[fs/lustre-release.git] / lustre / ptlrpc / client.c

/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 *  Copyright (c) 2002, 2003 Cluster File Systems, Inc.
 *
 *   This file is part of the Lustre file system, http://www.lustre.org
 *   Lustre is a trademark of Cluster File Systems, Inc.
 *
 *   You may have signed or agreed to another license before downloading
 *   this software.  If so, you are bound by the terms and conditions
 *   of that agreement, and the following does not apply to you.  See the
 *   LICENSE file included with this distribution for more information.
 *
 *   If you did not agree to a different license, then this copy of Lustre
 *   is open source software; you can redistribute it and/or modify it
 *   under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   In either case, Lustre is distributed in the hope that it will be
 *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   license text for more details.
 *
 */

#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 <lustre_lib.h>
#include <lustre_ha.h>
#include <lustre_import.h>

#include "ptlrpc_internal.h"

void ptlrpc_init_client(int req_portal, int rep_portal, char *name,
                        struct ptlrpc_client *cl)
{
        cl->cli_request_portal = req_portal;
        cl->cli_reply_portal   = rep_portal;
        cl->cli_name           = name;
}

struct ptlrpc_connection *ptlrpc_uuid_to_connection(struct obd_uuid *uuid)
{
        struct ptlrpc_connection *c;
        lnet_nid_t                self;
        lnet_process_id_t         peer;
        int                       err;

        err = ptlrpc_uuid_to_peer(uuid, &peer, &self);
        if (err != 0) {
                CERROR("cannot find peer %s!\n", uuid->uuid);
                return NULL;
        }

        c = ptlrpc_get_connection(peer, self, uuid);
        if (c) {
                memcpy(c->c_remote_uuid.uuid,
                       uuid->uuid, sizeof(c->c_remote_uuid.uuid));
        }

        CDEBUG(D_INFO, "%s -> %p\n", uuid->uuid, c);

        return c;
}

void ptlrpc_readdress_connection(struct ptlrpc_connection *conn,
                                 struct obd_uuid *uuid)
{
        lnet_nid_t        self;
        lnet_process_id_t peer;
        int               err;

        err = ptlrpc_uuid_to_peer(uuid, &peer, &self);
        if (err != 0) {
                CERROR("cannot find peer %s!\n", uuid->uuid);
                return;
        }

        conn->c_peer = peer;
        conn->c_self = self;
        return;
}

static inline 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;

        spin_lock_init(&desc->bd_lock);
        cfs_waitq_init(&desc->bd_waitq);
        desc->bd_max_iov = npages;
        desc->bd_iov_count = 0;
        desc->bd_md_h = LNET_INVALID_HANDLE;
        desc->bd_portal = portal;
        desc->bd_type = type;

        return desc;
}

struct ptlrpc_bulk_desc *ptlrpc_prep_bulk_imp (struct ptlrpc_request *req,
                                               int npages, int type, int portal)
{
        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);

        desc->bd_import_generation = req->rq_import_generation;
        desc->bd_import = class_import_get(imp);
        desc->bd_req = req;

        desc->bd_cbid.cbid_fn  = client_bulk_callback;
        desc->bd_cbid.cbid_arg = desc;

        /* This makes req own desc, and free it when she frees herself */
        req->rq_bulk = desc;

        return desc;
}

struct ptlrpc_bulk_desc *ptlrpc_prep_bulk_exp (struct ptlrpc_request *req,
                                               int npages, int type, int portal)
{
        struct obd_export *exp = req->rq_export;
        struct ptlrpc_bulk_desc *desc;

        ENTRY;
        LASSERT(type == BULK_PUT_SOURCE || type == BULK_GET_SINK);

        desc = new_bulk(npages, type, portal);
        if (desc == NULL)
                RETURN(NULL);

        desc->bd_export = class_export_get(exp);
        desc->bd_req = req;

        desc->bd_cbid.cbid_fn  = server_bulk_callback;
        desc->bd_cbid.cbid_arg = desc;

        /* NB we don't assign rq_bulk here; server-side requests are
         * re-used, and the handler frees the bulk desc explicitly. */

        return desc;
}

void ptlrpc_prep_bulk_page(struct ptlrpc_bulk_desc *desc,
                           cfs_page_t *page, int pageoffset, int len)
{
        LASSERT(desc->bd_iov_count < desc->bd_max_iov);
        LASSERT(page != NULL);
        LASSERT(pageoffset >= 0);
        LASSERT(len > 0);
        LASSERT(pageoffset + len <= CFS_PAGE_SIZE);

        desc->bd_nob += len;

        ptlrpc_add_bulk_page(desc, page, pageoffset, len);
}

void ptlrpc_free_bulk(struct ptlrpc_bulk_desc *desc)
{
        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));

        sptlrpc_enc_pool_put_pages(desc);

        if (desc->bd_export)
                class_export_put(desc->bd_export);
        else
                class_import_put(desc->bd_import);

        OBD_FREE(desc, offsetof(struct ptlrpc_bulk_desc,
                                bd_iov[desc->bd_max_iov]));
        EXIT;
}

void ptlrpc_free_rq_pool(struct ptlrpc_request_pool *pool)
{
        struct list_head *l, *tmp;
        struct ptlrpc_request *req;

        if (!pool)
                return;

        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(req->rq_reqbuf, pool->prp_rq_size);
                OBD_FREE(req, sizeof(*req));
        }
        OBD_FREE(pool, sizeof(*pool));
}

void ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq)
{
        int i;
        int size = 1;

        while (size < pool->prp_rq_size + SPTLRPC_MAX_PAYLOAD)
                size <<= 1;

        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);

        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);
                OBD_ALLOC(req, sizeof(struct ptlrpc_request));
                if (!req)
                        return;
                OBD_ALLOC_GFP(msg, size, CFS_ALLOC_STD);
                if (!msg) {
                        OBD_FREE(req, sizeof(struct ptlrpc_request));
                        return;
                }
                req->rq_reqbuf = msg;
                req->rq_reqbuf_len = size;
                req->rq_pool = pool;
                spin_lock(&pool->prp_lock);
                list_add_tail(&req->rq_list, &pool->prp_req_list);
        }
        spin_unlock(&pool->prp_lock);
        return;
}

struct ptlrpc_request_pool *ptlrpc_init_rq_pool(int num_rq, int msgsize,
                                                void (*populate_pool)(struct ptlrpc_request_pool *, int))
{
        struct ptlrpc_request_pool *pool;

        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 */

        spin_lock_init(&pool->prp_lock);
        CFS_INIT_LIST_HEAD(&pool->prp_req_list);
        pool->prp_rq_size = msgsize;
        pool->prp_populate = populate_pool;

        populate_pool(pool, num_rq);

        if (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;
}

static struct ptlrpc_request *ptlrpc_prep_req_from_pool(struct ptlrpc_request_pool *pool)
{
        struct ptlrpc_request *request;
        struct lustre_msg *reqbuf;

        if (!pool)
                return NULL;

