From owner-svn-src-stable-8@FreeBSD.ORG  Tue Jan 25 23:02:26 2011
Return-Path: <owner-svn-src-stable-8@FreeBSD.ORG>
Delivered-To: svn-src-stable-8@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 48E2E106564A;
	Tue, 25 Jan 2011 23:02:26 +0000 (UTC)
	(envelope-from jilles@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id 1CCE58FC16;
	Tue, 25 Jan 2011 23:02:26 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id p0PN2QV1055535;
	Tue, 25 Jan 2011 23:02:26 GMT (envelope-from jilles@svn.freebsd.org)
Received: (from jilles@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id p0PN2PKk055533;
	Tue, 25 Jan 2011 23:02:26 GMT (envelope-from jilles@svn.freebsd.org)
Message-Id: <201101252302.p0PN2PKk055533@svn.freebsd.org>
From: Jilles Tjoelker <jilles@FreeBSD.org>
Date: Tue, 25 Jan 2011 23:02:25 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org
X-SVN-Group: stable-8
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r217863 - stable/8/usr.bin/sed
X-BeenThere: svn-src-stable-8@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for only the 8-stable src tree
	<svn-src-stable-8.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-stable-8>, 
	<mailto:svn-src-stable-8-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-stable-8>
List-Post: <mailto:svn-src-stable-8@freebsd.org>
List-Help: <mailto:svn-src-stable-8-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-stable-8>, 
	<mailto:svn-src-stable-8-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 25 Jan 2011 23:02:26 -0000

Author: jilles
Date: Tue Jan 25 23:02:25 2011
New Revision: 217863
URL: http://svn.freebsd.org/changeset/base/217863

Log:
  MFC r217133:   sed: Try hard links to make -i target available continually.
  
  When creating a backup file, sed renamed the original before renaming the
  changed copy into place, leading to a short time when no file with the
  original name was present (usually only visible on SMP systems). Try
  creating the backup file using a hard link instead, avoiding this problem.
  If creating the hard link fails for any reason, fall back to the old rename
  method.
  
  When not creating a backup file, sed already renamed the changed copy onto
  the original. This remains unchanged.
  
  PR:		bin/153261
  Submitted by:	Pedro F. Giffuni
  Reviewed by:	dds (older version)
  Obtained from:	Illumos

Modified:
  stable/8/usr.bin/sed/main.c
Directory Properties:
  stable/8/usr.bin/sed/   (props changed)

Modified: stable/8/usr.bin/sed/main.c
==============================================================================
--- stable/8/usr.bin/sed/main.c	Tue Jan 25 22:55:50 2011	(r217862)
+++ stable/8/usr.bin/sed/main.c	Tue Jan 25 23:02:25 2011	(r217863)
@@ -338,18 +338,35 @@ mf_fgets(SPACE *sp, enum e_spflag spflag
 		if (infile != NULL) {
 			fclose(infile);
 			if (*oldfname != '\0') {
-				if (rename(fname, oldfname) != 0) {
+				/* if there was a backup file, remove it */
+				unlink(oldfname);
+				/*
+				 * Backup the original.  Note that hard links
+				 * are not supported on all filesystems.
+				 */
+				if ((link(fname, oldfname) != 0) &&
+				   (rename(fname, oldfname) != 0)) {
 					warn("rename()");
-					unlink(tmpfname);
+					if (*tmpfname)
+						unlink(tmpfname);
 					exit(1);
 				}
 				*oldfname = '\0';
 			}
 			if (*tmpfname != '\0') {
 				if (outfile != NULL && outfile != stdout)
-					fclose(outfile);
+					if (fclose(outfile) != 0) {
+						warn("fclose()");
+						unlink(tmpfname);
+						exit(1);
+					}
 				outfile = NULL;
-				rename(tmpfname, fname);
+				if (rename(tmpfname, fname) != 0) {
+					/* this should not happen really! */
+					warn("rename()");
+					unlink(tmpfname);
+					exit(1);
+				}
 				*tmpfname = '\0';
 			}
 			outfname = NULL;