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LU-12616 obclass: fix MDS start/stop race
[fs/lustre-release.git] / lustre / osp / osp_trans.c
index c1d1950..a69a9cb 100644 (file)
@@ -20,7 +20,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2014, Intel Corporation.
+ * Copyright (c) 2014, 2017, Intel Corporation.
  */
 /*
  * lustre/osp/osp_trans.c
@@ -66,6 +66,7 @@
 
 #define DEBUG_SUBSYSTEM S_MDS
 
+#include <lustre_net.h>
 #include "osp_internal.h"
 
 /**
@@ -76,6 +77,7 @@ struct osp_update_args {
        atomic_t                 *oaua_count;
        wait_queue_head_t        *oaua_waitq;
        bool                      oaua_flow_control;
+       const struct lu_env      *oaua_update_env;
 };
 
 /**
@@ -95,25 +97,72 @@ struct osp_update_callback {
        osp_update_interpreter_t        ouc_interpreter;
 };
 
-static struct object_update_request *object_update_request_alloc(size_t size)
+/**
+ * Allocate new update request
+ *
+ * Allocate new update request and insert it to the req_update_list.
+ *
+ * \param [in] our     osp_udate_request where to create a new
+ *                      update request
+ *
+ * \retval     0 if creation succeeds.
+ * \retval     negative errno if creation fails.
+ */
+int osp_object_update_request_create(struct osp_update_request *our,
+                                    size_t size)
 {
+       struct osp_update_request_sub *ours;
        struct object_update_request *ourq;
 
+       OBD_ALLOC_PTR(ours);
+       if (ours == NULL)
+               return -ENOMEM;
+
+       /* The object update request will be added to an SG list for
+        * bulk transfer. Some IB HW cannot handle partial pages in SG
+        * lists (since they create gaps in memory regions) so we
+        * round the size up to the next multiple of PAGE_SIZE. See
+        * LU-9983. */
+       LASSERT(size > 0);
+       size = round_up(size, PAGE_SIZE);
        OBD_ALLOC_LARGE(ourq, size);
-       if (ourq == NULL)
-               return ERR_PTR(-ENOMEM);
+       if (ourq == NULL) {
+               OBD_FREE_PTR(ours);
+               return -ENOMEM;
+       }
 
        ourq->ourq_magic = UPDATE_REQUEST_MAGIC;
        ourq->ourq_count = 0;
+       ours->ours_req = ourq;
+       ours->ours_req_size = size;
+       INIT_LIST_HEAD(&ours->ours_list);
+       list_add_tail(&ours->ours_list, &our->our_req_list);
+       our->our_req_nr++;
 
-       return ourq;
+       return 0;
 }
 
-static void object_update_request_free(struct object_update_request *ourq,
-                                      size_t ourq_size)
+/**
+ * Get current update request
+ *
+ * Get current object update request from our_req_list in
+ * osp_update_request, because we always insert the new update
+ * request in the last position, so the last update request
+ * in the list will be the current update req.
+ *
+ * \param[in] our      osp update request where to get the
+ *                      current object update.
+ *
+ * \retval             the current object update.
+ **/
+struct osp_update_request_sub *
+osp_current_object_update_request(struct osp_update_request *our)
 {
-       if (ourq != NULL)
-               OBD_FREE_LARGE(ourq, ourq_size);
+       if (list_empty(&our->our_req_list))
+               return NULL;
+
+       return list_entry(our->our_req_list.prev, struct osp_update_request_sub,
+                         ours_list);
 }
 
 /**
@@ -130,35 +179,67 @@ static void object_update_request_free(struct object_update_request *ourq,
  */
 struct osp_update_request *osp_update_request_create(struct dt_device *dt)
 {
-       struct osp_update_request *osp_update_req;
-       struct object_update_request *ourq;
+       struct osp_update_request *our;
+       int rc;
 
-       OBD_ALLOC_PTR(osp_update_req);
-       if (osp_update_req == NULL)
+       OBD_ALLOC_PTR(our);
+       if (our == NULL)
                return ERR_PTR(-ENOMEM);
 
-       ourq = object_update_request_alloc(OUT_UPDATE_INIT_BUFFER_SIZE);
-       if (IS_ERR(ourq)) {
-               OBD_FREE_PTR(osp_update_req);
-               return ERR_CAST(ourq);
-       }
-
-       osp_update_req->our_req = ourq;
-       osp_update_req->our_req_size = OUT_UPDATE_INIT_BUFFER_SIZE;
+       INIT_LIST_HEAD(&our->our_req_list);
+       INIT_LIST_HEAD(&our->our_cb_items);
+       INIT_LIST_HEAD(&our->our_list);
+       INIT_LIST_HEAD(&our->our_invalidate_cb_list);
+       spin_lock_init(&our->our_list_lock);
 
-       INIT_LIST_HEAD(&osp_update_req->our_cb_items);
-       INIT_LIST_HEAD(&osp_update_req->our_list);
-
-       return osp_update_req;
+       rc = osp_object_update_request_create(our, PAGE_SIZE);
+       if (rc != 0) {
+               OBD_FREE_PTR(our);
+               return ERR_PTR(rc);
+       }
+       return our;
 }
 
-void osp_update_request_destroy(struct osp_update_request *our)
+void osp_update_request_destroy(const struct lu_env *env,
+                               struct osp_update_request *our)
 {
+       struct osp_update_request_sub *ours;
+       struct osp_update_request_sub *tmp;
+
        if (our == NULL)
                return;
 
-       object_update_request_free(our->our_req,
-                                  our->our_req_size);
+       list_for_each_entry_safe(ours, tmp, &our->our_req_list, ours_list) {
+               list_del(&ours->ours_list);
+               if (ours->ours_req != NULL)
+                       OBD_FREE_LARGE(ours->ours_req, ours->ours_req_size);
+               OBD_FREE_PTR(ours);
+       }
+
+       if (!list_empty(&our->our_invalidate_cb_list)) {
+               struct lu_env lenv;
+               struct osp_object *obj;
+               struct osp_object *next;
+
+               if (env == NULL) {
+                       lu_env_init(&lenv, LCT_MD_THREAD | LCT_DT_THREAD);
+                       env = &lenv;
+               }
+
+               list_for_each_entry_safe(obj, next,
+                                        &our->our_invalidate_cb_list,
+                                        opo_invalidate_cb_list) {
+                       spin_lock(&obj->opo_lock);
+                       list_del_init(&obj->opo_invalidate_cb_list);
+                       spin_unlock(&obj->opo_lock);
+
+                       dt_object_put(env, &obj->opo_obj);
+               }
+
+               if (env == &lenv)
+                       lu_env_fini(&lenv);
+       }
+
        OBD_FREE_PTR(our);
 }
 
