WIP NFS RDMA support

.gitea/workflows/test.yml

@@ -288,6 +288,24 @@ jobs:
           echo ""
         done
 
+  test_create_halfhost:
+    runs-on: ubuntu-latest
+    needs: build
+    container: ${{env.TEST_IMAGE}}:${{github.sha}}
+    steps:
+    - name: Run test
+      id: test
+      timeout-minutes: 3
+      run: /root/vitastor/tests/test_create_halfhost.sh
+    - name: Print logs
+      if: always() && steps.test.outcome == 'failure'
+      run: |
+        for i in /root/vitastor/testdata/*.log /root/vitastor/testdata/*.txt; do
+          echo "-------- $i --------"
+          cat $i
+          echo ""
+        done
+
   test_failure_domain:
     runs-on: ubuntu-latest
     needs: build

docs/config/network.en.md

@@ -68,11 +68,17 @@ but they are not connected to the cluster.
 - Type: string
 
 RDMA device name to use for Vitastor OSD communications (for example,
-"rocep5s0f0"). Now Vitastor supports all adapters, even ones without
-ODP support, like Mellanox ConnectX-3 and non-Mellanox cards.
+"rocep5s0f0"). If not specified, Vitastor will try to find an RoCE
+device matching [osd_network](osd.en.md#osd_network), preferring RoCEv2,
+or choose the first available RDMA device if no RoCE devices are
+found or if `osd_network` is not specified. Auto-selection is also
+unsupported with old libibverbs < v32, like in Debian 10 Buster or
+CentOS 7.
 
-Versions up to Vitastor 1.2.0 required ODP which is only present in
-Mellanox ConnectX >= 4. See also [rdma_odp](#rdma_odp).
+Vitastor supports all adapters, even ones without ODP support, like
+Mellanox ConnectX-3 and non-Mellanox cards. Versions up to Vitastor
+1.2.0 required ODP which is only present in Mellanox ConnectX >= 4.
+See also [rdma_odp](#rdma_odp).
 
 Run `ibv_devinfo -v` as root to list available RDMA devices and their
 features.
@@ -95,15 +101,17 @@ your device has.
 ## rdma_gid_index
 
 - Type: integer
-- Default: 0
 
 Global address identifier index of the RDMA device to use. Different GID
 indexes may correspond to different protocols like RoCEv1, RoCEv2 and iWARP.
 Search for "GID" in `ibv_devinfo -v` output to determine which GID index
 you need.
 
-**IMPORTANT:** If you want to use RoCEv2 (as recommended) then the correct
-rdma_gid_index is usually 1 (IPv6) or 3 (IPv4).
+If not specified, Vitastor will try to auto-select a RoCEv2 IPv4 GID, then
+RoCEv2 IPv6 GID, then RoCEv1 IPv4 GID, then RoCEv1 IPv6 GID, then IB GID.
+GID auto-selection is unsupported with libibverbs < v32.
+
+A correct rdma_gid_index for RoCEv2 is usually 1 (IPv6) or 3 (IPv4).
 
 ## rdma_mtu
 

docs/config/network.ru.md

@@ -71,12 +71,17 @@ RDMA может быть нужно только если у клиентов е
 - Тип: строка
 
 Название RDMA-устройства для связи с Vitastor OSD (например, "rocep5s0f0").
-Сейчас Vitastor поддерживает все модели адаптеров, включая те, у которых
-нет поддержки ODP, то есть вы можете использовать RDMA с ConnectX-3 и
-картами производства не Mellanox.
+Если не указано, Vitastor попробует найти RoCE-устройство, соответствующее
+[osd_network](osd.en.md#osd_network), предпочитая RoCEv2, или выбрать первое
+попавшееся RDMA-устройство, если RoCE-устройств нет или если сеть `osd_network`
+не задана. Также автовыбор не поддерживается со старыми версиями библиотеки
+libibverbs < v32, например в Debian 10 Buster или CentOS 7.
 
-Версии Vitastor до 1.2.0 включительно требовали ODP, который есть только
-на Mellanox ConnectX 4 и более новых. См. также [rdma_odp](#rdma_odp).
+Vitastor поддерживает все модели адаптеров, включая те, у которых
+нет поддержки ODP, то есть вы можете использовать RDMA с ConnectX-3 и
+картами производства не Mellanox. Версии Vitastor до 1.2.0 включительно
+требовали ODP, который есть только на Mellanox ConnectX 4 и более новых.
+См. также [rdma_odp](#rdma_odp).
 
 Запустите `ibv_devinfo -v` от имени суперпользователя, чтобы посмотреть
 список доступных RDMA-устройств, их параметры и возможности.
@@ -101,15 +106,18 @@ Control) и ECN (Explicit Congestion Notification).
 ## rdma_gid_index
 
 - Тип: целое число
-- Значение по умолчанию: 0
 
 Номер глобального идентификатора адреса RDMA-устройства, который следует
 использовать. Разным gid_index могут соответствовать разные протоколы связи:
 RoCEv1, RoCEv2, iWARP. Чтобы понять, какой нужен вам - смотрите строчки со
 словом "GID" в выводе команды `ibv_devinfo -v`.
 
-**ВАЖНО:** Если вы хотите использовать RoCEv2 (как мы и рекомендуем), то
-правильный rdma_gid_index, как правило, 1 (IPv6) или 3 (IPv4).
+Если не указан, Vitastor попробует автоматически выбрать сначала GID,
+соответствующий RoCEv2 IPv4, потом RoCEv2 IPv6, потом RoCEv1 IPv4, потом
+RoCEv1 IPv6, потом IB. Авто-выбор GID не поддерживается со старыми версиями
+libibverbs < v32.
+
+Правильный rdma_gid_index для RoCEv2, как правило, 1 (IPv6) или 3 (IPv4).
 
 ## rdma_mtu
 

docs/config/src/network.yml

@@ -48,11 +48,17 @@
   type: string
   info: |
     RDMA device name to use for Vitastor OSD communications (for example,
-    "rocep5s0f0"). Now Vitastor supports all adapters, even ones without
-    ODP support, like Mellanox ConnectX-3 and non-Mellanox cards.
+    "rocep5s0f0"). If not specified, Vitastor will try to find an RoCE
+    device matching [osd_network](osd.en.md#osd_network), preferring RoCEv2,
+    or choose the first available RDMA device if no RoCE devices are
+    found or if `osd_network` is not specified. Auto-selection is also
+    unsupported with old libibverbs < v32, like in Debian 10 Buster or
+    CentOS 7.
 
-    Versions up to Vitastor 1.2.0 required ODP which is only present in
-    Mellanox ConnectX >= 4. See also [rdma_odp](#rdma_odp).
+    Vitastor supports all adapters, even ones without ODP support, like
+    Mellanox ConnectX-3 and non-Mellanox cards. Versions up to Vitastor
+    1.2.0 required ODP which is only present in Mellanox ConnectX >= 4.
+    See also [rdma_odp](#rdma_odp).
 
     Run `ibv_devinfo -v` as root to list available RDMA devices and their
     features.
@@ -64,12 +70,17 @@
     PFC (Priority Flow Control) and ECN (Explicit Congestion Notification).
   info_ru: |
     Название RDMA-устройства для связи с Vitastor OSD (например, "rocep5s0f0").
-    Сейчас Vitastor поддерживает все модели адаптеров, включая те, у которых
-    нет поддержки ODP, то есть вы можете использовать RDMA с ConnectX-3 и
-    картами производства не Mellanox.
+    Если не указано, Vitastor попробует найти RoCE-устройство, соответствующее
+    [osd_network](osd.en.md#osd_network), предпочитая RoCEv2, или выбрать первое
+    попавшееся RDMA-устройство, если RoCE-устройств нет или если сеть `osd_network`
+    не задана. Также автовыбор не поддерживается со старыми версиями библиотеки
+    libibverbs < v32, например в Debian 10 Buster или CentOS 7.
 
-    Версии Vitastor до 1.2.0 включительно требовали ODP, который есть только
-    на Mellanox ConnectX 4 и более новых. См. также [rdma_odp](#rdma_odp).
+    Vitastor поддерживает все модели адаптеров, включая те, у которых
+    нет поддержки ODP, то есть вы можете использовать RDMA с ConnectX-3 и
+    картами производства не Mellanox. Версии Vitastor до 1.2.0 включительно
+    требовали ODP, который есть только на Mellanox ConnectX 4 и более новых.
+    См. также [rdma_odp](#rdma_odp).
 
     Запустите `ibv_devinfo -v` от имени суперпользователя, чтобы посмотреть
     список доступных RDMA-устройств, их параметры и возможности.
@@ -94,23 +105,29 @@
     `ibv_devinfo -v`.
 - name: rdma_gid_index
   type: int
-  default: 0
   info: |
     Global address identifier index of the RDMA device to use. Different GID
     indexes may correspond to different protocols like RoCEv1, RoCEv2 and iWARP.
     Search for "GID" in `ibv_devinfo -v` output to determine which GID index
     you need.
 
-    **IMPORTANT:** If you want to use RoCEv2 (as recommended) then the correct
-    rdma_gid_index is usually 1 (IPv6) or 3 (IPv4).
+    If not specified, Vitastor will try to auto-select a RoCEv2 IPv4 GID, then
+    RoCEv2 IPv6 GID, then RoCEv1 IPv4 GID, then RoCEv1 IPv6 GID, then IB GID.
+    GID auto-selection is unsupported with libibverbs < v32.
+
+    A correct rdma_gid_index for RoCEv2 is usually 1 (IPv6) or 3 (IPv4).
   info_ru: |
     Номер глобального идентификатора адреса RDMA-устройства, который следует
     использовать. Разным gid_index могут соответствовать разные протоколы связи:
     RoCEv1, RoCEv2, iWARP. Чтобы понять, какой нужен вам - смотрите строчки со
     словом "GID" в выводе команды `ibv_devinfo -v`.
 
-    **ВАЖНО:** Если вы хотите использовать RoCEv2 (как мы и рекомендуем), то
-    правильный rdma_gid_index, как правило, 1 (IPv6) или 3 (IPv4).
+    Если не указан, Vitastor попробует автоматически выбрать сначала GID,
+    соответствующий RoCEv2 IPv4, потом RoCEv2 IPv6, потом RoCEv1 IPv4, потом
+    RoCEv1 IPv6, потом IB. Авто-выбор GID не поддерживается со старыми версиями
+    libibverbs < v32.
+
+    Правильный rdma_gid_index для RoCEv2, как правило, 1 (IPv6) или 3 (IPv4).
 - name: rdma_mtu
   type: int
   default: 4096

mon/etcd_adapter.js

@@ -232,6 +232,7 @@ class EtcdAdapter
     async become_master()
     {
         const state = { ...this.mon.get_mon_state(), id: ''+this.mon.etcd_lease_id };
+        console.log('Waiting to become master');
         // eslint-disable-next-line no-constant-condition
         while (1)
         {
@@ -243,7 +244,6 @@ class EtcdAdapter
             {
                 break;
             }
-            console.log('Waiting to become master');
             await new Promise(ok => setTimeout(ok, this.mon.config.etcd_start_timeout));
         }
         console.log('Became master');

mon/etcd_schema.js

@@ -56,6 +56,7 @@ const etcd_tree = {
             osd_out_time: 600, // seconds. min: 0
             placement_levels: { datacenter: 1, rack: 2, host: 3, osd: 4, ... },
             use_old_pg_combinator: false,
+            osd_backfillfull_ratio: 0.99,
             // client and osd
             tcp_header_buffer_size: 65536,
             use_sync_send_recv: false,

mon/mon.js

@@ -74,6 +74,7 @@ class Mon
         this.state = JSON.parse(JSON.stringify(etcd_tree));
         this.prev_stats = { osd_stats: {}, osd_diff: {} };
         this.recheck_pgs_active = false;
+        this.updating_total_stats = false;
         this.watcher_active = false;
         this.old_pg_config = false;
         this.old_pg_stats_seen = false;
@@ -658,7 +659,19 @@ class Mon
                 this.etcd_watch_revision, pool_id, up_osds, osd_tree, real_prev_pgs, pool_res.pgs, pg_history);
         }
         new_pg_config.hash = tree_hash;
-        return await this.save_pg_config(new_pg_config, etcd_request);
+        const { backfillfull_pools, backfillfull_osds } = sum_object_counts(
+            { ...this.state, pg: { ...this.state.pg, config: new_pg_config } }, this.config
+        );
+        if (backfillfull_pools.join(',') != ((this.state.pg.config||{}).backfillfull_pools||[]).join(','))
+        {
+            this.log_backfillfull(backfillfull_osds, backfillfull_pools);
+        }
+        new_pg_config.backfillfull_pools = backfillfull_pools.length ? backfillfull_pools : undefined;
+        if (!await this.save_pg_config(new_pg_config, etcd_request))
+        {
+            return false;
+        }
+        return true;
     }
 
