From patchwork Tue Mar 29 13:48:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12794869 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 C683FC433EF for ; Tue, 29 Mar 2022 13:50:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237563AbiC2NwG (ORCPT ); Tue, 29 Mar 2022 09:52:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237567AbiC2NwA (ORCPT ); Tue, 29 Mar 2022 09:52:00 -0400 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADA92186F9A for ; Tue, 29 Mar 2022 06:50:17 -0700 (PDT) Received: by mail-pf1-x429.google.com with SMTP id w7so13266579pfu.11 for ; Tue, 29 Mar 2022 06:50:17 -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=pquxx3qH2nuqmnC96VcgoZZu7sN0crimqByO4QYpxLI=; b=oQLhz53anwt4ILImkOxJ+rt/T/W68dglu9K98xYhD8rw+vwfthUTW0dlUF8vK73ffS Kv3IyJwBAManxnSc7qMd6HVrXGOcrmlEd9PUFM1/o4FKfPU7W/CIfqGtKeBwLXPu1Q4t rxxXG/rtme18YD+1HWkiEXrBu84RD8iXJNM00tyT9mm1bqKI5JGbw4yzwyfnFxAVrXbd Yk9O3W0irr+zwnhCLF3Xcvf/NWQURV1ee5Et+3KdaXBWcOjGFYjeMP2EgatcjC/6D/uG tQoLY1hSo0kNxBNJcz1UQn+rraUqyPegGACymxj/UrrDw/JhKQZPhtl4M52HOW6NNfsf RFKA== 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=pquxx3qH2nuqmnC96VcgoZZu7sN0crimqByO4QYpxLI=; b=Z46dOQNfRQPJXHogJNh7wBIG+13ZPj8Y2gcY52H9Tc6QWre9uQoH86Dx+iViPZOQtw FxFt0E9M2IzlDX5HMO4y9Ib4iWFTLhtKIfYelSeBMaW5C+0eajwo8xgnshykopIZfzkS LTLzAmgQKqgsPRTT/jJ/xDYtzOUoTS/tEcpv54mod11CM49Z2KiAYlGxmNhrl9iteEWR o2BDHEVnazU3N3V4Zk+aWEPt/N2B8LVvhUFQl1PxaIxjasNwkxG8v8ZHXAGMMFXzkjmK H0Z4T6SO/j0tcpxrHKJ65aTxkJHBKwg8kbqItWNUPGayeifpNI97SsvOp/JJlQeQ9LaC qu7g== X-Gm-Message-State: AOAM532IEAWpUfoGLOD8Nq69S6/7P0MCd9pSH1ciOizzMm/neZQJ3ZDS 3F19hlXu6TzOuhjNlHdnN74Frw== X-Google-Smtp-Source: ABdhPJyTEtUT0mAGxDz5bcPBQWC+tSTA07XI+vJ4sxeO4APu0XKS8tsBFbZC6aGY6wMBrL/C65Wt8Q== X-Received: by 2002:a63:f418:0:b0:382:b4f6:5f95 with SMTP id g24-20020a63f418000000b00382b4f65f95mr2084659pgi.619.1648561817153; Tue, 29 Mar 2022 06:50:17 -0700 (PDT) Received: from FVFYT0MHHV2J.bytedance.net ([139.177.225.239]) by smtp.gmail.com with ESMTPSA id o14-20020a056a0015ce00b004fab49cd65csm20911293pfu.205.2022.03.29.06.50.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Mar 2022 06:50:16 -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 , Christoph Hellwig Subject: [PATCH v6 6/6] mm: simplify follow_invalidate_pte() Date: Tue, 29 Mar 2022 21:48:53 +0800 Message-Id: <20220329134853.68403-7-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220329134853.68403-1-songmuchun@bytedance.com> References: <20220329134853.68403-1-songmuchun@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The only user (DAX) of range and pmdpp parameters of follow_invalidate_pte() is gone, it is safe to remove them and make it static to simlify the code. This is revertant of the following commits: 097963959594 ("mm: add follow_pte_pmd()") a4d1a8852513 ("dax: update to new mmu_notifier semantic") There is only one caller of the follow_invalidate_pte(). So just fold it into follow_pte() and remove it. Signed-off-by: Muchun Song Reviewed-by: Christoph Hellwig --- include/linux/mm.h | 3 -- mm/memory.c | 81 ++++++++++++++++-------------------------------------- 2 files changed, 23 insertions(+), 61 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index c9bada4096ac..be7ec4c37ebe 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1871,9 +1871,6 @@ void free_pgd_range(struct mmu_gather *tlb, unsigned long addr, unsigned long end, unsigned long floor, unsigned long ceiling); int copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma); -int follow_invalidate_pte(struct mm_struct *mm, unsigned long address, - struct mmu_notifier_range *range, pte_t **ptepp, - pmd_t **pmdpp, spinlock_t **ptlp); int