@@ -175,12 +256,13 @@ object_update_request_dump(const struct object_update_request *ourq,
 
                update = object_update_request_get(ourq, i, &size);
                LASSERT(update != NULL);
-               CDEBUG(mask, "i = %u fid = "DFID" op = %s master = %u"
-                      "params = %d batchid = "LPU64" size = %zu\n",
+               CDEBUG(mask, "i = %u fid = "DFID" op = %s "
+                      "params = %d batchid = %llu size = %zu repsize %u\n",
                       i, PFID(&update->ou_fid),
                       update_op_str(update->ou_type),
-                      update->ou_master_index, update->ou_params_count,
-                      update->ou_batchid, size);
+                      update->ou_params_count,
+                      update->ou_batchid, size,
+                      (unsigned)update->ou_result_size);
 
                total_size += size;
        }
@@ -189,7 +271,261 @@ object_update_request_dump(const struct object_update_request *ourq,
               ourq->ourq_magic, ourq->ourq_count, total_size);
 }
 
-static void osp_trans_stop_cb(struct osp_thandle *oth, int result)
+/**
+ * Prepare inline update request
+ *
+ * Prepare OUT update ptlrpc inline request, and the request usually includes
+ * one update buffer, which does not need bulk transfer.
+ *
+ * \param[in] env      execution environment
+ * \param[in] req      ptlrpc request
+ * \param[in] ours     sub osp_update_request to be packed
+ *
+ * \retval             0 if packing succeeds
+ * \retval             negative errno if packing fails
+ */
+int osp_prep_inline_update_req(const struct lu_env *env,
+                              struct ptlrpc_request *req,
+                              struct osp_update_request *our,
+                              int repsize)
+{
+       struct osp_update_request_sub *ours;
+       struct out_update_header *ouh;
+       __u32 update_req_size;
+       int rc;
+
+       ours = list_entry(our->our_req_list.next,
+                         struct osp_update_request_sub, ours_list);
+       update_req_size = object_update_request_size(ours->ours_req);
+       req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_HEADER, RCL_CLIENT,
+                            update_req_size + sizeof(*ouh));
+
+       rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, OUT_UPDATE);
+       if (rc != 0)
+               RETURN(rc);
+
+       ouh = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE_HEADER);
+       ouh->ouh_magic = OUT_UPDATE_HEADER_MAGIC;
+       ouh->ouh_count = 1;
+       ouh->ouh_inline_length = update_req_size;
+       ouh->ouh_reply_size = repsize;
+
+       memcpy(ouh->ouh_inline_data, ours->ours_req, update_req_size);
+
+       req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_REPLY,
+                            RCL_SERVER, repsize);
+
+       ptlrpc_request_set_replen(req);
+       req->rq_request_portal = OUT_PORTAL;
+       req->rq_reply_portal = OSC_REPLY_PORTAL;
+
+       RETURN(rc);
+}
+
+/**
+ * Prepare update request.
+ *
+ * Prepare OUT update ptlrpc request, and the request usually includes
+ * all of updates (stored in \param ureq) from one operation.
+ *
+ * \param[in] env      execution environment
+ * \param[in] imp      import on which ptlrpc request will be sent
+ * \param[in] ureq     hold all of updates which will be packed into the req
+ * \param[in] reqp     request to be created
+ *
+ * \retval             0 if preparation succeeds.
+ * \retval             negative errno if preparation fails.
+ */
+int osp_prep_update_req(const struct lu_env *env, struct obd_import *imp,
+                       struct osp_update_request *our,
+                       struct ptlrpc_request **reqp)
+{
+       struct ptlrpc_request           *req;
+       struct ptlrpc_bulk_desc         *desc;
+       struct osp_update_request_sub   *ours;
+       const struct object_update_request *ourq;
+       struct out_update_header        *ouh;
+       struct out_update_buffer        *oub;
+       __u32                           buf_count = 0;
+       int                             repsize = 0;
+       struct object_update_reply      *reply;
+       int                             rc, i;
+       int                             total = 0;
+       ENTRY;
+
+       list_for_each_entry(ours, &our->our_req_list, ours_list) {
+               object_update_request_dump(ours->ours_req, D_INFO);
+
+               ourq = ours->ours_req;
+               for (i = 0; i < ourq->ourq_count; i++) {
+                       struct object_update    *update;
+                       size_t                  size = 0;
+
+
+                       /* XXX: it's very inefficient to lookup update
+                        *      this way, iterating from the beginning
+                        *      each time */
+                       update = object_update_request_get(ourq, i, &size);
+                       LASSERT(update != NULL);
+
+                       repsize += sizeof(reply->ourp_lens[0]);
+                       repsize += sizeof(struct object_update_result);
+                       repsize += update->ou_result_size;
+               }
+
+               buf_count++;
+       }
+       repsize += sizeof(*reply);
+       if (repsize < OUT_UPDATE_REPLY_SIZE)
+               repsize = OUT_UPDATE_REPLY_SIZE;
+       LASSERT(buf_count > 0);
+
+       req = ptlrpc_request_alloc(imp, &RQF_OUT_UPDATE);
+       if (req == NULL)
+               RETURN(-ENOMEM);
+
+       if (buf_count == 1) {
+               ours = list_entry(our->our_req_list.next,
+                                 struct osp_update_request_sub, ours_list);
+
+               /* Let's check if it can be packed inline */
+               if (object_update_request_size(ours->ours_req) +
+                   sizeof(struct out_update_header) <
+                               OUT_UPDATE_MAX_INLINE_SIZE) {
+                       rc = osp_prep_inline_update_req(env, req, our, repsize);
+                       if (rc == 0)
+                               *reqp = req;
+                       GOTO(out_req, rc);
+               }
+       }
+
+       req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_HEADER, RCL_CLIENT,
+                            sizeof(struct osp_update_request));
+
+       req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_BUF, RCL_CLIENT,
+                            buf_count * sizeof(*oub));
+
+       rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, OUT_UPDATE);
+       if (rc != 0)
+               GOTO(out_req, rc);
+
+       ouh = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE_HEADER);
+       ouh->ouh_magic = OUT_UPDATE_HEADER_MAGIC;
+       ouh->ouh_count = buf_count;
+       ouh->ouh_inline_length = 0;
+       ouh->ouh_reply_size = repsize;
+       oub = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE_BUF);
+       list_for_each_entry(ours, &our->our_req_list, ours_list) {
+               oub->oub_size = ours->ours_req_size;
+               oub++;
+       }
+
+       req->rq_bulk_write = 1;
+       desc = ptlrpc_prep_bulk_imp(req, buf_count,
+               MD_MAX_BRW_SIZE >> LNET_MTU_BITS,
+               PTLRPC_BULK_GET_SOURCE | PTLRPC_BULK_BUF_KVEC,
+               MDS_BULK_PORTAL, &ptlrpc_bulk_kvec_ops);
+       if (desc == NULL)
+               GOTO(out_req, rc = -ENOMEM);
+
+       /* NB req now owns desc and will free it when it gets freed */
+       list_for_each_entry(ours, &our->our_req_list, ours_list) {
+               desc->bd_frag_ops->add_iov_frag(desc, ours->ours_req,
+                                               ours->ours_req_size);
+               total += ours->ours_req_size;
+       }
+       CDEBUG(D_OTHER, "total %d in %u\n", total, our->our_update_nr);
+
+       req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_REPLY,
+                            RCL_SERVER, repsize);
+
+       ptlrpc_request_set_replen(req);
+       req->rq_request_portal = OUT_PORTAL;
+       req->rq_reply_portal = OSC_REPLY_PORTAL;
+       *reqp = req;
+
+out_req:
+       if (rc < 0)
+               ptlrpc_req_finished(req);
+
+       RETURN(rc);
+}
+
+/**
+ * Send update RPC.
+ *
+ * Send update request to the remote MDT synchronously.
+ *
+ * \param[in] env      execution environment
+ * \param[in] imp      import on which ptlrpc request will be sent
+ * \param[in] our      hold all of updates which will be packed into the req
+ * \param[in] reqp     request to be created
+ *
+ * \retval             0 if RPC succeeds.
+ * \retval             negative errno if RPC fails.
+ */
+int osp_remote_sync(const struct lu_env *env, struct osp_device *osp,
+                   struct osp_update_request *our,
+                   struct ptlrpc_request **reqp)
+{
+       struct obd_import       *imp = osp->opd_obd->u.cli.cl_import;
+       struct ptlrpc_request   *req = NULL;
+       int                     rc;
+       ENTRY;
+
+       rc = osp_prep_update_req(env, imp, our, &req);
+       if (rc != 0)
+               RETURN(rc);
+
+       osp_set_req_replay(osp, req);
+       req->rq_allow_intr = 1;
+
+       /* Note: some dt index api might return non-zero result here, like
+        * osd_index_ea_lookup, so we should only check rc < 0 here */
+       rc = ptlrpc_queue_wait(req);
+       our->our_rc = rc;
+       if (rc < 0 || reqp == NULL)
+               ptlrpc_req_finished(req);
+       else
+               *reqp = req;
+
+       RETURN(rc);
+}
+
+/**
+ * Invalidate all objects in the osp thandle
+ *
+ * invalidate all of objects in the update request, which will be called
+ * when the transaction is aborted.
+ *
+ * \param[in] oth      osp thandle.
+ */
+static void osp_thandle_invalidate_object(const struct lu_env *env,
+                                         struct osp_thandle *oth,
+                                         int result)
+{
+       struct osp_update_request *our = oth->ot_our;
+       struct osp_object *obj;
+       struct osp_object *next;
+
+       if (our == NULL)
+               return;
+
+       list_for_each_entry_safe(obj, next, &our->our_invalidate_cb_list,
+                                opo_invalidate_cb_list) {
+               if (result < 0)
+                       osp_invalidate(env, &obj->opo_obj);
+
+               spin_lock(&obj->opo_lock);
+               list_del_init(&obj->opo_invalidate_cb_list);
+               spin_unlock(&obj->opo_lock);
+
+               dt_object_put(env, &obj->opo_obj);
+       }
+}
+
+static void osp_trans_stop_cb(const struct lu_env *env,
+                             struct osp_thandle *oth, int result)
 {
        struct dt_txn_commit_cb *dcb;
        struct dt_txn_commit_cb *tmp;
@@ -203,6 +539,8 @@ static void osp_trans_stop_cb(struct osp_thandle *oth, int result)
                list_del_init(&dcb->dcb_linkage);
                dcb->dcb_func(NULL, &oth->ot_super, dcb, result);
        }
+
+       osp_thandle_invalidate_object(env, oth, result);
 }
 
