s3-g_lock: Use dbwrap_record_watch_send/recv

This simplifies the g_lock implementation. The new implementation tries to
acquire a lock. If that fails due to a lock conflict, wait for the g_lock
record to change. Upon change, just try again. The old logic had to cope with
pending records and an ugly hack into ctdb itself. As a bonus, we now get a
really clean async g_lock_lock_send/recv that can asynchronously wait for a
global lock. This would have been almost impossible to do without the
dbwrap_record_watch infrastructure.

1 files changed, 170 insertions, 446 deletions

diff --git a/source3/lib/g_lock.c b/source3/lib/g_lock.c
index 1011584a25..06a14fac6c 100644
--- a/source3/lib/g_lock.c
+++ b/source3/lib/g_lock.c
@@ -21,16 +21,15 @@
 #include "system/filesys.h"
 #include "dbwrap/dbwrap.h"
 #include "dbwrap/dbwrap_open.h"
+#include "dbwrap/dbwrap_watch.h"
 #include "g_lock.h"
 #include "util_tdb.h"
 #include "ctdbd_conn.h"
 #include "../lib/util/select.h"
+#include "../lib/util/tevent_ntstatus.h"
 #include "system/select.h"
 #include "messages.h"
 
-static NTSTATUS g_lock_force_unlock(struct g_lock_ctx *ctx, const char *name,
-				    struct server_id pid);
-
 struct g_lock_ctx {
 	struct db_context *db;
 	struct messaging_context *msg;
@@ -39,7 +38,7 @@ struct g_lock_ctx {
 /*
  * The "g_lock.tdb" file contains records, indexed by the 0-terminated
  * lockname. The record contains an array of "struct g_lock_rec"
- * structures. Waiters have the lock_type with G_LOCK_PENDING or'ed.
+ * structures.
  */
 
 struct g_lock_rec {
@@ -67,453 +66,248 @@ struct g_lock_ctx *g_lock_ctx_init(TALLOC_CTX *mem_ctx,
 		TALLOC_FREE(result);
 		return NULL;
 	}
+	dbwrap_watch_db(result->db, msg);
 	return result;
 }
 
-static bool g_lock_conflicts(enum g_lock_type lock_type,
-			     const struct g_lock_rec *rec)
+static bool g_lock_conflicts(enum g_lock_type l1, enum g_lock_type l2)
 {
-	enum g_lock_type rec_lock = rec->lock_type;
-
-	if ((rec_lock & G_LOCK_PENDING) != 0) {
-		return false;
-	}
-
 	/*
 	 * Only tested write locks so far. Very likely this routine
 	 * needs to be fixed for read locks....
 	 */
-	if ((lock_type == G_LOCK_READ) && (rec_lock == G_LOCK_READ)) {
+	if ((l1 == G_LOCK_READ) && (l2 == G_LOCK_READ)) {
 		return false;
 	}
 	return true;
 }
 
 static bool g_lock_parse(TALLOC_CTX *mem_ctx, TDB_DATA data,
-			 int *pnum_locks, struct g_lock_rec **plocks)
+			 unsigned *pnum_locks, struct g_lock_rec **plocks)
 {
-	int i, num_locks;
+	unsigned num_locks;
 	struct g_lock_rec *locks;
 
