kmod: remove call_usermodehelper_fns()

This function suffers from not being able to determine if the cleanup is
called in case it returns -ENOMEM.  Nobody is using it anymore, so let's
remove it.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: 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>

include/linux/kmod.h

@@ -67,9 +67,7 @@ struct subprocess_info {
 };
 
 extern int
-call_usermodehelper_fns(char *path, char **argv, char **envp, int wait,
-			int (*init)(struct subprocess_info *info, struct cred *new),
-			void (*cleanup)(struct subprocess_info *), void *data);
+call_usermodehelper(char *path, char **argv, char **envp, int wait);
 
 extern struct subprocess_info *
 call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask,
@@ -79,13 +77,6 @@ call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask,
 extern int
 call_usermodehelper_exec(struct subprocess_info *info, int wait);
 
-static inline int
-call_usermodehelper(char *path, char **argv, char **envp, int wait)
-{
-	return call_usermodehelper_fns(path, argv, envp, wait,
-				       NULL, NULL, NULL);
-}
-
 extern struct ctl_table usermodehelper_table[];
 
 enum umh_disable_depth {

kernel/kmod.c

@@ -555,8 +555,8 @@ EXPORT_SYMBOL(call_usermodehelper_setup);
  * call_usermodehelper_exec - start a usermode application
  * @sub_info: information about the subprocessa
  * @wait: wait for the application to finish and return status.
- *        when -1 don't wait at all, but you get no useful error back when
- *        the program couldn't be exec'ed. This makes it safe to call
+ *        when UMH_NO_WAIT don't wait at all, but you get no useful error back
+ *        when the program couldn't be exec'ed. This makes it safe to call
  *        from interrupt context.
  *
  * Runs a user-space application.  The application is started
@@ -616,29 +616,32 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait)
 }
 EXPORT_SYMBOL(call_usermodehelper_exec);
 
-/*
- * call_usermodehelper_fns() will not run the caller-provided cleanup function
- * if a memory allocation failure is experienced.  So the caller might need to
- * check the call_usermodehelper_fns() return value: if it is -ENOMEM, perform
- * the necessaary cleanup within the caller.
+/**
+ * call_usermodehelper() - prepare and start a usermode application
+ * @path: path to usermode executable
+ * @argv: arg vector for process
+ * @envp: environment for process
+ * @wait: wait for the application to finish and return status.
+ *        when UMH_NO_WAIT don't wait at all, but you get no useful error back
+ *        when the program couldn't be exec'ed. This makes it safe to call
+ *        from interrupt context.
+ *
+ * This function is the equivalent to use call_usermodehelper_setup() and
+ * call_usermodehelper_exec().
  */
-int call_usermodehelper_fns(
-	char *path, char **argv, char **envp, int wait,
-	int (*init)(struct subprocess_info *info, struct cred *new),
-	void (*cleanup)(struct subprocess_info *), void *data)
+int call_usermodehelper(char *path, char **argv, char **envp, int wait)
 {
 	struct subprocess_info *info;
 	gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
 
 	info = call_usermodehelper_setup(path, argv, envp, gfp_mask,
-					 init, cleanup, data);
-
+					 NULL, NULL, NULL);
 	if (info == NULL)
 		return -ENOMEM;
 
 	return call_usermodehelper_exec(info, wait);
 }
-EXPORT_SYMBOL(call_usermodehelper_fns);
+EXPORT_SYMBOL(call_usermodehelper);
 
 static int proc_cap_handler(struct ctl_table *table, int write,
 			 void __user *buffer, size_t *lenp, loff_t *ppos)