Re: [PATCH V5] Save command pool address of Scsi_Host

[Hannes Reinecke]

On 08/04/2014 01:30 PM, jgross@xxxxxxxx wrote:
> From: Juergen Gross <jgross@xxxxxxxx>
>
> If a scsi host driver specifies .cmd_len in it's scsi_host_template, a driver's
> private command pool is needed. scsi_find_host_cmd_pool() will locate it, but
> scsi_alloc_host_cmd_pool() isn't saving the pool address in the host template.
>
> This will result in an access error when the host is removed.
>
> Avoid the problem by saving the address of a new allocated command pool where
> it is expected.
>
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> ---
>   drivers/scsi/scsi.c | 12 ++++++++++--
>   1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
> index 88d46fe..b0cef5b 100644
> --- a/drivers/scsi/scsi.c
> +++ b/drivers/scsi/scsi.c
> @@ -380,6 +380,10 @@ scsi_alloc_host_cmd_pool(struct Scsi_Host *shost)
>   		pool->slab_flags |= SLAB_CACHE_DMA;
>   		pool->gfp_mask = __GFP_DMA;
>   	}
> +
> +	if (hostt->cmd_size)
> +		hostt->cmd_pool = pool;
> +
>   	return pool;
>   }
>
> @@ -424,8 +428,10 @@ out:
>   out_free_slab:
>   	kmem_cache_destroy(pool->cmd_slab);
>   out_free_pool:
> -	if (hostt->cmd_size)
> +	if (hostt->cmd_size) {
>   		scsi_free_host_cmd_pool(pool);
> +		hostt->cmd_pool = NULL;
> +	}
>   	goto out;
>   }
>
> @@ -447,8 +453,10 @@ static void scsi_put_host_cmd_pool(struct Scsi_Host *shost)
>   	if (!--pool->users) {
>   		kmem_cache_destroy(pool->cmd_slab);
>   		kmem_cache_destroy(pool->sense_slab);
> -		if (hostt->cmd_size)
> +		if (hostt->cmd_size) {
>   			scsi_free_host_cmd_pool(pool);
> +			hostt->cmd_pool = NULL;
> +		}
>   	}
>   	mutex_unlock(&host_cmd_pool_mutex);
>   }
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke		      zSeries & Storage
hare@xxxxxxx			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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