Release 0.6.6

- New command-line tool: vitastor-cli
- Implement layer (snapshot/clone) merge and delete
- Remove 'bool' from the C header
- Fix a very rare flusher stall
- More diagnostics now printed for slow ops in the log

CMakeLists.txt

@@ -2,6 +2,6 @@ cmake_minimum_required(VERSION 2.8)
 
 project(vitastor)
 
-set(VERSION "0.6.4")
+set(VERSION "0.6.6")
 
 add_subdirectory(src)

README-ru.md

@@ -40,7 +40,7 @@ Vitastor на данный момент находится в статусе п
 - Драйвер диска для QEMU (собирается вне дерева исходников QEMU)
 - Драйвер диска для утилиты тестирования производительности fio (также собирается вне дерева исходников fio)
 - NBD-прокси для монтирования образов ядром ("блочное устройство в режиме пользователя")
-- Утилита удаления образов/инодов (vitastor-rm)
+- Утилита для удаления образов/инодов (vitastor-cli rm)
 - Пакеты для Debian и CentOS
 - Статистика операций ввода/вывода и занятого места в разрезе инодов
 - Именование инодов через хранение их метаданных в etcd
@@ -48,12 +48,15 @@ Vitastor на данный момент находится в статусе п
 - Сглаживание производительности случайной записи в SSD+HDD конфигурациях
 - Поддержка RDMA/RoCEv2 через libibverbs
 - CSI-плагин для Kubernetes
+- Базовая поддержка OpenStack: драйвер Cinder, патчи для Nova и libvirt
+- Слияние снапшотов (vitastor-cli {snap-rm,flatten,merge})
 
 ## Планы развития
 
+- Поддержка удаления снапшотов (слияния слоёв)
 - Более корректные скрипты разметки дисков и автоматического запуска OSD
 - Другие инструменты администрирования
-- Плагины для OpenStack, OpenNebula, Proxmox и других облачных систем
+- Плагины для OpenNebula, Proxmox и других облачных систем
 - iSCSI-прокси
 - Более быстрое переключение при отказах
 - Фоновая проверка целостности без контрольных сумм (сверка реплик)
@@ -370,7 +373,7 @@ Vitastor с однопоточной NBD прокси на том же стен
 - Установите gcc и g++ 8.x или новее.
 - Склонируйте данный репозиторий с подмодулями: `git clone https://yourcmc.ru/git/vitalif/vitastor/`.
 - Желательно пересобрать QEMU с патчем, который делает необязательным запуск через LD_PRELOAD.
-  См `qemu-*.*-vitastor.patch` - выберите версию, наиболее близкую вашей версии QEMU.
+  См `patches/qemu-*.*-vitastor.patch` - выберите версию, наиболее близкую вашей версии QEMU.
 - Установите QEMU 3.0 или новее, возьмите исходные коды установленного пакета, начните его пересборку,
   через некоторое время остановите её и скопируйте следующие заголовки:
    - `<qemu>/include` &rarr; `<vitastor>/qemu/include`
@@ -489,10 +492,10 @@ qemu-system-x86_64 -enable-kvm -m 1024
 
 ### Удалить образ
 
-Используйте утилиту vitastor-rm. Например:
+Используйте утилиту vitastor-cli rm. Например:
 
 ```
-vitastor-rm --etcd_address 10.115.0.10:2379/v3 --pool 1 --inode 1 --parallel_osds 16 --iodepth 32
+vitastor-cli rm --etcd_address 10.115.0.10:2379/v3 --pool 1 --inode 1 --parallel_osds 16 --iodepth 32
 ```
 
 ### NBD

README.md

@@ -34,7 +34,7 @@ breaking changes in the future. However, the following is implemented:
 - QEMU driver (built out-of-tree)
 - Loadable fio engine for benchmarks (also built out-of-tree)
 - NBD proxy for kernel mounts
-- Inode removal tool (vitastor-rm)
+- Inode removal tool (vitastor-cli rm)
 - Packaging for Debian and CentOS
 - Per-inode I/O and space usage statistics
 - Inode metadata storage in etcd
@@ -42,12 +42,15 @@ breaking changes in the future. However, the following is implemented:
 - Write throttling to smooth random write workloads in SSD+HDD configurations
 - RDMA/RoCEv2 support via libibverbs
 - CSI plugin for Kubernetes
+- Basic OpenStack support: Cinder driver, Nova and libvirt patches
+- Snapshot merge tool (vitastor-cli {snap-rm,flatten,merge})
 
 ## Roadmap
 
+- Snapshot deletion (layer merge) support
 - Better OSD creation and auto-start tools
 - Other administrative tools
-- Plugins for OpenStack, OpenNebula, Proxmox and other cloud systems
+- Plugins for OpenNebula, Proxmox and other cloud systems
 - iSCSI proxy
 - Faster failover
 - Scrubbing without checksums (verification of replicas)
@@ -338,7 +341,7 @@ Vitastor with single-thread NBD on the same hardware:
       * For QEMU 2.0+: `<qemu>/qapi-types.h` &rarr; `<vitastor>/qemu/b/qemu/qapi-types.h`
    - `config-host.h` and `qapi` are required because they contain generated headers
 - You can also rebuild QEMU with a patch that makes LD_PRELOAD unnecessary to load vitastor driver.
-  See `qemu-*.*-vitastor.patch`.
+  See `patches/qemu-*.*-vitastor.patch`.
 - Install fio 3.7 or later, get its source and symlink it into `<vitastor>/fio`.
 - Build & install Vitastor with `mkdir build && cd build && cmake .. && make -j8 && make install`.
   Pay attention to the `QEMU_PLUGINDIR` cmake option - it must be set to `qemu-kvm` on RHEL.

csi/Makefile

@@ -1,4 +1,4 @@
-VERSION ?= v0.6.4
+VERSION ?= v0.6.6
 
 all: build push
 

csi/deploy/004-csi-nodeplugin.yaml

@@ -49,7 +49,7 @@ spec:
             capabilities:
               add: ["SYS_ADMIN"]
             allowPrivilegeEscalation: true
-          image: vitalif/vitastor-csi:v0.6.4
+          image: vitalif/vitastor-csi:v0.6.6
           args:
             - "--node=$(NODE_ID)"
             - "--endpoint=$(CSI_ENDPOINT)"

csi/deploy/007-csi-provisioner.yaml

@@ -116,7 +116,7 @@ spec:
             privileged: true
             capabilities:
               add: ["SYS_ADMIN"]
-          image: vitalif/vitastor-csi:v0.6.4
+          image: vitalif/vitastor-csi:v0.6.6
           args:
             - "--node=$(NODE_ID)"
             - "--endpoint=$(CSI_ENDPOINT)"

csi/src/config.go

@@ -5,7 +5,7 @@ package vitastor
 
 const (
     vitastorCSIDriverName    = "csi.vitastor.io"
-    vitastorCSIDriverVersion = "0.6.4"
+    vitastorCSIDriverVersion = "0.6.6"
 )
 
 // Config struct fills the parameters of request or user input

csi/src/controllerserver.go

@@ -354,9 +354,9 @@ func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVol
         return nil, status.Error(codes.Internal, "invalid "+inodeCfgKey+" key in etcd: "+err.Error())
     }
 
-    // Delete inode data by invoking vitastor-rm
+    // Delete inode data by invoking vitastor-cli
     args := []string{
-        "--etcd_address", strings.Join(etcdUrl, ","),
+        "rm", "--etcd_address", strings.Join(etcdUrl, ","),
         "--pool", fmt.Sprintf("%d", idx.PoolId),
         "--inode", fmt.Sprintf("%d", idx.Id),
     }
@@ -364,7 +364,7 @@ func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVol
     {
         args = append(args, "--config_path", ctxVars["configPath"])
     }
-    c := exec.Command("/usr/bin/vitastor-rm", args...)
+    c := exec.Command("/usr/bin/vitastor-cli", args...)
     var stderr bytes.Buffer
     c.Stdout = nil
     c.Stderr = &stderr
@@ -372,7 +372,7 @@ func (cs *ControllerServer) DeleteVolume(ctx context.Context, req *csi.DeleteVol
     stderrStr := string(stderr.Bytes())
     if (err != nil)
     {
-        klog.Errorf("vitastor-rm failed: %s, status %s\n", stderrStr, err)
+        klog.Errorf("vitastor-cli rm failed: %s, status %s\n", stderrStr, err)
         return nil, status.Error(codes.Internal, stderrStr+" (status "+err.Error()+")")
     }
 

debian/changelog

@@ -1,4 +1,4 @@
-vitastor (0.6.4-1) unstable; urgency=medium
+vitastor (0.6.6-1) unstable; urgency=medium
 
   * RDMA support
   * Bugfixes

debian/patched-qemu.Dockerfile

@@ -11,6 +11,10 @@ RUN if [ "$REL" = "buster" ]; then \
         echo 'Package: *' >> /etc/apt/preferences; \
         echo 'Pin: release a=buster-backports' >> /etc/apt/preferences; \
         echo 'Pin-Priority: 500' >> /etc/apt/preferences; \
+        echo >> /etc/apt/preferences; \
+        echo 'Package: libglvnd* libgles* libglx* libgl1 libegl* libopengl* mesa*' >> /etc/apt/preferences; \
+        echo 'Pin: release a=buster-backports' >> /etc/apt/preferences; \
+        echo 'Pin-Priority: 50' >> /etc/apt/preferences; \
     fi; \
     grep '^deb ' /etc/apt/sources.list | perl -pe 's/^deb/deb-src/' >> /etc/apt/sources.list; \
     echo 'APT::Install-Recommends false;' >> /etc/apt/apt.conf; \
@@ -20,20 +24,22 @@ RUN apt-get update
 RUN apt-get -y install qemu fio liburing1 liburing-dev libgoogle-perftools-dev devscripts
 RUN apt-get -y build-dep qemu
 RUN apt-get -y build-dep fio
+# To build a custom version
+#RUN cp /root/packages/qemu-orig/* /root
 RUN apt-get --download-only source qemu
 RUN apt-get --download-only source fio
 
-ADD qemu-5.0-vitastor.patch qemu-5.1-vitastor.patch /root/vitastor/
+ADD patches/qemu-5.0-vitastor.patch patches/qemu-5.1-vitastor.patch /root/vitastor/patches/
 RUN set -e; \
     mkdir -p /root/packages/qemu-$REL; \
     rm -rf /root/packages/qemu-$REL/*; \
     cd /root/packages/qemu-$REL; \
     dpkg-source -x /root/qemu*.dsc; \
     if [ -d /root/packages/qemu-$REL/qemu-5.0 ]; then \
-        cp /root/vitastor/qemu-5.0-vitastor.patch /root/packages/qemu-$REL/qemu-5.0/debian/patches; \
+        cp /root/vitastor/patches/qemu-5.0-vitastor.patch /root/packages/qemu-$REL/qemu-5.0/debian/patches; \
         echo qemu-5.0-vitastor.patch >> /root/packages/qemu-$REL/qemu-5.0/debian/patches/series; \
     else \
-        cp /root/vitastor/qemu-5.1-vitastor.patch /root/packages/qemu-$REL/qemu-*/debian/patches; \
+        cp /root/vitastor/patches/qemu-5.1-vitastor.patch /root/packages/qemu-$REL/qemu-*/debian/patches; \
         P=`ls -d /root/packages/qemu-$REL/qemu-*/debian/patches`; \
         echo qemu-5.1-vitastor.patch >> $P/series; \
     fi; \

debian/vitastor.Dockerfile

@@ -40,10 +40,10 @@ RUN set -e -x; \
     mkdir -p /root/packages/vitastor-$REL; \
     rm -rf /root/packages/vitastor-$REL/*; \
     cd /root/packages/vitastor-$REL; \
-    cp -r /root/vitastor vitastor-0.6.4; \
-    ln -s /root/packages/qemu-$REL/qemu-*/ vitastor-0.6.4/qemu; \
-    ln -s /root/fio-build/fio-*/ vitastor-0.6.4/fio; \
-    cd vitastor-0.6.4; \
+    cp -r /root/vitastor vitastor-0.6.6; \
+    ln -s /root/packages/qemu-$REL/qemu-*/ vitastor-0.6.6/qemu; \
+    ln -s /root/fio-build/fio-*/ vitastor-0.6.6/fio; \
+    cd vitastor-0.6.6; \
     FIO=$(head -n1 fio/debian/changelog | perl -pe 's/^.*\((.*?)\).*$/$1/'); \
     QEMU=$(head -n1 qemu/debian/changelog | perl -pe 's/^.*\((.*?)\).*$/$1/'); \
     sh copy-qemu-includes.sh; \
@@ -59,8 +59,8 @@ RUN set -e -x; \
     echo "dep:fio=$FIO" > debian/substvars; \
     echo "dep:qemu=$QEMU" >> debian/substvars; \
     cd /root/packages/vitastor-$REL; \
-    tar --sort=name --mtime='2020-01-01' --owner=0 --group=0 --exclude=debian -cJf vitastor_0.6.4.orig.tar.xz vitastor-0.6.4; \
-    cd vitastor-0.6.4; \
+    tar --sort=name --mtime='2020-01-01' --owner=0 --group=0 --exclude=debian -cJf vitastor_0.6.6.orig.tar.xz vitastor-0.6.6; \
+    cd vitastor-0.6.6; \
     V=$(head -n1 debian/changelog | perl -pe 's/^.*\((.*?)\).*$/$1/'); \
     DEBFULLNAME="Vitaliy Filippov <vitalif@yourcmc.ru>" dch -D $REL -v "$V""$REL" "Rebuild for $REL"; \
     DEB_BUILD_OPTIONS=nocheck dpkg-buildpackage --jobs=auto -sa; \

docker/Dockerfile

@@ -0,0 +1,9 @@
+# Build Docker image with Vitastor packages
+
+FROM debian:bullseye
+
+ADD vitastor.list /etc/apt/sources.list.d
+ADD vitastor.gpg /etc/apt/trusted.gpg.d
+ADD vitastor.pref /etc/apt/preferences.d
+ADD apt.conf /etc/apt/
+RUN apt-get update && apt-get -y install vitastor qemu-system-x86 qemu-system-common && apt-get clean

docker/apt.conf

@@ -0,0 +1 @@
+APT::Install-Recommends false;

