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?


svn:r2365

src/common/log.c

@@ -139,22 +139,32 @@ logv(int severity, const char *funcname, const char *format, va_list ap)
   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 @@ void close_logs()
 /** 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;
   }
 }