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LU-2901 ldlm: fix resource/fid check, use DLDLMRES
[fs/lustre-release.git] / lustre / ldlm / ldlm_request.c
index 6dfeac7..95b2f63 100644 (file)
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2010, 2013, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  * Lustre is a trademark of Sun Microsystems, Inc.
  */
+/**
+ * This file contains Asynchronous System Trap (AST) handlers and related
+ * LDLM request-processing routines.
+ *
+ * An AST is a callback issued on a lock when its state is changed. There are
+ * several different types of ASTs (callbacks) registered for each lock:
+ *
+ * - completion AST: when a lock is enqueued by some process, but cannot be
+ *   granted immediately due to other conflicting locks on the same resource,
+ *   the completion AST is sent to notify the caller when the lock is
+ *   eventually granted
+ *
+ * - blocking AST: when a lock is granted to some process, if another process
+ *   enqueues a conflicting (blocking) lock on a resource, a blocking AST is
+ *   sent to notify the holder(s) of the lock(s) of the conflicting lock
+ *   request. The lock holder(s) must release their lock(s) on that resource in
+ *   a timely manner or be evicted by the server.
+ *
+ * - glimpse AST: this is used when a process wants information about a lock
+ *   (i.e. the lock value block (LVB)) but does not necessarily require holding
+ *   the lock. If the resource is locked, the lock holder(s) are sent glimpse
+ *   ASTs and the LVB is returned to the caller, and lock holder(s) may CANCEL
+ *   their lock(s) if they are idle. If the resource is not locked, the server
+ *   may grant the lock.
+ */
 
 #define DEBUG_SUBSYSTEM S_LDLM
 #ifndef __KERNEL__
@@ -50,6 +75,9 @@ int ldlm_enqueue_min = OBD_TIMEOUT_DEFAULT;
 CFS_MODULE_PARM(ldlm_enqueue_min, "i", int, 0644,
                 "lock enqueue timeout minimum");
 
+/* in client side, whether the cached locks will be canceled before replay */
+unsigned int ldlm_cancel_unused_locks_before_replay = 1;
+
 static void interrupted_completion_wait(void *data)
 {
 }
@@ -77,17 +105,22 @@ int ldlm_expired_completion_wait(void *data)
                 if (ptlrpc_check_suspend())
                         RETURN(0);
 
-                LDLM_ERROR(lock, "lock timed out (enqueued at "CFS_TIME_T", "
+               LCONSOLE_WARN("lock timed out (enqueued at "CFS_TIME_T", "
+                             CFS_DURATION_T"s ago)\n",
+                             lock->l_last_activity,
+                             cfs_time_sub(cfs_time_current_sec(),
+                                          lock->l_last_activity));
+               LDLM_DEBUG(lock, "lock timed out (enqueued at "CFS_TIME_T", "
                           CFS_DURATION_T"s ago); not entering recovery in "
-                           "server code, just going back to sleep",
-                          lock->l_enqueued_time.tv_sec,
-                           cfs_time_sub(cfs_time_current_sec(),
-                           lock->l_enqueued_time.tv_sec));
+                          "server code, just going back to sleep",
+                          lock->l_last_activity,
+                          cfs_time_sub(cfs_time_current_sec(),
+                                       lock->l_last_activity));
                 if (cfs_time_after(cfs_time_current(), next_dump)) {
                         last_dump = next_dump;
                         next_dump = cfs_time_shift(300);
                         ldlm_namespace_dump(D_DLMTRACE,
-                                            lock->l_resource->lr_namespace);
+                                            ldlm_lock_to_ns(lock));
                         if (last_dump == 0)
                                 libcfs_debug_dumplog();
                 }
@@ -99,43 +132,104 @@ int ldlm_expired_completion_wait(void *data)
         ptlrpc_fail_import(imp, lwd->lwd_conn_cnt);
         LDLM_ERROR(lock, "lock timed out (enqueued at "CFS_TIME_T", "
                   CFS_DURATION_T"s ago), entering recovery for %s@%s",
-                  lock->l_enqueued_time.tv_sec,
-                  cfs_time_sub(cfs_time_current_sec(),
-                  lock->l_enqueued_time.tv_sec),
+                  lock->l_last_activity,
+                  cfs_time_sub(cfs_time_current_sec(), lock->l_last_activity),
                   obd2cli_tgt(obd), imp->imp_connection->c_remote_uuid.uuid);
 
         RETURN(0);
 }
+EXPORT_SYMBOL(ldlm_expired_completion_wait);
 
 /* We use the same basis for both server side and client side functions
    from a single node. */
 int ldlm_get_enq_timeout(struct ldlm_lock *lock)
 {
-        int timeout = at_get(&lock->l_resource->lr_namespace->ns_at_estimate);
+        int timeout = at_get(ldlm_lock_to_ns_at(lock));
         if (AT_OFF)
                 return obd_timeout / 2;
         /* Since these are non-updating timeouts, we should be conservative.
            It would be nice to have some kind of "early reply" mechanism for
            lock callbacks too... */
-        timeout = timeout + (timeout >> 1); /* 150% */
+        timeout = min_t(int, at_max, timeout + (timeout >> 1)); /* 150% */
         return max(timeout, ldlm_enqueue_min);
 }
+EXPORT_SYMBOL(ldlm_get_enq_timeout);
 
-static int is_granted_or_cancelled(struct ldlm_lock *lock)
+/**
+ * Helper function for ldlm_completion_ast(), updating timings when lock is
+ * actually granted.
+ */
+static int ldlm_completion_tail(struct ldlm_lock *lock)
 {
-        int ret = 0;
+       long delay;
+       int  result;
+
+       if (lock->l_flags & (LDLM_FL_DESTROYED | LDLM_FL_FAILED)) {
+               LDLM_DEBUG(lock, "client-side enqueue: destroyed");
+               result = -EIO;
+       } else {
+               delay = cfs_time_sub(cfs_time_current_sec(),
+                                    lock->l_last_activity);
+               LDLM_DEBUG(lock, "client-side enqueue: granted after "
+                          CFS_DURATION_T"s", delay);
+
+               /* Update our time estimate */
+               at_measured(ldlm_lock_to_ns_at(lock),
+                           delay);
+               result = 0;
+       }
+       return result;
+}
 
-        lock_res_and_lock(lock);
-        if (((lock->l_req_mode == lock->l_granted_mode) &&
-             !(lock->l_flags & LDLM_FL_CP_REQD)) ||
-            (lock->l_flags & LDLM_FL_FAILED))
-                ret = 1;
-        unlock_res_and_lock(lock);
+/**
+ * Implementation of ->l_completion_ast() for a client, that doesn't wait
+ * until lock is granted. Suitable for locks enqueued through ptlrpcd, of
+ * other threads that cannot block for long.
+ */
+int ldlm_completion_ast_async(struct ldlm_lock *lock, __u64 flags, void *data)
+{
+        ENTRY;
+
+        if (flags == LDLM_FL_WAIT_NOREPROC) {
+                LDLM_DEBUG(lock, "client-side enqueue waiting on pending lock");
+                RETURN(0);
+        }
 
-        return ret;
+        if (!(flags & (LDLM_FL_BLOCK_WAIT | LDLM_FL_BLOCK_GRANTED |
+                       LDLM_FL_BLOCK_CONV))) {
+                cfs_waitq_signal(&lock->l_waitq);
+                RETURN(ldlm_completion_tail(lock));
+        }
+
+        LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, "
+                   "going forward");
+        ldlm_reprocess_all(lock->l_resource);
+        RETURN(0);
 }
+EXPORT_SYMBOL(ldlm_completion_ast_async);
 
-int ldlm_completion_ast(struct ldlm_lock *lock, int flags, void *data)
+/**
+ * Generic LDLM "completion" AST. This is called in several cases:
+ *
+ *     - when a reply to an ENQUEUE RPC is received from the server
+ *       (ldlm_cli_enqueue_fini()). Lock might be granted or not granted at
+ *       this point (determined by flags);
+ *
+ *     - when LDLM_CP_CALLBACK RPC comes to client to notify it that lock has
+ *       been granted;
+ *
+ *     - when ldlm_lock_match(LDLM_FL_LVB_READY) is about to wait until lock
+ *       gets correct lvb;
+ *
+ *     - to force all locks when resource is destroyed (cleanup_resource());
+ *
+ *     - during lock conversion (not used currently).
+ *
+ * If lock is not granted in the first case, this function waits until second
+ * or penultimate cases happen in some other thread.
+ *
+ */
+int ldlm_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
 {
         /* XXX ALLOCATE - 160 bytes */
         struct lock_wait_data lwd;
@@ -159,8 +253,6 @@ int ldlm_completion_ast(struct ldlm_lock *lock, int flags, void *data)
 
         LDLM_DEBUG(lock, "client-side enqueue returned a blocked lock, "
                    "sleeping");
-        ldlm_lock_dump(D_OTHER, lock, 0);
-        ldlm_reprocess_all(lock->l_resource);
 
 noreproc:
 
@@ -187,18 +279,21 @@ noreproc:
                                        interrupted_completion_wait, &lwd);
         }
 
-        if (imp != NULL) {
-                spin_lock(&imp->imp_lock);
-                lwd.lwd_conn_cnt = imp->imp_conn_cnt;
-                spin_unlock(&imp->imp_lock);
-        }
-
-        /* Go to sleep until the lock is granted or cancelled. */
-        rc = l_wait_event(lock->l_waitq, is_granted_or_cancelled(lock), &lwi);
-
-        if (lock->l_destroyed || lock->l_flags & LDLM_FL_FAILED) {
-                LDLM_DEBUG(lock, "client-side enqueue waking up: destroyed");
-                RETURN(-EIO);
+       if (imp != NULL) {
+               spin_lock(&imp->imp_lock);
+               lwd.lwd_conn_cnt = imp->imp_conn_cnt;
+               spin_unlock(&imp->imp_lock);
+       }
+
+        if (ns_is_client(ldlm_lock_to_ns(lock)) &&
+            OBD_FAIL_CHECK_RESET(OBD_FAIL_LDLM_INTR_CP_AST,
+                                 OBD_FAIL_LDLM_CP_BL_RACE | OBD_FAIL_ONCE)) {
+                lock->l_flags |= LDLM_FL_FAIL_LOC;
+                rc = -EINTR;
+        } else {
+                /* Go to sleep until the lock is granted or cancelled. */
+                rc = l_wait_event(lock->l_waitq,
+                                  is_granted_or_cancelled(lock), &lwi);
         }
 
         if (rc) {
@@ -207,25 +302,63 @@ noreproc:
                 RETURN(rc);
         }
 
-        LDLM_DEBUG(lock, "client-side enqueue waking up: granted after "
-                   CFS_DURATION_T"s",
-                   cfs_time_sub(cfs_time_current_sec(),
-                   lock->l_enqueued_time.tv_sec));
+        RETURN(ldlm_completion_tail(lock));
+}
+EXPORT_SYMBOL(ldlm_completion_ast);
 
-        /* Update our time estimate */
-        at_add(&lock->l_resource->lr_namespace->ns_at_estimate,
-               cfs_time_current_sec() - lock->l_enqueued_time.tv_sec);
+/**
+ * A helper to build a blocking AST function
+ *
+ * Perform a common operation for blocking ASTs:
+ * defferred lock cancellation.
+ *
+ * \param lock the lock blocking or canceling AST was called on
+ * \retval 0
+ * \see mdt_blocking_ast
+ * \see ldlm_blocking_ast
+ */
+int ldlm_blocking_ast_nocheck(struct ldlm_lock *lock)
+{
+        int do_ast;
+        ENTRY;
+
+        lock->l_flags |= LDLM_FL_CBPENDING;
+        do_ast = (!lock->l_readers && !lock->l_writers);
+        unlock_res_and_lock(lock);
 
+        if (do_ast) {
+                struct lustre_handle lockh;
+                int rc;
+
+                LDLM_DEBUG(lock, "already unused, calling ldlm_cli_cancel");
+                ldlm_lock2handle(lock, &lockh);
+               rc = ldlm_cli_cancel(&lockh, LCF_ASYNC);
+                if (rc < 0)
+                        CERROR("ldlm_cli_cancel: %d\n", rc);
+        } else {
+                LDLM_DEBUG(lock, "Lock still has references, will be "
+                           "cancelled later");
+        }
         RETURN(0);
 }
+EXPORT_SYMBOL(ldlm_blocking_ast_nocheck);
 
-/*
- * ->l_blocking_ast() callback for LDLM locks acquired by server-side OBDs.
+/**
+ * Server blocking AST
+ *
+ * ->l_blocking_ast() callback for LDLM locks acquired by server-side
+ * OBDs.
+ *
+ * \param lock the lock which blocks a request or cancelling lock
+ * \param desc unused
+ * \param data unused
+ * \param flag indicates whether this cancelling or blocking callback
+ * \retval 0
+ * \see ldlm_blocking_ast_nocheck
  */
 int ldlm_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
                       void *data, int flag)
 {
-        int do_ast;
         ENTRY;
 
         if (flag == LDLM_CB_CANCELING) {
@@ -236,35 +369,18 @@ int ldlm_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
         lock_res_and_lock(lock);
         /* Get this: if ldlm_blocking_ast is racing with intent_policy, such
          * that ldlm_blocking_ast is called just before intent_policy method
-         * takes the ns_lock, then by the time we get the lock, we might not
+         * takes the lr_lock, then by the time we get the lock, we might not
          * be the correct blocking function anymore.  So check, and return
          * early, if so. */
         if (lock->l_blocking_ast != ldlm_blocking_ast) {
                 unlock_res_and_lock(lock);
                 RETURN(0);
         }
-
-        lock->l_flags |= LDLM_FL_CBPENDING;
-        do_ast = (!lock->l_readers && !lock->l_writers);
-        unlock_res_and_lock(lock);
-
-        if (do_ast) {
-                struct lustre_handle lockh;
-                int rc;
-
-                LDLM_DEBUG(lock, "already unused, calling ldlm_cli_cancel");
-                ldlm_lock2handle(lock, &lockh);
-                rc = ldlm_cli_cancel(&lockh);
-                if (rc < 0)
-                        CERROR("ldlm_cli_cancel: %d\n", rc);
-        } else {
-                LDLM_DEBUG(lock, "Lock still has references, will be "
-                           "cancelled later");
-        }
-        RETURN(0);
+        RETURN(ldlm_blocking_ast_nocheck(lock));
 }
+EXPORT_SYMBOL(ldlm_blocking_ast);
 