docker/vitastor.list

@@ -0,0 +1 @@
+deb http://vitastor.io/debian bullseye main

docker/vitastor.pref

@@ -0,0 +1,3 @@
+Package: *
+Pin: origin "vitastor.io"
+Pin-Priority: 1000

patches/cinder-vitastor.py

@@ -0,0 +1,948 @@
+# Vitastor Driver for OpenStack Cinder
+#
+# --------------------------------------------
+# Install as cinder/volume/drivers/vitastor.py
+# --------------------------------------------
+#
+# Copyright 2020 Vitaliy Filippov
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+"""Cinder Vitastor Driver"""
+
+import binascii
+import base64
+import errno
+import json
+import math
+import os
+import tempfile
+
+from castellan import key_manager
+from oslo_config import cfg
+from oslo_log import log as logging
+from oslo_service import loopingcall
+from oslo_concurrency import processutils
+from oslo_utils import encodeutils
+from oslo_utils import excutils
+from oslo_utils import fileutils
+from oslo_utils import units
+import six
+from six.moves.urllib import request
+
+from cinder import exception
+from cinder.i18n import _
+from cinder.image import image_utils
+from cinder import interface
+from cinder import objects
+from cinder.objects import fields
+from cinder import utils
+from cinder.volume import configuration
+from cinder.volume import driver
+from cinder.volume import volume_utils
+
+VERSION = '0.6.6'
+
+LOG = logging.getLogger(__name__)
+
+VITASTOR_OPTS = [
+    cfg.StrOpt(
+        'vitastor_config_path',
+        default='/etc/vitastor/vitastor.conf',
+        help='Vitastor configuration file path'
+    ),
+    cfg.StrOpt(
+        'vitastor_etcd_address',
+        default='',
+        help='Vitastor etcd address(es)'),
+    cfg.StrOpt(
+        'vitastor_etcd_prefix',
+        default='/vitastor',
+        help='Vitastor etcd prefix'
+    ),
+    cfg.StrOpt(
+        'vitastor_pool_id',
+        default='',
+        help='Vitastor pool ID to use for volumes'
+    ),
+    # FIXME exclusive_cinder_pool ?
+]
+
+CONF = cfg.CONF
+CONF.register_opts(VITASTOR_OPTS, group = configuration.SHARED_CONF_GROUP)
+
+class VitastorDriverException(exception.VolumeDriverException):
+    message = _("Vitastor Cinder driver failure: %(reason)s")
+
+@interface.volumedriver
+class VitastorDriver(driver.CloneableImageVD,
+    driver.ManageableVD, driver.ManageableSnapshotsVD,
+    driver.BaseVD):
+    """Implements Vitastor volume commands."""
+
+    cfg = {}
+    _etcd_urls = []
+
+    def __init__(self, active_backend_id = None, *args, **kwargs):
+        super(VitastorDriver, self).__init__(*args, **kwargs)
+        self.configuration.append_config_values(VITASTOR_OPTS)
+
+    @classmethod
+    def get_driver_options(cls):
+        additional_opts = cls._get_oslo_driver_opts(
+            'reserved_percentage',
+            'max_over_subscription_ratio',
+            'volume_dd_blocksize'
+        )
+        return VITASTOR_OPTS + additional_opts
+
+    def do_setup(self, context):
+        """Performs initialization steps that could raise exceptions."""
+        super(VitastorDriver, self).do_setup(context)
+        # Make sure configuration is in UTF-8
+        for attr in [ 'config_path', 'etcd_address', 'etcd_prefix', 'pool_id' ]:
+            val = self.configuration.safe_get('vitastor_'+attr)
+            if val is not None:
+                self.cfg[attr] = utils.convert_str(val)
+        self.cfg = self._load_config(self.cfg)
+
+    def _load_config(self, cfg):
+        # Try to load configuration file
+        try:
+            f = open(cfg['config_path'] or '/etc/vitastor/vitastor.conf')
+            conf = json.loads(f.read())
+            f.close()
+            for k in conf:
+                cfg[k] = cfg.get(k, conf[k])
+        except:
+            pass
+        if isinstance(cfg['etcd_address'], str):
+            cfg['etcd_address'] = cfg['etcd_address'].split(',')
+        # Sanitize etcd URLs
+        for i, etcd_url in enumerate(cfg['etcd_address']):
+            ssl = False
+            if etcd_url.lower().startswith('http://'):
+                etcd_url = etcd_url[7:]
+            elif etcd_url.lower().startswith('https://'):
+                etcd_url = etcd_url[8:]
+                ssl = True
+            if etcd_url.find('/') < 0:
+                etcd_url += '/v3'
+            if ssl:
+                etcd_url = 'https://'+etcd_url
+            else:
+                etcd_url = 'http://'+etcd_url
+            cfg['etcd_address'][i] = etcd_url
+        return cfg
+
+    def check_for_setup_error(self):
+        """Returns an error if prerequisites aren't met."""
+
+    def _encode_etcd_key(self, key):
+        if not isinstance(key, bytes):
+            key = str(key).encode('utf-8')
+        return base64.b64encode(self.cfg['etcd_prefix'].encode('utf-8')+b'/'+key).decode('utf-8')
+
+    def _encode_etcd_value(self, value):
+        if not isinstance(value, bytes):
+            value = str(value).encode('utf-8')
+        return base64.b64encode(value).decode('utf-8')
+
+    def _encode_etcd_requests(self, obj):
+        for v in obj:
+            for rt in v:
+                if 'key' in v[rt]:
+                    v[rt]['key'] = self._encode_etcd_key(v[rt]['key'])
+                if 'range_end' in v[rt]:
+                    v[rt]['range_end'] = self._encode_etcd_key(v[rt]['range_end'])
+                if 'value' in v[rt]:
+                    v[rt]['value'] = self._encode_etcd_value(v[rt]['value'])
+
+    def _etcd_txn(self, params):
+        if 'compare' in params:
+            for v in params['compare']:
+                if 'key' in v:
+                    v['key'] = self._encode_etcd_key(v['key'])
+        if 'failure' in params:
+            self._encode_etcd_requests(params['failure'])
+        if 'success' in params:
+            self._encode_etcd_requests(params['success'])
+        body = json.dumps(params).encode('utf-8')
+        headers = {
+            'Content-Type': 'application/json'
+        }
+        err = None
+        for etcd_url in self.cfg['etcd_address']:
+            try:
+                resp = request.urlopen(request.Request(etcd_url+'/kv/txn', body, headers), timeout = 5)
+                data = json.loads(resp.read())
+                if 'responses' not in data:
+                    data['responses'] = []
+                for i, resp in enumerate(data['responses']):
+                    if 'response_range' in resp:
+                        if 'kvs' not in resp['response_range']:
+                            resp['response_range']['kvs'] = []
+                        for kv in resp['response_range']['kvs']:
+                            kv['key'] = base64.b64decode(kv['key'].encode('utf-8')).decode('utf-8')
+                            if kv['key'].startswith(self.cfg['etcd_prefix']+'/'):
+                                kv['key'] = kv['key'][len(self.cfg['etcd_prefix'])+1 : ]
+                            kv['value'] = json.loads(base64.b64decode(kv['value'].encode('utf-8')))
+                    if len(resp.keys()) != 1:
+                        LOG.exception('unknown responses['+str(i)+'] format: '+json.dumps(resp))
+                    else:
+                        resp = data['responses'][i] = resp[list(resp.keys())[0]]
+                return data
+            except Exception as e:
+                LOG.exception('error calling etcd transaction: '+body.decode('utf-8')+'\nerror: '+str(e))
+                err = e
+        raise err
+
+    def _etcd_foreach(self, prefix, add_fn):
+        total = 0
+        batch = 1000
+        begin = prefix+'/'
+        while True:
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': {
+                    'key': begin,
+                    'range_end': prefix+'0',
+                    'limit': batch+1,
+                } },
+            ] })
+            i = 0
+            while i < batch and i < len(resp['responses'][0]['kvs']):
+                kv = resp['responses'][0]['kvs'][i]
+                add_fn(kv)
+                i += 1
+            if len(resp['responses'][0]['kvs']) <= batch:
+                break
+            begin = resp['responses'][0]['kvs'][batch]['key']
+        return total
+
+    def _update_volume_stats(self):
+        location_info = json.dumps({
+            'config': self.configuration.vitastor_config_path,
+            'etcd_address': self.configuration.vitastor_etcd_address,
+            'etcd_prefix': self.configuration.vitastor_etcd_prefix,
+            'pool_id': self.configuration.vitastor_pool_id,
+        })
+
+        stats = {
+            'vendor_name': 'Vitastor',
+            'driver_version': self.VERSION,
+            'storage_protocol': 'vitastor',
+            'total_capacity_gb': 'unknown',
+            'free_capacity_gb': 'unknown',
+            # FIXME check if safe_get is required
+            'reserved_percentage': self.configuration.safe_get('reserved_percentage'),
+            'multiattach': True,
+            'thin_provisioning_support': True,
+            'max_over_subscription_ratio': self.configuration.safe_get('max_over_subscription_ratio'),
+            'location_info': location_info,
+            'backend_state': 'down',
+            'volume_backend_name': self.configuration.safe_get('volume_backend_name') or 'vitastor',
+            'replication_enabled': False,
+        }
+
+        try:
+            pool_stats = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'pool/stats/'+str(self.cfg['pool_id']) } }
+            ] })
+            total_provisioned = 0
+            def add_total(kv):
+                nonlocal total_provisioned
+                if kv['key'].find('@') >= 0:
+                    total_provisioned += kv['value']['size']
+            self._etcd_foreach('config/inode/'+str(self.cfg['pool_id']), lambda kv: add_total(kv))
+            stats['provisioned_capacity_gb'] = round(total_provisioned/1024.0/1024.0/1024.0, 2)
+            pool_stats = pool_stats['responses'][0]['kvs']
+            if len(pool_stats):
+                pool_stats = pool_stats[0]
+                stats['free_capacity_gb'] = round(1024.0*(pool_stats['total_raw_tb']-pool_stats['used_raw_tb'])/pool_stats['raw_to_usable'], 2)
+                stats['total_capacity_gb'] = round(1024.0*pool_stats['total_raw_tb'], 2)
+            stats['backend_state'] = 'up'
+        except Exception as e:
+            # just log and return unknown capacities
+            LOG.exception('error getting vitastor pool stats: '+str(e))
+
+        self._stats = stats
+
+    def _next_id(self, resp):
+        if len(resp['kvs']) == 0:
+            return (1, 0)
+        else:
+            return (1 + resp['kvs'][0]['value'], resp['kvs'][0]['mod_revision'])
+
+    def create_volume(self, volume):
+        """Creates a logical volume."""
+
+        size = int(volume.size) * units.Gi
+        # FIXME: Check if convert_str is really required
+        vol_name = utils.convert_str(volume.name)
+        if vol_name.find('@') >= 0 or vol_name.find('/') >= 0:
+            raise exception.VolumeBackendAPIException(data = '@ and / are forbidden in volume and snapshot names')
+
+        LOG.debug("creating volume '%s'", vol_name)
+
+        self._create_image(vol_name, { 'size': size })
+
+        if volume.encryption_key_id:
+            self._create_encrypted_volume(volume, volume.obj_context)
+
+        volume_update = {}
+        return volume_update
+
+    def _create_encrypted_volume(self, volume, context):
+        """Create a new LUKS encrypted image directly in Vitastor."""
+        vol_name = utils.convert_str(volume.name)
+        f, opts = self._encrypt_opts(volume, context)
+        # FIXME: Check if it works at all :-)
+        self._execute(
+            'qemu-img', 'convert', '-f', 'luks', *opts,
+            'vitastor:image='+vol_name.replace(':', '\\:')+self._qemu_args(),
+            '%sM' % (volume.size * 1024)
+        )
+        f.close()
+
+    def _encrypt_opts(self, volume, context):
+        encryption = volume_utils.check_encryption_provider(self.db, volume, context)
+        # Fetch the key associated with the volume and decode the passphrase
+        keymgr = key_manager.API(CONF)
+        key = keymgr.get(context, encryption['encryption_key_id'])
+        passphrase = binascii.hexlify(key.get_encoded()).decode('utf-8')
+        # Decode the dm-crypt style cipher spec into something qemu-img can use
+        cipher_spec = image_utils.decode_cipher(encryption['cipher'], encryption['key_size'])
+        tmp_dir = volume_utils.image_conversion_dir()
+        f = tempfile.NamedTemporaryFile(prefix = 'luks_', dir = tmp_dir)
+        f.write(passphrase)
+        f.flush()
+        return (f, [
+            '--object', 'secret,id=luks_sec,format=raw,file=%(passfile)s' % {'passfile': f.name},
+            '-o', 'key-secret=luks_sec,cipher-alg=%(cipher_alg)s,cipher-mode=%(cipher_mode)s,ivgen-alg=%(ivgen_alg)s' % cipher_spec,
+        ])
+
+    def create_snapshot(self, snapshot):
+        """Creates a volume snapshot."""
+
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = utils.convert_str(snapshot.name)
+        if snap_name.find('@') >= 0 or snap_name.find('/') >= 0:
+            raise exception.VolumeBackendAPIException(data = '@ and / are forbidden in volume and snapshot names')
+        self._create_snapshot(vol_name, vol_name+'@'+snap_name)
+
+    def snapshot_revert_use_temp_snapshot(self):
+        """Disable the use of a temporary snapshot on revert."""
+        return False
+
+    def revert_to_snapshot(self, context, volume, snapshot):
+        """Revert a volume to a given snapshot."""
+
+        # FIXME Delete the image, then recreate it from the snapshot
+
+    def delete_snapshot(self, snapshot):
+        """Deletes a snapshot."""
+
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = utils.convert_str(snapshot.name)
+
+        # Find the snapshot
+        resp = self._etcd_txn({ 'success': [
+            { 'request_range': { 'key': 'index/image/'+vol_name+'@'+snap_name } },
+        ] })
+        if len(resp['responses'][0]['kvs']) == 0:
+            raise exception.SnapshotNotFound(snapshot_id = snap_name)
+        inode_id = int(resp['responses'][0]['kvs'][0]['value']['id'])
+        pool_id = int(resp['responses'][0]['kvs'][0]['value']['pool_id'])
+        parents = {}
+        parents[(pool_id << 48) | (inode_id & 0xffffffffffff)] = True
+
+        # Check if there are child volumes
+        children = self._child_count(parents)
+        if children > 0:
+            raise exception.SnapshotIsBusy(snapshot_name = snap_name)
+
+        # FIXME: We can't delete snapshots because we can't merge layers yet
+        raise exception.VolumeBackendAPIException(data = 'Snapshot delete (layer merge) is not implemented yet')
+
+    def _child_count(self, parents):
+        children = 0
+        def add_child(kv):
+            nonlocal children
+            children += self._check_parent(kv, parents)
+        self._etcd_foreach('config/inode', lambda kv: add_child(kv))
+        return children
+
+    def _check_parent(self, kv, parents):
+        if 'parent_id' not in kv['value']:
+            return 0
+        parent_id = kv['value']['parent_id']
+        _, _, pool_id, inode_id = kv['key'].split('/')
+        parent_pool_id = pool_id
+        if 'parent_pool_id' in kv['value'] and kv['value']['parent_pool_id']:
+            parent_pool_id = kv['value']['parent_pool_id']
+        inode = (int(pool_id) << 48) | (int(inode_id) & 0xffffffffffff)
+        parent = (int(parent_pool_id) << 48) | (int(parent_id) & 0xffffffffffff)
+        if parent in parents and inode not in parents:
+            return 1
+        return 0
+
+    def create_cloned_volume(self, volume, src_vref):
+        """Create a cloned volume from another volume."""
+
+        size = int(volume.size) * units.Gi
+        src_name = utils.convert_str(src_vref.name)
+        dest_name = utils.convert_str(volume.name)
+        if dest_name.find('@') >= 0 or dest_name.find('/') >= 0:
+            raise exception.VolumeBackendAPIException(data = '@ and / are forbidden in volume and snapshot names')
+
+        # FIXME Do full copy if requested (cfg.disable_clone)
+
+        if src_vref.admin_metadata.get('readonly') == 'True':
+            # source volume is a volume-image cache entry or other readonly volume
+            # clone without intermediate snapshot
+            src = self._get_image(src_name)
+            LOG.debug("creating image '%s' from '%s'", dest_name, src_name)
+            new_cfg = self._create_image(dest_name, {
+                'size': size,
+                'parent_id': src['idx']['id'],
+                'parent_pool_id': src['idx']['pool_id'],
+            })
+            return {}
+
+        clone_snap = "%s@%s.clone_snap" % (src_name, dest_name)
+        make_img = True
+        if (volume.display_name and
+            volume.display_name.startswith('image-') and
+            src_vref.project_id != volume.project_id):
+            # idiotic openstack creates image-volume cache entries
+            # as clones of normal VM volumes... :-X prevent it :-D
+            clone_snap = dest_name
+            make_img = False
+
+        LOG.debug("creating layer '%s' under '%s'", clone_snap, src_name)
+        new_cfg = self._create_snapshot(src_name, clone_snap, True)
+        if make_img:
+            # Then create a clone from it
+            new_cfg = self._create_image(dest_name, {
+                'size': size,
+                'parent_id': new_cfg['parent_id'],
+                'parent_pool_id': new_cfg['parent_pool_id'],
+            })
+
+        return {}
+
+    def create_volume_from_snapshot(self, volume, snapshot):
+        """Creates a cloned volume from an existing snapshot."""
+
+        vol_name = utils.convert_str(volume.name)
+        snap_name = utils.convert_str(snapshot.name)
+
+        snap = self._get_image(vol_name+'@'+snap_name)
+        if not snap:
+            raise exception.SnapshotNotFound(snapshot_id = snap_name)
+        snap_inode_id = int(resp['responses'][0]['kvs'][0]['value']['id'])
+        snap_pool_id = int(resp['responses'][0]['kvs'][0]['value']['pool_id'])
+
+        size = snap['cfg']['size']
+        if int(volume.size):
+            size = int(volume.size) * units.Gi
+        new_cfg = self._create_image(vol_name, {
+            'size': size,
+            'parent_id': snap['idx']['id'],
+            'parent_pool_id': snap['idx']['pool_id'],
+        })
+
+        return {}
+
+    def _vitastor_args(self):
+        args = []
+        for k in [ 'config_path', 'etcd_address', 'etcd_prefix' ]:
+            v = self.configuration.safe_get('vitastor_'+k)
+            if v:
+                args.extend(['--'+k, v])
+        return args
+
+    def _qemu_args(self):
+        args = ''
+        for k in [ 'config_path', 'etcd_address', 'etcd_prefix' ]:
+            v = self.configuration.safe_get('vitastor_'+k)
+            kk = k
+            if kk == 'etcd_address':
+                # FIXME use etcd_address in qemu driver
+                kk = 'etcd_host'
+            if v:
+                args += ':'+kk+'='+v.replace(':', '\\:')
+        return args
+
+    def delete_volume(self, volume):
+        """Deletes a logical volume."""
+
+        vol_name = utils.convert_str(volume.name)
+
+        # Find the volume and all its snapshots
+        range_end = b'index/image/' + vol_name.encode('utf-8')
+        range_end = range_end[0 : len(range_end)-1] + six.int2byte(range_end[len(range_end)-1] + 1)
+        resp = self._etcd_txn({ 'success': [
+            { 'request_range': { 'key': 'index/image/'+vol_name, 'range_end': range_end } },
+        ] })
+        if len(resp['responses'][0]['kvs']) == 0:
+            # already deleted
+            LOG.info("volume %s no longer exists in backend", vol_name)
+            return
+        layers = resp['responses'][0]['kvs']
+        layer_ids = {}
+        for kv in layers:
+            inode_id = int(kv['value']['id'])
+            pool_id = int(kv['value']['pool_id'])
+            inode_pool_id = (pool_id << 48) | (inode_id & 0xffffffffffff)
+            layer_ids[inode_pool_id] = True
+
+        # Check if the volume has clones and raise 'busy' if so
+        children = self._child_count(layer_ids)
+        if children > 0:
+            raise exception.VolumeIsBusy(volume_name = vol_name)
+
+        # Clear data
+        for kv in layers:
+            args = [
+                'vitastor-cli', 'rm', '--pool', str(kv['value']['pool_id']),
+                '--inode', str(kv['value']['id']), '--progress', '0',
+                *(self._vitastor_args())
+            ]
+            try:
+                self._execute(*args)
+            except processutils.ProcessExecutionError as exc:
+                LOG.error("Failed to remove layer "+kv['key']+": "+exc)
+                raise exception.VolumeBackendAPIException(data = exc.stderr)
+
+        # Delete all layers from etcd
+        requests = []
+        for kv in layers:
+            requests.append({ 'request_delete_range': { 'key': kv['key'] } })
+            requests.append({ 'request_delete_range': { 'key': 'config/inode/'+str(kv['value']['pool_id'])+'/'+str(kv['value']['id']) } })
+        self._etcd_txn({ 'success': requests })
+
+    def retype(self, context, volume, new_type, diff, host):
+        """Change extra type specifications for a volume."""
+
+        # FIXME Maybe (in the future) support multiple pools as different types
+        return True, {}
+
+    def ensure_export(self, context, volume):
+        """Synchronously recreates an export for a logical volume."""
+        pass
+
+    def create_export(self, context, volume, connector):
+        """Exports the volume."""
+        pass
+
+    def remove_export(self, context, volume):
+        """Removes an export for a logical volume."""
+        pass
+
+    def _create_image(self, vol_name, cfg):
+        pool_s = str(self.cfg['pool_id'])
+        image_id = 0
+        while image_id == 0:
+            # check if the image already exists and find a free ID
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'index/image/'+vol_name } },
+                { 'request_range': { 'key': 'index/maxid/'+pool_s } },
+            ] })
+            if len(resp['responses'][0]['kvs']) > 0:
+                # already exists
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' already exists')
+            image_id, id_mod = self._next_id(resp['responses'][1])
+            # try to create the image
+            resp = self._etcd_txn({ 'compare': [
+                { 'target': 'MOD', 'mod_revision': id_mod, 'key': 'index/maxid/'+pool_s },
+                { 'target': 'VERSION', 'version': 0, 'key': 'index/image/'+vol_name },
+                { 'target': 'VERSION', 'version': 0, 'key': 'config/inode/'+pool_s+'/'+str(image_id) },
+            ], 'success': [
+                { 'request_put': { 'key': 'index/maxid/'+pool_s, 'value': image_id } },
+                { 'request_put': { 'key': 'index/image/'+vol_name, 'value': json.dumps({
+                    'id': image_id, 'pool_id': self.cfg['pool_id']
+                }) } },
+                { 'request_put': { 'key': 'config/inode/'+pool_s+'/'+str(image_id), 'value': json.dumps({
+                    **cfg, 'name': vol_name,
+                }) } },
+            ] })
+            if not resp.get('succeeded'):
+                # repeat
+                image_id = 0
+
+    def _create_snapshot(self, vol_name, snap_vol_name, allow_existing = False):
+        while True:
+            # check if the image already exists and snapshot doesn't
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'index/image/'+vol_name } },
+                { 'request_range': { 'key': 'index/image/'+snap_vol_name } },
+            ] })
+            if len(resp['responses'][0]['kvs']) == 0:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' does not exist')
+            if len(resp['responses'][1]['kvs']) > 0:
+                if allow_existing:
+                    snap_idx = resp['responses'][1]['kvs'][0]['value']
+                    resp = self._etcd_txn({ 'success': [
+                        { 'request_range': { 'key': 'config/inode/'+str(snap_idx['pool_id'])+'/'+str(snap_idx['id']) } },
+                    ] })
+                    if len(resp['responses'][0]['kvs']) == 0:
+                        raise exception.VolumeBackendAPIException(data =
+                            'Volume '+snap_vol_name+' is already indexed, but does not exist'
+                        )
+                    return resp['responses'][0]['kvs'][0]['value']
+                raise exception.VolumeBackendAPIException(
+                    data = 'Volume '+snap_vol_name+' already exists'
+                )
+            vol_idx = resp['responses'][0]['kvs'][0]['value']
+            vol_idx_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+            # get image inode config and find a new ID
+            resp = self._etcd_txn({ 'success': [
+                { 'request_range': { 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']) } },
+                { 'request_range': { 'key': 'index/maxid/'+str(self.cfg['pool_id']) } },
+            ] })
+            if len(resp['responses'][0]['kvs']) == 0:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' does not exist')
+            vol_cfg = resp['responses'][0]['kvs'][0]['value']
+            vol_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+            new_id, id_mod = self._next_id(resp['responses'][1])
+            # try to redirect image to the new inode
+            new_cfg = {
+                **vol_cfg, 'name': vol_name, 'parent_id': vol_idx['id'], 'parent_pool_id': vol_idx['pool_id']
+            }
+            resp = self._etcd_txn({ 'compare': [
+                { 'target': 'MOD', 'mod_revision': vol_idx_mod, 'key': 'index/image/'+vol_name },
+                { 'target': 'MOD', 'mod_revision': vol_mod, 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']) },
+                { 'target': 'MOD', 'mod_revision': id_mod, 'key': 'index/maxid/'+str(self.cfg['pool_id']) },
+                { 'target': 'VERSION', 'version': 0, 'key': 'index/image/'+snap_vol_name },
+                { 'target': 'VERSION', 'version': 0, 'key': 'config/inode/'+str(self.cfg['pool_id'])+'/'+str(new_id) },
+            ], 'success': [
+                { 'request_put': { 'key': 'index/maxid/'+str(self.cfg['pool_id']), 'value': new_id } },
+                { 'request_put': { 'key': 'index/image/'+vol_name, 'value': json.dumps({
+                    'id': new_id, 'pool_id': self.cfg['pool_id']
+                }) } },
+                { 'request_put': { 'key': 'config/inode/'+str(self.cfg['pool_id'])+'/'+str(new_id), 'value': json.dumps(new_cfg) } },
+                { 'request_put': { 'key': 'index/image/'+snap_vol_name, 'value': json.dumps({
+                    'id': vol_idx['id'], 'pool_id': vol_idx['pool_id']
+                }) } },
+                { 'request_put': { 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']), 'value': json.dumps({
+                    **vol_cfg, 'name': snap_vol_name, 'readonly': True
+                }) } }
+            ] })
+            if resp.get('succeeded'):
+                return new_cfg
+
+    def initialize_connection(self, volume, connector):
+        data = {
+            'driver_volume_type': 'vitastor',
+            'data': {
+                'config_path': self.configuration.vitastor_config_path,
+                'etcd_address': self.configuration.vitastor_etcd_address,
+                'etcd_prefix': self.configuration.vitastor_etcd_prefix,
+                'name': volume.name,
+                'logical_block_size': 512,
+                'physical_block_size': 4096,
+            }
+        }
+        LOG.debug('connection data: %s', data)
+        return data
+
+    def terminate_connection(self, volume, connector, **kwargs):
+        pass
+
+    def clone_image(self, context, volume, image_location, image_meta, image_service):
+        if image_location:
+            # Note: image_location[0] is glance image direct_url.
+            # image_location[1] contains the list of all locations (including
+            # direct_url) or None if show_multiple_locations is False in
+            # glance configuration.
+            if image_location[1]:
+                url_locations = [location['url'] for location in image_location[1]]
+            else:
+                url_locations = [image_location[0]]
+            # iterate all locations to look for a cloneable one.
+            for url_location in url_locations:
+                if url_location and url_location.startswith('cinder://'):
+                    # The idea is to use cinder://<volume-id> Glance volumes as base images
+                    base_vol = self.db.volume_get(context, url_location[len('cinder://') : ])
+                    if not base_vol or base_vol.volume_type_id != volume.volume_type_id:
+                        continue
+                    size = int(volume.size) * units.Gi
+                    dest_name = utils.convert_str(volume.name)
+                    # Find or create the base snapshot
+                    snap_cfg = self._create_snapshot(base_vol.name, base_vol.name+'@.clone_snap', True)
+                    # Then create a clone from it
+                    new_cfg = self._create_image(dest_name, {
+                        'size': size,
+                        'parent_id': snap_cfg['parent_id'],
+                        'parent_pool_id': snap_cfg['parent_pool_id'],
+                    })
+                    return ({}, True)
+        return ({}, False)
+
+    def copy_image_to_encrypted_volume(self, context, volume, image_service, image_id):
+        self.copy_image_to_volume(context, volume, image_service, image_id, encrypted = True)
+
+    def copy_image_to_volume(self, context, volume, image_service, image_id, encrypted = False):
+        tmp_dir = volume_utils.image_conversion_dir()
+        with tempfile.NamedTemporaryFile(dir = tmp_dir) as tmp:
+            image_utils.fetch_to_raw(
+                context, image_service, image_id, tmp.name,
+                self.configuration.volume_dd_blocksize, size = volume.size
+            )
+            out_format = [ '-O', 'raw' ]
+            if encrypted:
+                key_file, opts = self._encrypt_opts(volume, context)
+                out_format = [ '-O', 'luks', *opts ]
+            dest_name = utils.convert_str(volume.name)
+            self._try_execute(
+                'qemu-img', 'convert', '-f', 'raw', tmp.name, *out_format,
+                'vitastor:image='+dest_name.replace(':', '\\:')+self._qemu_args()
+            )
+            if encrypted:
+                key_file.close()
+
+    def copy_volume_to_image(self, context, volume, image_service, image_meta):
+        tmp_dir = volume_utils.image_conversion_dir()
+        tmp_file = os.path.join(tmp_dir, volume.name + '-' + image_meta['id'])
+        with fileutils.remove_path_on_error(tmp_file):
+            vol_name = utils.convert_str(volume.name)
+            self._try_execute(
+                'qemu-img', 'convert', '-f', 'raw',
+                'vitastor:image='+vol_name.replace(':', '\\:')+self._qemu_args(),
+                '-O', 'raw', tmp_file
+            )
+            # FIXME: Copy directly if the destination image is also in Vitastor
+            volume_utils.upload_volume(context, image_service, image_meta, tmp_file, volume)
+        os.unlink(tmp_file)
+
+    def _get_image(self, vol_name):
+        # find the image
+        resp = self._etcd_txn({ 'success': [
+            { 'request_range': { 'key': 'index/image/'+vol_name } },
+        ] })
+        if len(resp['responses'][0]['kvs']) == 0:
+            return None
+        vol_idx = resp['responses'][0]['kvs'][0]['value']
+        vol_idx_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+        # get image inode config
+        resp = self._etcd_txn({ 'success': [
+            { 'request_range': { 'key': 'config/inode/'+str(vol_idx['pool_id'])+'/'+str(vol_idx['id']) } },
+        ] })
+        if len(resp['responses'][0]['kvs']) == 0:
+            return None
+        vol_cfg = resp['responses'][0]['kvs'][0]['value']
+        vol_cfg_mod = resp['responses'][0]['kvs'][0]['mod_revision']
+        return {
+            'cfg': vol_cfg,
+            'cfg_mod': vol_cfg_mod,
+            'idx': vol_idx,
+            'idx_mod': vol_idx_mod,
+        }
+
+    def extend_volume(self, volume, new_size):
+        """Extend an existing volume."""
+        vol_name = utils.convert_str(volume.name)
+        while True:
+            vol = self._get_image(vol_name)
+            if not vol:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+vol_name+' does not exist')
+            # change size
+            size = int(new_size) * units.Gi
+            if size == vol['cfg']['size']:
+                break
+            resp = self._etcd_txn({ 'compare': [ {
+                'target': 'MOD',
+                'mod_revision': vol['cfg_mod'],
+                'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']),
+            } ], 'success': [
+                { 'request_put': {
+                    'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']),
+                    'value': json.dumps({ **vol['cfg'], 'size': size }),
+                } },
+            ] })
+            if resp.get('succeeded'):
+                break
+        LOG.debug(
+            "Extend volume from %(old_size)s GB to %(new_size)s GB.",
+            {'old_size': volume.size, 'new_size': new_size}
+        )
+
+    def _add_manageable_volume(self, kv, manageable_volumes, cinder_ids):
+        cfg = kv['value']
+        if kv['key'].find('@') >= 0:
+            # snapshot
+            return
+        image_id = volume_utils.extract_id_from_volume_name(cfg['name'])
+        image_info = {
+            'reference': {'source-name': image_name},
+            'size': int(math.ceil(float(cfg['size']) / units.Gi)),
+            'cinder_id': None,
+            'extra_info': None,
+        }
+        if image_id in cinder_ids:
+            image_info['cinder_id'] = image_id
+            image_info['safe_to_manage'] = False
+            image_info['reason_not_safe'] = 'already managed'
+        else:
+            image_info['safe_to_manage'] = True
+            image_info['reason_not_safe'] = None
+        manageable_volumes.append(image_info)
+
+    def get_manageable_volumes(self, cinder_volumes, marker, limit, offset, sort_keys, sort_dirs):
+        manageable_volumes = []
+        cinder_ids = [resource['id'] for resource in cinder_volumes]
+
+        # List all volumes
+        # FIXME: It's possible to use pagination in our case, but.. do we want it?
+        self._etcd_foreach('config/inode/'+str(self.cfg['pool_id']),
+            lambda kv: self._add_manageable_volume(kv, manageable_volumes, cinder_ids))
+
+        return volume_utils.paginate_entries_list(
+            manageable_volumes, marker, limit, offset, sort_keys, sort_dirs)
+
+    def _get_existing_name(existing_ref):
+        if not isinstance(existing_ref, dict):
+            existing_ref = {"source-name": existing_ref}
+        if 'source-name' not in existing_ref:
+            reason = _('Reference must contain source-name element.')
+            raise exception.ManageExistingInvalidReference(existing_ref=existing_ref, reason=reason)
+        src_name = utils.convert_str(existing_ref['source-name'])
+        if not src_name:
+            reason = _('Reference must contain source-name element.')
+            raise exception.ManageExistingInvalidReference(existing_ref=existing_ref, reason=reason)
+        return src_name
+
+    def manage_existing_get_size(self, volume, existing_ref):
+        """Return size of an existing image for manage_existing.
+
+        :param volume: volume ref info to be set
+        :param existing_ref: {'source-name': <image name>}
+        """
+        src_name = self._get_existing_name(existing_ref)
+        vol = self._get_image(src_name)
+        if not vol:
+            raise exception.VolumeBackendAPIException(data = 'Volume '+src_name+' does not exist')
+        return int(math.ceil(float(vol['cfg']['size']) / units.Gi))
+
+    def manage_existing(self, volume, existing_ref):
+        """Manages an existing image.
+
+        Renames the image name to match the expected name for the volume.
+
+        :param volume: volume ref info to be set
+        :param existing_ref: {'source-name': <image name>}
+        """
+        from_name = self._get_existing_name(existing_ref)
+        to_name = utils.convert_str(volume.name)
+        self._rename(from_name, to_name)
+
+    def _rename(self, from_name, to_name):
+        while True:
+            vol = self._get_image(from_name)
+            if not vol:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+from_name+' does not exist')
+            to = self._get_image(to_name)
+            if to:
+                raise exception.VolumeBackendAPIException(data = 'Volume '+to_name+' already exists')
+            resp = self._etcd_txn({ 'compare': [
+                { 'target': 'MOD', 'mod_revision': vol['idx_mod'], 'key': 'index/image/'+vol['cfg']['name'] },
+                { 'target': 'MOD', 'mod_revision': vol['cfg_mod'], 'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']) },
+                { 'target': 'VERSION', 'version': 0, 'key': 'index/image/'+to_name },
+            ], 'success': [
+                { 'request_delete_range': { 'key': 'index/image/'+vol['cfg']['name'] } },
+                { 'request_put': { 'key': 'index/image/'+to_name, 'value': json.dumps(vol['idx']) } },
+                { 'request_put': { 'key': 'config/inode/'+str(vol['idx']['pool_id'])+'/'+str(vol['idx']['id']),
+                    'value': json.dumps({ **vol['cfg'], 'name': to_name }) } },
+            ] })
+            if resp.get('succeeded'):
+                break
+
+    def unmanage(self, volume):
+        pass
+
+    def _add_manageable_snapshot(self, kv, manageable_snapshots, cinder_ids):
+        cfg = kv['value']
+        dog = kv['key'].find('@')
+        if dog < 0:
+            # snapshot
+            return
+        image_name = kv['key'][0 : dog]
+        snap_name = kv['key'][dog+1 : ]
+        snapshot_id = volume_utils.extract_id_from_snapshot_name(snap_name)
+        snapshot_info = {
+            'reference': {'source-name': snap_name},
+            'size': int(math.ceil(float(cfg['size']) / units.Gi)),
+            'cinder_id': None,
+            'extra_info': None,
+            'safe_to_manage': False,
+            'reason_not_safe': None,
+            'source_reference': {'source-name': image_name}
+        }
+        if snapshot_id in cinder_ids:
+            # Exclude snapshots already managed.
+            snapshot_info['reason_not_safe'] = ('already managed')
+            snapshot_info['cinder_id'] = snapshot_id
+        elif snap_name.endswith('.clone_snap'):
+            # Exclude clone snapshot.
+            snapshot_info['reason_not_safe'] = ('used for clone snap')
+        else:
+            snapshot_info['safe_to_manage'] = True
+        manageable_snapshots.append(snapshot_info)
+
+    def get_manageable_snapshots(self, cinder_snapshots, marker, limit, offset, sort_keys, sort_dirs):
+        """List manageable snapshots in Vitastor."""
+        manageable_snapshots = []
+        cinder_snapshot_ids = [resource['id'] for resource in cinder_snapshots]
+        # List all volumes
+        # FIXME: It's possible to use pagination in our case, but.. do we want it?
+        self._etcd_foreach('config/inode/'+str(self.cfg['pool_id']),
+            lambda kv: self._add_manageable_volume(kv, manageable_snapshots, cinder_snapshot_ids))
+        return volume_utils.paginate_entries_list(
+            manageable_snapshots, marker, limit, offset, sort_keys, sort_dirs)
+
+    def manage_existing_snapshot_get_size(self, snapshot, existing_ref):
+        """Return size of an existing image for manage_existing.
+
+        :param snapshot: snapshot ref info to be set
+        :param existing_ref: {'source-name': <name of snapshot>}
+        """
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = self._get_existing_name(existing_ref)
+        vol = self._get_image(vol_name+'@'+snap_name)
+        if not vol:
+            raise exception.ManageExistingInvalidReference(
+                existing_ref=snapshot_name, reason='Specified snapshot does not exist.'
+            )
+        return int(math.ceil(float(vol['cfg']['size']) / units.Gi))
+
+    def manage_existing_snapshot(self, snapshot, existing_ref):
+        """Manages an existing snapshot.
+
+        Renames the snapshot name to match the expected name for the snapshot.
+        Error checking done by manage_existing_get_size is not repeated.
+
+        :param snapshot: snapshot ref info to be set
+        :param existing_ref: {'source-name': <name of snapshot>}
+        """
+        vol_name = utils.convert_str(snapshot.volume_name)
+        snap_name = self._get_existing_name(existing_ref)
+        from_name = vol_name+'@'+snap_name
+        to_name = vol_name+'@'+utils.convert_str(snapshot.name)
+        self._rename(from_name, to_name)
+
+    def unmanage_snapshot(self, snapshot):
+        """Removes the specified snapshot from Cinder management."""
+        pass
+
+    def _dumps(self, obj):
+        return json.dumps(obj, separators=(',', ':'), sort_keys=True)

patches/devstack-local.conf

@@ -0,0 +1,23 @@
+# Devstack configuration for bridged networking
+
+[[local|localrc]]
+ADMIN_PASSWORD=secret
+DATABASE_PASSWORD=$ADMIN_PASSWORD
+RABBIT_PASSWORD=$ADMIN_PASSWORD
+SERVICE_PASSWORD=$ADMIN_PASSWORD
+HOST_IP=10.0.2.15
+Q_USE_SECGROUP=True
+FLOATING_RANGE="10.0.2.0/24"
+IPV4_ADDRS_SAFE_TO_USE="10.0.5.0/24"
+Q_FLOATING_ALLOCATION_POOL=start=10.0.2.50,end=10.0.2.100
+PUBLIC_NETWORK_GATEWAY=10.0.2.2
+PUBLIC_INTERFACE=ens3
+Q_USE_PROVIDERNET_FOR_PUBLIC=True
+Q_AGENT=linuxbridge
+Q_ML2_PLUGIN_MECHANISM_DRIVERS=linuxbridge
+LB_PHYSICAL_INTERFACE=ens3
+PUBLIC_PHYSICAL_NETWORK=default
+LB_INTERFACE_MAPPINGS=default:ens3
+Q_SERVICE_PLUGIN_CLASSES=
+Q_ML2_PLUGIN_TYPE_DRIVERS=flat
+Q_ML2_PLUGIN_EXT_DRIVERS=

patches/nova-20.diff

@@ -0,0 +1,287 @@
+diff --git a/nova/virt/image/model.py b/nova/virt/image/model.py
+index 971f7e9c07..70ed70d5e2 100644
+--- a/nova/virt/image/model.py
++++ b/nova/virt/image/model.py
+@@ -129,3 +129,22 @@ class RBDImage(Image):
+         self.user = user
+         self.password = password
+         self.servers = servers
++
++
++class VitastorImage(Image):
++    """Class for images in a remote Vitastor cluster"""
++
++    def __init__(self, name, etcd_address = None, etcd_prefix = None, config_path = None):
++        """Create a new Vitastor image object
++
++        :param name: name of the image
++        :param etcd_address: etcd URL(s) (optional)
++        :param etcd_prefix: etcd prefix (optional)
++        :param config_path: path to the configuration (optional)
++        """
++        super(RBDImage, self).__init__(FORMAT_RAW)
++
++        self.name = name
++        self.etcd_address = etcd_address
++        self.etcd_prefix = etcd_prefix
++        self.config_path = config_path
+diff --git a/nova/virt/images.py b/nova/virt/images.py
+index 5358f3766a..ebe3d6effb 100644
+--- a/nova/virt/images.py
++++ b/nova/virt/images.py
+@@ -41,7 +41,7 @@ IMAGE_API = glance.API()
+ 
+ def qemu_img_info(path, format=None):
+     """Return an object containing the parsed output from qemu-img info."""
+-    if not os.path.exists(path) and not path.startswith('rbd:'):
++    if not os.path.exists(path) and not path.startswith('rbd:') and not path.startswith('vitastor:'):
+         raise exception.DiskNotFound(location=path)
+ 
+     info = nova.privsep.qemu.unprivileged_qemu_img_info(path, format=format)
+@@ -50,7 +50,7 @@ def qemu_img_info(path, format=None):
+ 
+ def privileged_qemu_img_info(path, format=None, output_format='json'):
+     """Return an object containing the parsed output from qemu-img info."""
+-    if not os.path.exists(path) and not path.startswith('rbd:'):
++    if not os.path.exists(path) and not path.startswith('rbd:') and not path.startswith('vitastor:'):
+         raise exception.DiskNotFound(location=path)
+ 
+     info = nova.privsep.qemu.privileged_qemu_img_info(path, format=format)
+diff --git a/nova/virt/libvirt/config.py b/nova/virt/libvirt/config.py
+index f9475776b3..51573fe41d 100644
+--- a/nova/virt/libvirt/config.py
++++ b/nova/virt/libvirt/config.py
+@@ -1060,6 +1060,8 @@ class LibvirtConfigGuestDisk(LibvirtConfigGuestDevice):
+         self.driver_iommu = False
+         self.source_path = None
+         self.source_protocol = None
++        self.source_query = None
++        self.source_config = None
+         self.source_name = None
+         self.source_hosts = []
+         self.source_ports = []
+@@ -1186,7 +1188,8 @@ class LibvirtConfigGuestDisk(LibvirtConfigGuestDevice):
+         elif self.source_type == "mount":
+             dev.append(etree.Element("source", dir=self.source_path))
+         elif self.source_type == "network" and self.source_protocol:
+-            source = etree.Element("source", protocol=self.source_protocol)
++            source = etree.Element("source", protocol=self.source_protocol,
++                query=self.source_query, config=self.source_config)
+             if self.source_name is not None:
+                 source.set('name', self.source_name)
+             hosts_info = zip(self.source_hosts, self.source_ports)
+diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
+index 391231c527..34dc60dcdd 100644
+--- a/nova/virt/libvirt/driver.py
++++ b/nova/virt/libvirt/driver.py
+@@ -179,6 +179,7 @@ VOLUME_DRIVERS = {
+     'local': 'nova.virt.libvirt.volume.volume.LibvirtVolumeDriver',
+     'fake': 'nova.virt.libvirt.volume.volume.LibvirtFakeVolumeDriver',
+     'rbd': 'nova.virt.libvirt.volume.net.LibvirtNetVolumeDriver',
++    'vitastor': 'nova.virt.libvirt.volume.vitastor.LibvirtVitastorVolumeDriver',
+     'nfs': 'nova.virt.libvirt.volume.nfs.LibvirtNFSVolumeDriver',
+     'smbfs': 'nova.virt.libvirt.volume.smbfs.LibvirtSMBFSVolumeDriver',
+     'fibre_channel': 'nova.virt.libvirt.volume.fibrechannel.LibvirtFibreChannelVolumeDriver',  # noqa:E501
+@@ -385,10 +386,10 @@ class LibvirtDriver(driver.ComputeDriver):
+         # This prevents the risk of one test setting a capability
+         # which bleeds over into other tests.
+ 
+-        # LVM and RBD require raw images. If we are not configured to
++        # LVM, RBD, Vitastor require raw images. If we are not configured to
+         # force convert images into raw format, then we _require_ raw
+         # images only.
+-        raw_only = ('rbd', 'lvm')
++        raw_only = ('rbd', 'lvm', 'vitastor')
+         requires_raw_image = (CONF.libvirt.images_type in raw_only and
+                               not CONF.force_raw_images)
+         requires_ploop_image = CONF.libvirt.virt_type == 'parallels'
+@@ -775,12 +776,12 @@ class LibvirtDriver(driver.ComputeDriver):
+         # Some imagebackends are only able to import raw disk images,
+         # and will fail if given any other format. See the bug
+         # https://bugs.launchpad.net/nova/+bug/1816686 for more details.
+-        if CONF.libvirt.images_type in ('rbd',):
++        if CONF.libvirt.images_type in ('rbd', 'vitastor'):
+             if not CONF.force_raw_images:
+                 msg = _("'[DEFAULT]/force_raw_images = False' is not "
+-                        "allowed with '[libvirt]/images_type = rbd'. "
++                        "allowed with '[libvirt]/images_type = rbd' or 'vitastor'. "
+                         "Please check the two configs and if you really "
+-                        "do want to use rbd as images_type, set "
++                        "do want to use rbd or vitastor as images_type, set "
+                         "force_raw_images to True.")
+                 raise exception.InvalidConfiguration(msg)
+ 
+@@ -2603,6 +2604,16 @@ class LibvirtDriver(driver.ComputeDriver):
+                     if connection_info['data'].get('auth_enabled'):
+                         username = connection_info['data']['auth_username']
+                         path = f"rbd:{volume_name}:id={username}"
++                elif connection_info['driver_volume_type'] == 'vitastor':
++                    volume_name = connection_info['data']['name']
++                    path = 'vitastor:image='+volume_name.replace(':', '\\:')
++                    for k in [ 'config_path', 'etcd_address', 'etcd_prefix' ]:
++                        if k in connection_info['data']:
++                            kk = k
++                            if kk == 'etcd_address':
++                                # FIXME use etcd_address in qemu driver
++                                kk = 'etcd_host'
++                            path += ":"+kk+"="+connection_info['data'][k].replace(':', '\\:')
+                 else:
+                     path = 'unknown'
+                     raise exception.DiskNotFound(location='unknown')
+@@ -2827,8 +2838,8 @@ class LibvirtDriver(driver.ComputeDriver):
+ 
+         image_format = CONF.libvirt.snapshot_image_format or source_type
+ 
+-        # NOTE(bfilippov): save lvm and rbd as raw
+-        if image_format == 'lvm' or image_format == 'rbd':
++        # NOTE(bfilippov): save lvm and rbd and vitastor as raw
++        if image_format == 'lvm' or image_format == 'rbd' or image_format == 'vitastor':
+             image_format = 'raw'
+ 
+         metadata = self._create_snapshot_metadata(instance.image_meta,
+@@ -2899,7 +2910,7 @@ class LibvirtDriver(driver.ComputeDriver):
+                               expected_state=task_states.IMAGE_UPLOADING)
+ 
+             # TODO(nic): possibly abstract this out to the root_disk
+-            if source_type == 'rbd' and live_snapshot:
++            if (source_type == 'rbd' or source_type == 'vitastor') and live_snapshot:
+                 # Standard snapshot uses qemu-img convert from RBD which is
+                 # not safe to run with live_snapshot.
+                 live_snapshot = False
+@@ -4099,7 +4110,7 @@ class LibvirtDriver(driver.ComputeDriver):
+         # cleanup rescue volume
+         lvm.remove_volumes([lvmdisk for lvmdisk in self._lvm_disks(instance)
+                                 if lvmdisk.endswith('.rescue')])
+-        if CONF.libvirt.images_type == 'rbd':
++        if CONF.libvirt.images_type == 'rbd' or CONF.libvirt.images_type == 'vitastor':
+             filter_fn = lambda disk: (disk.startswith(instance.uuid) and
+                                       disk.endswith('.rescue'))
+             rbd_utils.RBDDriver().cleanup_volumes(filter_fn)
+@@ -4356,6 +4367,8 @@ class LibvirtDriver(driver.ComputeDriver):
+         # TODO(mikal): there is a bug here if images_type has
+         # changed since creation of the instance, but I am pretty
+         # sure that this bug already exists.
++        if CONF.libvirt.images_type == 'vitastor':
++            return 'vitastor'
+         return 'rbd' if CONF.libvirt.images_type == 'rbd' else 'raw'
+ 
+     @staticmethod
+@@ -4764,10 +4777,10 @@ class LibvirtDriver(driver.ComputeDriver):
+                 finally:
+                     # NOTE(mikal): if the config drive was imported into RBD,
+                     # then we no longer need the local copy
+-                    if CONF.libvirt.images_type == 'rbd':
++                    if CONF.libvirt.images_type == 'rbd' or CONF.libvirt.images_type == 'vitastor':
+                         LOG.info('Deleting local config drive %(path)s '
+-                                 'because it was imported into RBD.',
+-                                 {'path': config_disk_local_path},
++                                 'because it was imported into %(type).',
++                                 {'path': config_disk_local_path, 'type': CONF.libvirt.images_type},
+                                  instance=instance)
+                         os.unlink(config_disk_local_path)
+ 
+diff --git a/nova/virt/libvirt/utils.py b/nova/virt/libvirt/utils.py
+index da2a6e8b8a..52c02e72f1 100644
+--- a/nova/virt/libvirt/utils.py
++++ b/nova/virt/libvirt/utils.py
+@@ -340,6 +340,10 @@ def find_disk(guest: libvirt_guest.Guest) -> ty.Tuple[str, ty.Optional[str]]:
+             disk_path = disk.source_name
+             if disk_path:
+                 disk_path = 'rbd:' + disk_path
++        elif not disk_path and disk.source_protocol == 'vitastor':
++            disk_path = disk.source_name
++            if disk_path:
++                disk_path = 'vitastor:' + disk_path
+ 
+     if not disk_path:
+         raise RuntimeError(_("Can't retrieve root device path "
+@@ -354,6 +358,8 @@ def get_disk_type_from_path(path: str) -> ty.Optional[str]:
+         return 'lvm'
+     elif path.startswith('rbd:'):
+         return 'rbd'
++    elif path.startswith('vitastor:'):
++        return 'vitastor'
+     elif (os.path.isdir(path) and
+           os.path.exists(os.path.join(path, "DiskDescriptor.xml"))):
+         return 'ploop'
+diff --git a/nova/virt/libvirt/volume/vitastor.py b/nova/virt/libvirt/volume/vitastor.py
+new file mode 100644
+index 0000000000..0256df62c1
+--- /dev/null
++++ b/nova/virt/libvirt/volume/vitastor.py
+@@ -0,0 +1,75 @@
++# Copyright (c) 2021+, Vitaliy Filippov <vitalif@yourcmc.ru>
++#
++#    Licensed under the Apache License, Version 2.0 (the "License"); you may
++#    not use this file except in compliance with the License. You may obtain
++#    a copy of the License at
++#
++#         http://www.apache.org/licenses/LICENSE-2.0
++#
++#    Unless required by applicable law or agreed to in writing, software
++#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
++#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
++#    License for the specific language governing permissions and limitations
++#    under the License.
++
++from os_brick import exception as os_brick_exception
++from os_brick import initiator
++from os_brick.initiator import connector
++from oslo_log import log as logging
++
++import nova.conf
++from nova import utils
++from nova.virt.libvirt.volume import volume as libvirt_volume
++
++
++CONF = nova.conf.CONF
++LOG = logging.getLogger(__name__)
++
++
++class LibvirtVitastorVolumeDriver(libvirt_volume.LibvirtBaseVolumeDriver):
++    """Driver to attach Vitastor volumes to libvirt."""
++    def __init__(self, host):
++        super(LibvirtVitastorVolumeDriver, self).__init__(host, is_block_dev=False)
++
++    def connect_volume(self, connection_info, instance):
++        pass
++
++    def disconnect_volume(self, connection_info, instance):
++        pass
++
++    def get_config(self, connection_info, disk_info):
++        """Returns xml for libvirt."""
++        conf = super(LibvirtVitastorVolumeDriver, self).get_config(connection_info, disk_info)
++        conf.source_type = 'network'
++        conf.source_protocol = 'vitastor'
++        conf.source_name = connection_info['data'].get('name')
++        conf.source_query = connection_info['data'].get('etcd_prefix') or None
++        conf.source_config = connection_info['data'].get('config_path') or None
++        conf.source_hosts = []
++        conf.source_ports = []
++        addresses = connection_info['data'].get('etcd_address', '')
++        if addresses:
++            if not isinstance(addresses, list):
++                addresses = addresses.split(',')
++            for addr in addresses:
++                if addr.startswith('https://'):
++                    raise NotImplementedError('Vitastor block driver does not support SSL for etcd communication yet')
++                if addr.startswith('http://'):
++                    addr = addr[7:]
++                addr = addr.rstrip('/')
++                if addr.endswith('/v3'):
++                    addr = addr[0:-3]
++                p = addr.find('/')
++                if p > 0:
++                    raise NotImplementedError('libvirt does not support custom URL paths for Vitastor etcd yet. Use /etc/vitastor/vitastor.conf')
++                p = addr.find(':')
++                port = '2379'
++                if p > 0:
++                    port = addr[p+1:]
++                    addr = addr[0:p]
++                conf.source_hosts.append(addr)
++                conf.source_ports.append(port)
++        return conf
++
++    def extend_volume(self, connection_info, instance, requested_size):
++        raise NotImplementedError

rpm/build-tarball.sh

@@ -48,4 +48,4 @@ FIO=`rpm -qi fio | perl -e 'while(<>) { /^Epoch[\s:]+(\S+)/ && print "$1:"; /^Ve
 QEMU=`rpm -qi qemu qemu-kvm | perl -e 'while(<>) { /^Epoch[\s:]+(\S+)/ && print "$1:"; /^Version[\s:]+(\S+)/ && print $1; /^Release[\s:]+(\S+)/ && print "-$1"; }'`
 perl -i -pe 's/(Requires:\s*fio)([^\n]+)?/$1 = '$FIO'/' $VITASTOR/rpm/vitastor-el$EL.spec
 perl -i -pe 's/(Requires:\s*qemu(?:-kvm)?)([^\n]+)?/$1 = '$QEMU'/' $VITASTOR/rpm/vitastor-el$EL.spec
-tar --transform 's#^#vitastor-0.6.4/#' --exclude 'rpm/*.rpm' -czf $VITASTOR/../vitastor-0.6.4$(rpm --eval '%dist').tar.gz *
+tar --transform 's#^#vitastor-0.6.6/#' --exclude 'rpm/*.rpm' -czf $VITASTOR/../vitastor-0.6.6$(rpm --eval '%dist').tar.gz *

rpm/qemu-el8.Dockerfile

@@ -11,7 +11,7 @@ RUN rm -rf /var/lib/dnf/*; dnf download --disablerepo='*' --enablerepo='centos-a
 RUN rpm --nomd5 -i qemu*.src.rpm
 RUN cd ~/rpmbuild/SPECS && dnf builddep -y --enablerepo=PowerTools --spec qemu-kvm.spec
 
-ADD qemu-*-vitastor.patch /root/vitastor/
+ADD patches/qemu-*-vitastor.patch /root/vitastor/patches/
 
 RUN set -e; \
     mkdir -p /root/packages/qemu-el8; \
@@ -25,7 +25,7 @@ RUN set -e; \
     echo "Patch$((PN+1)): qemu-4.2-vitastor.patch" >> qemu-kvm.spec; \
     tail -n +2 xx01 >> qemu-kvm.spec; \
     perl -i -pe 's/(^Release:\s*\d+)/$1.vitastor/' qemu-kvm.spec; \
-    cp /root/vitastor/qemu-4.2-vitastor.patch ~/rpmbuild/SOURCES; \
+    cp /root/vitastor/patches/qemu-4.2-vitastor.patch ~/rpmbuild/SOURCES; \
     rpmbuild --nocheck -ba qemu-kvm.spec; \
     cp ~/rpmbuild/RPMS/*/*qemu* /root/packages/qemu-el8/; \
     cp ~/rpmbuild/SRPMS/*qemu* /root/packages/qemu-el8/

rpm/vitastor-el7.Dockerfile

@@ -15,8 +15,8 @@ RUN yumdownloader --disablerepo=centos-sclo-rh --source fio
 RUN rpm --nomd5 -i qemu*.src.rpm
 RUN rpm --nomd5 -i fio*.src.rpm
 RUN rm -f /etc/yum.repos.d/CentOS-Media.repo
-RUN cd ~/rpmbuild/SPECS && yum-builddep -y --enablerepo='*' --disablerepo=centos-sclo-rh --disablerepo=centos-sclo-rh-source --disablerepo=centos-sclo-sclo-testing qemu-kvm.spec
-RUN cd ~/rpmbuild/SPECS && yum-builddep -y --enablerepo='*' --disablerepo=centos-sclo-rh --disablerepo=centos-sclo-rh-source --disablerepo=centos-sclo-sclo-testing fio.spec
+RUN cd ~/rpmbuild/SPECS && yum-builddep -y qemu-kvm.spec
+RUN cd ~/rpmbuild/SPECS && yum-builddep -y fio.spec
 RUN yum -y install rdma-core-devel
 
 ADD https://vitastor.io/rpms/liburing-el7/liburing-0.7-2.el7.src.rpm /root
@@ -38,7 +38,7 @@ ADD . /root/vitastor
 RUN set -e; \
     cd /root/vitastor/rpm; \
     sh build-tarball.sh; \
-    cp /root/vitastor-0.6.4.el7.tar.gz ~/rpmbuild/SOURCES; \
+    cp /root/vitastor-0.6.6.el7.tar.gz ~/rpmbuild/SOURCES; \
     cp vitastor-el7.spec ~/rpmbuild/SPECS/vitastor.spec; \
     cd ~/rpmbuild/SPECS/; \
     rpmbuild -ba vitastor.spec; \

rpm/vitastor-el7.spec

@@ -1,11 +1,11 @@
 Name:           vitastor
-Version:        0.6.4
+Version:        0.6.6
 Release:        1%{?dist}
 Summary:        Vitastor, a fast software-defined clustered block storage
 
 License:        Vitastor Network Public License 1.1
 URL:            https://vitastor.io/
-Source0:        vitastor-0.6.4.el7.tar.gz
+Source0:        vitastor-0.6.6.el7.tar.gz
 
 BuildRequires:  liburing-devel >= 0.6
 BuildRequires:  gperftools-devel
@@ -57,6 +57,7 @@ cp -r mon %buildroot/usr/lib/vitastor/mon
 %_bindir/vitastor-dump-journal
 %_bindir/vitastor-nbd
 %_bindir/vitastor-osd
+%_bindir/vitastor-cli
 %_bindir/vitastor-rm
 %_libdir/qemu-kvm/block-vitastor.so
 %_libdir/libfio_vitastor.so

rpm/vitastor-el8.Dockerfile

@@ -15,7 +15,7 @@ RUN rpm --nomd5 -i qemu*.src.rpm
 RUN rpm --nomd5 -i fio*.src.rpm
 RUN cd ~/rpmbuild/SPECS && dnf builddep -y --enablerepo=powertools --spec qemu-kvm.spec
 RUN cd ~/rpmbuild/SPECS && dnf builddep -y --enablerepo=powertools --spec fio.spec && dnf install -y cmake
-RUN yum -y install libibverbs-devel
+RUN yum -y install libibverbs-devel libarchive
 
 ADD https://vitastor.io/rpms/liburing-el7/liburing-0.7-2.el7.src.rpm /root
 
@@ -36,7 +36,7 @@ ADD . /root/vitastor
 RUN set -e; \
     cd /root/vitastor/rpm; \
     sh build-tarball.sh; \
-    cp /root/vitastor-0.6.4.el8.tar.gz ~/rpmbuild/SOURCES; \
+    cp /root/vitastor-0.6.6.el8.tar.gz ~/rpmbuild/SOURCES; \
     cp vitastor-el8.spec ~/rpmbuild/SPECS/vitastor.spec; \
     cd ~/rpmbuild/SPECS/; \
     rpmbuild -ba vitastor.spec; \

rpm/vitastor-el8.spec

@@ -1,11 +1,11 @@
 Name:           vitastor
-Version:        0.6.4
+Version:        0.6.6
 Release:        1%{?dist}
 Summary:        Vitastor, a fast software-defined clustered block storage
 
 License:        Vitastor Network Public License 1.1
 URL:            https://vitastor.io/
-Source0:        vitastor-0.6.4.el8.tar.gz
+Source0:        vitastor-0.6.6.el8.tar.gz
 
 BuildRequires:  liburing-devel >= 0.6
 BuildRequires:  gperftools-devel
@@ -54,6 +54,7 @@ cp -r mon %buildroot/usr/lib/vitastor
 %_bindir/vitastor-dump-journal
 %_bindir/vitastor-nbd
 %_bindir/vitastor-osd
+%_bindir/vitastor-cli
 %_bindir/vitastor-rm
 %_libdir/qemu-kvm/block-vitastor.so
 %_libdir/libfio_vitastor.so

src/CMakeLists.txt

@@ -15,8 +15,8 @@ if("${CMAKE_INSTALL_PREFIX}" MATCHES "^/usr/local/?$")
 	set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR}")
 endif()
 
-add_definitions(-DVERSION="0.6.4")
-add_definitions(-Wall -Wno-sign-compare -Wno-comment -Wno-parentheses -Wno-pointer-arith -I ${CMAKE_SOURCE_DIR}/src)
+add_definitions(-DVERSION="0.6.6")
+add_definitions(-Wall -Wno-sign-compare -Wno-comment -Wno-parentheses -Wno-pointer-arith -fdiagnostics-color=always -I ${CMAKE_SOURCE_DIR}/src)
 if (${WITH_ASAN})
 	add_definitions(-fsanitize=address -fno-omit-frame-pointer)
 	add_link_options(-fsanitize=address -fno-omit-frame-pointer)
@@ -36,6 +36,11 @@ string(REGEX REPLACE "([\\/\\-]D) *NDEBUG" "" CMAKE_C_FLAGS_RELEASE "${CMAKE_C_F
 string(REGEX REPLACE "([\\/\\-]D) *NDEBUG" "" CMAKE_C_FLAGS_MINSIZEREL "${CMAKE_C_FLAGS_MINSIZEREL}")
 string(REGEX REPLACE "([\\/\\-]D) *NDEBUG" "" CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO}")
 
