r23806: update Samba4 with the latest ctdb code.

This doesn't get the ctdb code fully working in Samba4, it just gets
it building and not breaking non-clustered use of Samba. It will take
a bit longer to update some of the calling ctdb_cluster.c code to make
it work correctly in Samba4.

Note also that Samba4 now only links to the client portion of
ctdb. For the moment I am leaving the ctdbd as a separate daemon,
which you install separately from http://ctdb.samba.org/.
(This used to be commit b196077cbb55cbecad87065133c2d67198e31066)

1 files changed, 680 insertions, 0 deletions

diff --git a/source4/cluster/ctdb/server/ctdb_recover.c b/source4/cluster/ctdb/server/ctdb_recover.c
new file mode 100644
index 0000000000..82338d48ce
--- /dev/null
+++ b/source4/cluster/ctdb/server/ctdb_recover.c
@@ -0,0 +1,680 @@
+/* 
+   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 "includes.h"
+#include "lib/events/events.h"
+#include "lib/tdb/include/tdb.h"
+#include "system/network.h"
+#include "system/filesys.h"
+#include "system/wait.h"
+#include "../include/ctdb_private.h"
+#include "lib/util/dlinklist.h"
+#include "db_wrap.h"
+
+/*
+  lock all databases - mark only
+ */
+static int ctdb_lock_all_databases_mark(struct ctdb_context *ctdb)
+{
+	struct ctdb_db_context *ctdb_db;
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("Attempt to mark all databases locked when not frozen\n"));
+		return -1;
+	}
+	for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
+		if (tdb_lockall_mark(ctdb_db->ltdb->tdb) != 0) {
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/*
+  lock all databases - unmark only
+ */
+static int ctdb_lock_all_databases_unmark(struct ctdb_context *ctdb)
+{
+	struct ctdb_db_context *ctdb_db;
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("Attempt to unmark all databases locked when not frozen\n"));
+		return -1;
+	}
+	for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
+		if (tdb_lockall_unmark(ctdb_db->ltdb->tdb) != 0) {
+			return -1;
+		}
+	}
+	return 0;
+}
+
+
+int 
+ctdb_control_getvnnmap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
+{
+	CHECK_CONTROL_DATA_SIZE(0);
+	struct ctdb_vnn_map_wire *map;
+	size_t len;
+
+	len = offsetof(struct ctdb_vnn_map_wire, map) + sizeof(uint32_t)*ctdb->vnn_map->size;
+	map = talloc_size(outdata, len);
+	CTDB_NO_MEMORY_VOID(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->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("Attempt to set vnnmap when not frozen\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 *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, dbids) + 4*len;
+	outdata->dptr  = (unsigned char *)talloc_zero_size(outdata, outdata->dsize);
+	if (!outdata->dptr) {
+		DEBUG(0, (__location__ " Failed to allocate dbmap array\n"));
+		exit(1);
+	}
+
+	dbid_map = (struct ctdb_dbid_map *)outdata->dptr;
+	dbid_map->num = len;
+	for(i=0,ctdb_db=ctdb->db_list;ctdb_db;i++,ctdb_db=ctdb_db->next){
+		dbid_map->dbids[i] = ctdb_db->db_id;
+	}
+
+	return 0;
+}
+
+int 
+ctdb_control_getnodemap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
+{
+	uint32_t i, num_nodes;
+	struct ctdb_node_map *node_map;
+
+	CHECK_CONTROL_DATA_SIZE(0);
+
+	num_nodes = ctdb->num_nodes;
+
+	outdata->dsize = offsetof(struct ctdb_node_map, nodes) + num_nodes*sizeof(struct ctdb_node_and_flags);
+	outdata->dptr  = (unsigned char *)talloc_zero_size(outdata, outdata->dsize);
+	if (!outdata->dptr) {
+		DEBUG(0, (__location__ " Failed to allocate nodemap array\n"));
+		exit(1);
+	}
+
+	node_map = (struct ctdb_node_map *)outdata->dptr;
+	node_map->num = num_nodes;
+	for (i=0; i<num_nodes; i++) {
+		inet_aton(ctdb->nodes[i]->address.address, &node_map->nodes[i].sin.sin_addr);
+		node_map->nodes[i].vnn   = ctdb->nodes[i]->vnn;
+		node_map->nodes[i].flags = ctdb->nodes[i]->flags;
+	}
+
+	return 0;
+}
+
+struct getkeys_params {
+	struct ctdb_context *ctdb;
+	uint32_t lmaster;
+	uint32_t rec_count;
+	struct getkeys_rec {
+		TDB_DATA key;
+		TDB_DATA data;
+	} *recs;
+};
+
+static int traverse_getkeys(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
+{
+	struct getkeys_params *params = (struct getkeys_params *)p;
+	uint32_t lmaster;
+
+	lmaster = ctdb_lmaster(params->ctdb, &key);
+
+	/* only include this record if the lmaster matches or if
+	   the wildcard lmaster (-1) was specified.
