From patchwork Fri May 26 11:28:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 99447 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp399591vqr; Fri, 26 May 2023 04:34:44 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ4Q7M4AfUU5U9nOq7mAJYRTqdjjDHtn/eGFMm5qHjn5LtE/i94lye/7UT7OITYyH7TvOQf/ X-Received: by 2002:a17:903:11c3:b0:1ac:750e:33d5 with SMTP id q3-20020a17090311c300b001ac750e33d5mr2853386plh.15.1685100884054; Fri, 26 May 2023 04:34:44 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1685100884; cv=none; d=google.com; s=arc-20160816; b=mZ+6/bEWcS1PAT8kl2a8WrMbqfWpDf+AoZ1QUNPnW/rSyf8KHfBVUMNm5d9SGJMhiH a7Z1gcuLZZ0gZ73WJpg85RP+FtIDonWMEzQvL4xacz3ST08BpFqJC2VD0u2z+4Som7ZY fFz+EDmncVrEzRpX1XZ0pIeqRGCzjnvpZohROTwiG69jT9cj6FsbS9Sh1w/oZ2PBa9TL BjsI6yK98iTZIJbHXHJ7rDvSaWiYr53ap6zK1ZF3kyBuThfsliky81ydzhR/sfPc6Z+f 3XvpLLxcJsl113uvISLDnuJaRcD9ZCn3SGnfxB4k33xZ9jGHbMIeprXxVJkjtBjUV7Gd Ov9g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=/oa1BFyOPAnXCxzKNg+OmyZ2j7EgUWqexyoMi96HVck=; b=UUlF9QLMYkYNJmN7aB1gzpV/jXrJR12+Czfg/j8RbmVOpFR+kalcXSqt+oiE1VT/FC Ceqagm6fUQhYTLsA8ftPuaRXXIQA5ua9Yh5lyZ406mDjJbQ6XwYRGl7UyCgP97NCo9Tt Gb2JaUy1oVBq0MmcS5e4PrFr1NUF4uF3yUPTRII3i9TTRyGcjyjy2Gl00vm2Sov5ddM+ 9GJITznQX1lVBSFaz55TiWuugVEBUninU1sOVeTc2IChX98wGb8atsaURLVwV6JNVogl X+WjeAA/zMnN9+MoUbkbBWjmDjuvNg//uvOT71SY+oBo7dyBHKuBCF6aol5iVCDefXT2 6X2A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=HqBC27tJ; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id e2-20020a636902000000b0053440fe0817si3181206pgc.611.2023.05.26.04.34.31; Fri, 26 May 2023 04:34:44 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=HqBC27tJ; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243232AbjEZLaw (ORCPT + 99 others); Fri, 26 May 2023 07:30:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243235AbjEZLau (ORCPT ); Fri, 26 May 2023 07:30:50 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CD31198 for ; Fri, 26 May 2023 04:29:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685100564; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/oa1BFyOPAnXCxzKNg+OmyZ2j7EgUWqexyoMi96HVck=; b=HqBC27tJQj1Thw0dz9pYB07q4zpj6/Bb/pWVSO+9YTtCoNzZ5S4HknQ/OAydu7ub6VJYia bakR5/LMW/KlPIq5nwI++kesk8a1Gt1zf0FBMesJh1Cw/lndX9B1myxzoSiQP5xn7IyXq3 86qngfPOZ57oYCdif6qy9D5Du37G+Ok= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-460-5Dx9Zud5NgaNs8x-s-9Znw-1; Fri, 26 May 2023 07:29:19 -0400 X-MC-Unique: 5Dx9Zud5NgaNs8x-s-9Znw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B8933185A78F; Fri, 26 May 2023 11:29:17 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.192.68]) by smtp.corp.redhat.com (Postfix) with ESMTP id 470B0200AD47; Fri, 26 May 2023 11:29:15 +0000 (UTC) From: David Howells To: Christoph Hellwig , David Hildenbrand , Lorenzo Stoakes Cc: David Howells , Jens Axboe , Al Viro , Matthew Wilcox , Jan Kara , Jeff Layton , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton Subject: [PATCH v3 2/3] mm: Provide a function to get an additional pin on a page Date: Fri, 26 May 2023 12:28:58 +0100 Message-Id: <20230526112859.654506-3-dhowells@redhat.com> In-Reply-To: <20230526112859.654506-1-dhowells@redhat.com> References: <20230526112859.654506-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1766956345035089085?= X-GMAIL-MSGID: =?utf-8?q?1766956345035089085?= Provide a function to get an additional pin on a page that we already have a pin on. This will be used in fs/direct-io.c when dispatching multiple bios to a page we've extracted from a user-backed iter rather than redoing the extraction. Signed-off-by: David Howells cc: Christoph Hellwig cc: David Hildenbrand cc: Lorenzo Stoakes cc: Andrew Morton cc: Jens Axboe cc: Al Viro cc: Matthew Wilcox cc: Jan Kara cc: Jeff Layton cc: Jason Gunthorpe cc: Logan Gunthorpe cc: Hillf Danton cc: Christian Brauner cc: Linus Torvalds cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-kernel@vger.kernel.org cc: linux-mm@kvack.org --- Notes: ver #3) - Rename to folio_add_pin(). - Change to using is_zero_folio() include/linux/mm.h | 1 + mm/gup.c | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 3c2f6b452586..200068d98686 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2405,6 +2405,7 @@ int get_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages); int pin_user_pages_fast(unsigned long start, int nr_pages, unsigned int gup_flags, struct page **pages); +void folio_add_pin(struct folio *folio); int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc); int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc, diff --git a/mm/gup.c b/mm/gup.c index ad28261dcafd..08fdd84088d1 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -275,6 +275,33 @@ void unpin_user_page(struct page *page) } EXPORT_SYMBOL(unpin_user_page); +/** + * folio_add_pin - Try to get an additional pin on a pinned folio + * @folio: The folio to be pinned + * + * Get an additional pin on a folio we already have a pin on. Makes no change + * if the folio is a zero_page. + */ +void folio_add_pin(struct folio *folio) +{ + if (is_zero_folio(folio)) + return; + + /* + * Similar to try_grab_folio(): be sure to *also* increment the normal + * page refcount field at least once, so that the page really is + * pinned. + */ + if (folio_test_large(folio)) { + WARN_ON_ONCE(atomic_read(&folio->_pincount) < 1); + folio_ref_add(folio, 1); + atomic_add(1, &folio->_pincount); + } else { + WARN_ON_ONCE(folio_ref_count(folio) < GUP_PIN_COUNTING_BIAS); + folio_ref_add(folio, GUP_PIN_COUNTING_BIAS); + } +} + static inline struct folio *gup_folio_range_next(struct page *start, unsigned long npages, unsigned long i, unsigned int *ntails) {