kobject: kobject_uevent() returns manageable value

Since kobject_uevent() function does not return an integer value to
indicate if its operation was completed with success or not, it is worth
changing it in order to report a proper status (success or error) instead
of returning void.

[randy.dunlap@oracle.com: Fix inline kobject functions]
Cc: Mauricio Lin <mauriciolin@gmail.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index d1c8d28..76538fc 100644 (file)
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -265,8 +265,8 @@ extern int __must_check subsys_create_file(struct subsystem * ,
                                        struct subsys_attribute *);
 
 #if defined(CONFIG_HOTPLUG)
-void kobject_uevent(struct kobject *kobj, enum kobject_action action);
-void kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
+int kobject_uevent(struct kobject *kobj, enum kobject_action action);
+int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
                        char *envp[]);
 
 int add_uevent_var(char **envp, int num_envp, int *cur_index,
@@ -274,11 +274,12 @@ int add_uevent_var(char **envp, int num_envp, int *cur_index,
                        const char *format, ...)
        __attribute__((format (printf, 7, 8)));
 #else
-static inline void kobject_uevent(struct kobject *kobj, enum kobject_action action) { }
-static inline void kobject_uevent_env(struct kobject *kobj,
+static inline int kobject_uevent(struct kobject *kobj, enum kobject_action action)
+{ return 0; }
+static inline int kobject_uevent_env(struct kobject *kobj,
                                      enum kobject_action action,
                                      char *envp[])
-{ }
+{ return 0; }
 
 static inline int add_uevent_var(char **envp, int num_envp, int *cur_index,
                                      char *buffer, int buffer_size, int *cur_len, 

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index a192276..84272ed 100644 (file)
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -63,8 +63,11 @@ static char *action_to_string(enum kobject_action action)
  * @action: action that is happening (usually KOBJ_MOVE)
  * @kobj: struct kobject that the action is happening to
  * @envp_ext: pointer to environmental data
+ *
+ * Returns 0 if kobject_uevent() is completed with success or the
+ * corresponding error when it fails.
  */
-void kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
+int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
                        char *envp_ext[])
 {
        char **envp;
@@ -79,14 +82,16 @@ void kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
        u64 seq;
        char *seq_buff;
        int i = 0;
-       int retval;
+       int retval = 0;
        int j;
 
        pr_debug("%s\n", __FUNCTION__);
 
        action_string = action_to_string(action);
-       if (!action_string)
-               return;
+       if (!action_string) {
+               pr_debug("kobject attempted to send uevent without action_string!\n");
+               return -EINVAL;
+       }
 
        /* search the kset we belong to */
        top_kobj = kobj;
@@ -95,31 +100,39 @@ void kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
                        top_kobj = top_kobj->parent;
                } while (!top_kobj->kset && top_kobj->parent);
        }
-       if (!top_kobj->kset)
-               return;
+       if (!top_kobj->kset) {
+               pr_debug("kobject attempted to send uevent without kset!\n");
+               return -EINVAL;
+       }
 
        kset = top_kobj->kset;
        uevent_ops = kset->uevent_ops;
 
        /*  skip the event, if the filter returns zero. */
        if (uevent_ops && uevent_ops->filter)
-               if (!uevent_ops->filter(kset, kobj))
-                       return;
+               if (!uevent_ops->filter(kset, kobj)) {
+                       pr_debug("kobject filter function caused the event to drop!\n");
+                       return 0;
+               }
 
        /* environment index */
        envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL);
        if (!envp)
-               return;
+               return -ENOMEM;
 
        /* environment values */
        buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL);
-       if (!buffer)
+       if (!buffer) {
+               retval = -ENOMEM;
                goto exit;
+       }
 
        /* complete object path */
        devpath = kobject_get_path(kobj, GFP_KERNEL);
-       if (!devpath)
+       if (!devpath) {
+               retval = -ENOENT;
                goto exit;
+       }
 
        /* originating subsystem */
        if (uevent_ops && uevent_ops->name)
@@ -204,7 +217,7 @@ exit:
        kfree(devpath);
        kfree(buffer);
        kfree(envp);
-       return;
+       return retval;
 }
 
 EXPORT_SYMBOL_GPL(kobject_uevent_env);
@@ -214,10 +227,13 @@ EXPORT_SYMBOL_GPL(kobject_uevent_env);
  *
  * @action: action that is happening (usually KOBJ_ADD and KOBJ_REMOVE)
  * @kobj: struct kobject that the action is happening to
+ *
+ * Returns 0 if kobject_uevent() is completed with success or the
+ * corresponding error when it fails.
  */
-void kobject_uevent(struct kobject *kobj, enum kobject_action action)
+int kobject_uevent(struct kobject *kobj, enum kobject_action action)
 {
-       kobject_uevent_env(kobj, action, NULL);
+       return kobject_uevent_env(kobj, action, NULL);
 }
 
 EXPORT_SYMBOL_GPL(kobject_uevent);