Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 350 insertions, 0 deletions

diff --git a/ctdb/server/ctdb_lock_helper.c b/ctdb/server/ctdb_lock_helper.c
new file mode 100644
index 0000000..51d2992
--- /dev/null
+++ b/ctdb/server/ctdb_lock_helper.c
@@ -0,0 +1,350 @@
+/*
+   ctdb lock helper
+
+   Copyright (C) Amitay Isaacs  2013
+
+   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/filesys.h"
+#include "system/network.h"
+#include "system/wait.h"
+
+#include <talloc.h>
+#include <tevent.h>
+#include <tdb.h>
+
+#include "lib/util/sys_rw.h"
+#include "lib/util/tevent_unix.h"
+
+#include "protocol/protocol.h"
+
+#include "common/system.h"
+
+static bool realtime = true;
+
+struct lock_state {
+	struct tdb_context *tdb;
+	TDB_DATA key;
+};
+
+static void set_priority(void)
+{
+	const char *ptr;
+
+	ptr = getenv("CTDB_NOSETSCHED");
+	if (ptr != NULL) {
+		realtime = false;
+	}
+
+	if (! realtime) {
+		return;
+	}
+
+	realtime = set_scheduler();
+	if (! realtime) {
+		fprintf(stderr,
+			"locking: Unable to set real-time scheduler priority\n");
+	}
+}
+
+static void reset_priority(void)
+{
+	if (realtime) {
+		reset_scheduler();
+	}
+}
+
+static void send_result(int fd, char result)
+{
+	sys_write(fd, &result, 1);
+	if (result == 1) {
+		exit(1);
+	}
+}
+
+
+static void usage(const char *progname)
+{
+	fprintf(stderr, "\n");
+	fprintf(stderr, "Usage: %s <ctdbd-pid> <output-fd> RECORD <db-path> <db-flags> <db-key>\n", progname);
+	fprintf(stderr, "       %s <ctdbd-pid> <output-fd> DB <db-path> <db-flags>\n", progname);
+}
+
+static uint8_t *hex_decode_talloc(TALLOC_CTX *mem_ctx,
+				  const char *hex_in, size_t *len)
+{
+	unsigned int i;
+	int num;
+	uint8_t *buffer;
+
+	*len = strlen(hex_in) / 2;
+	buffer = talloc_array(mem_ctx, unsigned char, *len);
+
+	for (i=0; i<*len; i++) {
+		sscanf(&hex_in[i*2], "%02X", &num);
+		buffer[i] = (uint8_t)num;
+	}
+
+	return buffer;
+}
+
+static int lock_record(const char *dbpath, const char *dbflags,
+		       const char *dbkey, struct lock_state *state)
+{
+	int tdb_flags;
+
+	/* No error checking since CTDB always passes sane values */
+	tdb_flags = strtol(dbflags, NULL, 0);
+
+	/* Convert hex key to key */
+	if (strcmp(dbkey, "NULL") == 0) {
+		state->key.dptr = NULL;
+		state->key.dsize = 0;
+	} else {
+		state->key.dptr = hex_decode_talloc(NULL, dbkey,
+						    &state->key.dsize);
+	}
+
+	state->tdb = tdb_open(dbpath, 0, tdb_flags, O_RDWR, 0600);
+	if (state->tdb == NULL) {
+		fprintf(stderr, "locking: Error opening database %s\n", dbpath);
+		return 1;
+	}
+
+	set_priority();
+
+	if (tdb_chainlock(state->tdb, state->key) < 0) {
+		fprintf(stderr, "locking: Error getting record lock (%s)\n",
+			tdb_errorstr(state->tdb));
+		return 1;
+	}
+
+	reset_priority();
+
+	return 0;
+
+}
+
+static int lock_db(const char *dbpath, const char *dbflags,
+		   struct lock_state *state)
+{
+	int tdb_flags;
+
+	/* No error checking since CTDB always passes sane values */
+	tdb_flags = strtol(dbflags, NULL, 0);
+
+	state->tdb = tdb_open(dbpath, 0, tdb_flags, O_RDWR, 0600);
+	if (state->tdb == NULL) {
+		fprintf(stderr, "locking: Error opening database %s\n", dbpath);
+		return 1;
+	}
+
+	set_priority();
+
+	if (tdb_lockall(state->tdb) < 0) {
+		fprintf(stderr, "locking: Error getting db lock (%s)\n",
+			tdb_errorstr(state->tdb));
+		return 1;
+	}
+
+	reset_priority();
+
+	return 0;
+}
+
+struct wait_for_parent_state {
+	struct tevent_context *ev;
+	pid_t ppid;
+};
+
+static void wait_for_parent_check(struct tevent_req *subreq);
+
+static struct tevent_req *wait_for_parent_send(TALLOC_CTX *mem_ctx,
+					       struct tevent_context *ev,
