nsswitch:libwbclient - fix leak in wbcCtxPingDc2

[Samba.git] / ctdb / server / ctdb_recover.c

/* 
   ctdb recovery code

   Copyright (C) Andrew Tridgell  2007
   Copyright (C) Ronnie Sahlberg  2007

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "system/time.h"
#include "system/network.h"
#include "system/filesys.h"
#include "system/wait.h"

#include <talloc.h>
#include <tevent.h>
#include <tdb.h>

#include "lib/tdb_wrap/tdb_wrap.h"
#include "lib/util/dlinklist.h"
#include "lib/util/debug.h"
#include "lib/util/time.h"
#include "lib/util/util_process.h"

#include "ctdb_private.h"
#include "ctdb_client.h"

#include "common/system.h"
#include "common/common.h"
#include "common/logging.h"

#include "ctdb_cluster_mutex.h"

int 
ctdb_control_getvnnmap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
        struct ctdb_vnn_map_wire *map;
        size_t len;

        CHECK_CONTROL_DATA_SIZE(0);

        len = offsetof(struct ctdb_vnn_map_wire, map) + sizeof(uint32_t)*ctdb->vnn_map->size;
        map = talloc_size(outdata, len);
        CTDB_NO_MEMORY(ctdb, map);

        map->generation = ctdb->vnn_map->generation;
        map->size = ctdb->vnn_map->size;
        memcpy(map->map, ctdb->vnn_map->map, sizeof(uint32_t)*map->size);

        outdata->dsize = len;
        outdata->dptr  = (uint8_t *)map;

        return 0;
}

int
ctdb_control_setvnnmap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
        struct ctdb_vnn_map_wire *map = (struct ctdb_vnn_map_wire *)indata.dptr;

        if (ctdb->recovery_mode != CTDB_RECOVERY_ACTIVE) {
                DEBUG(DEBUG_ERR, ("Attempt to set vnnmap when not in recovery\n"));
                return -1;
        }

        talloc_free(ctdb->vnn_map);

        ctdb->vnn_map = talloc(ctdb, struct ctdb_vnn_map);
        CTDB_NO_MEMORY(ctdb, ctdb->vnn_map);

        ctdb->vnn_map->generation = map->generation;
        ctdb->vnn_map->size       = map->size;
        ctdb->vnn_map->map = talloc_array(ctdb->vnn_map, uint32_t, map->size);
        CTDB_NO_MEMORY(ctdb, ctdb->vnn_map->map);

        memcpy(ctdb->vnn_map->map, map->map, sizeof(uint32_t)*map->size);

        return 0;
}

int 
ctdb_control_getdbmap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
        uint32_t i, len;
        struct ctdb_db_context *ctdb_db;
        struct ctdb_dbid_map_old *dbid_map;

        CHECK_CONTROL_DATA_SIZE(0);

        len = 0;
        for(ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next){
                len++;
        }


        outdata->dsize = offsetof(struct ctdb_dbid_map_old, dbs) + sizeof(dbid_map->dbs[0])*len;
        outdata->dptr  = (unsigned char *)talloc_zero_size(outdata, outdata->dsize);
        if (!outdata->dptr) {
                DEBUG(DEBUG_ALERT, (__location__ " Failed to allocate dbmap array\n"));
                exit(1);
        }

        dbid_map = (struct ctdb_dbid_map_old *)outdata->dptr;
        dbid_map->num = len;
        for (i=0,ctdb_db=ctdb->db_list;ctdb_db;i++,ctdb_db=ctdb_db->next){
                dbid_map->dbs[i].db_id       = ctdb_db->db_id;
                dbid_map->dbs[i].flags       = ctdb_db->db_flags;
        }

        return 0;
}

int
ctdb_control_getnodemap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
        CHECK_CONTROL_DATA_SIZE(0);

        outdata->dptr  = (unsigned char *)ctdb_node_list_to_map(ctdb->nodes,
                                                                ctdb->num_nodes,
                                                                outdata);
        if (outdata->dptr == NULL) {
                return -1;
        }

        outdata->dsize = talloc_get_size(outdata->dptr);

        return 0;
}

/*
  reload the nodes file
*/
int
ctdb_control_reload_nodes_file(struct ctdb_context *ctdb, uint32_t opcode)
{
        unsigned int i, num_nodes;
        TALLOC_CTX *tmp_ctx;
        struct ctdb_node **nodes;

        tmp_ctx = talloc_new(ctdb);

        /* steal the old nodes file for a while */
        talloc_steal(tmp_ctx, ctdb->nodes);
        nodes = ctdb->nodes;
        ctdb->nodes = NULL;
        num_nodes = ctdb->num_nodes;
        ctdb->num_nodes = 0;

        /* load the new nodes file */
        ctdb_load_nodes_file(ctdb);

        for (i=0; i<ctdb->num_nodes; i++) {
                /* keep any identical pre-existing nodes and connections */
                if ((i < num_nodes) && ctdb_same_address(&ctdb->nodes[i]->address, &nodes[i]->address)) {
                        talloc_free(ctdb->nodes[i]);
                        ctdb->nodes[i] = talloc_steal(ctdb->nodes, nodes[i]);
                        continue;
                }

                if (ctdb->nodes[i]->flags & NODE_FLAGS_DELETED) {
                        continue;
                }

