From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D22D0C4320E for ; Fri, 27 Aug 2021 16:51:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3CD4604D7 for ; Fri, 27 Aug 2021 16:51:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239018AbhH0Qwq (ORCPT ); Fri, 27 Aug 2021 12:52:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:41695 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238525AbhH0Qw1 (ORCPT ); Fri, 27 Aug 2021 12:52:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1630083097; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=My07z1Y3p4MapI2JxW+Vnbyo3VlenRO2PNVTehC852I=; b=hFnv8kphF498vSSLvXwzgQVIji3fifLM3rjZmkRQtQydDAAUd2k8b394g/5IocwKWvShf0 tlH0IMwEDJ7ht4mjp1Sjg5yIJAscYs+g+qYez/BfRE1wnbLn0WEISPjqSoJR82FdFaeqZd pOBd051cuRCIsrsXCYndo++CLAvoAHc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-383-R4BJH5iZPRy05u14XGzQwA-1; Fri, 27 Aug 2021 12:51:36 -0400 X-MC-Unique: R4BJH5iZPRy05u14XGzQwA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EBEDC1009E20; Fri, 27 Aug 2021 16:51:34 +0000 (UTC) Received: from max.com (unknown [10.40.194.206]) by smtp.corp.redhat.com (Postfix) with ESMTP id 17BD660C82; Fri, 27 Aug 2021 16:51:26 +0000 (UTC) From: Andreas Gruenbacher To: Linus Torvalds , Alexander Viro , Christoph Hellwig , "Darrick J. Wong" Cc: Jan Kara , Matthew Wilcox , cluster-devel@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com, Andreas Gruenbacher Subject: [PATCH v7 18/19] iov_iter: Introduce nofault flag to disable page faults Date: Fri, 27 Aug 2021 18:49:25 +0200 Message-Id: <20210827164926.1726765-19-agruenba@redhat.com> In-Reply-To: <20210827164926.1726765-1-agruenba@redhat.com> References: <20210827164926.1726765-1-agruenba@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce a new nofault flag to indicate to get_user_pages to use the FOLL_NOFAULT flag. This will cause get_user_pages to fail when it would otherwise fault in a page. Currently, the noio flag is only checked in iov_iter_get_pages and iov_iter_get_pages_alloc. This is enough for iomaop_dio_rw, but it may make sense to check in other contexts as well. Signed-off-by: Andreas Gruenbacher --- include/linux/uio.h | 1 + lib/iov_iter.c | 20 +++++++++++++++----- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/include/linux/uio.h b/include/linux/uio.h index ffa431aeb067..ea35e511268f 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -29,6 +29,7 @@ enum iter_type { struct iov_iter { u8 iter_type; + bool nofault; bool data_source; size_t iov_offset; size_t count; diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 968f2d2595cd..22a82f272754 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -513,6 +513,7 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction, WARN_ON(direction & ~(READ | WRITE)); *i = (struct iov_iter) { .iter_type = ITER_IOVEC, + .nofault = false, .data_source = direction, .iov = iov, .nr_segs = nr_segs, @@ -1523,13 +1524,17 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, return 0; if (likely(iter_is_iovec(i))) { + unsigned int gup_flags = 0; unsigned long addr; + if (iov_iter_rw(i) != WRITE) + gup_flags |= FOLL_WRITE; + if (i->nofault) + gup_flags |= FOLL_NOFAULT; + addr = first_iovec_segment(i, &len, start, maxsize, maxpages); n = DIV_ROUND_UP(len, PAGE_SIZE); - res = get_user_pages_fast(addr, n, - iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, - pages); + res = get_user_pages_fast(addr, n, gup_flags, pages); if (unlikely(res <= 0)) return res; return (res == n ? len : res * PAGE_SIZE) - *start; @@ -1645,15 +1650,20 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, return 0; if (likely(iter_is_iovec(i))) { + unsigned int gup_flags = 0; unsigned long addr; + if (iov_iter_rw(i) != WRITE) + gup_flags |= FOLL_WRITE; + if (i->nofault) + gup_flags |= FOLL_NOFAULT; + addr = first_iovec_segment(i, &len, start, maxsize, ~0U); n = DIV_ROUND_UP(len, PAGE_SIZE); p = get_pages_array(n); if (!p) return -ENOMEM; - res = get_user_pages_fast(addr, n, - iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); + res = get_user_pages_fast(addr, n, gup_flags, p); if (unlikely(res <= 0)) { kvfree(p); *pages = NULL; -- 2.26.3 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49778C432BE for ; Fri, 27 Aug 2021 16:51:49 +0000 (UTC) Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EBDEF60EE5 for ; Fri, 27 Aug 2021 16:51:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org EBDEF60EE5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=oss.oracle.com Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 17RGPUF4015226; Fri, 27 Aug 2021 16:51:48 GMT Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by mx0b-00069f02.pphosted.com with ESMTP id 3ap4ekv6ct-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 27 Aug 2021 16:51:47 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 17RGpd9M180638; Fri, 27 Aug 2021 16:51:46 GMT Received: from oss.oracle.com (oss-old-reserved.oracle.com [137.254.22.2]) by userp3020.oracle.com with ESMTP id 3akb92ek51-1 (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO); Fri, 27 Aug 2021 16:51:46 +0000 Received: from localhost ([127.0.0.1] helo=lb-oss.oracle.com) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1mJf4z-00041Q-7i; Fri, 27 Aug 2021 09:51:45 -0700 Received: from userp3030.oracle.com ([156.151.31.80]) by oss.oracle.com with esmtp (Exim 4.63) (envelope-from ) id 1mJf4x-000415-Sn for ocfs2-devel@oss.oracle.com; Fri, 27 Aug 2021 09:51:43 -0700 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 17RGnn0d036159 for ; Fri, 27 Aug 2021 16:51:43 GMT Received: from mx0a-00069f01.pphosted.com (mx0a-00069f01.pphosted.com [205.220.165.26]) by userp3030.oracle.com with ESMTP id 3ajpm50jtx-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 27 Aug 2021 16:51:43 +0000 Received: from pps.filterd (m0246574.ppops.net [127.0.0.1]) by mx0b-00069f01.pphosted.com (8.16.1.2/8.16.0.43) with SMTP id 17RCpQIE014614 for ; Fri, 27 Aug 2021 16:51:42 GMT Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mx0b-00069f01.pphosted.com with ESMTP id 3aq0dwjjs0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 27 Aug 2021 16:51:41 +0000 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-383-R4BJH5iZPRy05u14XGzQwA-1; Fri, 27 Aug 2021 12:51:36 -0400 X-MC-Unique: R4BJH5iZPRy05u14XGzQwA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EBEDC1009E20; Fri, 27 Aug 2021 16:51:34 +0000 (UTC) Received: from max.com (unknown [10.40.194.206]) by smtp.corp.redhat.com (Postfix) with ESMTP id 17BD660C82; Fri, 27 Aug 2021 16:51:26 +0000 (UTC) From: Andreas Gruenbacher To: Linus Torvalds , Alexander Viro , Christoph Hellwig , "Darrick J. 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This will cause get_user_pages to fail when it would otherwise fault in a page. Currently, the noio flag is only checked in iov_iter_get_pages and iov_iter_get_pages_alloc. This is enough for iomaop_dio_rw, but it may make sense to check in other contexts as well. Signed-off-by: Andreas Gruenbacher --- include/linux/uio.h | 1 + lib/iov_iter.c | 20 +++++++++++++++----- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/include/linux/uio.h b/include/linux/uio.h index ffa431aeb067..ea35e511268f 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -29,6 +29,7 @@ enum iter_type { struct iov_iter { u8 iter_type; + bool nofault; bool data_source; size_t iov_offset; size_t count; diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 968f2d2595cd..22a82f272754 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -513,6 +513,7 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction, WARN_ON(direction & ~(READ | WRITE)); *i = (struct iov_iter) { .iter_type = ITER_IOVEC, + .nofault = false, .data_source = direction, .iov = iov, .nr_segs = nr_segs, @@ -1523,13 +1524,17 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, return 0; if (likely(iter_is_iovec(i))) { + unsigned int