From patchwork Fri Nov 10 21:54:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10053817 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B8E196032D for ; Fri, 10 Nov 2017 21:54:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A67B62B448 for ; Fri, 10 Nov 2017 21:54:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9B0EA2B488; Fri, 10 Nov 2017 21:54:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D810D2B448 for ; Fri, 10 Nov 2017 21:54:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751097AbdKJVyP (ORCPT ); Fri, 10 Nov 2017 16:54:15 -0500 Received: from bombadil.infradead.org ([65.50.211.133]:55354 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbdKJVyP (ORCPT ); Fri, 10 Nov 2017 16:54:15 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Message-Id:Date:Subject:Cc:To:From: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=YIkoLsYPhup6Fs1XGlcl5udF/uk1rzwIaTt7Z/EQlVM=; b=JG0NJysppING8lNnEtyv58xcU iAShhtA50VpWeAma19DC5Zl7JVT6XEwM07mYT3yMzdrelLxp0oU/1KfBmSZrxMxDvJh4en3vpAZZ0 Gyw9fuHaWN4uySfxBZEykR5ibzL53ho6So6Gy0P7mrPD6Ddd4AtIGw7dclXX1rqcp0r1e3xmN6zyU 3uTobDCteU0t0U+b8fY2KPhgI3Y3lnGxt5I9tk6qPqYsBYpB6xH+uNOiPMAUp4Mqmj8pwEem9Quuq 5VMfVzyQQri5XHBvVBCDsp6aodjhf8UDUV3saS2tdRr3DtfgRD6lYabLMIZKH3vetTQ81sU9sOotI xJS6W7L+g==; Received: from clnet-p099-196.ikbnet.co.at ([83.175.99.196] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.87 #1 (Red Hat Linux)) id 1eDHFe-0008DL-2M; Fri, 10 Nov 2017 21:54:14 +0000 From: Christoph Hellwig To: linux-man@vger.kernel.org Cc: milosz@adfin.com, willy@infradead.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v2] readv.2: document RWF_NOWAIT Date: Fri, 10 Nov 2017 22:54:10 +0100 Message-Id: <20171110215410.9943-1-hch@lst.de> X-Mailer: git-send-email 2.14.2 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Signed-off-by: Christoph Hellwig --- Changes since V1: - better wording provided by Matthew Wilcox man2/readv.2 | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/man2/readv.2 b/man2/readv.2 index 831cf6260..880435edf 100644 --- a/man2/readv.2 +++ b/man2/readv.2 @@ -232,6 +232,25 @@ This flag is meaningful only for .BR pwritev2 (), and its effect applies only to the data range written by the system call. .\" commit e864f39569f4092c2b2bc72c773b6e486c7e3bd9 +.TP +.BR RWF_NOWAIT " (since Linux 4.14)" +Do not wait for data which is not immediately available. +If this flag is specified the +.BR preadv2 () +system call will return instantly if it would have to read data from +the backing storage or wait for a lock. +If some data was successfully read, it will return the number of bytes read. +If no bytes were read, it will return -1 and set +.IR errno +to +.BR EAGAIN . +This flag is meaningful only for +.BR preadv2 () +at the moment. +.\" commit 3239d834847627b6634a4139cf1dc58f6f137a46 +.\" commit 91f9943e1c7b6638f27312d03fe71fcc67b23571 + + .SH RETURN VALUE On success, .BR readv (),