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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 CF2C4C388F7 for ; Thu, 12 Nov 2020 21:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7048A22246 for ; Thu, 12 Nov 2020 21:27:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="U30C+OFT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727550AbgKLV1I (ORCPT ); Thu, 12 Nov 2020 16:27:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727505AbgKLV1B (ORCPT ); Thu, 12 Nov 2020 16:27:01 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2EEC5C0613D1; Thu, 12 Nov 2020 13:27:01 -0800 (PST) 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=HzBDjinxaIupRQuRgbw6uvZwV6m7KZ5Scf5MNsXtHDY=; b=U30C+OFTvsiV3WiiA64yPKrS2h 0L/nxwCXdOgcaaXy0QOtr0vExD0rIZdj13SubElhEIVymcC/X0I1lqHpr7YqsDTbQSfNJq12fQ+kb 5Im5l689oE7qlKyeNCr4+TDKh4lHN+49GU3Oc8X5WOZxgogY5eBwglqtR5AZRLNa0u1bzsfVG+IOe XLEwAvv2v58YK5Bb4sAhumPNmKarS1N3L0EfyVgFGOQJ0Epc73visw9eyLxFUhZ9AN8uNkG3EnlSd zcxBsEvIiXEZeenFlsM1SiiATMzH4v1o9iEhXIUxocoxgCIRKF1OoemThpn379JjDqQ/F9a7/qNgM 1166Y06g==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdK7B-0007GN-90; Thu, 12 Nov 2020 21:26:45 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , akpm@linux-foundation.org, hughd@google.com, hch@lst.de, hannes@cmpxchg.org, yang.shi@linux.alibaba.com, dchinner@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH v4 04/16] mm: Add FGP_ENTRY Date: Thu, 12 Nov 2020 21:26:29 +0000 Message-Id: <20201112212641.27837-5-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20201112212641.27837-1-willy@infradead.org> References: <20201112212641.27837-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The functionality of find_lock_entry() and find_get_entry() can be provided by pagecache_get_pages(), which lets us delete find_lock_entry() and make find_get_entry() static. Signed-off-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 1 + mm/filemap.c | 44 ++++++++--------------------------------- mm/internal.h | 3 --- mm/shmem.c | 3 ++- mm/swap_state.c | 3 ++- 5 files changed, 13 insertions(+), 41 deletions(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index edb990f3b930..55e1bff1c4b9 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -313,6 +313,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping, #define FGP_NOWAIT 0x00000020 #define FGP_FOR_MMAP 0x00000040 #define FGP_HEAD 0x00000080 +#define FGP_ENTRY 0x00000100 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset, int fgp_flags, gfp_t cache_gfp_mask); diff --git a/mm/filemap.c b/mm/filemap.c index bb6f2ae5a68c..01603f021740 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1662,7 +1662,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping, } EXPORT_SYMBOL(page_cache_prev_miss); -/** +/* * find_get_entry - find and get a page cache entry * @mapping: the address_space to search * @index: The page cache index. @@ -1675,7 +1675,7 @@ EXPORT_SYMBOL(page_cache_prev_miss); * * Return: The head page or shadow entry, %NULL if nothing is found. */ -struct page *find_get_entry(struct address_space *mapping, pgoff_t index) +static struct page *find_get_entry(struct address_space *mapping, pgoff_t index) { XA_STATE(xas, &mapping->i_pages, index); struct page *page; @@ -1711,39 +1711,6 @@ struct page *find_get_entry(struct address_space *mapping, pgoff_t index) return page; } -/** - * find_lock_entry - Locate and lock a page cache entry. - * @mapping: The address_space to search. - * @index: The page cache index. - * - * Looks up the page at @mapping & @index. If there is a page in the - * cache, the head page is returned locked and with an increased refcount. - * - * If the slot holds a shadow entry of a previously evicted page, or a - * swap entry from shmem/tmpfs, it is returned. - * - * Context: May sleep. - * Return: The head page or shadow entry, %NULL if nothing is found. - */ -struct page *find_lock_entry(struct address_space *mapping, pgoff_t index) -{ - struct page *page; - -repeat: - page = find_get_entry(mapping, index); - if (page && !xa_is_value(page)) { - lock_page(page); - /* Has the page been truncated? */ - if (unlikely(page->mapping != mapping)) { - unlock_page(page); - put_page(page); - goto repeat; - } - VM_BUG_ON_PAGE(!thp_contains(page, index), page); - } - return page; -} - /** * pagecache_get_page - Find and get a reference to a page. * @mapping: The address_space to search. @@ -1759,6 +1726,8 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t index) * * %FGP_LOCK - The page is returned locked. * * %FGP_HEAD - If the page is present and a THP, return the head page * rather than the exact page specified by the index. + * * %FGP_ENTRY - If there is a shadow / swap / DAX entry, return it + * instead of allocating a new page to replace it. * * %FGP_CREAT - If no page is present then a new page is allocated using * @gfp_mask and added to the page cache and the VM's LRU list. * The page is returned locked and with an increased refcount. @@ -1783,8 +1752,11 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, repeat: page = find_get_entry(mapping, index); - if (xa_is_value(page)) + if (xa_is_value(page)) { + if (fgp_flags & FGP_ENTRY) + return page; page = NULL; + } if (!page) goto no_page; diff --git a/mm/internal.h b/mm/internal.h index c43ccdddb0f6..93880d460e12 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -60,9 +60,6 @@ static inline void force_page_cache_readahead(struct address_space *mapping, force_page_cache_ra(&ractl, &file->f_ra, nr_to_read); } -struct page *find_get_entry(struct address_space *mapping, pgoff_t index); -struct page *find_lock_entry(struct address_space *mapping, pgoff_t index); - /** * page_evictable - test whether a page is evictable * @page: the page to test diff --git a/mm/shmem.c b/mm/shmem.c index 8076c171731c..c4feb05425f2 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1831,7 +1831,8 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, sbinfo = SHMEM_SB(inode->i_sb); charge_mm = vma ? vma->vm_mm : current->mm; - page = find_lock_entry(mapping, index); + page = pagecache_get_page(mapping, index, + FGP_ENTRY | FGP_HEAD | FGP_LOCK, 0); if (xa_is_value(page)) { error = shmem_swapin_page(inode, index, &page, sgp, gfp, vma, fault_type); diff --git a/mm/swap_state.c b/mm/swap_state.c index d2161154d873..7cb4433edaa2 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -427,7 +427,8 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index) { swp_entry_t swp; struct swap_info_struct *si; - struct page *page = find_get_entry(mapping, index); + struct page *page = pagecache_get_page(mapping, index, + FGP_ENTRY | FGP_HEAD, 0); if (!page) return page; -- 2.28.0