On Thu, Oct 20, 2016 at 3:20 PM, Suvayu Ali <fatkasuvayu+li...@gmail.com> wrote: > Hi, > > (please CC me in replies, I'm not subscribed) > > I'm using kernel 4.7.7-100.fc23 with btrfs-progs v4.7.1. > > I had my /home, /var, and /opt as subvolumes in a btrfs partition. > Last night btrfs failed, and I was unable to mount it normally > (leading to boot failures). The journal had messages like this: > > BTRFS: open_ctree failed > BTRFS error: super_total_bytes ... mismatch with fs_devices total_rw_bytes > BTRFS error: failed to read chunk tree: -22 > > Finally I managed to mount it manually like this (after making a dd > image of the partition): > > # mount -t btrfs -o ro,recovery,nospace_cache /dev/sdb2 /mnt > > and managed to recover my data. Initially "btrfs check" yielded a few > > parent transid verify failed on 101679726592 wanted 822619 found 822617 > > and > > checksum verify failed on 101756387328 found 78C8A0BC wanted B7C59D79 > > however after backing up my data, I mounted without the "-o ro" (I got > a transid related message, but it did mount). "btrfs check" now spits > out a whole bunch of: > > Incorrect local backref count on 202118008832 root 259 owner 178928 > offset 41181184 found 2 wanted 7 back 0x55713fbbf150 > Incorrect global backref count on 202118008832 found 2 wanted 7 > backpointer mismatch on [202118008832 376832]
This is a known problem with btrfs-progs 4.7.1 it should not be used. https://btrfs.wiki.kernel.org/index.php/Changelog#btrfs-progs_4.7.1_.28Aug_2016.29 Upgrade to 4.7.3 or 4.8.1 is advised. > > followed by this summary: > > checking csums > checking root refs > checking quota groups > Counts for qgroup id: 0/257 are different > our: referenced 7746465792 referenced compressed 7746465792 > disk: referenced 7746461696 referenced compressed 7746461696 > diff: referenced 4096 referenced compressed 4096 > our: exclusive 7746465792 exclusive compressed 7746465792 > disk: exclusive 7746461696 exclusive compressed 7746461696 > diff: exclusive 4096 exclusive compressed 4096 > Counts for qgroup id: 0/259 are different > our: referenced 135641784320 referenced compressed 135641784320 > disk: referenced 135633862656 referenced compressed 135633862656 > diff: referenced 7921664 referenced compressed 7921664 > our: exclusive 135641784320 exclusive compressed 135641784320 > disk: exclusive 135633862656 exclusive compressed 135633862656 > diff: exclusive 7921664 exclusive compressed 7921664 > found 167864082432 bytes used err is 0 > total csum bytes: 161187492 > total tree bytes: 2021015552 > total fs tree bytes: 1725759488 > total extent tree bytes: 86228992 > btree space waste bytes: 386160897 > file data blocks allocated: 1269363683328 > referenced 164438126592 > > How do I repair this? Yeah good question. I can't tell from the message whether different counts is a bad thing, or if it's just a notification, or what. Yet again btrfs-progs does not help the user make informed decisions, it's really frustrating. I think that part can be ignored though for now, and see if btrfs check --repair can fix the problem now that you have a backup. -- Chris Murphy -- 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
