From mboxrd@z Thu Jan 1 00:00:00 1970 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 38E8BC05027 for ; Fri, 20 Jan 2023 17:56:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 27A416B0081; Fri, 20 Jan 2023 12:56:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2297E6B0082; Fri, 20 Jan 2023 12:56:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0F3AB6B0083; Fri, 20 Jan 2023 12:56:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id E8D856B0082 for ; Fri, 20 Jan 2023 12:56:13 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 9ED26160EEF for ; Fri, 20 Jan 2023 17:56:13 +0000 (UTC) X-FDA: 80375931426.14.F0E4676 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf30.hostedemail.com (Postfix) with ESMTP id E0AE780019 for ; Fri, 20 Jan 2023 17:56:11 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=DnX8E6YR; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf30.hostedemail.com: domain of dhowells@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=dhowells@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1674237371; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=CYkyXriQe+db2xB55AZm41G9E0QZGdRv8ItoT4z1ez8=; b=gp7vGKs+fCvbkzIJWweAONkWhbvkwBT+6gY1aZGyyooaITcFsdfdOtdwl2hoUDiiWz6x9e ffkac3/pg9CFsK2Iei2EE5pdzDYE0SLz0wN9N4Ky+rQOyw8r7cZw1TzyhQRWIAjlsa3F6d fEgOJQoGNg8sNaGQJh178OZXVvFaT4o= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=DnX8E6YR; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf30.hostedemail.com: domain of dhowells@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=dhowells@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1674237371; a=rsa-sha256; cv=none; b=3G1iDnLy7qP2gObQLvpCt3AuW7Ub4lmDssK5CUD2UzuyCIW7eLoXgwDSfQMi4kghFZIsJo /9jzY1BG2cxRz/jrzXepRarJ4kL+arzmfOrVfyUd3Sw+sPDnKUTwqBln3kx1GZUYnUg6qQ Lb1csQQV0HKwlBdfuNqQkbzozuF/LD0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674237371; 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=CYkyXriQe+db2xB55AZm41G9E0QZGdRv8ItoT4z1ez8=; b=DnX8E6YR6YfSVXc1ZjIMYWIzRI4t5utlbccxAQyFE91VBg8gBW7I6+/J3YECk0wF4Qm05O R6GDYXD3AnNsAvMuHTk2pLyr7QmRkC3CePiWorH1JpzVxzlegQ3ZvBn4rBdI7j1vnijPxy YyBfVmWZZiDi6/kw919N3kzUJpzTb5g= 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-569-rOeDDMKeNQmo4B5_T1HLmg-1; Fri, 20 Jan 2023 12:56:09 -0500 X-MC-Unique: rOeDDMKeNQmo4B5_T1HLmg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 04CEB185A794; Fri, 20 Jan 2023 17:56:09 +0000 (UTC) Received: from warthog.procyon.org.uk.com (unknown [10.33.36.23]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7C3A5492C3C; Fri, 20 Jan 2023 17:56:07 +0000 (UTC) From: David Howells To: Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jens Axboe , Jan Kara , Jeff Layton , Logan Gunthorpe , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , linux-mm@kvack.org Subject: [PATCH v7 3/8] mm: Provide a helper to drop a pin/ref on a page Date: Fri, 20 Jan 2023 17:55:51 +0000 Message-Id: <20230120175556.3556978-4-dhowells@redhat.com> In-Reply-To: <20230120175556.3556978-1-dhowells@redhat.com> References: <20230120175556.3556978-1-dhowells@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: E0AE780019 X-Stat-Signature: zt11mckcru4ear66d5qufw9wgyp6mja9 X-HE-Tag: 1674237371-820587 X-HE-Meta: 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 UFYET+6d 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 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: Provide a helper in the get_user_pages code to drop a pin or a ref on a page based on being given FOLL_GET or FOLL_PIN in its flags argument or do nothing if neither is set. Signed-off-by: David Howells cc: Al Viro cc: Christoph Hellwig cc: Matthew Wilcox cc: linux-fsdevel@vger.kernel.org cc: linux-block@vger.kernel.org cc: linux-mm@kvack.org --- include/linux/mm.h | 3 +++ mm/gup.c | 22 ++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index f3f196e4d66d..f1cf8f4eb946 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1367,6 +1367,9 @@ static inline bool is_cow_mapping(vm_flags_t flags) #define SECTION_IN_PAGE_FLAGS #endif +void folio_put_unpin(struct folio *folio, unsigned int flags); +void page_put_unpin(struct page *page, unsigned int flags); + /* * The identification function is mainly used by the buddy allocator for * determining if two pages could be buddies. We are not really identifying diff --git a/mm/gup.c b/mm/gup.c index f45a3a5be53a..3ee4b4c7e0cb 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -191,6 +191,28 @@ static void gup_put_folio(struct folio *folio, int refs, unsigned int flags) folio_put_refs(folio, refs); } +/** + * folio_put_unpin - Unpin/put a folio as appropriate + * @folio: The folio to release + * @flags: gup flags indicating the mode of release (FOLL_*) + * + * Release a folio according to the flags. If FOLL_GET is set, the folio has a + * ref dropped; if FOLL_PIN is set, it is unpinned; otherwise it is left + * unaltered. + */ +void folio_put_unpin(struct folio *folio, unsigned int flags) +{ + if (flags & (FOLL_GET | FOLL_PIN)) + gup_put_folio(folio, 1, flags); +} +EXPORT_SYMBOL_GPL(folio_put_unpin); + +void page_put_unpin(struct page *page, unsigned int flags) +{ + folio_put_unpin(page_folio(page), flags); +} +EXPORT_SYMBOL_GPL(page_put_unpin); + /** * try_grab_page() - elevate a page's refcount by a flag-dependent amount * @page: pointer to page to be grabbed