From patchwork Sat Nov 26 01:07:52 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wenchao Hao X-Patchwork-Id: 628776 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 02F07C4332F for ; Fri, 25 Nov 2022 11:50:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230086AbiKYLuL (ORCPT ); Fri, 25 Nov 2022 06:50:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229723AbiKYLuJ (ORCPT ); Fri, 25 Nov 2022 06:50:09 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9A8C21836; Fri, 25 Nov 2022 03:50:06 -0800 (PST) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4NJY7B6WlMzHv3k; Fri, 25 Nov 2022 19:49:26 +0800 (CST) Received: from dggpemm500017.china.huawei.com (7.185.36.178) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 25 Nov 2022 19:50:05 +0800 Received: from build.huawei.com (10.175.101.6) 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 15.1.2375.31; Fri, 25 Nov 2022 19:50:04 +0800 From: Wenchao Hao To: Lee Duncan , Chris Leech , "Mike Christie" , "James E . J . Bottomley" , "Martin K . Petersen" , , CC: , , , Wenchao Hao Subject: [PATCH v7] scsi:iscsi: Fix multiple iscsi session unbind event sent to userspace Date: Sat, 26 Nov 2022 09:07:52 +0800 Message-ID: <20221126010752.231917-1-haowenchao@huawei.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] 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-scsi@vger.kernel.org I found an issue that kernel would send ISCSI_KEVENT_UNBIND_SESSION for multiple times which should be fixed. This patch introduce target_state in iscsi_cls_session to make sure session would send only one ISCSI_KEVENT_UNBIND_SESSION. But this would break issue fixed in commit 13e60d3ba287 ("scsi: iscsi: Report unbind session event when the target has been removed"). The issue is iscsid died for any reason after it send unbind session to kernel, once iscsid restart again, it loss kernel's ISCSI_KEVENT_UNBIND_SESSION event. Now kernel think iscsi_cls_session has already sent an ISCSI_KEVENT_UNBIND_SESSION event and would not send it any more. Which would cause userspace unable to logout. Actually the session is in invalid state(it's target_id is INVALID), iscsid should not sync this session in it's restart. So we need to check session's target state during iscsid restart, if session is in unbound state, do not sync this session and perform session teardown. It's reasonable because once a session is unbound, we can not recover it any more(mainly because it's target id is INVALID) V7: - Define target state to string map and refer this map directly - Cleanup __iscsi_unbind_session, drop check for session's target_id == ISCSI_MAX_TARGET since it can be handled by target_state V6: - Set target state to ALLOCATED in iscsi_add_session - Rename state BOUND to SCANNED - Make iscsi_session_target_state_name() more efficient V5: - Add ISCSI_SESSION_TARGET_ALLOCATED to indicate the session's target has been allocated but not scanned yet. We should sync this session and scan this session when iscsid restarted. V4: - Move debug print out of spinlock critical section V3: - Make target bind state to a state kind rather than a bool. V2: - Using target_unbound rather than state to indicate session has been unbound Signed-off-by: Wenchao Hao Reviewed-by: Mike Christie Reviewed-by: Wu Bo --- drivers/scsi/scsi_transport_iscsi.c | 47 ++++++++++++++++++++++++++--- include/scsi/scsi_transport_iscsi.h | 9 ++++++ 2 files changed, 51 insertions(+), 5 deletions(-) diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index cd3db9684e52..812578c20fe5 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -1676,6 +1676,13 @@ static const char *iscsi_session_state_name(int state) return name; } +static char *iscsi_session_target_state_name[] = { + [ISCSI_SESSION_TARGET_UNBOUND] = "UNBOUND", + [ISCSI_SESSION_TARGET_ALLOCATED] = "ALLOCATED", + [ISCSI_SESSION_TARGET_SCANNED] = "SCANNED", + [ISCSI_SESSION_TARGET_UNBINDING] = "UNBINDING", +}; + int iscsi_session_chkready(struct iscsi_cls_session *session) { int err; @@ -1785,9 +1792,13 @@ static int iscsi_user_scan_session(struct device *dev, void *data) if ((scan_data->channel == SCAN_WILD_CARD || scan_data->channel == 0) && (scan_data->id == SCAN_WILD_CARD || - scan_data->id == id)) + scan_data->id == id)) { scsi_scan_target(&session->dev, 0, id, scan_data->lun, scan_data->rescan); + spin_lock_irqsave(&session->lock, flags); + session->target_state = ISCSI_SESSION_TARGET_SCANNED; + spin_unlock_irqrestore(&session->lock, flags); + } } user_scan_exit: @@ -1960,31 +1971,41 @@ static void __iscsi_unbind_session(struct work_struct *work) struct iscsi_cls_host *ihost = shost->shost_data; unsigned long flags; unsigned int target_id; + bool remove_target = true; ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n"); /* Prevent new scans and make sure scanning is not in progress */ mutex_lock(&ihost->mutex); spin_lock_irqsave(&session->lock, flags); - if (session->target_id == ISCSI_MAX_TARGET) { + if (session->target_state == ISCSI_SESSION_TARGET_ALLOCATED) { + remove_target = false; + } else if (session->target_state != ISCSI_SESSION_TARGET_SCANNED) { spin_unlock_irqrestore(&session->lock, flags); mutex_unlock(&ihost->mutex); - goto unbind_session_exit; + ISCSI_DBG_TRANS_SESSION(session, + "Skipping target unbinding: Session is unbound/unbinding.\n"); + return; } + session->target_state = ISCSI_SESSION_TARGET_UNBINDING; target_id = session->target_id; session->target_id = ISCSI_MAX_TARGET; spin_unlock_irqrestore(&session->lock, flags); mutex_unlock(&ihost->mutex); - scsi_remove_target(&session->dev); + if (remove_target) + scsi_remove_target(&session->dev); if (session->ida_used) ida_free(&iscsi_sess_ida, target_id); -unbind_session_exit: iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION); ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n"); + + spin_lock_irqsave(&session->lock, flags); + session->target_state = ISCSI_SESSION_TARGET_UNBOUND; + spin_unlock_irqrestore(&session->lock, flags); } static void __iscsi_destroy_session(struct work_struct *work) @@ -2061,6 +2082,9 @@ int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id) session->ida_used = true; } else session->target_id = target_id; + spin_lock_irqsave(&session->lock, flags); + session->target_state = ISCSI_SESSION_TARGET_ALLOCATED; + spin_unlock_irqrestore(&session->lock, flags); dev_set_name(&session->dev, "session%u", session->sid); err = device_add(&session->dev); @@ -4368,6 +4392,16 @@ iscsi_session_attr(def_taskmgmt_tmo, ISCSI_PARAM_DEF_TASKMGMT_TMO, 0); iscsi_session_attr(discovery_parent_idx, ISCSI_PARAM_DISCOVERY_PARENT_IDX, 0); iscsi_session_attr(discovery_parent_type, ISCSI_PARAM_DISCOVERY_PARENT_TYPE, 0); +static ssize_t +show_priv_session_target_state(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent); + return sysfs_emit(buf, "%s\n", + iscsi_session_target_state_name[session->target_state]); +} +static ISCSI_CLASS_ATTR(priv_sess, target_state, S_IRUGO, + show_priv_session_target_state, NULL); static ssize_t show_priv_session_state(struct device *dev, struct device_attribute *attr, char *buf) @@ -4470,6 +4504,7 @@ static struct attribute *iscsi_session_attrs[] = { &dev_attr_sess_boot_target.attr, &dev_attr_priv_sess_recovery_tmo.attr, &dev_attr_priv_sess_state.attr, + &dev_attr_priv_sess_target_state.attr, &dev_attr_priv_sess_creator.attr, &dev_attr_sess_chap_out_idx.attr, &dev_attr_sess_chap_in_idx.attr, @@ -4583,6 +4618,8 @@ static umode_t iscsi_session_attr_is_visible(struct kobject *kobj, return S_IRUGO | S_IWUSR; else if (attr == &dev_attr_priv_sess_state.attr) return S_IRUGO; + else if (attr == &dev_attr_priv_sess_target_state.attr) + return S_IRUGO; else if (attr == &dev_attr_priv_sess_creator.attr) return S_IRUGO; else if (attr == &dev_attr_priv_sess_target_id.attr) diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h index cab52b0f11d0..34c03707fb6e 100644 --- a/include/scsi/scsi_transport_iscsi.h +++ b/include/scsi/scsi_transport_iscsi.h @@ -236,6 +236,14 @@ enum { ISCSI_SESSION_FREE, }; +enum { + ISCSI_SESSION_TARGET_UNBOUND, + ISCSI_SESSION_TARGET_ALLOCATED, + ISCSI_SESSION_TARGET_SCANNED, + ISCSI_SESSION_TARGET_UNBINDING, + ISCSI_SESSION_TARGET_MAX, +}; + #define ISCSI_MAX_TARGET -1 struct iscsi_cls_session { @@ -264,6 +272,7 @@ struct iscsi_cls_session { */ pid_t creator; int state; + int target_state; /* session target bind state */ int sid; /* session id */ void *dd_data; /* LLD private data */ struct device dev; /* sysfs transport/container device */