usermodehelper: export call_usermodehelper_exec() and call_usermodehelper_setup()

call_usermodehelper_setup() + call_usermodehelper_exec() need to be
called instead of call_usermodehelper_fns() when the cleanup function
needs to be called even when an ENOMEM error occurs.  In this case using
call_usermodehelper_fns() the user can't distinguish if the cleanup
function was called or not.

[akpm@linux-foundation.org: export call_usermodehelper_setup() to modules]
Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 5398d58..7eebcf5 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -71,6 +71,14 @@
 			int (*init)(struct subprocess_info *info, struct cred *new),
 			void (*cleanup)(struct subprocess_info *), void *data);
 
+extern struct subprocess_info *
+call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask,
+			  int (*init)(struct subprocess_info *info, struct cred *new),
+			  void (*cleanup)(struct subprocess_info *), void *data);
+
+extern int
+call_usermodehelper_exec(struct subprocess_info *info, int wait);
+
 static inline int
 call_usermodehelper(char *path, char **argv, char **envp, int wait)
 {