Whamcloud - gitweb
LU-7079 ptlrpc: imp_peer_committed_transno should increase
[fs/lustre-release.git] / lustre / ptlrpc / client.c
index 6b50207..a791abf 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.
@@ -29,7 +27,7 @@
  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2012, Whamcloud, Inc.
+ * Copyright (c) 2011, 2014, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
 /** Implementation of client-side PortalRPC interfaces */
 
 #define DEBUG_SUBSYSTEM S_RPC
-#ifndef __KERNEL__
-#include <errno.h>
-#include <signal.h>
-#include <liblustre.h>
-#endif
 
 #include <obd_support.h>
 #include <obd_class.h>
 
 #include "ptlrpc_internal.h"
 
+const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_pin_ops = {
+       .add_kiov_frag  = ptlrpc_prep_bulk_page_pin,
+       .release_frags  = ptlrpc_release_bulk_page_pin,
+};
+EXPORT_SYMBOL(ptlrpc_bulk_kiov_pin_ops);
+
+const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_nopin_ops = {
+       .add_kiov_frag  = ptlrpc_prep_bulk_page_nopin,
+       .release_frags  = ptlrpc_release_bulk_noop,
+};
+EXPORT_SYMBOL(ptlrpc_bulk_kiov_nopin_ops);
+
+const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kvec_ops = {
+       .add_iov_frag = ptlrpc_prep_bulk_frag,
+};
+EXPORT_SYMBOL(ptlrpc_bulk_kvec_ops);
+
+static int ptlrpc_send_new_req(struct ptlrpc_request *req);
+static int ptlrpcd_check_work(struct ptlrpc_request *req);
+static int ptlrpc_unregister_reply(struct ptlrpc_request *request, int async);
+
 /**
  * Initialize passed in client structure \a cl.
  */
@@ -64,6 +78,7 @@ void ptlrpc_init_client(int req_portal, int rep_portal, char *name,
         cl->cli_reply_portal   = rep_portal;
         cl->cli_name           = name;
 }
+EXPORT_SYMBOL(ptlrpc_init_client);
 
 /**
  * Return PortalRPC connection for remore uud \a uuid
@@ -75,6 +90,9 @@ struct ptlrpc_connection *ptlrpc_uuid_to_connection(struct obd_uuid *uuid)
         lnet_process_id_t         peer;
         int                       err;
 
+       /* ptlrpc_uuid_to_peer() initializes its 2nd parameter
+        * before accessing its values. */
+       /* coverity[uninit_use_in_call] */
         err = ptlrpc_uuid_to_peer(uuid, &peer, &self);
         if (err != 0) {
                 CNETERR("cannot find peer %s!\n", uuid->uuid);
@@ -93,46 +111,77 @@ struct ptlrpc_connection *ptlrpc_uuid_to_connection(struct obd_uuid *uuid)
 }
 
 /**
- * Allocate and initialize new bulk descriptor
+ * Allocate and initialize new bulk descriptor on the sender.
  * Returns pointer to the descriptor or NULL on error.
  */
-struct ptlrpc_bulk_desc *new_bulk(int npages, int type, int portal)
-{
-        struct ptlrpc_bulk_desc *desc;
-
-        OBD_ALLOC(desc, offsetof (struct ptlrpc_bulk_desc, bd_iov[npages]));
-        if (!desc)
-                return NULL;
-
-        cfs_spin_lock_init(&desc->bd_lock);
-        cfs_waitq_init(&desc->bd_waitq);
-        desc->bd_max_iov = npages;
-        desc->bd_iov_count = 0;
-        LNetInvalidateHandle(&desc->bd_md_h);
-        desc->bd_portal = portal;
-        desc->bd_type = type;
-
-        return desc;
+struct ptlrpc_bulk_desc *ptlrpc_new_bulk(unsigned nfrags, unsigned max_brw,
+                                        enum ptlrpc_bulk_op_type type,
+                                        unsigned portal,
+                                        const struct ptlrpc_bulk_frag_ops *ops)
+{
+       struct ptlrpc_bulk_desc *desc;
+       int i;
+
+       /* ensure that only one of KIOV or IOVEC is set but not both */
+       LASSERT((ptlrpc_is_bulk_desc_kiov(type) &&
+                ops->add_kiov_frag != NULL) ||
+               (ptlrpc_is_bulk_desc_kvec(type) &&
+                ops->add_iov_frag != NULL));
+
+       if (type & PTLRPC_BULK_BUF_KIOV) {
+               OBD_ALLOC(desc,
+                         offsetof(struct ptlrpc_bulk_desc,
+                                  bd_u.bd_kiov.bd_vec[nfrags]));
+       } else {
+               OBD_ALLOC(desc,
+                         offsetof(struct ptlrpc_bulk_desc,
+                                  bd_u.bd_kvec.bd_kvec[nfrags]));
+       }
+
+       if (!desc)
+               return NULL;
+
+       spin_lock_init(&desc->bd_lock);
+       init_waitqueue_head(&desc->bd_waitq);
+       desc->bd_max_iov = nfrags;
+       desc->bd_iov_count = 0;
+       desc->bd_portal = portal;
+       desc->bd_type = type;
+       desc->bd_md_count = 0;
+       desc->bd_frag_ops = (struct ptlrpc_bulk_frag_ops *) ops;
+       LASSERT(max_brw > 0);
+       desc->bd_md_max_brw = min(max_brw, PTLRPC_BULK_OPS_COUNT);
+       /* PTLRPC_BULK_OPS_COUNT is the compile-time transfer limit for this
+        * node. Negotiated ocd_brw_size will always be <= this number. */
+       for (i = 0; i < PTLRPC_BULK_OPS_COUNT; i++)
+               LNetInvalidateHandle(&desc->bd_mds[i]);
+
+       return desc;
 }
 
 /**
  * Prepare bulk descriptor for specified outgoing request \a req that
- * can fit \a npages * pages. \a type is bulk type. \a portal is where
+ * can fit \a nfrags * pages. \a type is bulk type. \a portal is where
  * the bulk to be sent. Used on client-side.
  * Returns pointer to newly allocatrd initialized bulk descriptor or NULL on
  * error.
  */
 struct ptlrpc_bulk_desc *ptlrpc_prep_bulk_imp(struct ptlrpc_request *req,
-                                              int npages, int type, int portal)
+                                             unsigned nfrags, unsigned max_brw,
+                                             unsigned int type,
+                                             unsigned portal,
+                                             const struct ptlrpc_bulk_frag_ops
+                                               *ops)
 {
-        struct obd_import *imp = req->rq_import;
-        struct ptlrpc_bulk_desc *desc;
+       struct obd_import *imp = req->rq_import;
+       struct ptlrpc_bulk_desc *desc;
 
-        ENTRY;
-        LASSERT(type == BULK_PUT_SINK || type == BULK_GET_SOURCE);
-        desc = new_bulk(npages, type, portal);
-        if (desc == NULL)
-                RETURN(NULL);
+       ENTRY;
+       LASSERT(ptlrpc_is_bulk_op_passive(type));
+
+       desc = ptlrpc_new_bulk(nfrags, max_brw, type, portal, ops);
+       if (desc == NULL)
+               RETURN(NULL);
 
         desc->bd_import_generation = req->rq_import_generation;
         desc->bd_import = class_import_get(imp);
@@ -146,55 +195,92 @@ struct ptlrpc_bulk_desc *ptlrpc_prep_bulk_imp(struct ptlrpc_request *req,
 
         return desc;
 }
+EXPORT_SYMBOL(ptlrpc_prep_bulk_imp);
 
-/**
- * Add a page \a page to the bulk descriptor \a desc.
- * Data to transfer in the page starts at offset \a pageoffset and
- * amount of data to transfer from the page is \a len
- */
-void ptlrpc_prep_bulk_page(struct ptlrpc_bulk_desc *desc,
-                           cfs_page_t *page, int pageoffset, int len)
+void __ptlrpc_prep_bulk_page(struct ptlrpc_bulk_desc *desc,
+                            struct page *page, int pageoffset, int len,
+                            int pin)
 {
-        LASSERT(desc->bd_iov_count < desc->bd_max_iov);
-        LASSERT(page != NULL);
-        LASSERT(pageoffset >= 0);
-        LASSERT(len > 0);
-        LASSERT(pageoffset + len <= CFS_PAGE_SIZE);
+       lnet_kiov_t *kiov;
+
+       LASSERT(desc->bd_iov_count < desc->bd_max_iov);
+       LASSERT(page != NULL);
+       LASSERT(pageoffset >= 0);
+       LASSERT(len > 0);
+       LASSERT(pageoffset + len <= PAGE_CACHE_SIZE);
+       LASSERT(ptlrpc_is_bulk_desc_kiov(desc->bd_type));
+
+       kiov = &BD_GET_KIOV(desc, desc->bd_iov_count);
 
-        desc->bd_nob += len;
+       desc->bd_nob += len;
 
-        cfs_page_pin(page);
-        ptlrpc_add_bulk_page(desc, page, pageoffset, len);
+       if (pin)
+               page_cache_get(page);
+
+       kiov->kiov_page = page;
+       kiov->kiov_offset = pageoffset;
+       kiov->kiov_len = len;
+
+       desc->bd_iov_count++;
 }
+EXPORT_SYMBOL(__ptlrpc_prep_bulk_page);
+
+int ptlrpc_prep_bulk_frag(struct ptlrpc_bulk_desc *desc,
+                         void *frag, int len)
+{
+       struct kvec *iovec;
+       ENTRY;
+
+       LASSERT(desc->bd_iov_count < desc->bd_max_iov);
+       LASSERT(frag != NULL);
+       LASSERT(len > 0);
+       LASSERT(ptlrpc_is_bulk_desc_kvec(desc->bd_type));
+
+       iovec = &BD_GET_KVEC(desc, desc->bd_iov_count);
+
+       desc->bd_nob += len;
+
+       iovec->iov_base = frag;
+       iovec->iov_len = len;
+
+       desc->bd_iov_count++;
+
+       RETURN(desc->bd_nob);
+}
+EXPORT_SYMBOL(ptlrpc_prep_bulk_frag);
 
-/**
- * Uninitialize and free bulk descriptor \a desc.
- * Works on bulk descriptors both from server and client side.
- */
 void ptlrpc_free_bulk(struct ptlrpc_bulk_desc *desc)
 {
-        int i;
-        ENTRY;
+       ENTRY;
 
-        LASSERT(desc != NULL);
-        LASSERT(desc->bd_iov_count != LI_POISON); /* not freed already */
-        LASSERT(!desc->bd_network_rw);         /* network hands off or */
-        LASSERT((desc->bd_export != NULL) ^ (desc->bd_import != NULL));
+       LASSERT(desc != NULL);
+       LASSERT(desc->bd_iov_count != LI_POISON); /* not freed already */
+       LASSERT(desc->bd_md_count == 0);         /* network hands off */
+       LASSERT((desc->bd_export != NULL) ^ (desc->bd_import != NULL));
+       LASSERT(desc->bd_frag_ops != NULL);
 
-        sptlrpc_enc_pool_put_pages(desc);
+       if (ptlrpc_is_bulk_desc_kiov(desc->bd_type))
+               sptlrpc_enc_pool_put_pages(desc);
 
-        if (desc->bd_export)
-                class_export_put(desc->bd_export);
-        else
-                class_import_put(desc->bd_import);
+       if (desc->bd_export)
+               class_export_put(desc->bd_export);
+       else
+               class_import_put(desc->bd_import);
 
-        for (i = 0; i < desc->bd_iov_count ; i++)
-                cfs_page_unpin(desc->bd_iov[i].kiov_page);
+       if (desc->bd_frag_ops->release_frags != NULL)
+               desc->bd_frag_ops->release_frags(desc);
 
-        OBD_FREE(desc, offsetof(struct ptlrpc_bulk_desc,
-                                bd_iov[desc->bd_max_iov]));
-        EXIT;
+       if (ptlrpc_is_bulk_desc_kiov(desc->bd_type))
+               OBD_FREE(desc, offsetof(struct ptlrpc_bulk_desc,
+                                       bd_u.bd_kiov.bd_vec[desc->bd_max_iov]));
+       else
+               OBD_FREE(desc, offsetof(struct ptlrpc_bulk_desc,
+                                       bd_u.bd_kvec.bd_kvec[desc->
+                                               bd_max_iov]));
+
+       EXIT;
 }
+EXPORT_SYMBOL(ptlrpc_free_bulk);
 
 /**
  * Set server timelimit for this req, i.e. how long are we willing to wait
@@ -233,6 +319,7 @@ void ptlrpc_at_set_req_timeout(struct ptlrpc_request *req)
            reqmsg*/
         lustre_msg_set_timeout(req->rq_reqmsg, req->rq_timeout);
 }
+EXPORT_SYMBOL(ptlrpc_at_set_req_timeout);
 
 /* Adjust max service estimate based on server value */
 static void ptlrpc_at_adj_service(struct ptlrpc_request *req,
@@ -263,22 +350,35 @@ int ptlrpc_at_get_net_latency(struct ptlrpc_request *req)
 }
 
 /* Adjust expected network latency */
-static void ptlrpc_at_adj_net_latency(struct ptlrpc_request *req,
-                                      unsigned int service_time)
+void ptlrpc_at_adj_net_latency(struct ptlrpc_request *req,
+                              unsigned int service_time)
 {
         unsigned int nl, oldnl;
         struct imp_at *at;
         time_t now = cfs_time_current_sec();
 
         LASSERT(req->rq_import);
-        at = &req->rq_import->imp_at;
+
+       if (service_time > now - req->rq_sent + 3) {
+               /* bz16408, however, this can also happen if early reply
+                * is lost and client RPC is expired and resent, early reply
+                * or reply of original RPC can still be fit in reply buffer
+                * of resent RPC, now client is measuring time from the
+                * resent time, but server sent back service time of original
+                * RPC.
+                */
+               CDEBUG((lustre_msg_get_flags(req->rq_reqmsg) & MSG_RESENT) ?
+                      D_ADAPTTO : D_WARNING,
+                      "Reported service time %u > total measured time "
+                      CFS_DURATION_T"\n", service_time,
+                      cfs_time_sub(now, req->rq_sent));
+               return;
+       }
 
         /* Network latency is total time less server processing time */
-        nl = max_t(int, now - req->rq_sent - service_time, 0) +1/*st rounding*/;
-        if (service_time > now - req->rq_sent + 3 /* bz16408 */)
-                CWARN("Reported service time %u > total measured time "
-                      CFS_DURATION_T"\n", service_time,
-                      cfs_time_sub(now, req->rq_sent));
+       nl = max_t(int, now - req->rq_sent -
+                       service_time, 0) + 1; /* st rounding */
+       at = &req->rq_import->imp_at;
 
         oldnl = at_measured(&at->iat_net_latency, nl);
         if (oldnl != 0)
@@ -315,6 +415,7 @@ static int unpack_reply(struct ptlrpc_request *req)
  * If anything goes wrong just ignore it - same as if it never happened
  */
 static int ptlrpc_at_recv_early_reply(struct ptlrpc_request *req)
+__must_hold(&req->rq_lock)
 {
         struct ptlrpc_request *early_req;
         time_t                 olddl;
@@ -322,46 +423,79 @@ static int ptlrpc_at_recv_early_reply(struct ptlrpc_request *req)
         ENTRY;
 
         req->rq_early = 0;
-        cfs_spin_unlock(&req->rq_lock);
+       spin_unlock(&req->rq_lock);
 
-        rc = sptlrpc_cli_unwrap_early_reply(req, &early_req);
-        if (rc) {
-                cfs_spin_lock(&req->rq_lock);
-                RETURN(rc);
-        }
+       rc = sptlrpc_cli_unwrap_early_reply(req, &early_req);
+       if (rc) {
+               spin_lock(&req->rq_lock);
+               RETURN(rc);
+       }
 
-        rc = unpack_reply(early_req);
-        if (rc == 0) {
-                /* Expecting to increase the service time estimate here */
-                ptlrpc_at_adj_service(req,
-                        lustre_msg_get_timeout(early_req->rq_repmsg));
-                ptlrpc_at_adj_net_latency(req,
-                        lustre_msg_get_service_time(early_req->rq_repmsg));
-        }
+       rc = unpack_reply(early_req);
+       if (rc != 0) {
+               sptlrpc_cli_finish_early_reply(early_req);
+               spin_lock(&req->rq_lock);
+               RETURN(rc);
+       }
 
-        sptlrpc_cli_finish_early_reply(early_req);
+       /* Use new timeout value just to adjust the local value for this
+        * request, don't include it into at_history. It is unclear yet why
+        * service time increased and should it be counted or skipped, e.g.
+        * that can be recovery case or some error or server, the real reply
+        * will add all new data if it is worth to add. */
+       req->rq_timeout = lustre_msg_get_timeout(early_req->rq_repmsg);
+       lustre_msg_set_timeout(req->rq_reqmsg, req->rq_timeout);
 
-        cfs_spin_lock(&req->rq_lock);
+       /* Network latency can be adjusted, it is pure network delays */
+       ptlrpc_at_adj_net_latency(req,
+                       lustre_msg_get_service_time(early_req->rq_repmsg));
 
-        if (rc == 0) {
-                /* Adjust the local timeout for this req */
-                ptlrpc_at_set_req_timeout(req);
+       sptlrpc_cli_finish_early_reply(early_req);
 
-                olddl = req->rq_deadline;
-                /* server assumes it now has rq_timeout from when it sent the
-                   early reply, so client should give it at least that long. */
-                req->rq_deadline = cfs_time_current_sec() + req->rq_timeout +
-                            ptlrpc_at_get_net_latency(req);
+       spin_lock(&req->rq_lock);
+       olddl = req->rq_deadline;
+       /* server assumes it now has rq_timeout from when the request
+        * arrived, so the client should give it at least that long.
+        * since we don't know the arrival time we'll use the original
+        * sent time */
+       req->rq_deadline = req->rq_sent + req->rq_timeout +
+                          ptlrpc_at_get_net_latency(req);
 
-                DEBUG_REQ(D_ADAPTTO, req,
-                          "Early reply #%d, new deadline in "CFS_DURATION_T"s "
-                          "("CFS_DURATION_T"s)", req->rq_early_count,
-                          cfs_time_sub(req->rq_deadline,
-                                       cfs_time_current_sec()),
-                          cfs_time_sub(req->rq_deadline, olddl));
-        }
+       DEBUG_REQ(D_ADAPTTO, req,
+                 "Early reply #%d, new deadline in "CFS_DURATION_T"s "
+                 "("CFS_DURATION_T"s)", req->rq_early_count,
+                 cfs_time_sub(req->rq_deadline, cfs_time_current_sec()),
+                 cfs_time_sub(req->rq_deadline, olddl));
 
-        RETURN(rc);
+       RETURN(rc);
+}
+
+static struct kmem_cache *request_cache;
+
+int ptlrpc_request_cache_init(void)
+{
+       request_cache = kmem_cache_create("ptlrpc_cache",
+                                         sizeof(struct ptlrpc_request),
+                                         0, SLAB_HWCACHE_ALIGN, NULL);
+       return request_cache == NULL ? -ENOMEM : 0;
+}
+
+void ptlrpc_request_cache_fini(void)
+{
+       kmem_cache_destroy(request_cache);
+}
+
+struct ptlrpc_request *ptlrpc_request_cache_alloc(gfp_t flags)
+{
+       struct ptlrpc_request *req;
+
+       OBD_SLAB_ALLOC_PTR_GFP(req, request_cache, flags);
+       return req;
+}
+
+void ptlrpc_request_cache_free(struct ptlrpc_request *req)
+{
+       OBD_SLAB_FREE_PTR(req, request_cache);
 }
 
 /**
@@ -370,28 +504,29 @@ static int ptlrpc_at_recv_early_reply(struct ptlrpc_request *req)
  */
 void ptlrpc_free_rq_pool(struct ptlrpc_request_pool *pool)
 {
-        cfs_list_t *l, *tmp;
-        struct ptlrpc_request *req;
+       struct list_head *l, *tmp;
+       struct ptlrpc_request *req;
 
-        LASSERT(pool != NULL);
+       LASSERT(pool != NULL);
 
-        cfs_spin_lock(&pool->prp_lock);
-        cfs_list_for_each_safe(l, tmp, &pool->prp_req_list) {
-                req = cfs_list_entry(l, struct ptlrpc_request, rq_list);
-                cfs_list_del(&req->rq_list);
-                LASSERT(req->rq_reqbuf);
-                LASSERT(req->rq_reqbuf_len == pool->prp_rq_size);
-                OBD_FREE_LARGE(req->rq_reqbuf, pool->prp_rq_size);
-                OBD_FREE(req, sizeof(*req));
-        }
-        cfs_spin_unlock(&pool->prp_lock);
-        OBD_FREE(pool, sizeof(*pool));
+       spin_lock(&pool->prp_lock);
+       list_for_each_safe(l, tmp, &pool->prp_req_list) {
+               req = list_entry(l, struct ptlrpc_request, rq_list);
+               list_del(&req->rq_list);
+               LASSERT(req->rq_reqbuf);
+               LASSERT(req->rq_reqbuf_len == pool->prp_rq_size);
+               OBD_FREE_LARGE(req->rq_reqbuf, pool->prp_rq_size);
+               ptlrpc_request_cache_free(req);
+       }
+       spin_unlock(&pool->prp_lock);
+       OBD_FREE(pool, sizeof(*pool));
 }
+EXPORT_SYMBOL(ptlrpc_free_rq_pool);
 
 /**
  * Allocates, initializes and adds \a num_rq requests to the pool \a pool
  */
-void ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq)
+int ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq)
 {
         int i;
         int size = 1;
@@ -399,35 +534,36 @@ void ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq)
         while (size < pool->prp_rq_size)
                 size <<= 1;
 
-        LASSERTF(cfs_list_empty(&pool->prp_req_list) ||
+       LASSERTF(list_empty(&pool->prp_req_list) ||
                  size == pool->prp_rq_size,
                  "Trying to change pool size with nonempty pool "
                  "from %d to %d bytes\n", pool->prp_rq_size, size);
 
-        cfs_spin_lock(&pool->prp_lock);
-        pool->prp_rq_size = size;
-        for (i = 0; i < num_rq; i++) {
-                struct ptlrpc_request *req;
-                struct lustre_msg *msg;
-
-                cfs_spin_unlock(&pool->prp_lock);
-                OBD_ALLOC(req, sizeof(struct ptlrpc_request));
-                if (!req)
-                        return;
-                OBD_ALLOC_LARGE(msg, size);
-                if (!msg) {
-                        OBD_FREE(req, sizeof(struct ptlrpc_request));
-                        return;
+       spin_lock(&pool->prp_lock);
+       pool->prp_rq_size = size;
+       for (i = 0; i < num_rq; i++) {
+               struct ptlrpc_request *req;
+               struct lustre_msg *msg;
+
+               spin_unlock(&pool->prp_lock);
+               req = ptlrpc_request_cache_alloc(GFP_NOFS);
+               if (!req)
+                       return i;
+               OBD_ALLOC_LARGE(msg, size);
+               if (!msg) {
+                       ptlrpc_request_cache_free(req);
+                       return i;
                 }
                 req->rq_reqbuf = msg;
                 req->rq_reqbuf_len = size;
                 req->rq_pool = pool;
-                cfs_spin_lock(&pool->prp_lock);
-                cfs_list_add_tail(&req->rq_list, &pool->prp_req_list);
-        }
-        cfs_spin_unlock(&pool->prp_lock);
-        return;
+               spin_lock(&pool->prp_lock);
+               list_add_tail(&req->rq_list, &pool->prp_req_list);
+       }
+       spin_unlock(&pool->prp_lock);
+       return num_rq;
 }
+EXPORT_SYMBOL(ptlrpc_add_rqs_to_pool);
 
 /**
  * Create and initialize new request pool with given attributes:
@@ -439,31 +575,27 @@ void ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq)
  */
 struct ptlrpc_request_pool *
 ptlrpc_init_rq_pool(int num_rq, int msgsize,
-                    void (*populate_pool)(struct ptlrpc_request_pool *, int))
+                   int (*populate_pool)(struct ptlrpc_request_pool *, int))
 {
-        struct ptlrpc_request_pool *pool;
+       struct ptlrpc_request_pool *pool;
 
-        OBD_ALLOC(pool, sizeof (struct ptlrpc_request_pool));
-        if (!pool)
-                return NULL;
+       OBD_ALLOC(pool, sizeof(struct ptlrpc_request_pool));
+       if (!pool)
+               return NULL;
 
-        /* Request next power of two for the allocation, because internally
-           kernel would do exactly this */
+       /* Request next power of two for the allocation, because internally
+          kernel would do exactly this */
 
-        cfs_spin_lock_init(&pool->prp_lock);
-        CFS_INIT_LIST_HEAD(&pool->prp_req_list);
-        pool->prp_rq_size = msgsize + SPTLRPC_MAX_PAYLOAD;
-        pool->prp_populate = populate_pool;
+       spin_lock_init(&pool->prp_lock);
+       INIT_LIST_HEAD(&pool->prp_req_list);
+       pool->prp_rq_size = msgsize + SPTLRPC_MAX_PAYLOAD;
+       pool->prp_populate = populate_pool;
 
-        populate_pool(pool, num_rq);
+       populate_pool(pool, num_rq);
 
-        if (cfs_list_empty(&pool->prp_req_list)) {
-                /* have not allocated a single request for the pool */
-                OBD_FREE(pool, sizeof (struct ptlrpc_request_pool));
-                pool = NULL;
-        }
-        return pool;
+       return pool;
 }
+EXPORT_SYMBOL(ptlrpc_init_rq_pool);
 
 /**
  * Fetches one request from pool \a pool
@@ -477,21 +609,21 @@ ptlrpc_prep_req_from_pool(struct ptlrpc_request_pool *pool)
         if (!pool)
                 return NULL;
 
-        cfs_spin_lock(&pool->prp_lock);
+       spin_lock(&pool->prp_lock);
 
-        /* See if we have anything in a pool, and bail out if nothing,
-         * in writeout path, where this matters, this is safe to do, because
-         * nothing is lost in this case, and when some in-flight requests
-         * complete, this code will be called again. */
-        if (unlikely(cfs_list_empty(&pool->prp_req_list))) {
-                cfs_spin_unlock(&pool->prp_lock);
-                return NULL;
-        }
+       /* See if we have anything in a pool, and bail out if nothing,
+        * in writeout path, where this matters, this is safe to do, because
+        * nothing is lost in this case, and when some in-flight requests
+        * complete, this code will be called again. */
+       if (unlikely(list_empty(&pool->prp_req_list))) {
+               spin_unlock(&pool->prp_lock);
+               return NULL;
+       }
 
-        request = cfs_list_entry(pool->prp_req_list.next, struct ptlrpc_request,
-                                 rq_list);
-        cfs_list_del_init(&request->rq_list);
-        cfs_spin_unlock(&pool->prp_lock);
+       request = list_entry(pool->prp_req_list.next, struct ptlrpc_request,
+                            rq_list);
+       list_del_init(&request->rq_list);
+       spin_unlock(&pool->prp_lock);
 
         LASSERT(request->rq_reqbuf);
         LASSERT(request->rq_pool);
@@ -510,13 +642,13 @@ ptlrpc_prep_req_from_pool(struct ptlrpc_request_pool *pool)
  */
 static void __ptlrpc_free_req_to_pool(struct ptlrpc_request *request)
 {
-        struct ptlrpc_request_pool *pool = request->rq_pool;
+       struct ptlrpc_request_pool *pool = request->rq_pool;
 
-        cfs_spin_lock(&pool->prp_lock);
-        LASSERT(cfs_list_empty(&request->rq_list));
-        LASSERT(!request->rq_receiving_reply);
-        cfs_list_add_tail(&request->rq_list, &pool->prp_req_list);
-        cfs_spin_unlock(&pool->prp_lock);
+       spin_lock(&pool->prp_lock);
+       LASSERT(list_empty(&request->rq_list));
+       LASSERT(!request->rq_receiving_reply);
+       list_add_tail(&request->rq_list, &pool->prp_req_list);
+       spin_unlock(&pool->prp_lock);
 }
 
 static int __ptlrpc_request_bufs_pack(struct ptlrpc_request *request,
@@ -548,7 +680,6 @@ static int __ptlrpc_request_bufs_pack(struct ptlrpc_request *request,
         lustre_msg_add_version(request->rq_reqmsg, version);
         request->rq_send_state = LUSTRE_IMP_FULL;
         request->rq_type = PTL_RPC_MSG_REQUEST;
-        request->rq_export = NULL;
 
         request->rq_req_cbid.cbid_fn  = request_out_callback;
         request->rq_req_cbid.cbid_arg = request;
@@ -565,27 +696,14 @@ static int __ptlrpc_request_bufs_pack(struct ptlrpc_request *request,
 
         ptlrpc_at_set_req_timeout(request);
 
-        cfs_spin_lock_init(&request->rq_lock);
-        CFS_INIT_LIST_HEAD(&request->rq_list);
-        CFS_INIT_LIST_HEAD(&request->rq_timed_list);
-        CFS_INIT_LIST_HEAD(&request->rq_replay_list);
-        CFS_INIT_LIST_HEAD(&request->rq_ctx_chain);
-        CFS_INIT_LIST_HEAD(&request->rq_set_chain);
-        CFS_INIT_LIST_HEAD(&request->rq_history_list);
-        CFS_INIT_LIST_HEAD(&request->rq_exp_list);
-        cfs_waitq_init(&request->rq_reply_waitq);
-        cfs_waitq_init(&request->rq_set_waitq);
-        request->rq_xid = ptlrpc_next_xid();
-        cfs_atomic_set(&request->rq_refcount, 1);
-
-        lustre_msg_set_opc(request->rq_reqmsg, opcode);
+       lustre_msg_set_opc(request->rq_reqmsg, opcode);
 
-        RETURN(0);
+       RETURN(0);
 out_ctx:
-        sptlrpc_cli_ctx_put(request->rq_cli_ctx, 1);
+       sptlrpc_cli_ctx_put(request->rq_cli_ctx, 1);
 out_free:
-        class_import_put(imp);
-        return rc;
+       class_import_put(imp);
+       return rc;
 }
 
 int ptlrpc_request_bufs_pack(struct ptlrpc_request *request,
@@ -608,8 +726,32 @@ EXPORT_SYMBOL(ptlrpc_request_bufs_pack);
 int ptlrpc_request_pack(struct ptlrpc_request *request,
                         __u32 version, int opcode)
 {
-        return ptlrpc_request_bufs_pack(request, version, opcode, NULL, NULL);
-}
+       int rc;
+       rc = ptlrpc_request_bufs_pack(request, version, opcode, NULL, NULL);
+       if (rc)
+               return rc;
+
+       /* For some old 1.8 clients (< 1.8.7), they will LASSERT the size of
+        * ptlrpc_body sent from server equal to local ptlrpc_body size, so we
+        * have to send old ptlrpc_body to keep interoprability with these
+        * clients.
+        *
+        * Only three kinds of server->client RPCs so far:
+        *  - LDLM_BL_CALLBACK
+        *  - LDLM_CP_CALLBACK
+        *  - LDLM_GL_CALLBACK
+        *
+        * XXX This should be removed whenever we drop the interoprability with
+        *     the these old clients.
+        */
+       if (opcode == LDLM_BL_CALLBACK || opcode == LDLM_CP_CALLBACK ||
+           opcode == LDLM_GL_CALLBACK)
+               req_capsule_shrink(&request->rq_pill, &RMF_PTLRPC_BODY,
+                                  sizeof(struct ptlrpc_body_v2), RCL_CLIENT);
+
+       return rc;
+}
+EXPORT_SYMBOL(ptlrpc_request_pack);
 
 /**
  * Helper function to allocate new request on import \a imp
@@ -619,29 +761,30 @@ int ptlrpc_request_pack(struct ptlrpc_request *request,
  */
 static inline
 struct ptlrpc_request *__ptlrpc_request_alloc(struct obd_import *imp,
-                                              struct ptlrpc_request_pool *pool)
+                                             struct ptlrpc_request_pool *pool)
 {
-        struct ptlrpc_request *request = NULL;
+       struct ptlrpc_request *request = NULL;
 
-        if (pool)
-                request = ptlrpc_prep_req_from_pool(pool);
+       request = ptlrpc_request_cache_alloc(GFP_NOFS);
 
-        if (!request)
-                OBD_ALLOC_PTR(request);
+       if (!request && pool)
+               request = ptlrpc_prep_req_from_pool(pool);
 
-        if (request) {
-                LASSERTF((unsigned long)imp > 0x1000, "%p", imp);
-                LASSERT(imp != LP_POISON);
-                LASSERTF((unsigned long)imp->imp_client > 0x1000, "%p",
-                        imp->imp_client);
-                LASSERT(imp->imp_client != LP_POISON);
+       if (request) {
+               ptlrpc_cli_req_init(request);
 
-                request->rq_import = class_import_get(imp);
-        } else {
-                CERROR("request allocation out of memory\n");
-        }
+               LASSERTF((unsigned long)imp > 0x1000, "%p", imp);
+               LASSERT(imp != LP_POISON);
+               LASSERTF((unsigned long)imp->imp_client > 0x1000, "%p\n",
+                       imp->imp_client);
+               LASSERT(imp->imp_client != LP_POISON);
 
-        return request;
+               request->rq_import = class_import_get(imp);
+       } else {
+               CERROR("request allocation out of memory\n");
+       }
+
+       return request;
 }
 
 /**
@@ -675,6 +818,7 @@ struct ptlrpc_request *ptlrpc_request_alloc(struct obd_import *imp,
 {
         return ptlrpc_request_alloc_internal(imp, NULL, format);
 }
+EXPORT_SYMBOL(ptlrpc_request_alloc);
 
 /**
  * Allocate new request structure for import \a imp from pool \a pool and
@@ -686,6 +830,7 @@ struct ptlrpc_request *ptlrpc_request_alloc_pool(struct obd_import *imp,
 {
         return ptlrpc_request_alloc_internal(imp, pool, format);
 }
+EXPORT_SYMBOL(ptlrpc_request_alloc_pool);
 
 /**
  * For requests not from pool, free memory of the request structure.
@@ -693,11 +838,12 @@ struct ptlrpc_request *ptlrpc_request_alloc_pool(struct obd_import *imp,
  */
 void ptlrpc_request_free(struct ptlrpc_request *request)
 {
-        if (request->rq_pool)
-                __ptlrpc_free_req_to_pool(request);
-        else
-                OBD_FREE_PTR(request);
+       if (request->rq_pool)
+               __ptlrpc_free_req_to_pool(request);
+       else
+               ptlrpc_request_cache_free(request);
 }
+EXPORT_SYMBOL(ptlrpc_request_free);
 
 /**
  * Allocate new request for operatione \a opcode and immediatelly pack it for
@@ -722,6 +868,7 @@ struct ptlrpc_request *ptlrpc_request_alloc_pack(struct obd_import *imp,
         }
         return req;
 }
+EXPORT_SYMBOL(ptlrpc_request_alloc_pack);
 
 /**
  * Prepare request (fetched from pool \a poolif not NULL) on import \a imp
@@ -764,106 +911,59 @@ ptlrpc_prep_req(struct obd_import *imp, __u32 version, int opcode, int count,
 }
 
