[PATCH 12/27] xfs: factor out xfs_dir2_leaf_find_entry

Christoph Hellwig
2011-07-01T09:46:06Z

[-- Attachment #1: xfs-factor-dir2-leaf-code --]
[-- Type: text/plain, Size: 11010 bytes --]

Add a new xfs_dir2_leaf_find_entry helper to factor out some duplicate code
from xfs_dir2_leaf_addname xfs_dir2_leafn_add. Found by Eric Sandeen using
an automated code duplication checker.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Index: xfs/fs/xfs/xfs_dir2_leaf.c
===================================================================
--- xfs.orig/fs/xfs/xfs_dir2_leaf.c 2011-06-29 19:45:24.846962285 +0200
+++ xfs/fs/xfs/xfs_dir2_leaf.c 2011-06-30 09:29:24.446740960 +0200
@@ -152,6 +152,123 @@ xfs_dir2_block_to_leaf(
return 0;
}

+struct xfs_dir2_leaf_entry *
+xfs_dir2_leaf_find_entry(
+ xfs_dir2_leaf_t *leaf, /* leaf structure */
+ int index, /* leaf table position */
+ int compact, /* need to compact leaves */
+ int lowstale, /* index of prev stale leaf */
+ int highstale, /* index of next stale leaf */
+ int *lfloglow, /* low leaf logging index */
+ int *lfloghigh) /* high leaf logging index */
+{
+ if (!leaf->hdr.stale) {
+ xfs_dir2_leaf_entry_t *lep; /* leaf entry table pointer */
+
+ /*
+ * Now we need to make room to insert the leaf entry.
+ *
+ * If there are no stale entries, just insert a hole at index.
+ */
+ lep = &leaf->ents[index];
+ if (index < be16_to_cpu(leaf->hdr.count))
+ memmove(lep + 1, lep,
+ (be16_to_cpu(leaf->hdr.count) - index) *
+ sizeof(*lep));
+
+ /*
+ * Record low and high logging indices for the leaf.
+ */
+ *lfloglow = index;
+ *lfloghigh = be16_to_cpu(leaf->hdr.count);
+ be16_add_cpu(&leaf->hdr.count, 1);
+ return lep;
+ }
+
+ /*
+ * There are stale entries.
+ *
+ * We will use one of them for the new entry. It's probably not at
+ * the right location, so we'll have to shift some up or down first.
+ *
+ * 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 &&
+ be32_to_cpu(leaf->ents[lowstale].address) !=
+ 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) &&
+ be32_to_cpu(leaf->ents[highstale].address) !=
+ XFS_DIR2_NULL_DATAPTR &&
+ (lowstale < 0 ||
+ index - lowstale - 1 >= highstale - index);
+ highstale++)
+ continue;
+ }
+
+ /*
+ * If the low one is better, use it.
+ */
+ if (lowstale >= 0 &&
+ (highstale == be16_to_cpu(leaf->hdr.count) ||
+ index - lowstale - 1 < highstale - index)) {
+ ASSERT(index - lowstale - 1 >= 0);
+ ASSERT(be32_to_cpu(leaf->ents[lowstale].address) ==
+ XFS_DIR2_NULL_DATAPTR);
+
+ /*
+ * Copy entries up to cover the stale entry and make room
+ * for the new entry.
+ */
+ if (index - lowstale - 1 > 0) {
+ memmove(&leaf->ents[lowstale],
+ &leaf->ents[lowstale + 1],
+ (index - lowstale - 1) *
+ sizeof(xfs_dir2_leaf_entry_t));
+ }
+ *lfloglow = MIN(lowstale, *lfloglow);
+ *lfloghigh = MAX(index - 1, *lfloghigh);
+ be16_add_cpu(&leaf->hdr.stale, -1);
+ return &leaf->ents[index - 1];
+ }
+
+ /*
+ * The high one is better, so use that one.
+ */
+ ASSERT(highstale - index >= 0);
+ ASSERT(be32_to_cpu(leaf->ents[highstale].address) ==
+ XFS_DIR2_NULL_DATAPTR);
+
+ /*
+ * Copy entries down to cover the stale entry and make room for the
+ * new entry.
+ */
+ if (highstale - index > 0) {
+ memmove(&leaf->ents[index + 1],
+ &leaf->ents[index],
+ (highstale - index) * sizeof(xfs_dir2_leaf_entry_t));
