diff mbox

[4/9] md: raid5 nowait support

Message ID 20170726235806.12148-5-rgoldwyn@suse.de (mailing list archive)
State New, archived
Headers show

Commit Message

Goldwyn Rodrigues July 26, 2017, 11:58 p.m. UTC
From: Goldwyn Rodrigues <rgoldwyn@suse.com>

Return EAGAIN in case RAID5 would block because of waiting due to:
 + Reshaping
 + Suspension
 + Stripe Expansion

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
---
 drivers/md/raid5.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

Comments

Shaohua Li Aug. 8, 2017, 8:43 p.m. UTC | #1
On Wed, Jul 26, 2017 at 06:58:01PM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@suse.com>
> 
> Return EAGAIN in case RAID5 would block because of waiting due to:
>  + Reshaping
>  + Suspension
>  + Stripe Expansion
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@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.

>  					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 majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
Goldwyn Rodrigues Aug. 9, 2017, 11:45 a.m. UTC | #2
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@suse.com>
>>
>> Return EAGAIN in case RAID5 would block because of waiting due to:
>>  + Reshaping
>>  + Suspension
>>  + Stripe Expansion
>>
>> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@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 majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

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;
+					}
 					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;