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 AD1E0C433F5 for ; Mon, 4 Apr 2022 15:33:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3281F6B0072; Mon, 4 Apr 2022 11:33:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D7976B0073; Mon, 4 Apr 2022 11:33:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 19EB66B0074; Mon, 4 Apr 2022 11:33:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0084.hostedemail.com [216.40.44.84]) by kanga.kvack.org (Postfix) with ESMTP id 073DA6B0072 for ; Mon, 4 Apr 2022 11:33:06 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id BDD18183C8AA6 for ; Mon, 4 Apr 2022 15:32:55 +0000 (UTC) X-FDA: 79319589510.22.21FDBB3 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf30.hostedemail.com (Postfix) with ESMTP id AE29A8001D for ; Mon, 4 Apr 2022 15:32:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=SYr2TLjhGlOZxobWEY7RDAlP3qLX6lnM8lEfGNU7Who=; b=YtDXaz0GHV+kaFKec4Gbg/qSKw iluMjpKAovS3BE6Q+5NxvoLctO+LcJ2xP2/br78wpqAKs/XTplmFsaUc+lGRW6y0UmgyH4KRFt1Qx DZIal9b/Y1RY2bpBm95LSmf4tqk4OyCMzMlYoJvLGfreWE2KE2lEJAxmFyuN49fEUW2koJqA61ghl L4YbSzRtdcFnfhTJdc4XGt0sxPw0ZzfBk1LUWnsbrPq00bnywDvm7Tc8NFmCRs5DN5KvxUh4Fks7g DIYY6Oo3LluikXL2cuYvHcjklNhsB/rhcY/5X4k46PQvlSy2xiccuLYyNY64Ajzuh6IBsadNvZfgJ olhIFPIg==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nbOh0-005qrA-12; Mon, 04 Apr 2022 15:32:34 +0000 Date: Mon, 4 Apr 2022 16:32:34 +0100 From: Matthew Wilcox To: Miaohe Lin Cc: akpm@linux-foundation.org, dhowells@redhat.com, william.kucharski@oracle.com, vbabka@suse.cz, kirill.shutemov@linux.intel.com, hannes@cmpxchg.org, agruenba@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] filemap: remove obsolete comment in lock_page Message-ID: References: <20220402062218.30709-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220402062218.30709-1-linmiaohe@huawei.com> Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=YtDXaz0G; spf=none (imf30.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: AE29A8001D X-Stat-Signature: 334r9fnhndnugwj7jnprnbwf4targium X-HE-Tag: 1649086374-189996 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: On Sat, Apr 02, 2022 at 02:22:18PM +0800, Miaohe Lin wrote: > lock_page needs the caller to have a reference on the page->mapping inode > due to sync_page. Also lock_page_nosync is introduced which does not do a > sync_page via commit db37648cd6ce ("[PATCH] mm: non syncing lock_page()"). > But commit 7eaceaccab5f ("block: remove per-queue plugging") kills off the > old plugging along with aops->sync_page() and lock_page_nosync. So there > is no need to have a reference on the page->mapping inode when calling > lock_page anymore. Remove this obsolete and confusing comment. > > Signed-off-by: Miaohe Lin Thanks. I'll fix up the changelog (some of the tenses are a little strange) and take this through my pagecache tree. > include/linux/pagemap.h | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h > index 993994cd943a..8dfe8e49c427 100644 > --- a/include/linux/pagemap.h > +++ b/include/linux/pagemap.h > @@ -908,9 +908,6 @@ static inline void folio_lock(struct folio *folio) > __folio_lock(folio); > } > > -/* > - * lock_page may only be called if we have the page's inode pinned. > - */ > static inline void lock_page(struct page *page) > { > struct folio *folio; > -- > 2.23.0 >