From patchwork Tue Jun 28 15:02:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Yudaken X-Patchwork-Id: 12898417 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 526B3C43334 for ; Tue, 28 Jun 2022 15:02:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347668AbiF1PCr (ORCPT ); Tue, 28 Jun 2022 11:02:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347665AbiF1PCr (ORCPT ); Tue, 28 Jun 2022 11:02:47 -0400 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57F8033E3C for ; Tue, 28 Jun 2022 08:02:46 -0700 (PDT) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 25SAE7ZE013208 for ; Tue, 28 Jun 2022 08:02:46 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=/R5f40SX0myY+sLsV9T01ncFIwUnVx4ToYywqLxN6Ws=; b=nAmkmqYcEnu6uf8RChzrghN6IZgh+xpBiH/buD1YNVUMEa+yV/kZt21audq0wyzLI2Wa SA0G56fqKIuuDXji0ryQ8f3qg9zbr/mdZr9IhIXKNRj+Nuvsd16DBJ1u/9TDwlbUxlzZ Zs0yocp8KDIYQ6MXftU0nA52/ZvaUbkzA1Y= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3gyxx31y7r-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 28 Jun 2022 08:02:45 -0700 Received: from twshared25107.07.ash9.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Tue, 28 Jun 2022 08:02:44 -0700 Received: by devbig038.lla2.facebook.com (Postfix, from userid 572232) id 95F71244BBC5; Tue, 28 Jun 2022 08:02:37 -0700 (PDT) From: Dylan Yudaken To: Jens Axboe , Pavel Begunkov , CC: , , Dylan Yudaken Subject: [PATCH for-next 1/8] io_uring: allow 0 length for buffer select Date: Tue, 28 Jun 2022 08:02:21 -0700 Message-ID: <20220628150228.1379645-2-dylany@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220628150228.1379645-1-dylany@fb.com> References: <20220628150228.1379645-1-dylany@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: 4pRyPUqkcOetCK3N0_Ij-P_DEaR608vA X-Proofpoint-ORIG-GUID: 4pRyPUqkcOetCK3N0_Ij-P_DEaR608vA X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.883,Hydra:6.0.517,FMLib:17.11.122.1 definitions=2022-06-28_08,2022-06-28_01,2022-06-22_01 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org If user gives 0 for length, we can set it from the available buffer size. Signed-off-by: Dylan Yudaken --- io_uring/kbuf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 8e4f1e8aaf4a..4ed5102461bf 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -115,7 +115,7 @@ static void __user *io_provided_buffer_select(struct io_kiocb *req, size_t *len, kbuf = list_first_entry(&bl->buf_list, struct io_buffer, list); list_del(&kbuf->list); - if (*len > kbuf->len) + if (*len == 0 || *len > kbuf->len) *len = kbuf->len; req->flags |= REQ_F_BUFFER_SELECTED; req->kbuf = kbuf; @@ -145,7 +145,7 @@ static void __user *io_ring_buffer_select(struct io_kiocb *req, size_t *len, buf = page_address(bl->buf_pages[index]); buf += off; } - if (*len > buf->len) + if (*len == 0 || *len > buf->len) *len = buf->len; req->flags |= REQ_F_BUFFER_RING; req->buf_list = bl;