From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id E65927F3F for ; Wed, 4 Jun 2014 13:44:47 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay1.corp.sgi.com (Postfix) with ESMTP id BAB728F8040 for ; Wed, 4 Jun 2014 11:44:44 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id NFb8CAquBAER0XIx for ; Wed, 04 Jun 2014 11:44:43 -0700 (PDT) Date: Wed, 4 Jun 2014 14:44:40 -0400 From: Brian Foster Subject: Re: [PATCH v2] xfs: Fix rounding in xfs_alloc_fix_len() Message-ID: <20140604184440.GC55624@bfoster.bfoster> References: <1401900833-25485-1-git-send-email-jack@suse.cz> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1401900833-25485-1-git-send-email-jack@suse.cz> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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: Jan Kara Cc: xfs@oss.sgi.com On Wed, Jun 04, 2014 at 06:53:53PM +0200, Jan Kara wrote: > 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(). > > Also add an assertion that the result of xfs_alloc_fix_len() is of > expected form. > > Signed-off-by: Jan Kara > --- Looks good to me. Thanks Jan. Reviewed-by: Brian Foster > fs/xfs/xfs_alloc.c | 18 ++++++++---------- > 1 file changed, 8 insertions(+), 10 deletions(-) > > diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c > index c1cf6a336a72..1351a24d3cdc 100644 > --- a/fs/xfs/xfs_alloc.c > +++ b/fs/xfs/xfs_alloc.c > @@ -257,16 +257,14 @@ 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; > - } > - ASSERT(rlen >= args->minlen); > - ASSERT(rlen <= args->maxlen); > + 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 && rlen <= args->maxlen); > + ASSERT(rlen % args->prod == args->mod); > args->len = rlen; > } > > -- > 1.8.1.4 > > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs