Re: [PATCH 3/5] scsi: limit to set the host state

[Bart Van Assche]

On 3/24/23 18:17, Ye Bin wrote:
> From: Ye Bin <yebin10@xxxxxxxxxx>
>
> Now, we can set the host state with any value. Actually, it doesn't
> make sense. As previous patch introduce SHOST_BLOCKED state, set this
> state, it will blocking IO. So this patch limit to set the host with
> running/blocked state.
>
> Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
> ---
>   drivers/scsi/scsi_sysfs.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
> index b14f95ac594e..42c5936c7711 100644
> --- a/drivers/scsi/scsi_sysfs.c
> +++ b/drivers/scsi/scsi_sysfs.c
> @@ -203,6 +203,7 @@ store_shost_state(struct device *dev, struct device_attribute *attr,
>   	int i;
>   	struct Scsi_Host *shost = class_to_shost(dev);
>   	enum scsi_host_state state = 0;
> +	enum scsi_host_state old_state;
>   	unsigned long flags;
>   
>   	for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
> @@ -216,8 +217,13 @@ store_shost_state(struct device *dev, struct device_attribute *attr,
>   	if (!state)
>   		return -EINVAL;
>   
> +	if (state != SHOST_RUNNING && state != SHOST_BLOCKED)
> +		return -EINVAL;
> +
>   	spin_lock_irqsave(shost->host_lock, flags);
> -	if (scsi_host_set_state(shost, state)) {
> +	old_state = shost->shost_state;
> +	if ((old_state != SHOST_RUNNING && old_state != SHOST_BLOCKED) ||
> +	    scsi_host_set_state(shost, state)) {
>   		spin_unlock_irqrestore(shost->host_lock, flags);
>   		return -EINVAL;
>   	}

Please make sure that the "state != SHOST_RUNNING && state != 
SHOST_BLOCKED" check occurs only once and also that there is one 
spin_lock_irqsave() call in this function and only one 
spin_unlock_irqrestore() call.

Thanks,

Bart.