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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A073DC433B4 for ; Mon, 10 May 2021 07:52:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 739D661432 for ; Mon, 10 May 2021 07:52:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230163AbhEJHyA (ORCPT ); Mon, 10 May 2021 03:54:00 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:56138 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230172AbhEJHx5 (ORCPT ); Mon, 10 May 2021 03:53:57 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1620633173; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=2z80gbPhH136dYR4Fq2BEfvgVhJIsU7HqbSV3qvsj2c=; b=YyvJqUvP7AUa4mIkdVNELkYk3nxrTlxPqOKGaaRMkhzY5DoG+OQdcO961q1CUevKDVOx90Tv P+AFzZsdpMwGaYNMkeZrOzJmC7euEfx9//XrHNBtGeoRNxboQu2X2gKwmXFfChnEjc6JEv2T 8hWcGhvAvQ52rii9YtrDNbYs928= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyIxOTQxNiIsICJsaW51eC1mc2RldmVsQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n01.prod.us-east-1.postgun.com with SMTP id 6098e63a87ce1fbb56a01777 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 10 May 2021 07:52:26 GMT Sender: pragalla=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 63F1FC43145; Mon, 10 May 2021 07:52:24 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: pragalla) by smtp.codeaurora.org (Postfix) with ESMTPSA id BD7DEC4338A; Mon, 10 May 2021 07:52:23 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 10 May 2021 13:22:23 +0530 From: pragalla@codeaurora.org To: miklos@szeredi.hu Cc: stummala@codeaurora.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH V1] fuse: Set fuse request error upon fuse abort connection In-Reply-To: <1618582752-26178-1-git-send-email-pragalla@codeaurora.org> References: <1618582752-26178-1-git-send-email-pragalla@codeaurora.org> Message-ID: X-Sender: pragalla@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi Miklos, Did you get a chance to look on the below change ? could you please review and provide your comments if any. Thanks and Regards, Pradeep On 2021-04-16 19:49, Pradeep P V K wrote: > There is a minor race in setting the fuse out request error > between fuse_abort_conn() and fuse_dev_do_read() as explained > below. > > Thread-1 Thread-2 > ======== ======== > ->fuse_simple_request() ->shutdown > ->__fuse_request_send() > ->queue_request() ->fuse_abort_conn() > ->fuse_dev_do_read() ->acquire(fpq->lock) > ->wait_for(fpq->lock) ->set err to all req's in fpq->io > ->release(fpq->lock) > ->acquire(fpq->lock) > ->add req to fpq->io > > The above scenario may cause Thread-1 request to add into > fpq->io list after Thread-2 sets -ECONNABORTED err to all > its requests in fpq->io list. This leaves Thread-1 request > with unset err and this further misleads as a completed > request without an err set upon request_end(). > > Handle this by setting the err appropriately. > > Signed-off-by: Pradeep P V K > --- > fs/fuse/dev.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c > index a5ceccc..102c56f 100644 > --- a/fs/fuse/dev.c > +++ b/fs/fuse/dev.c > @@ -1283,6 +1283,7 @@ static ssize_t fuse_dev_do_read(struct fuse_dev > *fud, struct file *file, > clear_bit(FR_LOCKED, &req->flags); > if (!fpq->connected) { > err = fc->aborted ? -ECONNABORTED : -ENODEV; > + req->out.h.error = err; > goto out_end; > } > if (err) {