From: Andrew Bartlett <abartlet@samba.org>
Date: Tue, 25 Sep 2012 23:48:48 +0000 (+1000)
Subject: samba_dnsupdate: Move to using tmpfile/rename to keep the dns_hosts_file consistent
X-Git-Tag: talloc-2.0.8~138
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6d7c651f2f61b481c1e1ade1e2e0e756ccef2210;p=thirdparty%2Fsamba.git

samba_dnsupdate: Move to using tmpfile/rename to keep the dns_hosts_file consistent

This may be the cause of some of the large failure modes on the build farm.

Andrew Bartlett
---

diff --git a/source3/Makefile.in b/source3/Makefile.in
index 2ad8eccdb2a..0e72feae794 100644
--- a/source3/Makefile.in
+++ b/source3/Makefile.in
@@ -3328,7 +3328,7 @@ test:: all torture timelimit
 		VFSLIBDIR="$(builddir)/bin" \
 		RUN_FROM_BUILD_FARM="$(RUN_FROM_BUILD_FARM)" \
 		SUBUNIT_FORMATTER="$(SUBUNIT_FORMATTER)" \
-		PERL="$(PERL)" PYTHON="$(PYTHON)" \
+		PERL="$(PERL)" PYTHON="$(PYTHON)" PYTHONPATH="$(srcdir)/../bin/python" \
 		$(srcdir)/selftest/s3-selftest.sh
 
 test-%:
diff --git a/source4/scripting/bin/samba_dnsupdate b/source4/scripting/bin/samba_dnsupdate
index d21496ca219..ab873564840 100755
--- a/source4/scripting/bin/samba_dnsupdate
+++ b/source4/scripting/bin/samba_dnsupdate
@@ -278,10 +278,17 @@ def call_nsupdate(d):
         print "Calling nsupdate for %s" % d
 
     if opts.use_file is not None:
-        wfile = open(opts.use_file, 'a')
-        fcntl.lockf(wfile, fcntl.LOCK_EX)
+        rfile = open(opts.use_file, 'r+')
+        fcntl.lockf(rfile, fcntl.LOCK_EX)
+        (file_dir, file_name) = os.path.split(opts.use_file)
+        (tmp_fd, tmpfile) = tempfile.mkstemp(dir=file_dir, prefix=file_name, suffix="XXXXXX")
+        wfile = os.fdopen(tmp_fd, 'a')
+        rfile.seek(0)
+        for line in rfile:
+            wfile.write(line)
         wfile.write(str(d)+"\n")
-        fcntl.lockf(wfile, fcntl.LOCK_UN)
+        os.rename(tmpfile, opts.use_file)
+        fcntl.lockf(rfile, fcntl.LOCK_UN)
         return
 
     normalised_name = d.name.rstrip('.') + '.'