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Message-ID: <0ad818b10110c4c383afbc2c39235a4f7f17f4c7.camel@gmail.com>
Subject: Re: [PATCH 2/2] scsi: ufs: Protect PM ops and err_handler from user
 access through sysfs
From:   Bean Huo <huobean@gmail.com>
To:     Can Guo <cang@codeaurora.org>, asutoshd@codeaurora.org,
        nguyenb@codeaurora.org, hongwus@codeaurora.org,
        ziqichen@codeaurora.org, rnayak@codeaurora.org,
        linux-scsi@vger.kernel.org, kernel-team@android.com,
        saravanak@google.com, salyzyn@google.com
Cc:     Alim Akhtar <alim.akhtar@samsung.com>,
        Avri Altman <avri.altman@wdc.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>,
        Nitin Rawat <nitirawa@codeaurora.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Satya Tangirala <satyat@google.com>,
        open list <linux-kernel@vger.kernel.org>
Date:   Sun, 10 Jan 2021 17:18:05 +0100
In-Reply-To: <1609595975-12219-3-git-send-email-cang@codeaurora.org>
References: <1609595975-12219-1-git-send-email-cang@codeaurora.org>
         <1609595975-12219-3-git-send-email-cang@codeaurora.org>
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On Sat, 2021-01-02 at 05:59 -0800, Can Guo wrote:
> + * @shutting_down: flag to check if shutdown has been invoked
> + * @host_sem: semaphore used to serialize concurrent contexts
>   * @eh_wq: Workqueue that eh_work works on
>   * @eh_work: Worker to handle UFS errors that require s/w attention
>   * @eeh_work: Worker to handle exception events
> @@ -751,7 +753,8 @@ struct ufs_hba {
>         u32 intr_mask;
>         u16 ee_ctrl_mask;
>         bool is_powered;
> -       struct semaphore eh_sem;
> +       bool shutting_down;
> +       struct semaphore host_sem;
>  
>         /* Work Queues */
>         struct workqueue_struct *eh_wq;
> @@ -875,6 +878,11 @@ static inline bool ufshcd_is_wb_allowed(struct
> ufs_hba *hba)
>         return hba->caps & UFSHCD_CAP_WB_EN;
>  }
>  
> +static inline bool ufshcd_is_sysfs_allowed(struct ufs_hba *hba)
> +{
> +       return !hba->shutting_down;
> +}
> +


Can,

Instead adding new shutting_down flag, can we use availible variable
system_state?

Thanks,
Bean