LU-2791 ldlm: release reference against failed lock

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

diff --git a/lustre/ldlm/ldlm_lockd.c b/lustre/ldlm/ldlm_lockd.c
index c331276..18bbd28 100644 (file)
--- a/lustre/ldlm/ldlm_lockd.c
+++ b/lustre/ldlm/ldlm_lockd.c
@@ -976,8 +976,20 @@ int ldlm_server_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
                void *lvb = req_capsule_client_get(&req->rq_pill, &RMF_DLM_LVB);
 
                lvb_len = ldlm_lvbo_fill(lock, lvb, lvb_len);
-               req_capsule_shrink(&req->rq_pill, &RMF_DLM_LVB,
-                                  lvb_len, RCL_CLIENT);
+               if (lvb_len < 0) {
+                       /* We still need to send the RPC to wake up the blocked
+                        * enqueue thread on the client.
+                        *
+                        * Consider old client, there is no better way to notify
+                        * the failure, just zero-sized the LVB, then the client
+                        * will fail out as "-EPROTO". */
+                       req_capsule_shrink(&req->rq_pill, &RMF_DLM_LVB, 0,
+                                          RCL_CLIENT);
+                       instant_cancel = 1;
+               } else {
+                       req_capsule_shrink(&req->rq_pill, &RMF_DLM_LVB, lvb_len,
+                                          RCL_CLIENT);
+               }
         }
 
         LDLM_DEBUG(lock, "server preparing completion AST (after %lds wait)",
@@ -1038,7 +1050,7 @@ int ldlm_server_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
 
        rc = ldlm_ast_fini(req, arg, lock, instant_cancel);
 
-        RETURN(rc);
+       RETURN(lvb_len < 0 ? lvb_len : rc);
 }
 EXPORT_SYMBOL(ldlm_server_completion_ast);
 
@@ -1427,8 +1439,12 @@ existing_lock:
                                buflen = req_capsule_get_size(&req->rq_pill,
                                                &RMF_DLM_LVB, RCL_SERVER);
                                buflen = ldlm_lvbo_fill(lock, buf, buflen);
-                               req_capsule_shrink(&req->rq_pill, &RMF_DLM_LVB,
-                                                  buflen, RCL_SERVER);
+                               if (buflen >= 0)
+                                       req_capsule_shrink(&req->rq_pill,
+                                                          &RMF_DLM_LVB,
+                                                          buflen, RCL_SERVER);
+                               else
+                                       rc = buflen;
                        }
                 } else {
                         lock_res_and_lock(lock);