Re: [PATCH] tools: hv: introduce -n/--no-daemon option

[Vitaly Kuznetsov <vkuznets@redhat.com>]

KY Srinivasan <kys@microsoft.com> writes:

>> -----Original Message-----
>> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
>> Sent: Wednesday, October 22, 2014 9:07 AM
>> To: KY Srinivasan; Haiyang Zhang; devel@linuxdriverproject.org
>> Cc: linux-kernel@vger.kernel.org
>> Subject: [PATCH] tools: hv: introduce -n/--no-daemon option
>> 
>> All tools/hv daemons do mandatory daemon() on startup. However, no
>> pidfile is created, this make it difficult for an init system to track such
>> daemons.
>> Modern linux distros use systemd as their init system. It can handle the
>> daemonizing by itself, however, it requires a daemon to stay in foreground
>> for that. Some distros already carry distro-specific patch for hv tools which
>> switches off daemon().
>> 
>> Introduce -n/--no-daemon option for all 3 daemons in hv/tools. Parse
>> options with getopt() to make this part easily expandable.
>> 
>> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> You may want to include Greg KH in the "to" list.

For some reason he's missing on the get_maintainer.pl output for all
Hyper-V parts.

Greg, will you pick this up or do I need to resend?

> Signed-off-by:  K. Y. Srinivasan <kys@microsoft.com>
>

Thanks!