 	if ((data.dsize % sizeof(struct g_lock_rec)) != 0) {
 		DEBUG(1, ("invalid lock record length %d\n", (int)data.dsize));
 		return false;
 	}
-
 	num_locks = data.dsize / sizeof(struct g_lock_rec);
-	locks = talloc_array(mem_ctx, struct g_lock_rec, num_locks);
+	locks = talloc_memdup(mem_ctx, data.dptr, data.dsize);
 	if (locks == NULL) {
-		DEBUG(1, ("talloc failed\n"));
+		DEBUG(1, ("talloc_memdup failed\n"));
 		return false;
 	}
-
-	memcpy(locks, data.dptr, data.dsize);
-
-	DEBUG(10, ("locks:\n"));
-	for (i=0; i<num_locks; i++) {
-		DEBUGADD(10, ("%s: %s %s\n",
-			      server_id_str(talloc_tos(), &locks[i].pid),
-			      ((locks[i].lock_type & 1) == G_LOCK_READ) ?
-			      "read" : "write",
-			      (locks[i].lock_type & G_LOCK_PENDING) ?
-			      "(pending)" : "(owner)"));
-
-		if (((locks[i].lock_type & G_LOCK_PENDING) == 0)
-		    && !process_exists(locks[i].pid)) {
-
-			DEBUGADD(10, ("lock owner %s died -- discarding\n",
-				      server_id_str(talloc_tos(),
-						 &locks[i].pid)));
-
-			if (i < (num_locks-1)) {
-				locks[i] = locks[num_locks-1];
-			}
-			num_locks -= 1;
-		}
-	}
-
 	*plocks = locks;
 	*pnum_locks = num_locks;
 	return true;
 }
 
-static void g_lock_cleanup(int *pnum_locks, struct g_lock_rec *locks)
+static NTSTATUS g_lock_trylock(struct db_record *rec, struct server_id self,
+			       enum g_lock_type type)
 {
-	int i, num_locks;
+	TDB_DATA data;
+	unsigned i, num_locks;
+	struct g_lock_rec *locks, *tmp;
+	NTSTATUS status;
+	bool modified = false;
 
-	num_locks = *pnum_locks;
+	data = dbwrap_record_get_value(rec);
 
-	DEBUG(10, ("g_lock_cleanup: %d locks\n", num_locks));
+	if (!g_lock_parse(talloc_tos(), data, &num_locks, &locks)) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
 
 	for (i=0; i<num_locks; i++) {
-		if (process_exists(locks[i].pid)) {
-			continue;
+		if (procid_equal(&self, &locks[i].pid)) {
+			status = NT_STATUS_INTERNAL_ERROR;
+			goto done;
 		}
-		DEBUGADD(10, ("%s does not exist -- discarding\n",
-			      server_id_str(talloc_tos(), &locks[i].pid)));
+		if (g_lock_conflicts(type, locks[i].lock_type)) {
 
-		if (i < (num_locks-1)) {
+			if (process_exists(locks[i].pid)) {
+				status = NT_STATUS_LOCK_NOT_GRANTED;
+				goto done;
+			}
+
+			/*
+			 * Delete stale conflicting entry
+			 */
 			locks[i] = locks[num_locks-1];
+			num_locks -= 1;
+			modified = true;
 		}
-		num_locks -= 1;
 	}
-	*pnum_locks = num_locks;
-	return;
-}
 
-static struct g_lock_rec *g_lock_addrec(TALLOC_CTX *mem_ctx,
-					struct g_lock_rec *locks,
-					int *pnum_locks,
-					const struct server_id pid,
-					enum g_lock_type lock_type)
-{
-	struct g_lock_rec *result;
-	int num_locks = *pnum_locks;
-
-	result = talloc_realloc(mem_ctx, locks, struct g_lock_rec,
-				num_locks+1);
-	if (result == NULL) {
-		return NULL;
+	tmp = talloc_realloc(talloc_tos(), locks, struct g_lock_rec,
+			     num_locks+1);
+	if (tmp == NULL) {
+		status = NT_STATUS_NO_MEMORY;
+		goto done;
 	}
+	locks = tmp;
 
-	result[num_locks].pid = pid;
-	result[num_locks].lock_type = lock_type;
-	*pnum_locks += 1;
-	return result;
+	ZERO_STRUCT(locks[num_locks]);
+	locks[num_locks].pid = self;
+	locks[num_locks].lock_type = type;
+	num_locks += 1;
+	modified = true;
+
+	status = NT_STATUS_OK;
+done:
+	if (modified) {
+		NTSTATUS store_status;
+
+		data = make_tdb_data((uint8_t *)locks, num_locks * sizeof(*locks));
+		store_status = dbwrap_record_store(rec, data, 0);
+		if (!NT_STATUS_IS_OK(store_status)) {
+			DEBUG(1, ("rec->store failed: %s\n",
+				  nt_errstr(store_status)));
+			status = store_status;
+		}
+	}
+	TALLOC_FREE(locks);
+	return status;
 }
 
