From patchwork Sun Apr 3 05:39:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12799481 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8901C433EF for ; Sun, 3 Apr 2022 05:41:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238863AbiDCFn2 (ORCPT ); Sun, 3 Apr 2022 01:43:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238688AbiDCFnZ (ORCPT ); Sun, 3 Apr 2022 01:43:25 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17A15340D3 for ; Sat, 2 Apr 2022 22:41:32 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id i11so5717901plr.1 for ; Sat, 02 Apr 2022 22:41:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ss8jaoNqbCttgkdiicrTIYI1R2QuFynfz36gAXgUE7k=; b=ljK+nt2UNQ8zKRGE/zCfCxSLHdGZqaxkxh6a9KwpoVhKSi8iS7pzyFG5rUuCc4et/Y FSVM1Xf4ajyjXed3xauvnzbn4LoRQo2l7LRafjxetfr7eFZMr/NRuhrZg9qV7N4TFN09 Fg055h0MHAVQEzLwkOe7W3nbvuZqhE4jrho3aGzB+9TxiAw1nUibE8uCsMENUHr7sgb3 2+y0AbE9pYhCOu/Vm1jJ0f7ryZ0b7JYHyUL4YgLEiQehW0Sp5NpEnfwYu4CB2Z04zLVK 51yRZI2AJpzXQZFF31Na/4DZYHjtqwqKFaQ665+Osp4W0qnram+2HxYQV8U9EWtFRxoB DSpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ss8jaoNqbCttgkdiicrTIYI1R2QuFynfz36gAXgUE7k=; b=akotP8PRJEmOPHhKzH8iFbz0CQ3TetpazmQ1tN9TlYCk53KfW0PMFbk/GZh5F8n0ww X8ghEuZ0rXxJfY7tQ9YuplePlIuw8krxpcOvDI3TE+ufIU+l1MhdONjbY9jzIaMvjUUG luMQ2wO7mcaUGQ3rCmNpT+Kb4wmNe/4A7oaRQL0vkjLspawxUnwQZkaiyz2luBzwWMIo y21uIetl1bPhhyxJC08aEyOLwfKr2Q+ir9iyFaOK004lh4qhHjtgv6FX/ghyFHEVw+cy TcJdPuMjhpVokEPrcgcQrXF0tTCNW39X5bVi2IVqB1HQUuqnj6Pgs4LwM816b72s0fxI /eEg== X-Gm-Message-State: AOAM530EI2r97zCj7wMGQiAjQb6b1Yo8e7gjouBELNDcoTVDg3LeNxYA HJMnLYen1JylDr35VtGcV/RacA== X-Google-Smtp-Source: ABdhPJzb7n1x9H/3exn1YcDrylPGvv27RMTn16h2h9+bcsaRc2iqaKLat0zmBiFPgo3tmrFG1hAZGQ== X-Received: by 2002:a17:90a:488c:b0:1c7:b62e:8e8c with SMTP id b12-20020a17090a488c00b001c7b62e8e8cmr19839143pjh.157.1648964491520; Sat, 02 Apr 2022 22:41:31 -0700 (PDT) Received: from FVFYT0MHHV2J.bytedance.net ([139.177.225.245]) by smtp.gmail.com with ESMTPSA id a38-20020a056a001d2600b004f70d5e92basm8262479pfx.34.2022.04.02.22.41.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 02 Apr 2022 22:41:31 -0700 (PDT) From: Muchun Song To: dan.j.williams@intel.com, willy@infradead.org, jack@suse.cz, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, apopple@nvidia.com, shy828301@gmail.com, rcampbell@nvidia.com, hughd@google.com, xiyuyang19@fudan.edu.cn, kirill.shutemov@linux.intel.com, zwisler@kernel.org, hch@infradead.org Cc: linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org, duanxiongchun@bytedance.com, smuchun@gmail.com, Muchun Song Subject: [PATCH v7 3/6] mm: rmap: introduce pfn_mkclean_range() to cleans PTEs Date: Sun, 3 Apr 2022 13:39:54 +0800 Message-Id: <20220403053957.10770-4-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220403053957.10770-1-songmuchun@bytedance.com> References: <20220403053957.10770-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The page_mkclean_one() is supposed to be used with the pfn that has a associated struct page, but not all the pfns (e.g. DAX) have a struct page. Introduce a new function pfn_mkclean_range() to cleans the PTEs (including PMDs) mapped with range of pfns which has no struct page associated with them. This helper will be used by DAX device in the next patch to make pfns clean. Signed-off-by: Muchun Song --- include/linux/rmap.h | 3 +++ mm/internal.h | 26 +++++++++++++-------- mm/rmap.c | 65 +++++++++++++++++++++++++++++++++++++++++++--------- 3 files changed, 74 insertions(+), 20 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index b58ddb8b2220..a6ec0d3e40c1 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -263,6 +263,9 @@ unsigned long page_address_in_vma(struct page *, struct vm_area_struct *); */ int folio_mkclean(struct folio *); +int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff, + struct vm_area_struct *vma); + void remove_migration_ptes(struct folio *src, struct folio *dst, bool locked); /* diff --git a/mm/internal.h b/mm/internal.h index f45292dc4ef5..664e6d48607c 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -516,26 +516,22 @@ void mlock_page_drain(int cpu); extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma); /* - * At what user virtual address is page expected in vma? - * Returns -EFAULT if all of the page is outside the range of vma. - * If page is a compound head, the entire compound page is considered. + * Return the start of user virtual address at the specific offset within + * a vma. */ static inline unsigned long -vma_address(struct page *page, struct vm_area_struct *vma) +vma_pgoff_address(pgoff_t pgoff, unsigned long