define a handler to manage a container

Define a handler to store the resource informations for the container.
That allows to factor out some code and will help to encapsulate a
little more the 'start' code which is too big.

Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>

diff --git a/src/lxc/start.c b/src/lxc/start.c
index bf067091ff68c6e459e39df68e73a086181fa6b0..d729ebd492d60390b3d1dc7e7db26a9ef168a3dc 100644 (file)
--- a/src/lxc/start.c
+++ b/src/lxc/start.c
@@ -95,10 +95,15 @@ int signalfd(int fd, const sigset_t *mask, int flags)
 
 lxc_log_define(lxc_start, lxc);
 
-
 LXC_TTY_HANDLER(SIGINT);
 LXC_TTY_HANDLER(SIGQUIT);
 
+struct lxc_handler {
+       int sigfd;
+       pid_t pid;
+       struct lxc_tty_info tty_info;
+};
+
 static int setup_sigchld_fd(sigset_t *oldmask)
 {
        sigset_t mask;
@@ -234,9 +239,12 @@ out_close:
        goto out;
 }
 
-static int mainloop(const char *name, pid_t pid, int sigfd,
-                   const struct lxc_tty_info *tty_info)
+static int mainloop(const char *name, struct lxc_handler *handler)
 {
+       int sigfd = handler->sigfd;
+       int pid = handler->pid;
+       const struct lxc_tty_info *tty_info = &handler->tty_info;
+
        int nfds, ttyfd = -1, ret = -1;
        struct lxc_epoll_descr descr;
 
@@ -284,13 +292,12 @@ out_sigfd:
 
 int lxc_start(const char *name, char *argv[])
 {
-       struct lxc_tty_info tty_info = { 0 };
+       struct lxc_handler handler = { 0 };
        sigset_t oldmask;
        char init[MAXPATHLEN];
        char tty[MAXPATHLEN];
        char *val = NULL;
-       int fd, sigfd, lock, sv[2], sync = 0, err = -LXC_ERROR_INTERNAL;
-       pid_t pid;
+       int fd, lock, sv[2], sync = 0, err = -LXC_ERROR_INTERNAL;
        int clone_flags;
 
        lock = lxc_get_lock(name);
@@ -308,7 +315,7 @@ int lxc_start(const char *name, char *argv[])
        if (ttyname_r(0, tty, sizeof(tty))) 
                tty[0] = '\0';
 
-       if (lxc_create_tty(name, &tty_info)) {
+       if (lxc_create_tty(name, &handler.tty_info)) {
                ERROR("failed to create the ttys");
                goto out;
        }
@@ -316,8 +323,8 @@ int lxc_start(const char *name, char *argv[])
        /* the signal fd has to be created before forking otherwise
         * if the child process exits before we setup the signal fd,
         * the event will be lost and the command will be stuck */
-       sigfd = setup_sigchld_fd(&oldmask);
-       if (sigfd < 0) {
+       handler.sigfd = setup_sigchld_fd(&oldmask);
+       if (handler.sigfd < 0) {
                ERROR("failed to set sigchild fd handler");
                return -1;
        }
@@ -339,13 +346,13 @@ int lxc_start(const char *name, char *argv[])
                clone_flags |= CLONE_NEWNET;
 
        /* Create a process in a new set of namespaces */
-       pid = fork_ns(clone_flags);
-       if (pid < 0) {
+       handler.pid = fork_ns(clone_flags);
+       if (handler.pid < 0) {
                SYSERROR("failed to fork into a new namespace");
                goto err_fork_ns;
        }
 
-       if (!pid) {
+       if (!handler.pid) {
 
                if (sigprocmask(SIG_SETMASK, &oldmask, NULL)) {
                        SYSERROR("failed to set sigprocmask");
@@ -370,7 +377,7 @@ int lxc_start(const char *name, char *argv[])
                }
 
                /* Setup the container, ip, names, utsname, ... */
-               err = lxc_setup(name, tty, &tty_info);
+               err = lxc_setup(name, tty, &handler.tty_info);
                if (err) {
                        ERROR("failed to setup the container");
                        if (write(sv[0], &err, sizeof(err)) < 0)
@@ -403,11 +410,11 @@ int lxc_start(const char *name, char *argv[])
                goto err_pipe_read;
        }
 
-       if (lxc_link_nsgroup(name, pid))
+       if (lxc_link_nsgroup(name, handler.pid))
                WARN("cgroupfs not found: cgroup disabled");
 
        /* Create the network configuration */
-       if (clone_flags & CLONE_NEWNET && conf_create_network(name, pid)) {
+       if (clone_flags & CLONE_NEWNET && conf_create_network(name, handler.pid)) {
                ERROR("failed to create the configured network");
                goto err_create_network;
        }
@@ -427,11 +434,11 @@ int lxc_start(const char *name, char *argv[])
 
        if (err > 0) {
                err = sync;
-               waitpid(pid, NULL, 0);
+               waitpid(handler.pid, NULL, 0);
                goto err_child_failed;
        }
 
-       if (!asprintf(&val, "%d\n", pid)) {
+       if (!asprintf(&val, "%d\n", handler.pid)) {
                SYSERROR("failed to allocate memory");
                goto err_child_failed;
        }
@@ -457,7 +464,7 @@ int lxc_start(const char *name, char *argv[])
                goto err_state_failed;
        }
 
-       if (mainloop(name, pid, sigfd, &tty_info)) {
+       if (mainloop(name, &handler)) {
                ERROR("mainloop exited with an error");
                goto err_mailoop_failed;
        }
@@ -473,7 +480,7 @@ out:
        if (lxc_setstate(name, STOPPED))
                ERROR("failed to set state %s", lxc_state2str(STOPPED));
 
-       lxc_delete_tty(&tty_info);
+       lxc_delete_tty(&handler.tty_info);
        lxc_unlink_nsgroup(name);
        unlink(init);
        free(val);
@@ -498,7 +505,7 @@ err_mailoop_failed:
        if (lxc_setstate(name, ABORTING))
                ERROR("failed to set state %s", lxc_state2str(STOPPED));
 
-       kill(pid, SIGKILL);
+       kill(handler.pid, SIGKILL);
 err_fork_ns:
        close(sv[0]);
        close(sv[1]);