[PATCH] knfsd: fix return value for writes to some files in 'nfsd' filesystem

Most files in the 'nfsd' filesystem are transactional.  When you write, a
reply is generated that can be read back only on the same 'file'.

If the reply has zero length, the 'write' will incorrectly return a value of
'0' instead of the length that was written.  This causes 'rpc.nfsd' to give an
annoying warning.

This patch fixes the test.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/nfsd/nfsctl.c

@@ -123,7 +123,7 @@ static ssize_t nfsctl_transaction_write(struct file *file, const char __user *bu
 		return PTR_ERR(data);
 
 	rv =  write_op[ino](file, data, size);
-	if (rv>0) {
+	if (rv >= 0) {
 		simple_transaction_set(file, rv);
 		rv = size;
 	}