From owner-svn-src-all@FreeBSD.ORG  Mon Nov  3 10:01:57 2014
Return-Path: <owner-svn-src-all@FreeBSD.ORG>
Delivered-To: svn-src-all@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 3C9195BC;
 Mon,  3 Nov 2014 10:01:57 +0000 (UTC)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client did not present a certificate)
 by mx1.freebsd.org (Postfix) with ESMTPS id 2932287A;
 Mon,  3 Nov 2014 10:01:57 +0000 (UTC)
Received: from svn.freebsd.org ([127.0.1.70])
 by svn.freebsd.org (8.14.9/8.14.9) with ESMTP id sA3A1vtr003612;
 Mon, 3 Nov 2014 10:01:57 GMT (envelope-from kib@FreeBSD.org)
Received: (from kib@localhost)
 by svn.freebsd.org (8.14.9/8.14.9/Submit) id sA3A1vY7003611;
 Mon, 3 Nov 2014 10:01:57 GMT (envelope-from kib@FreeBSD.org)
Message-Id: <201411031001.sA3A1vY7003611@svn.freebsd.org>
X-Authentication-Warning: svn.freebsd.org: kib set sender to kib@FreeBSD.org
 using -f
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Mon, 3 Nov 2014 10:01:57 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r274023 - head/sys/kern
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.18-1
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 03 Nov 2014 10:01:57 -0000

Author: kib
Date: Mon Nov  3 10:01:56 2014
New Revision: 274023
URL: https://svnweb.freebsd.org/changeset/base/274023

Log:
  When other end of the pipe closed during the write, but some bytes
  were written, return short write instead of EPIPE.
  
  Update comment.
  
  Discussed with:	bde (long time ago)
  MFC after:	2 weeks

Modified:
  head/sys/kern/sys_pipe.c

Modified: head/sys/kern/sys_pipe.c
==============================================================================
--- head/sys/kern/sys_pipe.c	Mon Nov  3 09:26:39 2014	(r274022)
+++ head/sys/kern/sys_pipe.c	Mon Nov  3 10:01:56 2014	(r274023)
@@ -1296,13 +1296,13 @@ pipe_write(fp, uio, active_cred, flags, 
 	}
 
 	/*
-	 * Don't return EPIPE if I/O was successful
+	 * Don't return EPIPE if any byte was written.
+	 * EINTR and other interrupts are handled by generic I/O layer.
+	 * Do not pretend that I/O succeeded for obvious user error
+	 * like EFAULT.
 	 */
-	if ((wpipe->pipe_buffer.cnt == 0) &&
-	    (uio->uio_resid == 0) &&
-	    (error == EPIPE)) {
+	if (uio->uio_resid != orig_resid && error == EPIPE)
 		error = 0;
-	}
 
 	if (error == 0)
 		vfs_timestamp(&wpipe->pipe_mtime);