Debug prints

Handy for zero-copy RDMA tests (removes 4-byte s/g entries)

src/fio_cluster.cpp

@@ -127,7 +127,7 @@ static struct fio_option options[] = {
     },
     {
         .name   = "use_rdma",
-        .lname  = "OSD trace",
+        .lname  = "Use RDMA",
         .type   = FIO_OPT_BOOL,
         .off1   = offsetof(struct sec_options, use_rdma),
         .help   = "Use RDMA",
@@ -135,6 +135,16 @@ static struct fio_option options[] = {
         .category = FIO_OPT_C_ENGINE,
         .group  = FIO_OPT_G_FILENAME,
     },
+    {
+        .name   = "rdma_gid_index",
+        .lname  = "RDMA gid index",
+        .type   = FIO_OPT_INT,
+        .off1   = offsetof(struct sec_options, rdma_gid_index),
+        .help   = "RDMA gid index",
+        .def    = "0",
+        .category = FIO_OPT_C_ENGINE,
+        .group  = FIO_OPT_G_FILENAME,
+    },
     {
         .name = NULL,
     },
@@ -171,6 +181,7 @@ static int sec_setup(struct thread_data *td)
         { "etcd_prefix", std::string(o->etcd_prefix ? o->etcd_prefix : "/vitastor") },
         { "log_level", o->cluster_log },
         { "use_rdma", o->use_rdma },
+        { "rdma_gid_index", o->rdma_gid_index },
     };
 
     if (!o->image)

src/messenger.cpp

@@ -25,6 +25,8 @@ void osd_messenger_t::init()
         }
         else
         {
+            rdma_max_sge = rdma_max_sge < rdma_context->attrx.orig_attr.max_sge
+                ? rdma_max_sge : rdma_context->attrx.orig_attr.max_sge;
             printf("[OSD %lu] RDMA initialized successfully\n", osd_num);
             fcntl(rdma_context->channel->fd, F_SETFL, fcntl(rdma_context->channel->fd, F_GETFL, 0) | O_NONBLOCK);
             tfd->set_fd_handler(rdma_context->channel->fd, false, [this](int notify_fd, int epoll_events)
@@ -356,9 +358,6 @@ void osd_messenger_t::on_connect_peer(osd_num_t peer_osd, int peer_fd)
 
 void osd_messenger_t::check_peer_config(osd_client_t *cl)
 {
-#ifdef WITH_RDMA
-    msgr_rdma_connection_t *rdma_conn = NULL;
-#endif
     osd_op_t *op = new osd_op_t();
     op->op_type = OSD_OP_OUT;
     op->peer_fd = cl->peer_fd;
@@ -374,11 +373,25 @@ void osd_messenger_t::check_peer_config(osd_client_t *cl)
 #ifdef WITH_RDMA
     if (rdma_context)
     {
-        cl->rdma_conn = msgr_rdma_connection_t::create(rdma_context, max_rdma_send, max_rdma_recv, max_rdma_sge);
-        if (cl->rdma_conn)
+        for (int i = 0; i < rdma_queues_per_connection; i++)
         {
+            auto rdma_conn = msgr_rdma_connection_t::create(rdma_context, rdma_max_send, rdma_max_recv, rdma_max_sge);
+            if (!rdma_conn)
+            {
+                break;
+            }
+            cl->rdma_queues.push_back(rdma_conn);
+        }
+        if (cl->rdma_queues.size())
+        {
+            json11::Json::array addresses;
+            for (auto rdma_conn: cl->rdma_queues)
+            {
+                addresses.push_back(rdma_conn->addr.to_string());
+            }
             json11::Json payload = json11::Json::object {
-                { "connect_rdma", cl->rdma_conn->addr.to_string() },
+                { "rdma_queues", addresses },
+                { "rdma_max_sge", rdma_max_sge },
             };
             std::string payload_str = payload.dump();
             op->req.show_conf.json_len = payload_str.size();
@@ -388,11 +401,7 @@ void osd_messenger_t::check_peer_config(osd_client_t *cl)
         }
     }
 #endif
-    op->callback = [this, cl
-#ifdef WITH_RDMA
-    , rdma_conn
-#endif
-    ](osd_op_t *op)
+    op->callback = [this, cl](osd_op_t *op)
     {
         std::string json_err;
         json11::Json config;
@@ -434,33 +443,11 @@ void osd_messenger_t::check_peer_config(osd_client_t *cl)
             return;
         }
 #ifdef WITH_RDMA
-        if (config["rdma_address"].is_string())
+        if (!connect_rdma_server(cl, config["rdma_queues"], config["rdma_max_sge"].uint64_value()))
         {
-            msgr_rdma_address_t addr;
-            if (!msgr_rdma_address_t::from_string(config["rdma_address"].string_value().c_str(), &addr) ||
-                cl->rdma_conn->connect(&addr) != 0)
-            {
-                printf(
-                    "Failed to connect to OSD %lu (address %s) using RDMA\n",
-                    cl->osd_num, config["rdma_address"].string_value().c_str()
-                );
-                delete cl->rdma_conn;
-                cl->rdma_conn = NULL;
-                // FIXME: Keep TCP connection in this case
-                osd_num_t peer_osd = cl->osd_num;
-                stop_client(cl->peer_fd);
-                on_connect_peer(peer_osd, -1);
-                delete op;
-                return;
-            }
-            else
-            {
-                printf("Connected to OSD %lu using RDMA\n", cl->osd_num);
-                cl->peer_state = PEER_RDMA;
-                tfd->set_fd_handler(cl->peer_fd, false, NULL);
-                // Add the initial receive request
-                try_recv_rdma(cl);
-            }
+            // FIXME: Keep TCP connection in this case
+            delete op;
+            return;
         }
 #endif
         osd_peer_fds[cl->osd_num] = cl->peer_fd;

src/messenger.h

@@ -40,6 +40,7 @@
 
 #define MSGR_SENDP_HDR 1
 #define MSGR_SENDP_FREE 2
+#define MSGR_SENDP_BMP 4
 
 struct msgr_sendp_t
 {
@@ -63,7 +64,7 @@ struct osd_client_t
     void *in_buf = NULL;
 
 #ifdef WITH_RDMA
-    msgr_rdma_connection_t *rdma_conn = NULL;
+    std::vector<msgr_rdma_connection_t*> rdma_queues;
 #endif
 
     // Read state
@@ -137,7 +138,8 @@ protected:
     std::string rdma_device;
     uint64_t rdma_port_num = 1, rdma_gid_index = 0, rdma_mtu = 0;
     msgr_rdma_context_t *rdma_context = NULL;
-    int max_rdma_sge = 128, max_rdma_send = 32, max_rdma_recv = 32;
+    int rdma_queues_per_connection = 128;
+    int rdma_max_sge = 128, rdma_max_send = 32, rdma_max_recv = 32;
 #endif
 
     std::vector<int> read_ready_clients;
@@ -170,7 +172,8 @@ public:
 
