Re: [PATCH 0 of 7] blktap2: The tap-ctl userspace control utility and library

["Łukasz Oleś" <lukaszoles@gmail.com>]

On Monday 07 June 2010 23:54:47 Daniel Stodden wrote:
> Hi.
> 
> Apart from removing some dead code and tidying up tapdisk-vbd a
> little, the bigger introduces our new tap-ctl utility code.
> 
> The code aims to be a complete replacement for the original blktap2
> control path, run through sysfs. Fully implemented in userspace, all
> tapdisks now gained a small IPC layer on top of Unix domain sockets.
> 
> Sample usage:
> 
> # tap-ctl allocate
> /dev/xen/blktap-2/tapdev0
> 
> # tap-ctl spawn
> tapdisk spawned with pid 4168
> 
> # tap-ctl list
>     4168  -    -          - -
>        -  0    -          - -
> 
> # tap-ctl attach -p 4168 -m 0
> # tap-ctl list
>     4168  0    0          - -
> 
> # tap-ctl open -p 4168 -m 0 -a aio:/var/tmp/lenny.ext
> 
> # tap-ctl list
>     4168  0    0        aio /var/tmp/lenny.ext
> 
> # tap-ctl close -p 4168 -m 0
> # tap-ctl detach -p 4168 -m 0
> # tap-ctl free -m 0
> 
> The above example is a bit noisy, because it's mediating between minor
> number (block devices), tapdisks and tapdisk VBDs (the tapdisk I/O
> queue running a bdev) in detail.
> 
> There are shortcuts. At the same time, the low-level interface should
> be general enough to stay extensible, and help accomodate some of the
> more esoteric features, like shared images and/or multiple VBDs
> sharing the same tapdisk.

I think README file should be also updated.

And maybe its good idea to merge it to xen 4.0?

--
Łukasz Oleś