linux-kernel - Re: [PATCH v3 1/3] scsi: ufs: Fix task management request completion timeout

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b73ad496-1658-d587-146a-138ac8f522a9@acm.org>
Date:   Thu, 28 Jan 2021 19:22:45 -0800
From:   Bart Van Assche <bvanassche@....org>
To:     Can Guo <cang@...eaurora.org>, jaegeuk@...nel.org,
        asutoshd@...eaurora.org, nguyenb@...eaurora.org,
        hongwus@...eaurora.org, linux-scsi@...r.kernel.org,
        kernel-team@...roid.com
Cc:     Alim Akhtar <alim.akhtar@...sung.com>,
        Avri Altman <avri.altman@....com>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Stanley Chu <stanley.chu@...iatek.com>,
        Bean Huo <beanhuo@...ron.com>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 1/3] scsi: ufs: Fix task management request completion
 timeout

On 1/27/21 8:16 PM, Can Guo wrote:
> ufshcd_tmc_handler() calls blk_mq_tagset_busy_iter(fn = ufshcd_compl_tm()),
> but since blk_mq_tagset_busy_iter() only iterates over all reserved tags
> and requests which are not in IDLE state, ufshcd_compl_tm() never gets a
> chance to run. Thus, TMR always ends up with completion timeout. Fix it by
> calling blk_mq_start_request() in  __ufshcd_issue_tm_cmd().
> 
> Fixes: 69a6c269c097 ("scsi: ufs: Use blk_{get,put}_request() to allocate and free TMFs")
> 
> Signed-off-by: Can Guo <cang@...eaurora.org>
> ---
>  drivers/scsi/ufs/ufshcd.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 8da75e6..c0c5925 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -6395,6 +6395,7 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
>  
>  	spin_lock_irqsave(host->host_lock, flags);
>  	task_tag = hba->nutrs + free_slot;
> +	blk_mq_start_request(req);
>  
>  	treq->req_header.dword_0 |= cpu_to_be32(task_tag);

blk_mq_start_request() not only marks a request as in-flight but also
starts a timer. However, no timeout handler has been defined in
ufshcd_tmf_ops. Should a timeout handler be defined in that data structure?

Thanks,

Bart.