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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8328C433F5 for ; Sun, 27 Feb 2022 09:34:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4E1E18D0005; Sun, 27 Feb 2022 04:34:48 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 46C018D0001; Sun, 27 Feb 2022 04:34:48 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2E5D18D0005; Sun, 27 Feb 2022 04:34:48 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 19E188D0001 for ; Sun, 27 Feb 2022 04:34:48 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id E047C60A77 for ; Sun, 27 Feb 2022 09:34:47 +0000 (UTC) X-FDA: 79188050214.14.F750D90 Received: from mail-qv1-f52.google.com (mail-qv1-f52.google.com [209.85.219.52]) by imf31.hostedemail.com (Postfix) with ESMTP id 7543220005 for ; Sun, 27 Feb 2022 09:34:47 +0000 (UTC) Received: by mail-qv1-f52.google.com with SMTP id j11so10302356qvy.0 for ; Sun, 27 Feb 2022 01:34:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ItEq05ZSN1A4hvZTi4QQudlRbzhu6qS+hrN6bdKB7cI=; b=PZBjPgxyjRX0Or72xti11PNZ7haqtTUPt+l6GSVDIjPZvvHFsuzjj7D3LZpd2dlpuI QDBarJXEQFKVIDhBbsFsDTJyelJD1y+jkqX4QIJBbstGPEW9bNw3Mhxz2Sik5EOa4Vap 1Y9yLi5/mhlvOIJws68gsbtd9FOSaFcfZPIZzZe56mv7cJ5I1xpv2K/+kRldOPg5pFfy fp1XHYBBzolf8lr3/PZ9ccGYD+Et5/folofDnHM/8wny4qSLItKGNhYaeSkRR1F0h3RS TLQ+YwNORWbEjLneJOR03aiX2RAeaRgvo6Iw5rkoztgQICzpVEs9hhgA89D1X0DA80Xj zWaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ItEq05ZSN1A4hvZTi4QQudlRbzhu6qS+hrN6bdKB7cI=; b=pjXT6GmHnZxCjfbIwhq6qxlPl6c5xcxogvQu4HqL7IPCQxO+cM49wYwkDHVxlVwM9r prpE7101WKQSddodVKxYu+tJNvxCZJDqf4n9VkWip7owdOtD8ErDn7hjscb549+Z/SSI 7cegRtW3CIodmibe2jLW+mIjj8K/bS2Z07MUUTTlVAYCPkbqXTsOXVBrcVjnAgEyr1IF hifnlz3gGLuTSfP0kSDNkCiEzzFsHenX2f5GRChjeXvMrbVTduBTKwUEW3AgRJn6jsme y7NmYFKzEqPEHcOwXEt3oSVv+D8XoANEFJSGIOnD56x24hGFoYidA/LTwOP26CCyTrqV 5Crw== X-Gm-Message-State: AOAM5315OozkgSAL9QVn7TXMkhqEcQyaDqbpnMykyxi4wFS4eYWOfMF/ bzwrK/Xt5Rc6Mlg0uCrzvh7n2pYDwikPcJuWoTwxBg== X-Google-Smtp-Source: ABdhPJzG6l0z2OorcknGPNxVbjfzbPk10PdLFwWxQT69r0yaHLiCk0a02692yrZUIxBpFRCVItUsNg== X-Received: by 2002:a05:6214:4103:b0:42d:7ad0:44ff with SMTP id kc3-20020a056214410300b0042d7ad044ffmr10910530qvb.42.1645954486813; Sun, 27 Feb 2022 01:34:46 -0800 (PST) Received: from sandstorm.attlocal.net (76-242-90-12.lightspeed.sntcca.sbcglobal.net. [76.242.90.12]) by smtp.gmail.com with ESMTPSA id h3-20020a05622a170300b002e008a93f8fsm469815qtk.91.2022.02.27.01.34.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Feb 2022 01:34:46 -0800 (PST) From: jhubbard.send.patches@gmail.com X-Google-Original-From: jhubbard@nvidia.com To: Jens Axboe , Jan Kara , Christoph Hellwig , Dave Chinner , "Darrick J . Wong" , Theodore Ts'o , Alexander Viro , Miklos Szeredi , Andrew Morton , Chaitanya Kulkarni Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, LKML , John Hubbard Subject: [PATCH 2/6] iov_iter: new iov_iter_pin_pages*(), for FOLL_PIN pages Date: Sun, 27 Feb 2022 01:34:30 -0800 Message-Id: <20220227093434.2889464-3-jhubbard@nvidia.