 /**
- * Allocate "fake" request that would not be sent anywhere in the end.
- * Only used as a hack because we have no other way of performing
- * async actions in lustre between layers.
- * Used on MDS to request object preallocations from more than one OST at a
- * time.
- */
-struct ptlrpc_request *ptlrpc_prep_fakereq(struct obd_import *imp,
-                                           unsigned int timeout,
-                                           ptlrpc_interpterer_t interpreter)
-{
-        struct ptlrpc_request *request = NULL;
-        ENTRY;
-
-        OBD_ALLOC(request, sizeof(*request));
-        if (!request) {
-                CERROR("request allocation out of memory\n");
-                RETURN(NULL);
-        }
-
-        request->rq_send_state = LUSTRE_IMP_FULL;
-        request->rq_type = PTL_RPC_MSG_REQUEST;
-        request->rq_import = class_import_get(imp);
-        request->rq_export = NULL;
-        request->rq_import_generation = imp->imp_generation;
-
-        request->rq_timeout = timeout;
-        request->rq_sent = cfs_time_current_sec();
-        request->rq_deadline = request->rq_sent + timeout;
-        request->rq_reply_deadline = request->rq_deadline;
-        request->rq_interpret_reply = interpreter;
-        request->rq_phase = RQ_PHASE_RPC;
-        request->rq_next_phase = RQ_PHASE_INTERPRET;
-        /* don't want reply */
-        request->rq_receiving_reply = 0;
-        request->rq_must_unlink = 0;
-        request->rq_no_delay = request->rq_no_resend = 1;
-        request->rq_fake = 1;
-
-        cfs_spin_lock_init(&request->rq_lock);
-        CFS_INIT_LIST_HEAD(&request->rq_list);
-        CFS_INIT_LIST_HEAD(&request->rq_replay_list);
-        CFS_INIT_LIST_HEAD(&request->rq_set_chain);
-        CFS_INIT_LIST_HEAD(&request->rq_history_list);
-        CFS_INIT_LIST_HEAD(&request->rq_exp_list);
-        cfs_waitq_init(&request->rq_reply_waitq);
-        cfs_waitq_init(&request->rq_set_waitq);
-
-        request->rq_xid = ptlrpc_next_xid();
-        cfs_atomic_set(&request->rq_refcount, 1);
-
-        RETURN(request);
-}
-
-/**
- * Indicate that processing of "fake" request is finished.
+ * Allocate and initialize new request set structure on the current CPT.
+ * Returns a pointer to the newly allocated set structure or NULL on error.
  */
-void ptlrpc_fakereq_finished(struct ptlrpc_request *req)
+struct ptlrpc_request_set *ptlrpc_prep_set(void)
 {
-        struct ptlrpc_request_set *set = req->rq_set;
-        int wakeup = 0;
-
-        /* hold ref on the request to prevent others (ptlrpcd) to free it */
-        ptlrpc_request_addref(req);
-        cfs_list_del_init(&req->rq_list);
-
-        /* if we kill request before timeout - need adjust counter */
-        if (req->rq_phase == RQ_PHASE_RPC && set != NULL &&
-            cfs_atomic_dec_and_test(&set->set_remaining))
-                wakeup = 1;
-
-        ptlrpc_rqphase_move(req, RQ_PHASE_COMPLETE);
-
-        /* Only need to call wakeup once when to be empty. */
-        if (wakeup)
-                cfs_waitq_signal(&set->set_waitq);
-        ptlrpc_req_finished(req);
-}
+       struct ptlrpc_request_set       *set;
+       int                             cpt;
+
+       ENTRY;
+       cpt = cfs_cpt_current(cfs_cpt_table, 0);
+       OBD_CPT_ALLOC(set, cfs_cpt_table, cpt, sizeof *set);
+       if (!set)
+               RETURN(NULL);
+       atomic_set(&set->set_refcount, 1);
+       INIT_LIST_HEAD(&set->set_requests);
+       init_waitqueue_head(&set->set_waitq);
+       atomic_set(&set->set_new_count, 0);
+       atomic_set(&set->set_remaining, 0);
+       spin_lock_init(&set->set_new_req_lock);
+       INIT_LIST_HEAD(&set->set_new_requests);
+       INIT_LIST_HEAD(&set->set_cblist);
+       set->set_max_inflight = UINT_MAX;
+       set->set_producer     = NULL;
+       set->set_producer_arg = NULL;
+       set->set_rc           = 0;
+
+       RETURN(set);
+}
+EXPORT_SYMBOL(ptlrpc_prep_set);
 
 /**
- * Allocate and initialize new request set structure.
+ * Allocate and initialize new request set structure with flow control
+ * extension. This extension allows to control the number of requests in-flight
+ * for the whole set. A callback function to generate requests must be provided
+ * and the request set will keep the number of requests sent over the wire to
+ * @max_inflight.
  * Returns a pointer to the newly allocated set structure or NULL on error.
  */
-struct ptlrpc_request_set *ptlrpc_prep_set(void)
+struct ptlrpc_request_set *ptlrpc_prep_fcset(int max, set_producer_func func,
+                                            void *arg)
+
 {
-        struct ptlrpc_request_set *set;
+       struct ptlrpc_request_set *set;
 
-        ENTRY;
-        OBD_ALLOC(set, sizeof *set);
-        if (!set)
-                RETURN(NULL);
-        cfs_atomic_set(&set->set_refcount, 1);
-        CFS_INIT_LIST_HEAD(&set->set_requests);
-        cfs_waitq_init(&set->set_waitq);
-        cfs_atomic_set(&set->set_new_count, 0);
-        cfs_atomic_set(&set->set_remaining, 0);
-        cfs_spin_lock_init(&set->set_new_req_lock);
-        CFS_INIT_LIST_HEAD(&set->set_new_requests);
-        CFS_INIT_LIST_HEAD(&set->set_cblist);
+       set = ptlrpc_prep_set();
+       if (!set)
+               RETURN(NULL);
+
+       set->set_max_inflight  = max;
+       set->set_producer      = func;
+       set->set_producer_arg  = arg;
 
-        RETURN(set);
+       RETURN(set);
 }
 
 /**
@@ -876,54 +976,55 @@ struct ptlrpc_request_set *ptlrpc_prep_set(void)
  */
 void ptlrpc_set_destroy(struct ptlrpc_request_set *set)
 {
-        cfs_list_t       *tmp;
-        cfs_list_t       *next;
-        int               expected_phase;
-        int               n = 0;
-        ENTRY;
-
-        /* Requests on the set should either all be completed, or all be new */
-        expected_phase = (cfs_atomic_read(&set->set_remaining) == 0) ?
-                         RQ_PHASE_COMPLETE : RQ_PHASE_NEW;
-        cfs_list_for_each (tmp, &set->set_requests) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(tmp, struct ptlrpc_request,
-                                       rq_set_chain);
-
-                LASSERT(req->rq_phase == expected_phase);
-                n++;
-        }
-
-        LASSERTF(cfs_atomic_read(&set->set_remaining) == 0 || 
-                 cfs_atomic_read(&set->set_remaining) == n, "%d / %d\n",
-                 cfs_atomic_read(&set->set_remaining), n);
-
-        cfs_list_for_each_safe(tmp, next, &set->set_requests) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(tmp, struct ptlrpc_request,
-                                       rq_set_chain);
-                cfs_list_del_init(&req->rq_set_chain);
-
-                LASSERT(req->rq_phase == expected_phase);
-
-                if (req->rq_phase == RQ_PHASE_NEW) {
-                        ptlrpc_req_interpret(NULL, req, -EBADR);
-                        cfs_atomic_dec(&set->set_remaining);
-                }
-
-                cfs_spin_lock(&req->rq_lock);
-                req->rq_set = NULL;
-                req->rq_invalid_rqset = 0;
-                cfs_spin_unlock(&req->rq_lock);
+       struct list_head        *tmp;
+       struct list_head        *next;
+       int                      expected_phase;
+       int                      n = 0;
+       ENTRY;
+
+       /* Requests on the set should either all be completed, or all be new */
+       expected_phase = (atomic_read(&set->set_remaining) == 0) ?
+                        RQ_PHASE_COMPLETE : RQ_PHASE_NEW;
+       list_for_each(tmp, &set->set_requests) {
+               struct ptlrpc_request *req =
+                       list_entry(tmp, struct ptlrpc_request,
+                                  rq_set_chain);
+
+               LASSERT(req->rq_phase == expected_phase);
+               n++;
+       }
+
+       LASSERTF(atomic_read(&set->set_remaining) == 0 ||
+                atomic_read(&set->set_remaining) == n, "%d / %d\n",
+                atomic_read(&set->set_remaining), n);
+
+       list_for_each_safe(tmp, next, &set->set_requests) {
+               struct ptlrpc_request *req =
+                       list_entry(tmp, struct ptlrpc_request,
+                                  rq_set_chain);
+               list_del_init(&req->rq_set_chain);
+
+               LASSERT(req->rq_phase == expected_phase);
+
+               if (req->rq_phase == RQ_PHASE_NEW) {
+                       ptlrpc_req_interpret(NULL, req, -EBADR);
+                       atomic_dec(&set->set_remaining);
+               }
+
+               spin_lock(&req->rq_lock);
+               req->rq_set = NULL;
+               req->rq_invalid_rqset = 0;
+               spin_unlock(&req->rq_lock);
 
                 ptlrpc_req_finished (req);
         }
 
-        LASSERT(cfs_atomic_read(&set->set_remaining) == 0);
+       LASSERT(atomic_read(&set->set_remaining) == 0);
 
-        ptlrpc_reqset_put(set);
-        EXIT;
+       ptlrpc_reqset_put(set);
+       EXIT;
 }
+EXPORT_SYMBOL(ptlrpc_set_destroy);
 
 /**
  * Add a callback function \a fn to the set.
@@ -933,17 +1034,17 @@ void ptlrpc_set_destroy(struct ptlrpc_request_set *set)
 int ptlrpc_set_add_cb(struct ptlrpc_request_set *set,
                       set_interpreter_func fn, void *data)
 {
-        struct ptlrpc_set_cbdata *cbdata;
+       struct ptlrpc_set_cbdata *cbdata;
 
-        OBD_ALLOC_PTR(cbdata);
-        if (cbdata == NULL)
-                RETURN(-ENOMEM);
+       OBD_ALLOC_PTR(cbdata);
+       if (cbdata == NULL)
+               RETURN(-ENOMEM);
 
-        cbdata->psc_interpret = fn;
-        cbdata->psc_data = data;
-        cfs_list_add_tail(&cbdata->psc_item, &set->set_cblist);
+       cbdata->psc_interpret = fn;
+       cbdata->psc_data = data;
+       list_add_tail(&cbdata->psc_item, &set->set_cblist);
 
-        RETURN(0);
+       RETURN(0);
 }
 
 /**
@@ -953,14 +1054,23 @@ int ptlrpc_set_add_cb(struct ptlrpc_request_set *set,
 void ptlrpc_set_add_req(struct ptlrpc_request_set *set,
                         struct ptlrpc_request *req)
 {
-        LASSERT(cfs_list_empty(&req->rq_set_chain));
+       LASSERT(list_empty(&req->rq_set_chain));
+
+       /* The set takes over the caller's request reference */
+       list_add_tail(&req->rq_set_chain, &set->set_requests);
+       req->rq_set = set;
+       atomic_inc(&set->set_remaining);
+       req->rq_queued_time = cfs_time_current();
+
+       if (req->rq_reqmsg != NULL)
+               lustre_msg_set_jobid(req->rq_reqmsg, NULL);
 
-        /* The set takes over the caller's request reference */
-        cfs_list_add_tail(&req->rq_set_chain, &set->set_requests);
-        req->rq_set = set;
-        cfs_atomic_inc(&set->set_remaining);
-        req->rq_queued_time = cfs_time_current();
+       if (set->set_producer != NULL)
+               /* If the request set has a producer callback, the RPC must be
+                * sent straight away */
+               ptlrpc_send_new_req(req);
 }
+EXPORT_SYMBOL(ptlrpc_set_add_req);
 
 /**
  * Add a request to a request with dedicated server thread
@@ -974,28 +1084,28 @@ void ptlrpc_set_add_new_req(struct ptlrpcd_ctl *pc,
         int count, i;
 
         LASSERT(req->rq_set == NULL);
-        LASSERT(cfs_test_bit(LIOD_STOP, &pc->pc_flags) == 0);
-
-        cfs_spin_lock(&set->set_new_req_lock);
-        /*
-         * The set takes over the caller's request reference.
-         */
-        req->rq_set = set;
-        req->rq_queued_time = cfs_time_current();
-        cfs_list_add_tail(&req->rq_set_chain, &set->set_new_requests);
-        count = cfs_atomic_inc_return(&set->set_new_count);
-        cfs_spin_unlock(&set->set_new_req_lock);
-
-        /* Only need to call wakeup once for the first entry. */
-        if (count == 1) {
-                cfs_waitq_signal(&set->set_waitq);
-
-                /* XXX: It maybe unnecessary to wakeup all the partners. But to
-                 *      guarantee the async RPC can be processed ASAP, we have
-                 *      no other better choice. It maybe fixed in future. */
-                for (i = 0; i < pc->pc_npartners; i++)
-                        cfs_waitq_signal(&pc->pc_partners[i]->pc_set->set_waitq);
-        }
+       LASSERT(test_bit(LIOD_STOP, &pc->pc_flags) == 0);
+
+       spin_lock(&set->set_new_req_lock);
+       /*
+        * The set takes over the caller's request reference.
+        */
+       req->rq_set = set;
+       req->rq_queued_time = cfs_time_current();
+       list_add_tail(&req->rq_set_chain, &set->set_new_requests);
+       count = atomic_inc_return(&set->set_new_count);
+       spin_unlock(&set->set_new_req_lock);
+
+       /* Only need to call wakeup once for the first entry. */
+       if (count == 1) {
+               wake_up(&set->set_waitq);
+
+               /* XXX: It maybe unnecessary to wakeup all the partners. But to
+                *      guarantee the async RPC can be processed ASAP, we have
+                *      no other better choice. It maybe fixed in future. */
+               for (i = 0; i < pc->pc_npartners; i++)
+                       wake_up(&pc->pc_partners[i]->pc_set->set_waitq);
+       }
 }
 
 /**
@@ -1022,77 +1132,85 @@ static int ptlrpc_import_delay_req(struct obd_import *imp,
         } else if (imp->imp_state == LUSTRE_IMP_NEW) {
                 DEBUG_REQ(D_ERROR, req, "Uninitialized import.");
                 *status = -EIO;
-                LBUG();
-        } else if (imp->imp_state == LUSTRE_IMP_CLOSED) {
-                DEBUG_REQ(D_ERROR, req, "IMP_CLOSED ");
-                *status = -EIO;
+       } else if (imp->imp_state == LUSTRE_IMP_CLOSED) {
+               /* pings may safely race with umount */
+               DEBUG_REQ(lustre_msg_get_opc(req->rq_reqmsg) == OBD_PING ?
+                         D_HA : D_ERROR, req, "IMP_CLOSED ");
+               *status = -EIO;
         } else if (ptlrpc_send_limit_expired(req)) {
-                /* probably doesn't need to be a D_ERROR after initial testing */
-                DEBUG_REQ(D_ERROR, req, "send limit expired ");
-                *status = -EIO;
-        } else if (req->rq_send_state == LUSTRE_IMP_CONNECTING &&
-                   imp->imp_state == LUSTRE_IMP_CONNECTING) {
-                /* allow CONNECT even if import is invalid */ ;
-                if (cfs_atomic_read(&imp->imp_inval_count) != 0) {
-                        DEBUG_REQ(D_ERROR, req, "invalidate in flight");
-                        *status = -EIO;
-                }
-        } else if (imp->imp_invalid || imp->imp_obd->obd_no_recov) {
-                if (!imp->imp_deactive)
-                          DEBUG_REQ(D_ERROR, req, "IMP_INVALID");
-                *status = -ESHUTDOWN; /* bz 12940 */
-        } else if (req->rq_import_generation != imp->imp_generation) {
+               /* probably doesn't need to be a D_ERROR after initial testing*/
+               DEBUG_REQ(D_HA, req, "send limit expired ");
+               *status = -ETIMEDOUT;
+       } else if (req->rq_send_state == LUSTRE_IMP_CONNECTING &&
+                  imp->imp_state == LUSTRE_IMP_CONNECTING) {
+               /* allow CONNECT even if import is invalid */ ;
+               if (atomic_read(&imp->imp_inval_count) != 0) {
+                       DEBUG_REQ(D_ERROR, req, "invalidate in flight");
+                       *status = -EIO;
+               }
+       } else if (imp->imp_invalid || imp->imp_obd->obd_no_recov) {
+               if (!imp->imp_deactive)
+                       DEBUG_REQ(D_NET, req, "IMP_INVALID");
+               *status = -ESHUTDOWN; /* bz 12940 */
+       } else if (req->rq_import_generation != imp->imp_generation) {
                 DEBUG_REQ(D_ERROR, req, "req wrong generation:");
                 *status = -EIO;
         } else if (req->rq_send_state != imp->imp_state) {
                 /* invalidate in progress - any requests should be drop */
-                if (cfs_atomic_read(&imp->imp_inval_count) != 0) {
+               if (atomic_read(&imp->imp_inval_count) != 0) {
                         DEBUG_REQ(D_ERROR, req, "invalidate in flight");
                         *status = -EIO;
                 } else if (imp->imp_dlm_fake || req->rq_no_delay) {
                         *status = -EWOULDBLOCK;
-                } else {
-                        delay = 1;
-                }
-        }
+               } else if (req->rq_allow_replay &&
+                         (imp->imp_state == LUSTRE_IMP_REPLAY ||
+                          imp->imp_state == LUSTRE_IMP_REPLAY_LOCKS ||
+                          imp->imp_state == LUSTRE_IMP_REPLAY_WAIT ||
+                          imp->imp_state == LUSTRE_IMP_RECOVER)) {
+                       DEBUG_REQ(D_HA, req, "allow during recovery.\n");
+               } else {
+                       delay = 1;
+               }
+       }
 
-        RETURN(delay);
+       RETURN(delay);
 }
 
 /**
- * Decide if the eror message regarding provided request \a req
- * should be printed to the console or not.
- * Makes it's decision on request status and other properties.
- * Returns 1 to print error on the system console or 0 if not.
+ * Decide if the error message should be printed to the console or not.
+ * Makes its decision based on request type, status, and failure frequency.
+ *
+ * \param[in] req  request that failed and may need a console message
+ *
+ * \retval false if no message should be printed
+ * \retval true  if console message should be printed
  */
-static int ptlrpc_console_allow(struct ptlrpc_request *req)
+static bool ptlrpc_console_allow(struct ptlrpc_request *req)
 {
-        __u32 opc;
-        int err;
+       __u32 opc;
 
-        /* Fake requests include no rq_reqmsg */
-        if (req->rq_fake)
-                return 0;
+       LASSERT(req->rq_reqmsg != NULL);
+       opc = lustre_msg_get_opc(req->rq_reqmsg);
 
-        LASSERT(req->rq_reqmsg != NULL);
-        opc = lustre_msg_get_opc(req->rq_reqmsg);
+       /* Suppress particular reconnect errors which are to be expected. */
+       if (opc == OST_CONNECT || opc == MDS_CONNECT || opc == MGS_CONNECT) {
+               int err;
 
-        /* Suppress particular reconnect errors which are to be expected.  No
-         * errors are suppressed for the initial connection on an import */
-        if ((lustre_handle_is_used(&req->rq_import->imp_remote_handle)) &&
-            (opc == OST_CONNECT || opc == MDS_CONNECT || opc == MGS_CONNECT)) {
+               /* Suppress timed out reconnect requests */
+               if (lustre_handle_is_used(&req->rq_import->imp_remote_handle) ||
+                   req->rq_timedout)
+                       return false;
 
-                /* Suppress timed out reconnect requests */
-                if (req->rq_timedout)
-                        return 0;
-
-                /* Suppress unavailable/again reconnect requests */
-                err = lustre_msg_get_status(req->rq_repmsg);
-                if (err == -ENODEV || err == -EAGAIN)
-                        return 0;
-        }
+               /* Suppress most unavailable/again reconnect requests, but
+                * print occasionally so it is clear client is trying to
+                * connect to a server where no target is running. */
+               err = lustre_msg_get_status(req->rq_repmsg);
+               if ((err == -ENODEV || err == -EAGAIN) &&
+                   req->rq_import->imp_conn_cnt % 30 != 20)
+                       return false;
+       }
 
