LU-8246 ldlm: Do not grant a lock twice in a race

This leads to wrong ldlm pool accounting of granted locks.
Also handle the case of a destroyed lock.

Change-Id: Ied262d6688766e37f71304e6ee6659b48124e7ad
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Reviewed-on: http://review.whamcloud.com/20839
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>

diff --git a/lustre/ldlm/ldlm_inodebits.c b/lustre/ldlm/ldlm_inodebits.c
index 22d1382..9917607 100644 (file)
--- a/lustre/ldlm/ldlm_inodebits.c
+++ b/lustre/ldlm/ldlm_inodebits.c
@@ -234,14 +234,29 @@ int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
                 rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
                                        LDLM_WORK_BL_AST);
                 lock_res(res);
-               if (rc == -ERESTART)
+               if (rc == -ERESTART) {
+                       /* We were granted while waiting, nothing left to do */
+                       if (lock->l_granted_mode == lock->l_req_mode)
+                               GOTO(out, rc = 0);
+                       /* Lock was destroyed while we were waiting, abort */
+                       if (ldlm_is_destroyed(lock))
+                               GOTO(out, rc = -EAGAIN);
+
+                       /* Otherwise try again */
                        GOTO(restart, rc);
+               }
                 *flags |= LDLM_FL_BLOCK_GRANTED;
         } else {
                 ldlm_resource_unlink_lock(lock);
                 ldlm_grant_lock(lock, NULL);
         }
-        RETURN(0);
+
+       rc = 0;
+out:
+       *err = rc;
+       LASSERT(list_empty(&rpc_list));
+
+       RETURN(rc);
 }
 #endif /* HAVE_SERVER_SUPPORT */
 

diff --git a/lustre/ldlm/ldlm_plain.c b/lustre/ldlm/ldlm_plain.c
index c1ad996..32cf816 100644 (file)
--- a/lustre/ldlm/ldlm_plain.c
+++ b/lustre/ldlm/ldlm_plain.c
@@ -176,14 +176,29 @@ int ldlm_process_plain_lock(struct ldlm_lock *lock, __u64 *flags,
                 rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
                                        LDLM_WORK_BL_AST);
                 lock_res(res);
-               if (rc == -ERESTART)
+               if (rc == -ERESTART) {
+                       /* We were granted while waiting, nothing left to do */
+                       if (lock->l_granted_mode == lock->l_req_mode)
+                               GOTO(out, rc = 0);
+                       /* Lock was destroyed while we were waiting, abort */
+                       if (ldlm_is_destroyed(lock))
+                               GOTO(out, rc = -EAGAIN);
+
+                       /* Otherwise try again */
                        GOTO(restart, rc);
+               }
                 *flags |= LDLM_FL_BLOCK_GRANTED;
         } else {
                 ldlm_resource_unlink_lock(lock);
                 ldlm_grant_lock(lock, NULL);
         }
-        RETURN(0);
+
+       rc = 0;
+out:
+       *err = rc;
+       LASSERT(list_empty(&rpc_list));
+
+       RETURN(rc);
 }
 #endif /* HAVE_SERVER_SUPPORT */