NFSv4: Only pass the delegation to setattr if we're sending a truncate

Even then it isn't really necessary. The reason why we may not want to
pass in a stateid in other cases is that we cannot use the delegation
credential.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/nfs4proc.c

@@ -3032,7 +3032,6 @@ static int _nfs4_do_setattr(struct inode *inode,
 	};
 	struct rpc_cred *delegation_cred = NULL;
 	unsigned long timestamp = jiffies;
-	fmode_t fmode;
 	bool truncate;
 	int status;
 
@@ -3040,11 +3039,12 @@ static int _nfs4_do_setattr(struct inode *inode,
 
 	/* Servers should only apply open mode checks for file size changes */
 	truncate = (arg->iap->ia_valid & ATTR_SIZE) ? true : false;
-	fmode = truncate ? FMODE_WRITE : FMODE_READ;
+	if (!truncate)
+		goto zero_stateid;
 
-	if (nfs4_copy_delegation_stateid(inode, fmode, &arg->stateid, &delegation_cred)) {
+	if (nfs4_copy_delegation_stateid(inode, FMODE_WRITE, &arg->stateid, &delegation_cred)) {
 		/* Use that stateid */
-	} else if (truncate && ctx != NULL) {
+	} else if (ctx != NULL) {
 		struct nfs_lock_context *l_ctx;
 		if (!nfs4_valid_open_stateid(ctx->state))
 			return -EBADF;
@@ -3056,8 +3056,10 @@ static int _nfs4_do_setattr(struct inode *inode,
 		nfs_put_lock_context(l_ctx);
 		if (status == -EIO)
 			return -EBADF;
-	} else
+	} else {
+zero_stateid:
 		nfs4_stateid_copy(&arg->stateid, &zero_stateid);
+	}
 	if (delegation_cred)
 		msg.rpc_cred = delegation_cred;