From: Andreas Dilger Subject: Re: [PATCH 4/5] ext4: fallocate support in ext4 Date: Mon, 7 May 2007 15:21:04 -0700 Message-ID: <20070507222103.GJ8181@schatzie.adilger.int> References: <20070417125514.GA7574@amitarora.in.ibm.com> <20070418130600.GW5967@schatzie.adilger.int> <20070420135146.GA21352@amitarora.in.ibm.com> <20070420145918.GY355@devserv.devel.redhat.com> <20070424121632.GA10136@amitarora.in.ibm.com> <20070426175056.GA25321@amitarora.in.ibm.com> <20070426181332.GD7209@amitarora.in.ibm.com> <20070503213133.d1559f52.akpm@linux-foundation.org> <20070507113753.GA5439@schatzie.adilger.int> <20070507135825.f8545a65.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Amit K. Arora" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, xfs@oss.sgi.com, suparna@in.ibm.com, cmm@us.ibm.com To: Andrew Morton Return-path: Content-Disposition: inline In-Reply-To: <20070507135825.f8545a65.akpm@linux-foundation.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On May 07, 2007 13:58 -0700, Andrew Morton wrote: > Final point: it's fairly disappointing that the present implementation is > ext4-only, and extent-only. I do think we should be aiming at an ext4 > bitmap-based implementation and an ext3 implementation. Actually, this is a non-issue. The reason that it is handled for extent-only is that this is the only way to allocate space in the filesystem without doing the explicit zeroing. For other filesystems (including ext3 and ext4 with block-mapped files) the filesystem should return an error (e.g. -EOPNOTSUPP) and glibc will do manual zero-filling of the file in userspace. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.