From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Layton Subject: Re: [PATCH] ceph: update readpages osd request according to size of pages. Date: Thu, 19 Jan 2017 07:39:21 -0500 Message-ID: <1484829561.2704.1.camel@redhat.com> References: <20170119082423.44545-1-zyan@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-yb0-f180.google.com ([209.85.213.180]:36180 "EHLO mail-yb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751262AbdASNLK (ORCPT ); Thu, 19 Jan 2017 08:11:10 -0500 Received: by mail-yb0-f180.google.com with SMTP id 123so17330986ybe.3 for ; Thu, 19 Jan 2017 05:11:10 -0800 (PST) In-Reply-To: <20170119082423.44545-1-zyan@redhat.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: "Yan, Zheng" , ceph-devel@vger.kernel.org Cc: idryomov@gmail.com On Thu, 2017-01-19 at 16:24 +0800, Yan, Zheng wrote: > add_to_page_cache_lru() can fails, so the actual pages to read > can be smaller than the initial size of osd request. We need to > update osd request size in that case. > > Signed-off-by: "Yan, Zheng" > --- > fs/ceph/addr.c | 1 + > net/ceph/osd_client.c | 3 ++- > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c > index 3985256..4547bbf 100644 > --- a/fs/ceph/addr.c > +++ b/fs/ceph/addr.c > @@ -391,6 +391,7 @@ static int start_read(struct inode *inode, struct list_head *page_list, int max) > nr_pages = i; > if (nr_pages > 0) { > len = nr_pages << PAGE_SHIFT; > + osd_req_op_extent_update(req, 0, len); > break; > } > goto out_pages; > diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c > index 842f049..3a2417b 100644 > --- a/net/ceph/osd_client.c > +++ b/net/ceph/osd_client.c > @@ -672,7 +672,8 @@ void osd_req_op_extent_update(struct ceph_osd_request *osd_req, > BUG_ON(length > previous); > > op->extent.length = length; > - op->indata_len -= previous - length; > + if (op->op == CEPH_OSD_OP_WRITE || op->op == CEPH_OSD_OP_WRITEFULL) > + op->indata_len -= previous - length; > } > EXPORT_SYMBOL(osd_req_op_extent_update); > Looks right, but this special casing of the request types at this layer just seems so nasty. I guess it's unavoidable given the way the protocol works, but I can't help feeling like it's a layering violation when I look at it: Reviewed-by: Jeff Layton