From: Jim Meyering <meyering@redhat.com>
Date: Thu, 27 Jan 2011 16:30:08 +0000 (+0100)
Subject: fiemap copy: avoid a performance hit due to very small buffer
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=33f4a4a549afb3de94e546091c91586a1ece67ba;p=thirdparty%2Fcoreutils.git

fiemap copy: avoid a performance hit due to very small buffer

* src/copy.c (extent_copy): Don't let what should have been a
temporary reduction of buf_size (to handle a short ext_len) become
permanent and thus impact the performance of all further iterations.
---

diff --git a/src/copy.c b/src/copy.c
index ab18a76b47..9a3a8f7a6e 100644
--- a/src/copy.c
+++ b/src/copy.c
@@ -270,9 +270,8 @@ extent_copy (int src_fd, int dest_fd, char *buf, size_t buf_size,
             {
               /* Don't read from a following hole if EXT_LEN
                  is smaller than the buffer size.  */
-              buf_size = MIN (ext_len, buf_size);
-
-              ssize_t n_read = read (src_fd, buf, buf_size);
+              size_t b_size = MIN (ext_len, buf_size);
+              ssize_t n_read = read (src_fd, buf, b_size);
               if (n_read < 0)
                 {
 #ifdef EINTR