                /* any new or different nodes must be added */
                if (ctdb->methods->add_node(ctdb->nodes[i]) != 0) {
                        DEBUG(DEBUG_CRIT, (__location__ " methods->add_node failed at %d\n", i));
                        ctdb_fatal(ctdb, "failed to add node. shutting down\n");
                }
                if (ctdb->methods->connect_node(ctdb->nodes[i]) != 0) {
                        DEBUG(DEBUG_CRIT, (__location__ " methods->add_connect failed at %d\n", i));
                        ctdb_fatal(ctdb, "failed to connect to node. shutting down\n");
                }
        }

        /* tell the recovery daemon to reload the nodes file too */
        ctdb_daemon_send_message(ctdb, ctdb->pnn, CTDB_SRVID_RELOAD_NODES, tdb_null);

        talloc_free(tmp_ctx);

        return 0;
}

struct db_pull_state {
        struct ctdb_context *ctdb;
        struct ctdb_db_context *ctdb_db;
        struct ctdb_marshall_buffer *recs;
        uint32_t pnn;
        uint64_t srvid;
        uint32_t num_records;
};

static int traverse_db_pull(struct tdb_context *tdb, TDB_DATA key,
                            TDB_DATA data, void *private_data)
{
        struct db_pull_state *state = (struct db_pull_state *)private_data;
        struct ctdb_marshall_buffer *recs;

        recs = ctdb_marshall_add(state->ctdb, state->recs,
                                 state->ctdb_db->db_id, 0, key, NULL, data);
        if (recs == NULL) {
                TALLOC_FREE(state->recs);
                return -1;
        }
        state->recs = recs;

        if (talloc_get_size(state->recs) >=
                        state->ctdb->tunable.rec_buffer_size_limit) {
                TDB_DATA buffer;
                int ret;

                buffer = ctdb_marshall_finish(state->recs);
                ret = ctdb_daemon_send_message(state->ctdb, state->pnn,
                                               state->srvid, buffer);
                if (ret != 0) {
                        TALLOC_FREE(state->recs);
                        return -1;
                }

                state->num_records += state->recs->count;
                TALLOC_FREE(state->recs);
        }

        return 0;
}

int32_t ctdb_control_db_pull(struct ctdb_context *ctdb,
                             struct ctdb_req_control_old *c,
                             TDB_DATA indata, TDB_DATA *outdata)
{
        struct ctdb_pulldb_ext *pulldb_ext;
        struct ctdb_db_context *ctdb_db;
        struct db_pull_state state;
        int ret;

        pulldb_ext = (struct ctdb_pulldb_ext *)indata.dptr;

        ctdb_db = find_ctdb_db(ctdb, pulldb_ext->db_id);
        if (ctdb_db == NULL) {
                DEBUG(DEBUG_ERR,(__location__ " Unknown db 0x%08x\n",
                                 pulldb_ext->db_id));
                return -1;
        }

        if (!ctdb_db_frozen(ctdb_db)) {
                DEBUG(DEBUG_ERR,
                      ("rejecting ctdb_control_pull_db when not frozen\n"));
                return -1;
        }

        if (ctdb_db->unhealthy_reason) {
                /* this is just a warning, as the tdb should be empty anyway */
                DEBUG(DEBUG_WARNING,
                      ("db(%s) unhealty in ctdb_control_db_pull: %s\n",
                       ctdb_db->db_name, ctdb_db->unhealthy_reason));
        }

        state.ctdb = ctdb;
        state.ctdb_db = ctdb_db;
        state.recs = NULL;
        state.pnn = c->hdr.srcnode;
        state.srvid = pulldb_ext->srvid;
        state.num_records = 0;

        /* If the records are invalid, we are done */
        if (ctdb_db->invalid_records) {
                goto done;
        }

        if (ctdb_lockdb_mark(ctdb_db) != 0) {
                DEBUG(DEBUG_ERR,
                      (__location__ " Failed to get lock on entire db - failing\n"));
                return -1;
        }

        ret = tdb_traverse_read(ctdb_db->ltdb->tdb, traverse_db_pull, &state);
        if (ret == -1) {
                DEBUG(DEBUG_ERR,
                      (__location__ " Failed to get traverse db '%s'\n",
                       ctdb_db->db_name));
                ctdb_lockdb_unmark(ctdb_db);
                return -1;
        }

        /* Last few records */
        if (state.recs != NULL) {
                TDB_DATA buffer;

                buffer = ctdb_marshall_finish(state.recs);
                ret = ctdb_daemon_send_message(state.ctdb, state.pnn,
                                               state.srvid, buffer);
                if (ret != 0) {
                        TALLOC_FREE(state.recs);
                        ctdb_lockdb_unmark(ctdb_db);
                        return -1;
                }

                state.num_records += state.recs->count;
                TALLOC_FREE(state.recs);
        }

        ctdb_lockdb_unmark(ctdb_db);

done:
        outdata->dptr = talloc_size(outdata, sizeof(uint32_t));
        if (outdata->dptr == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " Memory allocation error\n"));
                return -1;
        }

