I have a BTRFS RAID 10 filesystem that was crashing and going into RO mode. A did a kernel upgrade, upgraded btrfs tools to the latest. A scrub was going ok ish. btrfs check showed a number of messages such as: Backref 16562625503232 root 14628 owner 3609 offset 23793664 num_refs 0 not found in extent tree Incorrect local backref count on 16562625503232 root 14628 owner 3609 offset 23793664 found 1 wanted 0 back 0x5639c37689d0 backpointer mismatch on [16562625503232 2703360] Root 14628 was a subvolume root ID (for docker), given that I didn't need any of that data, I removed all those subvolumes under the docker subvolume and the docker subvolume. This still showed errors, so I tried a btrfs check with repair, which eventually gave me the following. Backref 16563772112896 root 14628 owner 3608 offset 0 num_refs 0 not found in extent tree Incorrect local backref count on 16563772112896 root 14628 owner 3608 offset 0 found 1 wanted 0 back 0x55f3403f40b0 Backref disk bytenr does not match extent record, bytenr=16563772112896, ref bytenr=16563813335040 Backref bytes do not match extent backref, bytenr=16563772112896, ref bytes=134217728, backref bytes=133079040 Backref 16563772112896 root 14628 owner 3607 offset 0 num_refs 0 not found in extent tree Incorrect local backref count on 16563772112896 root 14628 owner 3607 offset 0 found 1 wanted 0 back 0x55f3470cfed0 Backref bytes do not match extent backref, bytenr=16563772112896, ref bytes=134217728, backref bytes=41222144 backpointer mismatch on [16563772112896 134217728] attempting to repair backref discrepency for bytenr 16563772112896 Ref is past the entry end, please take a btrfs-image of this file system and send it to a btrfs developer, ref 16563813335040 failed to repair damaged filesystem, aborting I've taken a btrfs-image, however it's 12Gb, not sure if the developers want that, but I do have it. Filesystem still crashes and goes read only if I try and make changes (even deletes). The latest dmesg that includes that crash is at https://drive.google.com/open?id=0B5bmQmu6UugIRFM0RUxwWFdqOGc. I don't have the earlier ones. https://drive.google.com/open?id=0B5bmQmu6UugIYjZkYnA4ZFFpdlE is the output from running btrfs check with repair, followed by a second run with repair to see if it got anything different. At this stage, I expect to just blow away the filesystem and restore from backups. However it would be nice to fix whatever the issue is. Smartctl shows no underlying errors. What else do the devs want from me before I blow this away? (Or is it fixable with something I've missed, as that would save me many hours of restoration. The 12Gb btrfs-image can be uploaded to Google Drive (or FTP) if needed. Thanks Tim $ lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux 9.1 (stretch) Release: 9.1 Codename: stretch $ uname -a Linux bruce 4.12.0-0.bpo.1-amd64 #1 SMP Debian 4.12.6-1~bpo9+1 (2017-08-27) x86_64 GNU/Linux $ btrfs --version btrfs-progs v4.9.1 $ btrfs fi show Label: 'Butter1' uuid: b8d081ac-0271-4481-9a58-c113c921bf49 Total devices 4 FS bytes used 5.19TiB devid 1 size 3.64TiB used 2.60TiB path /dev/sde devid 2 size 3.64TiB used 2.60TiB path /dev/sdf devid 3 size 3.64TiB used 2.60TiB path /dev/sdd devid 4 size 3.64TiB used 2.60TiB path /dev/sdc $ btrfs fi df /mnt/Butter1 Data, RAID10: total=5.19TiB, used=5.17TiB System, RAID10: total=128.00MiB, used=560.00KiB Metadata, RAID10: total=12.00GiB, used=10.34GiB Metadata, single: total=16.00MiB, used=0.00B GlobalReserve, single: total=512.00MiB, used=0.00B $btrfs subvolume list /mnt/Butter1 ID 258 gen 250368 top level 5 path data1 ID 259 gen 250516 top level 5 path data2 ID 3648 gen 250476 top level 5 path Photos ID 4597 gen 203041 top level 5 path Snapshots/Photos/20160304 ID 4608 gen 203041 top level 5 path Snapshots/Photos/20160328 ID 4628 gen 203041 top level 5 path Snapshots/Photos/20160421 ID 4654 gen 250368 top level 5 path imap ID 4656 gen 203041 top level 5 path Snapshots/Photos/20160523 ID 4893 gen 203041 top level 5 path Snapshots/Photos/20160702 ID 4946 gen 203041 top level 5 path Snapshots/Photos/20160731 ID 4947 gen 203041 top level 5 path Snapshots/Photos/20160813 ID 4948 gen 203041 top level 5 path Snapshots/Photos/2016081301 ID 4970 gen 203041 top level 5 path Snapshots/Photos/20160919 ID 5038 gen 203041 top level 5 path Snapshots/Photos/20161229_0911 ID 5063 gen 250515 top level 5 path mirror ID 13170 gen 250428 top level 5 path BizBackups ID 13214 gen 250368 top level 5 path SaraLaptopBackup ID 13485 gen 250368 top level 5 path PCOMDisks ID 16176 gen 229817 top level 5 path Snapshots/Photos/20170515 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
