From patchwork Sat Nov 21 14:13:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11923403 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 38A54C64E75 for ; Sat, 21 Nov 2020 14:13:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F02E522261 for ; Sat, 21 Nov 2020 14:13:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SrXwtr6u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727948AbgKUONs (ORCPT ); Sat, 21 Nov 2020 09:13:48 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:37328 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727920AbgKUONq (ORCPT ); Sat, 21 Nov 2020 09:13:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605968024; 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=JcWyfdmDr6kJ/GdHDBbHFKPN7p1aKQ7b6+idcK3zWxo=; b=SrXwtr6uXmOTaD5PKVbYGHsyTW1cFfp4qWcGRGS+s7wuBjL532xsFa2yrAtwEU9QY0CkCO sWyzYXl2J2/YDz7s2e0LTLBqzwABKGn0HZ7SX8jN/qogB2hxoxxP5o0cklMRcrDKagt+Pi rdch+QmTNY+GqRv+TDjs9ZvqgMENwu8= 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-290-vJNJYYrXOdWQ0EgNvmQI8g-1; Sat, 21 Nov 2020 09:13:42 -0500 X-MC-Unique: vJNJYYrXOdWQ0EgNvmQI8g-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 18DF1107AD44; Sat, 21 Nov 2020 14:13:41 +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 483236064B; Sat, 21 Nov 2020 14:13:39 +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 02/29] iov_iter: Split copy_page_to_iter() 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 14:13:38 +0000 Message-ID: <160596801844.154728.6494357560297311234.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 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Split copy_page_to_iter() by type. Signed-off-by: David Howells --- lib/iov_iter.c | 44 +++++++++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 19 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index e403d524c797..fee8e99fbb9c 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -19,6 +19,8 @@ static const struct iov_iter_ops bvec_iter_ops; static const struct iov_iter_ops pipe_iter_ops; static const struct iov_iter_ops discard_iter_ops; +static inline bool page_copy_sane(struct page *page, size_t offset, size_t n); + #define PIPE_PARANOIA /* for now */ #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ @@ -167,7 +169,7 @@ static int copyin(void *to, const void __user *from, size_t n) return n; } -static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes, +static size_t iovec_copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { size_t skip, copy, left, wanted; @@ -175,6 +177,8 @@ static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t b char __user *buf; void *kaddr, *from; + if (unlikely(!page_copy_sane(page, offset, bytes))) + return 0; if (unlikely(bytes > i->count)) bytes = i->count; @@ -378,7 +382,7 @@ static bool sanity(const struct iov_iter *i) #define sanity(i) true #endif -static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t bytes, +static size_t pipe_copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { struct pipe_inode_info *pipe = i->pipe; @@ -388,6 +392,8 @@ static size_t copy_page_to_iter_pipe(struct page *page, size_t offset, size_t by unsigned int i_head = i->head; size_t off; + if (unlikely(!page_copy_sane(page, offset, bytes))) + return 0; if (unlikely(bytes > i->count)) bytes = i->count; @@ -910,22 +916,22 @@ static inline bool page_copy_sane(struct page *page, size_t offset, size_t n) return false; } -static size_t xxx_copy_page_to_iter(struct page *page, size_t offset, size_t bytes, +static size_t bkvec_copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { - if (unlikely(!page_copy_sane(page, offset, bytes))) - return 0; - if (iov_iter_type(i) & (ITER_BVEC|ITER_KVEC)) { + size_t wanted = 0; + if (likely(page_copy_sane(page, offset, bytes))) { void *kaddr = kmap_atomic(page); - size_t wanted = copy_to_iter(kaddr + offset, bytes, i); + wanted = copy_to_iter(kaddr + offset, bytes, i); kunmap_atomic(kaddr); - return wanted; - } else if (unlikely(iov_iter_is_discard(i))) - return bytes; - else if (likely(!iov_iter_is_pipe(i))) - return copy_page_to_iter_iovec(page, offset, bytes, i); - else - return copy_page_to_iter_pipe(page, offset, bytes, i); + } + return wanted; +} + +static size_t discard_copy_page_to_iter(struct page *page, size_t offset, size_t bytes, + struct iov_iter *i) +{ + return bytes; } static size_t xxx_copy_page_from_iter(struct page *page, size_t offset, size_t bytes, @@ -1842,7 +1848,7 @@ static const struct iov_iter_ops iovec_iter_ops = { .revert = xxx_revert, .fault_in_readable = xxx_fault_in_readable, .single_seg_count = xxx_single_seg_count, - .copy_page_to_iter = xxx_copy_page_to_iter, + .copy_page_to_iter = iovec_copy_page_to_iter, .copy_page_from_iter = xxx_copy_page_from_iter, .copy_to_iter = xxx_copy_to_iter, .copy_from_iter = xxx_copy_from_iter, @@ -1876,7 +1882,7 @@ static const struct iov_iter_ops kvec_iter_ops = { .revert = xxx_revert, .fault_in_readable = xxx_fault_in_readable, .single_seg_count = xxx_single_seg_count, - .copy_page_to_iter = xxx_copy_page_to_iter, + .copy_page_to_iter = bkvec_copy_page_to_iter, .copy_page_from_iter = xxx_copy_page_from_iter, .copy_to_iter = xxx_copy_to_iter, .copy_from_iter = xxx_copy_from_iter, @@ -1910,7 +1916,7 @@ static const struct iov_iter_ops bvec_iter_ops = { .revert = xxx_revert, .fault_in_readable = xxx_fault_in_readable, .single_seg_count = xxx_single_seg_count, - .copy_page_to_iter = xxx_copy_page_to_iter, + .copy_page_to_iter = bkvec_copy_page_to_iter, .copy_page_from_iter = xxx_copy_page_from_iter, .copy_to_iter = xxx_copy_to_iter, .copy_from_iter = xxx_copy_from_iter, @@ -1944,7 +1950,7 @@ static const struct iov_iter_ops pipe_iter_ops = { .revert = xxx_revert, .fault_in_readable = xxx_fault_in_readable, .single_seg_count = xxx_single_seg_count, - .copy_page_to_iter = xxx_copy_page_to_iter, + .copy_page_to_iter = pipe_copy_page_to_iter, .copy_page_from_iter = xxx_copy_page_from_iter, .copy_to_iter = xxx_copy_to_iter, .copy_from_iter = xxx_copy_from_iter, @@ -1978,7 +1984,7 @@ static const struct iov_iter_ops discard_iter_ops = { .revert = xxx_revert, .fault_in_readable = xxx_fault_in_readable, .single_seg_count = xxx_single_seg_count, - .copy_page_to_iter = xxx_copy_page_to_iter, + .copy_page_to_iter = discard_copy_page_to_iter, .copy_page_from_iter = xxx_copy_page_from_iter, .copy_to_iter = xxx_copy_to_iter, .copy_from_iter = xxx_copy_from_iter,