-        return 1;
+       return true;
 }
 
 /**
@@ -1105,15 +1223,19 @@ static int ptlrpc_check_status(struct ptlrpc_request *req)
         ENTRY;
 
         err = lustre_msg_get_status(req->rq_repmsg);
-        if (lustre_msg_get_type(req->rq_repmsg) == PTL_RPC_MSG_ERR) {
-                struct obd_import *imp = req->rq_import;
-                __u32 opc = lustre_msg_get_opc(req->rq_reqmsg);
-                LCONSOLE_ERROR_MSG(0x011,"an error occurred while communicating"
-                                " with %s. The %s operation failed with %d\n",
-                                libcfs_nid2str(imp->imp_connection->c_peer.nid),
-                                ll_opcode2str(opc), err);
-                RETURN(err < 0 ? err : -EINVAL);
-        }
+       if (lustre_msg_get_type(req->rq_repmsg) == PTL_RPC_MSG_ERR) {
+               struct obd_import *imp = req->rq_import;
+               lnet_nid_t nid = imp->imp_connection->c_peer.nid;
+               __u32 opc = lustre_msg_get_opc(req->rq_reqmsg);
+
+               if (ptlrpc_console_allow(req))
+                       LCONSOLE_ERROR_MSG(0x11, "%s: operation %s to node %s "
+                                          "failed: rc = %d\n",
+                                          imp->imp_obd->obd_name,
+                                          ll_opcode2str(opc),
+                                          libcfs_nid2str(nid), err);
+               RETURN(err < 0 ? err : -EINVAL);
+       }
 
         if (err < 0) {
                 DEBUG_REQ(D_INFO, req, "status is %d", err);
@@ -1122,21 +1244,6 @@ static int ptlrpc_check_status(struct ptlrpc_request *req)
                 DEBUG_REQ(D_INFO, req, "status is %d", err);
         }
 
-        if (lustre_msg_get_type(req->rq_repmsg) == PTL_RPC_MSG_ERR) {
-                struct obd_import *imp = req->rq_import;
-                __u32 opc = lustre_msg_get_opc(req->rq_reqmsg);
-
-                if (ptlrpc_console_allow(req))
-                        LCONSOLE_ERROR_MSG(0x011,"an error occurred while "
-                                           "communicating with %s. The %s "
-                                           "operation failed with %d\n",
-                                           libcfs_nid2str(
-                                           imp->imp_connection->c_peer.nid),
-                                           ll_opcode2str(opc), err);
-
-                RETURN(err < 0 ? err : -EINVAL);
-        }
-
         RETURN(err);
 }
 
@@ -1176,14 +1283,15 @@ static int after_reply(struct ptlrpc_request *req)
         struct obd_device *obd = req->rq_import->imp_obd;
         int rc;
         struct timeval work_start;
+       __u64 committed;
         long timediff;
         ENTRY;
 
         LASSERT(obd != NULL);
         /* repbuf must be unlinked */
-        LASSERT(!req->rq_receiving_reply && !req->rq_must_unlink);
+       LASSERT(!req->rq_receiving_reply && req->rq_reply_unlinked);
 
-        if (req->rq_reply_truncate) {
+       if (req->rq_reply_truncated) {
                 if (ptlrpc_no_resend(req)) {
                         DEBUG_REQ(D_ERROR, req, "reply buffer overflow,"
                                   " expected: %d, actual size: %d",
@@ -1198,10 +1306,15 @@ static int after_reply(struct ptlrpc_request *req)
                  * will roundup it */
                 req->rq_replen       = req->rq_nob_received;
                 req->rq_nob_received = 0;
-                req->rq_resend       = 1;
+               spin_lock(&req->rq_lock);
+               req->rq_resend       = 1;
+               spin_unlock(&req->rq_lock);
                 RETURN(0);
         }
 
+       do_gettimeofday(&work_start);
+       timediff = cfs_timeval_sub(&work_start, &req->rq_sent_tv, NULL);
+
         /*
          * NB Until this point, the whole of the incoming message,
          * including buflens, status etc is in the sender's byte order.
@@ -1212,23 +1325,46 @@ static int after_reply(struct ptlrpc_request *req)
                 RETURN(rc);
         }
 
-        /*
-         * Security layer unwrap might ask resend this request.
-         */
-        if (req->rq_resend)
-                RETURN(0);
-
-        rc = unpack_reply(req);
-        if (rc)
-                RETURN(rc);
-
-        cfs_gettimeofday(&work_start);
-        timediff = cfs_timeval_sub(&work_start, &req->rq_arrival_time, NULL);
-        if (obd->obd_svc_stats != NULL) {
-                lprocfs_counter_add(obd->obd_svc_stats, PTLRPC_REQWAIT_CNTR,
-                                    timediff);
-                ptlrpc_lprocfs_rpc_sent(req, timediff);
-        }
+       /*
+        * Security layer unwrap might ask resend this request.
+        */
+       if (req->rq_resend)
+               RETURN(0);
+
+       rc = unpack_reply(req);
+       if (rc)
+               RETURN(rc);
+
+       /* retry indefinitely on EINPROGRESS */
+       if (lustre_msg_get_status(req->rq_repmsg) == -EINPROGRESS &&
+           ptlrpc_no_resend(req) == 0 && !req->rq_no_retry_einprogress) {
+               time_t  now = cfs_time_current_sec();
+
+               DEBUG_REQ(D_RPCTRACE, req, "Resending request on EINPROGRESS");
+               spin_lock(&req->rq_lock);
+               req->rq_resend = 1;
+               spin_unlock(&req->rq_lock);
+               req->rq_nr_resend++;
+
+               /* Readjust the timeout for current conditions */
+               ptlrpc_at_set_req_timeout(req);
+               /* delay resend to give a chance to the server to get ready.
+                * The delay is increased by 1s on every resend and is capped to
+                * the current request timeout (i.e. obd_timeout if AT is off,
+                * or AT service time x 125% + 5s, see at_est2timeout) */
+               if (req->rq_nr_resend > req->rq_timeout)
+                       req->rq_sent = now + req->rq_timeout;
+               else
+                       req->rq_sent = now + req->rq_nr_resend;
+
+               RETURN(0);
+       }
+
+       if (obd->obd_svc_stats != NULL) {
+               lprocfs_counter_add(obd->obd_svc_stats, PTLRPC_REQWAIT_CNTR,
+                                   timediff);
+               ptlrpc_lprocfs_rpc_sent(req, timediff);
+       }
 
         if (lustre_msg_get_type(req->rq_repmsg) != PTL_RPC_MSG_REPLY &&
             lustre_msg_get_type(req->rq_repmsg) != PTL_RPC_MSG_ERR) {
@@ -1246,20 +1382,20 @@ static int after_reply(struct ptlrpc_request *req)
         rc = ptlrpc_check_status(req);
         imp->imp_connect_error = rc;
 
-        if (rc) {
-                /*
-                 * Either we've been evicted, or the server has failed for
-                 * some reason. Try to reconnect, and if that fails, punt to
-                 * the upcall.
-                 */
-                if (ll_rpc_recoverable_error(rc)) {
-                        if (req->rq_send_state != LUSTRE_IMP_FULL ||
-                            imp->imp_obd->obd_no_recov || imp->imp_dlm_fake) {
-                                RETURN(rc);
-                        }
-                        ptlrpc_request_handle_notconn(req);
-                        RETURN(rc);
-                }
+       if (rc) {
+               /*
+                * Either we've been evicted, or the server has failed for
+                * some reason. Try to reconnect, and if that fails, punt to
+                * the upcall.
+                */
+               if (ptlrpc_recoverable_error(rc)) {
+                       if (req->rq_send_state != LUSTRE_IMP_FULL ||
+                           imp->imp_obd->obd_no_recov || imp->imp_dlm_fake) {
+                               RETURN(rc);
+                       }
+                       ptlrpc_request_handle_notconn(req);
+                       RETURN(rc);
+               }
         } else {
                 /*
                  * Let's look if server sent slv. Do it only for RPC with
@@ -1277,7 +1413,7 @@ static int after_reply(struct ptlrpc_request *req)
         }
 
         if (imp->imp_replayable) {
-                cfs_spin_lock(&imp->imp_lock);
+               spin_lock(&imp->imp_lock);
                 /*
                  * No point in adding already-committed requests to the replay
                  * list, we will just remove them immediately. b=9829
@@ -1289,28 +1425,43 @@ static int after_reply(struct ptlrpc_request *req)
                         /** version recovery */
                         ptlrpc_save_versions(req);
                         ptlrpc_retain_replayable_request(req, imp);
-                } else if (req->rq_commit_cb != NULL) {
-                        cfs_spin_unlock(&imp->imp_lock);
-                        req->rq_commit_cb(req);
-                        cfs_spin_lock(&imp->imp_lock);
+               } else if (req->rq_commit_cb != NULL &&
+                          list_empty(&req->rq_replay_list)) {
+                       /* NB: don't call rq_commit_cb if it's already on
+                        * rq_replay_list, ptlrpc_free_committed() will call
+                        * it later, see LU-3618 for details */
+                       spin_unlock(&imp->imp_lock);
+                       req->rq_commit_cb(req);
+                       spin_lock(&imp->imp_lock);
                 }
 
                 /*
                  * Replay-enabled imports return commit-status information.
                  */
-                if (lustre_msg_get_last_committed(req->rq_repmsg)) {
-                        imp->imp_peer_committed_transno =
-                                lustre_msg_get_last_committed(req->rq_repmsg);
-                }
-                ptlrpc_free_committed(imp);
+               committed = lustre_msg_get_last_committed(req->rq_repmsg);
+               if (likely(committed > imp->imp_peer_committed_transno))
+                       imp->imp_peer_committed_transno = committed;
 
-                if (req->rq_transno > imp->imp_peer_committed_transno)
-                        ptlrpc_pinger_commit_expected(imp);
+               ptlrpc_free_committed(imp);
 
-                cfs_spin_unlock(&imp->imp_lock);
-        }
+               if (!list_empty(&imp->imp_replay_list)) {
+                       struct ptlrpc_request *last;
 
-        RETURN(rc);
+                       last = list_entry(imp->imp_replay_list.prev,
+                                         struct ptlrpc_request,
+                                         rq_replay_list);
+                       /*
+                        * Requests with rq_replay stay on the list even if no
+                        * commit is expected.
+                        */
+                       if (last->rq_transno > imp->imp_peer_committed_transno)
+                               ptlrpc_pinger_commit_expected(imp);
+               }
+
+               spin_unlock(&imp->imp_lock);
+       }
+
+       RETURN(rc);
 }
 
 /**
@@ -1321,10 +1472,19 @@ static int after_reply(struct ptlrpc_request *req)
 static int ptlrpc_send_new_req(struct ptlrpc_request *req)
 {
         struct obd_import     *imp = req->rq_import;
+       struct list_head      *tmp;
+       __u64                  min_xid = ~0ULL;
         int rc;
         ENTRY;
 
         LASSERT(req->rq_phase == RQ_PHASE_NEW);
+
+       /* do not try to go further if there is not enough memory in enc_pool */
+       if (req->rq_sent && req->rq_bulk != NULL)
+               if (req->rq_bulk->bd_iov_count > get_free_pages_in_pool() &&
+                   pool_is_at_full_capacity())
+                       RETURN(-ENOMEM);
+
         if (req->rq_sent && (req->rq_sent > cfs_time_current_sec()) &&
             (!req->rq_generation_set ||
              req->rq_import_generation == imp->imp_generation))
@@ -1332,40 +1492,67 @@ static int ptlrpc_send_new_req(struct ptlrpc_request *req)
 
         ptlrpc_rqphase_move(req, RQ_PHASE_RPC);
 
-        cfs_spin_lock(&imp->imp_lock);
-
-        if (!req->rq_generation_set)
-                req->rq_import_generation = imp->imp_generation;
-
-        if (ptlrpc_import_delay_req(imp, req, &rc)) {
-                cfs_spin_lock(&req->rq_lock);
-                req->rq_waiting = 1;
-                cfs_spin_unlock(&req->rq_lock);
-
-                DEBUG_REQ(D_HA, req, "req from PID %d waiting for recovery: "
-                          "(%s != %s)", lustre_msg_get_status(req->rq_reqmsg),
-                          ptlrpc_import_state_name(req->rq_send_state),
-                          ptlrpc_import_state_name(imp->imp_state));
-                LASSERT(cfs_list_empty(&req->rq_list));
-                cfs_list_add_tail(&req->rq_list, &imp->imp_delayed_list);
-                cfs_atomic_inc(&req->rq_import->imp_inflight);
-                cfs_spin_unlock(&imp->imp_lock);
-                RETURN(0);
-        }
-
-        if (rc != 0) {
-                cfs_spin_unlock(&imp->imp_lock);
-                req->rq_status = rc;
-                ptlrpc_rqphase_move(req, RQ_PHASE_INTERPRET);
-                RETURN(rc);
-        }
-
-        LASSERT(cfs_list_empty(&req->rq_list));
-        cfs_list_add_tail(&req->rq_list, &imp->imp_sending_list);
-        cfs_atomic_inc(&req->rq_import->imp_inflight);
-        cfs_spin_unlock(&imp->imp_lock);
-
-        lustre_msg_set_status(req->rq_reqmsg, cfs_curproc_pid());
+       spin_lock(&imp->imp_lock);
+
+       /* the very first time we assign XID. it's important to assign XID
+        * and put it on the list atomically, so that the lowest assigned
+        * XID is always known. this is vital for multislot last_rcvd */
+       if (req->rq_send_state == LUSTRE_IMP_REPLAY) {
+               LASSERT(req->rq_xid != 0);
+       } else {
+               LASSERT(req->rq_xid == 0);
+               req->rq_xid = ptlrpc_next_xid();
+       }
+
+       if (!req->rq_generation_set)
+               req->rq_import_generation = imp->imp_generation;
+
+       if (ptlrpc_import_delay_req(imp, req, &rc)) {
+               spin_lock(&req->rq_lock);
+               req->rq_waiting = 1;
+               spin_unlock(&req->rq_lock);
+
+               DEBUG_REQ(D_HA, req, "req from PID %d waiting for recovery: "
+                         "(%s != %s)", lustre_msg_get_status(req->rq_reqmsg),
+                         ptlrpc_import_state_name(req->rq_send_state),
+                         ptlrpc_import_state_name(imp->imp_state));
+               LASSERT(list_empty(&req->rq_list));
+               list_add_tail(&req->rq_list, &imp->imp_delayed_list);
+               atomic_inc(&req->rq_import->imp_inflight);
+               spin_unlock(&imp->imp_lock);
+               RETURN(0);
+       }
+
+       if (rc != 0) {
+               spin_unlock(&imp->imp_lock);
+               req->rq_status = rc;
+               ptlrpc_rqphase_move(req, RQ_PHASE_INTERPRET);
+               RETURN(rc);
+       }
+
+       LASSERT(list_empty(&req->rq_list));
+       list_add_tail(&req->rq_list, &imp->imp_sending_list);
+       atomic_inc(&req->rq_import->imp_inflight);
+
+       /* find the lowest unreplied XID */
+       list_for_each(tmp, &imp->imp_delayed_list) {
+               struct ptlrpc_request *r;
+               r = list_entry(tmp, struct ptlrpc_request, rq_list);
+               if (r->rq_xid < min_xid)
+                       min_xid = r->rq_xid;
+       }
+       list_for_each(tmp, &imp->imp_sending_list) {
+               struct ptlrpc_request *r;
+               r = list_entry(tmp, struct ptlrpc_request, rq_list);
+               if (r->rq_xid < min_xid)
+                       min_xid = r->rq_xid;
+       }
+       spin_unlock(&imp->imp_lock);
+
+       if (likely(min_xid != ~0ULL))
+               lustre_msg_set_last_xid(req->rq_reqmsg, min_xid - 1);
+
+       lustre_msg_set_status(req->rq_reqmsg, current_pid());
 
         rc = sptlrpc_req_refresh_ctx(req, -1);
         if (rc) {
@@ -1373,49 +1560,99 @@ static int ptlrpc_send_new_req(struct ptlrpc_request *req)
                         req->rq_status = rc;
                         RETURN(1);
                 } else {
-                        req->rq_wait_ctx = 1;
+                       spin_lock(&req->rq_lock);
+                       req->rq_wait_ctx = 1;
+                       spin_unlock(&req->rq_lock);
                         RETURN(0);
                 }
         }
 
-        CDEBUG(D_RPCTRACE, "Sending RPC pname:cluuid:pid:xid:nid:opc"
-               " %s:%s:%d:"LPU64":%s:%d\n", cfs_curproc_comm(),
-               imp->imp_obd->obd_uuid.uuid,
-               lustre_msg_get_status(req->rq_reqmsg), req->rq_xid,
-               libcfs_nid2str(imp->imp_connection->c_peer.nid),
-               lustre_msg_get_opc(req->rq_reqmsg));
+       CDEBUG(D_RPCTRACE, "Sending RPC pname:cluuid:pid:xid:nid:opc"
+              " %s:%s:%d:"LPU64":%s:%d\n", current_comm(),
+              imp->imp_obd->obd_uuid.uuid,
+              lustre_msg_get_status(req->rq_reqmsg), req->rq_xid,
+              libcfs_nid2str(imp->imp_connection->c_peer.nid),
+              lustre_msg_get_opc(req->rq_reqmsg));
 
         rc = ptl_send_rpc(req, 0);
+       if (rc == -ENOMEM) {
+               spin_lock(&imp->imp_lock);
+               if (!list_empty(&req->rq_list)) {
+                       list_del_init(&req->rq_list);
+                       atomic_dec(&req->rq_import->imp_inflight);
+               }
+               spin_unlock(&imp->imp_lock);
+               ptlrpc_rqphase_move(req, RQ_PHASE_NEW);
+               RETURN(rc);
+       }
         if (rc) {
                 DEBUG_REQ(D_HA, req, "send failed (%d); expect timeout", rc);
-                req->rq_net_err = 1;
+               spin_lock(&req->rq_lock);
+               req->rq_net_err = 1;
+               spin_unlock(&req->rq_lock);
                 RETURN(rc);
         }
         RETURN(0);
 }
 
