We only need to access the log file from the logger process, so make sure
it only is available there and not exposed to the sheep which will keep
(leak) a reference to the initial one and won't be able to use it after
is has been rotate.

Also kill the unused log to syslog feature to make the change easier.

Signed-off-by: Christoph Hellwig <hch@lst.de>

---
 lib/logger.c |   68 +++++++++++++++++++++++++----------------------------------
 1 file changed, 29 insertions(+), 39 deletions(-)

Index: sheepdog/lib/logger.c
===================================================================
--- sheepdog.orig/lib/logger.c	2012-08-06 16:51:46.333339692 +0200
+++ sheepdog/lib/logger.c	2012-08-06 16:52:11.146673038 +0200
@@ -74,6 +74,7 @@ struct logmsg {
 	char *str;
 };
 
+static int log_fd = -1;
 static __thread const char *worker_name;
 static __thread int worker_idx;
 static struct logarea *la;
@@ -172,8 +173,8 @@ static notrace int logarea_init(int size
 
 static void notrace free_logarea(void)
 {
-	if (la->fd >= 0)
-		close(la->fd);
+	if (log_fd >= 0)
+		close(log_fd);
 	semctl(la->semid, 0, IPC_RMID, la->semarg);
 	shmdt(la->buff);
 	shmdt(la->start);
@@ -208,6 +209,8 @@ static notrace int log_enqueue(int prio,
 	char *p, buff[MAX_MSG_SIZE];
 	struct logmsg *msg;
 	struct logmsg *lastmsg;
+	time_t t;
+	struct tm *tmp;
 
 	lastmsg = (struct logmsg *)la->tail;
 
@@ -219,28 +222,23 @@ static notrace int log_enqueue(int prio,
 
 	p = buff;
 
-	if (la->fd != -1) {
-		time_t t;
-		struct tm *tmp;
-
-		t = time(NULL);
-		tmp = localtime(&t);
 
-		strftime(p, MAX_MSG_SIZE, "%b %2d %H:%M:%S", tmp);
-		p += strlen(p);
+	t = time(NULL);
+	tmp = localtime(&t);
 
-		if (worker_name && worker_idx)
-			snprintf(p, MAX_MSG_SIZE - strlen(buff), " [%s %d] ",
-				 worker_name, worker_idx);
-		else if (worker_name)
-			snprintf(p, MAX_MSG_SIZE - strlen(buff), " [%s] ",
-				 worker_name);
-		else
-			strncpy(p, " [main] ", MAX_MSG_SIZE - strlen(buff));
+	strftime(p, MAX_MSG_SIZE, "%b %2d %H:%M:%S", tmp);
+	p += strlen(p);
 
-		p += strlen(p);
-	}
+	if (worker_name && worker_idx)
+		snprintf(p, MAX_MSG_SIZE - strlen(buff), " [%s %d] ",
+			 worker_name, worker_idx);
+	else if (worker_name)
+		snprintf(p, MAX_MSG_SIZE - strlen(buff), " [%s] ",
+			 worker_name);
+	else
+		strncpy(p, " [main] ", MAX_MSG_SIZE - strlen(buff));
 
+	p += strlen(p);
 	snprintf(p, MAX_MSG_SIZE - strlen(buff), "%s(%d) ", func, line);
 
 	p += strlen(p);
@@ -322,8 +320,8 @@ static notrace void log_syslog(void *buf
 {
 	struct logmsg * msg = (struct logmsg *)buff;
 
-	if (la->fd >= 0)
-		xwrite(la->fd, (char *)&msg->str, strlen((char *)&msg->str));
+	if (log_fd >= 0)
+		xwrite(log_fd, (char *)&msg->str, strlen((char *)&msg->str));
 	else
 		syslog(msg->prio, "%s", (char *)&msg->str);
 }
@@ -388,7 +386,7 @@ static notrace void rotate_log(void)
 		exit(1);
 	}
 
-	if (dup2(new_fd, la->fd) < 0) {
+	if (dup2(new_fd, log_fd) < 0) {
 		syslog(LOG_ERR, "failed to dup2 the log fd\n");
 		exit(1);
 	}
@@ -472,26 +470,11 @@ notrace int log_init(char *program_name,
 		struct sigaction sa_new;
 		int fd;
 
-		if (outfile) {
-			fd = open(outfile, O_CREAT | O_RDWR | O_APPEND, 0644);
-			if (fd < 0) {
-				syslog(LOG_ERR, "failed to open %s\n", outfile);
-				return 1;
-			}
-		} else {
-			fd = -1;
-			openlog(log_name, LOG_CONS | LOG_PID, LOG_DAEMON);
-			setlogmask (LOG_UPTO (LOG_DEBUG));
-		}
-
 		if (logarea_init(size)) {
 			syslog(LOG_ERR, "failed to initialize the logger\n");
 			return 1;
 		}
 
-		la->active = 1;
-		la->fd = fd;
-
 		/*
 		 * Store the pid of the sheep process for use by the death
 		 * signal handler.  By the time the child is notified of
@@ -509,6 +492,13 @@ notrace int log_init(char *program_name,
 			return 0;
 		}
 
+		log_fd = open(outfile, O_CREAT | O_RDWR | O_APPEND, 0644);
+		if (log_fd < 0) {
+			syslog(LOG_ERR, "failed to open %s\n", outfile);
+			exit(1);
+		}
+		la->active = 1;
+
 		fd = open("/dev/null", O_RDWR);
 		if (fd < 0) {
 			syslog(LOG_ERR, "failed to open /dev/null: %m\n");
@@ -539,7 +529,7 @@ notrace int log_init(char *program_name,
 
 			if (max_logsize) {
 				pthread_mutex_lock(&logsize_lock);
-				offset = lseek(la->fd, 0, SEEK_END);
+				offset = lseek(log_fd, 0, SEEK_END);
 				if (offset < 0) {
 					syslog(LOG_ERR, "sheep log error\n");
 				} else {


