hash: fix lock release on add

When adding items to a hash table with multiple threads,
there is an spinlock used to prevent data corruption
(unless Transactional Memory is supported).

If there is a failure, the spinlock should be released,
but there were cases where that was not happening.

Fixes: be856325cba3 ("hash: add scalable multi-writer insertion with Intel TSX")
Cc: stable@dpdk.org
Signed-off-by: Mike Stolarchuk <mike.stolarchuk@bigswitch.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index 80391cf..5b2b8dd 100644 (file)
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -539,8 +539,10 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key,
                        n_slots = rte_ring_mc_dequeue_burst(h->free_slots,
                                        cached_free_slots->objs,
                                        LCORE_CACHE_SIZE, NULL);
-                       if (n_slots == 0)
-                               return -ENOSPC;
+                       if (n_slots == 0) {
+                               ret = -ENOSPC;
+                               goto failure;
+                       }
 
                        cached_free_slots->len += n_slots;
                }
@@ -549,8 +551,10 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key,
                cached_free_slots->len--;
                slot_id = cached_free_slots->objs[cached_free_slots->len];
        } else {
-               if (rte_ring_sc_dequeue(h->free_slots, &slot_id) != 0)
-                       return -ENOSPC;
+               if (rte_ring_sc_dequeue(h->free_slots, &slot_id) != 0) {
+                       ret = -ENOSPC;
+                       goto failure;
+               }
        }
 
        new_k = RTE_PTR_ADD(keys, (uintptr_t)slot_id * h->key_entry_size);
@@ -660,6 +664,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key,
        /* Error in addition, store new slot back in the ring and return error */
        enqueue_slot_back(h, cached_free_slots, (void *)((uintptr_t) new_idx));
 
+failure:
        if (h->add_key == ADD_KEY_MULTIWRITER)
                rte_spinlock_unlock(h->multiwriter_lock);
        return ret;