Thanks for all the comments and inputs.

  feature    xattr     btrfs-kernel-way
  [1]         No        Yes
  [2]         No        Yes
  [3]         Yes       No


  [1]. Ability to read subvol label without mount
  [2]. Full-ability to log and track the property
       when it is modified
  [3]. risk-free patch ?

  Any comments on why not the btrfs-kernel-way and a review
  of the patch ?

Thanks -Anand


On 11/02/2012 06:49 AM, Fajar A. Nugraha wrote:

On Fri, Nov 2, 2012 at 5:32 AM, Hugo Mills [off-list ref] wrote:

quoted

On Fri, Nov 02, 2012 at 05:28:01AM +0700, Fajar A. Nugraha wrote:

quoted

On Fri, Nov 2, 2012 at 5:16 AM, cwillu [off-list ref] wrote:

quoted

quoted

  btrfs fi label -t /btrfs/snap1-sv1
Prod-DB-sand-box-testing

Why is this better than:

# btrfs su snap /btrfs/Prod-DB /btrfs/Prod-DB-sand-box-testing
# mv /btrfs/Prod-DB-sand-box-testing /btrfs/Prod-DB-production-test
# ls /btrfs/
Prod-DB  Prod-DB-production-test

... because it would mean possibilty to decouple subvol name from
whatever-data-you-need (in this case, a label).

My request, though, is to just implement properties, and USER
properties, like what we have in zfs. This seems to be a cleaner,
saner approach. For example, this is on Ubutu + zfsonlinux:

# zfs create rpool/u
# zfs set user:label="Some test filesystem" rpool/u
# zfs get creation,user:label rpool/u
NAME     PROPERTY    VALUE                  SOURCE
rpool/u  creation    Fri Nov  2  5:24 2012  -
rpool/u  user:label  Some test filesystem   local

    Don't we already have an equivalent to that with user xattrs?

    Hugo.

Anand did say one way to implement the label is by using attr, so +1
from me for that approach.