-static void g_lock_got_retry(struct messaging_context *msg,
-			     void *private_data,
-			     uint32_t msg_type,
-			     struct server_id server_id,
-			     DATA_BLOB *data);
+struct g_lock_lock_state {
+	struct tevent_context *ev;
+	struct g_lock_ctx *ctx;
+	const char *name;
+	enum g_lock_type type;
+};
+
+static void g_lock_lock_retry(struct tevent_req *subreq);
 
-static NTSTATUS g_lock_trylock(struct g_lock_ctx *ctx, const char *name,
-			       enum g_lock_type lock_type)
+struct tevent_req *g_lock_lock_send(TALLOC_CTX *mem_ctx,
+				    struct tevent_context *ev,
+				    struct g_lock_ctx *ctx,
+				    const char *name,
+				    enum g_lock_type type)
 {
-	struct db_record *rec = NULL;
-	struct g_lock_rec *locks = NULL;
-	int i, num_locks;
+	struct tevent_req *req, *subreq;
+	struct g_lock_lock_state *state;
+	struct db_record *rec;
 	struct server_id self;
-	int our_index;
-	TDB_DATA data;
-	NTSTATUS status = NT_STATUS_OK;
-	NTSTATUS store_status;
-	TDB_DATA value;
+	NTSTATUS status;
+
+	req = tevent_req_create(mem_ctx, &state, struct g_lock_lock_state);
+	if (req == NULL) {
+		return NULL;
+	}
+	state->ev = ev;
+	state->ctx = ctx;
+	state->name = name;
+	state->type = type;
 
-again:
 	rec = dbwrap_fetch_locked(ctx->db, talloc_tos(),
-				  string_term_tdb_data(name));
+				  string_term_tdb_data(state->name));
 	if (rec == NULL) {
 		DEBUG(10, ("fetch_locked(\"%s\") failed\n", name));
-		status = NT_STATUS_LOCK_NOT_GRANTED;
-		goto done;
+		tevent_req_nterror(req, NT_STATUS_LOCK_NOT_GRANTED);
+		return tevent_req_post(req, ev);
 	}
 
-	value = dbwrap_record_get_value(rec);
-	if (!g_lock_parse(talloc_tos(), value, &num_locks, &locks)) {
-		DEBUG(10, ("g_lock_parse for %s failed\n", name));
-		status = NT_STATUS_INTERNAL_ERROR;
-		goto done;
-	}
-
-	self = messaging_server_id(ctx->msg);
-	our_index = -1;
+	self = messaging_server_id(state->ctx->msg);
 
