From patchwork Tue Nov 2 08:30:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 12598167 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7173C433F5 for ; Tue, 2 Nov 2021 08:31:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 985BC60F70 for ; Tue, 2 Nov 2021 08:31:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230407AbhKBIdv (ORCPT ); Tue, 2 Nov 2021 04:33:51 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23565 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229852AbhKBIdt (ORCPT ); Tue, 2 Nov 2021 04:33:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635841874; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vLfTBhx6LQCVG7VM7y5aSzwNWgHtW6qsvC0OR/rrG3s=; b=LtkcH7Mq8m0/doFmUd6vHvb6t8Ou4JagqUpfS+N44+W0mnXoVbGnC2ciOyml7cUXaRv0xn UOgmi53OlZd6KToj+Ly9sUm6XIZXvqmGBni9CdnmW9F6NnOLF7v4bEQx2UPALbOZNKZSJ7 JP9NuFA1n7eXfIxs0/e43+t9DPd8wZs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-513-KWyx_etcNmKuzSgMKmqzfg-1; Tue, 02 Nov 2021 04:31:11 -0400 X-MC-Unique: KWyx_etcNmKuzSgMKmqzfg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7480B362F8; Tue, 2 Nov 2021 08:31:09 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id 282931972D; Tue, 2 Nov 2021 08:30:47 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH v3 4/6] folio: Add a function to get the host inode for a folio From: David Howells To: "Matthew Wilcox (Oracle)" Cc: dhowells@redhat.com, Jeff Layton , Ilya Dryomov , Dominique Martinet , linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com, v9fs-developer@lists.sourceforge.net, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, devel@lists.orangefs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Tue, 02 Nov 2021 08:30:46 +0000 Message-ID: <163584184628.4023316.9386282630968981869.stgit@warthog.procyon.org.uk> In-Reply-To: <163584174921.4023316.8927114426959755223.stgit@warthog.procyon.org.uk> References: <163584174921.4023316.8927114426959755223.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Add a convenience function, folio_inode() that will get the host inode from a folio's mapping. Changes: ver #2: - Fix contradiction between doc and implementation by disallowing use with swap caches[1]. Signed-off-by: David Howells Link: https://lore.kernel.org/r/YST8OcVNy02Rivbm@casper.infradead.org/ [1] Link: https://lore.kernel.org/r/162880453171.3369675.3704943108660112470.stgit@warthog.procyon.org.uk/ # rfc Link: https://lore.kernel.org/r/162981151155.1901565.7010079316994382707.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163005744370.2472992.18324470937328925723.stgit@warthog.procyon.org.uk/ # v2 Reviewed-by: Matthew Wilcox (Oracle) --- include/linux/pagemap.h | 14 ++++++++++++++ mm/page-writeback.c | 2 +- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 569302e4defe..fc4b7fcf4cc5 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -203,6 +203,20 @@ static inline struct address_space *page_mapping_file(struct page *page) return folio_mapping(folio); } +/** + * folio_inode - Get the host inode for this folio. + * @folio: The folio. + * + * For folios which are in the page cache, return the inode that is hosting + * this folio belongs to. + * + * Do not call this for folios which aren't in the page cache. + */ +static inline struct inode *folio_inode(struct folio *folio) +{ + return folio->mapping->host; +} + static inline bool page_cache_add_speculative(struct page *page, int count) { VM_BUG_ON_PAGE(PageTail(page), page); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 9c64490171e0..c4d2414a92dd 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2960,7 +2960,7 @@ EXPORT_SYMBOL_GPL(folio_wait_writeback_killable); */ void folio_wait_stable(struct folio *folio) { - if (folio->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES) + if (folio_inode(folio)->i_sb->s_iflags & SB_I_STABLE_WRITES) folio_wait_writeback(folio); } EXPORT_SYMBOL_GPL(folio_wait_stable);