 /**
@@ -264,23 +602,34 @@ static void osp_update_callback_fini(const struct lu_env *env,
  * \retval             negative error number on failure
  */
 static int osp_update_interpret(const struct lu_env *env,
-                               struct ptlrpc_request *req, void *arg, int rc)
+                               struct ptlrpc_request *req, void *args, int rc)
 {
-       struct object_update_reply      *reply  = NULL;
-       struct osp_update_args          *oaua   = arg;
-       struct osp_update_request       *our = oaua->oaua_update;
-       struct osp_thandle              *oth;
-       struct osp_update_callback      *ouc;
-       struct osp_update_callback      *next;
-       int                              count  = 0;
-       int                              index  = 0;
-       int                              rc1    = 0;
+       struct object_update_reply *reply = NULL;
+       struct osp_update_args *oaua = args;
+       struct osp_update_request *our = oaua->oaua_update;
+       struct osp_thandle *oth;
+       struct osp_update_callback *ouc;
+       struct osp_update_callback *next;
+       int count = 0;
+       int index = 0;
+       int rc1 = 0;
 
        ENTRY;
 
        if (our == NULL)
                RETURN(0);
 
+       /* Sigh env might be NULL in some cases, see
+        * this calling path.
+        * osp_send_update_thread()
+        *  ptlrpc_set_wait() ----> null env.
+        *   ptlrpc_check_set()
+        *    osp_update_interpret()
+        * Let's use env in oaua for this case.
+        */
+       if (env == NULL)
+               env = oaua->oaua_update_env;
+
        oaua->oaua_update = NULL;
        oth = our->our_th;
        if (oaua->oaua_flow_control) {
@@ -292,16 +641,16 @@ static int osp_update_interpret(const struct lu_env *env,
        }
 
        /* Unpack the results from the reply message. */
-       if (req->rq_repmsg != NULL) {
+       if (req->rq_repmsg != NULL && req->rq_replied) {
                reply = req_capsule_server_sized_get(&req->rq_pill,
                                                     &RMF_OUT_UPDATE_REPLY,
                                                     OUT_UPDATE_REPLY_SIZE);
-               if (reply == NULL || reply->ourp_magic != UPDATE_REPLY_MAGIC)
-                       rc1 = -EPROTO;
-               else
+               if (reply == NULL || reply->ourp_magic != UPDATE_REPLY_MAGIC) {
+                       if (rc == 0)
+                               rc = -EPROTO;
+               } else {
                        count = reply->ourp_count;
-       } else {
-               rc1 = rc;
+               }
        }
 
        list_for_each_entry_safe(ouc, next, &our->our_cb_items, ouc_list) {
@@ -310,18 +659,21 @@ static int osp_update_interpret(const struct lu_env *env,
                /* The peer may only have handled some requests (indicated
                 * by the 'count') in the packaged OUT RPC, we can only get
                 * results for the handled part. */
-               if (index < count && reply->ourp_lens[index] > 0) {
+               if (index < count && reply->ourp_lens[index] > 0 && rc >= 0) {
                        struct object_update_result *result;
 
                        result = object_update_result_get(reply, index, NULL);
                        if (result == NULL)
-                               rc1 = -EPROTO;
+                               rc1 = rc = -EPROTO;
                        else
-                               rc1 = result->our_rc;
-               } else {
-                       rc1 = rc;
-                       if (unlikely(rc1 == 0))
+                               rc1 = rc = result->our_rc;
+               } else if (rc1 >= 0) {
+                       /* The peer did not handle these request, let's return
+                        * -EINVAL to update interpret for now */
+                       if (rc >= 0)
                                rc1 = -EINVAL;
+                       else
+                               rc1 = rc;
                }
 
                if (ouc->ouc_interpreter != NULL)
@@ -338,13 +690,13 @@ static int osp_update_interpret(const struct lu_env *env,
        if (oth != NULL) {
                /* oth and osp_update_requests will be destoryed in
                 * osp_thandle_put */
-               osp_trans_stop_cb(oth, rc);
-               osp_thandle_put(oth);
+               osp_trans_stop_cb(env, oth, rc);
+               osp_thandle_put(env, oth);
        } else {
-               osp_update_request_destroy(our);
+               osp_update_request_destroy(env, our);
        }
 
-       RETURN(0);
+       RETURN(rc);
 }
 
 /**
@@ -367,7 +719,7 @@ int osp_unplug_async_request(const struct lu_env *env,
        int                      rc;
 
        rc = osp_prep_update_req(env, osp->opd_obd->u.cli.cl_import,
-                                our->our_req, &req);
+                                our, &req);
        if (rc != 0) {
                struct osp_update_callback *ouc;
                struct osp_update_callback *next;
@@ -381,15 +733,19 @@ int osp_unplug_async_request(const struct lu_env *env,
                                                     ouc->ouc_data, 0, rc);
                        osp_update_callback_fini(env, ouc);
                }
-               osp_update_request_destroy(our);
+               osp_update_request_destroy(env, our);
        } else {
                args = ptlrpc_req_async_args(req);
                args->oaua_update = our;
                args->oaua_count = NULL;
                args->oaua_waitq = NULL;
+               /* Note: this is asynchronous call for the request, so the
+                * interrupte cb and current function will be different
+                * thread, so we need use different env */
+               args->oaua_update_env = NULL;
                args->oaua_flow_control = false;
                req->rq_interpret_reply = osp_update_interpret;
-               ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
+               ptlrpcd_add_req(req);
        }
 
        return rc;
@@ -474,6 +830,7 @@ int osp_insert_update_callback(const struct lu_env *env,
  * \param[in] lens             buffer length array for the subsequent \a bufs
  * \param[in] bufs             the buffers to compose the request
  * \param[in] data             pointer to the data used by the interpreter
+ * \param[in] repsize          how many bytes the caller allocated for \a data
  * \param[in] interpreter      pointer to the interpreter function
  *
  * \retval                     0 for success
@@ -481,7 +838,8 @@ int osp_insert_update_callback(const struct lu_env *env,
  */
 int osp_insert_async_request(const struct lu_env *env, enum update_type op,
                             struct osp_object *obj, int count,
-                            __u16 *lens, const void **bufs, void *data,
+                            __u16 *lens, const void **bufs,
+                            void *data, __u32 repsize,
                             osp_update_interpreter_t interpreter)
 {
        struct osp_device               *osp;
@@ -489,6 +847,7 @@ int osp_insert_async_request(const struct lu_env *env, enum update_type op,
        struct object_update            *object_update;
        size_t                          max_update_size;
        struct object_update_request    *ureq;
+       struct osp_update_request_sub   *ours;
        int                             rc = 0;
        ENTRY;
 
@@ -498,12 +857,16 @@ int osp_insert_async_request(const struct lu_env *env, enum update_type op,
                RETURN(PTR_ERR(our));
 
 again:
-       ureq = our->our_req;
-       max_update_size = our->our_req_size - object_update_request_size(ureq);
+       ours = osp_current_object_update_request(our);
+
+       ureq = ours->ours_req;
+       max_update_size = ours->ours_req_size -
+                         object_update_request_size(ureq);
 
        object_update = update_buffer_get_update(ureq, ureq->ourq_count);
-       rc = out_update_pack(env, object_update, max_update_size, op,
-                            lu_object_fid(osp2lu_obj(obj)), count, lens, bufs);
+       rc = out_update_pack(env, object_update, &max_update_size, op,
+                            lu_object_fid(osp2lu_obj(obj)), count, lens, bufs,
+                            repsize);
        /* The queue is full. */
        if (rc == -E2BIG) {
                osp->opd_async_requests = NULL;
@@ -524,6 +887,7 @@ again:
                        RETURN(rc);
 
                ureq->ourq_count++;
+               our->our_update_nr++;
        }
 
        rc = osp_insert_update_callback(env, our, obj, data, interpreter);
@@ -548,19 +912,17 @@ int osp_trans_update_request_create(struct thandle *th)
        oth->ot_our = our;
        our->our_th = oth;
 