-/*
+/**
  * ->l_glimpse_ast() for DLM extent locks acquired on the server-side. See
  * comment in filter_intent_policy() on why you may need this.
  */
@@ -290,15 +406,20 @@ int ldlm_glimpse_ast(struct ldlm_lock *lock, void *reqp)
          */
         return -ELDLM_NO_LOCK_DATA;
 }
+EXPORT_SYMBOL(ldlm_glimpse_ast);
 
+/**
+ * Enqueue a local lock (typically on a server).
+ */
 int ldlm_cli_enqueue_local(struct ldlm_namespace *ns,
                            const struct ldlm_res_id *res_id,
                            ldlm_type_t type, ldlm_policy_data_t *policy,
-                           ldlm_mode_t mode, int *flags,
+                          ldlm_mode_t mode, __u64 *flags,
                            ldlm_blocking_callback blocking,
                            ldlm_completion_callback completion,
                            ldlm_glimpse_callback glimpse,
-                           void *data, __u32 lvb_len, void *lvb_swabber,
+                          void *data, __u32 lvb_len, enum lvb_type lvb_type,
+                           const __u64 *client_cookie,
                            struct lustre_handle *lockh)
 {
         struct ldlm_lock *lock;
@@ -315,21 +436,24 @@ int ldlm_cli_enqueue_local(struct ldlm_namespace *ns,
                 LBUG();
         }
 
-        lock = ldlm_lock_create(ns, res_id, type, mode, &cbs, data, lvb_len);
+       lock = ldlm_lock_create(ns, res_id, type, mode, &cbs, data, lvb_len,
+                               lvb_type);
         if (unlikely(!lock))
                 GOTO(out_nolock, err = -ENOMEM);
-        LDLM_DEBUG(lock, "client-side local enqueue handler, new lock created");
 
-        ldlm_lock_addref_internal(lock, mode);
         ldlm_lock2handle(lock, lockh);
-        lock_res_and_lock(lock);
+
+        /* NB: we don't have any lock now (lock_res_and_lock)
+         * because it's a new lock */
+        ldlm_lock_addref_internal_nolock(lock, mode);
         lock->l_flags |= LDLM_FL_LOCAL;
         if (*flags & LDLM_FL_ATOMIC_CB)
                 lock->l_flags |= LDLM_FL_ATOMIC_CB;
-        lock->l_lvb_swabber = lvb_swabber;
-        unlock_res_and_lock(lock);
+
         if (policy != NULL)
                 lock->l_policy_data = *policy;
+        if (client_cookie != NULL)
+                lock->l_client_cookie = *client_cookie;
         if (type == LDLM_EXTENT)
                 lock->l_req_extent = policy->l_extent;
 
@@ -340,50 +464,76 @@ int ldlm_cli_enqueue_local(struct ldlm_namespace *ns,
         if (policy != NULL)
                 *policy = lock->l_policy_data;
 
-        LDLM_DEBUG_NOLOCK("client-side local enqueue handler END (lock %p)",
-                          lock);
-
         if (lock->l_completion_ast)
                 lock->l_completion_ast(lock, *flags, NULL);
 
-        LDLM_DEBUG(lock, "client-side local enqueue END");
+        LDLM_DEBUG(lock, "client-side local enqueue handler, new lock created");
         EXIT;
  out:
-        LDLM_LOCK_PUT(lock);
+        LDLM_LOCK_RELEASE(lock);
  out_nolock:
         return err;
 }
+EXPORT_SYMBOL(ldlm_cli_enqueue_local);
 
 static void failed_lock_cleanup(struct ldlm_namespace *ns,
-                                struct ldlm_lock *lock,
-                                struct lustre_handle *lockh, int mode)
+                                struct ldlm_lock *lock, int mode)
 {
+        int need_cancel = 0;
+
         /* Set a flag to prevent us from sending a CANCEL (bug 407) */
         lock_res_and_lock(lock);
-        lock->l_flags |= LDLM_FL_LOCAL_ONLY;
+        /* Check that lock is not granted or failed, we might race. */
+        if ((lock->l_req_mode != lock->l_granted_mode) &&
+            !(lock->l_flags & LDLM_FL_FAILED)) {
+                /* Make sure that this lock will not be found by raced
+                 * bl_ast and -EINVAL reply is sent to server anyways.
+                 * bug 17645 */
+                lock->l_flags |= LDLM_FL_LOCAL_ONLY | LDLM_FL_FAILED |
+                                 LDLM_FL_ATOMIC_CB | LDLM_FL_CBPENDING;
+                need_cancel = 1;
+        }
         unlock_res_and_lock(lock);
-        LDLM_DEBUG(lock, "setting FL_LOCAL_ONLY");
 
-        ldlm_lock_decref_and_cancel(lockh, mode);
+        if (need_cancel)
+                LDLM_DEBUG(lock,
+                           "setting FL_LOCAL_ONLY | LDLM_FL_FAILED | "
+                           "LDLM_FL_ATOMIC_CB | LDLM_FL_CBPENDING");
+        else
+                LDLM_DEBUG(lock, "lock was granted or failed in race");
+
+        ldlm_lock_decref_internal(lock, mode);
 
         /* XXX - HACK because we shouldn't call ldlm_lock_destroy()
          *       from llite/file.c/ll_file_flock(). */
+        /* This code makes for the fact that we do not have blocking handler on
+         * a client for flock locks. As such this is the place where we must
+         * completely kill failed locks. (interrupted and those that
+         * were waiting to be granted when server evicted us. */
         if (lock->l_resource->lr_type == LDLM_FLOCK) {
-                ldlm_lock_destroy(lock);
+                lock_res_and_lock(lock);
+                ldlm_resource_unlink_lock(lock);
+                ldlm_lock_destroy_nolock(lock);
+                unlock_res_and_lock(lock);
         }
 }
 
+/**
+ * Finishing portion of client lock enqueue code.
+ *
+ * Called after receiving reply from server.
+ */
 int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
                           ldlm_type_t type, __u8 with_policy, ldlm_mode_t mode,
-                          int *flags, void *lvb, __u32 lvb_len,
-                          void *lvb_swabber, struct lustre_handle *lockh,int rc)
+                         __u64 *flags, void *lvb, __u32 lvb_len,
+                          struct lustre_handle *lockh,int rc)
 {
         struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
         int is_replay = *flags & LDLM_FL_REPLAY;
-        struct lustre_handle old_hash_key;
         struct ldlm_lock *lock;
         struct ldlm_reply *reply;
         int cleanup_phase = 1;
+       int size = 0;
         ENTRY;
 
         lock = ldlm_handle2lock(lockh);
@@ -393,59 +543,73 @@ int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
                 RETURN(-ENOLCK);
         }
 
+       LASSERTF(ergo(lvb_len != 0, lvb_len == lock->l_lvb_len),
+                "lvb_len = %d, l_lvb_len = %d\n", lvb_len, lock->l_lvb_len);
+
         if (rc != ELDLM_OK) {
                 LASSERT(!is_replay);
                 LDLM_DEBUG(lock, "client-side enqueue END (%s)",
                            rc == ELDLM_LOCK_ABORTED ? "ABORTED" : "FAILED");
-                if (rc == ELDLM_LOCK_ABORTED) {
-                        /* Before we return, swab the reply */
-                        reply = req_capsule_server_get(&req->rq_pill,
-                                                       &RMF_DLM_REP);
-                        if (reply == NULL)
-                                rc = -EPROTO;
-                        if (lvb_len) {
-                                struct ost_lvb *tmplvb;
-
-                                req_capsule_set_size(&req->rq_pill,
-                                                     &RMF_DLM_LVB, RCL_SERVER,
-                                                     lvb_len);
-                            tmplvb = req_capsule_server_swab_get(&req->rq_pill,
-                                                                 &RMF_DLM_LVB,
-                                                                 lvb_swabber);
-                                if (tmplvb == NULL)
-                                        GOTO(cleanup, rc = -EPROTO);
-                                if (lvb != NULL)
-                                        memcpy(lvb, tmplvb, lvb_len);
-                        }
-                }
-                GOTO(cleanup, rc);
-        }
 
-        reply = req_capsule_server_get(&req->rq_pill, &RMF_DLM_REP);
-        if (reply == NULL)
-                GOTO(cleanup, rc = -EPROTO);
+               if (rc != ELDLM_LOCK_ABORTED)
+                       GOTO(cleanup, rc);
+       }
+
+       /* Before we return, swab the reply */
+       reply = req_capsule_server_get(&req->rq_pill, &RMF_DLM_REP);
+       if (reply == NULL)
+               GOTO(cleanup, rc = -EPROTO);
+
+       if (lvb_len != 0) {
+               LASSERT(lvb != NULL);
+
+               size = req_capsule_get_size(&req->rq_pill, &RMF_DLM_LVB,
+                                           RCL_SERVER);
+               if (size < 0) {
+                       LDLM_ERROR(lock, "Fail to get lvb_len, rc = %d", size);
+                       GOTO(cleanup, rc = size);
+               } else if (unlikely(size > lvb_len)) {
+                       LDLM_ERROR(lock, "Replied LVB is larger than "
+                                  "expectation, expected = %d, replied = %d",
+                                  lvb_len, size);
+                       GOTO(cleanup, rc = -EINVAL);
+               }
+       }
+
+       if (rc == ELDLM_LOCK_ABORTED) {
+               if (lvb_len != 0)
+                       rc = ldlm_fill_lvb(lock, &req->rq_pill, RCL_SERVER,
+                                          lvb, size);
+               GOTO(cleanup, rc = (rc != 0 ? rc : ELDLM_LOCK_ABORTED));
+       }
 
         /* lock enqueued on the server */
         cleanup_phase = 0;
 
         lock_res_and_lock(lock);
-        old_hash_key = lock->l_remote_handle;
-        lock->l_remote_handle = reply->lock_handle;
-
         /* Key change rehash lock in per-export hash with new key */
-        if (exp->exp_lock_hash)
-                lustre_hash_rehash_key(exp->exp_lock_hash, &old_hash_key,
-                                       &lock->l_remote_handle,
-                                       &lock->l_exp_hash);
+        if (exp->exp_lock_hash) {
+               /* In the function below, .hs_keycmp resolves to
+                * ldlm_export_lock_keycmp() */
+               /* coverity[overrun-buffer-val] */
+                cfs_hash_rehash_key(exp->exp_lock_hash,
+                                    &lock->l_remote_handle,
+                                    &reply->lock_handle,
+                                    &lock->l_exp_hash);
+        } else {
+                lock->l_remote_handle = reply->lock_handle;
+        }
 
-        *flags = reply->lock_flags;
-        lock->l_flags |= reply->lock_flags & LDLM_INHERIT_FLAGS;
+       *flags = ldlm_flags_from_wire(reply->lock_flags);
+       lock->l_flags |= ldlm_flags_from_wire(reply->lock_flags &
+                                             LDLM_INHERIT_FLAGS);
         /* move NO_TIMEOUT flag to the lock to force ldlm_lock_match()
          * to wait with no timeout as well */
-        lock->l_flags |= reply->lock_flags & LDLM_FL_NO_TIMEOUT;
+       lock->l_flags |= ldlm_flags_from_wire(reply->lock_flags &
+                                             LDLM_FL_NO_TIMEOUT);
         unlock_res_and_lock(lock);
 
-        CDEBUG(D_INFO, "local: %p, remote cookie: "LPX64", flags: 0x%x\n",
+       CDEBUG(D_INFO, "local: %p, remote cookie: "LPX64", flags: 0x%llx\n",
                lock, reply->lock_handle.cookie, *flags);
 
         /* If enqueue returned a blocked lock but the completion handler has
@@ -460,30 +624,27 @@ int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
                         lock->l_req_mode = newmode;
                 }
 
-                if (memcmp(reply->lock_desc.l_resource.lr_name.name,
-                          lock->l_resource->lr_name.name,
-                          sizeof(struct ldlm_res_id))) {
-                        CDEBUG(D_INFO, "remote intent success, locking "
-                                        "(%ld,%ld,%ld) instead of "
-                                        "(%ld,%ld,%ld)\n",
-                              (long)reply->lock_desc.l_resource.lr_name.name[0],
-                              (long)reply->lock_desc.l_resource.lr_name.name[1],
-                              (long)reply->lock_desc.l_resource.lr_name.name[2],
-                              (long)lock->l_resource->lr_name.name[0],
-                              (long)lock->l_resource->lr_name.name[1],
-                              (long)lock->l_resource->lr_name.name[2]);
-
-                        rc = ldlm_lock_change_resource(ns, lock,
-                                        &reply->lock_desc.l_resource.lr_name);
-                        if (rc || lock->l_resource == NULL)
-                                GOTO(cleanup, rc = -ENOMEM);
-                        LDLM_DEBUG(lock, "client-side enqueue, new resource");
-                }
-                if (with_policy)
-                        if (!(type == LDLM_IBITS && !(exp->exp_connect_flags &
-                                                    OBD_CONNECT_IBITS)))
-                                lock->l_policy_data =
-                                                 reply->lock_desc.l_policy_data;
+               if (!ldlm_res_eq(&reply->lock_desc.l_resource.lr_name,
+                                &lock->l_resource->lr_name)) {
+                       CDEBUG(D_INFO, "remote intent success, locking "DLDLMRES
+                                      " instead of "DLDLMRES"\n",
+                              PLDLMRES(&reply->lock_desc.l_resource),
+                              PLDLMRES(lock->l_resource));
+
+                       rc = ldlm_lock_change_resource(ns, lock,
+                                       &reply->lock_desc.l_resource.lr_name);
+                       if (rc || lock->l_resource == NULL)
+                               GOTO(cleanup, rc = -ENOMEM);
+                       LDLM_DEBUG(lock, "client-side enqueue, new resource");
+               }
+               if (with_policy)
+                       if (!(type == LDLM_IBITS &&
+                             !(exp_connect_flags(exp) & OBD_CONNECT_IBITS)))
+                               /* We assume lock type cannot change on server*/
+                               ldlm_convert_policy_to_local(exp,
+                                               lock->l_resource->lr_type,
+                                               &reply->lock_desc.l_policy_data,
+                                               &lock->l_policy_data);
                 if (type != LDLM_PLAIN)
                         LDLM_DEBUG(lock,"client-side enqueue, new policy data");
         }
@@ -501,17 +662,20 @@ int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
 
