Re: Crash in __btrfs_reserve_extent

[Tore Anderson <tore.anderson@redpill-linpro.com>]

* Josef Bacik

> Ooookay, now that I'm awake lets try this again :).  You are right, I
> thought it was 212GB used, not 16GB used.  Something has gone
> horribly wrong, btrfs seems to think thats all the space it can use.
> The command you need to use is btrfs-vol -b.  Please try that and see
> if it behaves better.  Before you run that please do a btrfs-show and
> post the output, I'd like to see how big the fs thinks its supposed
> to be.

It doesn't print much of anything, I'm afraid:

root@echo:~/misc/btrfs-progs-unstable# ./btrfs-show /dev/mapper/vg_echo-lv_root  
failed to read /dev/sr0
failed to read /dev/sdf
failed to read /dev/sde
failed to read /dev/sdd
failed to read /dev/sdc
failed to read /dev/sdb
Btrfs Btrfs v0.19

Same output with btrfs-progs-0.19.  The devices it's complaining about
is a USB memory card reader and my optical drive, if I disconnect
those from the SCSI layer the output is simply "Btrfs Btrfs v0.19".

I tried to run btrfsck earlier today, but it only gave me an error
message.  Perhaps that just made things worse?

I've got a btrfs-image dump that I took right after the problem showed
for the first time (before the fsck), by the way.  It's available at
<http://greed.fud.no/hosed_rootfs.btrfsimage.Z> in case you have any
use for it.

Best regards,
-- 
Tore Anderson
Redpill Linpro AS - http://www.redpill-linpro.com/
Tel: +47 21 54 41 27