From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sandeen Subject: [PATCH] ext4: fix overhead calculations in ext4_stats, again Date: Thu, 25 Oct 2012 11:59:02 -0500 Message-ID: <50896FD6.1010807@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: ext4 development Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43127 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946136Ab2JYQ7E (ORCPT ); Thu, 25 Oct 2012 12:59:04 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q9PGx3Uf026404 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 25 Oct 2012 12:59:04 -0400 Received: from liberator.sandeen.net (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q9PGx2O6026852 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO) for ; Thu, 25 Oct 2012 12:59:03 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: "overhead" was a write-only variable in this function after commit 952fc18e; we set it to 0 for minixdf, or to sbi->s_overhead if !minixdf, but never read it again after that. We need to use it, not sbi->s_overhead, when subtracting out overhead for f_blocks, or we get the wrong answer for minixdf. Signed-off-by: Eric Sandeen --- "Once more, with feeling!" ;) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index e44b233..2feaf78 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4758,7 +4758,7 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf) buf->f_type = EXT4_SUPER_MAGIC; buf->f_bsize = sb->s_blocksize; - buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, sbi->s_overhead); + buf->f_blocks = ext4_blocks_count(es) - EXT4_C2B(sbi, overhead); bfree = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) - percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter); /* prevent underflow in case that few free space is available */