        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(list_empty(&pool->prp_req_list))) {
                spin_unlock(&pool->prp_lock);
                return NULL;
        }

        request = list_entry(pool->prp_req_list.next, struct ptlrpc_request,
                             rq_list);
        list_del(&request->rq_list);
        spin_unlock(&pool->prp_lock);

        LASSERT(request->rq_reqbuf);
        LASSERT(request->rq_pool);

        reqbuf = request->rq_reqbuf;
        memset(request, 0, sizeof(*request));
        request->rq_reqbuf = reqbuf;
        request->rq_reqbuf_len = pool->prp_rq_size;
        request->rq_pool = pool;
        return request;
}

static void __ptlrpc_free_req_to_pool(struct ptlrpc_request *request)
{
        struct ptlrpc_request_pool *pool = request->rq_pool;

        spin_lock(&pool->prp_lock);
        LASSERT(list_empty(&request->rq_list));
        list_add_tail(&request->rq_list, &pool->prp_req_list);
        spin_unlock(&pool->prp_lock);
}

struct ptlrpc_request *
ptlrpc_prep_req_pool(struct obd_import *imp, __u32 version, int opcode,
                     int count, int *lengths, char **bufs,
                     struct ptlrpc_request_pool *pool,
                     struct ptlrpc_cli_ctx *ctx)
{
        struct ptlrpc_request *request = NULL;
        int rc;
        ENTRY;

        /* The obd disconnected */
        if (imp == NULL)
                return NULL;

        LASSERT(imp != LP_POISON);
        LASSERT((unsigned long)imp->imp_client > 0x1000);
        LASSERT(imp->imp_client != LP_POISON);

        if (pool)
                request = ptlrpc_prep_req_from_pool(pool);

        if (!request)
                OBD_ALLOC(request, sizeof(*request));

        if (!request) {
                CERROR("request allocation out of memory\n");
                RETURN(NULL);
        }

        request->rq_import = class_import_get(imp);

        if (unlikely(ctx))
                request->rq_cli_ctx = sptlrpc_cli_ctx_get(ctx);
        else {
                rc = sptlrpc_req_get_ctx(request);
                if (rc)
                        GOTO(out_free, rc);
        }

        sptlrpc_req_set_flavor(request, opcode);

        rc = lustre_pack_request(request, imp->imp_msg_magic, count, lengths,
                                 bufs);
        if (rc) {
                LASSERT(!request->rq_pool);
                GOTO(out_ctx, rc);
        }

        lustre_msg_add_version(request->rq_reqmsg, version);

        if (imp->imp_server_timeout)
                request->rq_timeout = obd_timeout / 2;
        else
                request->rq_timeout = obd_timeout;
        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;

        request->rq_reply_cbid.cbid_fn  = reply_in_callback;
        request->rq_reply_cbid.cbid_arg = request;

        request->rq_phase = RQ_PHASE_NEW;

        /* XXX FIXME bug 249 */
        request->rq_request_portal = imp->imp_client->cli_request_portal;
        request->rq_reply_portal = imp->imp_client->cli_reply_portal;

        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_ctx_chain);
        CFS_INIT_LIST_HEAD(&request->rq_set_chain);
        cfs_waitq_init(&request->rq_reply_waitq);
        request->rq_xid = ptlrpc_next_xid();
        atomic_set(&request->rq_refcount, 1);

        lustre_msg_set_opc(request->rq_reqmsg, opcode);
        lustre_msg_set_flags(request->rq_reqmsg, 0);

        RETURN(request);
out_ctx:
        sptlrpc_req_put_ctx(request);
out_free:
        class_import_put(imp);
        if (request->rq_pool)
                __ptlrpc_free_req_to_pool(request);
        else
                OBD_FREE(request, sizeof(*request));
        return NULL;
}

struct ptlrpc_request *
ptlrpc_prep_req(struct obd_import *imp, __u32 version, int opcode, int count,
                int *lengths, char **bufs)
{
        return ptlrpc_prep_req_pool(imp, version, opcode, count, lengths, bufs,
                                    NULL, NULL);
}

struct ptlrpc_request_set *ptlrpc_prep_set(void)
{
        struct ptlrpc_request_set *set;

        ENTRY;
        OBD_ALLOC(set, sizeof *set);
        if (!set)
                RETURN(NULL);
        CFS_INIT_LIST_HEAD(&set->set_requests);
        cfs_waitq_init(&set->set_waitq);
        set->set_remaining = 0;
        spin_lock_init(&set->set_new_req_lock);
        CFS_INIT_LIST_HEAD(&set->set_new_requests);

        RETURN(set);
}

/* Finish with this set; opposite of prep_set. */
void ptlrpc_set_destroy(struct ptlrpc_request_set *set)
{
        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 = (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++;
        }

        LASSERT(set->set_remaining == 0 || 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) {

                        if (req->rq_interpret_reply != NULL) {
                                int (*interpreter)(struct ptlrpc_request *,
                                                   void *, int) =
                                        req->rq_interpret_reply;

                                /* higher level (i.e. LOV) failed;
                                 * let the sub reqs clean up */
                                req->rq_status = -EBADR;
                                interpreter(req, &req->rq_async_args,
                                            req->rq_status);
                        }
                        set->set_remaining--;
                }

                req->rq_set = NULL;
                ptlrpc_req_finished (req);
        }

        LASSERT(set->set_remaining == 0);

        OBD_FREE(set, sizeof(*set));
        EXIT;
}

void ptlrpc_set_add_req(struct ptlrpc_request_set *set,
                        struct ptlrpc_request *req)
{
        /* The set takes over the caller's request reference */
        list_add_tail(&req->rq_set_chain, &set->set_requests);
        req->rq_set = set;
        set->set_remaining++;

        atomic_inc(&req->rq_import->imp_inflight);
}

/* lock so many callers can add things, the context that owns the set
 * is supposed to notice these and move them into the set proper. */
void ptlrpc_set_add_new_req(struct ptlrpc_request_set *set,
                            struct ptlrpc_request *req)
{
        spin_lock(&set->set_new_req_lock);
        /* The set takes over the caller's request reference */
        list_add_tail(&req->rq_set_chain, &set->set_new_requests);
        req->rq_set = set;
        spin_unlock(&set->set_new_req_lock);
}

/*
 * Based on the current state of the import, determine if the request
 * can be sent, is an error, or should be delayed.
 *
 * Returns true if this request should be delayed. If false, and
 * *status is set, then the request can not be sent and *status is the
 * error code.  If false and status is 0, then request can be sent.
 *
 * The imp->imp_lock must be held.
 */
static int ptlrpc_import_delay_req(struct obd_import *imp,
                                   struct ptlrpc_request *req, int *status)
{
        int delay = 0;
        ENTRY;

