btrfs-image: flush_pending: Assertion `!(!eb)` failed. Aborted. btrfsck also fails.

[Martin Pool]

I have a machine running Precise with a btrfs root filesystem. It panicked the other day and now neither btrfsck or btrfs-image will run:

# btrfs-image /dev/sdc2 /backup/grace/...
checksum verify failed on 896765952 wanted 1d6bdc08 found 1931370
checksum verify failed on 896765952 wanted 1d6bdc08 found 1931370
checksum verify failed on 896765952 wanted 1d6bdc08 found 1931370
btrfs-image: btrfs-image.c:394: flush_pending: Assertion `!(!eb)` failed.

checksum verify failed on 896765952 wanted 1d6bdc08 found 26093d0
checksum verify failed on 896765952 wanted 1d6bdc08 found 26093d0
checksum verify failed on 896765952 wanted 1d6bdc08 found 26093d0
fsck.btrfs[699]: segfault at b4 ip 000040f486 sp 00007fff8c803990 error 4 in btrfsck[4000000+1f000]
Warning... fsck.btrfs for device /dev/sdc2 exited with signal 11.
mountal: fsck / [697] terminated with status 8

the oops was
lookup_extent_backref
__btrfs_free_extent
run_delayed_tree_ref
...

screenshots https://plus.google.com/photos/112646476239496153808/albums/5778858506731162865?hl=en

[Dimitri John Ledkov (xnox)]

please try btrfs-tools from quantal. It has improved, maybe it will help.
If not, try btrfs wiki / mailing list, they are usually helpful.

[Martin Pool (mbp)]

Current Quantal's alternate image doesn't seem to have a btrfs on it. (??)

If I try to mount that partition from Quantal, it fails with:

 BUG: Bad page state in process btrfs-cache-1 pn:2187fb
 page:ffffea000.... count:0 mapcount:0 mapping:ffff88021... index:0x36e9
 page flags: 0x2000...010c(referenced|uptodate|owner_priv_1)

That's kernel 3.5.0-14-generic #15-Ubuntu

[Martin Pool (mbp)]

Current Quantal's alternate image doesn't seem to have a btrfs on it. (??)

If I try to mount that partition from Quantal, it fails with:

> BUG: Bad page state in process btrfs-cache-1 pn:2187fb
> page:ffffea000.... count:0 mapcount:0 mapping:ffff88021... index:0x36e9
> page flags: 0x2000...010c(referenced|uptodate|owner_priv_1)

That's kernel 3.5.0-14-generic #15-Ubuntu

--
Martin