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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 14684C388F7 for ; Wed, 4 Nov 2020 20:42:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8EF920782 for ; Wed, 4 Nov 2020 20:42:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="C0Z8ozkg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732235AbgKDUmh (ORCPT ); Wed, 4 Nov 2020 15:42:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731475AbgKDUm1 (ORCPT ); Wed, 4 Nov 2020 15:42:27 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5DC8C061A4C for ; Wed, 4 Nov 2020 12:42:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=9CL+S7Fi5xbteEEqYAzcQmFqJbUHwSVAW/7+GqlnElo=; b=C0Z8ozkgSg6mNgnD3anPbyeVoW bkLT+SwwEaO2KHeph6uQAn/So2NFZ5XUN/nG4kF+0dn1AfmbjSxl8ZO5QZggf/YeLNHij3viO1HHk wMs2vARWeHFz81/RRFtot6jGpwPhHD/FIOnYL0MQwu1uCqK7d4AbtM+4e/azKSVBusyr3BaTB6dPB mCYrf/x2xdZB3RG4E73xM8ZkkjMwxwQjtASJZaUc8gfiO7HyOgUSLbWcYa/Yau7KCIxvk4ESGfnsn ZCw0zSqtODXjVX4isvGSsszB+5hFAI1pVwkQx2JAS78SJupnswH2v9Db64Iu4JLrUYOIQoR7iUV3y WpPvvmEA==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kaPbt-0006E6-0o; Wed, 04 Nov 2020 20:42:25 +0000 From: "Matthew Wilcox (Oracle)" To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Cc: "Matthew Wilcox (Oracle)" , hch@lst.de, kent.overstreet@gmail.com Subject: [PATCH v2 12/18] mm/filemap: Move the iocb checks into filemap_update_page Date: Wed, 4 Nov 2020 20:42:13 +0000 Message-Id: <20201104204219.23810-13-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20201104204219.23810-1-willy@infradead.org> References: <20201104204219.23810-1-willy@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org We don't need to give up when a non-blocking request sees a !Uptodate page. We may be able to satisfy the read from a partially-uptodate page. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Kent Overstreet Reviewed-by: Christoph Hellwig --- mm/filemap.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 93c054f51677..9db94876122c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2236,17 +2236,18 @@ static int filemap_update_page(struct kiocb *iocb, struct page *page, loff_t pos, loff_t count) { struct inode *inode = mapping->host; - int error; + int error = -EAGAIN; - if (iocb->ki_flags & IOCB_WAITQ) { - error = lock_page_async(page, iocb->ki_waitq); - if (error) + if (!trylock_page(page)) { + if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_NOIO)) goto error; - } else { - if (!trylock_page(page)) { + if (!(iocb->ki_flags & IOCB_WAITQ)) { put_and_wait_on_page_locked(page, TASK_KILLABLE); return AOP_TRUNCATED_PAGE; } + error = __lock_page_async(page, iocb->ki_waitq); + if (error) + goto error; } if (!page->mapping) @@ -2368,14 +2369,9 @@ static int filemap_get_pages(struct kiocb *iocb, struct iov_iter *iter, } if (!PageUptodate(page)) { - if ((iocb->ki_flags & IOCB_NOWAIT) || - ((iocb->ki_flags & IOCB_WAITQ) && pvec->nr > 1)) { - put_page(page); - pvec->nr--; - err = -EAGAIN; - goto err; - } - + if ((iocb->ki_flags & IOCB_WAITQ) && + pagevec_count(pvec) > 1) + iocb->ki_flags |= IOCB_NOWAIT; err = filemap_update_page(iocb, mapping, iter, page, pg_pos, pg_count); if (err) -- 2.28.0