From patchwork Thu Feb 16 10:14:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nuno Sa X-Patchwork-Id: 13142826 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 0A486C61DA4 for ; Thu, 16 Feb 2023 10:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229828AbjBPKNc (ORCPT ); Thu, 16 Feb 2023 05:13:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229844AbjBPKNa (ORCPT ); Thu, 16 Feb 2023 05:13:30 -0500 Received: from mx0a-00128a01.pphosted.com (mx0a-00128a01.pphosted.com [148.163.135.77]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04DE7518CF for ; Thu, 16 Feb 2023 02:13:28 -0800 (PST) Received: from pps.filterd (m0167088.ppops.net [127.0.0.1]) by mx0a-00128a01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 31G9ob1X002341; Thu, 16 Feb 2023 05:13:11 -0500 Received: from nwd2mta4.analog.com ([137.71.173.58]) by mx0a-00128a01.pphosted.com (PPS) with ESMTPS id 3ns89qb1vf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 16 Feb 2023 05:13:10 -0500 Received: from ASHBMBX9.ad.analog.com (ASHBMBX9.ad.analog.com [10.64.17.10]) by nwd2mta4.analog.com (8.14.7/8.14.7) with ESMTP id 31GAD9O3042594 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 16 Feb 2023 05:13:09 -0500 Received: from ASHBMBX9.ad.analog.com (10.64.17.10) by ASHBMBX9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.14; Thu, 16 Feb 2023 05:13:08 -0500 Received: from zeus.spd.analog.com (10.66.68.11) by ashbmbx9.ad.analog.com (10.64.17.10) with Microsoft SMTP Server id 15.2.986.14 via Frontend Transport; Thu, 16 Feb 2023 05:13:08 -0500 Received: from nsa.sphairon.box ([10.44.3.102]) by zeus.spd.analog.com (8.15.1/8.15.1) with ESMTP id 31GAD0rt028929; Thu, 16 Feb 2023 05:13:06 -0500 From: =?utf-8?q?Nuno_S=C3=A1?= To: CC: Lars-Peter Clausen , Jonathan Cameron Subject: [PATCH 2/3] iio: buffer: make sure O_NONBLOCK is respected Date: Thu, 16 Feb 2023 11:14:51 +0100 Message-ID: <20230216101452.591805-3-nuno.sa@analog.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230216101452.591805-1-nuno.sa@analog.com> References: <20230216101452.591805-1-nuno.sa@analog.com> MIME-Version: 1.0 X-ADIRuleOP-NewSCL: Rule Triggered X-Proofpoint-ORIG-GUID: VGV6LwmizW9LA0TM7UT0Ff2hTF6FeVfK X-Proofpoint-GUID: VGV6LwmizW9LA0TM7UT0Ff2hTF6FeVfK X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.930,Hydra:6.0.562,FMLib:17.11.170.22 definitions=2023-02-16_07,2023-02-15_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 mlxscore=0 malwarescore=0 phishscore=0 spamscore=0 bulkscore=0 suspectscore=0 adultscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2212070000 definitions=main-2302160085 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org For output buffers, there's no guarantee that the buffer won't be full in the first iteration of the loop in which case we would block independently of userspace passing O_NONBLOCK or not. Fix it by always checking the flag before going to sleep. While at it (and as it's a bit related), refactored the loop so that the stop condition is 'written != n', i.e, run the loop until all data has been copied into the IIO buffers. This makes the code a bit simpler. Fixes: 9eeee3b0bf190 ("iio: Add output buffer support") Signed-off-by: Nuno Sá Reviewed-by: Lars-Peter Clausen --- drivers/iio/industrialio-buffer.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index c56cf748fde1..7e7ee307a3f7 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -203,21 +203,24 @@ static ssize_t iio_buffer_write(struct file *filp, const char __user *buf, break; } + if (filp->f_flags & O_NONBLOCK) { + if (!written) + ret = -EAGAIN; + break; + } + wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); continue; } ret = rb->access->write(rb, n - written, buf + written); - if (ret == 0 && (filp->f_flags & O_NONBLOCK)) - ret = -EAGAIN; + if (ret < 0) + break; - if (ret > 0) { - written += ret; - if (written != n && !(filp->f_flags & O_NONBLOCK)) - continue; - } - } while (ret == 0); + written += ret; + + } while (written != n); remove_wait_queue(&rb->pollq, &wait); return ret < 0 ? ret : written;