From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAC5BC282DD for ; Tue, 23 Apr 2019 08:29:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7A6E220645 for ; Tue, 23 Apr 2019 08:29:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BuBIkpxD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727201AbfDWI3C (ORCPT ); Tue, 23 Apr 2019 04:29:02 -0400 Received: from mail-it1-f194.google.com ([209.85.166.194]:35671 "EHLO mail-it1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725888AbfDWI3A (ORCPT ); Tue, 23 Apr 2019 04:29:00 -0400 Received: by mail-it1-f194.google.com with SMTP id w15so22420608itc.0; Tue, 23 Apr 2019 01:29:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=gNYp5B3WW49wZuSSd+AU4UVnQVS79h4V7MG01aCk1c4=; b=BuBIkpxDnqhVJQGHtHsevkVcisx8RJSEdl3bpUqmj9luxaikK6hvXmmbttnMEWmrZ/ BW2x7ne3jfVbZgtzkn1N3GIVELGJ/3XB1nWojR+h3w7D8wrVzDrkSZ1zwoT/s36CFxo+ RhIWH2MHdf2bwXXp31WRrE8fbiQ4I2HrjvSQMpxxA4RaqC4vn9/wpxRdtzekIdz/zGup UP7i09Pt/cUBlcecq3NkxTYi1qkC+M5XY89dac/u6qcm1DGgt1kbBPbCAIqElT6/BTnU HnZBAN4PHEaqKjWHh7v9PJA1N1fcAR9BHSf0OsBRtkF46+MdV3dZzxnadWZS7O1S3gXr VusA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=gNYp5B3WW49wZuSSd+AU4UVnQVS79h4V7MG01aCk1c4=; b=dZNRwpb++/FTy3Kby+rnfqgRJ1MIXAaD+WCalN1opBzMrLsDS3Er7JhEvmOM9bwYic jKRNUjnLEa34vG0Qq3U0gks5/eqIuF4TfEUr5QRagmaDqWGaqb8twvOIYsXsp6ZUcR+5 M/1Bk6rAT+t8YRI1gPvinudjZ/1Ah16745Cql1hNDCZUmFyNnUjI66yT7bVIw8uITh+U 7OZmyB0///gr1W1bMZlLaKqbD/GQX1Gn97hGE58we22MoweOMzJD+faryVXgNW0yIFPt yWsq2dFBdvX/eyHEXrCm9KYQ8G2+RV8aUKS1UFfAaME0uqL0P6lT08iDx+D6PO5iU6ar OMGg== X-Gm-Message-State: APjAAAWZfTQL8FJJId+rcUSY9KBLg8YwN6YxCQnvu9IYwtp+7l9hBHti uwHSWZvPB21TGBKrVCKhflC4tfmAQwU3Kw4zFnU= X-Google-Smtp-Source: APXvYqzLDCMUCv6ZvlQ0I9CVUZt9W66tc9GWIZDk1Mun3mpum1TYnPYBmKPnhwPaaahn0GMdUcIHk6lNrNJ60EsoHH4= X-Received: by 2002:a02:c4cf:: with SMTP id h15mr16634119jaj.96.1556008139688; Tue, 23 Apr 2019 01:28:59 -0700 (PDT) MIME-Version: 1.0 References: <20190422194205.10404-1-sashal@kernel.org> <20190422194205.10404-61-sashal@kernel.org> In-Reply-To: <20190422194205.10404-61-sashal@kernel.org> From: Ilya Dryomov Date: Tue, 23 Apr 2019 10:28:56 +0200 Message-ID: Subject: Re: [PATCH AUTOSEL 5.0 61/98] libceph: fix breakage caused by multipage bvecs To: Sasha Levin Cc: LKML , stable@vger.kernel.org, Ceph Development , netdev Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 22, 2019 at 9:44 PM Sasha Levin wrote: > > From: Ilya Dryomov > > [ Upstream commit 187df76325af5d9e12ae9daec1510307797e54f0 ] > > A bvec can now consist of multiple physically contiguous pages. > This means that bvec_iter_advance() can move to a different page while > staying in the same bvec (i.e. ->bi_bvec_done != 0). > > The messenger works in terms of segments which can now be defined as > the smaller of a bvec and a page. The "more bytes to process in this > segment" condition holds only if bvec_iter_advance() leaves us in the > same bvec _and_ in the same page. On next bvec (possibly in the same > page) and on next page (possibly in the same bvec) we may need to set > ->last_piece. > > Signed-off-by: Ilya Dryomov > Signed-off-by: Sasha Levin (Microsoft) > --- > net/ceph/messenger.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c > index 7e71b0df1fbc..3083988ce729 100644 > --- a/net/ceph/messenger.c > +++ b/net/ceph/messenger.c > @@ -840,6 +840,7 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor, > size_t bytes) > { > struct ceph_bio_iter *it = &cursor->bio_iter; > + struct page *page = bio_iter_page(it->bio, it->iter); > > BUG_ON(bytes > cursor->resid); > BUG_ON(bytes > bio_iter_len(it->bio, it->iter)); > @@ -851,7 +852,8 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor, > return false; /* no more data */ > } > > - if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done)) > + if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done && > + page == bio_iter_page(it->bio, it->iter))) > return false; /* more bytes to process in this segment */ > > if (!it->iter.bi_size) { > @@ -899,6 +901,7 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor, > size_t bytes) > { > struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs; > + struct page *page = bvec_iter_page(bvecs, cursor->bvec_iter); > > BUG_ON(bytes > cursor->resid); > BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter)); > @@ -910,7 +913,8 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor, > return false; /* no more data */ > } > > - if (!bytes || cursor->bvec_iter.bi_bvec_done) > + if (!bytes || (cursor->bvec_iter.bi_bvec_done && > + page == bvec_iter_page(bvecs, cursor->bvec_iter))) > return false; /* more bytes to process in this segment */ > > BUG_ON(cursor->last_piece); Same here, shouldn't be needed. Thanks, Ilya