[PATCH 1/2] drbd: implement replicated checkpointing disk

[Lai Jiangshan <laijs@cn.fujitsu.com>]

Implement remus-drbd-replicated-checkpointing-disk based on
generic remus devices framework.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 tools/hotplug/Linux/Makefile         |    1 +
 tools/hotplug/Linux/block-drbd-probe |   84 +++++++++++++++++
 tools/libxl/Makefile                 |    2 +-
 tools/libxl/libxl_remus_device.c     |    1 +
 tools/libxl/libxl_remus_device.h     |    1 +
 tools/libxl/libxl_remus_disk_drbd.c  |  164 ++++++++++++++++++++++++++++++++++
 6 files changed, 252 insertions(+), 1 deletions(-)
 create mode 100755 tools/hotplug/Linux/block-drbd-probe
 create mode 100644 tools/libxl/libxl_remus_disk_drbd.c

diff --git a/tools/hotplug/Linux/Makefile b/tools/hotplug/Linux/Makefile
index baaaa41..31d9e00 100644
--- a/tools/hotplug/Linux/Makefile
+++ b/tools/hotplug/Linux/Makefile
@@ -23,6 +23,7 @@ XEN_SCRIPTS += xen-hotplug-cleanup
 XEN_SCRIPTS += external-device-migrate
 XEN_SCRIPTS += vscsi
 XEN_SCRIPTS += block-iscsi
+XEN_SCRIPTS += block-drbd-probe
 XEN_SCRIPTS += $(XEN_SCRIPTS-y)
 
 XEN_SCRIPT_DATA = xen-script-common.sh locking.sh logging.sh
diff --git a/tools/hotplug/Linux/block-drbd-probe b/tools/hotplug/Linux/block-drbd-probe
new file mode 100755
index 0000000..163ad04
--- /dev/null
+++ b/tools/hotplug/Linux/block-drbd-probe
@@ -0,0 +1,84 @@
+#! /bin/bash
+#
+# Copyright (C) 2014 FUJITSU LIMITED
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of version 2.1 of the GNU Lesser General Public
+# License as published by the Free Software Foundation.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Usage:
+#     block-drbd-probe devicename
+#
+# Return value:
+#     0: the device is drbd device
+#     1: the device is not drbd device
+#     2: unkown error
+#     3: the drbd device does not use protocol D
+#     4: the drbd device is not ready
+
+drbd_res=
+
+function get_res_name()
+{
+    local drbd_dev=$1
+    local drbd_dev_list=($(drbdadm sh-dev all))
+    local drbd_res_list=($(drbdadm sh-resource all))
+    local temp_drbd_dev temp_drbd_res
+    local found=0
+
+    for temp_drbd_dev in ${drbd_dev_list[@]}; do
+        if [[ "$temp_drbd_dev" == "$drbd_dev" ]]; then
+            found=1
+            break
+        fi
+    done
+
+    if [[ $found -eq 0 ]]; then
+        return 1
+    fi
+
+    for temp_drbd_res in ${drbd_res_list[@]}; do
+        temp_drbd_dev=$(drbdadm sh-dev $temp_drbd_res)
+        if [[ "$temp_drbd_dev" == "$drbd_dev" ]]; then
+            drbd_res="$temp_drbd_res"
+            return 0
+        fi
+    done
+
+    # OOPS
+    return 2
+}
+
+get_res_name $1
+if [[ $? -ne 0 ]]; then
+    exit $?
+fi
+
+# check protocol
+drbdsetup $1 show | grep -q "protocol D;"
+if [[ $? -ne 0 ]]; then
+    exit 3
+fi
+
+# check connect status
+state=$(drbdadm cstate "$drbd_res")
+if [[ "$state" != "Connected" ]]; then
+    exit 4
+fi
+
+# check role
+role=$(drbdadm role "$drbd_res")
+if [[ "$role" != "Primary/Secondary" ]]; then
+    exit 4
+fi
+
+exit 0
diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index 8398386..53461ab 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -52,7 +52,7 @@ else
 LIBXL_OBJS-y += libxl_nonetbuffer.o
 endif
 
-LIBXL_OBJS-y += libxl_remus.o libxl_remus_device.o
+LIBXL_OBJS-y += libxl_remus.o libxl_remus_device.o libxl_remus_disk_drbd.o
 
 LIBXL_OBJS-$(CONFIG_X86) += libxl_cpuid.o libxl_x86.o
 LIBXL_OBJS-$(CONFIG_ARM) += libxl_nocpuid.o libxl_arm.o
diff --git a/tools/libxl/libxl_remus_device.c b/tools/libxl/libxl_remus_device.c
index 1564bd1..c323773 100644
--- a/tools/libxl/libxl_remus_device.c
+++ b/tools/libxl/libxl_remus_device.c
@@ -38,6 +38,7 @@ typedef struct libxl__remus_device_state {
 
 static libxl__remus_device_type *device_types[] = {
     &remus_device_nic,
+    &remus_device_drbd_disk,
 };
 
 int libxl__remus_device_postsuspend(libxl__remus_state *remus_state)
diff --git a/tools/libxl/libxl_remus_device.h b/tools/libxl/libxl_remus_device.h
index 30b368d..4b41021 100644
--- a/tools/libxl/libxl_remus_device.h
+++ b/tools/libxl/libxl_remus_device.h
@@ -95,5 +95,6 @@ struct libxl__remus_device {
 };
 
 extern libxl__remus_device_type remus_device_nic;
+extern libxl__remus_device_type remus_device_drbd_disk;
 
