btrfs filesystems can only be mounted after an unclean shutdown if btrfsck is run and immediately killed!

Hi all,
I have two multi-disk btrfs filesystems on a Arch linux 3.4.0 system. After a power failure, both filesystems refuse to mount

[   10.402284] Btrfs loaded
[   10.402714] device fsid 1e7c18a4-02d6-44b1-8eaf-c01378009cd3 devid 4 transid 65282 /dev/sdc
[   10.403108] btrfs: force zlib compression
[   10.403130] btrfs: enabling inode map caching
[   10.403152] btrfs: disk space caching is enabled
[   10.403377] btrfs: failed to read the system array on sdc
[   10.403557] btrfs: open_ctree failed
[   10.431763] device fsid 7f7be913-e359-400f-8bdb-7ef48aad3f03 devid 2 transid 3916 /dev/sdb
[   10.432180] btrfs: force zlib compression
[   10.433040] btrfs: enabling inode map caching
[   10.433892] btrfs: disk space caching is enabled
[   10.434930] btrfs: failed to read the system array on sdb
[   10.435945] btrfs: open_ctree failed

fstab:

UUID=1e7c18a4-02d6-44b1-8eaf-c01378009cd3 /storage/btrfs btrfs noatime,compress-force=zlib,space_cache,inode_cache 0 0 UUID=7f7be913-e359-400f-8bdb-7ef48aad3f03 /storage/btrfs2 btrfs noatime,compress-force=zlib,space_cache,inode_cache 0 0

The funny thing is that if i run btrfsck for one second on the first filesystem and then kill it with ctrl-c, then both filesystems can be mounted without any problems!

I have this problem for many months, probably for all 3.x kernels and maybe a bit older, all git btrfs tools since at least late last year.

[root@linuxserver ~/btrfs-progs]# btrfs fi show /dev/sdb
Label: none uuid: 7f7be913-e359-400f-8bdb-7ef48aad3f03
Total devices 2 FS bytes used 1.54TB
devid 1 size 1.82TB used 1.04TB path /dev/sda
devid 2 size 1.82TB used 1.04TB path /dev/sdb

Btrfs Btrfs v0.19
[root@linuxserver ~/btrfs-progs]# btrfs fi show /dev/sdf
Label: none uuid: 1e7c18a4-02d6-44b1-8eaf-c01378009cd3
Total devices 4 FS bytes used 4.33TB
devid 5 size 1.82TB used 1.82TB path /dev/sdg
devid 4 size 1.82TB used 1.82TB path /dev/sdc
devid 3 size 1.82TB used 1.79TB path /dev/sdf
devid 1 size 1.82TB used 1.82TB path /dev/sdd

Btrfs Btrfs v0.19

Multi-device filesystem had to be first fully discovered by
"btrfs device scan". It is typically done from udev rules. Also, dracut does it in initramfs for quite a long time.

Tomasz Torcz                        To co nierealne -- tutaj jest normalne.
xmpp: [email protected]          Ziomale na życie mają tu patenty specjalne.

(Added cc to btrfs list)

You are right, i have forgotten to enable it (arch linux has a new rc.conf option for that), i will reboot in a few minutes to test it.
Maybe it would be prudent to give a better error message when such a thing happens, or even make mount run btrfs device scan if it detects that a multi-drive fs is being mounted?