LU-11102 ldlm: run local lock bl_ast only when necessary

[fs/lustre-release.git] / lustre / ldlm / ldlm_inodebits.c

diff --git a/lustre/ldlm/ldlm_inodebits.c b/lustre/ldlm/ldlm_inodebits.c
index c5d5d5a..d6ededf 100644 (file)
--- a/lustre/ldlm/ldlm_inodebits.c
+++ b/lustre/ldlm/ldlm_inodebits.c
@@ -57,6 +57,42 @@
 #include "ldlm_internal.h"
 
 #ifdef HAVE_SERVER_SUPPORT
+/*
+ * local lock will be canceled after use, and it should run blocking ast only
+ * when it should trigger Commit-on-Sharing, otherwise if the blocking ast
+ * is run and does nothing, it will prevent subsequent operations to trigger
+ * Commit-on-Sharing, see LU-11102.
+ */
+static bool ldlm_should_run_bl_ast(const struct ldlm_lock *lock,
+                                  const struct ldlm_lock *req)
+{
+       /* no blocking ast */
+       if (!lock->l_blocking_ast)
+               return false;
+
+       /* not local lock */
+       if (!ldlm_is_local(lock))
+               return true;
+
+       /* should trigger Commit-on-Sharing */
+       if ((lock->l_req_mode & LCK_COS))
+               return true;
+
+       /* local read lock will be canceld after use */
+       if (!(lock->l_req_mode & (LCK_PW | LCK_EX)))
+               return false;
+
+       /* if CoS enabled, check if @req is from different client */
+       if (ldlm_is_cos_enabled(req))
+               return lock->l_client_cookie != req->l_client_cookie;
+
+       /* check if @req is COS incompatible */
+       if (ldlm_is_cos_incompat(req))
+               return true;
+
+       return false;
+}
+
 /**
  * Determine if the lock is compatible with all locks on the queue.
  *
@@ -168,12 +204,12 @@ ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 
                                /* Add locks of the policy group to @work_list
                                 * as blocking locks for @req */
-                               if (lock->l_blocking_ast)
+                               if (ldlm_should_run_bl_ast(lock, req))
                                        ldlm_add_ast_work_item(lock, req,
                                                               work_list);
                                head = &lock->l_sl_policy;
                                list_for_each_entry(lock, head, l_sl_policy)
-                                       if (lock->l_blocking_ast)
+                                       if (ldlm_should_run_bl_ast(lock, req))
                                                ldlm_add_ast_work_item(lock,
                                                                req, work_list);
                        }