From patchwork Mon Feb 28 06:35:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12762412 Received: from mail-pg1-f176.google.com (mail-pg1-f176.google.com [209.85.215.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 36490512D for ; Mon, 28 Feb 2022 06:36:18 +0000 (UTC) Received: by mail-pg1-f176.google.com with SMTP id e6so9183991pgn.2 for ; Sun, 27 Feb 2022 22:36:18 -0800 (PST) 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=5g/0QWFd98PH+GDbIHxo8Dsrvq3fGfzY+G57IkW5WS4=; b=HX8+nAEYjlfswBQ5nj4httJxCQA4BhPACV7BlZZAhSmNF0RdD2JCR6g8o4WwpkGQ/5 hdB9bW1/6Cyhwei8IAElPg1nVq2znfvIiObfUNOK6N4Fyb5pxX7qE/pXvjnIyhIwL40E a9YCpF/qt8VRsYBdacCTFnwT6ah4GTtRXmr0c87QhDFiMpPed23MpSM5wpqu5sU/JMma bOFrDgqAx9BHJS8YWgjV21MrYg3L8NljxaWZJYlhOIQZeRKwCYTHSPMBssrX0cRnbhG8 uHiOoTE4yCZESmFPEX3p+4dWs6VwKTJqUYTjUYYqBUeXPkcEzinYEyBSFitJIYZyk2mL NezQ== 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=5g/0QWFd98PH+GDbIHxo8Dsrvq3fGfzY+G57IkW5WS4=; b=Y7NmPbpVPVu/GMESf1kDXFMeEetMLPgZvINIuykplS+mtO3G/ZvS/XCF96aOR1oJKL AAxNz42hMTd6z67JesuYiuN6jJcFeMZeLMoTttewfmjqJyRYkrXffoZrm0s/8KZZ52Th GBcCWJTqB9/ujCQJw/Hrh/jHKnI+xfGOIFhzAnpr5uNIbmYwnFxnMzSZfqxNXzLX8U0w e34iKvJS0hx6/9uARVn9weMZlxc3n4E+rtgp8abnSrfTyyg3P9WYOyxkMa0zPy51oSJg OdL6JmQ6/wnQtfX/ae4n6eozvPk1WegzXdksxVIsyUiLLVQNueyLcc8YGkXMzQzdb8UU d0DQ== X-Gm-Message-State: AOAM533Yv3gEio8lEv2PJMyhhmNHx1rIEuzpyddw9jc819jrgl6vAjPz xmp3Fyy6bUDIkWygSE17yekLdg== X-Google-Smtp-Source: ABdhPJypY+8lhMBAxJc6LX0WefVBcScVdW93PI4OxjW8x5PZWFmpys0R1IuEdZjE11NT+4jWvS1kBA== X-Received: by 2002:a63:3e45:0:b0:378:c5a9:abd1 with SMTP id l66-20020a633e45000000b00378c5a9abd1mr167718pga.25.1646030177716; Sun, 27 Feb 2022 22:36:17 -0800 (PST) Received: from FVFYT0MHHV2J.tiktokcdn.com ([139.177.225.227]) by smtp.gmail.com with ESMTPSA id q13-20020aa7960d000000b004f13804c100sm11126472pfg.165.2022.02.27.22.36.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 27 Feb 2022 22:36:17 -0800 (PST) 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 v3 3/6] mm: rmap: introduce pfn_mkclean_range() to cleans PTEs Date: Mon, 28 Feb 2022 14:35:33 +0800 Message-Id: <20220228063536.24911-4-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220228063536.24911-1-songmuchun@bytedance.com> References: <20220228063536.24911-1-songmuchun@bytedance.com> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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..ff873944749f 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