[RFC PATCH v2 07/18] user_statfs(): import pathname only once

[Al Viro <viro@zeniv.linux.org.uk>]

Convert the user_path_at() call inside a retry loop into getname_flags() +
filename_lookup() + putname() and leave only filename_lookup() inside
the loop.

In this case we never pass LOOKUP_EMPTY, so getname_flags() is equivalent
to plain getname().

The things could be further simplified by use of cleanup.h stuff, but
let's not clutter the patch with that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/statfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/statfs.c b/fs/statfs.c
index a45ac85e6048..a5671bf6c7f0 100644
--- a/fs/statfs.c
+++ b/fs/statfs.c
@@ -99,8 +99,9 @@ int user_statfs(const char __user *pathname, struct kstatfs *st)
 	struct path path;
 	int error;
 	unsigned int lookup_flags = LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT;
+	struct filename *name = getname(pathname);
 retry:
-	error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
+	error = filename_lookup(AT_FDCWD, name, lookup_flags, &path, NULL);
 	if (!error) {
 		error = vfs_statfs(&path, st);
 		path_put(&path);
@@ -109,6 +110,7 @@ int user_statfs(const char __user *pathname, struct kstatfs *st)
 			goto retry;
 		}
 	}
+	putname(name);
 	return error;
 }
 
-- 
2.47.3