Whamcloud - gitweb
LU-10841 ldlm: ASSERTION(lock->l_granted_mode!=lock->l_req_mode)
[fs/lustre-release.git] / lustre / ldlm / ldlm_lock.c
index 03ba8c2..b5c68b2 100644 (file)
@@ -23,7 +23,7 @@
  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2010, 2015, Intel Corporation.
+ * Copyright (c) 2010, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -44,6 +44,9 @@
 
 #include "ldlm_internal.h"
 
+struct kmem_cache *ldlm_glimpse_work_kmem;
+EXPORT_SYMBOL(ldlm_glimpse_work_kmem);
+
 /* lock types */
 char *ldlm_lockname[] = {
        [0] = "--",
@@ -252,7 +255,7 @@ int ldlm_lock_remove_from_lru_nolock(struct ldlm_lock *lock)
  *           otherwise, the lock hasn't been in the LRU list.
  * \retval 1 the lock was in LRU list and removed.
  */
-int ldlm_lock_remove_from_lru_check(struct ldlm_lock *lock, cfs_time_t last_use)
+int ldlm_lock_remove_from_lru_check(struct ldlm_lock *lock, ktime_t last_use)
 {
        struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
        int rc = 0;
@@ -264,7 +267,8 @@ int ldlm_lock_remove_from_lru_check(struct ldlm_lock *lock, cfs_time_t last_use)
        }
 
        spin_lock(&ns->ns_lock);
-       if (last_use == 0 || last_use == lock->l_last_used)
+       if (!ktime_compare(last_use, ktime_set(0, 0)) ||
+           !ktime_compare(last_use, lock->l_last_used))
                rc = ldlm_lock_remove_from_lru_nolock(lock);
        spin_unlock(&ns->ns_lock);
 
@@ -278,7 +282,7 @@ void ldlm_lock_add_to_lru_nolock(struct ldlm_lock *lock)
 {
        struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
 
-       lock->l_last_used = cfs_time_current();
+       lock->l_last_used = ktime_get();
        LASSERT(list_empty(&lock->l_lru));
        LASSERT(lock->l_resource->lr_type != LDLM_FLOCK);
        list_add_tail(&lock->l_lru, &ns->ns_unused_list);
@@ -1068,16 +1072,14 @@ static void ldlm_granted_list_add_lock(struct ldlm_lock *lock,
  * Add a lock to granted list on a resource maintaining skiplist
  * correctness.
  */
-static void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
+void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
 {
-        struct sl_insert_point prev;
-        ENTRY;
+       struct sl_insert_point prev;
 
-        LASSERT(lock->l_req_mode == lock->l_granted_mode);
+       LASSERT(lock->l_req_mode == lock->l_granted_mode);
 
-        search_granted_lock(&lock->l_resource->lr_granted, lock, &prev);
-        ldlm_granted_list_add_lock(lock, &prev);
-        EXIT;
+       search_granted_lock(&lock->l_resource->lr_granted, lock, &prev);
+       ldlm_granted_list_add_lock(lock, &prev);
 }
 
 /**
@@ -1087,7 +1089,6 @@ static void ldlm_grant_lock_with_skiplist(struct ldlm_lock *lock)
  * NOTE: called by
  *  - ldlm_lock_enqueue
  *  - ldlm_reprocess_queue
- *  - ldlm_lock_convert
  *
  * must be called with lr_lock held
  */
@@ -1410,9 +1411,6 @@ enum ldlm_mode ldlm_lock_match(struct ldlm_namespace *ns, __u64 flags,
                GOTO(out, rc = 1);
        if (flags & LDLM_FL_BLOCK_GRANTED)
                GOTO(out, rc = 0);
-       lock = search_queue(&res->lr_converting, &data);
-       if (lock != NULL)
-               GOTO(out, rc = 1);
        lock = search_queue(&res->lr_waiting, &data);
        if (lock != NULL)
                GOTO(out, rc = 1);
@@ -1691,6 +1689,33 @@ out:
        RETURN(ERR_PTR(rc));
 }
 