 #ifdef WITH_RDMA
     bool is_rdma_enabled();
-    bool connect_rdma(int peer_fd, std::string rdma_address);
+    bool connect_rdma_client(osd_client_t *cl, json11::Json rdma_addresses, uint64_t client_max_sge);
+    int get_rdma_max_sge();
 #endif
 
 protected:
@@ -194,8 +197,9 @@ protected:
     void handle_reply_ready(osd_op_t *op);
 
 #ifdef WITH_RDMA
-    bool try_send_rdma(osd_client_t *cl);
-    bool try_recv_rdma(osd_client_t *cl);
+    void try_send_rdma(osd_client_t *cl);
+    void try_recv_rdma(osd_client_t *cl, msgr_rdma_connection_t *rc);
     void handle_rdma_events();
+    bool connect_rdma_server(osd_client_t *cl, json11::Json rdma_addresses, uint64_t server_max_sge);
 #endif
 };

src/msgr_rdma.cpp

@@ -293,75 +293,237 @@ int msgr_rdma_connection_t::connect(msgr_rdma_address_t *dest)
     return 0;
 }
 
-bool osd_messenger_t::connect_rdma(int peer_fd, std::string rdma_address)
+// Being the client, connect all server's RDMA queues to our local (client) queues
+bool osd_messenger_t::connect_rdma_server(osd_client_t *cl, json11::Json rdma_addresses, uint64_t server_max_sge)
 {
-    // Try to connect to the peer using RDMA
-    msgr_rdma_address_t addr;
-    if (msgr_rdma_address_t::from_string(rdma_address.c_str(), &addr))
+    if (rdma_addresses.array_items().size() > 0)
     {
-        auto rdma_conn = msgr_rdma_connection_t::create(rdma_context, max_rdma_send, max_rdma_recv, max_rdma_sge);
-        if (rdma_conn)
+        if (!server_max_sge || server_max_sge > rdma_max_sge)
         {
-            int r = rdma_conn->connect(&addr);
-            if (r != 0)
+            server_max_sge = rdma_max_sge;
+        }
+        int n_conn = rdma_addresses.array_items().size();
+        if (n_conn < cl->rdma_queues.size())
+        {
+            for (int i = n_conn; i < cl->rdma_queues.size(); i++)
+            {
+                delete cl->rdma_queues[i];
+            }
+            cl->rdma_queues.resize(n_conn);
+        }
+        else if (n_conn > cl->rdma_queues.size())
+        {
+            n_conn = cl->rdma_queues.size();
+        }
+        for (int i = 0; i < n_conn; i++)
+        {
+            msgr_rdma_address_t addr;
+            if (!msgr_rdma_address_t::from_string(rdma_addresses[i].string_value().c_str(), &addr) ||
+                cl->rdma_queues[i]->connect(&addr) != 0)
             {
-                delete rdma_conn;
                 printf(
-                    "Failed to connect RDMA queue pair to %s (client %d)\n",
-                    addr.to_string().c_str(), peer_fd
+                    "Failed to connect to OSD %lu (address %s) using RDMA\n",
+                    cl->osd_num, rdma_addresses[i].string_value().c_str()
                 );
+                // FIXME: Keep TCP connection in this case
+                osd_num_t peer_osd = cl->osd_num;
+                stop_client(cl->peer_fd);
+                on_connect_peer(peer_osd, -1);
+                return false;
             }
             else
             {
-                // Remember connection, but switch to RDMA only after sending the configuration response
-                auto cl = clients.at(peer_fd);
-                cl->rdma_conn = rdma_conn;
-                cl->peer_state = PEER_RDMA_CONNECTING;
-                return true;
+                printf("Connected local queue %d to OSD %lu queue %d using RDMA\n", cl->rdma_queues[i]->qp->qp_num, cl->osd_num, addr.qpn);
+                if (cl->rdma_queues[i]->max_sge > server_max_sge)
+                {
+                    cl->rdma_queues[i]->max_sge = server_max_sge;
+                }
             }
         }
+        cl->peer_state = PEER_RDMA;
+        tfd->set_fd_handler(cl->peer_fd, false, NULL);
     }
-    return false;
+    else
+    {
+        for (auto rdma_conn: cl->rdma_queues)
+        {
+            delete rdma_conn;
+        }
+        cl->rdma_queues.resize(0);
+    }
+    return true;
 }
 
-static void try_send_rdma_wr(osd_client_t *cl, ibv_sge *sge, int op_sge)
+// Being the server, try to connect all client's RDMA queues to our local (server) queues
+bool osd_messenger_t::connect_rdma_client(osd_client_t *cl, json11::Json rdma_addresses, uint64_t client_max_sge)
 {
+    if (rdma_addresses.array_items().size() > 0)
+    {
+        if (!client_max_sge || client_max_sge > rdma_max_sge)
+        {
+            client_max_sge = rdma_max_sge;
+        }
+        int n_conn = rdma_addresses.array_items().size();
+        if (n_conn > rdma_queues_per_connection)
+        {
+            n_conn = rdma_queues_per_connection;
+        }
+        for (int i = 0; i < n_conn; i++)
+        {
+            msgr_rdma_address_t addr;
+            if (msgr_rdma_address_t::from_string(rdma_addresses[i].string_value().c_str(), &addr))
+            {
+                auto rdma_conn = msgr_rdma_connection_t::create(rdma_context, rdma_max_send, rdma_max_recv, client_max_sge);
+                if (rdma_conn && rdma_conn->connect(&addr) == 0)
+                {
+                    printf("Connected local queue %d to client %d queue %d using RDMA\n", rdma_conn->qp->qp_num, cl->peer_fd, addr.qpn);
+                    cl->rdma_queues.push_back(rdma_conn);
+                }
+                else
+                {
+                    if (rdma_conn)
+                    {
+                        delete rdma_conn;
+                    }
+                    printf(
+                        "Failed to connect RDMA queue pair to %s (client %d queue %d)\n",
+                        addr.to_string().c_str(), cl->peer_fd, i+1
+                    );
+                    // Delete all RDMA queues to keep the TCP connection
+                    for (int j = 0; j < cl->rdma_queues.size(); j++)
+                    {
+                        delete cl->rdma_queues[j];
+                    }
+                    cl->rdma_queues.resize(0);
+                    return false;
+                }
+            }
+        }
+        // Switch to RDMA state only after sending the configuration response
+        cl->peer_state = PEER_RDMA_CONNECTING;
+        for (int i = 0; i < cl->rdma_queues.size(); i++)
+        {
+            try_recv_rdma(cl, cl->rdma_queues[i]);
+        }
+    }
+    return true;
+}
+
+static void try_send_rdma_wr(msgr_rdma_connection_t *rc, uint64_t wr_id, ibv_sge *sge, int op_sge)
+{
+    timespec tv;
+    clock_gettime(CLOCK_REALTIME, &tv);
+    uint64_t total = 0;
+    for (int i = 0; i < op_sge; i++)
+        total += sge[i].length;
+    printf("%lu.%09lu RDMA send to queue %d: %lu bytes\n", tv.tv_sec, tv.tv_nsec, rc->qp->qp_num, total);
     ibv_send_wr *bad_wr = NULL;
     ibv_send_wr wr = {
-        .wr_id = (uint64_t)(cl->peer_fd*2+1),
+        .wr_id = wr_id,
         .sg_list = sge,
         .num_sge = op_sge,
         .opcode = IBV_WR_SEND,
         .send_flags = IBV_SEND_SIGNALED,
     };
-    int err = ibv_post_send(cl->rdma_conn->qp, &wr, &bad_wr);
+    int err = ibv_post_send(rc->qp, &wr, &bad_wr);
     if (err || bad_wr)
     {
         printf("RDMA send failed: %s\n", strerror(err));
         exit(1);
     }
-    cl->rdma_conn->cur_send++;
+    rc->cur_send++;
 }
 
