afs: Support interacting with multiple user namespaces

Modify struct afs_file_status to store owner as a kuid_t and group as
a kgid_t.

In xdr_decode_AFSFetchStatus as owner is now a kuid_t and group is now
a kgid_t don't use the EXTRACT macro.  Instead perform the work of
the extract macro explicitly.  Read the value with ntohl and
convert it to the appropriate type with make_kuid or make_kgid.
Test if the value is different from what is stored in status and
update changed.   Update the value in status.

In xdr_encode_AFS_StoreStatus call from_kuid or from_kgid as
we are computing the on the wire encoding.

Initialize uids with GLOBAL_ROOT_UID instead of 0.
Initialize gids with GLOBAL_ROOT_GID instead of 0.

Cc: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 95cffd38239f..789bc253b5f6 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -69,7 +69,7 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
 
 	set_nlink(inode, vnode->status.nlink);
 	inode->i_uid		= vnode->status.owner;
-	inode->i_gid		= 0;
+	inode->i_gid		= GLOBAL_ROOT_GID;
 	inode->i_size		= vnode->status.size;
 	inode->i_ctime.tv_sec	= vnode->status.mtime_server;
 	inode->i_ctime.tv_nsec	= 0;
@@ -175,8 +175,8 @@ struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
 	inode->i_mode		= S_IFDIR | S_IRUGO | S_IXUGO;
 	inode->i_op		= &afs_autocell_inode_operations;
 	set_nlink(inode, 2);
-	inode->i_uid		= 0;
-	inode->i_gid		= 0;
+	inode->i_uid		= GLOBAL_ROOT_UID;
+	inode->i_gid		= GLOBAL_ROOT_GID;
 	inode->i_ctime.tv_sec	= get_seconds();
 	inode->i_ctime.tv_nsec	= 0;
 	inode->i_atime		= inode->i_mtime = inode->i_ctime;