ubirmvol:ing gluebied volumes

ubirmvol:ing gluebied volumes

[Ricard Wanderlof]

I enabled the gluebi MTD emulation layer in the kernel, and was pleased to 
see all the UBI volumes coming up in /proc/mtd as mtd volumes.

However, one thing though, if I try to ubirmvol one of the UBI volumes, I 
get:

ubirmvol: error!: cannot UBI remove volume
           error 16 (Device or resource busy)

similar to what I get if I have a mounted ubifs residing in an UBI volume 
and try and ubirmvol the volume without umounting the file system.

Fair enough, I guess gluebi is keeping the UBI volume busy? But then how 
do I free it up? There's normally no way to disassociate mtd partitions 
from the underlying media, and I can't see any ubi tool that would do this 
either.

So is this an (unfortunate) consequence of using gluebi: that the 
underlying UBI volumes can't be removed?

Same thing happens if I try and ubidetach the UBI partition from the 
underlying mtd partition: Device or resource busy.

/Ricard
-- 
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30

Re: ubirmvol:ing gluebied volumes

[Artem Bityutskiy]

On Fri, 2011-05-06 at 14:17 +0200, Ricard Wanderlof wrote:
> I enabled the gluebi MTD emulation layer in the kernel, and was pleased to 
> see all the UBI volumes coming up in /proc/mtd as mtd volumes.

Hehe :-)

> However, one thing though, if I try to ubirmvol one of the UBI volumes, I 
> get:
> 
> ubirmvol: error!: cannot UBI remove volume
>            error 16 (Device or resource busy)

Yeah.

> similar to what I get if I have a mounted ubifs residing in an UBI volume 
> and try and ubirmvol the volume without umounting the file system.

Yes.

> Fair enough, I guess gluebi is keeping the UBI volume busy? But then how 
> do I free it up?

I think the only way is to rmmod gluebi.

>  There's normally no way to disassociate mtd partitions 
> from the underlying media, and I can't see any ubi tool that would do this 
> either.

Right.

> So is this an (unfortunate) consequence of using gluebi: that the 
> underlying UBI volumes can't be removed?

In current implementation yes. But you can rmomod it, shuffle UBI
volumes, and modprobe it again.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)

Re: ubirmvol:ing gluebied volumes

[Ricard Wanderlof]

On Fri, 6 May 2011, Artem Bityutskiy wrote:

>> Fair enough, I guess gluebi is keeping the UBI volume busy? But then how
>> do I free it up?
>
> I think the only way is to rmmod gluebi.
>
>> So is this an (unfortunate) consequence of using gluebi: that the
>> underlying UBI volumes can't be removed?
>
> In current implementation yes. But you can rmomod it, shuffle UBI
> volumes, and modprobe it again.

Aha! Hadn't thought of that. I built gluebi into the kernel, not as a 
module, so the thought never crossed my mind. Thanks!

/Ricard
-- 
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30