static int lxc_mount_auto_mounts(struct lxc_conf *conf, int flags, struct lxc_handler *handler)
{
	int r;
	size_t i;
	static struct {
		int match_mask;
		int match_flag;
		const char *source;
		const char *destination;
		const char *fstype;
		unsigned long flags;
		const char *options;
	} default_mounts[] = {
		/* Read-only bind-mounting... In older kernels, doing that required
		 * to do one MS_BIND mount and then MS_REMOUNT|MS_RDONLY the same
		 * one. According to mount(2) manpage, MS_BIND honors MS_RDONLY from
		 * kernel 2.6.26 onwards. However, this apparently does not work on
		 * kernel 3.8. Unfortunately, on that very same kernel, doing the
		 * same trick as above doesn't seem to work either, there one needs
		 * to ALSO specify MS_BIND for the remount, otherwise the entire
		 * fs is remounted read-only or the mount fails because it's busy...
		 * MS_REMOUNT|MS_BIND|MS_RDONLY seems to work for kernels as low as
		 * 2.6.32...
		 */
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "proc",                                              "%r/proc",                      "proc",     MS_NODEV|MS_NOEXEC|MS_NOSUID,   NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys/net",                                   "%r/proc/net",                  NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys",                                       "%r/proc/sys",                  NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL,                                                "%r/proc/sys",                  NULL,       MS_REMOUNT|MS_BIND|MS_RDONLY,   NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/net",                                       "%r/proc/sys/net",              NULL,       MS_MOVE,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sysrq-trigger",                             "%r/proc/sysrq-trigger",        NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL,                                                "%r/proc/sysrq-trigger",        NULL,       MS_REMOUNT|MS_BIND|MS_RDONLY,   NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_RW,    "proc",                                              "%r/proc",                      "proc",     MS_NODEV|MS_NOEXEC|MS_NOSUID,   NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_RW,     "sysfs",                                             "%r/sys",                       "sysfs",    0,                              NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_RO,     "sysfs",                                             "%r/sys",                       "sysfs",    MS_RDONLY,                      NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "sysfs",                                             "%r/sys",                       "sysfs",    MS_NODEV|MS_NOEXEC|MS_NOSUID,   NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "%r/sys",                                            "%r/sys",                       NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  NULL,                                                "%r/sys",                       NULL,       MS_REMOUNT|MS_BIND|MS_RDONLY,   NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "sysfs",                                             "%r/sys/devices/virtual/net",   "sysfs",    0,                              NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "%r/sys/devices/virtual/net/devices/virtual/net",    "%r/sys/devices/virtual/net",   NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  NULL,                                                "%r/sys/devices/virtual/net",   NULL,       MS_REMOUNT|MS_BIND|MS_NOSUID|MS_NODEV|MS_NOEXEC,   NULL },
		{ 0,                  0,                   NULL,                                                NULL,                           NULL,       0,                              NULL }
	};

	for (i = 0; default_mounts[i].match_mask; i++) {
		if ((flags & default_mounts[i].match_mask) == default_mounts[i].match_flag) {
			char *source = NULL;
			char *destination = NULL;
			int saved_errno;
			unsigned long mflags;

			if (default_mounts[i].source) {
				/* will act like strdup if %r is not present */
				source = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].source);
				if (!source) {
					SYSERROR("memory allocation error");
					return -1;
				}
			}
			if (default_mounts[i].destination) {
				/* will act like strdup if %r is not present */
				destination = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].destination);
				if (!destination) {
					saved_errno = errno;
					SYSERROR("memory allocation error");
					free(source);
					errno = saved_errno;
					return -1;
				}
			}
			mflags = add_required_remount_flags(source, destination,
					default_mounts[i].flags);
			r = mount(source, destination, default_mounts[i].fstype, mflags, default_mounts[i].options);
			saved_errno = errno;
			if (r < 0 && errno == ENOENT) {
				INFO("Mount source or target for %s on %s doesn't exist. Skipping.", source, destination);
				r = 0;
			}
			else if (r < 0)
				SYSERROR("error mounting %s on %s flags %lu", source, destination, mflags);

			free(source);
			free(destination);
			if (r < 0) {
				errno = saved_errno;
				return -1;
			}
		}
	}

	if (flags & LXC_AUTO_CGROUP_MASK) {
		int cg_flags;

		cg_flags = flags & LXC_AUTO_CGROUP_MASK;
		/* If the type of cgroup mount was not specified, it depends on the
		 * container's capabilities as to what makes sense: if we have
		 * CAP_SYS_ADMIN, the read-only part can be remounted read-write
		 * anyway, so we may as well default to read-write; then the admin
		 * will not be given a false sense of security. (And if they really
		 * want mixed r/o r/w, then they can explicitly specify :mixed.)
		 * OTOH, if the container lacks CAP_SYS_ADMIN, do only default to
		 * :mixed, because then the container can't remount it read-write. */
		if (cg_flags == LXC_AUTO_CGROUP_NOSPEC || cg_flags == LXC_AUTO_CGROUP_FULL_NOSPEC) {
			int has_sys_admin = 0;
			if (!lxc_list_empty(&conf->keepcaps)) {
				has_sys_admin = in_caplist(CAP_SYS_ADMIN, &conf->keepcaps);
			} else {
				has_sys_admin = !in_caplist(CAP_SYS_ADMIN, &conf->caps);
			}
			if (cg_flags == LXC_AUTO_CGROUP_NOSPEC) {
				cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_RW : LXC_AUTO_CGROUP_MIXED;
			} else {
				cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_FULL_RW : LXC_AUTO_CGROUP_FULL_MIXED;
			}
		}

		if (!cgroup_mount(conf->rootfs.path ? conf->rootfs.mount : "", handler, cg_flags)) {
			SYSERROR("error mounting /sys/fs/cgroup");
			return -1;
		}
	}

	return 0;
}
static int lxc_mount_auto_mounts(struct lxc_conf *conf, int flags, struct lxc_handler *handler)
{
	int r;
	size_t i;
	static struct {
		int match_mask;
		int match_flag;
		const char *source;
		const char *destination;
		const char *fstype;
		unsigned long flags;
		const char *options;
	} default_mounts[] = {
		 