-	for (i=0; i<num_locks; i++) {
-		if (procid_equal(&self, &locks[i].pid)) {
-			if (our_index != -1) {
-				DEBUG(1, ("g_lock_trylock: Added ourself "
-					  "twice!\n"));
-				status = NT_STATUS_INTERNAL_ERROR;
-				goto done;
-			}
-			if ((locks[i].lock_type & G_LOCK_PENDING) == 0) {
-				DEBUG(1, ("g_lock_trylock: Found ourself not "
-					  "pending!\n"));
-				status = NT_STATUS_INTERNAL_ERROR;
-				goto done;
-			}
-
-			our_index = i;
-
-			/* never conflict with ourself */
-			continue;
-		}
-		if (g_lock_conflicts(lock_type, &locks[i])) {
-			struct server_id pid = locks[i].pid;
-
-			if (!process_exists(pid)) {
-				TALLOC_FREE(locks);
-				TALLOC_FREE(rec);
-				status = g_lock_force_unlock(ctx, name, pid);
-				if (!NT_STATUS_IS_OK(status)) {
-					DEBUG(1, ("Could not unlock dead lock "
-						  "holder!\n"));
-					goto done;
-				}
-				goto again;
-			}
-			lock_type |= G_LOCK_PENDING;
-		}
-	}
-
-	if (our_index == -1) {
-		/* First round, add ourself */
-
-		locks = g_lock_addrec(talloc_tos(), locks, &num_locks,
-				      self, lock_type);
-		if (locks == NULL) {
-			DEBUG(10, ("g_lock_addrec failed\n"));
-			status = NT_STATUS_NO_MEMORY;
-			goto done;
-		}
-	} else {
-		/*
-		 * Retry. We were pending last time. Overwrite the
-		 * stored lock_type with what we calculated, we might
-		 * have acquired the lock this time.
-		 */
-		locks[our_index].lock_type = lock_type;
+	status = g_lock_trylock(rec, self, state->type);
+	if (NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(rec);
+		tevent_req_done(req);
+		return tevent_req_post(req, ev);
 	}
-
-	if (NT_STATUS_IS_OK(status) && ((lock_type & G_LOCK_PENDING) == 0)) {
-		/*
-		 * Walk through the list of locks, search for dead entries
-		 */
-		g_lock_cleanup(&num_locks, locks);
-	}
-
-	data = make_tdb_data((uint8_t *)locks, num_locks * sizeof(*locks));
-	store_status = dbwrap_record_store(rec, data, 0);
-	if (!NT_STATUS_IS_OK(store_status)) {
-		DEBUG(1, ("rec->store failed: %s\n",
-			  nt_errstr(store_status)));
-		status = store_status;
+	if (!NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
+		TALLOC_FREE(rec);
+		tevent_req_nterror(req, status);
+		return tevent_req_post(req, ev);
 	}
-
-done:
-	TALLOC_FREE(locks);
+	subreq = dbwrap_record_watch_send(state, state->ev, rec,
+					  state->ctx->msg);
 	TALLOC_FREE(rec);
-
-	if (NT_STATUS_IS_OK(status) && (lock_type & G_LOCK_PENDING) != 0) {
-		return STATUS_PENDING;
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
 	}
-
-	return NT_STATUS_OK;
+	tevent_req_set_callback(subreq, g_lock_lock_retry, req);
+	return req;
 }
 
-NTSTATUS g_lock_lock(struct g_lock_ctx *ctx, const char *name,
-		     enum g_lock_type lock_type, struct timeval timeout)
+static void g_lock_lock_retry(struct tevent_req *subreq)
 {
-	struct tevent_timer *te = NULL;
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct g_lock_lock_state *state = tevent_req_data(
+		req, struct g_lock_lock_state);
+	struct server_id self = messaging_server_id(state->ctx->msg);
+	struct db_record *rec;
 	NTSTATUS status;
-	bool retry = false;
-	struct timeval timeout_end;
-	struct timeval time_now;
-
-	DEBUG(10, ("Trying to acquire lock %d for %s\n", (int)lock_type,
-		   name));
 
