Re: FS Remounted RO due to false-positive for OOS?

[Nikolay Borisov <nborisov@suse.com>]

On 3.03.20 г. 23:32 ч., Ellis H. Wilson III wrote:
> Hi all,
> 
> I encountered the following issue and wasn't sure if it was known or not
> yet.  I'll be glad to hear it matches a fingerprint of a known or fixed
> bug as I'm admittedly running an older kernel, but my searching skills
> have failed me.
> 
> I have an mdraid array formatted with BTRFS.  6x12TB drives in raid0.
> Only about 240GB of 72TB consumed at the time of OOS.
> 
> /etc/fstab mount options:
> 
> /dev/md0        /pandata/0      btrfs   defaults,space_cache=v2,noauto  0 0
> 
> uname:
> 
> Linux 4d00fa3d419078 4.12.14-lp150.11-default #1 SMP Fri May 11 08:28:30
> UTC 2018 (a9fee09) x86_64 x86_64 x86_64 GNU/Linux
> 
> dmesg output:
> 
> [17939.536301] BTRFS: Transaction aborted (error -28)
> [17939.536331] ------------[ cut here ]------------
> [17939.542058] WARNING: CPU: 7 PID: 3372 at
> ../fs/btrfs/extent-tree.c:6988 __btrfs_free_extent.isra.64+0xb9d/0xd40
> [btrfs]
> [17939.553779] Modules linked in: binfmt_misc af_packet bonding
> iscsi_ibft iscsi_boot_sysfs msr nls_iso8859_1 nls_cp437 vfat intel_rapl
> fat skx_edac x86_pkg_temp_thermal btrfs intel_powerclamp coretemp xor
> ipmi_ssif kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul
> crc32c_intel raid0 iTCO_wdt iTCO_vendor_support ghash_clmulni_intel pcbc
> dax_pmem ixgbe device_dax md_mod ptp nd_pmem pps_core mdio nd_btt
> aesni_intel aes_x86_64 raid6_pq crypto_simd glue_helper cryptd i2c_i801
> lpc_ich ioatdma ipmi_si pcspkr mei_me mei nfit ipmi_devintf shpchp dca
> wmi ipmi_msghandler libnvdimm acpi_pad button joydev hid_generic usbhid
> ast i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt
> fb_sys_fops xhci_pci ttm xhci_hcd nvme drm ahci
> drm_panel_orientation_quirks nvme_core usbcore libahci sg dm_multipath
> dm_mod
> [17939.631713]  scsi_dh_rdac scsi_dh_emc scsi_dh_alua efivarfs
> [17939.638341] CPU: 7 PID: 3372 Comm: btrfs-transacti Not tainted
> 4.12.14-lp150.11-default #1 openSUSE Leap 15.0 (unreleased)
> [17939.650466] Hardware name: Supermicro SYS-F629P3-RTB/X11DPFR-S, BIOS
> 3.0c_PI021_2e 11/26/2019
> [17939.660095] task: ffff88083b975680 task.stack: ffffc9000a238000
> [17939.667128] RIP: 0010:__btrfs_free_extent.isra.64+0xb9d/0xd40 [btrfs]
> [17939.674653] RSP: 0018:ffffc9000a23bc78 EFLAGS: 00010296
> [17939.680953] RAX: 0000000000000026 RBX: 0000000000000000 RCX:
> 0000000000000000
> [17939.689172] RDX: ffff88085c1dfd40 RSI: ffff88085c1d7a68 RDI:
> ffff88085c1d7a68
> [17939.697386] RBP: 00000012b9a5c000 R08: 0000000000000511 R09:
> 0000000000000007
> [17939.705602] R10: 0000000000000001 R11: 0000000000000001 R12:
> ffff8808530ae000
> [17939.713803] R13: 00000000ffffffe4 R14: ffff8802edf64870 R15:
> ffff8801368c0230
> [17939.722017] FS:  0000000000000000(0000) GS:ffff88085c1c0000(0000)
> knlGS:0000000000000000
> [17939.731203] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [17939.738051] CR2: 00007f12998bea08 CR3: 000000000200a003 CR4:
> 00000000007606e0
> [17939.746292] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000
> [17939.754525] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
> 0000000000000400
> [17939.762735] PKRU: 55555554
> [17939.766521] Call Trace:
> [17939.770075]  __btrfs_run_delayed_refs+0x5b9/0x1300 [btrfs]
> [17939.776682]  btrfs_run_delayed_refs+0x68/0x250 [btrfs]
> [17939.782948]  btrfs_commit_transaction+0x2df/0x900 [btrfs]
> [17939.789462]  ? wait_woken+0x80/0x80
> [17939.794087]  transaction_kthread+0x186/0x1a0 [btrfs]
> [17939.800201]  ? btrfs_cleanup_transaction+0x4e0/0x4e0 [btrfs]
> [17939.806983]  kthread+0x11a/0x130
> [17939.811308]  ? kthread_create_on_node+0x40/0x40
> [17939.816939]  ret_from_fork+0x1f/0x40
> [17939.821591] Code: 00 00 48 c7 c6 c0 07 8e a0 4c 89 f7 41 bd ea ff ff
> ff e8 4d d0 09 00 e9 a0 f5 ff ff 44 89 ee 48 c7 c7 18 71 8e a0 e8 d9 95
> 96 e0 <0f> 0b e9 73 f5 ff ff 49 8b 46 60 f0 0f ba a8 30 17 00 00 02 72
> [17939.842686] ---[ end trace 179787a3004a4525 ]---
> [17939.848482] BTRFS: error (device md0) in __btrfs_free_extent:6988:
> errno=-28 No space left
> [17939.857923] BTRFS info (device md0): forced readonly
> [17939.864081] BTRFS: error (device md0) in btrfs_run_delayed_refs:3016:
> errno=-28 No space left
> [17939.873811] BTRFS warning (device md0): Skipping commit of aborted
> transaction.
> [17939.882319] BTRFS: error (device md0) in cleanup_transaction:1876:
> errno=-28 No space left
> [17940.192941] BTRFS error (device md0): pending csums is 334954496
> 

There were multiple fixes to the ENOSPC machinery. In particular:

https://patchwork.kernel.org/cover/10709795/

But this series might depend on other fixes you'd have to do the
backporting yourself.