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Commit 583024d2 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm thin: suspend/resume active thin devices when reloading thin-pool 



Before this change it was expected that userspace would first suspend
all active thin devices, reload/resize the thin-pool target, then resume
all active thin devices.  Now the thin-pool suspend/resume will trigger
the suspend/resume of all active thins via appropriate calls to
dm_internal_suspend and dm_internal_resume.

Store the mapped_device for each thin device in struct thin_c to make
these calls possible.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Acked-by: default avatarJoe Thornber <ejt@redhat.com>
parent ffcc3936

drivers/md/dm-thin.c

+38 −2
Original line number Diff line number Diff line
@@ -292,6 +292,8 @@ struct thin_c { 


	struct pool *pool;

	struct dm_thin_device *td;

	struct mapped_device *thin_md;



	bool requeue_mode:1;

	spinlock_t lock;

	struct list_head deferred_cells;
@@ -3113,19 +3115,48 @@ static int pool_preresume(struct dm_target *ti) 
	return 0;

}



static void pool_suspend_active_thins(struct pool *pool)

{

	struct thin_c *tc;



	/* Suspend all active thin devices */

	tc = get_first_thin(pool);

	while (tc) {

		dm_internal_suspend_noflush(tc->thin_md);

		tc = get_next_thin(pool, tc);

	}

}



static void pool_resume_active_thins(struct pool *pool)

{

	struct thin_c *tc;



	/* Resume all active thin devices */

	tc = get_first_thin(pool);

	while (tc) {

		dm_internal_resume(tc->thin_md);

		tc = get_next_thin(pool, tc);

	}

}



static void pool_resume(struct dm_target *ti)

{

	struct pool_c *pt = ti->private;

	struct pool *pool = pt->pool;

	unsigned long flags;



	/*

	 * Must requeue active_thins' bios and then resume

	 * active_thins _before_ clearing 'suspend' flag.

	 */

	requeue_bios(pool);

	pool_resume_active_thins(pool);



	spin_lock_irqsave(&pool->lock, flags);

	pool->low_water_triggered = false;

	pool->suspended = false;

	spin_unlock_irqrestore(&pool->lock, flags);



	requeue_bios(pool);



	do_waker(&pool->waker.work);

}
@@ -3138,6 +3169,8 @@ static void pool_presuspend(struct dm_target *ti) 
	spin_lock_irqsave(&pool->lock, flags);

	pool->suspended = true;

	spin_unlock_irqrestore(&pool->lock, flags);



	pool_suspend_active_thins(pool);

}



static void pool_presuspend_undo(struct dm_target *ti)
@@ -3146,6 +3179,8 @@ static void pool_presuspend_undo(struct dm_target *ti) 
	struct pool *pool = pt->pool;

	unsigned long flags;



	pool_resume_active_thins(pool);



	spin_lock_irqsave(&pool->lock, flags);

	pool->suspended = false;

	spin_unlock_irqrestore(&pool->lock, flags);
@@ -3703,6 +3738,7 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv) 
		r = -ENOMEM;

		goto out_unlock;

	}

	tc->thin_md = dm_table_get_md(ti->table);

	spin_lock_init(&tc->lock);

	INIT_LIST_HEAD(&tc->deferred_cells);

	bio_list_init(&tc->deferred_bio_list);