        memcpy(outdata->dptr, (uint8_t *)&state.num_records, sizeof(uint32_t));
        outdata->dsize = sizeof(uint32_t);

        return 0;
}

struct db_push_state {
        struct ctdb_context *ctdb;
        struct ctdb_db_context *ctdb_db;
        uint64_t srvid;
        uint32_t num_records;
        bool failed;
};

static void db_push_msg_handler(uint64_t srvid, TDB_DATA indata,
                                void *private_data)
{
        struct db_push_state *state = talloc_get_type(
                private_data, struct db_push_state);
        struct ctdb_marshall_buffer *recs;
        struct ctdb_rec_data_old *rec;
        unsigned int i;
        int ret;

        if (state->failed) {
                return;
        }

        recs = (struct ctdb_marshall_buffer *)indata.dptr;
        rec = (struct ctdb_rec_data_old *)&recs->data[0];

        DEBUG(DEBUG_INFO, ("starting push of %u records for dbid 0x%x\n",
                           recs->count, recs->db_id));

        for (i=0; i<recs->count; i++) {
                TDB_DATA key, data;
                struct ctdb_ltdb_header *hdr;

                key.dptr = &rec->data[0];
                key.dsize = rec->keylen;
                data.dptr = &rec->data[key.dsize];
                data.dsize = rec->datalen;

                if (data.dsize < sizeof(struct ctdb_ltdb_header)) {
                        DEBUG(DEBUG_CRIT,(__location__ " bad ltdb record\n"));
                        goto failed;
                }

                hdr = (struct ctdb_ltdb_header *)data.dptr;
                /* Strip off any read only record flags.
                 * All readonly records are revoked implicitely by a recovery.
                 */
                hdr->flags &= ~CTDB_REC_RO_FLAGS;

                data.dptr += sizeof(*hdr);
                data.dsize -= sizeof(*hdr);

                ret = ctdb_ltdb_store(state->ctdb_db, key, hdr, data);
                if (ret != 0) {
                        DEBUG(DEBUG_ERR,
                              (__location__ " Unable to store record\n"));
                        goto failed;
                }

                rec = (struct ctdb_rec_data_old *)(rec->length + (uint8_t *)rec);
        }

        DEBUG(DEBUG_DEBUG, ("finished push of %u records for dbid 0x%x\n",
                            recs->count, recs->db_id));

        state->num_records += recs->count;
        return;

failed:
        state->failed = true;
}

int32_t ctdb_control_db_push_start(struct ctdb_context *ctdb, TDB_DATA indata)
{
        struct ctdb_pulldb_ext *pulldb_ext;
        struct ctdb_db_context *ctdb_db;
        struct db_push_state *state;
        int ret;

        pulldb_ext = (struct ctdb_pulldb_ext *)indata.dptr;

        ctdb_db = find_ctdb_db(ctdb, pulldb_ext->db_id);
        if (ctdb_db == NULL) {
                DEBUG(DEBUG_ERR,
                      (__location__ " Unknown db 0x%08x\n", pulldb_ext->db_id));
                return -1;
        }

        if (!ctdb_db_frozen(ctdb_db)) {
                DEBUG(DEBUG_ERR,
                      ("rejecting ctdb_control_db_push_start when not frozen\n"));
                return -1;
        }

        if (ctdb_db->push_started) {
                DEBUG(DEBUG_WARNING,
                      (__location__ " DB push already started for %s\n",
                       ctdb_db->db_name));

                /* De-register old state */
                state = (struct db_push_state *)ctdb_db->push_state;
                if (state != NULL) {
                        srvid_deregister(ctdb->srv, state->srvid, state);
                        talloc_free(state);
                        ctdb_db->push_state = NULL;
                }
        }

        state = talloc_zero(ctdb_db, struct db_push_state);
        if (state == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " Memory allocation error\n"));
                return -1;
        }

        state->ctdb = ctdb;
        state->ctdb_db = ctdb_db;
        state->srvid = pulldb_ext->srvid;
        state->failed = false;

        ret = srvid_register(ctdb->srv, state, state->srvid,
                             db_push_msg_handler, state);
        if (ret != 0) {
                DEBUG(DEBUG_ERR,
                      (__location__ " Failed to register srvid for db push\n"));
                talloc_free(state);
                return -1;
        }

        if (ctdb_lockdb_mark(ctdb_db) != 0) {
                DEBUG(DEBUG_ERR,
                      (__location__ " Failed to get lock on entire db - failing\n"));
                srvid_deregister(ctdb->srv, state->srvid, state);
                talloc_free(state);
                return -1;
        }

        ctdb_db->push_started = true;
        ctdb_db->push_state = state;

        return 0;
}

int32_t ctdb_control_db_push_confirm(struct ctdb_context *ctdb,
                                     TDB_DATA indata, TDB_DATA *outdata)
{
        uint32_t db_id;
        struct ctdb_db_context *ctdb_db;
        struct db_push_state *state;

        db_id = *(uint32_t *)indata.dptr;

        ctdb_db = find_ctdb_db(ctdb, db_id);
        if (ctdb_db == NULL) {
                DEBUG(DEBUG_ERR,(__location__ " Unknown db 0x%08x\n", db_id));
                return -1;
        }

