Re: [RFC][PATCH] fs: configfs: programmatically create config groups

From: Michal Nazarewicz
Date: Mon Nov 26 2012 - 08:21:02 EST


On Mon, Nov 26 2012, Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxx> wrote:
> In some parts of the kernel (e.g. planned configfs integration into usb
> gadget) there is a need to programmatically create config groups
> (directories) but it would be preferable to disallow creating them by
> the user. This is more or less what default_groups used to be for.
> But e.g. in the mass storage gadget, after storing the number of
> luns (logical units) into some configfs attribute, the corresponding lun#
> directories should be created, their number is not known up front so
> default_groups are no good for this.
>
> Example:
>
> $ echo 3 > /cfg/..../mass_storage/luns
>
> causes
>
> /cfg/....../mass_storage/lun0
> /cfg/....../mass_storage/lun1
> /cfg/....../mass_storage/lun2
>
> to be created. Yet
>
> $ mkdir /cfg/..../mass_storage/<any name>
>
> should not be allowed.
>
> With create_group exported it is very easily achieved: make_group and make_item
> are set to NULL in mass_storage's config_group, yet the kernel can
> create_groups at will.

I think the above description should be part of the commit message. :)

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Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, MichaÅ âmina86â Nazarewicz (o o)
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