On 08/08/2017 03:43 PM, Shaohua Li wrote:
> On Wed, Jul 26, 2017 at 06:58:01PM -0500, Goldwyn Rodrigues wrote:
>> From: Goldwyn Rodrigues <rgold...@suse.com>
>>
>> Return EAGAIN in case RAID5 would block because of waiting due to:
>>  + Reshaping
>>  + Suspension
>>  + Stripe Expansion
>>
>> Signed-off-by: Goldwyn Rodrigues <rgold...@suse.com>
>> ---
>>  drivers/md/raid5.c | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>
>> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
>> index aeeb8d6854e2..d1b3bcf26d29 100644
>> --- a/drivers/md/raid5.c
>> +++ b/drivers/md/raid5.c
>> @@ -5635,6 +5635,11 @@ static bool raid5_make_request(struct mddev *mddev, 
>> struct bio * bi)
>>                                  ? logical_sector < conf->reshape_safe
>>                                  : logical_sector >= conf->reshape_safe) {
>>                                      spin_unlock_irq(&conf->device_lock);
>> +                                    if (bi->bi_opf & REQ_NOWAIT) {
>> +                                            bio_wouldblock_error(bi);
>> +                                            
>> finish_wait(&conf->wait_for_overlap, &w);
>> +                                            return true;
>> +                                    }
> 
> A bio could use several stripes. If one stripe block, simpliy return bio here
> doesn't really make the whole bio finish.

My understanding is a little weak here.
How would you have to terminate the entire bio since one of the stripes
is blocking?

> 
>>                                      schedule();
>>                                      do_prepare = true;
>>                                      goto retry;
>> @@ -5672,6 +5677,11 @@ static bool raid5_make_request(struct mddev *mddev, 
>> struct bio * bi)
>>                              spin_unlock_irq(&conf->device_lock);
>>                              if (must_retry) {
>>                                      raid5_release_stripe(sh);
>> +                                    if (bi->bi_opf & REQ_NOWAIT) {
>> +                                            bio_wouldblock_error(bi);
>> +                                            
>> finish_wait(&conf->wait_for_overlap, &w);
>> +                                            return true;
>> +                                    }
>>                                      schedule();
>>                                      do_prepare = true;
>>                                      goto retry;
>> @@ -5700,6 +5710,11 @@ static bool raid5_make_request(struct mddev *mddev, 
>> struct bio * bi)
>>                                      sigset_t full, old;
>>                                      sigfillset(&full);
>>                                      sigprocmask(SIG_BLOCK, &full, &old);
>> +                                    if (bi->bi_opf & REQ_NOWAIT) {
>> +                                            bio_wouldblock_error(bi);
>> +                                            
>> finish_wait(&conf->wait_for_overlap, &w);
>> +                                            return true;
>> +                                    }
>>                                      schedule();
>>                                      sigprocmask(SIG_SETMASK, &old, NULL);
>>                                      do_prepare = true;
>> @@ -5715,6 +5730,11 @@ static bool raid5_make_request(struct mddev *mddev, 
>> struct bio * bi)
>>                               */
>>                              md_wakeup_thread(mddev->thread);
>>                              raid5_release_stripe(sh);
>> +                            if (bi->bi_opf & REQ_NOWAIT) {
>> +                                    bio_wouldblock_error(bi);
>> +                                    finish_wait(&conf->wait_for_overlap, 
>> &w);
>> +                                    return true;
>> +                            }
>>                              schedule();
>>                              do_prepare = true;
>>                              goto retry;
>> -- 
>> 2.12.3
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>> the body of a message to majord...@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
Goldwyn

Reply via email to