        if (!ctdb_db_frozen(ctdb_db)) {
                DEBUG(DEBUG_ERR,
                      ("rejecting ctdb_control_db_push_confirm when not frozen\n"));
                return -1;
        }

        if (!ctdb_db->push_started) {
                DEBUG(DEBUG_ERR, (__location__ " DB push not started\n"));
                return -1;
        }

        if (ctdb_db_readonly(ctdb_db)) {
                DEBUG(DEBUG_ERR,
                      ("Clearing the tracking database for dbid 0x%x\n",
                       ctdb_db->db_id));
                if (tdb_wipe_all(ctdb_db->rottdb) != 0) {
                        DEBUG(DEBUG_ERR,
                              ("Failed to wipe tracking database for 0x%x."
                               " Dropping read-only delegation support\n",
                               ctdb_db->db_id));
                        tdb_close(ctdb_db->rottdb);
                        ctdb_db->rottdb = NULL;
                        ctdb_db_reset_readonly(ctdb_db);
                }

                while (ctdb_db->revokechild_active != NULL) {
                        talloc_free(ctdb_db->revokechild_active);
                }
        }

        ctdb_lockdb_unmark(ctdb_db);

        state = (struct db_push_state *)ctdb_db->push_state;
        if (state == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " Missing push db state\n"));
                return -1;
        }

        srvid_deregister(ctdb->srv, state->srvid, state);

        outdata->dptr = talloc_size(outdata, sizeof(uint32_t));
        if (outdata->dptr == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " Memory allocation error\n"));
                talloc_free(state);
                ctdb_db->push_state = NULL;
                return -1;
        }

        memcpy(outdata->dptr, (uint8_t *)&state->num_records, sizeof(uint32_t));
        outdata->dsize = sizeof(uint32_t);

        talloc_free(state);
        ctdb_db->push_started = false;
        ctdb_db->push_state = NULL;

        return 0;
}

struct set_recmode_state {
        struct ctdb_context *ctdb;
        struct ctdb_req_control_old *c;
};

static void set_recmode_handler(char status,
                                double latency,
                                void *private_data)
{
        struct set_recmode_state *state = talloc_get_type_abort(
                private_data, struct set_recmode_state);
        int s = 0;
        const char *err = NULL;

        switch (status) {
        case '0':
                /* Mutex taken */
                DEBUG(DEBUG_ERR,
                      ("ERROR: Daemon able to take recovery lock on \"%s\" during recovery\n",
                       state->ctdb->recovery_lock));
                s = -1;
                err = "Took recovery lock from daemon during recovery - probably a cluster filesystem lock coherence problem";
                break;

        case '1':
                /* Contention */
                DEBUG(DEBUG_DEBUG, (__location__ " Recovery lock check OK\n"));
                state->ctdb->recovery_mode = CTDB_RECOVERY_NORMAL;
                ctdb_process_deferred_attach(state->ctdb);

                s = 0;

                CTDB_UPDATE_RECLOCK_LATENCY(state->ctdb, "daemon reclock",
                                            reclock.ctdbd, latency);
                break;

        case '2':
                /* Timeout.  Consider this a success, not a failure,
                 * as we failed to set the recovery lock which is what
                 * we wanted.  This can be caused by the cluster
                 * filesystem being very slow to arbitrate locks
                 * immediately after a node failure. */
                DEBUG(DEBUG_WARNING,
                      (__location__
                       "Time out getting recovery lock, allowing recmode set anyway\n"));
                state->ctdb->recovery_mode = CTDB_RECOVERY_NORMAL;
                ctdb_process_deferred_attach(state->ctdb);

                s = 0;
                break;

        default:
                DEBUG(DEBUG_ERR,
                      ("Unexpected error when testing recovery lock\n"));
                s = -1;
                err = "Unexpected error when testing recovery lock";
        }

        ctdb_request_control_reply(state->ctdb, state->c, NULL, s, err);
        talloc_free(state);
}

static void
ctdb_drop_all_ips_event(struct tevent_context *ev, struct tevent_timer *te,
                        struct timeval t, void *private_data)
{
        struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);

        DEBUG(DEBUG_ERR,(__location__ " Been in recovery mode for too long. Dropping all IPS\n"));
        talloc_free(ctdb->release_ips_ctx);
        ctdb->release_ips_ctx = NULL;

        ctdb_release_all_ips(ctdb);
}

/*
 * Set up an event to drop all public ips if we remain in recovery for too
 * long
 */
int ctdb_deferred_drop_all_ips(struct ctdb_context *ctdb)
{
        if (ctdb->release_ips_ctx != NULL) {
                talloc_free(ctdb->release_ips_ctx);
        }
        ctdb->release_ips_ctx = talloc_new(ctdb);
        CTDB_NO_MEMORY(ctdb, ctdb->release_ips_ctx);

        tevent_add_timer(ctdb->ev, ctdb->release_ips_ctx,
                         timeval_current_ofs(ctdb->tunable.recovery_drop_all_ips, 0),
                         ctdb_drop_all_ips_event, ctdb);
        return 0;
}