gup_flags = 0; unsigned long addr; + if (iov_iter_rw(i) != WRITE) + gup_flags |= FOLL_WRITE; + if (i->nofault) + gup_flags |= FOLL_NOFAULT; + addr = first_iovec_segment(i, &len, start, maxsize, maxpages); n = DIV_ROUND_UP(len, PAGE_SIZE); - res = get_user_pages_fast(addr, n, - iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, - pages); + res = get_user_pages_fast(addr, n, gup_flags, pages); if (unlikely(res <= 0)) return res; return (res == n ? len : res * PAGE_SIZE) - *start; @@ -1645,15 +1650,20 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, return 0; if (likely(iter_is_iovec(i))) { + unsigned int gup_flags = 0; unsigned long addr; + if (iov_iter_rw(i) != WRITE) + gup_flags |= FOLL_WRITE; + if (i->nofault) + gup_flags |= FOLL_NOFAULT; + addr = first_iovec_segment(i, &len, start, maxsize, ~0U); n = DIV_ROUND_UP(len, PAGE_SIZE); p = get_pages_array(n); if (!p) return -ENOMEM; - res = get_user_pages_fast(addr, n, - iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); + res = get_user_pages_fast(addr, n, gup_flags, p); if (unlikely(res <= 0)) { kvfree(p); *pages = NULL; -- 2.26.3 _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Gruenbacher Date: Fri, 27 Aug 2021 18:49:25 +0200 Subject: [Cluster-devel] [PATCH v7 18/19] iov_iter: Introduce nofault flag to disable page faults In-Reply-To: <20210827164926.1726765-1-agruenba@redhat.com> References: <20210827164926.1726765-1-agruenba@redhat.com> Message-ID: <20210827164926.1726765-19-agruenba@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Introduce a new nofault flag to indicate to get_user_pages to use the FOLL_NOFAULT flag. This will cause get_user_pages to fail when it would otherwise fault in a page. Currently, the noio flag is only checked in iov_iter_get_pages and iov_iter_get_pages_alloc. This is enough for iomaop_dio_rw, but it may make sense to check in other contexts as well. Signed-off-by: Andreas Gruenbacher --- include/linux/uio.h | 1 + lib/iov_iter.c | 20 +++++++++++++++----- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/include/linux/uio.h b/include/linux/uio.h index ffa431aeb067..ea35e511268f 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -29,6 +29,7 @@ enum iter_type { struct iov_iter { u8 iter_type; + bool nofault; bool data_source; size_t iov_offset; size_t count; diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 968f2d2595cd..22a82f272754 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -513,6 +513,7 @@ void iov_iter_init(struct iov_iter *i, unsigned int direction, WARN_ON(direction & ~(READ | WRITE)); *i = (struct iov_iter) { .iter_type = ITER_IOVEC, + .nofault = false, .data_source = direction, .iov = iov, .nr_segs = nr_segs, @@ -1523,13 +1524,17 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, return 0; if (likely(iter_is_iovec(i))) { + unsigned int gup_flags = 0; unsigned long addr; + if (iov_iter_rw(i) != WRITE) + gup_flags |= FOLL_WRITE; + if (i->nofault) + gup_flags |= FOLL_NOFAULT; + addr = first_iovec_segment(i, &len, start, maxsize, maxpages); n = DIV_ROUND_UP(len, PAGE_SIZE); - res = get_user_pages_fast(addr, n, - iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, - pages); + res = get_user_pages_fast(addr, n, gup_flags, pages); if (unlikely(res <= 0)) return res; return (res == n ? len : res * PAGE_SIZE) - *start; @@ -1645,15 +1650,20 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, return 0; if (likely(iter_is_iovec(i))) { + unsigned int gup_flags = 0; unsigned long addr; + if (iov_iter_rw(i) != WRITE) + gup_flags |= FOLL_WRITE; + if (i->nofault) + gup_flags |= FOLL_NOFAULT; + addr = first_iovec_segment(i, &len, start, maxsize, ~0U); n = DIV_ROUND_UP(len, PAGE_SIZE); p = get_pages_array(n); if (!p) return -ENOMEM; - res = get_user_pages_fast(addr, n, - iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); + res = get_user_pages_fast(addr, n, gup_flags, p); if (unlikely(res <= 0)) { kvfree(p); *pages = NULL; -- 2.26.3