devfs fixes

[Sascha Hauer]

We have some places in the code where we expect a cdev name, but
also allow a full /dev/ path. We handle this by doing:

	if (!strncmp(name, "/dev/", 5))
		name += 5;

As Peter noticed this of course only works when devfs is mounted on
/dev/. With this series we actually enforce that to avoid surprises.
Also we "officially" allow to pass a /dev/ path for opening a cdev
by moving the above code to cdev_open.

Sascha

----------------------------------------------------------------
Sascha Hauer (4):
      fs: devfs: Allow mounting only on /dev/
      fs: devfs: Allow mount path in cdev_open
      filetype: Use cdev_open
      fs: pass path directly to cdev_open

 common/filetype.c | 4 +++-
 fs/devfs-core.c   | 6 +++++-
 fs/devfs.c        | 7 +++++++
 fs/fs.c           | 9 +--------
 4 files changed, 16 insertions(+), 10 deletions(-)