[or-cvs] bugfix: when we run out of disk space, or other log writing...

[arma@seul.org (Roger Dingledine)]

Update of /home/or/cvsroot/src/common
In directory moria.mit.edu:/home2/arma/work/onion/cvs/src/common

Modified Files:
	log.c 
Log Message:
bugfix: when we run out of disk space, or other log writing error,
don't crash. just stop logging to that log and continue.

nick, can you find the bug i've cleverly hidden in this commit?


Index: log.c
===================================================================
RCS file: /home/or/cvsroot/src/common/log.c,v
retrieving revision 1.50
retrieving revision 1.51
diff -u -d -r1.50 -r1.51
--- log.c	18 Aug 2004 11:21:50 -0000	1.50
+++ log.c	23 Sep 2004 03:51:45 -0000	1.51
@@ -139,22 +139,32 @@
   logfile_t *lf;
 
   assert(format);
-  for (lf = logfiles; lf; lf = lf->next) {
-    if (severity < lf->loglevel || severity > lf->max_loglevel)
+  lf = logfiles;
+  while(lf) {
+    if (severity < lf->loglevel || severity > lf->max_loglevel) {
+      lf = lf->next;
       continue;
-    if (!lf->file)
+    }
+    if (!lf->file) {
+      lf = lf->next;
       continue;
+    }
 
     if (!formatted) {
-      format_msg(buf, 10024, severity, funcname, format, ap);
+      format_msg(buf, sizeof(buf), severity, funcname, format, ap);
       formatted = 1;
     }
-    if(fputs(buf, lf->file) == EOF) { /* error */
-      assert(0); /* XXX */
-    }
-    if(fflush(lf->file) == EOF) { /* error */
-      /* don't log the error! */
-      assert(0); /* XXX fail for now. what's better to do? */
+    if(fputs(buf, lf->file) == EOF ||
+       fflush(lf->file) == EOF) { /* error */
+      /* don't log the error! Blow away this log entry and continue. */
+      logfile_t *victim = lf;
+      lf = victim->next;
+      if(victim == logfiles)
+        logfiles = lf;
+      tor_free(victim->filename);
+      tor_free(victim);
+    } else {
+      lf = lf->next;
     }
   }
 }
@@ -194,13 +204,24 @@
 /** Close and re-open all log files; used to rotate logs on SIGHUP. */
 void reset_logs()
 {
-  logfile_t *lf;
-  for (lf = logfiles; lf; lf = lf->next) {
+  logfile_t *lf = logfiles;
+  while(lf) {
     if (lf->needs_close) {
-      fclose(lf->file);
-      lf->file = fopen(lf->filename, "a");
-      log_tor_version(lf, 1);
+      if(fclose(lf->file)==EOF ||
+        !(lf->file = fopen(lf->filename, "a"))) {
+        /* error. don't log it. delete the log entry and continue. */
+        logfile_t *victim = lf;
+        lf = victim->next;
+        if(victim == logfiles)
+          logfiles = lf;
+        tor_free(victim->filename);
+        tor_free(victim);
+        continue;
+      } else {
+        log_tor_version(lf, 1);
+      }
     }
+    lf = lf->next;
   }
 }