[PATCH] xfs: fix missing error check in xfs_rtfree_range

[Alex Elder]

Dave Chinner wrote:
> When xfs_rtfind_forw() returns an error, the block is returned
> uninitialised.  xfs_rtfree_range() is not checking the error return,
> so could be using an uninitialised block number for modifying bitmap
> summary info.
> 
> The problem was found by gcc when compiling the *userspace* libxfs
> code - it is an copy of the kernel code with the exact same bug.
> gcc gives an uninitialised variable warning on the userspace code
> but not on the kernel code. You gotta love the consistency (Mmmm,
> slightly chewy today!).

Looks good.  I'll send this for 2.6.33-rc4.

> Signed-off-by: Dave Chinner <david at fromorbit.com>

Reviewed-by: Alex Elder <aelder at sgi.com>


>  fs/xfs/xfs_rtalloc.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
> index 9e15a11..6be05f7 100644
> --- a/fs/xfs/xfs_rtalloc.c
> +++ b/fs/xfs/xfs_rtalloc.c
> @@ -1517,6 +1517,8 @@ xfs_rtfree_range(
>  	 */
>  	error = xfs_rtfind_forw(mp, tp, end, mp->m_sb.sb_rextents - 1,
>  		&postblock);
> +	if (error)
> +		return error;
>  	/*
>  	 * If there are blocks not being freed at the front of the
>  	 * old extent, add summary data for them to be allocated.