From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "J. Bruce Fields" Date: Sun, 29 Dec 2013 03:08:43 +0100 Message-ID: Subject: [PATCH 3.2 074/185] nfsd4: fix xdr decoding of large non-write compounds In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "J. Bruce Fields" commit 365da4adebb1c012febf81019ad3dc5bb52e2a13 upstream. This fixes a regression from 247500820ebd02ad87525db5d9b199e5b66f6636 "nfsd4: fix decoding of compounds across page boundaries". The previous code was correct: argp->pagelist is initialized in nfs4svc_deocde_compoundargs to rqstp->rq_arg.pages, and is therefore a pointer to the page *after* the page we are currently decoding. The reason that patch nevertheless fixed a problem with decoding compounds containing write was a bug in the write decoding introduced by 5a80a54d21c96590d013378d8c5f65f879451ab4 "nfsd4: reorganize write decoding", after which write decoding no longer adhered to the rule that argp->pagelist point to the next page. Signed-off-by: J. Bruce Fields [bwh: Backported to 3.2: adjust context; there is only one instance to fix] Signed-off-by: Ben Hutchings --- fs/nfsd/nfs4xdr.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -177,8 +177,8 @@ static __be32 *read_buf(struct nfsd4_com */ memcpy(p, argp->p, avail); /* step to next page */ - argp->pagelist++; argp->p = page_address(argp->pagelist[0]); + argp->pagelist++; if (argp->pagelen < PAGE_SIZE) { argp->end = argp->p + (argp->pagelen>>2); argp->pagelen = 0;