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: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index f1b53e3..e9e9584 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -292,6 +292,8 @@
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 @@
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 @@
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 @@
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 @@
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);