hash: fix race condition at creation

[dpdk.git] / lib / librte_hash / rte_cuckoo_hash.c

diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c
index b00cc12..7b7d1f8 100644 (file)
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -295,19 +295,48 @@ rte_hash_create(const struct rte_hash_parameters *params)
        if (params->extra_flag & RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT)
                hw_trans_mem_support = 1;
 
+       /* Store all keys and leave the first entry as a dummy entry for lookup_bulk */
+       if (hw_trans_mem_support)
+               /*
+                * Increase number of slots by total number of indices
+                * that can be stored in the lcore caches
+                * except for the first cache
+                */
+               num_key_slots = params->entries + (RTE_MAX_LCORE - 1) *
+                                       LCORE_CACHE_SIZE + 1;
+       else
+               num_key_slots = params->entries + 1;
+
+       snprintf(ring_name, sizeof(ring_name), "HT_%s", params->name);
+       r = rte_ring_create(ring_name, rte_align32pow2(num_key_slots),
+                       params->socket_id, 0);
+       if (r == NULL) {
+               RTE_LOG(ERR, HASH, "memory allocation failed\n");
+               goto err;
+       }
+
        snprintf(hash_name, sizeof(hash_name), "HT_%s", params->name);
 
-       /* Guarantee there's no existing */
-       h = rte_hash_find_existing(params->name);
-       if (h != NULL) {
+       rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
+
+       /* guarantee there's no existing: this is normally already checked
+        * by ring creation above */
+       TAILQ_FOREACH(te, hash_list, next) {
+               h = (struct rte_hash *) te->data;
+               if (strncmp(params->name, h->name, RTE_HASH_NAMESIZE) == 0)
+                       break;
+       }
+       h = NULL;
+       if (te != NULL) {
                rte_errno = EEXIST;
-               return NULL;
+               te = NULL;
+               goto err_unlock;
        }
 
        te = rte_zmalloc("HASH_TAILQ_ENTRY", sizeof(*te), 0);
        if (te == NULL) {
                RTE_LOG(ERR, HASH, "tailq entry allocation failed\n");
-               goto err;
+               goto err_unlock;
        }
 
        h = (struct rte_hash *)rte_zmalloc_socket(hash_name, sizeof(struct rte_hash),
@@ -315,7 +344,7 @@ rte_hash_create(const struct rte_hash_parameters *params)
 
        if (h == NULL) {
                RTE_LOG(ERR, HASH, "memory allocation failed\n");
-               goto err;
+               goto err_unlock;
        }
 
        const uint32_t num_buckets = rte_align32pow2(params->entries)
@@ -327,23 +356,10 @@ rte_hash_create(const struct rte_hash_parameters *params)
 
        if (buckets == NULL) {
                RTE_LOG(ERR, HASH, "memory allocation failed\n");
-               goto err;
+               goto err_unlock;
        }
 
        const uint32_t key_entry_size = sizeof(struct rte_hash_key) + params->key_len;
-
-       /* Store all keys and leave the first entry as a dummy entry for lookup_bulk */
-       if (hw_trans_mem_support)
-               /*
-                * Increase number of slots by total number of indices
-                * that can be stored in the lcore caches
-                * except for the first cache
-                */
-               num_key_slots = params->entries + (RTE_MAX_LCORE - 1) *
-                                       LCORE_CACHE_SIZE + 1;
-       else
-               num_key_slots = params->entries + 1;
-
        const uint64_t key_tbl_size = (uint64_t) key_entry_size * num_key_slots;
 
        k = rte_zmalloc_socket(NULL, key_tbl_size,
@@ -351,7 +367,7 @@ rte_hash_create(const struct rte_hash_parameters *params)
 
        if (k == NULL) {
                RTE_LOG(ERR, HASH, "memory allocation failed\n");
-               goto err;
+               goto err_unlock;
        }
 
 /*
@@ -393,14 +409,6 @@ rte_hash_create(const struct rte_hash_parameters *params)
        h->cmp_jump_table_idx = KEY_OTHER_BYTES;
 #endif
 
-       snprintf(ring_name, sizeof(ring_name), "HT_%s", params->name);
-       r = rte_ring_create(ring_name, rte_align32pow2(num_key_slots),
-                       params->socket_id, 0);
-       if (r == NULL) {
-               RTE_LOG(ERR, HASH, "memory allocation failed\n");
-               goto err;
-       }
-
        if (hw_trans_mem_support) {
                h->local_free_slots = rte_zmalloc_socket(NULL,
                                sizeof(struct lcore_cache) * RTE_MAX_LCORE,
@@ -427,13 +435,15 @@ rte_hash_create(const struct rte_hash_parameters *params)
        for (i = 1; i < params->entries + 1; i++)
                rte_ring_sp_enqueue(r, (void *)((uintptr_t) i));
 
-       rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
        te->data = (void *) h;
        TAILQ_INSERT_TAIL(hash_list, te, next);
        rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
 
        return h;
+err_unlock:
+       rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
 err:
+       rte_ring_free(r);
        rte_free(te);
        rte_free(h);
        rte_free(buckets);