         /* If the lock has already been granted by a completion AST, don't
          * clobber the LVB with an older one. */
-        if (lvb_len && (lock->l_req_mode != lock->l_granted_mode)) {
-                void *tmplvb;
-
-                req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER,
-                                     lvb_len);
-                tmplvb = req_capsule_server_swab_get(&req->rq_pill,
-                                                     &RMF_DLM_LVB,
-                                                     lvb_swabber);
-                if (tmplvb == NULL)
-                        GOTO(cleanup, rc = -EPROTO);
-                memcpy(lock->l_lvb_data, tmplvb, lvb_len);
+       if (lvb_len != 0) {
+               /* We must lock or a racing completion might update lvb without
+                * letting us know and we'll clobber the correct value.
+                * Cannot unlock after the check either, a that still leaves
+                * a tiny window for completion to get in */
+               lock_res_and_lock(lock);
+               if (lock->l_req_mode != lock->l_granted_mode)
+                       rc = ldlm_fill_lvb(lock, &req->rq_pill, RCL_SERVER,
+                                          lock->l_lvb_data, size);
+               unlock_res_and_lock(lock);
+               if (rc < 0) {
+                       cleanup_phase = 1;
+                       GOTO(cleanup, rc);
+               }
         }
 
         if (!is_replay) {
@@ -520,7 +684,7 @@ int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
                         int err = lock->l_completion_ast(lock, *flags, NULL);
                         if (!rc)
                                 rc = err;
-                        if (rc && type != LDLM_FLOCK) /* bug 9425, bug 10250 */
+                        if (rc)
                                 cleanup_phase = 1;
                 }
         }
@@ -535,22 +699,29 @@ int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
         EXIT;
 cleanup:
         if (cleanup_phase == 1 && rc)
-                failed_lock_cleanup(ns, lock, lockh, mode);
+                failed_lock_cleanup(ns, lock, mode);
         /* Put lock 2 times, the second reference is held by ldlm_cli_enqueue */
         LDLM_LOCK_PUT(lock);
-        LDLM_LOCK_PUT(lock);
+        LDLM_LOCK_RELEASE(lock);
         return rc;
 }
+EXPORT_SYMBOL(ldlm_cli_enqueue_fini);
 
-/* PAGE_SIZE-512 is to allow TCP/IP and LNET headers to fit into
- * a single page on the send/receive side. XXX: 512 should be changed
- * to more adequate value. */
+/**
+ * Estimate number of lock handles that would fit into request of given
+ * size.  PAGE_SIZE-512 is to allow TCP/IP and LNET headers to fit into
+ * a single page on the send/receive side. XXX: 512 should be changed to
+ * more adequate value.
+ */
 static inline int ldlm_req_handles_avail(int req_size, int off)
 {
         int avail;
 
-        avail = min_t(int, LDLM_MAXREQSIZE, CFS_PAGE_SIZE - 512) - req_size;
-        avail /= sizeof(struct lustre_handle);
+       avail = min_t(int, LDLM_MAXREQSIZE, PAGE_CACHE_SIZE - 512) - req_size;
+        if (likely(avail >= 0))
+                avail /= (int)sizeof(struct lustre_handle);
+        else
+                avail = 0;
         avail += LDLM_LOCKREQ_HANDLES - off;
 
         return avail;
@@ -572,35 +743,41 @@ static inline int ldlm_format_handles_avail(struct obd_import *imp,
         return ldlm_req_handles_avail(size, off);
 }
 
-/* Cancel lru locks and pack them into the enqueue request. Pack there the given
- * @count locks in @cancels. */
+/**
+ * Cancel LRU locks and pack them into the enqueue request. Pack there the given
+ * \a count locks in \a cancels.
+ *
+ * This is to be called by functions preparing their own requests that
+ * might contain lists of locks to cancel in addition to actual operation
+ * that needs to be performed.
+ */
 int ldlm_prep_elc_req(struct obd_export *exp, struct ptlrpc_request *req,
                       int version, int opc, int canceloff,
-                      struct list_head *cancels, int count)
+                      cfs_list_t *cancels, int count)
 {
         struct ldlm_namespace   *ns = exp->exp_obd->obd_namespace;
         struct req_capsule      *pill = &req->rq_pill;
         struct ldlm_request     *dlm = NULL;
-        int flags, avail, to_free, bufcount, pack = 0;
+        int flags, avail, to_free, pack = 0;
         CFS_LIST_HEAD(head);
         int rc;
         ENTRY;
 
         if (cancels == NULL)
                 cancels = &head;
-        if (exp_connect_cancelset(exp)) {
+       if (ns_connect_cancelset(ns)) {
                 /* Estimate the amount of available space in the request. */
-                bufcount = req_capsule_filled_sizes(pill, RCL_CLIENT);
+                req_capsule_filled_sizes(pill, RCL_CLIENT);
                 avail = ldlm_capsule_handles_avail(pill, RCL_CLIENT, canceloff);
 
-                flags = ns_connect_lru_resize(ns) ? 
+                flags = ns_connect_lru_resize(ns) ?
                         LDLM_CANCEL_LRUR : LDLM_CANCEL_AGED;
                 to_free = !ns_connect_lru_resize(ns) &&
                           opc == LDLM_ENQUEUE ? 1 : 0;
 
-                /* Cancel lru locks here _only_ if the server supports 
-                 * EARLY_CANCEL. Otherwise we have to send extra CANCEL
-                 * rpc, what will make us slower. */
+               /* Cancel LRU locks here _only_ if the server supports
+                * EARLY_CANCEL. Otherwise we have to send extra CANCEL
+                * RPC, which will make us slower. */
                 if (avail > count)
                         count += ldlm_cancel_lru_local(ns, cancels, to_free,
                                                        avail - count, 0, flags);
@@ -618,7 +795,7 @@ int ldlm_prep_elc_req(struct obd_export *exp, struct ptlrpc_request *req,
                 RETURN(rc);
         }
 
-        if (exp_connect_cancelset(exp)) {
+       if (ns_connect_cancelset(ns)) {
                 if (canceloff) {
                         dlm = req_capsule_client_get(pill, &RMF_DLM_REQ);
                         LASSERT(dlm);
@@ -630,35 +807,63 @@ int ldlm_prep_elc_req(struct obd_export *exp, struct ptlrpc_request *req,
                 }
                 /* Pack into the request @pack lock handles. */
                 ldlm_cli_cancel_list(cancels, pack, req, 0);
-                /* Prepare and send separate cancel rpc for others. */
+               /* Prepare and send separate cancel RPC for others. */
                 ldlm_cli_cancel_list(cancels, count - pack, NULL, 0);
         } else {
                 ldlm_lock_list_put(cancels, l_bl_ast, count);
         }
         RETURN(0);
 }
+EXPORT_SYMBOL(ldlm_prep_elc_req);
 
 int ldlm_prep_enqueue_req(struct obd_export *exp, struct ptlrpc_request *req,
-                          struct list_head *cancels, int count)
+                          cfs_list_t *cancels, int count)
 {
         return ldlm_prep_elc_req(exp, req, LUSTRE_DLM_VERSION, LDLM_ENQUEUE,
                                  LDLM_ENQUEUE_CANCEL_OFF, cancels, count);
 }
+EXPORT_SYMBOL(ldlm_prep_enqueue_req);
 
-/* If a request has some specific initialisation it is passed in @reqp,
+struct ptlrpc_request *ldlm_enqueue_pack(struct obd_export *exp, int lvb_len)
+{
+       struct ptlrpc_request *req;
+       int rc;
+       ENTRY;
+
+       req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_LDLM_ENQUEUE);
+       if (req == NULL)
+               RETURN(ERR_PTR(-ENOMEM));
+
+       rc = ldlm_prep_enqueue_req(exp, req, NULL, 0);
+       if (rc) {
+               ptlrpc_request_free(req);
+               RETURN(ERR_PTR(rc));
+       }
+
+       req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER, lvb_len);
+       ptlrpc_request_set_replen(req);
+       RETURN(req);
+}
+EXPORT_SYMBOL(ldlm_enqueue_pack);
+
+/**
+ * Client-side lock enqueue.
+ *
+ * If a request has some specific initialisation it is passed in \a reqp,
  * otherwise it is created in ldlm_cli_enqueue.
  *
- * Supports sync and async requests, pass @async flag accordingly. If a
+ * Supports sync and async requests, pass \a async flag accordingly. If a
  * request was created in ldlm_cli_enqueue and it is the async request,
- * pass it to the caller in @reqp. */
+ * pass it to the caller in \a reqp.
+ */
 int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
                      struct ldlm_enqueue_info *einfo,
                      const struct ldlm_res_id *res_id,
-                     ldlm_policy_data_t *policy, int *flags,
-                     void *lvb, __u32 lvb_len, void *lvb_swabber,
-                     struct lustre_handle *lockh, int async)
+                    ldlm_policy_data_t const *policy, __u64 *flags,
+                    void *lvb, __u32 lvb_len, enum lvb_type lvb_type,
+                    struct lustre_handle *lockh, int async)
 {
-        struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
+       struct ldlm_namespace *ns;
         struct ldlm_lock      *lock;
         struct ldlm_request   *body;
         int                    is_replay = *flags & LDLM_FL_REPLAY;
@@ -669,6 +874,8 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
 
         LASSERT(exp != NULL);
 
+       ns = exp->exp_obd->obd_namespace;
+
         /* If we're replaying this lock, just check some invariants.
          * If we're creating a new lock, get everything all setup nice. */
         if (is_replay) {
@@ -677,21 +884,19 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
                 LDLM_DEBUG(lock, "client-side enqueue START");
                 LASSERT(exp == lock->l_conn_export);
         } else {
-                const struct ldlm_callback_suite cbs = {
-                        .lcs_completion = einfo->ei_cb_cp,
-                        .lcs_blocking   = einfo->ei_cb_bl,
-                        .lcs_glimpse    = einfo->ei_cb_gl,
-                        .lcs_weigh      = einfo->ei_cb_wg
-                };
-                lock = ldlm_lock_create(ns, res_id, einfo->ei_type,
-                                        einfo->ei_mode, &cbs, einfo->ei_cbdata,
-                                        lvb_len);
-                if (lock == NULL)
-                        RETURN(-ENOMEM);
+               const struct ldlm_callback_suite cbs = {
+                       .lcs_completion = einfo->ei_cb_cp,
+                       .lcs_blocking   = einfo->ei_cb_bl,
+                       .lcs_glimpse    = einfo->ei_cb_gl
+               };
+               lock = ldlm_lock_create(ns, res_id, einfo->ei_type,
+                                       einfo->ei_mode, &cbs, einfo->ei_cbdata,
+                                       lvb_len, lvb_type);
+               if (lock == NULL)
+                       RETURN(-ENOMEM);
                 /* for the local lock, add the reference */
                 ldlm_lock_addref_internal(lock, einfo->ei_mode);
                 ldlm_lock2handle(lock, lockh);
-                lock->l_lvb_swabber = lvb_swabber;
                 if (policy != NULL) {
                         /* INODEBITS_INTEROP: If the server does not support
                          * inodebits, we will request a plain lock in the
@@ -699,7 +904,8 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
                          * inodebits lock internally with both bits set.
                          */
                         if (einfo->ei_type == LDLM_IBITS &&
-                            !(exp->exp_connect_flags & OBD_CONNECT_IBITS))
+                           !(exp_connect_flags(exp) &
+                             OBD_CONNECT_IBITS))
                                 lock->l_policy_data.l_inodebits.bits =
                                         MDS_INODELOCK_LOOKUP |
                                         MDS_INODELOCK_UPDATE;
@@ -709,9 +915,15 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
 
                 if (einfo->ei_type == LDLM_EXTENT)
                         lock->l_req_extent = policy->l_extent;
-                LDLM_DEBUG(lock, "client-side enqueue START");
+                LDLM_DEBUG(lock, "client-side enqueue START, flags %llx\n",
+                          *flags);
         }
 
+       lock->l_conn_export = exp;
+       lock->l_export = NULL;
+       lock->l_blocking_ast = einfo->ei_cb_bl;
+       lock->l_flags |= (*flags & (LDLM_FL_NO_LRU | LDLM_FL_EXCL));
+
         /* lock not sent to server yet */
 
         if (reqp == NULL || *reqp == NULL) {
@@ -720,8 +932,8 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
                                                 LUSTRE_DLM_VERSION,
                                                 LDLM_ENQUEUE);
                 if (req == NULL) {
-                        failed_lock_cleanup(ns, lock, lockh, einfo->ei_mode);
-                        LDLM_LOCK_PUT(lock);
+                        failed_lock_cleanup(ns, lock, einfo->ei_mode);
+                        LDLM_LOCK_RELEASE(lock);
                         RETURN(-ENOMEM);
                 }
                 req_passed_in = 0;
@@ -737,25 +949,20 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
                          DLM_LOCKREQ_OFF, len, (int)sizeof(*body));
         }
 
