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 D0B008084 for ; Thu, 14 Feb 2013 17:42:44 -0600 (CST) Date: Thu, 14 Feb 2013 17:42:44 -0600 From: Ben Myers Subject: Re: [PATCH] xfs: xfs_bmap_add_attrfork_local is too generic Message-ID: <20130214234244.GM22182@sgi.com> References: <1360558693-20354-1-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1360558693-20354-1-git-send-email-david@fromorbit.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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com On Mon, Feb 11, 2013 at 03:58:13PM +1100, Dave Chinner wrote: > From: Dave Chinner > > When we are converting local data to an extent format as a result of > adding an attribute, the type of data contained in the local fork > determines the behaviour that needs to occur. > > xfs_bmap_add_attrfork_local() already handles the directory data > case specially by using S_ISDIR() and calling out to > xfs_dir2_sf_to_block(), but with verifiers we now need to handle > each different type of metadata specially and different metadata > formats require different verifiers (and eventually block header > initialisation). > > There is only a single place that we add and attribute fork to > the inode, but that is in the attribute code and it knows nothing > about the specific contents of the data fork. It is only the case of > local data that is the issue here, so adding code to hadnle this > case in the attribute specific code is wrong. Hence we are really > stuck trying to detect the data fork contents in > xfs_bmap_add_attrfork_local() and performing the correct callout > there. > > Luckily the current cases can be determined by S_IS* macros, and we > can push the work off to data specific callouts, but each of those > callouts does a lot of work in common with > xfs_bmap_local_to_extents(). The only reason that this fails for > symlinks right now is is that xfs_bmap_local_to_extents() assumes > the data fork contains extent data, and so attaches a a bmap extent > data verifier to the buffer and simply copies the data fork > information straight into it. > > To fix this, allow us to pass a "formatting" callback into > xfs_bmap_local_to_extents() which is responsible for setting the > buffer type, initialising it and copying the data fork contents over > to the new buffer. This allows callers to specify how they want to > format the new buffer (which is necessary for the upcoming CRC > enabled metadata blocks) and hence make xfs_bmap_local_to_extents() > useful for any type of data fork content. > > Signed-off-by: Dave Chinner Applied. We'd like this one in 3.8, one way or the other. Regards, Ben _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs