From patchwork Thu Jul 15 03:36:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12378735 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=-16.6 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,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 5B956C47E48 for ; Thu, 15 Jul 2021 04:41:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0F6F861362 for ; Thu, 15 Jul 2021 04:41:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0F6F861362 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 621188D0055; Thu, 15 Jul 2021 00:41:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5F82A8D004B; Thu, 15 Jul 2021 00:41:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4C0E58D0055; Thu, 15 Jul 2021 00:41:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0179.hostedemail.com [216.40.44.179]) by kanga.kvack.org (Postfix) with ESMTP id 29B3A8D004B for ; Thu, 15 Jul 2021 00:41:51 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id F35EA20F0F for ; Thu, 15 Jul 2021 04:41:49 +0000 (UTC) X-FDA: 78363574380.20.E494997 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf30.hostedemail.com (Postfix) with ESMTP id 85819E00181A for ; Thu, 15 Jul 2021 04:41:49 +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=mOZR97vqhEKo31GvUk0y72ueq9pa4KcTUloIAzr8f6s=; b=vsjO4l71AveQPK3b7poPZDY+0m mc6AMqFx5wcad/fdRUbeup8u/oQV529KHDjd+GvuzVkNS6QyDXLH5Vj2KrkN1Zq6jOw3ejAvLgcQD BstOrfcoMcpILjKjR+wKjYHIkkquZ53qEiNvVvAG6jx1Ggvd4bqYDaEkpwVpqGIMMyNNaZtn2tjf1 PI4eOv+x9lu1zn1/Df62VOHlLzRXmwUy9lBQiV05Y60N32TNMJPjYfa7kxynMpKNC5gKr5InHb5Z9 beUL0wZha8sfgYJA2xhYpLaabVVLAHTnf1iXZxYOkLPCGCunxsqglV1XHs4zkU6zwL28SDFwr+eSp ZmQ4rYug==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3tAo-002yEG-MX; Thu, 15 Jul 2021 04:40:47 +0000 From: "Matthew Wilcox (Oracle)" To: linux-kernel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig Subject: [PATCH v14 079/138] mm/filemap: Add readahead_folio() Date: Thu, 15 Jul 2021 04:36:05 +0100 Message-Id: <20210715033704.692967-80-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210715033704.692967-1-willy@infradead.org> References: <20210715033704.692967-1-willy@infradead.org> MIME-Version: 1.0 Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=vsjO4l71; spf=none (imf30.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-Rspamd-Server: rspam02 X-Stat-Signature: zhqi8peksydiazn3udh9ocun7rpxjiie X-Rspamd-Queue-Id: 85819E00181A X-HE-Tag: 1626324109-761222 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: The pointers stored in the page cache are folios, by definition. This change comes with a behaviour change -- callers of readahead_folio() are no longer required to put the page reference themselves. This matches how readpage works, rather than matching how readpages used to work. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: David Howells Acked-by: Vlastimil Babka --- include/linux/pagemap.h | 53 +++++++++++++++++++++++++++++------------ 1 file changed, 38 insertions(+), 15 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 18c06c3e42c3..bd4daebaf70e 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -988,33 +988,56 @@ void page_cache_async_readahead(struct address_space *mapping, page_cache_async_ra(&ractl, page, req_count); } +static inline struct folio *__readahead_folio(struct readahead_control *ractl) +{ + struct folio *folio; + + BUG_ON(ractl->_batch_count > ractl->_nr_pages); + ractl->_nr_pages -= ractl->_batch_count; + ractl->_index += ractl->_batch_count; + + if (!ractl->_nr_pages) { + ractl->_batch_count = 0; + return NULL; + } + + folio = xa_load(&ractl->mapping->i_pages, ractl->_index); + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); + ractl->_batch_count = folio_nr_pages(folio); + + return folio; +} + /** * readahead_page - Get the next page to read. - * @rac: The current readahead request. + * @ractl: The current readahead request. * * Context: The page is locked and has an elevated refcount. The caller * should decreases the refcount once the page has been submitted for I/O * and unlock the page once all I/O to that page has completed. * Return: A pointer to the next page, or %NULL if we are done. */ -static inline struct page *readahead_page(struct readahead_control *rac) +static inline struct page *readahead_page(struct readahead_control *ractl) { - struct page *page; + struct folio *folio = __readahead_folio(ractl); - BUG_ON(rac->_batch_count > rac->_nr_pages); - rac->_nr_pages -= rac->_batch_count; - rac->_index += rac->_batch_count; - - if (!rac->_nr_pages) { - rac->_batch_count = 0; - return NULL; - } + return &folio->page; +} - page = xa_load(&rac->mapping->i_pages, rac->_index); - VM_BUG_ON_PAGE(!PageLocked(page), page); - rac->_batch_count = thp_nr_pages(page); +/** + * readahead_folio - Get the next folio to read. + * @ractl: The current readahead request. + * + * Context: The folio is locked. The caller should unlock the folio once + * all I/O to that folio has completed. + * Return: A pointer to the next folio, or %NULL if we are done. + */ +static inline struct folio *readahead_folio(struct readahead_control *ractl) +{ + struct folio *folio = __readahead_folio(ractl); - return page; + folio_put(folio); + return folio; } static inline unsigned int __readahead_batch(struct readahead_control *rac,