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 <rgoldwyn@xxxxxxxx>
>>
>> Return EAGAIN in case RAID5 would block because of waiting due to:
>> + Reshaping
>> + Suspension
>> + Stripe Expansion
>>
>> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
>> ---
>> 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
>>
>> --
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--
Goldwyn
--
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