+ }
+ *lfloglow = MIN(index, *lfloglow);
+ *lfloghigh = MAX(highstale, *lfloghigh);
+ be16_add_cpu(&leaf->hdr.stale, -1);
+ return &leaf->ents[index];
+}
+
/*
* Add an entry to a leaf form directory.
*/
@@ -430,102 +547,10 @@ xfs_dir2_leaf_addname(
if (!grown)
xfs_dir2_leaf_log_bests(tp, lbp, use_block, use_block);
}
- /*
- * Now we need to make room to insert the leaf entry.
- * If there are no stale entries, we just insert a hole at index.
- */
- if (!leaf->hdr.stale) {
- /*
- * lep is still good as the index leaf entry.
- */
- if (index < be16_to_cpu(leaf->hdr.count))
- memmove(lep + 1, lep,
- (be16_to_cpu(leaf->hdr.count) - index) * sizeof(*lep));
- /*
- * Record low and high logging indices for the leaf.
- */
- lfloglow = index;
- lfloghigh = be16_to_cpu(leaf->hdr.count);
- be16_add_cpu(&leaf->hdr.count, 1);
- }
- /*
- * There are stale entries.
- * We will use one of them for the new entry.
- * It's probably not at the right location, so we'll have to
- * shift some up or down first.
- */
- else {
- /*
- * 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 &&
- be32_to_cpu(leaf->ents[lowstale].address) !=
- 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) &&
- be32_to_cpu(leaf->ents[highstale].address) !=
- XFS_DIR2_NULL_DATAPTR &&
- (lowstale < 0 ||
- index - lowstale - 1 >= highstale - index);
- highstale++)
- continue;
- }
- /*
- * If the low one is better, use it.
- */
- if (lowstale >= 0 &&
- (highstale == be16_to_cpu(leaf->hdr.count) ||
- index - lowstale - 1 < highstale - index)) {
- ASSERT(index - lowstale - 1 >= 0);
- ASSERT(be32_to_cpu(leaf->ents[lowstale].address) ==
- XFS_DIR2_NULL_DATAPTR);
- /*
- * Copy entries up to cover the stale entry
- * and make room for the new entry.
- */
- if (index - lowstale - 1 > 0)
- memmove(&leaf->ents[lowstale],
- &leaf->ents[lowstale + 1],
- (index - lowstale - 1) * sizeof(*lep));
- lep = &leaf->ents[index - 1];
- lfloglow = MIN(lowstale, lfloglow);
- lfloghigh = MAX(index - 1, lfloghigh);
- }
- /*
- * The high one is better, so use that one.
- */
- else {
- ASSERT(highstale - index >= 0);
- ASSERT(be32_to_cpu(leaf->ents[highstale].address) ==
- XFS_DIR2_NULL_DATAPTR);
- /*
- * Copy entries down to cover the stale entry
- * and make room for the new entry.
- */
- if (highstale - index > 0)
- memmove(&leaf->ents[index + 1],
- &leaf->ents[index],
- (highstale - index) * sizeof(*lep));
- lep = &leaf->ents[index];
- lfloglow = MIN(index, lfloglow);
- lfloghigh = MAX(highstale, lfloghigh);
- }
- be16_add_cpu(&leaf->hdr.stale, -1);
- }
+
+ lep = xfs_dir2_leaf_find_entry(leaf, index, compact, lowstale,
+ highstale, &lfloglow, &lfloghigh);
+
/*
* Fill in the new leaf entry.
*/
Index: xfs/fs/xfs/xfs_dir2_leaf.h
===================================================================
--- xfs.orig/fs/xfs/xfs_dir2_leaf.h 2011-06-29 19:45:24.856962230 +0200
+++ xfs/fs/xfs/xfs_dir2_leaf.h 2011-06-30 09:18:07.263416117 +0200
@@ -248,6 +248,9 @@ extern int xfs_dir2_leaf_search_hash(str
struct xfs_dabuf *lbp);
extern int xfs_dir2_leaf_trim_data(struct xfs_da_args *args,
struct xfs_dabuf *lbp, xfs_dir2_db_t db);
+extern xfs_dir2_leaf_entry_t *xfs_dir2_leaf_find_entry(xfs_dir2_leaf_t *, int,
+ int, int, int,
+ int *, int *);
extern int xfs_dir2_node_to_leaf(struct xfs_da_state *state);

#endif /* __XFS_DIR2_LEAF_H__ */
Index: xfs/fs/xfs/xfs_dir2_node.c
===================================================================
--- xfs.orig/fs/xfs/xfs_dir2_node.c 2011-06-29 19:45:24.870295493 +0200
+++ xfs/fs/xfs/xfs_dir2_node.c 2011-06-30 09:27:19.103409194 +0200
@@ -244,89 +244,13 @@ xfs_dir2_leafn_add(
lfloglow = be16_to_cpu(leaf->hdr.count);
lfloghigh = -1;
}
- /*
- * No stale entries, just insert a space for the new entry.
- */
- if (!leaf->hdr.stale) {
- lep = &leaf->ents[index];
- if (index < be16_to_cpu(leaf->hdr.count))
- memmove(lep + 1, lep,
- (be16_to_cpu(leaf->hdr.count) - index) * sizeof(*lep));
- lfloglow = index;
- lfloghigh = be16_to_cpu(leaf->hdr.count);
- be16_add_cpu(&leaf->hdr.count, 1);
- }
- /*
- * There are stale entries. We'll use one for the new entry.
- */
- else {
- /*
- * If we didn't do a compact then we need to figure out
- * which stale entry will be used.
- */
- if (compact == 0) {
- /*
- * Find first stale entry before our insertion point.
- */
- for (lowstale = index - 1;
- lowstale >= 0 &&
- be32_to_cpu(leaf->ents[lowstale].address) !=
- XFS_DIR2_NULL_DATAPTR;
- lowstale--)
- continue;
- /*
- * Find next stale entry after insertion point.
- * Stop looking if the answer would be worse than
- * lowstale already found.
- */
- for (highstale = index;
- highstale < be16_to_cpu(leaf->hdr.count) &&
- be32_to_cpu(leaf->ents[highstale].address) !=
- XFS_DIR2_NULL_DATAPTR &&
- (lowstale < 0 ||
- index - lowstale - 1 >= highstale - index);
- highstale++)
- continue;
- }
- /*
- * Using the low stale entry.
- * Shift entries up toward the stale slot.
- */
- if (lowstale >= 0 &&
- (highstale == be16_to_cpu(leaf->hdr.count) ||
- index - lowstale - 1 < highstale - index)) {
- ASSERT(be32_to_cpu(leaf->ents[lowstale].address) ==
- XFS_DIR2_NULL_DATAPTR);
- ASSERT(index - lowstale - 1 >= 0);
- if (index - lowstale - 1 > 0)
- memmove(&leaf->ents[lowstale],
- &leaf->ents[lowstale + 1],
- (index - lowstale - 1) * sizeof(*lep));
- lep = &leaf->ents[index - 1];
- lfloglow = MIN(lowstale, lfloglow);
- lfloghigh = MAX(index - 1, lfloghigh);
- }
- /*
- * Using the high stale entry.
- * Shift entries down toward the stale slot.
- */
- else {
- ASSERT(be32_to_cpu(leaf->ents[highstale].address) ==
- XFS_DIR2_NULL_DATAPTR);
- ASSERT(highstale - index >= 0);
- if (highstale - index > 0)
- memmove(&leaf->ents[index + 1],
- &leaf->ents[index],
- (highstale - index) * sizeof(*lep));
- lep = &leaf->ents[index];
- lfloglow = MIN(index, lfloglow);
- lfloghigh = MAX(highstale, lfloghigh);
- }
- be16_add_cpu(&leaf->hdr.stale, -1);
- }
+
/*
* Insert the new entry, log everything.
*/
+ lep = xfs_dir2_leaf_find_entry(leaf, index, compact, lowstale,
+ highstale, &lfloglow, &lfloghigh);
+
lep->hashval = cpu_to_be32(args->hashval);
lep->address = cpu_to_be32(xfs_dir2_db_off_to_dataptr(mp,
args->blkno, args->index));