From mboxrd@z Thu Jan 1 00:00:00 1970 From: wangyijing Subject: Question for Patch"libsas: fix "sysfs group not found" warnings at port teardown time" Date: Fri, 5 Feb 2016 17:20:03 +0800 Message-ID: <56B46943.5040808@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from szxga05-in.huawei.com ([58.251.152.179]:36987 "EHLO szxga05-in.huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752366AbcBEJWq (ORCPT ); Fri, 5 Feb 2016 04:22:46 -0500 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dan.j.williams@intel.com, Praveen Murali Cc: linux-scsi@vger.kernel.org Hi Dan and Praveen, I found a patch titled "libsas: fix "sysfs group not found" warnings at port teardown time" by google, https://www.mail-archive.com/linux-scsi@vger.kernel.org/msg39187.html I found the same warning calltrace in my platform, but I didn't find the patch changes in the latest kernel 4.5-rc2. So is this issue still in kernel ? I think your patch could fix this issue we found, but I'm worried about another problem. Now when unplug a disk LLDD report a event loss_of_singal sas_deform_port sas_unregister_domain_devices sas_unregister_dev sas_discover_event(dev->port, DISCE_DESTRUCT); sas_port_delete phy->port = NULL; and after your patch changes LLDD report a event loss_of_singal sas_deform_port sas_unregister_domain_devices sas_unregister_dev sas_discover_event(dev->port, DISCE_DESTRUCT); phy->port = NULL; ... sas_destruct_devices sas_port_delete //now we actually delete the port device, but we set phy->port = NULL; before this time. So if we hotplug the disk quickly, plug,unplug,plug, The new dmaed event(plug) would try to alloc and add a new port, but the old port device is still alive. Another calltrace would occur WARNING: CPU: 0 PID: 1038 at lib/kobject.c:240 kobject_add_internal+0x258/0x318() kobject_add_internal failed for port-0:0 with -EEXIST, don't try to register things with the same name in the same directory. CPU: 0 PID: 1038 Comm: kworker/u64:2 Tainted: G W 4.1.6+ #140 [] dump_backtrace+0x0/0x124 [] show_stack+0x10/0x1c [] warn_slowpath_fmt+0x4c/0x58 [] device_add+0x28c/0x5b8 [] sas_port_add+0x20/0xbc [] sas_porte_bytes_dmaed [] process_one_work+0x13c/0x344 Because I am not a sas guy, so if you could comment this or post new patch, I would be thanks a lot! Thanks! Yijing.