Return-Path: Received: from daytona.panasas.com ([67.152.220.89]:20116 "EHLO daytona.panasas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932372Ab1EZOSU (ORCPT ); Thu, 26 May 2011 10:18:20 -0400 Message-ID: <4DDE612D.3050807@panasas.com> Date: Thu, 26 May 2011 17:18:21 +0300 From: Boaz Harrosh To: Benny Halevy CC: Trond Myklebust , linux-nfs@vger.kernel.org Subject: Re: [PATCH v8 31/32] NFSv4.1: define nfs_generic_pg_test References: <4DDD7392.6040505@panasas.com> <1306359021-17987-1-git-send-email-bhalevy@panasas.com> In-Reply-To: <1306359021-17987-1-git-send-email-bhalevy@panasas.com> Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On 05/26/2011 12:30 AM, Benny Halevy wrote: > By default, unless pnfs is used coalesce pages until pg_bsize > (rsize or wsize) is reached. > > pnfs layout drivers define their own pg_test methods that use > pnfs_generic_pg_test and need to define their own I/O size > limits (e.g. based on the file stripe size). > > Signed-off-by: Benny Halevy > --- > fs/nfs/pagelist.c | 17 +++++++---------- > 1 files changed, 7 insertions(+), 10 deletions(-) > > diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c > index 0209ffb..c795660 100644 > --- a/fs/nfs/pagelist.c > +++ b/fs/nfs/pagelist.c > @@ -204,6 +204,11 @@ nfs_wait_on_request(struct nfs_page *req) > TASK_UNINTERRUPTIBLE); > } > > +static bool nfs_generic_pg_test(struct nfs_pageio_descriptor *desc, struct nfs_page *prev, struct nfs_page *req) > +{ > + return desc->pg_count + req->wb_bytes <= desc->pg_bsize; > +} > + > /** > * nfs_pageio_init - initialise a page io descriptor > * @desc: pointer to descriptor > @@ -229,7 +234,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc, > desc->pg_ioflags = io_flags; > desc->pg_error = 0; > desc->pg_lseg = NULL; > - desc->pg_test = NULL; > + desc->pg_test = nfs_generic_pg_test; > } > > /** > @@ -259,13 +264,7 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev, > return false; > if (prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE) > return false; > - /* > - * Non-whole file layouts need to check that req is inside of > - * pgio->pg_lseg. > - */ > - if (pgio->pg_test && !pgio->pg_test(pgio, prev, req)) > - return false; > - return true; > + return pgio->pg_test(pgio, prev, req); > } > > /** > @@ -294,8 +293,6 @@ static int nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, > if (desc->pg_bsize < PAGE_SIZE) > return 0; What about this part? what is desc->pg_bsize? Is it not what was negotiated with the MDS? this too should be ignored in PNFS. Maybe just add it to the generic test? me think Boaz > newlen += desc->pg_count; > - if (newlen > desc->pg_bsize) > - return 0; > prev = nfs_list_entry(desc->pg_list.prev); > if (!nfs_can_coalesce_requests(prev, req, desc)) > return 0;