Re: [PATCH 1/2] scsi: ufs: Put SCSI host after remove it

From: cang@codeaurora.org
To: Bart Van Assche <bvanassche@acm.org>
Cc: asutoshd@codeaurora.org, nguyenb@codeaurora.org,
	rnayak@codeaurora.org, linux-scsi@vger.kernel.org,
	kernel-team@android.com, saravanak@google.com,
	salyzyn@google.com, Alim Akhtar <alim.akhtar@samsung.com>,
	Avri Altman <avri.altman@wdc.com>,
	Pedro Sousa <pedrom.sousa@synopsys.com>,
	"James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Stanley Chu <stanley.chu@mediatek.com>,
	Bean Huo <beanhuo@micron.com>,
	Venkat Gopalakrishnan <venkatg@codeaurora.org>,
	Tomas Winkler <tomas.winkler@intel.com>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] scsi: ufs: Put SCSI host after remove it
Date: Mon, 16 Dec 2019 11:12:53 +0800	[thread overview]
Message-ID: <0419d33a1ea98a2da9263131aba2ca71@codeaurora.org> (raw)
In-Reply-To: <5b77c25f-3cc7-f90b-fcd7-dd4c1e2f46d2@acm.org>

On 2019-12-16 10:39, Bart Van Assche wrote:
> On 2019-12-15 17:34, cang@codeaurora.org wrote:
>> This is applied to 5.5/scsi-queue. The two changes I patsed from you 
>> are
>> not merged yet, I am still doing code review to them, so there is no
>> blk_cleanup_queue() calls in my code base. I am just saying you may 
>> move
>> your blk_cleanup_queue() calls below cancel_work_sync(&hba->eh_work) 
>> if
>> my change applies. How do you think?
>> 
>> scsi_host_put() was there before but explicitly removed by
>> afa3dfd42d205b106787476647735aa1de1a5d02. I agree with you, without 
>> this
>> change, there is memory leak.
> 
> Hi Can,
> 
> Since your patch restores a call that was removed earlier, please
> consider adding a Fixes: tag to your patch.
> 
> Please also have a look at
> https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git/log/?h=5.6/scsi-queue.
> As one can see my patches that introduce blk_cleanup_queue() and
> blk_mq_free_tag_set() calls have already been queued on Martin's
> 5.6/scsi-queue branch.
> 
> Bart.

Hi Bart,

Sure, I will add the Fixes tag and rebase my changes. How about the 
logic
part of this change? Does it look good to you?

Sorry I was not aware of that your changes have been applied to 
5.6/scsi-queue.
I am still trying to get it tested on my setups...
Anyways, aside of hba->cmd_queue, tearing down hba->tmf_queue before
scsi_remove_host() may be problem too. Requests can still be
sent before and during scsi_remove_host(). If a request timed out,
task abort will be invoked to abort the request, during which
hba->tmf_queue is expected to be present. Please correct me if I am 
wrong.

Thanks,

Can Guo.