>> ---
>>  tools/hv/hv_fcopy_daemon.c | 33 +++++++++++++++++++++++++++++++-
>> -
>>  tools/hv/hv_kvp_daemon.c   | 34
>> ++++++++++++++++++++++++++++++++--
>>  tools/hv/hv_vss_daemon.c   | 33 +++++++++++++++++++++++++++++++--
>>  3 files changed, 94 insertions(+), 6 deletions(-)
>> 
>> diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c
>> index 8f96b3e..f437d73 100644
>> --- a/tools/hv/hv_fcopy_daemon.c
>> +++ b/tools/hv/hv_fcopy_daemon.c
>> @@ -33,6 +33,7 @@
>>  #include <sys/stat.h>
>>  #include <fcntl.h>
>>  #include <dirent.h>
>> +#include <getopt.h>
>> 
>>  static int target_fd;
>>  static char target_fname[W_MAX_PATH];
>> @@ -126,15 +127,43 @@ static int hv_copy_cancel(void)
>> 
>>  }
>> 
>> -int main(void)
>> +void print_usage(char *argv[])
>> +{
>> +	fprintf(stderr, "Usage: %s [options]\n"
>> +		"Options are:\n"
>> +		"  -n, --no-daemon        stay in foreground, don't
>> daemonize\n"
>> +		"  -h, --help             print this help\n", argv[0]);
>> +}
>> +
>> +int main(int argc, char *argv[])
>>  {
>>  	int fd, fcopy_fd, len;
>>  	int error;
>> +	int daemonize = 1, long_index = 0, opt;
>>  	int version = FCOPY_CURRENT_VERSION;
>>  	char *buffer[4096 * 2];
>>  	struct hv_fcopy_hdr *in_msg;
>> 
>> -	if (daemon(1, 0)) {
>> +	static struct option long_options[] = {
>> +		{"help",	no_argument,	   0,  'h' },
>> +		{"no-daemon",	no_argument,	   0,  'n' },
>> +		{0,		0,		   0,  0   }
>> +	};
>> +
>> +	while ((opt = getopt_long(argc, argv, "hn", long_options,
>> +				  &long_index)) != -1) {
>> +		switch (opt) {
>> +		case 'n':
>> +			daemonize = 0;
>> +			break;
>> +		case 'h':
>> +		default:
>> +			print_usage(argv);
>> +			exit(EXIT_FAILURE);
>> +		}
>> +	}
>> +
>> +	if (daemonize && daemon(1, 0)) {
>>  		syslog(LOG_ERR, "daemon() failed; error: %s",
>> strerror(errno));
>>  		exit(EXIT_FAILURE);
>>  	}
>> diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c index
>> 4088b81..22b0764 100644
>> --- a/tools/hv/hv_kvp_daemon.c
>> +++ b/tools/hv/hv_kvp_daemon.c
>> @@ -43,6 +43,7 @@
>>  #include <fcntl.h>
>>  #include <dirent.h>
>>  #include <net/if.h>
>> +#include <getopt.h>
>> 
>>  /*
>>   * KVP protocol: The user mode component first registers with the @@ -
>> 1417,7 +1418,15 @@ netlink_send(int fd, struct cn_msg *msg)
>>  	return sendmsg(fd, &message, 0);
>>  }
>> 
>> -int main(void)
>> +void print_usage(char *argv[])
>> +{
>> +	fprintf(stderr, "Usage: %s [options]\n"
>> +		"Options are:\n"
>> +		"  -n, --no-daemon        stay in foreground, don't
>> daemonize\n"
>> +		"  -h, --help             print this help\n", argv[0]);
>> +}
>> +
>> +int main(int argc, char *argv[])
>>  {
>>  	int fd, len, nl_group;
>>  	int error;
>> @@ -1435,9 +1444,30 @@ int main(void)
>>  	struct hv_kvp_ipaddr_value *kvp_ip_val;
>>  	char *kvp_recv_buffer;
>>  	size_t kvp_recv_buffer_len;
>> +	int daemonize = 1, long_index = 0, opt;
>> +
>> +	static struct option long_options[] = {
>> +		{"help",	no_argument,	   0,  'h' },
>> +		{"no-daemon",	no_argument,	   0,  'n' },
>> +		{0,		0,		   0,  0   }
>> +	};
>> +
>> +	while ((opt = getopt_long(argc, argv, "hn", long_options,
>> +				  &long_index)) != -1) {
>> +		switch (opt) {
>> +		case 'n':
>> +			daemonize = 0;
>> +			break;
>> +		case 'h':
>> +		default:
>> +			print_usage(argv);
>> +			exit(EXIT_FAILURE);
>> +		}
>> +	}
>> 
>> -	if (daemon(1, 0))
>> +	if (daemonize && daemon(1, 0))
>>  		return 1;
>> +
>>  	openlog("KVP", 0, LOG_USER);
>>  	syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());
>> 
>> diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c index
>> 6a213b8..9ae2b6e 100644
>> --- a/tools/hv/hv_vss_daemon.c
>> +++ b/tools/hv/hv_vss_daemon.c
>> @@ -36,6 +36,7 @@
>>  #include <linux/hyperv.h>
>>  #include <linux/netlink.h>
>>  #include <syslog.h>
>> +#include <getopt.h>
>> 
>>  static struct sockaddr_nl addr;
>> 
>> @@ -131,7 +132,15 @@ static int netlink_send(int fd, struct cn_msg *msg)
>>  	return sendmsg(fd, &message, 0);
>>  }
>> 
>> -int main(void)
>> +void print_usage(char *argv[])
>> +{
>> +	fprintf(stderr, "Usage: %s [options]\n"
>> +		"Options are:\n"
>> +		"  -n, --no-daemon        stay in foreground, don't
>> daemonize\n"
>> +		"  -h, --help             print this help\n", argv[0]);
>> +}
>> +
>> +int main(int argc, char *argv[])
>>  {
>>  	int fd, len, nl_group;
>>  	int error;
>> @@ -143,8 +152,28 @@ int main(void)
>>  	struct hv_vss_msg *vss_msg;
>>  	char *vss_recv_buffer;
>>  	size_t vss_recv_buffer_len;
>> +	int daemonize = 1, long_index = 0, opt;
>> +
>> +	static struct option long_options[] = {
>> +		{"help",	no_argument,	   0,  'h' },
>> +		{"no-daemon",	no_argument,	   0,  'n' },
>> +		{0,		0,		   0,  0   }
>> +	};
>> +
>> +	while ((opt = getopt_long(argc, argv, "hn", long_options,
>> +				  &long_index)) != -1) {
>> +		switch (opt) {
>> +		case 'n':
>> +			daemonize = 0;
>> +			break;
>> +		case 'h':
>> +		default:
>> +			print_usage(argv);
>> +			exit(EXIT_FAILURE);
>> +		}
>> +	}
>> 
>> -	if (daemon(1, 0))
>> +	if (daemonize && daemon(1, 0))
>>  		return 1;
>> 
>>  	openlog("Hyper-V VSS", 0, LOG_USER);
>> --
>> 1.9.3

-- 
  Vitaly