Merge branch '2018-09-13-radix-tree-bug'

base/Makefile

@@ -12,7 +12,7 @@
 
 # Uncomment this to build the simple radix tree. You'll need to make clean too.
 # Comment to build the advanced radix tree.
-base/data-struct/radix-tree.o: CFLAGS += -DSIMPLE_RADIX_TREE
+#base/data-struct/radix-tree.o: CFLAGS += -DSIMPLE_RADIX_TREE
 
 BASE_SOURCE=\
  base/data-struct/radix-tree.c \

base/data-struct/radix-tree-adaptive.c

@@ -581,12 +581,11 @@ static void _degrade_to_n16(struct node48 *n48, struct value *result)
  for (i = 0; i < 256; i++) {
  if (n48->keys[i] < 48) {
  n16->keys[count] = i;
+ n16->values[count] = n48->values[n48->keys[i]];
  count++;
  }
  }
 
- memcpy(n16->values, n48->values, n48->nr_entries * sizeof(*n16->values));
-
  free(n48);
 
  result->type = NODE16;
@@ -598,16 +597,16 @@ static void _degrade_to_n48(struct node256 *n256, struct value *result)
  unsigned i, count = 0;
  struct node48 *n48 = zalloc(sizeof(*n48));
 
- memset(n48->keys, 48, sizeof(n48->keys));
-
  n48->nr_entries = n256->nr_entries;
  for (i = 0; i < 256; i++) {
  if (n256->values[i].type == UNSET)
- continue;
+ n48->keys[i] = 48;
 
- n48->keys[i] = count;
- n48->values[count] = n256->values[i];
- count++;
+ else {
+ n48->keys[i] = count;
+ n48->values[count] = n256->values[i];
+ count++;
+ }
  }
 
  free(n256);
@@ -1036,6 +1035,7 @@ void radix_tree_iterate(struct radix_tree *rt, uint8_t *kb, uint8_t *ke,
 
 static bool _check_nodes(struct value *v, unsigned *count)
 {
+ uint64_t bits;
  unsigned i, ncount;
  struct value_chain *vc;
  struct prefix_chain *pc;
@@ -1090,22 +1090,47 @@ static bool _check_nodes(struct value *v, unsigned *count)
  return true;
 
  case NODE48:
+ bits = 0;
  n48 = v->value.ptr;
  ncount = 0;
  for (i = 0; i < 256; i++) {
  if (n48->keys[i] < 48) {
+ if (n48->keys[i] >= n48->nr_entries) {
+ fprintf(stderr, "referencing value past nr_entries (n48)\n");
+ return false;
+ }
+
+ if (bits & (1ull << n48->keys[i])) {
+ fprintf(stderr, "duplicate entry (n48) %u\n", (unsigned) n48->keys[i]);
+ return false;
+ }
+ bits = bits | (1ull << n48->keys[i]);
  ncount++;
+
  if (!_check_nodes(n48->values + n48->keys[i], count))
  return false;
  }
  }
 
+ for (i = 0; i < n48->nr_entries; i++) {
+ if (!(bits & (1ull << i))) {
+ fprintf(stderr, "not all values are referenced (n48)\n");
+ return false;
+ }
+ }
+
  if (ncount != n48->nr_entries) {
  fprintf(stderr, "incorrect number of entries in n48, n48->nr_entries = %u, actual = %u\n",
  n48->nr_entries, ncount);
  return false;
  }
 
+ for (i = 0; i < n48->nr_entries; i++)
+ if (n48->values[i].type == UNSET) {
+ fprintf(stderr, "value in UNSET (n48)\n");
+ return false;
+ }
+
  for (i = n48->nr_entries; i < 48; i++)
  if (n48->values[i].type != UNSET) {
  fprintf(stderr, "unused value is not UNSET (n48)\n");
@@ -1234,9 +1259,10 @@ static void _dump(FILE *out, struct value v, unsigned indent)
  fprintf(out, "%x ", i);
  fprintf(out, ">\n");
 
- for (i = 0; i < 256; i++)
- if (n48->keys[i] < 48)
- _dump(out, n48->values[i], indent + 1);
+ for (i = 0; i < n48->nr_entries; i++) {
+ assert(n48->values[i].type != UNSET);
+ _dump(out, n48->values[i], indent + 1);
+ }
  break;
 
  case NODE256:

test/unit/Makefile

@@ -29,6 +29,8 @@ UNIT_SOURCE=\
  test/unit/string_t.c \
  test/unit/vdo_t.c
 
+test/unit/radix_tree_t.o: test/unit/rt_case1.c
+
 UNIT_DEPENDS=$(subst .c,.d,$(UNIT_SOURCE))
 UNIT_OBJECTS=$(UNIT_SOURCE:%.c=%.o)
 CLEAN_TARGETS+=$(UNIT_DEPENDS) $(UNIT_OBJECTS)

test/unit/radix_tree_t.c

@@ -750,6 +750,65 @@ static void test_bcache_scenario2(void *fixture)
 
 //----------------------------------------------------------------
 
+struct key_parts {
+ uint32_t fd;
+ uint64_t b;
+} __attribute__ ((packed));
+
+union key {
+ struct key_parts parts;
+ uint8_t bytes[12];
+};
+
+static void __lookup_matches(struct radix_tree *rt, int fd, uint64_t b, uint64_t expected)
+{
+ union key k;
+ union radix_value v;
+
+ k.parts.fd = fd;
+ k.parts.b = b;
+ T_ASSERT(radix_tree_lookup(rt, k.bytes, k.bytes + sizeof(k.bytes), &v));
+ T_ASSERT(v.n == expected);
+}
+
+static void __lookup_fails(struct radix_tree *rt, int fd, uint64_t b)
+{
+ union key k;
+ union radix_value v;
+
+ k.parts.fd = fd;
+ k.parts.b = b;
+ T_ASSERT(!radix_tree_lookup(rt, k.bytes, k.bytes + sizeof(k.bytes), &v));
+}
+
+static void __insert(struct radix_tree *rt, int fd, uint64_t b, uint64_t n)
+{
+ union key k;
+ union radix_value v;
+
+ k.parts.fd = fd;
+ k.parts.b = b;
+ v.n = n;
+ T_ASSERT(radix_tree_insert(rt, k.bytes, k.bytes + sizeof(k.bytes), v));
+}
+
+static void __invalidate(struct radix_tree *rt, int fd)
+{
+ union key k;
+
+ k.parts.fd = fd;
+ radix_tree_remove_prefix(rt, k.bytes, k.bytes + sizeof(k.parts.fd));
+ radix_tree_is_well_formed(rt);
+}
+
+static void test_bcache_scenario3(void *fixture)
+{
+ struct radix_tree *rt = fixture;
+
+ #include "test/unit/rt_case1.c"
+}
+
+//----------------------------------------------------------------
 #define T(path, desc, fn) register_test(ts, "/base/data-struct/radix-tree/" path, desc, fn)
 
 void radix_tree_tests(struct dm_list *all_tests)
@@ -784,6 +843,7 @@ void radix_tree_tests(struct dm_list *all_tests)
  T("destroy-calls-dtr", "destroy should call the dtr for all values", test_destroy_calls_dtr);
  T("bcache-scenario", "A specific series of keys from a bcache scenario", test_bcache_scenario);
  T("bcache-scenario-2", "A second series of keys from a bcache scenario", test_bcache_scenario2);
+ T("bcache-scenario-3", "A third series of keys from a bcache scenario", test_bcache_scenario3);
 
  dm_list_add(all_tests, &ts->list);
 }