+#ifdef HAVE_SERVER_SUPPORT
+static enum ldlm_error ldlm_lock_enqueue_helper(struct ldlm_lock *lock,
+                                            __u64 *flags)
+{
+       struct ldlm_resource *res = lock->l_resource;
+       enum ldlm_error rc = ELDLM_OK;
+       struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
+       ldlm_processing_policy policy;
+       ENTRY;
+
+       policy = ldlm_processing_policy_table[res->lr_type];
+restart:
+       policy(lock, flags, LDLM_PROCESS_ENQUEUE, &rc, &rpc_list);
+       if (rc == ELDLM_OK && lock->l_granted_mode != lock->l_req_mode &&
+           res->lr_type != LDLM_FLOCK) {
+               rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list);
+               if (rc == -ERESTART)
+                       GOTO(restart, rc);
+       }
+
+       if (!list_empty(&rpc_list))
+               ldlm_discard_bl_list(&rpc_list);
+
+       RETURN(rc);
+}
+#endif
+
 /**
  * Enqueue (request) a lock.
  *
@@ -1708,9 +1733,6 @@ enum ldlm_error ldlm_lock_enqueue(struct ldlm_namespace *ns,
        struct ldlm_lock *lock = *lockp;
        struct ldlm_resource *res = lock->l_resource;
        int local = ns_is_client(ldlm_res_to_ns(res));
-#ifdef HAVE_SERVER_SUPPORT
-       ldlm_processing_policy policy;
-#endif
        enum ldlm_error rc = ELDLM_OK;
        struct ldlm_interval *node = NULL;
        ENTRY;
@@ -1810,33 +1832,27 @@ enum ldlm_error ldlm_lock_enqueue(struct ldlm_namespace *ns,
         * more or less trusting the clients not to lie.
         *
         * FIXME (bug 268): Detect obvious lies by checking compatibility in
-        * granted/converting queues. */
+        * granted queue. */
         if (local) {
-                if (*flags & LDLM_FL_BLOCK_CONV)
-                        ldlm_resource_add_lock(res, &res->lr_converting, lock);
-                else if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
-                        ldlm_resource_add_lock(res, &res->lr_waiting, lock);
-                else
-                        ldlm_grant_lock(lock, NULL);
+               if (*flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED))
+                       ldlm_resource_add_lock(res, &res->lr_waiting, lock);
+               else
+                       ldlm_grant_lock(lock, NULL);
                GOTO(out, rc = ELDLM_OK);
 #ifdef HAVE_SERVER_SUPPORT
-        } else if (*flags & LDLM_FL_REPLAY) {
-                if (*flags & LDLM_FL_BLOCK_CONV) {
-                        ldlm_resource_add_lock(res, &res->lr_converting, lock);
-                       GOTO(out, rc = ELDLM_OK);
-                } else if (*flags & LDLM_FL_BLOCK_WAIT) {
-                        ldlm_resource_add_lock(res, &res->lr_waiting, lock);
+       } else if (*flags & LDLM_FL_REPLAY) {
+               if (*flags & LDLM_FL_BLOCK_WAIT) {
+                       ldlm_resource_add_lock(res, &res->lr_waiting, lock);
                        GOTO(out, rc = ELDLM_OK);
-                } else if (*flags & LDLM_FL_BLOCK_GRANTED) {
-                        ldlm_grant_lock(lock, NULL);
+               } else if (*flags & LDLM_FL_BLOCK_GRANTED) {
+                       ldlm_grant_lock(lock, NULL);
                        GOTO(out, rc = ELDLM_OK);
-                }
-                /* If no flags, fall through to normal enqueue path. */
-        }
+               }
+               /* If no flags, fall through to normal enqueue path. */
+       }
 
-        policy = ldlm_processing_policy_table[res->lr_type];
-        policy(lock, flags, 1, &rc, NULL);
-        GOTO(out, rc);
+       rc = ldlm_lock_enqueue_helper(lock, flags);
+       GOTO(out, rc);
 #else
         } else {
                 CERROR("This is client-side-only module, cannot handle "
@@ -1860,35 +1876,165 @@ out:
  * Must be called with resource lock held.
  */
 int ldlm_reprocess_queue(struct ldlm_resource *res, struct list_head *queue,
-                        struct list_head *work_list)
+                        struct list_head *work_list,
+                        enum ldlm_process_intention intention)
 {
        struct list_head *tmp, *pos;
        ldlm_processing_policy policy;
        __u64 flags;
        int rc = LDLM_ITER_CONTINUE;
        enum ldlm_error err;
+       struct list_head bl_ast_list = LIST_HEAD_INIT(bl_ast_list);
        ENTRY;
 
        check_res_locked(res);
 
        policy = ldlm_processing_policy_table[res->lr_type];
        LASSERT(policy);
+       LASSERT(intention == LDLM_PROCESS_RESCAN ||
+               intention == LDLM_PROCESS_RECOVERY);
 
