From patchwork Mon Dec 18 15:35:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13497145 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB7C971441; Mon, 18 Dec 2023 15:36:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="QbDL69GR" 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=FNt5drM75tskFSjmTVt5X4B1n0+AI4vg4FZ50KNwnlI=; b=QbDL69GRW7vcyaByv+sL4EM+jX e1QFZOSXKXPkEb+eHP3GiM6UxRPacz9vafLmcd5vlzhMaNWjnWNm72N3eC5D3DOMxmjaWumGDpjGr XM6FXOQJMz+HmusWg+1LvjoRZGZU2wpeb6PIpggTeUTU3a+7tMOXiJPs2b8G376PygzwpKTNPmEIs hMmgGXMFBpTBYKLuq7Eb1xdpwVhL/ExPQOMB+E9OezOoHgfinlWKM3AQzMwJIsUS75WJ0yGWCDtN5 eQcmtSldtT3O7o6PWVWQLoa8KFVGz3GXZDRsAm5iHAYmgw9nL9j365MYyfJKPnp5qDf1Z929i1sSr k+mKxi/w==; Received: from 2a02-8389-2341-5b80-39d3-4735-9a3c-88d8.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:39d3:4735:9a3c:88d8] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1rFFfE-00BEOe-2o; Mon, 18 Dec 2023 15:36:17 +0000 From: Christoph Hellwig To: linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , Jan Kara , David Howells , Brian Foster , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 08/17] writeback: Factor should_writeback_folio() out of write_cache_pages() Date: Mon, 18 Dec 2023 16:35:44 +0100 Message-Id: <20231218153553.807799-9-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231218153553.807799-1-hch@lst.de> References: <20231218153553.807799-1-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 798e5264dc0353..2a004c0b9bdfbf 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2406,6 +2406,36 @@ static void writeback_get_batch(struct address_space *mapping, wbc_to_tag(wbc), &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 @@ -2470,38 +2500,13 @@ int write_cache_pages(struct address_space *mapping, unsigned long nr; 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); wbc->nr_to_write -= nr;