On Wed, Oct 11, 2017 at 06:43:26PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> Check the free space information in a directory.
....
> diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
> index e2a8f90..a41310f 100644
> --- a/fs/xfs/scrub/dir.c
> +++ b/fs/xfs/scrub/dir.c
> @@ -250,6 +250,426 @@ xfs_scrub_dir_rec(
> return error;
> }
>
> +/*
> + * Is this unused entry either in the bestfree or smaller than all of them?
> + * We assume the bestfrees are sorted longest to shortest, and that there
> + * aren't any bogus entries.
s/We assume/We've already checked/
> + */
> +static inline void
> +xfs_scrub_directory_check_free_entry(
> + struct xfs_scrub_context *sc,
> + xfs_dablk_t lblk,
> + struct xfs_dir2_data_free *bf,
> + struct xfs_dir2_data_unused *dup)
....
> + 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;
> + if (endptr < ptr)
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
> + lblk);
> + 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 (endptr < ptr)
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
I'd prefer this matches the loop logic order. ie.
if (ptr >= endptr)
> + else
> + nr_frees++;
> + }
> +
> + /* Did we see at least as many free slots as there are bestfrees? */
> + if (nr_frees < nr_bestfrees)
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
> +out_buf:
> + xfs_trans_brelse(sc->tp, bp);
> +out:
> + return error;
> +}
> +
> +/*
> + * Does the free space length in the free space index block ($len) match
> + * the longest length in the directory data block's bestfree array?
> + * Assume that we've already checked that the data block's bestfree
> + * array is in order.
> + */
> +static inline void
> +xfs_scrub_directory_check_freesp(
No need for inline here, the compiler will do that automatically if
appropriate.
> + struct xfs_scrub_context *sc,
> + xfs_dablk_t lblk,
> + struct xfs_buf *dbp,
> + unsigned int len)
> +{
> + struct xfs_dir2_data_free *bf;
> + struct xfs_dir2_data_free *dfp;
> + int offset;
> +
> + if (len == 0)
> + return;
> +
> + bf = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
> + for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
> + offset = be16_to_cpu(dfp->offset);
> + if (offset == 0)
> + break;
> + if (len == be16_to_cpu(dfp->length))
> + return;
> + /* Didn't find the best length in the bestfree data */
> + break;
> + }
> +
> + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
> +}
> +
> +/* Check free space info in a directory leaf1 block. */
> +STATIC int
> +xfs_scrub_directory_leaf1_bestfree(
> + struct xfs_scrub_context *sc,
> + struct xfs_da_args *args,
> + xfs_dablk_t lblk)
> +{
> + struct xfs_dir2_leaf_tail *ltp;
> + struct xfs_buf *dbp;
> + struct xfs_buf *bp;
> + struct xfs_mount *mp = sc->mp;
> + __be16 *bestp;
> + __u16 best;
> + int i;
> + int error;
> +
> + /*
> + * Read the free space block. The verifier will check for hash
> + * value ordering problems and check the stale entry count.
> + */
> + error = xfs_dir3_leaf_read(sc->tp, sc->ip, lblk, -1, &bp);
> + if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
> + goto out;
> +
> + /* Check all the entries. */
> + ltp = xfs_dir2_leaf_tail_p(mp->m_dir_geo, bp->b_addr);
> + bestp = xfs_dir2_leaf_bests_p(ltp);
> + for (i = 0; i < be32_to_cpu(ltp->bestcount); i++, bestp++) {
> + best = be16_to_cpu(*bestp);
> + if (best == NULLDATAOFF)
> + continue;
Count stale entries, check if matches hdr->stale ?
> + error = xfs_dir3_data_read(sc->tp, sc->ip,
> + i * args->geo->fsbcount, -1, &dbp);
> + if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk,
> + &error))
> + continue;
> + xfs_scrub_directory_check_freesp(sc, lblk, dbp, best);
> + xfs_trans_brelse(sc->tp, dbp);
> + }
> +out:
> + return error;
> +}
> +
> +/* Check free space info in a directory freespace block. */
> +STATIC int
> +xfs_scrub_directory_free_bestfree(
> + struct xfs_scrub_context *sc,
> + struct xfs_da_args *args,
> + xfs_dablk_t lblk)
> +{
> + struct xfs_dir3_icfree_hdr freehdr;
> + struct xfs_buf *dbp;
> + struct xfs_buf *bp;
> + __be16 *bestp;
> + __be16 best;
> + int i;
> + int error;
> +
> + /* Read the free space block */
> + error = xfs_dir2_free_read(sc->tp, sc->ip, lblk, &bp);
> + if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
> + goto out;
> +
> + /* Check all the entries. */
> + sc->ip->d_ops->free_hdr_from_disk(&freehdr, bp->b_addr);
> + bestp = sc->ip->d_ops->free_bests_p(bp->b_addr);
> + for (i = 0; i < freehdr.nvalid; i++, bestp++) {
> + best = be16_to_cpu(*bestp);
> + if (best == NULLDATAOFF)
> + continue;
Count stale entries, check freehdr.nvalid + stale = freehdr.nused?
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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