+restart:
        list_for_each_safe(tmp, pos, queue) {
                struct ldlm_lock *pending;
+               struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
 
                pending = list_entry(tmp, struct ldlm_lock, l_res_link);
 
                 CDEBUG(D_INFO, "Reprocessing lock %p\n", pending);
 
                 flags = 0;
-                rc = policy(pending, &flags, 0, &err, work_list);
-                if (rc != LDLM_ITER_CONTINUE)
-                        break;
+               rc = policy(pending, &flags, intention, &err, &rpc_list);
+               if (pending->l_granted_mode == pending->l_req_mode ||
+                   res->lr_type == LDLM_FLOCK) {
+                       list_splice(&rpc_list, work_list);
+               } else {
+                       list_splice(&rpc_list, &bl_ast_list);
+               }
+               /*
+                * When this is called from recovery done, we always want
+                * to scan the whole list no matter what 'rc' is returned.
+                */
+               if (rc != LDLM_ITER_CONTINUE &&
+                   intention == LDLM_PROCESS_RESCAN)
+                       break;
         }
 
-        RETURN(rc);
+       if (!list_empty(&bl_ast_list)) {
+               unlock_res(res);
+
+               LASSERT(intention == LDLM_PROCESS_RECOVERY);
+
+               rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &bl_ast_list,
+                                      LDLM_WORK_BL_AST);
+
+               lock_res(res);
+               if (rc == -ERESTART)
+                       GOTO(restart, rc);
+       }
+
+       if (!list_empty(&bl_ast_list))
+               ldlm_discard_bl_list(&bl_ast_list);
+
+        RETURN(intention == LDLM_PROCESS_RESCAN ? rc : LDLM_ITER_CONTINUE);
+}
+
+/**
+ * Conflicting locks are detected for a lock to be enqueued, add the lock
+ * into waiting list and send blocking ASTs to the conflicting locks.
+ *
+ * \param[in] lock             The lock to be enqueued.
+ * \param[out] flags           Lock flags for the lock to be enqueued.
+ * \param[in] rpc_list         Conflicting locks list.
+ *
+ * \retval -ERESTART:  Some lock was instantly canceled while sending
+ *                     blocking ASTs, caller needs to re-check conflicting
+ *                     locks.
+ * \retval -EAGAIN:    Lock was destroyed, caller should return error.
+ * \reval 0:           Lock is successfully added in waiting list.
+ */
+int ldlm_handle_conflict_lock(struct ldlm_lock *lock, __u64 *flags,
+                             struct list_head *rpc_list)
+{
+       struct ldlm_resource *res = lock->l_resource;
+       int rc;
+       ENTRY;
+
+       check_res_locked(res);
+
+       /* If either of the compat_queue()s returned failure, then we
+        * have ASTs to send and must go onto the waiting list.
+        *
+        * bug 2322: we used to unlink and re-add here, which was a
+        * terrible folly -- if we goto restart, we could get
+        * re-ordered!  Causes deadlock, because ASTs aren't sent! */
+       if (list_empty(&lock->l_res_link))
+               ldlm_resource_add_lock(res, &res->lr_waiting, lock);
+       unlock_res(res);
+
+       rc = ldlm_run_ast_work(ldlm_res_to_ns(res), rpc_list,
+                              LDLM_WORK_BL_AST);
+
+       if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_OST_FAIL_RACE) &&
+           !ns_is_client(ldlm_res_to_ns(res)))
+               class_fail_export(lock->l_export);
+
+       lock_res(res);
+       if (rc == -ERESTART) {
+               /* 15715: The lock was granted and destroyed after
+                * resource lock was dropped. Interval node was freed
+                * in ldlm_lock_destroy. Anyway, this always happens
+                * when a client is being evicted. So it would be
+                * ok to return an error. -jay */
+               if (ldlm_is_destroyed(lock))
+                       RETURN(-EAGAIN);
+
+               /* lock was granted while resource was unlocked. */
+               if (lock->l_granted_mode == lock->l_req_mode) {
+                       /* bug 11300: if the lock has been granted,
+                        * break earlier because otherwise, we will go
+                        * to restart and ldlm_resource_unlink will be
+                        * called and it causes the interval node to be
+                        * freed. Then we will fail at
+                        * ldlm_extent_add_lock() */
+                       *flags &= ~LDLM_FL_BLOCKED_MASK;
+                       RETURN(0);
+               }
+
+               RETURN(rc);
+       }
+       *flags |= LDLM_FL_BLOCK_GRANTED;
+
+       RETURN(0);
+}
+
+/**
+ * Discard all AST work items from list.
+ *
+ * If for whatever reason we do not want to send ASTs to conflicting locks
+ * anymore, disassemble the list with this function.
+ */
+void ldlm_discard_bl_list(struct list_head *bl_list)
+{
+       struct list_head *tmp, *pos;
+        ENTRY;
+
+       list_for_each_safe(pos, tmp, bl_list) {
+                struct ldlm_lock *lock =
+                       list_entry(pos, struct ldlm_lock, l_bl_ast);
+
+               list_del_init(&lock->l_bl_ast);
+               LASSERT(ldlm_is_ast_sent(lock));
+               ldlm_clear_ast_sent(lock);
+               LASSERT(lock->l_bl_ast_run == 0);
+               LASSERT(lock->l_blocking_lock);
+               LDLM_LOCK_RELEASE(lock->l_blocking_lock);
+               lock->l_blocking_lock = NULL;
+               LDLM_LOCK_RELEASE(lock);
+       }
+       EXIT;
 }
+
 #endif
 
