Merge tag 'pci-v3.16-changes-2' of git://git.kernel.org/pub/scm/linux/kernel/git...

[karo-tx-linux.git] / drivers / md / dm-thin.c

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 13abade76ad9bbd65c83c67d35f075506b17b63f..242ac2ea5f295c0bf2ad2db85fdd86812936851d 100644 (file)
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -27,6 +27,9 @@
 #define MAPPING_POOL_SIZE 1024
 #define PRISON_CELLS 1024
 #define COMMIT_PERIOD HZ
+#define NO_SPACE_TIMEOUT_SECS 60
+
+static unsigned no_space_timeout_secs = NO_SPACE_TIMEOUT_SECS;
 
 DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
                "A percentage of time allocated for copy on write");
@@ -175,6 +178,7 @@ 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;
@@ -935,7 +939,7 @@ static int commit(struct pool *pool)
 {
        int r;
 
-       if (get_pool_mode(pool) != PM_WRITE)
+       if (get_pool_mode(pool) >= PM_READ_ONLY)
                return -EINVAL;
 
        r = dm_pool_commit_metadata(pool->pmd);
@@ -1590,6 +1594,20 @@ 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 {
@@ -1654,6 +1672,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
        struct pool_c *pt = pool->ti->private;
        bool needs_check = dm_pool_metadata_needs_check(pool->pmd);
        enum pool_mode old_mode = get_pool_mode(pool);
+       unsigned long no_space_timeout = ACCESS_ONCE(no_space_timeout_secs) * HZ;
 
        /*
         * Never allow the pool to transition to PM_WRITE mode if user
@@ -1715,6 +1734,9 @@ 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 && no_space_timeout)
+                       queue_delayed_work(pool->wq, &pool->no_space_timeout, no_space_timeout);
                break;
 
        case PM_WRITE:
@@ -2100,6 +2122,7 @@ 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 +2685,7 @@ 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);
 }
@@ -3487,6 +3511,9 @@ static void dm_thin_exit(void)
 module_init(dm_thin_init);
 module_exit(dm_thin_exit);
 
+module_param_named(no_space_timeout, no_space_timeout_secs, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(no_space_timeout, "Out of data space queue IO timeout in seconds");
+
 MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
 MODULE_LICENSE("GPL");