+	*/
+	if ((params->lmaster != CTDB_LMASTER_ANY) && (params->lmaster != lmaster)) {
+		return 0;
+	}
+
+	params->recs = talloc_realloc(NULL, params->recs, struct getkeys_rec, params->rec_count+1);
+	key.dptr = talloc_memdup(params->recs, key.dptr, key.dsize);
+	data.dptr = talloc_memdup(params->recs, data.dptr, data.dsize);
+	params->recs[params->rec_count].key = key;
+	params->recs[params->rec_count].data = data;
+	params->rec_count++;
+
+	return 0;
+}
+
+/*
+  pul a bunch of records from a ltdb, filtering by lmaster
+ */
+int32_t ctdb_control_pull_db(struct ctdb_context *ctdb, TDB_DATA indata, TDB_DATA *outdata)
+{
+	struct ctdb_control_pulldb *pull;
+	struct ctdb_db_context *ctdb_db;
+	struct getkeys_params params;
+	struct ctdb_control_pulldb_reply *reply;
+	int i;
+	size_t len = 0;
+
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("rejecting ctdb_control_pull_db when not frozen\n"));
+		return -1;
+	}
+
+	pull = (struct ctdb_control_pulldb *)indata.dptr;
+	
+	ctdb_db = find_ctdb_db(ctdb, pull->db_id);
+	if (!ctdb_db) {
+		DEBUG(0,(__location__ " Unknown db\n"));
+		return -1;
+	}
+
+	params.ctdb = ctdb;
+	params.lmaster = pull->lmaster;
+
+	params.rec_count = 0;
+	params.recs = talloc_array(outdata, struct getkeys_rec, 0);
+	CTDB_NO_MEMORY(ctdb, params.recs);
+
+	if (ctdb_lock_all_databases_mark(ctdb) != 0) {
+		DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
+		return -1;
+	}
+
+	tdb_traverse_read(ctdb_db->ltdb->tdb, traverse_getkeys, &params);
+
+	ctdb_lock_all_databases_unmark(ctdb);
+
+	reply = talloc(outdata, struct ctdb_control_pulldb_reply);
+	CTDB_NO_MEMORY(ctdb, reply);
+
+	reply->db_id = pull->db_id;
+	reply->count = params.rec_count;
+
+	len = offsetof(struct ctdb_control_pulldb_reply, data);
+
+	for (i=0;i<reply->count;i++) {
+		struct ctdb_rec_data *rec;
+		rec = ctdb_marshall_record(outdata, 0, params.recs[i].key, params.recs[i].data);
+		reply = talloc_realloc_size(outdata, reply, rec->length + len);
+		memcpy(len+(uint8_t *)reply, rec, rec->length);
+		len += rec->length;
+		talloc_free(rec);
+	}
+
+	talloc_free(params.recs);
+
+	outdata->dptr = (uint8_t *)reply;
+	outdata->dsize = len;
+
+	return 0;
+}
+
+/*
+  push a bunch of records into a ltdb, filtering by rsn
+ */
+int32_t ctdb_control_push_db(struct ctdb_context *ctdb, TDB_DATA indata)
+{
+	struct ctdb_control_pulldb_reply *reply = (struct ctdb_control_pulldb_reply *)indata.dptr;
+	struct ctdb_db_context *ctdb_db;
+	int i, ret;
+	struct ctdb_rec_data *rec;
+
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("rejecting ctdb_control_push_db when not frozen\n"));
+		return -1;
+	}
+
+	if (indata.dsize < offsetof(struct ctdb_control_pulldb_reply, data)) {
+		DEBUG(0,(__location__ " invalid data in pulldb reply\n"));
+		return -1;
+	}
+
+	ctdb_db = find_ctdb_db(ctdb, reply->db_id);
+	if (!ctdb_db) {
+		DEBUG(0,(__location__ " Unknown db 0x%08x\n", reply->db_id));
+		return -1;
+	}
+
+	if (ctdb_lock_all_databases_mark(ctdb) != 0) {
+		DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
+		return -1;
+	}
+
+	rec = (struct ctdb_rec_data *)&reply->data[0];
+
+	DEBUG(3,("starting push of %u records for dbid 0x%x\n",