 /**
@@ -2024,14 +2170,17 @@ int ldlm_work_gl_ast_lock(struct ptlrpc_request_set *rqset, void *opaq)
 
        /* transfer the glimpse descriptor to ldlm_cb_set_arg */
        arg->gl_desc = gl_work->gl_desc;
+       arg->gl_interpret_reply = gl_work->gl_interpret_reply;
+       arg->gl_interpret_data = gl_work->gl_interpret_data;
 
        /* invoke the actual glimpse callback */
        if (lock->l_glimpse_ast(lock, (void*)arg) == 0)
                rc = 1;
 
        LDLM_LOCK_RELEASE(lock);
-
-       if ((gl_work->gl_flags & LDLM_GL_WORK_NOFREE) == 0)
+       if (gl_work->gl_flags & LDLM_GL_WORK_SLAB_ALLOCATED)
+               OBD_SLAB_FREE_PTR(gl_work, ldlm_glimpse_work_kmem);
+       else
                OBD_FREE_PTR(gl_work);
 
        RETURN(rc);
@@ -2100,47 +2249,16 @@ out:
        return rc;
 }
 
-static int reprocess_one_queue(struct ldlm_resource *res, void *closure)
-{
-        ldlm_reprocess_all(res);
-        return LDLM_ITER_CONTINUE;
-}
-
-static int ldlm_reprocess_res(struct cfs_hash *hs, struct cfs_hash_bd *bd,
-                             struct hlist_node *hnode, void *arg)
-{
-        struct ldlm_resource *res = cfs_hash_object(hs, hnode);
-        int    rc;
-
-        rc = reprocess_one_queue(res, arg);
-
-        return rc == LDLM_ITER_STOP;
-}
-
-/**
- * Iterate through all resources on a namespace attempting to grant waiting
- * locks.
- */
-void ldlm_reprocess_all_ns(struct ldlm_namespace *ns)
-{
-       ENTRY;
-
-       if (ns != NULL) {
-               cfs_hash_for_each_nolock(ns->ns_rs_hash,
-                                        ldlm_reprocess_res, NULL, 0);
-       }
-       EXIT;
-}
-
 /**
  * Try to grant all waiting locks on a resource.
  *
- * Calls ldlm_reprocess_queue on converting and waiting queues.
+ * Calls ldlm_reprocess_queue on waiting queue.
  *
  * Typically called after some resource locks are cancelled to see
  * if anything could be granted as a result of the cancellation.
  */
-void ldlm_reprocess_all(struct ldlm_resource *res)
+static void __ldlm_reprocess_all(struct ldlm_resource *res,
+                                enum ldlm_process_intention intention)
 {
        struct list_head rpc_list;
 #ifdef HAVE_SERVER_SUPPORT
@@ -2163,18 +2281,16 @@ void ldlm_reprocess_all(struct ldlm_resource *res)
            atomic_read(&obd->obd_req_replay_clients) == 0)
                RETURN_EXIT;
 restart:
-        lock_res(res);
-        rc = ldlm_reprocess_queue(res, &res->lr_converting, &rpc_list);
-        if (rc == LDLM_ITER_CONTINUE)
-                ldlm_reprocess_queue(res, &res->lr_waiting, &rpc_list);
-        unlock_res(res);
+       lock_res(res);
+       ldlm_reprocess_queue(res, &res->lr_waiting, &rpc_list, intention);
+       unlock_res(res);
 
