From patchwork Thu Jan 21 04:16:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 12034477 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 3DF80C433E0 for ; Thu, 21 Jan 2021 04:29:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 792D82389B for ; Thu, 21 Jan 2021 04:28:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732066AbhAUE2u (ORCPT ); Wed, 20 Jan 2021 23:28:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726094AbhAUE2H (ORCPT ); Wed, 20 Jan 2021 23:28:07 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4BCCC061757 for ; Wed, 20 Jan 2021 20:27:26 -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=JFA/0PQnOiQvHSolbGA9rFsFxqdMHN7no15nOhIz7Hg=; b=BuKLB1Q6AnAHxfvAWT1imcs1en dbMyi7i2SP5wmLLUFOcinkQQhnpTV9aNOqxi83WI0wB4q+dIvkmk4JAtpC3Ht8ez+Cju+EH6mLdRM 0uLf0EfuKLJm62Ypb6UnnnsPVmQRJTHyVYdWwk25yMT+wXkZfztWqFNagQaLMVBQ1D+ipnkx7axm0 8rgELgELSPNX6Oq0OSoZebBq4kIo7r1adrzb9e6/l6WrIV6YQEksczvyOUtcx9e0DTHyKIuFNlxkX tcL0cZ1pBCRqsBmHIdPCZ284YIiGBf6XvQBGal/0KvTADDzSbeoFRYRziZyztie5K4R04DaHaymce A9XUeFVg==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l2RXA-00Gbbs-R8; Thu, 21 Jan 2021 04:25:37 +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 v4 12/18] mm/filemap: Move the iocb checks into filemap_update_page Date: Thu, 21 Jan 2021 04:16:10 +0000 Message-Id: <20210121041616.3955703-13-willy@infradead.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210121041616.3955703-1-willy@infradead.org> References: <20210121041616.3955703-1-willy@infradead.org> MIME-Version: 1.0 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 adac12ed48415..141d5917770d6 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2230,15 +2230,16 @@ 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) @@ -2356,14 +2357,9 @@ 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) {