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>

diff --git a/fs/nfs/nfs4filelayout.c b/fs/nfs/nfs4filelayout.c
index 7e1d457..4285584 100644 (file)
--- 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;
        }