Remove the usage of a lock file

src/lxc/create.c

@@ -120,7 +120,7 @@ static int copy_config_file(const char *name, const char *file)
 
 int lxc_create(const char *name, const char *confile)
 {
-	int lock, err = -1;
+	int err = -1;
 
 	if (create_lxc_directory(name))
 		return err;
@@ -128,26 +128,21 @@ int lxc_create(const char *name, const char *confile)
 	if (!confile)
 		return 0;
 
-	lock = lxc_get_lock(name);
-	if (lock < 0)
-		goto err;
-
 	if (copy_config_file(name, confile)) {
 		ERROR("failed to copy the configuration file");
-		goto err_state;
+		goto err;
 	}
 
 	err = 0;
 out:
-	lxc_put_lock(lock);
 	return err;
 
-err_state:
+err:
 	lxc_unconfigure(name);
 
 	if (lxc_rmstate(name))
 		ERROR("failed to remove state file for %s", name);
-err:
+
 	if (remove_lxc_directory(name))
 		ERROR("failed to cleanup lxc directory for %s", name);
 	goto out;

src/lxc/destroy.c

@@ -71,19 +71,15 @@ static int remove_config_file(const char *name)
 
 int lxc_destroy(const char *name)
 {
-	int lock, ret = -1;
+	int ret = -1;
 	char path[MAXPATHLEN];
 
-	lock = lxc_get_lock(name);
-	if (lock < 0)
-		return ret;
-
 	if (remove_config_file(name))
 		WARN("failed to remove the configuration file");
 
 	if (lxc_rmstate(name)) {
 		ERROR("failed to remove state file for %s", name);
-		goto out_lock;
+		return -1;
 	}
 	
 #warning keep access to LXCPATH/<name> to destroy old created container
@@ -95,17 +91,13 @@ int lxc_destroy(const char *name)
 
 	if (lxc_unconfigure(name)) {
 		ERROR("failed to cleanup %s", name);
-		goto out_lock;
+		return -1;
 	}
 
 	if (remove_lxc_directory(name)) {
 		SYSERROR("failed to remove '%s'", name);
-		goto out_lock;
+		return -1;
 	}
 
-	ret = 0;
-	
-out_lock:
-	lxc_put_lock(lock);
-	return ret;
+	return 0;
 }

src/lxc/lock.c

-/*
- * lxc: linux Container library
- *
- * (C) Copyright IBM Corp. 2007, 2008
- *
- * Authors:
- * Daniel Lezcano <dlezcano at fr.ibm.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library 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
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-
-#define _GNU_SOURCE
-#include <stdio.h>
-#undef _GNU_SOURCE
-#include <errno.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <sys/file.h>
-#include <sys/param.h>
-
-#include "error.h"
-#include "config.h"
-
-#include <lxc/lxc.h>
-
-lxc_log_define(lxc_lock, lxc);
-
-static int __lxc_get_lock(const char *name)
-{
-	char lock[MAXPATHLEN];
-	int fd, ret;
-
-	snprintf(lock, MAXPATHLEN, LXCPATH "/%s", name);
-
-	/* need to check access because of cap_dac_override */
-	if (access(lock, R_OK |W_OK | X_OK))
-		return -errno;
-
-	fd = open(lock, O_RDONLY|O_DIRECTORY, S_IRUSR|S_IWUSR);
-	if (fd < 0)
-		return -errno;
-
-        fcntl(fd, F_SETFD, FD_CLOEXEC);
-
-	if (flock(fd, LOCK_EX|LOCK_NB)) {
-		ret = -errno;
-		close(fd);
-		goto out;
-	}
-
-	ret = fd;
-out:
-	return ret;
-}
-
-int lxc_get_lock(const char *name)
-{
-	int ret;
-
-	ret = __lxc_get_lock(name);
-	if (ret < 0)
-		goto out_err;
-
-	return ret;
-out_err:
-	switch (-ret) {
-	case EWOULDBLOCK:
-		ERROR("container '%s' is busy", name);
-		break;
-	case ENOENT:
-		ERROR("container '%s' is not found", name);
-		break;
-	case EACCES:
-		ERROR("not enough privilege to use container '%s'", name);
-		break;
-	default:
-		ERROR("container '%s' failed to lock : %s",
-		      name, strerror(-ret));
-	}
-	return -1;
-}
-
-int lxc_check_lock(const char *name)
-{
-	int ret;
-
-	ret = __lxc_get_lock(name);
-	if (ret >= 0) {
-		ERROR("container '%s' is not active", name);
-		lxc_put_lock(ret);
-		return -1;
-	}
-	if (ret != -EWOULDBLOCK) {
-		ERROR("container '%s' : %s", name, strerror(-ret));
-		return -1;
-	}
-	return 0;
-}
-
-void lxc_put_lock(int lock)
-{
-	flock(lock, LOCK_UN);
-	close(lock);
-}

src/lxc/lock.h

-/*
- * lxc: linux Container library
- *
- * (C) Copyright IBM Corp. 2007, 2008
- *
- * Authors:
- * Daniel Lezcano <dlezcano at fr.ibm.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library 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
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-#ifndef _lock_h
-#define _lock_h
-
-extern int lxc_get_lock(const char *name);
-extern int lxc_check_lock(const char *name);
-extern void lxc_put_lock(int lock);
-
-#endif

src/lxc/lxc.h

@@ -37,7 +37,6 @@ extern "C" {
 #include <lxc/list.h>
 #include <lxc/log.h>
 #include <lxc/conf.h>
-#include <lxc/lock.h>
 #include <lxc/namespace.h>
 #include <lxc/utils.h>
 #include <lxc/error.h>

src/lxc/start.c

@@ -246,14 +246,10 @@ struct lxc_handler *lxc_init(const char *name)
 
 	memset(handler, 0, sizeof(*handler));
 
-	handler->lock = lxc_get_lock(name);
-	if (handler->lock < 0)
-		goto out_free;
-
 	/* Begin the set the state to STARTING*/
 	if (set_state(name, handler, STARTING)) {
 		ERROR("failed to set state '%s'", lxc_state2str(STARTING));
-		goto out_put_lock;
+		goto out_free;
 	}
 
 	if (lxc_conf_init(&handler->conf)) {
@@ -302,8 +298,6 @@ out_delete_tty:
 	lxc_delete_tty(&handler->conf.tty_info);
 out_aborting:
 	set_state(name, handler, ABORTING);
-out_put_lock:
-	lxc_put_lock(handler->lock);
 out_free:
 	free(handler);
 	handler = NULL;
@@ -322,7 +316,6 @@ void lxc_fini(const char *name, struct lxc_handler *handler)
 	if (handler) {
 		remove_init_pid(name, handler->pid);
 		lxc_delete_tty(&handler->conf.tty_info);
-		lxc_put_lock(handler->lock);
 		free(handler);
 	}
 

src/lxc/start.h

@@ -27,7 +27,6 @@ struct lxc_handler {
 	lxc_state_t state;
 
 	int sigfd;
-	int lock;
 	char nsgroup[MAXPATHLEN];
 	sigset_t oldmask;
 	struct lxc_conf conf;