1 files changed, 26 insertions, 4 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 9f0ff7187136..58f140bef999 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -72,6 +72,7 @@ static struct workqueue_struct *md_misc_wq;
 
 static int remove_and_add_spares(struct mddev *mddev,
                                  struct md_rdev *this);
+static void mddev_detach(struct mddev *mddev);
 
 /*
  * Default number of read corrections we'll attempt on an rdev
@@ -3372,6 +3373,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
 
         /* Looks like we have a winner */
         mddev_suspend(mddev);
+        mddev_detach(mddev);
         mddev->pers->stop(mddev);
 
         if (mddev->pers->sync_request == NULL &&
@@ -4928,18 +4930,17 @@ int md_run(struct mddev *mddev)
                        (unsigned long long)mddev->array_sectors / 2,
                        (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
                 err = -EINVAL;
-                mddev->pers->stop(mddev);
         }
         if (err == 0 && mddev->pers->sync_request &&
             (mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
                 err = bitmap_create(mddev);
-                if (err) {
+                if (err)
                         printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
                                mdname(mddev), err);
-                        mddev->pers->stop(mddev);
-                }
         }
         if (err) {
+                mddev_detach(mddev);
+                mddev->pers->stop(mddev);
                 module_put(mddev->pers->owner);
                 mddev->pers = NULL;
                 bitmap_destroy(mddev);
@@ -5112,9 +5113,30 @@ void md_stop_writes(struct mddev *mddev)
 }
 EXPORT_SYMBOL_GPL(md_stop_writes);
 
+static void mddev_detach(struct mddev *mddev)
+{
+        struct bitmap *bitmap = mddev->bitmap;
+        /* wait for behind writes to complete */
+        if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
+                printk(KERN_INFO "md:%s: behind writes in progress - waiting to stop.\n",
+                       mdname(mddev));
+                /* need to kick something here to make sure I/O goes? */
+                wait_event(bitmap->behind_wait,
+                           atomic_read(&bitmap->behind_writes) == 0);
+        }
+        if (mddev->pers->quiesce) {
+                mddev->pers->quiesce(mddev, 1);
+                mddev->pers->quiesce(mddev, 0);
+        }
+        md_unregister_thread(&mddev->thread);
+        if (mddev->queue)
+                blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+}
+
 static void __md_stop(struct mddev *mddev)
 {
         mddev->ready = 0;
+        mddev_detach(mddev);
         mddev->pers->stop(mddev);
         if (mddev->pers->sync_request && mddev->to_remove == NULL)
                 mddev->to_remove = &md_redundancy_group;