/*
  set the recovery mode
 */
int32_t ctdb_control_set_recmode(struct ctdb_context *ctdb, 
                                 struct ctdb_req_control_old *c,
                                 TDB_DATA indata, bool *async_reply,
                                 const char **errormsg)
{
        uint32_t recmode = *(uint32_t *)indata.dptr;
        struct ctdb_db_context *ctdb_db;
        struct set_recmode_state *state;
        struct ctdb_cluster_mutex_handle *h;

        if (recmode == ctdb->recovery_mode) {
                D_INFO("Recovery mode already set to %s\n",
                       recmode == CTDB_RECOVERY_NORMAL ? "NORMAL" : "ACTIVE");
                return 0;
        }

        D_NOTICE("Recovery mode set to %s\n",
                 recmode == CTDB_RECOVERY_NORMAL ? "NORMAL" : "ACTIVE");

        /* if we enter recovery but stay in recovery for too long
           we will eventually drop all our ip addresses
        */
        if (recmode == CTDB_RECOVERY_ACTIVE) {
                if (ctdb_deferred_drop_all_ips(ctdb) != 0) {
                        D_ERR("Failed to set up deferred drop all ips\n");
                }

                ctdb->recovery_mode = CTDB_RECOVERY_ACTIVE;
                return 0;
        }

        /* From this point: recmode == CTDB_RECOVERY_NORMAL
         *
         * Therefore, what follows is special handling when setting
         * recovery mode back to normal */

        TALLOC_FREE(ctdb->release_ips_ctx);

        for (ctdb_db = ctdb->db_list; ctdb_db != NULL; ctdb_db = ctdb_db->next) {
                if (ctdb_db->generation != ctdb->vnn_map->generation) {
                        DEBUG(DEBUG_ERR,
                              ("Inconsistent DB generation %u for %s\n",
                               ctdb_db->generation, ctdb_db->db_name));
                        DEBUG(DEBUG_ERR, ("Recovery mode set to ACTIVE\n"));
                        return -1;
                }
        }

        /* force the databases to thaw */
        if (ctdb_db_all_frozen(ctdb)) {
                ctdb_control_thaw(ctdb, false);
        }

        if (ctdb->recovery_lock == NULL) {
                /* Not using recovery lock file */
                ctdb->recovery_mode = CTDB_RECOVERY_NORMAL;
                ctdb_process_deferred_attach(ctdb);
                return 0;
        }

        state = talloc_zero(ctdb, struct set_recmode_state);
        if (state == NULL) {
                DEBUG(DEBUG_ERR, (__location__ " out of memory\n"));
                return -1;
        }
        state->ctdb = ctdb;
        state->c = NULL;

        h = ctdb_cluster_mutex(state, ctdb, ctdb->recovery_lock, 5,
                               set_recmode_handler, state, NULL, NULL);
        if (h == NULL) {
                talloc_free(state);
                return -1;
        }

        state->c = talloc_steal(state, c);
        *async_reply = true;

        return 0;
}


/*
  delete a record as part of the vacuum process
  only delete if we are not lmaster or dmaster, and our rsn is <= the provided rsn
  use non-blocking locks

  return 0 if the record was successfully deleted (i.e. it does not exist
  when the function returns)
  or !0 is the record still exists in the tdb after returning.
 */
static int delete_tdb_record(struct ctdb_context *ctdb, struct ctdb_db_context *ctdb_db, struct ctdb_rec_data_old *rec)
{
        TDB_DATA key, data, data2;
        struct ctdb_ltdb_header *hdr, *hdr2;
        
        /* these are really internal tdb functions - but we need them here for
           non-blocking lock of the freelist */
        int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype);
        int tdb_unlock(struct tdb_context *tdb, int list, int ltype);


        key.dsize = rec->keylen;
        key.dptr  = &rec->data[0];
        data.dsize = rec->datalen;
        data.dptr = &rec->data[rec->keylen];

        if (ctdb_lmaster(ctdb, &key) == ctdb->pnn) {
                DBG_INFO("Called delete on record where we are lmaster\n");
                return -1;
        }

        if (data.dsize != sizeof(struct ctdb_ltdb_header)) {
                DBG_ERR("Bad record size\n");
                return -1;
        }

        hdr = (struct ctdb_ltdb_header *)data.dptr;

        /* use a non-blocking lock */
        if (tdb_chainlock_nonblock(ctdb_db->ltdb->tdb, key) != 0) {
                DBG_INFO("Failed to get non-blocking chain lock\n");
                return -1;
        }

        data2 = tdb_fetch(ctdb_db->ltdb->tdb, key);
        if (data2.dptr == NULL) {
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                return 0;
        }

        if (data2.dsize < sizeof(struct ctdb_ltdb_header)) {
                if (tdb_lock_nonblock(ctdb_db->ltdb->tdb, -1, F_WRLCK) == 0) {
                        if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
                                DBG_ERR("Failed to delete corrupt record\n");
                        }
                        tdb_unlock(ctdb_db->ltdb->tdb, -1, F_WRLCK);
                        DBG_ERR("Deleted corrupt record\n");
                }
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                free(data2.dptr);
                return 0;
        }
        
        hdr2 = (struct ctdb_ltdb_header *)data2.dptr;

        if (hdr2->rsn > hdr->rsn) {
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                DBG_INFO("Skipping record with rsn=%llu - called with rsn=%llu\n",
                         (unsigned long long)hdr2->rsn,
                         (unsigned long long)hdr->rsn);
                free(data2.dptr);
                return -1;
        }