 #endif
diff --git a/tools/libxl/libxl_remus_disk_drbd.c b/tools/libxl/libxl_remus_disk_drbd.c
new file mode 100644
index 0000000..583b8a3
--- /dev/null
+++ b/tools/libxl/libxl_remus_disk_drbd.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2014 FUJITSU LIMITED
+ * Author Lai Jiangshan <laijs@cn.fujitsu.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#include "libxl_osdeps.h" /* must come before any other headers */
+
+#include "libxl_internal.h"
+
+#include "libxl_remus_device.h"
+
+/*** drbd implementation ***/
+const int DRBD_SEND_CHECKPOINT = 20;
+const int DRBD_WAIT_CHECKPOINT_ACK = 30;
+
+typedef struct libxl__remus_drbd_disk {
+    libxl__remus_device remus_dev;
+    int ctl_fd;
+    int ackwait;
+    const char *path;
+} libxl__remus_drbd_disk;
+
+typedef struct libxl__remus_drbd_state {
+    char *drbd_probe_script;
+    libxl__ao *ao;
+} libxl__remus_drbd_state;
+
+static int drbd_postsuspend(libxl__remus_device *remus_dev)
+{
+    libxl__remus_drbd_disk *drbd_disk =
+        CONTAINER_OF(remus_dev, *drbd_disk, remus_dev);
+
+    if (!drbd_disk->ackwait) {
+        if (ioctl(drbd_disk->ctl_fd, DRBD_SEND_CHECKPOINT, 0) <= 0)
+            drbd_disk->ackwait = 1;
+    }
+
+    return 0;
+}
+
+static int drbd_preresume(libxl__remus_device *remus_dev)
+{
+    libxl__remus_drbd_disk *drbd_disk =
+        CONTAINER_OF(remus_dev, *drbd_disk, remus_dev);
+
+    if (drbd_disk->ackwait) {
+        ioctl(drbd_disk->ctl_fd, DRBD_WAIT_CHECKPOINT_ACK, 0);
+        drbd_disk->ackwait = 0;
+    }
+
+    return 0;
+}
+
+static int drbd_commit(libxl__remus_device *remus_dev)
+{
+    /* nothing to do, all work are done by DRBD's protocal-D. */
+    return 0;
+}
+
+static int drbd_init(libxl__remus_device_type *self,
+                     libxl__remus_state *remus_state)
+{
+    libxl__remus_drbd_state *drbd_state;
+
+    STATE_AO_GC(remus_state->dss->ao);
+
+    GCNEW(drbd_state);
+    self->data = drbd_state;
+    drbd_state->ao = ao;
+    drbd_state->drbd_probe_script = GCSPRINTF("%s/block-drbd-probe",
+                                              libxl__xen_script_dir_path());
+
+
+    return REMUS_OK;
+}
+
+static void drbd_destroy(libxl__remus_device_type *self)
+{
+    return;
+}
+
+static int drbd_match(const libxl__remus_device_type *self,
+                      const void *libxl_device, int device_type,
+                      libxl_async_exec *async_exec)
+{
+    int arraysize, nr = 0;
+    const libxl_device_disk *disk = libxl_device;
+    libxl__remus_drbd_state *drbd_state = self->data;
+    STATE_AO_GC(drbd_state->ao);
+
+    if (device_type != REMUS_DISK)
+        return REMUS_NOT_SUPPORT;
+
+    /* setup env & args */
+    arraysize = 1;
+    GCNEW_ARRAY(async_exec->env, arraysize);
+    async_exec->env[nr++] = NULL;
+    assert(nr <= arraysize);
+
+    arraysize = 3;
+    nr = 0;
+    GCNEW_ARRAY(async_exec->args, arraysize);
+    async_exec->args[nr++] = drbd_state->drbd_probe_script;
+    async_exec->args[nr++] = disk->pdev_path;
+    async_exec->args[nr++] = NULL;
+    assert(nr <= arraysize);
+
+    async_exec->allow_fail = true;
+    async_exec->timeout = LIBXL_HOTPLUG_TIMEOUT;
+
+    if (libxl_async_exec_script(gc, async_exec))
+        return REMUS_FAIL;
+
+    return REMUS_INPROGRESS;
+}
+
+static int drbd_setup(libxl__remus_device *remus_dev,
+                      libxl_async_exec *async_exec)
+{
+    libxl__remus_drbd_disk *drbd_disk =
+        CONTAINER_OF(remus_dev, *drbd_disk, remus_dev);
+    const libxl_device_disk *disk = remus_dev->libxl_device;
+
+    drbd_disk->path = disk->pdev_path;
+    drbd_disk->ctl_fd = open(drbd_disk->path, O_RDONLY);
+    drbd_disk->ackwait = 0;
+
+    if (drbd_disk->ctl_fd < 0)
+        return REMUS_FAIL;
+
+    return REMUS_OK;
+}
+
+static int drbd_teardown(libxl__remus_device *remus_dev,
+                         libxl_async_exec *async_exec)
+{
+    libxl__remus_drbd_disk *drbd_disk =
+        CONTAINER_OF(remus_dev, *drbd_disk, remus_dev);
+
+    close(drbd_disk->ctl_fd);
+    return REMUS_OK;
+}
+
+libxl__remus_device_type remus_device_drbd_disk = {
+    .init = drbd_init,
+    .destroy = drbd_destroy,
+    .postsuspend = drbd_postsuspend,
+    .preresume = drbd_preresume,
+    .commit = drbd_commit,
+    .match = drbd_match,
+    .setup = drbd_setup,
+    .teardown = drbd_teardown,
+    .size = sizeof(libxl__remus_drbd_disk),
+};
-- 
1.7.4.4