-       if (oth->ot_super.th_sync)
-               oth->ot_our->our_flags |= UPDATE_FL_SYNC;
-
        return 0;
 }
 
-void osp_thandle_destroy(struct osp_thandle *oth)
+void osp_thandle_destroy(const struct lu_env *env,
+                        struct osp_thandle *oth)
 {
        LASSERT(oth->ot_magic == OSP_THANDLE_MAGIC);
        LASSERT(list_empty(&oth->ot_commit_dcb_list));
        LASSERT(list_empty(&oth->ot_stop_dcb_list));
        if (oth->ot_our != NULL)
-               osp_update_request_destroy(oth->ot_our);
+               osp_update_request_destroy(env, oth->ot_our);
        OBD_FREE_PTR(oth);
 }
 
@@ -604,7 +966,6 @@ struct thandle *osp_trans_create(const struct lu_env *env, struct dt_device *d)
        oth->ot_magic = OSP_THANDLE_MAGIC;
        th = &oth->ot_super;
        th->th_dev = d;
-       th->th_tags = LCT_TX_HANDLE;
 
        atomic_set(&oth->ot_refcount, 1);
        INIT_LIST_HEAD(&oth->ot_commit_dcb_list);
@@ -614,112 +975,6 @@ struct thandle *osp_trans_create(const struct lu_env *env, struct dt_device *d)
 }
 
 /**
- * Prepare update request.
- *
- * Prepare OUT update ptlrpc request, and the request usually includes
- * all of updates (stored in \param ureq) from one operation.
- *
- * \param[in] env      execution environment
- * \param[in] imp      import on which ptlrpc request will be sent
- * \param[in] ureq     hold all of updates which will be packed into the req
- * \param[in] reqp     request to be created
- *
- * \retval             0 if preparation succeeds.
- * \retval             negative errno if preparation fails.
- */
-int osp_prep_update_req(const struct lu_env *env, struct obd_import *imp,
-                       const struct object_update_request *ureq,
-                       struct ptlrpc_request **reqp)
-{
-       struct ptlrpc_request           *req;
-       struct object_update_request    *tmp;
-       size_t                          ureq_len;
-       int                             rc;
-       ENTRY;
-
-       object_update_request_dump(ureq, D_INFO);
-       req = ptlrpc_request_alloc(imp, &RQF_OUT_UPDATE);
-       if (req == NULL)
-               RETURN(-ENOMEM);
-
-       ureq_len = object_update_request_size(ureq);
-       req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE, RCL_CLIENT,
-                            ureq_len);
-
-       rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, OUT_UPDATE);
-       if (rc != 0) {
-               ptlrpc_req_finished(req);
-               RETURN(rc);
-       }
-
-       req_capsule_set_size(&req->rq_pill, &RMF_OUT_UPDATE_REPLY,
-                            RCL_SERVER, OUT_UPDATE_REPLY_SIZE);
-
-       tmp = req_capsule_client_get(&req->rq_pill, &RMF_OUT_UPDATE);
-       memcpy(tmp, ureq, ureq_len);
-
-       ptlrpc_request_set_replen(req);
-       req->rq_request_portal = OUT_PORTAL;
-       req->rq_reply_portal = OSC_REPLY_PORTAL;
-       *reqp = req;
-
-       RETURN(rc);
-}
-
-/**
- * Send update RPC.
- *
- * Send update request to the remote MDT synchronously.
- *
- * \param[in] env      execution environment
- * \param[in] imp      import on which ptlrpc request will be sent
- * \param[in] our      hold all of updates which will be packed into the req
- * \param[in] reqp     request to be created
- *
- * \retval             0 if RPC succeeds.
- * \retval             negative errno if RPC fails.
- */
-
-int osp_remote_sync(const struct lu_env *env, struct osp_device *osp,
-                   struct osp_update_request *our,
-                   struct ptlrpc_request **reqp)
-{
-       struct obd_import       *imp = osp->opd_obd->u.cli.cl_import;
-       struct ptlrpc_request   *req = NULL;
-       int                     rc;
-       ENTRY;
-
-       rc = osp_prep_update_req(env, imp, our->our_req, &req);
-       if (rc != 0)
-               RETURN(rc);
-
-       /* This will only be called with read-only update, and these updates
-        * might be used to retrieve update log during recovery process, so
-        * it will be allowed to send during recovery process */
-       req->rq_allow_replay = 1;
-
-       /* Note: some dt index api might return non-zero result here, like
-        * osd_index_ea_lookup, so we should only check rc < 0 here */
-       rc = ptlrpc_queue_wait(req);
-       if (rc < 0) {
-               ptlrpc_req_finished(req);
-               our->our_rc = rc;
-               RETURN(rc);
-       }
-
-       if (reqp != NULL) {
-               *reqp = req;
-               RETURN(rc);
-       }
-
-       our->our_rc = rc;
-
-       ptlrpc_req_finished(req);
-
-       RETURN(rc);
-}
-
-/**
  * Add commit callback to transaction.
  *
  * Add commit callback to the osp thandle, which will be called
@@ -772,7 +1027,8 @@ static void osp_request_commit_cb(struct ptlrpc_request *req)
                RETURN_EXIT;
 
        oth = thandle_to_osp_thandle(th);
-       if (lustre_msg_get_last_committed(req->rq_repmsg))
+       if (req->rq_repmsg != NULL &&
+           lustre_msg_get_last_committed(req->rq_repmsg))
                last_committed_transno =
                        lustre_msg_get_last_committed(req->rq_repmsg);
 
@@ -781,7 +1037,7 @@ static void osp_request_commit_cb(struct ptlrpc_request *req)
                last_committed_transno =
                        req->rq_import->imp_peer_committed_transno;
 
-       CDEBUG(D_HA, "trans no "LPU64" committed transno "LPU64"\n",
+       CDEBUG(D_HA, "trans no %llu committed transno %llu\n",
               req->rq_transno, last_committed_transno);
 
        /* If the transaction is not really committed, mark result = 1 */
@@ -791,7 +1047,7 @@ static void osp_request_commit_cb(struct ptlrpc_request *req)
 
        osp_trans_commit_cb(oth, result);
        req->rq_committed = 1;
-       osp_thandle_put(oth);
+       osp_thandle_put(NULL, oth);
        EXIT;
 }
 
