From: Christoph Hellwig Subject: Re: [RFC] Heads up on sys_fallocate() Date: Thu, 1 Mar 2007 23:38:19 +0000 Message-ID: <20070301233819.GB31072@infradead.org> References: <20070117094658.GA17390@amitarora.in.ibm.com> <20070225022326.137b4875.akpm@linux-foundation.org> <20070301183445.GA7911@amitarora.in.ibm.com> <20070301142537.b5950cd7.akpm@linux-foundation.org> <1172789056.11165.42.camel@kleikamp.austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , "Amit K. Arora" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, suparna@in.ibm.com, cmm@us.ibm.com, alex@clusterfs.com, suzuki@in.ibm.com, Ulrich Drepper To: Dave Kleikamp Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:54737 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161132AbXCAXiY (ORCPT ); Thu, 1 Mar 2007 18:38:24 -0500 Content-Disposition: inline In-Reply-To: <1172789056.11165.42.camel@kleikamp.austin.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, Mar 01, 2007 at 10:44:16PM +0000, Dave Kleikamp wrote: > Would EINVAL (or whatever) make it back to the caller of > posix_fallocate(), or would glibc fall back to its current > implementation? > > Forgive me if I haven't put enough thought into it, but would it be > useful to create a generic_fallocate() that writes zeroed pages for any > non-existent pages in the range? I don't know how glibc currently > implements posix_fallocate(), but maybe the kernel could do it more > efficiently, even in generic code. Maybe we don't care, since the major > file systems can probably do something better in their own code. I'd be more happy to have the write out zeroes loop in glibc. And glibc needs to have it anyway, for older kernels.