1 files changed, 45 insertions, 10 deletions

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 64fd4de2986f..f1b53e31d868 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -224,6 +224,7 @@ struct pool {
 
         struct pool_features pf;
         bool low_water_triggered:1;     /* A dm event has been sent */
+        bool suspended:1;
 
         struct dm_bio_prison *prison;
         struct dm_kcopyd_client *copier;
@@ -2575,6 +2576,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
         INIT_LIST_HEAD(&pool->prepared_discards);
         INIT_LIST_HEAD(&pool->active_thins);
         pool->low_water_triggered = false;
+        pool->suspended = true;
 
         pool->shared_read_ds = dm_deferred_set_create();
         if (!pool->shared_read_ds) {
@@ -3119,12 +3121,36 @@ static void pool_resume(struct dm_target *ti)
 
         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);
 }
 
+static void pool_presuspend(struct dm_target *ti)
+{
+        struct pool_c *pt = ti->private;
+        struct pool *pool = pt->pool;
+        unsigned long flags;
+
+        spin_lock_irqsave(&pool->lock, flags);
+        pool->suspended = true;
+        spin_unlock_irqrestore(&pool->lock, flags);
+}
+
+static void pool_presuspend_undo(struct dm_target *ti)
+{
+        struct pool_c *pt = ti->private;
+        struct pool *pool = pt->pool;
+        unsigned long flags;
+
+        spin_lock_irqsave(&pool->lock, flags);
+        pool->suspended = false;
+        spin_unlock_irqrestore(&pool->lock, flags);
+}
+
 static void pool_postsuspend(struct dm_target *ti)
 {
         struct pool_c *pt = ti->private;
@@ -3592,6 +3618,8 @@ static struct target_type pool_target = {
         .ctr = pool_ctr,
         .dtr = pool_dtr,
         .map = pool_map,
+        .presuspend = pool_presuspend,
+        .presuspend_undo = pool_presuspend_undo,
         .postsuspend = pool_postsuspend,
         .preresume = pool_preresume,
         .resume = pool_resume,
@@ -3721,18 +3749,18 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
         if (get_pool_mode(tc->pool) == PM_FAIL) {
                 ti->error = "Couldn't open thin device, Pool is in fail mode";
                 r = -EINVAL;
-                goto bad_thin_open;
+                goto bad_pool;
         }
 
         r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
         if (r) {
                 ti->error = "Couldn't open thin internal device";
-                goto bad_thin_open;
+                goto bad_pool;
         }
 
         r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
         if (r)
-                goto bad_target_max_io_len;
+                goto bad;
 
         ti->num_flush_bios = 1;
         ti->flush_supported = true;
@@ -3747,14 +3775,16 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
                 ti->split_discard_bios = true;
         }
 
-        dm_put(pool_md);
-
         mutex_unlock(&dm_thin_pool_table.mutex);
 
-        atomic_set(&tc->refcount, 1);
-        init_completion(&tc->can_destroy);
-
         spin_lock_irqsave(&tc->pool->lock, flags);
+        if (tc->pool->suspended) {
+                spin_unlock_irqrestore(&tc->pool->lock, flags);
+                mutex_lock(&dm_thin_pool_table.mutex); /* reacquire for __pool_dec */
+                ti->error = "Unable to activate thin device while pool is suspended";
+                r = -EINVAL;
+                goto bad;
+        }
         list_add_tail_rcu(&tc->list, &tc->pool->active_thins);
         spin_unlock_irqrestore(&tc->pool->lock, flags);
         /*
@@ -3765,11 +3795,16 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)
          */
         synchronize_rcu();
 
+        dm_put(pool_md);
+
+        atomic_set(&tc->refcount, 1);
+        init_completion(&tc->can_destroy);
+
         return 0;
 
-bad_target_max_io_len:
+bad:
         dm_pool_close_thin_device(tc->td);
-bad_thin_open:
+bad_pool:
         __pool_dec(tc->pool);
 bad_pool_lookup:
         dm_put(pool_md);