-        rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
-                               LDLM_WORK_CP_AST);
-        if (rc == -ERESTART) {
+       rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
+                              LDLM_WORK_CP_AST);
+       if (rc == -ERESTART) {
                LASSERT(list_empty(&rpc_list));
-                goto restart;
-        }
+               goto restart;
+       }
 #else
         ENTRY;
 
@@ -2187,19 +2303,36 @@ restart:
 #endif
         EXIT;
 }
+
+void ldlm_reprocess_all(struct ldlm_resource *res)
+{
+       __ldlm_reprocess_all(res, LDLM_PROCESS_RESCAN);
+}
 EXPORT_SYMBOL(ldlm_reprocess_all);
 
-static bool is_bl_done(struct ldlm_lock *lock)
+static int ldlm_reprocess_res(struct cfs_hash *hs, struct cfs_hash_bd *bd,
+                             struct hlist_node *hnode, void *arg)
 {
-       bool bl_done = true;
+       struct ldlm_resource *res = cfs_hash_object(hs, hnode);
 
-       if (!ldlm_is_bl_done(lock)) {
-               lock_res_and_lock(lock);
-               bl_done = ldlm_is_bl_done(lock);
-               unlock_res_and_lock(lock);
-       }
+       /* This is only called once after recovery done. LU-8306. */
+       __ldlm_reprocess_all(res, LDLM_PROCESS_RECOVERY);
+       return 0;
+}
+
+/**
+ * Iterate through all resources on a namespace attempting to grant waiting
+ * locks.
+ */
+void ldlm_reprocess_recovery_done(struct ldlm_namespace *ns)
+{
+       ENTRY;
 
-       return bl_done;
+       if (ns != NULL) {
+               cfs_hash_for_each_nolock(ns->ns_rs_hash,
+                                        ldlm_reprocess_res, NULL, 0);
+       }
+       EXIT;
 }
 
 /**
@@ -2327,7 +2460,7 @@ static void ldlm_cancel_lock_for_export(struct obd_export *exp,
 
        res = ldlm_resource_getref(lock->l_resource);
 
-       ldlm_res_lvbo_update(res, NULL, 1);
+       ldlm_lvbo_update(res, lock, NULL, 1);
        ldlm_lock_cancel(lock);
        if (!exp->exp_obd->obd_stopping)
                ldlm_reprocess_all(res);
@@ -2419,171 +2552,58 @@ int ldlm_export_cancel_locks(struct obd_export *exp)
               "left on hash table %d.\n", exp, ecl.ecl_loop,
               atomic_read(&exp->exp_lock_hash->hs_count));
 
+       if (ecl.ecl_loop > 0 &&
+           atomic_read(&exp->exp_lock_hash->hs_count) == 0 &&
+           exp->exp_obd->obd_stopping)
+               ldlm_reprocess_recovery_done(exp->exp_obd->obd_namespace);
+
        return ecl.ecl_loop;
 }
 
