Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1164375AbdDXDQi (ORCPT ); Sun, 23 Apr 2017 23:16:38 -0400 Received: from mx2.suse.de ([195.135.220.15]:42816 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1164448AbdDXDQa (ORCPT ); Sun, 23 Apr 2017 23:16:30 -0400 From: NeilBrown To: Ming Lei , Christoph Hellwig Date: Mon, 24 Apr 2017 13:16:21 +1000 Cc: Jens Axboe , linux-block , Linux Kernel Mailing List Subject: Re: [PATCH 11/11] block: don't check for BIO_MAX_PAGES in blk_bio_segment_split() In-Reply-To: References: <149266645258.27388.14083229348123176454.stgit@noble> <149266673048.27388.6882396367486800999.stgit@noble> <20170421113408.GJ12523@infradead.org> Message-ID: <878tmqqyuy.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2156 Lines: 55 --=-=-= Content-Type: text/plain On Fri, Apr 21 2017, Ming Lei wrote: > On Fri, Apr 21, 2017 at 7:34 PM, Christoph Hellwig wrote: >> On Thu, Apr 20, 2017 at 03:38:50PM +1000, NeilBrown wrote: >>> blk_bio_segment_split() makes sure bios have no more than >>> BIO_MAX_PAGES entries in the bi_io_vec. >>> This was done because bio_clone_bioset() (when given a >>> mempool bioset) could not handle larger io_vecs. >>> >>> No driver uses bio_clone_bioset() any more, they all >>> use bio_clone_fast() if anything, and bio_clone_fast() >>> doesn't clone the bi_io_vec. >> >> Hmm. From Jens tree: >> >> drivers/lightnvm/pblk-read.c: int_bio = bio_clone_bioset(bio, GFP_KERNEL, fs_bio_set); >> drivers/md/raid1.c: mbio = bio_clone_bioset_partial(bio, GFP_NOIO, >> drivers/md/raid1.c: mbio = bio_clone_bioset_partial(bio, GFP_NOIO, > > Btrfs use bio_clone_bioset() too: > > fs/btrfs/extent_io.c:2703: new = bio_clone_bioset(bio, > gfp_mask, btrfs_bioset); > btrfs is a filesystem, not a driver. So it doesn't count. The bios it uses were not yet processed by blk_bio_segment_split(), so changes there cannot be relevant to btrfs. Thanks, NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAlj9bgUACgkQOeye3VZi gbkexg//Vu0MbnyaDyQRsfjC0UmYjsGqYCtnyV6DfdpCeu4yQs3NuyVh7VdZMER8 p4h6DP58l2+ZnLCH3qEiDgfsYmkXM7dM6U9bt4Zs2bxTjYiclLTCSS7fORJihA1h XcldClZABiHs3FntbUhEwQJshI4t7mmcKsRr5TZBEuAPYs90rFk+1dSd2zU8ZBuG agoJBnARRCqE07aMiQdhdLucu6VsUvYwMTbQeFnpdySHvBtV//1NIakNWZgvZFeV OdcZWyMEaSGypj9gCp3N+9DzdL8Te+vCWJS7bd7auqayg//NOW9ISlNUChGVUIFF lluLSZQUUR76yw3pkeexYRMQ/79+16SUENiF07/2TjAQOTGwcrQRVu58cGvTdnBK i/Y3PyuzUn2NA0GKF96j1egXNQj1cV460G9jHXbXYRmqjHwGovR0rJWc8lHlicMB qysBYI7Qd/qYh7UNNn4MtfB26sIgaLIteWPWzxCaptD0eKwYJj4CWmD7KUy8eXEd 9xOe5Jx6lgvDOLpspG2WLZf4fH6th1X9hekjUAgvIC5ezmtcc/Sz03ey7JZDmCPD YxFYLCfCZJJig1ygfykX4gd0fYuNhlQ/YXW7h0Bzt0wJUzjsM0PfM+EyHSKY6254 8gk2jpjx3JvtY+4OD+GWW+aKq6jXvhej8ts0CCHa6N0vxfltZcg= =e2/g -----END PGP SIGNATURE----- --=-=-=--