X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lustre%2Fofd%2Fofd_dlm.c;h=972d6ecd2fb4abfb323f62d83314d90e4e927649;hb=1736c1befd27e3dacb424269ad987fe5dd480827;hp=03bd7b606c939782149fe8ce913cbeb2cd2814ea;hpb=2df57a9de0a36a356240655c3c84ff96de4f63ae;p=fs%2Flustre-release.git

diff --git a/lustre/ofd/ofd_dlm.c b/lustre/ofd/ofd_dlm.c
index 03bd7b6..972d6ec 100644
--- a/lustre/ofd/ofd_dlm.c
+++ b/lustre/ofd/ofd_dlm.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
  */
@@ -27,7 +23,7 @@
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2012, Intel Corporation.
+ * Copyright (c) 2012, 2015, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -35,8 +31,13 @@
  *
  * lustre/ofd/ofd_dlm.c
  *
- * Author: Mike Pershin <tappro@whamcloud.com>
- * Author: Alex Zhuravlev <bzzz@whamcloud.com>
+ * This file contains OBD Filter Device (OFD) LDLM-related code which is just
+ * intent handling for glimpse lock.
+ *
+ * Author: Andreas Dilger <andreas.dilger@intel.com>
+ * Author: Jinshan Xiong <jinshan.xiong@intel.com>
+ * Author: Alexey Zhuravlev <alexey.zhuravlev@intel.com>
+ * Author: Mikhail Pershin <mike.pershin@intel.com>
  */
 
 #define DEBUG_SUBSYSTEM S_FILTER
@@ -49,6 +50,22 @@ struct ofd_intent_args {
 	int			*liblustre;
 };
 
+/**
+ * OFD interval callback.
+ *
+ * The interval_callback_t is part of interval_iterate_reverse() and is called
+ * for each interval in tree. The OFD interval callback searches for locks
+ * covering extents beyond the given args->size. This is used to decide if LVB
+ * data is outdated.
+ *
+ * \param[in] n		interval node
+ * \param[in] args	intent arguments
+ *
+ * \retval		INTERVAL_ITER_STOP if the interval is lower than
+ *			file size, caller stops execution
+ * \retval		INTERVAL_ITER_CONT if callback finished successfully
+ *			and caller may continue execution
+ */
 static enum interval_iter ofd_intent_cb(struct interval_node *n, void *args)
 {
 	struct ldlm_interval	 *node = (struct ldlm_interval *)n;
@@ -87,27 +104,49 @@ static enum interval_iter ofd_intent_cb(struct interval_node *n, void *args)
 	return INTERVAL_ITER_CONT;
 }
 
+/**
+ * OFD lock intent policy
+ *
+ * This defines ldlm_namespace::ns_policy interface for OFD.
+ * Intent policy is called when lock has an intent, for OFD that
+ * means glimpse lock and policy fills Lock Value Block (LVB).
+ *
+ * If already granted lock is found it will be placed in \a lockp and
+ * returned back to caller function.
+ *
+ * \param[in] ns	 namespace
+ * \param[in,out] lockp	 pointer to the lock
+ * \param[in] req_cookie incoming request
+ * \param[in] mode	 LDLM mode
+ * \param[in] flags	 LDLM flags
+ * \param[in] data	 opaque data, not used in OFD policy
+ *
+ * \retval		ELDLM_LOCK_REPLACED if already granted lock was found
+ *			and placed in \a lockp
+ * \retval		ELDLM_LOCK_ABORTED in other cases except error
+ * \retval		negative value on error
+ */
 int ofd_intent_policy(struct ldlm_namespace *ns, struct ldlm_lock **lockp,
-		      void *req_cookie, ldlm_mode_t mode, __u64 flags,
+		      void *req_cookie, enum ldlm_mode mode, __u64 flags,
 		      void *data)
 {
-	struct ptlrpc_request		*req = req_cookie;
-	struct ldlm_lock		*lock = *lockp, *l = NULL;
-	struct ldlm_resource		*res = lock->l_resource;
-	ldlm_processing_policy		 policy;
-	struct ost_lvb			*res_lvb, *reply_lvb;
-	struct ldlm_reply		*rep;
-	ldlm_error_t			 err;
-	int				 idx, rc, only_liblustre = 1;
-	struct ldlm_interval_tree	*tree;
-	struct ofd_intent_args		 arg;
-	__u32				 repsize[3] = {
+	struct ptlrpc_request *req = req_cookie;
+	struct ldlm_lock *lock = *lockp, *l = NULL;
+	struct ldlm_resource *res = lock->l_resource;
+	ldlm_processing_policy policy;
+	struct ost_lvb *res_lvb, *reply_lvb;
+	struct ldlm_reply *rep;
+	enum ldlm_error err;
+	int idx, rc, only_liblustre = 1;
+	struct ldlm_interval_tree *tree;
+	struct ofd_intent_args arg;
+	__u32 repsize[3] = {
 		[MSG_PTLRPC_BODY_OFF] = sizeof(struct ptlrpc_body),
 		[DLM_LOCKREPLY_OFF]   = sizeof(*rep),
 		[DLM_REPLY_REC_OFF]   = sizeof(*reply_lvb)
 	};
-	struct ldlm_glimpse_work	 gl_work;
-	struct list_head		 gl_list;
+	struct ldlm_glimpse_work gl_work;
+	struct list_head gl_list;
 	ENTRY;
 
 	INIT_LIST_HEAD(&gl_list);
@@ -225,11 +264,11 @@ int ofd_intent_policy(struct ldlm_namespace *ns, struct ldlm_lock **lockp,
 	}
 
 	/*
-	 * This check is for lock taken in ofd_prepare_destroy() that does
+	 * This check is for lock taken in ofd_destroy_by_fid() that does
 	 * not have l_glimpse_ast set. So the logic is: if there is a lock
 	 * with no l_glimpse_ast set, this object is being destroyed already.
 	 * Hence, if you are grabbing DLM locks on the server, always set
-	 * non-NULL glimpse_ast (e.g., ldlm_request.c:ldlm_glimpse_ast()).
+	 * non-NULL glimpse_ast (e.g., ldlm_request.c::ldlm_glimpse_ast()).
 	 */
 	if (l->l_glimpse_ast == NULL) {
 		/* We are racing with unlink(); just return -ENOENT */