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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BEA2C433EF for ; Fri, 15 Apr 2022 09:33:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351758AbiDOJfy (ORCPT ); Fri, 15 Apr 2022 05:35:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351754AbiDOJft (ORCPT ); Fri, 15 Apr 2022 05:35:49 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 992A5A7752; Fri, 15 Apr 2022 02:33:21 -0700 (PDT) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Kfrfj0HbPzFprm; Fri, 15 Apr 2022 17:30:53 +0800 (CST) Received: from dggpemm500017.china.huawei.com (7.185.36.178) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 15 Apr 2022 17:33:19 +0800 Received: from [10.174.178.220] (10.174.178.220) by dggpemm500017.china.huawei.com (7.185.36.178) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 15 Apr 2022 17:33:19 +0800 Message-ID: <1e4b47e5-2bd3-2766-7d47-d14d3a4fbd65@huawei.com> Date: Fri, 15 Apr 2022 17:33:18 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH 1/2] scsi: iscsi: introduce session UNBOUND state to avoid multiple unbind event Content-Language: en-US To: Mike Christie , Lee Duncan , Chris Leech , "James E . J . Bottomley" , "Martin K . Petersen" , , , , Wenchao Hao CC: References: <20220414014947.4168447-1-haowenchao@huawei.com> <20220414014947.4168447-2-haowenchao@huawei.com> <137ec5f5-dbdc-99f0-e9b7-deeef5001a01@oracle.com> From: Wenchao Hao In-Reply-To: <137ec5f5-dbdc-99f0-e9b7-deeef5001a01@oracle.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.220] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500017.china.huawei.com (7.185.36.178) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/4/14 23:22, Mike Christie wrote: > On 4/13/22 8:49 PM, Wenchao Hao wrote: >> Fix the issue of kernel send multiple ISCSI_KEVENT_UNBIND_SESSION event. >> If session is in UNBOUND state, do not perform unbind operations anymore, >> else unbind session and set session to UNBOUND state. >> > > I don't think we want this to be a state because you can have a session > with no target or it could be partially deleted and it could be in the > logged in or failed state. If scsi-ml is sending SYNC_CACHEs as part of > the target/device removal operation, and we lose the session then we could > go through recovery and the state will go from failed to logged in, and > your new unbound state will have been overwritten. > > I think it might be better to have a new sysfs file, target_state, for > this where you could have values like scanning, bound, unbinding, and > unbound, or just a sysfs file, target_bound, that is bool. > Thanks for your review, I would modify and send another patch. >> Reference:https://github.com/open-iscsi/open-iscsi/issues/338 >> > > You should add a description of the problem in the commit, because that > link might be gone one day. > > >> Signed-off-by: Wenchao Hao >> --- >> drivers/scsi/scsi_transport_iscsi.c | 19 +++++++++++++++++-- >> include/scsi/scsi_transport_iscsi.h | 1 + >> 2 files changed, 18 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c >> index 27951ea05dd4..97a9fee02efa 100644 >> --- a/drivers/scsi/scsi_transport_iscsi.c >> +++ b/drivers/scsi/scsi_transport_iscsi.c >> @@ -1656,6 +1656,7 @@ static struct { >> { ISCSI_SESSION_LOGGED_IN, "LOGGED_IN" }, >> { ISCSI_SESSION_FAILED, "FAILED" }, >> { ISCSI_SESSION_FREE, "FREE" }, >> + { ISCSI_SESSION_UNBOUND, "UNBOUND" }, >> }; >> >> static const char *iscsi_session_state_name(int state) >> @@ -1686,6 +1687,9 @@ int iscsi_session_chkready(struct iscsi_cls_session *session) >> case ISCSI_SESSION_FREE: >> err = DID_TRANSPORT_FAILFAST << 16; >> break; >> + case ISCSI_SESSION_UNBOUND: >> + err = DID_NO_CONNECT << 16; >> + break; >> default: >> err = DID_NO_CONNECT << 16; >> break; >> @@ -1838,7 +1842,8 @@ int iscsi_block_scsi_eh(struct scsi_cmnd *cmd) >> >> spin_lock_irqsave(&session->lock, flags); >> while (session->state != ISCSI_SESSION_LOGGED_IN) { >> - if (session->state == ISCSI_SESSION_FREE) { >> + if ((session->state == ISCSI_SESSION_FREE) || >> + (session->state == ISCSI_SESSION_UNBOUND)) { >> ret = FAST_IO_FAIL; >> break; >> } >> @@ -1869,6 +1874,7 @@ static void session_recovery_timedout(struct work_struct *work) >> break; >> case ISCSI_SESSION_LOGGED_IN: >> case ISCSI_SESSION_FREE: >> + case ISCSI_SESSION_UNBOUND: >> /* we raced with the unblock's flush */ >> spin_unlock_irqrestore(&session->lock, flags); >> return; >> @@ -1957,6 +1963,14 @@ static void __iscsi_unbind_session(struct work_struct *work) >> unsigned long flags; >> unsigned int target_id; >> >> + spin_lock_irqsave(&session->lock, flags); >> + if (session->state == ISCSI_SESSION_UNBOUND) { >> + spin_unlock_irqrestore(&session->lock, flags); >> + return; >> + } >> + session->state = ISCSI_SESSION_UNBOUND; >> + spin_unlock_irqrestore(&session->lock, flags); >> + >> ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n"); >> >> /* Prevent new scans and make sure scanning is not in progress */ >> @@ -4329,7 +4343,8 @@ store_priv_session_##field(struct device *dev, \ >> struct iscsi_cls_session *session = \ >> iscsi_dev_to_session(dev->parent); \ >> if ((session->state == ISCSI_SESSION_FREE) || \ >> - (session->state == ISCSI_SESSION_FAILED)) \ >> + (session->state == ISCSI_SESSION_FAILED) || \ >> + (session->state == ISCSI_SESSION_UNBOUND)) \ >> return -EBUSY; \ >> if (strncmp(buf, "off", 3) == 0) { \ >> session->field = -1; \ >> diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h >> index 38e4a67f5922..80149643cbcd 100644 >> --- a/include/scsi/scsi_transport_iscsi.h >> +++ b/include/scsi/scsi_transport_iscsi.h >> @@ -232,6 +232,7 @@ enum { >> ISCSI_SESSION_LOGGED_IN, >> ISCSI_SESSION_FAILED, >> ISCSI_SESSION_FREE, >> + ISCSI_SESSION_UNBOUND, >> }; >> >> #define ISCSI_MAX_TARGET -1 > > .