+macro(install_symlink filepath sympath)
+	install(CODE "execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink ${filepath} ${sympath})")
+	install(CODE "message(\"-- Created symlink: ${sympath} -> ${filepath}\")")
+endmacro(install_symlink)
+
 find_package(PkgConfig)
 pkg_check_modules(LIBURING REQUIRED liburing)
 if (${WITH_QEMU})
@@ -116,6 +121,7 @@ endif (${WITH_FIO})
 # libvitastor_client.so
 add_library(vitastor_client SHARED
 	cluster_client.cpp
+	cluster_client_list.cpp
 	vitastor_c.cpp
 )
 set_target_properties(vitastor_client PROPERTIES PUBLIC_HEADER "vitastor_c.h")
@@ -145,11 +151,11 @@ target_link_libraries(vitastor-nbd
 	vitastor_client
 )
 
-# vitastor-rm
-add_executable(vitastor-rm
-	rm_inode.cpp
+# vitastor-cli
+add_executable(vitastor-cli
+	cli.cpp cli_flatten.cpp cli_merge.cpp cli_rm.cpp cli_snap_rm.cpp
 )
-target_link_libraries(vitastor-rm
+target_link_libraries(vitastor-cli
 	vitastor_client
 )
 
@@ -220,7 +226,7 @@ target_link_libraries(test_cas
 # test_cluster_client
 add_executable(test_cluster_client
 	test_cluster_client.cpp
-	pg_states.cpp osd_ops.cpp cluster_client.cpp msgr_op.cpp mock/messenger.cpp msgr_stop.cpp
+	pg_states.cpp osd_ops.cpp cluster_client.cpp cluster_client_list.cpp msgr_op.cpp mock/messenger.cpp msgr_stop.cpp
 	etcd_state_client.cpp timerfd_manager.cpp ../json11/json11.cpp
 )
 target_compile_definitions(test_cluster_client PUBLIC -D__MOCK__)
@@ -234,7 +240,8 @@ target_include_directories(test_cluster_client PUBLIC ${CMAKE_SOURCE_DIR}/src/mo
 
 ### Install
 
-install(TARGETS vitastor-osd vitastor-dump-journal vitastor-nbd vitastor-rm RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+install(TARGETS vitastor-osd vitastor-dump-journal vitastor-nbd vitastor-cli RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+install_symlink(${CMAKE_INSTALL_BINDIR}/vitastor-rm vitastor-cli)
 install(
 	TARGETS vitastor_blk vitastor_client
 	LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}

src/blockstore.cpp

@@ -48,6 +48,11 @@ std::map<uint64_t, uint64_t> & blockstore_t::get_inode_space_stats()
     return impl->inode_space_stats;
 }
 
+void blockstore_t::dump_diagnostics()
+{
+    return impl->dump_diagnostics();
+}
+
 uint32_t blockstore_t::get_block_size()
 {
     return impl->get_block_size();

src/blockstore.h

@@ -186,6 +186,9 @@ public:
     // Get per-inode space usage statistics
     std::map<uint64_t, uint64_t> & get_inode_space_stats();
 
+    // Print diagnostics to stdout
+    void dump_diagnostics();
+
     // FIXME rename to object_size
     uint32_t get_block_size();
     uint64_t get_block_count();

src/blockstore_flush.cpp

@@ -182,6 +182,75 @@ void journal_flusher_t::release_trim()
     trim_wanted--;
 }
 
+void journal_flusher_t::dump_diagnostics()
+{
+    const char *unflushable_type = "";
+    obj_ver_id unflushable = { 0 };
+    // Try to find out if there is a flushable object for information
+    for (object_id cur_oid: flush_queue)
+    {
+        obj_ver_id cur = { .oid = cur_oid, .version = flush_versions[cur_oid] };
+        auto dirty_end = bs->dirty_db.find(cur);
+        if (dirty_end == bs->dirty_db.end())
+        {
+            // Already flushed
+            continue;
+        }
+        auto repeat_it = sync_to_repeat.find(cur.oid);
+        if (repeat_it != sync_to_repeat.end())
+        {
+            // Someone is already flushing it
+            unflushable_type = "locked,";
+            unflushable = cur;
+            break;
+        }
+        if (dirty_end->second.journal_sector >= bs->journal.dirty_start &&
+            (bs->journal.dirty_start >= bs->journal.used_start ||
+            dirty_end->second.journal_sector < bs->journal.used_start))
+        {
+            // Object is more recent than possible to flush
+            bool found = try_find_older(dirty_end, cur);
+            if (!found)
+            {
+                unflushable_type = "dirty,";
+                unflushable = cur;
+                break;
+            }
+        }
+        unflushable_type = "ok,";
+        unflushable = cur;
+        break;
+    }
+    printf(
+        "Flusher: queued=%ld first=%s%lx:%lx trim_wanted=%d dequeuing=%d trimming=%d cur=%d target=%d active=%d syncing=%d\n",
+        flush_queue.size(), unflushable_type, unflushable.oid.inode, unflushable.oid.stripe,
+        trim_wanted, dequeuing, trimming, cur_flusher_count, target_flusher_count,
+        active_flushers, syncing_flushers
+    );
+}
+
+bool journal_flusher_t::try_find_older(std::map<obj_ver_id, dirty_entry>::iterator & dirty_end, obj_ver_id & cur)
+{
+    bool found = false;
+    while (dirty_end != bs->dirty_db.begin())
+    {
+        dirty_end--;
+        if (dirty_end->first.oid != cur.oid)
+        {
+            break;
+        }
+        if (!(dirty_end->second.journal_sector >= bs->journal.dirty_start &&
+            (bs->journal.dirty_start >= bs->journal.used_start ||
+            dirty_end->second.journal_sector < bs->journal.used_start)))
+        {
+            found = true;
+            cur.version = dirty_end->first.version;
+            break;
+        }
+    }
+    return found;
+}
+
 #define await_sqe(label) \
     resume_##label:\
         sqe = bs->get_sqe();\
@@ -286,30 +355,15 @@ stop_flusher:
             // And it may even block writes if we don't flush the older version
             // (if it's in the beginning of the journal)...
             // So first try to find an older version of the same object to flush.
-            bool found = false;
-            while (dirty_end != bs->dirty_db.begin())
-            {
-                dirty_end--;
-                if (dirty_end->first.oid != cur.oid)
-                {
-                    break;
-                }
-                if (!(dirty_end->second.journal_sector >= bs->journal.dirty_start &&
-                    (bs->journal.dirty_start >= bs->journal.used_start ||
-                    dirty_end->second.journal_sector < bs->journal.used_start)))
-                {
-                    found = true;
-                    cur.version = dirty_end->first.version;
-                    break;
-                }
-            }
+            bool found = flusher->try_find_older(dirty_end, cur);
             if (!found)
             {
                 // Try other objects
                 flusher->sync_to_repeat.erase(cur.oid);
                 int search_left = flusher->flush_queue.size() - 1;
 #ifdef BLOCKSTORE_DEBUG
-                printf("Flusher overran writers (dirty_start=%08lx) - searching for older flushes (%d left)\n", bs->journal.dirty_start, search_left);
+                printf("Flusher overran writers (%lx:%lx v%lu, dirty_start=%08lx) - searching for older flushes (%d left)\n",
+                    cur.oid.inode, cur.oid.stripe, cur.version, bs->journal.dirty_start, search_left);
 #endif
                 while (search_left > 0)
                 {
@@ -332,7 +386,12 @@ stop_flusher:
                         else
                         {
                             repeat_it = flusher->sync_to_repeat.find(cur.oid);
-                            if (repeat_it == flusher->sync_to_repeat.end())
+                            if (repeat_it != flusher->sync_to_repeat.end())
+                            {
+                                if (repeat_it->second < cur.version)
+                                    repeat_it->second = cur.version;
+                            }
+                            else
                             {
                                 flusher->sync_to_repeat[cur.oid] = 0;
                                 break;

src/blockstore_flush.h

@@ -97,6 +97,9 @@ class journal_flusher_t
     std::map<uint64_t, meta_sector_t> meta_sectors;
     std::deque<object_id> flush_queue;
     std::map<object_id, uint64_t> flush_versions;
+
+    bool try_find_older(std::map<obj_ver_id, dirty_entry>::iterator & dirty_end, obj_ver_id & cur);
+
 public:
     journal_flusher_t(blockstore_impl_t *bs);
     ~journal_flusher_t();
@@ -108,4 +111,5 @@ public:
     void enqueue_flush(obj_ver_id oid);
     void unshift_flush(obj_ver_id oid, bool force);
     void remove_flush(object_id oid);
+    void dump_diagnostics();
 };

src/blockstore_impl.cpp

@@ -595,3 +595,9 @@ void blockstore_impl_t::process_list(blockstore_op_t *op)
     op->buf = stable;
     FINISH_OP(op);
 }
+
+void blockstore_impl_t::dump_diagnostics()
+{
+    journal.dump_diagnostics();
+    flusher->dump_diagnostics();
+}

src/blockstore_impl.h

@@ -361,6 +361,9 @@ public:
     // Space usage statistics
     std::map<uint64_t, uint64_t> inode_space_stats;
 
+    // Print diagnostics to stdout
+    void dump_diagnostics();
+
     inline uint32_t get_block_size() { return block_size; }
     inline uint64_t get_block_count() { return block_count; }
     inline uint64_t get_free_block_count() { return data_alloc->get_free_count(); }

src/blockstore_journal.cpp

@@ -218,3 +218,19 @@ uint64_t journal_t::get_trim_pos()
     // Can't trim journal
     return used_start;
 }
+
+void journal_t::dump_diagnostics()
+{
+    auto journal_used_it = used_sectors.lower_bound(used_start);
+    if (journal_used_it == used_sectors.end())
+    {
+        // Journal is cleared to its end, restart from the beginning
+        journal_used_it = used_sectors.begin();
+    }
+    printf(
+        "Journal: used_start=%08lx next_free=%08lx dirty_start=%08lx trim_to=%08lx trim_to_refs=%ld\n",
+        used_start, next_free, dirty_start,
+        journal_used_it == used_sectors.end() ? 0 : journal_used_it->first,
+        journal_used_it == used_sectors.end() ? 0 : journal_used_it->second
+    );
+}

src/blockstore_journal.h

@@ -180,6 +180,7 @@ struct journal_t
     ~journal_t();
     bool trim();
     uint64_t get_trim_pos();
+    void dump_diagnostics();
     inline bool entry_fits(int size)
     {
         return !(block_size - in_sector_pos < size ||

src/blockstore_write.cpp

@@ -478,15 +478,15 @@ resume_2:
     }
 resume_4:
     // Switch object state
-#ifdef BLOCKSTORE_DEBUG
-    printf("Ack write %lx:%lx v%lu = state 0x%x\n", op->oid.inode, op->oid.stripe, op->version, dirty_it->second.state);
-#endif
     {
         auto dirty_it = dirty_db.find((obj_ver_id){
             .oid = op->oid,
             .version = op->version,
         });
         assert(dirty_it != dirty_db.end());
+#ifdef BLOCKSTORE_DEBUG
+        printf("Ack write %lx:%lx v%lu = state 0x%x\n", op->oid.inode, op->oid.stripe, op->version, dirty_it->second.state);
+#endif
         bool is_big = (dirty_it->second.state & BS_ST_TYPE_MASK) == BS_ST_BIG_WRITE;
         bool imm = is_big ? (immediate_commit == IMMEDIATE_ALL) : (immediate_commit != IMMEDIATE_NONE);
         if (imm)

src/cli.cpp

@@ -0,0 +1,251 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+/**
+ * CLI tool
+ * Currently can (a) remove inodes and (b) merge snapshot/clone layers
+ */
+
+#include <vector>
+#include <algorithm>
+
+#include "cli.h"
+#include "epoll_manager.h"
+#include "cluster_client.h"
+#include "pg_states.h"
+#include "base64.h"
+
+static const char *exe_name = NULL;
+
+json11::Json::object cli_tool_t::parse_args(int narg, const char *args[])
+{
+    json11::Json::object cfg;
+    json11::Json::array cmd;
+    cfg["progress"] = "1";
+    for (int i = 1; i < narg; i++)
+    {
+        if (!strcmp(args[i], "-h") || !strcmp(args[i], "--help"))
+        {
+            help();
+        }
+        else if (args[i][0] == '-' && args[i][1] == '-')
+        {
+            const char *opt = args[i]+2;
+            cfg[opt] = !strcmp(opt, "json") || !strcmp(opt, "wait-list") || i == narg-1 ? "1" : args[++i];
+        }
+        else
+        {
+            cmd.push_back(std::string(args[i]));
+        }
+    }
+    if (!cmd.size())
+    {
+        std::string exe(exe_name);
+        if (exe.substr(exe.size()-11) == "vitastor-rm")
+        {
+            cmd.push_back("rm-data");
+        }
+    }
+    cfg["command"] = cmd;
+    return cfg;
+}
+
+void cli_tool_t::help()
+{
+    printf(
+        "Vitastor command-line tool\n"
+        "(c) Vitaliy Filippov, 2019+ (VNPL-1.1)\n\n"
+        "USAGE:\n"
+        "%s rm-data [OPTIONS] --pool <pool> --inode <inode> [--wait-list]\n"
+        "  Remove inode data without changing metadata.\n"
+        "  --wait-list means first retrieve objects listings and then remove it.\n"
+        "  --wait-list requires more memory, but allows to show correct stats.\n"
+        "\n"
+        "%s merge-data [OPTIONS] <from> <to> [--target <target>]\n"
+        "  Merge layer data without changing metadata. Merge <from>..<to> to <target>.\n"
+        "  <to> must be a child of <from> and <target> may be one of the layers between\n"
+        "  <from> and <to>, including <from> and <to>.\n"
+        "\n"
+        "%s flatten [OPTIONS] <layer>\n"
+        "  Flatten a layer, i.e. merge data and detach it from parents\n"
+        "\n"
+        "%s rm [OPTIONS] <from> [<to>] [--writers-stopped 1]\n"
+        "  Remove <from> or all layers between <from> and <to> (<to> must be a child of <from>),\n"
+        "  rebasing all their children accordingly. One of deleted parents may be renamed to one\n"
+        "  of children \"to be rebased\", but only if that child itself is readonly or if\n"
+        "  --writers-stopped 1 is specified\n"
+        "\n"
+        "OPTIONS (global):\n"
+        "  --etcd_address <etcd_address>\n"
+        "  --iodepth N         Send N operations in parallel to each OSD when possible (default 32)\n"
+        "  --parallel_osds M   Work with M osds in parallel when possible (default 4)\n"
+        "  --progress 1|0      Report progress (default 1)\n"
+        "  --cas 1|0           Use online CAS writes when possible (default auto)\n"
+        ,
+        exe_name, exe_name, exe_name, exe_name
+    );
+    exit(0);
+}
+
+void cli_tool_t::change_parent(inode_t cur, inode_t new_parent)
+{
+    auto cur_cfg_it = cli->st_cli.inode_config.find(cur);
+    if (cur_cfg_it == cli->st_cli.inode_config.end())
+    {
+        fprintf(stderr, "Inode 0x%lx disappeared\n", cur);
+        exit(1);
+    }
+    inode_config_t new_cfg = cur_cfg_it->second;
+    std::string cur_name = new_cfg.name;
+    std::string cur_cfg_key = base64_encode(cli->st_cli.etcd_prefix+
+        "/config/inode/"+std::to_string(INODE_POOL(cur))+
+        "/"+std::to_string(INODE_NO_POOL(cur)));
+    new_cfg.parent_id = new_parent;
+    json11::Json::object cur_cfg_json = cli->st_cli.serialize_inode_cfg(&new_cfg);
+    waiting++;
+    cli->st_cli.etcd_txn(json11::Json::object {
+        { "compare", json11::Json::array {
+            json11::Json::object {
+                { "target", "MOD" },
+                { "key", cur_cfg_key },
+                { "result", "LESS" },
+                { "mod_revision", new_cfg.mod_revision+1 },
+            },
+        } },
+        { "success", json11::Json::array {
+            json11::Json::object {
+                { "request_put", json11::Json::object {
+                    { "key", cur_cfg_key },
+                    { "value", base64_encode(json11::Json(cur_cfg_json).dump()) },
+                } }
+            },
+        } },
+    }, ETCD_SLOW_TIMEOUT, [this, new_parent, cur, cur_name](std::string err, json11::Json res)
+    {
+        if (err != "")
+        {
+            fprintf(stderr, "Error changing parent of %s: %s\n", cur_name.c_str(), err.c_str());
+            exit(1);
+        }
+        if (!res["succeeded"].bool_value())
+        {
+            fprintf(stderr, "Inode %s was modified during snapshot deletion\n", cur_name.c_str());
+            exit(1);
+        }
+        if (new_parent)
+        {
+            auto new_parent_it = cli->st_cli.inode_config.find(new_parent);
+            std::string new_parent_name = new_parent_it != cli->st_cli.inode_config.end()
+                ? new_parent_it->second.name : "<unknown>";
+            printf(
+                "Parent of layer %s (inode %lu in pool %u) changed to %s (inode %lu in pool %u)\n",
+                cur_name.c_str(), INODE_NO_POOL(cur), INODE_POOL(cur),
+                new_parent_name.c_str(), INODE_NO_POOL(new_parent), INODE_POOL(new_parent)
+            );
+        }
+        else
+        {
+            printf(
+                "Parent of layer %s (inode %lu in pool %u) detached\n",
+                cur_name.c_str(), INODE_NO_POOL(cur), INODE_POOL(cur)
+            );
+        }
+        waiting--;
+        ringloop->wakeup();
+    });
+}
+
+inode_config_t* cli_tool_t::get_inode_cfg(const std::string & name)
+{
+    for (auto & ic: cli->st_cli.inode_config)
+    {
+        if (ic.second.name == name)
+        {
+            return &ic.second;
+        }
+    }
+    fprintf(stderr, "Layer %s not found\n", name.c_str());
+    exit(1);
+}
+
+void cli_tool_t::run(json11::Json cfg)
+{
+    json11::Json::array cmd = cfg["command"].array_items();
+    if (!cmd.size())
+    {
+        fprintf(stderr, "command is missing\n");
+        exit(1);
+    }
+    else if (cmd[0] == "rm-data")
+    {
+        // Delete inode data
+        action_cb = start_rm(cfg);
+    }
+    else if (cmd[0] == "merge-data")
+    {
+        // Merge layer data without affecting metadata
+        action_cb = start_merge(cfg);
+    }
+    else if (cmd[0] == "flatten")
+    {
+        // Merge layer data without affecting metadata
+        action_cb = start_flatten(cfg);
+    }
+    else if (cmd[0] == "rm")
+    {
+        // Remove multiple snapshots and rebase their children
+        action_cb = start_snap_rm(cfg);
+    }
+    else
+    {
+        fprintf(stderr, "unknown command: %s\n", cmd[0].string_value().c_str());
+        exit(1);
+    }
+    iodepth = cfg["iodepth"].uint64_value();
+    if (!iodepth)
+        iodepth = 32;
+    parallel_osds = cfg["parallel_osds"].uint64_value();
+    if (!parallel_osds)
+        parallel_osds = 4;
+    log_level = cfg["log_level"].int64_value();
+    progress = cfg["progress"].uint64_value() ? true : false;
+    list_first = cfg["wait-list"].uint64_value() ? true : false;
+    // Create client
+    ringloop = new ring_loop_t(512);
+    epmgr = new epoll_manager_t(ringloop);
+    cli = new cluster_client_t(ringloop, epmgr->tfd, cfg);
+    cli->on_ready([this]()
+    {
+        // Initialize job
+        consumer.loop = [this]()
+        {
+            if (action_cb != NULL)
+            {
+                bool done = action_cb();
+                if (done)
+                {
+                    action_cb = NULL;
+                }
+            }
+            ringloop->submit();
+        };
+        ringloop->register_consumer(&consumer);
+        consumer.loop();
+    });
+    // Loop until it completes
+    while (action_cb != NULL)
+    {
+        ringloop->loop();
+        ringloop->wait();
+    }
+}
+
+int main(int narg, const char *args[])
+{
+    setvbuf(stdout, NULL, _IONBF, 0);
+    setvbuf(stderr, NULL, _IONBF, 0);
+    exe_name = args[0];
+    cli_tool_t *p = new cli_tool_t();
+    p->run(cli_tool_t::parse_args(narg, args));
+    return 0;
+}

src/cli.h

@@ -0,0 +1,56 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+// Common CLI tool header
+
+#pragma once
+
+#include "json11/json11.hpp"
+#include "object_id.h"
+#include "ringloop.h"
+#include <functional>
+
+struct rm_inode_t;
+struct snap_merger_t;
+struct snap_flattener_t;
+struct snap_remover_t;
+
+class epoll_manager_t;
+class cluster_client_t;
+struct inode_config_t;
+
+class cli_tool_t
+{
+public:
+    uint64_t iodepth = 0, parallel_osds = 0;
+    bool progress = true;
+    bool list_first = false;
+    int log_level = 0;
+    int mode = 0;
+
+    ring_loop_t *ringloop = NULL;
+    epoll_manager_t *epmgr = NULL;
+    cluster_client_t *cli = NULL;
+
+    int waiting = 0;
+    ring_consumer_t consumer;
+    std::function<bool(void)> action_cb;
+
+    void run(json11::Json cfg);
+
+    void change_parent(inode_t cur, inode_t new_parent);
+    inode_config_t* get_inode_cfg(const std::string & name);
+
+    static json11::Json::object parse_args(int narg, const char *args[]);
+    static void help();
+
+    friend struct rm_inode_t;
+    friend struct snap_merger_t;
+    friend struct snap_flattener_t;
+    friend struct snap_remover_t;
+
+    std::function<bool(void)> start_rm(json11::Json);
+    std::function<bool(void)> start_merge(json11::Json);
+    std::function<bool(void)> start_flatten(json11::Json);
+    std::function<bool(void)> start_snap_rm(json11::Json);
+};

src/cli_flatten.cpp

@@ -0,0 +1,124 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+#include "cli.h"
+#include "cluster_client.h"
+
+// Flatten a layer: merge all parents into a layer and break the connection completely
+struct snap_flattener_t
+{
+    cli_tool_t *parent;
+
+    // target to flatten
+    std::string target_name;
+    // writers are stopped, we can safely change writable layers
+    bool writers_stopped = false;
+    // use CAS writes (0 = never, 1 = auto, 2 = always)
+    int use_cas = 1;
+    // interval between fsyncs
+    int fsync_interval = 128;
+
+    std::string top_parent_name;
+    inode_t target_id = 0;
+    int state = 0;
+    std::function<bool(void)> merger_cb;
+
+    void get_merge_parents()
+    {
+        // Get all parents of target
+        inode_config_t *target_cfg = parent->get_inode_cfg(target_name);
+        target_id = target_cfg->num;
+        std::vector<inode_t> chain_list;
+        inode_config_t *cur = target_cfg;
+        chain_list.push_back(cur->num);
+        while (cur->parent_id != 0 && cur->parent_id != target_cfg->num)
+        {
+            auto it = parent->cli->st_cli.inode_config.find(cur->parent_id);
+            if (it == parent->cli->st_cli.inode_config.end())
+            {
+                fprintf(stderr, "Parent inode of layer %s (id %ld) not found\n", cur->name.c_str(), cur->parent_id);
+                exit(1);
+            }
+            cur = &it->second;
+            chain_list.push_back(cur->num);
+        }
+        if (cur->parent_id != 0)
+        {
+            fprintf(stderr, "Layer %s has a loop in parents\n", target_name.c_str());
+            exit(1);
+        }
+        top_parent_name = cur->name;
+    }
+
+    bool is_done()
+    {
+        return state == 5;
+    }
+
+    void loop()
+    {
+        if (state == 1)
+            goto resume_1;
+        else if (state == 2)
+            goto resume_2;
+        else if (state == 3)
+            goto resume_3;
+        // Get parent layers
+        get_merge_parents();
+        // Start merger
+        merger_cb = parent->start_merge(json11::Json::object {
+            { "command", json11::Json::array{ "merge-data", top_parent_name, target_name } },
+            { "target", target_name },
+            { "delete-source", false },
+            { "cas", use_cas },
+            { "fsync-interval", fsync_interval },
+        });
+        // Wait for it
+resume_1:
+        while (!merger_cb())
+        {
+            state = 1;
+            return;
+        }
+        merger_cb = NULL;
+        // Change parent
+        parent->change_parent(target_id, 0);
+        // Wait for it to complete
+        state = 2;
+resume_2:
+        if (parent->waiting > 0)
+            return;
+        state = 3;
+resume_3:
+        // Done
+        return;
+    }
+};
+
+std::function<bool(void)> cli_tool_t::start_flatten(json11::Json cfg)
+{
+    json11::Json::array cmd = cfg["command"].array_items();
+    auto flattener = new snap_flattener_t();
+    flattener->parent = this;
+    flattener->target_name = cmd.size() > 1 ? cmd[1].string_value() : "";
+    if (flattener->target_name == "")
+    {
+        fprintf(stderr, "Layer to flatten argument is missing\n");
+        exit(1);
+    }
+    flattener->fsync_interval = cfg["fsync-interval"].uint64_value();
+    if (!flattener->fsync_interval)
+        flattener->fsync_interval = 128;
+    if (!cfg["cas"].is_null())
+        flattener->use_cas = cfg["cas"].uint64_value() ? 2 : 0;
+    return [flattener]()
+    {
+        flattener->loop();
+        if (flattener->is_done())
+        {
+            delete flattener;
+            return true;
+        }
+        return false;
+    };
+}

