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 X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F29D6C07E95 for ; Tue, 13 Jul 2021 06:25:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8A63660FF2 for ; Tue, 13 Jul 2021 06:25:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8A63660FF2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 909956B008C; Tue, 13 Jul 2021 02:25:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8E1206B0095; Tue, 13 Jul 2021 02:25:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7A7A96B0096; Tue, 13 Jul 2021 02:25:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0109.hostedemail.com [216.40.44.109]) by kanga.kvack.org (Postfix) with ESMTP id 542056B008C for ; Tue, 13 Jul 2021 02:25:59 -0400 (EDT) Received: from smtpin34.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 5C5411F23D for ; Tue, 13 Jul 2021 06:25:58 +0000 (UTC) X-FDA: 78356579196.34.4CECCED Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id ED3201005F4D for ; Tue, 13 Jul 2021 06:25:57 +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=5NJ/GobYssN7on3zOlsbOWTmiBv2EzLNZy86W7YdGXg=; b=fbsmLbOQszWOm3dv8Pr5kj2E7C 2oH8QijCtEXZ3EozE81NW39ttgW8OJljVf+LGGn1grSH4J/TUVDG0j2e/NTp+MRk4wJ9nnd3+guTz +uiAyPZWdlJAz/ObZcfnq4duRgc9SCYl6elA/kg4FjqqjxRWiSyctVBKCNGsl9KYTYO892oJYWZI5 TrvEbdC7HmPZPoevV1PUKcLJ6czjAami4Jbi7sr+F0PnKOI41Qf+ldIkfRpOlaioGlDjqxR3FtMJ3 yq3YPlebvzDtb55VjfVt14OhvN5M9EDIMhIcPqpI3SwMoNGZzFinwEFn0SbUkZR/uo311WDKHFLwQ 3JuzSKBg==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3Bqr-000oBA-3D; Tue, 13 Jul 2021 06:25:10 +0000 Date: Tue, 13 Jul 2021 07:25:05 +0100 From: Christoph Hellwig To: Jan Kara Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, Christoph Hellwig , "Darrick J. Wong" , Ted Tso , Dave Chinner , Matthew Wilcox , linux-mm@kvack.org, linux-xfs@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, Christoph Hellwig Subject: Re: [PATCH 03/14] mm: Protect operations adding pages to page cache with invalidate_lock Message-ID: References: <20210712163901.29514-1-jack@suse.cz> <20210712165609.13215-3-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210712165609.13215-3-jack@suse.cz> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=fbsmLbOQ; spf=none (imf13.hostedemail.com: domain of BATV@casper.srs.infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=BATV@casper.srs.infradead.org; dmarc=none X-Stat-Signature: sncw4wo8pnmxrzen885cssnj8e37eq6b X-Rspamd-Queue-Id: ED3201005F4D X-Rspamd-Server: rspam01 X-HE-Tag: 1626157557-513001 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: Still looks good. That being said the additional conditional locking in filemap_fault makes it fall over the readbility cliff for me. Something like this on top of your series would help: diff --git a/mm/filemap.c b/mm/filemap.c index fd3f94d36c49..0fad08331cf4 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3040,21 +3040,23 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) * Do we have something in the page cache already? */ page = find_get_page(mapping, offset); - if (likely(page) && !(vmf->flags & FAULT_FLAG_TRIED)) { + if (likely(page)) { /* - * We found the page, so try async readahead before - * waiting for the lock. + * We found the page, so try async readahead before waiting for + * the lock. */ - fpin = do_async_mmap_readahead(vmf, page); - } else if (!page) { + if (!(vmf->flags & FAULT_FLAG_TRIED)) + fpin = do_async_mmap_readahead(vmf, page); + if (unlikely(!PageUptodate(page))) { + filemap_invalidate_lock_shared(mapping); + mapping_locked = true; + } + } else { /* No page in the page cache at all */ count_vm_event(PGMAJFAULT); count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT); ret = VM_FAULT_MAJOR; fpin = do_sync_mmap_readahead(vmf); - } - - if (!page) { retry_find: /* * See comment in filemap_create_page() why we need @@ -3073,9 +3075,6 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) filemap_invalidate_unlock_shared(mapping); return VM_FAULT_OOM; } - } else if (unlikely(!PageUptodate(page))) { - filemap_invalidate_lock_shared(mapping); - mapping_locked = true; } if (!lock_page_maybe_drop_mmap(vmf, page, &fpin))