 /**
- * Downgrade an exclusive lock.
+ * Downgrade an PW/EX lock to COS mode.
  *
- * A fast variant of ldlm_lock_convert for convertion of exclusive
- * locks. The convertion is always successful.
- * Used by Commit on Sharing (COS) code.
+ * A lock mode convertion from PW/EX mode to less conflict mode. The
+ * convertion may fail if lock was canceled before downgrade, but it doesn't
+ * indicate any problem, because such lock has no reader or writer, and will
+ * be released soon.
+ * Used by Commit on Sharing (COS) code only for now.
  *
  * \param lock A lock to convert
  * \param new_mode new lock mode
  */
-void ldlm_lock_downgrade(struct ldlm_lock *lock, enum ldlm_mode new_mode)
-{
-        ENTRY;
-
-        LASSERT(lock->l_granted_mode & (LCK_PW | LCK_EX));
-        LASSERT(new_mode == LCK_COS);
-
-        lock_res_and_lock(lock);
-        ldlm_resource_unlink_lock(lock);
-        /*
-         * Remove the lock from pool as it will be added again in
-         * ldlm_grant_lock() called below.
-         */
-        ldlm_pool_del(&ldlm_lock_to_ns(lock)->ns_pool, lock);
-
-        lock->l_req_mode = new_mode;
-        ldlm_grant_lock(lock, NULL);
-        unlock_res_and_lock(lock);
-        ldlm_reprocess_all(lock->l_resource);
-
-        EXIT;
-}
-EXPORT_SYMBOL(ldlm_lock_downgrade);
-
-/**
- * Attempt to convert already granted lock to a different mode.
- *
- * While lock conversion is not currently used, future client-side
- * optimizations could take advantage of it to avoid discarding cached
- * pages on a file.
- */
-struct ldlm_resource *ldlm_lock_convert(struct ldlm_lock *lock,
-                                       enum ldlm_mode new_mode, __u32 *flags)
+void ldlm_lock_mode_downgrade(struct ldlm_lock *lock, enum ldlm_mode new_mode)
 {
-       struct list_head rpc_list;
-       struct ldlm_resource *res;
-       struct ldlm_namespace *ns;
-       int granted = 0;
-#ifdef HAVE_SERVER_SUPPORT
-       int old_mode;
-       struct sl_insert_point prev;
-#endif
-       struct ldlm_interval *node;
        ENTRY;
 
-       INIT_LIST_HEAD(&rpc_list);
-       /* Just return if mode is unchanged. */
-       if (new_mode == lock->l_granted_mode) {
-               *flags |= LDLM_FL_BLOCK_GRANTED;
-               RETURN(lock->l_resource);
-       }
-
-       /* I can't check the type of lock here because the bitlock of lock
-        * is not held here, so do the allocation blindly. -jay */
-       OBD_SLAB_ALLOC_PTR_GFP(node, ldlm_interval_slab, GFP_NOFS);
-       if (node == NULL)  /* Actually, this causes EDEADLOCK to be returned */
-               RETURN(NULL);
-
-       LASSERTF((new_mode == LCK_PW && lock->l_granted_mode == LCK_PR),
-                "new_mode %u, granted %u\n", new_mode, lock->l_granted_mode);
+       LASSERT(new_mode == LCK_COS);
 
        lock_res_and_lock(lock);
 
-       res = lock->l_resource;
-       ns  = ldlm_res_to_ns(res);
+       if (!(lock->l_granted_mode & (LCK_PW | LCK_EX))) {
+               unlock_res_and_lock(lock);
 
-#ifdef HAVE_SERVER_SUPPORT
-       old_mode = lock->l_req_mode;
-#endif
-       lock->l_req_mode = new_mode;
-       if (res->lr_type == LDLM_PLAIN || res->lr_type == LDLM_IBITS) {
-#ifdef HAVE_SERVER_SUPPORT
-               /* remember the lock position where the lock might be
-                * added back to the granted list later and also
-                * remember the join mode for skiplist fixing. */
-               prev.res_link = lock->l_res_link.prev;
-               prev.mode_link = lock->l_sl_mode.prev;
-               prev.policy_link = lock->l_sl_policy.prev;
-#endif
-                ldlm_resource_unlink_lock(lock);
-        } else {
-                ldlm_resource_unlink_lock(lock);
-                if (res->lr_type == LDLM_EXTENT) {
-                        /* FIXME: ugly code, I have to attach the lock to a
-                         * interval node again since perhaps it will be granted
-                         * soon */
-                       INIT_LIST_HEAD(&node->li_group);
-                        ldlm_interval_attach(node, lock);
-                        node = NULL;
-                }
-        }
+               LASSERT(lock->l_granted_mode == LCK_MINMODE);
+               LDLM_DEBUG(lock, "lock was canceled before downgrade");
+               RETURN_EXIT;
+       }
 