        LASSERT (status != NULL);
        *status = 0;

        if (req->rq_ctx_init || req->rq_ctx_fini) {
                /* always allow ctx init/fini rpc go through */
        } 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 (req->rq_send_state == LUSTRE_IMP_CONNECTING &&
                 imp->imp_state == LUSTRE_IMP_CONNECTING) {
                /* allow CONNECT even if import is invalid */ ;
        } else if (imp->imp_invalid) {
                /* If the import has been invalidated (such as by an OST
                 * failure), the request must fail with -EIO. */
                if (!imp->imp_deactive)
                        DEBUG_REQ(D_ERROR, req, "IMP_INVALID");
                *status = -EIO;
        } 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) {
                if (imp->imp_obd->obd_no_recov || imp->imp_dlm_fake ||
                    req->rq_no_delay)
                        *status = -EWOULDBLOCK;
                else
                        delay = 1;
        }

        RETURN(delay);
}

static int ptlrpc_check_reply(struct ptlrpc_request *req)
{
        int rc = 0;
        ENTRY;

        /* serialise with network callback */
        spin_lock(&req->rq_lock);

        if (req->rq_replied)
                GOTO(out, rc = 1);

        if (req->rq_net_err && !req->rq_timedout) {
                spin_unlock(&req->rq_lock);
                rc = ptlrpc_expire_one_request(req);
                spin_lock(&req->rq_lock);
                GOTO(out, rc);
        }

        if (req->rq_err)
                GOTO(out, rc = 1);

        if (req->rq_resend)
                GOTO(out, rc = 1);

        if (req->rq_restart)
                GOTO(out, rc = 1);
        EXIT;
 out:
        spin_unlock(&req->rq_lock);
        DEBUG_REQ(D_NET, req, "rc = %d for", rc);
        return rc;
}

static int ptlrpc_check_status(struct ptlrpc_request *req)
{
        int err;
        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 (err < 0) {
                DEBUG_REQ(D_INFO, req, "status is %d", err);
        } else if (err > 0) {
                /* XXX: translate this error from net to host */
                DEBUG_REQ(D_INFO, req, "status is %d", err);
        }

        RETURN(err);
}

static int after_reply(struct ptlrpc_request *req)
{
        struct obd_import *imp = req->rq_import;
        int rc;
        ENTRY;

        LASSERT(!req->rq_receiving_reply);
        LASSERT(req->rq_nob_received <= req->rq_repbuf_len);

        /* NB Until this point, the whole of the incoming message,
         * including buflens, status etc is in the sender's byte order. */

#if SWAB_PARANOIA
        /* Clear reply swab mask; this is a new reply in sender's byte order */
        req->rq_rep_swab_mask = 0;
#endif
        rc = sptlrpc_cli_unwrap_reply(req);
        if (rc) {
                DEBUG_REQ(D_ERROR, req, "unwrap reply failed (%d):", rc);
                RETURN(rc);
        }

        /* security layer unwrap might ask resend this request */
        if (req->rq_resend)
                RETURN(0);

        rc = lustre_unpack_msg(req->rq_repmsg, req->rq_replen);
        if (rc) {
                DEBUG_REQ(D_ERROR, req, "unpack_rep failed: %d", rc);
                RETURN(-EPROTO);
        }

        rc = lustre_unpack_rep_ptlrpc_body(req, MSG_PTLRPC_BODY_OFF);
        if (rc) {
                DEBUG_REQ(D_ERROR, req, "unpack ptlrpc body failed: %d", rc);
                RETURN(-EPROTO);
        }

        if (lustre_msg_get_type(req->rq_repmsg) != PTL_RPC_MSG_REPLY &&
            lustre_msg_get_type(req->rq_repmsg) != PTL_RPC_MSG_ERR) {
                DEBUG_REQ(D_ERROR, req, "invalid packet received (type=%u)",
                          lustre_msg_get_type(req->rq_repmsg));
                RETURN(-EPROTO);
        }

        rc = ptlrpc_check_status(req);
        imp->imp_connect_error = 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 ((rc == -ENOTCONN) || (rc == -ENODEV)) {
                if (req->rq_send_state != LUSTRE_IMP_FULL ||
                    imp->imp_obd->obd_no_recov || imp->imp_dlm_fake) {
                        RETURN(-ENOTCONN);
                }

                ptlrpc_request_handle_notconn(req);

                RETURN(rc);
        }

        /* Store transno in reqmsg for replay. */
        req->rq_transno = lustre_msg_get_transno(req->rq_repmsg);
        lustre_msg_set_transno(req->rq_reqmsg, req->rq_transno);

        if (req->rq_import->imp_replayable) {
                spin_lock(&imp->imp_lock);
                /* no point in adding already-committed requests to the replay
                 * list, we will just remove them immediately. b=9829 */
                if (req->rq_transno != 0 && 
                    (req->rq_transno > 
                     lustre_msg_get_last_committed(req->rq_repmsg) ||
                     req->rq_replay))
                        ptlrpc_retain_replayable_request(req, imp);
                else if (req->rq_commit_cb != NULL) {
                        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);
                spin_unlock(&imp->imp_lock);
        }

        RETURN(rc);
}

static int ptlrpc_send_new_req(struct ptlrpc_request *req)
{
        struct obd_import     *imp;
        int rc;
        ENTRY;

        LASSERT(req->rq_phase == RQ_PHASE_NEW);
        req->rq_phase = RQ_PHASE_RPC;

        imp = req->rq_import;
        spin_lock(&imp->imp_lock);

        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);
                spin_unlock(&imp->imp_lock);
                RETURN(0);
        }

        if (rc != 0) {
                spin_unlock(&imp->imp_lock);
                req->rq_status = rc;
                req->rq_phase = RQ_PHASE_INTERPRET;
                RETURN(rc);
        }

        /* XXX this is the same as ptlrpc_queue_wait */
        LASSERT(list_empty(&req->rq_list));
        list_add_tail(&req->rq_list, &imp->imp_sending_list);
        spin_unlock(&imp->imp_lock);

        lustre_msg_set_status(req->rq_reqmsg, cfs_curproc_pid());

        rc = sptlrpc_req_refresh_ctx(req, -1);
        if (rc) {
                if (req->rq_err) {
                        req->rq_status = rc;
                        RETURN(1);
                } else {
                        /* here begins timeout counting */
                        req->rq_sent = CURRENT_SECONDS;
                        req->rq_wait_ctx = 1;
                        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));

        rc = ptl_send_rpc(req, 0);
        if (rc) {
                DEBUG_REQ(D_HA, req, "send failed (%d); expect timeout", rc);
                req->rq_net_err = 1;
                RETURN(rc);
        }
        RETURN(0);
}

/* this sends any unsent RPCs in @set and returns TRUE if all are sent */
int ptlrpc_check_set(struct ptlrpc_request_set *set)
{
        struct list_head *tmp;
        int force_timer_recalc = 0;
        ENTRY;

        if (set->set_remaining == 0)
                RETURN(1);

        list_for_each(tmp, &set->set_requests) {
                struct ptlrpc_request *req =
                        list_entry(tmp, struct ptlrpc_request, rq_set_chain);
                struct obd_import *imp = req->rq_import;
                int rc = 0;

                if (req->rq_phase == RQ_PHASE_NEW &&
                    ptlrpc_send_new_req(req)) {
                        force_timer_recalc = 1;
                }

                if (!(req->rq_phase == RQ_PHASE_RPC ||
                      req->rq_phase == RQ_PHASE_BULK ||
                      req->rq_phase == RQ_PHASE_INTERPRET ||
                      req->rq_phase == RQ_PHASE_COMPLETE)) {
                        DEBUG_REQ(D_ERROR, req, "bad phase %x", req->rq_phase);
                        LBUG();
                }

                if (req->rq_phase == RQ_PHASE_COMPLETE)
                        continue;

                if (req->rq_phase == RQ_PHASE_INTERPRET)
                        GOTO(interpret, req->rq_status);

                if (req->rq_net_err && !req->rq_timedout)
                        ptlrpc_expire_one_request(req);

                if (req->rq_err) {
                        ptlrpc_unregister_reply(req);
                        req->rq_replied = 0;
                        if (req->rq_status == 0)
                                req->rq_status = -EIO;
                        req->rq_phase = RQ_PHASE_INTERPRET;

                        spin_lock(&imp->imp_lock);
                        list_del_init(&req->rq_list);
                        spin_unlock(&imp->imp_lock);

                        GOTO(interpret, req->rq_status);
                }

                /* ptlrpc_queue_wait->l_wait_event guarantees that rq_intr
                 * will only be set after rq_timedout, but the oig 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 */
                if (req->rq_intr && (req->rq_timedout || req->rq_waiting ||
                                     req->rq_wait_ctx)) {
                        /* NB could be on delayed list */
                        ptlrpc_unregister_reply(req);
                        req->rq_status = -EINTR;
                        req->rq_phase = RQ_PHASE_INTERPRET;

                        spin_lock(&imp->imp_lock);
                        list_del_init(&req->rq_list);
                        spin_unlock(&imp->imp_lock);

                        GOTO(interpret, req->rq_status);
                }

                if (req->rq_phase == RQ_PHASE_RPC) {
                        if (req->rq_timedout || req->rq_resend ||
                            req->rq_waiting || req->rq_wait_ctx) {
                                int status;

                                /* rq_wait_ctx is only touched in ptlrpcd,
                                 * no lock needed here.
                                 */
                                if (req->rq_wait_ctx)
                                        goto check_ctx;

                                ptlrpc_unregister_reply(req);

                                spin_lock(&imp->imp_lock);

                                if (ptlrpc_import_delay_req(imp, req, &status)){
                                        spin_unlock(&imp->imp_lock);
                                        continue;
                                }

                                list_del_init(&req->rq_list);
                                if (status != 0)  {
                                        req->rq_status = status;
                                        req->rq_phase = RQ_PHASE_INTERPRET;
                                        spin_unlock(&imp->imp_lock);
                                        GOTO(interpret, req->rq_status);
                                }
                                if (req->rq_no_resend && !req->rq_wait_ctx) {
                                        req->rq_status = -ENOTCONN;
                                        req->rq_phase = RQ_PHASE_INTERPRET;
                                        spin_unlock(&imp->imp_lock);
                                        GOTO(interpret, req->rq_status);
                                }
                                list_add_tail(&req->rq_list,
                                              &imp->imp_sending_list);

                                spin_unlock(&imp->imp_lock);

                                req->rq_waiting = 0;
                                if (req->rq_resend) {
                                        lustre_msg_add_flags(req->rq_reqmsg,
                                                             MSG_RESENT);
                                        if (req->rq_bulk) {
                                                __u64 old_xid = req->rq_xid;

                                                ptlrpc_unregister_bulk (req);

                                                /* 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);
                                        }
                                }
check_ctx:
                                status = sptlrpc_req_refresh_ctx(req, -1);
                                if (status) {
                                        if (req->rq_err) {
                                                req->rq_status = status;
                                                force_timer_recalc = 1;
                                        }
                                        if (!req->rq_wait_ctx) {
                                                /* begins timeout counting */
                                                req->rq_sent = CURRENT_SECONDS;
                                                req->rq_wait_ctx = 1;
                                        }
                                        continue;
                                } else {
                                        req->rq_sent = 0;
                                        req->rq_wait_ctx = 0;
                                }

                                rc = ptl_send_rpc(req, 0);
                                if (rc) {
                                        DEBUG_REQ(D_HA, req, "send failed (%d)",
                                                  rc);
                                        force_timer_recalc = 1;
                                        req->rq_net_err = 1;
                                }
                                /* need to reset the timeout */
                                force_timer_recalc = 1;
                        }

                        /* Still waiting for a reply? */
                        if (ptlrpc_client_receiving_reply(req))
                                continue;

                        /* Did we actually receive a reply? */
                        if (!ptlrpc_client_replied(req))
                                continue;

                        spin_lock(&imp->imp_lock);
                        list_del_init(&req->rq_list);
                        spin_unlock(&imp->imp_lock);

                        req->rq_status = after_reply(req);
                        if (req->rq_resend) {
                                /* Add this req to the delayed list so
                                   it can be errored if the import is
                                   evicted after recovery. */
                                spin_lock(&imp->imp_lock);
                                list_add_tail(&req->rq_list,
                                              &imp->imp_delayed_list);
                                spin_unlock(&imp->imp_lock);
                                continue;
                        }

                        /* If there is no bulk associated with this request,
                         * then we're done and should let the interpreter
                         * process the reply.  Similarly if the RPC returned
                         * an error, and therefore the bulk will never arrive.
                         */
                        if (req->rq_bulk == NULL || req->rq_status != 0) {
                                req->rq_phase = RQ_PHASE_INTERPRET;
                                GOTO(interpret, req->rq_status);
                        }

                        req->rq_phase = RQ_PHASE_BULK;
                }

                LASSERT(req->rq_phase == RQ_PHASE_BULK);
                if (ptlrpc_bulk_active(req->rq_bulk))
                        continue;

                if (!req->rq_bulk->bd_success) {
                        /* The RPC reply arrived OK, but the bulk screwed
                         * up!  Dead wierd 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");
                        LBUG();
                }

                req->rq_phase = RQ_PHASE_INTERPRET;

        interpret:
                LASSERT(req->rq_phase == RQ_PHASE_INTERPRET);
                LASSERT(!req->rq_receiving_reply);

                ptlrpc_unregister_reply(req);
                if (req->rq_bulk != NULL)
                        ptlrpc_unregister_bulk (req);

                req->rq_phase = RQ_PHASE_COMPLETE;

                if (req->rq_interpret_reply != NULL) {
                        int (*interpreter)(struct ptlrpc_request *,void *,int) =
                                req->rq_interpret_reply;
                        req->rq_status = interpreter(req, &req->rq_async_args,
                                                     req->rq_status);
                }

                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,
                       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));

                set->set_remaining--;

                atomic_dec(&imp->imp_inflight);
                cfs_waitq_signal(&imp->imp_recovery_waitq);
        }

        /* If we hit an error, we want to recover promptly. */
        RETURN(set->set_remaining == 0 || force_timer_recalc);
}

int ptlrpc_expire_one_request(struct ptlrpc_request *req)
{
        struct obd_import *imp = req->rq_import;
        int rc = 0;
        ENTRY;

        DEBUG_REQ(D_ERROR|D_NETERROR, req, "%s (sent at %lu, %lus ago)",
                  req->rq_net_err ? "network error" : "timeout",
                  (long)req->rq_sent, CURRENT_SECONDS - req->rq_sent);

        if (imp != NULL && obd_debug_peer_on_timeout)
                LNetCtl(IOC_LIBCFS_DEBUG_PEER, &imp->imp_connection->c_peer);

        spin_lock(&req->rq_lock);
        req->rq_timedout = 1;
        req->rq_wait_ctx = 0;
        spin_unlock(&req->rq_lock);

        ptlrpc_unregister_reply (req);

        if (obd_dump_on_timeout)
                libcfs_debug_dumplog();

        if (req->rq_bulk != NULL)
                ptlrpc_unregister_bulk (req);

        if (imp == NULL) {
                DEBUG_REQ(D_HA, req, "NULL import: already cleaned up?");
                RETURN(1);
        }

        /* The DLM server doesn't want recovery run on its imports. */
        if (imp->imp_dlm_fake)
                RETURN(1);

        /* If this request is for recovery or other primordial tasks,
         * then error it out here. */
        if (req->rq_ctx_init || req->rq_ctx_fini ||
            req->rq_send_state != LUSTRE_IMP_FULL ||
            imp->imp_obd->obd_no_recov) {
                spin_lock(&req->rq_lock);
                req->rq_status = -ETIMEDOUT;
                req->rq_err = 1;
                spin_unlock(&req->rq_lock);
                RETURN(1);
        }
        
        /* if request can't be resend we can't wait answer after timeout */
        if (req->rq_no_resend) {
                DEBUG_REQ(D_RPCTRACE, req, "TIMEOUT-NORESEND:");
                rc = 1;
        }

        ptlrpc_fail_import(imp, lustre_msg_get_conn_cnt(req->rq_reqmsg));

        RETURN(rc);
}

int ptlrpc_expired_set(void *data)
{
        struct ptlrpc_request_set *set = data;
        struct list_head          *tmp;
        time_t                     now = CURRENT_SECONDS;
        ENTRY;

        LASSERT(set != NULL);

        /* 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);

                /* request in-flight? */
                if (!((req->rq_phase == RQ_PHASE_RPC && !req->rq_waiting &&
                       !req->rq_resend) ||
                      (req->rq_phase == RQ_PHASE_BULK)))
                        continue;

                if (req->rq_timedout ||           /* already dealt with */
                    req->rq_sent + req->rq_timeout > now) /* not expired */
                        continue;

                /* deal with this guy */
                ptlrpc_expire_one_request (req);
        }

        /* When waiting for a whole set, we always to break out of the
         * sleep so we can recalculate the timeout, or enable interrupts
         * iff everyone's timed out.
         */
        RETURN(1);
}

void ptlrpc_mark_interrupted(struct ptlrpc_request *req)
{
        spin_lock(&req->rq_lock);
        req->rq_intr = 1;
        spin_unlock(&req->rq_lock);
}

void ptlrpc_interrupted_set(void *data)
{
        struct ptlrpc_request_set *set = data;
        struct list_head *tmp;

        LASSERT(set != NULL);
        CERROR("INTERRUPTED SET %p\n", set);

        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)
                        continue;

                ptlrpc_mark_interrupted(req);
        }
}

int ptlrpc_set_next_timeout(struct ptlrpc_request_set *set)
{
        struct list_head      *tmp;
        time_t                 now = CURRENT_SECONDS;
        time_t                 deadline;
        int                    timeout = 0;
        struct ptlrpc_request *req;
        ENTRY;

        SIGNAL_MASK_ASSERT(); /* XXX BUG 1511 */

        list_for_each(tmp, &set->set_requests) {
                req = list_entry(tmp, struct ptlrpc_request, rq_set_chain);

                /* request in-flight? */
                if (!((req->rq_phase == RQ_PHASE_RPC && !req->rq_waiting) ||
                      (req->rq_phase == RQ_PHASE_BULK)))
                        continue;

                if (req->rq_timedout)   /* already timed out */
                        continue;

                deadline = req->rq_sent + req->rq_timeout;
                if (deadline <= now)    /* actually expired already */
                        timeout = 1;    /* ASAP */
                else if (timeout == 0 || timeout > deadline - now)
                        timeout = deadline - now;
        }
        RETURN(timeout);
}

int ptlrpc_set_wait(struct ptlrpc_request_set *set)
{
        struct list_head      *tmp;
        struct ptlrpc_request *req;
        struct l_wait_info     lwi;
        int                    rc, timeout;
        ENTRY;

        if (list_empty(&set->set_requests))
                RETURN(0);

        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);
        }

        do {
                timeout = ptlrpc_set_next_timeout(set);

                /* wait until all complete, interrupted, or an in-flight
                 * req times out */
                CDEBUG(D_HA, "set %p going to sleep for %d seconds\n",
                       set, timeout);
                lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(timeout ? timeout : 1),
                                       ptlrpc_expired_set,
                                       ptlrpc_interrupted_set, set);
                rc = l_wait_event(set->set_waitq, ptlrpc_check_set(set), &lwi);

                LASSERT(rc == 0 || rc == -EINTR || rc == -ETIMEDOUT);

                /* -EINTR => all requests have been flagged rq_intr so next
                 * check completes.
                 * -ETIMEOUTD => someone timed out.  When all reqs have
                 * timed out, signals are enabled allowing completion with
                 * EINTR.
                 * I don't really care if we go once more round the loop in
                 * the error cases -eeb. */
        } while (rc != 0 || set->set_remaining != 0);