+static inline int ptlrpc_set_producer(struct ptlrpc_request_set *set)
+{
+       int remaining, rc;
+       ENTRY;
+
+       LASSERT(set->set_producer != NULL);
+
+       remaining = atomic_read(&set->set_remaining);
+
+       /* populate the ->set_requests list with requests until we
+        * reach the maximum number of RPCs in flight for this set */
+       while (atomic_read(&set->set_remaining) < set->set_max_inflight) {
+               rc = set->set_producer(set, set->set_producer_arg);
+               if (rc == -ENOENT) {
+                       /* no more RPC to produce */
+                       set->set_producer     = NULL;
+                       set->set_producer_arg = NULL;
+                       RETURN(0);
+               }
+       }
+
+       RETURN((atomic_read(&set->set_remaining) - remaining));
+}
+
 /**
  * this sends any unsent RPCs in \a set and returns 1 if all are sent
  * and no more replies are expected.
  * (it is possible to get less replies than requests sent e.g. due to timed out
  * requests or requests that we had trouble to send out)
+ *
+ * NOTE: This function contains a potential schedule point (cond_resched()).
  */
 int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
 {
-        cfs_list_t *tmp;
-        int force_timer_recalc = 0;
-        ENTRY;
-
-        if (cfs_atomic_read(&set->set_remaining) == 0)
-                RETURN(1);
-
-        cfs_list_for_each(tmp, &set->set_requests) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(tmp, struct ptlrpc_request,
-                                       rq_set_chain);
-                struct obd_import *imp = req->rq_import;
-                int unregistered = 0;
-                int rc = 0;
+       struct list_head *tmp, *next;
+       struct list_head  comp_reqs;
+       int force_timer_recalc = 0;
+       ENTRY;
+
+       if (atomic_read(&set->set_remaining) == 0)
+               RETURN(1);
+
+       INIT_LIST_HEAD(&comp_reqs);
+       list_for_each_safe(tmp, next, &set->set_requests) {
+               struct ptlrpc_request *req =
+                       list_entry(tmp, struct ptlrpc_request,
+                                  rq_set_chain);
+               struct obd_import *imp = req->rq_import;
+               int unregistered = 0;
+               int rc = 0;
+
+               /* This schedule point is mainly for the ptlrpcd caller of this
+                * function.  Most ptlrpc sets are not long-lived and unbounded
+                * in length, but at the least the set used by the ptlrpcd is.
+                * Since the processing time is unbounded, we need to insert an
+                * explicit schedule point to make the thread well-behaved.
+                */
+               cond_resched();
 
                 if (req->rq_phase == RQ_PHASE_NEW &&
                     ptlrpc_send_new_req(req)) {
@@ -1424,7 +1661,12 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
 
                 /* delayed send - skip */
                 if (req->rq_phase == RQ_PHASE_NEW && req->rq_sent)
-                        continue;
+                       continue;
+
+               /* delayed resend - skip */
+               if (req->rq_phase == RQ_PHASE_RPC && req->rq_resend &&
+                   req->rq_sent > cfs_time_current_sec())
+                       continue;
 
                 if (!(req->rq_phase == RQ_PHASE_RPC ||
                       req->rq_phase == RQ_PHASE_BULK ||
@@ -1470,8 +1712,10 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
                         ptlrpc_rqphase_move(req, req->rq_next_phase);
                 }
 
-                if (req->rq_phase == RQ_PHASE_COMPLETE)
+                if (req->rq_phase == RQ_PHASE_COMPLETE) {
+                       list_move_tail(&req->rq_set_chain, &comp_reqs);
                         continue;
+               }
 
                 if (req->rq_phase == RQ_PHASE_INTERPRET)
                         GOTO(interpret, req->rq_status);
@@ -1500,9 +1744,9 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
                 }
 
                 if (req->rq_err) {
-                        cfs_spin_lock(&req->rq_lock);
-                        req->rq_replied = 0;
-                        cfs_spin_unlock(&req->rq_lock);
+                       spin_lock(&req->rq_lock);
+                       req->rq_replied = 0;
+                       spin_unlock(&req->rq_lock);
                         if (req->rq_status == 0)
                                 req->rq_status = -EIO;
                         ptlrpc_rqphase_move(req, RQ_PHASE_INTERPRET);
@@ -1511,7 +1755,7 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
 
                 /* ptlrpc_set_wait->l_wait_event sets lwi_allow_intr
                  * so it sets rq_intr regardless of individual rpc
-                 * timeouts. The synchronous IO waiting path sets 
+                * timeouts. The synchronous IO waiting path sets
                  * rq_intr irrespective of whether ptlrpcd
                  * has seen a timeout.  Our policy is to only interpret
                  * interrupted rpcs after they have timed out, so we
@@ -1530,18 +1774,20 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
                             req->rq_waiting || req->rq_wait_ctx) {
                                 int status;
 
-                                if (!ptlrpc_unregister_reply(req, 1))
-                                        continue;
-
-                                cfs_spin_lock(&imp->imp_lock);
-                                if (ptlrpc_import_delay_req(imp, req, &status)){
-                                        /* put on delay list - only if we wait
-                                         * recovery finished - before send */
-                                        cfs_list_del_init(&req->rq_list);
-                                        cfs_list_add_tail(&req->rq_list,
-                                                          &imp-> \
-                                                          imp_delayed_list);
-                                        cfs_spin_unlock(&imp->imp_lock);
+                               if (!ptlrpc_unregister_reply(req, 1)) {
+                                       ptlrpc_unregister_bulk(req, 1);
+                                       continue;
+                               }
+
+                               spin_lock(&imp->imp_lock);
+                               if (ptlrpc_import_delay_req(imp, req, &status)){
+                                       /* put on delay list - only if we wait
+                                        * recovery finished - before send */
+                                       list_del_init(&req->rq_list);
+                                       list_add_tail(&req->rq_list,
+                                                         &imp->
+                                                         imp_delayed_list);
+                                       spin_unlock(&imp->imp_lock);
                                         continue;
                                 }
 
@@ -1549,47 +1795,38 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
                                         req->rq_status = status;
                                         ptlrpc_rqphase_move(req,
                                                 RQ_PHASE_INTERPRET);
-                                        cfs_spin_unlock(&imp->imp_lock);
-                                        GOTO(interpret, req->rq_status);
-                                }
-                                if (ptlrpc_no_resend(req) && !req->rq_wait_ctx) {
-                                        req->rq_status = -ENOTCONN;
-                                        ptlrpc_rqphase_move(req,
-                                                RQ_PHASE_INTERPRET);
-                                        cfs_spin_unlock(&imp->imp_lock);
-                                        GOTO(interpret, req->rq_status);
-                                }
-
-                                cfs_list_del_init(&req->rq_list);
-                                cfs_list_add_tail(&req->rq_list,
-                                              &imp->imp_sending_list);
-
-                                cfs_spin_unlock(&imp->imp_lock);
-
-                                cfs_spin_lock(&req->rq_lock);
-                                req->rq_waiting = 0;
-                                cfs_spin_unlock(&req->rq_lock);
-
-                                if (req->rq_timedout || req->rq_resend) {
-                                        /* This is re-sending anyways,
-                                         * let's mark req as resend. */
-                                        cfs_spin_lock(&req->rq_lock);
-                                        req->rq_resend = 1;
-                                        cfs_spin_unlock(&req->rq_lock);
-                                        if (req->rq_bulk) {
-                                                __u64 old_xid;
-
-                                                if (!ptlrpc_unregister_bulk(req, 1))
-                                                        continue;
-
-                                                /* ensure previous bulk fails */
-                                                old_xid = req->rq_xid;
-                                                req->rq_xid = ptlrpc_next_xid();
-                                                CDEBUG(D_HA, "resend bulk "
-                                                       "old x"LPU64
-                                                       " new x"LPU64"\n",
-                                                       old_xid, req->rq_xid);
-                                        }
+                                       spin_unlock(&imp->imp_lock);
+                                       GOTO(interpret, req->rq_status);
+                               }
+                               if (ptlrpc_no_resend(req) &&
+                                   !req->rq_wait_ctx) {
+                                       req->rq_status = -ENOTCONN;
+                                       ptlrpc_rqphase_move(req,
+                                                           RQ_PHASE_INTERPRET);
+                                       spin_unlock(&imp->imp_lock);
+                                       GOTO(interpret, req->rq_status);
+                               }
+
+                               list_del_init(&req->rq_list);
+                               list_add_tail(&req->rq_list,
+                                                 &imp->imp_sending_list);
+
+                               spin_unlock(&imp->imp_lock);
+
+                               spin_lock(&req->rq_lock);
+                               req->rq_waiting = 0;
+                               spin_unlock(&req->rq_lock);
+
+                               if (req->rq_timedout || req->rq_resend) {
+                                       /* This is re-sending anyways,
+                                        * let's mark req as resend. */
+                                       spin_lock(&req->rq_lock);
+                                       req->rq_resend = 1;
+                                       spin_unlock(&req->rq_lock);
+
+                                       if (req->rq_bulk != NULL &&
+                                           !ptlrpc_unregister_bulk(req, 1))
+                                               continue;
                                 }
                                 /*
                                  * rq_wait_ctx is only touched by ptlrpcd,
@@ -1599,57 +1836,66 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
                                 if (status) {
                                         if (req->rq_err) {
                                                 req->rq_status = status;
-                                                cfs_spin_lock(&req->rq_lock);
-                                                req->rq_wait_ctx = 0;
-                                                cfs_spin_unlock(&req->rq_lock);
-                                                force_timer_recalc = 1;
-                                        } else {
-                                                cfs_spin_lock(&req->rq_lock);
-                                                req->rq_wait_ctx = 1;
-                                                cfs_spin_unlock(&req->rq_lock);
-                                        }
-
-                                        continue;
-                                } else {
-                                        cfs_spin_lock(&req->rq_lock);
-                                        req->rq_wait_ctx = 0;
-                                        cfs_spin_unlock(&req->rq_lock);
-                                }
-
-                                rc = ptl_send_rpc(req, 0);
-                                if (rc) {
-                                        DEBUG_REQ(D_HA, req, "send failed (%d)",
-                                                  rc);
-                                        force_timer_recalc = 1;
-                                        cfs_spin_lock(&req->rq_lock);
-                                        req->rq_net_err = 1;
-                                        cfs_spin_unlock(&req->rq_lock);
-                                }
-                                /* need to reset the timeout */
-                                force_timer_recalc = 1;
-                        }
-
-                        cfs_spin_lock(&req->rq_lock);
-
-                        if (ptlrpc_client_early(req)) {
-                                ptlrpc_at_recv_early_reply(req);
-                                cfs_spin_unlock(&req->rq_lock);
-                                continue;
-                        }
-
-                        /* Still waiting for a reply? */
-                        if (ptlrpc_client_recv(req)) {
-                                cfs_spin_unlock(&req->rq_lock);
-                                continue;
-                        }
-
-                        /* Did we actually receive a reply? */
-                        if (!ptlrpc_client_replied(req)) {
-                                cfs_spin_unlock(&req->rq_lock);
-                                continue;
-                        }
-
-                        cfs_spin_unlock(&req->rq_lock);
+                                               spin_lock(&req->rq_lock);
+                                               req->rq_wait_ctx = 0;
+                                               spin_unlock(&req->rq_lock);
+                                               force_timer_recalc = 1;
+                                       } else {
+                                               spin_lock(&req->rq_lock);
+                                               req->rq_wait_ctx = 1;
+                                               spin_unlock(&req->rq_lock);
+                                       }
+
+                                       continue;
+                               } else {
+                                       spin_lock(&req->rq_lock);
+                                       req->rq_wait_ctx = 0;
+                                       spin_unlock(&req->rq_lock);
+                               }
+
+                               rc = ptl_send_rpc(req, 0);
+                               if (rc == -ENOMEM) {
+                                       spin_lock(&imp->imp_lock);
+                                       if (!list_empty(&req->rq_list))
+                                               list_del_init(&req->rq_list);
+                                       spin_unlock(&imp->imp_lock);
+                                       ptlrpc_rqphase_move(req, RQ_PHASE_NEW);
+                                       continue;
+                               }
+                               if (rc) {
+                                       DEBUG_REQ(D_HA, req,
+                                                 "send failed: rc = %d", rc);
+                                       force_timer_recalc = 1;
+                                       spin_lock(&req->rq_lock);
+                                       req->rq_net_err = 1;
+                                       spin_unlock(&req->rq_lock);
+                                       continue;
+                               }
+                               /* need to reset the timeout */
+                               force_timer_recalc = 1;
+                       }
+
+                       spin_lock(&req->rq_lock);
+
+                       if (ptlrpc_client_early(req)) {
+                               ptlrpc_at_recv_early_reply(req);
+                               spin_unlock(&req->rq_lock);
+                               continue;
+                       }
+
+                       /* Still waiting for a reply? */
+                       if (ptlrpc_client_recv(req)) {
+                               spin_unlock(&req->rq_lock);
+                               continue;
+                       }
+
+                       /* Did we actually receive a reply? */
+                       if (!ptlrpc_client_replied(req)) {
+                               spin_unlock(&req->rq_lock);
+                               continue;
+                       }
+
+                       spin_unlock(&req->rq_lock);
 
                         /* unlink from net because we are going to
                          * swab in-place of reply buffer */
@@ -1678,14 +1924,14 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
                 if (ptlrpc_client_bulk_active(req))
                         continue;
 
-                if (!req->rq_bulk->bd_success) {
-                        /* The RPC reply arrived OK, but the bulk screwed
-                         * up!  Dead weird since the server told us the RPC
-                         * was good after getting the REPLY for her GET or
-                         * the ACK for her PUT. */
-                        DEBUG_REQ(D_ERROR, req, "bulk transfer failed");
-                        req->rq_status = -EIO;
-                }
+               if (req->rq_bulk->bd_failure) {
+                       /* The RPC reply arrived OK, but the bulk screwed
+                        * up!  Dead weird since the server told us the RPC
+                        * was good after getting the REPLY for her GET or
+                        * the ACK for her PUT. */
+                       DEBUG_REQ(D_ERROR, req, "bulk transfer failed");
+                       req->rq_status = -EIO;
+               }
 
                 ptlrpc_rqphase_move(req, RQ_PHASE_INTERPRET);
 
@@ -1709,34 +1955,64 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
 
                 ptlrpc_req_interpret(env, req, req->rq_status);
 
-                ptlrpc_rqphase_move(req, RQ_PHASE_COMPLETE);
-
-                CDEBUG(D_RPCTRACE, "Completed RPC pname:cluuid:pid:xid:nid:"
-                       "opc %s:%s:%d:"LPU64":%s:%d\n", cfs_curproc_comm(),
-                       imp->imp_obd->obd_uuid.uuid,
-                       req->rq_reqmsg ? lustre_msg_get_status(req->rq_reqmsg):-1,
-                       req->rq_xid,
-                       libcfs_nid2str(imp->imp_connection->c_peer.nid),
-                       req->rq_reqmsg ? lustre_msg_get_opc(req->rq_reqmsg) : -1);
-
-                cfs_spin_lock(&imp->imp_lock);
-                /* Request already may be not on sending or delaying list. This
-                 * may happen in the case of marking it erroneous for the case
-                 * ptlrpc_import_delay_req(req, status) find it impossible to
-                 * allow sending this rpc and returns *status != 0. */
-                if (!cfs_list_empty(&req->rq_list)) {
-                        cfs_list_del_init(&req->rq_list);
-                        cfs_atomic_dec(&imp->imp_inflight);
-                }
-                cfs_spin_unlock(&imp->imp_lock);
-
-                cfs_atomic_dec(&set->set_remaining);
-                cfs_waitq_broadcast(&imp->imp_recovery_waitq);
-        }
-
-        /* If we hit an error, we want to recover promptly. */
-        RETURN(cfs_atomic_read(&set->set_remaining) == 0 || force_timer_recalc);
-}
+               if (ptlrpcd_check_work(req)) {
+                       atomic_dec(&set->set_remaining);
+                       continue;
+               }
+               ptlrpc_rqphase_move(req, RQ_PHASE_COMPLETE);
+
+               CDEBUG(req->rq_reqmsg != NULL ? D_RPCTRACE : 0,
+                       "Completed RPC pname:cluuid:pid:xid:nid:"
+                       "opc %s:%s:%d:"LPU64":%s:%d\n",
+                       current_comm(), imp->imp_obd->obd_uuid.uuid,
+                       lustre_msg_get_status(req->rq_reqmsg), req->rq_xid,
+                       libcfs_nid2str(imp->imp_connection->c_peer.nid),
+                       lustre_msg_get_opc(req->rq_reqmsg));
+
+               spin_lock(&imp->imp_lock);
+               /* Request already may be not on sending or delaying list. This
+                * may happen in the case of marking it erroneous for the case
+                * ptlrpc_import_delay_req(req, status) find it impossible to
+                * allow sending this rpc and returns *status != 0. */
+               if (!list_empty(&req->rq_list)) {
+                       list_del_init(&req->rq_list);
+                       atomic_dec(&imp->imp_inflight);
+               }
+               spin_unlock(&imp->imp_lock);
+
+               atomic_dec(&set->set_remaining);
+               wake_up_all(&imp->imp_recovery_waitq);
+
+               if (set->set_producer) {
+                       /* produce a new request if possible */
+                       if (ptlrpc_set_producer(set) > 0)
+                               force_timer_recalc = 1;
+
+                       /* free the request that has just been completed
+                        * in order not to pollute set->set_requests */
+                       list_del_init(&req->rq_set_chain);
+                       spin_lock(&req->rq_lock);
+                       req->rq_set = NULL;
+                       req->rq_invalid_rqset = 0;
+                       spin_unlock(&req->rq_lock);
+
+                       /* record rq_status to compute the final status later */
+                       if (req->rq_status != 0)
+                               set->set_rc = req->rq_status;
+                       ptlrpc_req_finished(req);
+               } else {
+                       list_move_tail(&req->rq_set_chain, &comp_reqs);
+               }
+       }
+
+       /* move completed request at the head of list so it's easier for
+        * caller to find them */
+       list_splice(&comp_reqs, &set->set_requests);
+
+       /* If we hit an error, we want to recover promptly. */
+       RETURN(atomic_read(&set->set_remaining) == 0 || force_timer_recalc);
+}
+EXPORT_SYMBOL(ptlrpc_check_set);
 
 /**
  * Time out request \a req. is \a async_unlink is set, that means do not wait
@@ -1745,17 +2021,16 @@ int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set)
  */
 int ptlrpc_expire_one_request(struct ptlrpc_request *req, int async_unlink)
 {
-        struct obd_import *imp = req->rq_import;
-        int rc = 0;
-        ENTRY;
+       struct obd_import *imp = req->rq_import;
+       int rc = 0;
+       ENTRY;
 
-        cfs_spin_lock(&req->rq_lock);
-        req->rq_timedout = 1;
-        cfs_spin_unlock(&req->rq_lock);
+       spin_lock(&req->rq_lock);
+       req->rq_timedout = 1;
+       spin_unlock(&req->rq_lock);
 
-        DEBUG_REQ(req->rq_fake ? D_INFO : D_WARNING, req, "Request "
-                  " sent has %s: [sent "CFS_DURATION_T"/"
-                  "real "CFS_DURATION_T"]",
+       DEBUG_REQ(D_WARNING, req, "Request sent has %s: [sent "CFS_DURATION_T
+                 "/real "CFS_DURATION_T"]",
                   req->rq_net_err ? "failed due to network error" :
                      ((req->rq_real_sent == 0 ||
                        cfs_time_before(req->rq_real_sent, req->rq_sent) ||
@@ -1777,10 +2052,7 @@ int ptlrpc_expire_one_request(struct ptlrpc_request *req, int async_unlink)
                 RETURN(1);
         }
 