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220227093434.2889464-1-jhubbard@nvidia.com> References: <20220227093434.2889464-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 7543220005 X-Stat-Signature: egsrxhit7cw654k31pho3851p36gkjin X-Rspam-User: Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=PZBjPgxy; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf31.hostedemail.com: domain of jhubbard.send.patches@gmail.com designates 209.85.219.52 as permitted sender) smtp.mailfrom=jhubbard.send.patches@gmail.com X-Rspamd-Server: rspam03 X-HE-Tag: 1645954487-366911 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: John Hubbard Provide two new specialized routines that only handle user space pages, and invoke pin_user_pages_fast() on them: iov_iter_pin_pages() and iov_iter_pin_pages_alloc(). This allows subsequent patches to convert various callers of iov_iter_get_pages*(), to the new calls, without having to attempt a mass conversion all at once. Signed-off-by: John Hubbard --- include/linux/uio.h | 4 +++ lib/iov_iter.c | 78 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 82 insertions(+) diff --git a/include/linux/uio.h b/include/linux/uio.h index 739285fe5a2f..208020c2b75a 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -236,6 +236,10 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start); ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start); +ssize_t iov_iter_pin_pages(struct iov_iter *i, struct page **pages, + size_t maxsize, unsigned int maxpages, size_t *start); +ssize_t iov_iter_pin_pages_alloc(struct iov_iter *i, struct page ***pages, + size_t maxsize, size_t *start); int iov_iter_npages(const struct iov_iter *i, int maxpages); void iov_iter_restore(struct iov_iter *i, struct iov_iter_state *state); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 6dd5330f7a99..e64e8e4edd0c 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1560,6 +1560,41 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, } EXPORT_SYMBOL(iov_iter_get_pages); +ssize_t iov_iter_pin_pages(struct iov_iter *i, + struct page **pages, size_t maxsize, unsigned int maxpages, + size_t *start) +{ + size_t len; + int n, res; + + if (maxsize > i->count) + maxsize = i->count; + if (!maxsize) + return 0; + + WARN_ON_ONCE(!iter_is_iovec(i)); + + 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 = pin_user_pages_fast(addr, n, gup_flags, pages); + if (unlikely(res <= 0)) + return res; + return (res == n ? len : res * PAGE_SIZE) - *start; + } + + return -EFAULT; +} +EXPORT_SYMBOL(iov_iter_pin_pages); + static struct page **get_pages_array(size_t n) { return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); @@ -1696,6 +1731,49 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, } EXPORT_SYMBOL(iov_iter_get_pages_alloc); +ssize_t iov_iter_pin_pages_alloc(struct iov_iter *i, + struct page ***pages, size_t maxsize, + size_t *start) +{ + struct page **p; + size_t len; + int n, res; + + if (maxsize > i->count) + maxsize = i->count; + if (!maxsize) + return 0; + + WARN_ON_ONCE(!iter_is_iovec(i)); + + 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 = pin_user_pages_fast(addr, n, gup_flags, p); + if (unlikely(res <= 0)) { + kvfree(p); + *pages = NULL; + return res; + } + *pages = p; + return (res == n ? len : res * PAGE_SIZE) - *start; + } + + return -EFAULT; +} +EXPORT_SYMBOL(iov_iter_pin_pages_alloc); + size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i) { -- 2.35.1