From b47b0201f3b1bb346ca5088f0cbf9b53ee483b3c Mon Sep 17 00:00:00 2001
From: Pavel Emelyanov <xemul@parallels.com>
Date: Thu, 4 Sep 2014 20:39:07 +0400
Subject: [PATCH] page-server: Don't setup options in parent task

When service starts page server all the preparations (log, wdir, img dir, etc.)
happen in parent task, then we fork page server.

This is OK for now, but when we will serve several requests per connection, all
these resources would be leaked in parent.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
---
 cr-service.c        | 29 ++++++++++++++++++++++++-----
 crtools.c           |  2 +-
 include/page-xfer.h |  2 +-
 include/util.h      |  2 +-
 page-xfer.c         |  4 ++--
 util.c              |  8 +++++++-
 6 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/cr-service.c b/cr-service.c
index bbf4edd32..43840d611 100644
--- a/cr-service.c
+++ b/cr-service.c
@@ -496,7 +496,7 @@ static int pre_dump_loop(int sk, CriuReq *msg)
 
 static int start_page_server_req(int sk, CriuOpts *req)
 {
-	int ret;
+	int ret, pid, start_pipe[2];
 	bool success = false;
 	CriuResp resp = CRIU_RESP__INIT;
 	CriuPageServerInfo ps = CRIU_PAGE_SERVER_INFO__INIT;
@@ -506,14 +506,33 @@ static int start_page_server_req(int sk, CriuOpts *req)
 		goto out;
 	}
 
-	if (setup_opts_from_req(sk, req))
+	if (pipe(start_pipe)) {
+		pr_perror("No start pipe");
 		goto out;
+	}
 
-	setproctitle("page-server --rpc --address %s --port %hu", opts.addr, opts.ps_port);
+	pid = fork();
+	if (pid == 0) {
+		close(start_pipe[0]);
 
-	pr_debug("Starting page server\n");
+		if (setup_opts_from_req(sk, req))
+			goto out_ch;
 
-	ret = cr_page_server(true);
+		setproctitle("page-server --rpc --address %s --port %hu", opts.addr, opts.ps_port);
+
+		pr_debug("Starting page server\n");
+
+		ret = cr_page_server(true, start_pipe[1]);
+out_ch:
+		write(start_pipe[1], &ret, sizeof(ret));
+		close(start_pipe[1]);
+		exit(0);
+	}
+
+	close(start_pipe[1]);
+	wait(NULL);
+	ret = -1;
+	read(start_pipe[0], &ret, sizeof(ret));
 	if (ret > 0) {
 		success = true;
 		ps.has_pid = true;
diff --git a/crtools.c b/crtools.c
index 8528cbc16..1c31392d5 100644
--- a/crtools.c
+++ b/crtools.c
@@ -496,7 +496,7 @@ int main(int argc, char *argv[], char *envp[])
 	}
 
 	if (!strcmp(argv[optind], "page-server"))
-		return cr_page_server(opts.restore_detach) > 0 ? 0 : 1;
+		return cr_page_server(opts.restore_detach, -1) > 0 ? 0 : 1;
 
 	if (!strcmp(argv[optind], "service"))
 		return cr_service(opts.restore_detach);
diff --git a/include/page-xfer.h b/include/page-xfer.h
index 9e66261e6..d90093204 100644
--- a/include/page-xfer.h
+++ b/include/page-xfer.h
@@ -2,7 +2,7 @@
 #define __CR_PAGE_XFER__H__
 #include "page-read.h"
 
-extern int cr_page_server(bool daemon_mode);
+extern int cr_page_server(bool daemon_mode, int cfd);
 
 /*
  * page_xfer -- transfer pages into image file.
diff --git a/include/util.h b/include/util.h
index 732605c72..eb5e35fc9 100644
--- a/include/util.h
+++ b/include/util.h
@@ -263,7 +263,7 @@ extern void *shmalloc(size_t bytes);
 extern void shfree_last(void *ptr);
 
 extern int cr_system(int in, int out, int err, char *cmd, char *const argv[]);
-extern int cr_daemon(int nochdir, int noclose);
+extern int cr_daemon(int nochdir, int noclose, int *keep_fd, int close_fd);
 extern int is_root_user(void);
 
 static inline bool dir_dots(struct dirent *de)
diff --git a/page-xfer.c b/page-xfer.c
index 3e38cccb0..3aefb61e0 100644
--- a/page-xfer.c
+++ b/page-xfer.c
@@ -254,7 +254,7 @@ static int get_sockaddr_in(struct sockaddr_in *addr)
 	return 0;
 }
 
-int cr_page_server(bool daemon_mode)
+int cr_page_server(bool daemon_mode, int cfd)
 {
 	int sk = -1, ask = -1, ret;
 	struct sockaddr_in saddr, caddr;
@@ -292,7 +292,7 @@ int cr_page_server(bool daemon_mode)
 
 no_server:
 	if (daemon_mode) {
-		ret = cr_daemon(1, 0);
+		ret = cr_daemon(1, 0, &ask, cfd);
 		if (ret == -1) {
 			pr_perror("Can't run in the background");
 			goto out;
diff --git a/util.c b/util.c
index ad153b566..3fae835fd 100644
--- a/util.c
+++ b/util.c
@@ -560,7 +560,7 @@ out:
 	return ret;
 }
 
-int cr_daemon(int nochdir, int noclose)
+int cr_daemon(int nochdir, int noclose, int *keep_fd, int close_fd)
 {
 	int pid;
 
@@ -580,6 +580,12 @@ int cr_daemon(int nochdir, int noclose)
 	if (!noclose) {
 		int fd;
 
+		if (close_fd != -1)
+			close(close_fd);
+
+		if (*keep_fd != -1)
+			*keep_fd = dup2(*keep_fd, 3);
+
 		fd = open("/dev/null", O_RDWR);
 		if (fd < 0) {
 			pr_perror("Can't open /dev/null");