glusterd: group server-quorum related code together

Server-quorum implementation was spread in many files.  This patch
brings them all together into a single file, namely
glusterd-server-quorum.c. All exported functions are available via
glusterd-server-quorum.h

Change-Id: I8fd77114b5bc6b05127cb8a6a641e0295f0be7bb
BUG: 1205592
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/9492
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaushal M <kaushal@redhat.com>

1 files changed, 423 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-server-quorum.c b/xlators/mgmt/glusterd/src/glusterd-server-quorum.c
new file mode 100644
index 00000000000..cb707a0caae
--- /dev/null
+++ b/xlators/mgmt/glusterd/src/glusterd-server-quorum.c
@@ -0,0 +1,423 @@
+/*
+   Copyright (c) 2015 Red Hat, Inc. <http://www.redhat.com>
+   This file is part of GlusterFS.
+
+   This file is licensed to you under your choice of the GNU Lesser
+   General Public License, version 3 or any later version (LGPLv3 or
+   later), or the GNU General Public License, version 2 (GPLv2), in all
+   cases as published by the Free Software Foundation.
+*/
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include "config.h"
+#endif
+
+#include "common-utils.h"
+#include "glusterd.h"
+#include "glusterd-utils.h"
+#include "glusterd-messages.h"
+#include "glusterd-server-quorum.h"
+#include "glusterd-syncop.h"
+#include "glusterd-op-sm.h"
+
+#define CEILING_POS(X) (((X)-(int)(X)) > 0 ? (int)((X)+1) : (int)(X))
+
+static gf_boolean_t
+glusterd_is_get_op (xlator_t *this, glusterd_op_t op, dict_t *dict)
+{
+        char            *key            = NULL;
+        char            *volname        = NULL;
+        int             ret             = 0;
+
+        if (op == GD_OP_STATUS_VOLUME)
+                return _gf_true;
+
+        if (op == GD_OP_SET_VOLUME) {
+                /*check for set volume help*/
+                ret = dict_get_str (dict, "volname", &volname);
+                if (volname &&
+                    ((strcmp (volname, "help") == 0) ||
+                     (strcmp (volname, "help-xml") == 0))) {
+                        ret = dict_get_str (dict, "key1", &key);
+                        if (ret < 0)
+                                return _gf_true;
+                }
+        }
+        return _gf_false;
+}
+
+gf_boolean_t
+glusterd_is_quorum_validation_required (xlator_t *this, glusterd_op_t op,
+                                        dict_t *dict)
+{
+        gf_boolean_t    required        = _gf_true;
+        char            *key            = NULL;
+        char            *key_fixed      = NULL;
+        int             ret             = -1;
+
+        if (glusterd_is_get_op (this, op, dict)) {
+                required = _gf_false;
+                goto out;
+        }
+        if ((op != GD_OP_SET_VOLUME) && (op != GD_OP_RESET_VOLUME))
+                goto out;
+        if (op == GD_OP_SET_VOLUME)
+                ret = dict_get_str (dict, "key1", &key);
+        else if (op == GD_OP_RESET_VOLUME)
+                ret = dict_get_str (dict, "key", &key);
+        if (ret)
+                goto out;
+        ret = glusterd_check_option_exists (key, &key_fixed);
+        if (ret <= 0)
+                goto out;
+        if (key_fixed)
+                key = key_fixed;
+        if (glusterd_is_quorum_option (key))
+                required = _gf_false;
+out:
+        GF_FREE (key_fixed);
+        return required;
+}
+
+/* This function should not be used when the quorum validation needs to happen
+ * on non-global peer list */
+int
+glusterd_validate_quorum (xlator_t *this, glusterd_op_t op,
+                             dict_t *dict, char **op_errstr)
+{
+        int                      ret     = 0;
+        char                    *volname = NULL;
+        glusterd_volinfo_t      *volinfo = NULL;
+        char                    *errstr  = NULL;
+
+        errstr = "Quorum not met. Volume operation not allowed.";
+        if (!glusterd_is_quorum_validation_required (this, op, dict))
+                goto out;
+
+        ret = dict_get_str (dict, "volname", &volname);
+        if (ret) {
+                ret = 0;
+                goto out;
+        }
+
+        ret = glusterd_volinfo_find (volname, &volinfo);