src/cli_merge.cpp

@@ -0,0 +1,583 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+#include "cli.h"
+#include "cluster_client.h"
+#include "cpp-btree/safe_btree_set.h"
+
+struct snap_rw_op_t
+{
+    uint64_t offset = 0;
+    void *buf = NULL;
+    cluster_op_t op;
+    int todo = 0;
+    uint32_t start = 0, end = 0;
+};
+
+// Layer merge is the base for multiple operations:
+// 1) Delete snapshot "up" = merge child layer into the parent layer, remove the child
+//    and rename the parent to the child
+// 2) Delete snapshot "down" = merge parent layer into the child layer and remove the parent
+// 3) Flatten image = merge parent layers into the child layer and break the connection
+struct snap_merger_t
+{
+    cli_tool_t *parent;
+
+    // -- CONFIGURATION --
+    // merge from..to into target (target may be one of from..to)
+    std::string from_name, to_name, target_name;
+    // inode=>rank (bigger rank means child layers)
+    std::map<inode_t,int> sources;
+    // delete merged source inode data during merge
+    bool delete_source = false;
+    // use CAS writes (0 = never, 1 = auto, 2 = always)
+    int use_cas = 1;
+    // don't necessarily delete source data, but perform checks as if we were to do it
+    bool check_delete_source = false;
+    // interval between fsyncs
+    int fsync_interval = 128;
+
+    // -- STATE --
+    inode_t target;
+    int target_rank;
+    bool inside_continue = false;
+    int state = 0;
+    int lists_todo = 0;
+    uint64_t target_block_size = 0;
+    btree::safe_btree_set<uint64_t> merge_offsets;
+    btree::safe_btree_set<uint64_t>::iterator oit;
+    std::map<inode_t, std::vector<uint64_t>> layer_lists;
+    std::map<inode_t, uint64_t> layer_block_size;
+    std::map<inode_t, uint64_t> layer_list_pos;
+    int in_flight = 0;
+    uint64_t last_fsync_offset = 0;
+    uint64_t last_written_offset = 0;
+    int deleted_unsynced = 0;
+    uint64_t processed = 0, to_process = 0;
+
+    void start_merge()
+    {
+        check_delete_source = delete_source || check_delete_source;
+        inode_config_t *from_cfg = parent->get_inode_cfg(from_name);
+        inode_config_t *to_cfg = parent->get_inode_cfg(to_name);
+        inode_config_t *target_cfg = target_name == "" ? from_cfg : parent->get_inode_cfg(target_name);
+        if (to_cfg->num == from_cfg->num)
+        {
+            fprintf(stderr, "Only one layer specified, nothing to merge\n");
+            exit(1);
+        }
+        // Check that to_cfg is actually a child of from_cfg and target_cfg is somewhere between them
+        std::vector<inode_t> chain_list;
+        inode_config_t *cur = to_cfg;
+        chain_list.push_back(cur->num);
+        layer_block_size[cur->num] = get_block_size(cur->num);
+        while (cur->parent_id != from_cfg->num &&
+            cur->parent_id != to_cfg->num &&
+            cur->parent_id != 0)
+        {
+            auto it = parent->cli->st_cli.inode_config.find(cur->parent_id);
+            if (it == parent->cli->st_cli.inode_config.end())
+            {
+                fprintf(stderr, "Parent inode of layer %s (id %ld) not found\n", cur->name.c_str(), cur->parent_id);
+                exit(1);
+            }
+            cur = &it->second;
+            chain_list.push_back(cur->num);
+            layer_block_size[cur->num] = get_block_size(cur->num);
+        }
+        if (cur->parent_id != from_cfg->num)
+        {
+            fprintf(stderr, "Layer %s is not a child of %s\n", to_name.c_str(), from_name.c_str());
+            exit(1);
+        }
+        chain_list.push_back(from_cfg->num);
+        layer_block_size[from_cfg->num] = get_block_size(from_cfg->num);
+        int i = chain_list.size()-1;
+        for (inode_t item: chain_list)
+        {
+            sources[item] = i--;
+        }
+        if (sources.find(target_cfg->num) == sources.end())
+        {
+            fprintf(stderr, "Layer %s is not between %s and %s\n", target_name.c_str(), to_name.c_str(), from_name.c_str());
+            exit(1);
+        }
+        target = target_cfg->num;
+        target_rank = sources.at(target);
+        int to_rank = sources.at(to_cfg->num);
+        bool to_has_children = false;
+        // Check that there are no other inodes dependent on altered layers
+        //
+        // 1) everything between <target> and <to> except <to> is not allowed
+        //    to have children other than <to> if <to> is a child of <target>:
+        //
+        //    <target> - <layer 3> - <to>
+        //            \- <layer 4> <--------X--------- NOT ALLOWED
+        //
+        // 2) everything between <from> and <target>, except <target>, is not allowed
+        //    to have children other than <target> if sources are to be deleted after merging:
+        //
+        //    <from> - <layer 1> - <target> - <to>
+        //          \- <layer 2> <---------X-------- NOT ALLOWED
+        for (auto & ic: parent->cli->st_cli.inode_config)
+        {
+            auto it = sources.find(ic.second.num);
+            if (it == sources.end() && ic.second.parent_id != 0)
+            {
+                it = sources.find(ic.second.parent_id);
+                if (it != sources.end())
+                {
+                    int parent_rank = it->second;
+                    if (parent_rank < to_rank && (parent_rank >= target_rank || check_delete_source))
+                    {
+                        fprintf(
+                            stderr, "Layers at or above %s, but below %s are not allowed"
+                                " to have other children, but %s is a child of %s\n",
+                            (check_delete_source ? from_name.c_str() : target_name.c_str()),
+                            to_name.c_str(), ic.second.name.c_str(),
+                            parent->cli->st_cli.inode_config.at(ic.second.parent_id).name.c_str()
+                        );
+                        exit(1);
+                    }
+                    if (parent_rank >= to_rank)
+                    {
+                        to_has_children = true;
+                    }
+                }
+            }
+        }
+        if ((target_rank < to_rank || to_has_children) && use_cas == 1)
+        {
+            // <to> has children itself, no need for CAS
+            use_cas = 0;
+        }
+        sources.erase(target);
+        printf(
+            "Merging %ld layer(s) into target %s%s (inode %lu in pool %u)\n",
+            sources.size(), target_cfg->name.c_str(),
+            use_cas ? " online (with CAS)" : "", INODE_NO_POOL(target), INODE_POOL(target)
+        );
+        target_block_size = get_block_size(target);
+    }
+
+    uint64_t get_block_size(inode_t inode)
+    {
+        auto & pool_cfg = parent->cli->st_cli.pool_config.at(INODE_POOL(inode));
+        uint64_t pg_data_size = (pool_cfg.scheme == POOL_SCHEME_REPLICATED ? 1 : pool_cfg.pg_size-pool_cfg.parity_chunks);
+        return parent->cli->get_bs_block_size() * pg_data_size;
+    }
+
+    void continue_merge_reent()
+    {
+        if (!inside_continue)
+        {
+            inside_continue = true;
+            continue_merge();
+            inside_continue = false;
+        }
+    }
+
+    bool is_done()
+    {
+        return state == 6;
+    }
+
+    void continue_merge()
+    {
+        if (state == 1)
+            goto resume_1;
+        else if (state == 2)
+            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)
+            goto resume_6;
+        // Get parents and so on
+        start_merge();
+        // First list lower layers
+        list_layers(true);
+        state = 1;
+    resume_1:
+        while (lists_todo > 0)
+        {
+            // Wait for lists
+            return;
+        }
+        if (merge_offsets.size() > 0)
+        {
+            state = 2;
+            oit = merge_offsets.begin();
+            processed = 0;
+            to_process = merge_offsets.size();
+    resume_2:
+            // Then remove blocks already filled in target by issuing zero-length reads and checking bitmaps
+            while (in_flight < parent->iodepth*parent->parallel_osds && oit != merge_offsets.end())
+            {
+                in_flight++;
+                check_if_full(*oit);
+                oit++;
+                processed++;
+                if (parent->progress && !(processed % 128))
+                {
+                    printf("\rFiltering target blocks: %lu/%lu", processed, to_process);
+                }
+            }
+            if (in_flight > 0 || oit != merge_offsets.end())
+            {
+                // Wait until reads finish
+                return;
+            }
+            if (parent->progress)
+            {
+                printf("\r%lu full blocks of target filtered out\n", to_process-merge_offsets.size());
+            }
+        }
+        state = 3;
+    resume_3:
+        // Then list upper layers
+        list_layers(false);
+        state = 4;
+    resume_4:
+        while (lists_todo > 0)
+        {
+            // Wait for lists
+            return;
+        }
+        state = 5;
+        processed = 0;
+        to_process = merge_offsets.size();
+        oit = merge_offsets.begin();
+    resume_5:
+        // Now read, overwrite and optionally delete offsets one by one
+        while (in_flight < parent->iodepth*parent->parallel_osds && oit != merge_offsets.end())
+        {
+            in_flight++;
+            read_and_write(*oit);
+            oit++;
+            processed++;
+            if (parent->progress && !(processed % 128))
+            {
+                printf("\rOverwriting blocks: %lu/%lu", processed, to_process);
+            }
+        }
+        if (in_flight > 0 || oit != merge_offsets.end())
+        {
+            // Wait until overwrites finish
+            return;
+        }
+        if (parent->progress)
+        {
+            printf("\rOverwriting blocks: %lu/%lu\n", to_process, to_process);
+        }
+        // Done
+        printf("Done, layers from %s to %s merged into %s\n", from_name.c_str(), to_name.c_str(), target_name.c_str());
+        state = 6;
+    resume_6:
+        return;
+    }
+
+    void list_layers(bool lower)
+    {
+        for (auto & sp: sources)
+        {
+            inode_t src = sp.first;
+            if (lower ? (sp.second < target_rank) : (sp.second > target_rank))
+            {
+                lists_todo++;
+                inode_list_t* lst = parent->cli->list_inode_start(src, [this, src](
+                    inode_list_t *lst, std::set<object_id>&& objects, pg_num_t pg_num, osd_num_t primary_osd, int status)
+                {
+                    uint64_t layer_block = layer_block_size.at(src);
+                    for (object_id obj: objects)
+                    {
+                        merge_offsets.insert(obj.stripe - obj.stripe % target_block_size);
+                        for (int i = target_block_size; i < layer_block; i += target_block_size)
+                        {
+                            merge_offsets.insert(obj.stripe - obj.stripe % target_block_size + i);
+                        }
+                    }
+                    if (delete_source)
+                    {
+                        // Also store individual lists
+                        auto & layer_list = layer_lists[src];
+                        int pos = layer_list.size();
+                        layer_list.resize(pos + objects.size());
+                        for (object_id obj: objects)
+                        {
+                            layer_list[pos++] = obj.stripe;
+                        }
+                    }
+                    if (status & INODE_LIST_DONE)
+                    {
+                        auto & name = parent->cli->st_cli.inode_config.at(src).name;
+                        printf("Got listing of layer %s (inode %lu in pool %u)\n", name.c_str(), INODE_NO_POOL(src), INODE_POOL(src));
+                        if (delete_source)
+                        {
+                            // Sort the inode listing
+                            std::sort(layer_lists[src].begin(), layer_lists[src].end());
+                        }
+                        lists_todo--;
+                        continue_merge_reent();
+                    }
+                    else
+                    {
+                        parent->cli->list_inode_next(lst, 1);
+                    }
+                });
+                parent->cli->list_inode_next(lst, parent->parallel_osds);
+            }
+        }
+    }
+
+    // Check if <offset> is fully written in <target> and remove it from merge_offsets if so
+    void check_if_full(uint64_t offset)
+    {
+        cluster_op_t *op = new cluster_op_t;
+        op->opcode = OSD_OP_READ_BITMAP;
+        op->inode = target;
+        op->offset = offset;
+        op->len = 0;
+        op->callback = [this](cluster_op_t *op)
+        {
+            if (op->retval < 0)
+            {
+                fprintf(stderr, "error reading target bitmap at offset %lx: %s\n", op->offset, strerror(-op->retval));
+            }
+            else
+            {
+                uint64_t bitmap_bytes = target_block_size/parent->cli->get_bs_bitmap_granularity()/8;
+                int i;
+                for (i = 0; i < bitmap_bytes; i++)
+                {
+                    if (((uint8_t*)op->bitmap_buf)[i] != 0xff)
+                    {
+                        break;
+                    }
+                }
+                if (i == bitmap_bytes)
+                {
+                    // full
+                    merge_offsets.erase(op->offset);
+                }
+            }
+            delete op;
+            in_flight--;
+            continue_merge_reent();
+        };
+        parent->cli->execute(op);
+    }
+
+    // Read <offset> from <to>, write it to <target> and optionally delete it
+    // from all layers except <target> after fsync'ing
+    void read_and_write(uint64_t offset)
+    {
+        snap_rw_op_t *rwo = new snap_rw_op_t;
+        // Initialize counter to 1 to later allow write_subop() to return immediately
+        // (even though it shouldn't really do that)
+        rwo->todo = 1;
+        rwo->buf = malloc(target_block_size);
+        rwo->offset = offset;
+        rwo_read(rwo);
+    }
+
+    void rwo_read(snap_rw_op_t *rwo)
+    {
+        cluster_op_t *op = &rwo->op;
+        op->opcode = OSD_OP_READ;
+        op->inode = target;
+        op->offset = rwo->offset;
+        op->len = target_block_size;
+        op->iov.push_back(rwo->buf, target_block_size);
+        op->callback = [this, rwo](cluster_op_t *op)
+        {
+            if (op->retval != op->len)
+            {
+                fprintf(stderr, "error reading target at offset %lx: %s\n", op->offset, strerror(-op->retval));
+                exit(1);
+            }
+            next_write(rwo);
+        };
+        parent->cli->execute(op);
+    }
+
+    void next_write(snap_rw_op_t *rwo)
+    {
+        // Write each non-empty range using an individual operation
+        // FIXME: Allow to use single write with "holes" (OSDs don't allow it yet)
+        uint32_t gran = parent->cli->get_bs_bitmap_granularity();
+        uint64_t bitmap_size = target_block_size / gran;
+        while (rwo->end < bitmap_size)
+        {
+            auto bit = ((*(uint8_t*)(rwo->op.bitmap_buf + (rwo->end >> 3))) & (1 << (rwo->end & 0x7)));
+            if (!bit)
+            {
+                if (rwo->end > rwo->start)
+                {
+                    // write start->end
+                    rwo->todo++;
+                    write_subop(rwo, rwo->start*gran, rwo->end*gran, use_cas ? 1+rwo->op.version : 0);
+                    rwo->start = rwo->end;
+                    if (use_cas)
+                    {
+                        // Submit one by one if using CAS writes
+                        return;
+                    }
+                }
+                rwo->start = rwo->end = rwo->end+1;
+            }
+            else
+            {
+                rwo->end++;
+            }
+        }
+        if (rwo->end > rwo->start)
+        {
+            // write start->end
+            rwo->todo++;
+            write_subop(rwo, rwo->start*gran, rwo->end*gran, use_cas ? 1+rwo->op.version : 0);
+            rwo->start = rwo->end;
+            if (use_cas)
+            {
+                return;
+            }
+        }
+        rwo->todo--;
+        // Just in case, if everything is done
+        autofree_op(rwo);
+    }
+
+    void write_subop(snap_rw_op_t *rwo, uint32_t start, uint32_t end, uint64_t version)
+    {
+        cluster_op_t *subop = new cluster_op_t;
+        subop->opcode = OSD_OP_WRITE;
+        subop->inode = target;
+        subop->offset = rwo->offset+start;
+        subop->len = end-start;
+        subop->version = version;
+        subop->flags = OSD_OP_IGNORE_READONLY;
+        subop->iov.push_back(rwo->buf+start, end-start);
+        subop->callback = [this, rwo](cluster_op_t *subop)
+        {
+            rwo->todo--;
+            if (subop->retval != subop->len)
+            {
+                if (use_cas && subop->retval == -EINTR)
+                {
+                    // CAS failure - reread and repeat optimistically
+                    rwo->start = subop->offset - rwo->offset;
+                    rwo_read(rwo);
+                    delete subop;
+                    return;
+                }
+                fprintf(stderr, "error writing target at offset %lx: %s\n", subop->offset, strerror(-subop->retval));
+                exit(1);
+            }
+            // Increment CAS version
+            rwo->op.version++;
+            if (use_cas)
+                next_write(rwo);
+            else
+                autofree_op(rwo);
+            delete subop;
+        };
+        parent->cli->execute(subop);
+    }
+
+    void delete_offset(inode_t inode_num, uint64_t offset)
+    {
+        cluster_op_t *subop = new cluster_op_t;
+        subop->opcode = OSD_OP_DELETE;
+        subop->inode = inode_num;
+        subop->offset = offset;
+        subop->len = 0;
+        subop->flags = OSD_OP_IGNORE_READONLY;
+        subop->callback = [this](cluster_op_t *subop)
+        {
+            if (subop->retval != 0)
+            {
+                fprintf(stderr, "error deleting from layer 0x%lx at offset %lx: %s", subop->inode, subop->offset, strerror(-subop->retval));
+            }
+            delete subop;
+        };
+        parent->cli->execute(subop);
+    }
+
+    void autofree_op(snap_rw_op_t *rwo)
+    {
+        if (!rwo->todo)
+        {
+            if (last_written_offset < rwo->op.offset+target_block_size)
+            {
+                last_written_offset = rwo->op.offset+target_block_size;
+            }
+            if (delete_source)
+            {
+                deleted_unsynced++;
+                if (deleted_unsynced >= fsync_interval)
+                {
+                    uint64_t from = last_fsync_offset, to = last_written_offset;
+                    cluster_op_t *subop = new cluster_op_t;
+                    subop->opcode = OSD_OP_SYNC;
+                    subop->callback = [this, from, to](cluster_op_t *subop)
+                    {
+                        delete subop;
+                        // We can now delete source data between <from> and <to>
+                        // But to do this we have to keep all object lists in memory :-(
+                        for (auto & lp: layer_list_pos)
+                        {
+                            auto & layer_list = layer_lists.at(lp.first);
+                            uint64_t layer_block = layer_block_size.at(lp.first);
+                            int cur_pos = lp.second;
+                            while (cur_pos < layer_list.size() && layer_list[cur_pos]+layer_block < to)
+                            {
+                                delete_offset(lp.first, layer_list[cur_pos]);
+                                cur_pos++;
+                            }
+                            lp.second = cur_pos;
+                        }
+                    };
+                    parent->cli->execute(subop);
+                }
+            }
+            free(rwo->buf);
+            delete rwo;
+            in_flight--;
+            continue_merge_reent();
+        }
+    }
+};
+
+std::function<bool(void)> cli_tool_t::start_merge(json11::Json cfg)
+{
+    json11::Json::array cmd = cfg["command"].array_items();
+    auto merger = new snap_merger_t();
+    merger->parent = this;
+    merger->from_name = cmd.size() > 1 ? cmd[1].string_value() : "";
+    merger->to_name = cmd.size() > 2 ? cmd[2].string_value() : "";
+    merger->target_name = cfg["target"].string_value();
+    if (merger->from_name == "" || merger->to_name == "")
+    {
+        fprintf(stderr, "Beginning or end of the merge sequence is missing\n");
+        exit(1);
+    }
+    merger->delete_source = cfg["delete-source"].string_value() != "";
+    merger->fsync_interval = cfg["fsync-interval"].uint64_value();
+    if (!merger->fsync_interval)
+        merger->fsync_interval = 128;
+    if (!cfg["cas"].is_null())
+        merger->use_cas = cfg["cas"].uint64_value() ? 2 : 0;
+    return [merger]()
+    {
+        merger->continue_merge_reent();
+        if (merger->is_done())
+        {
+            delete merger;
+            return true;
+        }
+        return false;
+    };
+}

src/cli_rm.cpp

@@ -0,0 +1,195 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+#include "cli.h"
+#include "cluster_client.h"
+
+#define RM_LISTING 1
+#define RM_REMOVING 2
+#define RM_END 3
+
+struct rm_pg_t
+{
+    pg_num_t pg_num;
+    osd_num_t rm_osd_num;
+    std::set<object_id> objects;
+    std::set<object_id>::iterator obj_pos;
+    uint64_t obj_count = 0, obj_done = 0, obj_prev_done = 0;
+    int state = 0;
+    int in_flight = 0;
+};
+
+struct rm_inode_t
+{
+    uint64_t inode = 0;
+    pool_id_t pool_id = 0;
+
+    cli_tool_t *parent = NULL;
+    inode_list_t *lister = NULL;
+    std::vector<rm_pg_t*> lists;
+    uint64_t total_count = 0, total_done = 0, total_prev_pct = 0;
+    uint64_t pgs_to_list = 0;
+    bool lists_done = false;
+    int state = 0;
+
+    void start_delete()
+    {
+        lister = parent->cli->list_inode_start(inode, [this](inode_list_t *lst,
+            std::set<object_id>&& objects, pg_num_t pg_num, osd_num_t primary_osd, int status)
+        {
+            rm_pg_t *rm = new rm_pg_t((rm_pg_t){
+                .pg_num = pg_num,
+                .rm_osd_num = primary_osd,
+                .objects = objects,
+                .obj_count = objects.size(),
+                .obj_done = 0,
+                .obj_prev_done = 0,
+            });
+            rm->obj_pos = rm->objects.begin();
+            lists.push_back(rm);
+            if (parent->list_first)
+            {
+                parent->cli->list_inode_next(lister, 1);
+            }
+            if (status & INODE_LIST_DONE)
+            {
+                lists_done = true;
+            }
+            pgs_to_list--;
+            continue_delete();
+        });
+        if (!lister)
+        {
+            fprintf(stderr, "Failed to list inode %lu from pool %u objects\n", INODE_NO_POOL(inode), INODE_POOL(inode));
+            exit(1);
+        }
+        pgs_to_list = parent->cli->list_pg_count(lister);
+        parent->cli->list_inode_next(lister, parent->parallel_osds);
+    }
+
+    void send_ops(rm_pg_t *cur_list)
+    {
+        if (parent->cli->msgr.osd_peer_fds.find(cur_list->rm_osd_num) ==
+            parent->cli->msgr.osd_peer_fds.end())
+        {
+            // Initiate connection
+            parent->cli->msgr.connect_peer(cur_list->rm_osd_num, parent->cli->st_cli.peer_states[cur_list->rm_osd_num]);
+            return;
+        }
+        while (cur_list->in_flight < parent->iodepth && cur_list->obj_pos != cur_list->objects.end())
+        {
+            osd_op_t *op = new osd_op_t();
+            op->op_type = OSD_OP_OUT;
+            op->peer_fd = parent->cli->msgr.osd_peer_fds[cur_list->rm_osd_num];
+            op->req = (osd_any_op_t){
+                .rw = {
+                    .header = {
+                        .magic = SECONDARY_OSD_OP_MAGIC,
+                        .id = parent->cli->next_op_id(),
+                        .opcode = OSD_OP_DELETE,
+                    },
+                    .inode = cur_list->obj_pos->inode,
+                    .offset = cur_list->obj_pos->stripe,
+                    .len = 0,
+                },
+            };
+            op->callback = [this, cur_list](osd_op_t *op)
+            {
+                cur_list->in_flight--;
+                if (op->reply.hdr.retval < 0)
+                {
+                    fprintf(stderr, "Failed to remove object %lx:%lx from PG %u (OSD %lu) (retval=%ld)\n",
+                        op->req.rw.inode, op->req.rw.offset,
+                        cur_list->pg_num, cur_list->rm_osd_num, op->reply.hdr.retval);
+                }
+                delete op;
+                cur_list->obj_done++;
+                total_done++;
+                continue_delete();
+            };
+            cur_list->obj_pos++;
+            cur_list->in_flight++;
+            parent->cli->msgr.outbox_push(op);
+        }
+    }
+
+    void continue_delete()
+    {
+        if (parent->list_first && !lists_done)
+        {
+            return;
+        }
+        for (int i = 0; i < lists.size(); i++)
+        {
+            if (!lists[i]->in_flight && lists[i]->obj_pos == lists[i]->objects.end())
+            {
+                delete lists[i];
+                lists.erase(lists.begin()+i, lists.begin()+i+1);
+                i--;
+                if (!lists_done)
+                {
+                    parent->cli->list_inode_next(lister, 1);
+                }
+            }
+            else
+            {
+                send_ops(lists[i]);
+            }
+        }
+        if (parent->progress && total_count > 0 && total_done*1000/total_count != total_prev_pct)
+        {
+            printf("\rRemoved %lu/%lu objects, %lu more PGs to list...", total_done, total_count, pgs_to_list);
+            total_prev_pct = total_done*1000/total_count;
+        }
+        if (lists_done && !lists.size())
+        {
+            printf("Done, inode %lu in pool %u data removed\n", INODE_NO_POOL(inode), pool_id);
+            state = 2;
+        }
+    }
+
+    bool loop()
+    {
+        if (state == 0)
+        {
+            start_delete();
+            state = 1;
+        }
+        else if (state == 1)
+        {
+            continue_delete();
+        }
+        else if (state == 2)
+        {
+            return true;
+        }
+        return false;
+    }
+};
+
+std::function<bool(void)> cli_tool_t::start_rm(json11::Json cfg)
+{
+    auto remover = new rm_inode_t();
+    remover->parent = this;
+    remover->inode = cfg["inode"].uint64_value();
+    remover->pool_id = cfg["pool"].uint64_value();
+    if (remover->pool_id)
+    {
+        remover->inode = (remover->inode & ((1l << (64-POOL_ID_BITS)) - 1)) | (((uint64_t)remover->pool_id) << (64-POOL_ID_BITS));
+    }
+    remover->pool_id = INODE_POOL(remover->inode);
+    if (!remover->pool_id)
+    {
+        fprintf(stderr, "pool is missing\n");
+        exit(1);
+    }
+    return [remover]()
+    {
+        if (remover->loop())
+        {
+            delete remover;
+            return true;
+        }
+        return false;
+    };
+}