-bool osd_messenger_t::try_send_rdma(osd_client_t *cl)
+static void try_recv_rdma_wr(msgr_rdma_connection_t *rc, uint64_t wr_id, ibv_sge *sge, int op_sge)
 {
-    auto rc = cl->rdma_conn;
-    if (!cl->send_list.size() || rc->cur_send > 0)
+    timespec tv;
+    clock_gettime(CLOCK_REALTIME, &tv);
+    uint64_t total = 0;
+    for (int i = 0; i < op_sge; i++)
+        total += sge[i].length;
+    printf("%lu.%09lu RDMA receive from queue %d: %lu bytes\n", tv.tv_sec, tv.tv_nsec, rc->qp->qp_num, total);
+    ibv_recv_wr *bad_wr = NULL;
+    ibv_recv_wr wr = {
+        .wr_id = wr_id,
+        .sg_list = sge,
+        .num_sge = op_sge,
+    };
+    int err = ibv_post_recv(rc->qp, &wr, &bad_wr);
+    if (err || bad_wr)
     {
-        // Only send one batch at a time
-        return true;
+        printf("RDMA receive failed: %s\n", strerror(err));
+        exit(1);
     }
-    int op_size = 0, op_sge = 0, op_max = rc->max_sge*bs_bitmap_granularity;
-    // FIXME: rc->max_sge should be negotiated between client & server
+    rc->cur_recv++;
+}
+
+static bool try_recv_rdma_read(osd_client_t *cl, msgr_rdma_connection_t *rc, osd_op_t *cur_op, uint32_t bs_bitmap_granularity)
+{
+    int op_size = bs_bitmap_granularity, op_sge = 1, op_max = rc->max_sge*bs_bitmap_granularity;
+    iovec *segments = cur_op->iov.get_iovec();
     ibv_sge sge[rc->max_sge];
-    while (rc->send_pos < cl->send_list.size())
+    sge[0] = {
+        .addr = (uintptr_t)cur_op->reply.buf,
+        .length = (uint32_t)OSD_PACKET_SIZE,
+        .lkey = rc->ctx->mr->lkey,
+    };
+    while (rc->recv_pos < cur_op->iov.get_size())
+    {
+        iovec & iov = segments[rc->recv_pos];
+        if (op_size >= op_max || op_sge >= rc->max_sge)
+        {
+            try_recv_rdma_wr(rc, cl->peer_fd, sge, op_sge);
+            op_sge = 0;
+            op_size = 0;
+            if (rc->cur_recv >= rc->max_recv)
+            {
+                // FIXME
+                exit(1);
+            }
+        }
+        // Receive in (max_sge*4k) fragments
+        uint32_t len = (uint32_t)(op_size+iov.iov_len-rc->recv_buf_pos < op_max
+            ? iov.iov_len-rc->recv_buf_pos : op_max-op_size);
+        sge[op_sge++] = {
+            .addr = (uintptr_t)(iov.iov_base+rc->recv_buf_pos),
+            .length = len,
+            .lkey = rc->ctx->mr->lkey,
+        };
+        op_size += len;
+        rc->recv_buf_pos += len;
+        if (rc->recv_buf_pos >= iov.iov_len)
+        {
+            rc->recv_pos++;
+            rc->recv_buf_pos = 0;
+        }
+    }
+    if (op_sge > 0)
+    {
+        try_recv_rdma_wr(rc, cl->peer_fd, sge, op_sge);
+    }
+    rc->recv_pos = 0;
+    rc->recv_buf_pos = 0;
+    return true;
+}
+
+static bool try_send_rdma_read(osd_client_t *cl, msgr_rdma_connection_t *rc, osd_op_t *cur_op, int op_list_size, uint32_t bs_bitmap_granularity)
+{
+    ibv_sge sge[rc->max_sge];
+    int op_size = bs_bitmap_granularity, op_sge = 1, op_max = rc->max_sge*bs_bitmap_granularity;
+    sge[0] = {
+        .addr = (uintptr_t)cl->send_list[0].iov_base,
+        .length = (uint32_t)cl->send_list[0].iov_len,
+        .lkey = rc->ctx->mr->lkey,
+    };
+    rc->send_pos = 1;
+    while (rc->send_pos < op_list_size)
     {
         iovec & iov = cl->send_list[rc->send_pos];
         if (cl->outbox[rc->send_pos].flags & MSGR_SENDP_HDR)
         {
             if (op_sge > 0)
             {
-                try_send_rdma_wr(cl, sge, op_sge);
+                try_send_rdma_wr(rc, cl->peer_fd, sge, op_sge);
                 op_sge = 0;
                 op_size = 0;
                 if (rc->cur_send >= rc->max_send)
@@ -373,7 +535,7 @@ bool osd_messenger_t::try_send_rdma(osd_client_t *cl)
                 .length = (uint32_t)iov.iov_len,
                 .lkey = rc->ctx->mr->lkey,
             };
-            try_send_rdma_wr(cl, sge, 1);
+            try_send_rdma_wr(rc, cl->peer_fd, sge, 1);
             rc->send_pos++;
             if (rc->cur_send >= rc->max_send)
                 break;
@@ -382,7 +544,7 @@ bool osd_messenger_t::try_send_rdma(osd_client_t *cl)
         {
             if (op_size >= op_max || op_sge >= rc->max_sge)
             {
-                try_send_rdma_wr(cl, sge, op_sge);
+                try_send_rdma_wr(rc, cl->peer_fd, sge, op_sge);
                 op_sge = 0;
                 op_size = 0;
                 if (rc->cur_send >= rc->max_send)
@@ -407,80 +569,222 @@ bool osd_messenger_t::try_send_rdma(osd_client_t *cl)
     }
     if (op_sge > 0)
     {
-        try_send_rdma_wr(cl, sge, op_sge);
+        try_send_rdma_wr(rc, cl->peer_fd, sge, op_sge);
+    }
+    if (op_list_size == 1)
+    {
+        if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ ||
+            cur_op->req.hdr.opcode == OSD_OP_READ)
+        {
+            sge[0] = {
+                .addr = 0,
+                .length = 0,
+                .lkey = rc->ctx->mr->lkey,
+            };
+            uint64_t data_size = cur_op->req.hdr.opcode == OSD_OP_SEC_READ
+                ? cur_op->req.sec_rw.len
+                : cur_op->req.rw.len;
+            while (data_size >= op_max)
+            {
+                try_send_rdma_wr(rc, cl->peer_fd, sge, 1);
+                data_size -= op_max;
+            }
+            if (data_size > 0)
+                try_send_rdma_wr(rc, cl->peer_fd, sge, 1);
+        }
+        else if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ_BMP)
+        {
+            sge[0] = {
+                .addr = 0,
+                .length = 0,
+                .lkey = rc->ctx->mr->lkey,
+            };
+            try_send_rdma_wr(rc, cl->peer_fd, sge, 1);
+        }
+        else
+            return true;
     }
     return true;
 }
 
