fs: use type safe idmapping helpers

We already ported most parts and filesystems over for v6.0 to the new
vfs{g,u}id_t type and associated helpers for v6.0. Convert the remaining
places so we can remove all the old helpers.
This is a non-functional change.

Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
diff --git a/fs/exec.c b/fs/exec.c
index 349a5da..dd91ade 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1591,8 +1591,8 @@ static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
 	struct user_namespace *mnt_userns;
 	struct inode *inode = file_inode(file);
 	unsigned int mode;
-	kuid_t uid;
-	kgid_t gid;
+	vfsuid_t vfsuid;
+	vfsgid_t vfsgid;
 
 	if (!mnt_may_suid(file->f_path.mnt))
 		return;
@@ -1611,23 +1611,23 @@ static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
 
 	/* reload atomically mode/uid/gid now that lock held */
 	mode = inode->i_mode;
-	uid = i_uid_into_mnt(mnt_userns, inode);
-	gid = i_gid_into_mnt(mnt_userns, inode);
+	vfsuid = i_uid_into_vfsuid(mnt_userns, inode);
+	vfsgid = i_gid_into_vfsgid(mnt_userns, inode);
 	inode_unlock(inode);
 
 	/* We ignore suid/sgid if there are no mappings for them in the ns */
-	if (!kuid_has_mapping(bprm->cred->user_ns, uid) ||
-		 !kgid_has_mapping(bprm->cred->user_ns, gid))
+	if (!vfsuid_has_mapping(bprm->cred->user_ns, vfsuid) ||
+	    !vfsgid_has_mapping(bprm->cred->user_ns, vfsgid))
 		return;
 
 	if (mode & S_ISUID) {
 		bprm->per_clear |= PER_CLEAR_ON_SETID;
-		bprm->cred->euid = uid;
+		bprm->cred->euid = vfsuid_into_kuid(vfsuid);
 	}
 
 	if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
 		bprm->per_clear |= PER_CLEAR_ON_SETID;
-		bprm->cred->egid = gid;
+		bprm->cred->egid = vfsgid_into_kgid(vfsgid);
 	}
 }