LU-12616 obclass: fix MDS start/stop race

[fs/lustre-release.git] / lustre / ofd / ofd_trans.c

diff --git a/lustre/ofd/ofd_trans.c b/lustre/ofd/ofd_trans.c
index 67cc912..41e0971 100644 (file)
--- a/lustre/ofd/ofd_trans.c
+++ b/lustre/ofd/ofd_trans.c
@@ -15,11 +15,7 @@
  *
  * You should have received a copy of the GNU General Public License
  * version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
  *
  * GPL HEADER END
  */
@@ -27,22 +23,37 @@
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2012, 2013, Intel Corporation.
+ * Copyright (c) 2012, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  * Lustre is a trademark of Sun Microsystems, Inc.
  *
- * lustre/ofd/ofd_recovery.c
+ * lustre/ofd/ofd_trans.c
+ *
+ * This file provides functions for OBD Filter Device (OFD) transaction
+ * management.
  *
- * Author: Alex Zhuravlev <bzzz@whamcloud.com>
- * Author: Mikhail Pershin <tappro@whamcloud.com>
+ * Author: Alex Zhuravlev <alexey.zhuravlev@intel.com>
+ * Author: Mikhail Pershin <mike.pershin@intel.com>
  */
 
 #define DEBUG_SUBSYSTEM S_FILTER
 
 #include "ofd_internal.h"
 
+/**
+ * Create new transaction in OFD.
+ *
+ * This function creates a transaction with dt_trans_create()
+ * and makes it synchronous if required by the export state.
+ *
+ * \param[in] env      execution environment
+ * \param[in] ofd      OFD device
+ *
+ * \retval             struct thandle if transaction was created successfully
+ * \retval             ERR_PTR on negative value in case of error
+ */
 struct thandle *ofd_trans_create(const struct lu_env *env,
                                 struct ofd_device *ofd)
 {
@@ -61,6 +72,20 @@ struct thandle *ofd_trans_create(const struct lu_env *env,
        return th;
 }
 
+/**
+ * Start transaction in OFD.
+ *
+ * This function updates the given \a obj object version and calls
+ * dt_trans_start().
+ *
+ * \param[in] env      execution environment
+ * \param[in] ofd      OFD device
+ * \param[in] obj      OFD object affected by this transaction
+ * \param[in] th       transaction handle
+ *
+ * \retval             0 if successful
+ * \retval             negative value in case of error
+ */
 int ofd_trans_start(const struct lu_env *env, struct ofd_device *ofd,
                    struct ofd_object *obj, struct thandle *th)
 {
@@ -71,9 +96,23 @@ int ofd_trans_start(const struct lu_env *env, struct ofd_device *ofd,
        return dt_trans_start(env, ofd->ofd_osd, th);
 }
 
-void ofd_trans_stop(const struct lu_env *env, struct ofd_device *ofd,
+/**
+ * Stop transaction in OFD.
+ *
+ * This function fills thandle::th_result with result of whole operation
+ * and calls dt_trans_stop().
+ *
+ * \param[in] env      execution environment
+ * \param[in] ofd      OFD device
+ * \param[in] th       transaction handle
+ * \param[in] rc       result code of whole operation
+ *
+ * \retval             0 if successful
+ * \retval             negative value if case of error
+ */
+int ofd_trans_stop(const struct lu_env *env, struct ofd_device *ofd,
                    struct thandle *th, int rc)
 {
        th->th_result = rc;
-       dt_trans_stop(env, ofd->ofd_osd, th);
+       return dt_trans_stop(env, ofd->ofd_osd, th);
 }