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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 01C6BC433B4 for ; Wed, 5 May 2021 16:31:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7D35610A1 for ; Wed, 5 May 2021 16:31:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234008AbhEEQcL (ORCPT ); Wed, 5 May 2021 12:32:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37492 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233826AbhEEQcK (ORCPT ); Wed, 5 May 2021 12:32:10 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B7F0EC061574; Wed, 5 May 2021 09:31:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=nI9lCM1C11RSMX9mr5wZgr4g67mkfOZVIXRulnGLED0=; b=NVEbDkgSTcGEjcdWw2YB2EKFR4 sKdm3fflfwJg/yVRja8shrLxdPXgSo6pI5hgfQamAuyQ1uXWxl2ZcUv0M3bnSCtoHIcpRoBomdX98 JMoKYthWHWyN/IYsog5rj407j1Ko00Z6glZk42QlfeIc8R9H0VTqNBXg1ohpAZKp15jsqgkxYd6of F+u/NyKwZAnQ/Gh7cIgFHkordBG2IwMcdzSIGUYkVZ6tVYOy0f6T24T+uHjgz+e0ol9hqBArhRJei Q/ZjGq8u5LIiwXBvoxNXPtCJF2q4mEVkl+wAe4uZfJ+JCS+Aex97d2jl2DAKTkVgg0W6C4DnTPFpJ Na9mTyZQ==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1leKOS-000abl-5P; Wed, 05 May 2021 16:29:45 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-kernel@vger.kernel.org Subject: [PATCH v9 69/96] mm/filemap: Add folio_mkwrite_check_truncate Date: Wed, 5 May 2021 16:06:01 +0100 Message-Id: <20210505150628.111735-70-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210505150628.111735-1-willy@infradead.org> References: <20210505150628.111735-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This is the folio equivalent of page_mkwrite_check_truncate(). Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 2f896574aad7..8fd00dc5ebd5 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -1195,6 +1195,34 @@ static inline unsigned long dir_pages(struct inode *inode) PAGE_SHIFT; } +/** + * folio_mkwrite_check_truncate - check if folio was truncated + * @folio: the folio to check + * @inode: the inode to check the folio against + * + * Return: the number of bytes in the folio up to EOF, + * or -EFAULT if the folio was truncated. + */ +static inline ssize_t folio_mkwrite_check_truncate(struct folio *folio, + struct inode *inode) +{ + loff_t size = i_size_read(inode); + pgoff_t index = size >> PAGE_SHIFT; + size_t offset = offset_in_folio(folio, size); + + if (!folio->mapping) + return -EFAULT; + + /* folio is wholly inside EOF */ + if (folio_next_index(folio) - 1 < index) + return folio_size(folio); + /* folio is wholly past EOF */ + if (folio->index > index || !offset) + return -EFAULT; + /* folio is partially inside EOF */ + return offset; +} + /** * page_mkwrite_check_truncate - check if page was truncated * @page: the page to check -- 2.30.2