Re: [RFC] vfs generic subtree support

[Matthew Wilcox <matthew@wil.cx>]

On Tue, Feb 16, 2010 at 06:00:32PM +0300, Dmitry Monakhov wrote:
> Use-cases:
> *Assing maximum disc space consumption for some hierarchy *
> 
>   1) Create chroot environment
>     # tar  xf chroot_env.tar /var/xxx/chroot
>   2) Assign some metagroup id to the chroot content (via not yet
>      existent ./metagroup cmd-tool)
>     # find /var/xxx/chroot  | xargs ./metagroup --set 1000
> 
>   3) Setup quota limits
>     # quota-set --type metagroup --blk_soft=1024M blk_hard=1024M /var
> 
>   4) Export this tree (it may be more complex)
>     # mount /var/xxx/chroot /mnt/chroot -obound
> 
>   5)Now we may use this /mnt/chroot as:
>     5A) A regular chroot envirement, user is unable to exceed metagroup
>         quota, regardless to real available space on /var/
>     5B) As a container's (namespace) root. 
>     5C) export this /mnt/chroot to nfs server and nfs client can not
>         overcome given metagroup quota limit. 

This all seems quota-related ... do you envisage uses that aren't
quota-related?

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."