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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 D5495C4743E for ; Sun, 6 Jun 2021 19:13:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B731C61421 for ; Sun, 6 Jun 2021 19:13:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231577AbhFFTPE (ORCPT ); Sun, 6 Jun 2021 15:15:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230237AbhFFTMw (ORCPT ); Sun, 6 Jun 2021 15:12:52 -0400 Received: from zeniv-ca.linux.org.uk (zeniv-ca.linux.org.uk [IPv6:2607:5300:60:148a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CA18C061789; Sun, 6 Jun 2021 12:11:02 -0700 (PDT) Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lpyAh-0056cl-Rp; Sun, 06 Jun 2021 19:10:55 +0000 From: Al Viro To: Linus Torvalds Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, David Sterba , Miklos Szeredi , Anton Altaparmakov , David Howells , Matthew Wilcox , Pavel Begunkov Subject: [RFC PATCH 34/37] iov_iter: clean csum_and_copy_...() primitives up a bit Date: Sun, 6 Jun 2021 19:10:48 +0000 Message-Id: <20210606191051.1216821-34-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210606191051.1216821-1-viro@zeniv.linux.org.uk> References: <20210606191051.1216821-1-viro@zeniv.linux.org.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 1) kmap_atomic() is not needed here, kmap_local_page() is enough. 2) No need to make sum = csum_block_add(sum, next, off); conditional upon next != 0 - adding 0 is a no-op as far as csum_block_add() is concerned. Signed-off-by: Al Viro --- lib/iov_iter.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 0a9e246178c1..56d2606a47e4 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -611,9 +611,9 @@ static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, return 0; do { size_t chunk = min_t(size_t, n, PAGE_SIZE - r); - char *p = kmap_atomic(pipe->bufs[i_head & p_mask].page); + char *p = kmap_local_page(pipe->bufs[i_head & p_mask].page); sum = csum_and_memcpy(p + r, addr, chunk, sum, off); - kunmap_atomic(p); + kunmap_local(p); i->head = i_head; i->iov_offset = r + chunk; n -= chunk; @@ -1678,8 +1678,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, } iterate_and_advance(i, bytes, base, len, off, ({ next = csum_and_copy_from_user(base, addr + off, len); - if (next) - sum = csum_block_add(sum, next, off); + sum = csum_block_add(sum, next, off); next ? 0 : len; }), ({ sum = csum_and_memcpy(addr + off, base, len, sum, off); @@ -1706,8 +1705,7 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate, } iterate_and_advance(i, bytes, base, len, off, ({ next = csum_and_copy_to_user(addr + off, base, len); - if (next) - sum = csum_block_add(sum, next, off); + sum = csum_block_add(sum, next, off); next ? 0 : len; }), ({ sum = csum_and_memcpy(base, addr + off, len, sum, off); -- 2.11.0