tools/xenstore: rename hashtable_insert() and let it return 0 on success

Today hashtable_insert() returns 0 in case of an error. Change that to
let it return an errno value in the error case and 0 in case of success.
In order to avoid any missed return value checks or related future
backport errors, rename hashtable_insert() to hashtable_add().

Even if not used today, do the same switch for the return value of
hashtable_expand().

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>

tools/xenstore/hashtable.c

@@ -105,14 +105,15 @@ static int hashtable_expand(struct hashtable *h)
     struct entry **pE;
     unsigned int newsize, i, index;
     /* Check we're not hitting max capacity */
-    if (h->primeindex == (PRIME_TABLE_LEN - 1)) return 0;
+    if (h->primeindex == (PRIME_TABLE_LEN - 1))
+        return ENOSPC;
     newsize = primes[++(h->primeindex)];
 
     newtable = talloc_realloc(h, h->table, struct entry *, newsize);
     if (!newtable)
     {
         h->primeindex--;
-        return 0;
+        return ENOMEM;
     }
 
     h->table = newtable;
@@ -136,10 +137,10 @@ static int hashtable_expand(struct hashtable *h)
 
     h->tablelength = newsize;
     h->loadlimit   = loadlimit(h->primeindex);
-    return -1;
+    return 0;
 }
 
-int hashtable_insert(struct hashtable *h, void *k, void *v)
+int hashtable_add(struct hashtable *h, void *k, void *v)
 {
     /* This method allows duplicate keys - but they shouldn't be used */
     unsigned int index;
@@ -153,7 +154,11 @@ int hashtable_insert(struct hashtable *h, void *k, void *v)
         hashtable_expand(h);
     }
     e = talloc_zero(h, struct entry);
-    if (NULL == e) { --(h->entrycount); return 0; } /*oom*/
+    if (NULL == e)
+    {
+        --h->entrycount;
+       return ENOMEM;
+    }
     e->h = hash(h,k);
     index = indexFor(h->tablelength,e->h);
     e->k = k;
@@ -164,7 +169,7 @@ int hashtable_insert(struct hashtable *h, void *k, void *v)
         talloc_steal(e, v);
     e->next = h->table[index];
     h->table[index] = e;
-    return -1;
+    return 0;
 }
 
 void *hashtable_search(const struct hashtable *h, const void *k)

tools/xenstore/hashtable.h

@@ -30,13 +30,13 @@ create_hashtable(const void *ctx, const char *name,
 );
 
 /*****************************************************************************
- * hashtable_insert
+ * hashtable_add
    
- * @name        hashtable_insert
+ * @name        hashtable_add
  * @param   h   the hashtable to insert into
  * @param   k   the key - hashtable claims ownership and will free on removal
  * @param   v   the value - does not claim ownership
- * @return      non-zero for successful insertion
+ * @return      zero for successful insertion
  *
  * This function will cause the table to expand if the insertion would take
  * the ratio of entries to table size over the maximum load factor.
@@ -49,7 +49,7 @@ create_hashtable(const void *ctx, const char *name,
  */
 
 int 
-hashtable_insert(struct hashtable *h, void *k, void *v);
+hashtable_add(struct hashtable *h, void *k, void *v);
 
 /*****************************************************************************
  * hashtable_search

tools/xenstore/xenstored_core.c

@@ -2404,8 +2404,8 @@ int remember_string(struct hashtable *hash, const char *str)
 	char *k = talloc_strdup(NULL, str);
 
 	if (!k)
-		return 0;
-	return hashtable_insert(hash, k, (void *)1);
+		return ENOMEM;
+	return hashtable_add(hash, k, (void *)1);
 }
 
 /**
@@ -2438,7 +2438,7 @@ static int check_store_step(const void *ctx, struct connection *conn,
 				: WALK_TREE_SKIP_CHILDREN;
 	}
 
-	if (!remember_string(data->reachable, node->name))
+	if (remember_string(data->reachable, node->name))
 		return WALK_TREE_ERROR_STOP;
 
 	domain_check_acc_add(node, data->domains);

tools/xenstore/xenstored_domain.c

@@ -537,7 +537,7 @@ static struct domain *alloc_domain(const void *context, unsigned int domid)
 	domain->generation = generation;
 	domain->introduced = false;
 
-	if (!hashtable_insert(domhash, &domain->domid, domain)) {
+	if (hashtable_add(domhash, &domain->domid, domain)) {
 		talloc_free(domain);
 		errno = ENOMEM;
 		return NULL;
@@ -1794,7 +1794,7 @@ static int domain_check_acc_init_sub(const void *k, void *v, void *arg)
 	 */
 	dom->nodes = -d->acc[ACC_NODES].val;
 
-	if (!hashtable_insert(domains, &dom->domid, dom)) {
+	if (hashtable_add(domains, &dom->domid, dom)) {
 		talloc_free(dom);
 		return -1;
 	}

tools/xenstore/xenstored_transaction.c

@@ -601,13 +601,13 @@ int check_transactions(struct hashtable *hash)
 		list_for_each_entry(trans, &conn->transaction_list, list) {
 			tname = talloc_asprintf(trans, "%"PRIu64,
 						trans->generation);
-			if (!tname || !remember_string(hash, tname))
+			if (!tname || remember_string(hash, tname))
 				goto nomem;
 
 			list_for_each_entry(i, &trans->accessed, list) {
 				if (!i->ta_node)
 					continue;
-				if (!remember_string(hash, i->trans_name))
+				if (remember_string(hash, i->trans_name))
 					goto nomem;
 			}