xfs: factor out xfs_dir2_leaf_find_stale

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
This commit is contained in:
Christoph Hellwig 2011-07-13 13:43:48 +02:00
parent a00b7745c6
commit a230a1df40
1 changed files with 37 additions and 46 deletions

View File

@ -148,6 +148,38 @@ xfs_dir2_block_to_leaf(
return 0;
}
STATIC void
xfs_dir2_leaf_find_stale(
struct xfs_dir2_leaf *leaf,
int index,
int *lowstale,
int *highstale)
{
/*
* Find the first stale entry before our index, if any.
*/
for (*lowstale = index - 1; *lowstale >= 0; --*lowstale) {
if (leaf->ents[*lowstale].address ==
cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
break;
}
/*
* Find the first stale entry at or after our index, if any.
* Stop if the result would require moving more entries than using
* lowstale.
*/
for (*highstale = index;
*highstale < be16_to_cpu(leaf->hdr.count);
++*highstale) {
if (leaf->ents[*highstale].address ==
cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
break;
if (*lowstale >= 0 && index - *lowstale <= *highstale - index)
break;
}
}
struct xfs_dir2_leaf_entry *
xfs_dir2_leaf_find_entry(
xfs_dir2_leaf_t *leaf, /* leaf structure */
@ -190,32 +222,8 @@ xfs_dir2_leaf_find_entry(
* If we didn't compact before, we need to find the nearest stale
* entries before and after our insertion point.
*/
if (compact == 0) {
/*
* Find the first stale entry before the insertion point,
* if any.
*/
for (lowstale = index - 1;
lowstale >= 0 &&
leaf->ents[lowstale].address !=
cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
lowstale--)
continue;
/*
* Find the next stale entry at or after the insertion point,
* if any. Stop if we go so far that the lowstale entry
* would be better.
*/
for (highstale = index;
highstale < be16_to_cpu(leaf->hdr.count) &&
leaf->ents[highstale].address !=
cpu_to_be32(XFS_DIR2_NULL_DATAPTR) &&
(lowstale < 0 ||
index - lowstale - 1 >= highstale - index);
highstale++)
continue;
}
if (compact == 0)
xfs_dir2_leaf_find_stale(leaf, index, &lowstale, &highstale);
/*
* If the low one is better, use it.
@ -689,26 +697,9 @@ xfs_dir2_leaf_compact_x1(
leaf = bp->data;
ASSERT(be16_to_cpu(leaf->hdr.stale) > 1);
index = *indexp;
/*
* Find the first stale entry before our index, if any.
*/
for (lowstale = index - 1;
lowstale >= 0 &&
leaf->ents[lowstale].address !=
cpu_to_be32(XFS_DIR2_NULL_DATAPTR);
lowstale--)
continue;
/*
* Find the first stale entry at or after our index, if any.
* Stop if the answer would be worse than lowstale.
*/
for (highstale = index;
highstale < be16_to_cpu(leaf->hdr.count) &&
leaf->ents[highstale].address !=
cpu_to_be32(XFS_DIR2_NULL_DATAPTR) &&
(lowstale < 0 || index - lowstale > highstale - index);
highstale++)
continue;
xfs_dir2_leaf_find_stale(leaf, index, &lowstale, &highstale);
/*
* Pick the better of lowstale and highstale.
*/