[ovs-dev] [PATCH] Fix hindex iteration incomplete bug

[ZhengLingyun]

hindex_next() shouldn't jump over different hashs in the same bucket.
tests/test-hindex did not detect it, add a multipart_hash() method to detect it.


Signed-off-by: ZhengLingyun <konghuarukhr at 163.com>
---
 lib/hindex.c        |   21 ++++++++++++++++++---
 tests/test-hindex.c |    7 +++++++
 2 files changed, 25 insertions(+), 3 deletions(-)


diff --git a/lib/hindex.c b/lib/hindex.c
index dc0f1b7..37b1d0b 100644
--- a/lib/hindex.c
+++ b/lib/hindex.c
@@ -287,6 +287,17 @@ hindex_node_with_hash(const struct hindex *hindex, size_t hash)
     return node;
 }
 
+/* Returns the head node of 'node', 'node' can be head node or body node. */
+static struct hindex_node *
+hindex_head_node(const struct hindex *hindex OVS_UNUSED,
+                 const struct hindex_node *node)
+{
+    while (hindex_node_is_body(node)) {
+        node = node->d;
+    }
+    return node;
+}
+
 static struct hindex_node *
 hindex_next__(const struct hindex *hindex, size_t start)
 {
@@ -318,7 +329,11 @@ hindex_first(const struct hindex *hindex)
 struct hindex_node *
 hindex_next(const struct hindex *hindex, const struct hindex_node *node)
 {
-    return (node->s ? node->s
-            : node->d && node->d->hash != node->hash ? node->d
-            : hindex_next__(hindex, (node->hash & hindex->mask) + 1));
+    if (node->s) {
+        return node->s;
+    }
+
+    node = hindex_head_node(hindex, node);
+    return node->d ? node->d
+           : hindex_next__(hindex, (node->hash & hindex->mask) + 1);
 }
diff --git a/tests/test-hindex.c b/tests/test-hindex.c
index 7a3ef72..f0a8b93 100644
--- a/tests/test-hindex.c
+++ b/tests/test-hindex.c
@@ -178,6 +178,12 @@ mod2_hash(int value)
     return value % 2;
 }
 
+static size_t
+multipart_hash(int value)
+{
+    return (mod4_hash(value) << 16) | (constant_hash(value) & 0xFFFF);
+}
+
 /* Tests basic hindex insertion and deletion. */
 static void
 test_hindex_insert_delete(hash_func *hash)
@@ -298,6 +304,7 @@ run_test(void (*function)(hash_func *))
         mod4_hash,
         mod3_hash,
         mod2_hash,
+        multipart_hash,
     };
     size_t i;
 
-- 
1.7.9.5

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