-static void try_recv_rdma_wr(osd_client_t *cl, ibv_sge *sge, int op_sge)
+void osd_messenger_t::try_send_rdma(osd_client_t *cl)
 {
-    ibv_recv_wr *bad_wr = NULL;
-    ibv_recv_wr wr = {
-        .wr_id = (uint64_t)(cl->peer_fd*2),
-        .sg_list = sge,
-        .num_sge = op_sge,
+    // Two different algorithms for outgoing and incoming operations
+    while (cl->outbox.size() > 0)
+    {
+        osd_op_t *cur_op = cl->outbox[0].op;
+        if (cur_op->op_type == OSD_OP_OUT)
+        {
+            // Pick a queue. Send operation to it in one part.
+            int qi;
+            for (qi = 0; qi < cl->rdma_queues.size() && cl->rdma_queues[qi]->cur_op != NULL; qi++) {}
+            if (qi >= cl->rdma_queues.size())
+            {
+                // No free queues, retry later.
+                // We only post 1 operation per queue to use the queue pair number as a 'tag'.
+                return;
+            }
+            // Pick all entries for the operation from the queue
+            int op_list_size = 0;
+            while (op_list_size < cl->outbox.size() && cl->outbox[op_list_size].op == cur_op)
+            {
+                op_list_size++;
+            }
+            auto rq = cl->rdma_queues[qi];
+            rq->cur_op = cur_op;
+            ibv_sge sge[rq->max_sge];
+            // FIXME: This won't work with long bitmaps. But I don't care, I want to finally test fucking RDMA
+            // header or header+data
+            sge[0] = {
+                .addr = (uintptr_t)cl->send_list[0].iov_base,
+                .length = (uint32_t)cl->send_list[0].iov_len,
+                .lkey = rq->ctx->mr->lkey,
+            };
+            if (op_list_size == 2)
+            {
+                auto & iov = cl->send_list[1];
+                sge[1] = {
+                    .addr = (uintptr_t)iov.iov_base,
+                    .length = (uint32_t)iov.iov_len,
+                    .lkey = rq->ctx->mr->lkey,
+                };
+                try_send_rdma_wr(rq, cl->peer_fd, sge, 2);
+            }
+            else if (op_list_size == 1)
+            {
+                try_send_rdma_wr(rq, cl->peer_fd, sge, 1);
+            }
+            else
+            {
+                printf("unexpected long send_list for opcode %lu: %lu entries\n", cur_op->req.hdr.opcode, cl->send_list.size());
+                exit(1);
+            }
+            cl->send_list.erase(cl->send_list.begin(), cl->send_list.begin()+op_list_size);
+            cl->outbox.erase(cl->outbox.begin(), cl->outbox.begin()+op_list_size);
+            // Post a receive request for the reply at the same time
+            if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ ||
+                cur_op->req.hdr.opcode == OSD_OP_READ)
+            {
+                try_recv_rdma_read(cl, rq, cur_op, bs_bitmap_granularity);
+            }
+            else if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ_BMP)
+            {
+                assert(!cur_op->iov.count);
+// FIXME: hardcode
+#define clean_entry_bitmap_size 4
+                // Reply size is known
+                uint64_t data_size = cur_op->req.sec_read_bmp.len / sizeof(obj_ver_id) * (8 + clean_entry_bitmap_size);
+                cur_op->rmw_buf = malloc_or_die(data_size);
+                sge[0] = {
+                    .addr = (uintptr_t)cur_op->reply.buf,
+                    .length = (uint32_t)OSD_PACKET_SIZE,
+                    .lkey = rq->ctx->mr->lkey,
+                };
+                sge[1] = {
+                    .addr = (uintptr_t)cur_op->rmw_buf,
+                    .length = (uint32_t)data_size,
+                    .lkey = rq->ctx->mr->lkey,
+                };
+                try_recv_rdma_wr(rq, cl->peer_fd, sge, 2);
+            }
+            else
+            {
+                // No reply or reply size is unknown
+                sge[0] = {
+                    .addr = (uintptr_t)cur_op->reply.buf,
+                    .length = (uint32_t)OSD_PACKET_SIZE,
+                    .lkey = rq->ctx->mr->lkey,
+                };
+                try_recv_rdma_wr(rq, cl->peer_fd, sge, 1);
+            }
+        }
+        else
+        {
+            // Send reply to the same queue the operation came from.
+            // Fragment it into parts no longer than (max_sge*4k) to always
+            // be able to send and receive them correctly.
+            int qi;
+            for (qi = 0; qi < cl->rdma_queues.size() && cl->rdma_queues[qi]->cur_op != cur_op; qi++) {}
+            if (qi >= cl->rdma_queues.size())
+            {
+                printf("Unknown incoming operation for client %d\n", cl->peer_fd);
+                exit(1);
+            }
+            // Pick all entries for the operation from the queue
+            int op_list_size = 0;
+            while (op_list_size < cl->outbox.size() && cl->outbox[op_list_size].op == cur_op)
