From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755479Ab2CMUu1 (ORCPT ); Tue, 13 Mar 2012 16:50:27 -0400 Received: from ozlabs.org ([203.10.76.45]:56602 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752371Ab2CMUu0 (ORCPT ); Tue, 13 Mar 2012 16:50:26 -0400 Date: Wed, 14 Mar 2012 07:50:10 +1100 From: Anton Blanchard To: David Howells Cc: linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: [PATCH] afs: Read of file returns EBADMSG Message-ID: <20120314075010.4bd92311@kryten> X-Mailer: Claws Mail 3.7.8 (GTK+ 2.24.4; 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A read of a large file on an afs mount failed: # cat junk.file > /dev/null cat: junk.file: Bad message Looking at the trace, call->offset wrapped since it is only an unsigned short. In afs_extract_data: _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count); ... if (call->offset < count) { if (last) { _leave(" = -EBADMSG [%d < %zu]", call->offset, count); return -EBADMSG; } Which matches the trace: [cat ] ==> afs_extract_data({65132},{524},1,,65536) [cat ] <== afs_extract_data() = -EBADMSG [0 < 65536] call->offset went from 65132 to 0. Fix this by making call->offset an unsigned int. Signed-off-by: Anton Blanchard Cc: --- Index: linux-build/fs/afs/internal.h =================================================================== --- linux-build.orig/fs/afs/internal.h 2012-03-14 07:47:22.169945898 +1100 +++ linux-build/fs/afs/internal.h 2012-03-14 07:47:32.398126509 +1100 @@ -109,7 +109,7 @@ struct afs_call { unsigned reply_size; /* current size of reply */ unsigned first_offset; /* offset into mapping[first] */ unsigned last_to; /* amount of mapping[last] */ - unsigned short offset; /* offset into received data store */ + unsigned offset; /* offset into received data store */ unsigned char unmarshall; /* unmarshalling phase */ bool incoming; /* T if incoming call */ bool send_pages; /* T if data from mapping should be sent */