+        if (ret) {
+                ret = 0;
+                goto out;
+        }
+
+        /* Passing NULL implies quorum calculation will happen on global peer
+         * list */
+        if (does_gd_meet_server_quorum (this, NULL, _gf_false)) {
+                ret = 0;
+                goto out;
+        }
+
+        if (glusterd_is_volume_in_server_quorum (volinfo)) {
+                ret = -1;
+                *op_errstr = gf_strdup (errstr);
+                goto out;
+        }
+        ret = 0;
+out:
+        return ret;
+}
+
+gf_boolean_t
+glusterd_is_quorum_option (char *option)
+{
+        gf_boolean_t    res     = _gf_false;
+        int             i       = 0;
+        char            *keys[] = {GLUSTERD_QUORUM_TYPE_KEY,
+                                   GLUSTERD_QUORUM_RATIO_KEY, NULL};
+
+        for (i = 0; keys[i]; i++) {
+                if (strcmp (option, keys[i]) == 0) {
+                        res = _gf_true;
+                        break;
+                }
+        }
+        return res;
+}
+
+gf_boolean_t
+glusterd_is_quorum_changed (dict_t *options, char *option, char *value)
+{
+        int             ret             = 0;
+        gf_boolean_t    reconfigured    = _gf_false;
+        gf_boolean_t    all             = _gf_false;
+        char            *oldquorum      = NULL;
+        char            *newquorum      = NULL;
+        char            *oldratio       = NULL;
+        char            *newratio       = NULL;
+
+        if ((strcmp ("all", option) != 0) &&
+            !glusterd_is_quorum_option (option))
+                goto out;
+
+        if (strcmp ("all", option) == 0)
+                all = _gf_true;
+
+        if (all || (strcmp (GLUSTERD_QUORUM_TYPE_KEY, option) == 0)) {
+                newquorum = value;
+                ret = dict_get_str (options, GLUSTERD_QUORUM_TYPE_KEY,
+                                    &oldquorum);
+        }
+
+        if (all || (strcmp (GLUSTERD_QUORUM_RATIO_KEY, option) == 0)) {
+                newratio = value;
+                ret = dict_get_str (options, GLUSTERD_QUORUM_RATIO_KEY,
+                                    &oldratio);
+        }
+
+        reconfigured = _gf_true;
+
+        if (oldquorum && newquorum && (strcmp (oldquorum, newquorum) == 0))
+                reconfigured = _gf_false;
+        if (oldratio && newratio && (strcmp (oldratio, newratio) == 0))
+                reconfigured = _gf_false;
+
+        if ((oldratio == NULL) && (newratio == NULL) && (oldquorum == NULL) &&
+            (newquorum == NULL))
+                reconfigured = _gf_false;
+out:
+        return reconfigured;
+}
+
+static inline gf_boolean_t
+_is_contributing_to_quorum (gd_quorum_contrib_t contrib)
+{
+        if ((contrib == QUORUM_UP) || (contrib == QUORUM_DOWN))
+                return _gf_true;
+        return _gf_false;
+}
+
+static inline gf_boolean_t
+_does_quorum_meet (int active_count, int quorum_count)
+{
+        return (active_count >= quorum_count);
+}
+
+int
+glusterd_get_quorum_cluster_counts (xlator_t *this, int *active_count,
+                                    int *quorum_count,
+                                    struct list_head *peer_list,
+                                    gf_boolean_t _local_xaction_peers)
+{
+        glusterd_peerinfo_t *peerinfo      = NULL;
+        glusterd_conf_t     *conf          = NULL;
+        int                 ret            = -1;
+        int                 inquorum_count = 0;
+        char                *val           = NULL;
+        double              quorum_percentage = 0.0;
+        gf_boolean_t        ratio          = _gf_false;
+        int                 count          = 0;
+
+        conf = this->private;
+
+        /* Start with counting self */
+        inquorum_count = 1;
+        if (active_count)
+                *active_count = 1;
+
+        if (!peer_list) {
+                list_for_each_entry (peerinfo, &conf->peers, uuid_list) {
+                        glusterd_quorum_count(peerinfo, inquorum_count,
+                                                active_count, out);
+                }
+        } else {
+                if (_local_xaction_peers) {
