Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley
	Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United
	Kingdom.
	Registered in England and Wales under Company Registration No. 3798903
From: David Howells <dhowells@redhat.com>
In-Reply-To: <20090403134927.GA31907@infradead.org>
References: <20090403134927.GA31907@infradead.org> <20090403094138.9510.80681.stgit@warthog.procyon.org.uk>
To: Christoph Hellwig <hch@infradead.org>
Cc: dhowells@redhat.com, nickpiggin@yahoo.com.au, nfsv4@linux-nfs.org,
       linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 1/4] CacheFiles: Use the ->write() file op rather than a special kernel aop
Date: Fri, 03 Apr 2009 14:57:19 +0100
Message-ID: <11023.1238767039@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 818
Lines: 20

Christoph Hellwig <hch@infradead.org> wrote:

> > +			if (!aops->bmap)
> >  				goto check_error;
> 
> What are you doing using bmap?  You really shouldn't call into it from
> anywhere but FIBMAP.  Yes, swap currently does but it's a major pain
> in the neck and Peter has been working on a proper interface for swap
> for a while.

Checking to see whether there's a hole in the file.  If there's a hole, that
represents data I need to fetch; if there isn't that represents data I have in
the cache.  I don't care _where_ the data is, only whether it exists or not.

David
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/