[PATCH v5 02/19] vfs: add a kern_path_at function

[Jeff Layton <jlayton@redhat.com>]

This will function like user_path_at, but does not do the getname and
putname, leaving that to the caller.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 fs/namei.c            | 27 +++++++++++++++++++--------
 include/linux/namei.h |  1 +
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index dc792e5..83a6f46 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2092,20 +2092,31 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 	return __lookup_hash(&this, base, 0);
 }
 
+int kern_path_at(int dfd, const char *name, unsigned flags, struct path *path)
+{
+	struct nameidata nd;
+	int err;
+
+	BUG_ON(flags & LOOKUP_PARENT);
+
+	err = do_path_lookup(dfd, name, flags, &nd);
+	if (!err)
+		*path = nd.path;
+
+	return err;
+}
+
 int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
 		 struct path *path, int *empty)
 {
-	struct nameidata nd;
 	char *tmp = getname_flags(name, flags, empty);
-	int err = PTR_ERR(tmp);
-	if (!IS_ERR(tmp)) {
-
-		BUG_ON(flags & LOOKUP_PARENT);
+	int err;
 
-		err = do_path_lookup(dfd, tmp, flags, &nd);
+	if (IS_ERR(tmp)) {
+		err = PTR_ERR(tmp);
+	} else {
+		err = kern_path_at(dfd, tmp, flags, path);
 		putname(tmp);
-		if (!err)
-			*path = nd.path;
 	}
 	return err;
 }
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 4bf19d8..482f87f 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -55,6 +55,7 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT, LAST_BIND};
 #define LOOKUP_ROOT		0x2000
 #define LOOKUP_EMPTY		0x4000
 
+extern int kern_path_at(int, const char *, unsigned, struct path *);
 extern int user_path_at(int, const char __user *, unsigned, struct path *);
 extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
 
-- 
1.7.11.2