+            {
+                op_list_size++;
+            }
+            auto rq = cl->rdma_queues[qi];
+            if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ ||
+                cur_op->req.hdr.opcode == OSD_OP_READ)
+            {
+                try_send_rdma_read(cl, rq, cur_op, op_list_size, bs_bitmap_granularity);
+                rq->send_pos = 0;
+                rq->send_buf_pos = 0;
+            }
+            else if (op_list_size == 1)
+            {
+                ibv_sge sge[1];
+                sge[0] = {
+                    .addr = (uintptr_t)cl->send_list[0].iov_base,
+                    .length = (uint32_t)cl->send_list[0].iov_len,
+                    .lkey = rq->ctx->mr->lkey,
+                };
+                try_send_rdma_wr(rq, cl->peer_fd, sge, 1);
+            }
+            else if (op_list_size == 2)
+            {
+                ibv_sge sge[2];
+                sge[0] = {
+                    .addr = (uintptr_t)cl->send_list[0].iov_base,
+                    .length = (uint32_t)cl->send_list[0].iov_len,
+                    .lkey = rq->ctx->mr->lkey,
+                };
+                sge[1] = {
+                    .addr = (uintptr_t)cl->send_list[1].iov_base,
+                    .length = (uint32_t)cl->send_list[1].iov_len,
+                    .lkey = rq->ctx->mr->lkey,
+                };
+                if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ_BMP)
+                    try_send_rdma_wr(rq, cl->peer_fd, sge, 2);
+                else
+                {
+                    try_send_rdma_wr(rq, cl->peer_fd, sge, 1);
+                    try_send_rdma_wr(rq, cl->peer_fd, sge+1, 1);
+                }
+            }
+            else if (op_list_size > 2)
+            {
+                printf("Unexpected long send_list for opcode %lu: %lu entries\n", cur_op->req.hdr.opcode, cl->send_list.size());
+                exit(1);
+            }
+            cl->send_list.erase(cl->send_list.begin(), cl->send_list.begin()+op_list_size);
+            cl->outbox.erase(cl->outbox.begin(), cl->outbox.begin()+op_list_size);
+        }
+    }
+}
+
+// Try to receive an incoming operation via RDMA
+void osd_messenger_t::try_recv_rdma(osd_client_t *cl, msgr_rdma_connection_t *rc)
+{
+    rc->cur_op = new osd_op_t;
+    rc->cur_op->peer_fd = cl->peer_fd;
+    rc->cur_op->op_type = OSD_OP_IN;
+    rc->cur_op->buf = memalign_or_die(MEM_ALIGNMENT, 128*1024); // FIXME hardcode for tests
+    ibv_sge sge[2];
+    sge[0] = {
+        .addr = (uintptr_t)rc->cur_op->req.buf,
+        .length = (uint32_t)OSD_PACKET_SIZE,
+        .lkey = rc->ctx->mr->lkey,
     };
-    int err = ibv_post_recv(cl->rdma_conn->qp, &wr, &bad_wr);
-    if (err || bad_wr)
-    {
-        printf("RDMA receive failed: %s\n", strerror(err));
-        exit(1);
-    }
-    cl->rdma_conn->cur_recv++;
-}
-
-bool osd_messenger_t::try_recv_rdma(osd_client_t *cl)
-{
-    auto rc = cl->rdma_conn;
-    if (rc->cur_recv > 0)
-    {
-        return true;
-    }
-    if (!cl->recv_list.get_size())
-    {
-        cl->recv_list.reset();
-        cl->read_op = new osd_op_t;
-        cl->read_op->peer_fd = cl->peer_fd;
-        cl->read_op->op_type = OSD_OP_IN;
-        cl->recv_list.push_back(cl->read_op->req.buf, OSD_PACKET_SIZE);
-        cl->read_remaining = OSD_PACKET_SIZE;
-        cl->read_state = CL_READ_HDR;
-    }
-    int op_size = 0, op_sge = 0, op_max = rc->max_sge*bs_bitmap_granularity;
-    iovec *segments = cl->recv_list.get_iovec();
-    // FIXME: rc->max_sge should be negotiated between client & server
-    ibv_sge sge[rc->max_sge];
-    while (rc->recv_pos < cl->recv_list.get_size())
-    {
-        iovec & iov = segments[rc->recv_pos];
-        if (op_size >= op_max || op_sge >= rc->max_sge)
-        {
-            try_recv_rdma_wr(cl, sge, op_sge);
-            op_sge = 0;
-            op_size = 0;
-            if (rc->cur_recv >= rc->max_recv)
-                break;
-        }
-        // Receive in identical (max_sge*4k) fragments
-        uint32_t len = (uint32_t)(op_size+iov.iov_len-rc->recv_buf_pos < op_max ? iov.iov_len-rc->recv_buf_pos : op_max-op_size);
-        sge[op_sge++] = {
-            .addr = (uintptr_t)(iov.iov_base+rc->recv_buf_pos),
-            .length = len,
-            .lkey = rc->ctx->mr->lkey,
-        };
-        op_size += len;
-        rc->recv_buf_pos += len;
-        if (rc->recv_buf_pos >= iov.iov_len)
-        {
-            rc->recv_pos++;
-            rc->recv_buf_pos = 0;
-        }
-    }
-    if (op_sge > 0)
-    {
-        try_recv_rdma_wr(cl, sge, op_sge);
-    }
-    return true;
+    sge[1] = {
+        .addr = (uintptr_t)rc->cur_op->buf,
+        .length = (uint32_t)128*1024,
+        .lkey = rc->ctx->mr->lkey,
+    };
+    try_recv_rdma_wr(rc, cl->peer_fd, sge, 2);
 }
 
