[Cluster-devel] [gfs2-utils PATCH 03/47] libgfs2: let dir_split_leaf receive a "broken" lindex

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On Tue, 2013-05-14 at 11:21 -0500, Bob Peterson wrote:
> For ordinary leaf blocks, the hash table must follow the rules,
> which means it needs to follow a power-of-two boundary. In other
> words, it needs to enforce that: start = (lindex & ~(len - 1));
> But when doing repairs, fsck will need to detect when hash tables
> violate this rule and fix it. In that case, it may need to pass
> in an invalid starting offset for a leaf to split. This patch
> moves the responsibility for checking the starting block to the
> calling function.
> 
> rhbz#902920
> ---
>  gfs2/libgfs2/fs_ops.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/gfs2/libgfs2/fs_ops.c b/gfs2/libgfs2/fs_ops.c
> index 89adf32..11ef6b4 100644
> --- a/gfs2/libgfs2/fs_ops.c
> +++ b/gfs2/libgfs2/fs_ops.c
> @@ -957,7 +957,7 @@ void dir_split_leaf(struct gfs2_inode *dip, uint32_t lindex, uint64_t leaf_no,
>  	len = 1 << (dip->i_di.di_depth - be16_to_cpu(oleaf->lf_depth));
>  	half_len = len >> 1;
>  
> -	start = (lindex & ~(len - 1));
> +	start = lindex;
Why not just rename the lindex as start? Otherwise this might be
confusing to have two names for the same variable,

Steve.

>  
>  	lp = calloc(1, half_len * sizeof(uint64_t));
>  	if (lp == NULL) {
> @@ -1160,7 +1160,7 @@ static int dir_e_add(struct gfs2_inode *dip, const char *filename, int len,
>  	struct gfs2_buffer_head *bh, *nbh;
>  	struct gfs2_leaf *leaf, *nleaf;
>  	struct gfs2_dirent *dent;
> -	uint32_t lindex;
> +	uint32_t lindex, llen;
>  	uint32_t hash;
>  	uint64_t leaf_no, bn;
>  	int err = 0;
> @@ -1182,7 +1182,10 @@ restart:
>  		if (dirent_alloc(dip, bh, len, &dent)) {
>  
>  			if (be16_to_cpu(leaf->lf_depth) < dip->i_di.di_depth) {
> -				dir_split_leaf(dip, lindex, leaf_no, bh);
> +				llen = 1 << (dip->i_di.di_depth -
> +					     be16_to_cpu(leaf->lf_depth));
> +				dir_split_leaf(dip, lindex & ~(llen - 1),
> +					       leaf_no, bh);
>  				brelse(bh);
>  				goto restart;
>