lxc: add --statefile opt to lxc-checkpoint/restart

src/lxc/checkpoint.c

@@ -25,7 +25,8 @@
 
 lxc_log_define(lxc_checkpoint, lxc);
 
-int lxc_checkpoint(const char *name, const char *statefile, int flags)
+int lxc_checkpoint(const char *name, int sfd, int flags)
 {
-	return 0;
+	ERROR("'checkpoint' function not implemented");
+	return -1;
 }

src/lxc/lxc.h

@@ -142,23 +142,23 @@ extern const char *lxc_strerror(int error);
 /*
  * Checkpoint a container
  * @name : the name of the container being checkpointed
- * @statefile: string object on which the container is checkpointed
+ * @sfd: fd on which the container is checkpointed
  * @flags : checkpoint flags (an ORed value)
  * Returns 0 on success, < 0 otherwise
  */
-extern int lxc_checkpoint(const char *name, const char *statefile, int flags);
+extern int lxc_checkpoint(const char *name, int sfd, int flags);
 #define LXC_FLAG_PAUSE 1
 #define LXC_FLAG_HALT  2
 
 /*
  * Restart a container
  * @name : the name of the container being restarted
- * @statefile: string object from which the container is restarted
+ * @sfd: fd from which the container is restarted
  * @conf: lxc_conf structure.
  * @flags : restart flags (an ORed value)
  * Returns 0 on success, < 0 otherwise
  */
-extern int lxc_restart(const char *, const char *, struct lxc_conf *, int);
+extern int lxc_restart(const char *, int, struct lxc_conf *, int);
 
 /*
  * Returns the version number of the library

src/lxc/lxc_checkpoint.c

@@ -27,6 +27,7 @@
 #include <errno.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <fcntl.h>
 
 #include <lxc/lxc.h>
 #include <lxc/log.h>
@@ -52,7 +53,7 @@ static int my_parser(struct lxc_arguments* args, int c, char* arg)
 	switch (c) {
 	case 'k': args->flags = LXC_FLAG_HALT; break;
 	case 'p': args->flags = LXC_FLAG_PAUSE; break;
-	case 'd': args->statefile = arg; break;
+	case 'S': args->statefile = arg; break;
 	}
 	return 0;
 }
@@ -60,14 +61,14 @@ static int my_parser(struct lxc_arguments* args, int c, char* arg)
 static const struct option my_longopts[] = {
 	{"kill", no_argument, 0, 'k'},
 	{"pause", no_argument, 0, 'p'},
-	{"directory", required_argument, 0, 'd'},
+	{"statefile", required_argument, 0, 'S'},
 	LXC_COMMON_OPTIONS
 };
 
 static struct lxc_arguments my_args = {
 	.progname = "lxc-checkpoint",
 	.help     = "\
---name=NAME --directory STATEFILE\n\
+--name=NAME --statefile STATEFILE\n\
 \n\
 lxc-checkpoint checkpoints in STATEFILE the NAME container\n\
 \n\
@@ -75,7 +76,7 @@ Options :\n\
   -n, --name=NAME      NAME for name of the container\n\
   -k, --kill           stop the container after checkpoint\n\
   -p, --pause          don't unfreeze the container after the checkpoint\n\
-  -d, --directory=STATEFILE where to store the statefile\n",
+  -S, --statefile=STATEFILE file in which to store the statefile\n",
 
 	.options  = my_longopts,
 	.parser   = my_parser,
@@ -84,19 +85,10 @@ Options :\n\
 	.rcfile   = NULL,
 };
 
-static int create_statefile(const char *dir)
-{
-	if (mkdir(dir, 0700) == -1 && errno != EEXIST) {
-		ERROR("'%s' creation error : %m", dir);
-		return -1;
-	}
-
-	return 0;
-}
-
 int main(int argc, char *argv[])
 {
 	int ret;
+	int sfd = -1;
 
 	ret = lxc_arguments_parse(&my_args, argc, argv);
 	if (ret)
@@ -107,11 +99,14 @@ int main(int argc, char *argv[])
 	if (ret)
 		return ret;
 
