llists: move llist_reverse_order from raid5 to llist.c
Christoph Hellwig [Thu, 14 Nov 2013 22:32:11 +0000 (14:32 -0800)]
Make this useful helper available for other users.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Conflicts:
drivers/md/raid5.c

Change-Id: Ibfc31e7289ffe9bda511c88543bc2deb70a4691b

include/linux/llist.h
lib/llist.c

index 30019d8..15f4d1b 100644 (file)
@@ -189,4 +189,6 @@ extern bool llist_add_batch(struct llist_node *new_first,
                            struct llist_head *head);
 extern struct llist_node *llist_del_first(struct llist_head *head);
 
+struct llist_node *llist_reverse_order(struct llist_node *head);
+
 #endif /* LLIST_H */
index 4a15115..36d657c 100644 (file)
@@ -86,3 +86,25 @@ struct llist_node *llist_del_first(struct llist_head *head)
        return entry;
 }
 EXPORT_SYMBOL_GPL(llist_del_first);
+
+/**
+ * llist_reverse_order - reverse order of a llist chain
+ * @head:      first item of the list to be reversed
+ *
+ * Reverse the oder of a chain of llist entries and return the
+ * new first entry.
+ */
+struct llist_node *llist_reverse_order(struct llist_node *head)
+{
+       struct llist_node *new_head = NULL;
+
+       while (head) {
+               struct llist_node *tmp = head;
+               head = head->next;
+               tmp->next = new_head;
+               new_head = tmp;
+       }
+
+       return new_head;
+}
+EXPORT_SYMBOL_GPL(llist_reverse_order);