From patchwork Thu Dec 14 13:25:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13493046 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Ymphf93h" Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3265A126; Thu, 14 Dec 2023 05:26:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=kn8CvxNi5qh4QD11jnSpjHpiIFyaVQYj8SeXOQ3UR/M=; b=Ymphf93hcUsna9RWYEJ1i5FWvm QO6gwTupm7fmG37py0aAXd+CtC/OWntiYIUrRYG0S0iL4KGmW9loE7n35WfYgdg691tA0ruuq6o4g IeDqgCs8n01sx4MFcEbNm+2m0hZqKnCp7Zw9dtKciOW7NNtD0AEDtDyqISiSMDti0I1itZcbNUgD/ jMgr3PyeOqtJrmyP2pLCfONU1HegzPe9JqCZ9Csc0091UoP3UlDRA//18mMkH7b69/r2MpVkIq0Uo nDWtlbXZyGAC+4temfdUdkV73P7SE/c7vhXe5EQDsJCuWNGfcAJjCphLs5vTZ+zr6TS9uVwvaxdhL m8a+e+BQ==; Received: from [88.128.88.27] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1rDlj2-000N2I-1X; Thu, 14 Dec 2023 13:26:04 +0000 From: Christoph Hellwig To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Jan Kara , David Howells Subject: [PATCH 03/11] writeback: Factor should_writeback_folio() out of write_cache_pages() Date: Thu, 14 Dec 2023 14:25:36 +0100 Message-Id: <20231214132544.376574-4-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231214132544.376574-1-hch@lst.de> References: <20231214132544.376574-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html From: "Matthew Wilcox (Oracle)" Reduce write_cache_pages() by about 30 lines; much of it is commentary, but it all bundles nicely into an obvious function. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara --- mm/page-writeback.c | 59 ++++++++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 27 deletions(-) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 5d33e7b468e2cc..5a3df8665ff4f9 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2394,6 +2394,36 @@ static void writeback_get_batch(struct address_space *mapping, &wbc->fbatch); } +static bool should_writeback_folio(struct address_space *mapping, + struct writeback_control *wbc, struct folio *folio) +{ + /* + * Folio truncated or invalidated. We can freely skip it then, + * even for data integrity operations: the folio has disappeared + * concurrently, so there could be no real expectation of this + * data integrity operation even if there is now a new, dirty + * folio at the same pagecache index. + */ + if (unlikely(folio->mapping != mapping)) + return false; + + /* Did somebody write it for us? */ + if (!folio_test_dirty(folio)) + return false; + + if (folio_test_writeback(folio)) { + if (wbc->sync_mode == WB_SYNC_NONE) + return false; + folio_wait_writeback(folio); + } + + BUG_ON(folio_test_writeback(folio)); + if (!folio_clear_dirty_for_io(folio)) + return false; + + return true; +} + /** * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. * @mapping: address space structure to write @@ -2462,38 +2492,13 @@ int write_cache_pages(struct address_space *mapping, wbc->done_index = folio->index; folio_lock(folio); - - /* - * Page truncated or invalidated. We can freely skip it - * then, even for data integrity operations: the page - * has disappeared concurrently, so there could be no - * real expectation of this data integrity operation - * even if there is now a new, dirty page at the same - * pagecache address. - */ - if (unlikely(folio->mapping != mapping)) { -continue_unlock: + if (!should_writeback_folio(mapping, wbc, folio)) { folio_unlock(folio); continue; } - if (!folio_test_dirty(folio)) { - /* someone wrote it for us */ - goto continue_unlock; - } - - if (folio_test_writeback(folio)) { - if (wbc->sync_mode != WB_SYNC_NONE) - folio_wait_writeback(folio); - else - goto continue_unlock; - } - - 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(folio, wbc, data); nr = folio_nr_pages(folio); if (unlikely(error)) {