From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266665AbUGVJlq (ORCPT ); Thu, 22 Jul 2004 05:41:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266670AbUGVJlq (ORCPT ); Thu, 22 Jul 2004 05:41:46 -0400 Received: from [194.243.27.136] ([194.243.27.136]:34322 "HELO venere.pandoraonline.it") by vger.kernel.org with SMTP id S266665AbUGVJli (ORCPT ); Thu, 22 Jul 2004 05:41:38 -0400 X-Qmail-Scanner-Mail-From: devel@integra-sc.it via venere.pandoraonline.it X-Qmail-Scanner-Rcpt-To: shesha@inostor.com,linux-kernel@vger.kernel.org,kernelnewbies@nl.linux.org X-Qmail-Scanner: 1.22 (Clear:RC:1(213.140.22.76):. Processed in 0.056464 secs) Date: Thu, 22 Jul 2004 11:46:45 +0200 From: Devel To: Shesha Sreenivasamurthy Cc: linux-kernel@vger.kernel.org, kernelnewbies@nl.linux.org Subject: Re: O_DIRECT Message-Id: <20040722114645.4b64429b.devel@integra-sc.it> In-Reply-To: <40FE9F3F.2090205@inostor.com> References: <40FD561D.1010404@inostor.com> <20040720184824.GA30090@outpost.ds9a.nl> <20040721164510.3086b49f.devel@integra-sc.it> <40FE9F3F.2090205@inostor.com> Organization: Integra Solutions X-Mailer: Sylpheed version 0.9.10 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Thanks a lot for your answare. So if i would write information on a partition without a fs i have to write additional information to "retrive" the first one. Do you know some readable material about o project about that? Il Wed, 21 Jul 2004 09:52:15 -0700 Shesha Sreenivasamurthy scrisse: > Usually what you do is, partition the disk, create filesystem and read > or write files. > Reading and writing is without a filesystem. > Assume you have maintained some superblock information of your own > driver say last 512 bytes you have designated as superblock. You can > seek to that position and read the last 512 bytes which is meaningful > only to you. Note that I am read/writing raw bytes not any file. > Therefore you can read/write without a filesystem and even without any > partition, > > -Shesha > > > Devel wrote: > > >Hi all, > >how i can write data on a partition without a filesystem?? > > > >Saluti Carlo! > > > >Il Tue, 20 Jul 2004 20:48:24 +0200 > >bert hubert scrisse: > > > > > > > >>On Tue, Jul 20, 2004 at 10:27:57AM -0700, Shesha Sreenivasamurthy wrote: > >> > >> > >>>I am having trouble with O_DIRECT. Trying to read or write from a block > >>>device partition. > >>> > >>>1. Can O_DIRECT be used on a plain block device partition say > >>>"/dev/sda11" without having a filesystem on it. > >>> > >>> > >>As fas as I know, yes, but be aware that O_DIRECT requires page aligned > >>addresses! (an integral of 4096 on most systems). > >> > >> > >> > >>>2. If no file system is created then what should be the softblock size. > >>>I am using the IOCTL "BLKBSZGET". Is this correct? > >>> > >>> > >>No idea what you mean - but see above about the aligned addresses. > >> > >> > >> > >>>3. Can we use SEEK_END with O_DIRECT on a partition without filesystem. > >>> > >>> > >>I see no reason why not. Good luck! > >> > >>-- > >>http://www.PowerDNS.com Open source, database driven DNS Software > >>http://lartc.org Linux Advanced Routing & Traffic Control HOWTO > >>- > >>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/ > >> > >> > >> > > > >-- > >Kernelnewbies: Help each other learn about the Linux kernel. > >Archive: http://mail.nl.linux.org/kernelnewbies/ > >FAQ: http://kernelnewbies.org/faq/ > > > > > >. > > > > > > >