@@ -824,7 +1080,7 @@ void osp_trans_callback(const struct lu_env *env,
                        osp_update_callback_fini(env, ouc);
                }
        }
-       osp_trans_stop_cb(oth, rc);
+       osp_trans_stop_cb(env, oth, rc);
        osp_trans_commit_cb(oth, rc);
 }
 
@@ -850,15 +1106,13 @@ static int osp_send_update_req(const struct lu_env *env,
 {
        struct osp_update_args  *args;
        struct ptlrpc_request   *req;
-       struct lu_device *top_device;
        struct osp_thandle      *oth = our->our_th;
        int     rc = 0;
        ENTRY;
 
        LASSERT(oth != NULL);
-       LASSERT(our->our_req_sent == 0);
        rc = osp_prep_update_req(env, osp->opd_obd->u.cli.cl_import,
-                                our->our_req, &req);
+                                our, &req);
        if (rc != 0) {
                osp_trans_callback(env, oth, rc);
                RETURN(rc);
@@ -866,19 +1120,22 @@ static int osp_send_update_req(const struct lu_env *env,
 
        args = ptlrpc_req_async_args(req);
        args->oaua_update = our;
+       /* set env to NULL, in case the interrupt cb and current function
+        * are in different thread */
+       args->oaua_update_env = NULL;
        osp_thandle_get(oth); /* hold for update interpret */
        req->rq_interpret_reply = osp_update_interpret;
        if (!oth->ot_super.th_wait_submit && !oth->ot_super.th_sync) {
                if (!osp->opd_imp_active || !osp->opd_imp_connected) {
                        osp_trans_callback(env, oth, rc);
-                       osp_thandle_put(oth);
+                       osp_thandle_put(env, oth);
                        GOTO(out, rc = -ENOTCONN);
                }
 
                rc = obd_get_request_slot(&osp->opd_obd->u.cli);
                if (rc != 0) {
                        osp_trans_callback(env, oth, rc);
-                       osp_thandle_put(oth);
+                       osp_thandle_put(env, oth);
                        GOTO(out, rc = -ENOTCONN);
                }
                args->oaua_flow_control = true;
@@ -886,12 +1143,12 @@ static int osp_send_update_req(const struct lu_env *env,
                if (!osp->opd_connect_mdt) {
                        down_read(&osp->opd_async_updates_rwsem);
                        args->oaua_count = &osp->opd_async_updates_count;
-                       args->oaua_waitq = &osp->opd_syn_barrier_waitq;
+                       args->oaua_waitq = &osp->opd_sync_barrier_waitq;
                        up_read(&osp->opd_async_updates_rwsem);
                        atomic_inc(args->oaua_count);
                }
 
-               ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
+               ptlrpcd_add_req(req);
                req = NULL;
        } else {
                osp_thandle_get(oth); /* hold for commit callback */
@@ -905,26 +1162,33 @@ static int osp_send_update_req(const struct lu_env *env,
                 * status, in case the other target is being recoveried
                 * at the same time, and if we wait here for the import
                 * to be recoveryed, it might cause deadlock */
-               top_device = osp->opd_dt_dev.dd_lu_dev.ld_site->ls_top_dev;
-               if (top_device->ld_obd->obd_recovering)
-                       req->rq_allow_replay = 1;
-
-               osp_get_rpc_lock(osp);
+               osp_set_req_replay(osp, req);
+
+               /* Because this req will be synchronus, i.e. it will be called
+                * in the same thread, so it will be safe to use current
+                * env */
+               args->oaua_update_env = env;
+               if (osp->opd_connect_mdt)
+                       osp_get_rpc_lock(osp);
                rc = ptlrpc_queue_wait(req);
-               osp_put_rpc_lock(osp);
-               if ((rc == -ENOMEM && req->rq_set == NULL) ||
+               if (osp->opd_connect_mdt)
+                       osp_put_rpc_lock(osp);
+
+               /* We use rq_queued_time to distinguish between local
+                * and remote -ENOMEM. */
+               if ((rc == -ENOMEM && req->rq_queued_time == 0) ||
                    (req->rq_transno == 0 && !req->rq_committed)) {
                        if (args->oaua_update != NULL) {
                                /* If osp_update_interpret is not being called,
                                 * release the osp_thandle */
                                args->oaua_update = NULL;
-                               osp_thandle_put(oth);
+                               osp_thandle_put(env, oth);
                        }
 
                        req->rq_cb_data = NULL;
                        rc = rc == 0 ? req->rq_status : rc;
                        osp_trans_callback(env, oth, rc);
-                       osp_thandle_put(oth);
+                       osp_thandle_put(env, oth);
                        GOTO(out, rc);
                }
        }
@@ -939,7 +1203,7 @@ out:
  * Get local thandle for osp_thandle
  *
  * Get the local OSD thandle from the OSP thandle. Currently, there
- * are a few OSP API (osp_object_create() and osp_sync_add()) needs
+ * are a few OSP API (osp_create() and osp_sync_add()) needs
  * to update the object on local OSD device.
  *
  * If the osp_thandle comes from normal stack (MDD->LOD->OSP), then
@@ -987,16 +1251,17 @@ struct thandle *osp_get_storage_thandle(const struct lu_env *env,
 /**
  * Set version for the transaction
  *
- * Set the version for the transaction, then the osp RPC will be
- * sent in the order of version, i.e. the transaction with lower
- * version will be sent first.
+ * Set the version for the transaction and add the request to
+ * the sending list, then after transaction stop, the request
+ * will be sent in the order of version by the sending thread.
  *
  * \param [in] oth     osp thandle to be set version.
  *
  * \retval             0 if set version succeeds
  *                      negative errno if set version fails.
  */
-int osp_check_and_set_rpc_version(struct osp_thandle *oth)
+int osp_check_and_set_rpc_version(struct osp_thandle *oth,
+                                 struct osp_object *obj)
 {
        struct osp_device *osp = dt2osp_dev(oth->ot_super.th_dev);
        struct osp_updates *ou = osp->opd_update;
@@ -1004,15 +1269,31 @@ int osp_check_and_set_rpc_version(struct osp_thandle *oth)
        if (ou == NULL)
                return -EIO;
 
