coda: Restrict coda messages to the initial user namespace

Remove the slight chance that uids and gids in coda messages will be
interpreted in the wrong user namespace.

- Only allow processes in the initial user namespace to open the coda
  character device to communicate with coda filesystems.
- Explicitly convert the uids in the coda header into the initial user
  namespace.
- In coda_vattr_to_attr make kuids and kgids from the initial user
  namespace uids and gids in struct coda_vattr that just came from
  userspace.
- In coda_iattr_to_vattr convert kuids and kgids into uids and gids
  in the intial user namespace and store them in struct coda_vattr for
  sending to coda userspace programs.

Nothing needs to be changed with mounts as coda does not support
being mounted in anything other than the initial user namespace.

Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/coda_psdev.h b/include/linux/coda_psdev.h
index 8031d6eef10..5b8721efa94 100644
--- a/include/linux/coda_psdev.h
+++ b/include/linux/coda_psdev.h
@@ -34,7 +34,7 @@ int venus_lookup(struct super_block *sb, struct CodaFid *fid,
 		 const char *name, int length, int *type, 
 		 struct CodaFid *resfid);
 int venus_close(struct super_block *sb, struct CodaFid *fid, int flags,
-		vuid_t uid);
+		kuid_t uid);
 int venus_open(struct super_block *sb, struct CodaFid *fid, int flags,
 	       struct file **f);
 int venus_mkdir(struct super_block *sb, struct CodaFid *dirfid,