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 38C3DC55ABD for ; Tue, 10 Nov 2020 03:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF24720829 for ; Tue, 10 Nov 2020 03:37:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="acOJjM2i" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731474AbgKJDhU (ORCPT ); Mon, 9 Nov 2020 22:37:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730857AbgKJDhR (ORCPT ); Mon, 9 Nov 2020 22:37:17 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75ACAC0613CF for ; Mon, 9 Nov 2020 19:37:17 -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=lVuZuFVfNijs5cAJJuh1IhLvCBBPHWyHx4iPvOy8Rp0=; b=acOJjM2iGEmrOi2I8aVILPkAPZ Etc+Y4Rtb5ZUfgazghWg/RQDyGEtTUMFlk/m6GQZX2Cv9/53dRXrTAEJe/EYOJF6QdtoHSMbx0GYe efy9w315TkPikU1yhy7+hRrUWfXCVz/Cqw72RkB6hGBYrUeWGLK9vWHXvs8pXebqwsAsZHYQbIl5g p7JSZ659sIF7EI5LvCtfstfChzqYINmJ9a3yM9Mzf7jYC8a95SKkuDuwRj77ypD6a9XvGmh50yD+S At9Rczew2mR0JT8Wy5/OMCSdh0ieQQ6+UaKQA1Uf8lPOJ95ktXCH/ChoGZJFVrrX97e6+Xx6DqVwH SXNg3mWg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kcKT3-00066Q-TG; Tue, 10 Nov 2020 03:37:14 +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 v3 12/18] mm/filemap: Move the iocb checks into filemap_update_page Date: Tue, 10 Nov 2020 03:36:57 +0000 Message-Id: <20201110033703.23261-13-willy@infradead.org> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20201110033703.23261-1-willy@infradead.org> References: <20201110033703.23261-1-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 60ce7f15cc7e..2218fe610c42 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2238,15 +2238,16 @@ static int filemap_update_page(struct kiocb *iocb, struct inode *inode = mapping->host; int error; - if (iocb->ki_flags & IOCB_WAITQ) { - error = lock_page_async(page, iocb->ki_waitq); - if (error) - return error; - } else { - if (!trylock_page(page)) { + if (!trylock_page(page)) { + if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_NOIO)) + return -EAGAIN; + 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) + return error; } if (!page->mapping) @@ -2364,14 +2365,9 @@ 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