src/cli_snap_rm.cpp

@@ -0,0 +1,565 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 (see README.md for details)
+
+#include "cli.h"
+#include "cluster_client.h"
+#include "base64.h"
+
+// Remove layer(s): similar to merge, but alters metadata and processes multiple merge targets
+//
+// Exactly one child of the requested layers may be merged using the "inverted" workflow,
+// where we merge it "down" into one of the "to-be-removed" layers and then rename the
+// "to-be-removed" layer to the child. It may be done either if all writers are stopped
+// before trying to delete layers (which is signaled by --writers-stopped) or if that child
+// is a read-only layer (snapshot) itself.
+//
+// This "inverted" workflow trades copying data of one of the deleted layers for copying
+// data of one child of the chain which is also a child of the "traded" layer. So we
+// choose the (parent,child) pair which has the largest difference between "parent" and
+// "child" inode sizes.
+//
+// All other children of the chain are processed by iterating though them, merging removed
+// parents into them and rebasing them to the last layer which isn't a member of the removed
+// chain.
+//
+// Example:
+//
+// <parent> - <from> - <layer 2> - <to> - <child 1>
+//                 \           \       \- <child 2>
+//                  \           \- <child 3>
+//                   \-<child 4>
+//
+// 1) Find optimal pair for the "reverse" scenario
+//    Imagine that it's (<layer 2>, <child 1>) in this example
+// 2) Process all children except <child 1>:
+//    - Merge <from>..<to> to <child 2>
+//    - Set <child 2> parent to <parent>
+//    - Repeat for others
+// 3) Process <child 1>:
+//    - Merge <from>..<child 1> to <layer 2>
+//    - Set <layer 2> parent to <parent>
+//    - Rename <layer 2> to <child 1>
+// 4) Delete other layers of the chain (<from>, <to>)
+struct snap_remover_t
+{
+    cli_tool_t *parent;
+
+    // remove from..to
+    std::string from_name, to_name;
+    // writers are stopped, we can safely change writable layers
+    bool writers_stopped = false;
+    // use CAS writes (0 = never, 1 = auto, 2 = always)
+    int use_cas = 1;
+    // interval between fsyncs
+    int fsync_interval = 128;
+
+    std::map<inode_t,int> sources;
+    std::map<inode_t,uint64_t> inode_used;
+    std::vector<inode_t> merge_children;
+    std::vector<inode_t> chain_list;
+    std::map<inode_t,int> inverse_candidates;
+    inode_t inverse_parent = 0, inverse_child = 0;
+    inode_t new_parent = 0;
+    int state = 0;
+    int current_child = 0;
+    std::function<bool(void)> cb;
+
+    bool is_done()
+    {
+        return state == 9;
+    }
+
+    void loop()
+    {
+        if (state == 1)
+            goto resume_1;
+        else if (state == 2)
+            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)
+            goto resume_6;
+        else if (state == 7)
+            goto resume_7;
+        else if (state == 8)
+            goto resume_8;
+        else if (state == 9)
+            goto resume_9;
+        // Get children to merge
+        get_merge_children();
+        // Try to select an inode for the "inverse" optimized scenario
+        // Read statistics from etcd to do it
+        read_stats();
+        state = 1;
+resume_1:
+        if (parent->waiting > 0)
+            return;
+        choose_inverse_candidate();
+        // Merge children one by one, except our "inverse" child
+        for (current_child = 0; current_child < merge_children.size(); current_child++)
+        {
+            if (merge_children[current_child] == inverse_child)
+                continue;
+            start_merge_child(merge_children[current_child], merge_children[current_child]);
+resume_2:
+            while (!cb())
+            {
+                state = 2;
+                return;
+            }
+            cb = NULL;
+            parent->change_parent(merge_children[current_child], new_parent);
+            state = 3;
+resume_3:
+            if (parent->waiting > 0)
+                return;
+        }
+        // Merge our "inverse" child into our "inverse" parent
+        if (inverse_child != 0)
+        {
+            start_merge_child(inverse_child, inverse_parent);
+resume_4:
+            while (!cb())
+            {
+                state = 4;
+                return;
+            }
+            cb = NULL;
+            // Delete "inverse" child data
+            start_delete_source(inverse_child);
+resume_5:
+            while (!cb())
+            {
+                state = 5;
+                return;
+            }
+            cb = NULL;
+            // Delete "inverse" child metadata, rename parent over it,
+            // and also change parent links of the previous "inverse" child
+            rename_inverse_parent();
+            state = 6;
+resume_6:
+            if (parent->waiting > 0)
+                return;
+        }
+        // Delete parents, except the "inverse" one
+        for (current_child = 0; current_child < chain_list.size(); current_child++)
+        {
+            if (chain_list[current_child] == inverse_parent)
+                continue;
+            start_delete_source(chain_list[current_child]);
+resume_7:
+            while (!cb())
+            {
+                state = 7;
+                return;
+            }
+            cb = NULL;
+            delete_inode_config(chain_list[current_child]);
+            state = 8;
+resume_8:
+            if (parent->waiting > 0)
+                return;
+        }
+        state = 9;
+resume_9:
+        // Done
+        return;
+    }
+
+    void get_merge_children()
+    {
+        // Get all children of from..to
+        inode_config_t *from_cfg = parent->get_inode_cfg(from_name);
+        inode_config_t *to_cfg = parent->get_inode_cfg(to_name);
+        // Check that to_cfg is actually a child of from_cfg
+        // FIXME de-copypaste the following piece of code with snap_merger_t
+        inode_config_t *cur = to_cfg;
+        chain_list.push_back(cur->num);
+        while (cur->num != from_cfg->num && cur->parent_id != 0)
+        {
+            auto it = parent->cli->st_cli.inode_config.find(cur->parent_id);
+            if (it == parent->cli->st_cli.inode_config.end())
+            {
+                fprintf(stderr, "Parent inode of layer %s (id %ld) not found\n", cur->name.c_str(), cur->parent_id);
+                exit(1);
+            }
+            cur = &it->second;
+            chain_list.push_back(cur->num);
+        }
+        if (cur->num != from_cfg->num)
+        {
+            fprintf(stderr, "Layer %s is not a child of %s\n", to_name.c_str(), from_name.c_str());
+            exit(1);
+        }
+        new_parent = from_cfg->parent_id;
+        // Calculate ranks
+        int i = chain_list.size()-1;
+        for (inode_t item: chain_list)
+        {
+            sources[item] = i--;
+        }
+        for (auto & ic: parent->cli->st_cli.inode_config)
+        {
+            if (!ic.second.parent_id)
+            {
+                continue;
+            }
+            auto it = sources.find(ic.second.parent_id);
+            if (it != sources.end() && sources.find(ic.second.num) == sources.end())
+            {
+                merge_children.push_back(ic.second.num);
+                if (ic.second.readonly || writers_stopped)
+                {
+                    inverse_candidates[ic.second.num] = it->second;
+                }
+            }
+        }
+    }
+
+    void read_stats()
+    {
+        if (inverse_candidates.size() == 0)
+        {
+            return;
+        }
+        json11::Json::array reads;
+        for (auto cp: inverse_candidates)
+        {
+            inode_t inode = cp.first;
+            reads.push_back(json11::Json::object {
+                { "request_range", json11::Json::object {
+                    { "key", base64_encode(
+                        parent->cli->st_cli.etcd_prefix+
+                        "/inode/stats/"+std::to_string(INODE_POOL(inode))+
+                        "/"+std::to_string(INODE_NO_POOL(inode))
+                    ) },
+                } }
+            });
+        }
+        for (auto cp: sources)
+        {
+            inode_t inode = cp.first;
+            reads.push_back(json11::Json::object {
+                { "request_range", json11::Json::object {
+                    { "key", base64_encode(
+                        parent->cli->st_cli.etcd_prefix+
+                        "/inode/stats/"+std::to_string(INODE_POOL(inode))+
+                        "/"+std::to_string(INODE_NO_POOL(inode))
+                    ) },
+                } }
+            });
+        }
+        parent->waiting++;
+        parent->cli->st_cli.etcd_txn(json11::Json::object {
+            { "success", reads },
+        }, ETCD_SLOW_TIMEOUT, [this](std::string err, json11::Json data)
+        {
+            parent->waiting--;
+            if (err != "")
+            {
+                fprintf(stderr, "Error reading layer statistics from etcd: %s\n", err.c_str());
+                exit(1);
+            }
+            for (auto inode_result: data["responses"].array_items())
+            {
+                auto kv = parent->cli->st_cli.parse_etcd_kv(inode_result["kvs"][0]);
+                pool_id_t pool_id = 0;
+                inode_t inode = 0;
+                char null_byte = 0;
+                sscanf(kv.key.c_str() + parent->cli->st_cli.etcd_prefix.length()+13, "%u/%lu%c", &pool_id, &inode, &null_byte);
+                if (!inode || null_byte != 0)
+                {
+                    fprintf(stderr, "Bad key returned from etcd: %s\n", kv.key.c_str());
+                    exit(1);
+                }
+                auto pool_cfg_it = parent->cli->st_cli.pool_config.find(pool_id);
+                if (pool_cfg_it == parent->cli->st_cli.pool_config.end())
+                {
+                    fprintf(stderr, "Pool %u does not exist\n", pool_id);
+                    exit(1);
+                }
+                inode = INODE_WITH_POOL(pool_id, inode);
+                auto & pool_cfg = pool_cfg_it->second;
+                uint64_t used_bytes = kv.value["raw_used"].uint64_value() / pool_cfg.pg_size;
+                if (pool_cfg.scheme != POOL_SCHEME_REPLICATED)
+                {
+                    used_bytes *= (pool_cfg.pg_size - pool_cfg.parity_chunks);
+                }
+                inode_used[inode] = used_bytes;
+            }
+            parent->ringloop->wakeup();
+        });
+    }
+
+    void choose_inverse_candidate()
+    {
+        uint64_t max_diff = 0;
+        for (auto cp: inverse_candidates)
+        {
+            inode_t child = cp.first;
+            uint64_t child_used = inode_used[child];
+            int rank = cp.second;
+            for (int i = chain_list.size()-rank; i < chain_list.size(); i++)
+            {
+                inode_t parent = chain_list[i];
+                uint64_t parent_used = inode_used[parent];
+                if (parent_used > child_used && (!max_diff || max_diff < (parent_used-child_used)))
+                {
+                    max_diff = (parent_used-child_used);
+                    inverse_parent = parent;
+                    inverse_child = child;
+                }
+            }
+        }
+    }
+
+    void rename_inverse_parent()
+    {
+        auto child_it = parent->cli->st_cli.inode_config.find(inverse_child);
+        if (child_it == parent->cli->st_cli.inode_config.end())
+        {
+            fprintf(stderr, "Inode %ld disappeared\n", inverse_child);
+            exit(1);
+        }
+        auto target_it = parent->cli->st_cli.inode_config.find(inverse_parent);
+        if (target_it == parent->cli->st_cli.inode_config.end())
+        {
+            fprintf(stderr, "Inode %ld disappeared\n", inverse_parent);
+            exit(1);
+        }
+        inode_config_t *child_cfg = &child_it->second;
+        inode_config_t *target_cfg = &target_it->second;
+        std::string child_name = child_cfg->name;
+        std::string target_name = target_cfg->name;
+        std::string child_cfg_key = base64_encode(
+            parent->cli->st_cli.etcd_prefix+
+            "/config/inode/"+std::to_string(INODE_POOL(inverse_child))+
+            "/"+std::to_string(INODE_NO_POOL(inverse_child))
+        );
+        std::string target_cfg_key = base64_encode(
+            parent->cli->st_cli.etcd_prefix+
+            "/config/inode/"+std::to_string(INODE_POOL(inverse_parent))+
+            "/"+std::to_string(INODE_NO_POOL(inverse_parent))
+        );
+        // Fill new configuration
+        inode_config_t new_cfg = *child_cfg;
+        new_cfg.num = target_cfg->num;
+        new_cfg.parent_id = new_parent;
+        json11::Json::array cmp = json11::Json::array {
+            json11::Json::object {
+                { "target", "MOD" },
+                { "key", child_cfg_key },
+                { "result", "LESS" },
+                { "mod_revision", child_cfg->mod_revision+1 },
+            },
+            json11::Json::object {
+                { "target", "MOD" },
+                { "key", target_cfg_key },
+                { "result", "LESS" },
+                { "mod_revision", target_cfg->mod_revision+1 },
+            },
+        };
+        json11::Json::array txn = json11::Json::array {
+            json11::Json::object {
+                { "request_delete_range", json11::Json::object {
+                    { "key", child_cfg_key },
+                } },
+            },
+            json11::Json::object {
+                { "request_put", json11::Json::object {
+                    { "key", target_cfg_key },
+                    { "value", base64_encode(json11::Json(parent->cli->st_cli.serialize_inode_cfg(&new_cfg)).dump()) },
+                } },
+            },
+            json11::Json::object {
+                { "request_put", json11::Json::object {
+                    { "key", base64_encode(parent->cli->st_cli.etcd_prefix+"/index/image/"+child_cfg->name) },
+                    { "value", base64_encode(json11::Json({
+                        { "id", INODE_NO_POOL(inverse_parent) },
+                        { "pool_id", (uint64_t)INODE_POOL(inverse_parent) },
+                    }).dump()) },
+                } },
+            },
+        };
+        // Reparent children of inverse_child
+        for (auto & cp: parent->cli->st_cli.inode_config)
+        {
+            if (cp.second.parent_id == child_cfg->num)
+            {
+                auto cp_cfg = cp.second;
+                cp_cfg.parent_id = inverse_parent;
+                auto cp_key = base64_encode(
+                    parent->cli->st_cli.etcd_prefix+
+                    "/config/inode/"+std::to_string(INODE_POOL(cp.second.num))+
+                    "/"+std::to_string(INODE_NO_POOL(cp.second.num))
+                );
+                cmp.push_back(json11::Json::object {
+                    { "target", "MOD" },
+                    { "key", cp_key },
+                    { "result", "LESS" },
+                    { "mod_revision", cp.second.mod_revision+1 },
+                });
+                txn.push_back(json11::Json::object {
+                    { "request_put", json11::Json::object {
+                        { "key", cp_key },
+                        { "value", base64_encode(json11::Json(parent->cli->st_cli.serialize_inode_cfg(&cp_cfg)).dump()) },
+                    } },
+                });
+            }
+        }
+        parent->waiting++;
+        parent->cli->st_cli.etcd_txn(json11::Json::object {
+            { "compare", cmp },
+            { "success", txn },
+        }, ETCD_SLOW_TIMEOUT, [this, target_name, child_name](std::string err, json11::Json res)
+        {
+            parent->waiting--;
+            if (err != "")
+            {
+                fprintf(stderr, "Error renaming %s to %s: %s\n", target_name.c_str(), child_name.c_str(), err.c_str());
+                exit(1);
+            }
+            if (!res["succeeded"].bool_value())
+            {
+                fprintf(
+                    stderr, "Parent (%s), child (%s), or one of its children"
+                    " configuration was modified during rename\n", target_name.c_str(), child_name.c_str()
+                );
+                exit(1);
+            }
+            printf("Layer %s renamed to %s\n", target_name.c_str(), child_name.c_str());
+            parent->ringloop->wakeup();
+        });
+    }
+
+    void delete_inode_config(inode_t cur)
+    {
+        auto cur_cfg_it = parent->cli->st_cli.inode_config.find(cur);
+        if (cur_cfg_it == parent->cli->st_cli.inode_config.end())
+        {
+            fprintf(stderr, "Inode 0x%lx disappeared\n", cur);
+            exit(1);
+        }
+        inode_config_t *cur_cfg = &cur_cfg_it->second;
+        std::string cur_name = cur_cfg->name;
+        std::string cur_cfg_key = base64_encode(
+            parent->cli->st_cli.etcd_prefix+
+            "/config/inode/"+std::to_string(INODE_POOL(cur))+
+            "/"+std::to_string(INODE_NO_POOL(cur))
+        );
+        parent->waiting++;
+        parent->cli->st_cli.etcd_txn(json11::Json::object {
+            { "compare", json11::Json::array {
+                json11::Json::object {
+                    { "target", "MOD" },
+                    { "key", cur_cfg_key },
+                    { "result", "LESS" },
+                    { "mod_revision", cur_cfg->mod_revision+1 },
+                },
+            } },
+            { "success", json11::Json::array {
+                json11::Json::object {
+                    { "request_delete_range", json11::Json::object {
+                        { "key", cur_cfg_key },
+                    } },
+                    { "request_delete_range", json11::Json::object {
+                        { "key", base64_encode(parent->cli->st_cli.etcd_prefix+"/index/image/"+cur_name) },
+                    } },
+                },
+            } },
+        }, ETCD_SLOW_TIMEOUT, [this, cur_name](std::string err, json11::Json res)
+        {
+            parent->waiting--;
+            if (err != "")
+            {
+                fprintf(stderr, "Error deleting %s: %s\n", cur_name.c_str(), err.c_str());
+                exit(1);
+            }
+            if (!res["succeeded"].bool_value())
+            {
+                fprintf(stderr, "Layer %s configuration was modified during deletion\n", cur_name.c_str());
+                exit(1);
+            }
+            printf("Layer %s deleted\n", cur_name.c_str());
+            parent->ringloop->wakeup();
+        });
+    }
+
+    void start_merge_child(inode_t child_inode, inode_t target_inode)
+    {
+        auto child_it = parent->cli->st_cli.inode_config.find(child_inode);
+        if (child_it == parent->cli->st_cli.inode_config.end())
+        {
+            fprintf(stderr, "Inode %ld disappeared\n", child_inode);
+            exit(1);
+        }
+        auto target_it = parent->cli->st_cli.inode_config.find(target_inode);
+        if (target_it == parent->cli->st_cli.inode_config.end())
+        {
+            fprintf(stderr, "Inode %ld disappeared\n", target_inode);
+            exit(1);
+        }
+        cb = parent->start_merge(json11::Json::object {
+            { "command", json11::Json::array{ "merge-data", from_name, child_it->second.name } },
+            { "target", target_it->second.name },
+            { "delete-source", false },
+            { "cas", use_cas },
+            { "fsync-interval", fsync_interval },
+        });
+    }
+
+    void start_delete_source(inode_t inode)
+    {
+        auto source = parent->cli->st_cli.inode_config.find(inode);
+        if (source == parent->cli->st_cli.inode_config.end())
+        {
+            fprintf(stderr, "Inode %ld disappeared\n", inode);
+            exit(1);
+        }
+        cb = parent->start_rm(json11::Json::object {
+            { "inode", inode },
+            { "pool", (uint64_t)INODE_POOL(inode) },
+            { "fsync-interval", fsync_interval },
+        });
+    }
+};
+
+std::function<bool(void)> cli_tool_t::start_snap_rm(json11::Json cfg)
+{
+    json11::Json::array cmd = cfg["command"].array_items();
+    auto snap_remover = new snap_remover_t();
+    snap_remover->parent = this;
+    snap_remover->from_name = cmd.size() > 1 ? cmd[1].string_value() : "";
+    snap_remover->to_name = cmd.size() > 2 ? cmd[2].string_value() : "";
+    if (snap_remover->from_name == "")
+    {
+        fprintf(stderr, "Layer to remove argument is missing\n");
+        exit(1);
+    }
+    if (snap_remover->to_name == "")
+    {
+        snap_remover->to_name = snap_remover->from_name;
+    }
+    snap_remover->fsync_interval = cfg["fsync-interval"].uint64_value();
+    if (!snap_remover->fsync_interval)
+        snap_remover->fsync_interval = 128;
+    if (!cfg["cas"].is_null())
+        snap_remover->use_cas = cfg["cas"].uint64_value() ? 2 : 0;
+    if (!cfg["writers_stopped"].is_null())
+        snap_remover->writers_stopped = true;
+    return [snap_remover]()
+    {
+        snap_remover->loop();
+        if (snap_remover->is_done())
+        {
+            delete snap_remover;
+            return true;
+        }
+        return false;
+    };
+}

src/cluster_client.cpp

@@ -12,7 +12,7 @@
 #define CACHE_DIRTY 1
 #define CACHE_FLUSHING 2
 #define CACHE_REPEATING 3
-#define OP_FLUSH_BUFFER 2
+#define OP_FLUSH_BUFFER 0x02
 