-        lock->l_conn_export = exp;
-        lock->l_export = NULL;
-        lock->l_blocking_ast = einfo->ei_cb_bl;
-
         /* Dump lock data into the request buffer */
         body = req_capsule_client_get(&req->rq_pill, &RMF_DLM_REQ);
         ldlm_lock2desc(lock, &body->lock_desc);
-        body->lock_flags = *flags;
+       body->lock_flags = ldlm_flags_to_wire(*flags);
         body->lock_handle[0] = *lockh;
 
         /* Continue as normal. */
         if (!req_passed_in) {
-                if (lvb_len > 0) {
-                        req_capsule_extend(&req->rq_pill,
-                                           &RQF_LDLM_ENQUEUE_LVB);
-                        req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB,
-                                             RCL_SERVER, lvb_len);
-                }
-                ptlrpc_request_set_replen(req);
+               if (lvb_len > 0)
+                       req_capsule_extend(&req->rq_pill,
+                                          &RQF_LDLM_ENQUEUE_LVB);
+               req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER,
+                                    lvb_len);
+               ptlrpc_request_set_replen(req);
         }
 
         /*
@@ -772,15 +979,17 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
         }
 
         LDLM_DEBUG(lock, "sending request");
+
         rc = ptlrpc_queue_wait(req);
+
         err = ldlm_cli_enqueue_fini(exp, req, einfo->ei_type, policy ? 1 : 0,
                                     einfo->ei_mode, flags, lvb, lvb_len,
-                                    lvb_swabber, lockh, rc);
+                                    lockh, rc);
 
         /* If ldlm_cli_enqueue_fini did not find the lock, we need to free
          * one reference that we took */
         if (err == -ENOLCK)
-                LDLM_LOCK_PUT(lock);
+                LDLM_LOCK_RELEASE(lock);
         else
                 rc = err;
 
@@ -792,6 +1001,7 @@ int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
 
         RETURN(rc);
 }
+EXPORT_SYMBOL(ldlm_cli_enqueue);
 
 static int ldlm_cli_convert_local(struct ldlm_lock *lock, int new_mode,
                                   __u32 *flags)
@@ -799,7 +1009,7 @@ static int ldlm_cli_convert_local(struct ldlm_lock *lock, int new_mode,
         struct ldlm_resource *res;
         int rc;
         ENTRY;
-        if (ns_is_client(lock->l_resource->lr_namespace)) {
+        if (ns_is_client(ldlm_lock_to_ns(lock))) {
                 CERROR("Trying to cancel local lock\n");
                 LBUG();
         }
@@ -810,7 +1020,7 @@ static int ldlm_cli_convert_local(struct ldlm_lock *lock, int new_mode,
                 ldlm_reprocess_all(res);
                 rc = 0;
         } else {
-                rc = EDEADLOCK;
+               rc = LUSTRE_EDEADLK;
         }
         LDLM_DEBUG(lock, "client-side local convert handler END");
         LDLM_LOCK_PUT(lock);
@@ -855,7 +1065,7 @@ int ldlm_cli_convert(struct lustre_handle *lockh, int new_mode, __u32 *flags)
         body->lock_handle[0] = lock->l_remote_handle;
 
         body->lock_desc.l_req_mode = new_mode;
-        body->lock_flags = *flags;
+       body->lock_flags = ldlm_flags_to_wire(*flags);
 
 
         ptlrpc_request_set_replen(req);
@@ -882,7 +1092,7 @@ int ldlm_cli_convert(struct lustre_handle *lockh, int new_mode, __u32 *flags)
                                 GOTO(out, rc);
                 }
         } else {
-                rc = EDEADLOCK;
+               rc = LUSTRE_EDEADLK;
         }
         EXIT;
  out:
@@ -890,26 +1100,29 @@ int ldlm_cli_convert(struct lustre_handle *lockh, int new_mode, __u32 *flags)
         ptlrpc_req_finished(req);
         return rc;
 }
+EXPORT_SYMBOL(ldlm_cli_convert);
 
-/* Cancel locks locally.
+/**
+ * Cancel locks locally.
  * Returns:
- * LDLM_FL_LOCAL_ONLY if tere is no need in a CANCEL rpc to the server;
- * LDLM_FL_CANCELING otherwise;
- * LDLM_FL_BL_AST if there is a need in a separate CANCEL rpc. */
-static int ldlm_cli_cancel_local(struct ldlm_lock *lock)
+ * \retval LDLM_FL_LOCAL_ONLY if there is no need for a CANCEL RPC to the server
+ * \retval LDLM_FL_CANCELING otherwise;
+ * \retval LDLM_FL_BL_AST if there is a need for a separate CANCEL RPC.
+ */
+static __u64 ldlm_cli_cancel_local(struct ldlm_lock *lock)
 {
-        int rc = LDLM_FL_LOCAL_ONLY;
+       __u64 rc = LDLM_FL_LOCAL_ONLY;
         ENTRY;
-        
+
         if (lock->l_conn_export) {
-                int local_only;
+                bool local_only;
 
                 LDLM_DEBUG(lock, "client-side cancel");
                 /* Set this flag to prevent others from getting new references*/
                 lock_res_and_lock(lock);
                 lock->l_flags |= LDLM_FL_CBPENDING;
-                local_only = (lock->l_flags &
-                              (LDLM_FL_LOCAL_ONLY|LDLM_FL_CANCEL_ON_BLOCK));
+               local_only = !!(lock->l_flags &
+                               (LDLM_FL_LOCAL_ONLY|LDLM_FL_CANCEL_ON_BLOCK));
                 ldlm_cancel_callback(lock);
                 rc = (lock->l_flags & LDLM_FL_BL_AST) ?
                         LDLM_FL_BL_AST : LDLM_FL_CANCELING;
@@ -922,23 +1135,23 @@ static int ldlm_cli_cancel_local(struct ldlm_lock *lock)
                 }
                 ldlm_lock_cancel(lock);
         } else {
-                if (ns_is_client(lock->l_resource->lr_namespace)) {
+                if (ns_is_client(ldlm_lock_to_ns(lock))) {
                         LDLM_ERROR(lock, "Trying to cancel local lock");
                         LBUG();
                 }
                 LDLM_DEBUG(lock, "server-side local cancel");
                 ldlm_lock_cancel(lock);
                 ldlm_reprocess_all(lock->l_resource);
-                LDLM_DEBUG(lock, "server-side local cancel handler END");
         }
 
         RETURN(rc);
 }
 
-/* Pack @count locks in @head into ldlm_request buffer at the offset @off,
-   of the request @req. */
+/**
+ * Pack \a count locks in \a head into ldlm_request buffer of request \a req.
+ */
 static void ldlm_cancel_pack(struct ptlrpc_request *req,
-                             struct list_head *head, int count)
+                             cfs_list_t *head, int count)
 {
         struct ldlm_request *dlm;
         struct ldlm_lock *lock;
@@ -949,7 +1162,7 @@ static void ldlm_cancel_pack(struct ptlrpc_request *req,
         LASSERT(dlm != NULL);
 
         /* Check the room in the request buffer. */
-        max = req_capsule_get_size(&req->rq_pill, &RMF_DLM_REQ, RCL_CLIENT) - 
+        max = req_capsule_get_size(&req->rq_pill, &RMF_DLM_REQ, RCL_CLIENT) -
                 sizeof(struct ldlm_request);
         max /= sizeof(struct lustre_handle);
         max += LDLM_LOCKREQ_HANDLES;
@@ -958,7 +1171,7 @@ static void ldlm_cancel_pack(struct ptlrpc_request *req,
         /* XXX: it would be better to pack lock handles grouped by resource.
          * so that the server cancel would call filter_lvbo_update() less
          * frequently. */
-        list_for_each_entry(lock, head, l_bl_ast) {
+        cfs_list_for_each_entry(lock, head, l_bl_ast) {
                 if (!count--)
                         break;
                 LASSERT(lock->l_conn_export);
@@ -971,10 +1184,11 @@ static void ldlm_cancel_pack(struct ptlrpc_request *req,
         EXIT;
 }
 
-/* Prepare and send a batched cancel rpc, it will include count lock handles
- * of locks given in @head. */
-int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
-                        int count, int flags)
+/**
+ * Prepare and send a batched cancel RPC. It will include \a count lock
+ * handles of locks given in \a cancels list. */
+int ldlm_cli_cancel_req(struct obd_export *exp, cfs_list_t *cancels,
+                        int count, ldlm_cancel_flags_t flags)
 {
         struct ptlrpc_request *req = NULL;
         struct obd_import *imp;
@@ -985,9 +1199,9 @@ int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
         LASSERT(exp != NULL);
         LASSERT(count > 0);
 
-        OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_PAUSE_CANCEL, obd_fail_val);
+        CFS_FAIL_TIMEOUT(OBD_FAIL_LDLM_PAUSE_CANCEL, cfs_fail_val);
 
-        if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_RACE))
+        if (CFS_FAIL_CHECK(OBD_FAIL_LDLM_CANCEL_RACE))
                 RETURN(count);
 
         free = ldlm_format_handles_avail(class_exp2cliimp(exp),
@@ -996,8 +1210,6 @@ int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
                 count = free;
 
         while (1) {
-                int bufcount;
-
                 imp = class_exp2cliimp(exp);
                 if (imp == NULL || imp->imp_invalid) {
                         CDEBUG(D_DLMTRACE,
@@ -1009,7 +1221,7 @@ int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
                 if (req == NULL)
                         GOTO(out, rc = -ENOMEM);
 
-                bufcount = req_capsule_filled_sizes(&req->rq_pill, RCL_CLIENT);
+                req_capsule_filled_sizes(&req->rq_pill, RCL_CLIENT);
                 req_capsule_set_size(&req->rq_pill, &RMF_DLM_REQ, RCL_CLIENT,
                                      ldlm_request_bufsize(count, LDLM_CANCEL));
 
@@ -1018,8 +1230,6 @@ int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
                         ptlrpc_request_free(req);
                         GOTO(out, rc);
                 }
-                req->rq_no_resend = 1;
-                req->rq_no_delay = 1;
 
                 req->rq_request_portal = LDLM_CANCEL_REQUEST_PORTAL;
                 req->rq_reply_portal = LDLM_CANCEL_REPLY_PORTAL;
@@ -1028,14 +1238,14 @@ int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
                 ldlm_cancel_pack(req, cancels, count);
 
                 ptlrpc_request_set_replen(req);
-                if (flags & LDLM_FL_ASYNC) {
-                        ptlrpcd_add_req(req);
+                if (flags & LCF_ASYNC) {
+                        ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
                         sent = count;
                         GOTO(out, 0);
                 } else {
                         rc = ptlrpc_queue_wait(req);
                 }
-                if (rc == ESTALE) {
+               if (rc == LUSTRE_ESTALE) {
                         CDEBUG(D_DLMTRACE, "client/server (nid %s) "
                                "out of sync -- not fatal\n",
                                libcfs_nid2str(req->rq_import->
@@ -1046,9 +1256,11 @@ int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
                         ptlrpc_req_finished(req);
                         continue;
                 } else if (rc != ELDLM_OK) {
-                        CERROR("Got rc %d from cancel RPC: canceling "
-                               "anyway\n", rc);
-                        break;
+                       /* -ESHUTDOWN is common on umount */
+                       CDEBUG_LIMIT(rc == -ESHUTDOWN ? D_DLMTRACE : D_ERROR,
+                                    "Got rc %d from cancel RPC: "
+                                    "canceling anyway\n", rc);
+                       break;
                 }
                 sent = count;
                 break;
@@ -1059,6 +1271,7 @@ int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *cancels,
 out:
         return sent ? sent : rc;
 }
+EXPORT_SYMBOL(ldlm_cli_cancel_req);
 
 static inline struct ldlm_pool *ldlm_imp2pl(struct obd_import *imp)
 {
@@ -1067,36 +1280,33 @@ static inline struct ldlm_pool *ldlm_imp2pl(struct obd_import *imp)
 }
 
 /**
- * Update client's obd pool related fields with new SLV and Limit from \a req.
+ * Update client's OBD pool related fields with new SLV and Limit from \a req.
  */
 int ldlm_cli_update_pool(struct ptlrpc_request *req)
 {
         struct obd_device *obd;
-        __u64 old_slv, new_slv;
+        __u64 new_slv;
         __u32 new_limit;
         ENTRY;
-    
-        if (unlikely(!req->rq_import || !req->rq_import->imp_obd || 
+        if (unlikely(!req->rq_import || !req->rq_import->imp_obd ||
                      !imp_connect_lru_resize(req->rq_import)))
         {
-                /* 
-                 * Do nothing for corner cases. 
+                /*
+                 * Do nothing for corner cases.
                  */
                 RETURN(0);
         }
 
-        /* 
-         * In some cases RPC may contain slv and limit zeroed out. This is 
-         * the case when server does not support lru resize feature. This is
-         * also possible in some recovery cases when server side reqs have no
-         * ref to obd export and thus access to server side namespace is no 
-         * possible. 
-         */
-        if (lustre_msg_get_slv(req->rq_repmsg) == 0 || 
+       /* In some cases RPC may contain SLV and limit zeroed out. This
+        * is the case when server does not support LRU resize feature.
+        * This is also possible in some recovery cases when server-side
+        * reqs have no reference to the OBD export and thus access to
+        * server-side namespace is not possible. */
+        if (lustre_msg_get_slv(req->rq_repmsg) == 0 ||
             lustre_msg_get_limit(req->rq_repmsg) == 0) {
                 DEBUG_REQ(D_HA, req, "Zero SLV or Limit found "
-                          "(SLV: "LPU64", Limit: %u)", 
-                          lustre_msg_get_slv(req->rq_repmsg), 
+                          "(SLV: "LPU64", Limit: %u)",
+                          lustre_msg_get_slv(req->rq_repmsg),
                           lustre_msg_get_limit(req->rq_repmsg));
                 RETURN(0);
         }
@@ -1105,49 +1315,53 @@ int ldlm_cli_update_pool(struct ptlrpc_request *req)
         new_slv = lustre_msg_get_slv(req->rq_repmsg);
         obd = req->rq_import->imp_obd;
 