+					       pid_t ppid)
+{
+	struct tevent_req *req, *subreq;
+	struct wait_for_parent_state *state;
+
+	req = tevent_req_create(mem_ctx, &state, struct wait_for_parent_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	state->ev = ev;
+	state->ppid = ppid;
+
+	if (ppid == 1) {
+		tevent_req_done(req);
+		return tevent_req_post(req, ev);
+	}
+
+	subreq = tevent_wakeup_send(state, ev,
+				    tevent_timeval_current_ofs(5,0));
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, wait_for_parent_check, req);
+
+	return req;
+}
+
+static void wait_for_parent_check(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct wait_for_parent_state *state = tevent_req_data(
+		req, struct wait_for_parent_state);
+	bool status;
+
+	status = tevent_wakeup_recv(subreq);
+	TALLOC_FREE(subreq);
+	if (! status) {
+		/* Ignore error */
+		fprintf(stderr, "locking: tevent_wakeup_recv() failed\n");
+	}
+
+	if (kill(state->ppid, 0) == -1 && errno == ESRCH) {
+		tevent_req_done(req);
+		return;
+	}
+
+	subreq = tevent_wakeup_send(state, state->ev,
+				    tevent_timeval_current_ofs(5,0));
+	if (tevent_req_nomem(subreq, req)) {
+		return;
+	}
+	tevent_req_set_callback(subreq, wait_for_parent_check, req);
+}
+
+static bool wait_for_parent_recv(struct tevent_req *req, int *perr)
+{
+	if (tevent_req_is_unix_error(req, perr)) {
+		return false;
+	}
+
+	return true;
+}
+
+static void cleanup(struct lock_state *state)
+{
+	if (state->tdb != NULL) {
+		if (state->key.dsize == 0) {
+			tdb_unlockall(state->tdb);
+		} else {
+			tdb_chainunlock(state->tdb, state->key);
+		}
+		tdb_close(state->tdb);
+	}
+}
+
+static void signal_handler(struct tevent_context *ev,
+			   struct tevent_signal *se,
+			   int signum, int count, void *siginfo,
+			   void *private_data)
+{
+	struct lock_state *state = (struct lock_state *)private_data;
+
+	cleanup(state);
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	struct tevent_context *ev;
+	struct tevent_signal *se;
+	struct tevent_req *req;
+	struct lock_state state = { 0 };
+	int write_fd;
+	char result = 0;
+	int ppid;
+	const char *lock_type;
+	bool status;
+	int err;
+
+	reset_scheduler();
+
+	if (argc < 4) {
+		usage(argv[0]);
+		exit(1);
+	}
+
+	ppid = atoi(argv[1]);
+	write_fd = atoi(argv[2]);
+	lock_type = argv[3];
+
+	ev = tevent_context_init(NULL);
+	if (ev == NULL) {
+		fprintf(stderr, "locking: tevent_context_init() failed\n");
+		exit(1);
+	}
+
+	se = tevent_add_signal(ev, ev, SIGTERM, 0,
+			       signal_handler, &state);
+	if (se == NULL) {
+		fprintf(stderr, "locking: tevent_add_signal() failed\n");
+		talloc_free(ev);
+		exit(1);
+	}
+
+	if (strcmp(lock_type, "RECORD") == 0) {
+		if (argc != 7) {
+			fprintf(stderr,
+				"locking: Invalid number of arguments (%d)\n",
+				argc);
+			usage(argv[0]);
+			exit(1);
+		}
+		result = lock_record(argv[4], argv[5], argv[6], &state);
+
+	} else if (strcmp(lock_type, "DB") == 0) {
+		if (argc != 6) {
+			fprintf(stderr,
+				"locking: Invalid number of arguments (%d)\n",
+				argc);
+			usage(argv[0]);
+			exit(1);
+		}
+		result = lock_db(argv[4], argv[5], &state);
+
+	} else {
+		fprintf(stderr, "locking: Invalid lock-type '%s'\n", lock_type);
+		usage(argv[0]);
+		exit(1);
+	}
+
+	send_result(write_fd, result);
+
+	req = wait_for_parent_send(ev, ev, ppid);
+	if (req == NULL) {
+		fprintf(stderr, "locking: wait_for_parent_send() failed\n");
+		cleanup(&state);
+		exit(1);
+	}
+
+	tevent_req_poll(req, ev);
+
+	status = wait_for_parent_recv(req, &err);
+	if (! status) {
+		fprintf(stderr,
+			"locking: wait_for_parent_recv() failed (%d)\n",
+			err);
+	}
+
+	talloc_free(ev);
+	cleanup(&state);
+	return 0;
+}