Re: [PATCH] usb: uas: wait for pending commands before unbinding

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] usb: uas: pass &shost->host_lock pointer in uas_pre_disconnect()
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commit 8e251b22758d30ff0f9e6d2743bdddf6dd61fc28
Author: Jiayi Li <lijiayi@kylinos.cn>

usb: uas: wait for pending commands before unbinding

This commit enables soft_unbind on the uas driver and introduces
uas_pre_disconnect() to block new SCSI requests and wait for pending
commands and URBs to complete before unbinding.

> diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
> index 8655edbd66b16..4ece8f15bd170 100644
> --- a/drivers/usb/storage/uas.c
> +++ b/drivers/usb/storage/uas.c

[ ... ]

> @@ -1211,16 +1212,55 @@ static int uas_reset_resume(struct usb_interface *intf)
>  	return 0;
>  }
>  
> +static void uas_pre_disconnect(struct usb_interface *intf)
> +{
> +	struct Scsi_Host *shost = usb_get_intfdata(intf);
> +	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
> +	unsigned long flags, start_time;
> +
> +	spin_lock_irqsave(shost->host_lock, flags);
> +	scsi_block_requests(shost);
> +	spin_unlock_irqrestore(shost->host_lock, flags);

[Severity: Low]
In uas_pre_disconnect() in drivers/usb/storage/uas.c, shost->host_lock is
passed by value to spin_lock_irqsave() and spin_unlock_irqrestore(), which
causes a build failure when CONFIG_USB_UAS is enabled.

In struct Scsi_Host (include/scsi/scsi_host.h), host_lock is an embedded
spinlock_t rather than a pointer (changed in commit e83b47309f73 ("scsi:
core: Drop Scsi_Host.default_lock")):

    struct Scsi_Host {
        ...
        spinlock_t		host_lock;

Other callers in drivers/usb/storage/uas.c, such as uas_reset_resume(), pass
&shost->host_lock:

    spin_lock_irqsave(&shost->host_lock, flags);
    scsi_report_bus_reset(shost, 0);
    spin_unlock_irqrestore(&shost->host_lock, flags);

Should uas_pre_disconnect() pass &shost->host_lock here as well?

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261022123401.319479-1-lijiayi@kylinos.cn?part=1