 #define RDMA_EVENTS_AT_ONCE 32
@@ -491,6 +795,7 @@ void osd_messenger_t::handle_rdma_events()
     ibv_cq *ev_cq;
     void *ev_ctx;
     // FIXME: This is inefficient as it calls read()...
+    timespec tv;
     if (ibv_get_cq_event(rdma_context->channel, &ev_cq, &ev_ctx) == 0)
     {
         ibv_ack_cq_events(rdma_context->cq, 1);
@@ -507,8 +812,8 @@ void osd_messenger_t::handle_rdma_events()
         event_count = ibv_poll_cq(rdma_context->cq, RDMA_EVENTS_AT_ONCE, wc);
         for (int i = 0; i < event_count; i++)
         {
-            int client_id = wc[i].wr_id >> 1;
-            bool is_send = wc[i].wr_id & 1;
+            int client_id = wc[i].wr_id;
+            bool is_send = wc[i].opcode == IBV_WC_SEND;
             auto cl_it = clients.find(client_id);
             if (cl_it == clients.end())
             {
@@ -526,55 +831,120 @@ void osd_messenger_t::handle_rdma_events()
                 stop_client(client_id);
                 continue;
             }
+            int q;
+            for (q = 0; q < cl->rdma_queues.size() && cl->rdma_queues[q]->qp->qp_num != wc[i].qp_num; q++) {}
+            if (q >= cl->rdma_queues.size())
+            {
+                printf("Unknown queue %d for client %d\n", wc[i].qp_num, cl->peer_fd);
+                exit(1);
+            }
+            auto rc = cl->rdma_queues[q];
+            if (is_send)
+            {
+                clock_gettime(CLOCK_REALTIME, &tv);
+                printf("%lu.%09lu Done RDMA send on queue %d\n", tv.tv_sec, tv.tv_nsec, wc[i].qp_num);
+            }
+            else
+            {
+                clock_gettime(CLOCK_REALTIME, &tv);
+                printf("%lu.%09lu Done RDMA recv on queue %d, %d bytes\n", tv.tv_sec, tv.tv_nsec, wc[i].qp_num, wc[i].byte_len);
+            }
             if (!is_send)
             {
-                cl->rdma_conn->cur_recv--;
-                if (!cl->rdma_conn->cur_recv)
+                rc->cur_recv--;
+                if (!rc->cur_recv)
                 {
-                    cl->recv_list.done += cl->rdma_conn->recv_pos;
-                    cl->rdma_conn->recv_pos = 0;
-                    if (!cl->recv_list.get_size())
+                    // Fucking shit...
+                    if (rc->cur_op->op_type == OSD_OP_IN)
                     {
-                        cl->read_remaining = 0;
-                        if (handle_finished_read(cl))
+                        if (wc[i].byte_len <= OSD_PACKET_SIZE)
                         {
-                            try_recv_rdma(cl);
+                            free(rc->cur_op->buf);
+                            rc->cur_op->buf = NULL;
                         }
+                        cl->received_ops.push_back(rc->cur_op);
+                        set_immediate.push_back([this, op = rc->cur_op]() { exec_op(op); });
                     }
-                    else
+                    else /* if (rc->cur_op->op_type == OSD_OP_OUT) */
                     {
-                        // Continue to receive data
-                        try_recv_rdma(cl);
+                        if (rc->cur_op->reply.hdr.opcode == OSD_OP_SEC_READ ||
+                            rc->cur_op->reply.hdr.opcode == OSD_OP_READ)
+                        {
+                            // Data is already received
+                            cl->sent_ops.erase(rc->cur_op->req.hdr.id);
+                            handle_reply_ready(rc->cur_op);
+                            rc->cur_op = NULL;
+                            try_send_rdma(cl);
+                        }
+                        else if (rc->cur_op->reply.hdr.opcode == OSD_OP_SEC_READ_BMP)
+                        {
+                            // Data is already received, but we need to switch buffers
+                            cl->sent_ops.erase(rc->cur_op->req.hdr.id);
+                            free(rc->cur_op->buf);
+                            rc->cur_op->buf = rc->cur_op->rmw_buf;
+                            handle_reply_ready(rc->cur_op);
+                            rc->cur_op = NULL;
+                            try_send_rdma(cl);
+                        }
+                        else if (rc->cur_op->reply.hdr.opcode == OSD_OP_SEC_LIST && rc->cur_op->reply.hdr.retval > 0 ||
+                            rc->cur_op->reply.hdr.opcode == OSD_OP_SHOW_CONFIG && rc->cur_op->reply.hdr.retval > 0)
+                        {
+                            if (rc->recv_pos != 1)
+                            {
+                                // Data is not received yet (RNR)
+                                uint32_t len;
+                                if (rc->cur_op->reply.hdr.opcode == OSD_OP_SEC_LIST)
+                                    len = sizeof(obj_ver_id) * rc->cur_op->reply.hdr.retval;
+                                else
+                                    len = rc->cur_op->reply.hdr.retval;
+                                rc->cur_op->buf = malloc_or_die(len);
+                                ibv_sge sge[1];
+                                sge[0] = {
+                                    .addr = (uintptr_t)rc->cur_op->buf,
+                                    .length = len,
+                                    .lkey = rc->ctx->mr->lkey,
+                                };
+                                try_recv_rdma_wr(rc, cl->peer_fd, sge, 1);
+                                rc->recv_pos = 1;
+                            }
+                            else
+                            {
+                                // Done
+                                cl->sent_ops.erase(rc->cur_op->req.hdr.id);
+                                handle_reply_ready(rc->cur_op);
+                                rc->cur_op = NULL;
+                                rc->recv_pos = 0;
+                                try_send_rdma(cl);
+                            }
+                        }
+                        else
+                        {
+                            // No data
+                            cl->sent_ops.erase(rc->cur_op->req.hdr.id);
+                            handle_reply_ready(rc->cur_op);
+                            rc->cur_op = NULL;
+                            try_send_rdma(cl);
+                        }
                     }
                 }
             }
             else
             {
-                cl->rdma_conn->cur_send--;
-                if (!cl->rdma_conn->cur_send)
+                rc->cur_send--;
+                if (!rc->cur_send)
                 {
-                    // Wait for the whole batch
-                    for (int i = 0; i < cl->rdma_conn->send_pos; i++)
+                    if (rc->cur_op->op_type == OSD_OP_OUT)
                     {
-                        if (cl->outbox[i].flags & MSGR_SENDP_FREE)
-                        {
-                            // Reply fully sent
-                            delete cl->outbox[i].op;
-                        }
+                        // Nothing
                     }
-                    if (cl->rdma_conn->send_pos > 0)
+                    else /* if (rc->cur_op->op_type == OSD_OP_IN) */
                     {
-                        cl->send_list.erase(cl->send_list.begin(), cl->send_list.begin()+cl->rdma_conn->send_pos);
-                        cl->outbox.erase(cl->outbox.begin(), cl->outbox.begin()+cl->rdma_conn->send_pos);
-                        cl->rdma_conn->send_pos = 0;
+                        // Reply fully sent
+                        delete rc->cur_op;
+                        rc->cur_op = NULL;
+                        // Post receive for the next incoming op
+                        try_recv_rdma(cl, rc);
                     }
-                    if (cl->rdma_conn->send_buf_pos > 0)
-                    {
-                        cl->send_list[0].iov_base += cl->rdma_conn->send_buf_pos;
-                        cl->send_list[0].iov_len -= cl->rdma_conn->send_buf_pos;
-                        cl->rdma_conn->send_buf_pos = 0;
-                    }
-                    try_send_rdma(cl);
                 }
             }
         }
@@ -585,3 +955,8 @@ void osd_messenger_t::handle_rdma_events()
     }
     set_immediate.clear();
 }
+
+int osd_messenger_t::get_rdma_max_sge()
+{
+    return rdma_max_sge;
+}