     async save_pg_config(new_pg_config, etcd_request = { compare: [], success: [] })
@@ -730,7 +743,7 @@ class Mon
     async update_total_stats()
     {
         const txn = [];
-        const { object_counts, object_bytes } = sum_object_counts(this.state, this.config);
+        const { object_counts, object_bytes, backfillfull_pools, backfillfull_osds } = sum_object_counts(this.state, this.config);
         let stats = sum_op_stats(this.state.osd, this.prev_stats);
         let { inode_stats, seen_pools } = sum_inode_stats(this.state, this.prev_stats);
         stats.object_counts = object_counts;
@@ -783,6 +796,27 @@ class Mon
         {
             await this.etcd.etcd_call('/kv/txn', { success: txn }, this.config.etcd_mon_timeout, 0);
         }
+        if (!this.recheck_pgs_active &&
+            backfillfull_pools.join(',') != ((this.state.pg.config||{}).backfillfull_pools||[]).join(','))
+        {
+            this.log_backfillfull(backfillfull_osds, backfillfull_pools);
+            const new_pg_config = { ...this.state.pg.config, backfillfull_pools: backfillfull_pools.length ? backfillfull_pools : undefined };
+            await this.save_pg_config(new_pg_config);
+        }
+    }
+
+    log_backfillfull(osds, pools)
+    {
+        for (const osd in osds)
+        {
+            const bf = osds[osd];
+            console.log('OSD '+osd+' may fill up during rebalance: capacity '+(bf.cap/1024n/1024n)+
+                ' MB, target user data '+(bf.clean/1024n/1024n)+' MB');
+        }
+        console.log(
+            (pools.length ? 'Pool(s) '+pools.join(', ') : 'No pools')+
+            ' are backfillfull now, applying rebalance configuration'
+        );
     }
 
     schedule_update_stats()
@@ -794,7 +828,21 @@ class Mon
         this.stats_timer = setTimeout(() =>
         {
             this.stats_timer = null;
+            if (this.updating_total_stats)
+            {
+                this.schedule_update_stats();
+                return;
+            }
+            this.updating_total_stats = true;
+            try
+            {
                 this.update_total_stats().catch(console.error);
+            }
+            catch (e)
+            {
+                console.error(e);
+            }
+            this.updating_total_stats = false;
         }, this.config.mon_stats_timeout);
     }
 

mon/stats.js

@@ -109,6 +109,8 @@ function sum_object_counts(state, global_config)
             pgstats[pool_id] = { ...(state.pg.stats[pool_id] || {}), ...(pgstats[pool_id] || {}) };
         }
     }
+    const pool_per_osd = {};
+    const clean_per_osd = {};
     for (const pool_id in pgstats)
     {
         let object_size = 0;
@@ -143,10 +145,45 @@ function sum_object_counts(state, global_config)
                         object_bytes[k] += BigInt(st[k+'_count']) * object_size;
                     }
                 }
+                if (st.object_count)
+                {
+                    for (const pg_osd of (((state.pg.config.items||{})[pool_id]||{})[pg_num]||{}).osd_set||[])
+                    {
+                        if (!(pg_osd in clean_per_osd))
+                        {
+                            clean_per_osd[pg_osd] = 0n;
+                        }
+                        clean_per_osd[pg_osd] += BigInt(st.object_count);
+                        pool_per_osd[pg_osd] = pool_per_osd[pg_osd]||{};
+                        pool_per_osd[pg_osd][pool_id] = true;
                     }
                 }
             }
-    return { object_counts, object_bytes };
+        }
+    }
+    // If clean_per_osd[osd] is larger than osd capacity then it will fill up during rebalance
+    let backfillfull_pools = {};
+    let backfillfull_osds = {};
+    for (const osd in clean_per_osd)
+    {
+        const st = state.osd.stats[osd];
+        if (!st || !st.size || !st.data_block_size)
+        {
+            continue;
+        }
+        let cap = BigInt(st.size)/BigInt(st.data_block_size);
+        cap = cap * BigInt((global_config.osd_backfillfull_ratio||0.99)*1000000) / 1000000n;
+        if (cap < clean_per_osd[osd])
+        {
+            backfillfull_osds[osd] = { cap: BigInt(st.size), clean: clean_per_osd[osd]*BigInt(st.data_block_size) };
+            for (const pool_id in pool_per_osd[osd])
+            {
+                backfillfull_pools[pool_id] = true;
+            }
+        }
+    }
+    backfillfull_pools = Object.keys(backfillfull_pools).sort();
+    return { object_counts, object_bytes, backfillfull_pools, backfillfull_osds };
 }
 
 // sum_inode_stats(this.state, this.prev_stats)

src/CMakeLists.txt

@@ -61,6 +61,10 @@ pkg_check_modules(ISAL libisal)
 if (ISAL_LIBRARIES)
 	add_definitions(-DWITH_ISAL)
 endif (ISAL_LIBRARIES)
+pkg_check_modules(RDMACM librdmacm)
+if (RDMACM_LIBRARIES)
+	add_definitions(-DWITH_RDMACM)
+endif (RDMACM_LIBRARIES)
 
 add_custom_target(build_tests)
 add_custom_target(test

src/client/etcd_state_client.cpp

@@ -785,7 +785,7 @@ void etcd_state_client_t::parse_state(const etcd_kv_t & kv)
         }
         for (auto & pool_item: value.object_items())
         {
-            pool_config_t pc;
+            pool_config_t pc = {};
             // ID
             pool_id_t pool_id;
             char null_byte = 0;
@@ -931,12 +931,28 @@ void etcd_state_client_t::parse_state(const etcd_kv_t & kv)
             // Ignore old key if the new one is present
             return;
         }
+        for (auto & pool_id_json: value["backfillfull_pools"].array_items())
+        {
+            auto pool_id = pool_id_json.uint64_value();
+            auto pool_it = this->pool_config.find(pool_id);
+            if (pool_it != this->pool_config.end())
+            {
+                pool_it->second.backfillfull |= 2;
+            }
+        }
         for (auto & pool_item: this->pool_config)
         {
             for (auto & pg_item: pool_item.second.pg_config)
             {
                 pg_item.second.config_exists = false;
             }
+            // 3 = was 1 and became 1, 0 = was 0 and became 0
+            if (pool_item.second.backfillfull == 2 || pool_item.second.backfillfull == 1)
+            {
+                if (on_change_backfillfull_hook)
+                    on_change_backfillfull_hook(pool_item.first);
+            }
+            pool_item.second.backfillfull = pool_item.second.backfillfull >> 1;
         }
         for (auto & pool_item: value["items"].object_items())
         {

src/client/etcd_state_client.h

@@ -62,6 +62,7 @@ struct pool_config_t
     std::map<pg_num_t, pg_config_t> pg_config;
     uint64_t scrub_interval;
     std::string used_for_fs;
+    int backfillfull;
 };
 
 struct inode_config_t
@@ -131,6 +132,7 @@ public:
     std::function<json11::Json()> load_pgs_checks_hook;
     std::function<void(bool)> on_load_pgs_hook;
     std::function<void()> on_change_pool_config_hook;
+    std::function<void(pool_id_t)> on_change_backfillfull_hook;
     std::function<void(pool_id_t, pg_num_t, osd_num_t)> on_change_pg_state_hook;
     std::function<void(pool_id_t, pg_num_t)> on_change_pg_history_hook;
     std::function<void(osd_num_t)> on_change_osd_state_hook;

src/client/msgr_rdma.cpp

@@ -70,6 +70,7 @@ msgr_rdma_connection_t::~msgr_rdma_connection_t()
     send_out_size = 0;
 }
 
+#ifdef IBV_ADVISE_MR_ADVICE_PREFETCH_NO_FAULT
 static bool is_ipv4_gid(ibv_gid_entry *gidx)
 {
     return (((uint64_t*)gidx->gid.raw)[0] == 0 &&
@@ -131,6 +132,7 @@ static matched_dev match_device(ibv_device **dev_list, addr_mask_t *networks, in
     ibv_port_attr portinfo;
     ibv_gid_entry best_gidx;
     int res;
+    bool have_non_roce = false, have_roce = false;
     for (int i = 0; dev_list[i]; ++i)
     {
         auto dev = dev_list[i];
@@ -161,6 +163,11 @@ static matched_dev match_device(ibv_device **dev_list, addr_mask_t *networks, in
                     else
                         break;
                 }
+                if (gidx.gid_type != IBV_GID_TYPE_ROCE_V1 &&
+                    gidx.gid_type != IBV_GID_TYPE_ROCE_V2)
+                    have_non_roce = true;
+                else
+                    have_roce = true;
                 if (match_gid(&gidx, networks, nnet))
                 {
                     // Prefer RoCEv2
@@ -186,8 +193,13 @@ cleanup:
     {
         log_rdma_dev_port_gid(dev_list[best.dev], best.port, best.gid, best_gidx);
     }
+    if (best.dev < 0 && have_non_roce && !have_roce)
+    {
+        best.dev = -2;
+    }
     return best;
 }
+#endif
 
 msgr_rdma_context_t *msgr_rdma_context_t::create(std::vector<std::string> osd_networks, const char *ib_devname, uint8_t ib_port, uint8_t gid_index, uint32_t mtu, bool odp, int log_level)
 {
@@ -229,6 +241,7 @@ msgr_rdma_context_t *msgr_rdma_context_t::create(std::vector<std::string> osd_ne
             goto cleanup;
         }
     }
+#ifdef IBV_ADVISE_MR_ADVICE_PREFETCH_NO_FAULT
     else if (osd_networks.size())
     {
         std::vector<addr_mask_t> nets;
@@ -237,11 +250,17 @@ msgr_rdma_context_t *msgr_rdma_context_t::create(std::vector<std::string> osd_ne
             nets.push_back(cidr_parse(netstr));
         }
         auto best = match_device(dev_list, nets.data(), nets.size(), log_level);
-        if (best.dev < 0)
+        if (best.dev == -2)
+        {
+            best.dev = 0;
+            if (log_level > 0)
+                fprintf(stderr, "No RoCE devices found, using first available RDMA device %s\n", ibv_get_device_name(*dev_list));
+        }
+        else if (best.dev < 0)
         {
             if (log_level > 0)
-                fprintf(stderr, "RDMA device matching osd_network is not found, using first available device\n");
-            best.dev = 0;
+                fprintf(stderr, "RDMA device matching osd_network is not found, disabling RDMA\n");
+            goto cleanup;
         }
         else
         {
@@ -250,6 +269,7 @@ msgr_rdma_context_t *msgr_rdma_context_t::create(std::vector<std::string> osd_ne
         }
         ctx->dev = dev_list[best.dev];
     }
+#endif
     else
     {
         ctx->dev = *dev_list;
@@ -275,18 +295,22 @@ msgr_rdma_context_t *msgr_rdma_context_t::create(std::vector<std::string> osd_ne
         goto cleanup;
     }
 
+#ifdef IBV_ADVISE_MR_ADVICE_PREFETCH_NO_FAULT
     if (gid_index != -1)
+#endif
     {
-        ctx->gid_index = gid_index;
-        if (ibv_query_gid_ex(ctx->context, ib_port, gid_index, &ctx->my_gid, 0))
+        ctx->gid_index = gid_index < 0 ? 0 : gid_index;
+        if (ibv_query_gid(ctx->context, ib_port, gid_index, &ctx->my_gid))
         {
             fprintf(stderr, "Couldn't read RDMA device %s GID index %d\n", ibv_get_device_name(ctx->dev), gid_index);
             goto cleanup;
         }
     }
+#ifdef IBV_ADVISE_MR_ADVICE_PREFETCH_NO_FAULT
     else
     {
         // Auto-guess GID
+        ibv_gid_entry best_gidx;
         for (int k = 0; k < ctx->portinfo.gid_tbl_len; k++)
         {
             ibv_gid_entry gidx;
@@ -301,21 +325,24 @@ msgr_rdma_context_t *msgr_rdma_context_t::create(std::vector<std::string> osd_ne
             {
                 continue;
             }
-            // Prefer IPv4 RoCEv2 GID by default
+            // Prefer IPv4 RoCEv2 -> IPv6 RoCEv2 -> IPv4 RoCEv1 -> IPv6 RoCEv1 -> IB
             if (gid_index == -1 ||
-                gidx.gid_type == IBV_GID_TYPE_ROCE_V2 &&
-                (ctx->my_gid.gid_type != IBV_GID_TYPE_ROCE_V2 || is_ipv4_gid(&gidx)))
+                gidx.gid_type == IBV_GID_TYPE_ROCE_V2 && best_gidx.gid_type != IBV_GID_TYPE_ROCE_V2 ||
+                gidx.gid_type == IBV_GID_TYPE_ROCE_V1 && best_gidx.gid_type == IBV_GID_TYPE_IB ||
+                gidx.gid_type == best_gidx.gid_type && is_ipv4_gid(&gidx))
             {
                 gid_index = k;
-                ctx->my_gid = gidx;
+                best_gidx = gidx;
             }
         }
         ctx->gid_index = gid_index = (gid_index == -1 ? 0 : gid_index);
         if (log_level > 0)
         {
-            log_rdma_dev_port_gid(ctx->dev, ctx->ib_port, ctx->gid_index, ctx->my_gid);
+            log_rdma_dev_port_gid(ctx->dev, ctx->ib_port, ctx->gid_index, best_gidx);
         }
+        ctx->my_gid = best_gidx.gid;
     }
+#endif
 
     ctx->pd = ibv_alloc_pd(ctx->context);
     if (!ctx->pd)
@@ -431,7 +458,7 @@ msgr_rdma_connection_t *msgr_rdma_connection_t::create(msgr_rdma_context_t *ctx,
     }
 
     conn->addr.lid = ctx->my_lid;
-    conn->addr.gid = ctx->my_gid.gid;
+    conn->addr.gid = ctx->my_gid;
     conn->addr.qpn = conn->qp->qp_num;
     conn->addr.psn = lrand48() & 0xffffff;
 

src/client/msgr_rdma.h

@@ -31,7 +31,7 @@ struct msgr_rdma_context_t
     uint8_t ib_port;
     uint8_t gid_index;
     uint16_t my_lid;
-    ibv_gid_entry my_gid;
+    ibv_gid my_gid;
     uint32_t mtu;
     int max_cqe = 0;
     int used_max_cqe = 0;

src/client/nbd_proxy.cpp

@@ -64,7 +64,7 @@ static void netlink_sock_alloc(struct netlink_ctx *ctx)
     if (nl_driver_id < 0)
     {
         nl_socket_free(sk);
-        fail("Couldn't resolve the nbd netlink family\n");
+        fail("Couldn't resolve the nbd netlink family: %s (code %d)\n", nl_geterror(nl_driver_id), nl_driver_id);
     }
 
     ctx->driver_id = nl_driver_id;
@@ -555,7 +555,12 @@ help:
         fcntl(sockfd[0], F_SETFL, fcntl(sockfd[0], F_GETFL, 0) | O_NONBLOCK);
         nbd_fd = sockfd[0];
         load_module();
+
         bool bg = cfg["foreground"].is_null();
+        if (cfg["logfile"].string_value() != "")
+        {
+            logfile = cfg["logfile"].string_value();
+        }
 
         if (netlink)
         {
@@ -588,6 +593,10 @@ help:
             }
             close(sockfd[1]);
             printf("/dev/nbd%d\n", err);
+            if (bg)
+            {
+                daemonize_reopen_stdio();
+            }
 #else
             fprintf(stderr, "netlink support is disabled in this build\n");
             exit(1);
@@ -631,15 +640,11 @@ help:
                     }
                 }
             }
-        }
-        if (cfg["logfile"].string_value() != "")
-        {
-            logfile = cfg["logfile"].string_value();
-        }
             if (bg)
             {
                 daemonize();
             }
+        }
         // Initialize read state
         read_state = CL_READ_HDR;
         recv_buf = malloc_or_die(receive_buffer_size);
@@ -716,13 +721,17 @@ help:
         }
     }
 