nr_pages, + struct vm_area_struct *vma) { - pgoff_t pgoff; unsigned long address; - VM_BUG_ON_PAGE(PageKsm(page), page); /* KSM page->index unusable */ - pgoff = page_to_pgoff(page); if (pgoff >= vma->vm_pgoff) { address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); /* Check for address beyond vma (or wrapped through 0?) */ if (address < vma->vm_start || address >= vma->vm_end) address = -EFAULT; - } else if (PageHead(page) && - pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) { + } else if (pgoff + nr_pages - 1 >= vma->vm_pgoff) { /* Test above avoids possibility of wrap to 0 on 32-bit */ address = vma->vm_start; } else { @@ -545,6 +541,18 @@ vma_address(struct page *page, struct vm_area_struct *vma) } /* + * Return the start of user virtual address of a page within a vma. + * Returns -EFAULT if all of the page is outside the range of vma. + * If page is a compound head, the entire compound page is considered. + */ +static inline unsigned long +vma_address(struct page *page, struct vm_area_struct *vma) +{ + VM_BUG_ON_PAGE(PageKsm(page), page); /* KSM page->index unusable */ + return vma_pgoff_address(page_to_pgoff(page), compound_nr(page), vma); +} + +/* * Then at what user virtual address will none of the range be found in vma? * Assumes that vma_address() already returned a good starting address. */ diff --git a/mm/rmap.c b/mm/rmap.c index 723682ddb9e8..ad5cf0e45a73 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -929,12 +929,12 @@ int folio_referenced(struct folio *folio, int is_locked, return pra.referenced; } -static bool page_mkclean_one(struct folio *folio, struct vm_area_struct *vma, - unsigned long address, void *arg) +static int page_vma_mkclean_one(struct page_vma_mapped_walk *pvmw) { - DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, address, PVMW_SYNC); + int cleaned = 0; + struct vm_area_struct *vma = pvmw->vma; struct mmu_notifier_range range; - int *cleaned = arg; + unsigned long address = pvmw->address; /* * We have to assume the worse case ie pmd for invalidation. Note that @@ -942,16 +942,16 @@ static bool page_mkclean_one(struct folio *folio, struct vm_area_struct *vma, */ mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_PAGE, 0, vma, vma->vm_mm, address, - vma_address_end(&pvmw)); + vma_address_end(pvmw)); mmu_notifier_invalidate_range_start(&range); - while (page_vma_mapped_walk(&pvmw)) { + while (page_vma_mapped_walk(pvmw)) { int ret = 0; - address = pvmw.address; - if (pvmw.pte) { + address = pvmw->address; + if (pvmw->pte) { pte_t entry; - pte_t *pte = pvmw.pte; + pte_t *pte = pvmw->pte; if (!pte_dirty(*pte) && !pte_write(*pte)) continue; @@ -964,7 +964,7 @@ static bool page_mkclean_one(struct folio *folio, struct vm_area_struct *vma, ret = 1; } else { #ifdef CONFIG_TRANSPARENT_HUGEPAGE - pmd_t *pmd = pvmw.pmd; + pmd_t *pmd = pvmw->pmd; pmd_t entry; if (!pmd_dirty(*pmd) && !pmd_write(*pmd)) @@ -991,11 +991,22 @@ static bool page_mkclean_one(struct folio *folio, struct vm_area_struct *vma, * See Documentation/vm/mmu_notifier.rst */ if (ret) - (*cleaned)++; + cleaned++; } mmu_notifier_invalidate_range_end(&range); + return cleaned; +} + +static bool page_mkclean_one(struct folio *folio, struct vm_area_struct *vma, + unsigned long address, void *arg) +{ + DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, address, PVMW_SYNC); + int *cleaned = arg; + + *cleaned += page_vma_mkclean_one(&pvmw); + return true; } @@ -1033,6 +1044,38 @@ int folio_mkclean(struct folio *folio) EXPORT_SYMBOL_GPL(folio_mkclean); /** + * pfn_mkclean_range - Cleans the PTEs (including PMDs) mapped with range of + * [@pfn, @pfn + @nr_pages) at the specific offset (@pgoff) + * within the @vma of shared mappings. And since clean PTEs + * should also be readonly, write protects them too. + * @pfn: start pfn. + * @nr_pages: number of physically contiguous pages srarting with @pfn. + * @pgoff: page offset that the @pfn mapped with. + * @vma: vma that @pfn mapped within. + * + * Returns the number of cleaned PTEs (including PMDs). + */ +int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff, + struct vm_area_struct *vma) +{ + struct page_vma_mapped_walk pvmw = { + .pfn = pfn, + .nr_pages = nr_pages, + .pgoff = pgoff, + .vma = vma, + .flags = PVMW_SYNC, + }; + + if (invalid_mkclean_vma(vma, NULL)) + return 0; + + pvmw.address = vma_pgoff_address(pgoff, nr_pages, vma); + VM_BUG_ON_VMA(pvmw.address == -EFAULT, vma); + + return page_vma_mkclean_one(&pvmw); +} + +/** * page_move_anon_rmap - move a page to our anon_vma * @page: the page to move to our anon_vma * @vma: the vma the page belongs to