pNFS: LAYOUTRETURN should only update the stateid if the layout is valid

If the layout was completely returned, then ignore the returned layout
stateid.
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4proc.c

@@ -8130,7 +8130,7 @@ static void nfs4_layoutreturn_release(void *calldata)
 	pnfs_mark_matching_lsegs_invalid(lo, &freeme, &lrp->args.range,
 			be32_to_cpu(lrp->args.stateid.seqid));
 	pnfs_mark_layout_returned_if_empty(lo);
-	if (lrp->res.lrs_present)
+	if (lrp->res.lrs_present && pnfs_layout_is_valid(lo))
 		pnfs_set_layout_stateid(lo, &lrp->res.stateid, true);
 	pnfs_clear_layoutreturn_waitbit(lo);
 	spin_unlock(&lo->plh_inode->i_lock);

fs/nfs/pnfs.h

@@ -375,6 +375,11 @@ static inline bool nfs_have_layout(struct inode *inode)
 	return NFS_I(inode)->layout != NULL;
 }
 
+static inline bool pnfs_layout_is_valid(const struct pnfs_layout_hdr *lo)
+{
+	return test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) == 0;
+}
+
 static inline struct nfs4_deviceid_node *
 nfs4_get_deviceid(struct nfs4_deviceid_node *d)
 {