Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756428AbZJ2GAy (ORCPT ); Thu, 29 Oct 2009 02:00:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756367AbZJ2GAx (ORCPT ); Thu, 29 Oct 2009 02:00:53 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:41373 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756361AbZJ2GAx (ORCPT ); Thu, 29 Oct 2009 02:00:53 -0400 Date: Wed, 28 Oct 2009 23:00:22 -0700 From: Andrew Morton To: Mike Hommey Cc: Alexander Viro , Linus Torvalds , linux-kernel@vger.kernel.org, Steven Whitehouse , "Theodore Ts'o" , Eric Sandeen , Josef Bacik , Mark Fasheh Subject: Re: [PATCH] Fix generic_block_fiemap for files bigger than 4GB Message-Id: <20091028230022.e15b1e9c.akpm@linux-foundation.org> In-Reply-To: <1256577868-30484-1-git-send-email-mh@glandium.org> References: <1256577868-30484-1-git-send-email-mh@glandium.org> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1793 Lines: 48 On Mon, 26 Oct 2009 18:24:28 +0100 Mike Hommey wrote: > Because of an integer overflow on start_blk, various kind of wrong results > would be returned by the generic_block_fiemap handler, such as no extents > when there is a 4GB+ hole at the beginning of the file, or wrong fe_logical > when an extent starts after the first 4GB. > > Signed-off-by: Mike Hommey > --- > fs/ioctl.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/fs/ioctl.c b/fs/ioctl.c > index 7b17a14..6c75110 100644 > --- a/fs/ioctl.c > +++ b/fs/ioctl.c > @@ -254,7 +254,7 @@ int __generic_block_fiemap(struct inode *inode, > u64 len, get_block_t *get_block) > { > struct buffer_head tmp; > - unsigned int start_blk; > + unsigned long long start_blk; > long long length = 0, map_len = 0; > u64 logical = 0, phys = 0, size = 0; > u32 flags = FIEMAP_EXTENT_MERGED; Well. Should it be unsigned long long, or u64 or sector_t? Or even loff_t. The code's a bit confused about types in there. And it's made much more confusing by the moronic and wholly unnecessary use of macros for blk_to_logical() and logical_to_blk(). It's also unhelpful that the `u64 start' argument forgot to get itself documented in the kerneldoc comment. Sigh. Ah, generic_block_fiemap() has it: * @start: The initial block to map I guess u64 was logical there as it comes in from userspace. But at some boundary we should start talking kernel types so I suspect the correct thing to do here is to use sector_t? -- 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/