        /* do not allow deleting record that have readonly flags set. */
        if (hdr->flags & CTDB_REC_RO_FLAGS) {
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                DBG_INFO("Skipping record with readonly flags set\n");
                free(data2.dptr);
                return -1;
        }
        if (hdr2->flags & CTDB_REC_RO_FLAGS) {
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                DBG_INFO("Skipping record with readonly flags set locally\n");
                free(data2.dptr);
                return -1;
        }

        if (hdr2->dmaster == ctdb->pnn) {
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                DBG_INFO("Attempted delete record where we are the dmaster\n");
                free(data2.dptr);
                return -1;
        }

        if (tdb_lock_nonblock(ctdb_db->ltdb->tdb, -1, F_WRLCK) != 0) {
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                DBG_INFO("Failed to get non-blocking freelist lock\n");
                free(data2.dptr);
                return -1;
        }

        if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
                tdb_unlock(ctdb_db->ltdb->tdb, -1, F_WRLCK);
                tdb_chainunlock(ctdb_db->ltdb->tdb, key);
                DBG_INFO("Failed to delete record\n");
                free(data2.dptr);
                return -1;
        }

        tdb_unlock(ctdb_db->ltdb->tdb, -1, F_WRLCK);
        tdb_chainunlock(ctdb_db->ltdb->tdb, key);
        free(data2.dptr);
        return 0;
}



struct recovery_callback_state {
        struct ctdb_req_control_old *c;
};


/*
  called when the 'recovered' event script has finished
 */
static void ctdb_end_recovery_callback(struct ctdb_context *ctdb, int status, void *p)
{
        struct recovery_callback_state *state = talloc_get_type(p, struct recovery_callback_state);

        CTDB_INCREMENT_STAT(ctdb, num_recoveries);

        if (status != 0) {
                DEBUG(DEBUG_ERR,(__location__ " recovered event script failed (status %d)\n", status));
                if (status == -ETIMEDOUT) {
                        ctdb_ban_self(ctdb);
                }
        }

        ctdb_request_control_reply(ctdb, state->c, NULL, status, NULL);
        talloc_free(state);

        gettimeofday(&ctdb->last_recovery_finished, NULL);

        if (ctdb->runstate == CTDB_RUNSTATE_FIRST_RECOVERY) {
                ctdb_set_runstate(ctdb, CTDB_RUNSTATE_STARTUP);
        }
}

/*
  recovery has finished
 */
int32_t ctdb_control_end_recovery(struct ctdb_context *ctdb, 
                                struct ctdb_req_control_old *c,
                                bool *async_reply)
{
        int ret;
        struct recovery_callback_state *state;

        DEBUG(DEBUG_ERR,("Recovery has finished\n"));

        ctdb_persistent_finish_trans3_commits(ctdb);

        state = talloc(ctdb, struct recovery_callback_state);
        CTDB_NO_MEMORY(ctdb, state);

        state->c    = c;

        ret = ctdb_event_script_callback(ctdb, state,
                                         ctdb_end_recovery_callback, 
                                         state, 
                                         CTDB_EVENT_RECOVERED, "%s", "");

        if (ret != 0) {
                DEBUG(DEBUG_ERR,(__location__ " Failed to end recovery\n"));
                talloc_free(state);
                return -1;
        }

        /* tell the control that we will be reply asynchronously */
        state->c    = talloc_steal(state, c);
        *async_reply = true;
        return 0;
}

/*
  called when the 'startrecovery' event script has finished
 */
static void ctdb_start_recovery_callback(struct ctdb_context *ctdb, int status, void *p)
{
        struct recovery_callback_state *state = talloc_get_type(p, struct recovery_callback_state);

        if (status != 0) {
                DEBUG(DEBUG_ERR,(__location__ " startrecovery event script failed (status %d)\n", status));
        }

        ctdb_request_control_reply(ctdb, state->c, NULL, status, NULL);
        talloc_free(state);
}

static void run_start_recovery_event(struct ctdb_context *ctdb,
                                     struct recovery_callback_state *state)
{
        int ret;

        ret = ctdb_event_script_callback(ctdb, state,
                                         ctdb_start_recovery_callback,
                                         state,
                                         CTDB_EVENT_START_RECOVERY,
                                         "%s", "");

        if (ret != 0) {
                DEBUG(DEBUG_ERR,("Unable to run startrecovery event\n"));
                ctdb_request_control_reply(ctdb, state->c, NULL, -1, NULL);
                talloc_free(state);
                return;
        }

        return;
}

static bool reclock_strings_equal(const char *a, const char *b)
{
        return (a == NULL && b == NULL) ||
                (a != NULL && b != NULL && strcmp(a, b) == 0);
}

static void start_recovery_reclock_callback(struct ctdb_context *ctdb,
                                                int32_t status,
                                                TDB_DATA data,
                                                const char *errormsg,
                                                void *private_data)
{
        struct recovery_callback_state *state = talloc_get_type_abort(
                private_data, struct recovery_callback_state);
        const char *local = ctdb->recovery_lock;
        const char *remote = NULL;

        if (status != 0) {
                DEBUG(DEBUG_ERR, (__location__ " GET_RECLOCK failed\n"));
                ctdb_request_control_reply(ctdb, state->c, NULL,
                                           status, errormsg);
                talloc_free(state);
                return;
        }