-	if (lock_type & ~1) {
-		DEBUG(1, ("Got invalid lock type %d for %s\n",
-			  (int)lock_type, name));
-		return NT_STATUS_INVALID_PARAMETER;
+	status = dbwrap_record_watch_recv(subreq, talloc_tos(), &rec);
+	TALLOC_FREE(subreq);
+	if (tevent_req_nterror(req, status)) {
+		return;
 	}
-
-#ifdef CLUSTER_SUPPORT
-	if (lp_clustering()) {
-		status = ctdb_watch_us(messaging_ctdbd_connection());
-		if (!NT_STATUS_IS_OK(status)) {
-			DEBUG(10, ("could not register retry with ctdb: %s\n",
-				   nt_errstr(status)));
-			goto done;
-		}
+	status = g_lock_trylock(rec, self, state->type);
+	if (NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(rec);
+		tevent_req_done(req);
+		return;
 	}
-#endif
-
-	status = messaging_register(ctx->msg, &retry, MSG_DBWRAP_G_LOCK_RETRY,
-				    g_lock_got_retry);
-	if (!NT_STATUS_IS_OK(status)) {
-		DEBUG(10, ("messaging_register failed: %s\n",
-			   nt_errstr(status)));
-		return status;
+	if (!NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
+		TALLOC_FREE(rec);
+		tevent_req_nterror(req, status);
+		return;
 	}
-
-	time_now = timeval_current();
-	timeout_end = timeval_sum(&time_now, &timeout);
-
-	while (true) {
-		struct pollfd *pollfds;
-		int num_pollfds;
-		int saved_errno;
-		int ret;
-		struct timeval timeout_remaining, select_timeout;
-
-		status = g_lock_trylock(ctx, name, lock_type);
-		if (NT_STATUS_IS_OK(status)) {
-			DEBUG(10, ("Got lock %s\n", name));
-			break;
-		}
-		if (!NT_STATUS_EQUAL(status, STATUS_PENDING)) {
-			DEBUG(10, ("g_lock_trylock failed: %s\n",
-				   nt_errstr(status)));
-			break;
-		}
-
-		DEBUG(10, ("g_lock_trylock: Did not get lock, waiting...\n"));
-
-		/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-		 *             !!! HACK ALERT --- FIX ME !!!
-		 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-		 * What we really want to do here is to react to
-		 * MSG_DBWRAP_G_LOCK_RETRY messages that are either sent
-		 * by a client doing g_lock_unlock or by ourselves when
-		 * we receive a CTDB_SRVID_SAMBA_NOTIFY or
-		 * CTDB_SRVID_RECONFIGURE message from ctdbd, i.e. when
-		 * either a client holding a lock or a complete node
-		 * has died.
-		 *
-		 * Doing this properly involves calling tevent_loop_once(),
-		 * but doing this here with the main ctdbd messaging context
-		 * creates a nested event loop when g_lock_lock() is called
-		 * from the main event loop, e.g. in a tcon_and_X where the
-		 * share_info.tdb needs to be initialized and is locked by
-		 * another process, or when the remore registry is accessed
-		 * for writing and some other process already holds a lock
-		 * on the registry.tdb.
-		 *
-		 * So as a quick fix, we act a little coarsely here: we do
-		 * a select on the ctdb connection fd and when it is readable
-		 * or we get EINTR, then we retry without actually parsing
-		 * any ctdb packages or dispatching messages. This means that
-		 * we retry more often than intended by design, but this does
-		 * not harm and it is unobtrusive. When we have finished,
-		 * the main loop will pick up all the messages and ctdb
-		 * packets. The only extra twist is that we cannot use timed
-		 * events here but have to handcode a timeout.
-		 */
-
-		/*
-		 * We allocate 1 entries here. In the clustering case
-		 * we might have to add the ctdb fd. This avoids the
-		 * realloc then.
-		 */
-		pollfds = talloc_array(talloc_tos(), struct pollfd, 1);
-		if (pollfds == NULL) {
-			status = NT_STATUS_NO_MEMORY;
-			break;
-		}
-		num_pollfds = 0;
-
-#ifdef CLUSTER_SUPPORT
-		if (lp_clustering()) {
-			struct ctdbd_connection *conn;
-			conn = messaging_ctdbd_connection();
-
-			pollfds[0].fd = ctdbd_conn_get_fd(conn);
-			pollfds[0].events = POLLIN|POLLHUP;
-
-			num_pollfds += 1;
-		}
-#endif
-
-		time_now = timeval_current();
-		timeout_remaining = timeval_until(&time_now, &timeout_end);
-		select_timeout = timeval_set(60, 0);
-
-		select_timeout = timeval_min(&select_timeout,
-					     &timeout_remaining);
-
-		ret = poll(pollfds, num_pollfds,
-			   timeval_to_msec(select_timeout));
-
-		/*
-		 * We're not *really interested in the actual flags. We just
-		 * need to retry this whole thing.
-		 */
-		saved_errno = errno;
-		TALLOC_FREE(pollfds);
-		errno = saved_errno;
-
-		if (ret == -1) {
-			if (errno != EINTR) {
-				DEBUG(1, ("error calling select: %s\n",
-					  strerror(errno)));
-				status = NT_STATUS_INTERNAL_ERROR;
-				break;
-			}
-			/*
-			 * errno == EINTR:
-			 * This means a signal was received.
-			 * It might have been a MSG_DBWRAP_G_LOCK_RETRY message.
-			 * ==> retry
-			 */
-		} else if (ret == 0) {
-			if (timeval_expired(&timeout_end)) {
-				DEBUG(10, ("g_lock_lock timed out\n"));
-				status = NT_STATUS_LOCK_NOT_GRANTED;
-				break;
-			} else {
-				DEBUG(10, ("select returned 0 but timeout not "
-					   "not expired, retrying\n"));
-			}
-		} else if (ret != 1) {
-			DEBUG(1, ("invalid return code of select: %d\n", ret));
-			status = NT_STATUS_INTERNAL_ERROR;
-			break;
-		}
-		/*
-		 * ret == 1:
-		 * This means ctdbd has sent us some data.
-		 * Might be a CTDB_SRVID_RECONFIGURE or a
-		 * CTDB_SRVID_SAMBA_NOTIFY message.
-		 * ==> retry
-		 */
-	}
-
-#ifdef CLUSTER_SUPPORT
-done:
-#endif
-
-	if (!NT_STATUS_IS_OK(status)) {
-		NTSTATUS unlock_status;
-
-		unlock_status = g_lock_unlock(ctx, name);
-
-		if (!NT_STATUS_IS_OK(unlock_status)) {
-			DEBUG(1, ("Could not remove ourself from the locking "
-				  "db: %s\n", nt_errstr(status)));
-		}
+	subreq = dbwrap_record_watch_send(state, state->ev, rec,
+					  state->ctx->msg);
+	if (tevent_req_nomem(subreq, req)) {
+		return;
 	}
+	tevent_req_set_callback(subreq, g_lock_lock_retry, req);
+	return;
 