 cluster_client_t::cluster_client_t(ring_loop_t *ringloop, timerfd_manager_t *tfd, json11::Json & config)
 {
@@ -31,6 +31,7 @@ cluster_client_t::cluster_client_t(ring_loop_t *ringloop, timerfd_manager_t *tfd
         {
             // peer_osd just connected
             continue_ops();
+            continue_lists();
         }
         else if (dirty_buffers.size())
         {
@@ -139,7 +140,7 @@ void cluster_client_t::calc_wait(cluster_op_t *op)
         if (!op->prev_wait && pgs_loaded)
             continue_sync(op);
     }
-    else
+    else /* if (op->opcode == OSD_OP_READ || op->opcode == OSD_OP_READ_BITMAP) */
     {
         for (auto prev = op->prev; prev; prev = prev->prev)
         {
@@ -147,7 +148,7 @@ void cluster_client_t::calc_wait(cluster_op_t *op)
             {
                 op->prev_wait++;
             }
-            else if (prev->opcode == OSD_OP_WRITE || prev->opcode == OSD_OP_READ)
+            else if (prev->opcode == OSD_OP_WRITE || prev->opcode == OSD_OP_READ || prev->opcode == OSD_OP_READ_BITMAP)
             {
                 // Flushes are always in the beginning
                 break;
@@ -167,7 +168,7 @@ void cluster_client_t::inc_wait(uint64_t opcode, uint64_t flags, cluster_op_t *n
             auto n2 = next->next;
             if (next->opcode == OSD_OP_SYNC ||
                 next->opcode == OSD_OP_WRITE && (flags & OP_FLUSH_BUFFER) && !(next->flags & OP_FLUSH_BUFFER) ||
-                next->opcode == OSD_OP_READ && (flags & OP_FLUSH_BUFFER))
+                (next->opcode == OSD_OP_READ || next->opcode == OSD_OP_READ_BITMAP) && (flags & OP_FLUSH_BUFFER))
             {
                 next->prev_wait += inc;
                 if (!next->prev_wait)
@@ -357,7 +358,7 @@ void cluster_client_t::on_change_hook(std::map<std::string, etcd_kv_t> & changes
             // And now they have to be resliced!
             for (auto op = op_queue_head; op; op = op->next)
             {
-                if ((op->opcode == OSD_OP_WRITE || op->opcode == OSD_OP_READ) &&
+                if ((op->opcode == OSD_OP_WRITE || op->opcode == OSD_OP_READ || op->opcode == OSD_OP_READ_BITMAP) &&
                     INODE_POOL(op->cur_inode) == pool_item.first)
                 {
                     op->needs_reslice = true;
@@ -417,7 +418,8 @@ void cluster_client_t::on_ready(std::function<void(void)> fn)
  */
 void cluster_client_t::execute(cluster_op_t *op)
 {
-    if (op->opcode != OSD_OP_SYNC && op->opcode != OSD_OP_READ && op->opcode != OSD_OP_WRITE)
+    if (op->opcode != OSD_OP_SYNC && op->opcode != OSD_OP_READ &&
+        op->opcode != OSD_OP_READ_BITMAP && op->opcode != OSD_OP_WRITE)
     {
         op->retval = -EINVAL;
         std::function<void(cluster_op_t*)>(op->callback)(op);
@@ -557,7 +559,7 @@ void cluster_client_t::flush_buffer(const object_id & oid, cluster_buffer_t *wr)
 {
     wr->state = CACHE_REPEATING;
     cluster_op_t *op = new cluster_op_t;
-    op->flags = OP_FLUSH_BUFFER;
+    op->flags = OSD_OP_IGNORE_READONLY|OP_FLUSH_BUFFER;
     op->opcode = OSD_OP_WRITE;
     op->cur_inode = op->inode = oid.inode;
     op->offset = oid.stripe;
@@ -594,7 +596,8 @@ int cluster_client_t::continue_rw(cluster_op_t *op)
     else if (op->state == 3)
         goto resume_3;
 resume_0:
-    if (!op->len || op->offset % bs_bitmap_granularity || op->len % bs_bitmap_granularity)
+    if ((op->opcode == OSD_OP_READ || op->opcode == OSD_OP_WRITE) && !op->len ||
+        op->offset % bs_bitmap_granularity || op->len % bs_bitmap_granularity)
     {
         op->retval = -EINVAL;
         erase_op(op);
@@ -615,16 +618,19 @@ resume_0:
             return 0;
         }
     }
-    if (op->opcode == OSD_OP_WRITE)
+    if (op->opcode == OSD_OP_WRITE || op->opcode == OSD_OP_DELETE)
     {
-        auto ino_it = st_cli.inode_config.find(op->inode);
-        if (ino_it != st_cli.inode_config.end() && ino_it->second.readonly)
+        if (!(op->flags & OSD_OP_IGNORE_READONLY))
         {
-            op->retval = -EINVAL;
-            erase_op(op);
-            return 1;
+            auto ino_it = st_cli.inode_config.find(op->inode);
+            if (ino_it != st_cli.inode_config.end() && ino_it->second.readonly)
+            {
+                op->retval = -EINVAL;
+                erase_op(op);
+                return 1;
+            }
         }
-        if (!immediate_commit && !(op->flags & OP_FLUSH_BUFFER))
+        if (op->opcode == OSD_OP_WRITE && !immediate_commit && !(op->flags & OP_FLUSH_BUFFER))
         {
             copy_write(op, dirty_buffers);
         }
@@ -633,7 +639,7 @@ resume_1:
     // Slice the operation into parts
     slice_rw(op);
     op->needs_reslice = false;
-    if (op->opcode == OSD_OP_WRITE && op->version && op->parts.size() > 1)
+    if ((op->opcode == OSD_OP_WRITE || op->opcode == OSD_OP_DELETE) && op->version && op->parts.size() > 1)
     {
         // Atomic writes to multiple stripes are unsupported
         op->retval = -EINVAL;
@@ -793,13 +799,13 @@ void cluster_client_t::slice_rw(cluster_op_t *op)
     uint32_t pg_data_size = (pool_cfg.scheme == POOL_SCHEME_REPLICATED ? 1 : pool_cfg.pg_size-pool_cfg.parity_chunks);
     uint64_t pg_block_size = bs_block_size * pg_data_size;
     uint64_t first_stripe = (op->offset / pg_block_size) * pg_block_size;
-    uint64_t last_stripe = ((op->offset + op->len + pg_block_size - 1) / pg_block_size - 1) * pg_block_size;
+    uint64_t last_stripe = op->len > 0 ? ((op->offset + op->len - 1) / pg_block_size) * pg_block_size : first_stripe;
     op->retval = 0;
     op->parts.resize((last_stripe - first_stripe) / pg_block_size + 1);
-    if (op->opcode == OSD_OP_READ)
+    if (op->opcode == OSD_OP_READ || op->opcode == OSD_OP_READ_BITMAP)
     {
         // Allocate memory for the bitmap
-        unsigned object_bitmap_size = ((op->len / bs_bitmap_granularity + 7) / 8);
+        unsigned object_bitmap_size = (((op->opcode == OSD_OP_READ_BITMAP ? pg_block_size : op->len) / bs_bitmap_granularity + 7) / 8);
         object_bitmap_size = (object_bitmap_size < 8 ? 8 : object_bitmap_size);
         unsigned bitmap_mem = object_bitmap_size + (bs_bitmap_size * pg_data_size) * op->parts.size();
         if (op->bitmap_buf_size < bitmap_mem)
@@ -863,13 +869,13 @@ void cluster_client_t::slice_rw(cluster_op_t *op)
             if (end == begin)
                 op->done_count++;
         }
-        else
+        else if (op->opcode != OSD_OP_READ_BITMAP && op->opcode != OSD_OP_DELETE)
         {
             add_iov(end-begin, false, op, iov_idx, iov_pos, op->parts[i].iov, NULL, 0);
         }
         op->parts[i].parent = op;
         op->parts[i].offset = begin;
-        op->parts[i].len = (uint32_t)(end - begin);
+        op->parts[i].len = op->opcode == OSD_OP_READ_BITMAP || op->opcode == OSD_OP_DELETE ? 0 : (uint32_t)(end - begin);
         op->parts[i].pg_num = pg_num;
         op->parts[i].osd_num = 0;
         op->parts[i].flags = 0;
@@ -883,7 +889,7 @@ bool cluster_client_t::affects_osd(uint64_t inode, uint64_t offset, uint64_t len
     uint32_t pg_data_size = (pool_cfg.scheme == POOL_SCHEME_REPLICATED ? 1 : pool_cfg.pg_size-pool_cfg.parity_chunks);
     uint64_t pg_block_size = bs_block_size * pg_data_size;
     uint64_t first_stripe = (offset / pg_block_size) * pg_block_size;
-    uint64_t last_stripe = ((offset + len + pg_block_size - 1) / pg_block_size - 1) * pg_block_size;
+    uint64_t last_stripe = len > 0 ? ((offset + len - 1) / pg_block_size) * pg_block_size : first_stripe;
     for (uint64_t stripe = first_stripe; stripe <= last_stripe; stripe += pg_block_size)
     {
         pg_num_t pg_num = (stripe/pool_cfg.pg_stripe_size) % pool_cfg.real_pg_count + 1; // like map_to_pg()
@@ -916,9 +922,12 @@ bool cluster_client_t::try_send(cluster_op_t *op, int i)
                 pool_cfg.scheme == POOL_SCHEME_REPLICATED ? 1 : pool_cfg.pg_size-pool_cfg.parity_chunks
             );
             uint64_t meta_rev = 0;
-            auto ino_it = st_cli.inode_config.find(op->inode);
-            if (ino_it != st_cli.inode_config.end())
-                meta_rev = ino_it->second.mod_revision;
+            if (op->opcode != OSD_OP_READ_BITMAP && op->opcode != OSD_OP_DELETE)
+            {
+                auto ino_it = st_cli.inode_config.find(op->inode);
+                if (ino_it != st_cli.inode_config.end())
+                    meta_rev = ino_it->second.mod_revision;
+            }
             part->op = (osd_op_t){
                 .op_type = OSD_OP_OUT,
                 .peer_fd = peer_fd,
@@ -926,16 +935,16 @@ bool cluster_client_t::try_send(cluster_op_t *op, int i)
                     .header = {
                         .magic = SECONDARY_OSD_OP_MAGIC,
                         .id = op_id++,
-                        .opcode = op->opcode,
+                        .opcode = op->opcode == OSD_OP_READ_BITMAP ? OSD_OP_READ : op->opcode,
                     },
                     .inode = op->cur_inode,
                     .offset = part->offset,
                     .len = part->len,
                     .meta_revision = meta_rev,
-                    .version = op->opcode == OSD_OP_WRITE ? op->version : 0,
+                    .version = op->opcode == OSD_OP_WRITE || op->opcode == OSD_OP_DELETE ? op->version : 0,
                 } },
-                .bitmap = op->opcode == OSD_OP_WRITE ? NULL : op->part_bitmaps + pg_bitmap_size*i,
-                .bitmap_len = (unsigned)(op->opcode == OSD_OP_WRITE ? 0 : pg_bitmap_size),
+                .bitmap = (op->opcode == OSD_OP_READ || op->opcode == OSD_OP_READ_BITMAP ? op->part_bitmaps + pg_bitmap_size*i : NULL),
+                .bitmap_len = (unsigned)(op->opcode == OSD_OP_READ || op->opcode == OSD_OP_READ_BITMAP ? pg_bitmap_size : 0),
                 .callback = [this, part](osd_op_t *op_part)
                 {
                     handle_op_part(part);
@@ -1117,7 +1126,7 @@ void cluster_client_t::handle_op_part(cluster_op_part_t *part)
         dirty_osds.insert(part->osd_num);
         part->flags |= PART_DONE;
         op->done_count++;
-        if (op->opcode == OSD_OP_READ)
+        if (op->opcode == OSD_OP_READ || op->opcode == OSD_OP_READ_BITMAP)
         {
             copy_part_bitmap(op, part);
             op->version = op->parts.size() == 1 ? part->op.reply.rw.version : 0;
@@ -1141,7 +1150,7 @@ void cluster_client_t::copy_part_bitmap(cluster_op_t *op, cluster_op_part_t *par
     );
     uint32_t object_offset = (part->op.req.rw.offset - op->offset) / bs_bitmap_granularity;
     uint32_t part_offset = (part->op.req.rw.offset % pg_block_size) / bs_bitmap_granularity;
-    uint32_t part_len = part->op.req.rw.len / bs_bitmap_granularity;
+    uint32_t part_len = (op->opcode == OSD_OP_READ_BITMAP ? pg_block_size : part->op.req.rw.len) / bs_bitmap_granularity;
     if (!(object_offset & 0x7) && !(part_offset & 0x7) && (part_len >= 8))
     {
         // Copy bytes
@@ -1161,3 +1170,8 @@ void cluster_client_t::copy_part_bitmap(cluster_op_t *op, cluster_op_part_t *par
         part_len--;
     }
 }
+
+uint64_t cluster_client_t::next_op_id()
+{
+    return op_id++;
+}

src/cluster_client.h

@@ -10,6 +10,11 @@
 #define MAX_BLOCK_SIZE 128*1024*1024
 #define DEFAULT_CLIENT_MAX_DIRTY_BYTES 32*1024*1024
 #define DEFAULT_CLIENT_MAX_DIRTY_OPS 1024
+#define INODE_LIST_DONE 1
+#define INODE_LIST_HAS_UNSTABLE 2
+#define OSD_OP_READ_BITMAP OSD_OP_SEC_READ_BMP
+
+#define OSD_OP_IGNORE_READONLY 0x08
 
 struct cluster_op_t;
 
@@ -27,19 +32,22 @@ struct cluster_op_part_t
 
 struct cluster_op_t
 {
-    uint64_t opcode; // OSD_OP_READ, OSD_OP_WRITE, OSD_OP_SYNC
+    uint64_t opcode; // OSD_OP_READ, OSD_OP_WRITE, OSD_OP_SYNC, OSD_OP_DELETE, OSD_OP_READ_BITMAP
     uint64_t inode;
     uint64_t offset;
     uint64_t len;
     // for reads and writes within a single object (stripe),
     // reads can return current version and writes can use "CAS" semantics
     uint64_t version = 0;
+    // now only OSD_OP_IGNORE_READONLY is supported
+    uint64_t flags = 0;
     int retval;
     osd_op_buf_list_t iov;
+    // READ and READ_BITMAP return the bitmap here
+    void *bitmap_buf = NULL;
     std::function<void(cluster_op_t*)> callback;
     ~cluster_op_t();
 protected:
-    uint64_t flags = 0;
     int state = 0;
     uint64_t cur_inode; // for snapshot reads
     void *buf = NULL;
@@ -48,7 +56,7 @@ protected:
     bool up_wait = false;
     int inflight_count = 0, done_count = 0;
     std::vector<cluster_op_part_t> parts;
-    void *bitmap_buf = NULL, *part_bitmaps = NULL;
+    void *part_bitmaps = NULL;
     unsigned bitmap_buf_size = 0;
     cluster_op_t *prev = NULL, *next = NULL;
     int prev_wait = 0;
@@ -62,6 +70,9 @@ struct cluster_buffer_t
     int state;
 };
 
+struct inode_list_t;
+struct inode_list_osd_t;
+
 // FIXME: Split into public and private interfaces
 class cluster_client_t
 {
@@ -93,6 +104,7 @@ class cluster_client_t
     bool pgs_loaded = false;
     ring_consumer_t consumer;
     std::vector<std::function<void(void)>> on_ready_hooks;
+    std::vector<inode_list_t*> lists;
     int continuing_ops = 0;
 
 public:
@@ -108,6 +120,14 @@ public:
 
     static void copy_write(cluster_op_t *op, std::map<object_id, cluster_buffer_t> & dirty_buffers);
     void continue_ops(bool up_retry = false);
+    inode_list_t *list_inode_start(inode_t inode,
+        std::function<void(inode_list_t* lst, std::set<object_id>&& objects, pg_num_t pg_num, osd_num_t primary_osd, int status)> callback);
+    int list_pg_count(inode_list_t *lst);
+    void list_inode_next(inode_list_t *lst, int next_pgs);
+    inline uint32_t get_bs_bitmap_granularity() { return bs_bitmap_granularity; }
+    inline uint64_t get_bs_block_size() { return bs_block_size; }
+    uint64_t next_op_id();
+
 protected:
     bool affects_osd(uint64_t inode, uint64_t offset, uint64_t len, osd_num_t osd);
     void flush_buffer(const object_id & oid, cluster_buffer_t *wr);
@@ -125,4 +145,7 @@ protected:
     void erase_op(cluster_op_t *op);
     void calc_wait(cluster_op_t *op);
     void inc_wait(uint64_t opcode, uint64_t flags, cluster_op_t *next, int inc);
+    void continue_lists();
+    void continue_listing(inode_list_t *lst);
+    void send_list(inode_list_osd_t *cur_list);
 };

src/cluster_client_list.cpp

@@ -0,0 +1,285 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
+
+#include <algorithm>
+#include "pg_states.h"
+#include "cluster_client.h"
+
+struct inode_list_t;
+
+struct inode_list_pg_t;
+
+struct inode_list_osd_t
+{
+    inode_list_pg_t *pg = NULL;
+    osd_num_t osd_num = 0;
+    bool sent = false;
+};
+
+struct inode_list_pg_t
+{
+    inode_list_t *lst = NULL;
+    int pos = 0;
+    pg_num_t pg_num;
+    osd_num_t cur_primary;
+    bool has_unstable = false;
+    int sent = 0;
+    int done = 0;
+    std::vector<inode_list_osd_t> list_osds;
+    std::set<object_id> objects;
+};
+
+struct inode_list_t
+{
+    cluster_client_t *cli = NULL;
+    pool_id_t pool_id = 0;
+    inode_t inode = 0;
+    int done_pgs = 0;
+    int want = 0;
+    std::vector<inode_list_pg_t*> pgs;
+    std::function<void(inode_list_t* lst, std::set<object_id>&& objects, pg_num_t pg_num, osd_num_t primary_osd, int status)> callback;
+};
+
+inode_list_t* cluster_client_t::list_inode_start(inode_t inode,
+    std::function<void(inode_list_t* lst, std::set<object_id>&& objects, pg_num_t pg_num, osd_num_t primary_osd, int status)> callback)
+{
+    int skipped_pgs = 0;
+    pool_id_t pool_id = INODE_POOL(inode);
+    if (!pool_id || st_cli.pool_config.find(pool_id) == st_cli.pool_config.end())
+    {
+        if (log_level > 0)
+        {
+            fprintf(stderr, "Pool %u does not exist\n", pool_id);
+        }
+        return NULL;
+    }
+    inode_list_t *lst = new inode_list_t();
+    lst->cli = this;
+    lst->pool_id = pool_id;
+    lst->inode = inode;
+    lst->callback = callback;
+    auto pool_cfg = st_cli.pool_config[pool_id];
+    for (auto & pg_item: pool_cfg.pg_config)
+    {
+        auto & pg = pg_item.second;
+        if (pg.pause || !pg.cur_primary || !(pg.cur_state & PG_ACTIVE))
+        {
+            skipped_pgs++;
+            if (log_level > 0)
+            {
+                fprintf(stderr, "PG %u is inactive, skipping\n", pg_item.first);
+            }
+            continue;
+        }
+        inode_list_pg_t *r = new inode_list_pg_t();
+        r->lst = lst;
+        r->pg_num = pg_item.first;
+        r->cur_primary = pg.cur_primary;
+        if (pg.cur_state != PG_ACTIVE)
+        {
+            // Not clean
+            std::set<osd_num_t> all_peers;
+            for (osd_num_t pg_osd: pg.target_set)
+            {
+                if (pg_osd != 0)
+                {
+                    all_peers.insert(pg_osd);
+                }
+            }
+            for (osd_num_t pg_osd: pg.all_peers)
+            {
+                if (pg_osd != 0)
+                {
+                    all_peers.insert(pg_osd);
+                }
+            }
+            for (auto & hist_item: pg.target_history)
+            {
+                for (auto pg_osd: hist_item)
+                {
+                    if (pg_osd != 0)
+                    {
+                        all_peers.insert(pg_osd);
+                    }
+                }
+            }
+            for (osd_num_t peer_osd: all_peers)
+            {
+                r->list_osds.push_back((inode_list_osd_t){
+                    .pg = r,
+                    .osd_num = peer_osd,
+                    .sent = false,
+                });
+            }
+        }
+        else
+        {
+            // Clean
+            r->list_osds.push_back((inode_list_osd_t){
+                .pg = r,
+                .osd_num = pg.cur_primary,
+                .sent = false,
+            });
+        }
+        lst->pgs.push_back(r);
+    }
+    std::sort(lst->pgs.begin(), lst->pgs.end(), [](inode_list_pg_t *a, inode_list_pg_t *b)
+    {
+        return a->cur_primary < b->cur_primary ? true : false;
+    });
+    for (int i = 0; i < lst->pgs.size(); i++)
+    {
+        lst->pgs[i]->pos = i;
+    }
+    lists.push_back(lst);
+    return lst;
+}
+
+int cluster_client_t::list_pg_count(inode_list_t *lst)
+{
+    return lst->pgs.size();
+}
+
+void cluster_client_t::list_inode_next(inode_list_t *lst, int next_pgs)
+{
+    if (next_pgs >= 0)
+    {
+        lst->want += next_pgs;
+    }
+    continue_listing(lst);
+}
+
+void cluster_client_t::continue_listing(inode_list_t *lst)
+{
+    if (lst->done_pgs >= lst->pgs.size())
+    {
+        // All done
+        for (int i = 0; i < lists.size(); i++)
+        {
+            if (lists[i] == lst)
+            {
+                lists.erase(lists.begin()+i, lists.begin()+i+1);
+                break;
+            }
+        }
+        delete lst;
+        return;
+    }
+    if (lst->want <= 0)
+    {
+        return;
+    }
+    for (int i = 0; i < lst->pgs.size(); i++)
+    {
+        if (lst->pgs[i] && lst->pgs[i]->sent < lst->pgs[i]->list_osds.size())
+        {
+            for (int j = 0; j < lst->pgs[i]->list_osds.size(); j++)
+            {
+                send_list(&lst->pgs[i]->list_osds[j]);
+                if (lst->want <= 0)
+                {
+                    break;
+                }
+            }
+        }
+    }
+}
+
+void cluster_client_t::send_list(inode_list_osd_t *cur_list)
+{
+    if (cur_list->sent)
+    {
+        return;
+    }
+    if (msgr.osd_peer_fds.find(cur_list->osd_num) == msgr.osd_peer_fds.end())
+    {
+        // Initiate connection
+        msgr.connect_peer(cur_list->osd_num, st_cli.peer_states[cur_list->osd_num]);
+        return;
+    }
+    auto & pool_cfg = st_cli.pool_config[cur_list->pg->lst->pool_id];
+    osd_op_t *op = new osd_op_t();
+    op->op_type = OSD_OP_OUT;
+    op->peer_fd = msgr.osd_peer_fds[cur_list->osd_num];
+    op->req = (osd_any_op_t){
+        .sec_list = {
+            .header = {
+                .magic = SECONDARY_OSD_OP_MAGIC,
+                .id = op_id++,
+                .opcode = OSD_OP_SEC_LIST,
+            },
+            .list_pg = cur_list->pg->pg_num,
+            .pg_count = (pg_num_t)pool_cfg.real_pg_count,
+            .pg_stripe_size = pool_cfg.pg_stripe_size,
+            .min_inode = cur_list->pg->lst->inode,
+            .max_inode = cur_list->pg->lst->inode,
+        },
+    };
+    op->callback = [this, cur_list](osd_op_t *op)
+    {
+        if (op->reply.hdr.retval < 0)
+        {
+            fprintf(stderr, "Failed to get PG %u/%u object list from OSD %lu (retval=%ld), skipping\n",
+                cur_list->pg->lst->pool_id, cur_list->pg->pg_num, cur_list->osd_num, op->reply.hdr.retval);
+        }
+        else
+        {
+            if (op->reply.sec_list.stable_count < op->reply.hdr.retval)
+            {
+                // Unstable objects, if present, mean that someone still writes into the inode. Warn the user about it.
+                cur_list->pg->has_unstable = true;
+                fprintf(
+                    stderr, "[PG %u/%u] Inode still has %lu unstable object versions out of total %lu - is it still open?\n",
+                    cur_list->pg->lst->pool_id, cur_list->pg->pg_num, op->reply.hdr.retval - op->reply.sec_list.stable_count,
+                    op->reply.hdr.retval
+                );
+            }
+            if (log_level > 0)
+            {
+                fprintf(
+                    stderr, "[PG %u/%u] Got inode object list from OSD %lu: %ld object versions\n",
+                    cur_list->pg->lst->pool_id, cur_list->pg->pg_num, cur_list->osd_num, op->reply.hdr.retval
+                );
+            }
+            for (uint64_t i = 0; i < op->reply.hdr.retval; i++)
+            {
+                object_id oid = ((obj_ver_id*)op->buf)[i].oid;
+                oid.stripe = oid.stripe & ~STRIPE_MASK;
+                cur_list->pg->objects.insert(oid);
+            }
+        }
+        delete op;
+        auto lst = cur_list->pg->lst;
+        auto pg = cur_list->pg;
+        pg->done++;
+        if (pg->done >= pg->list_osds.size())
+        {
+            int status = 0;
+            lst->done_pgs++;
+            if (lst->done_pgs >= lst->pgs.size())
+            {
+                status |= INODE_LIST_DONE;
+            }
+            if (pg->has_unstable)
+            {
+                status |= INODE_LIST_HAS_UNSTABLE;
+            }
+            lst->callback(lst, std::move(pg->objects), pg->pg_num, pg->cur_primary, status);
+            lst->pgs[pg->pos] = NULL;
+            delete pg;
+        }
+        continue_listing(lst);
+    };
+    msgr.outbox_push(op);
+    cur_list->sent = true;
+    cur_list->pg->sent++;
+    cur_list->pg->lst->want--;
+}
+
+void cluster_client_t::continue_lists()
+{
+    for (auto lst: lists)
+    {
+        continue_listing(lst);
+    }
+}

src/etcd_state_client.cpp

@@ -765,3 +765,22 @@ void etcd_state_client_t::close_watch(inode_watch_t* watch)
     }
     delete watch;
 }
+
+json11::Json::object & etcd_state_client_t::serialize_inode_cfg(inode_config_t *cfg)
+{
+    json11::Json::object new_cfg = json11::Json::object {
+        { "name", cfg->name },
+        { "size", cfg->size },
+    };
+    if (cfg->parent_id)
+    {
+        if (INODE_POOL(cfg->num) != INODE_POOL(cfg->parent_id))
+            new_cfg["parent_pool"] = (uint64_t)INODE_POOL(cfg->parent_id);
+        new_cfg["parent_id"] = (uint64_t)INODE_NO_POOL(cfg->parent_id);
+    }
+    if (cfg->readonly)
+    {
+        new_cfg["readonly"] = true;
+    }
+    return new_cfg;
+}

src/etcd_state_client.h

@@ -99,6 +99,7 @@ public:
     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;
 
+    json11::Json::object & serialize_inode_cfg(inode_config_t *cfg);
     etcd_kv_t parse_etcd_kv(const json11::Json & kv_json);
     void etcd_call(std::string api, json11::Json payload, int timeout, std::function<void(std::string, json11::Json)> callback);
     void etcd_txn(json11::Json txn, int timeout, std::function<void(std::string, json11::Json)> callback);

src/messenger.cpp

@@ -117,7 +117,7 @@ osd_messenger_t::~osd_messenger_t()
     }
     while (clients.size() > 0)
     {
-        stop_client(clients.begin()->first, true);
+        stop_client(clients.begin()->first, true, true);
     }
 #ifdef WITH_RDMA
     if (rdma_context)

src/messenger.h

@@ -156,7 +156,7 @@ public:
     void init();
     void parse_config(const json11::Json & config);
     void connect_peer(uint64_t osd_num, json11::Json peer_state);
-    void stop_client(int peer_fd, bool force = false);
+    void stop_client(int peer_fd, bool force = false, bool force_delete = false);
     void outbox_push(osd_op_t *cur_op);
     std::function<void(osd_op_t*)> exec_op;
     std::function<void(osd_num_t)> repeer_pgs;

src/mock/messenger.cpp

@@ -15,7 +15,7 @@ osd_messenger_t::~osd_messenger_t()
 {
     while (clients.size() > 0)
     {
-        stop_client(clients.begin()->first, true);
+        stop_client(clients.begin()->first, true, true);
     }
 }
 

src/msgr_rdma.cpp

@@ -46,6 +46,9 @@ msgr_rdma_connection_t::~msgr_rdma_connection_t()
     ctx->used_max_cqe -= max_send+max_recv;
     if (qp)
         ibv_destroy_qp(qp);
+    if (recv_buffers.size())
+        for (auto b: recv_buffers)
+            free(b);
 }
 
 msgr_rdma_context_t *msgr_rdma_context_t::create(const char *ib_devname, uint8_t ib_port, uint8_t gid_index, uint32_t mtu)
@@ -55,6 +58,7 @@ msgr_rdma_context_t *msgr_rdma_context_t::create(const char *ib_devname, uint8_t
     msgr_rdma_context_t *ctx = new msgr_rdma_context_t();
     ctx->mtu = mtu;
 
+    srand48(time(NULL));
     dev_list = ibv_get_device_list(NULL);
     if (!dev_list)
     {
@@ -477,7 +481,11 @@ void osd_messenger_t::handle_rdma_events()
             if (!is_send)
             {
                 cl->rdma_conn->cur_recv--;
-                handle_read_buffer(cl, cl->rdma_conn->recv_buffers[0], wc[i].byte_len);
+                if (!handle_read_buffer(cl, cl->rdma_conn->recv_buffers[0], wc[i].byte_len))
+                {
+                    // handle_read_buffer may stop the client
+                    continue;
+                }
                 free(cl->rdma_conn->recv_buffers[0]);
                 cl->rdma_conn->recv_buffers.erase(cl->rdma_conn->recv_buffers.begin(), cl->rdma_conn->recv_buffers.begin()+1);
                 try_recv_rdma(cl);

src/msgr_stop.cpp

@@ -41,7 +41,7 @@ void osd_messenger_t::cancel_op(osd_op_t *op)
     }
 }
 
-void osd_messenger_t::stop_client(int peer_fd, bool force)
+void osd_messenger_t::stop_client(int peer_fd, bool force, bool force_delete)
 {
     assert(peer_fd != 0);
     auto it = clients.find(peer_fd);
@@ -136,7 +136,7 @@ void osd_messenger_t::stop_client(int peer_fd, bool force)
         clients.erase(it);
     }
     cl->refs--;
-    if (cl->refs <= 0)
+    if (cl->refs <= 0 || force_delete)
     {
         delete cl;
     }

src/osd.cpp

@@ -7,6 +7,8 @@
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
 
+#include "blockstore_impl.h"
+#include "osd_primary.h"
 #include "osd.h"
 #include "http_client.h"
 
