.39TiB >> System, DUP: total=8.00MiB, used=4.34MiB >> Metadata, DUP: total=286.50GiB, used=199.91GiB >> GlobalReserve, single: total=512.00MiB, used=0.00B >> >> # btrfs filesystem show /vmbackup/ >> Label: none uuid: c8c3abf7-8280-4baa-bb51-a8c599e48002 >> Total devices 1 FS bytes used 27.59TiB >> devid1 size 36.38TiB used 28.43TiB path >> /dev/mapper/stripe0-vmbackup >> >> # mount | grep vmbackup >> /dev/mapper/stripe0-vmbackup on /vmbackup type btrfs >> (rw,noatime,compress-force=zlib,nossd,noacl,space_cache=v2,clear_cache,commit=300,subvolid=5,subvol=/) >> >> >> dmesg is empty. >> >> if i umount the volume i get traces (i already did a clear_cache 4 days >> ago to recalculate the space_tree): >> >> [545031.675797] [ cut here ] >> [545031.725166] WARNING: CPU: 1 PID: 17711 at >> fs/btrfs/extent-tree.c:5710 btrfs_free_block_groups+0x35a/0x400 [btrfs]() >> [545031.778329] Modules linked in: netconsole ipt_REJECT nf_reject_ipv4 >> mpt3sas raid_class scsi_transport_sas xt_multiport iptable_filter >> ip_tables x_tables 8021q garp bonding coretemp loop i40e(O) vxlan >> ip6_udp_tunnel usbhid udp_tunnel sb_edac ehci_pci edac_core ehci_hcd >> i2c_i801 i2c_core usbcore shpchp usb_common ipmi_si ipmi_msghandler >> button btrfs dm_mod raid1 raid456 async_raid6_recov async_memcpy >> async_pq async_xor async_tx xor raid6_pq md_mod ixgbe mdio sg sd_mod >> ahci ptp libahci megaraid_sas pps_core >> [545032.081037] CPU: 1 PID: 17711 Comm: umount Tainted: G O >> 4.4.15+43-ph #1 >> [545032.145078] Hardware name: Supermicro X10DRH/X10DRH-iT, BIOS 1.0c >> 02/18/2015 >> [545032.210238] 88010c40bcd8 bd3c712f >> >> [545032.275650] c03ec603 88010c40bd18 bd0837e7 >> 0047a000 >> [545032.341525] 88105e0ea400 881054a76088 >> 881054a76000 >> [545032.408500] Call Trace: >> [545032.475272] [] dump_stack+0x63/0x84 >> [545032.543620] [] warn_slowpath_common+0x97/0xe0 >> [545032.612900] [] warn_slowpath_null+0x1a/0x20 >> [545032.682026] [] >> btrfs_free_block_groups+0x35a/0x400 [btrfs] >> [545032.750297] [] close_ctree+0x15b/0x330 [btrfs] >> [545032.817085] [] btrfs_put_super+0x19/0x20 [btrfs] >> [545032.883439] [] generic_shutdown_super+0x6f/0x100 >> [545032.949302] [] kill_anon_super+0x16/0x30 >> [545033.014327] [] btrfs_kill_super+0x1a/0xb0 [btrfs] >> [545033.079031] [] deactivate_locked_super+0x51/0x90 >> [545033.143275] [] deactivate_super+0x4e/0x70 >> [545033.206535] [] cleanup_mnt+0x43/0x90 >> [545033.268842] [] __cleanup_mnt+0x12/0x20 >> [545033.331629] [] task_work_run+0x7e/0xa0 >> [545033.393350] [] exit_to_usermode_loop+0x66/0x95 >> [545033.454685] [] syscall_return_slowpath+0xa6/0xf0 >> [545033.515485] [] int_ret_from_sys_call+0x25/0x8f >> [545033.575890] ---[ end trace bd985b05cc90617c ]--- >> [545033.636708] [ cut here ] >> [545033.696339] WARNING: CPU: 1 PID: 17711 at >> fs/btrfs/extent-tree.c:5711 btrfs_free_block_groups+0x3f4/0x400 [btrfs]() >> [545033.758031] Modules linked in: netconsole ipt_REJECT nf_reject_ipv4 >> mpt3sas raid_class scsi_transport_sas xt_multiport iptable_filter >> ip_tables x_tables 8021q garp bonding coretemp loop i40e(O) vxlan >> ip6_udp_tunnel usbhid udp_tunnel sb_edac ehci_pci edac_core ehci_hcd >> i2c_i801 i2c_core usbcore shpchp usb_common ipmi_si ipmi_msghandle
Re: ENOSPC / no space on very large devices
Am 20.07.2016 um 09:35 schrieb Holger Hoffstätte: > On 07/20/16 07:31, Stefan Priebe - Profihost AG wrote: >> Hi list, >> >> while i didn't had the problem for some month i'm now getting ENOSPC on >> a regular basis on one host. > > Well, it's getting better. :) Again the same problem. > >> if i umount the volume i get traces (i already did a clear_cache 4 days >> ago to recalculate the space_tree): >> >> [545031.675797] [ cut here ] >> [545031.725166] WARNING: CPU: 1 PID: 17711 at >> fs/btrfs/extent-tree.c:5710 btrfs_free_block_groups+0x35a/0x400 [btrfs]() > > This is "only" a warning, but as we can see below it indicates a real > problem. The warning was