From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trond Myklebust Subject: Re: [PATCH 7/7] nfsd: nfs4xdr decode_stateid helper function Date: Wed, 13 Aug 2008 13:59:09 -0400 Message-ID: <1218650349.9042.20.camel@localhost> References: <48A1CB0C.4090906@panasas.com> <1218563178-25480-1-git-send-email-bhalevy@panasas.com> <20080812190410.GC30729@fieldses.org> <48A28DEA.5060406@panasas.com> <20080813150329.GF21004@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain Cc: Benny Halevy , NFS list , pNFS Mailing List , Chuck Lever To: "J. Bruce Fields" Return-path: Received: from mail-out2.uio.no ([129.240.10.58]:52405 "EHLO mail-out2.uio.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752178AbYHMR7X (ORCPT ); Wed, 13 Aug 2008 13:59:23 -0400 In-Reply-To: <20080813150329.GF21004@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, 2008-08-13 at 11:03 -0400, J. Bruce Fields wrote: > On Wed, Aug 13, 2008 at 10:31:54AM +0300, Benny Halevy wrote: > > On Aug. 12, 2008, 22:04 +0300, "J. Bruce Fields" wrote: > > > On Tue, Aug 12, 2008 at 08:46:18PM +0300, Benny Halevy wrote: > > >> Signed-off-by: Benny Halevy > > >> --- > > >> fs/nfsd/nfs4xdr.c | 99 +++++++++++++++++++++++++++++----------------------- > > >> 1 files changed, 55 insertions(+), 44 deletions(-) > > >> > > >> diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c > > >> index 47ac498..9570b1b 100644 > > >> --- a/fs/nfsd/nfs4xdr.c > > >> +++ b/fs/nfsd/nfs4xdr.c > > >> static __be32 > > >> @@ -929,9 +939,10 @@ nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write) > > >> int len; > > >> DECODE_HEAD; > > >> > > >> - READ_BUF(sizeof(stateid_opaque_t) + 20); > > >> - READ32(write->wr_stateid.si_generation); > > >> - COPYMEM(&write->wr_stateid.si_opaque, sizeof(stateid_opaque_t)); > > >> + status = nfsd4_decode_stateid(argp, &write->wr_stateid); > > >> + if (status) > > >> + return status; > > >> + READ_BUF(16); > > > > > > How did that 20 become a 16? > > > > It was sizeof(stateid_opaque_t) + 20 == sizeof(stateid_t) - 4 + 20 == > > sizeof(stateid_t) + 16. > > Whoops! Even now I still fall into the stateid_opaque_t/stateid_t trap! Which is a good reason for ditching the entire confusing typedef, and replacing it with a packed structure instead: struct stateid { __be32 generation; char opaque[12]; } __attribute__((packed)); Trond