* [PATCH net 1/2] rhashtable: Fix rhltable duplicates insertion
2018-03-04 12:34 [PATCH net 0/2] rhashtable: Fix rhltable duplicates insertion Paul Blakey
@ 2018-03-04 12:34 ` Paul Blakey
2018-03-04 12:57 ` Herbert Xu
2018-03-04 14:16 ` Herbert Xu
2018-03-04 12:34 ` [PATCH net 2/2] test_rhashtable: add test case for rhl_table with duplicate objects Paul Blakey
1 sibling, 2 replies; 6+ messages in thread
From: Paul Blakey @ 2018-03-04 12:34 UTC (permalink / raw)
To: Thomas Graf, Herbert Xu, David Miller
Cc: netdev, Yevgeny Kliteynik, Roi Dayan, Shahar Klein, Mark Bloch,
Jiri Pirko, Or Gerlitz, Matan Barak, Paul Blakey
When inserting duplicate objects (those with the same key),
current rhashtable implementation messes up the chain pointers by
updating the bucket pointer instead of prev next pointer to the
newly inserted node. This causes missing elements on removal and
travesal.
Fix that by properly updating pprev pointer to point to
the correct rhash_head next pointer.
Fixes: ca26893f05e8 ('rhashtable: Add rhlist interface')
Signed-off-by: Paul Blakey <paulb@mellanox.com>
---
include/linux/rhashtable.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index c9df252..668a21f 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -766,8 +766,10 @@ static inline void *__rhashtable_insert_fast(
if (!key ||
(params.obj_cmpfn ?
params.obj_cmpfn(&arg, rht_obj(ht, head)) :
- rhashtable_compare(&arg, rht_obj(ht, head))))
+ rhashtable_compare(&arg, rht_obj(ht, head)))) {
+ pprev = &head->next;
continue;
+ }
data = rht_obj(ht, head);
--
1.8.4.3
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH net 2/2] test_rhashtable: add test case for rhl_table with duplicate objects
2018-03-04 12:34 [PATCH net 0/2] rhashtable: Fix rhltable duplicates insertion Paul Blakey
2018-03-04 12:34 ` [PATCH net 1/2] " Paul Blakey
@ 2018-03-04 12:34 ` Paul Blakey
1 sibling, 0 replies; 6+ messages in thread
From: Paul Blakey @ 2018-03-04 12:34 UTC (permalink / raw)
To: Thomas Graf, Herbert Xu, David Miller
Cc: netdev, Yevgeny Kliteynik, Roi Dayan, Shahar Klein, Mark Bloch,
Jiri Pirko, Or Gerlitz, Matan Barak, Paul Blakey
Tries to insert duplicates in the middle of bucket's chain:
bucket 1: [[val 21 (tid=1)]] -> [[ val 1 (tid=2), val 1 (tid=0) ]]
Reuses tid to distinguish the elements insertion order.