-        /*
-         * Remove old lock from the pool before adding the lock with new
-         * mode below in ->policy()
-         */
-        ldlm_pool_del(&ns->ns_pool, lock);
+       ldlm_resource_unlink_lock(lock);
+       /*
+        * Remove the lock from pool as it will be added again in
+        * ldlm_grant_lock() called below.
+        */
+       ldlm_pool_del(&ldlm_lock_to_ns(lock)->ns_pool, lock);
+       lock->l_req_mode = new_mode;
+       ldlm_grant_lock(lock, NULL);
 
-        /* If this is a local resource, put it on the appropriate list. */
-        if (ns_is_client(ldlm_res_to_ns(res))) {
-                if (*flags & (LDLM_FL_BLOCK_CONV | LDLM_FL_BLOCK_GRANTED)) {
-                        ldlm_resource_add_lock(res, &res->lr_converting, lock);
-                } else {
-                        /* This should never happen, because of the way the
-                         * server handles conversions. */
-                       LDLM_ERROR(lock, "Erroneous flags %x on local lock\n",
-                                   *flags);
-                        LBUG();
+       unlock_res_and_lock(lock);
 
-                        ldlm_grant_lock(lock, &rpc_list);
-                        granted = 1;
-                        /* FIXME: completion handling not with lr_lock held ! */
-                        if (lock->l_completion_ast)
-                                lock->l_completion_ast(lock, 0, NULL);
-                }
-#ifdef HAVE_SERVER_SUPPORT
-       } else {
-               int rc;
-               enum ldlm_error err;
-               __u64 pflags = 0;
-               ldlm_processing_policy policy;
-
-                policy = ldlm_processing_policy_table[res->lr_type];
-                rc = policy(lock, &pflags, 0, &err, &rpc_list);
-                if (rc == LDLM_ITER_STOP) {
-                        lock->l_req_mode = old_mode;
-                        if (res->lr_type == LDLM_EXTENT)
-                                ldlm_extent_add_lock(res, lock);
-                        else
-                                ldlm_granted_list_add_lock(lock, &prev);
-
-                        res = NULL;
-                } else {
-                        *flags |= LDLM_FL_BLOCK_GRANTED;
-                        granted = 1;
-                }
-        }
-#else
-        } else {
-                CERROR("This is client-side-only module, cannot handle "
-                       "LDLM_NAMESPACE_SERVER resource type lock.\n");
-                LBUG();
-        }
-#endif
-        unlock_res_and_lock(lock);
+       ldlm_reprocess_all(lock->l_resource);
 
-        if (granted)
-                ldlm_run_ast_work(ns, &rpc_list, LDLM_WORK_CP_AST);
-        if (node)
-                OBD_SLAB_FREE(node, ldlm_interval_slab, sizeof(*node));
-        RETURN(res);
+       EXIT;
 }
+EXPORT_SYMBOL(ldlm_lock_mode_downgrade);
 
 /**
  * Print lock with lock handle \a lockh description into debug log.
@@ -2617,23 +2637,33 @@ void _ldlm_lock_debug(struct ldlm_lock *lock,
 {
         va_list args;
         struct obd_export *exp = lock->l_export;
-        struct ldlm_resource *resource = lock->l_resource;
+       struct ldlm_resource *resource = NULL;
         char *nid = "local";
 
+       /* on server-side resource of lock doesn't change */
+       if ((lock->l_flags & LDLM_FL_NS_SRV) != 0) {
+               if (lock->l_resource != NULL)
+                       resource = ldlm_resource_getref(lock->l_resource);
+       } else if (spin_trylock(&lock->l_lock)) {
+               if (lock->l_resource != NULL)
+                       resource = ldlm_resource_getref(lock->l_resource);
+               spin_unlock(&lock->l_lock);
+       }
+
         va_start(args, fmt);
 