-        if (req->rq_fake)
-               RETURN(1);
-
-        cfs_atomic_inc(&imp->imp_timeouts);
+       atomic_inc(&imp->imp_timeouts);
 
         /* The DLM server doesn't want recovery run on its imports. */
         if (imp->imp_dlm_fake)
@@ -1794,11 +2066,11 @@ int ptlrpc_expire_one_request(struct ptlrpc_request *req, int async_unlink)
                 DEBUG_REQ(D_RPCTRACE, req, "err -110, sent_state=%s (now=%s)",
                           ptlrpc_import_state_name(req->rq_send_state),
                           ptlrpc_import_state_name(imp->imp_state));
-                cfs_spin_lock(&req->rq_lock);
-                req->rq_status = -ETIMEDOUT;
-                req->rq_err = 1;
-                cfs_spin_unlock(&req->rq_lock);
-                RETURN(1);
+               spin_lock(&req->rq_lock);
+               req->rq_status = -ETIMEDOUT;
+               req->rq_err = 1;
+               spin_unlock(&req->rq_lock);
+               RETURN(1);
         }
 
         /* if a request can't be resent we can't wait for an answer after
@@ -1820,20 +2092,20 @@ int ptlrpc_expire_one_request(struct ptlrpc_request *req, int async_unlink)
  */
 int ptlrpc_expired_set(void *data)
 {
-        struct ptlrpc_request_set *set = data;
-        cfs_list_t                *tmp;
-        time_t                     now = cfs_time_current_sec();
-        ENTRY;
+       struct ptlrpc_request_set       *set = data;
+       struct list_head                *tmp;
+       time_t                          now = cfs_time_current_sec();
+       ENTRY;
 
-        LASSERT(set != NULL);
+       LASSERT(set != NULL);
 
-        /*
-         * A timeout expired. See which reqs it applies to...
-         */
-        cfs_list_for_each (tmp, &set->set_requests) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(tmp, struct ptlrpc_request,
-                                       rq_set_chain);
+       /*
+        * A timeout expired. See which reqs it applies to...
+        */
+       list_for_each(tmp, &set->set_requests) {
+               struct ptlrpc_request *req =
+                       list_entry(tmp, struct ptlrpc_request,
+                                  rq_set_chain);
 
                 /* don't expire request waiting for context */
                 if (req->rq_wait_ctx)
@@ -1867,34 +2139,34 @@ int ptlrpc_expired_set(void *data)
  */
 void ptlrpc_mark_interrupted(struct ptlrpc_request *req)
 {
-        cfs_spin_lock(&req->rq_lock);
-        req->rq_intr = 1;
-        cfs_spin_unlock(&req->rq_lock);
+       spin_lock(&req->rq_lock);
+       req->rq_intr = 1;
+       spin_unlock(&req->rq_lock);
 }
+EXPORT_SYMBOL(ptlrpc_mark_interrupted);
 
 /**
  * Interrupts (sets interrupted flag) all uncompleted requests in
  * a set \a data. Callback for l_wait_event for interruptible waits.
  */
-void ptlrpc_interrupted_set(void *data)
+static void ptlrpc_interrupted_set(void *data)
 {
-        struct ptlrpc_request_set *set = data;
-        cfs_list_t *tmp;
+       struct ptlrpc_request_set *set = data;
+       struct list_head *tmp;
 
-        LASSERT(set != NULL);
-        CDEBUG(D_RPCTRACE, "INTERRUPTED SET %p\n", set);
+       LASSERT(set != NULL);
+       CDEBUG(D_RPCTRACE, "INTERRUPTED SET %p\n", set);
 
-        cfs_list_for_each(tmp, &set->set_requests) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(tmp, struct ptlrpc_request,
-                                       rq_set_chain);
+       list_for_each(tmp, &set->set_requests) {
+               struct ptlrpc_request *req =
+                       list_entry(tmp, struct ptlrpc_request, rq_set_chain);
 
-                if (req->rq_phase != RQ_PHASE_RPC &&
-                    req->rq_phase != RQ_PHASE_UNREGISTERING)
-                        continue;
+               if (req->rq_phase != RQ_PHASE_RPC &&
+                   req->rq_phase != RQ_PHASE_UNREGISTERING)
+                       continue;
 
-                ptlrpc_mark_interrupted(req);
-        }
+               ptlrpc_mark_interrupted(req);
+       }
 }
 
 /**
@@ -1902,17 +2174,15 @@ void ptlrpc_interrupted_set(void *data)
  */
 int ptlrpc_set_next_timeout(struct ptlrpc_request_set *set)
 {
-        cfs_list_t            *tmp;
-        time_t                 now = cfs_time_current_sec();
-        int                    timeout = 0;
-        struct ptlrpc_request *req;
-        int                    deadline;
-        ENTRY;
-
-        SIGNAL_MASK_ASSERT(); /* XXX BUG 1511 */
+       struct list_head        *tmp;
+       time_t                   now = cfs_time_current_sec();
+       int                      timeout = 0;
+       struct ptlrpc_request   *req;
+       int                      deadline;
+       ENTRY;
 
-        cfs_list_for_each(tmp, &set->set_requests) {
-                req = cfs_list_entry(tmp, struct ptlrpc_request, rq_set_chain);
+       list_for_each(tmp, &set->set_requests) {
+               req = list_entry(tmp, struct ptlrpc_request, rq_set_chain);
 
                 /*
                  * Request in-flight?
@@ -1936,6 +2206,8 @@ int ptlrpc_set_next_timeout(struct ptlrpc_request_set *set)
 
                 if (req->rq_phase == RQ_PHASE_NEW)
                         deadline = req->rq_sent;
+               else if (req->rq_phase == RQ_PHASE_RPC && req->rq_resend)
+                       deadline = req->rq_sent;
                 else
                         deadline = req->rq_sent + req->rq_timeout;
 
@@ -1955,21 +2227,25 @@ int ptlrpc_set_next_timeout(struct ptlrpc_request_set *set)
  */
 int ptlrpc_set_wait(struct ptlrpc_request_set *set)
 {
-        cfs_list_t            *tmp;
+       struct list_head            *tmp;
         struct ptlrpc_request *req;
         struct l_wait_info     lwi;
         int                    rc, timeout;
         ENTRY;
 
-        if (cfs_list_empty(&set->set_requests))
+       if (set->set_producer)
+               (void)ptlrpc_set_producer(set);
+       else
+               list_for_each(tmp, &set->set_requests) {
+                       req = list_entry(tmp, struct ptlrpc_request,
+                                        rq_set_chain);
+                       if (req->rq_phase == RQ_PHASE_NEW)
+                               (void)ptlrpc_send_new_req(req);
+               }
+
+       if (list_empty(&set->set_requests))
                 RETURN(0);
 
-        cfs_list_for_each(tmp, &set->set_requests) {
-                req = cfs_list_entry(tmp, struct ptlrpc_request, rq_set_chain);
-                if (req->rq_phase == RQ_PHASE_NEW)
-                        (void)ptlrpc_send_new_req(req);
-        }
-
         do {
                 timeout = ptlrpc_set_next_timeout(set);
 
@@ -1978,21 +2254,21 @@ int ptlrpc_set_wait(struct ptlrpc_request_set *set)
                 CDEBUG(D_RPCTRACE, "set %p going to sleep for %d seconds\n",
                        set, timeout);
 
-                if (timeout == 0 && !cfs_signal_pending())
+               if (timeout == 0 && !signal_pending(current))
                         /*
                          * No requests are in-flight (ether timed out
                          * or delayed), so we can allow interrupts.
                          * We still want to block for a limited time,
                          * so we allow interrupts during the timeout.
                          */
-                        lwi = LWI_TIMEOUT_INTR_ALL(cfs_time_seconds(1), 
+                       lwi = LWI_TIMEOUT_INTR_ALL(cfs_time_seconds(1),
                                                    ptlrpc_expired_set,
                                                    ptlrpc_interrupted_set, set);
                 else
                         /*
                          * At least one request is in flight, so no
                          * interrupts are allowed. Wait until all
-                         * complete, or an in-flight req times out. 
+                        * complete, or an in-flight req times out.
                          */
                         lwi = LWI_TIMEOUT(cfs_time_seconds(timeout? timeout : 1),
                                           ptlrpc_expired_set, set);
@@ -2002,19 +2278,19 @@ int ptlrpc_set_wait(struct ptlrpc_request_set *set)
                 /* LU-769 - if we ignored the signal because it was already
                  * pending when we started, we need to handle it now or we risk
                  * it being ignored forever */
-                if (rc == -ETIMEDOUT && !lwi.lwi_allow_intr &&
-                    cfs_signal_pending()) {
-                        cfs_sigset_t blocked_sigs =
-                                           cfs_block_sigsinv(LUSTRE_FATAL_SIGS);
-
-                        /* In fact we only interrupt for the "fatal" signals
-                         * like SIGINT or SIGKILL. We still ignore less
-                         * important signals since ptlrpc set is not easily
-                         * reentrant from userspace again */
-                        if (cfs_signal_pending())
-                                ptlrpc_interrupted_set(set);
-                        cfs_block_sigs(blocked_sigs);
-                }
+               if (rc == -ETIMEDOUT && !lwi.lwi_allow_intr &&
+                   signal_pending(current)) {
+                       sigset_t blocked_sigs =
+                                          cfs_block_sigsinv(LUSTRE_FATAL_SIGS);
+
+                       /* In fact we only interrupt for the "fatal" signals
+                        * like SIGINT or SIGKILL. We still ignore less
+                        * important signals since ptlrpc set is not easily
+                        * reentrant from userspace again */
+                       if (signal_pending(current))
+                               ptlrpc_interrupted_set(set);
+                       cfs_restore_sigs(blocked_sigs);
+               }
 
                 LASSERT(rc == 0 || rc == -EINTR || rc == -ETIMEDOUT);
 
@@ -2025,22 +2301,22 @@ int ptlrpc_set_wait(struct ptlrpc_request_set *set)
                  * EINTR.
                  * I don't really care if we go once more round the loop in
                  * the error cases -eeb. */
-                if (rc == 0 && cfs_atomic_read(&set->set_remaining) == 0) {
-                        cfs_list_for_each(tmp, &set->set_requests) {
-                                req = cfs_list_entry(tmp, struct ptlrpc_request,
-                                                     rq_set_chain);
-                                cfs_spin_lock(&req->rq_lock);
-                                req->rq_invalid_rqset = 1;
-                                cfs_spin_unlock(&req->rq_lock);
-                        }
-                }
-        } while (rc != 0 || cfs_atomic_read(&set->set_remaining) != 0);
-
-        LASSERT(cfs_atomic_read(&set->set_remaining) == 0);
-
-        rc = 0;
-        cfs_list_for_each(tmp, &set->set_requests) {
-                req = cfs_list_entry(tmp, struct ptlrpc_request, rq_set_chain);
+               if (rc == 0 && atomic_read(&set->set_remaining) == 0) {
+                       list_for_each(tmp, &set->set_requests) {
+                               req = list_entry(tmp, struct ptlrpc_request,
+                                                rq_set_chain);
+                               spin_lock(&req->rq_lock);
+                               req->rq_invalid_rqset = 1;
+                               spin_unlock(&req->rq_lock);
+                       }
+               }
+       } while (rc != 0 || atomic_read(&set->set_remaining) != 0);
+
+       LASSERT(atomic_read(&set->set_remaining) == 0);
+
+        rc = set->set_rc; /* rq_status of already freed requests if any */
+       list_for_each(tmp, &set->set_requests) {
+               req = list_entry(tmp, struct ptlrpc_request, rq_set_chain);
 
                 LASSERT(req->rq_phase == RQ_PHASE_COMPLETE);
                 if (req->rq_status != 0)
@@ -2055,9 +2331,9 @@ int ptlrpc_set_wait(struct ptlrpc_request_set *set)
                 struct ptlrpc_set_cbdata *cbdata, *n;
                 int err;
 
-                cfs_list_for_each_entry_safe(cbdata, n,
+               list_for_each_entry_safe(cbdata, n,
                                          &set->set_cblist, psc_item) {
-                        cfs_list_del_init(&cbdata->psc_item);
+                       list_del_init(&cbdata->psc_item);
                         err = cbdata->psc_interpret(set, cbdata->psc_data, rc);
                         if (err && !rc)
                                 rc = err;
@@ -2067,6 +2343,7 @@ int ptlrpc_set_wait(struct ptlrpc_request_set *set)
 
         RETURN(rc);
 }
+EXPORT_SYMBOL(ptlrpc_set_wait);
 
 /**
  * Helper fuction for request freeing.
@@ -2078,50 +2355,46 @@ int ptlrpc_set_wait(struct ptlrpc_request_set *set)
  */
 static void __ptlrpc_free_req(struct ptlrpc_request *request, int locked)
 {
-        ENTRY;
-        if (request == NULL) {
-                EXIT;
-                return;
-        }
+       ENTRY;
 
-        LASSERTF(!request->rq_receiving_reply, "req %p\n", request);
-        LASSERTF(request->rq_rqbd == NULL, "req %p\n",request);/* client-side */
-        LASSERTF(cfs_list_empty(&request->rq_list), "req %p\n", request);
-        LASSERTF(cfs_list_empty(&request->rq_set_chain), "req %p\n", request);
-        LASSERTF(cfs_list_empty(&request->rq_exp_list), "req %p\n", request);
-        LASSERTF(!request->rq_replay, "req %p\n", request);
+       if (request == NULL)
+               RETURN_EXIT;
 
-        req_capsule_fini(&request->rq_pill);
+       LASSERT(!request->rq_srv_req);
+       LASSERT(request->rq_export == NULL);
+       LASSERTF(!request->rq_receiving_reply, "req %p\n", request);
+       LASSERTF(list_empty(&request->rq_list), "req %p\n", request);
+       LASSERTF(list_empty(&request->rq_set_chain), "req %p\n", request);
+       LASSERTF(!request->rq_replay, "req %p\n", request);
 
-        /* We must take it off the imp_replay_list first.  Otherwise, we'll set
-         * request->rq_reqmsg to NULL while osc_close is dereferencing it. */
-        if (request->rq_import != NULL) {
-                if (!locked)
-                        cfs_spin_lock(&request->rq_import->imp_lock);
-                cfs_list_del_init(&request->rq_replay_list);
-                if (!locked)
-                        cfs_spin_unlock(&request->rq_import->imp_lock);
-        }
-        LASSERTF(cfs_list_empty(&request->rq_replay_list), "req %p\n", request);
+       req_capsule_fini(&request->rq_pill);
 
-        if (cfs_atomic_read(&request->rq_refcount) != 0) {
-                DEBUG_REQ(D_ERROR, request,
-                          "freeing request with nonzero refcount");
-                LBUG();
+       /* We must take it off the imp_replay_list first.  Otherwise, we'll set
+        * request->rq_reqmsg to NULL while osc_close is dereferencing it. */
+       if (request->rq_import != NULL) {
+               if (!locked)
+                       spin_lock(&request->rq_import->imp_lock);
+               list_del_init(&request->rq_replay_list);
+               if (!locked)
+                       spin_unlock(&request->rq_import->imp_lock);
         }
+       LASSERTF(list_empty(&request->rq_replay_list), "req %p\n", request);
+
+       if (atomic_read(&request->rq_refcount) != 0) {
+               DEBUG_REQ(D_ERROR, request,
+                         "freeing request with nonzero refcount");
+               LBUG();
+       }
 
         if (request->rq_repbuf != NULL)
                 sptlrpc_cli_free_repbuf(request);
-        if (request->rq_export != NULL) {
-                class_export_put(request->rq_export);
-                request->rq_export = NULL;
-        }
+
         if (request->rq_import != NULL) {
                 class_import_put(request->rq_import);
                 request->rq_import = NULL;
         }
-        if (request->rq_bulk != NULL)
-                ptlrpc_free_bulk(request->rq_bulk);
+       if (request->rq_bulk != NULL)
+               ptlrpc_free_bulk(request->rq_bulk);
 
         if (request->rq_reqbuf != NULL || request->rq_clrbuf != NULL)
                 sptlrpc_cli_free_reqbuf(request);
@@ -2132,19 +2405,19 @@ static void __ptlrpc_free_req(struct ptlrpc_request *request, int locked)
         if (request->rq_pool)
                 __ptlrpc_free_req_to_pool(request);
         else
-                OBD_FREE(request, sizeof(*request));
-        EXIT;
+               ptlrpc_request_cache_free(request);
+       EXIT;
 }
 
 static int __ptlrpc_req_finished(struct ptlrpc_request *request, int locked);
 /**
  * Drop one request reference. Must be called with import imp_lock held.
- * When reference count drops to zero, reuqest is freed.
+ * When reference count drops to zero, request is freed.
  */
 void ptlrpc_req_finished_with_imp_lock(struct ptlrpc_request *request)
 {
-        LASSERT_SPIN_LOCKED(&request->rq_import->imp_lock);
-        (void)__ptlrpc_req_finished(request, 1);
+       assert_spin_locked(&request->rq_import->imp_lock);
+       (void)__ptlrpc_req_finished(request, 1);
 }
 
 /**
@@ -2167,9 +2440,9 @@ static int __ptlrpc_req_finished(struct ptlrpc_request *request, int locked)
         }
 
         DEBUG_REQ(D_INFO, request, "refcount now %u",
-                  cfs_atomic_read(&request->rq_refcount) - 1);
+                 atomic_read(&request->rq_refcount) - 1);
 
-        if (cfs_atomic_dec_and_test(&request->rq_refcount)) {
+       if (atomic_dec_and_test(&request->rq_refcount)) {
                 __ptlrpc_free_req(request, locked);
                 RETURN(1);
         }
@@ -2184,6 +2457,7 @@ void ptlrpc_req_finished(struct ptlrpc_request *request)
 {
         __ptlrpc_req_finished(request, 0);
 }
+EXPORT_SYMBOL(ptlrpc_req_finished);
 
 /**
  * Returns xid of a \a request
@@ -2201,20 +2475,19 @@ EXPORT_SYMBOL(ptlrpc_req_xid);
  * The request owner (i.e. the thread doing the I/O) must call...
  * Returns 0 on success or 1 if unregistering cannot be made.
  */
-int ptlrpc_unregister_reply(struct ptlrpc_request *request, int async)
+static int ptlrpc_unregister_reply(struct ptlrpc_request *request, int async)
 {
-        int                rc;
-        cfs_waitq_t       *wq;
-        struct l_wait_info lwi;
+       int                rc;
+       struct l_wait_info lwi;
 
