userns: Store uid and gid types in vfs structures with kuid_t and kgid_t types

The conversion of all of the users is not done yet there are too many to change
in one go and leave the code reviewable. For now I change just the header and
a few trivial users and rely on CONFIG_UIDGID_STRICT_TYPE_CHECKS not being set
to ensure that the code will still compile during the transition.

Helper functions i_uid_read, i_uid_write, i_gid_read, i_gid_write are added
so that in most cases filesystems can avoid the complexities of multiple user
namespaces and can concentrate on moving their raw numeric values into and
out of the vfs data structures.

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/inode.c b/fs/inode.c
index f0c4ace408e4..deb72f6c2b4f 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -135,8 +135,8 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
         inode->i_fop = &empty_fops;
         inode->__i_nlink = 1;
         inode->i_opflags = 0;
-        inode->i_uid = 0;
-        inode->i_gid = 0;
+        i_uid_write(inode, 0);
+        i_gid_write(inode, 0);
         atomic_set(&inode->i_writecount, 0);
         inode->i_size = 0;
         inode->i_blocks = 0;
@@ -1732,7 +1732,7 @@ EXPORT_SYMBOL(inode_init_owner);
  */
 bool inode_owner_or_capable(const struct inode *inode)
 {
-        if (current_fsuid() == inode->i_uid)
+        if (uid_eq(current_fsuid(), inode->i_uid))
                 return true;
         if (inode_capable(inode, CAP_FOWNER))
                 return true;