-       if (oth->ot_version != 0)
+       if (oth->ot_our->our_version != 0)
                return 0;
 
        spin_lock(&ou->ou_lock);
-       oth->ot_version = ou->ou_version++;
+       spin_lock(&oth->ot_our->our_list_lock);
+       if (obj->opo_stale) {
+               spin_unlock(&oth->ot_our->our_list_lock);
+               spin_unlock(&ou->ou_lock);
+               return -ESTALE;
+       }
+
+       /* Assign the version and add it to the sending list */
+       osp_thandle_get(oth);
+       oth->ot_our->our_version = ou->ou_version++;
+       oth->ot_our->our_generation = ou->ou_generation;
+       list_add_tail(&oth->ot_our->our_list,
+                     &osp->opd_update->ou_list);
+       oth->ot_our->our_req_ready = 0;
+       spin_unlock(&oth->ot_our->our_list_lock);
        spin_unlock(&ou->ou_lock);
 
-       CDEBUG(D_INFO, "%s: version "LPU64" oth:version %p:"LPU64"\n",
-              osp->opd_obd->obd_name, ou->ou_version, oth, oth->ot_version);
+       LASSERT(oth->ot_super.th_wait_submit == 1);
+       CDEBUG(D_INFO, "%s: version %llu gen %llu oth:version %p:%llu\n",
+              osp->opd_obd->obd_name, ou->ou_version, ou->ou_generation, oth,
+              oth->ot_our->our_version);
 
        return 0;
 }
@@ -1040,38 +1321,98 @@ osp_get_next_request(struct osp_updates *ou, struct osp_update_request **ourp)
        spin_lock(&ou->ou_lock);
        list_for_each_entry_safe(our, tmp, &ou->ou_list, our_list) {
                LASSERT(our->our_th != NULL);
-               CDEBUG(D_INFO, "our %p version "LPU64" rpc_version "LPU64"\n",
-                      our, our->our_th->ot_version, ou->ou_rpc_version);
-               if (our->our_th->ot_version == 0) {
-                       list_del_init(&our->our_list);
-                       *ourp = our;
-                       got_req = true;
-                       break;
-               }
-
+               CDEBUG(D_HA, "ou %p version %llu rpc_version %llu\n",
+                      ou, our->our_version, ou->ou_rpc_version);
+               spin_lock(&our->our_list_lock);
                /* Find next osp_update_request in the list */
-               if (our->our_th->ot_version == ou->ou_rpc_version) {
+               if (our->our_version == ou->ou_rpc_version &&
+                   our->our_req_ready) {
                        list_del_init(&our->our_list);
+                       spin_unlock(&our->our_list_lock);
                        *ourp = our;
                        got_req = true;
                        break;
                }
+               spin_unlock(&our->our_list_lock);
        }
        spin_unlock(&ou->ou_lock);
 
        return got_req;
 }
 
-static void osp_update_rpc_version(struct osp_updates *ou,
-                                  struct osp_thandle *oth)
+/**
+ * Invalidate update request
+ *
+ * Invalidate update request in the OSP sending list, so all of
+ * requests in the sending list will return error, which happens
+ * when it finds one update (with writing llog) requests fails or
+ * the OSP is evicted by remote target. see osp_send_update_thread().
+ *
+ * \param[in] osp      OSP device whose update requests will be
+ *                      invalidated.
+ **/
+void osp_invalidate_request(struct osp_device *osp)
 {
-       if (oth->ot_version == 0)
+       struct lu_env env;
+       struct osp_updates *ou = osp->opd_update;
+       struct osp_update_request *our;
+       struct osp_update_request *tmp;
+       LIST_HEAD(list);
+       int                     rc;
+       ENTRY;
+
+       if (ou == NULL)
+               return;
+
+       rc = lu_env_init(&env, osp->opd_dt_dev.dd_lu_dev.ld_type->ldt_ctx_tags);
+       if (rc < 0) {
+               CERROR("%s: init env error: rc = %d\n", osp->opd_obd->obd_name,
+                      rc);
+
+               spin_lock(&ou->ou_lock);
+               ou->ou_generation++;
+               spin_unlock(&ou->ou_lock);
+
                return;
+       }
+
+       INIT_LIST_HEAD(&list);
 
-       LASSERT(oth->ot_version == ou->ou_rpc_version);
        spin_lock(&ou->ou_lock);
-       ou->ou_rpc_version++;
+       /* invalidate all of request in the sending list */
+       list_for_each_entry_safe(our, tmp, &ou->ou_list, our_list) {
+               spin_lock(&our->our_list_lock);
+               if (our->our_req_ready)
+                       list_move(&our->our_list, &list);
+               else
+                       list_del_init(&our->our_list);
+
+               if (our->our_th->ot_super.th_result == 0)
+                       our->our_th->ot_super.th_result = -EIO;
+
+               if (our->our_version >= ou->ou_rpc_version)
+                       ou->ou_rpc_version = our->our_version + 1;
+               spin_unlock(&our->our_list_lock);
+
+               CDEBUG(D_HA, "%s invalidate our %p\n", osp->opd_obd->obd_name,
+                      our);
+       }
+
+       /* Increase the generation, then the update request with old generation
+        * will fail with -EIO. */
+       ou->ou_generation++;
        spin_unlock(&ou->ou_lock);
+
+       /* invalidate all of request in the sending list */
+       list_for_each_entry_safe(our, tmp, &list, our_list) {
+               spin_lock(&our->our_list_lock);
+               list_del_init(&our->our_list);
+               spin_unlock(&our->our_list_lock);
+               osp_trans_callback(&env, our->our_th,
+                                  our->our_th->ot_super.th_result);
+               osp_thandle_put(&env, our->our_th);
+       }
+       lu_env_fini(&env);
 }
 
 /**
@@ -1112,32 +1453,44 @@ int osp_send_update_thread(void *arg)
                our = NULL;
                l_wait_event(ou->ou_waitq,
                             !osp_send_update_thread_running(osp) ||
-                            osp_get_next_request(ou, &our),
-                            &lwi);
+                            osp_get_next_request(ou, &our), &lwi);
 
                if (!osp_send_update_thread_running(osp)) {
-                       if (our != NULL && our->our_th != NULL) {
+                       if (our != NULL) {
                                osp_trans_callback(&env, our->our_th, -EINTR);
-                               osp_thandle_put(our->our_th);
+                               osp_thandle_put(&env, our->our_th);
                        }
                        break;
                }
 
