ktest.pl: Fix the logic for truncating the size of the log file for email

The logic for truncating the log file for emailing based on the
MAIL_MAX_SIZE option is confusing and incorrect. Simplify it and have the
tail of the log file truncated to the max size specified in the config.

Cc: stable@vger.kernel.org
Fixes: 855d8abd2e8ff ("ktest.pl: Change the logic to control the size of the log file emailed")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/tools/testing/ktest/ktest.pl b/tools/testing/ktest/ktest.pl
index 54f7d008e840cfbc2a9ce808647d973d10f530a1..4e2450964517381833766082fb4d4b71e4e095ad 100755 (executable)
--- a/tools/testing/ktest/ktest.pl
+++ b/tools/testing/ktest/ktest.pl
@@ -1499,17 +1499,16 @@ sub dodie {
        my $log_file;
 
        if (defined($opt{"LOG_FILE"})) {
-           my $whence = 0; # beginning of file
-           my $pos = $test_log_start;
+           my $whence = 2; # End of file
+           my $log_size = tell LOG;
+           my $size = $log_size - $test_log_start;
 
            if (defined($mail_max_size)) {
-               my $log_size = tell LOG;
-               $log_size -= $test_log_start;
-               if ($log_size > $mail_max_size) {
-                   $whence = 2; # end of file
-                   $pos = - $mail_max_size;
+               if ($size > $mail_max_size) {
+                   $size = $mail_max_size;
                }
            }
+           my $pos = - $size;
            $log_file = "$tmpdir/log";
            open (L, "$opt{LOG_FILE}") or die "Can't open $opt{LOG_FILE} to read)";
            open (O, "> $tmpdir/log") or die "Can't open $tmpdir/log\n";