From patchwork Fri Sep 25 20:44:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ralph Campbell X-Patchwork-Id: 11800731 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 81C7E92C for ; Fri, 25 Sep 2020 20:44:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 149D9221E5 for ; Fri, 25 Sep 2020 20:44:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="ppmFHJw0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 149D9221E5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E52B86B0062; Fri, 25 Sep 2020 16:44:55 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id DDBC66B006E; Fri, 25 Sep 2020 16:44:55 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CADA76B006C; Fri, 25 Sep 2020 16:44:55 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0208.hostedemail.com [216.40.44.208]) by kanga.kvack.org (Postfix) with ESMTP id ADE0A6B005D for ; Fri, 25 Sep 2020 16:44:55 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 6894A824999B for ; Fri, 25 Sep 2020 20:44:55 +0000 (UTC) X-FDA: 77302762950.07.mass15_4d10fbf2716a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 478221803F9AC for ; Fri, 25 Sep 2020 20:44:55 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,rcampbell@nvidia.com,,RULES_HIT:30003:30054:30064,0,RBL:216.228.121.64:@nvidia.com:.lbl8.mailshell.net-64.10.201.10 62.18.0.100;04yriyioyhgoigdfgexkifuhi9u8wycy1edutj3oroo31hdymtggkboce1mjx9t.6tusq3pko5gix1zeinfsgz3ym8gu4raz8i9a48ebim1kb8388ny9wgpcuop4fh7.e-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:ft,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: mass15_4d10fbf2716a X-Filterd-Recvd-Size: 5868 Received: from hqnvemgate25.nvidia.com (hqnvemgate25.nvidia.com [216.228.121.64]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Fri, 25 Sep 2020 20:44:52 +0000 (UTC) Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Fri, 25 Sep 2020 13:44:03 -0700 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 25 Sep 2020 20:44:48 +0000 Received: from rcampbell-dev.nvidia.com (10.124.1.5) by mail.nvidia.com (172.20.187.18) with Microsoft SMTP Server id 15.0.1473.3 via Frontend Transport; Fri, 25 Sep 2020 20:44:48 +0000 From: Ralph Campbell To: , , , CC: Dan Williams , Ira Weiny , Matthew Wilcox , Jerome Glisse , John Hubbard , Alistair Popple , Christoph Hellwig , Jason Gunthorpe , "Bharata B Rao" , Zi Yan , "Kirill A . Shutemov" , Yang Shi , Paul Mackerras , Ben Skeggs , "Andrew Morton" , Ralph Campbell Subject: [PATCH 1/2] ext4/xfs: add page refcount helper Date: Fri, 25 Sep 2020 13:44:41 -0700 Message-ID: <20200925204442.31348-2-rcampbell@nvidia.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200925204442.31348-1-rcampbell@nvidia.com> References: <20200925204442.31348-1-rcampbell@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1601066643; bh=4UbYfQo9AxoYDYhHzSM52zo+QqA5U/JvLsALQgToAcw=; h=From:To:CC:Subject:Date:Message-ID:X-Mailer:In-Reply-To: References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=ppmFHJw0FcvTTLsqEzpQGv1+HRZOAwtVEIxm0dWqH7qfJliBWPFv0mr0+bEjH9zMw 27oZK0wp+klIF1aR8bjlS0PCzsozHz0RU7MoXCOJoKJMskpwWXSYldy1pORDmvC6R6 nwaNeCE1ezdMPk1zip1/0XO+Y98S809xcq0vKiH1bot2OZ/NB/eLGflsWUFgvZXkC9 YCqnNcLDseWWA7vraoWncwMoTeSoOBhEK7AuZ8NEMrgLd7zwRTsmFjoPT1sSduX3aj aJXHU048cE+Gn7/oz0w8gMVrcgsNwJMIen9Fpp2fqb9izIrKOoovFISrkv3h1lyN0d xtnrv3qv5fzZg== 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: There are several places where ZONE_DEVICE struct pages assume a reference count == 1 means the page is idle and free. Instead of open coding this, add a helper function to hide this detail. Signed-off-by: Ralph Campbell --- fs/dax.c | 8 ++++---- fs/ext4/inode.c | 2 +- fs/xfs/xfs_file.c | 2 +- include/linux/dax.h | 5 +++++ 4 files changed, 11 insertions(+), 6 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 994ab66a9907..8eddbcc0e149 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); - WARN_ON_ONCE(trunc && page_ref_count(page) > 1); + WARN_ON_ONCE(trunc && !dax_layout_is_idle_page(page)); WARN_ON_ONCE(page->mapping && page->mapping != mapping); page->mapping = NULL; page->index = 0; @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); - if (page_ref_count(page) > 1) + if (!dax_layout_is_idle_page(page)) return page; } return NULL; @@ -560,11 +560,11 @@ static void *grab_mapping_entry(struct xa_state *xas, /** * dax_layout_busy_page - find first pinned page in @mapping - * @mapping: address space to scan for a page with ref count > 1 + * @mapping: address space to scan for a page with ref count > 0 * * DAX requires ZONE_DEVICE mapped pages. These pages are never * 'onlined' to the page allocator so they are considered idle when - * page->count == 1. A filesystem uses this interface to determine if + * page->count == 0. A filesystem uses this interface to determine if * any page in the mapping is busy, i.e. for DMA, or other * get_user_pages() usages. * diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index bf596467c234..d9f8ad55523a 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3927,7 +3927,7 @@ int ext4_break_layouts(struct inode *inode) return 0; error = ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) == 1, + dax_layout_is_idle_page(page), TASK_INTERRUPTIBLE, 0, 0, ext4_wait_dax_page(ei)); } while (error == 0); diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index a29f78a663ca..29ab96541bc1 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -750,7 +750,7 @@ xfs_break_dax_layouts( *retry = true; return ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, + dax_layout_is_idle_page(page), TASK_INTERRUPTIBLE, 0, 0, xfs_wait_dax_page(inode)); } diff --git a/include/linux/dax.h b/include/linux/dax.h index 43b39ab9de1a..3f78ed78d1d6 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -238,4 +238,9 @@ static inline bool dax_mapping(struct address_space *mapping) return mapping->host && IS_DAX(mapping->host); } +static inline bool dax_layout_is_idle_page(struct page *page) +{ + return page_ref_count(page) <= 1; +} + #endif