From: dingxiang <dingxiang@huawei.com>
To: Tejun Heo <tj@kernel.org>, Dan Williams <dan.j.williams@intel.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
<jejb@linux.vnet.ibm.com>, Wei Fang <fangwei1@huawei.com>,
<miaoxie@huawei.com>, <wangyijing@huawei.com>,
<zhangaihua1@huawei.com>, <zhaohongjiang@huawei.com>,
<houtao1@huawei.com>, linux-scsi <linux-scsi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH V2 resend] libata:fix kernel panic when hotplug
Date: Wed, 22 Jun 2016 14:46:24 +0800 [thread overview]
Message-ID: <576A3440.9090803@huawei.com> (raw)
In-Reply-To: <20160621154700.GH3262@mtj.duckdns.org>
Hi,All
> Hello,
>
> On Mon, Jun 20, 2016 at 06:46:55PM -0700, Dan Williams wrote:
>> On Mon, Jun 20, 2016 at 6:22 PM, Martin K. Petersen
>> <martin.petersen@oracle.com> wrote:
>>>>>>>> "Tejun" == Tejun Heo <tj@kernel.org> writes:
>>>>> In fact,we don't need libata to deal with hotplug in sas environment.
>>>>> So we can't run ata hotplug task when ata port is sas host.
>>> Tejun> Martin, can you please confirm whether the above is true. If so,
>>> Tejun> I'll route the patch through libata w/ stable cc'd.
>>>
>>> Not exactly a libsas expert. James? Dan?
>> While it is true that libsas itself handles adding / removing devices
>> we have historically avoided this conflict because
>> ATA_PFLAG_SCSI_HOTPLUG is never set for libsas ata_ports. So the bug
>> / behavior change is that ATA_PFLAG_SCSI_HOTPLUG gets set in the
>> first place. Ignoring it is a band-aid / not the real fix afaics.
> I see. I'll hold off for now then. Ding Xiang, can you find out
> where that flag is getting set?
>
> Thanks!
There are two places will set flag ATA_PFLAG_SCSI_HOTPLUG in libata-eh.c.
I think both places should be protected. Here is the suggestion.
Thanks~
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 61dc7a9..2bee041 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1385,7 +1385,8 @@ void ata_eh_detach_dev(struct ata_device *dev)
if (ata_scsi_offline_dev(dev)) {
dev->flags |= ATA_DFLAG_DETACHED;
- ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
+ if (!(ap->pflags & ATA_FLAG_SAS_HOST))
+ ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
}
/* clear per-dev EH info */
@@ -3299,7 +3300,8 @@ static int ata_eh_revalidate_and_attach(struct
ata_link *link,
}
spin_lock_irqsave(ap->lock, flags);
- ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
+ if (!(ap->pflags & ATA_FLAG_SAS_HOST))
+ ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
spin_unlock_irqrestore(ap->lock, flags);
/* new device discovered, configure xfermode */
prev parent reply other threads:[~2016-06-22 6:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-16 4:45 [PATCH V2 resend] libata:fix kernel panic when hotplug DingXiang
2016-06-16 20:20 ` Tejun Heo
2016-06-21 1:22 ` Martin K. Petersen
2016-06-21 1:46 ` Dan Williams
2016-06-21 15:47 ` Tejun Heo
2016-06-22 6:46 ` dingxiang [this message]
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