-    void daemonize()
+    void daemonize_fork()
     {
         if (fork())
             exit(0);
         setsid();
         if (fork())
             exit(0);
+    }
+
+    void daemonize_reopen_stdio()
+    {
         close(0);
         close(1);
         close(2);
@@ -733,6 +742,12 @@ help:
             fprintf(stderr, "Warning: Failed to chdir into /\n");
     }
 
+    void daemonize()
+    {
+        daemonize_fork();
+        daemonize_reopen_stdio();
+    }
+
     json11::Json::object list_mapped()
     {
         const char *self_filename = exe_name;
@@ -783,8 +798,9 @@ help:
                 if (!strcmp(pid_filename, self_filename))
                 {
                     json11::Json::object cfg = nbd_proxy::parse_args(argv.size(), argv.data());
-                    if (cfg["command"] == "map")
+                    if (cfg["command"] == "map" || cfg["command"] == "netlink-map")
                     {
+                        cfg["interface"] = (cfg["command"] == "netlink-map") ? "netlink" : "nbd";
                         cfg.erase("command");
                         cfg["pid"] = pid;
                         mapped["/dev/nbd"+std::to_string(dev_num)] = cfg;

src/cmd/cli_dd.cpp

@@ -261,6 +261,7 @@ struct dd_out_info_t
             else
             {
                 // ok
+                out_size = owatch->cfg.size;
                 return true;
             }
             // Wait for sub-command
@@ -882,6 +883,8 @@ resume_2:
         oinfo.end_fsync = oinfo.end_fsync && oinfo.out_seekable;
         read_offset = 0;
         read_end = iinfo.in_seekable ? iinfo.in_size-iseek : 0;
+        if (oinfo.out_size && (!read_end || read_end > oinfo.out_size-oseek))
+            read_end = oinfo.out_size-oseek;
         if (bytelimit && (!read_end || read_end > bytelimit))
             read_end = bytelimit;
         clock_gettime(CLOCK_REALTIME, &tv_begin);

src/cmd/cli_pool_create.cpp

@@ -35,6 +35,7 @@ struct pool_creator_t
     uint64_t new_pools_mod_rev;
     json11::Json state_node_tree;
     json11::Json new_pools;
+    std::map<osd_num_t, json11::Json> osd_stats;
 
     bool is_done() { return state == 100; }
 
@@ -46,8 +47,6 @@ struct pool_creator_t
             goto resume_2;
         else if (state == 3)
             goto resume_3;
-        else if (state == 4)
-            goto resume_4;
         else if (state == 5)
             goto resume_5;
         else if (state == 6)
@@ -90,13 +89,19 @@ resume_1:
         // If not forced, check that we have enough osds for pg_size
         if (!force)
         {
-            // Get node_placement configuration from etcd
+            // Get node_placement configuration from etcd and OSD stats
             parent->etcd_txn(json11::Json::object {
                 { "success", json11::Json::array {
                     json11::Json::object {
                         { "request_range", json11::Json::object {
                             { "key", base64_encode(parent->cli->st_cli.etcd_prefix+"/config/node_placement") },
-                        } }
+                        } },
+                    },
+                    json11::Json::object {
+                        { "request_range", json11::Json::object {
+                            { "key", base64_encode(parent->cli->st_cli.etcd_prefix+"/osd/stats/") },
+                            { "range_end", base64_encode(parent->cli->st_cli.etcd_prefix+"/osd/stats0") },
+                        } },
                     },
                 } },
             });
@@ -112,10 +117,21 @@ resume_2:
                 return;
             }
 
-            // Get state_node_tree based on node_placement and osd peer states
+            // Get state_node_tree based on node_placement and osd stats
             {
-                auto kv = parent->cli->st_cli.parse_etcd_kv(parent->etcd_result["responses"][0]["response_range"]["kvs"][0]);
-                state_node_tree = get_state_node_tree(kv.value.object_items());
+                auto node_placement_kv = parent->cli->st_cli.parse_etcd_kv(parent->etcd_result["responses"][0]["response_range"]["kvs"][0]);
+                timespec tv_now;
+                clock_gettime(CLOCK_REALTIME, &tv_now);
+                uint64_t osd_out_time = parent->cli->config["osd_out_time"].uint64_value();
+                if (!osd_out_time)
+                    osd_out_time = 600;
+                osd_stats.clear();
+                parent->iterate_kvs_1(parent->etcd_result["responses"][1]["response_range"]["kvs"], "/osd/stats/", [&](uint64_t cur_osd, json11::Json value)
+                {
+                    if ((uint64_t)value["time"].number_value()+osd_out_time >= tv_now.tv_sec)
+                        osd_stats[cur_osd] = value;
+                });
+                state_node_tree = get_state_node_tree(node_placement_kv.value.object_items(), osd_stats);
             }
 
             // Skip tag checks, if pool has none
@@ -158,42 +174,18 @@ resume_3:
                 }
             }
 
-            // Get stats (for block_size, bitmap_granularity, ...) of osds in state_node_tree
-            {
-                json11::Json::array osd_stats;
-
-                for (auto osd_num: state_node_tree["osds"].array_items())
-                {
-                    osd_stats.push_back(json11::Json::object {
-                        { "request_range", json11::Json::object {
-                            { "key", base64_encode(parent->cli->st_cli.etcd_prefix+"/osd/stats/"+osd_num.as_string()) },
-                        } }
-                    });
-                }
-
-                parent->etcd_txn(json11::Json::object{ { "success", osd_stats } });
-            }
-
-            state = 4;
-resume_4:
-            if (parent->waiting > 0)
-                return;
-            if (parent->etcd_err.err)
-            {
-                result = parent->etcd_err;
-                state = 100;
-                return;
-            }
-
             // Filter osds from state_node_tree based on pool parameters and osd stats
             {
-                std::vector<json11::Json> osd_stats;
-                for (auto & ocr: parent->etcd_result["responses"].array_items())
+                std::vector<json11::Json> filtered_osd_stats;
+                for (auto & osd_num: state_node_tree["osds"].array_items())
                 {
-                    auto kv = parent->cli->st_cli.parse_etcd_kv(ocr["response_range"]["kvs"][0]);
-                    osd_stats.push_back(kv.value);
+                    auto st_it = osd_stats.find(osd_num.uint64_value());
+                    if (st_it != osd_stats.end())
+                    {
+                        filtered_osd_stats.push_back(st_it->second);
                     }
-                guess_block_size(osd_stats);
+                }
+                guess_block_size(filtered_osd_stats);
                 state_node_tree = filter_state_node_tree_by_stats(state_node_tree, osd_stats);
             }
 
@@ -201,8 +193,7 @@ resume_4:
             {
                 auto failure_domain = cfg["failure_domain"].string_value() == ""
                     ? "host" : cfg["failure_domain"].string_value();
-                uint64_t max_pg_size = get_max_pg_size(state_node_tree["nodes"].object_items(),
-                    failure_domain, cfg["root_node"].string_value());
+                uint64_t max_pg_size = get_max_pg_size(state_node_tree, failure_domain, cfg["root_node"].string_value());
 
                 if (cfg["pg_size"].uint64_value() > max_pg_size)
                 {
@@ -358,42 +349,35 @@ resume_8:
 
     // Returns a JSON object of form {"nodes": {...}, "osds": [...]} that
     // contains: all nodes (osds, hosts, ...) based on node_placement config
-    // and current peer state, and a list of active peer osds.
-    json11::Json get_state_node_tree(json11::Json::object node_placement)
+    // and current osd stats.
+    json11::Json get_state_node_tree(json11::Json::object node_placement, std::map<osd_num_t, json11::Json> & osd_stats)
     {
-        // Erase non-peer osd nodes from node_placement
+        // Erase non-existing osd nodes from node_placement
         for (auto np_it = node_placement.begin(); np_it != node_placement.end();)
         {
             // Numeric nodes are osds
             osd_num_t osd_num = stoull_full(np_it->first);
 
-            // If node is osd and it is not in peer states, erase it
-            if (osd_num > 0 &&
-                parent->cli->st_cli.peer_states.find(osd_num) == parent->cli->st_cli.peer_states.end())
-            {
+            // If node is osd and its stats do not exist, erase it
+            if (osd_num > 0 && osd_stats.find(osd_num) == osd_stats.end())
                 node_placement.erase(np_it++);
-            }
             else
                 np_it++;
         }
 
-        // List of peer osds
-        std::vector<std::string> peer_osds;
+        // List of osds
+        std::vector<std::string> existing_osds;
 
-        // Record peer osds and add missing osds/hosts to np
-        for (auto & ps: parent->cli->st_cli.peer_states)
+        // Record osds and add missing osds/hosts to np
+        for (auto & ps: osd_stats)
         {
             std::string osd_num = std::to_string(ps.first);
 
-            // Record peer osd
-            peer_osds.push_back(osd_num);
+            // Record osd
+            existing_osds.push_back(osd_num);
 
-            // Add osd, if necessary
-            if (node_placement.find(osd_num) == node_placement.end())
-            {
+            // Add host if necessary
             std::string osd_host = ps.second["host"].as_string();
-
-                // Add host, if necessary
             if (node_placement.find(osd_host) == node_placement.end())
             {
                 node_placement[osd_host] = json11::Json::object {
@@ -401,13 +385,14 @@ resume_8:
                 };
             }
 
+            // Add osd
             node_placement[osd_num] = json11::Json::object {
-                    { "parent", osd_host }
+                { "parent", node_placement[osd_num]["parent"].is_null() ? osd_host : node_placement[osd_num]["parent"] },
+                { "level", "osd" },
             };
         }
-        }
 
-        return json11::Json::object { { "osds", peer_osds }, { "nodes", node_placement } };
+        return json11::Json::object { { "osds", existing_osds }, { "nodes", node_placement } };
     }
 
     // Returns new state_node_tree based on given state_node_tree with osds
@@ -534,15 +519,13 @@ resume_8:
     // filtered out by stats parameters (block_size, bitmap_granularity) in
     // given osd_stats and current pool config.
     // Requires: state_node_tree["osds"] must match osd_stats 1-1
-    json11::Json filter_state_node_tree_by_stats(const json11::Json & state_node_tree, std::vector<json11::Json> & osd_stats)
+    json11::Json filter_state_node_tree_by_stats(const json11::Json & state_node_tree, std::map<osd_num_t, json11::Json> & osd_stats)
     {
-        auto & osds = state_node_tree["osds"].array_items();
-
         // Accepted state_node_tree nodes
         auto accepted_nodes = state_node_tree["nodes"].object_items();
 
         // List of accepted osds
-        std::vector<std::string> accepted_osds;
+        json11::Json::array accepted_osds;
 
         block_size = cfg["block_size"].uint64_value()
             ? cfg["block_size"].uint64_value()
@@ -554,21 +537,25 @@ resume_8:
             ? etcd_state_client_t::parse_immediate_commit(cfg["immediate_commit"].string_value(), IMMEDIATE_ALL)
             : parent->cli->st_cli.global_immediate_commit;
 
-        for (size_t i = 0; i < osd_stats.size(); i++)
+        for (auto osd_num_json: state_node_tree["osds"].array_items())
         {
-            auto & os = osd_stats[i];
-            // Get osd number
-            auto osd_num = osds[i].as_string();
+            auto osd_num = osd_num_json.uint64_value();
+            auto os_it = osd_stats.find(osd_num);
+            if (os_it == osd_stats.end())
+            {
+                continue;
+            }
+            auto & os = os_it->second;
             if (!os["data_block_size"].is_null() && os["data_block_size"] != block_size ||
                 !os["bitmap_granularity"].is_null() && os["bitmap_granularity"] != bitmap_granularity ||
                 !os["immediate_commit"].is_null() &&
                 etcd_state_client_t::parse_immediate_commit(os["immediate_commit"].string_value(), IMMEDIATE_NONE) < immediate_commit)
             {
-                accepted_nodes.erase(osd_num);
+                accepted_nodes.erase(osd_num_json.as_string());
             }
             else
             {
-                accepted_osds.push_back(osd_num);
+                accepted_osds.push_back(osd_num_json);
             }
         }
 
