1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 15f748ba6754..2e71de8e0048 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -27,6 +27,7 @@
 #define MAPPING_POOL_SIZE 1024
 #define PRISON_CELLS 1024
 #define COMMIT_PERIOD HZ
+#define NO_SPACE_TIMEOUT (HZ * 60)
 
 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
                 "A percentage of time allocated for copy on write");
@@ -175,6 +176,7 @@ struct pool {
         struct workqueue_struct *wq;
         struct work_struct worker;
         struct delayed_work waker;
+        struct delayed_work no_space_timeout;
 
         unsigned long last_commit_jiffies;
         unsigned ref_count;
@@ -1590,6 +1592,20 @@ static void do_waker(struct work_struct *ws)
         queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD);
 }
 
+/*
+ * We're holding onto IO to allow userland time to react.  After the
+ * timeout either the pool will have been resized (and thus back in
+ * PM_WRITE mode), or we degrade to PM_READ_ONLY and start erroring IO.
+ */
+static void do_no_space_timeout(struct work_struct *ws)
+{
+        struct pool *pool = container_of(to_delayed_work(ws), struct pool,
+                                         no_space_timeout);
+
+        if (get_pool_mode(pool) == PM_OUT_OF_DATA_SPACE && !pool->pf.error_if_no_space)
+                set_pool_mode(pool, PM_READ_ONLY);
+}
+
 /*----------------------------------------------------------------*/
 
 struct noflush_work {
@@ -1715,6 +1731,9 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
                 pool->process_discard = process_discard;
                 pool->process_prepared_mapping = process_prepared_mapping;
                 pool->process_prepared_discard = process_prepared_discard_passdown;
+
+                if (!pool->pf.error_if_no_space)
+                        queue_delayed_work(pool->wq, &pool->no_space_timeout, NO_SPACE_TIMEOUT);
                 break;
 
         case PM_WRITE:
@@ -2100,6 +2119,7 @@ static struct pool *pool_create(struct mapped_device *pool_md,
 
         INIT_WORK(&pool->worker, do_worker);
         INIT_DELAYED_WORK(&pool->waker, do_waker);
+        INIT_DELAYED_WORK(&pool->no_space_timeout, do_no_space_timeout);
         spin_lock_init(&pool->lock);
         bio_list_init(&pool->deferred_flush_bios);
         INIT_LIST_HEAD(&pool->prepared_mappings);
@@ -2662,6 +2682,7 @@ static void pool_postsuspend(struct dm_target *ti)
         struct pool *pool = pt->pool;
 
         cancel_delayed_work(&pool->waker);
+        cancel_delayed_work(&pool->no_space_timeout);
         flush_workqueue(pool->wq);
         (void) commit(pool);
 }