[PATCH 32/46] xfs: cleanup xchk_directory_data_bestfree

Christoph Hellwig
2019-11-07T18:25:38Z

Use an offset as the main means for iteration, and only do pointer
arithmetics to find the data/unused entries.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/scrub/dir.c | 31 +++++++++++++++----------------
1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index 501d60c9b09a..4cef21b9d336 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -327,14 +327,13 @@ xchk_directory_data_bestfree(
struct xfs_dir2_data_free *bf;
struct xfs_mount *mp = sc->mp;
const struct xfs_dir_ops *d_ops;
- char *ptr;
- char *endptr;
u16 tag;
unsigned int nr_bestfrees = 0;
unsigned int nr_frees = 0;
unsigned int smallest_bestfree;
int newlen;
- int offset;
+ unsigned int offset;
+ unsigned int end;
int error;

d_ops = sc->ip->d_ops;
@@ -368,13 +367,13 @@ xchk_directory_data_bestfree(
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
- dup = (struct xfs_dir2_data_unused *)(bp->b_addr + offset);
+ dup = bp->b_addr + offset;
tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));

/* bestfree doesn't match the entry it points at? */
if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG) ||
be16_to_cpu(dup->length) != be16_to_cpu(dfp->length) ||
- tag != ((char *)dup - (char *)bp->b_addr)) {
+ tag != offset) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
@@ -390,30 +389,30 @@ xchk_directory_data_bestfree(
}

/* Make sure the bestfrees are actually the best free spaces. */
- ptr = (char *)d_ops->data_entry_p(bp->b_addr);
- endptr = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr);
+ offset = d_ops->data_entry_offset;
+ end = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr) - bp->b_addr;

/* Iterate the entries, stopping when we hit or go past the end. */
- while (ptr < endptr) {
- dup = (struct xfs_dir2_data_unused *)ptr;
+ while (offset < end) {
+ dup = bp->b_addr + offset;
+
/* Skip real entries */
if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
- struct xfs_dir2_data_entry *dep;
+ struct xfs_dir2_data_entry *dep = bp->b_addr + offset;

- dep = (struct xfs_dir2_data_entry *)ptr;
newlen = d_ops->data_entsize(dep->namelen);
if (newlen <= 0) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
lblk);
goto out_buf;
}
- ptr += newlen;
+ offset += 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)) {
+ if (tag != offset) {
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
@@ -432,13 +431,13 @@ xchk_directory_data_bestfree(
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
goto out_buf;
}
- ptr += newlen;
- if (ptr <= endptr)
+ offset += newlen;
+ if (offset <= end)
nr_frees++;
}

/* We're required to fill all the space. */
- if (ptr != endptr)
+ if (offset != end)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);

/* Did we see at least as many free slots as there are bestfrees? */
--
2.20.1