From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1945940AbbDXUbg (ORCPT ); Fri, 24 Apr 2015 16:31:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32966 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031005AbbDXUbc (ORCPT ); Fri, 24 Apr 2015 16:31:32 -0400 From: Jeff Moyer To: Christoph Hellwig Cc: Jens Axboe , Tejun Heo , Ming Lin , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] block: remove BIO_EOPNOTSUPP References: <1429904462-16998-1-git-send-email-hch@lst.de> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Fri, 24 Apr 2015 16:31:29 -0400 In-Reply-To: <1429904462-16998-1-git-send-email-hch@lst.de> (Christoph Hellwig's message of "Fri, 24 Apr 2015 21:41:01 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig writes: > Since the big barrier rewrite/removal in 2007 we never fail FLUSH or > FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag > to help propagating those to the buffer_head layer. I had a look through the kernel, checking for places where maybe we were relying on an EOPNOTSUPP from REQ_DISCARD, just to ensure you weren't pulling out an error path that could still be used. I think everything checks out. > diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h > index 992ef58..c2ee937 100644 > --- a/include/linux/blk_types.h > +++ b/include/linux/blk_types.h > @@ -118,7 +118,6 @@ struct bio { > #define BIO_CLONED 4 /* doesn't own data */ > #define BIO_BOUNCED 5 /* bio is a bounce bio */ > #define BIO_USER_MAPPED 6 /* contains user pages */ > -#define BIO_EOPNOTSUPP 7 /* not supported */ > #define BIO_NULL_MAPPED 8 /* contains invalid user pages */ > #define BIO_QUIET 9 /* Make BIO Quiet */ > #define BIO_SNAP_STABLE 10 /* bio data must be snapshotted during write */ Should we leave a hole in the numbering scheme? Reviewed-by: Jeff Moyer