btrfs-progs: shared: copy ulist_del from kernel

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/kernel-shared/ulist.c b/kernel-shared/ulist.c
index c5eca45..e25af2d 100644 (file)
--- a/kernel-shared/ulist.c
+++ b/kernel-shared/ulist.c
@@ -134,6 +134,15 @@ static struct ulist_node *ulist_rbtree_search(struct ulist *ulist, u64 val)
        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;
@@ -211,6 +220,33 @@ int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
        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

diff --git a/kernel-shared/ulist.h b/kernel-shared/ulist.h
index 88f5b82..aa172c5 100644 (file)
--- a/kernel-shared/ulist.h
+++ b/kernel-shared/ulist.h
@@ -58,6 +58,7 @@ void ulist_free(struct ulist *ulist);
 int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
 int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
                    u64 *old_aux, gfp_t gfp_mask);
+int ulist_del(struct ulist *ulist, u64 val, u64 aux);
 
 /* just like ulist_add_merge() but take a pointer for the aux data */
 static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,