btrfs: ulist: Add ulist_del() function.
This function will delete unode with given (val,aux) pair.
And with this patch, seqnum for debug usage doesn't have any meaning
now, so remove them.
This is used by later patches to skip snapshot root.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/ulist.c b/fs/btrfs/ulist.c
index 840a38b..91feb2b 100644
--- a/fs/btrfs/ulist.c
+++ b/fs/btrfs/ulist.c
@@ -132,6 +132,15 @@
return NULL;
}
+static void ulist_rbtree_erase(struct ulist *ulist, struct ulist_node *node)
+{
+ rb_erase(&node->rb_node, &ulist->root);
+ list_del(&node->list);
+ kfree(node);
+ BUG_ON(ulist->nnodes == 0);
+ ulist->nnodes--;
+}
+
static int ulist_rbtree_insert(struct ulist *ulist, struct ulist_node *ins)
{
struct rb_node **p = &ulist->root.rb_node;
@@ -197,9 +206,6 @@
node->val = val;
node->aux = aux;
-#ifdef CONFIG_BTRFS_DEBUG
- node->seqnum = ulist->nnodes;
-#endif
ret = ulist_rbtree_insert(ulist, node);
ASSERT(!ret);
@@ -209,6 +215,33 @@
return 1;
}
+/*
+ * ulist_del - delete one node from ulist
+ * @ulist: ulist to remove node from
+ * @val: value to delete
+ * @aux: aux to delete
+ *
+ * The deletion will only be done when *BOTH* val and aux matches.
+ * Return 0 for successful delete.
+ * Return > 0 for not found.
+ */
+int ulist_del(struct ulist *ulist, u64 val, u64 aux)
+{
+ struct ulist_node *node;
+
+ node = ulist_rbtree_search(ulist, val);
+ /* Not found */
+ if (!node)
+ return 1;
+
+ if (node->aux != aux)
+ return 1;
+
+ /* Found and delete */
+ ulist_rbtree_erase(ulist, node);
+ return 0;
+}
+
/**
* ulist_next - iterate ulist
* @ulist: ulist to iterate
@@ -237,15 +270,7 @@
uiter->cur_list = uiter->cur_list->next;
} else {
uiter->cur_list = ulist->nodes.next;
-#ifdef CONFIG_BTRFS_DEBUG
- uiter->i = 0;
-#endif
}
node = list_entry(uiter->cur_list, struct ulist_node, list);
-#ifdef CONFIG_BTRFS_DEBUG
- ASSERT(node->seqnum == uiter->i);
- ASSERT(uiter->i >= 0 && uiter->i < ulist->nnodes);
- uiter->i++;
-#endif
return node;
}