follow_pte(struct mm_struct *mm, unsigned long address, pte_t **ptepp, spinlock_t **ptlp); int follow_pfn(struct vm_area_struct *vma, unsigned long address, diff --git a/mm/memory.c b/mm/memory.c index cc6968dc8e4e..84f7250e6cd1 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4964,9 +4964,29 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) } #endif /* __PAGETABLE_PMD_FOLDED */ -int follow_invalidate_pte(struct mm_struct *mm, unsigned long address, - struct mmu_notifier_range *range, pte_t **ptepp, - pmd_t **pmdpp, spinlock_t **ptlp) +/** + * follow_pte - look up PTE at a user virtual address + * @mm: the mm_struct of the target address space + * @address: user virtual address + * @ptepp: location to store found PTE + * @ptlp: location to store the lock for the PTE + * + * On a successful return, the pointer to the PTE is stored in @ptepp; + * the corresponding lock is taken and its location is stored in @ptlp. + * The contents of the PTE are only stable until @ptlp is released; + * any further use, if any, must be protected against invalidation + * with MMU notifiers. + * + * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore + * should be taken for read. + * + * KVM uses this function. While it is arguably less bad than ``follow_pfn``, + * it is not a good general-purpose API. + * + * Return: zero on success, -ve otherwise. + */ +int follow_pte(struct mm_struct *mm, unsigned long address, + pte_t **ptepp, spinlock_t **ptlp) { pgd_t *pgd; p4d_t *p4d; @@ -4989,35 +5009,9 @@ int follow_invalidate_pte(struct mm_struct *mm, unsigned long address, pmd = pmd_offset(pud, address); VM_BUG_ON(pmd_trans_huge(*pmd)); - if (pmd_huge(*pmd)) { - if (!pmdpp) - goto out; - - if (range) { - mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0, - NULL, mm, address & PMD_MASK, - (address & PMD_MASK) + PMD_SIZE); - mmu_notifier_invalidate_range_start(range); - } - *ptlp = pmd_lock(mm, pmd); - if (pmd_huge(*pmd)) { - *pmdpp = pmd; - return 0; - } - spin_unlock(*ptlp); - if (range) - mmu_notifier_invalidate_range_end(range); - } - if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) goto out; - if (range) { - mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0, NULL, mm, - address & PAGE_MASK, - (address & PAGE_MASK) + PAGE_SIZE); - mmu_notifier_invalidate_range_start(range); - } ptep = pte_offset_map_lock(mm, pmd, address, ptlp); if (!pte_present(*ptep)) goto unlock; @@ -5025,38 +5019,9 @@ int follow_invalidate_pte(struct mm_struct *mm, unsigned long address, return 0; unlock: pte_unmap_unlock(ptep, *ptlp); - if (range) - mmu_notifier_invalidate_range_end(range); out: return -EINVAL; } - -/** - * follow_pte - look up PTE at a user virtual address - * @mm: the mm_struct of the target address space - * @address: user virtual address - * @ptepp: location to store found PTE - * @ptlp: location to store the lock for the PTE - * - * On a successful return, the pointer to the PTE is stored in @ptepp; - * the corresponding lock is taken and its location is stored in @ptlp. - * The contents of the PTE are only stable until @ptlp is released; - * any further use, if any, must be protected against invalidation - * with MMU notifiers. - * - * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore - * should be taken for read. - * - * KVM uses this function. While it is arguably less bad than ``follow_pfn``, - * it is not a good general-purpose API. - * - * Return: zero on success, -ve otherwise. - */ -int follow_pte(struct mm_struct *mm, unsigned long address, - pte_t **ptepp, spinlock_t **ptlp) -{ - return follow_invalidate_pte(mm, address, NULL, ptepp, NULL, ptlp); -} EXPORT_SYMBOL_GPL(follow_pte); /**