From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031685AbXEHTrj (ORCPT ); Tue, 8 May 2007 15:47:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031678AbXEHTr1 (ORCPT ); Tue, 8 May 2007 15:47:27 -0400 Received: from mx1.redhat.com ([66.187.233.31]:49403 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031665AbXEHTrW (ORCPT ); Tue, 8 May 2007 15:47:22 -0400 Date: Tue, 8 May 2007 20:47:12 +0100 From: Alasdair G Kergon To: Andrew Morton Cc: dm-devel@redhat.com, linux-kernel@vger.kernel.org, Heinz Mauelshagen , Milan Broz Subject: [2.6.22 PATCH 14/26] dm io: delay dec_count Message-ID: <20070508194712.GU24114@agk.fab.redhat.com> Mail-Followup-To: Andrew Morton , dm-devel@redhat.com, linux-kernel@vger.kernel.org, Heinz Mauelshagen , Milan Broz Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Organization: Red Hat UK Ltd. Registered in England and Wales, number 04098903. Registered Office: Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Heinz Mauelshagen Delay decrementing the 'struct io' reference count until after the bio has been freed so that a bio destructor function may reference it. Required by a later patch. Signed-off-by: Heinz Mauelshagen Signed-off-by: Alasdair G Kergon Cc: Milan Broz --- drivers/md/dm-io.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) Index: linux-2.6.21/drivers/md/dm-io.c =================================================================== --- linux-2.6.21.orig/drivers/md/dm-io.c 2007-05-01 17:38:32.000000000 +0100 +++ linux-2.6.21/drivers/md/dm-io.c 2007-05-01 17:40:52.000000000 +0100 @@ -126,7 +126,8 @@ static void dec_count(struct io *io, uns static int endio(struct bio *bio, unsigned int done, int error) { - struct io *io = (struct io *) bio->bi_private; + struct io *io; + unsigned region; /* keep going until we've finished */ if (bio->bi_size) @@ -135,10 +136,17 @@ static int endio(struct bio *bio, unsign if (error && bio_data_dir(bio) == READ) zero_fill_bio(bio); - dec_count(io, bio_get_region(bio), error); + /* + * The bio destructor in bio_put() may use the io object. + */ + io = bio->bi_private; + region = bio_get_region(bio); + bio->bi_max_vecs++; bio_put(bio); + dec_count(io, region, error); + return 0; }