        LASSERT(set->set_remaining == 0);

        rc = 0;
        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)
                        rc = req->rq_status;
        }

        if (set->set_interpret != NULL) {
                int (*interpreter)(struct ptlrpc_request_set *set,void *,int) =
                        set->set_interpret;
                rc = interpreter (set, set->set_arg, rc);
        }

        RETURN(rc);
}

static void __ptlrpc_free_req(struct ptlrpc_request *request, int locked)
{
        ENTRY;
        if (request == NULL) {
                EXIT;
                return;
        }

        LASSERTF(!request->rq_receiving_reply, "req %p\n", request);
        LASSERTF(request->rq_rqbd == NULL, "req %p\n",request);/* client-side */
        LASSERTF(list_empty(&request->rq_list), "req %p\n", request);
        LASSERTF(list_empty(&request->rq_set_chain), "req %p\n", request);
        LASSERT(request->rq_cli_ctx);

        /* 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_reqbuf != NULL || request->rq_clrbuf != NULL)
                sptlrpc_cli_free_reqbuf(request);

        sptlrpc_req_put_ctx(request);

        if (request->rq_pool)
                __ptlrpc_free_req_to_pool(request);
        else
                OBD_FREE(request, sizeof(*request));
        EXIT;
}

void ptlrpc_free_req(struct ptlrpc_request *request)
{
        __ptlrpc_free_req(request, 0);
}

static int __ptlrpc_req_finished(struct ptlrpc_request *request, int locked);
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);
}

static int __ptlrpc_req_finished(struct ptlrpc_request *request, int locked)
{
        ENTRY;
        if (request == NULL)
                RETURN(1);

        if (request == LP_POISON ||
            request->rq_reqmsg == LP_POISON) {
                CERROR("dereferencing freed request (bug 575)\n");
                LBUG();
                RETURN(1);
        }

        DEBUG_REQ(D_INFO, request, "refcount now %u",
                  atomic_read(&request->rq_refcount) - 1);

        if (atomic_dec_and_test(&request->rq_refcount)) {
                __ptlrpc_free_req(request, locked);
                RETURN(1);
        }

        RETURN(0);
}

void ptlrpc_req_finished(struct ptlrpc_request *request)
{
        __ptlrpc_req_finished(request, 0);
}

__u64 ptlrpc_req_xid(struct ptlrpc_request *request)
{
        return request->rq_xid;
}
EXPORT_SYMBOL(ptlrpc_req_xid);

/* Disengage the client's reply buffer from the network
 * NB does _NOT_ unregister any client-side bulk.
 * IDEMPOTENT, but _not_ safe against concurrent callers.
 * The request owner (i.e. the thread doing the I/O) must call...
 */
void ptlrpc_unregister_reply (struct ptlrpc_request *request)
{
        int                rc;
        cfs_waitq_t       *wq;
        struct l_wait_info lwi;

        LASSERT(!in_interrupt ());             /* might sleep */

        if (!ptlrpc_client_receiving_reply(request))
                return;

        LNetMDUnlink (request->rq_reply_md_h);

        /* We have to l_wait_event() whatever the result, to give liblustre
         * a chance to run reply_in_callback() */

        if (request->rq_set != NULL)
                wq = &request->rq_set->set_waitq;
        else
                wq = &request->rq_reply_waitq;

        for (;;) {
                /* Network access will complete in finite time but the HUGE
                 * timeout lets us CWARN for visibility of sluggish NALs */
                lwi = LWI_TIMEOUT(cfs_time_seconds(300), NULL, NULL);
                rc = l_wait_event (*wq, !ptlrpc_client_receiving_reply(request), &lwi);
                if (rc == 0)
                        return;

                LASSERT (rc == -ETIMEDOUT);
                DEBUG_REQ(D_WARNING, request, "Unexpectedly long timeout");
        }
}

/* caller must hold imp->imp_lock */
void ptlrpc_free_committed(struct obd_import *imp)
{
        struct list_head *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);


        if (imp->imp_peer_committed_transno == imp->imp_last_transno_checked &&
            imp->imp_generation == imp->imp_last_generation_checked) {
                CDEBUG(D_HA, "%s: skip recheck for last_committed "LPU64"\n",
                       imp->imp_obd->obd_name, imp->imp_peer_committed_transno);
                return;
        }
        
        CDEBUG(D_HA, "%s: committing for last_committed "LPU64" gen %d\n",
               imp->imp_obd->obd_name, imp->imp_peer_committed_transno,
               imp->imp_generation);
        imp->imp_last_transno_checked = imp->imp_peer_committed_transno;
        imp->imp_last_generation_checked = imp->imp_generation;

        list_for_each_safe(tmp, saved, &imp->imp_replay_list) {
                req = list_entry(tmp, struct ptlrpc_request, rq_replay_list);

                /* XXX ok to remove when 1357 resolved - rread 05/29/03  */
                LASSERT(req != last_req);
                last_req = req;

                if (req->rq_import_generation < imp->imp_generation) {
                        DEBUG_REQ(D_HA, req, "freeing request with old gen");
                        GOTO(free_req, 0);
                }

                if (req->rq_replay) {
                        DEBUG_REQ(D_HA, req, "keeping (FL_REPLAY)");
                        continue;
                }

                /* not yet committed */
                if (req->rq_transno > imp->imp_peer_committed_transno) {
                        DEBUG_REQ(D_HA, req, "stopping search");
                        break;
                }

                DEBUG_REQ(D_HA, req, "committing (last_committed "LPU64")",
                          imp->imp_peer_committed_transno);
free_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);
        }

        EXIT;
        return;
}

void ptlrpc_cleanup_client(struct obd_import *imp)
{
        ENTRY;
        EXIT;
        return;
}

void ptlrpc_resend_req(struct ptlrpc_request *req)
{
        DEBUG_REQ(D_HA, req, "going to resend");
        lustre_msg_set_handle(req->rq_reqmsg, &(struct lustre_handle){ 0 });
        req->rq_status = -EAGAIN;

        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_wake_client_req(req);
        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;

        spin_lock(&req->rq_lock);
        req->rq_restart = 1;
        req->rq_timedout = 0;
        ptlrpc_wake_client_req(req);
        spin_unlock(&req->rq_lock);
}

static int expired_request(void *data)
{
        struct ptlrpc_request *req = data;
        ENTRY;

        /* some failure can suspend regular timeouts */
        if (ptlrpc_check_suspend())
                RETURN(1);