        /* Check reclock consistency */
        if (data.dsize > 0) {
                /* Ensure NUL-termination */
                data.dptr[data.dsize-1] = '\0';
                remote = (const char *)data.dptr;
        }
        if (! reclock_strings_equal(local, remote)) {
                /* Inconsistent */
                ctdb_request_control_reply(ctdb, state->c, NULL, -1, NULL);
                DEBUG(DEBUG_ERR,
                      ("Recovery lock configuration inconsistent: "
                       "recmaster has %s, this node has %s, shutting down\n",
                       remote == NULL ? "NULL" : remote,
                       local == NULL ? "NULL" : local));
                talloc_free(state);
                ctdb_shutdown_sequence(ctdb, 1);
        }
        DEBUG(DEBUG_INFO,
              ("Recovery lock consistency check successful\n"));

        run_start_recovery_event(ctdb, state);
}

/* Check recovery lock consistency and run eventscripts for the
 * "startrecovery" event */
int32_t ctdb_control_start_recovery(struct ctdb_context *ctdb,
                                    struct ctdb_req_control_old *c,
                                    bool *async_reply)
{
        int ret;
        struct recovery_callback_state *state;
        uint32_t recmaster = c->hdr.srcnode;

        DEBUG(DEBUG_ERR, ("Recovery has started\n"));
        gettimeofday(&ctdb->last_recovery_started, NULL);

        state = talloc(ctdb, struct recovery_callback_state);
        CTDB_NO_MEMORY(ctdb, state);

        state->c = c;

        /* Although the recovery master sent this node a start
         * recovery control, this node might still think the recovery
         * master is disconnected.  In this case defer the recovery
         * lock consistency check. */
        if (ctdb->nodes[recmaster]->flags & NODE_FLAGS_DISCONNECTED) {
                run_start_recovery_event(ctdb, state);
        } else {
                /* Ask the recovery master about its reclock setting */
                ret = ctdb_daemon_send_control(ctdb,
                                               recmaster,
                                               0,
                                               CTDB_CONTROL_GET_RECLOCK_FILE,
                                               0, 0,
                                               tdb_null,
                                               start_recovery_reclock_callback,
                                               state);

                if (ret != 0) {
                        DEBUG(DEBUG_ERR, (__location__ " GET_RECLOCK failed\n"));
                        talloc_free(state);
                        return -1;
                }
        }

        /* tell the control that we will be reply asynchronously */
        state->c = talloc_steal(state, c);
        *async_reply = true;

        return 0;
}

/*
 try to delete all these records as part of the vacuuming process
 and return the records we failed to delete
*/
int32_t ctdb_control_try_delete_records(struct ctdb_context *ctdb, TDB_DATA indata, TDB_DATA *outdata)
{
        struct ctdb_marshall_buffer *reply = (struct ctdb_marshall_buffer *)indata.dptr;
        struct ctdb_db_context *ctdb_db;
        unsigned int i;
        struct ctdb_rec_data_old *rec;
        struct ctdb_marshall_buffer *records;

        if (indata.dsize < offsetof(struct ctdb_marshall_buffer, data)) {
                DEBUG(DEBUG_ERR,(__location__ " invalid data in try_delete_records\n"));
                return -1;
        }

        ctdb_db = find_ctdb_db(ctdb, reply->db_id);
        if (!ctdb_db) {
                DEBUG(DEBUG_ERR,(__location__ " Unknown db 0x%08x\n", reply->db_id));
                return -1;
        }


        DEBUG(DEBUG_DEBUG,("starting try_delete_records of %u records for dbid 0x%x\n",
                 reply->count, reply->db_id));


        /* create a blob to send back the records we couldnt delete */  
        records = (struct ctdb_marshall_buffer *)
                        talloc_zero_size(outdata, 
                                    offsetof(struct ctdb_marshall_buffer, data));
        if (records == NULL) {
                DEBUG(DEBUG_ERR,(__location__ " Out of memory\n"));
                return -1;
        }
        records->db_id = ctdb_db->db_id;


        rec = (struct ctdb_rec_data_old *)&reply->data[0];
        for (i=0;i<reply->count;i++) {
                TDB_DATA key, data;

                key.dptr = &rec->data[0];
                key.dsize = rec->keylen;
                data.dptr = &rec->data[key.dsize];
                data.dsize = rec->datalen;

                if (data.dsize < sizeof(struct ctdb_ltdb_header)) {
                        DEBUG(DEBUG_CRIT,(__location__ " bad ltdb record in indata\n"));
                        talloc_free(records);
                        return -1;
                }

                /* If we cant delete the record we must add it to the reply
                   so the lmaster knows it may not purge this record
                */
                if (delete_tdb_record(ctdb, ctdb_db, rec) != 0) {
                        size_t old_size;
                        struct ctdb_ltdb_header *hdr;

                        hdr = (struct ctdb_ltdb_header *)data.dptr;
                        data.dptr += sizeof(*hdr);
                        data.dsize -= sizeof(*hdr);

