From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Altaparmakov Subject: Re: stat64 for over 2TB file returned invalid st_blocks Date: Thu, 08 Dec 2005 14:50:46 +0000 Message-ID: <1134053446.17436.51.camel@imp.csi.cam.ac.uk> References: <000001c5fb1d$0a27c8d0$4168010a@bsd.tnes.nec.co.jp> <1133963528.27373.4.camel@lade.trondhjem.org> <1133967716.8910.5.camel@kleikamp.austin.ibm.com> <1133969671.27373.47.camel@lade.trondhjem.org> <1133973247.8907.33.camel@kleikamp.austin.ibm.com> <02ab01c5fbeb$faf7d740$4168010a@bsd.tnes.nec.co.jp> <1134052043.7998.26.camel@lade.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Takashi Sato , Dave Kleikamp , 'Andreas Dilger' , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Return-path: To: Trond Myklebust In-Reply-To: <1134052043.7998.26.camel@lade.trondhjem.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, 2005-12-08 at 09:27 -0500, Trond Myklebust wrote: > On Thu, 2005-12-08 at 20:38 +0900, Takashi Sato wrote: > > > I prefer sector_t for i_blocks rather than newly defined blkcnt_t. > > The reasons are: > > > > - Both i_blocks and common sector_t are for on-disk 512-byte unit. > > In this point of view, they have the same character. > > One is a count of the number of blocks used by a file, and exists only > in order to help filesystems cache this value. The other is a handle to > a block. How is that the same? > > > - If we created the type blkcnt_t newly, the patch would have to > > touch a lot of files as follows, like sector_t does. > > block/Kconfig, asm-i386/types.h, asm-x86_64/types.h, > > asm-ppc/types.h, asm-s390/types.h, asm-sh/types.h, > > asm-h8300/types.h, asm-mips/types.h > > It will be simple if we use sector_t for i_blocks. > > That is not a particularly good reason. > > > Also, I cannot imagine the situation that > 2TB files are used over > > network with CONFIG_LBD disabled kernel. Is there such a thing > > realistically? > > Apart from this and the kstat wart, there is no reason to set CONFIG_LBD > for a networked filesystem. Why would you want to buy a > 2TB local disk > on an HPC cluster node if you already have a server? > > I suppose we can make NFS use a private field instead, and just set > i_blocks to 0, but that's unnecessarily wasteful too. And it breaks applications, too (e.g. du will then report all your files to be zero size)... Best regards, Anton -- Anton Altaparmakov (replace at with @) Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK Linux NTFS maintainer / IRC: #ntfs on irc.freenode.net WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/