@@ -365,6 +367,7 @@ void osd_t::print_stats()
 
 void osd_t::print_slow()
 {
+    bool has_slow = false;
     char alloc[1024];
     timespec now;
     clock_gettime(CLOCK_REALTIME, &now);
@@ -426,9 +429,32 @@ void osd_t::print_slow()
                 {
                     bufprintf(" inode=%lx offset=%lx len=%x", op->req.rw.inode, op->req.rw.offset, op->req.rw.len);
                 }
+                if (op->req.hdr.opcode == OSD_OP_SEC_READ || op->req.hdr.opcode == OSD_OP_SEC_WRITE ||
+                    op->req.hdr.opcode == OSD_OP_SEC_WRITE_STABLE || op->req.hdr.opcode == OSD_OP_SEC_DELETE ||
+                    op->req.hdr.opcode == OSD_OP_SEC_SYNC || op->req.hdr.opcode == OSD_OP_SEC_LIST ||
+                    op->req.hdr.opcode == OSD_OP_SEC_STABILIZE || op->req.hdr.opcode == OSD_OP_SEC_ROLLBACK ||
+                    op->req.hdr.opcode == OSD_OP_SEC_READ_BMP)
+                {
+                    bufprintf(" state=%d", PRIV(op->bs_op)->op_state);
+                    int wait_for = PRIV(op->bs_op)->wait_for;
+                    if (wait_for)
+                    {
+                        bufprintf(" wait=%d (detail=%lu)", wait_for, PRIV(op->bs_op)->wait_detail);
+                    }
+                }
+                else if (op->req.hdr.opcode == OSD_OP_READ || op->req.hdr.opcode == OSD_OP_WRITE ||
+                    op->req.hdr.opcode == OSD_OP_SYNC || op->req.hdr.opcode == OSD_OP_DELETE)
+                {
+                    bufprintf(" state=%d", !op->op_data ? -1 : op->op_data->st);
+                }
 #undef bufprintf
                 printf("%s\n", alloc);
+                has_slow = true;
             }
         }
     }
+    if (has_slow)
+    {
+        bs->dump_diagnostics();
+    }
 }

src/osd_id.h

@@ -9,6 +9,8 @@
 #define POOL_ID_MAX 0x10000
 #define POOL_ID_BITS 16
 #define INODE_POOL(inode) (pool_id_t)((inode) >> (64 - POOL_ID_BITS))
+#define INODE_NO_POOL(inode) (inode_t)(inode & ((1l << (64-POOL_ID_BITS)) - 1))
+#define INODE_WITH_POOL(pool_id, inode) (((inode_t)(pool_id) << (64-POOL_ID_BITS)) | INODE_NO_POOL(inode))
 
 // Pool ID is 16 bits long
 typedef uint32_t pool_id_t;

src/osd_primary.cpp

@@ -198,7 +198,7 @@ void osd_t::continue_primary_read(osd_op_t *cur_op)
         {
             // Fast happy-path
             cur_op->buf = alloc_read_buffer(op_data->stripes, op_data->pg_data_size, 0);
-            submit_primary_subops(SUBMIT_READ, op_data->target_ver, pg.cur_set.data(), cur_op);
+            submit_primary_subops(SUBMIT_RMW_READ, op_data->target_ver, pg.cur_set.data(), cur_op);
             op_data->st = 1;
         }
         else
@@ -215,7 +215,7 @@ void osd_t::continue_primary_read(osd_op_t *cur_op)
             op_data->scheme = pg.scheme;
             op_data->degraded = 1;
             cur_op->buf = alloc_read_buffer(op_data->stripes, pg.pg_size, 0);
-            submit_primary_subops(SUBMIT_READ, op_data->target_ver, cur_set, cur_op);
+            submit_primary_subops(SUBMIT_RMW_READ, op_data->target_ver, cur_set, cur_op);
             op_data->st = 1;
         }
     }
@@ -353,6 +353,7 @@ resume_3:
     if (cur_op->req.rw.version && op_data->fact_ver != (cur_op->req.rw.version-1))
     {
         cur_op->reply.hdr.retval = -EINTR;
+        cur_op->reply.rw.version = op_data->fact_ver;
         goto continue_others;
     }
     // Save version override for parallel reads

src/osd_primary_write.cpp

@@ -100,6 +100,7 @@ resume_3:
     if (cur_op->req.rw.version && op_data->fact_ver != (cur_op->req.rw.version-1))
     {
         cur_op->reply.hdr.retval = -EINTR;
+        cur_op->reply.rw.version = op_data->fact_ver;
         goto continue_others;
     }
     if (op_data->scheme == POOL_SCHEME_REPLICATED)
@@ -260,6 +261,7 @@ resume_9:
         }
     }
     cur_op->reply.hdr.retval = cur_op->req.rw.len;
+    cur_op->reply.rw.version = op_data->fact_ver;
 continue_others:
     osd_op_t *next_op = NULL;
     auto next_it = pg.write_queue.find(op_data->oid);

src/rm_inode.cpp

@@ -1,410 +0,0 @@
-// Copyright (c) Vitaliy Filippov, 2019+
-// License: VNPL-1.1 (see README.md for details)
-
-/**
- * Inode removal tool
- * May be included into a bigger "command-line management interface" in the future
- */
-
-#include <vector>
-#include <algorithm>
-
-#include "epoll_manager.h"
-#include "cluster_client.h"
-#include "pg_states.h"
-
-#define RM_LISTING 1
-#define RM_REMOVING 2
-#define RM_END 3
-
-const char *exe_name = NULL;
-
-struct rm_pg_t;
-
-struct rm_pg_osd_t
-{
-    rm_pg_t *pg = NULL;
-    osd_num_t osd_num;
-    bool sent = false;
-};
-
-struct rm_pg_t
-{
-    pg_num_t pg_num;
-    osd_num_t rm_osd_num;
-    std::vector<rm_pg_osd_t> list_osds;
-    int state = 0;
-    int to_list;
-    std::set<object_id> objects;
-    std::set<object_id>::iterator obj_pos;
-    uint64_t obj_count = 0, obj_done = 0, obj_prev_done = 0;
-    int in_flight = 0;
-};
-
-class rm_inode_t
-{
-protected:
-    uint64_t inode = 0;
-    pool_id_t pool_id = 0;
-    uint64_t iodepth = 0, parallel_osds = 0;
-
-    ring_loop_t *ringloop = NULL;
-    epoll_manager_t *epmgr = NULL;
-    cluster_client_t *cli = NULL;
-    ring_consumer_t consumer;
-
-    std::vector<rm_pg_t*> lists;
-    uint64_t total_count = 0, total_done = 0, total_prev_pct = 0;
-    uint64_t pgs_to_list = 0;
-    bool started = false;
-    bool progress = true;
-    bool list_first = false;
-    int log_level = 0;
-
-public:
-    static json11::Json::object parse_args(int narg, const char *args[])
-    {
-        json11::Json::object cfg;
-        cfg["progress"] = "1";
-        for (int i = 1; i < narg; i++)
-        {
-            if (!strcmp(args[i], "-h") || !strcmp(args[i], "--help"))
-            {
-                help();
-            }
-            else if (args[i][0] == '-' && args[i][1] == '-')
-            {
-                const char *opt = args[i]+2;
-                cfg[opt] = !strcmp(opt, "json") || !strcmp(opt, "wait-list") || i == narg-1 ? "1" : args[++i];
-            }
-        }
-        return cfg;
-    }
-
-    static void help()
-    {
-        printf(
-            "Vitastor inode removal tool\n"
-            "(c) Vitaliy Filippov, 2020 (VNPL-1.1)\n\n"
-            "USAGE:\n"
-            "  %s [--etcd_address <etcd_address>] --pool <pool> --inode <inode> [--wait-list]\n",
-            exe_name
-        );
-        exit(0);
-    }
-
-    void run(json11::Json cfg)
-    {
-        inode = cfg["inode"].uint64_value();
-        pool_id = cfg["pool"].uint64_value();
-        if (pool_id)
-            inode = (inode & ((1l << (64-POOL_ID_BITS)) - 1)) | (((uint64_t)pool_id) << (64-POOL_ID_BITS));
-        pool_id = INODE_POOL(inode);
-        if (!pool_id)
-        {
-            fprintf(stderr, "pool is missing");
-            exit(1);
-        }
-        iodepth = cfg["iodepth"].uint64_value();
-        if (!iodepth)
-            iodepth = 32;
-        parallel_osds = cfg["parallel_osds"].uint64_value();
-        if (!parallel_osds)
-            parallel_osds = 4;
-        log_level = cfg["log_level"].int64_value();
-        progress = cfg["progress"].uint64_value() ? true : false;
-        list_first = cfg["wait-list"].uint64_value() ? true : false;
-        // Create client
-        ringloop = new ring_loop_t(512);
-        epmgr = new epoll_manager_t(ringloop);
-        cli = new cluster_client_t(ringloop, epmgr->tfd, cfg);
-        cli->on_ready([this]() { start_delete(); });
-        // Initialize job
-        consumer.loop = [this]()
-        {
-            if (started)
-                continue_delete();
-            ringloop->submit();
-        };
-        ringloop->register_consumer(&consumer);
-        // Loop until it completes
-        while (1)
-        {
-            ringloop->loop();
-            ringloop->wait();
-        }
-    }
-
-    void start_delete()
-    {
-        if (cli->st_cli.pool_config.find(pool_id) == cli->st_cli.pool_config.end())
-        {
-            fprintf(stderr, "Pool %u does not exist\n", pool_id);
-            exit(1);
-        }
-        auto pool_cfg = cli->st_cli.pool_config[pool_id];
-        for (auto & pg_item: pool_cfg.pg_config)
-        {
-            auto & pg = pg_item.second;
-            if (pg.pause || !pg.cur_primary || !(pg.cur_state & PG_ACTIVE))
-            {
-                fprintf(stderr, "PG %u is inactive, skipping\n", pg_item.first);
-                continue;
-            }
-            rm_pg_t *r = new rm_pg_t();
-            r->pg_num = pg_item.first;
-            r->rm_osd_num = pg.cur_primary;
-            r->state = RM_LISTING;
-            if (pg.cur_state != PG_ACTIVE)
-            {
-                std::set<osd_num_t> all_peers;
-                for (osd_num_t pg_osd: pg.target_set)
-                {
-                    if (pg_osd != 0)
-                    {
-                        all_peers.insert(pg_osd);
-                    }
-                }
-                for (osd_num_t pg_osd: pg.all_peers)
-                {
-                    if (pg_osd != 0)
-                    {
-                        all_peers.insert(pg_osd);
-                    }
-                }
-                for (auto & hist_item: pg.target_history)
-                {
-                    for (auto pg_osd: hist_item)
-                    {
-                        if (pg_osd != 0)
-                        {
-                            all_peers.insert(pg_osd);
-                        }
-                    }
-                }
-                for (osd_num_t peer_osd: all_peers)
-                {
-                    r->list_osds.push_back((rm_pg_osd_t){ .pg = r, .osd_num = peer_osd, .sent = false });
-                }
-            }
-            else
-            {
-                r->list_osds.push_back((rm_pg_osd_t){ .pg = r, .osd_num = pg.cur_primary, .sent = false });
-            }
-            r->to_list = r->list_osds.size();
-            lists.push_back(r);
-        }
-        std::sort(lists.begin(), lists.end(), [](rm_pg_t *a, rm_pg_t *b)
-        {
-            return a->rm_osd_num < b->rm_osd_num ? true : false;
-        });
-        pgs_to_list = lists.size();
-        started = true;
-        continue_delete();
-    }
-
-    void send_list(rm_pg_osd_t *cur_list)
-    {
-        if (cur_list->sent)
-        {
-            return;
-        }
-        if (cli->msgr.osd_peer_fds.find(cur_list->osd_num) ==
-            cli->msgr.osd_peer_fds.end())
-        {
-            // Initiate connection
-            cli->msgr.connect_peer(cur_list->osd_num, cli->st_cli.peer_states[cur_list->osd_num]);
-            return;
-        }
-        osd_op_t *op = new osd_op_t();
-        op->op_type = OSD_OP_OUT;
-        op->peer_fd = cli->msgr.osd_peer_fds[cur_list->osd_num];
-        op->req = (osd_any_op_t){
-            .sec_list = {
-                .header = {
-                    .magic = SECONDARY_OSD_OP_MAGIC,
-                    .id = cli->msgr.next_subop_id++,
-                    .opcode = OSD_OP_SEC_LIST,
-                },
-                .list_pg = cur_list->pg->pg_num,
-                .pg_count = (pg_num_t)cli->st_cli.pool_config[pool_id].real_pg_count,
-                .pg_stripe_size = cli->st_cli.pool_config[pool_id].pg_stripe_size,
-                .min_inode = inode,
-                .max_inode = inode,
-            },
-        };
-        op->callback = [this, cur_list](osd_op_t *op)
-        {
-            cur_list->pg->to_list--;
-            if (op->reply.hdr.retval < 0)
-            {
-                fprintf(stderr, "Failed to get PG %u/%u object list from OSD %lu (retval=%ld), skipping\n",
-                    pool_id, cur_list->pg->pg_num, cur_list->osd_num, op->reply.hdr.retval);
-            }
-            else
-            {
-                if (op->reply.sec_list.stable_count < op->reply.hdr.retval)
-                {
-                    // Unstable objects, if present, mean that someone still writes into the inode. Warn the user about it.
-                    printf(
-                        "[PG %u/%u] Inode still has %lu unstable object versions - is it still open? Not a good idea to delete it.\n",
-                        pool_id, cur_list->pg->pg_num, op->reply.hdr.retval - op->reply.sec_list.stable_count
-                    );
-                }
-                if (log_level > 0)
-                {
-                    printf(
-                        "[PG %u/%u] Got inode object list from OSD %lu: %ld object versions\n",
-                        pool_id, cur_list->pg->pg_num, cur_list->osd_num, op->reply.hdr.retval
-                    );
-                }
-                for (uint64_t i = 0; i < op->reply.hdr.retval; i++)
-                {
-                    object_id oid = ((obj_ver_id*)op->buf)[i].oid;
-                    oid.stripe = oid.stripe & ~STRIPE_MASK;
-                    cur_list->pg->objects.insert(oid);
-                }
-            }
-            delete op;
-            if (cur_list->pg->to_list <= 0)
-            {
-                cur_list->pg->obj_done = cur_list->pg->obj_prev_done = 0;
-                cur_list->pg->obj_pos = cur_list->pg->objects.begin();
-                cur_list->pg->obj_count = cur_list->pg->objects.size();
-                total_count += cur_list->pg->obj_count;
-                total_prev_pct = 0;
-                cur_list->pg->state = RM_REMOVING;
-                pgs_to_list--;
-            }
-            continue_delete();
-        };
-        cli->msgr.outbox_push(op);
-        cur_list->sent = true;
-    }
-
-    void send_ops(rm_pg_t *cur_list)
-    {
-        if (cli->msgr.osd_peer_fds.find(cur_list->rm_osd_num) ==
-            cli->msgr.osd_peer_fds.end())
-        {
-            // Initiate connection
-            cli->msgr.connect_peer(cur_list->rm_osd_num, cli->st_cli.peer_states[cur_list->rm_osd_num]);
-            return;
-        }
-        while (cur_list->in_flight < iodepth && cur_list->obj_pos != cur_list->objects.end())
-        {
-            osd_op_t *op = new osd_op_t();
-            op->op_type = OSD_OP_OUT;
-            op->peer_fd = cli->msgr.osd_peer_fds[cur_list->rm_osd_num];
-            op->req = (osd_any_op_t){
-                .rw = {
-                    .header = {
-                        .magic = SECONDARY_OSD_OP_MAGIC,
-                        .id = cli->msgr.next_subop_id++,
-                        .opcode = OSD_OP_DELETE,
-                    },
-                    .inode = cur_list->obj_pos->inode,
-                    .offset = (cur_list->obj_pos->stripe & ~STRIPE_MASK),
-                    .len = 0,
-                },
-            };
-            op->callback = [this, cur_list](osd_op_t *op)
-            {
-                cur_list->in_flight--;
-                if (op->reply.hdr.retval < 0)
-                {
-                    fprintf(stderr, "Failed to remove object from PG %u (OSD %lu) (retval=%ld)\n",
-                        cur_list->pg_num, cur_list->rm_osd_num, op->reply.hdr.retval);
-                }
-                delete op;
-                cur_list->obj_done++;
-                total_done++;
-                continue_delete();
-            };
-            cli->msgr.outbox_push(op);
-            cur_list->obj_pos++;
-            cur_list->in_flight++;
-        }
-        if (!cur_list->in_flight && cur_list->obj_pos == cur_list->objects.end())
-        {
-            cur_list->obj_count = 0;
-            cur_list->obj_done = cur_list->obj_prev_done = 0;
-            cur_list->state = RM_END;
-        }
-    }
-
-    void continue_delete()
-    {
-        int par_osd = 0;
-        osd_num_t max_seen_osd = 0;
-        bool no_del = false;
-        if (list_first)
-        {
-            int i, n = 0;
-            for (i = 0; i < lists.size(); i++)
-            {
-                if (lists[i]->state == RM_LISTING)
-                {
-                    n++;
-                }
-            }
-            if (n > 0)
-            {
-                no_del = true;
-            }
-        }
-        for (int i = 0; i < lists.size(); i++)
-        {
-            if (lists[i]->state == RM_END)
-            {
-                delete lists[i];
-                lists.erase(lists.begin()+i, lists.begin()+i+1);
-                i--;
-            }
-            else if (lists[i]->rm_osd_num > max_seen_osd)
-            {
-                if (lists[i]->state == RM_LISTING)
-                {
-                    for (int j = 0; j < lists[i]->list_osds.size(); j++)
-                    {
-                        send_list(&lists[i]->list_osds[j]);
-                    }
-                }
-                else if (lists[i]->state == RM_REMOVING)
-                {
-                    if (no_del)
-                    {
-                        continue;
-                    }
-                    send_ops(lists[i]);
-                }
-                par_osd++;
-                max_seen_osd = lists[i]->rm_osd_num;
-                if (par_osd >= parallel_osds)
-                {
-                    break;
-                }
-            }
-        }
-        if (progress && total_count > 0 && total_done*1000/total_count != total_prev_pct)
-        {
-            printf("\rRemoved %lu/%lu objects, %lu more PGs to list...", total_done, total_count, pgs_to_list);
-            total_prev_pct = total_done*1000/total_count;
-        }
-        if (!lists.size())
-        {
-            printf("Done, inode %lu in pool %u removed\n", (inode & ((1l << (64-POOL_ID_BITS)) - 1)), pool_id);
-            exit(0);
-        }
-    }
-};
-
-int main(int narg, const char *args[])
-{
-    setvbuf(stdout, NULL, _IONBF, 0);
-    setvbuf(stderr, NULL, _IONBF, 0);
-    exe_name = args[0];
-    rm_inode_t *p = new rm_inode_t();
-    p->run(rm_inode_t::parse_args(narg, args));
-    return 0;
-}

src/vitastor_c.cpp

@@ -72,7 +72,7 @@ static void vitastor_c_write_handler(void *opaque)
 
 vitastor_c *vitastor_c_create_qemu(QEMUSetFDHandler *aio_set_fd_handler, void *aio_context,
     const char *config_path, const char *etcd_host, const char *etcd_prefix,
-    bool use_rdma, const char *rdma_device, int rdma_port_num, int rdma_gid_index, int rdma_mtu, int log_level)
+    int use_rdma, const char *rdma_device, int rdma_port_num, int rdma_gid_index, int rdma_mtu, int log_level)
 {
     json11::Json cfg_json = vitastor_c_common_config(
         config_path, etcd_host, etcd_prefix, use_rdma,

src/vitastor_c.h

@@ -28,7 +28,7 @@ typedef void QEMUSetFDHandler(void *ctx, int fd, int is_external, IOHandler *fd_
 
 vitastor_c *vitastor_c_create_qemu(QEMUSetFDHandler *aio_set_fd_handler, void *aio_context,
     const char *config_path, const char *etcd_host, const char *etcd_prefix,
-    bool use_rdma, const char *rdma_device, int rdma_port_num, int rdma_gid_index, int rdma_mtu, int log_level);
+    int use_rdma, const char *rdma_device, int rdma_port_num, int rdma_gid_index, int rdma_mtu, int log_level);
 vitastor_c *vitastor_c_create_uring(const char *config_path, const char *etcd_host, const char *etcd_prefix,
     int use_rdma, const char *rdma_device, int rdma_port_num, int rdma_gid_index, int rdma_mtu, int log_level);
 vitastor_c *vitastor_c_create_uring_json(const char **options, int options_len);

tests/run_3osds.sh

@@ -3,6 +3,7 @@
 . `dirname $0`/common.sh
 
 OSD_SIZE=${OSD_SIZE:-1024}
+PG_COUNT=${PG_COUNT:-1}
 
 dd if=/dev/zero of=./testdata/test_osd1.bin bs=1024 count=1 seek=$((OSD_SIZE*1024-1))
 dd if=/dev/zero of=./testdata/test_osd2.bin bs=1024 count=1 seek=$((OSD_SIZE*1024-1))
@@ -25,16 +26,16 @@ if [ -n "$GLOBAL_CONF" ]; then
     $ETCDCTL put /vitastor/config/global "$GLOBAL_CONF"
 fi
 
-$ETCDCTL put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"xor","pg_size":3,"pg_minsize":2,"parity_chunks":1,"pg_count":1,"failure_domain":"osd"}}'
+$ETCDCTL put /vitastor/config/pools '{"1":{"name":"testpool","scheme":"xor","pg_size":3,"pg_minsize":2,"parity_chunks":1,"pg_count":'$PG_COUNT',"failure_domain":"osd"}}'
 
 sleep 2
 
-if ! ($ETCDCTL get /vitastor/config/pgs --print-value-only | jq -s -e '(. | length) != 0 and (.[0].items["1"]["1"].osd_set | sort) == ["1","2","3"]'); then
-    format_error "FAILED: 1 PG NOT CONFIGURED"
+if ! ($ETCDCTL get /vitastor/config/pgs --print-value-only | jq -s -e '(. | length) != 0 and ([ .[0].items["1"][] | select((.osd_set | sort) == ["1","2","3"]) ] | length) == '$PG_COUNT); then
+    format_error "FAILED: $PG_COUNT PG(s) NOT CONFIGURED"
 fi
 
-if ! ($ETCDCTL get /vitastor/pg/state/1/1 --print-value-only | jq -s -e '(. | length) != 0 and .[0].state == ["active"]'); then
-    format_error "FAILED: 1 PG NOT UP"
+if ! ($ETCDCTL get /vitastor/pg/state/1/ --prefix --print-value-only | jq -s -e '[ .[] | select(.state == ["active"]) ] | length == '$PG_COUNT); then
+    format_error "FAILED: $PG_COUNT PG(s) NOT UP"
 fi
 
 if ! cmp build/src/block-vitastor.so /usr/lib/x86_64-linux-gnu/qemu/block-vitastor.so; then

tests/test_rm.sh

@@ -0,0 +1,14 @@
+#!/bin/bash -ex
+
+PG_COUNT=16
+. `dirname $0`/run_3osds.sh
+
+LD_PRELOAD=libasan.so.5 \
+    fio -thread -name=test -ioengine=build/src/libfio_vitastor.so -bs=4M -direct=1 -iodepth=1 \
+        -end_fsync=1 -fsync=1 -rw=write -etcd=$ETCD_URL -pool=1 -inode=1 -size=128M -cluster_log_level=10
+
+$ETCDCTL get --prefix '/vitastor/pg/state'
+
+build/src/vitastor-cli rm-data --etcd_address $ETCD_URL --pool 1 --inode 1
+
+format_green OK

tests/test_snapshot.sh

@@ -6,18 +6,19 @@
 
 $ETCDCTL put /vitastor/config/inode/1/2 '{"name":"testimg","size":'$((32*1024*1024))'}'
 
-LD_PRELOAD=libasan.so.5 \
+LD_PRELOAD="libasan.so.5 build/src/libfio_vitastor.so" \
     fio -thread -name=test -ioengine=build/src/libfio_vitastor.so -bs=4M -direct=1 -iodepth=1 -fsync=1 -rw=write \
         -etcd=$ETCD_URL -pool=1 -inode=2 -size=32M -cluster_log_level=10
 
 $ETCDCTL put /vitastor/config/inode/1/2 '{"name":"testimg@0","size":'$((32*1024*1024))'}'
 $ETCDCTL put /vitastor/config/inode/1/3 '{"parent_id":2,"name":"testimg","size":'$((32*1024*1024))'}'
 
-LD_PRELOAD=libasan.so.5 \
+# Preload build/src/libfio_vitastor.so so libasan detects all symbols
+LD_PRELOAD="libasan.so.5 build/src/libfio_vitastor.so" \
     fio -thread -name=test -ioengine=build/src/libfio_vitastor.so -bs=4k -direct=1 -iodepth=1 -fsync=32 -buffer_pattern=0xdeadface \
         -rw=randwrite -etcd=$ETCD_URL -image=testimg -number_ios=1024
 
-LD_PRELOAD=libasan.so.5 \
+LD_PRELOAD="libasan.so.5 build/src/libfio_vitastor.so" \
     fio -thread -name=test -ioengine=build/src/libfio_vitastor.so -bs=4M -direct=1 -iodepth=1 -rw=read -etcd=$ETCD_URL -pool=1 -inode=3 -size=32M
 
 qemu-img convert -S 4096 -p \
@@ -38,4 +39,16 @@ node mon/merge.js ./testdata/layer0.bin ./testdata/layer1.bin ./testdata/check.b
 
 cmp ./testdata/merged.bin ./testdata/check.bin
 
+# Test merge
+
+$ETCDCTL put /vitastor/config/inode/1/3 '{"parent_id":2,"name":"testimg","size":'$((32*1024*1024))'}'
+
+build/src/vitastor-cli rm --etcd_address $ETCD_URL testimg@0
+
+qemu-img convert -S 4096 -p \
+    -f raw "vitastor:etcd_host=127.0.0.1\:$ETCD_PORT/v3:image=testimg" \
+    -O raw ./testdata/merged-by-tool.bin
+
+cmp ./testdata/merged.bin ./testdata/merged-by-tool.bin
+
 format_green OK