Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267951AbUIGMJa (ORCPT ); Tue, 7 Sep 2004 08:09:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267973AbUIGMJ3 (ORCPT ); Tue, 7 Sep 2004 08:09:29 -0400 Received: from mail.fh-wedel.de ([213.39.232.194]:64424 "EHLO mail.fh-wedel.de") by vger.kernel.org with ESMTP id S267951AbUIGMIi (ORCPT ); Tue, 7 Sep 2004 08:08:38 -0400 Date: Tue, 7 Sep 2004 14:08:16 +0200 From: =?iso-8859-1?Q?J=F6rn?= Engel To: Gunnar Ritter Cc: Steve French , linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH 1/3] copyfile: generic_sendpage Message-ID: <20040907120816.GB26972@wohnheim.fh-wedel.de> References: <20040904165733.GC8579@wohnheim.fh-wedel.de> <20040904153902.6ac075ea.akpm@osdl.org> <413C5BF2.nail2RA1138AG@pluto.uni-freiburg.de> <20040906133523.GC25429@wohnheim.fh-wedel.de> <413C74E6.nail3YF11Y0TT@pluto.uni-freiburg.de> <20040907110913.GA25802@wohnheim.fh-wedel.de> <20040907114536.GA26630@wohnheim.fh-wedel.de> <413DA387.nailA2K1PT2WH@pluto.uni-freiburg.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <413DA387.nailA2K1PT2WH@pluto.uni-freiburg.de> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1487 Lines: 54 On Tue, 7 September 2004 14:03:19 +0200, Gunnar Ritter wrote: > J?rn Engel wrote: > > Also it might perhaps make sense to add the kernel programmer's > equivalent of > > > + while (count) { > > + size_t n = min(count, (size_t)4096); > > + ret = in_file->f_op->sendfile(in_file, ppos, n, actor,out_file); > > + if (ret < 0) { > > + if (done) > > + return done; > > + else > > + return ret; > > + } > > + > > + done += ret; > > + count -= ret; > > + > > + if ((ret == 0) || signal_pending(current)) > { > if (count == 0) { > done = -1; > errno = EINTR; > } > > + break; > } > > + cond_resched(); > > + } > > + return done; > > +} > > here, for write-like semantics, too. Is that really needed? If in_file->f_op->sendfile() returns some error, it's already handled above. If it returns 0, done remains 0 and we return 0, indicating EOF. And the check for pending signals happens after handling the first chunk, so -EINTR shouldn't be necessary. But I could be stupid and miss something. J?rn -- Public Domain - Free as in Beer General Public - Free as in Speech BSD License - Free as in Enterprise Shared Source - Free as in "Work will make you..." - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/