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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C7CDC43219 for ; Tue, 18 Oct 2022 21:02:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230210AbiJRVCj (ORCPT ); Tue, 18 Oct 2022 17:02:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230121AbiJRVCi (ORCPT ); Tue, 18 Oct 2022 17:02:38 -0400 Received: from mail104.syd.optusnet.com.au (mail104.syd.optusnet.com.au [211.29.132.246]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4B7F622288; Tue, 18 Oct 2022 14:02:27 -0700 (PDT) Received: from dread.disaster.area (pa49-181-106-210.pa.nsw.optusnet.com.au [49.181.106.210]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id 967678AE0CC; Wed, 19 Oct 2022 08:01:53 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1oktii-003bE7-4J; Wed, 19 Oct 2022 08:01:52 +1100 Date: Wed, 19 Oct 2022 08:01:52 +1100 From: Dave Chinner To: "Vishal Moola (Oracle)" Cc: linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, cluster-devel@redhat.com, linux-nilfs@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 04/23] page-writeback: Convert write_cache_pages() to use filemap_get_folios_tag() Message-ID: <20221018210152.GH2703033@dread.disaster.area> References: <20220901220138.182896-1-vishal.moola@gmail.com> <20220901220138.182896-5-vishal.moola@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220901220138.182896-5-vishal.moola@gmail.com> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.4 cv=e9dl9Yl/ c=1 sm=1 tr=0 ts=634f1443 a=j6JUzzrSC7wlfFge/rmVbg==:117 a=j6JUzzrSC7wlfFge/rmVbg==:17 a=kj9zAlcOel0A:10 a=Qawa6l4ZSaYA:10 a=pGLkceISAAAA:8 a=7-415B0cAAAA:8 a=K-JhRxFi-CGouRt9WdAA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Thu, Sep 01, 2022 at 03:01:19PM -0700, Vishal Moola (Oracle) wrote: > Converted function to use folios throughout. This is in preparation for > the removal of find_get_pages_range_tag(). > > Signed-off-by: Vishal Moola (Oracle) > --- > mm/page-writeback.c | 44 +++++++++++++++++++++++--------------------- > 1 file changed, 23 insertions(+), 21 deletions(-) > > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index 032a7bf8d259..087165357a5a 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -2285,15 +2285,15 @@ int write_cache_pages(struct address_space *mapping, > int ret = 0; > int done = 0; > int error; > - struct pagevec pvec; > - int nr_pages; > + struct folio_batch fbatch; > + int nr_folios; > pgoff_t index; > pgoff_t end; /* Inclusive */ > pgoff_t done_index; > int range_whole = 0; > xa_mark_t tag; > > - pagevec_init(&pvec); > + folio_batch_init(&fbatch); > if (wbc->range_cyclic) { > index = mapping->writeback_index; /* prev offset */ > end = -1; > @@ -2313,17 +2313,18 @@ int write_cache_pages(struct address_space *mapping, > while (!done && (index <= end)) { > int i; > > - nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end, > - tag); > - if (nr_pages == 0) > + nr_folios = filemap_get_folios_tag(mapping, &index, end, > + tag, &fbatch); This can find and return dirty multi-page folios if the filesystem enables them in the mapping at instantiation time, right? > + > + if (nr_folios == 0) > break; > > - for (i = 0; i < nr_pages; i++) { > - struct page *page = pvec.pages[i]; > + for (i = 0; i < nr_folios; i++) { > + struct folio *folio = fbatch.folios[i]; > > - done_index = page->index; > + done_index = folio->index; > > - lock_page(page); > + folio_lock(folio); > > /* > * Page truncated or invalidated. We can freely skip it > @@ -2333,30 +2334,30 @@ int write_cache_pages(struct address_space *mapping, > * even if there is now a new, dirty page at the same > * pagecache address. > */ > - if (unlikely(page->mapping != mapping)) { > + if (unlikely(folio->mapping != mapping)) { > continue_unlock: > - unlock_page(page); > + folio_unlock(folio); > continue; > } > > - if (!PageDirty(page)) { > + if (!folio_test_dirty(folio)) { > /* someone wrote it for us */ > goto continue_unlock; > } > > - if (PageWriteback(page)) { > + if (folio_test_writeback(folio)) { > if (wbc->sync_mode != WB_SYNC_NONE) > - wait_on_page_writeback(page); > + folio_wait_writeback(folio); > else > goto continue_unlock; > } > > - BUG_ON(PageWriteback(page)); > - if (!clear_page_dirty_for_io(page)) > + BUG_ON(folio_test_writeback(folio)); > + if (!folio_clear_dirty_for_io(folio)) > goto continue_unlock; > > trace_wbc_writepage(wbc, inode_to_bdi(mapping->host)); > - error = (*writepage)(page, wbc, data); > + error = writepage(&folio->page, wbc, data); Yet, IIUC, this treats all folios as if they are single page folios. i.e. it passes the head page of a multi-page folio to a callback that will treat it as a single PAGE_SIZE page, because that's all the writepage callbacks are currently expected to be passed... So won't this break writeback of dirty multipage folios? -Dave. -- Dave Chinner david@fromorbit.com