         if (exp && exp->exp_connection) {
-                nid = libcfs_nid2str(exp->exp_connection->c_peer.nid);
+               nid = obd_export_nid2str(exp);
         } else if (exp && exp->exp_obd != NULL) {
                 struct obd_import *imp = exp->exp_obd->u.cli.cl_import;
-                nid = libcfs_nid2str(imp->imp_connection->c_peer.nid);
+               nid = obd_import_nid2str(imp);
         }
 
         if (resource == NULL) {
                 libcfs_debug_vmsg2(msgdata, fmt, args,
                       " ns: \?\? lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s "
                       "res: \?\? rrc=\?\? type: \?\?\? flags: %#llx nid: %s "
-                      "remote: %#llx expref: %d pid: %u timeout: %lu "
+                      "remote: %#llx expref: %d pid: %u timeout: %lld "
                       "lvb_type: %d\n",
                        lock,
                       lock->l_handle.h_cookie, atomic_read(&lock->l_refc),
@@ -2653,7 +2683,7 @@ void _ldlm_lock_debug(struct ldlm_lock *lock,
                        " ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s "
                        "res: "DLDLMRES" rrc: %d type: %s [%llu->%llu] "
                        "(req %llu->%llu) flags: %#llx nid: %s remote: "
-                       "%#llx expref: %d pid: %u timeout: %lu lvb_type: %d\n",
+                       "%#llx expref: %d pid: %u timeout: %lld lvb_type: %d\n",
                        ldlm_lock_to_ns_name(lock), lock,
                        lock->l_handle.h_cookie, atomic_read(&lock->l_refc),
                        lock->l_readers, lock->l_writers,
@@ -2676,7 +2706,7 @@ void _ldlm_lock_debug(struct ldlm_lock *lock,
                        " ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s "
                        "res: "DLDLMRES" rrc: %d type: %s pid: %d "
                        "[%llu->%llu] flags: %#llx nid: %s "
-                       "remote: %#llx expref: %d pid: %u timeout: %lu\n",
+                       "remote: %#llx expref: %d pid: %u timeout: %lld\n",
                        ldlm_lock_to_ns_name(lock), lock,
                        lock->l_handle.h_cookie, atomic_read(&lock->l_refc),
                        lock->l_readers, lock->l_writers,
@@ -2696,9 +2726,9 @@ void _ldlm_lock_debug(struct ldlm_lock *lock,
        case LDLM_IBITS:
                libcfs_debug_vmsg2(msgdata, fmt, args,
                        " ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s "
-                       "res: "DLDLMRES" bits %#llx rrc: %d type: %s "
+                       "res: "DLDLMRES" bits %#llx/%#llx rrc: %d type: %s "
                        "flags: %#llx nid: %s remote: %#llx expref: %d "
-                       "pid: %u timeout: %lu lvb_type: %d\n",
+                       "pid: %u timeout: %lld lvb_type: %d\n",
                        ldlm_lock_to_ns_name(lock),
                        lock, lock->l_handle.h_cookie,
                        atomic_read(&lock->l_refc),
@@ -2707,6 +2737,7 @@ void _ldlm_lock_debug(struct ldlm_lock *lock,
                        ldlm_lockname[lock->l_req_mode],
                        PLDLMRES(resource),
                        lock->l_policy_data.l_inodebits.bits,
+                       lock->l_policy_data.l_inodebits.try_bits,
                        atomic_read(&resource->lr_refcount),
                        ldlm_typename[resource->lr_type],
                        lock->l_flags, nid, lock->l_remote_handle.cookie,
@@ -2720,7 +2751,7 @@ void _ldlm_lock_debug(struct ldlm_lock *lock,
                        " ns: %s lock: %p/%#llx lrc: %d/%d,%d mode: %s/%s "
                        "res: "DLDLMRES" rrc: %d type: %s flags: %#llx "
                        "nid: %s remote: %#llx expref: %d pid: %u "
-                       "timeout: %lu lvb_type: %d\n",
+                       "timeout: %lld lvb_type: %d\n",
                        ldlm_lock_to_ns_name(lock),
                        lock, lock->l_handle.h_cookie,
                        atomic_read(&lock->l_refc),
@@ -2737,5 +2768,6 @@ void _ldlm_lock_debug(struct ldlm_lock *lock,
                break;
        }
        va_end(args);
+       ldlm_resource_putref(resource);
 }
 EXPORT_SYMBOL(_ldlm_lock_debug);