        RETURN(ptlrpc_expire_one_request(req));
}

static void interrupted_request(void *data)
{
        struct ptlrpc_request *req = data;
        DEBUG_REQ(D_HA, req, "request interrupted");
        spin_lock(&req->rq_lock);
        req->rq_intr = 1;
        spin_unlock(&req->rq_lock);
}

struct ptlrpc_request *ptlrpc_request_addref(struct ptlrpc_request *req)
{
        ENTRY;
        atomic_inc(&req->rq_refcount);
        RETURN(req);
}

void ptlrpc_retain_replayable_request(struct ptlrpc_request *req,
                                      struct obd_import *imp)
{
        struct list_head *tmp;

        LASSERT_SPIN_LOCKED(&imp->imp_lock);

        /* clear this for new requests that were resent as well
           as resent replayed requests. */
        lustre_msg_clear_flags(req->rq_reqmsg, MSG_RESENT);

        /* 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);

        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
                 * opens, so use req->rq_xid as a secondary key.
                 * (See bugs 684, 685, and 428.)
                 * XXX no longer needed, but all opens need transnos!
                 */
                if (iter->rq_transno > req->rq_transno)
                        continue;

                if (iter->rq_transno == req->rq_transno) {
                        LASSERT(iter->rq_xid != req->rq_xid);
                        if (iter->rq_xid > req->rq_xid)
                                continue;
                }

                list_add(&req->rq_replay_list, &iter->rq_replay_list);
                return;
        }

        list_add_tail(&req->rq_replay_list, &imp->imp_replay_list);
}

int ptlrpc_queue_wait(struct ptlrpc_request *req)
{
        int rc = 0;
        int brc;
        struct l_wait_info lwi;
        struct obd_import *imp = req->rq_import;
        cfs_duration_t timeout = 0;
        ENTRY;

        LASSERT(req->rq_set == NULL);
        LASSERT(!req->rq_receiving_reply);
        atomic_inc(&imp->imp_inflight);

        /* for distributed debugging */
        lustre_msg_set_status(req->rq_reqmsg, cfs_curproc_pid());
        LASSERT(imp->imp_obd != NULL);
        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));

        /* Mark phase here for a little debug help */
        req->rq_phase = RQ_PHASE_RPC;

        spin_lock(&imp->imp_lock);
        req->rq_import_generation = imp->imp_generation;
restart:
        if (ptlrpc_import_delay_req(imp, req, &rc)) {
                list_del(&req->rq_list);

                list_add_tail(&req->rq_list, &imp->imp_delayed_list);
                spin_unlock(&imp->imp_lock);

                DEBUG_REQ(D_HA, req, "\"%s\" waiting for recovery: (%s != %s)",
                          cfs_curproc_comm(),
                          ptlrpc_import_state_name(req->rq_send_state),
                          ptlrpc_import_state_name(imp->imp_state));
                lwi = LWI_INTR(interrupted_request, req);
                rc = l_wait_event(req->rq_reply_waitq,
                                  (req->rq_send_state == imp->imp_state ||
                                   req->rq_err || req->rq_intr),
                                  &lwi);
                DEBUG_REQ(D_HA, req, "\"%s\" awake: (%s == %s or %d/%d == 1)",
                          cfs_curproc_comm(),
                          ptlrpc_import_state_name(imp->imp_state),
                          ptlrpc_import_state_name(req->rq_send_state),
                          req->rq_err, req->rq_intr);

                spin_lock(&imp->imp_lock);
                list_del_init(&req->rq_list);

                if (req->rq_err) {
                        rc = -EIO;
                }
                else if (req->rq_intr) {
                        rc = -EINTR;
                }
                else if (req->rq_no_resend) {
                        spin_unlock(&imp->imp_lock);
                        GOTO(out, rc = -ETIMEDOUT);
                }
                else {
                        GOTO(restart, rc);
                }
        }

        if (rc != 0) {
                list_del_init(&req->rq_list);
                spin_unlock(&imp->imp_lock);
                req->rq_status = rc; // XXX this ok?
                GOTO(out, rc);
        }

        if (req->rq_resend) {
                lustre_msg_add_flags(req->rq_reqmsg, MSG_RESENT);

                if (req->rq_bulk != NULL) {
                        ptlrpc_unregister_bulk (req);

                        /* bulk requests are supposed to be
                         * idempotent, so we are free to bump the xid
                         * here, which we need to do before
                         * registering the bulk again (bug 6371).
                         * print the old xid first for sanity.
                         */
                        DEBUG_REQ(D_HA, req, "bumping xid for bulk: ");
                        req->rq_xid = ptlrpc_next_xid();
                }

                DEBUG_REQ(D_HA, req, "resending: ");
        }

        /* XXX this is the same as ptlrpc_set_wait */
        LASSERT(list_empty(&req->rq_list));
        list_add_tail(&req->rq_list, &imp->imp_sending_list);
        spin_unlock(&imp->imp_lock);

        rc = sptlrpc_req_refresh_ctx(req, 0);
        if (rc) {
                if (req->rq_err) {
                        /* we got fatal ctx refresh error, directly jump out
                         * thus we can pass back the actual error code.
                         */
                        spin_lock(&imp->imp_lock);
                        list_del_init(&req->rq_list);
                        spin_unlock(&imp->imp_lock);

                        CERROR("Failed to refresh ctx of req %p: %d\n", req, rc);
                        GOTO(out, rc);
                }
                /* simulating we got error during send rpc */
                goto after_send;
        }

        rc = ptl_send_rpc(req, 0);
        if (rc) {
                DEBUG_REQ(D_HA, req, "send failed (%d); recovering", rc);
                timeout = CFS_TICK;
        } else {
                timeout = cfs_timeout_cap(cfs_time_seconds(req->rq_timeout));
                DEBUG_REQ(D_NET, req, 
                          "-- sleeping for "CFS_DURATION_T" jiffies", timeout);
        }
repeat:
        lwi = LWI_TIMEOUT_INTR(timeout, expired_request, interrupted_request,
                               req);
        rc = l_wait_event(req->rq_reply_waitq, ptlrpc_check_reply(req), &lwi);
        if (rc == -ETIMEDOUT && ptlrpc_check_and_wait_suspend(req))
                goto repeat;

after_send:
        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,
               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);
        list_del_init(&req->rq_list);
        spin_unlock(&imp->imp_lock);

        /* If the reply was received normally, this just grabs the spinlock
         * (ensuring the reply callback has returned), sees that
         * req->rq_receiving_reply is clear and returns. */
        ptlrpc_unregister_reply (req);

        if (req->rq_err)
                GOTO(out, rc = -EIO);

