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=-14.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 54F7CC433ED for ; Wed, 19 May 2021 19:56:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 289A76135A for ; Wed, 19 May 2021 19:56:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232317AbhEST5l (ORCPT ); Wed, 19 May 2021 15:57:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232233AbhEST5k (ORCPT ); Wed, 19 May 2021 15:57:40 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53C82C06175F; Wed, 19 May 2021 12:56:20 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id n8so2446557plf.7; Wed, 19 May 2021 12:56:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=q6qp+y0b7E4RD0dE7eFD/KyO3v3EYWq2TwYTARfgrfo=; b=DJsaMMymn/AhkUuHSDxlHhqe6L1wpqni/4qxPEFK282dnjxtLxeTs7zg8X9ZO57/x0 iRIKvqif7q2Ce/Yapiez9RQf/Grxafr7DccqRAvwhrpC1PPXEq24ZXHebPu7g527pcX5 oWNtY5zaIWNiEHOZt/vZw3EvyOTss8jvestBlCzJhZ7tIPU9nAVBiWMCWIVsAV179kdp Yv6T3YqJi5IJknSJLWsr+KkWkUqi+in6nFXy5kaDNM1mFCcuesBiJOkRA/qZNb0FAcDx Y9x77YbYrIVdyraHNzQ/F9h0evU88JAkVZcZTlljSuTDPl0NZdvwzUAkJaXY1bqu6HmH FQ7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=q6qp+y0b7E4RD0dE7eFD/KyO3v3EYWq2TwYTARfgrfo=; b=YEkZHmw3SK4jeqBThjSUiqzG6/8/NjHAlxPuEIaJOdjfuTSRuP82xglKoHfrrBoHBD vm4+e9wdLO3WcQO5wKngjMH4ZfOOcZ2KwIjeeOxkW1UA610rY5txKfNQUlNjGr11e0K0 EnAgK6Qdh7lX3kDXvdOIEnWP3BIfNzyTxjeXL4402VJr8aQZa+SCpIrYhyk0bOEY6zGP JzEIu4HfGvKitiw6Z9Y0oVjXxt01Sifg7e98pZDmcxgxWezf6UNQ3c1rUQ2W5ekHsrMR RsIQmgc/Mw7zfagXE8cYnTg1IZlnhEolkjvb7Zs4+6J04OUCPkA5XtbZ6BrL2G+TnAZt A2ng== X-Gm-Message-State: AOAM53217GC6SKNPbLaexaTel+7WqM2nUMvdf0JmgZ7glS14BK19Rb2x YQymXSBmBhfbMeXdkNNvLxc= X-Google-Smtp-Source: ABdhPJyZO5fAGR+vKyFVigDGtIUNgQqvvxyxqJhBPAITxMffW5yyiMGetXScTcimnzBCwgwngeZb7w== X-Received: by 2002:a17:90a:55c5:: with SMTP id o5mr644852pjm.191.1621454179762; Wed, 19 May 2021 12:56:19 -0700 (PDT) Received: from google.com ([2620:15c:211:201:4102:f4c7:9246:e6c4]) by smtp.gmail.com with ESMTPSA id i20sm161597pgb.38.2021.05.19.12.56.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 May 2021 12:56:19 -0700 (PDT) Sender: Minchan Kim Date: Wed, 19 May 2021 12:56:17 -0700 From: Minchan Kim To: Luis Chamberlain Cc: ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, axboe@kernel.dk, mbenes@suse.com, jpoimboe@redhat.com, tglx@linutronix.de, keescook@chromium.org, jikos@kernel.org, rostedt@goodmis.org, peterz@infradead.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/4] zram: avoid disksize setting when device is being claimed Message-ID: References: <20210423011108.11988-1-mcgrof@kernel.org> <20210423011108.11988-3-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210423011108.11988-3-mcgrof@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Apr 23, 2021 at 01:11:06AM +0000, Luis Chamberlain wrote: > As with other areas of the zram diver, check if the zram > block device is being claimed but do it early to avoid > trying to set something up for a zram device which may > be on its way out. I guess you're talking about zram_remove race with disksize_store. Please add some code sequence diagram like previous patch, which makes thing more clear. Otherwise, looks good to me. > > This doesn't fix a known crash, however the potential for > an issue issue is found through code inspection. > > Signed-off-by: Luis Chamberlain > --- > drivers/block/zram/zram_drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index 431b60cd85c1..6051d20b88c3 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -1729,7 +1729,7 @@ static ssize_t disksize_store(struct device *dev, > > mutex_lock(&zram_index_mutex); > > - if (!zram_up) { > + if (!zram_up || zram->claim) { > err = -ENODEV; > goto out; > } > -- > 2.27.0 >