Btrfs: Add failure handling for read_sys_array

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/disk-io.c

@@ -1278,7 +1278,11 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	mutex_lock(&fs_info->fs_mutex);
 
 	ret = btrfs_read_sys_array(tree_root);
-	BUG_ON(ret);
+	if (ret) {
+		printk("btrfs: failed to read the system array on %s\n",
+		       sb->s_id);
+		goto fail_sys_array;
+	}
 
 	blocksize = btrfs_level_size(tree_root,
 				     btrfs_super_chunk_root_level(disk_super));
@@ -1335,8 +1339,9 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 fail_extent_root:
 	free_extent_buffer(extent_root->node);
 fail_tree_root:
-	mutex_unlock(&fs_info->fs_mutex);
 	free_extent_buffer(tree_root->node);
+fail_sys_array:
+	mutex_unlock(&fs_info->fs_mutex);
 fail_sb_buffer:
 	free_extent_buffer(fs_info->sb_buffer);
 	extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
@@ -1344,6 +1349,8 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 	iput(fs_info->btree_inode);
 fail:
 	close_all_devices(fs_info);
+	btrfs_mapping_tree_free(&fs_info->mapping_tree);
+
 	kfree(extent_root);
 	kfree(tree_root);
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)

fs/btrfs/volumes.c

@@ -1365,14 +1365,14 @@ int btrfs_read_sys_array(struct btrfs_root *root)
 	struct extent_buffer *sb = root->fs_info->sb_buffer;
 	struct btrfs_disk_key *disk_key;
 	struct btrfs_chunk *chunk;
-	struct btrfs_key key;
+	u8 *ptr;
+	unsigned long sb_ptr;
+	int ret = 0;
 	u32 num_stripes;
 	u32 array_size;
 	u32 len = 0;
-	u8 *ptr;
-	unsigned long sb_ptr;
 	u32 cur;
-	int ret;
+	struct btrfs_key key;
 
 	array_size = btrfs_super_sys_array_size(super_copy);
 
@@ -1397,17 +1397,19 @@ int btrfs_read_sys_array(struct btrfs_root *root)
 		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
 			chunk = (struct btrfs_chunk *)sb_ptr;
 			ret = read_one_chunk(root, &key, sb, chunk);
-			BUG_ON(ret);
+			if (ret)
+				break;
 			num_stripes = btrfs_chunk_num_stripes(sb, chunk);
 			len = btrfs_chunk_item_size(num_stripes);
 		} else {
-			BUG();
+			ret = -EIO;
+			break;
 		}
 		ptr += len;
 		sb_ptr += len;
 		cur += len;
 	}
-	return 0;
+	return ret;
 }
 
 int btrfs_read_chunk_tree(struct btrfs_root *root)