From: short <>
Date: Tue, 9 Aug 2005 06:57:40 +0000 (+0000)
Subject: Some prevention of stale locks by unlocking it whenever possible.
X-Git-Url: http://git.jankratochvil.net/?p=inetdmx.git;a=commitdiff_plain;h=be1836412ce05f1ed3902fa90d433a95e4ff8281

Some prevention of stale locks by unlocking it whenever possible.
 - Not sure if it helps anything and if it is even White Box Linux bug at all.
---

diff --git a/inetdmx.c b/inetdmx.c
index 13efc7f..006a4f2 100644
--- a/inetdmx.c
+++ b/inetdmx.c
@@ -77,6 +77,9 @@ static char *opt_command;
 
 static void fatal(const char *fmt,...) G_GNUC_PRINTF(1,2) G_GNUC_NORETURN;
 
+/* for atexit(3) function */
+static int verror_quiet;
+
 static void verror(const char *fmt,va_list ap) G_GNUC_PRINTF(1,0);
 static void verror(const char *fmt,va_list ap)
 {
@@ -84,6 +87,8 @@ int use_syslog=opt_syslog,use_stderr=opt_stderr;
 char *string;
 const char *const double_error="Error printing error message";
 
+	if (verror_quiet)
+		return;
 	if (!use_syslog && !use_stderr)
 		use_stderr=1;
 	if (-1==vasprintf(&string,fmt,ap)) {
@@ -237,13 +242,25 @@ static void lock_touch(void)
 
 static void lock_close(void)
 {
-	if (lock_fd==-1)
+	if (lock_fd==-1 || !opt_lock)
 		return;
+	/* It should not be needed but some stale locks were seen on:
+	 * 	White Box Linux kernel-smp-2.6.9-5.0.5.EL
+	 */
+	if (flock(lock_fd,LOCK_UN|LOCK_NB))
+		fatal("Error unlocking lock file \"%s\": %m",opt_lock);
 	if (close(lock_fd))
 		fatal("Error closing lock file \"%s\": %m",opt_lock);
 	lock_fd=-1;
 }
 
+static void lock_close_atexit(void)
+{
+	/* Prevent some crashes of malloc(3) etc. */
+	verror_quiet=1;
+	lock_close();
+}
+
 static int connect_try(void)
 {
 int fdtcp;
@@ -497,6 +514,8 @@ char *s;
 	else
 		program_name=argv[0];
 
+	atexit(lock_close_atexit);
+
 	optarg=NULL; optind=0;	/* FIXME: Possible portability problem. */
 	while ((optc=getopt_long(argc,argv,"01T:i:Sel:p:Ih",longopts,NULL))!=EOF) switch (optc) {
 long l;