tools/xenstore: switch transaction accounting to generic accounting

As transaction accounting is active for unprivileged domains only, it
can easily be added to the generic per-domain accounting.

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

tools/xenstore/xenstored_core.c

@@ -2093,7 +2093,7 @@ static void consider_message(struct connection *conn)
 	 * stalled. This will ignore new requests until Live-Update happened
 	 * or it was aborted.
 	 */
-	if (lu_is_pending() && conn->transaction_started == 0 &&
+	if (lu_is_pending() && list_empty(&conn->transaction_list) &&
 	    conn->in->hdr.msg.type == XS_TRANSACTION_START) {
 		trace("Delaying transaction start for connection %p req_id %u\n",
 		      conn, conn->in->hdr.msg.req_id);
@@ -2200,7 +2200,6 @@ struct connection *new_connection(const struct interface_funcs *funcs)
 	new->funcs = funcs;
 	new->is_ignored = false;
 	new->is_stalled = false;
-	new->transaction_started = 0;
 	INIT_LIST_HEAD(&new->out_list);
 	INIT_LIST_HEAD(&new->acc_list);
 	INIT_LIST_HEAD(&new->ref_list);

tools/xenstore/xenstored_core.h

@@ -151,7 +151,6 @@ struct connection
 	/* List of in-progress transactions. */
 	struct list_head transaction_list;
 	uint32_t next_transaction_id;
-	unsigned int transaction_started;
 	time_t ta_start_time;
 
 	/* List of delayed requests. */

tools/xenstore/xenstored_domain.c

@@ -416,12 +416,10 @@ int domain_get_quota(const void *ctx, struct connection *conn,
 {
 	struct domain *d = find_domain_struct(domid);
 	char *resp;
-	int ta;
 
 	if (!d)
 		return ENOENT;
 
-	ta = d->conn ? d->conn->transaction_started : 0;
 	resp = talloc_asprintf(ctx, "Domain %u:\n", domid);
 	if (!resp)
 		return ENOMEM;
@@ -432,7 +430,7 @@ int domain_get_quota(const void *ctx, struct connection *conn,
 
 	ent(nodes, d->acc[ACC_NODES]);
 	ent(watches, d->acc[ACC_WATCH]);
-	ent(transactions, ta);
+	ent(transactions, d->acc[ACC_TRANS]);
 	ent(outstanding, d->acc[ACC_OUTST]);
 	ent(memory, d->acc[ACC_MEM]);
 
@@ -1297,6 +1295,23 @@ void domain_outstanding_dec(struct connection *conn, unsigned int domid)
 	domain_acc_add(conn, domid, ACC_OUTST, -1, true);
 }
 
+void domain_transaction_inc(struct connection *conn)
+{
+	domain_acc_add(conn, conn->id, ACC_TRANS, 1, true);
+}
+
+void domain_transaction_dec(struct connection *conn)
+{
+	domain_acc_add(conn, conn->id, ACC_TRANS, -1, true);
+}
+
+unsigned int domain_transaction_get(struct connection *conn)
+{
+	return (domain_is_unprivileged(conn))
+		? domain_acc_add(conn, conn->id, ACC_TRANS, 0, true)
+		: 0;
+}
+
 static wrl_creditt wrl_config_writecost      = WRL_FACTOR;
 static wrl_creditt wrl_config_rate           = WRL_RATE   * WRL_FACTOR;
 static wrl_creditt wrl_config_dburst         = WRL_DBURST * WRL_FACTOR;

tools/xenstore/xenstored_domain.h

@@ -32,6 +32,7 @@ enum accitem {
 	ACC_WATCH = ACC_TR_N,
 	ACC_OUTST,
 	ACC_MEM,
+	ACC_TRANS,
 	ACC_N,			/* Number of elements per domain. */
 };
 
@@ -113,6 +114,9 @@ void domain_watch_dec(struct connection *conn);
 int domain_watch(struct connection *conn);
 void domain_outstanding_inc(struct connection *conn);
 void domain_outstanding_dec(struct connection *conn, unsigned int domid);
+void domain_transaction_inc(struct connection *conn);
+void domain_transaction_dec(struct connection *conn);
+unsigned int domain_transaction_get(struct connection *conn);
 int domain_get_quota(const void *ctx, struct connection *conn,
 		     unsigned int domid);
 

tools/xenstore/xenstored_transaction.c

@@ -479,8 +479,7 @@ int do_transaction_start(const void *ctx, struct connection *conn,
 	if (conn->transaction)
 		return EBUSY;
 
-	if (domain_is_unprivileged(conn) &&
-	    conn->transaction_started > quota_max_transaction)
+	if (domain_transaction_get(conn) > quota_max_transaction)
 		return ENOSPC;
 
 	/* Attach transaction to ctx for autofree until it's complete */
@@ -501,13 +500,14 @@ int do_transaction_start(const void *ctx, struct connection *conn,
 		exists = transaction_lookup(conn, conn->next_transaction_id++);
 	} while (!IS_ERR(exists));
 
+	if (list_empty(&conn->transaction_list))
+		conn->ta_start_time = time(NULL);
+
 	/* Now we own it. */
 	list_add_tail(&trans->list, &conn->transaction_list);
 	talloc_steal(conn, trans);
 	talloc_set_destructor(trans, destroy_transaction);
-	if (!conn->transaction_started)
-		conn->ta_start_time = time(NULL);
-	conn->transaction_started++;
+	domain_transaction_inc(conn);
 	wrl_ntransactions++;
 
 	snprintf(id_str, sizeof(id_str), "%u", trans->id);
@@ -533,8 +533,8 @@ int do_transaction_end(const void *ctx, struct connection *conn,
 
 	conn->transaction = NULL;
 	list_del(&trans->list);
-	conn->transaction_started--;
-	if (!conn->transaction_started)
+	domain_transaction_dec(conn);
+	if (list_empty(&conn->transaction_list))
 		conn->ta_start_time = 0;
 
 	chk_quota = trans->node_created && domain_is_unprivileged(conn);
@@ -588,7 +588,6 @@ void conn_delete_all_transactions(struct connection *conn)
 
 	assert(conn->transaction == NULL);
 
-	conn->transaction_started = 0;
 	conn->ta_start_time = 0;
 }