From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx147.postini.com [74.125.245.147]) by kanga.kvack.org (Postfix) with SMTP id 499BC6B0083 for ; Thu, 24 May 2012 09:37:34 -0400 (EDT) Received: by ggm4 with SMTP id 4so10950415ggm.14 for ; Thu, 24 May 2012 06:37:33 -0700 (PDT) Date: Thu, 24 May 2012 21:38:21 +0800 From: "majianpeng" Subject: the max size of block device on 32bit os,when using do_generic_file_read() proceed. Message-ID: <201205242138175936268@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: akpm , hughd Cc: linux-mm Hi all: I readed a raid5,which size 30T.OS is RHEL6 32bit. I reaed the raid5(as a whole,not parted) and found read address which not i wanted. So I tested the newest kernel code,the problem is still. I review the code, in function do_generic_file_read() index = *ppos >> PAGE_CACHE_SHIFT; index is u32.and *ppos is long long. So when *ppos is larger than 0xFFFF FFFF * PAGE_CACHE_SHIFT(16T Byte),then the index is error. I wonder this .In 32bit os ,block devices size do not large then 16T,in other words, if block devices larger than 16T,must parted. Thanks all. -------------- majianpeng 2012-05-24 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org