-        /* 
-         * Set new SLV and Limit to obd fields to make accessible for pool 
-         * thread. We do not access obd_namespace and pool directly here
-         * as there is no reliable way to make sure that they are still
-         * alive in cleanup time. Evil races are possible which may cause
-         * oops in that time. 
-         */
-        write_lock(&obd->obd_pool_lock);
-        old_slv = obd->obd_pool_slv;
+       /* Set new SLV and limit in OBD fields to make them accessible
+        * to the pool thread. We do not access obd_namespace and pool
+        * directly here as there is no reliable way to make sure that
+        * they are still alive at cleanup time. Evil races are possible
+        * which may cause Oops at that time. */
+       write_lock(&obd->obd_pool_lock);
         obd->obd_pool_slv = new_slv;
         obd->obd_pool_limit = new_limit;
-        write_unlock(&obd->obd_pool_lock);
+       write_unlock(&obd->obd_pool_lock);
 
         RETURN(0);
 }
 EXPORT_SYMBOL(ldlm_cli_update_pool);
 
-int ldlm_cli_cancel(struct lustre_handle *lockh)
+/**
+ * Client side lock cancel.
+ *
+ * Lock must not have any readers or writers by this time.
+ */
+int ldlm_cli_cancel(struct lustre_handle *lockh,
+                   ldlm_cancel_flags_t cancel_flags)
 {
         struct obd_export *exp;
-        int avail, flags, count = 1, rc = 0;
+       int avail, flags, count = 1;
+       __u64 rc = 0;
         struct ldlm_namespace *ns;
         struct ldlm_lock *lock;
         CFS_LIST_HEAD(cancels);
         ENTRY;
 
         /* concurrent cancels on the same handle can happen */
-        lock = __ldlm_handle2lock(lockh, LDLM_FL_CANCELING);
+        lock = ldlm_handle2lock_long(lockh, LDLM_FL_CANCELING);
         if (lock == NULL) {
                 LDLM_DEBUG_NOLOCK("lock is already being destroyed\n");
                 RETURN(0);
         }
 
         rc = ldlm_cli_cancel_local(lock);
-        if (rc < 0 || rc == LDLM_FL_LOCAL_ONLY) {
-                LDLM_LOCK_PUT(lock);
-                RETURN(rc < 0 ? rc : 0);
-        }
-        /* Even if the lock is marked as LDLM_FL_BL_AST, this is a LDLM_CANCEL
-         * rpc which goes to canceld portal, so we can cancel other lru locks
-         * here and send them all as one LDLM_CANCEL rpc. */
-        LASSERT(list_empty(&lock->l_bl_ast));
-        list_add(&lock->l_bl_ast, &cancels);
+       if (rc == LDLM_FL_LOCAL_ONLY || cancel_flags & LCF_LOCAL) {
+               LDLM_LOCK_RELEASE(lock);
+               RETURN(0);
+       }
+       /* Even if the lock is marked as LDLM_FL_BL_AST, this is a LDLM_CANCEL
+        * RPC which goes to canceld portal, so we can cancel other LRU locks
+        * here and send them all as one LDLM_CANCEL RPC. */
+        LASSERT(cfs_list_empty(&lock->l_bl_ast));
+        cfs_list_add(&lock->l_bl_ast, &cancels);
 
         exp = lock->l_conn_export;
         if (exp_connect_cancelset(exp)) {
@@ -1156,49 +1370,57 @@ int ldlm_cli_cancel(struct lustre_handle *lockh)
                                                   RCL_CLIENT, 0);
                 LASSERT(avail > 0);
 
-                ns = lock->l_resource->lr_namespace;
+                ns = ldlm_lock_to_ns(lock);
                 flags = ns_connect_lru_resize(ns) ?
                         LDLM_CANCEL_LRUR : LDLM_CANCEL_AGED;
                 count += ldlm_cancel_lru_local(ns, &cancels, 0, avail - 1,
-                                               LDLM_FL_BL_AST, flags);
+                                               LCF_BL_AST, flags);
         }
-        ldlm_cli_cancel_list(&cancels, count, NULL, 0);
+       ldlm_cli_cancel_list(&cancels, count, NULL, cancel_flags);
         RETURN(0);
 }
+EXPORT_SYMBOL(ldlm_cli_cancel);
 
-/* XXX until we will have compound requests and can cut cancels from generic rpc
- * we need send cancels with LDLM_FL_BL_AST flag as separate rpc */
-static int ldlm_cancel_list(struct list_head *cancels, int count, int flags)
+/**
+ * Locally cancel up to \a count locks in list \a cancels.
+ * Return the number of cancelled locks.
+ */
+int ldlm_cli_cancel_list_local(cfs_list_t *cancels, int count,
+                               ldlm_cancel_flags_t flags)
 {
         CFS_LIST_HEAD(head);
         struct ldlm_lock *lock, *next;
-        int left = 0, bl_ast = 0, rc;
+       int left = 0, bl_ast = 0;
+       __u64 rc;
 
         left = count;
-        list_for_each_entry_safe(lock, next, cancels, l_bl_ast) {
+        cfs_list_for_each_entry_safe(lock, next, cancels, l_bl_ast) {
                 if (left-- == 0)
                         break;
 
-                if (flags & LDLM_FL_LOCAL_ONLY) {
+                if (flags & LCF_LOCAL) {
                         rc = LDLM_FL_LOCAL_ONLY;
                         ldlm_lock_cancel(lock);
                 } else {
                         rc = ldlm_cli_cancel_local(lock);
                 }
-                if (!(flags & LDLM_FL_BL_AST) && (rc == LDLM_FL_BL_AST)) {
-                        LDLM_DEBUG(lock, "Cancel lock separately");
-                        list_del_init(&lock->l_bl_ast);
-                        list_add(&lock->l_bl_ast, &head);
-                        bl_ast ++;
+               /* Until we have compound requests and can send LDLM_CANCEL
+                * requests batched with generic RPCs, we need to send cancels
+                * with the LDLM_FL_BL_AST flag in a separate RPC from
+                * the one being generated now. */
+               if (!(flags & LCF_BL_AST) && (rc == LDLM_FL_BL_AST)) {
+                       LDLM_DEBUG(lock, "Cancel lock separately");
+                       cfs_list_del_init(&lock->l_bl_ast);
+                       cfs_list_add(&lock->l_bl_ast, &head);
+                       bl_ast++;
                         continue;
                 }
                 if (rc == LDLM_FL_LOCAL_ONLY) {
                         /* CANCEL RPC should not be sent to server. */
-                        list_del_init(&lock->l_bl_ast);
-                        LDLM_LOCK_PUT(lock);
+                        cfs_list_del_init(&lock->l_bl_ast);
+                        LDLM_LOCK_RELEASE(lock);
                         count--;
                 }
-
         }
         if (bl_ast > 0) {
                 count -= bl_ast;
@@ -1207,84 +1429,51 @@ static int ldlm_cancel_list(struct list_head *cancels, int count, int flags)
 
         RETURN(count);
 }
+EXPORT_SYMBOL(ldlm_cli_cancel_list_local);
 
-/** 
- * Callback function for shrink policy. Makes decision whether to keep
- * \a lock in LRU for current \a LRU size \a unused, added in current scan
- * \a added and number of locks to be preferably canceled \a count.
- *
- * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning
- *
- * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU
+/**
+ * Cancel as many locks as possible w/o sending any RPCs (e.g. to write back
+ * dirty data, to close a file, ...) or waiting for any RPCs in-flight (e.g.
+ * readahead requests, ...)
  */
-static ldlm_policy_res_t ldlm_cancel_shrink_policy(struct ldlm_namespace *ns,
-                                                   struct ldlm_lock *lock,
-                                                   int unused, int added, 
-                                                   int count)
+static ldlm_policy_res_t ldlm_cancel_no_wait_policy(struct ldlm_namespace *ns,
+                                                    struct ldlm_lock *lock,
+                                                    int unused, int added,
+                                                    int count)
 {
-        int lock_cost;
-        __u64 page_nr;
-
-        /* 
-         * Stop lru processing when we reached passed @count or checked all 
-         * locks in lru. 
-         */
-        if (count && added >= count)
-                return LDLM_POLICY_KEEP_LOCK;
-
-        if (lock->l_resource->lr_type == LDLM_EXTENT) {
-                struct ldlm_extent *l_extent;
+        ldlm_policy_res_t result = LDLM_POLICY_CANCEL_LOCK;
+        ldlm_cancel_for_recovery cb = ns->ns_cancel_for_recovery;
+        lock_res_and_lock(lock);
 
-                /* 
-                 * For all extent locks cost is 1 + number of pages in
-                 * their extent. 
-                 */
-                l_extent = &lock->l_policy_data.l_extent;
-                page_nr = (l_extent->end - l_extent->start);
-                do_div(page_nr, CFS_PAGE_SIZE);
-
-#ifdef __KERNEL__
-                /* 
-                 * XXX: In fact this is evil hack, we can't access inode
-                 * here. For doing it right we need somehow to have number
-                 * of covered by lock. This should be fixed later when 10718 
-                 * is landed. 
-                 */
-                if (lock->l_ast_data != NULL) {
-                        struct inode *inode = lock->l_ast_data;
-                        if (page_nr > inode->i_mapping->nrpages)
-                                page_nr = inode->i_mapping->nrpages;
-                }
-#endif
-                lock_cost = 1 + page_nr;
-        } else {
-                /* 
-                 * For all locks which are not extent ones cost is 1 
-                 */
-                lock_cost = 1;
+        /* don't check added & count since we want to process all locks
+         * from unused list */
+        switch (lock->l_resource->lr_type) {
+                case LDLM_EXTENT:
+                case LDLM_IBITS:
+                        if (cb && cb(lock))
+                                break;
+                default:
+                        result = LDLM_POLICY_SKIP_LOCK;
+                        lock->l_flags |= LDLM_FL_SKIPPED;
+                        break;
         }
 
-        /* 
-         * Keep all expensive locks in lru for the memory pressure time
-         * cancel policy. They anyways may be canceled by lru resize
-         * pplicy if they have not small enough CLV. 
-         */
-        return lock_cost > ns->ns_shrink_thumb ? 
-                LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK;
+        unlock_res_and_lock(lock);
+        RETURN(result);
 }
 
 /**
- * Callback function for lru-resize policy. Makes decision whether to keep
- * \a lock in LRU for current \a LRU size \a unused, added in current scan
- * \a added and number of locks to be preferably canceled \a count.
+ * Callback function for LRU-resize policy. Decides whether to keep
+ * \a lock in LRU for current \a LRU size \a unused, added in current
+ * scan \a added and number of locks to be preferably canceled \a count.
  *
  * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning
  *
  * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU
  */
 static ldlm_policy_res_t ldlm_cancel_lrur_policy(struct ldlm_namespace *ns,
-                                                 struct ldlm_lock *lock, 
-                                                 int unused, int added, 
+                                                 struct ldlm_lock *lock,
+                                                 int unused, int added,
                                                  int count)
 {
         cfs_time_t cur = cfs_time_current();
@@ -1292,111 +1481,102 @@ static ldlm_policy_res_t ldlm_cancel_lrur_policy(struct ldlm_namespace *ns,
         __u64 slv, lvf, lv;
         cfs_time_t la;
 
-        /* 
-         * Stop lru processing when we reached passed @count or checked all 
-         * locks in lru.
-         */
+       /* Stop LRU processing when we reach past @count or have checked all
+        * locks in LRU. */
         if (count && added >= count)
                 return LDLM_POLICY_KEEP_LOCK;
 
         slv = ldlm_pool_get_slv(pl);
         lvf = ldlm_pool_get_lvf(pl);
-        la = cfs_duration_sec(cfs_time_sub(cur, 
+        la = cfs_duration_sec(cfs_time_sub(cur,
                               lock->l_last_used));
+       lv = lvf * la * unused;
 
-        /* 
-         * Stop when slv is not yet come from server or lv is smaller than 
-         * it is.
-         */
-        lv = lvf * la * unused;
-        
-        /* 
-         * Inform pool about current CLV to see it via proc. 
-         */
-        ldlm_pool_set_clv(pl, lv);
-        return (slv == 1 || lv < slv) ? 
-                LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK;
+       /* Inform pool about current CLV to see it via proc. */
+       ldlm_pool_set_clv(pl, lv);
+
+       /* Stop when SLV is not yet come from server or lv is smaller than
+        * it is. */
+       return (slv == 0 || lv < slv) ?
+               LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK;
 }
 
 /**
  * Callback function for proc used policy. Makes decision whether to keep
- * \a lock in LRU for current \a LRU size \a unused, added in current scan
- * \a added and number of locks to be preferably canceled \a count.
+ * \a lock in LRU for current \a LRU size \a unused, added in current scan \a
+ * added and number of locks to be preferably canceled \a count.
  *
  * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning
  *
  * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU
  */
 static ldlm_policy_res_t ldlm_cancel_passed_policy(struct ldlm_namespace *ns,
-                                                   struct ldlm_lock *lock, 
+                                                   struct ldlm_lock *lock,
                                                    int unused, int added,
                                                    int count)
 {
-        /* 
-         * Stop lru processing when we reached passed @count or checked all 
-         * locks in lru. 
-         */
-        return (added >= count) ? 
-                LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK;
+       /* Stop LRU processing when we reach past @count or have checked all
+        * locks in LRU. */
+       return (added >= count) ?
+               LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK;
 }
 
 /**
- * Callback function for aged policy. Makes decision whether to keep
- * \a lock in LRU for current \a LRU size \a unused, added in current scan
- * \a added and number of locks to be preferably canceled \a count.
+ * Callback function for aged policy. Makes decision whether to keep \a lock in
+ * LRU for current LRU size \a unused, added in current scan \a added and
+ * number of locks to be preferably canceled \a count.
  *
  * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning
  *
  * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU
  */
 static ldlm_policy_res_t ldlm_cancel_aged_policy(struct ldlm_namespace *ns,
-                                                 struct ldlm_lock *lock, 
-                                                 int unused, int added,
-                                                 int count)
+                                                struct ldlm_lock *lock,
+                                                int unused, int added,
+                                                int count)
 {
-        /* 
-         * Stop lru processing if young lock is found and we reached passed 
-         * @count. 
-         */
-        return ((added >= count) && 
+       /* Stop LRU processing if young lock is found and we reach past count */
+        return ((added >= count) &&
                 cfs_time_before(cfs_time_current(),
                                 cfs_time_add(lock->l_last_used,
-                                             ns->ns_max_age))) ? 
+                                             ns->ns_max_age))) ?
                 LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK;
 }
 
 /**
- * Callback function for default policy. Makes decision whether to keep
- * \a lock in LRU for current \a LRU size \a unused, added in current scan
- * \a added and number of locks to be preferably canceled \a count.
+ * Callback function for default policy. Makes decision whether to keep \a lock
+ * in LRU for current LRU size \a unused, added in current scan \a added and
+ * number of locks to be preferably canceled \a count.
  *
  * \retval LDLM_POLICY_KEEP_LOCK keep lock in LRU in stop scanning
  *
  * \retval LDLM_POLICY_CANCEL_LOCK cancel lock from LRU
  */
 static ldlm_policy_res_t ldlm_cancel_default_policy(struct ldlm_namespace *ns,
-                                                    struct ldlm_lock *lock, 
-                                                    int unused, int added,
-                                                    int count)
+                                                   struct ldlm_lock *lock,
+                                                   int unused, int added,
+                                                   int count)
 {
-        /* 
-         * Stop lru processing when we reached passed @count or checked all 
-         * locks in lru. 
-         */
-        return (added >= count) ? 
+       /* Stop LRU processing when we reach past count or have checked all
+        * locks in LRU. */
+        return (added >= count) ?
                 LDLM_POLICY_KEEP_LOCK : LDLM_POLICY_CANCEL_LOCK;
 }
 
-typedef ldlm_policy_res_t (*ldlm_cancel_lru_policy_t)(struct ldlm_namespace *, 
-                                                      struct ldlm_lock *, int, 
+typedef ldlm_policy_res_t (*ldlm_cancel_lru_policy_t)(struct ldlm_namespace *,
+                                                      struct ldlm_lock *, int,
                                                       int, int);
 
 static ldlm_cancel_lru_policy_t
 ldlm_cancel_lru_policy(struct ldlm_namespace *ns, int flags)
 {
+        if (flags & LDLM_CANCEL_NO_WAIT)
+                return ldlm_cancel_no_wait_policy;
+
         if (ns_connect_lru_resize(ns)) {
                 if (flags & LDLM_CANCEL_SHRINK)
-                        return ldlm_cancel_shrink_policy;
+                        /* We kill passed number of old locks. */
+                        return ldlm_cancel_passed_policy;
                 else if (flags & LDLM_CANCEL_LRUR)
                         return ldlm_cancel_lrur_policy;
                 else if (flags & LDLM_CANCEL_PASSED)
@@ -1405,64 +1585,84 @@ ldlm_cancel_lru_policy(struct ldlm_namespace *ns, int flags)
                 if (flags & LDLM_CANCEL_AGED)
                         return ldlm_cancel_aged_policy;
         }
-        
+
         return ldlm_cancel_default_policy;
 }
-/* - Free space in lru for @count new locks,
+
+/**
+ * - Free space in LRU for \a count new locks,
  *   redundant unused locks are canceled locally;
  * - also cancel locally unused aged locks;
- * - do not cancel more than @max locks;
- * - GET the found locks and add them into the @cancels list.
+ * - do not cancel more than \a max locks;
+ * - GET the found locks and add them into the \a cancels list.
  *
  * A client lock can be added to the l_bl_ast list only when it is
- * marked LDLM_FL_CANCELING. Otherwise, somebody is already doing CANCEL.
- * There are the following use cases: ldlm_cancel_resource_local(),
- * ldlm_cancel_lru_local() and ldlm_cli_cancel(), which check&set this
- * flag properly. As any attempt to cancel a lock rely on this flag,
- * l_bl_ast list is accessed later without any special locking.
+ * marked LDLM_FL_CANCELING. Otherwise, somebody is already doing
+ * CANCEL.  There are the following use cases:
+ * ldlm_cancel_resource_local(), ldlm_cancel_lru_local() and
+ * ldlm_cli_cancel(), which check and set this flag properly. As any
+ * attempt to cancel a lock rely on this flag, l_bl_ast list is accessed
+ * later without any special locking.
  *
- * Calling policies for enabled lru resize:
+ * Calling policies for enabled LRU resize:
  * ----------------------------------------
- * flags & LDLM_CANCEL_LRUR - use lru resize policy (SLV from server) to
- *                            cancel not more than @count locks;
+ * flags & LDLM_CANCEL_LRUR - use LRU resize policy (SLV from server) to
+ *                            cancel not more than \a count locks;
  *
- * flags & LDLM_CANCEL_PASSED - cancel @count number of old locks (located at
- *                              the beginning of lru list);
+ * flags & LDLM_CANCEL_PASSED - cancel \a count number of old locks (located at
+ *                              the beginning of LRU list);
  *
- * flags & LDLM_CANCEL_SHRINK - cancel not more than @count locks according to
+ * flags & LDLM_CANCEL_SHRINK - cancel not more than \a count locks according to
  *                              memory pressre policy function;
  *
- * flags & LDLM_CANCEL_AGED -   cancel alocks according to "aged policy".
+ * flags & LDLM_CANCEL_AGED - cancel \a count locks according to "aged policy".
+ *
+ * flags & LDLM_CANCEL_NO_WAIT - cancel as many unused locks as possible
+ *                               (typically before replaying locks) w/o
+ *                               sending any RPCs or waiting for any
+ *                               outstanding RPC to complete.
  */
-int ldlm_cancel_lru_local(struct ldlm_namespace *ns, struct list_head *cancels,
-                          int count, int max, int cancel_flags, int flags)
+static int ldlm_prepare_lru_list(struct ldlm_namespace *ns, cfs_list_t *cancels,
+                                 int count, int max, int flags)
 {
-        ldlm_cancel_lru_policy_t pf;
-        struct ldlm_lock *lock, *next;
-        int added = 0, unused;
-        ENTRY;
+       ldlm_cancel_lru_policy_t pf;
+       struct ldlm_lock *lock, *next;
+       int added = 0, unused, remained;
+       ENTRY;
 
-        spin_lock(&ns->ns_unused_lock);
+       spin_lock(&ns->ns_lock);
         unused = ns->ns_nr_unused;
+        remained = unused;
 
         if (!ns_connect_lru_resize(ns))
                 count += unused - ns->ns_max_unused;
 
         pf = ldlm_cancel_lru_policy(ns, flags);
         LASSERT(pf != NULL);
-        
-        while (!list_empty(&ns->ns_unused_list)) {
+
+        while (!cfs_list_empty(&ns->ns_unused_list)) {
+                ldlm_policy_res_t result;
+
+                /* all unused locks */
+                if (remained-- <= 0)
+                        break;
+
                 /* For any flags, stop scanning if @max is reached. */
                 if (max && added >= max)
                         break;
 
-                list_for_each_entry_safe(lock, next, &ns->ns_unused_list, l_lru){
+                cfs_list_for_each_entry_safe(lock, next, &ns->ns_unused_list,
+                                            l_lru) {
                         /* No locks which got blocking requests. */
                         LASSERT(!(lock->l_flags & LDLM_FL_BL_AST));
 
-                        /* Somebody is already doing CANCEL. No need in this
-                         * lock in lru, do not traverse it again. */
+                        if (flags & LDLM_CANCEL_NO_WAIT &&
+                            lock->l_flags & LDLM_FL_SKIPPED)
+                                /* already processed */
+                                continue;
+
+                       /* Somebody is already doing CANCEL. No need for this
+                        * lock in LRU, do not traverse it again. */
                         if (!(lock->l_flags & LDLM_FL_CANCELING))
                                 break;
 
@@ -1471,45 +1671,60 @@ int ldlm_cancel_lru_local(struct ldlm_namespace *ns, struct list_head *cancels,
                 if (&lock->l_lru == &ns->ns_unused_list)
                         break;
 
-                /* Pass the lock through the policy filter and see if it
-                 * should stay in lru.
-                 *
-                 * Even for shrinker policy we stop scanning if
-                 * we find a lock that should stay in the cache.
-                 * We should take into account lock age anyway
-                 * as new lock even if it is small of weight is
-                 * valuable resource. 
-                 *
-                 * That is, for shrinker policy we drop only
-                 * old locks, but additionally chose them by
-                 * their weight. Big extent locks will stay in 
-                 * the cache. */
-                if (pf(ns, lock, unused, added, count) == LDLM_POLICY_KEEP_LOCK)
-                        break;
-
-                LDLM_LOCK_GET(lock); /* dropped by bl thread */
-                spin_unlock(&ns->ns_unused_lock);
+                LDLM_LOCK_GET(lock);
+               spin_unlock(&ns->ns_lock);
+                lu_ref_add(&lock->l_reference, __FUNCTION__, cfs_current());
+
+               /* Pass the lock through the policy filter and see if it
+                * should stay in LRU.
+                *
+                * Even for shrinker policy we stop scanning if
+                * we find a lock that should stay in the cache.
+                * We should take into account lock age anyway
+                * as a new lock is a valuable resource even if
+                * it has a low weight.
+                *
+                * That is, for shrinker policy we drop only
+                * old locks, but additionally choose them by
+                * their weight. Big extent locks will stay in
+                * the cache. */
+                result = pf(ns, lock, unused, added, count);
+                if (result == LDLM_POLICY_KEEP_LOCK) {
+                        lu_ref_del(&lock->l_reference,
+                                   __FUNCTION__, cfs_current());
+                        LDLM_LOCK_RELEASE(lock);
+                       spin_lock(&ns->ns_lock);
+                       break;
+               }
+               if (result == LDLM_POLICY_SKIP_LOCK) {
+                       lu_ref_del(&lock->l_reference,
+                                  __func__, cfs_current());
+                       LDLM_LOCK_RELEASE(lock);
+                       spin_lock(&ns->ns_lock);
+                        continue;
+                }
 
                 lock_res_and_lock(lock);
                 /* Check flags again under the lock. */
                 if ((lock->l_flags & LDLM_FL_CANCELING) ||
                     (ldlm_lock_remove_from_lru(lock) == 0)) {
-                        /* other thread is removing lock from lru or
-                         * somebody is already doing CANCEL or
-                         * there is a blocking request which will send
-                         * cancel by itseft or the lock is matched
-                         * is already not unused. */
+                       /* Another thread is removing lock from LRU, or
+                        * somebody is already doing CANCEL, or there
+                        * is a blocking request which will send cancel
+                        * by itself, or the lock is no longer unused. */
                         unlock_res_and_lock(lock);
-                        LDLM_LOCK_PUT(lock);
-                        spin_lock(&ns->ns_unused_lock);
+                        lu_ref_del(&lock->l_reference,
+                                   __FUNCTION__, cfs_current());
+                        LDLM_LOCK_RELEASE(lock);
+                       spin_lock(&ns->ns_lock);
                         continue;
                 }
                 LASSERT(!lock->l_readers && !lock->l_writers);
 
                 /* If we have chosen to cancel this lock voluntarily, we
                  * better send cancel notification to server, so that it
-                 * frees appropriate state. This might lead to a race 
-                 * where while we are doing cancel here, server is also 
+                 * frees appropriate state. This might lead to a race
+                 * where while we are doing cancel here, server is also
                  * silently cancelling this lock. */
                 lock->l_flags &= ~LDLM_FL_CANCEL_ON_BLOCK;
 
@@ -1523,102 +1738,79 @@ int ldlm_cancel_lru_local(struct ldlm_namespace *ns, struct list_head *cancels,
 
                 /* We can't re-add to l_lru as it confuses the
                  * refcounting in ldlm_lock_remove_from_lru() if an AST
-                 * arrives after we drop ns_lock below. We use l_bl_ast
+                 * arrives after we drop lr_lock below. We use l_bl_ast
                  * and can't use l_pending_chain as it is used both on
                  * server and client nevertheless bug 5666 says it is
                  * used only on server */
-                LASSERT(list_empty(&lock->l_bl_ast));
-                list_add(&lock->l_bl_ast, cancels);
+                LASSERT(cfs_list_empty(&lock->l_bl_ast));
+                cfs_list_add(&lock->l_bl_ast, cancels);
                 unlock_res_and_lock(lock);
-                spin_lock(&ns->ns_unused_lock);
-                added++;
-                unused--;
-        }
-        spin_unlock(&ns->ns_unused_lock);
-        RETURN(ldlm_cancel_list(cancels, added, cancel_flags));
+                lu_ref_del(&lock->l_reference, __FUNCTION__, cfs_current());
+               spin_lock(&ns->ns_lock);
+               added++;
+               unused--;
+       }
+       spin_unlock(&ns->ns_lock);
+       RETURN(added);
 }
 
-/* Returns number of locks which could be canceled next time when 
- * ldlm_cancel_lru() is called. Used from locks pool shrinker. */
-int ldlm_cancel_lru_estimate(struct ldlm_namespace *ns,
-                             int count, int max, int flags)
+int ldlm_cancel_lru_local(struct ldlm_namespace *ns, cfs_list_t *cancels,
+                          int count, int max, ldlm_cancel_flags_t cancel_flags,
+                          int flags)
 {
-        ldlm_cancel_lru_policy_t pf;
-        struct ldlm_lock *lock;
-        int added = 0, unused;
-        ENTRY;
-
-        pf = ldlm_cancel_lru_policy(ns, flags);
-        LASSERT(pf != NULL);
-        spin_lock(&ns->ns_unused_lock);
-        unused = ns->ns_nr_unused;
-
-        list_for_each_entry(lock, &ns->ns_unused_list, l_lru) {
-                /* For any flags, stop scanning if @max is reached. */
-                if (max && added >= max)
-                        break;
-
-                /* Somebody is already doing CANCEL or there is a
-                 * blocking request will send cancel. Let's not count 
-                 * this lock. */
-                if ((lock->l_flags & LDLM_FL_CANCELING) ||
-                    (lock->l_flags & LDLM_FL_BL_AST)) 
-                        continue;
-
-                /* Pass the lock through the policy filter and see if it
-                 * should stay in lru. */
-                if (pf(ns, lock, unused, added, count) == LDLM_POLICY_KEEP_LOCK)
-                        break;
-
-                added++;
-                unused--;
-        }
-        spin_unlock(&ns->ns_unused_lock);
-        RETURN(added);
+        int added;
+        added = ldlm_prepare_lru_list(ns, cancels, count, max, flags);
+        if (added <= 0)
+                return added;
+        return ldlm_cli_cancel_list_local(cancels, added, cancel_flags);
 }
 
-/* when called with LDLM_ASYNC the blocking callback will be handled
+/**
+ * Cancel at least \a nr locks from given namespace LRU.
+ *
+ * When called with LCF_ASYNC the blocking callback will be handled
  * in a thread and this function will return after the thread has been
- * asked to call the callback.  when called with LDLM_SYNC the blocking
- * callback will be performed in this function. */
-int ldlm_cancel_lru(struct ldlm_namespace *ns, int nr, ldlm_sync_t sync, 
-                    int flags)
+ * asked to call the callback.  When called with LCF_ASYNC the blocking
+ * callback will be performed in this function.
+ */
+int ldlm_cancel_lru(struct ldlm_namespace *ns, int nr,
+                   ldlm_cancel_flags_t cancel_flags,
+                   int flags)
 {
-        CFS_LIST_HEAD(cancels);
-        int count, rc;
-        ENTRY;
+       CFS_LIST_HEAD(cancels);
+       int count, rc;
+       ENTRY;
 
 #ifndef __KERNEL__
-        sync = LDLM_SYNC; /* force to be sync in user space */
+       cancel_flags &= ~LCF_ASYNC; /* force to be sync in user space */
 #endif
-        count = ldlm_cancel_lru_local(ns, &cancels, nr, 0, 0, flags);
-        if (sync == LDLM_ASYNC) {
-                rc = ldlm_bl_to_thread_list(ns, NULL, &cancels, count);
-                if (rc == 0)
-                        RETURN(count);
-        }
-
-        /* If an error occured in ASYNC mode, or
-         * this is SYNC mode, cancel the list. */
-        ldlm_cli_cancel_list(&cancels, count, NULL, 0);
-        RETURN(count);
+       /* Just prepare the list of locks, do not actually cancel them yet.
+        * Locks are cancelled later in a separate thread. */
+       count = ldlm_prepare_lru_list(ns, &cancels, nr, 0, flags);
+       rc = ldlm_bl_to_thread_list(ns, NULL, &cancels, count, cancel_flags);
+       if (rc == 0)
+               RETURN(count);
+
+       RETURN(0);
 }
 
-/* Find and cancel locally unused locks found on resource, matched to the
- * given policy, mode. GET the found locks and add them into the @cancels
- * list. */
+/**
+ * Find and cancel locally unused locks found on resource, matched to the
+ * given policy, mode. GET the found locks and add them into the \a cancels
+ * list.
+ */
 int ldlm_cancel_resource_local(struct ldlm_resource *res,
-                               struct list_head *cancels,
+                               cfs_list_t *cancels,
                                ldlm_policy_data_t *policy,
                                ldlm_mode_t mode, int lock_flags,
-                               int cancel_flags, void *opaque)
+                               ldlm_cancel_flags_t cancel_flags, void *opaque)
 {
         struct ldlm_lock *lock;
         int count = 0;
         ENTRY;
 
         lock_res(res);
-        list_for_each_entry(lock, &res->lr_granted, l_res_link) {
+        cfs_list_for_each_entry(lock, &res->lr_granted, l_res_link) {
                 if (opaque != NULL && lock->l_ast_data != opaque) {
                         LDLM_ERROR(lock, "data %p doesn't match opaque %p",
                                    lock->l_ast_data, opaque);
@@ -1626,17 +1818,12 @@ int ldlm_cancel_resource_local(struct ldlm_resource *res,
                         continue;
                 }
 
-                if (lock->l_readers || lock->l_writers) {
-                        if (cancel_flags & LDLM_FL_WARN) {
-                                LDLM_ERROR(lock, "lock in use");
-                                //LBUG();
-                        }
+                if (lock->l_readers || lock->l_writers)
                         continue;
-                }
 
-                /* If somebody is already doing CANCEL, or blocking ast came,
-                 * skip this lock. */
-                if (lock->l_flags & LDLM_FL_BL_AST || 
+               /* If somebody is already doing CANCEL, or blocking AST came,
+                * skip this lock. */
+                if (lock->l_flags & LDLM_FL_BL_AST ||
                     lock->l_flags & LDLM_FL_CANCELING)
                         continue;
 
@@ -1654,40 +1841,46 @@ int ldlm_cancel_resource_local(struct ldlm_resource *res,
                 lock->l_flags |= LDLM_FL_CBPENDING | LDLM_FL_CANCELING |
                                  lock_flags;
 
-                LASSERT(list_empty(&lock->l_bl_ast));
-                list_add(&lock->l_bl_ast, cancels);
+                LASSERT(cfs_list_empty(&lock->l_bl_ast));
+                cfs_list_add(&lock->l_bl_ast, cancels);
                 LDLM_LOCK_GET(lock);
                 count++;
         }
         unlock_res(res);
 
-        RETURN(ldlm_cancel_list(cancels, count, cancel_flags));
+        RETURN(ldlm_cli_cancel_list_local(cancels, count, cancel_flags));
 }
+EXPORT_SYMBOL(ldlm_cancel_resource_local);
 
-/* If @req is NULL, send CANCEL request to server with handles of locks 
- * in the @cancels. If EARLY_CANCEL is not supported, send CANCEL requests 
+/**
+ * Cancel client-side locks from a list and send/prepare cancel RPCs to the
+ * server.
+ * If \a req is NULL, send CANCEL request to server with handles of locks
+ * in the \a cancels. If EARLY_CANCEL is not supported, send CANCEL requests
  * separately per lock.
- * If @req is not NULL, put handles of locks in @cancels into the request 
- * buffer at the offset @off.
- * Destroy @cancels at the end. */
-int ldlm_cli_cancel_list(struct list_head *cancels, int count,
-                         struct ptlrpc_request *req, int flags)
+ * If \a req is not NULL, put handles of locks in \a cancels into the request
+ * buffer at the offset \a off.
+ * Destroy \a cancels at the end.
+ */
+int ldlm_cli_cancel_list(cfs_list_t *cancels, int count,
+                         struct ptlrpc_request *req, ldlm_cancel_flags_t flags)
 {
         struct ldlm_lock *lock;
         int res = 0;
         ENTRY;
 
-        if (list_empty(cancels) || count == 0)
+        if (cfs_list_empty(cancels) || count == 0)
                 RETURN(0);
-        
-        /* XXX: requests (both batched and not) could be sent in parallel. 
+
+        /* XXX: requests (both batched and not) could be sent in parallel.
          * Usually it is enough to have just 1 RPC, but it is possible that
-         * there are to many locks to be cancelled in LRU or on a resource.
+         * there are too many locks to be cancelled in LRU or on a resource.
          * It would also speed up the case when the server does not support
          * the feature. */
         while (count > 0) {
-                LASSERT(!list_empty(cancels));
-                lock = list_entry(cancels->next, struct ldlm_lock, l_bl_ast);
+                LASSERT(!cfs_list_empty(cancels));
+                lock = cfs_list_entry(cancels->next, struct ldlm_lock,
+                                      l_bl_ast);
                 LASSERT(lock->l_conn_export);
 
                 if (exp_connect_cancelset(lock->l_conn_export)) {
@@ -1703,10 +1896,11 @@ int ldlm_cli_cancel_list(struct list_head *cancels, int count,
                                                   cancels, 1, flags);
                 }
 
-                if (res < 0) {
-                        CERROR("ldlm_cli_cancel_list: %d\n", res);
-                        res = count;
-                }
+               if (res < 0) {
+                       CDEBUG_LIMIT(res == -ESHUTDOWN ? D_DLMTRACE : D_ERROR,
+                                    "ldlm_cli_cancel_list: %d\n", res);
+                       res = count;
+               }
 
                 count -= res;
                 ldlm_lock_list_put(cancels, l_bl_ast, res);
@@ -1714,11 +1908,19 @@ int ldlm_cli_cancel_list(struct list_head *cancels, int count,
         LASSERT(count == 0);
         RETURN(0);
 }
+EXPORT_SYMBOL(ldlm_cli_cancel_list);
 
+/**
+ * Cancel all locks on a resource that have 0 readers/writers.
+ *
+ * If flags & LDLM_FL_LOCAL_ONLY, throw the locks away without trying
+ * to notify the server. */
 int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns,
                                     const struct ldlm_res_id *res_id,
                                     ldlm_policy_data_t *policy,
-                                    ldlm_mode_t mode, int flags, void *opaque)
+                                    ldlm_mode_t mode,
+                                    ldlm_cancel_flags_t flags,
+                                    void *opaque)
 {
         struct ldlm_resource *res;
         CFS_LIST_HEAD(cancels);
@@ -1733,84 +1935,76 @@ int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns,
                 RETURN(0);
         }
 
+        LDLM_RESOURCE_ADDREF(res);
         count = ldlm_cancel_resource_local(res, &cancels, policy, mode,
-                                           0, flags, opaque);
+                                           0, flags | LCF_BL_AST, opaque);
         rc = ldlm_cli_cancel_list(&cancels, count, NULL, flags);
         if (rc != ELDLM_OK)
-                CERROR("ldlm_cli_cancel_unused_resource: %d\n", rc);
+               CERROR("canceling unused lock "DLDLMRES": rc = %d\n",
+                      PLDLMRES(res), rc);
 
+        LDLM_RESOURCE_DELREF(res);
         ldlm_resource_putref(res);
         RETURN(0);
 }
+EXPORT_SYMBOL(ldlm_cli_cancel_unused_resource);
 
-static inline int have_no_nsresource(struct ldlm_namespace *ns)
-{
-        int no_resource = 0;
-
-        spin_lock(&ns->ns_hash_lock);
-        if (ns->ns_resources == 0)
-                no_resource = 1;
-        spin_unlock(&ns->ns_hash_lock);
+struct ldlm_cli_cancel_arg {
+        int     lc_flags;
+        void   *lc_opaque;
+};
 
-        RETURN(no_resource);
+static int ldlm_cli_hash_cancel_unused(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+                                      cfs_hlist_node_t *hnode, void *arg)
+{
+       struct ldlm_resource           *res = cfs_hash_object(hs, hnode);
+       struct ldlm_cli_cancel_arg     *lc = arg;
+
+       ldlm_cli_cancel_unused_resource(ldlm_res_to_ns(res), &res->lr_name,
+                                       NULL, LCK_MINMODE, lc->lc_flags,
+                                       lc->lc_opaque);
+       /* must return 0 for hash iteration */
+       return 0;
 }
 
-/* Cancel all locks on a namespace (or a specific resource, if given)
+/**
+ * Cancel all locks on a namespace (or a specific resource, if given)
  * that have 0 readers/writers.
  *
- * If flags & LDLM_FL_LOCAL_ONLY, throw the locks away without trying
+ * If flags & LCF_LOCAL, throw the locks away without trying
  * to notify the server. */
 int ldlm_cli_cancel_unused(struct ldlm_namespace *ns,
                            const struct ldlm_res_id *res_id,
-                           int flags, void *opaque)
+                           ldlm_cancel_flags_t flags, void *opaque)
 {
-        int i;
+        struct ldlm_cli_cancel_arg arg = {
+                .lc_flags       = flags,
+                .lc_opaque      = opaque,
+        };
+
         ENTRY;
 
         if (ns == NULL)
                 RETURN(ELDLM_OK);
 
-        if (res_id)
+        if (res_id != NULL) {
                 RETURN(ldlm_cli_cancel_unused_resource(ns, res_id, NULL,
                                                        LCK_MINMODE, flags,
                                                        opaque));
-
-        spin_lock(&ns->ns_hash_lock);
-        for (i = 0; i < RES_HASH_SIZE; i++) {
-                struct list_head *tmp;
-                tmp = ns->ns_hash[i].next;
-                while (tmp != &(ns->ns_hash[i])) {
-                        struct ldlm_resource *res;
-                        int rc;
-
-                        res = list_entry(tmp, struct ldlm_resource, lr_hash);
-                        ldlm_resource_getref(res);
-                        spin_unlock(&ns->ns_hash_lock);
-
-                        rc = ldlm_cli_cancel_unused_resource(ns, &res->lr_name,
-                                                             NULL, LCK_MINMODE,
-                                                             flags, opaque);
-
-                        if (rc)
-                                CERROR("ldlm_cli_cancel_unused ("LPU64"): %d\n",
-                                       res->lr_name.name[0], rc);
-
-                        spin_lock(&ns->ns_hash_lock);
-                        tmp = tmp->next;
-                        ldlm_resource_putref_locked(res);
-                }
+        } else {
+                cfs_hash_for_each_nolock(ns->ns_rs_hash,
+                                         ldlm_cli_hash_cancel_unused, &arg);
+                RETURN(ELDLM_OK);
         }
-        spin_unlock(&ns->ns_hash_lock);
-
-        RETURN(ELDLM_OK);
 }
+EXPORT_SYMBOL(ldlm_cli_cancel_unused);
 
 /* Lock iterators. */
 
 int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter,
                           void *closure)
 {
-        struct list_head *tmp, *next;
+        cfs_list_t *tmp, *next;
         struct ldlm_lock *lock;
         int rc = LDLM_ITER_CONTINUE;
 