+		 reply->count, reply->db_id));
+
+	for (i=0;i<reply->count;i++) {
+		TDB_DATA key, data;
+		struct ctdb_ltdb_header *hdr, header;
+
+		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(0,(__location__ " bad ltdb record\n"));
+			goto failed;
+		}
+		hdr = (struct ctdb_ltdb_header *)data.dptr;
+		data.dptr += sizeof(*hdr);
+		data.dsize -= sizeof(*hdr);
+
+		ret = ctdb_ltdb_fetch(ctdb_db, key, &header, NULL, NULL);
+		if (ret != 0) {
+			DEBUG(0, (__location__ " Unable to fetch record\n"));
+			goto failed;
+		}
+		/* The check for dmaster gives priority to the dmaster
+		   if the rsn values are equal */
+		if (header.rsn < hdr->rsn ||
+		    (header.dmaster != ctdb->vnn && header.rsn == hdr->rsn)) {
+			ret = ctdb_ltdb_store(ctdb_db, key, hdr, data);
+			if (ret != 0) {
+				DEBUG(0, (__location__ " Unable to store record\n"));
+				goto failed;
+			}
+		}
+
+		rec = (struct ctdb_rec_data *)(rec->length + (uint8_t *)rec);
+	}	    
+
+	DEBUG(3,("finished push of %u records for dbid 0x%x\n",
+		 reply->count, reply->db_id));
+
+	ctdb_lock_all_databases_unmark(ctdb);
+	return 0;
+
+failed:
+	ctdb_lock_all_databases_unmark(ctdb);
+	return -1;
+}
+
+
+static int traverse_setdmaster(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
+{
+	uint32_t *dmaster = (uint32_t *)p;
+	struct ctdb_ltdb_header *header = (struct ctdb_ltdb_header *)data.dptr;
+	int ret;
+
+	header->dmaster = *dmaster;
+
+	ret = tdb_store(tdb, key, data, TDB_REPLACE);
+	if (ret) {
+		DEBUG(0,(__location__ " failed to write tdb data back  ret:%d\n",ret));
+		return ret;
+	}
+	return 0;
+}
+
+int32_t ctdb_control_set_dmaster(struct ctdb_context *ctdb, TDB_DATA indata)
+{
+	struct ctdb_control_set_dmaster *p = (struct ctdb_control_set_dmaster *)indata.dptr;
+	struct ctdb_db_context *ctdb_db;
+
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("rejecting ctdb_control_set_dmaster when not frozen\n"));
+		return -1;
+	}
+
+	ctdb_db = find_ctdb_db(ctdb, p->db_id);
+	if (!ctdb_db) {
+		DEBUG(0,(__location__ " Unknown db 0x%08x\n", p->db_id));
+		return -1;
+	}
+
+	if (ctdb_lock_all_databases_mark(ctdb) != 0) {
+		DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
+		return -1;
+	}
+
+	tdb_traverse(ctdb_db->ltdb->tdb, traverse_setdmaster, &p->dmaster);
+
+	ctdb_lock_all_databases_unmark(ctdb);
+	
+	return 0;
+}
+
+struct ctdb_set_recmode_state {
+	struct ctdb_req_control *c;
+	uint32_t recmode;
+};
+
+/*
+  called when the 'recovered' event script has finished
+ */
+static void ctdb_recovered_callback(struct ctdb_context *ctdb, int status, void *p)
+{
+	struct ctdb_set_recmode_state *state = talloc_get_type(p, struct ctdb_set_recmode_state);
+
+	ctdb_start_monitoring(ctdb);
+
+	if (status == 0) {
+		ctdb->recovery_mode = state->recmode;
+	} else {
+		DEBUG(0,(__location__ " recovered event script failed (status %d)\n", status));
+	}
+
+	ctdb_request_control_reply(ctdb, state->c, NULL, status, NULL);
+	talloc_free(state);
+}
+
+/*
+  set the recovery mode
+ */
+int32_t ctdb_control_set_recmode(struct ctdb_context *ctdb, 
+				 struct ctdb_req_control *c,
+				 TDB_DATA indata, bool *async_reply,
+				 const char **errormsg)
