From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q0OI3cQG061051 for ; Tue, 24 Jan 2012 12:03:38 -0600 Date: Tue, 24 Jan 2012 13:03:37 -0500 From: Christoph Hellwig Subject: Re: [PATCH 05/11] xfs: make i_flags an unsigned long Message-ID: <20120124180336.GE23671@infradead.org> References: <20111208155755.323930705@bombadil.infradead.org> <20111208155918.348628833@bombadil.infradead.org> <20120113190716.GA6271@sgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120113190716.GA6271@sgi.com> 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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Ben Myers Cc: Christoph Hellwig , xfs@oss.sgi.com On Fri, Jan 13, 2012 at 01:07:16PM -0600, Ben Myers wrote: > On Thu, Dec 08, 2011 at 10:58:00AM -0500, Christoph Hellwig wrote: > > To be used for bit wakeup i_flags needs to be an unsigned long or we'll > > run into trouble on big endian systems. Beause of the 1-byte i_update > Because > > field right after it this actually causes a fairly large size increase > > on its own (4 or 8 bytes), but that increase will be more than offset > > by the next two patches. > > > > Signed-off-by: Christoph Hellwig > > Reviewed-by: Alex Elder > > Reviewed-by: Dave Chinner > > Looks good to me. But I could go for a thorough explanation of 'trouble > on big endian systems'. If we use the bitops that expect to operate on a 64-bit value on a 32-bit value on big endian we'll actually use the 32-bit longword next to it, not the one we intended for the first half of the bits. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs