Re: [PATCH 3/4] scsi: core: put .shost_dev in failure path if host state becomes running

[Bart Van Assche <bvanassche@acm.org>]

On 6/2/21 6:30 AM, Ming Lei wrote:
> scsi_host_dev_release() only works around for us by freeing
> dev_name(&shost->shost_dev) when host state is SHOST_CREATED. After host
> state is changed to SHOST_RUNNING, scsi_host_dev_release() doesn't do
> that any more.
> 
> So fix the issue by put .shost_dev in failure path if host state becomes
> running, meantime move get_device(&shost->shost_gendev) before
> device_add(&shost->shost_dev), so that scsi_host_cls_release() can put
> this reference.
> 
> Reported-by: John Garry <john.garry@huawei.com>
> Cc: Bart Van Assche <bvanassche@acm.org>
> Cc: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
>  drivers/scsi/hosts.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
> index 796736e47764..7049844adb6b 100644
> --- a/drivers/scsi/hosts.c
> +++ b/drivers/scsi/hosts.c
> @@ -257,12 +257,11 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
>  
>  	device_enable_async_suspend(&shost->shost_dev);
>  
> +	get_device(&shost->shost_gendev);
>  	error = device_add(&shost->shost_dev);
>  	if (error)
>  		goto out_del_gendev;
>  
> -	get_device(&shost->shost_gendev);
> -
>  	if (shost->transportt->host_size) {
>  		shost->shost_data = kzalloc(shost->transportt->host_size,
>  					 GFP_KERNEL);
> @@ -300,6 +299,11 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
>   out_del_dev:
>  	device_del(&shost->shost_dev);
>   out_del_gendev:
> +	/*
> +	 * host state has become SHOST_RUNNING, so we have to release
> +	 * ->shost_dev explicitly
> +	 */
> +	put_device(&shost->shost_dev);
>  	device_del(&shost->shost_gendev);
>   out_disable_runtime_pm:
>  	device_disable_async_suspend(&shost->shost_gendev);

Shouldn't this change be merged into patch 2/4 since both patches touch
the same function? Anyway, this patch also looks good to me.

Bart.