From 75247affd7930cc3dcf57f850f0d7898379ef3b3 Mon Sep 17 00:00:00 2001
From: Benny Halevy <bhalevy@panasas.com>
Date: Tue, 22 Feb 2011 15:56:01 -0800
Subject: [PATCH] NFSv4.1: reject zero layout with zeroed stripe unit

Allowing stripe_unit==0 causes the client to crash later on
when dividing by zero.

Reported-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---
 fs/nfs/nfs4filelayout.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 7e1d4571b7b2..428558464817 100644
--- a/fs/nfs/nfs4filelayout.c
+++ b/fs/nfs/nfs4filelayout.c
@@ -369,8 +369,8 @@ filelayout_check_layout(struct pnfs_layout_hdr *lo,
 		goto out;
 	}
 
-	if (fl->stripe_unit % PAGE_SIZE) {
-		dprintk("%s Stripe unit (%u) not page aligned\n",
+	if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
+		dprintk("%s Invalid stripe unit (%u)\n",
 			__func__, fl->stripe_unit);
 		goto out;
 	}