-               if (our->our_req_sent == 0) {
-                       if (our->our_th != NULL &&
-                           our->our_th->ot_super.th_result != 0)
-                               osp_trans_callback(&env, our->our_th,
-                                       our->our_th->ot_super.th_result);
-                       else
-                               rc = osp_send_update_req(&env, osp, our);
+               LASSERT(our->our_th != NULL);
+               if (our->our_th->ot_super.th_result != 0) {
+                       osp_trans_callback(&env, our->our_th,
+                               our->our_th->ot_super.th_result);
+                       rc = our->our_th->ot_super.th_result;
+               } else if (ou->ou_generation != our->our_generation ||
+                          OBD_FAIL_CHECK(OBD_FAIL_INVALIDATE_UPDATE)) {
+                       rc = -EIO;
+                       osp_trans_callback(&env, our->our_th, rc);
+               } else {
+                       rc = osp_send_update_req(&env, osp, our);
                }
 
-               if (our->our_th != NULL) {
-                       /* Update the rpc version */
-                       osp_update_rpc_version(ou, our->our_th);
-                       /* Balanced for thandle_get in osp_trans_trigger() */
-                       osp_thandle_put(our->our_th);
-               }
+               /* Update the rpc version */
+               spin_lock(&ou->ou_lock);
+               if (our->our_version == ou->ou_rpc_version)
+                       ou->ou_rpc_version++;
+               spin_unlock(&ou->ou_lock);
+
+               /* If one update request fails, let's fail all of the requests
+                * in the sending list, because the request in the sending
+                * list are dependent on either other, continue sending these
+                * request might cause llog or filesystem corruption */
+               if (rc < 0)
+                       osp_invalidate_request(osp);
+
+               /* Balanced for thandle_get in osp_check_and_set_rpc_version */
+               osp_thandle_put(&env, our->our_th);
        }
 
        thread->t_flags = SVC_STOPPED;
@@ -1148,36 +1501,6 @@ int osp_send_update_thread(void *arg)
 }
 
 /**
- * Trigger the request for remote updates.
- *
- * Add the request to the sending list, and wake up osp update
- * sending thread.
- *
- * \param[in] env              pointer to the thread context
- * \param[in] osp              pointer to the OSP device
- * \param[in] oth              pointer to the transaction handler
- *
- */
-static void osp_trans_trigger(const struct lu_env *env,
-                            struct osp_device *osp,
-                            struct osp_thandle *oth)
-{
-
-       CDEBUG(D_INFO, "%s: add oth %p with version "LPU64"\n",
-              osp->opd_obd->obd_name, oth, oth->ot_version);
-
-       LASSERT(oth->ot_magic == OSP_THANDLE_MAGIC);
-       osp_thandle_get(oth);
-       LASSERT(oth->ot_our != NULL);
-       spin_lock(&osp->opd_update->ou_lock);
-       list_add_tail(&oth->ot_our->our_list,
-                     &osp->opd_update->ou_list);
-       spin_unlock(&osp->opd_update->ou_lock);
-
-       wake_up(&osp->opd_update->ou_waitq);
-}
-
-/**
  * The OSP layer dt_device_operations::dt_trans_start() interface
  * to start the transaction.
  *
@@ -1197,6 +1520,8 @@ int osp_trans_start(const struct lu_env *env, struct dt_device *dt,
 {
        struct osp_thandle      *oth = thandle_to_osp_thandle(th);
 
+       if (oth->ot_super.th_sync)
+               oth->ot_our->our_flags |= UPDATE_FL_SYNC;
        /* For remote thandle, if there are local thandle, start it here*/
        if (is_only_remote_trans(th) && oth->ot_storage_th != NULL)
                return dt_trans_start(env, oth->ot_storage_th->th_dev,
@@ -1209,7 +1534,7 @@ int osp_trans_start(const struct lu_env *env, struct dt_device *dt,
  * to stop the transaction.
  *
  * If the transaction is a remote transaction, related remote
- * updates will be triggered here via osp_trans_trigger().
+ * updates will be triggered at the end of this function.
  *
  * For synchronous mode update or any failed update, the request
  * will be destroyed explicitly when the osp_trans_stop().
@@ -1240,13 +1565,13 @@ int osp_trans_stop(const struct lu_env *env, struct dt_device *dt,
                oth->ot_storage_th = NULL;
        }
 
-       if (our == NULL || our->our_req == NULL ||
-           our->our_req->ourq_count == 0) {
+       if (our == NULL || list_empty(&our->our_req_list)) {
                osp_trans_callback(env, oth, th->th_result);
                GOTO(out, rc = th->th_result);
        }
 
        if (!osp->opd_connect_mdt) {
+               osp_trans_callback(env, oth, th->th_result);
                rc = osp_send_update_req(env, osp, oth->ot_our);
                GOTO(out, rc);
        }
@@ -1257,19 +1582,27 @@ int osp_trans_stop(const struct lu_env *env, struct dt_device *dt,
                GOTO(out, rc = -EIO);
        }
 
-       if (th->th_sync) {
-               /* if th_sync is set, then it needs to be sent
-                * right away. Note: even thought the RPC has been
-                * sent, it still needs to be added to the sending
-                * list (see osp_trans_trigger()), so ou_rpc_version
-                * can be updated correctly. */
+       CDEBUG(D_HA, "%s: add oth %p with version %llu\n",
+              osp->opd_obd->obd_name, oth, our->our_version);
+
+       LASSERT(our->our_req_ready == 0);
+       spin_lock(&our->our_list_lock);
+       if (likely(!list_empty(&our->our_list))) {
+               /* notify sending thread */
+               our->our_req_ready = 1;
+               wake_up(&osp->opd_update->ou_waitq);
+               spin_unlock(&our->our_list_lock);
+       } else if (th->th_result == 0) {
+               /* if the request does not needs to be serialized,
+                * read-only request etc, let's send it right away */
+               spin_unlock(&our->our_list_lock);
                rc = osp_send_update_req(env, osp, our);
-               our->our_req_sent = 1;
+       } else {
+               spin_unlock(&our->our_list_lock);
+               osp_trans_callback(env, oth, th->th_result);
        }
-
-       osp_trans_trigger(env, osp, oth);
 out:
-       osp_thandle_put(oth);
+       osp_thandle_put(env, oth);
 
        RETURN(rc);
 }