From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE20815D5C8; Tue, 18 Jun 2024 11:46:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718711165; cv=none; b=Io409czbgaMyOFojKOh3L5jDCHWRVqSGsjq1RfPuIpFKtInAVKnOw0BKt3oljXUZhjiCmazyMamnR0Jajr1u6cfTGqhyTdZvf1dbOXpAt/JmS7VSPMHKlOto4zydmL9PpgV8XrQkc/lK0vUHWm/gS1fY5Ioo7K0tG38xsZQfs/E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718711165; c=relaxed/simple; bh=1QIcrNptfaU/0/hqEe+Sb9+thzwL6QqBhrUZ3lP5deU=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=E8f28h2KWWbrZwT6KBKyA+veCTDYO58V9VAenoBNzu9bM5sum52+5a+5bZYAvIw/UNqyhWVTGHxH/KtEbA1e5kHLs30uLqF/UlH/W+Sb0nmz5+PEs74X54Mxoj/UlL07xALEnHIMB7hfUBaQYrqCRjgtuInv4q8lr6hlZtREIXc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.105]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4W3Pzx5LGBzdc8F; Tue, 18 Jun 2024 19:44:29 +0800 (CST) Received: from dggpemd100001.china.huawei.com (unknown [7.185.36.94]) by mail.maildlp.com (Postfix) with ESMTPS id EAC25140361; Tue, 18 Jun 2024 19:45:59 +0800 (CST) Received: from [10.67.120.108] (10.67.120.108) by dggpemd100001.china.huawei.com (7.185.36.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Tue, 18 Jun 2024 19:45:59 +0800 Message-ID: <815fcddf-85cc-126e-4be1-618b5ba8f823@huawei.com> Date: Tue, 18 Jun 2024 19:45:59 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.3.1 Subject: Re: [PATCH v3] scsi: libsas: Fix exp-attached end device cannot be scanned in again after probe failed Content-Language: en-CA To: John Garry , , , , CC: , , , , , References: <20240613122355.7797-1-yangxingui@huawei.com> <437c99f4-a67d-48d9-98ee-58cbbc3d19f4@oracle.com> From: yangxingui In-Reply-To: <437c99f4-a67d-48d9-98ee-58cbbc3d19f4@oracle.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggpemm500002.china.huawei.com (7.185.36.229) To dggpemd100001.china.huawei.com (7.185.36.94) Hi, John, Thanks for your reply. On 2024/6/18 16:55, John Garry wrote: > On 13/06/2024 13:23, Xingui Yang wrote: > > Sorry for delay in responding and asking further questions. It doesn't matter. > >> We found that it is judged as broadcast flutter when the exp-attached end >> device reconnects after probe failed, as follows: >> >> [78779.654026] sas: broadcast received: 0 >> [78779.654037] sas: REVALIDATING DOMAIN on port 0, pid:10 >> [78779.654680] sas: ex 500e004aaaaaaa1f phy05 change count has changed >> [78779.662977] sas: ex 500e004aaaaaaa1f phy05 originated >> BROADCAST(CHANGE) >> [78779.662986] sas: ex 500e004aaaaaaa1f phy05 new device attached >> [78779.663079] sas: ex 500e004aaaaaaa1f phy05:U:8 attached: >> 500e004aaaaaaa05 (stp) >> [78779.693542] hisi_sas_v3_hw 0000:b4:02.0: dev[16:5] found >> [78779.701155] sas: done REVALIDATING DOMAIN on port 0, pid:10, res 0x0 >> [78779.707864] sas: Enter sas_scsi_recover_host busy: 0 failed: 0 >> ... >> [78835.161307] sas: --- Exit sas_scsi_recover_host: busy: 0 failed: 0 >> tries: 1 >> [78835.171344] sas: sas_probe_sata: for exp-attached device >> 500e004aaaaaaa05 returned -19 >> [78835.180879] hisi_sas_v3_hw 0000:b4:02.0: dev[16:5] is gone >> [78835.187487] sas: broadcast received: 0 >> [78835.187504] sas: REVALIDATING DOMAIN on port 0, pid:10 >> [78835.188263] sas: ex 500e004aaaaaaa1f phy05 change count has changed >> [78835.195870] sas: ex 500e004aaaaaaa1f phy05 originated >> BROADCAST(CHANGE) >> [78835.195875] sas: ex 500e004aaaaaaa1f rediscovering phy05 >> [78835.196022] sas: ex 500e004aaaaaaa1f