From patchwork Sat Nov 21 14:16:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11923479 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=-15.8 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 4697AC64E7A for ; Sat, 21 Nov 2020 14:16:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FB7F2224C for ; Sat, 21 Nov 2020 14:16:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XE3kgxLo" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728321AbgKUOQO (ORCPT ); Sat, 21 Nov 2020 09:16:14 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:55437 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728299AbgKUOQO (ORCPT ); Sat, 21 Nov 2020 09:16:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605968172; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bw9ipJWjx8AimfhLoz84wN1/imOFmg/xGA0Qomc1kTU=; b=XE3kgxLo7vLZ769FdDzmVGibdQRXsPLf1/wWWj2bGULBbrvZK3HyBWQgmqwqzN2JLljChU 3XteXmPwaIrDL3++hIzKc8ApdD0saUvR2B4k+R/Z1uG6vns3BFtfkurdlrjeqoeeLa2Itl QScSm/yz5gqjvd3Asnhl7WIeIKXKzvA= 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-284-bkI6hkIANsCc6_3NDXBAfg-1; Sat, 21 Nov 2020 09:16:09 -0500 X-MC-Unique: bkI6hkIANsCc6_3NDXBAfg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 718DF814409; Sat, 21 Nov 2020 14:16:08 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-112-246.rdu2.redhat.com [10.10.112.246]) by smtp.corp.redhat.com (Postfix) with ESMTP id B7B305C22B; Sat, 21 Nov 2020 14:16:06 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 21/29] iov_iter: Split iov_iter_get_pages() From: David Howells To: Pavel Begunkov , Matthew Wilcox , Jens Axboe , Alexander Viro Cc: dhowells@redhat.com, Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Date: Sat, 21 Nov 2020 14:16:05 +0000 Message-ID: <160596816579.154728.8100196610696982437.stgit@warthog.procyon.org.uk> In-Reply-To: <160596800145.154728.7192318545120181269.stgit@warthog.procyon.org.uk> References: <160596800145.154728.7192318545120181269.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Split iov_iter_get_pages() by type. Signed-off-by: David Howells --- lib/iov_iter.c | 46 +++++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 17 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 5744ddec854f..a2de201b947f 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1611,6 +1611,8 @@ static ssize_t pipe_get_pages(struct iov_iter *i, unsigned int iter_head, npages; size_t capacity; + if (maxsize > i->count) + maxsize = i->count; if (!maxsize) return 0; @@ -1625,19 +1627,14 @@ static ssize_t pipe_get_pages(struct iov_iter *i, return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start); } -static ssize_t xxx_get_pages(struct iov_iter *i, +static ssize_t iovec_get_pages(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start) { if (maxsize > i->count) maxsize = i->count; - if (unlikely(iov_iter_is_pipe(i))) - return pipe_get_pages(i, pages, maxsize, maxpages, start); - if (unlikely(iov_iter_is_discard(i))) - return -EFAULT; - - iterate_all_kinds(i, maxsize, v, ({ + iterate_over_iovec(i, maxsize, v, ({ unsigned long addr = (unsigned long)v.iov_base; size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1)); int n; @@ -1653,18 +1650,33 @@ static ssize_t xxx_get_pages(struct iov_iter *i, if (unlikely(res < 0)) return res; return (res == n ? len : res * PAGE_SIZE) - *start; - 0;}),({ + 0;})); + return 0; +} + +static ssize_t bvec_get_pages(struct iov_iter *i, + struct page **pages, size_t maxsize, unsigned maxpages, + size_t *start) +{ + if (maxsize > i->count) + maxsize = i->count; + + iterate_over_bvec(i, maxsize, v, ({ /* can't be more than PAGE_SIZE */ *start = v.bv_offset; get_page(*pages = v.bv_page); return v.bv_len; - }),({ - return -EFAULT; - }) - ) + })); return 0; } +static ssize_t no_get_pages(struct iov_iter *i, + struct page **pages, size_t maxsize, unsigned maxpages, + size_t *start) +{ + return -EFAULT; +} + static struct page **get_pages_array(size_t n) { return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); @@ -2179,7 +2191,7 @@ static const struct iov_iter_ops iovec_iter_ops = { .zero = iovec_zero, .alignment = iovec_alignment, .gap_alignment = iovec_gap_alignment, - .get_pages = xxx_get_pages, + .get_pages = iovec_get_pages, .get_pages_alloc = xxx_get_pages_alloc, .npages = xxx_npages, .dup_iter = xxx_dup_iter, @@ -2213,7 +2225,7 @@ static const struct iov_iter_ops kvec_iter_ops = { .zero = kvec_zero, .alignment = kvec_alignment, .gap_alignment = kvec_gap_alignment, - .get_pages = xxx_get_pages, + .get_pages = no_get_pages, .get_pages_alloc = xxx_get_pages_alloc, .npages = xxx_npages, .dup_iter = xxx_dup_iter, @@ -2247,7 +2259,7 @@ static const struct iov_iter_ops bvec_iter_ops = { .zero = bvec_zero, .alignment = bvec_alignment, .gap_alignment = bvec_gap_alignment, - .get_pages = xxx_get_pages, + .get_pages = bvec_get_pages, .get_pages_alloc = xxx_get_pages_alloc, .npages = xxx_npages, .dup_iter = xxx_dup_iter, @@ -2281,7 +2293,7 @@ static const struct iov_iter_ops pipe_iter_ops = { .zero = pipe_zero, .alignment = pipe_alignment, .gap_alignment = no_gap_alignment, - .get_pages = xxx_get_pages, + .get_pages = pipe_get_pages, .get_pages_alloc = xxx_get_pages_alloc, .npages = xxx_npages, .dup_iter = xxx_dup_iter, @@ -2315,7 +2327,7 @@ static const struct iov_iter_ops discard_iter_ops = { .zero = discard_zero, .alignment = no_alignment, .gap_alignment = no_gap_alignment, - .get_pages = xxx_get_pages, + .get_pages = no_get_pages, .get_pages_alloc = xxx_get_pages_alloc, .npages = xxx_npages, .dup_iter = xxx_dup_iter,