1 files changed, 76 insertions, 39 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 63e632746d8a..f27c0f7c387e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2568,58 +2568,49 @@ static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
 	return ret;
 }
 
-static int btrfs_relocate_chunk(struct btrfs_root *root,
-			 u64 chunk_tree, u64 chunk_objectid,
-			 u64 chunk_offset)
+int btrfs_remove_chunk(struct btrfs_trans_handle *trans,
+		       struct btrfs_root *root, u64 chunk_offset)
 {
 	struct extent_map_tree *em_tree;
-	struct btrfs_root *extent_root;
-	struct btrfs_trans_handle *trans;
-	struct btrfs_device *device;
 	struct extent_map *em;
+	struct btrfs_root *extent_root = root->fs_info->extent_root;
 	struct map_lookup *map;
 	u64 dev_extent_len = 0;
-	int ret;
-	int i;
+	u64 chunk_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
+	u64 chunk_tree = root->fs_info->chunk_root->objectid;
+	int i, ret = 0;
 
+	/* Just in case */
 	root = root->fs_info->chunk_root;
-	extent_root = root->fs_info->extent_root;
 	em_tree = &root->fs_info->mapping_tree.map_tree;
 
-	ret = btrfs_can_relocate(extent_root, chunk_offset);
-	if (ret)
-		return -ENOSPC;
-
-	/* step one, relocate all the extents inside this chunk */
-	ret = btrfs_relocate_block_group(extent_root, chunk_offset);
-	if (ret)
-		return ret;
-
-	trans = btrfs_start_transaction(root, 0);
-	if (IS_ERR(trans)) {
-		ret = PTR_ERR(trans);
-		btrfs_std_error(root->fs_info, ret);
-		return ret;
-	}
-
-	/*
-	 * step two, delete the device extents and the
-	 * chunk tree entries
-	 */
 	read_lock(&em_tree->lock);
 	em = lookup_extent_mapping(em_tree, chunk_offset, 1);
 	read_unlock(&em_tree->lock);
 
-	BUG_ON(!em || em->start > chunk_offset ||
-	       em->start + em->len < chunk_offset);
+	if (!em || em->start > chunk_offset ||
+	    em->start + em->len < chunk_offset) {
+		/*
+		 * This is a logic error, but we don't want to just rely on the
+		 * user having built with ASSERT enabled, so if ASSERT doens't
+		 * do anything we still error out.
+		 */
+		ASSERT(0);
+		if (em)
+			free_extent_map(em);
+		return -EINVAL;
+	}
 	map = (struct map_lookup *)em->bdev;
 
 	for (i = 0; i < map->num_stripes; i++) {
-		device = map->stripes[i].dev;
+		struct btrfs_device *device = map->stripes[i].dev;
 		ret = btrfs_free_dev_extent(trans, device,
 					    map->stripes[i].physical,
 					    &dev_extent_len);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_abort_transaction(trans, root, ret);
+			goto out;
+		}
 
 		if (device->bytes_used > 0) {
 			lock_chunks(root);
@@ -2634,23 +2625,34 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 
 		if (map->stripes[i].dev) {
 			ret = btrfs_update_device(trans, map->stripes[i].dev);
-			BUG_ON(ret);
+			if (ret) {
+				btrfs_abort_transaction(trans, root, ret);
+				goto out;
+			}
 		}
 	}
 	ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
 			       chunk_offset);
-
-	BUG_ON(ret);
+	if (ret) {
+		btrfs_abort_transaction(trans, root, ret);
+		goto out;
+	}
 
 	trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
 
 	if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
 		ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
-		BUG_ON(ret);
+		if (ret) {
+			btrfs_abort_transaction(trans, root, ret);
+			goto out;
+		}
 	}
 
 	ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
-	BUG_ON(ret);
+	if (ret) {
+		btrfs_abort_transaction(trans, extent_root, ret);
+		goto out;
+	}
 
 	write_lock(&em_tree->lock);
 	remove_extent_mapping(em_tree, em);
@@ -2658,11 +2660,46 @@ static int btrfs_relocate_chunk(struct btrfs_root *root,
 
 	/* once for the tree */
 	free_extent_map(em);
+out:
 	/* once for us */
 	free_extent_map(em);
+	return ret;
+}
+
+static int btrfs_relocate_chunk(struct btrfs_root *root,
+			 u64 chunk_tree, u64 chunk_objectid,
+			 u64 chunk_offset)
+{
+	struct btrfs_root *extent_root;
+	struct btrfs_trans_handle *trans;
+	int ret;
+
+	root = root->fs_info->chunk_root;
+	extent_root = root->fs_info->extent_root;
+
+	ret = btrfs_can_relocate(extent_root, chunk_offset);
+	if (ret)
+		return -ENOSPC;
+
+	/* step one, relocate all the extents inside this chunk */
+	ret = btrfs_relocate_block_group(extent_root, chunk_offset);
+	if (ret)
+		return ret;
 
+	trans = btrfs_start_transaction(root, 0);
+	if (IS_ERR(trans)) {
+		ret = PTR_ERR(trans);
+		btrfs_std_error(root->fs_info, ret);
+		return ret;
+	}
+
+	/*
+	 * step two, delete the device extents and the
+	 * chunk tree entries
+	 */
+	ret = btrfs_remove_chunk(trans, root, chunk_offset);
 	btrfs_end_transaction(trans, root);
-	return 0;
+	return ret;
 }
 
 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)