1 files changed, 30 insertions, 3 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 35bb2d4..2854c82 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -684,6 +684,12 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 		__btrfs_close_devices(fs_devices);
 		free_fs_devices(fs_devices);
 	}
+	/*
+	 * Wait for rcu kworkers under __btrfs_close_devices
+	 * to finish all blkdev_puts so device is really
+	 * free when umount is done.
+	 */
+	rcu_barrier();
 	return ret;
 }
 
@@ -2379,7 +2385,11 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 		return ret;
 
 	trans = btrfs_start_transaction(root, 0);
-	BUG_ON(IS_ERR(trans));
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		btrfs_std_error(root->fs_info, ret);
+		return ret;
+	}
 
 	lock_chunks(root);
 
@@ -3050,7 +3060,8 @@ static void __cancel_balance(struct btrfs_fs_info *fs_info)
 
 	unset_balance_control(fs_info);
 	ret = del_balance_item(fs_info->tree_root);
-	BUG_ON(ret);
+	if (ret)
+		btrfs_std_error(fs_info, ret);
 
 	atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
 }
@@ -3230,6 +3241,11 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
 		update_ioctl_balance_args(fs_info, 0, bargs);
 	}
 
+	if ((ret && ret != -ECANCELED && ret != -ENOSPC) ||
+	    balance_need_close(fs_info)) {
+		__cancel_balance(fs_info);
+	}
+
 	wake_up(&fs_info->balance_wait_q);
 
 	return ret;
@@ -4919,7 +4935,18 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 	em = lookup_extent_mapping(em_tree, chunk_start, 1);
 	read_unlock(&em_tree->lock);
 
-	BUG_ON(!em || em->start != chunk_start);
+	if (!em) {
+		printk(KERN_ERR "btrfs: couldn't find em for chunk %Lu\n",
+		       chunk_start);
+		return -EIO;
+	}
+
+	if (em->start != chunk_start) {
+		printk(KERN_ERR "btrfs: bad chunk start, em=%Lu, wanted=%Lu\n",
+		       em->start, chunk_start);
+		free_extent_map(em);
+		return -EIO;
+	}
 	map = (struct map_lookup *)em->bdev;
 
 	length = em->len;