On Thu, Sep 1, 2016 at 11:59 AM, Chris Murphy <li...@colorremedies.com> wrote: > OK so I have a 2nd volume, which is only ever used to 'btrfs receive' > from the 1st volume. The 2nd volume is never persistently mounted. But > it too has bunches of these incorrect backref messages, where > btrfs-progs 4.6.1 comes up clean. A 3rd volume, is only ever used to > receive rsync from the 1st and it comes up clean with 4.6.1, and > 4.7.1, i.e. no such incorrect backref messages. > > The 1st volume says: > found 438074621952 bytes used err is 0 > > So if "err is 0" then there should be nothing to fix. > > I'm going to btrfs check and btrfs-image the 1st volume to capture the > current state, and then try a --repair and if it breaks the file > system I'm probably going to go ballistic...
OK so I did a repair on the primary volume, it claim to fix a bunch of stuff, without errors. It mounts fine afterward, just like it did before repair. And a subsequent check still finds all kinds of backref problems that were in fact not fixed even though repair claimed to fix them. But it doesn't crash at least. I'll file a bug on the Ux of this, which is pretty bad, aside from the fact it appears to not repair what it claims to repair. Example from repair: adding new data backref on 16913485824 root 659 owner 143234 offset 0 found 1 and from the after check Backref 16913485824 root 659 owner 143234 offset 0 num_refs 0 not found in extent tree Incorrect local backref count on 16913485824 root 659 owner 143234 offset 0 found 1 wanted 0 back 0x55e44e85ccd0 Incorrect local backref count on 16913485824 root 659 owner 143234 offset 0 found 0 wanted 1 back 0x55e44eb83910 Backref disk bytenr does not match extent record, bytenr=16913485824, ref bytenr=79553 Backref bytes do not match extent backref, bytenr=16913485824, ref bytes=7577600, backref bytes=4096 Backref 16913485824 root 659 owner 143233 offset 0 num_refs 0 not found in extent tree Which is identical to what's found in the before check. -- 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