-        /*
-         * Might sleep.
-         */
-        LASSERT(!cfs_in_interrupt());
+       /*
+        * Might sleep.
+        */
+       LASSERT(!in_interrupt());
 
-        /*
-         * Let's setup deadline for reply unlink.
-         */
+       /*
+        * Let's setup deadline for reply unlink.
+        */
         if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_LONG_REPL_UNLINK) &&
             async && request->rq_reply_deadline == 0)
                 request->rq_reply_deadline = cfs_time_current_sec()+LONG_UNLINK;
@@ -2249,12 +2522,11 @@ int ptlrpc_unregister_reply(struct ptlrpc_request *request, int async)
          * a chance to run reply_in_callback(), and to make sure we've
          * unlinked before returning a req to the pool.
          */
-        if (request->rq_set != NULL)
-                wq = &request->rq_set->set_waitq;
-        else
-                wq = &request->rq_reply_waitq;
-
         for (;;) {
+               /* The wq argument is ignored by user-space wait_event macros */
+               wait_queue_head_t *wq = (request->rq_set != NULL) ?
+                                       &request->rq_set->set_waitq :
+                                       &request->rq_reply_waitq;
                 /* Network access will complete in finite time but the HUGE
                  * timeout lets us CWARN for visibility of sluggish NALs */
                 lwi = LWI_TIMEOUT_INTERVAL(cfs_time_seconds(LONG_UNLINK),
@@ -2267,13 +2539,48 @@ int ptlrpc_unregister_reply(struct ptlrpc_request *request, int async)
                 }
 
                 LASSERT(rc == -ETIMEDOUT);
-                DEBUG_REQ(D_WARNING, request, "Unexpectedly long timeout "
-                          "rvcng=%d unlnk=%d", request->rq_receiving_reply,
-                          request->rq_must_unlink);
+               DEBUG_REQ(D_WARNING, request, "Unexpectedly long timeout "
+                         "receiving_reply=%d req_ulinked=%d reply_unlinked=%d",
+                         request->rq_receiving_reply,
+                         request->rq_req_unlinked,
+                         request->rq_reply_unlinked);
         }
         RETURN(0);
 }
 
+static void ptlrpc_free_request(struct ptlrpc_request *req)
+{
+       spin_lock(&req->rq_lock);
+       req->rq_replay = 0;
+       spin_unlock(&req->rq_lock);
+
+       if (req->rq_commit_cb != NULL)
+               req->rq_commit_cb(req);
+       list_del_init(&req->rq_replay_list);
+
+       __ptlrpc_req_finished(req, 1);
+}
+
+/**
+ * the request is committed and dropped from the replay list of its import
+ */
+void ptlrpc_request_committed(struct ptlrpc_request *req, int force)
+{
+       struct obd_import       *imp = req->rq_import;
+
+       spin_lock(&imp->imp_lock);
+       if (list_empty(&req->rq_replay_list)) {
+               spin_unlock(&imp->imp_lock);
+               return;
+       }
+
+       if (force || req->rq_transno <= imp->imp_peer_committed_transno)
+               ptlrpc_free_request(req);
+
+       spin_unlock(&imp->imp_lock);
+}
+EXPORT_SYMBOL(ptlrpc_request_committed);
+
 /**
  * Iterates through replay_list on import and prunes
  * all requests have transno smaller than last_committed for the
@@ -2284,33 +2591,33 @@ int ptlrpc_unregister_reply(struct ptlrpc_request *request, int async)
  */
 void ptlrpc_free_committed(struct obd_import *imp)
 {
-        cfs_list_t *tmp, *saved;
-        struct ptlrpc_request *req;
-        struct ptlrpc_request *last_req = NULL; /* temporary fire escape */
-        ENTRY;
-
-        LASSERT(imp != NULL);
-
-        LASSERT_SPIN_LOCKED(&imp->imp_lock);
+       struct ptlrpc_request   *req, *saved;
+       struct ptlrpc_request   *last_req = NULL; /* temporary fire escape */
+       bool                     skip_committed_list = true;
+       ENTRY;
 
+       LASSERT(imp != NULL);
+       assert_spin_locked(&imp->imp_lock);
 
         if (imp->imp_peer_committed_transno == imp->imp_last_transno_checked &&
             imp->imp_generation == imp->imp_last_generation_checked) {
                 CDEBUG(D_INFO, "%s: skip recheck: last_committed "LPU64"\n",
                        imp->imp_obd->obd_name, imp->imp_peer_committed_transno);
-                EXIT;
-                return;
+               RETURN_EXIT;
         }
         CDEBUG(D_RPCTRACE, "%s: committing for last_committed "LPU64" gen %d\n",
                imp->imp_obd->obd_name, imp->imp_peer_committed_transno,
                imp->imp_generation);
+
+       if (imp->imp_generation != imp->imp_last_generation_checked ||
+           imp->imp_last_transno_checked == 0)
+               skip_committed_list = false;
+
         imp->imp_last_transno_checked = imp->imp_peer_committed_transno;
         imp->imp_last_generation_checked = imp->imp_generation;
 
-        cfs_list_for_each_safe(tmp, saved, &imp->imp_replay_list) {
-                req = cfs_list_entry(tmp, struct ptlrpc_request,
-                                     rq_replay_list);
-
+       list_for_each_entry_safe(req, saved, &imp->imp_replay_list,
+                                    rq_replay_list) {
                 /* XXX ok to remove when 1357 resolved - rread 05/29/03  */
                 LASSERT(req != last_req);
                 last_req = req;
@@ -2324,38 +2631,47 @@ void ptlrpc_free_committed(struct obd_import *imp)
                         GOTO(free_req, 0);
                 }
 
-                if (req->rq_replay) {
-                        DEBUG_REQ(D_RPCTRACE, req, "keeping (FL_REPLAY)");
-                        continue;
-                }
-
                 /* not yet committed */
                 if (req->rq_transno > imp->imp_peer_committed_transno) {
                         DEBUG_REQ(D_RPCTRACE, req, "stopping search");
                         break;
                 }
 
+               if (req->rq_replay) {
+                       DEBUG_REQ(D_RPCTRACE, req, "keeping (FL_REPLAY)");
+                       list_move_tail(&req->rq_replay_list,
+                                          &imp->imp_committed_list);
+                       continue;
+               }
+
                 DEBUG_REQ(D_INFO, req, "commit (last_committed "LPU64")",
                           imp->imp_peer_committed_transno);
 free_req:
-                cfs_spin_lock(&req->rq_lock);
-                req->rq_replay = 0;
-                cfs_spin_unlock(&req->rq_lock);
-                if (req->rq_commit_cb != NULL)
-                        req->rq_commit_cb(req);
-                cfs_list_del_init(&req->rq_replay_list);
-                __ptlrpc_req_finished(req, 1);
-        }
-
+               ptlrpc_free_request(req);
+        }
+
+       if (skip_committed_list)
+               GOTO(out, 0);
+
+       list_for_each_entry_safe(req, saved, &imp->imp_committed_list,
+                                    rq_replay_list) {
+               LASSERT(req->rq_transno != 0);
+               if (req->rq_import_generation < imp->imp_generation) {
+                       DEBUG_REQ(D_RPCTRACE, req, "free stale open request");
+                       ptlrpc_free_request(req);
+               } else if (!req->rq_replay) {
+                       DEBUG_REQ(D_RPCTRACE, req, "free closed open request");
+                       ptlrpc_free_request(req);
+               }
+       }
+out:
         EXIT;
-        return;
 }
 
 void ptlrpc_cleanup_client(struct obd_import *imp)
 {
         ENTRY;
         EXIT;
-        return;
 }
 
 /**
@@ -2367,36 +2683,38 @@ void ptlrpc_cleanup_client(struct obd_import *imp)
 void ptlrpc_resend_req(struct ptlrpc_request *req)
 {
         DEBUG_REQ(D_HA, req, "going to resend");
+       spin_lock(&req->rq_lock);
+
+       /* Request got reply but linked to the import list still.
+          Let ptlrpc_check_set() to process it. */
+       if (ptlrpc_client_replied(req)) {
+               spin_unlock(&req->rq_lock);
+               DEBUG_REQ(D_HA, req, "it has reply, so skip it");
+               return;
+       }
+
         lustre_msg_set_handle(req->rq_reqmsg, &(struct lustre_handle){ 0 });
         req->rq_status = -EAGAIN;
 
-        cfs_spin_lock(&req->rq_lock);
         req->rq_resend = 1;
         req->rq_net_err = 0;
         req->rq_timedout = 0;
-        if (req->rq_bulk) {
-                __u64 old_xid = req->rq_xid;
 
-                /* ensure previous bulk fails */
-                req->rq_xid = ptlrpc_next_xid();
-                CDEBUG(D_HA, "resend bulk old x"LPU64" new x"LPU64"\n",
-                       old_xid, req->rq_xid);
-        }
         ptlrpc_client_wake_req(req);
-        cfs_spin_unlock(&req->rq_lock);
+       spin_unlock(&req->rq_lock);
 }
 
 /* XXX: this function and rq_status are currently unused */
 void ptlrpc_restart_req(struct ptlrpc_request *req)
 {
-        DEBUG_REQ(D_HA, req, "restarting (possibly-)completed request");
-        req->rq_status = -ERESTARTSYS;
+       DEBUG_REQ(D_HA, req, "restarting (possibly-)completed request");
+       req->rq_status = -ERESTARTSYS;
 
-        cfs_spin_lock(&req->rq_lock);
-        req->rq_restart = 1;
-        req->rq_timedout = 0;
-        ptlrpc_client_wake_req(req);
-        cfs_spin_unlock(&req->rq_lock);
+       spin_lock(&req->rq_lock);
+       req->rq_restart = 1;
+       req->rq_timedout = 0;
+       ptlrpc_client_wake_req(req);
+       spin_unlock(&req->rq_lock);
 }
 
 /**
@@ -2404,10 +2722,11 @@ void ptlrpc_restart_req(struct ptlrpc_request *req)
  */
 struct ptlrpc_request *ptlrpc_request_addref(struct ptlrpc_request *req)
 {
-        ENTRY;
-        cfs_atomic_inc(&req->rq_refcount);
-        RETURN(req);
+       ENTRY;
+       atomic_inc(&req->rq_refcount);
+       RETURN(req);
 }
+EXPORT_SYMBOL(ptlrpc_request_addref);
 
 /**
  * Add a request to import replay_list.
@@ -2416,9 +2735,9 @@ struct ptlrpc_request *ptlrpc_request_addref(struct ptlrpc_request *req)
 void ptlrpc_retain_replayable_request(struct ptlrpc_request *req,
                                       struct obd_import *imp)
 {
-        cfs_list_t *tmp;
+       struct list_head *tmp;
 
-        LASSERT_SPIN_LOCKED(&imp->imp_lock);
+       assert_spin_locked(&imp->imp_lock);
 
         if (req->rq_transno == 0) {
                 DEBUG_REQ(D_EMERG, req, "saving request with zero transno");
@@ -2429,19 +2748,23 @@ void ptlrpc_retain_replayable_request(struct ptlrpc_request *req,
            as resent replayed requests. */
         lustre_msg_clear_flags(req->rq_reqmsg, MSG_RESENT);
 
-        /* don't re-add requests that have been replayed */
-        if (!cfs_list_empty(&req->rq_replay_list))
-                return;
+       /* don't re-add requests that have been replayed */
+       if (!list_empty(&req->rq_replay_list))
+               return;
 
-        lustre_msg_add_flags(req->rq_reqmsg, MSG_REPLAY);
+       lustre_msg_add_flags(req->rq_reqmsg, MSG_REPLAY);
 
-        LASSERT(imp->imp_replayable);
-        /* Balanced in ptlrpc_free_committed, usually. */
-        ptlrpc_request_addref(req);
-        cfs_list_for_each_prev(tmp, &imp->imp_replay_list) {
-                struct ptlrpc_request *iter =
-                        cfs_list_entry(tmp, struct ptlrpc_request,
-                                       rq_replay_list);
+       spin_lock(&req->rq_lock);
+       req->rq_resend = 0;
+       spin_unlock(&req->rq_lock);
+
+       LASSERT(imp->imp_replayable);
+       /* Balanced in ptlrpc_free_committed, usually. */
+       ptlrpc_request_addref(req);
+       list_for_each_prev(tmp, &imp->imp_replay_list) {
+               struct ptlrpc_request *iter = list_entry(tmp,
+                                                        struct ptlrpc_request,
+                                                        rq_replay_list);
 
                 /* We may have duplicate transnos if we create and then
                  * open a file, or for closes retained if to match creating
@@ -2458,11 +2781,11 @@ void ptlrpc_retain_replayable_request(struct ptlrpc_request *req,
                                 continue;
                 }
 
-                cfs_list_add(&req->rq_replay_list, &iter->rq_replay_list);
-                return;
-        }
+               list_add(&req->rq_replay_list, &iter->rq_replay_list);
+               return;
+       }
 
-        cfs_list_add(&req->rq_replay_list, &imp->imp_replay_list);
+       list_add(&req->rq_replay_list, &imp->imp_replay_list);
 }
 
 /**
@@ -2478,14 +2801,14 @@ int ptlrpc_queue_wait(struct ptlrpc_request *req)
         LASSERT(req->rq_set == NULL);
         LASSERT(!req->rq_receiving_reply);
 
-        set = ptlrpc_prep_set();
-        if (set == NULL) {
-                CERROR("Unable to allocate ptlrpc set.");
-                RETURN(-ENOMEM);
-        }
+       set = ptlrpc_prep_set();
+       if (set == NULL) {
+               CERROR("cannot allocate ptlrpc set: rc = %d\n", -ENOMEM);
+               RETURN(-ENOMEM);
+       }
 
-        /* for distributed debugging */
-        lustre_msg_set_status(req->rq_reqmsg, cfs_curproc_pid());
+       /* for distributed debugging */
+       lustre_msg_set_status(req->rq_reqmsg, current_pid());
 
         /* add a ref for the set (see comment in ptlrpc_set_add_req) */
         ptlrpc_request_addref(req);
@@ -2495,31 +2818,32 @@ int ptlrpc_queue_wait(struct ptlrpc_request *req)
 
         RETURN(rc);
 }
-
-struct ptlrpc_replay_async_args {
-        int praa_old_state;
-        int praa_old_status;
-};
+EXPORT_SYMBOL(ptlrpc_queue_wait);
 
 /**
  * Callback used for replayed requests reply processing.
- * In case of succesful reply calls registeresd request replay callback.
+ * In case of successful reply calls registered request replay callback.
  * In case of error restart replay process.
  */
 static int ptlrpc_replay_interpret(const struct lu_env *env,
-                                   struct ptlrpc_request *req,
-                                   void * data, int rc)
+                                  struct ptlrpc_request *req,
+                                  void * data, int rc)
 {
-        struct ptlrpc_replay_async_args *aa = data;
-        struct obd_import *imp = req->rq_import;
+       struct ptlrpc_replay_async_args *aa = data;
+       struct obd_import *imp = req->rq_import;
 
-        ENTRY;
-        cfs_atomic_dec(&imp->imp_replay_inflight);
+       ENTRY;
+       atomic_dec(&imp->imp_replay_inflight);
 
-        if (!ptlrpc_client_replied(req)) {
-                CERROR("request replay timed out, restarting recovery\n");
-                GOTO(out, rc = -ETIMEDOUT);
-        }
+       /* Note: if it is bulk replay (MDS-MDS replay), then even if
+        * server got the request, but bulk transfer timeout, let's
+        * replay the bulk req again */
+       if (!ptlrpc_client_replied(req) ||
+           (req->rq_bulk != NULL &&
+            lustre_msg_get_status(req->rq_repmsg) == -ETIMEDOUT)) {
+               DEBUG_REQ(D_ERROR, req, "request replay timed out.\n");
+               GOTO(out, rc = -ETIMEDOUT);
+       }
 
         if (lustre_msg_get_type(req->rq_repmsg) == PTL_RPC_MSG_ERR &&
             (lustre_msg_get_status(req->rq_repmsg) == -ENOTCONN ||
@@ -2528,13 +2852,13 @@ static int ptlrpc_replay_interpret(const struct lu_env *env,
 
         /** VBR: check version failure */
         if (lustre_msg_get_status(req->rq_repmsg) == -EOVERFLOW) {
-                /** replay was failed due to version mismatch */
-                DEBUG_REQ(D_WARNING, req, "Version mismatch during replay\n");
-                cfs_spin_lock(&imp->imp_lock);
-                imp->imp_vbr_failed = 1;
-                imp->imp_no_lock_replay = 1;
-                cfs_spin_unlock(&imp->imp_lock);
-                lustre_msg_set_status(req->rq_repmsg, aa->praa_old_status);
+               /** replay was failed due to version mismatch */
+               DEBUG_REQ(D_WARNING, req, "Version mismatch during replay\n");
+               spin_lock(&imp->imp_lock);
+               imp->imp_vbr_failed = 1;
+               imp->imp_no_lock_replay = 1;
+               spin_unlock(&imp->imp_lock);
+               lustre_msg_set_status(req->rq_repmsg, aa->praa_old_status);
         } else {
                 /** The transno had better not change over replay. */
                 LASSERTF(lustre_msg_get_transno(req->rq_reqmsg) ==
@@ -2545,12 +2869,12 @@ static int ptlrpc_replay_interpret(const struct lu_env *env,
                          lustre_msg_get_transno(req->rq_repmsg));
         }
 
-        cfs_spin_lock(&imp->imp_lock);
-        /** if replays by version then gap was occur on server, no trust to locks */
-        if (lustre_msg_get_flags(req->rq_repmsg) & MSG_VERSION_REPLAY)
-                imp->imp_no_lock_replay = 1;
-        imp->imp_last_replay_transno = lustre_msg_get_transno(req->rq_reqmsg);
-        cfs_spin_unlock(&imp->imp_lock);
+       spin_lock(&imp->imp_lock);
+       /** if replays by version then gap occur on server, no trust to locks */
+       if (lustre_msg_get_flags(req->rq_repmsg) & MSG_VERSION_REPLAY)
+               imp->imp_no_lock_replay = 1;
+       imp->imp_last_replay_transno = lustre_msg_get_transno(req->rq_reqmsg);
+       spin_unlock(&imp->imp_lock);
         LASSERT(imp->imp_last_replay_transno);
 
         /* transaction number shouldn't be bigger than the latest replayed */
@@ -2631,11 +2955,11 @@ int ptlrpc_replay_req(struct ptlrpc_request *req)
                                     ptlrpc_at_get_net_latency(req));
         DEBUG_REQ(D_HA, req, "REPLAY");
 
-        cfs_atomic_inc(&req->rq_import->imp_replay_inflight);
-        ptlrpc_request_addref(req); /* ptlrpcd needs a ref */
+       atomic_inc(&req->rq_import->imp_replay_inflight);
+       ptlrpc_request_addref(req);     /* ptlrpcd needs a ref */
 
