Re: [PATCH 1/2] Btrfs: fix OOPS of empty filesystem after balance

[liubo <liubo2009@cn.fujitsu.com>]

On 03/07/2011 10:13 AM, liubo wrote:
> btrfs will remove unused block groups after balance.
> When a empty filesystem is balanced, the block group with tag "DATA" may be
> dropped, and after umount and mount again, it will not find "DATA" space_info
> and lead to OOPS.
> So we initial the necessary space_infos(DATA, SYSTEM, METADATA) to avoid OOPS.
> 

Hi, Chirs,

These two fixes are for critical problems(one OOPS and one memory leak), so would
you please take some time to review them and check if they are ready for the next
git pull? 

Seems that you have been a lot busy these days. ;)

thanks,
liubo

> Reported-by: Daniel J Blueman <daniel.blueman@gmail.com>
> Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
> ---
>  fs/btrfs/ctree.h       |    1 +
>  fs/btrfs/disk-io.c     |    6 ++++++
>  fs/btrfs/extent-tree.c |   23 +++++++++++++++++++++++
>  3 files changed, 30 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 28188a7..49c50e5 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -2221,6 +2221,7 @@ int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
>  			       u64 num_bytes);
>  int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
>  			    struct btrfs_root *root, u64 type);
> +int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
>  
>  /* ctree.c */
>  int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 3e1ea3e..8bcdc62 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -1967,6 +1967,12 @@ struct btrfs_root *open_ctree(struct super_block *sb,
>  	fs_info->metadata_alloc_profile = (u64)-1;
>  	fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
>  
> +	ret = btrfs_init_space_info(fs_info);
> +	if (ret) {
> +		printk(KERN_ERR "Failed to initial space info: %d\n", ret);
> +		goto fail_block_groups;
> +	}
> +
>  	ret = btrfs_read_block_groups(extent_root);
>  	if (ret) {
>  		printk(KERN_ERR "Failed to read block groups: %d\n", ret);
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 100e409..08525ee 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -8714,6 +8714,29 @@ out:
>  	return ret;
>  }
>  
> +int btrfs_init_space_info(struct btrfs_fs_info *fs_info)
> +{
> +	struct btrfs_space_info *space_info;
> +	int ret;
> +
> +	ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM, 0, 0,
> +								 &space_info);
> +	if (ret)
> +		return ret;
> +
> +	ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA, 0, 0,
> +								 &space_info);
> +	if (ret)
> +		return ret;
> +
> +	ret = update_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA, 0, 0,
> +								 &space_info);
> +	if (ret)
> +		return ret;
> +
> +	return ret;
> +}
> +
>  int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
>  {
>  	return unpin_extent_range(root, start, end);