@@ -576,87 +563,28 @@ resume_8:
     }
 
     // Returns maximum pg_size possible for given node_tree and failure_domain, starting at parent_node
-    uint64_t get_max_pg_size(json11::Json::object node_tree, const std::string & level, const std::string & parent_node)
+    uint64_t get_max_pg_size(json11::Json state_node_tree, const std::string & level, const std::string & root_node)
     {
-        uint64_t max_pg_sz = 0;
-
-        std::vector<std::string> nodes;
-
-        // Check if parent node is an osd (numeric)
-        if (parent_node != "" && stoull_full(parent_node))
+        std::set<std::string> level_seen;
+        for (auto & osd: state_node_tree["osds"].array_items())
         {
-            // Add it to node list if osd is in node tree
-            if (node_tree.find(parent_node) != node_tree.end())
-                nodes.push_back(parent_node);
-        }
-        // If parent node given, ...
-        else if (parent_node != "")
+            // find OSD parent at <level>, but stop at <root_node>
+            auto cur_id = osd.string_value();
+            auto cur = state_node_tree["nodes"][cur_id];
+            while (!cur.is_null())
             {
-            // ... look for children nodes of this parent
-            for (auto & sn: node_tree)
+                if (cur["level"] == level)
                 {
-                auto & props = sn.second.object_items();
-
-                auto parent_prop = props.find("parent");
-                if (parent_prop != props.end() && (parent_prop->second.as_string() == parent_node))
-                {
-                    nodes.push_back(sn.first);
-
-                    // If we're not looking for all osds, we only need a single
-                    // child osd node
-                    if (level != "osd" && stoull_full(sn.first))
+                    level_seen.insert(cur_id);
                     break;
                 }
+                if (cur_id == root_node)
+                    break;
+                cur_id = cur["parent"].string_value();
+                cur = state_node_tree["nodes"][cur_id];
             }
         }
-        // No parent node given, and we're not looking for all osds
-        else if (level != "osd")
-        {
-            // ... look for all level nodes
-            for (auto & sn: node_tree)
-            {
-                auto & props = sn.second.object_items();
-
-                auto level_prop = props.find("level");
-                if (level_prop != props.end() && (level_prop->second.as_string() == level))
-                {
-                    nodes.push_back(sn.first);
-                }
-            }
-        }
-        // Otherwise, ...
-        else
-        {
-            // ... we're looking for osd nodes only
-            for (auto & sn: node_tree)
-            {
-                if (stoull_full(sn.first))
-                {
-                    nodes.push_back(sn.first);
-                }
-            }
-        }
-
-        // Process gathered nodes
-        for (auto & node: nodes)
-        {
-            // Check for osd node, return constant max size
-            if (stoull_full(node))
-            {
-                max_pg_sz += 1;
-            }
-            // Otherwise, ...
-            else
-            {
-                // ... exclude parent node from tree, and ...
-                node_tree.erase(parent_node);
-
-                // ... descend onto the resulting tree
-                max_pg_sz += get_max_pg_size(node_tree, level, node);
-            }
-        }
-
-        return max_pg_sz;
+        return level_seen.size();
     }
 
     json11::Json create_pool(const etcd_kv_t & kv)

src/nfs/nfs_block.cpp

@@ -315,7 +315,7 @@ static int block_nfs3_read_proc(void *opaque, rpc_op_t *rop)
     if (aligned_count % alignment)
         aligned_count = aligned_count + alignment - (aligned_count % alignment);
     aligned_count -= aligned_offset;
-    void *buf = malloc_or_die(aligned_count);
+    void *buf = malloc_or_die(aligned_count); // тут нужен RDMA-доступный буфер
     xdr_add_malloc(rop->xdrs, buf);
     cluster_op_t *op = new cluster_op_t;
     op->opcode = OSD_OP_READ;

src/nfs/nfs_proxy.cpp

@@ -499,6 +499,19 @@ void nfs_proxy_t::check_default_pool()
     }
 }
 
+void nfs_proxy_t::create_client()
+{
+    auto cli = new nfs_client_t();
+    cli->parent = this->proxy;
+    if (kvfs)
+        nfs_kv_procs(cli);
+    else
+        nfs_block_procs(cli);
+    for (auto & fn: pmap.proc_table)
+        cli->proc_table.insert(fn);
+    rpc_clients.insert(cli);
+}
+
 void nfs_proxy_t::do_accept(int listen_fd)
 {
     struct sockaddr_storage addr;
@@ -512,18 +525,8 @@ void nfs_proxy_t::do_accept(int listen_fd)
         fcntl(nfs_fd, F_SETFL, fcntl(nfs_fd, F_GETFL, 0) | O_NONBLOCK);
         int one = 1;
         setsockopt(nfs_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
-        auto cli = new nfs_client_t();
-        if (kvfs)
-            nfs_kv_procs(cli);
-        else
-            nfs_block_procs(cli);
-        cli->parent = this;
+        auto cli = this->create_client();
         cli->nfs_fd = nfs_fd;
-        for (auto & fn: pmap.proc_table)
-        {
-            cli->proc_table.insert(fn);
-        }
-        rpc_clients[nfs_fd] = cli;
         epmgr->tfd->set_fd_handler(nfs_fd, true, [cli](int nfs_fd, int epoll_events)
         {
             // Handle incoming event
@@ -781,7 +784,7 @@ void nfs_client_t::stop()
     if (refs <= 0)
     {
         auto parent = this->parent;
-        parent->rpc_clients.erase(nfs_fd);
+        parent->rpc_clients.erase(this);
         parent->active_connections--;
         parent->epmgr->tfd->set_fd_handler(nfs_fd, true, NULL);
         close(nfs_fd);
@@ -885,6 +888,8 @@ void rpc_queue_reply(rpc_op_t *rop)
         r = xdr_encode(rop->xdrs, rop->reply_fn, rop->reply);
         assert(r);
     }
+    if (!self->rdma_conn)
+    {
         xdr_encode_finish(rop->xdrs, &iov_list, &iov_count);
         assert(iov_count > 0);
         rop->reply_marker = 0;
@@ -904,6 +909,11 @@ void rpc_queue_reply(rpc_op_t *rop)
         }
         to_outbox[to_outbox.size()-1] = rop;
         self->submit_send();
+    }
+    else
+    {
+        self->rdma_conn->queue_reply(rop, iov_list, iov_count);
+    }
 }
 
 int nfs_client_t::handle_rpc_message(void *base_buf, void *msg_buf, uint32_t msg_len)
@@ -968,6 +978,11 @@ int nfs_client_t::handle_rpc_message(void *base_buf, void *msg_buf, uint32_t msg
         // Incoming buffer isn't needed to handle request, so return 0
         return 0;
     }
+    return handle_rpc_body(xdrs, &inmsg);
+}
+
+int nfs_client_t::handle_rpc_body(XDR *xdrs, rpc_msg *inmsg, rdma_msg *rmsg)
+{
     // Find decoder for the request
     auto proc_it = proc_table.find((rpc_service_proc_t){
         .prog = inmsg->body.cbody.prog,
@@ -1045,7 +1060,12 @@ int nfs_client_t::handle_rpc_message(void *base_buf, void *msg_buf, uint32_t msg
         .request = ((uint8_t*)rop) + sizeof(rpc_op_t),
         .reply = ((uint8_t*)rop) + sizeof(rpc_op_t) + proc_it->req_size,
     };
+    // FIXME: malloc and avoid copy?
     memcpy(&rop->in_msg, inmsg, sizeof(rpc_msg));
+    if (rmsg)
+    {
+        memcpy(&rop->in_rdma_msg, rmsg, sizeof(rdma_msg));
+    }
     // Try to decode the request
     // req_fn may be NULL, that means function has no arguments
     if (proc_it->req_fn && !proc_it->req_fn(xdrs, rop->request))
@@ -1068,8 +1088,8 @@ void nfs_proxy_t::daemonize()
     // Stop all clients because client I/O sometimes breaks during daemonize
     // I.e. the new process stops receiving events on the old FD
     // It doesn't happen if we call sleep(1) here, but we don't want to call sleep(1)...
-    for (auto & clp: rpc_clients)
-        clp.second->stop();
+    for (auto & cli: rpc_clients)
+        cli->stop();
     if (fork())
         exit(0);
     setsid();

src/nfs/nfs_proxy.h

@@ -55,7 +55,7 @@ public:
     vitastorkv_dbw_t *db = NULL;
     kv_fs_state_t *kvfs = NULL;
     block_fs_state_t *blockfs = NULL;
-    std::map<int, nfs_client_t*> rpc_clients;
+    std::set<nfs_client_t*> rpc_clients;
 
     std::vector<XDR*> xdr_pool;
 
@@ -72,6 +72,7 @@ public:
     void watch_stats();
     void parse_stats(etcd_kv_t & kv);
     void check_default_pool();
+    nfs_client_t* create_client();
     void do_accept(int listen_fd);
     void daemonize();
     void write_pid();
@@ -101,15 +102,20 @@ struct rpc_free_buffer_t
     unsigned size;
 };
 
+struct nfs_rdma_conn_t;
+
 class nfs_client_t
 {
 public:
     nfs_proxy_t *parent = NULL;
-    int nfs_fd;
-    int epoll_events = 0;
     int refs = 0;
     bool stopped = false;
     std::set<rpc_service_proc_t> proc_table;
+    nfs_rdma_conn_t *rdma_conn = NULL;
+
+    // <TCP>
+    int nfs_fd;
+    int epoll_events = 0;
 
     // Read state
     rpc_cur_buffer_t cur_buffer = { 0 };
@@ -130,7 +136,9 @@ public:
     void submit_send();
     void handle_send(int result);
     int handle_rpc_message(void *base_buf, void *msg_buf, uint32_t msg_len);
+    // </TCP>
 
+    int handle_rpc_body(XDR *xdrs, rpc_msg *inmsg, rdma_msg *rmsg);
     bool deref();
     void stop();
 };

