Re: [PATCH 6/7] btrfs: Don't BUG_ON alloc_path errors in find_next_chunk

[Tsutomu Itoh <t-itoh@jp.fujitsu.com>]

(2011/07/22 4:48), Mark Fasheh wrote:
> I also removed the BUG_ON from error return of find_next_chunk in
> init_first_rw_device(). It turns out that the only caller of
> init_first_rw_device() also BUGS on any nonzero return so no actual behavior
> change has occurred here.
> 
> do_chunk_alloc() also needed an update since it calls btrfs_alloc_chunk()
> which can now return -ENOMEM. Instead of setting space_info->full on any
> error from btrfs_alloc_chunk() I catch and return every error value _except_
> -ENOSPC. Thanks goes to Tsutomu Itoh for pointing that issue out.
> 
> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
> ---
>  fs/btrfs/extent-tree.c |    3 +++
>  fs/btrfs/volumes.c     |    6 ++++--
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index aa91773..ff339b2 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -3277,6 +3277,9 @@ again:
>  	}
>  
>  	ret = btrfs_alloc_chunk(trans, extent_root, flags);
> +	if (ret < 0 && ret != -ENOSPC)
> +		return ret;
> +

You need mutex_unlock() before return.

Thanks,
Tsutomu


>  	spin_lock(&space_info->lock);
>  	if (ret)
>  		space_info->full = 1;
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 530a2fc..90d956c 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -1037,7 +1037,8 @@ static noinline int find_next_chunk(struct btrfs_root *root,
>  	struct btrfs_key found_key;
>  
>  	path = btrfs_alloc_path();
> -	BUG_ON(!path);
> +	if (!path)
> +		return -ENOMEM;
>  
>  	key.objectid = objectid;
>  	key.offset = (u64)-1;
> @@ -2663,7 +2664,8 @@ static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
>  
>  	ret = find_next_chunk(fs_info->chunk_root,
>  			      BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
> -	BUG_ON(ret);
> +	if (ret)
> +		return ret;
>  
>  	alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
>  			(fs_info->metadata_alloc_profile &