+                        list_for_each_local_xaction_peers (peerinfo,
+                                                           peer_list) {
+                                glusterd_quorum_count(peerinfo, inquorum_count,
+                                                      active_count, out);
+                        }
+                } else {
+                        list_for_each_entry (peerinfo, peer_list,
+                                             op_peers_list) {
+                                glusterd_quorum_count(peerinfo, inquorum_count,
+                                                      active_count, out);
+                        }
+                }
+        }
+        ret = dict_get_str (conf->opts, GLUSTERD_QUORUM_RATIO_KEY, &val);
+        if (ret == 0) {
+                ratio = _gf_true;
+                ret = gf_string2percent (val, &quorum_percentage);
+                if (!ret)
+                        ratio = _gf_true;
+        }
+        if (ratio)
+                count = CEILING_POS (inquorum_count *
+                                     quorum_percentage / 100.0);
+        else
+                count = (inquorum_count * 50 / 100) + 1;
+
+        *quorum_count = count;
+        ret = 0;
+out:
+        return ret;
+}
+
+gf_boolean_t
+glusterd_is_volume_in_server_quorum (glusterd_volinfo_t *volinfo)
+{
+        gf_boolean_t    res             = _gf_false;
+        char            *quorum_type    = NULL;
+        int             ret             = 0;
+
+        ret = dict_get_str (volinfo->dict, GLUSTERD_QUORUM_TYPE_KEY,
+                            &quorum_type);
+        if (ret)
+                goto out;
+
+        if (strcmp (quorum_type, GLUSTERD_SERVER_QUORUM) == 0)
+                res = _gf_true;
+out:
+        return res;
+}
+
+gf_boolean_t
+glusterd_is_any_volume_in_server_quorum (xlator_t *this)
+{
+        glusterd_conf_t     *conf     = NULL;
+        glusterd_volinfo_t  *volinfo  = NULL;
+
+        conf = this->private;
+        list_for_each_entry (volinfo, &conf->volumes, vol_list) {
+                if (glusterd_is_volume_in_server_quorum (volinfo)) {
+                        return _gf_true;
+                }
+        }
+        return _gf_false;
+}
+
+gf_boolean_t
+does_gd_meet_server_quorum (xlator_t *this, struct list_head *peers_list,
+                            gf_boolean_t _local_xaction_peers)
+{
+        int                     quorum_count    = 0;
+        int                     active_count    = 0;
+        gf_boolean_t            in              = _gf_false;
+        glusterd_conf_t         *conf           = NULL;
+        int                     ret             = -1;
+
+        conf = this->private;
+        ret = glusterd_get_quorum_cluster_counts (this, &active_count,
+                                                  &quorum_count,
+                                                  peers_list,
+                                                  _local_xaction_peers);
+        if (ret)
+                goto out;
+
+        if (!_does_quorum_meet (active_count, quorum_count)) {
+                goto out;
+        }
+
+        in = _gf_true;
+out:
+        return in;
+}
+
+void
+glusterd_do_volume_quorum_action (xlator_t *this, glusterd_volinfo_t *volinfo,
+                                  gf_boolean_t meets_quorum)
+{
+        glusterd_brickinfo_t *brickinfo     = NULL;
+        glusterd_conf_t      *conf          = NULL;
+        gd_quorum_status_t   quorum_status  = NOT_APPLICABLE_QUORUM;
+        gf_boolean_t         follows_quorum = _gf_false;
+
+        conf = this->private;
+        if (volinfo->status != GLUSTERD_STATUS_STARTED) {
+                volinfo->quorum_status = NOT_APPLICABLE_QUORUM;
+                goto out;
+        }
+
+        follows_quorum = glusterd_is_volume_in_server_quorum (volinfo);
+        if (follows_quorum) {
+                if (meets_quorum)
+                        quorum_status = MEETS_QUORUM;
+                else
+                        quorum_status = DOESNT_MEET_QUORUM;
+        } else {
+                quorum_status = NOT_APPLICABLE_QUORUM;
+        }
+
+        /*
+         * The following check is added to prevent spurious brick starts when
+         * events occur that affect quorum.
