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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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_RED,USER_AGENT_GIT autolearn=unavailable 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 34707C433E9 for ; Mon, 15 Mar 2021 14:34:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0272864FF9 for ; Mon, 15 Mar 2021 14:34:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232404AbhCOOdo (ORCPT ); Mon, 15 Mar 2021 10:33:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:35186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233286AbhCOOBW (ORCPT ); Mon, 15 Mar 2021 10:01:22 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4831F64F69; Mon, 15 Mar 2021 14:00:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816859; bh=ksqVK6wcCdbE1lO+qgCPDlFPW+GJdXp7WZ6R2M3NcWs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=af9cwx1mAHKJ3rW6r7tuwSGWkUxjfQb8bqMZpfF5JYU6phOo0OiVLxmwD+QxpRuQ0 m3A+jqR1RLBpw6EZT07KYHyog329VRpJ6/eT9kb84tvJYz8Wo+nNWt/zE4Ie9MExY+ YgvYTHrM3PjrhGYtVhWGr4vqPiYp2v9m+K9yTfBk= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Minchan Kim , Sergey Senozhatsky , Colin Ian King , John Dias , Andrew Morton , Linus Torvalds Subject: [PATCH 5.4 156/168] zram: fix return value on writeback_store Date: Mon, 15 Mar 2021 14:56:28 +0100 Message-Id: <20210315135555.473229970@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135550.333963635@linuxfoundation.org> References: <20210315135550.333963635@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman From: Minchan Kim commit 57e0076e6575a7b7cef620a0bd2ee2549ef77818 upstream. writeback_store's return value is overwritten by submit_bio_wait's return value. Thus, writeback_store will return zero since there was no IO error. In the end, write syscall from userspace will see the zero as return value, which could make the process stall to keep trying the write until it will succeed. Link: https://lkml.kernel.org/r/20210312173949.2197662-1-minchan@kernel.org Fixes: 3b82a051c101("drivers/block/zram/zram_drv.c: fix error return codes not being returned in writeback_store") Signed-off-by: Minchan Kim Cc: Sergey Senozhatsky Cc: Colin Ian King Cc: John Dias Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/block/zram/zram_drv.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -627,7 +627,7 @@ static ssize_t writeback_store(struct de struct bio_vec bio_vec; struct page *page; ssize_t ret = len; - int mode; + int mode, err; unsigned long blk_idx = 0; if (sysfs_streq(buf, "idle")) @@ -719,12 +719,17 @@ static ssize_t writeback_store(struct de * XXX: A single page IO would be inefficient for write * but it would be not bad as starter. */ - ret = submit_bio_wait(&bio); - if (ret) { + err = submit_bio_wait(&bio); + if (err) { zram_slot_lock(zram, index); zram_clear_flag(zram, index, ZRAM_UNDER_WB); zram_clear_flag(zram, index, ZRAM_IDLE); zram_slot_unlock(zram, index); + /* + * Return last IO error unless every IO were + * not suceeded. + */ + ret = err; continue; }