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=-13.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 2DBE4C4363D for ; Wed, 7 Oct 2020 21:49:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC9F52137B for ; Wed, 7 Oct 2020 21:49:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="qVPPzYo5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728229AbgJGVth (ORCPT ); Wed, 7 Oct 2020 17:49:37 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:10433 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726105AbgJGVth (ORCPT ); Wed, 7 Oct 2020 17:49:37 -0400 Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Wed, 07 Oct 2020 14:49:24 -0700 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 7 Oct 2020 21:49:36 +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; Wed, 7 Oct 2020 21:49:36 +0000 From: Ralph Campbell To: , , , , , CC: Dan Williams , Matthew Wilcox , Jan Kara , Alexander Viro , Theodore Ts'o , Christoph Hellwig , Andreas Dilger , "Darrick J. Wong" , Andrew Morton , "Ralph Campbell" Subject: [PATCH v2] ext4/xfs: add page refcount helper Date: Wed, 7 Oct 2020 14:49:25 -0700 Message-ID: <20201007214925.11181-1-rcampbell@nvidia.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-NVConfidentiality: public Content-Transfer-Encoding: quoted-printable Content-Type: text/plain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1602107364; bh=REj8QP14NN2VWymC9pd1yxt9jHOscnBs9nwknQCUye0=; h=From:To:CC:Subject:Date:Message-ID:X-Mailer:MIME-Version: X-NVConfidentiality:Content-Transfer-Encoding:Content-Type; b=qVPPzYo5AsUUHwus/S8Ekhyio/IAdtBrC6rBk43gpPR44t506lOgv7FACMlrPcebX ZLxuBFBl+bbjpwzC5xKe3ZNDanoYq3hpP9YuWHoKAUFkpmQzwlZtKUjo5MMT4ltMyS Wduyz1Xy7k+v+rJnc/V1Qw8MiHeuuhrppUxCc/wNr9+xtaawmxmlOPjQKfE8ulelhi XdmOd/vMiAsj5HqRLP3zkooeipjGcmVtyFPw5s1SjWeUqiFWlZt3xkIK7oyDXa8xkr QgaPDWkuP1DQJ2io/rptyAJIfDUGJDOKgktAodAK73J42JSasCWO5KuvnY52qevauN hd7lr9rnqU5jg== Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org There are several places where ZONE_DEVICE struct pages assume a reference count =3D=3D 1 means the page is idle and free. Instead of open coding this= , add helper functions to hide this detail. Signed-off-by: Ralph Campbell Reviewed-by: Christoph Hellwig Acked-by: Darrick J. Wong Acked-by: Theodore Ts'o # for fs/ext4/inode.c --- Changes in v2: I strongly resisted the idea of extending this patch but after Jan Kara's comment about there being more places that could be cleaned up, I felt compelled to make this one tensy wensy change to add a dax_wakeup_page() to match the dax_wait_page(). I kept the Reviewed/Acked-bys since I don't think this substantially changes the patch. fs/dax.c | 4 ++-- fs/ext4/inode.c | 5 +---- fs/xfs/xfs_file.c | 4 +--- include/linux/dax.h | 15 +++++++++++++++ mm/memremap.c | 3 ++- 5 files changed, 21 insertions(+), 10 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 5b47834f2e1b..85c63f735909 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 =3D pfn_to_page(pfn); =20 - 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 !=3D mapping); page->mapping =3D NULL; page->index =3D 0; @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) for_each_mapped_pfn(entry, pfn) { struct page *page =3D pfn_to_page(pfn); =20 - if (page_ref_count(page) > 1) + if (!dax_layout_is_idle_page(page)) return page; } return NULL; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 771ed8b1fadb..132620cbfa13 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3937,10 +3937,7 @@ int ext4_break_layouts(struct inode *inode) if (!page) return 0; =20 - error =3D ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) =3D=3D 1, - TASK_INTERRUPTIBLE, 0, 0, - ext4_wait_dax_page(ei)); + error =3D dax_wait_page(ei, page, ext4_wait_dax_page); } while (error =3D=3D 0); =20 return error; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 3d1b95124744..a5304aaeaa3a 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -749,9 +749,7 @@ xfs_break_dax_layouts( return 0; =20 *retry =3D true; - return ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) =3D=3D 1, TASK_INTERRUPTIBLE, - 0, 0, xfs_wait_dax_page(inode)); + return dax_wait_page(inode, page, xfs_wait_dax_page); } =20 int diff --git a/include/linux/dax.h b/include/linux/dax.h index b52f084aa643..e2da78e87338 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -243,6 +243,21 @@ static inline bool dax_mapping(struct address_space *m= apping) return mapping->host && IS_DAX(mapping->host); } =20 +static inline bool dax_layout_is_idle_page(struct page *page) +{ + return page_ref_count(page) =3D=3D 1; +} + +static inline void dax_wakeup_page(struct page *page) +{ + wake_up_var(&page->_refcount); +} + +#define dax_wait_page(_inode, _page, _wait_cb) \ + ___wait_var_event(&(_page)->_refcount, \ + dax_layout_is_idle_page(_page), \ + TASK_INTERRUPTIBLE, 0, 0, _wait_cb(_inode)) + #ifdef CONFIG_DEV_DAX_HMEM_DEVICES void hmem_register_device(int target_nid, struct resource *r); #else diff --git a/mm/memremap.c b/mm/memremap.c index 2bb276680837..504a10ff2edf 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -12,6 +12,7 @@ #include #include #include +#include =20 static DEFINE_XARRAY(pgmap_array); =20 @@ -508,7 +509,7 @@ void free_devmap_managed_page(struct page *page) { /* notify page idle for dax */ if (!is_device_private_page(page)) { - wake_up_var(&page->_refcount); + dax_wakeup_page(page); return; } =20 --=20 2.20.1