-	messaging_deregister(ctx->msg, MSG_DBWRAP_G_LOCK_RETRY, &retry);
-	TALLOC_FREE(te);
-
-	return status;
 }
 
-static void g_lock_got_retry(struct messaging_context *msg,
-			     void *private_data,
-			     uint32_t msg_type,
-			     struct server_id server_id,
-			     DATA_BLOB *data)
+NTSTATUS g_lock_lock_recv(struct tevent_req *req)
 {
-	bool *pretry = (bool *)private_data;
+	return tevent_req_simple_recv_ntstatus(req);
+}
 
-	DEBUG(10, ("Got retry message from pid %s\n",
-		   server_id_str(talloc_tos(), &server_id)));
+NTSTATUS g_lock_lock(struct g_lock_ctx *ctx, const char *name,
+		     enum g_lock_type type, struct timeval timeout)
+{
+	TALLOC_CTX *frame = talloc_stackframe();
+	struct tevent_context *ev;
+	struct tevent_req *req;
+	struct timeval end;
+	NTSTATUS status = NT_STATUS_NO_MEMORY;
 
-	*pretry = true;
+	ev = tevent_context_init(frame);
+	if (ev == NULL) {
+		goto fail;
+	}
+	req = g_lock_lock_send(frame, ev, ctx, name, type);
+	if (req == NULL) {
+		goto fail;
+	}
+	end = timeval_current_ofs(timeout.tv_sec, timeout.tv_usec);
+	if (!tevent_req_set_endtime(req, ev, end)) {
+		goto fail;
+	}
+	if (!tevent_req_poll_ntstatus(req, ev, &status)) {
+		goto fail;
+	}
+	status = g_lock_lock_recv(req);
+ fail:
+	TALLOC_FREE(frame);
+	return status;
 }
 
-static NTSTATUS g_lock_force_unlock(struct g_lock_ctx *ctx, const char *name,
-				    struct server_id pid)
+NTSTATUS g_lock_unlock(struct g_lock_ctx *ctx, const char *name)
 {
+	struct server_id self = messaging_server_id(ctx->msg);
 	struct db_record *rec = NULL;
 	struct g_lock_rec *locks = NULL;
-	int i, num_locks;
-	enum g_lock_type lock_type;
+	unsigned i, num_locks;
 	NTSTATUS status;
 	TDB_DATA value;
 