src/nfs/nfs_proxy_rdma.cpp

@@ -0,0 +1,697 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+//
+// NFS RDMA support
+
+#define _XOPEN_SOURCE
+#include <limits.h>
+
+#include <netinet/tcp.h>
+#include <sys/epoll.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#include "proto/nfs.h"
+#include "proto/rpc.h"
+#include "proto/portmap.h"
+
+#include "addr_util.h"
+#include "str_util.h"
+#include "json_util.h"
+#include "nfs_proxy.h"
+#include "nfs_kv.h"
+#include "nfs_block.h"
+#include "nfs_common.h"
+#include "http_client.h"
+#include "cli.h"
+
+#define NFS_RDMACM_PRIVATE_DATA_MAGIC_LE 0x180eabf6
+
+struct __attribute__((__packed__)) nfs_rdmacm_private
+{
+    uint32_t format_identifier; // magic, should be 0xf6ab0e18 in big endian
+    uint8_t version;            // version, 1
+    uint8_t remote_invalidate;  // remote invalidation flag (1 or 0)
+    uint8_t max_send_size;      // maximum RDMA Send operation size / 1024 - 1 (i.e. 0 is 1 KB, 255 is 256 KB)
+    uint8_t max_recv_size;      // maximum RDMA Receive operation size / 1024 - 1 (i.e. 0 is 1 KB, 255 is 256 KB)
+};
+
+struct nfs_rdma_context_t
+{
+    std::string bind_address;
+    int rdmacm_port = 0;
+    int max_send = 8, max_recv = 8; --- FIXME max_send and max_recv should probably be equal
+    uint64_t max_send_size = 256*1024, max_recv_size = 256*1024;
+
+    nfs_proxy_t *proxy = NULL;
+    epoll_manager_t *epmgr = NULL;
+
+    int max_cqe = 0, used_max_cqe = 0;
+    rdma_event_channel *rdmacm_evch = NULL;
+    rdma_cm_id *listener_id = NULL;
+    ibv_comp_channel *channel = NULL;
+    ibv_cq *cq = NULL;
+};
+
+struct nfs_rdma_buf_t
+{
+    void *buf = NULL;
+    size_t len = 0;
+    ibv_mr *mr = NULL;
+};
+
+struct nfs_rdma_conn_t
+{
+    rdma_cm_id *id = NULL;
+    int max_send = 8, max_recv = 8;
+    bool established = false;
+    std::vector<nfs_rdma_buf_t> recv_buffers;
+    int next_recv_buf = 0;
+    std::vector<nfs_rdma_buf_t> send_buffers;
+    std::vector<rpc_op_t*> outbox;
+    int outbox_pos = 0;
+};
+
+nfs_rdma_context_t* nfs_proxy_t::create_rdma(const std::string & bind_address, int rdmacm_port)
+{
+    nfs_rdma_context_t* self = new nfs_rdma_context_t;
+    self->proxy = this;
+    self->epmgr = epmgr;
+    self->bind_address = bind_address;
+    self->rdmacm_port = rdmacm_port;
+    self->rdmacm_evch = rdma_create_event_channel();
+    if (!self->rdmacm_evch)
+    {
+        fprintf(stderr, "Failed to initialize RDMA-CM event channel: %s (code %d)\n", strerror(errno), errno);
+        delete self;
+        return NULL;
+    }
+    fcntl(self->rdmacm_evch->fd, F_SETFL, fcntl(self->rdmacm_evch->fd, F_GETFL, 0) | O_NONBLOCK);
+    epmgr->tfd->set_fd_handler(self->rdmacm_evch->fd, false, [this](int rdmacm_eventfd, int epoll_events)
+    {
+        self->handle_rdmacm_events();
+    });
+    int r = rdma_create_id(self->rdmacm_evch, &self->listener_id, NULL, RDMA_PS_TCP);
+    if (r != 0)
+    {
+        fprintf(stderr, "Failed to create RDMA-CM ID: %s (code %d)\n", strerror(errno), errno);
+        delete self;
+        return NULL;
+    }
+    sockaddr_storage addr;
+    if (!string_to_addr(bind_address, 0, rdmacm_port, &addr))
+    {
+        fprintf(stderr, "Server address: %s is not valid\n", bind_address.c_str());
+        delete self;
+        return NULL;
+    }
+    r = rdma_bind_addr(self->listener_id, (sockaddr*)&addr);
+    if (r != 0)
+    {
+        fprintf(stderr, "Failed to bind RDMA-CM to %s:%d: %s (code %d)\n", bind_address.c_str(), rdmacm_port, strerror(errno), errno);
+        delete self;
+        return NULL;
+    }
+    r = rdma_listen(self->listener_id, 128);
+    if (r != 0)
+    {
+        fprintf(stderr, "Failed to listen RDMA-CM: %s (code %d)\n", strerror(errno), errno);
+        delete self;
+        return NULL;
+    }
+    self->channel = ibv_create_comp_channel(self->listener_id->ibv_context);
+    if (!self->channel)
+    {
+        fprintf(stderr, "Couldn't create RDMA completion channel\n");
+        delete self;
+        return NULL;
+    }
+    fcntl(self->channel->fd, F_SETFL, fcntl(self->channel->fd, F_GETFL, 0) | O_NONBLOCK);
+    epmgr->tfd->set_fd_handler(self->channel->fd, false, [this](int channel_eventfd, int epoll_events)
+    {
+        handle_io();
+    });
+    self->max_cqe = 4096;
+    self->cq = ibv_create_cq(self->listener_id->ibv_context, self->max_cqe, NULL, self->channel, 0);
+    if (!self->cq)
+    {
+        fprintf(stderr, "Couldn't create RDMA completion queue\n");
+        delete self;
+        return NULL;
+    }
+    return self;
+}
+
+nfs_rdma_context_t::~nfs_rdma_context_t()
+{
+    if (listener_id)
+    {
+        int r = rdma_destroy_id(listener_id);
+        if (r != 0)
+            fprintf(stderr, "Failed to destroy RDMA-CM ID: %s (code %d)\n", strerror(errno), errno);
+        else
+            listener_id = NULL;
+    }
+    if (rdmacm_evch)
+    {
+        epmgr->tfd->set_fd_handler(rdmacm_evch->fd, false, NULL);
+        rdma_destroy_event_channel(rdmacm_evch);
+        rdmacm_evch = NULL;
+    }
+    if (cq)
+    {
+        ibv_destroy_cq(cq);
+        cq = NULL;
+    }
+    if (channel)
+    {
+        ibv_destroy_comp_channel(channel);
+        channel = NULL;
+    }
+    //if (mr)
+    //    ibv_dereg_mr(mr);
+    //if (pd)
+    //    ibv_dealloc_pd(pd);
+    //if (context)
+    //    ibv_close_device(context);
+}
+
+void nfs_proxy_t::handle_rdmacm_events()
+{
+    rdma_cm_event *ev = NULL;
+    while (1)
+    {
+        int r = rdma_get_cm_event(rdmacm_evch, &ev);
+        if (r != 0)
+        {
+            if (errno == EAGAIN || errno == EINTR)
+                break;
+            fprintf(stderr, "Failed to get RDMA-CM event: %s (code %d)\n", strerror(errno), errno);
+            exit(1);
+        }
+        if (ev->event == RDMA_CM_EVENT_CONNECT_REQUEST)
+        {
+            rdmacm_accept(ev);
+        }
+        else if (ev->event == RDMA_CM_EVENT_CONNECT_ERROR ||
+            ev->event == RDMA_CM_EVENT_REJECTED ||
+            ev->event == RDMA_CM_EVENT_DISCONNECTED ||
+            ev->event == RDMA_CM_EVENT_DEVICE_REMOVAL)
+        {
+            auto event_type_name = ev->event == RDMA_CM_EVENT_CONNECT_ERROR ? "RDMA_CM_EVENT_CONNECT_ERROR" : (
+                ev->event == RDMA_CM_EVENT_REJECTED ? "RDMA_CM_EVENT_REJECTED" : (
+                ev->event == RDMA_CM_EVENT_DISCONNECTED ? "RDMA_CM_EVENT_DISCONNECTED" : "RDMA_CM_EVENT_DEVICE_REMOVAL"));
+            auto conn_it = rdma_connections.find(ev->id);
+            if (conn_it == rdma_connections.end())
+            {
+                fprintf(stderr, "Received %s event for an unknown connection 0x%lx - ignoring\n",
+                    event_type_name, (uint64_t)ev->id);
+            }
+            else
+            {
+                fprintf(stderr, "Received %s event for connection 0x%lx - closing it\n",
+                    event_type_name, (uint64_t)ev->id);
+                auto conn = conn_it->second;
+                delete conn;
+            }
+        }
+        else if (ev->event == RDMA_CM_EVENT_ESTABLISHED)
+        {
+            rdmacm_established(ev);
+        }
+        else if (ev->event == RDMA_CM_EVENT_ADDR_CHANGE || ev->event == RDMA_CM_EVENT_TIMEWAIT_EXIT)
+        {
+            // Do nothing
+        }
+        else
+        {
+            // Other events are unexpected
+            fprintf(stderr, "Unexpected RDMA-CM event type: %d\n", ev->event);
+        }
+        r = rdma_ack_cm_event(ev);
+        if (r != 0)
+        {
+            fprintf(stderr, "Failed to ack (free) RDMA-CM event: %s (code %d)\n", strerror(errno), errno);
+            exit(1);
+        }
+    }
+}
+
+void nfs_rdma_context_t::rdmacm_accept(rdma_cm_event *ev)
+{
+    ctx->used_max_cqe += max_send+max_recv;
+    if (ctx->used_max_cqe > ctx->max_cqe)
+    {
+        // Resize CQ
+        int new_max_cqe = ctx->max_cqe;
+        while (ctx->used_max_cqe > new_max_cqe)
+        {
+            new_max_cqe *= 2;
+        }
+        if (ibv_resize_cq(ctx->cq, new_max_cqe) != 0)
+        {
+            fprintf(stderr, "Couldn't resize RDMA completion queue to %d entries\n", new_max_cqe);
+            delete conn;
+            return NULL;
+        }
+        ctx->max_cqe = new_max_cqe;
+    }
+    ibv_qp_init_attr init_attr = {
+        .send_cq = ctx->cq,
+        .recv_cq = ctx->cq,
+        .cap     = {
+            .max_send_wr  = max_send*2, // ?????? тут большой вопрос сколько на самом деле
+            .max_recv_wr  = max_recv,
+            .max_send_sge = max_sge,
+            .max_recv_sge = max_sge,
+        },
+        .qp_type = IBV_QPT_RC,
+    };
+    r = rdma_create_qp(ev->id, NULL, &init_attr);
+    if (r != 0)
+    {
+        fprintf(stderr, "Failed to create a queue pair via RDMA-CM: %s (code %d)\n", strerror(errno), errno);
+        exit(1);
+    }
+    nfs_rdmacm_private private_data = {
+        .format_identifier = NFS_RDMACM_PRIVATE_DATA_MAGIC_LE,
+        .version = 1,
+        .remote_invalidate = ?,
+        .max_send_size = (max_send_size <= 256*1024 ? max_send_size/1024 - 1 : 255),
+        .max_recv_size = (max_recv_size <= 256*1024 ? max_recv_size/1024 - 1 : 255),
+    };
+    rdma_conn_param conn_params = {
+        .private_data = &private_data,
+        .private_data_len = sizeof(private_data),
+        //.responder_resources = max_qp_rd_atom of the device?,
+        //.initiator_depth = max_qp_init_rd_atom of the device?,
+        .rnr_retry_count = 7,
+        //.qp_num = manually created QP number?,
+    };
+    r = rdma_accept(ev->id, &conn_params);
+    if (r != 0)
+    {
+        fprintf(stderr, "Failed to accept RDMA-CM connection: %s (code %d)\n", strerror(errno), errno);
+        rdma_destroy_qp(ev->id);
+        rdma_destroy_id(ev->id);
+    }
+    else
+    {
+        auto conn = new nfs_rdma_conn_t();
+        conn->id = ctx->id;
+        rdma_connections[ctx->id] = conn;
+        rdma_connections_by_qp[conn->id->qp->qp_num];
+        auto cli = this->proxy->create_client();
+        cli->rdma_conn = conn;
+    }
+}
+
+nfs_rdma_conn_t::~nfs_rdma_conn_t()
+{
+    if (id)
+    {
+        parent->rdma_connections.erase(id);
+        if (id->qp)
+        {
+            parent->rdma_connections_by_qp.erase(id->qp->qp_num);
+            rdma_destroy_qp(id);
+        }
+        rdma_destroy_id(id);
+    }
+}
+
+void nfs_rdma_context_t::rdmacm_established(rdma_cm_event *ev)
+{
+    auto conn_it = rdma_connections.find(ev->id);
+    if (conn_it == rdma_connections.end())
+    {
+        fprintf(stderr, "Received RDMA_CM_EVENT_ESTABLISHED event for an unknown connection 0x%lx - ignoring\n", (uint64_t)ev->id);
+        return;
+    }
+    fprintf(stderr, "Received RDMA_CM_EVENT_ESTABLISHED event for connection 0x%lx - connection established\n", (uint64_t)ev->id);
+    auto conn = conn_it->second;
+    conn->established = true;
+    // Handle NFS private_data
+    if (ev->private_data_len >= sizeof(nfs_rdmacm_private))
+    {
+        nfs_rdmacm_private *private_data = (nfs_rdmacm_private *)ev->private_data;
+        if (private_data->format_identifier == NFS_RDMACM_PRIVATE_DATA_MAGIC_LE &&
+            private_data->version == 1)
+        {
+            conn->remote_invalidate = private_data->remote_invalidate;
+            conn->remote_max_send = (private_data->max_send_size+1) * 1024;
+            conn->remote_max_recv = (private_data->max_recv_size+1) * 1024;
+            if (conn->remote_max_recv < conn->max_send)
+                conn->max_send = conn->remote_max_recv;
+        }
+    }
+    // Post initial receive requests
+    conn->post_initial_receives();
+}
+
+void nfs_rdma_conn_t::post_initial_receives()
+{
+    while (cur_recv < max_recv)
+    {
+        auto b = create_buf(max_recv_size);
+        recv_buffers.push_back(b);
+        post_recv(b);
+    }
+}
+
+nfs_rdma_buf_t nfs_rdma_conn_t::create_buf(size_t len)
+{
+    nfs_rdma_buf_t b;
+    b.buf = malloc_or_die(len);
+    b.len = len;
+    b.mr = ibv_reg_mr(id->pd, b.buf, len, IBV_ACCESS_LOCAL_WRITE);
+    if (!b.mr)
+    {
+        fprintf(stderr, "Failed to register RDMA memory region: %s\n", strerror(errno));
+        exit(1);
+    }
+    return b;
+}
+
+void nfs_rdma_conn_t::post_recv(nfs_rdma_buf_t b)
+{
+    ibv_sge sge = {
+        .addr = (uintptr_t)b.buf,
+        .length = (uint32_t)b.len,
+        .lkey = b.mr->lkey,
+    };
+    ibv_recv_wr *bad_wr = NULL;
+    ibv_recv_wr wr = {
+        .wr_id   = 1, // 1 is any read, 2 is any write :)
+        .sg_list = &sge,
+        .num_sge = 1,
+    };
+    int err = ibv_post_recv(id->qp, &wr, &bad_wr);
+    if (err || bad_wr)
+    {
+        fprintf(stderr, "RDMA receive failed: %s\n", strerror(err));
+        exit(1);
+    }
+    cur_recv++;
+}
+
+void nfs_rdma_conn_t::queue_reply(rpc_op_t *rop)
+{
+    outbox.push_back(rop);
+    post_send();
+}
+
+void nfs_rdma_conn_t::post_send()
+{
+    while (outbox.size() > outbox_pos)
+    {
+        auto rop = outbox[outbox_pos];
+        // Check that exactly 1 write chunk is provided for READ3 and READLINK3
+        if (rop->in_msg.body.cbody.prog == NFS_PROGRAM &&
+            (rop->in_msg.body.cbody.proc == NFS3_READ || rop->in_msg.body.cbody.proc == NFS3_READLINK) &&
+            (!rop->in_rdma_msg.rdma_body.rdma_msg.rdma_writes ||
+            rop->in_rdma_msg.rdma_body.rdma_msg.rdma_writes->next))
+        {
+            rop->rdma_error = ERR_CHUNK;
+            ...
+        }
+        iovec *iov_list = NULL;
+        unsigned iov_count = 0;
+        xdr_encode_finish(rop->xdrs, &iov_list, &iov_count);
+        assert(iov_count > 0);
+        nfs_rdma_buf_t b;
+        if (send_buffers.size())
+        {
+            b = send_buffers.back();
+            send_buffers.pop_back();
+        }
+        else
+        {
+            b = create_buf(max_send_size);
+        }
+        // READ3resok and READLINK3resok - extract last byte buffer from iovecs and send it in a "write chunk"
+        iovec *chunk_iov = NULL;
+        if (rop->in_msg.body.cbody.prog == NFS_PROGRAM &&
+            (rop->in_msg.body.cbody.proc == NFS3_READ && ((READ3res*)rop->reply)->status == NFS3_OK ||
+            rop->in_msg.body.cbody.proc == NFS3_READLINK && ((READLINK3res*)rop->reply)->status == NFS3_OK))
+        {
+            assert(iov_count > 1);
+            iov_count--;
+            chunk_iov = &iov_list[iov_count];
+        }
+        // FIXME: Avoid extra copy - to do that we have to initially encode into nfs_rdma_buf_t
+        size_t pos = 0;
+        for (unsigned i = 0; i < iov_count; i++)
+        {
+            assert(pos + iov_list[i].iov_len <= b.len);
+            memcpy(b.buf + pos, iov_list[i].iov_base, iov_list[i].iov_len);
+            pos += iov_list[i].iov_len;
+        }
+        ibv_sge chunk_sge;
+        ibv_send_wr chunk_wr;
+        ibv_sge sge = {
+            .addr = (uintptr_t)b.buf,
+            .length = (uint32_t)pos,
+            .lkey = b.mr->lkey,
+        };
+        ibv_send_wr *bad_wr = NULL;
+        ibv_send_wr wr = {
+            .wr_id = 2, // 2 is send
+            .sg_list = &sge,
+            .num_sge = 1,
+            .opcode = IBV_WR_SEND,
+            .send_flags = IBV_SEND_SIGNALED,
+        };
+        ibv_send_wr *send_wr = &wr;
+        if (chunk_iov != NULL)
+        {
+            auto & wr_chunk = rop->in_rdma_msg.rdma_body.rdma_msg.rdma_writes->entry.target;
+            chunk_sge = {
+                .addr = (uintptr_t)chunk_iov->iov_base,
+                .length = (uint32_t)chunk_iov->iov_len,
+                .lkey = parent->get_rdma_data_lkey(chunk_iov->iov_base),
+            };
+            chunk_wr = {
+                .wr_id = 4, // 2 is chunk write
+                .sg_list = &chunk_sge,
+                .num_sge = 1,
+                .opcode = IBV_WR_RDMA_WRITE,
+                .wr = {
+                    .rdma = {
+                        .remote_addr = wr_chunk.offset,
+                        .rkey = wr_chunk.handle,
+                    },
+                },
+            };
+            // send chunk_wr first, then normal wr
+            chunk_wr.next = &wr;
+            send_wr = &chunk_wr;
+        }
+        int err = ibv_post_send(id->qp, send_wr, &bad_wr);
+        if (err || bad_wr)
+        {
+            fprintf(stderr, "RDMA send failed: %s\n", strerror(err));
+            exit(1);
+        }
+        cl->rdma_conn->cur_send++;
+    }
+}
+
+#define RDMA_EVENTS_AT_ONCE 32
+
+void nfs_rdma_context_t::handle_io()
+{
+    // Request next notification
+    ibv_cq *ev_cq;
+    void *ev_ctx;
+    // FIXME: This is inefficient as it calls read()...
+    if (ibv_get_cq_event(channel, &ev_cq, &ev_ctx) == 0)
+    {
+        ibv_ack_cq_events(cq, 1);
+    }
+    if (ibv_req_notify_cq(cq, 0) != 0)
+    {
+        fprintf(stderr, "Failed to request RDMA completion notification, exiting\n");
+        exit(1);
+    }
+    ibv_wc wc[RDMA_EVENTS_AT_ONCE];
+    int event_count;
+    do
+    {
+        event_count = ibv_poll_cq(cq, RDMA_EVENTS_AT_ONCE, wc);
+        for (int i = 0; i < event_count; i++)
+        {
+            auto conn_it = rdma_connections_by_qp.find(wc[i].qp_num);
+            if (conn_it == rdma_connections_by_qp.end())
+            {
+                continue;
+            }
+            auto conn = conn_it->second;
+            if (wc[i].status != IBV_WC_SUCCESS)
+            {
+                fprintf(stderr, "RDMA work request failed for queue %d with status: %s, stopping client\n", wc[i].qp_num, ibv_wc_status_str(wc[i].status));
+                delete conn;
+                continue;
+            }
+            //auto read_buf_it = conn->buffers.find(wc[i].wr_id);
+            //auto read_buf = read_buf_it != conn->buffers.end() ? read_buf_it->second : NULL;
+            auto is_send = wc[i].wr_id == 2;//conn->sends.at(wc[i].wr_id);
+            if (!is_send)
+            {
+                conn->cur_recv--;
+                auto & b = conn->recv_buffers[conn->next_recv_buf];
+                auto is_continued = conn->handle_recv(b.buf, wc[i].byte_len);
+                if (is_continued)
+                {
+                    // Buffer is required to handle request
+                    // Due to the credit-based flow control in RPC-RDMA, we can just remove that buffer and reuse it later
+                    used_buffers[b.buf] = b;
+                    conn->recv_buffers.erase(conn->recv_buffers.begin()+conn->next_recv_buf, conn->recv_buffers.begin()+conn->next_recv_buf+1);
+                }
+                else
+                {
+                    // Buffer is not required to handle request and can be reused immediately
+                    conn->post_recv(b);
+                    conn->next_recv_buf = (conn->next_recv_buf+1) % conn->recv_buffers.size();
+                }
+            }
+            else
+            {
+                auto rop = conn->outbox[0];
+                conn->outbox.erase(conn->outbox.begin(), conn->outbox.begin()+1);
+                xdr_reset(rop->xdrs);
+                parent->xdr_pool.push_back(rop->xdrs);
+                if (rop->buffer && rop->referenced)
+                {
+                    // Reuse the buffer
+                    auto & ub = conn->used_buffers.at(rop->buffer);
+                    conn->recv_buffers.push_back(ub);
+                    conn->post_recv(ub);
+                }
+                free(rop);
+                conn->post_send();
+            }
+        }
+    } while (event_count > 0);
+}
+
+// returns false if handling is done, returns true if handling is continued asynchronously
+bool nfs_rdma_conn_t::handle_recv(uint8_t *buf, size_t len)
+{
+    // Take an XDR object from the pool
+    XDR *xdrs;
+    if (parent->xdr_pool.size())
+    {
+        xdrs = parent->xdr_pool.back();
+        parent->xdr_pool.pop_back();
+    }
+    else
+    {
+        xdrs = xdr_create();
+    }
+    // Decode the RDMA-RPC header
+    rdma_msg rmsg;
+    if (!xdr_decode(xdrs, buf, len, (xdrproc_t)xdr_rdma_msg, &rmsg))
+    {
+        // Invalid message, ignore it
+        xdr_reset(xdrs);
+        parent->xdr_pool.push_back(xdrs);
+        return 0;
+    }
+    if (rmsg.rdma_vers != 1 || rmsg.rdma_body.proc != RDMA_MSG /*&& rmsg.rdma_body.proc != RDMA_NOMSG*/)
+    {
+        // Bad RDMA-RPC version
+        rpc_op_t *rop = (rpc_op_t*)malloc_or_die(sizeof(rpc_op_t));
+        *rop = (rpc_op_t){
+            .client = this,
+            .xdrs = xdrs,
+            .rdma_error = ERR_VERS,
+/*
+        uint32_t x = 1;
+            .out_rdma_msg = (rdma_msg){
+                .rdma_xid = rmsg.rdma_xid,
+                .rdma_vers = rmsg.rdma_vers,
+                .rdma_credit = rmsg.rdma_credit,
+                .rdma_body = (rdma_body){
+                    .proc = RDMA_ERROR,
+                    .rdma_error = (rpc_rdma_error){
+                        .err = ERR_VERS,
+                        .range = (rpc_rdma_errvers){
+                            .rdma_vers_low = x,
+                            .rdma_vers_high = x,
+                        },
+                    },
+                },
+            },
+*/
+        };
+        rpc_queue_reply(rop);
+        // Incoming buffer isn't needed to handle request, so return 0
+        return 0;
+    }
+    rpc_msg inmsg = { .xid = rmsg.rdma_xid };
+    if (!xdr_rpc_msg_body(xdrs, &inmsg.body) || inmsg.body.dir != RPC_CALL)
+    {
+        // Invalid message, ignore it
+        xdr_reset(xdrs);
+        parent->xdr_pool.push_back(xdrs);
+        return 0;
+    }
+    // Check that exactly 1 read chunk is provided for WRITE3 and SYMLINK3
+    if (inmsg.body.cbody.prog == NFS_PROGRAM &&
+        (inmsg.body.cbody.proc == NFS3_WRITE || inmsg.body.cbody.proc == NFS3_SYMLINK) &&
+        (!rmsg.rdma_body.rdma_msg.rdma_reads || rmsg.rdma_body.rdma_msg.rdma_reads->next))
+    {
+        rpc_op_t *rop = (rpc_op_t*)malloc_or_die(sizeof(rpc_op_t));
+        *rop = (rpc_op_t){
+            .client = this,
+            .xdrs = xdrs,
+            .rdma_error = ERR_CHUNK,
+        };
+        rpc_queue_reply(rop);
+        return 0;
+    }
+    // Read that chunk
+    if (inmsg.body.cbody.prog == NFS_PROGRAM && inmsg.body.cbody.proc == NFS3_WRITE)
+    {
+        auto & rd_chunk = rmsg.rdma_body.rdma_msg.rdma_reads->entry.target;
+        auto buf = parent->malloc_rdma(rd_chunk.length);
+        ibv_sge chunk_sge = {
+            .addr = (uintptr_t)buf,
+            .length = rd_chunk.length,
+            .lkey = parent->get_rdma_data_lkey(buf),
+        };
+        ibv_recv_wr *bad_wr = NULL;
+        ibv_recv_wr wr = {
+            .wr_id = 3, // 3 is chunk read
+            .sg_list = &chunk_sge,
+            .num_sge = 1,
+            .opcode = IBV_WR_RDMA_READ,
+            .wr = {
+                .rdma = {
+                    .remote_addr = rd_chunk.offset,
+                    .rkey = rd_chunk.handle,
+                },
+            },
+        };
+        int err = ibv_post_recv(id->qp, &wr, &bad_wr);
+        if (err || bad_wr)
+        {
+            fprintf(stderr, "RDMA receive failed: %s\n", strerror(err));
+            exit(1);
+        }
+        cur_recv++;
+        rpc_op_t *rop = (rpc_op_t*)malloc_or_die(sizeof(rpc_op_t));
+        *rop = (rpc_op_t){
+            .client = this,
+            .xdrs = xdrs,
+            .request = ((uint8_t*)rop) + sizeof(rpc_op_t),
+            .reply = ((uint8_t*)rop) + sizeof(rpc_op_t) + proc_it->req_size,
+        };
+        chunk_inbox.push_back();
+        return 1;
+    }
+    return client->handle_rpc_body(xdrs, &inmsg, &rmsg);
+}