added only recently to for-next by the patch called > "Btrfs: warn_on for unaccounted spaces" [1], but I've had it in my tree > forever. Never seen the warning myself. > > (snip) >> [545037.909700] BTRFS: space_info 4 has 18446743523026157568 free, is >> not full > > Wow, ~18.4 exabytes really is a lot of free space. :) > So it looks like something underflowed the space_info and now things are > confused for about ~550 GB. Unfortunately I have no good idea how to fix > that. :( umount triggered this one: [983102.838217] [ cut here ] [983102.864383] WARNING: CPU: 1 PID: 483 at fs/btrfs/extent-tree.c:5710 btrfs_free_block_groups+0x35a/0x400 [btrfs]() [983102.894424] Modules linked in: netconsole xt_multiport iptable_filter ip_tables x_tables 8021q garp bonding usbhid coretemp loop xhci_pci ehci_pci xhci_hcd ehci_hcd i40e(O) sb_edac vxlan ip6_udp_tunnel usbcore ipmi_si i2c_i801 shpchp usb_common udp_tunnel edac_core ipmi_msghandler button btrfs dm_mod raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq raid1 md_mod igb i2c_algo_bit i2c_core sg sd_mod ptp ahci libahci pps_core aacraid [983103.043010] CPU: 1 PID: 483 Comm: umount Tainted: G O 4.4.15+43-ph #1 [983103.084441] Hardware name: Supermicro Super Server/X10SRi-F, BIOS 2.0 12/17/2015 [983103.127289] 880074673cd8 ad3c712f [983103.171816] c0298603 880074673d18 ad0837e7 000b2000 [983103.216766] 88103bd7e600 881037c92088 881037c92000 [983103.262776] Call Trace: [983103.308602] [] dump_stack+0x63/0x84 [983103.355609] [] warn_slowpath_common+0x97/0xe0 [983103.403528] [] warn_slowpath_null+0x1a/0x20 [983103.451297] [] btrfs_free_block_groups+0x35a/0x400 [btrfs] [983103.500439] [] close_ctree+0x15b/0x330 [btrfs] [983103.548805] [] btrfs_put_super+0x19/0x20 [btrfs] [983103.597122] [] generic_shutdown_super+0x6f/0x100 [983103.645398] [] kill_anon_super+0x16/0x30 [983103.693384] [] btrfs_kill_super+0x1a/0xb0 [btrfs] [983103.742430] [] deactivate_locked_super+0x51/0x90 [983103.791501] [] deactivate_super+0x4e/0x70 [983103.839979] [] cleanup_mnt+0x43/0x90 [983103.889050] [] __cleanup_mnt+0x12/0x20 [983103.937756] [] task_work_run+0x7e/0xa0 [983103.986032] [] exit_to_usermode_loop+0x66/0x95 [983104.035214] [] syscall_return_slowpath+0xa6/0xf0 [983104.084312] [] int_ret_from_sys_call+0x25/0x8f [983104.134098] ---[ end trace ca97a745adcb888f ]--- [983104.184540] [ cut here ] [983104.235514] WARNING: CPU: 1 PID: 483 at fs/btrfs/extent-tree.c:5711 btrfs_free_block_groups+0x3f4/0x400 [btrfs]() [983104.290282] Modules linked in: netconsole xt_multiport iptable_filter ip_tables x_tables 8021q garp bonding usbhid coretemp loop xhci_pci ehci_pci xhci_hcd ehci_hcd i40e(O) sb_edac vxlan ip6_udp_tunnel usbcore ipmi_si i2c_i801 shpchp usb_common udp_tunnel edac_core ipmi_msghandler button btrfs dm_mod raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq raid1 md_mod igb i2c_algo_bit i2c_core sg sd_mod ptp ahci libahci pps_core aacraid [983104.536076] CPU: 1 PID: 483 Comm: umount Tainted: GW O 4.4.15+43-ph #1 [983104.601962] Hardware name: Supermicro Super Server/X10SRi-F, BIOS 2.0 12/17/2015 [983104.669312] 880074673cd8 ad3c712f [983104.738337] c0298603 880074673d18 ad0837e7 000b2000 [983104.807874] 88103bd7e600 881037c92088 881037c92000 [983104.878415] Call Trace: [983104.948803] [] dump_stack+0x63/0x84 [983105.020781] [] warn_slowpath_common+0x97/0xe0 [983105.093734] [] warn_slowpath_null+0x1a/0x20 [983105.166888] [] btrfs_free_block_groups+0x3f4/0x400 [btrfs] [983105.241461] [] close_ctree+0x15b/0x330 [btrfs] [983105.316744] [] btrfs_put_super+0x19/0x20 [btrfs] [983105.392021] [] generic_shutdown_super+0x6f/0x100 [983105.465852] [] kill_anon_super+0x16/0x30 [983105.537829] [] btrfs_kill_super+0x1a/0xb0 [btrfs] [983105.608078] [] deactivate_locked_super+0x51/0x90 [983105.676494] [] deactivate_super+0x4e/0x70 [983105.742614] [] cleanup_mnt+0x43/0x90 [983105.807432] [] __cleanup_mnt+0x12/0x20 [983105.871301] [] task_work_run+0x7e/0xa0 [9