From 84e5274f7e6a01044d51f1cfad8b2c2c2ed5eb23 Mon Sep 17 00:00:00 2001
From: =?utf8?q?P=C3=A1draig=20Brady?= <P@draigBrady.com>
Date: Mon, 31 Jan 2011 22:04:35 +0000
Subject: [PATCH] cp: fix the buffer size used when writing zeros

* src/copy.c (write_zeros): This bug caused 4 or 8 bytes to
be written at a time which is very inefficient.  One could
trigger the issue with `cp --sparse=never sparse non-sparse`
on a file system that supports fiemap.
---
 src/copy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/copy.c b/src/copy.c
index 04c678d..f429c00 100644
--- a/src/copy.c
+++ b/src/copy.c
@@ -291,7 +291,7 @@ write_zeros (int fd, uint64_t n_bytes)
 
   while (n_bytes)
     {
-      uint64_t n = MIN (sizeof nz, n_bytes);
+      uint64_t n = MIN (nz, n_bytes);
       if ((full_write (fd, zeros, n)) != n)
         return false;
       n_bytes -= n;
-- 
2.7.4