@@ -532,24 +326,18 @@ static NTSTATUS g_lock_force_unlock(struct g_lock_ctx *ctx, const char *name,
 		status = NT_STATUS_FILE_INVALID;
 		goto done;
 	}
-
 	for (i=0; i<num_locks; i++) {
-		if (procid_equal(&pid, &locks[i].pid)) {
+		if (procid_equal(&self, &locks[i].pid)) {
 			break;
 		}
 	}
-
 	if (i == num_locks) {
 		DEBUG(10, ("g_lock_force_unlock: Lock not found\n"));
 		status = NT_STATUS_NOT_FOUND;
 		goto done;
 	}
 
-	lock_type = locks[i].lock_type;
-
-	if (i < (num_locks-1)) {
-		locks[i] = locks[num_locks-1];
-	}
+	locks[i] = locks[num_locks-1];
 	num_locks -= 1;
 
 	if (num_locks == 0) {
@@ -560,78 +348,19 @@ static NTSTATUS g_lock_force_unlock(struct g_lock_ctx *ctx, const char *name,
 				     sizeof(struct g_lock_rec) * num_locks);
 		status = dbwrap_record_store(rec, data, 0);
 	}
-
 	if (!NT_STATUS_IS_OK(status)) {
 		DEBUG(1, ("g_lock_force_unlock: Could not store record: %s\n",
 			  nt_errstr(status)));
 		goto done;
 	}
 
-	TALLOC_FREE(rec);
-
-	if ((lock_type & G_LOCK_PENDING) == 0) {
-		int num_wakeups = 0;
-
-		/*
-		 * We've been the lock holder. Others to retry. Don't
-		 * tell all others to avoid a thundering herd. In case
-		 * this leads to a complete stall because we miss some
-		 * processes, the loop in g_lock_lock tries at least
-		 * once a minute.
-		 */
-
-		for (i=0; i<num_locks; i++) {
-			if ((locks[i].lock_type & G_LOCK_PENDING) == 0) {
-				continue;
-			}
-			if (!process_exists(locks[i].pid)) {
-				continue;
-			}
-
-			/*
-			 * Ping all waiters to retry
-			 */
-			status = messaging_send(ctx->msg, locks[i].pid,
-						MSG_DBWRAP_G_LOCK_RETRY,
-						&data_blob_null);
-			if (!NT_STATUS_IS_OK(status)) {
-				DEBUG(1, ("sending retry to %s failed: %s\n",
-					  server_id_str(talloc_tos(),
-						     &locks[i].pid),
-					  nt_errstr(status)));
-			} else {
-				num_wakeups += 1;
-			}
-			if (num_wakeups > 5) {
-				break;
-			}
-		}
-	}
+	status = NT_STATUS_OK;
 done:
-	/*
-	 * For the error path, TALLOC_FREE(rec) as well. In the good
-	 * path we have already freed it.
-	 */
 	TALLOC_FREE(rec);
-
 	TALLOC_FREE(locks);
 	return status;
 }
 
-NTSTATUS g_lock_unlock(struct g_lock_ctx *ctx, const char *name)
-{
-	NTSTATUS status;
-
-	status = g_lock_force_unlock(ctx, name, messaging_server_id(ctx->msg));
-
-#ifdef CLUSTER_SUPPORT
-	if (lp_clustering()) {
-		ctdb_unwatch(messaging_ctdbd_connection());
-	}
-#endif
-	return status;
-}
-
 struct g_lock_locks_state {
 	int (*fn)(const char *name, void *private_data);
 	void *private_data;
@@ -676,7 +405,7 @@ NTSTATUS g_lock_dump(struct g_lock_ctx *ctx, const char *name,
 		     void *private_data)
 {
 	TDB_DATA data;
-	int i, num_locks;
+	unsigned i, num_locks;
 	struct g_lock_rec *locks = NULL;
 	bool ret;
 	NTSTATUS status;
@@ -717,11 +446,6 @@ static int g_lock_get_fn(struct server_id pid, enum g_lock_type lock_type,
 			 void *priv)
 {
 	struct g_lock_get_state *state = (struct g_lock_get_state *)priv;
-
-	if ((lock_type & G_LOCK_PENDING) != 0) {
-		return 0;
-	}
-
 	state->found = true;
 	*state->pid = pid;
 	return 1;