+{
+	uint32_t recmode = *(uint32_t *)indata.dptr;
+	int ret;
+	struct ctdb_set_recmode_state *state;
+
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("Attempt to change recovery mode to %u when not frozen\n", 
+			 recmode));
+		(*errormsg) = "Cannot change recovery mode while not frozen";
+		return -1;
+	}
+
+	if (recmode != CTDB_RECOVERY_NORMAL ||
+	    ctdb->recovery_mode != CTDB_RECOVERY_ACTIVE) {
+		ctdb->recovery_mode = recmode;
+		return 0;
+	}
+
+	/* some special handling when ending recovery mode */
+	state = talloc(ctdb, struct ctdb_set_recmode_state);
+	CTDB_NO_MEMORY(ctdb, state);
+
+	/* we should not be able to get the lock on the nodes list, as it should be
+	   held by the recovery master */
+	if (ctdb_recovery_lock(ctdb, false)) {
+		DEBUG(0,("ERROR: recovery lock file %s not locked when recovering!\n",
+			 ctdb->recovery_lock_file));
+		return -1;
+	}	
+
+	state->c = talloc_steal(state, c);
+	state->recmode = recmode;
+	
+	ctdb_stop_monitoring(ctdb);
+
+	/* call the events script to tell all subsystems that we have recovered */
+	ret = ctdb_event_script_callback(ctdb, 
+					 timeval_current_ofs(ctdb->tunable.script_timeout, 0),
+					 state, 
+					 ctdb_recovered_callback, 
+					 state, "recovered");
+	if (ret != 0) {
+		return ret;
+	}
+	*async_reply = true;
+
+	return 0;
+}
+
+/*
+  callback for ctdb_control_max_rsn
+ */
+static int traverse_max_rsn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
+{
+	struct ctdb_ltdb_header *h = (struct ctdb_ltdb_header *)data.dptr;
+	uint64_t *max_rsn = (uint64_t *)p;
+
+	if (data.dsize >= sizeof(*h)) {
+		(*max_rsn) = MAX(*max_rsn, h->rsn);
+	}
+	return 0;
+}
+
+/*
+  get max rsn across an entire db
+ */
+int32_t ctdb_control_max_rsn(struct ctdb_context *ctdb, TDB_DATA indata, TDB_DATA *outdata)
+{
+	struct ctdb_db_context *ctdb_db;
+	uint32_t db_id = *(uint32_t *)indata.dptr;
+	uint64_t max_rsn = 0;
+	int ret;
+
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("rejecting ctdb_control_max_rsn when not frozen\n"));
+		return -1;
+	}
+
+	ctdb_db = find_ctdb_db(ctdb, db_id);
+	if (!ctdb_db) {
+		DEBUG(0,(__location__ " Unknown db\n"));
+		return -1;
+	}
+
+	if (ctdb_lock_all_databases_mark(ctdb) != 0) {
+		DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
+		return -1;
+	}
+
+	ret = tdb_traverse_read(ctdb_db->ltdb->tdb, traverse_max_rsn, &max_rsn);
+	if (ret < 0) {
+		DEBUG(0,(__location__ " traverse failed in ctdb_control_max_rsn\n"));
+		return -1;
+	}
+
+	ctdb_lock_all_databases_unmark(ctdb);
+
+	outdata->dptr = (uint8_t *)talloc(outdata, uint64_t);
+	if (!outdata->dptr) {
+		return -1;
+	}
+	(*(uint64_t *)outdata->dptr) = max_rsn;
+	outdata->dsize = sizeof(uint64_t);
+
+	return 0;
+}
+
+
+/*
+  callback for ctdb_control_set_rsn_nonempty
+ */
+static int traverse_set_rsn_nonempty(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
+{
+	struct ctdb_ltdb_header *h = (struct ctdb_ltdb_header *)data.dptr;
+	uint64_t *rsn = (uint64_t *)p;
+
+	if (data.dsize > sizeof(*h)) {
+		h->rsn = *rsn;
+		if (tdb_store(tdb, key, data, TDB_REPLACE) != 0) {
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/*
