From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [pnfs] [PATCH] nfs41: get rid of unused struct nfs41_exchange_id_res members Date: Tue, 5 May 2009 18:43:02 -0400 Message-ID: <20090505224302.GF27790@fieldses.org> References: <89c397150905010756h503498d4n9fd2f8bb3ce403c3@mail.gmail.com> <1241208886-5748-1-git-send-email-bhalevy@panasas.com> <1241552053.5174.44.camel@heimdal.trondhjem.org> <1241552374.5174.48.camel@heimdal.trondhjem.org> <1241552508.5174.50.camel@heimdal.trondhjem.org> <4A00A187.4040801@panasas.com> <4A00A309.8000305@panasas.com> <1241561521.5174.97.camel@heimdal.trondhjem.org> <4A00BA9D.6080501@panasas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.fieldses.org ([141.211.133.115]:36144 "EHLO pickle.fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752169AbZEEWnI (ORCPT ); Tue, 5 May 2009 18:43:08 -0400 Content-Disposition: inline In-Reply-To: <4A00BA9D.6080501@panasas.com> Sender: linux-next-owner@vger.kernel.org List-ID: To: Benny Halevy Cc: Trond Myklebust , Andy Adamson , pnfs@linux-nfs.org, linux-next@vger.kernel.org, Stephen Rothwell On Wed, May 06, 2009 at 01:15:57AM +0300, Benny Halevy wrote: > On 2009-05-06 01:12, Trond Myklebust wrote: > > On Tue, 2009-05-05 at 23:35 +0300, Benny Halevy wrote: > >> On 2009-05-05 23:28, Benny Halevy wrote: > >>> On May. 05, 2009, 22:41 +0300, Trond Myklebust wrote: > >>>> On Tue, 2009-05-05 at 15:39 -0400, Trond Myklebust wrote: > >>>>> On Tue, 2009-05-05 at 15:34 -0400, Trond Myklebust wrote: > >>>>>> On Fri, 2009-05-01 at 23:14 +0300, Benny Halevy wrote: > >>>>>>> struct nfs41_exchange_id_res is currently allocated on the stack > >>>>>>> insanely taking over 2K of stack space due to the NFS4_OPAQUE_LIMIT (1K( > >>>>>>> byte arrays embedded in server_owner and server_scope. > >>>>>>> Since these are not in use yet, this patch gets rid of them for the > >>>>>>> time being. > >>>>>>> > >>>>>>> Signed-off-by: Benny Halevy > >>>>>>> --- > >>>>>>> fs/nfs/nfs4xdr.c | 27 ++++++++++++++------------- > >>>>>>> include/linux/nfs_xdr.h | 3 --- > >>>>>>> 2 files changed, 14 insertions(+), 16 deletions(-) > >>>>>>> > >>>>>>> diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c > >>>>>>> index 80af0ae..3350d19 100644 > >>>>>>> --- a/fs/nfs/nfs4xdr.c > >>>>>>> +++ b/fs/nfs/nfs4xdr.c > >>>>>>> @@ -4185,8 +4185,8 @@ static int decode_delegreturn(struct xdr_stream *xdr) > >>>>>>> static int decode_exchange_id(struct xdr_stream *xdr, > >>>>>>> struct nfs41_exchange_id_res *res) > >>>>>>> { > >>>>>>> - uint32_t *p; > >>>>>>> - int status, dummy; > >>>>>>> + uint32_t *p, dummy; > >>>> Oh, and 'p' _always_ has to be of type '__be32', otherwise the 'sparse' > >>>> checker will yell at you. > >>> Thanks! I'll send a fixed version > >>> of this patch and also look into the rest of the xdr code. > >>> > >>>>>>> + int status; > >>>>>>> struct nfs_client *clp = res->client; > >>>>>>> > >>>>>>> status = decode_op_hdr(xdr, OP_EXCHANGE_ID); > >>>>>>> @@ -4204,25 +4204,26 @@ static int decode_exchange_id(struct xdr_stream *xdr, > >>>>>>> if (dummy != SP4_NONE) > >>>>>>> return -EIO; > >>>>>>> > >>>>>>> - /* minor_id */ > >>>>>>> + /* Throw away minor_id */ > >>>>>>> READ_BUF(8); > >>>>>>> - READ64(res->server_owner.minor_id); > >>>>>>> + p += 8; > >>>>>> ^^^^^^^^ Err... This isn't the same thing at all! > >>> Ouch, of course. What did I smoke that day? > >>> > >>>>>> You're suddenly skipping 10=words instead of the original 2. READ_BUF() > >>>>>> will already take care of updating the 'p' pointer. > >>> Which p? > >>> It takes care of argp->p, not the local 'p' variable, doesn't it. > >> Grr, I meant "xdr->p" of course, via xdr_inline_decode > >> (argp is the server's READ_BUF, sigh) > >> > >>> p += 2 has an equivalent side effect on 'p' as doing READ64. > >>> I can do "p = argp;" instead though to reset 'p' onto > >> p = xdr->p; ... > > > > Not necessary. Look again at the first line of the READ_BUF(nbytes) > > macro: > > > > p = xdr_inline_decode(xdr, nbytes); > > > > So the value of 'p' is always correctly set to the beginning of the > > buffer of length 'nbytes'. > > Right, but then we want to skip over the buffer. > > > > > I'll make a point of removing those macro references from the client > > code in the next week or so. I'm getting really tired of them... > > Yeah, I'm all for it. > Let me know if there's anything I can do to help with that. Ditto. (I'll probably follow your example in fs/nfsd.) --b.