@@ -1820,22 +2014,22 @@ int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter,
                 RETURN(LDLM_ITER_CONTINUE);
 
         lock_res(res);
-        list_for_each_safe(tmp, next, &res->lr_granted) {
-                lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+        cfs_list_for_each_safe(tmp, next, &res->lr_granted) {
+                lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
 
                 if (iter(lock, closure) == LDLM_ITER_STOP)
                         GOTO(out, rc = LDLM_ITER_STOP);
         }
 
-        list_for_each_safe(tmp, next, &res->lr_converting) {
-                lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+        cfs_list_for_each_safe(tmp, next, &res->lr_converting) {
+                lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
 
                 if (iter(lock, closure) == LDLM_ITER_STOP)
                         GOTO(out, rc = LDLM_ITER_STOP);
         }
 
-        list_for_each_safe(tmp, next, &res->lr_waiting) {
-                lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+        cfs_list_for_each_safe(tmp, next, &res->lr_waiting) {
+                lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
 
                 if (iter(lock, closure) == LDLM_ITER_STOP)
                         GOTO(out, rc = LDLM_ITER_STOP);
@@ -1844,6 +2038,7 @@ int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter,
         unlock_res(res);
         RETURN(rc);
 }
+EXPORT_SYMBOL(ldlm_resource_foreach);
 
 struct iter_helper_data {
         ldlm_iterator_t iter;
@@ -1856,54 +2051,39 @@ static int ldlm_iter_helper(struct ldlm_lock *lock, void *closure)
         return helper->iter(lock, helper->closure);
 }
 
-static int ldlm_res_iter_helper(struct ldlm_resource *res, void *closure)
+static int ldlm_res_iter_helper(cfs_hash_t *hs, cfs_hash_bd_t *bd,
+                                cfs_hlist_node_t *hnode, void *arg)
+
 {
-        return ldlm_resource_foreach(res, ldlm_iter_helper, closure);
+        struct ldlm_resource *res = cfs_hash_object(hs, hnode);
+
+        return ldlm_resource_foreach(res, ldlm_iter_helper, arg) ==
+               LDLM_ITER_STOP;
 }
 
-int ldlm_namespace_foreach(struct ldlm_namespace *ns, ldlm_iterator_t iter,
-                           void *closure)
+void ldlm_namespace_foreach(struct ldlm_namespace *ns,
+                            ldlm_iterator_t iter, void *closure)
+
 {
         struct iter_helper_data helper = { iter: iter, closure: closure };
-        return ldlm_namespace_foreach_res(ns, ldlm_res_iter_helper, &helper);
-}
 
-int ldlm_namespace_foreach_res(struct ldlm_namespace *ns,
-                               ldlm_res_iterator_t iter, void *closure)
-{
-        int i, rc = LDLM_ITER_CONTINUE;
-        struct ldlm_resource *res;
-        struct list_head *tmp;
+        cfs_hash_for_each_nolock(ns->ns_rs_hash,
+                                 ldlm_res_iter_helper, &helper);
 
-        ENTRY;
-        spin_lock(&ns->ns_hash_lock);
-        for (i = 0; i < RES_HASH_SIZE; i++) {
-                tmp = ns->ns_hash[i].next;
-                while (tmp != &(ns->ns_hash[i])) {
-                        res = list_entry(tmp, struct ldlm_resource, lr_hash);
-                        ldlm_resource_getref(res);
-                        spin_unlock(&ns->ns_hash_lock);
-
-                        rc = iter(res, closure);
-
-                        spin_lock(&ns->ns_hash_lock);
-                        tmp = tmp->next;
-                        ldlm_resource_putref_locked(res);
-                        if (rc == LDLM_ITER_STOP)
-                                GOTO(out, rc);
-                }
-        }
- out:
-        spin_unlock(&ns->ns_hash_lock);
-        RETURN(rc);
 }
+EXPORT_SYMBOL(ldlm_namespace_foreach);
 
-/* non-blocking function to manipulate a lock whose cb_data is being put away.*/
-void ldlm_resource_iterate(struct ldlm_namespace *ns,
-                           const struct ldlm_res_id *res_id,
-                           ldlm_iterator_t iter, void *data)
+/* non-blocking function to manipulate a lock whose cb_data is being put away.
+ * return  0:  find no resource
+ *       > 0:  must be LDLM_ITER_STOP/LDLM_ITER_CONTINUE.
+ *       < 0:  errors
+ */
+int ldlm_resource_iterate(struct ldlm_namespace *ns,
+                          const struct ldlm_res_id *res_id,
+                          ldlm_iterator_t iter, void *data)
 {
         struct ldlm_resource *res;
+        int rc;
         ENTRY;
 
         if (ns == NULL) {
@@ -1912,41 +2092,49 @@ void ldlm_resource_iterate(struct ldlm_namespace *ns,
         }
 
         res = ldlm_resource_get(ns, NULL, res_id, 0, 0);
-        if (res == NULL) {
-                EXIT;
-                return;
-        }
+        if (res == NULL)
+                RETURN(0);
 
-        ldlm_resource_foreach(res, iter, data);
+        LDLM_RESOURCE_ADDREF(res);
+        rc = ldlm_resource_foreach(res, iter, data);
+        LDLM_RESOURCE_DELREF(res);
         ldlm_resource_putref(res);
-        EXIT;
+        RETURN(rc);
 }
+EXPORT_SYMBOL(ldlm_resource_iterate);
 
 /* Lock replay */
 
 static int ldlm_chain_lock_for_replay(struct ldlm_lock *lock, void *closure)
 {
-        struct list_head *list = closure;
+        cfs_list_t *list = closure;
 
         /* we use l_pending_chain here, because it's unused on clients. */
-        LASSERTF(list_empty(&lock->l_pending_chain),"lock %p next %p prev %p\n",
+        LASSERTF(cfs_list_empty(&lock->l_pending_chain),
+                 "lock %p next %p prev %p\n",
                  lock, &lock->l_pending_chain.next,&lock->l_pending_chain.prev);
-        /* bug 9573: don't replay locks left after eviction */
-        if (!(lock->l_flags & LDLM_FL_FAILED))
-                list_add(&lock->l_pending_chain, list);
+        /* bug 9573: don't replay locks left after eviction, or
+         * bug 17614: locks being actively cancelled. Get a reference
+         * on a lock so that it does not disapear under us (e.g. due to cancel)
+         */
+        if (!(lock->l_flags & (LDLM_FL_FAILED|LDLM_FL_CANCELING))) {
+                cfs_list_add(&lock->l_pending_chain, list);
+                LDLM_LOCK_GET(lock);
+        }
+
         return LDLM_ITER_CONTINUE;
 }
 
-static int replay_lock_interpret(struct ptlrpc_request *req,
+static int replay_lock_interpret(const struct lu_env *env,
+                                 struct ptlrpc_request *req,
                                  struct ldlm_async_args *aa, int rc)
 {
-        struct lustre_handle  old_hash_key;
         struct ldlm_lock     *lock;
         struct ldlm_reply    *reply;
         struct obd_export    *exp;
 
         ENTRY;
-        atomic_dec(&req->rq_import->imp_replay_inflight);
+        cfs_atomic_dec(&req->rq_import->imp_replay_inflight);
         if (rc != ELDLM_OK)
                 GOTO(out, rc);
 
@@ -1965,22 +2153,26 @@ static int replay_lock_interpret(struct ptlrpc_request *req,
                 GOTO(out, rc = -ESTALE);
         }
 
-        old_hash_key = lock->l_remote_handle;
-        lock->l_remote_handle = reply->lock_handle;
-
         /* Key change rehash lock in per-export hash with new key */
-       exp = req->rq_export;
-        if (exp && exp->exp_lock_hash)
-                lustre_hash_rehash_key(exp->exp_lock_hash, &old_hash_key,
-                                      &lock->l_remote_handle,
-                                       &lock->l_exp_hash);
+        exp = req->rq_export;
+        if (exp && exp->exp_lock_hash) {
+               /* In the function below, .hs_keycmp resolves to
+                * ldlm_export_lock_keycmp() */
+               /* coverity[overrun-buffer-val] */
+                cfs_hash_rehash_key(exp->exp_lock_hash,
+                                    &lock->l_remote_handle,
+                                    &reply->lock_handle,
+                                    &lock->l_exp_hash);
+        } else {
+                lock->l_remote_handle = reply->lock_handle;
+        }
 
         LDLM_DEBUG(lock, "replayed lock:");
         ptlrpc_import_recovery_state_machine(req->rq_import);
         LDLM_LOCK_PUT(lock);
 out:
         if (rc != ELDLM_OK)
-                ptlrpc_connect_import(req->rq_import, NULL);
+                ptlrpc_connect_import(req->rq_import);
 
         RETURN(rc);
 }
@@ -2008,6 +2200,7 @@ static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
                 ldlm_lock_cancel(lock);
                 RETURN(0);
         }
+
         /*
          * If granted mode matches the requested mode, this lock is granted.
          *
@@ -2026,7 +2219,7 @@ static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_GRANTED;
         else if (lock->l_granted_mode)
                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_CONV;
-        else if (!list_empty(&lock->l_res_link))
+        else if (!cfs_list_empty(&lock->l_res_link))
                 flags = LDLM_FL_REPLAY | LDLM_FL_BLOCK_WAIT;
         else
                 flags = LDLM_FL_REPLAY;
@@ -2041,14 +2234,13 @@ static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
 
         body = req_capsule_client_get(&req->rq_pill, &RMF_DLM_REQ);
         ldlm_lock2desc(lock, &body->lock_desc);
-        body->lock_flags = flags;
+       body->lock_flags = ldlm_flags_to_wire(flags);
 
         ldlm_lock2handle(lock, &body->lock_handle[0]);
-        if (lock->l_lvb_len != 0) {
-                req_capsule_extend(&req->rq_pill, &RQF_LDLM_ENQUEUE_LVB);
-                req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER,
-                                     lock->l_lvb_len);
-        }
+       if (lock->l_lvb_len > 0)
+               req_capsule_extend(&req->rq_pill, &RQF_LDLM_ENQUEUE_LVB);
+       req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER,
+                            lock->l_lvb_len);
         ptlrpc_request_set_replen(req);
         /* notify the server we've replayed all requests.
          * also, we mark the request to be put on a dedicated
@@ -2058,16 +2250,45 @@ static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
 
         LDLM_DEBUG(lock, "replaying lock:");
 
-        atomic_inc(&req->rq_import->imp_replay_inflight);
+        cfs_atomic_inc(&req->rq_import->imp_replay_inflight);
         CLASSERT(sizeof(*aa) <= sizeof(req->rq_async_args));
         aa = ptlrpc_req_async_args(req);
         aa->lock_handle = body->lock_handle[0];
-        req->rq_interpret_reply = replay_lock_interpret;
-        ptlrpcd_add_req(req);
+        req->rq_interpret_reply = (ptlrpc_interpterer_t)replay_lock_interpret;
+        ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
 
         RETURN(0);
 }
 
+/**
+ * Cancel as many unused locks as possible before replay. since we are
+ * in recovery, we can't wait for any outstanding RPCs to send any RPC
+ * to the server.
+ *
+ * Called only in recovery before replaying locks. there is no need to
+ * replay locks that are unused. since the clients may hold thousands of
+ * cached unused locks, dropping the unused locks can greatly reduce the
+ * load on the servers at recovery time.
+ */
+static void ldlm_cancel_unused_locks_for_replay(struct ldlm_namespace *ns)
+{
+        int canceled;
+        CFS_LIST_HEAD(cancels);
+
+        CDEBUG(D_DLMTRACE, "Dropping as many unused locks as possible before"
+                           "replay for namespace %s (%d)\n",
+                           ldlm_ns_name(ns), ns->ns_nr_unused);
+
+        /* We don't need to care whether or not LRU resize is enabled
+         * because the LDLM_CANCEL_NO_WAIT policy doesn't use the
+         * count parameter */
+        canceled = ldlm_cancel_lru_local(ns, &cancels, ns->ns_nr_unused, 0,
+                                         LCF_LOCAL, LDLM_CANCEL_NO_WAIT);
+
+        CDEBUG(D_DLMTRACE, "Canceled %d unused locks from namespace %s\n",
+                           canceled, ldlm_ns_name(ns));
+}
+
 int ldlm_replay_locks(struct obd_import *imp)
 {
         struct ldlm_namespace *ns = imp->imp_obd->obd_namespace;
@@ -2077,21 +2298,32 @@ int ldlm_replay_locks(struct obd_import *imp)
 
         ENTRY;
 
-        LASSERT(atomic_read(&imp->imp_replay_inflight) == 0);
+        LASSERT(cfs_atomic_read(&imp->imp_replay_inflight) == 0);
+
+        /* don't replay locks if import failed recovery */
+        if (imp->imp_vbr_failed)
+                RETURN(0);
 
         /* ensure this doesn't fall to 0 before all have been queued */
-        atomic_inc(&imp->imp_replay_inflight);
+        cfs_atomic_inc(&imp->imp_replay_inflight);
+
+        if (ldlm_cancel_unused_locks_before_replay)
+                ldlm_cancel_unused_locks_for_replay(ns);
 
-        (void)ldlm_namespace_foreach(ns, ldlm_chain_lock_for_replay, &list);
+        ldlm_namespace_foreach(ns, ldlm_chain_lock_for_replay, &list);
 
-        list_for_each_entry_safe(lock, next, &list, l_pending_chain) {
-                list_del_init(&lock->l_pending_chain);
-                if (rc)
+        cfs_list_for_each_entry_safe(lock, next, &list, l_pending_chain) {
+                cfs_list_del_init(&lock->l_pending_chain);
+                if (rc) {
+                        LDLM_LOCK_RELEASE(lock);
                         continue; /* or try to do the rest? */
+                }
                 rc = replay_one_lock(imp, lock);
+                LDLM_LOCK_RELEASE(lock);
         }
 
-        atomic_dec(&imp->imp_replay_inflight);
+        cfs_atomic_dec(&imp->imp_replay_inflight);
 
         RETURN(rc);
 }
+EXPORT_SYMBOL(ldlm_replay_locks);