These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / include / linux / radix-tree.h

diff --git a/kernel/include/linux/radix-tree.h b/kernel/include/linux/radix-tree.h
index 933ff69..8ddbd6e 100644 (file)
--- a/kernel/include/linux/radix-tree.h
+++ b/kernel/include/linux/radix-tree.h
@@ -374,13 +374,29 @@ radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start)
 void **radix_tree_next_chunk(struct radix_tree_root *root,
                             struct radix_tree_iter *iter, unsigned flags);
 
+/**
+ * radix_tree_iter_retry - retry this chunk of the iteration
+ * @iter:      iterator state
+ *
+ * If we iterate over a tree protected only by the RCU lock, a race
+ * against deletion or creation may result in seeing a slot for which
+ * radix_tree_deref_retry() returns true.  If so, call this function
+ * and continue the iteration.
+ */
+static inline __must_check
+void **radix_tree_iter_retry(struct radix_tree_iter *iter)
+{
+       iter->next_index = iter->index;
+       return NULL;
+}
+
 /**
  * radix_tree_chunk_size - get current chunk size
  *
  * @iter:      pointer to radix tree iterator
  * Returns:    current chunk size
  */
-static __always_inline unsigned
+static __always_inline long
 radix_tree_chunk_size(struct radix_tree_iter *iter)
 {
        return iter->next_index - iter->index;
@@ -414,9 +430,9 @@ radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags)
                        return slot + offset + 1;
                }
        } else {
-               unsigned size = radix_tree_chunk_size(iter) - 1;
+               long size = radix_tree_chunk_size(iter);
 
-               while (size--) {
+               while (--size > 0) {
                        slot++;
                        iter->index++;
                        if (likely(*slot))