From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 6E24D7F50 for ; Wed, 4 Jun 2014 04:48:33 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay2.corp.sgi.com (Postfix) with ESMTP id 66FE930406B for ; Wed, 4 Jun 2014 02:48:33 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by cuda.sgi.com with ESMTP id shaHUmzUc4d3CycG (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Wed, 04 Jun 2014 02:48:23 -0700 (PDT) Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 36DF8AC7A for ; Wed, 4 Jun 2014 09:48:22 +0000 (UTC) From: Jan Kara Subject: [PATCH] xfs: Fix rounding in xfs_alloc_fix_len() Date: Wed, 4 Jun 2014 11:48:13 +0200 Message-Id: <1401875293-16227-1-git-send-email-jack@suse.cz> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: Jan Kara Rounding in xfs_alloc_fix_len() is wrong. As the comment states, the result should be a number of a form (k*prod+mod) however due to sign mistake the result is different. As a result allocations on raid arrays could be misaligned in some cases. This also seems to fix occasional assertion failure: XFS_WANT_CORRUPTED_GOTO(rlen <= flen, error0) in xfs_alloc_ag_vextent_size(). Signed-off-by: Jan Kara --- fs/xfs/xfs_alloc.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c index c1cf6a336a72..6a0281b16451 100644 --- a/fs/xfs/xfs_alloc.c +++ b/fs/xfs/xfs_alloc.c @@ -257,14 +257,12 @@ xfs_alloc_fix_len( k = rlen % args->prod; if (k == args->mod) return; - if (k > args->mod) { - if ((int)(rlen = rlen - k - args->mod) < (int)args->minlen) - return; - } else { - if ((int)(rlen = rlen - args->prod - (args->mod - k)) < - (int)args->minlen) - return; - } + if (k > args->mod) + rlen = rlen - (k - args->mod); + else + rlen = rlen - args->prod + (args->mod - k); + if ((int)rlen < (int)args->minlen) + return; ASSERT(rlen >= args->minlen); ASSERT(rlen <= args->maxlen); args->len = rlen; -- 1.8.1.4 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs