From patchwork Tue Jun 22 11:40:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12336977 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=-16.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 8BA5BC2B9F4 for ; Tue, 22 Jun 2021 11:53:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3D0076135F for ; Tue, 22 Jun 2021 11:53:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3D0076135F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CDCF06B0036; Tue, 22 Jun 2021 07:53:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CB3F46B006C; Tue, 22 Jun 2021 07:53:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7C176B0070; Tue, 22 Jun 2021 07:53:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0032.hostedemail.com [216.40.44.32]) by kanga.kvack.org (Postfix) with ESMTP id 84D996B0036 for ; Tue, 22 Jun 2021 07:53:58 -0400 (EDT) Received: from smtpin38.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 10759181AC9C6 for ; Tue, 22 Jun 2021 11:53:58 +0000 (UTC) X-FDA: 78281200956.38.75B770D Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id 71EBE801935E for ; Tue, 22 Jun 2021 11:53:57 +0000 (UTC) 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=r683nMLaZLKs8tsYoRXzNGw3gI6FDaN66DZVn/Mk92Q=; b=pljPnBHf7fyrKo4XK79gWfCFhJ nW144VKaJnvEAP/epDqomRsnqYZppB/2Dqgamq6hmozUM0YWSphbLrcZksV+pTyqhyvgO1Q63yekh G20MH7seCbOtdoatTb9cGk02N2DQcm5dQr9JF8c393QYyx8xFHdeKnXss7ZbpF9qag+E7UVCG8mgc EWCiXg+3McgLOZPCOdUfMv4J09jn1SQ5rS61SWsKwhHBj0E99LaJJ8ntRVJTvh+etXMRsVbGAvs01 N9uBrE5RN7B0Icbe1KHwTWCotSIzuLxmVjT3BqcLNfDNnkKsfN+Zxs8zjblIeqlLTw9qHiwckyfcX pxdBEJ1w==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lvewj-00EEE6-9C; Tue, 22 Jun 2021 11:52:16 +0000 From: "Matthew Wilcox (Oracle)" To: akpm@linux-foundation.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Jeff Layton , "Kirill A . Shutemov" , Vlastimil Babka , William Kucharski , David Howells Subject: [PATCH v12 13/33] mm/filemap: Add folio_index(), folio_file_page() and folio_contains() Date: Tue, 22 Jun 2021 12:40:58 +0100 Message-Id: <20210622114118.3388190-14-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210622114118.3388190-1-willy@infradead.org> References: <20210622114118.3388190-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 71EBE801935E Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=pljPnBHf; spf=none (imf08.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Stat-Signature: x4m1girgjhd4odhyjsgmga6jzzgnx5ky X-HE-Tag: 1624362837-378015 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: folio_index() is the equivalent of page_index() for folios. folio_file_page() is the equivalent of find_subpage(). folio_contains() is the equivalent of thp_contains(). No changes to generated code. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Jeff Layton Acked-by: Kirill A. Shutemov Acked-by: Vlastimil Babka Reviewed-by: William Kucharski Reviewed-by: David Howells --- include/linux/pagemap.h | 56 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 28a241fdb1a2..3af2bcd13a9b 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -386,6 +386,62 @@ static inline bool thp_contains(struct page *head, pgoff_t index) return page_index(head) == (index & ~(thp_nr_pages(head) - 1UL)); } +#define swapcache_index(folio) __page_file_index(&(folio)->page) + +/** + * folio_index - File index of a folio. + * @folio: The folio. + * + * For a folio which is either in the page cache or the swap cache, + * return its index within the address_space it belongs to. If you know + * the page is definitely in the page cache, you can look at the folio's + * index directly. + * + * Return: The index (offset in units of pages) of a folio in its file. + */ +static inline pgoff_t folio_index(struct folio *folio) +{ + if (unlikely(folio_swapcache(folio))) + return swapcache_index(folio); + return folio->index; +} + +/** + * folio_file_page - The page for a particular index. + * @folio: The folio which contains this index. + * @index: The index we want to look up. + * + * Sometimes after looking up a folio in the page cache, we need to + * obtain the specific page for an index (eg a page fault). + * + * Return: The page containing the file data for this index. + */ +static inline struct page *folio_file_page(struct folio *folio, pgoff_t index) +{ + /* HugeTLBfs indexes the page cache in units of hpage_size */ + if (folio_hugetlb(folio)) + return &folio->page; + return folio_page(folio, index & (folio_nr_pages(folio) - 1)); +} + +/** + * folio_contains - Does this folio contain this index? + * @folio: The folio. + * @index: The page index within the file. + * + * Context: The caller should have the page locked in order to prevent + * (eg) shmem from moving the page between the page cache and swap cache + * and changing its index in the middle of the operation. + * Return: true or false. + */ +static inline bool folio_contains(struct folio *folio, pgoff_t index) +{ + /* HugeTLBfs indexes the page cache in units of hpage_size */ + if (folio_hugetlb(folio)) + return folio->index == index; + return index - folio_index(folio) < folio_nr_pages(folio); +} + /* * Given the page we found in the page cache, return the page corresponding * to this index in the file