shmctl should NOT fail in utmpfix, but when something wrong

in SHM, this would happen and utmp is still dirty. so now
shmctl will fork(2) before real utmpfix, and if it fails,
utmpfix will start again automatically.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk/pttbbs@2265 63ad8ddf-47c3-0310-b6dd-a9e9d9715204

1 files changed, 31 insertions, 4 deletions

diff --git a/util/shmctl.c b/util/shmctl.c
index deebf459..f3067fc2 100644
--- a/util/shmctl.c
+++ b/util/shmctl.c
@@ -55,13 +55,13 @@ int sfIDLE(const void *a, const void *b)
 int utmpfix(int argc, char **argv)
 {
     int     i, fast = 0, lowerbound = 100, nownum = SHM->UTMPnumber;
-    int     which, nactive = 0;
+    int     which, nactive = 0, dofork = 1;
     time_t  now, timeout = -1;
     char    *clean, buf[1024], ch;
     IDLE_t  idle[USHM_SIZE];
     char    changeflag = 0;
 
-    while( (ch = getopt(argc, argv, "nt:l:")) != -1 )
+    while( (ch = getopt(argc, argv, "nt:l:F")) != -1 )
 	switch( ch ){
 	case 'n':
 	    fast = 1;
@@ -72,8 +72,11 @@ int utmpfix(int argc, char **argv)
 	case 'l':
 	    lowerbound = atoi(optarg);
 	    break;
+	case 'F':
+	    dofork = 0;
+	    break;
 	default:
-	    printf("usage:\tshmctl\tutmpfix [-n] [-t timeout]\n");
+	    printf("usage:\tshmctl\tutmpfix [-n] [-t timeout] [-F]\n");
 	    return 1;
 	}
 
@@ -84,8 +87,32 @@ int utmpfix(int argc, char **argv)
 	    puts("utmpshm is busy....");
 	    sleep(1);
 	}
-
     SHM->UTMPbusystate = 1;
+
+    if( dofork ){
+	int     times, status;
+	pid_t   pid;
+	printf("forking mode\n");
+	for( times = 0 ; times < 100 ; ++times ){
+	    switch( (pid = fork()) ){
+	    case -1:
+		perror("fork()");
+		sleep(1);
+		break;
+	    case 0:
+		goto DoUtmpfix;
+		break;
+	    default:
+		waitpid(pid, &status, 0);
+		printf("status: %d\n", status);
+		if( WIFEXITED(status) )
+		    return 0;
+		changeflag = 1;
+	    }
+	}
+    }
+
+ DoUtmpfix:
     printf("starting scaning... %s \n", (fast ? "(fast mode)" : ""));
 #ifdef OUTTA_TIMER
     now = SHM->GV2.e.now;