fs: rename inode member of struct filep to priv ...

Because that's what it is. 'inode' will become confusing
once we support real inodes.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: efivars: implement write support ...

Implement the standard FS ops for writing/manipulating
efivars.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: efivars: don't store attributes in file ...

We don't have a use-case yet where we need to manipulate
the attributes of a variable and it confuses "normal"
users of the variables.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: efivar: preserve more info in inode ...

Preserve info needed for easy manipulation of variables.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: efivar: move variable discovery into probe ...

So we can manipulate things easier.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: efivar: switch to standard list implementation ...

Cleans the code a bit and will allow us to implement
removing of vars quite a bit easier.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: efivars: cosmetic changes ...

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

fs: implement EFI variable filesystem driver ...

This implements a filesystem for accessing EFI variables.
It is compatible to the Linux Kernel efivarfs filesystem.
Currently the variables can only be accessed readonly.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>