src/nfs/proto/nfs.x

@@ -168,7 +168,7 @@ struct WRITE3args {
 	offset3     offset;
 	count3      count;
 	stable_how  stable;
-	opaque      data<>;
+	opaque      data<>; /* RDMA DDP-eligible */
 };
 
 typedef opaque writeverf3[NFS3_WRITEVERFSIZE];
@@ -409,7 +409,7 @@ struct READ3resok {
 	post_op_attr   file_attributes;
 	count3         count;
 	bool           eof;
-	opaque         data<>;
+	opaque         data<>; /* RDMA DDP-eligible */
 };
 
 struct READ3resfail {
@@ -514,7 +514,7 @@ typedef string nfspath3<>;
 
 struct symlinkdata3 {
 	sattr3    symlink_attributes;
-	nfspath3  symlink_data;
+	nfspath3  symlink_data; /* RDMA DDP-eligible */
 };
 
 struct SYMLINK3args {
@@ -546,7 +546,7 @@ struct READLINK3args {
 
 struct READLINK3resok {
 	post_op_attr   symlink_attributes;
-	nfspath3       data;
+	nfspath3       data; /* RDMA DDP-eligible */
 };
 
 struct READLINK3resfail {

src/nfs/proto/nfs_xdr.cpp

@@ -272,7 +272,7 @@ xdr_WRITE3args (XDR *xdrs, WRITE3args *objp)
 		 return FALSE;
 	 if (!xdr_stable_how (xdrs, &objp->stable))
 		 return FALSE;
-	 if (!xdr_bytes(xdrs, &objp->data, ~0))
+	 if (!xdr_bytes(xdrs, &objp->data, ~0, true))
 		 return FALSE;
 	return TRUE;
 }
@@ -829,7 +829,7 @@ xdr_READ3resok (XDR *xdrs, READ3resok *objp)
 		 return FALSE;
 	 if (!xdr_bool (xdrs, &objp->eof))
 		 return FALSE;
-	 if (!xdr_bytes(xdrs, &objp->data, ~0))
+	 if (!xdr_bytes(xdrs, &objp->data, ~0, true))
 		 return FALSE;
 	return TRUE;
 }
@@ -1173,10 +1173,10 @@ xdr_PATHCONF3res (XDR *xdrs, PATHCONF3res *objp)
 }
 
 bool_t
-xdr_nfspath3 (XDR *xdrs, nfspath3 *objp)
+xdr_nfspath3 (XDR *xdrs, nfspath3 *objp, bool rdma_chunk)
 {
 	
-	 if (!xdr_string (xdrs, objp, ~0))
+	 if (!xdr_string (xdrs, objp, ~0, rdma_chunk))
 		 return FALSE;
 	return TRUE;
 }
@@ -1187,7 +1187,7 @@ xdr_symlinkdata3 (XDR *xdrs, symlinkdata3 *objp)
 	
 	 if (!xdr_sattr3 (xdrs, &objp->symlink_attributes))
 		 return FALSE;
-	 if (!xdr_nfspath3 (xdrs, &objp->symlink_data))
+	 if (!xdr_nfspath3 (xdrs, &objp->symlink_data, true))
 		 return FALSE;
 	return TRUE;
 }
@@ -1259,7 +1259,7 @@ xdr_READLINK3resok (XDR *xdrs, READLINK3resok *objp)
 	
 	 if (!xdr_post_op_attr (xdrs, &objp->symlink_attributes))
 		 return FALSE;
-	 if (!xdr_nfspath3 (xdrs, &objp->data))
+	 if (!xdr_nfspath3 (xdrs, &objp->data, true))
 		 return FALSE;
 	return TRUE;
 }

src/nfs/proto/rpc_impl.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "rpc.h"
+#include "rpc_rdma.h"
 
 struct rpc_op_t;
 
@@ -27,12 +28,15 @@ inline bool operator < (const rpc_service_proc_t & a, const rpc_service_proc_t &
     return a.prog < b.prog || a.prog == b.prog && (a.vers < b.vers || a.vers == b.vers && a.proc < b.proc);
 }
 
+struct rdma_msg;
+
 struct rpc_op_t
 {
     void *client;
     uint8_t *buffer;
     XDR *xdrs;
     rpc_msg in_msg, out_msg;
+    rdma_msg in_rdma_msg;
     void *request;
     void *reply;
     xdrproc_t reply_fn;

src/nfs/proto/rpc_rdma.h

@@ -0,0 +1,144 @@
+/*
+ * Please do not edit this file.
+ * It was generated using rpcgen.
+ */
+
+#ifndef _RPC_RDMA_H_RPCGEN
+#define _RPC_RDMA_H_RPCGEN
+
+#include "xdr_impl.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+struct xdr_rdma_segment {
+	uint32 handle;
+	uint32 length;
+	uint64 offset;
+};
+typedef struct xdr_rdma_segment xdr_rdma_segment;
+
+struct xdr_read_chunk {
+	uint32 position;
+	struct xdr_rdma_segment target;
+};
+typedef struct xdr_read_chunk xdr_read_chunk;
+
+struct xdr_read_list {
+	struct xdr_read_chunk entry;
+	struct xdr_read_list *next;
+};
+typedef struct xdr_read_list xdr_read_list;
+
+struct xdr_write_chunk {
+	struct {
+		u_int target_len;
+		struct xdr_rdma_segment *target_val;
+	} target;
+};
+typedef struct xdr_write_chunk xdr_write_chunk;
+
+struct xdr_write_list {
+	struct xdr_write_chunk entry;
+	struct xdr_write_list *next;
+};
+typedef struct xdr_write_list xdr_write_list;
+
+struct rpc_rdma_header {
+	struct xdr_read_list *rdma_reads;
+	struct xdr_write_list *rdma_writes;
+	struct xdr_write_chunk *rdma_reply;
+};
+typedef struct rpc_rdma_header rpc_rdma_header;
+
+struct rpc_rdma_header_nomsg {
+	struct xdr_read_list *rdma_reads;
+	struct xdr_write_list *rdma_writes;
+	struct xdr_write_chunk *rdma_reply;
+};
+typedef struct rpc_rdma_header_nomsg rpc_rdma_header_nomsg;
+
+struct rpc_rdma_header_padded {
+	uint32 rdma_align;
+	uint32 rdma_thresh;
+	struct xdr_read_list *rdma_reads;
+	struct xdr_write_list *rdma_writes;
+	struct xdr_write_chunk *rdma_reply;
+};
+typedef struct rpc_rdma_header_padded rpc_rdma_header_padded;
+
+enum rpc_rdma_errcode {
+	ERR_VERS = 1,
+	ERR_CHUNK = 2,
+};
+typedef enum rpc_rdma_errcode rpc_rdma_errcode;
+
+struct rpc_rdma_errvers {
+	uint32 rdma_vers_low;
+	uint32 rdma_vers_high;
+};
+typedef struct rpc_rdma_errvers rpc_rdma_errvers;
+
+struct rpc_rdma_error {
+	rpc_rdma_errcode err;
+	union {
+		rpc_rdma_errvers range;
+	};
+};
+typedef struct rpc_rdma_error rpc_rdma_error;
+
+enum rdma_proc {
+	RDMA_MSG = 0,
+	RDMA_NOMSG = 1,
+	RDMA_MSGP = 2,
+	RDMA_DONE = 3,
+	RDMA_ERROR = 4,
+};
+typedef enum rdma_proc rdma_proc;
+
+struct rdma_body {
+	rdma_proc proc;
+	union {
+		rpc_rdma_header rdma_msg;
+		rpc_rdma_header_nomsg rdma_nomsg;
+		rpc_rdma_header_padded rdma_msgp;
+		rpc_rdma_error rdma_error;
+	};
+};
+typedef struct rdma_body rdma_body;
+
+struct rdma_msg {
+	uint32 rdma_xid;
+	uint32 rdma_vers;
+	uint32 rdma_credit;
+	rdma_body rdma_body;
+};
+typedef struct rdma_msg rdma_msg;
+
+/* the xdr functions */
+
+
+extern  bool_t xdr_xdr_rdma_segment (XDR *, xdr_rdma_segment*);
+extern  bool_t xdr_xdr_read_chunk (XDR *, xdr_read_chunk*);
+extern  bool_t xdr_xdr_read_list (XDR *, xdr_read_list*);
+extern  bool_t xdr_xdr_write_chunk (XDR *, xdr_write_chunk*);
+extern  bool_t xdr_xdr_write_list (XDR *, xdr_write_list*);
+extern  bool_t xdr_rpc_rdma_header (XDR *, rpc_rdma_header*);
+extern  bool_t xdr_rpc_rdma_header_nomsg (XDR *, rpc_rdma_header_nomsg*);
+extern  bool_t xdr_rpc_rdma_header_padded (XDR *, rpc_rdma_header_padded*);
+extern  bool_t xdr_rpc_rdma_errcode (XDR *, rpc_rdma_errcode*);
+extern  bool_t xdr_rpc_rdma_errvers (XDR *, rpc_rdma_errvers*);
+extern  bool_t xdr_rpc_rdma_error (XDR *, rpc_rdma_error*);
+extern  bool_t xdr_rdma_proc (XDR *, rdma_proc*);
+extern  bool_t xdr_rdma_body (XDR *, rdma_body*);
+extern  bool_t xdr_rdma_msg (XDR *, rdma_msg*);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !_RPC_RDMA_H_RPCGEN */

src/nfs/proto/rpc_rdma.x

@@ -0,0 +1,166 @@
+/* RFC 8166 - Remote Direct Memory Access Transport for Remote Procedure Call Version 1 */
+
+/*
+ * Copyright (c) 2010-2017 IETF Trust and the persons
+ * identified as authors of the code.  All rights reserved.
+ *
+ * The authors of the code are:
+ * B. Callaghan, T. Talpey, and C. Lever
+ *
+ * Redistribution and use in source and binary forms, with
+ * or without modification, are permitted provided that the
+ * following conditions are met:
+ *
+ * - Redistributions of source code must retain the above
+ *   copyright notice, this list of conditions and the
+ *   following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the
+ *   following disclaimer in the documentation and/or other
+ *   materials provided with the distribution.
+ *
+ * - Neither the name of Internet Society, IETF or IETF
+ *   Trust, nor the names of specific contributors, may be
+ *   used to endorse or promote products derived from this
+ *   software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
+ *   AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
+ *   WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
+ *   EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ *   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ *   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ *   SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ *   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ *   IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ *   ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Plain RDMA segment (Section 3.4.3)
+ */
+struct xdr_rdma_segment {
+	uint32 handle;           /* Registered memory handle */
+	uint32 length;           /* Length of the chunk in bytes */
+	uint64 offset;           /* Chunk virtual address or offset */
+};
+
+/*
+ * RDMA read segment (Section 3.4.5)
+ */
+struct xdr_read_chunk {
+	uint32 position;        /* Position in XDR stream */
+	struct xdr_rdma_segment target;
+};
+
+/*
+ * Read list (Section 4.3.1)
+ */
+struct xdr_read_list {
+	struct xdr_read_chunk entry;
+	struct xdr_read_list  *next;
+};
+
+/*
+ * Write chunk (Section 3.4.6)
+ */
+struct xdr_write_chunk {
+	struct xdr_rdma_segment target<>;
+};
+
+/*
+ * Write list (Section 4.3.2)
+ */
+struct xdr_write_list {
+	struct xdr_write_chunk entry;
+	struct xdr_write_list  *next;
+};
+
+/*
+ * Chunk lists (Section 4.3)
+ */
+struct rpc_rdma_header {
+	struct xdr_read_list   *rdma_reads;
+	struct xdr_write_list  *rdma_writes;
+	struct xdr_write_chunk *rdma_reply;
+	/* rpc body follows */
+};
+
+struct rpc_rdma_header_nomsg {
+	struct xdr_read_list   *rdma_reads;
+	struct xdr_write_list  *rdma_writes;
+	struct xdr_write_chunk *rdma_reply;
+};
+
+/* Not to be used */
+struct rpc_rdma_header_padded {
+	uint32                 rdma_align;
+	uint32                 rdma_thresh;
+	struct xdr_read_list   *rdma_reads;
+	struct xdr_write_list  *rdma_writes;
+	struct xdr_write_chunk *rdma_reply;
+	/* rpc body follows */
+};
+
+/*
+ * Error handling (Section 4.5)
+ */
+enum rpc_rdma_errcode {
+	ERR_VERS = 1,       /* Value fixed for all versions */
+	ERR_CHUNK = 2
+};
+
+/* Structure fixed for all versions */
+struct rpc_rdma_errvers {
+	uint32 rdma_vers_low;
+	uint32 rdma_vers_high;
+};
+
+union rpc_rdma_error switch (rpc_rdma_errcode err) {
+	case ERR_VERS:
+		rpc_rdma_errvers range;
+	case ERR_CHUNK:
+		void;
+};
+
+/*
+ * Procedures (Section 4.2.4)
+ */
+enum rdma_proc {
+	RDMA_MSG = 0,     /* Value fixed for all versions */
+	RDMA_NOMSG = 1,   /* Value fixed for all versions */
+	RDMA_MSGP = 2,    /* Not to be used */
+	RDMA_DONE = 3,    /* Not to be used */
+	RDMA_ERROR = 4    /* Value fixed for all versions */
+};
+
+/* The position of the proc discriminator field is
+ * fixed for all versions */
+union rdma_body switch (rdma_proc proc) {
+	case RDMA_MSG:
+		rpc_rdma_header rdma_msg;
+	case RDMA_NOMSG:
+		rpc_rdma_header_nomsg rdma_nomsg;
+	case RDMA_MSGP:   /* Not to be used */
+		rpc_rdma_header_padded rdma_msgp;
+	case RDMA_DONE:   /* Not to be used */
+		void;
+	case RDMA_ERROR:
+		rpc_rdma_error rdma_error;
+};
+
+/*
+ * Fixed header fields (Section 4.2)
+ */
+struct rdma_msg {
+	uint32    rdma_xid;      /* Position fixed for all versions */
+	uint32    rdma_vers;     /* Position fixed for all versions */
+	uint32    rdma_credit;   /* Position fixed for all versions */
+	rdma_body rdma_body;
+};

src/nfs/proto/rpc_rdma_xdr.cpp

@@ -0,0 +1,200 @@
+/*
+ * Please do not edit this file.
+ * It was generated using rpcgen.
+ */
+
+#include "rpc_rdma.h"
+#include "xdr_impl_inline.h"
+
+bool_t
+xdr_xdr_rdma_segment (XDR *xdrs, xdr_rdma_segment *objp)
+{
+	
+	 if (!xdr_uint32 (xdrs, &objp->handle))
+		 return FALSE;
+	 if (!xdr_uint32 (xdrs, &objp->length))
+		 return FALSE;
+	 if (!xdr_uint64 (xdrs, &objp->offset))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_xdr_read_chunk (XDR *xdrs, xdr_read_chunk *objp)
+{
+	
+	 if (!xdr_uint32 (xdrs, &objp->position))
+		 return FALSE;
+	 if (!xdr_xdr_rdma_segment (xdrs, &objp->target))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_xdr_read_list (XDR *xdrs, xdr_read_list *objp)
+{
+	
+	 if (!xdr_xdr_read_chunk (xdrs, &objp->entry))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->next, sizeof (xdr_read_list), (xdrproc_t) xdr_xdr_read_list))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_xdr_write_chunk (XDR *xdrs, xdr_write_chunk *objp)
+{
+	
+	 if (!xdr_array (xdrs, (char **)&objp->target.target_val, (u_int *) &objp->target.target_len, ~0,
+		sizeof (xdr_rdma_segment), (xdrproc_t) xdr_xdr_rdma_segment))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_xdr_write_list (XDR *xdrs, xdr_write_list *objp)
+{
+	
+	 if (!xdr_xdr_write_chunk (xdrs, &objp->entry))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->next, sizeof (xdr_write_list), (xdrproc_t) xdr_xdr_write_list))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_rpc_rdma_header (XDR *xdrs, rpc_rdma_header *objp)
+{
+	
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_reads, sizeof (xdr_read_list), (xdrproc_t) xdr_xdr_read_list))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_writes, sizeof (xdr_write_list), (xdrproc_t) xdr_xdr_write_list))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_reply, sizeof (xdr_write_chunk), (xdrproc_t) xdr_xdr_write_chunk))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_rpc_rdma_header_nomsg (XDR *xdrs, rpc_rdma_header_nomsg *objp)
+{
+	
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_reads, sizeof (xdr_read_list), (xdrproc_t) xdr_xdr_read_list))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_writes, sizeof (xdr_write_list), (xdrproc_t) xdr_xdr_write_list))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_reply, sizeof (xdr_write_chunk), (xdrproc_t) xdr_xdr_write_chunk))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_rpc_rdma_header_padded (XDR *xdrs, rpc_rdma_header_padded *objp)
+{
+	
+	 if (!xdr_uint32 (xdrs, &objp->rdma_align))
+		 return FALSE;
+	 if (!xdr_uint32 (xdrs, &objp->rdma_thresh))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_reads, sizeof (xdr_read_list), (xdrproc_t) xdr_xdr_read_list))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_writes, sizeof (xdr_write_list), (xdrproc_t) xdr_xdr_write_list))
+		 return FALSE;
+	 if (!xdr_pointer (xdrs, (char **)&objp->rdma_reply, sizeof (xdr_write_chunk), (xdrproc_t) xdr_xdr_write_chunk))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_rpc_rdma_errcode (XDR *xdrs, rpc_rdma_errcode *objp)
+{
+	
+	 if (!xdr_enum (xdrs, (enum_t *) objp))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_rpc_rdma_errvers (XDR *xdrs, rpc_rdma_errvers *objp)
+{
+	
+	 if (!xdr_uint32 (xdrs, &objp->rdma_vers_low))
+		 return FALSE;
+	 if (!xdr_uint32 (xdrs, &objp->rdma_vers_high))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_rpc_rdma_error (XDR *xdrs, rpc_rdma_error *objp)
+{
+	
+	 if (!xdr_rpc_rdma_errcode (xdrs, &objp->err))
+		 return FALSE;
+	switch (objp->err) {
+	case ERR_VERS:
+		 if (!xdr_rpc_rdma_errvers (xdrs, &objp->range))
+			 return FALSE;
+		break;
+	case ERR_CHUNK:
+		break;
+	default:
+		return FALSE;
+	}
+	return TRUE;
+}
+
+bool_t
+xdr_rdma_proc (XDR *xdrs, rdma_proc *objp)
+{
+	
+	 if (!xdr_enum (xdrs, (enum_t *) objp))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_rdma_body (XDR *xdrs, rdma_body *objp)
+{
+	
+	 if (!xdr_rdma_proc (xdrs, &objp->proc))
+		 return FALSE;
+	switch (objp->proc) {
+	case RDMA_MSG:
+		 if (!xdr_rpc_rdma_header (xdrs, &objp->rdma_msg))
+			 return FALSE;
+		break;
+	case RDMA_NOMSG:
+		 if (!xdr_rpc_rdma_header_nomsg (xdrs, &objp->rdma_nomsg))
+			 return FALSE;
+		break;
+	case RDMA_MSGP:
+		 if (!xdr_rpc_rdma_header_padded (xdrs, &objp->rdma_msgp))
+			 return FALSE;
+		break;
+	case RDMA_DONE:
+		break;
+	case RDMA_ERROR:
+		 if (!xdr_rpc_rdma_error (xdrs, &objp->rdma_error))
+			 return FALSE;
+		break;
+	default:
+		return FALSE;
+	}
+	return TRUE;
+}
+
+bool_t
+xdr_rdma_msg (XDR *xdrs, rdma_msg *objp)
+{
+	
+	 if (!xdr_uint32 (xdrs, &objp->rdma_xid))
+		 return FALSE;
+	 if (!xdr_uint32 (xdrs, &objp->rdma_vers))
+		 return FALSE;
+	 if (!xdr_uint32 (xdrs, &objp->rdma_credit))
+		 return FALSE;
+	 if (!xdr_rdma_body (xdrs, &objp->rdma_body))
+		 return FALSE;
+	return TRUE;
+}

src/nfs/proto/run-rpcgen.sh

@@ -46,3 +46,4 @@ run_rpcgen() {
 run_rpcgen nfs
 run_rpcgen rpc
 run_rpcgen portmap
+run_rpcgen rpc_rdma

src/nfs/proto/xdr_impl_inline.h

@@ -28,6 +28,19 @@
 // RPC over TCP:
 //
 // BE 32bit length, then rpc_msg, then the procedure message itself
+//
+// RPC over RDMA:
+// RFC 8166 - Remote Direct Memory Access Transport for Remote Procedure Call Version 1
+// RFC 8267 - Network File System (NFS) Upper-Layer Binding to RPC-over-RDMA Version 1
+// RFC 8797 - Remote Direct Memory Access - Connection Manager (RDMA-CM) Private Data for RPC-over-RDMA Version 1
+// message is received in an RDMA Receive operation
+// message: list of read chunks, list of write chunks, optional reply write chunk, then actual RPC body if present
+// read chunk: BE 32bit position, BE 32bit registered memory key, BE 32bit length, BE 64bit offset
+// write chunk: BE 32bit registered memory key, BE 32bit length, BE 64bit offset
+// in reality for NFS 3.0: only 1 read chunk in write3 and symlink3, only 1 write chunk in read3 and readlink3
+// read chunk is read by the server using RDMA Read from the client memory after receiving RPC request
+// write chunk is pushed by the server using RDMA Write to the client memory before sending RPC reply
+// connection is established using RDMA-CM at default port 20049
 
 #pragma once
 
@@ -106,13 +119,19 @@ inline int xdr_opaque(XDR *xdrs, void *data, uint32_t len)
     return 1;
 }
 
-inline int xdr_bytes(XDR *xdrs, xdr_string_t *data, uint32_t maxlen)
+inline int xdr_bytes(XDR *xdrs, xdr_string_t *data, uint32_t maxlen, bool rdma_chunk = false)
 {
     if (xdrs->x_op == XDR_DECODE)
     {
         if (xdrs->avail < 4)
             return 0;
         uint32_t len = be32toh(*((uint32_t*)xdrs->buf));
+        if (rdma_chunk && xdrs->rdma)
+        {
+            // Skip RDMA chunks while decoding
+            data->size = len;
+            return 1;
+        }
         uint32_t padded = len_pad4(len);
         if (xdrs->avail < 4+padded)
             return 0;
@@ -123,7 +142,8 @@ inline int xdr_bytes(XDR *xdrs, xdr_string_t *data, uint32_t maxlen)
     }
     else
     {
-        if (data->size < XDR_COPY_LENGTH)
+        // Always encode RDMA chunks as separate iovecs
+        if (data->size < XDR_COPY_LENGTH && (!rdma_chunk || !xdrs->rdma))
         {
             unsigned old = xdrs->cur_out.size();
             xdrs->cur_out.resize(old + 4+data->size);
@@ -146,8 +166,9 @@ inline int xdr_bytes(XDR *xdrs, xdr_string_t *data, uint32_t maxlen)
                 .iov_len = data->size,
             });
         }
-        if (data->size & 3)
+        if ((data->size & 3) && (!rdma_chunk || !xdrs->rdma))
         {
+            // No padding for RDMA chunks
             int pad = 4-(data->size & 3);
             unsigned old = xdrs->cur_out.size();
             xdrs->cur_out.resize(old+pad);
@@ -158,9 +179,9 @@ inline int xdr_bytes(XDR *xdrs, xdr_string_t *data, uint32_t maxlen)
     return 1;
 }
 
-inline int xdr_string(XDR *xdrs, xdr_string_t *data, uint32_t maxlen)
+inline int xdr_string(XDR *xdrs, xdr_string_t *data, uint32_t maxlen, bool rdma_chunk = false)
 {
-    return xdr_bytes(xdrs, data, maxlen);
+    return xdr_bytes(xdrs, data, maxlen, rdma_chunk);
 }
 
 inline int xdr_u_int(XDR *xdrs, void *data)

src/osd/osd.h

@@ -226,6 +226,7 @@ class osd_t
     void parse_config(bool init);
     void init_cluster();
     void on_change_osd_state_hook(osd_num_t peer_osd);
+    void on_change_backfillfull_hook(pool_id_t pool_id);
     void on_change_pg_history_hook(pool_id_t pool_id, pg_num_t pg_num);
     void on_change_etcd_state_hook(std::map<std::string, etcd_kv_t> & changes);
     void on_load_config_hook(json11::Json::object & changes);

src/osd/osd_cluster.cpp

@@ -65,6 +65,7 @@ void osd_t::init_cluster()
         st_cli.tfd = tfd;
         st_cli.log_level = log_level;
         st_cli.on_change_osd_state_hook = [this](osd_num_t peer_osd) { on_change_osd_state_hook(peer_osd); };
+        st_cli.on_change_backfillfull_hook = [this](pool_id_t pool_id) { on_change_backfillfull_hook(pool_id); };
         st_cli.on_change_pg_history_hook = [this](pool_id_t pool_id, pg_num_t pg_num) { on_change_pg_history_hook(pool_id, pg_num); };
         st_cli.on_change_hook = [this](std::map<std::string, etcd_kv_t> & changes) { on_change_etcd_state_hook(changes); };
         st_cli.on_load_config_hook = [this](json11::Json::object & cfg) { on_load_config_hook(cfg); };
@@ -414,6 +415,14 @@ void osd_t::on_change_osd_state_hook(osd_num_t peer_osd)
     }
 }
 
+void osd_t::on_change_backfillfull_hook(pool_id_t pool_id)
+{
+    if (!(peering_state & (OSD_RECOVERING | OSD_FLUSHING_PGS)))
+    {
+        peering_state = peering_state | OSD_RECOVERING;
+    }
+}
+
 void osd_t::on_change_etcd_state_hook(std::map<std::string, etcd_kv_t> & changes)
 {
     if (changes.find(st_cli.etcd_prefix+"/config/global") != changes.end())

src/osd/osd_flush.cpp

@@ -252,10 +252,18 @@ bool osd_t::pick_next_recovery(osd_recovery_op_t &op)
             auto mask = recovery_last_degraded ? (PG_ACTIVE | PG_HAS_DEGRADED) : (PG_ACTIVE | PG_DEGRADED | PG_HAS_MISPLACED);
             auto check = recovery_last_degraded ? (PG_ACTIVE | PG_HAS_DEGRADED) : (PG_ACTIVE | PG_HAS_MISPLACED);
             // Restart scanning from the same PG as the last time
+        restart:
             for (auto pg_it = pgs.lower_bound(recovery_last_pg); pg_it != pgs.end(); pg_it++)
             {
                 if ((pg_it->second.state & mask) == check)
                 {
+                    auto pool_it = st_cli.pool_config.find(pg_it->first.pool_id);
+                    if (pool_it != st_cli.pool_config.end() && pool_it->second.backfillfull)
+                    {
+                        // Skip the pool
+                        recovery_last_pg.pool_id++;
+                        goto restart;
+                    }
                     auto & src = recovery_last_degraded ? pg_it->second.degraded_objects : pg_it->second.misplaced_objects;
                     assert(src.size() > 0);
                     // Restart scanning from the next object

tests/run_tests.sh

@@ -19,9 +19,12 @@ ANTIETCD=1 ./test_etcd_fail.sh
 
 ./test_interrupted_rebalance.sh
 IMMEDIATE_COMMIT=1 ./test_interrupted_rebalance.sh
+
 SCHEME=ec ./test_interrupted_rebalance.sh
 SCHEME=ec IMMEDIATE_COMMIT=1 ./test_interrupted_rebalance.sh
 
+./test_create_halfhost.sh
+
 ./test_failure_domain.sh
 
 ./test_snapshot.sh

tests/test_create_halfhost.sh

@@ -0,0 +1,35 @@
+#!/bin/bash -ex
+
+. `dirname $0`/common.sh
+
+node mon/mon-main.js $MON_PARAMS --etcd_address $ETCD_URL --etcd_prefix "/vitastor" >>./testdata/mon.log 2>&1 &
+MON_PID=$!
+wait_etcd
+
+TIME=$(date '+%s')
+$ETCDCTL put /vitastor/config/global '{"placement_levels":{"dc":10,"host":100,"half":105,"osd":110}}'
+$ETCDCTL put /vitastor/config/node_placement '{
+  "h11":{"level":"half","parent":"host1"},
+  "h12":{"level":"half","parent":"host1"},
+  "h21":{"level":"half","parent":"host2"},
+  "h22":{"level":"half","parent":"host2"},
+  "h31":{"level":"half","parent":"host3"},
+  "h32":{"level":"half","parent":"host3"},
+  "1":{"parent":"h11"},
+  "2":{"parent":"h12"},
+  "3":{"parent":"h21"},
+  "4":{"parent":"h22"},
+  "5":{"parent":"h31"},
+  "6":{"parent":"h32"}
+}'
+$ETCDCTL put /vitastor/osd/stats/1 '{"host":"host1","size":1073741824,"time":"'$TIME'"}'
+$ETCDCTL put /vitastor/osd/stats/2 '{"host":"host1","size":1073741824,"time":"'$TIME'"}'
+$ETCDCTL put /vitastor/osd/stats/3 '{"host":"host2","size":1073741824,"time":"'$TIME'"}'
+$ETCDCTL put /vitastor/osd/stats/4 '{"host":"host2","size":1073741824,"time":"'$TIME'"}'
+$ETCDCTL put /vitastor/osd/stats/5 '{"host":"host3","size":1073741824,"time":"'$TIME'"}'
+$ETCDCTL put /vitastor/osd/stats/6 '{"host":"host3","size":1073741824,"time":"'$TIME'"}'
+build/src/cmd/vitastor-cli --etcd_address $ETCD_URL osd-tree
+# check that it doesn't fail
+build/src/cmd/vitastor-cli --etcd_address $ETCD_URL create-pool testpool --ec 2+1 -n 32
+
+format_green OK