-        ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
-        RETURN(0);
+       ptlrpcd_add_req(req);
+       RETURN(0);
 }
 
 /**
@@ -2643,57 +2967,58 @@ int ptlrpc_replay_req(struct ptlrpc_request *req)
  */
 void ptlrpc_abort_inflight(struct obd_import *imp)
 {
-        cfs_list_t *tmp, *n;
-        ENTRY;
+       struct list_head *tmp, *n;
+       ENTRY;
 
-        /* Make sure that no new requests get processed for this import.
-         * ptlrpc_{queue,set}_wait must (and does) hold imp_lock while testing
-         * this flag and then putting requests on sending_list or delayed_list.
-         */
-        cfs_spin_lock(&imp->imp_lock);
+       /* Make sure that no new requests get processed for this import.
+        * ptlrpc_{queue,set}_wait must (and does) hold imp_lock while testing
+        * this flag and then putting requests on sending_list or delayed_list.
+        */
+       spin_lock(&imp->imp_lock);
 
-        /* XXX locking?  Maybe we should remove each request with the list
-         * locked?  Also, how do we know if the requests on the list are
-         * being freed at this time?
-         */
-        cfs_list_for_each_safe(tmp, n, &imp->imp_sending_list) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(tmp, struct ptlrpc_request, rq_list);
+       /* XXX locking?  Maybe we should remove each request with the list
+        * locked?  Also, how do we know if the requests on the list are
+        * being freed at this time?
+        */
+       list_for_each_safe(tmp, n, &imp->imp_sending_list) {
+               struct ptlrpc_request *req = list_entry(tmp,
+                                                       struct ptlrpc_request,
+                                                       rq_list);
 
                 DEBUG_REQ(D_RPCTRACE, req, "inflight");
 
-                cfs_spin_lock (&req->rq_lock);
-                if (req->rq_import_generation < imp->imp_generation) {
-                        req->rq_err = 1;
-                        req->rq_status = -EINTR;
-                        ptlrpc_client_wake_req(req);
-                }
-                cfs_spin_unlock (&req->rq_lock);
-        }
+               spin_lock(&req->rq_lock);
+               if (req->rq_import_generation < imp->imp_generation) {
+                       req->rq_err = 1;
+                       req->rq_status = -EIO;
+                       ptlrpc_client_wake_req(req);
+               }
+               spin_unlock(&req->rq_lock);
+       }
 
-        cfs_list_for_each_safe(tmp, n, &imp->imp_delayed_list) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(tmp, struct ptlrpc_request, rq_list);
+       list_for_each_safe(tmp, n, &imp->imp_delayed_list) {
+               struct ptlrpc_request *req =
+                       list_entry(tmp, struct ptlrpc_request, rq_list);
 
-                DEBUG_REQ(D_RPCTRACE, req, "aborting waiting req");
+               DEBUG_REQ(D_RPCTRACE, req, "aborting waiting req");
 
-                cfs_spin_lock (&req->rq_lock);
-                if (req->rq_import_generation < imp->imp_generation) {
-                        req->rq_err = 1;
-                        req->rq_status = -EINTR;
-                        ptlrpc_client_wake_req(req);
-                }
-                cfs_spin_unlock (&req->rq_lock);
-        }
+               spin_lock(&req->rq_lock);
+               if (req->rq_import_generation < imp->imp_generation) {
+                       req->rq_err = 1;
+                       req->rq_status = -EIO;
+                       ptlrpc_client_wake_req(req);
+               }
+               spin_unlock(&req->rq_lock);
+       }
 
-        /* Last chance to free reqs left on the replay list, but we
-         * will still leak reqs that haven't committed.  */
-        if (imp->imp_replayable)
-                ptlrpc_free_committed(imp);
+       /* Last chance to free reqs left on the replay list, but we
+        * will still leak reqs that haven't committed.  */
+       if (imp->imp_replayable)
+               ptlrpc_free_committed(imp);
 
-        cfs_spin_unlock(&imp->imp_lock);
+       spin_unlock(&imp->imp_lock);
 
-        EXIT;
+       EXIT;
 }
 
 /**
@@ -2701,30 +3026,30 @@ void ptlrpc_abort_inflight(struct obd_import *imp)
  */
 void ptlrpc_abort_set(struct ptlrpc_request_set *set)
 {
-        cfs_list_t *tmp, *pos;
+       struct list_head *tmp, *pos;
 
-        LASSERT(set != NULL);
+       LASSERT(set != NULL);
 
-        cfs_list_for_each_safe(pos, tmp, &set->set_requests) {
-                struct ptlrpc_request *req =
-                        cfs_list_entry(pos, struct ptlrpc_request,
-                                       rq_set_chain);
+       list_for_each_safe(pos, tmp, &set->set_requests) {
+               struct ptlrpc_request *req =
+                       list_entry(pos, struct ptlrpc_request,
+                                  rq_set_chain);
 
-                cfs_spin_lock(&req->rq_lock);
-                if (req->rq_phase != RQ_PHASE_RPC) {
-                        cfs_spin_unlock(&req->rq_lock);
-                        continue;
-                }
+               spin_lock(&req->rq_lock);
+               if (req->rq_phase != RQ_PHASE_RPC) {
+                       spin_unlock(&req->rq_lock);
+                       continue;
+               }
 
-                req->rq_err = 1;
-                req->rq_status = -EINTR;
-                ptlrpc_client_wake_req(req);
-                cfs_spin_unlock(&req->rq_lock);
-        }
+               req->rq_err = 1;
+               req->rq_status = -EINTR;
+               ptlrpc_client_wake_req(req);
+               spin_unlock(&req->rq_lock);
+       }
 }
 
 static __u64 ptlrpc_last_xid;
-static cfs_spinlock_t ptlrpc_last_xid_lock;
+static spinlock_t ptlrpc_last_xid_lock;
 
 /**
  * Initialize the XID for the node.  This is common among all requests on
@@ -2744,28 +3069,81 @@ static cfs_spinlock_t ptlrpc_last_xid_lock;
 #define YEAR_2004 (1ULL << 30)
 void ptlrpc_init_xid(void)
 {
-        time_t now = cfs_time_current_sec();
+       time_t now = cfs_time_current_sec();
 
-        cfs_spin_lock_init(&ptlrpc_last_xid_lock);
-        if (now < YEAR_2004) {
-                cfs_get_random_bytes(&ptlrpc_last_xid, sizeof(ptlrpc_last_xid));
-                ptlrpc_last_xid >>= 2;
-                ptlrpc_last_xid |= (1ULL << 61);
-        } else {
-                ptlrpc_last_xid = (__u64)now << 20;
-        }
+       spin_lock_init(&ptlrpc_last_xid_lock);
+       if (now < YEAR_2004) {
+               cfs_get_random_bytes(&ptlrpc_last_xid, sizeof(ptlrpc_last_xid));
+               ptlrpc_last_xid >>= 2;
+               ptlrpc_last_xid |= (1ULL << 61);
+       } else {
+               ptlrpc_last_xid = (__u64)now << 20;
+       }
+
+       /* Need to always be aligned to a power-of-two for mutli-bulk BRW */
+       CLASSERT((PTLRPC_BULK_OPS_COUNT & (PTLRPC_BULK_OPS_COUNT - 1)) == 0);
+       ptlrpc_last_xid &= PTLRPC_BULK_OPS_MASK;
 }
 
 /**
- * Increase xid and returns resultng new value to the caller.
+ * Increase xid and returns resulting new value to the caller.
+ *
+ * Multi-bulk BRW RPCs consume multiple XIDs for each bulk transfer, starting
+ * at the returned xid, up to xid + PTLRPC_BULK_OPS_COUNT - 1. The BRW RPC
+ * itself uses the last bulk xid needed, so the server can determine the
+ * the number of bulk transfers from the RPC XID and a bitmask.  The starting
+ * xid must align to a power-of-two value.
+ *
+ * This is assumed to be true due to the initial ptlrpc_last_xid
+ * value also being initialized to a power-of-two value. LU-1431
  */
 __u64 ptlrpc_next_xid(void)
 {
-        __u64 tmp;
-        cfs_spin_lock(&ptlrpc_last_xid_lock);
-        tmp = ++ptlrpc_last_xid;
-        cfs_spin_unlock(&ptlrpc_last_xid_lock);
-        return tmp;
+       __u64 next;
+
+       spin_lock(&ptlrpc_last_xid_lock);
+       next = ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT;
+       ptlrpc_last_xid = next;
+       spin_unlock(&ptlrpc_last_xid_lock);
+
+       return next;
+}
+
+/**
+ * If request has a new allocated XID (new request or EINPROGRESS resend),
+ * use this XID as matchbits of bulk, otherwise allocate a new matchbits for
+ * request to ensure previous bulk fails and avoid problems with lost replies
+ * and therefore several transfers landing into the same buffer from different
+ * sending attempts.
+ */
+void ptlrpc_set_bulk_mbits(struct ptlrpc_request *req)
+{
+       struct ptlrpc_bulk_desc *bd = req->rq_bulk;
+
+       LASSERT(bd != NULL);
+
+       if (!req->rq_resend || req->rq_nr_resend != 0) {
+               /* this request has a new xid, just use it as bulk matchbits */
+               req->rq_mbits = req->rq_xid;
+
+       } else { /* needs to generate a new matchbits for resend */
+               __u64   old_mbits = req->rq_mbits;
+
+               if ((bd->bd_import->imp_connect_data.ocd_connect_flags &
+                   OBD_CONNECT_BULK_MBITS) != 0)
+                       req->rq_mbits = ptlrpc_next_xid();
+               else /* old version transfers rq_xid to peer as matchbits */
+                       req->rq_mbits = req->rq_xid = ptlrpc_next_xid();
+
+               CDEBUG(D_HA, "resend bulk old x"LPU64" new x"LPU64"\n",
+                      old_mbits, req->rq_mbits);
+       }
+
+       /* For multi-bulk RPCs, rq_mbits is the last mbits needed for bulks so
+        * that server can infer the number of bulks that were prepared,
+        * see LU-1431 */
+       req->rq_mbits += ((bd->bd_iov_count + LNET_MAX_IOV - 1) /
+                         LNET_MAX_IOV) - 1;
 }
 
 /**
@@ -2775,15 +3153,17 @@ __u64 ptlrpc_next_xid(void)
 __u64 ptlrpc_sample_next_xid(void)
 {
 #if BITS_PER_LONG == 32
-        /* need to avoid possible word tearing on 32-bit systems */
-        __u64 tmp;
-        cfs_spin_lock(&ptlrpc_last_xid_lock);
-        tmp = ptlrpc_last_xid + 1;
-        cfs_spin_unlock(&ptlrpc_last_xid_lock);
-        return tmp;
+       /* need to avoid possible word tearing on 32-bit systems */
+       __u64 next;
+
+       spin_lock(&ptlrpc_last_xid_lock);
+       next = ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT;
+       spin_unlock(&ptlrpc_last_xid_lock);
+
+       return next;
 #else
-        /* No need to lock, since returned value is racy anyways */
-        return ptlrpc_last_xid + 1;
+       /* No need to lock, since returned value is racy anyways */
+       return ptlrpc_last_xid + PTLRPC_BULK_OPS_COUNT;
 #endif
 }
 EXPORT_SYMBOL(ptlrpc_sample_next_xid);
@@ -2806,73 +3186,90 @@ EXPORT_SYMBOL(ptlrpc_sample_next_xid);
  *    have delay before it really runs by ptlrpcd thread.
  */
 struct ptlrpc_work_async_args {
-        __u64   magic;
-        int   (*cb)(const struct lu_env *, void *);
-        void   *cbdata;
+       int   (*cb)(const struct lu_env *, void *);
+       void   *cbdata;
 };
 
-#define PTLRPC_WORK_MAGIC 0x6655436b676f4f44ULL /* magic code */
+static void ptlrpcd_add_work_req(struct ptlrpc_request *req)
+{
+       /* re-initialize the req */
+       req->rq_timeout         = obd_timeout;
+       req->rq_sent            = cfs_time_current_sec();
+       req->rq_deadline        = req->rq_sent + req->rq_timeout;
+       req->rq_reply_deadline  = req->rq_deadline;
+       req->rq_phase           = RQ_PHASE_INTERPRET;
+       req->rq_next_phase      = RQ_PHASE_COMPLETE;
+       req->rq_xid             = ptlrpc_next_xid();
+       req->rq_import_generation = req->rq_import->imp_generation;
+
+       ptlrpcd_add_req(req);
+}
 
 static int work_interpreter(const struct lu_env *env,
-                            struct ptlrpc_request *req, void *data, int rc)
+                           struct ptlrpc_request *req, void *data, int rc)
 {
-        struct ptlrpc_work_async_args *arg = data;
+       struct ptlrpc_work_async_args *arg = data;
+
+       LASSERT(ptlrpcd_check_work(req));
+       LASSERT(arg->cb != NULL);
+
+       rc = arg->cb(env, arg->cbdata);
+
+       list_del_init(&req->rq_set_chain);
+       req->rq_set = NULL;
+
+       if (atomic_dec_return(&req->rq_refcount) > 1) {
+               atomic_set(&req->rq_refcount, 2);
+               ptlrpcd_add_work_req(req);
+       }
+       return rc;
+}
 
-        LASSERT(arg->magic == PTLRPC_WORK_MAGIC);
-        LASSERT(arg->cb != NULL);
+static int worker_format;
 
-        return arg->cb(env, arg->cbdata);
+static int ptlrpcd_check_work(struct ptlrpc_request *req)
+{
+       return req->rq_pill.rc_fmt == (void *)&worker_format;
 }
 
 /**
  * Create a work for ptlrpc.
  */
 void *ptlrpcd_alloc_work(struct obd_import *imp,
-                         int (*cb)(const struct lu_env *, void *), void *cbdata)
+                        int (*cb)(const struct lu_env *, void *), void *cbdata)
 {
-        struct ptlrpc_request         *req = NULL;
-        struct ptlrpc_work_async_args *args;
-        ENTRY;
+       struct ptlrpc_request         *req = NULL;
+       struct ptlrpc_work_async_args *args;
+       ENTRY;
 
-        cfs_might_sleep();
+       might_sleep();
 
-        if (cb == NULL)
-                RETURN(ERR_PTR(-EINVAL));
+       if (cb == NULL)
+               RETURN(ERR_PTR(-EINVAL));
 
-        /* copy some code from deprecated fakereq. */
-        OBD_ALLOC_PTR(req);
-        if (req == NULL) {
-                CERROR("ptlrpc: run out of memory!\n");
-                RETURN(ERR_PTR(-ENOMEM));
-        }
+       /* copy some code from deprecated fakereq. */
+       req = ptlrpc_request_cache_alloc(GFP_NOFS);
+       if (req == NULL) {
+               CERROR("ptlrpc: run out of memory!\n");
+               RETURN(ERR_PTR(-ENOMEM));
+       }
+
+       ptlrpc_cli_req_init(req);
+
+       req->rq_send_state = LUSTRE_IMP_FULL;
+       req->rq_type = PTL_RPC_MSG_REQUEST;
+       req->rq_import = class_import_get(imp);
+       req->rq_interpret_reply = work_interpreter;
+       /* don't want reply */
+       req->rq_no_delay = req->rq_no_resend = 1;
+       req->rq_pill.rc_fmt = (void *)&worker_format;
+
+       CLASSERT (sizeof(*args) <= sizeof(req->rq_async_args));
+       args = ptlrpc_req_async_args(req);
+       args->cb     = cb;
+       args->cbdata = cbdata;
 
-        req->rq_send_state = LUSTRE_IMP_FULL;
-        req->rq_type = PTL_RPC_MSG_REQUEST;
-        req->rq_import = class_import_get(imp);
-        req->rq_export = NULL;
-        req->rq_interpret_reply = work_interpreter;
-        /* don't want reply */
-        req->rq_receiving_reply = 0;
-        req->rq_must_unlink = 0;
-        req->rq_no_delay = req->rq_no_resend = 1;
-
-        cfs_spin_lock_init(&req->rq_lock);
-        CFS_INIT_LIST_HEAD(&req->rq_list);
-        CFS_INIT_LIST_HEAD(&req->rq_replay_list);
-        CFS_INIT_LIST_HEAD(&req->rq_set_chain);
-        CFS_INIT_LIST_HEAD(&req->rq_history_list);
-        CFS_INIT_LIST_HEAD(&req->rq_exp_list);
-        cfs_waitq_init(&req->rq_reply_waitq);
-        cfs_waitq_init(&req->rq_set_waitq);
-        cfs_atomic_set(&req->rq_refcount, 1);
-
-        CLASSERT (sizeof(*args) <= sizeof(req->rq_async_args));
-        args = ptlrpc_req_async_args(req);
-        args->magic  = PTLRPC_WORK_MAGIC;
-        args->cb     = cb;
-        args->cbdata = cbdata;
-
-        RETURN(req);
+       RETURN(req);
 }
 EXPORT_SYMBOL(ptlrpcd_alloc_work);
 
@@ -2887,7 +3284,7 @@ EXPORT_SYMBOL(ptlrpcd_destroy_work);
 
 int ptlrpcd_queue_work(void *handler)
 {
-        struct ptlrpc_request *req = handler;
+       struct ptlrpc_request *req = handler;
 
         /*
          * Check if the req is already being queued.
@@ -2897,26 +3294,9 @@ int ptlrpcd_queue_work(void *handler)
          * for this purpose. This is okay because the caller should use this
          * req as opaque data. - Jinshan
          */
-        LASSERT(cfs_atomic_read(&req->rq_refcount) > 0);
-        if (cfs_atomic_read(&req->rq_refcount) > 1)
-                return -EBUSY;
-
-        if (cfs_atomic_inc_return(&req->rq_refcount) > 2) { /* race */
-                cfs_atomic_dec(&req->rq_refcount);
-                return -EBUSY;
-        }
-
-        /* re-initialize the req */
-        req->rq_timeout        = obd_timeout;
-        req->rq_sent           = cfs_time_current_sec();
-        req->rq_deadline       = req->rq_sent + req->rq_timeout;
-        req->rq_reply_deadline = req->rq_deadline;
-        req->rq_phase          = RQ_PHASE_INTERPRET;
-        req->rq_next_phase     = RQ_PHASE_COMPLETE;
-        req->rq_xid            = ptlrpc_next_xid();
-        req->rq_import_generation = req->rq_import->imp_generation;
-
-        ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
-        return 0;
+       LASSERT(atomic_read(&req->rq_refcount) > 0);
+       if (atomic_inc_return(&req->rq_refcount) == 2)
+               ptlrpcd_add_work_req(req);
+       return 0;
 }
 EXPORT_SYMBOL(ptlrpcd_queue_work);