        /* Resend if we need to, unless we were interrupted. */
        if (req->rq_resend && !req->rq_intr) {
                /* ...unless we were specifically told otherwise. */
                if (req->rq_no_resend)
                        GOTO(out, rc = -ETIMEDOUT);
                spin_lock(&imp->imp_lock);
                goto restart;
        }

        if (req->rq_intr) {
                /* Should only be interrupted if we timed out. */
                if (!req->rq_timedout)
                        DEBUG_REQ(D_ERROR, req,
                                  "rq_intr set but rq_timedout not");
                GOTO(out, rc = -EINTR);
        }

        if (req->rq_timedout) {                 /* non-recoverable timeout */
                GOTO(out, rc = -ETIMEDOUT);
        }

        if (!req->rq_replied) {
                /* How can this be? -eeb */
                DEBUG_REQ(D_ERROR, req, "!rq_replied: ");
                LBUG();
                GOTO(out, rc = req->rq_status);
        }

        rc = after_reply(req);
        /* NB may return +ve success rc */
        if (req->rq_resend) {
                spin_lock(&imp->imp_lock);
                goto restart;
        }

 out:
        if (req->rq_bulk != NULL) {
                if (rc >= 0) {
                        /* success so far.  Note that anything going wrong
                         * with bulk now, is EXTREMELY strange, since the
                         * server must have believed that the bulk
                         * tranferred OK before she replied with success to
                         * me. */
                        lwi = LWI_TIMEOUT(timeout, NULL, NULL);
                        brc = l_wait_event(req->rq_reply_waitq,
                                           !ptlrpc_bulk_active(req->rq_bulk),
                                           &lwi);
                        LASSERT(brc == 0 || brc == -ETIMEDOUT);
                        if (brc != 0) {
                                LASSERT(brc == -ETIMEDOUT);
                                DEBUG_REQ(D_ERROR, req, "bulk timed out");
                                rc = brc;
                        } else if (!req->rq_bulk->bd_success) {
                                DEBUG_REQ(D_ERROR, req, "bulk transfer failed");
                                rc = -EIO;
                        }
                }
                if (rc < 0)
                        ptlrpc_unregister_bulk (req);
        }

        LASSERT(!req->rq_receiving_reply);
        req->rq_phase = RQ_PHASE_INTERPRET;

        atomic_dec(&imp->imp_inflight);
        cfs_waitq_signal(&imp->imp_recovery_waitq);
        RETURN(rc);
}

struct ptlrpc_replay_async_args {
        int praa_old_state;
        int praa_old_status;
};

static int ptlrpc_replay_interpret(struct ptlrpc_request *req,
                                    void * data, int rc)
{
        struct ptlrpc_replay_async_args *aa = data;
        struct obd_import *imp = req->rq_import;

        ENTRY;
        atomic_dec(&imp->imp_replay_inflight);

        if (!req->rq_replied) {
                CERROR("request replay timed out, restarting recovery\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)
                GOTO(out, rc = lustre_msg_get_status(req->rq_repmsg));

        /* The transno had better not change over replay. */
        LASSERT(lustre_msg_get_transno(req->rq_reqmsg) ==
                lustre_msg_get_transno(req->rq_repmsg));

        DEBUG_REQ(D_HA, req, "got rep");

        /* let the callback do fixups, possibly including in the request */
        if (req->rq_replay_cb)
                req->rq_replay_cb(req);

        if (req->rq_replied &&
            lustre_msg_get_status(req->rq_repmsg) != aa->praa_old_status) {
                DEBUG_REQ(D_ERROR, req, "status %d, old was %d",
                          lustre_msg_get_status(req->rq_repmsg),
                          aa->praa_old_status);
        } else {
                /* Put it back for re-replay. */
                lustre_msg_set_status(req->rq_repmsg, aa->praa_old_status);
        }

        /*
         * Errors while replay can set transno to 0, but
         * imp_last_replay_transno shouldn't be set to 0 anyway
         */
        if (req->rq_transno > 0) {
                spin_lock(&imp->imp_lock);
                LASSERT(req->rq_transno <= imp->imp_last_replay_transno);
                imp->imp_last_replay_transno = req->rq_transno;
                spin_unlock(&imp->imp_lock);
        } else
                CERROR("Transno is 0 during replay!\n");
        /* continue with recovery */
        rc = ptlrpc_import_recovery_state_machine(imp);
 out:
        req->rq_send_state = aa->praa_old_state;

        if (rc != 0)
                /* this replay failed, so restart recovery */
                ptlrpc_connect_import(imp, NULL);

        RETURN(rc);
}

int ptlrpc_replay_req(struct ptlrpc_request *req)
{
        struct ptlrpc_replay_async_args *aa;
        ENTRY;

        LASSERT(req->rq_import->imp_state == LUSTRE_IMP_REPLAY);

        /* Not handling automatic bulk replay yet (or ever?) */
        LASSERT(req->rq_bulk == NULL);

        DEBUG_REQ(D_HA, req, "REPLAY");

        LASSERT (sizeof (*aa) <= sizeof (req->rq_async_args));
        aa = (struct ptlrpc_replay_async_args *)&req->rq_async_args;
        memset(aa, 0, sizeof *aa);

        /* Prepare request to be resent with ptlrpcd */
        aa->praa_old_state = req->rq_send_state;
        req->rq_send_state = LUSTRE_IMP_REPLAY;
        req->rq_phase = RQ_PHASE_NEW;
        aa->praa_old_status = lustre_msg_get_status(req->rq_repmsg);
        req->rq_status = 0;

        req->rq_interpret_reply = ptlrpc_replay_interpret;
        atomic_inc(&req->rq_import->imp_replay_inflight);
        ptlrpc_request_addref(req); /* ptlrpcd needs a ref */

        ptlrpcd_add_req(req);
        RETURN(0);
}

void ptlrpc_abort_inflight(struct obd_import *imp)
{
        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.
         */
        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?
         */
        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_HA, req, "inflight");

                spin_lock (&req->rq_lock);
                if (req->rq_import_generation < imp->imp_generation) {
                        req->rq_err = 1;
                        ptlrpc_wake_client_req(req);
                }
                spin_unlock (&req->rq_lock);
        }

        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_HA, req, "aborting waiting req");

                spin_lock (&req->rq_lock);
                if (req->rq_import_generation < imp->imp_generation) {
                        req->rq_err = 1;
                        ptlrpc_wake_client_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);

        spin_unlock(&imp->imp_lock);

        EXIT;
}

static __u64 ptlrpc_last_xid = 0;
spinlock_t ptlrpc_last_xid_lock;

__u64 ptlrpc_next_xid(void)
{
        __u64 tmp;
        spin_lock(&ptlrpc_last_xid_lock);
        tmp = ++ptlrpc_last_xid;
        spin_unlock(&ptlrpc_last_xid_lock);
        return tmp;
}

__u64 ptlrpc_sample_next_xid(void)
{
        __u64 tmp;
        spin_lock(&ptlrpc_last_xid_lock);
        tmp = ptlrpc_last_xid + 1;
        spin_unlock(&ptlrpc_last_xid_lock);
        return tmp;
}
EXPORT_SYMBOL(ptlrpc_sample_next_xid);