From mboxrd@z Thu Jan 1 00:00:00 1970 From: Max Subject: Re: files of size larger than fs size Date: Tue, 15 Mar 2005 18:57:40 -0800 Message-ID: <4237A0A4.9000103@unn.ac.ru> References: <42379750.9030604@unn.ac.ru> <42378A0E.90401@lougher.demon.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org Received: from pimout4-ext.prodigy.net ([207.115.63.98]:28304 "EHLO pimout4-ext.prodigy.net") by vger.kernel.org with ESMTP id S262483AbVCPC5u (ORCPT ); Tue, 15 Mar 2005 21:57:50 -0500 To: Phillip Lougher In-Reply-To: <42378A0E.90401@lougher.demon.co.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Thanks for the explanation. I closed my bugreport as INVALID. But anyway it's ineteresting why the resulting sparse files have different size on different fs? Max Phillip Lougher wrote: > Max wrote: > >> Hello! >> >> I've discovered that it is possible to create files of size much >> larger than partition size. >> I thought that this is JFS bug, so I've filed a bugreport against it >> at http://bugzilla.kernel.org/show_bug.cgi?id=4345 >> Detailed info and testcase program are provided there. >> >> Later I've found that at least XFS and EXT3 filesystems have the same >> problem (though the resulting filesize is different for each fs). So >> the problem may be not in fs code but in some other piece of kernel. >> >> Could kernel gurus please investigate the problem? >> > > Your test case isn't writing a full file, it is only writing 4 bytes at > various offsets (1^32, 1^40, 1^48, 1^56). > > The filesystems you mention support files with "holes" in them, in > otherwords they support gaps between data which don't take up any storage. > > Even though your test case is creating a huge file, only a couple of > bytes are written, the rest of the huge file doesn't take up any space. > > The behaviour you're seeing isn't a bug... > > Phillip Lougher > > > - > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >