Messages in this thread | | | From | Andrzej Pietrasiewicz <> | Subject | [RFC][PATCH] fs: configfs: programmatically create config groups | Date | Mon, 26 Nov 2012 09:35:09 +0100 |
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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 kindly ask for comments. In particular, I would like to discuss if this is the right approach. A counterpart to remove config groups is also required. It is not implemented in this patch, though. What are your opinions?
Andrzej Pietrasiewicz (1): fs: configfs: allow other kernel parts to programmatically create config groups
fs/configfs/dir.c | 5 +++-- include/linux/configfs.h | 2 ++ 2 files changed, 5 insertions(+), 2 deletions(-)
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