From nobody Sun Feb 8 13:12:05 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B6F6C7EE23 for ; Tue, 9 May 2023 17:00:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235077AbjEIRAP (ORCPT ); Tue, 9 May 2023 13:00:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234932AbjEIQ6j (ORCPT ); Tue, 9 May 2023 12:58:39 -0400 Received: from out-51.mta1.migadu.com (out-51.mta1.migadu.com [IPv6:2001:41d0:203:375::33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54F5F55BB for ; Tue, 9 May 2023 09:57:36 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1683651452; 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=oQzCDYvJ0lsDeSo/s7SzXt92I5sJ/6Jd0MY/kK+yD7U=; b=PHvXBmFrG1haHZH++ByGkbPhrVLFCqbuynFUtixhqKw8mL0m5MIf5c7OUEjz7eapdhaScW hCJHsByetQerY+RW9TsdnWKMQdY24yvdwZbxmirMlKSiBi5Di6g55JhMWL5pXOi8+suAQa Dg3gJDde1WSrFwgXqlCxQnFt2d4bGZY= From: Kent Overstreet To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-bcachefs@vger.kernel.org Cc: Kent Overstreet , Alexander Viro , Matthew Wilcox Subject: [PATCH 23/32] iov_iter: copy_folio_from_iter_atomic() Date: Tue, 9 May 2023 12:56:48 -0400 Message-Id: <20230509165657.1735798-24-kent.overstreet@linux.dev> In-Reply-To: <20230509165657.1735798-1-kent.overstreet@linux.dev> References: <20230509165657.1735798-1-kent.overstreet@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a foliated version of copy_page_from_iter_atomic() Signed-off-by: Kent Overstreet Cc: Alexander Viro Cc: Matthew Wilcox --- include/linux/uio.h | 2 ++ lib/iov_iter.c | 53 ++++++++++++++++++++++++++++++++++++--------- 2 files changed, 45 insertions(+), 10 deletions(-) diff --git a/include/linux/uio.h b/include/linux/uio.h index 27e3fd9429..b2c281cb10 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -154,6 +154,8 @@ static inline struct iovec iov_iter_iovec(const struct = iov_iter *iter) =20 size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes, struct iov_iter *i); +size_t copy_folio_from_iter_atomic(struct folio *folio, size_t offset, + size_t bytes, struct iov_iter *i); void iov_iter_advance(struct iov_iter *i, size_t bytes); void iov_iter_revert(struct iov_iter *i, size_t bytes); size_t fault_in_iov_iter_readable(const struct iov_iter *i, size_t bytes); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 274014e4ea..27ba7e9f9e 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -800,18 +800,10 @@ size_t iov_iter_zero(size_t bytes, struct iov_iter *i) } EXPORT_SYMBOL(iov_iter_zero); =20 -size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size= _t bytes, - struct iov_iter *i) +static inline size_t __copy_page_from_iter_atomic(struct page *page, unsig= ned offset, + size_t bytes, struct iov_iter *i) { char *kaddr =3D kmap_atomic(page), *p =3D kaddr + offset; - if (!page_copy_sane(page, offset, bytes)) { - kunmap_atomic(kaddr); - return 0; - } - if (WARN_ON_ONCE(!i->data_source)) { - kunmap_atomic(kaddr); - return 0; - } iterate_and_advance(i, bytes, base, len, off, copyin(p + off, base, len), memcpy(p + off, base, len) @@ -819,8 +811,49 @@ size_t copy_page_from_iter_atomic(struct page *page, u= nsigned offset, size_t byt kunmap_atomic(kaddr); return bytes; } + +size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size= _t bytes, + struct iov_iter *i) +{ + if (!page_copy_sane(page, offset, bytes)) + return 0; + if (WARN_ON_ONCE(!i->data_source)) + return 0; + return __copy_page_from_iter_atomic(page, offset, bytes, i); +} EXPORT_SYMBOL(copy_page_from_iter_atomic); =20 +size_t copy_folio_from_iter_atomic(struct folio *folio, size_t offset, + size_t bytes, struct iov_iter *i) +{ + size_t ret =3D 0; + + if (WARN_ON(offset + bytes > folio_size(folio))) + return 0; + if (WARN_ON_ONCE(!i->data_source)) + return 0; + +#ifdef CONFIG_HIGHMEM + while (bytes) { + struct page *page =3D folio_page(folio, offset >> PAGE_SHIFT); + unsigned b =3D min(bytes, PAGE_SIZE - (offset & PAGE_MASK)); + unsigned r =3D __copy_page_from_iter_atomic(page, offset, b, i); + + offset +=3D r; + bytes -=3D r; + ret +=3D r; + + if (r !=3D b) + break; + } +#else + ret =3D __copy_page_from_iter_atomic(&folio->page, offset, bytes, i); +#endif + + return ret; +} +EXPORT_SYMBOL(copy_folio_from_iter_atomic); + static void pipe_advance(struct iov_iter *i, size_t size) { struct pipe_inode_info *pipe =3D i->pipe; --=20 2.40.1