-	ret = create_statefile(my_args.statefile);
-	if (ret)
-		return ret;
+#define OPEN_WRITE_MODE O_CREAT | O_RDWR | O_EXCL | O_CLOEXEC | O_LARGEFILE
+	sfd = open(my_args.statefile, OPEN_WRITE_MODE, 0600);
+	if (sfd < 0) {
+		ERROR("'%s' open failure : %m", my_args.statefile);
+		return sfd;
+	}
 
-	ret = lxc_checkpoint(my_args.name, my_args.statefile, my_args.flags);
+	ret = lxc_checkpoint(my_args.name, sfd, my_args.flags);
 	if (ret)
 		ERROR("failed to checkpoint '%s'", my_args.name);
 	else

src/lxc/lxc_restart.c

@@ -27,6 +27,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <sys/types.h>
+#include <fcntl.h>
 
 #include "log.h"
 #include "lxc.h"
@@ -52,7 +53,7 @@ static int my_checker(const struct lxc_arguments* args)
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
 	switch (c) {
-	case 'd': args->statefile = arg; break;
+	case 'S': args->statefile = arg; break;
 	case 'f': args->rcfile = arg; break;
 	case 'p': args->flags = LXC_FLAG_PAUSE; break;
 	case 's': return lxc_config_define_add(&defines, arg);
@@ -62,7 +63,7 @@ static int my_parser(struct lxc_arguments* args, int c, char* arg)
 }
 
 static const struct option my_longopts[] = {
-	{"directory", required_argument, 0, 'd'},
+	{"statefile", required_argument, 0, 'S'},
 	{"rcfile", required_argument, 0, 'f'},
 	{"pause", no_argument, 0, 'p'},
 	{"define", required_argument, 0, 's'},
@@ -72,14 +73,14 @@ static const struct option my_longopts[] = {
 static struct lxc_arguments my_args = {
 	.progname = "lxc-restart",
 	.help     = "\
---name=NAME --directory STATEFILE\n\
+--name=NAME --statefile STATEFILE\n\
 \n\
 lxc-restart restarts from STATEFILE the NAME container\n\
 \n\
 Options :\n\
   -n, --name=NAME      NAME for name of the container\n\
   -p, --pause          do not release the container after the restart\n\
-  -d, --directory=STATEFILE for name of statefile\n\
+  -S, --statefile=STATEFILE file from which to read data\n\
   -f, --rcfile=FILE Load configuration file FILE\n\
   -s, --define KEY=VAL Assign VAL to configuration variable KEY\n",
 	.options  = my_longopts,
@@ -89,6 +90,7 @@ Options :\n\
 
 int main(int argc, char *argv[])
 {
+	int sfd = -1;
 	char *rcfile = NULL;
 	struct lxc_conf *conf;
 
@@ -131,6 +133,12 @@ int main(int argc, char *argv[])
 	if (lxc_config_define_load(&defines, conf))
 		return -1;
 
-	return lxc_restart(my_args.name, my_args.statefile, conf,
-			   my_args.flags);
+#define OPEN_READ_MODE O_RDONLY | O_CLOEXEC | O_LARGEFILE
+	sfd = open(my_args.statefile, OPEN_READ_MODE, 0);
+	if (sfd < 0) {
+		ERROR("'%s' open failure : %m", my_args.statefile);
+		return sfd;
+	}
+
+	return lxc_restart(my_args.name, sfd, conf, my_args.flags);
 }

src/lxc/restart.c

@@ -25,8 +25,8 @@
 
 lxc_log_define(lxc_restart, lxc);
 
-int lxc_restart(const char *name, const char *statefile, struct lxc_conf *conf,
-		int flags)
+int lxc_restart(const char *name, int sfd, struct lxc_conf *conf, int flags)
 {
-	return 0;
+	ERROR("'restart' function not implemented");
+	return -1;
 }