Re: [PATCH v6 10/13] Make scsi_remove_host() wait for device removal

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

On 12/03/12 17:42, Tejun Heo wrote:
> On Mon, Dec 03, 2012 at 05:38:52PM +0100, Bart Van Assche wrote:
>> It is indeed possible to invoke complete() only if the device list
>> became empty with the host state equal to SHOST_CANCEL,
>> SHOST_CANCEL_RECOVERY, SHOST_DEL or SHOST_DEL_RECOVERY and in
>
> We can test this with !scsi_host_scan_allowed(), right?
>
>> scsi_remove_host() to wait for that completion only if the device
>> list was not empty before the host state was changed into one of the
>> four mentioned states. Do you really prefer this approach over the
>> approach in the patch at the start of this thread ?
>
> Maybe I'm missing something but if possible completion tends to be
> much simpler than using waitqueue directly.  I *think* that's the case
> here.  Am I missing something?

Hello Tejun,

You are right that it should be possible to use a completion in this 
context instead of a wait queue. However, I'm not enthusiast about using 
a completion for this patch because it would mean introducing several 
additional if-statements. Such if-statements would make this patch even 
harder to test then it already is now.

Note: all your other review comments should have been addressed in v7 of 
this patch series.

Bart.