+
+/* Cache LRU list management functions. These manage the doubly-linked list of
+ * inodes sorted by accessed/modified time. The FS lock should be held while
+ * calling these.
+ *
+ * _remove will unlink an inode from the linked list.
+ *
+ * _prepend and _append insert an inode at the head or tail of the linked list,
+ * and return a pointer to the linked list element (which should be stored in
+ * the inode); the inode should not already be in the list.
+ *
+ * _head and _tail simply return the first or last item inode in the list. */
+void bluesky_list_unlink(GList *head, GList *item)
+{
+ if (item == NULL)
+ return;
+
+ if (head->prev == item)
+ head->prev = item->prev;
+ head->next = g_list_delete_link(head->next, item);
+}
+
+GList *bluesky_list_prepend(GList *head, BlueSkyInode *inode)
+{
+ head->next = g_list_prepend(head->next, inode);
+ if (head->prev == NULL)
+ head->prev = g_list_last(head->next);
+ return head->next;
+}
+
+GList *bluesky_list_append(GList *head, BlueSkyInode *inode)
+{
+ if (head->next == NULL)
+ return bluesky_list_prepend(head, inode);
+
+ g_assert(head->prev != NULL && head->prev->next == NULL);
+
+ GList *link = g_list_alloc();
+ link->data = inode;
+ link->next = NULL;
+ link->prev = head->prev;
+ head->prev->next = link;
+ head->prev = link;
+ return link;
+}
+
+BlueSkyInode *bluesky_list_head(GList *head)
+{
+ if (head->next == NULL)
+ return NULL;
+ else
+ return (BlueSkyInode *)head->next->data;
+}
+
+BlueSkyInode *bluesky_list_tail(GList *head)
+{
+ if (head->prev == NULL)
+ return NULL;
+ else
+ return (BlueSkyInode *)head->prev->data;
+}