Signed-off-by: Paul Blakey <paulb@mellanox.com>
---
lib/test_rhashtable.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 121 insertions(+)
diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
index 76d3667..4a5f331 100644
--- a/lib/test_rhashtable.c
+++ b/lib/test_rhashtable.c
@@ -79,6 +79,21 @@ struct thread_data {
struct test_obj *objs;
};
+static u32 my_hashfn(const void *data, u32 len, u32 seed)
+{
+ const struct test_obj_rhl *obj = data;
+
+ return (obj->value.id % 10) << RHT_HASH_RESERVED_SPACE;
+}
+
+static int my_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
+{
+ const struct test_obj_rhl *test_obj = obj;
+ const struct test_obj_val *val = arg->key;
+
+ return test_obj->value.id - val->id;
+}
+
static struct rhashtable_params test_rht_params = {
.head_offset = offsetof(struct test_obj, node),
.key_offset = offsetof(struct test_obj, value),
@@ -87,6 +102,17 @@ struct thread_data {
.nulls_base = (3U << RHT_BASE_SHIFT),
};
+static struct rhashtable_params test_rht_params_dup = {
+ .head_offset = offsetof(struct test_obj_rhl, list_node),
+ .key_offset = offsetof(struct test_obj_rhl, value),
+ .key_len = sizeof(struct test_obj_val),
+ .hashfn = jhash,
+ .obj_hashfn = my_hashfn,
+ .obj_cmpfn = my_cmpfn,
+ .nelem_hint = 128,
+ .automatic_shrinking = false,
+};
+
static struct semaphore prestart_sem;
static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0);
@@ -465,6 +491,99 @@ static int __init test_rhashtable_max(struct test_obj *array,
return err;
}
+static unsigned int __init print_ht(struct rhltable *rhlt)
+{
+ struct rhashtable *ht;
+ const struct bucket_table *tbl;
+ char buff[512] = "";
+ unsigned int i, cnt = 0;
+
+ ht = &rhlt->ht;
+ tbl = rht_dereference(ht->tbl, ht);
+ for (i = 0; i < tbl->size; i++) {
+ struct rhash_head *pos, *next;
+ struct test_obj_rhl *p;
+
+ pos = rht_dereference(tbl->buckets[i], ht);
+ next = !rht_is_a_nulls(pos) ? rht_dereference(pos->next, ht) : NULL;
+
+ if (!rht_is_a_nulls(pos)) {
+ sprintf(buff, "%s\nbucket[%d] -> ", buff, i);
+ }
+
+ while (!rht_is_a_nulls(pos)) {
+ struct rhlist_head *list = container_of(pos, struct rhlist_head, rhead);
+ sprintf(buff, "%s[[", buff);
+ do {
+ pos = &list->rhead;
+ list = rht_dereference(list->next, ht);
+ p = rht_obj(ht, pos);
+
+ sprintf(buff, "%s val %d (tid=%d)%s", buff, p->value.id, p->value.tid,
+ list? ", " : " ");
+ cnt++;
+ } while (list);
+
+ pos = next,
+ next = !rht_is_a_nulls(pos) ?
+ rht_dereference(pos->next, ht) : NULL;
+
+ sprintf(buff, "%s]]%s", buff, !rht_is_a_nulls(pos) ? " -> " : "");
+ }
+ }
+ printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff);
+
+ return cnt;
+}
+
+static int __init test_insert_dup(struct test_obj_rhl *rhl_test_objects,
+ int cnt)
+{
+ struct rhltable rhlt;
+ unsigned int i, ret;
+ int err;
+
+ err = rhltable_init(&rhlt, &test_rht_params_dup);
+ if (WARN_ON(err))
+ return err;
+
+ for (i = 0; i < cnt; i++) {
+ rhl_test_objects[i].value.tid = i;
+ err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node,
+ test_rht_params_dup);
+ if (WARN(err, "error %d on element %d\n", err, i))
+ goto skip_print;
+ }
+
+ ret = print_ht(&rhlt);
+ WARN(ret != cnt, "missing rhltable elements (%d != %d)\n", ret, cnt);
+
+skip_print:
+ rhltable_destroy(&rhlt);
+
+ return 0;
+}
+
+static int __init test_insert_duplicates_run(void)
+{
+ struct test_obj_rhl rhl_test_objects[3] = {};
+
+ pr_info("test inserting duplicates\n");
+
+ /* two different values that map to same bucket */
+ rhl_test_objects[0].value.id = 1;
+ rhl_test_objects[1].value.id = 21;
+
+ /* and another duplicate with same as [0] value
+ * which will be second on the bucket list */
+ rhl_test_objects[2].value.id = rhl_test_objects[0].value.id;
+
+ test_insert_dup(rhl_test_objects, 2);
+ test_insert_dup(rhl_test_objects, 3);
+
+ return 0;
+}
+
static int thread_lookup_test(struct thread_data *tdata)
{
unsigned int entries = tdata->entries;
@@ -613,6 +732,8 @@ static int __init test_rht_init(void)
do_div(total_time, runs);
pr_info("Average test time: %llu\n", total_time);
+ test_insert_duplicates_run();
+
if (!tcount)
return 0;
--
1.8.4.3
^ permalink raw reply related [flat|nested] 6+ messages in thread