src/msgr_rdma.h

@@ -3,6 +3,8 @@
 #include <string>
 #include <vector>
 
+struct osd_op_t;
+
 struct msgr_rdma_address_t
 {
     ibv_gid gid;
@@ -44,6 +46,7 @@ struct msgr_rdma_connection_t
     int max_send = 0, max_recv = 0, max_sge = 0;
     int cur_send = 0, cur_recv = 0;
 
+    osd_op_t *cur_op = NULL;
     int send_pos = 0, send_buf_pos = 0;
     int recv_pos = 0, recv_buf_pos = 0;
 

src/msgr_receive.cpp

@@ -207,20 +207,26 @@ void osd_messenger_t::handle_op_hdr(osd_client_t *cl)
     else if (cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
         cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE)
     {
-        if (cur_op->req.sec_rw.attr_len > 0)
+        if (cur_op->req.sec_rw.bitmap_len > 0)
         {
-            if (cur_op->req.sec_rw.attr_len > sizeof(unsigned))
-                cur_op->bitmap = cur_op->rmw_buf = malloc_or_die(cur_op->req.sec_rw.attr_len);
+            if (cur_op->req.sec_rw.bitmap_len > sizeof(void*))
+                cur_op->bitmap = cur_op->rmw_buf = malloc_or_die(cur_op->req.sec_rw.bitmap_len);
             else
                 cur_op->bitmap = &cur_op->bmp_data;
-            cl->recv_list.push_back(cur_op->bitmap, cur_op->req.sec_rw.attr_len);
+            if (cur_op->req.sec_rw.bitmap_len <= 8)
+                memcpy(cur_op->bitmap, &cur_op->req.sec_rw.bitmap, cur_op->req.sec_rw.bitmap_len);
+            else
+            {
+                cl->recv_list.push_back(cur_op->bitmap, cur_op->req.sec_rw.bitmap_len);
+                cl->read_remaining += cur_op->req.sec_rw.bitmap_len;
+            }
         }
         if (cur_op->req.sec_rw.len > 0)
         {
             cur_op->buf = memalign_or_die(MEM_ALIGNMENT, cur_op->req.sec_rw.len);
             cl->recv_list.push_back(cur_op->buf, cur_op->req.sec_rw.len);
+            cl->read_remaining += cur_op->req.sec_rw.len;
         }
-        cl->read_remaining = cur_op->req.sec_rw.len + cur_op->req.sec_rw.attr_len;
     }
     else if (cur_op->req.hdr.opcode == OSD_OP_SEC_STABILIZE ||
         cur_op->req.hdr.opcode == OSD_OP_SEC_ROLLBACK)
@@ -295,7 +301,7 @@ bool osd_messenger_t::handle_reply_hdr(osd_client_t *cl)
     if (op->reply.hdr.opcode == OSD_OP_SEC_READ || op->reply.hdr.opcode == OSD_OP_READ)
     {
         // Read data. In this case we assume that the buffer is preallocated by the caller (!)
-        unsigned bmp_len = (op->reply.hdr.opcode == OSD_OP_SEC_READ ? op->reply.sec_rw.attr_len : op->reply.rw.bitmap_len);
+        unsigned bmp_len = (op->reply.hdr.opcode == OSD_OP_SEC_READ ? op->reply.sec_rw.bitmap_len : op->reply.rw.bitmap_len);
         unsigned expected_size = (op->reply.hdr.opcode == OSD_OP_SEC_READ ? op->req.sec_rw.len : op->req.rw.len);
         if (op->reply.hdr.retval >= 0 && (op->reply.hdr.retval != expected_size || bmp_len > op->bitmap_len))
         {
@@ -309,14 +315,24 @@ bool osd_messenger_t::handle_reply_hdr(osd_client_t *cl)
         if (op->reply.hdr.retval >= 0 && bmp_len > 0)
         {
             assert(op->bitmap);
-            cl->recv_list.push_back(op->bitmap, bmp_len);
+            if (bmp_len <= 8)
+            {
+                memcpy(op->bitmap, (op->reply.hdr.opcode == OSD_OP_SEC_READ
+                    ? &op->reply.sec_rw.bitmap
+                    : &op->reply.rw.bitmap), bmp_len);
+            }
+            else
+            {
+                cl->recv_list.push_back(op->bitmap, bmp_len);
+                cl->read_remaining += bmp_len;
+            }
         }
         if (op->reply.hdr.retval > 0)
         {
             assert(op->iov.count > 0);
             cl->recv_list.append(op->iov);
+            cl->read_remaining += op->reply.hdr.retval;
         }
-        cl->read_remaining = op->reply.hdr.retval + bmp_len;
         if (cl->read_remaining == 0)
         {
             goto reuse;

src/msgr_send.cpp

@@ -50,23 +50,37 @@ void osd_messenger_t::outbox_push(osd_op_t *cur_op)
     // Bitmap
     if (cur_op->op_type == OSD_OP_IN &&
         cur_op->req.hdr.opcode == OSD_OP_SEC_READ &&
-        cur_op->reply.sec_rw.attr_len > 0)
+        cur_op->reply.sec_rw.bitmap_len > 0)
     {
-        to_send_list.push_back((iovec){
-            .iov_base = cur_op->bitmap,
-            .iov_len = cur_op->reply.sec_rw.attr_len,
-        });
-        to_outbox.push_back((msgr_sendp_t){ .op = cur_op, .flags = 0 });
+        if (cur_op->reply.sec_rw.bitmap_len <= 8)
+        {
+            memcpy(&cur_op->reply.sec_rw.bitmap, cur_op->bitmap, cur_op->reply.sec_rw.bitmap_len);
+        }
+        else
+        {
+            to_send_list.push_back((iovec){
+                .iov_base = cur_op->bitmap,
+                .iov_len = cur_op->reply.sec_rw.bitmap_len,
+            });
+            to_outbox.push_back((msgr_sendp_t){ .op = cur_op, .flags = MSGR_SENDP_BMP });
+        }
     }
     else if (cur_op->op_type == OSD_OP_OUT &&
         (cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE || cur_op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE) &&
-        cur_op->req.sec_rw.attr_len > 0)
+        cur_op->req.sec_rw.bitmap_len > 0)
     {
-        to_send_list.push_back((iovec){
-            .iov_base = cur_op->bitmap,
-            .iov_len = cur_op->req.sec_rw.attr_len,
-        });
-        to_outbox.push_back((msgr_sendp_t){ .op = cur_op, .flags = 0 });
+        if (cur_op->req.sec_rw.bitmap_len <= 8)
+        {
+            memcpy(&cur_op->req.sec_rw.bitmap, cur_op->bitmap, cur_op->req.sec_rw.bitmap_len);
+        }
+        else
+        {
+            to_send_list.push_back((iovec){
+                .iov_base = cur_op->bitmap,
+                .iov_len = cur_op->req.sec_rw.attr_len,
+            });
+            to_outbox.push_back((msgr_sendp_t){ .op = cur_op, .flags = MSGR_SENDP_BMP });
+        }
     }
     // Operation data
     if ((cur_op->op_type == OSD_OP_IN
@@ -268,15 +282,13 @@ void osd_messenger_t::handle_send(int result, osd_client_t *cl)
         }
         cl->write_state = cl->outbox.size() > 0 ? CL_WRITE_READY : 0;
 #ifdef WITH_RDMA
-        if (cl->rdma_conn && !cl->outbox.size() && cl->peer_state == PEER_RDMA_CONNECTING)
+        if (cl->peer_state == PEER_RDMA_CONNECTING && cl->rdma_queues.size() > 0 && !cl->outbox.size())
         {
             // FIXME: Do something better than just forgetting the FD
             // FIXME: Ignore pings during RDMA state transition
             printf("Successfully connected with client %d using RDMA\n", cl->peer_fd);
             cl->peer_state = PEER_RDMA;
             tfd->set_fd_handler(cl->peer_fd, false, NULL);
-            // Add the initial receive request
-            try_recv_rdma(cl);
         }
 #endif
     }

src/msgr_stop.cpp

@@ -123,10 +123,11 @@ void osd_messenger_t::stop_client(int peer_fd, bool force)
     // ...because peer_fd number can get reused after close()
     close(peer_fd);
 #ifdef WITH_RDMA
-    if (cl->rdma_conn)
+    for (auto rdma_conn: cl->rdma_queues)
     {
-        delete cl->rdma_conn;
+        delete rdma_conn;
     }
+    cl->rdma_queues.resize(0);
 #endif
 #endif
     // Find the item again because it can be invalidated at this point

src/osd_ops.h

@@ -35,7 +35,7 @@
 #define MEM_ALIGNMENT               512
 #endif
 #define OSD_RW_MAX                  64*1024*1024
-#define OSD_PROTOCOL_VERSION        1
+#define OSD_PROTOCOL_VERSION        2
 
