Re: [PATCH 1/1] md: Do only necessary operations when adding device to RO array

Re: [PATCH 1/1] md: Do only necessary operations when adding device to RO array

[NeilBrown]

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On Fri, 30 May 2014 13:17:14 +0000 "Baldysiak, Pawel"
<pawel.baldysiak@intel.com> wrote:

> Commit 8313b8e57f55b15e5b7f7fc5d1630bbf686a9a97 changed
> way of adding device to read-only array. Used routine
> md_reap_sync_thread() which also trigger finish_reshape(),
> can break reshape process, if it was restarted.

Exactly how can it break?

This is probably fixed by a couple of patches in my for-next branch which I
will be sending to Linus shortly.

NeilBrown


> This part of function should do only necessary operations, that is:
> 1) call ->spare_active
> 2) clear saved_raid_disk if array is no longer degraded
> 
> Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
> Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
> 
> ---
> drivers/md/md.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 237b7e0..cf073de2 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -7820,11 +7820,13 @@ void md_check_recovery(struct mddev *mddev)
>                                                 * As we only add devices that are already in-sync,
>                                                 * we can activate the spares immediately.
>                                                 */
> +                                             struct md_rdev *rdev;
>                                                remove_and_add_spares(mddev, NULL);
> -                                              /* There is no thread, but we need to call
> -                                              * ->spare_active and clear saved_raid_disk
> -                                              */
> -                                              md_reap_sync_thread(mddev);
> +                                             mddev->pers->spare_active(mddev);
> +                                             rdev_for_each(rdev, mddev)
> +                                                             if (!mddev->degraded ||
> +                                                                 test_bit(In_sync, &rdev->flags))
> +                                                                             rdev->saved_raid_disk = -1;
>                                                clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
>                                                goto unlock;
>                                }
> --
> 1.9.0


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RE: [PATCH 1/1] md: Do only necessary operations when adding device to RO array

[Baldysiak, Pawel]

> On Monday, June 02, 2014 4:34 AM NeilBrown Wrote:
> To: Baldysiak, Pawel
> Cc: linux-raid@vger.kernel.org; linux-kernel@vger.kernel.org; Paszkiewicz,
> Artur
> Subject: Re: [PATCH 1/1] md: Do only necessary operations when adding
> device to RO array
> 
> On Fri, 30 May 2014 13:17:14 +0000 "Baldysiak, Pawel"
> <pawel.baldysiak@intel.com> wrote:
> 
> > Commit 8313b8e57f55b15e5b7f7fc5d1630bbf686a9a97 changed way of
> adding
> > device to read-only array. Used routine
> > md_reap_sync_thread() which also trigger finish_reshape(), can break
> > reshape process, if it was restarted.
> 
> Exactly how can it break?
> 
> This is probably fixed by a couple of patches in my for-next branch which I will
> be sending to Linus shortly.
> 
> NeilBrown
> 
 
Hi Neil, 
I have checked your patches from "for-next", and this issue is fixed.
Reshape process is continued correctly after restart.
Thanks!

Pawel Baldysiak

> > This part of function should do only necessary operations, that is:
> > 1) call ->spare_active
> > 2) clear saved_raid_disk if array is no longer degraded
> >
> > Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
> > Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
> >
> > ---
> > drivers/md/md.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/md/md.c b/drivers/md/md.c index 237b7e0..cf073de2
> > 100644
> > --- a/drivers/md/md.c
> > +++ b/drivers/md/md.c
> > @@ -7820,11 +7820,13 @@ void md_check_recovery(struct mddev
> *mddev)
> >                                                 * As we only add devices that are already in-sync,
> >                                                 * we can activate the spares immediately.
> >                                                 */
> > +                                             struct md_rdev *rdev;
> >                                                remove_and_add_spares(mddev, NULL);
> > -                                              /* There is no thread, but we need to call
> > -                                              * ->spare_active and clear saved_raid_disk
> > -                                              */
> > -                                              md_reap_sync_thread(mddev);
> > +                                             mddev->pers->spare_active(mddev);
> > +                                             rdev_for_each(rdev, mddev)
> > +                                                             if (!mddev->degraded ||
> > +                                                                 test_bit(In_sync, &rdev->flags))
> > +
> > + rdev->saved_raid_disk = -1;
> >                                                clear_bit(MD_RECOVERY_NEEDED, &mddev-
> >recovery);
> >                                                goto unlock;
> >                                }
> > --
> > 1.9.0

[PATCH 1/1] md: Do only necessary operations when adding device to RO array

[Baldysiak, Pawel]

Commit 8313b8e57f55b15e5b7f7fc5d1630bbf686a9a97 changed
way of adding device to read-only array. Used routine
md_reap_sync_thread() which also trigger finish_reshape(),
can break reshape process, if it was restarted.
This part of function should do only necessary operations, that is:
1) call ->spare_active
2) clear saved_raid_disk if array is no longer degraded

Signed-off-by: Pawel Baldysiak <pawel.baldysiak@intel.com>
Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>

---
drivers/md/md.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 237b7e0..cf073de2 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7820,11 +7820,13 @@ void md_check_recovery(struct mddev *mddev)
                                                * As we only add devices that are already in-sync,
                                                * we can activate the spares immediately.
                                                */
+                                             struct md_rdev *rdev;
                                               remove_and_add_spares(mddev, NULL);
-                                              /* There is no thread, but we need to call
-                                              * ->spare_active and clear saved_raid_disk
-                                              */
-                                              md_reap_sync_thread(mddev);
+                                             mddev->pers->spare_active(mddev);
+                                             rdev_for_each(rdev, mddev)
+                                                             if (!mddev->degraded ||
+                                                                 test_bit(In_sync, &rdev->flags))
+                                                                             rdev->saved_raid_disk = -1;
                                               clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                                               goto unlock;
                               }
-- 
1.9.0