Commit 19c4d2f9 authored by Chris Mason's avatar Chris Mason
Browse files

Revert "btrfs: let btrfs_delete_unused_bgs() to clean relocated bgs" 



This reverts commit 5d8eb6fe.

When we remove devices, we free the device structures.  Delaying
btfs_remove_chunk() ends up hitting a use-after-free on them.

Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 196e0249

fs/btrfs/extent-tree.c

+1 −1
Original line number Diff line number Diff line
@@ -10849,7 +10849,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) 
		spin_lock(&block_group->lock);

		if (block_group->reserved ||

		    btrfs_block_group_used(&block_group->item) ||

		    (block_group->ro && !block_group->removed) ||

		    block_group->ro ||

		    list_is_singular(&block_group->list)) {

			/*

			 * We want to bail if we made new allocations or have

fs/btrfs/volumes.c

+14 −10
Original line number Diff line number Diff line
@@ -2906,8 +2906,8 @@ int btrfs_remove_chunk(struct btrfs_trans_handle *trans, 
static int btrfs_relocate_chunk(struct btrfs_root *root, u64 chunk_offset)

{

	struct btrfs_root *extent_root;

	struct btrfs_trans_handle *trans;

	int ret;

	struct btrfs_block_group_cache *block_group;



	root = root->fs_info->chunk_root;

	extent_root = root->fs_info->extent_root;
@@ -2937,17 +2937,21 @@ static int btrfs_relocate_chunk(struct btrfs_root *root, u64 chunk_offset) 
	if (ret)

		return ret;



	trans = btrfs_start_trans_remove_block_group(root->fs_info,

						     chunk_offset);

	if (IS_ERR(trans)) {

		ret = PTR_ERR(trans);

		btrfs_handle_fs_error(root->fs_info, ret, NULL);

		return ret;

	}



	/*

	 * step two, flag the chunk as removed and let

	 * btrfs_delete_unused_bgs() remove it.

	 * step two, delete the device extents and the

	 * chunk tree entries

	 */

	block_group = btrfs_lookup_block_group(root->fs_info, chunk_offset);

	spin_lock(&block_group->lock);

	block_group->removed = 1;

	spin_unlock(&block_group->lock);

	btrfs_put_block_group(block_group);



	return 0;

	ret = btrfs_remove_chunk(trans, root, chunk_offset);

	btrfs_end_transaction(trans, extent_root);

	return ret;

}



static int btrfs_relocate_sys_chunks(struct btrfs_root *root)