> -----Original Message----- > From: linux-btrfs-ow...@vger.kernel.org [mailto:linux-btrfs- > ow...@vger.kernel.org] On Behalf Of Christoph Anton Mitterer > Sent: Sunday, 4 September 2016 2:51 PM > To: linux-btrfs@vger.kernel.org > Subject: gazillions of Incorrect local/global backref count > > Hey. > > I just did a btrfs check on my notebooks root fs, with: > $ uname -a > Linux heisenberg 4.7.0-1-amd64 #1 SMP Debian 4.7.2-1 (2016-08-28) > x86_64 GNU/Linux > $ btrfs --version > btrfs-progs v4.7.1 > > > > during: > checking extents > > it found gazillions of these: > Incorrect local backref count on 1107980288 root 257 owner 17807428 > offset 13568135168 found 2 wanted 3 back 0x2d69990 > Incorrect local backref count on 1107980288 root 257 owner 14055042 > offset 13568135168 found 2 wanted 3 back 0x2d69930 > Incorrect global backref count on 1107980288 found 4 wanted 6 > backpointer mismatch on [1107980288 61440] > Incorrect local backref count on 1108049920 root 257 owner 17807428 > offset 13568262144 found 2 wanted 5 back 0x2d69ac0 > Incorrect local backref count on 1108049920 root 257 owner 14055042 > offset 13568262144 found 2 wanted 5 back 0x2d69b20 > Incorrect global backref count on 1108049920 found 4 wanted 10 > backpointer mismatch on [1108049920 77824] > > See stdout/err[0] logfiles from the check. > > > What do they mean? > > And does this now mean that data is corrupted and I should try to > recover that from a backup? > And if so... how to I map the affected addresses above back to files? > > Or can I somehow simply (and foremost cleanly/perfectly) correct these > errors?
The errors are wrong. I nearly ruined my filesystem a few days ago by trying to repair similar errors, thankfully all seems ok. Check again with btrfs-progs 4.6.1 and see if the errors go away, mine did. See open bug https://bugzilla.kernel.org/show_bug.cgi?id=155791 for more details. Cheers, Paul.