phy05:U:A attached: >> 500e004aaaaaaa05 (stp) >> [78835.196026] sas: ex 500e004aaaaaaa1f phy05 broadcast flutter >> [78835.197615] sas: done REVALIDATING DOMAIN on port 0, pid:10, res 0x0 >> >> The cause of the problem is that the related ex_phy's >> attached_sas_addr was >> not cleared after the end device probe failed. In order to solve the >> above >> problem, a function sas_ex_unregister_end_dev() is defined to clear the >> ex_phy information and unregister the end device after the >> exp-attached end >> device probe failed. > > Can you just manually clear the ex_phy's attached_sas_addr at the > appropiate point (along with calling sas_unregister_dev())? It seems > that we are using heavy-handed approach in calling > sas_unregister_devs_sas_addr(), which does the clearing and much more. I just tried it and it worked. If we only clear ex_phy's attached_sas_addr, there is no need to call sas_destruct_ports(). We are currently using sas_unregister_devs_sas_addr() which will add the port to sas_port_del_list, so we need to call sas_destruct_ports() separately to delete the port. Should we also delete the port after the devices probe failed? Maybe I can update another version and only clear ex_phy's attached_sas_addr based on your suggestions. > >> >> As devices may probe failed after done REVALIDATING DOMAIN when call >> sas_probe_devices(). Then after its port is added to the >> sas_port_del_list, >> the port will not be deleted until the end of the next REVALIDATING >> DOMAIN >> and sas_destruct_ports() is called. A warning about creating a duplicate >> port will occur in the new REVALIDATING DOMAIN when the end device >> reconnects. Therefore, the previous destroy_list and sas_port_del_list >> should be handled after devices probe failed. >> >> Signed-off-by: Xingui Yang >> --- >> Changes since v2: >> - Add a helper for calling sas_destruct_devices() and >> sas_destruct_ports(), >>    and put the new call at the end of sas_probe_devices() based on John's >>    suggestion. >> >> Changes since v1: >> - Simplify the process of getting ex_phy id based on Jason's suggestion. >> - Update commit information. >> --- >>   drivers/scsi/libsas/sas_discover.c | 32 +++++++++++++++++++----------- >>   drivers/scsi/libsas/sas_expander.c |  8 ++++++++ >>   drivers/scsi/libsas/sas_internal.h |  6 +++++- >>   3 files changed, 33 insertions(+), 13 deletions(-) >> >> diff --git a/drivers/scsi/libsas/sas_discover.c >> b/drivers/scsi/libsas/sas_discover.c >> index 8fb7c41c0962..8c517e47d2b9 100644 >> --- a/drivers/scsi/libsas/sas_discover.c >> +++ b/drivers/scsi/libsas/sas_discover.c >> @@ -17,6 +17,22 @@ >>   #include >>   #include "scsi_sas_internal.h" >> +static void sas_destruct_ports(struct asd_sas_port *port) >> +{ >> +    struct sas_port *sas_port, *p; >> + >> +    list_for_each_entry_safe(sas_port, p, &port->sas_port_del_list, >> del_list) { >> +        list_del_init(&sas_port->del_list); >> +        sas_port_delete(sas_port); >> +    } >> +} >> + >> +static void sas_destruct_devices_and_ports(struct asd_sas_port *port) > > "and" in a function name never sounds right. > > Can you just call sas_destruct_port(), as it takes a port arg? Maybe > rename sas_destruct_ports() to sas_delete_ports(), as it does "delete" - > this may avoid some confusion in names. As described above, if we only clear ex_phy's attached_sas_addr, we do not need to call sas_destruct_ports(). Thanks, Xingui