[Btrfs-devel] hugely experimental changes pushed out

[Chris Mason]

On Mon, 27 Aug 2007 16:55:46 -0400
Chris Mason <chris.mason at oracle.com> wrote:

> Hello everyone,
> 
> I've pushed out my current patch queue so that I can start merging in
> all those pending patches.  It has some really experimental stuff in
> there, and it disables data file checksums for now.  Don't pull from
> the hg tree unless you want to delete your files once checksums go
> back in (I'll put in a -o nocsum mount option too so you can still
> read things).

And one more push, which has everything I've been sent recently
integrated.  This includes Josef's /sys/fs/btrfs/<device> stuff to
expose details about blocks used in each root.  If you want to look
at the block accounting, you will want to pull the related changesets
from the btrfs-progs tree as well.

I modified Yan Zheng's port of Christoph's mount-into-subdir patch.
If you mount a btrfs volume, you will end up in the default subvolume
by default.  You can mount as many subvolumes as you want:

mount -t btrfs -o subvol=name /dev/xxxx /mount_point

Note the -t btrfs, mount needs it if you've already got something
mounted from that device.

You can create snapshots right off the mount points:

btrfsctl -s snapname /mount_point

But to create a new subvolume, you have to mount the tree root:

mount -t btrfs -o subvol=. /dev/xxx /mount_point

Which will give you the same directory tree btrfs used to have at its
root.

-chris