LU-11003 ldlm: fix for l_lru usage

Fixes for lock convert code to prevent false assertion and
busy locks in LRU:
- ensure no l_readers and l_writers when add lock to LRU after
  convert.
- don't verify l_lru without ns_lock.

Signed-off-by: Yang Sheng <yang.sheng@intel.com>
Change-Id: I8bcbdef3cb72db241ad03c50f5ce2b968e3ee3e4
Reviewed-on: https://review.whamcloud.com/32309
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/ldlm/ldlm_inodebits.c b/lustre/ldlm/ldlm_inodebits.c
index 269c49a..626c624 100644 (file)
--- a/lustre/ldlm/ldlm_inodebits.c
+++ b/lustre/ldlm/ldlm_inodebits.c
@@ -412,7 +412,6 @@ int ldlm_cli_dropbits(struct ldlm_lock *lock, __u64 drop_bits)
                ldlm_set_cbpending(lock);
                ldlm_set_bl_ast(lock);
                unlock_res_and_lock(lock);
-               LASSERT(list_empty(&lock->l_lru));
                GOTO(exit, rc);
        }
        EXIT;

diff --git a/lustre/ldlm/ldlm_request.c b/lustre/ldlm/ldlm_request.c
index 1ab84a5..07520c3 100644 (file)
--- a/lustre/ldlm/ldlm_request.c
+++ b/lustre/ldlm/ldlm_request.c
@@ -1098,21 +1098,25 @@ static int lock_convert_interpret(const struct lu_env *env,
        } else {
                ldlm_clear_converting(lock);
 
-               /* Concurrent BL AST has arrived, it may cause another convert
-                * or cancel so just exit here.
+               /* Concurrent BL AST may arrive and cause another convert
+                * or cancel so just do nothing here if bl_ast is set,
+                * finish with convert otherwise.
                 */
                if (!ldlm_is_bl_ast(lock)) {
                        struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
 
                        /* Drop cancel_bits since there are no more converts
-                        * and put lock into LRU if it is not there yet.
+                        * and put lock into LRU if it is still not used and
+                        * is not there yet.
                         */
                        lock->l_policy_data.l_inodebits.cancel_bits = 0;
-                       spin_lock(&ns->ns_lock);
-                       if (!list_empty(&lock->l_lru))
+                       if (!lock->l_readers && !lock->l_writers) {
+                               spin_lock(&ns->ns_lock);
+                               /* there is check for list_empty() inside */
                                ldlm_lock_remove_from_lru_nolock(lock);
-                       ldlm_lock_add_to_lru_nolock(lock);
-                       spin_unlock(&ns->ns_lock);
+                               ldlm_lock_add_to_lru_nolock(lock);
+                               spin_unlock(&ns->ns_lock);
+                       }
                }
        }
        unlock_res_and_lock(lock);
@@ -1120,7 +1124,6 @@ out:
        if (rc) {
                lock_res_and_lock(lock);
                if (ldlm_is_converting(lock)) {
-                       LASSERT(list_empty(&lock->l_lru));
                        ldlm_clear_converting(lock);
                        ldlm_set_cbpending(lock);
                        ldlm_set_bl_ast(lock);