On Mon, Oct 16, 2017 at 06:10:45PM -0700, Darrick J. Wong wrote:
> Check the free space information in a directory.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> v2: make the freespace and leaf checks more complete
> ---
.....
> + /* Make sure the bestfrees are actually the best free spaces. */
> + ptr = (char *)d_ops->data_entry_p(bp->b_addr);
> + if (is_block) {
> + struct xfs_dir2_block_tail *btp;
> +
> + btp = xfs_dir2_block_tail_p(mp->m_dir_geo, bp->b_addr);
> + endptr = (char *)xfs_dir2_block_leaf_p(btp);
> + } else
> + endptr = (char *)bp->b_addr + BBTOB(bp->b_length);
> + while (ptr < endptr) {
> + dup = (struct xfs_dir2_data_unused *)ptr;
> + /* Skip real entries */
> + if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
> + struct xfs_dir2_data_entry *dep;
> +
> + dep = (struct xfs_dir2_data_entry *)ptr;
> + newlen = d_ops->data_entsize(dep->namelen);
> + if (newlen <= 0) {
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
> + lblk);
> + goto out_buf;
> + }
> + ptr += newlen;
> + continue;
> + }
> +
> + /* Spot check this free entry */
> + tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
> + if (tag != ((char *)dup - (char *)bp->b_addr))
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
> +
> + /*
> + * Either this entry is a bestfree or it's smaller than
> + * any of the bestfrees.
> + */
> + xfs_scrub_directory_check_free_entry(sc, lblk, bf, dup);
> +
> + /* Move on. */
> + newlen = be16_to_cpu(dup->length);
> + if (newlen <= 0) {
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
> + goto out_buf;
> + }
> + ptr += newlen;
> + if (ptr <= endptr)
> + nr_frees++;
> + }
> +
> + /* Did we go off the end? */
> + if (ptr > endptr)
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
ptr >= endptr?
Otherwise looks good.
Reviewed-by: Dave Chinner <dchinner@xxxxxxxxxx>
--
Dave Chinner
david@xxxxxxxxxxxxx
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