+         * Example:
+         * There is a cluster of 10 peers. Volume is in quorum. User
+         * takes down one brick from the volume to perform maintenance.
+         * Suddenly one of the peers go down. Cluster is still in quorum. But
+         * because of this 'peer going down' event, quorum is calculated and
+         * the bricks that are down are brought up again. In this process it
+         * also brings up the brick that is purposefully taken down.
+         */
+        if (volinfo->quorum_status == quorum_status)
+                goto out;
+
+        if (quorum_status == MEETS_QUORUM) {
+                gf_msg (this->name, GF_LOG_CRITICAL, 0,
+                        GD_MSG_SERVER_QUORUM_MET_STARTING_BRICKS,
+                        "Server quorum regained for volume %s. Starting local "
+                        "bricks.", volinfo->volname);
+        } else if (quorum_status == DOESNT_MEET_QUORUM) {
+                gf_msg (this->name, GF_LOG_CRITICAL, 0,
+                        GD_MSG_SERVER_QUORUM_LOST_STOPPING_BRICKS,
+                        "Server quorum lost for volume %s. Stopping local "
+                        "bricks.", volinfo->volname);
+        }
+
+        list_for_each_entry (brickinfo, &volinfo->bricks, brick_list) {
+                if (!glusterd_is_local_brick (this, volinfo, brickinfo))
+                        continue;
+                if (quorum_status == DOESNT_MEET_QUORUM)
+                        glusterd_brick_stop (volinfo, brickinfo, _gf_false);
+                else
+                        glusterd_brick_start (volinfo, brickinfo, _gf_false);
+        }
+        volinfo->quorum_status = quorum_status;
+out:
+        return;
+}
+
+int
+glusterd_do_quorum_action ()
+{
+        xlator_t            *this          = NULL;
+        glusterd_conf_t     *conf          = NULL;
+        glusterd_volinfo_t  *volinfo       = NULL;
+        int                 ret            = 0;
+        int                 active_count   = 0;
+        int                 quorum_count   = 0;
+        gf_boolean_t        meets          = _gf_false;
+
+        this = THIS;
+        conf = this->private;
+
+        conf->pending_quorum_action = _gf_true;
+        ret = glusterd_lock (conf->uuid);
+        if (ret)
+                goto out;
+
+        {
+                ret = glusterd_get_quorum_cluster_counts (this, &active_count,
+                                                          &quorum_count, NULL,
+                                                          _gf_false);
+                if (ret)
+                        goto unlock;
+
+                if (_does_quorum_meet (active_count, quorum_count))
+                        meets = _gf_true;
+                list_for_each_entry (volinfo, &conf->volumes, vol_list) {
+                        glusterd_do_volume_quorum_action (this, volinfo, meets);
+                }
+        }
+unlock:
+        (void)glusterd_unlock (conf->uuid);
+        conf->pending_quorum_action = _gf_false;
+out:
+        return ret;
+}