 // common request and reply headers
 struct __attribute__((__packed__)) osd_op_header_t
@@ -74,8 +74,10 @@ struct __attribute__((__packed__)) osd_op_sec_rw_t
     // length
     uint32_t len;
     // bitmap/attribute length - bitmap comes after header, but before data
-    uint32_t attr_len;
+    uint32_t bitmap_len;
     uint32_t pad0;
+    // inline bitmap (when it's no longer than 8 bytes)
+    uint64_t bitmap;
 };
 
 struct __attribute__((__packed__)) osd_reply_sec_rw_t
@@ -84,8 +86,10 @@ struct __attribute__((__packed__)) osd_reply_sec_rw_t
     // for reads and writes: assigned or read version number
     uint64_t version;
     // for reads: bitmap/attribute length (just to double-check)
-    uint32_t attr_len;
+    uint32_t bitmap_len;
     uint32_t pad0;
+    // inline bitmap (when it's no longer than 8 bytes)
+    uint64_t bitmap;
 };
 
 // delete object on the secondary OSD
@@ -199,6 +203,8 @@ struct __attribute__((__packed__)) osd_reply_rw_t
     // for reads: bitmap length
     uint32_t bitmap_len;
     uint32_t pad0;
+    // inline bitmap (when it's no longer than 8 bytes)
+    uint64_t bitmap;
 };
 
 // sync to the primary OSD

src/osd_primary.cpp

@@ -235,7 +235,10 @@ resume_2:
         {
             reconstruct_stripes_jerasure(stripes, op_data->pg_size, op_data->pg_data_size, clean_entry_bitmap_size);
         }
-        cur_op->iov.push_back(op_data->stripes[0].bmp_buf, cur_op->reply.rw.bitmap_len);
+        if (cur_op->reply.rw.bitmap_len <= 8)
+            memcpy(&cur_op->reply.rw.bitmap, op_data->stripes[0].bmp_buf, cur_op->reply.rw.bitmap_len);
+        else
+            cur_op->iov.push_back(op_data->stripes[0].bmp_buf, cur_op->reply.rw.bitmap_len);
         for (int role = 0; role < op_data->pg_size; role++)
         {
             if (stripes[role].req_end != 0)
@@ -250,7 +253,10 @@ resume_2:
     }
     else
     {
-        cur_op->iov.push_back(op_data->stripes[0].bmp_buf, cur_op->reply.rw.bitmap_len);
+        if (cur_op->reply.rw.bitmap_len <= 8)
+            memcpy(&cur_op->reply.rw.bitmap, op_data->stripes[0].bmp_buf, cur_op->reply.rw.bitmap_len);
+        else
+            cur_op->iov.push_back(op_data->stripes[0].bmp_buf, cur_op->reply.rw.bitmap_len);
         cur_op->iov.push_back(cur_op->buf, cur_op->req.rw.len);
     }
     finish_op(cur_op, cur_op->req.rw.len);

src/osd_primary_subops.cpp

@@ -200,7 +200,7 @@ int osd_t::submit_primary_subop_batch(int submit_type, inode_t inode, uint64_t o
                     .version = op_version,
                     .offset = wr ? stripes[stripe_num].write_start : stripes[stripe_num].read_start,
                     .len = wr ? stripes[stripe_num].write_end - stripes[stripe_num].write_start : stripes[stripe_num].read_end - stripes[stripe_num].read_start,
-                    .attr_len = wr ? clean_entry_bitmap_size : 0,
+                    .bitmap_len = wr ? clean_entry_bitmap_size : 0,
                 };
 #ifdef OSD_DEBUG
                 printf(

src/osd_secondary.cpp

@@ -20,9 +20,9 @@ void osd_t::secondary_op_callback(osd_op_t *op)
     if (op->req.hdr.opcode == OSD_OP_SEC_READ)
     {
         if (op->bs_op->retval >= 0)
-            op->reply.sec_rw.attr_len = clean_entry_bitmap_size;
+            op->reply.sec_rw.bitmap_len = clean_entry_bitmap_size;
         else
-            op->reply.sec_rw.attr_len = 0;
+            op->reply.sec_rw.bitmap_len = 0;
         if (op->bs_op->retval > 0)
             op->iov.push_back(op->buf, op->bs_op->retval);
     }
@@ -81,7 +81,7 @@ void osd_t::exec_secondary(osd_op_t *cur_op)
         if (cur_op->req.hdr.opcode == OSD_OP_SEC_READ)
         {
             // Allocate memory for the read operation
-            if (clean_entry_bitmap_size > sizeof(unsigned))
+            if (clean_entry_bitmap_size > sizeof(void*))
                 cur_op->bitmap = cur_op->rmw_buf = malloc_or_die(clean_entry_bitmap_size);
             else
                 cur_op->bitmap = &cur_op->bmp_data;
@@ -166,14 +166,20 @@ void osd_t::exec_show_config(osd_op_t *cur_op)
     {
         // Indicate that RDMA is enabled
         wire_config["rdma_enabled"] = true;
-        if (req_json["connect_rdma"].is_string())
+        if (req_json["rdma_queues"].array_items().size())
         {
             // Peer is trying to connect using RDMA, try to satisfy him
-            bool ok = msgr.connect_rdma(cur_op->peer_fd, req_json["connect_rdma"].string_value());
+            auto cl = msgr.clients.at(cur_op->peer_fd);
+            bool ok = msgr.connect_rdma_client(cl, req_json["rdma_queues"], req_json["rdma_max_sge"].uint64_value());
             if (ok)
             {
-                wire_config["rdma_connected"] = true;
-                wire_config["rdma_address"] = msgr.clients.at(cur_op->peer_fd)->rdma_conn->addr.to_string();
+                json11::Json::array rdma_queues;
+                for (auto rdma_conn: cl->rdma_queues)
+                {
+                    rdma_queues.push_back(rdma_conn->addr.to_string());
+                }
+                wire_config["rdma_queues"] = rdma_queues;
+                wire_config["rdma_max_sge"] = msgr.get_rdma_max_sge();
             }
         }
     }