Re: [PATCH] xfs: fix directory readahead offset off-by-one

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

On Tue, May 06, 2014 at 01:42:08PM +1000, Dave Chinner wrote:
> Fix the warning by ensuring that the readahead offset is correctly
> incremented.
> 
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
>  fs/xfs/xfs_dir2_readdir.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_dir2_readdir.c b/fs/xfs/xfs_dir2_readdir.c
> index 50b72f7..fe2db98 100644
> --- a/fs/xfs/xfs_dir2_readdir.c
> +++ b/fs/xfs/xfs_dir2_readdir.c
> @@ -456,7 +456,7 @@ xfs_dir2_leaf_readbuf(
>               /*
>                * Advance offset through the mapping table.
>                */
> -             for (j = 0; j < mp->m_dirblkfsbs; j++) {
> +             for (j = 0; j < mp->m_dirblkfsbs; ) {
>                       /*
>                        * The rest of this extent but not more than a dir
>                        * block.

This looks correct, but it would seem a little more idiomatic to write
this as:

                for (j = 0; j < mp->m_dirblkfsbs; j += length) {

and remove the j increment from the body.