[PATCH 30/46] xfs: cleanup xfs_dir2_leaf_getdents

Christoph Hellwig
2019-11-07T18:25:33Z

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/xfs_dir2_readdir.c | 34 +++++++++++++++++-----------------
1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/fs/xfs/xfs_dir2_readdir.c b/fs/xfs/xfs_dir2_readdir.c
index 0d234b649d65..c4314e9e3dd8 100644
--- a/fs/xfs/xfs_dir2_readdir.c
+++ b/fs/xfs/xfs_dir2_readdir.c
@@ -351,13 +351,13 @@ xfs_dir2_leaf_getdents(
xfs_dir2_data_hdr_t *hdr; /* data block header */
xfs_dir2_data_entry_t *dep; /* data entry */
xfs_dir2_data_unused_t *dup; /* unused entry */
- char *ptr = NULL; /* pointer to current data */
struct xfs_da_geometry *geo = args->geo;
xfs_dablk_t rablk = 0; /* current readahead block */
xfs_dir2_off_t curoff; /* current overall offset */
int length; /* temporary length value */
int byteoff; /* offset in current block */
int lock_mode;
+ unsigned int offset = 0;
int error = 0; /* error return value */

/*
@@ -384,7 +384,7 @@ xfs_dir2_leaf_getdents(
* If we have no buffer, or we're off the end of the
* current buffer, need to get another one.
*/
- if (!bp || ptr >= (char *)bp->b_addr + geo->blksize) {
+ if (!bp || offset + geo->blksize) {
if (bp) {
xfs_trans_brelse(args->trans, bp);
bp = NULL;
@@ -402,7 +402,7 @@ xfs_dir2_leaf_getdents(
/*
* Find our position in the block.
*/
- ptr = (char *)dp->d_ops->data_entry_p(hdr);
+ offset = dp->d_ops->data_entry_offset;
byteoff = xfs_dir2_byte_to_off(geo, curoff);
/*
* Skip past the header.
@@ -413,20 +413,20 @@ xfs_dir2_leaf_getdents(
* Skip past entries until we reach our offset.
*/
else {
- while ((char *)ptr - (char *)hdr < byteoff) {
- dup = (xfs_dir2_data_unused_t *)ptr;
+ while (offset < byteoff) {
+ dup = bp->b_addr + offset;

if (be16_to_cpu(dup->freetag)
== XFS_DIR2_DATA_FREE_TAG) {

length = be16_to_cpu(dup->length);
- ptr += length;
+ offset += length;
continue;
}
- dep = (xfs_dir2_data_entry_t *)ptr;
+ dep = bp->b_addr + offset;
length =
dp->d_ops->data_entsize(dep->namelen);
- ptr += length;
+ offset += length;
}
/*
* Now set our real offset.
@@ -434,28 +434,28 @@ xfs_dir2_leaf_getdents(
curoff =
xfs_dir2_db_off_to_byte(geo,
xfs_dir2_byte_to_db(geo, curoff),
- (char *)ptr - (char *)hdr);
- if (ptr >= (char *)hdr + geo->blksize) {
+ offset);
+ if (offset >= geo->blksize)
continue;
- }
}
}
+
/*
- * We have a pointer to an entry.
- * Is it a live one?
+ * We have a pointer to an entry. Is it a live one?
*/
- dup = (xfs_dir2_data_unused_t *)ptr;
+ dup = bp->b_addr + offset;
+
/*
* No, it's unused, skip over it.
*/
if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
length = be16_to_cpu(dup->length);
- ptr += length;
+ offset += length;
curoff += length;
continue;
}

- dep = (xfs_dir2_data_entry_t *)ptr;
+ dep = bp->b_addr + offset;
length = dp->d_ops->data_entsize(dep->namelen);
filetype = dp->d_ops->data_get_ftype(dep);

@@ -474,7 +474,7 @@ xfs_dir2_leaf_getdents(
/*
* Advance to next entry in the block.
*/
- ptr += length;
+ offset += length;
curoff += length;
/* bufsize may have just been a guess; don't go negative */
bufsize = bufsize > length ? bufsize - length : 0;
--
2.20.1