From patchwork Mon Jul 12 03:06:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12370135 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 29D81C07E9C for ; Mon, 12 Jul 2021 04:18:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 16D09610E6 for ; Mon, 12 Jul 2021 04:18:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231835AbhGLEVm (ORCPT ); Mon, 12 Jul 2021 00:21:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230272AbhGLEVm (ORCPT ); Mon, 12 Jul 2021 00:21:42 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBDCAC0613DD; Sun, 11 Jul 2021 21:18:54 -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=sfMLZBeiOB2qS+Bk0B7KnvwuPwNpIRnPkMH45C5t3Go=; b=SGnXM486m/BaQ66ljNRwYcXvZD 7PV8RlA+s/W9tkukQ9xgw7pROllza4lC+tUadlbaEfSwmCWUkbiVIn61mltc4mNunSsH/uXujr3t5 9o07BLxoj/FOEwal2BaVmjhN3Q4XQM4arTyIPQ5Dh99OR4uZC/hnVlkkVNMQY3We48VMFOtyan6Wd db8jeB4b7loRtA7NTYu+j9A5spuFgeCAHs7xJXwJ7Ce9BEGKFUY76tkY+dgb+6RsyPorwe8AwGkvE JGtByU5VlFTWQtfo6sxKDoI6/IujFktl8jVdBFkMkriHbpJconFxXoSs4Sxw60UhZ8sQsVmWn1Uke kFuZS3kg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2nOA-00GrjM-Ui; Mon, 12 Jul 2021 04:17:58 +0000 From: "Matthew Wilcox (Oracle)" To: linux-kernel@vger.kernel.org Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v13 134/137] mm/filemap: Allow multi-page folios to be added to the page cache Date: Mon, 12 Jul 2021 04:06:58 +0100 Message-Id: <20210712030701.4000097-135-willy@infradead.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210712030701.4000097-1-willy@infradead.org> References: <20210712030701.4000097-1-willy@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org We return -EEXIST if there are any non-shadow entries in the page cache in the range covered by the folio. If there are multiple shadow entries in the range, we set *shadowp to one of them (currently the one at the highest index). If that turns out to be the wrong answer, we can implement something more complex. This is mostly modelled after the equivalent function in the shmem code. Signed-off-by: Matthew Wilcox (Oracle) --- mm/filemap.c | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index c8fc0d07fa92..57dd01c5060c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -848,26 +848,27 @@ noinline int __filemap_add_folio(struct address_space *mapping, { XA_STATE(xas, &mapping->i_pages, index); int huge = folio_hugetlb(folio); - int error; bool charged = false; + unsigned int nr = 1; VM_BUG_ON_FOLIO(!folio_locked(folio), folio); VM_BUG_ON_FOLIO(folio_swapbacked(folio), folio); mapping_set_update(&xas, mapping); - folio_get(folio); - folio->mapping = mapping; - folio->index = index; - if (!huge) { - error = mem_cgroup_charge(folio, NULL, gfp); + int error = mem_cgroup_charge(folio, NULL, gfp); VM_BUG_ON_FOLIO(index & (folio_nr_pages(folio) - 1), folio); if (error) - goto error; + return error; charged = true; + xas_set_order(&xas, index, folio_order(folio)); + nr = folio_nr_pages(folio); } gfp &= GFP_RECLAIM_MASK; + folio_ref_add(folio, nr); + folio->mapping = mapping; + folio->index = xas.xa_index; do { unsigned int order = xa_get_order(xas.xa, xas.xa_index); @@ -891,6 +892,8 @@ noinline int __filemap_add_folio(struct address_space *mapping, /* entry may have been split before we acquired lock */ order = xa_get_order(xas.xa, xas.xa_index); if (order > folio_order(folio)) { + /* How to handle large swap entries? */ + BUG_ON(shmem_mapping(mapping)); xas_split(&xas, old, order); xas_reset(&xas); } @@ -900,29 +903,32 @@ noinline int __filemap_add_folio(struct address_space *mapping, if (xas_error(&xas)) goto unlock; - mapping->nrpages++; + mapping->nrpages += nr; /* hugetlb pages do not participate in page cache accounting */ - if (!huge) - __lruvec_stat_add_folio(folio, NR_FILE_PAGES); + if (!huge) { + __lruvec_stat_mod_folio(folio, NR_FILE_PAGES, nr); + if (nr > 1) + __lruvec_stat_mod_folio(folio, + NR_FILE_THPS, nr); + } unlock: xas_unlock_irq(&xas); } while (xas_nomem(&xas, gfp)); - if (xas_error(&xas)) { - error = xas_error(&xas); - if (charged) - mem_cgroup_uncharge(folio); + if (xas_error(&xas)) goto error; - } trace_mm_filemap_add_to_page_cache(&folio->page); return 0; error: + if (charged) + mem_cgroup_uncharge(folio); folio->mapping = NULL; /* Leave page->index set: truncation relies upon it */ - folio_put(folio); - return error; + folio_ref_sub(folio, nr); + VM_BUG_ON_FOLIO(folio_ref_count(folio) <= 0, folio); + return xas_error(&xas); } ALLOW_ERROR_INJECTION(__filemap_add_folio, ERRNO);