+  set rsn for all non-empty records in a database to a given rsn
+ */
+int32_t ctdb_control_set_rsn_nonempty(struct ctdb_context *ctdb, TDB_DATA indata, TDB_DATA *outdata)
+{
+	struct ctdb_control_set_rsn_nonempty *p = (struct ctdb_control_set_rsn_nonempty *)indata.dptr;
+	struct ctdb_db_context *ctdb_db;
+	int ret;
+
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("rejecting ctdb_control_set_rsn_nonempty when not frozen\n"));
+		return -1;
+	}
+
+	ctdb_db = find_ctdb_db(ctdb, p->db_id);
+	if (!ctdb_db) {
+		DEBUG(0,(__location__ " Unknown db\n"));
+		return -1;
+	}
+
+	if (ctdb_lock_all_databases_mark(ctdb) != 0) {
+		DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
+		return -1;
+	}
+
+	ret = tdb_traverse(ctdb_db->ltdb->tdb, traverse_set_rsn_nonempty, &p->rsn);
+	if (ret < 0) {
+		DEBUG(0,(__location__ " traverse failed in ctdb_control_set_rsn_nonempty\n"));
+		return -1;
+	}
+
+	ctdb_lock_all_databases_unmark(ctdb);
+
+	return 0;
+}
+
+
+/*
+  callback for ctdb_control_delete_low_rsn
+ */
+static int traverse_delete_low_rsn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
+{
+	struct ctdb_ltdb_header *h = (struct ctdb_ltdb_header *)data.dptr;
+	uint64_t *rsn = (uint64_t *)p;
+
+	if (data.dsize < sizeof(*h) || h->rsn < *rsn) {
+		if (tdb_delete(tdb, key) != 0) {
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/*
+  delete any records with a rsn < the given rsn
+ */
+int32_t ctdb_control_delete_low_rsn(struct ctdb_context *ctdb, TDB_DATA indata, TDB_DATA *outdata)
+{
+	struct ctdb_control_delete_low_rsn *p = (struct ctdb_control_delete_low_rsn *)indata.dptr;
+	struct ctdb_db_context *ctdb_db;
+	int ret;
+
+	if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
+		DEBUG(0,("rejecting ctdb_control_delete_low_rsn when not frozen\n"));
+		return -1;
+	}
+
+	ctdb_db = find_ctdb_db(ctdb, p->db_id);
+	if (!ctdb_db) {
+		DEBUG(0,(__location__ " Unknown db\n"));
+		return -1;
+	}
+
+	if (ctdb_lock_all_databases_mark(ctdb) != 0) {
+		DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
+		return -1;
+	}
+
+	ret = tdb_traverse(ctdb_db->ltdb->tdb, traverse_delete_low_rsn, &p->rsn);
+	if (ret < 0) {
+		DEBUG(0,(__location__ " traverse failed in ctdb_control_delete_low_rsn\n"));
+		return -1;
+	}
+
+	ctdb_lock_all_databases_unmark(ctdb);
+
+	return 0;
+}
+
+
+/*
+  try and get the recovery lock in shared storage - should only work
+  on the recovery master recovery daemon. Anywhere else is a bug
+ */
+bool ctdb_recovery_lock(struct ctdb_context *ctdb, bool keep)
+{
+	struct flock lock;
+
+	if (ctdb->recovery_lock_fd != -1) {
+		close(ctdb->recovery_lock_fd);
+	}
+	ctdb->recovery_lock_fd = open(ctdb->recovery_lock_file, O_RDWR|O_CREAT, 0600);
+	if (ctdb->recovery_lock_fd == -1) {
+		DEBUG(0,("Unable to open %s - (%s)\n", 
+			 ctdb->recovery_lock_file, strerror(errno)));
+		return false;
+	}
+
+	lock.l_type = F_WRLCK;
+	lock.l_whence = SEEK_SET;
+	lock.l_start = 0;
+	lock.l_len = 1;
+	lock.l_pid = 0;
+
+	if (fcntl(ctdb->recovery_lock_fd, F_SETLK, &lock) != 0) {
+		return false;
+	}
+
+	if (!keep) {
+		close(ctdb->recovery_lock_fd);
+		ctdb->recovery_lock_fd = -1;
+	}
+
+	return true;
+}