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=-15.8 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 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 76BEAC4332B for ; Fri, 26 Feb 2021 01:18:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32C9064F29 for ; Fri, 26 Feb 2021 01:18:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230014AbhBZBSM (ORCPT ); Thu, 25 Feb 2021 20:18:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:49664 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230018AbhBZBRv (ORCPT ); Thu, 25 Feb 2021 20:17:51 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2B53264F10; Fri, 26 Feb 2021 01:17:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1614302230; bh=nj2mn8PzokQPH3M4TxUFd6o6AkalNQNeB1bNFp6zETM=; h=Date:From:To:Subject:In-Reply-To:From; b=MF+gD3sDqkyRT893WRwo+iqIaLxMJ+k+AbEE490enaVq/J9Bb2F4E2wXRxjo4RgMt v4qomVfK708HeiHnGcN40rCxH69XZAl/Ewg7NqeI7b3xAYtfElaBiO9bOtLd8bX8Un Fj+07ZlUz9KIgY2ukXR8bS69sSNKO9WUV43DCfe8= Date: Thu, 25 Feb 2021 17:17:08 -0800 From: Andrew Morton To: akpm@linux-foundation.org, cai@lca.pw, dan.j.williams@intel.com, david@redhat.com, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, naoya.horiguchi@nec.com, osalvador@suse.de, torvalds@linux-foundation.org Subject: [patch 029/118] mm: fix memory_failure() handling of dax-namespace metadata Message-ID: <20210226011708.N4sC0luia%akpm@linux-foundation.org> In-Reply-To: <20210225171452.713967e96554bb6a53e44a19@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Dan Williams Subject: mm: fix memory_failure() handling of dax-namespace metadata Given 'struct dev_pagemap' spans both data pages and metadata pages be careful to consult the altmap if present to delineate metadata. In fact the pfn_first() helper already identifies the first valid data pfn, so export that helper for other code paths via pgmap_pfn_valid(). Other usage of get_dev_pagemap() are not a concern because those are operating on known data pfns having been looked up by get_user_pages(). I.e. metadata pfns are never user mapped. Link: https://lkml.kernel.org/r/161058501758.1840162.4239831989762604527.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 6100e34b2526 ("mm, memory_failure: Teach memory_failure() about dev_pagemap pages") Signed-off-by: Dan Williams Reported-by: David Hildenbrand Reviewed-by: David Hildenbrand Reviewed-by: Naoya Horiguchi Cc: Michal Hocko Cc: Oscar Salvador Cc: Qian Cai Signed-off-by: Andrew Morton --- include/linux/memremap.h | 6 ++++++ mm/memory-failure.c | 6 ++++++ mm/memremap.c | 15 +++++++++++++++ 3 files changed, 27 insertions(+) --- a/include/linux/memremap.h~mm-fix-memory_failure-handling-of-dax-namespace-metadata +++ a/include/linux/memremap.h @@ -137,6 +137,7 @@ void *devm_memremap_pages(struct device void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap); struct dev_pagemap *get_dev_pagemap(unsigned long pfn, struct dev_pagemap *pgmap); +bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn); unsigned long vmem_altmap_offset(struct vmem_altmap *altmap); void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns); @@ -165,6 +166,11 @@ static inline struct dev_pagemap *get_de return NULL; } +static inline bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn) +{ + return false; +} + static inline unsigned long vmem_altmap_offset(struct vmem_altmap *altmap) { return 0; --- a/mm/memory-failure.c~mm-fix-memory_failure-handling-of-dax-namespace-metadata +++ a/mm/memory-failure.c @@ -1312,6 +1312,12 @@ static int memory_failure_dev_pagemap(un */ put_page(page); + /* device metadata space is not recoverable */ + if (!pgmap_pfn_valid(pgmap, pfn)) { + rc = -ENXIO; + goto out; + } + /* * Prevent the inode from being freed while we are interrogating * the address_space, typically this would be handled by --- a/mm/memremap.c~mm-fix-memory_failure-handling-of-dax-namespace-metadata +++ a/mm/memremap.c @@ -80,6 +80,21 @@ static unsigned long pfn_first(struct de return pfn + vmem_altmap_offset(pgmap_altmap(pgmap)); } +bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn) +{ + int i; + + for (i = 0; i < pgmap->nr_range; i++) { + struct range *range = &pgmap->ranges[i]; + + if (pfn >= PHYS_PFN(range->start) && + pfn <= PHYS_PFN(range->end)) + return pfn >= pfn_first(pgmap, i); + } + + return false; +} + static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id) { const struct range *range = &pgmap->ranges[range_id]; _