                        DEBUG(DEBUG_INFO, (__location__ " Failed to vacuum delete record with hash 0x%08x\n", ctdb_hash(&key)));

                        old_size = talloc_get_size(records);
                        records = talloc_realloc_size(outdata, records, old_size + rec->length);
                        if (records == NULL) {
                                DEBUG(DEBUG_ERR,(__location__ " Failed to expand\n"));
                                return -1;
                        }
                        records->count++;
                        memcpy(old_size+(uint8_t *)records, rec, rec->length);
                } 

                rec = (struct ctdb_rec_data_old *)(rec->length + (uint8_t *)rec);
        }           


        *outdata = ctdb_marshall_finish(records);

        return 0;
}

/*
  report capabilities
 */
int32_t ctdb_control_get_capabilities(struct ctdb_context *ctdb, TDB_DATA *outdata)
{
        uint32_t *capabilities = NULL;

        capabilities = talloc(outdata, uint32_t);
        CTDB_NO_MEMORY(ctdb, capabilities);
        *capabilities = ctdb->capabilities;

        outdata->dsize = sizeof(uint32_t);
        outdata->dptr = (uint8_t *)capabilities;

        return 0;       
}

/* The recovery daemon will ping us at regular intervals.
   If we havent been pinged for a while we assume the recovery
   daemon is inoperable and we restart.
*/
static void ctdb_recd_ping_timeout(struct tevent_context *ev,
                                   struct tevent_timer *te,
                                   struct timeval t, void *p)
{
        struct ctdb_context *ctdb = talloc_get_type(p, struct ctdb_context);
        uint32_t *count = talloc_get_type(ctdb->recd_ping_count, uint32_t);

        DEBUG(DEBUG_ERR, ("Recovery daemon ping timeout. Count : %u\n", *count));

        if (*count < ctdb->tunable.recd_ping_failcount) {
                (*count)++;
                tevent_add_timer(ctdb->ev, ctdb->recd_ping_count,
                                 timeval_current_ofs(ctdb->tunable.recd_ping_timeout, 0),
                                 ctdb_recd_ping_timeout, ctdb);
                return;
        }

        DEBUG(DEBUG_ERR, ("Final timeout for recovery daemon ping. Restarting recovery daemon. (This can be caused if the cluster filesystem has hung)\n"));

        ctdb_stop_recoverd(ctdb);
        ctdb_start_recoverd(ctdb);
}

int32_t ctdb_control_recd_ping(struct ctdb_context *ctdb)
{
        talloc_free(ctdb->recd_ping_count);

        ctdb->recd_ping_count = talloc_zero(ctdb, uint32_t);
        CTDB_NO_MEMORY(ctdb, ctdb->recd_ping_count);

        if (ctdb->tunable.recd_ping_timeout != 0) {
                tevent_add_timer(ctdb->ev, ctdb->recd_ping_count,
                                 timeval_current_ofs(ctdb->tunable.recd_ping_timeout, 0),
                                 ctdb_recd_ping_timeout, ctdb);
        }

        return 0;
}

void ctdb_node_become_inactive(struct ctdb_context *ctdb)
{
        struct ctdb_db_context *ctdb_db;

        D_WARNING("Making node INACTIVE\n");

        /*
         * Do not service database calls - reset generation to invalid
         * so this node ignores any REQ/REPLY CALL/DMASTER
         */
        ctdb->vnn_map->generation = INVALID_GENERATION;
        for (ctdb_db = ctdb->db_list; ctdb_db != NULL; ctdb_db = ctdb_db->next) {
                ctdb_db->generation = INVALID_GENERATION;
        }

        /*
         * Although this bypasses the control, the only thing missing
         * is the deferred drop of all public IPs, which isn't
         * necessary because they are dropped below
         */
        if (ctdb->recovery_mode != CTDB_RECOVERY_ACTIVE) {
                D_NOTICE("Recovery mode set to ACTIVE\n");
                ctdb->recovery_mode = CTDB_RECOVERY_ACTIVE;
        }

        /*
         * Initiate database freeze - this will be scheduled for
         * immediate execution and will be in progress long before the
         * calling control returns
         */
        ctdb_daemon_send_control(ctdb,
                                 ctdb->pnn,
                                 0,
                                 CTDB_CONTROL_FREEZE,
                                 0,
                                 CTDB_CTRL_FLAG_NOREPLY,
                                 tdb_null,
                                 NULL,
                                 NULL);

        D_NOTICE("Dropping all public IP addresses\n");
        ctdb_release_all_ips(ctdb);
}

int32_t ctdb_control_stop_node(struct ctdb_context *ctdb)
{
        DEBUG(DEBUG_ERR, ("Stopping node\n"));
        ctdb->nodes[ctdb->pnn]->flags |= NODE_FLAGS_STOPPED;

        ctdb_node_become_inactive(ctdb);

        return 0;
}

int32_t ctdb_control_continue_node(struct ctdb_context *ctdb)
{
        DEBUG(DEBUG_ERR, ("Continue node\n"));
        ctdb->nodes[ctdb->pnn]->flags &= ~NODE_FLAGS_STOPPED;

        return 0;
}