From patchwork Fri Mar 18 07:45:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Muchun Song X-Patchwork-Id: 12784967 Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) (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 2DDF04350 for ; Fri, 18 Mar 2022 07:48:11 +0000 (UTC) Received: by mail-pj1-f53.google.com with SMTP id mj15-20020a17090b368f00b001c637aa358eso9801659pjb.0 for ; Fri, 18 Mar 2022 00:48:11 -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=CiqL2201i/r2h3p8KI/NBkw6WGqzhDfT//6vVp9Lies=; b=bXFvZFfrI9C/L+NvtlIM0LtbMc9OI6fpHgmIV5gvdFRnQP6DfETLgq8COcZHL9qIFx 5bzIBwfZrjgZShT0Nv6dg54gHhhnaS+mQfdF2z26zWuGr24FPRLmgQBRSiE0LFYz4OhI z1C9H8HtntVzRG07BglBrccoNz4ssJmAHMPjGfWDGQ35UoQhAlnZMSDwyGW2Ku/yFday 2pQYFWEWfQKrVCP9HKKBqVxFgdWYlk4mjpKHgnJTbiluPaEdXtrU+2B9lJCccSPLEgEG NnoeI7zIaBwYpcQe+ULKS1L4X7Ikmta5Nes7W+xQB3j8evY6Uj7EXtFPq9iaiwoqA4Oh AVnA== 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=CiqL2201i/r2h3p8KI/NBkw6WGqzhDfT//6vVp9Lies=; b=cV8pYsUT9zz2f5YEh2N8BJ/BzPyvIz9PpcI6LDL9FetA9Cvs1J7q4iYB7LXjb9V7Ws FriPEPP8Prlrr9lkvCHinyodt0MhU3KlO1xQJEMbJ9a/1ChYbU6M0Jt2A80EAGqKEBOz IxVzL6XJrlXioUoONQR4G3LeHxSshAud3UpGNJlK/0G4rRmgcGsIJyadgs/SvMykI7XJ CUWl5xuQrAldLQHGl1rSWA0PEN/W5SR4/F5TfdIarcBpPh/5Ask3CUbUWwTRDfNSEeOr YCZnGldG01h0oEe2EZjLxHgK9b6MwRDdEFGep7PAzGunKuJ6DgE+02/hgu6RPKA2eqE+ sm0w== X-Gm-Message-State: AOAM533V0KRcKcqjyg6OYMJM+GdQ0KSC1MEc2SFJYNTAHDBWAMcsnjgE I/3f1qjqFE2ON78ptclEQpmNug== X-Google-Smtp-Source: ABdhPJx6Gb2cl0kaRKMvmsLEzJyKu4bc+A6kr/eo/U8JztFBvDzyQCyUtAKxuHv1+XJWl0bol5r0fw== X-Received: by 2002:a17:902:cf02:b0:14f:e0c2:1514 with SMTP id i2-20020a170902cf0200b0014fe0c21514mr8557186plg.90.1647589690731; Fri, 18 Mar 2022 00:48:10 -0700 (PDT) Received: from localhost.localdomain ([139.177.225.233]) by smtp.gmail.com with ESMTPSA id a38-20020a056a001d2600b004f72acd4dadsm8770941pfx.81.2022.03.18.00.48.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Mar 2022 00:48:10 -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 v5 6/6] mm: simplify follow_invalidate_pte() Date: Fri, 18 Mar 2022 15:45:29 +0800 Message-Id: <20220318074529.5261-7-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220318074529.5261-1-songmuchun@bytedance.com> References: <20220318074529.5261-1-songmuchun@bytedance.com> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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); /**