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* [PATCH] dm raid: avoid mddev->suspended access
@ 2017-07-13 15:34 heinzm
  2017-07-25 18:17 ` Mike Snitzer
  0 siblings, 1 reply; 3+ messages in thread
From: heinzm @ 2017-07-13 15:34 UTC (permalink / raw)
  To: dm-devel; +Cc: heinzm

From: Heinz Mauelshagen <heinzm@redhat.com>

Use runtime flag to ensure that an mddev gets suspended/resumed just once.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
---
 drivers/md/dm-raid.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index b409015..60c524b 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -208,6 +208,7 @@ struct raid_dev {
 #define RT_FLAG_RS_BITMAP_LOADED	2
 #define RT_FLAG_UPDATE_SBS		3
 #define RT_FLAG_RESHAPE_RS		4
+#define RT_FLAG_RS_SUSPENDED		5
 
 /* Array elements of 64 bit needed for rebuild/failed disk bits */
 #define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
@@ -3169,6 +3170,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 
 	mddev_suspend(&rs->md);
+	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
 
 	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
 	if (rs_is_raid456(rs)) {
@@ -3626,7 +3628,7 @@ static void raid_postsuspend(struct dm_target *ti)
 {
 	struct raid_set *rs = ti->private;
 
-	if (!rs->md.suspended)
+	if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
 		mddev_suspend(&rs->md);
 
 	rs->md.ro = 1;
@@ -3760,7 +3762,7 @@ static int rs_start_reshape(struct raid_set *rs)
 		return r;
 
 	/* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */
-	if (mddev->suspended)
+	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
 		mddev_resume(mddev);
 
 	/*
@@ -3787,8 +3789,8 @@ static int rs_start_reshape(struct raid_set *rs)
 	}
 
 	/* Suspend because a resume will happen in raid_resume() */
-	if (!mddev->suspended)
-		mddev_suspend(mddev);
+	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
+	mddev_suspend(mddev);
 
 	/*
 	 * Now reshape got set up, update superblocks to
@@ -3884,7 +3886,7 @@ static void raid_resume(struct dm_target *ti)
 	if (!(rs->ctr_flags & RESUME_STAY_FROZEN_FLAGS))
 		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 
-	if (mddev->suspended)
+	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
 		mddev_resume(mddev);
 }
 
-- 
2.9.4

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: dm raid: avoid mddev->suspended access
  2017-07-13 15:34 [PATCH] dm raid: avoid mddev->suspended access heinzm
@ 2017-07-25 18:17 ` Mike Snitzer
  2017-07-25 18:29   ` Mike Snitzer
  0 siblings, 1 reply; 3+ messages in thread
From: Mike Snitzer @ 2017-07-25 18:17 UTC (permalink / raw)
  To: heinzm; +Cc: dm-devel

On Thu, Jul 13 2017 at 11:34am -0400,
heinzm@redhat.com <heinzm@redhat.com> wrote:

> From: Heinz Mauelshagen <heinzm@redhat.com>
> 
> Use runtime flag to ensure that an mddev gets suspended/resumed just once.
> 
> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
> ---
>  drivers/md/dm-raid.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
> index b409015..60c524b 100644
> --- a/drivers/md/dm-raid.c
> +++ b/drivers/md/dm-raid.c
> @@ -208,6 +208,7 @@ struct raid_dev {
>  #define RT_FLAG_RS_BITMAP_LOADED	2
>  #define RT_FLAG_UPDATE_SBS		3
>  #define RT_FLAG_RESHAPE_RS		4
> +#define RT_FLAG_RS_SUSPENDED		5
>  
>  /* Array elements of 64 bit needed for rebuild/failed disk bits */
>  #define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
> @@ -3169,6 +3170,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
>  	}
>  
>  	mddev_suspend(&rs->md);
> +	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
>  
>  	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
>  	if (rs_is_raid456(rs)) {
> @@ -3626,7 +3628,7 @@ static void raid_postsuspend(struct dm_target *ti)
>  {
>  	struct raid_set *rs = ti->private;
>  
> -	if (!rs->md.suspended)
> +	if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
>  		mddev_suspend(&rs->md);
>  
>  	rs->md.ro = 1;
> @@ -3760,7 +3762,7 @@ static int rs_start_reshape(struct raid_set *rs)
>  		return r;
>  
>  	/* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */
> -	if (mddev->suspended)
> +	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
>  		mddev_resume(mddev);
>  
>  	/*
> @@ -3787,8 +3789,8 @@ static int rs_start_reshape(struct raid_set *rs)
>  	}
>  
>  	/* Suspend because a resume will happen in raid_resume() */
> -	if (!mddev->suspended)
> -		mddev_suspend(mddev);
> +	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
> +	mddev_suspend(mddev);
>  
>  	/*
>  	 * Now reshape got set up, update superblocks to

Shouldn't this be the following?

if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
   mddev_suspend(mddev);

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: dm raid: avoid mddev->suspended access
  2017-07-25 18:17 ` Mike Snitzer
@ 2017-07-25 18:29   ` Mike Snitzer
  0 siblings, 0 replies; 3+ messages in thread
From: Mike Snitzer @ 2017-07-25 18:29 UTC (permalink / raw)
  To: heinzm; +Cc: dm-devel

On Tue, Jul 25 2017 at  2:17pm -0400,
Mike Snitzer <snitzer@redhat.com> wrote:

> On Thu, Jul 13 2017 at 11:34am -0400,
> heinzm@redhat.com <heinzm@redhat.com> wrote:
> 
> > From: Heinz Mauelshagen <heinzm@redhat.com>
> > 
> > Use runtime flag to ensure that an mddev gets suspended/resumed just once.
> > 
> > Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
> > ---
> >  drivers/md/dm-raid.c | 12 +++++++-----
> >  1 file changed, 7 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
> > index b409015..60c524b 100644
> > --- a/drivers/md/dm-raid.c
> > +++ b/drivers/md/dm-raid.c
> > @@ -3760,7 +3762,7 @@ static int rs_start_reshape(struct raid_set *rs)
> >  		return r;
> >  
> >  	/* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */
> > -	if (mddev->suspended)
> > +	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
> >  		mddev_resume(mddev);
> >  
> >  	/*
> > @@ -3787,8 +3789,8 @@ static int rs_start_reshape(struct raid_set *rs)
> >  	}
> >  
> >  	/* Suspend because a resume will happen in raid_resume() */
> > -	if (!mddev->suspended)
> > -		mddev_suspend(mddev);
> > +	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
> > +	mddev_suspend(mddev);
> >  
> >  	/*
> >  	 * Now reshape got set up, update superblocks to
> 
> Shouldn't this be the following?
> 
> if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
>    mddev_suspend(mddev);

Looking closer, the preceding test_and_clear_bit() should ensure that
the device is always resumed by the time it gets to the code I called
into question.

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2017-07-25 18:29 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2017-07-13 15:34 [PATCH] dm raid: avoid mddev->suspended access heinzm
2017-07-25 18:17 ` Mike Snitzer
2017-07-25 18:29   ` Mike Snitzer

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