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "proc",                                              "%r/proc",                      "proc",     MS_NODEV|MS_NOEXEC|MS_NOSUID,   NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys/net",                                   "%r/proc/net",                  NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sys",                                       "%r/proc/sys",                  NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL,                                                "%r/proc/sys",                  NULL,       MS_REMOUNT|MS_BIND|MS_RDONLY,   NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/net",                                       "%r/proc/sys/net",              NULL,       MS_MOVE,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, "%r/proc/sysrq-trigger",                             "%r/proc/sysrq-trigger",        NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_MIXED, NULL,                                                "%r/proc/sysrq-trigger",        NULL,       MS_REMOUNT|MS_BIND|MS_RDONLY,   NULL },
		{ LXC_AUTO_PROC_MASK, LXC_AUTO_PROC_RW,    "proc",                                              "%r/proc",                      "proc",     MS_NODEV|MS_NOEXEC|MS_NOSUID,   NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_RW,     "sysfs",                                             "%r/sys",                       "sysfs",    0,                              NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_RO,     "sysfs",                                             "%r/sys",                       "sysfs",    MS_RDONLY,                      NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "sysfs",                                             "%r/sys",                       "sysfs",    MS_NODEV|MS_NOEXEC|MS_NOSUID,   NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "%r/sys",                                            "%r/sys",                       NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  NULL,                                                "%r/sys",                       NULL,       MS_REMOUNT|MS_BIND|MS_RDONLY,   NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "sysfs",                                             "%r/sys/devices/virtual/net",   "sysfs",    0,                              NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  "%r/sys/devices/virtual/net/devices/virtual/net",    "%r/sys/devices/virtual/net",   NULL,       MS_BIND,                        NULL },
		{ LXC_AUTO_SYS_MASK,  LXC_AUTO_SYS_MIXED,  NULL,                                                "%r/sys/devices/virtual/net",   NULL,       MS_REMOUNT|MS_BIND|MS_NOSUID|MS_NODEV|MS_NOEXEC,   NULL },
		{ 0,                  0,                   NULL,                                                NULL,                           NULL,       0,                              NULL }
	};

	for (i = 0; default_mounts[i].match_mask; i++) {
		if ((flags & default_mounts[i].match_mask) == default_mounts[i].match_flag) {
			char *source = NULL;
			char *destination = NULL;
			int saved_errno;
			unsigned long mflags;

			if (default_mounts[i].source) {
				 
				source = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].source);
				if (!source) {
					SYSERROR("memory allocation error");
					return -1;
				}
			}
			if (default_mounts[i].destination) {
				 
				destination = lxc_string_replace("%r", conf->rootfs.path ? conf->rootfs.mount : "", default_mounts[i].destination);
				if (!destination) {
					saved_errno = errno;
					SYSERROR("memory allocation error");
					free(source);
					errno = saved_errno;
					return -1;
				}
			}
			mflags = add_required_remount_flags(source, destination,
					default_mounts[i].flags);
			r = mount(source, destination, default_mounts[i].fstype, mflags, default_mounts[i].options);
			saved_errno = errno;
			if (r < 0 && errno == ENOENT) {
				INFO("Mount source or target for %s on %s doesn't exist. Skipping.", source, destination);
				r = 0;
			}
			else if (r < 0)
				SYSERROR("error mounting %s on %s flags %lu", source, destination, mflags);

			free(source);
			free(destination);
			if (r < 0) {
				errno = saved_errno;
				return -1;
			}
		}
	}

	if (flags & LXC_AUTO_CGROUP_MASK) {
		int cg_flags;

		cg_flags = flags & LXC_AUTO_CGROUP_MASK;
		 
		if (cg_flags == LXC_AUTO_CGROUP_NOSPEC || cg_flags == LXC_AUTO_CGROUP_FULL_NOSPEC) {
			int has_sys_admin = 0;
			if (!lxc_list_empty(&conf->keepcaps)) {
				has_sys_admin = in_caplist(CAP_SYS_ADMIN, &conf->keepcaps);
			} else {
				has_sys_admin = !in_caplist(CAP_SYS_ADMIN, &conf->caps);
			}
			if (cg_flags == LXC_AUTO_CGROUP_NOSPEC) {
				cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_RW : LXC_AUTO_CGROUP_MIXED;
			} else {
				cg_flags = has_sys_admin ? LXC_AUTO_CGROUP_FULL_RW : LXC_AUTO_CGROUP_FULL_MIXED;
			}
		}

		if (!cgroup_mount(conf->rootfs.path ? conf->rootfs.mount : "", handler, cg_flags)) {
			SYSERROR("error mounting /sys/fs/cgroup");
			return -1;
		}
	}

	return 0;
}