Re: An oops will occur while SCSI core is being used in 3.4-rc1

[Bart Van Assche <bvanassche-HInyCGIudOg@public.gmane.org>]

On 04/11/12 16:40, Bart Van Assche wrote:

> On 04/11/12 16:10, Martin K. Petersen wrote:
>> index 377df4a..1e11985 100644
>> --- a/include/scsi/scsi_cmnd.h
>> +++ b/include/scsi/scsi_cmnd.h
>> @@ -134,6 +134,9 @@ struct scsi_cmnd {
>>  
>>  static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
>>  {
>> +	if (!cmd->request->rq_disk)
>> +		return NULL;
>> +
>>  	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
>>  }
> 
> What if the rq_disk pointer is cleared by another kernel thread after it
> has been checked but before it is used ?


(replying to my own e-mail)

That comment didn't make sense - request.rq_disk is not modified after
it has been initialized. Yet it would make me more happy if
scsi_send_eh_cmnd() could be modified such that it doesn't have to
access struct scsi_driver.

Bart.
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