tools: hv: Improve error logging in KVP daemon.

Use errno and strerror() when logging errors to provide
more information.
Signed-off-by: NTomas Hozza <thozza@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/hv/hv_kvp_daemon.c

@@ -127,7 +127,8 @@ static void kvp_acquire_lock(int pool)
 	fl.l_pid = getpid();
 
 	if (fcntl(kvp_file_info[pool].fd, F_SETLKW, &fl) == -1) {
-		syslog(LOG_ERR, "Failed to acquire the lock pool: %d", pool);
+		syslog(LOG_ERR, "Failed to acquire the lock pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
 		exit(EXIT_FAILURE);
 	}
 }
@@ -138,8 +139,8 @@ static void kvp_release_lock(int pool)
 	fl.l_pid = getpid();
 
 	if (fcntl(kvp_file_info[pool].fd, F_SETLK, &fl) == -1) {
-		perror("fcntl");
-		syslog(LOG_ERR, "Failed to release the lock pool: %d", pool);
+		syslog(LOG_ERR, "Failed to release the lock pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
 		exit(EXIT_FAILURE);
 	}
 }
@@ -157,8 +158,9 @@ static void kvp_update_file(int pool)
 
 	filep = fopen(kvp_file_info[pool].fname, "we");
 	if (!filep) {
+		syslog(LOG_ERR, "Failed to open file, pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
 		kvp_release_lock(pool);
-		syslog(LOG_ERR, "Failed to open file, pool: %d", pool);
 		exit(EXIT_FAILURE);
 	}
 
@@ -188,8 +190,9 @@ static void kvp_update_mem_state(int pool)
 
 	filep = fopen(kvp_file_info[pool].fname, "re");
 	if (!filep) {
+		syslog(LOG_ERR, "Failed to open file, pool: %d; error: %d %s", pool,
+				errno, strerror(errno));
 		kvp_release_lock(pool);
-		syslog(LOG_ERR, "Failed to open file, pool: %d", pool);
 		exit(EXIT_FAILURE);
 	}
 	for (;;) {
@@ -240,7 +243,8 @@ static int kvp_file_init(void)
 
 	if (access(KVP_CONFIG_LOC, F_OK)) {
 		if (mkdir(KVP_CONFIG_LOC, 0755 /* rwxr-xr-x */)) {
-			syslog(LOG_ERR, " Failed to create %s", KVP_CONFIG_LOC);
+			syslog(LOG_ERR, "Failed to create '%s'; error: %d %s", KVP_CONFIG_LOC,
+					errno, strerror(errno));
 			exit(EXIT_FAILURE);
 		}
 	}
@@ -1280,7 +1284,8 @@ static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val)
 	file = fopen(if_file, "w");
 
 	if (file == NULL) {
-		syslog(LOG_ERR, "Failed to open config file");
+		syslog(LOG_ERR, "Failed to open config file; error: %d %s",
+				errno, strerror(errno));
 		return HV_E_FAIL;
 	}
 
@@ -1447,7 +1452,8 @@ int main(void)
 
 	fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
 	if (fd < 0) {
-		syslog(LOG_ERR, "netlink socket creation failed; error:%d", fd);
+		syslog(LOG_ERR, "netlink socket creation failed; error: %d %s", errno,
+				strerror(errno));
 		exit(EXIT_FAILURE);
 	}
 	addr.nl_family = AF_NETLINK;
@@ -1458,7 +1464,7 @@ int main(void)
 
 	error = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
 	if (error < 0) {
-		syslog(LOG_ERR, "bind failed; error:%d", error);
+		syslog(LOG_ERR, "bind failed; error: %d %s", errno, strerror(errno));
 		close(fd);
 		exit(EXIT_FAILURE);
 	}
@@ -1484,7 +1490,7 @@ int main(void)
 
 	len = netlink_send(fd, message);
 	if (len < 0) {
-		syslog(LOG_ERR, "netlink_send failed; error:%d", len);
+		syslog(LOG_ERR, "netlink_send failed; error: %d %s", errno, strerror(errno));
 		close(fd);
 		exit(EXIT_FAILURE);
 	}
@@ -1716,7 +1722,8 @@ int main(void)
 
 		len = netlink_send(fd, incoming_cn_msg);
 		if (len < 0) {
-			syslog(LOG_ERR, "net_link send failed; error:%d", len);
+			syslog(LOG_ERR, "net_link send failed; error: %d %s", errno,
+					strerror(errno));
 			exit(EXIT_FAILURE);
 		}
 	}