[lxc-devel] [RFC PATCH 1/2] loop: Add loop filesystem

[Randy Dunlap]

On 05/27/2014 02:58 PM, Seth Forshee wrote:
> Add limited capability for use of loop devices in containers via
> a loopfs psuedo fs. When mounted this filesystem will contain
> only a loop-control device node. This can be used to request free
> loop devices which will be "owned" by that mount. Device nodes
> appear automatically for these devices, and the same device will
> not be given to another loopfs mount. Privileged loop ioctls
> (for encrypted loop) will be allowed within the namespace which
> mounted the loopfs.
> 
> Privileged block ioctls are not permitted, so features such as
> partitions are not supported for unprivileged users.
> 
> Signed-off-by: Seth Forshee <seth.forshee at canonical.com>
> ---
>  drivers/block/loop.c       | 110 +++++++++++---
>  drivers/block/loop.h       |   2 +
>  fs/Makefile                |   1 +
>  fs/loopfs/Makefile         |   6 +
>  fs/loopfs/inode.c          | 349 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/loopfs.h     |  46 ++++++
>  include/uapi/linux/magic.h |   1 +
>  7 files changed, 495 insertions(+), 20 deletions(-)
>  create mode 100644 fs/loopfs/Makefile
>  create mode 100644 fs/loopfs/inode.c
>  create mode 100644 include/linux/loopfs.h
> 

> diff --git a/fs/loopfs/Makefile b/fs/loopfs/Makefile
> new file mode 100644
> index 000000000000..01aedfb2f841
> --- /dev/null
> +++ b/fs/loopfs/Makefile
> @@ -0,0 +1,6 @@
> +#
> +# Makefile for the loopfs virtual filesystem
> +#
> +
> +obj-$(CONFIG_BLK_DEV_LOOP)		+= loopfs.o
> +loopfs-$(CONFIG_BLK_DEV_LOOP)		:= inode.o

I guess that you need to update the BLK_DEV_LOOP entry in
drivers/block/Kconfig to mention this?


-- 
~Randy