From patchwork Wed Mar 2 08:27:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12765611 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB250C433F5 for ; Wed, 2 Mar 2022 08:29:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 45A188D0008; Wed, 2 Mar 2022 03:29:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4090A8D0007; Wed, 2 Mar 2022 03:29:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2D1E58D0008; Wed, 2 Mar 2022 03:29:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0212.hostedemail.com [216.40.44.212]) by kanga.kvack.org (Postfix) with ESMTP id 1DC2E8D0007 for ; Wed, 2 Mar 2022 03:29:31 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id C2AD79F5E9 for ; Wed, 2 Mar 2022 08:29:30 +0000 (UTC) X-FDA: 79198772100.22.8FEA4A8 Received: from mail-pj1-f45.google.com (mail-pj1-f45.google.com [209.85.216.45]) by imf30.hostedemail.com (Postfix) with ESMTP id 58E128000A for ; Wed, 2 Mar 2022 08:29:30 +0000 (UTC) Received: by mail-pj1-f45.google.com with SMTP id b8so1132166pjb.4 for ; Wed, 02 Mar 2022 00:29:30 -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=AAVeeC/1N3G5GcQ+K6GvknxUpCVQsZK39/oE0xJ/wgZT1GfB7gPbGuBOafACxBd/c6 MkH1O0a51SjPMpZ4wg2yNC3c4zpZ9dE5JglFpUNSIXG0tww4bCfNAXwvDe+a5pT1A/P+ 9CUnfcNARVTbx0MaJya8bS1PjE/9KiSW76Iaio2gwlTnxUnXAbKEpjLj6kKMXhDjR6b7 OefsDv/keodJ7ewbycR7dyDT1rZ4Oos4YZlqHiUed2rus7fSEtveiT6lBZy0JF1vvXVe LKMCP0ft+vVnndO2ogo+gRfdYi8O/h6hMPqKgldeWsB49c0/KdDg4htf5wEE883PpJ0B zUow== 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=wPPaMTX0/zX2MOF02gjVESAqYg4k6VWg5KEswsG3RBlbP4XAVGQxpiGfu6En6B/k7V WwoUcg+UMt7vipIZH9vtZCasOwzKLVkapiqPYPVm3SE7YvTqNzjR5aCS9DVQN4GCl03B UUM+Zjd6f+HiXRonnFGjV1Z4x1uNRN3AuHG9D4jT/JBQ07fAksIEcJNzJNzT/sUl3458 n/Vs33Pyb1K0CfJG0hSJWR1brKWKbgYtxhfb0QVZVhqE7pZZPC7dC2RaIoVMA1LKpfwj 2uAAEuiyzbTwomK034BlKV6xmTIPK7YBqTRD4ubSRQsET34sXbmUOhUJp581/rFDlCuZ OdiA== X-Gm-Message-State: AOAM532aPD+4I2c8NXhu+eFXy5lPMsvnNP1EZ5CfGlezK4iDOlz2Emsf ScQrYqDFsq45kFYXoHQSuZBHZw== X-Google-Smtp-Source: ABdhPJwYRvyK+lr9AitLQt9EnXiJDHe8rcmZLfe5ZnI1R9iF0WxPL6NhcheQihzz2A5zbJdCIhQ0vg== X-Received: by 2002:a17:90a:ab89:b0:1bc:71a7:f93a with SMTP id n9-20020a17090aab8900b001bc71a7f93amr25812348pjq.111.1646209769383; Wed, 02 Mar 2022 00:29:29 -0800 (PST) Received: from FVFYT0MHHV2J.bytedance.net ([61.120.150.70]) by smtp.gmail.com with ESMTPSA id a20-20020a056a000c9400b004f396b965a9sm20922228pfv.49.2022.03.02.00.29.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Mar 2022 00:29:29 -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 v4 3/6] mm: rmap: introduce pfn_mkclean_range() to cleans PTEs Date: Wed, 2 Mar 2022 16:27:15 +0800 Message-Id: <20220302082718.32268-4-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220302082718.32268-1-songmuchun@bytedance.com> References: <20220302082718.32268-1-songmuchun@bytedance.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 58E128000A X-Stat-Signature: 181s8zwy4qnjjx3da1wadjfintzppizb X-Rspam-User: Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b="AAVeeC/1"; dmarc=pass (policy=none) header.from=bytedance.com; spf=pass (imf30.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.216.45 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com X-Rspamd-Server: rspam03 X-HE-Tag: 1646209770-331522 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: 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