radix-tree: tidy up next_chunk
Convert radix_tree_next_chunk to use 'child' instead of 'slot' as the
name of the child node. Also use node_maxindex() where it makes sense.
The 'rnode' variable was unnecessary; it doesn't overlap in usage with
'node', so we can just use 'node' the whole way through the function.
Improve the testcase to start the walk from every index in the carefully
constructed tree, and to accept any index within the range covered by
the entry.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 4b4a2a2..c42867a 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -876,7 +876,7 @@
struct radix_tree_iter *iter, unsigned flags)
{
unsigned shift, tag = flags & RADIX_TREE_ITER_TAG_MASK;
- struct radix_tree_node *rnode, *node;
+ struct radix_tree_node *node, *child;
unsigned long index, offset, maxindex;
if ((flags & RADIX_TREE_ITER_TAGGED) && !root_tag_get(root, tag))
@@ -896,38 +896,29 @@
return NULL;
restart:
- shift = radix_tree_load_root(root, &rnode, &maxindex);
+ shift = radix_tree_load_root(root, &child, &maxindex);
if (index > maxindex)
return NULL;
+ if (!child)
+ return NULL;
- if (radix_tree_is_internal_node(rnode)) {
- rnode = entry_to_node(rnode);
- } else if (rnode) {
+ if (!radix_tree_is_internal_node(child)) {
/* Single-slot tree */
iter->index = index;
iter->next_index = maxindex + 1;
iter->tags = 1;
- __set_iter_shift(iter, shift);
+ __set_iter_shift(iter, 0);
return (void **)&root->rnode;
- } else
- return NULL;
+ }
- shift -= RADIX_TREE_MAP_SHIFT;
- offset = index >> shift;
-
- node = rnode;
- while (1) {
- struct radix_tree_node *slot;
- unsigned new_off = radix_tree_descend(node, &slot, offset);
-
- if (new_off < offset) {
- offset = new_off;
- index &= ~((RADIX_TREE_MAP_SIZE << shift) - 1);
- index |= offset << shift;
- }
+ do {
+ node = entry_to_node(child);
+ shift -= RADIX_TREE_MAP_SHIFT;
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+ offset = radix_tree_descend(node, &child, offset);
if ((flags & RADIX_TREE_ITER_TAGGED) ?
- !tag_get(node, tag, offset) : !slot) {
+ !tag_get(node, tag, offset) : !child) {
/* Hole detected */
if (flags & RADIX_TREE_ITER_CONTIG)
return NULL;
@@ -945,29 +936,23 @@
if (slot)
break;
}
- index &= ~((RADIX_TREE_MAP_SIZE << shift) - 1);
+ index &= ~node_maxindex(node);
index += offset << shift;
/* Overflow after ~0UL */
if (!index)
return NULL;
if (offset == RADIX_TREE_MAP_SIZE)
goto restart;
- slot = rcu_dereference_raw(node->slots[offset]);
+ child = rcu_dereference_raw(node->slots[offset]);
}
- if ((slot == NULL) || (slot == RADIX_TREE_RETRY))
+ if ((child == NULL) || (child == RADIX_TREE_RETRY))
goto restart;
- if (!radix_tree_is_internal_node(slot))
- break;
-
- node = entry_to_node(slot);
- shift -= RADIX_TREE_MAP_SHIFT;
- offset = (index >> shift) & RADIX_TREE_MAP_MASK;
- }
+ } while (radix_tree_is_internal_node(child));
/* Update the iterator state */
- iter->index = index & ~((1 << shift) - 1);
- iter->next_index = (index | ((RADIX_TREE_MAP_SIZE << shift) - 1)) + 1;
+ iter->index = (index &~ node_maxindex(node)) | (offset << node->shift);
+ iter->next_index = (index | node_maxindex(node)) + 1;
__set_iter_shift(iter, shift);
/* Construct iter->tags bit-mask from node->tags[tag] array */
diff --git a/tools/testing/radix-tree/multiorder.c b/tools/testing/radix-tree/multiorder.c
index c061f4b..39d9b95 100644
--- a/tools/testing/radix-tree/multiorder.c
+++ b/tools/testing/radix-tree/multiorder.c
@@ -202,7 +202,7 @@
RADIX_TREE(tree, GFP_KERNEL);
struct radix_tree_iter iter;
void **slot;
- int i, err;
+ int i, j, err;
printf("Multiorder iteration test\n");
@@ -215,29 +215,21 @@
assert(!err);
}
- i = 0;
- /* start from index 1 to verify we find the multi-order entry at 0 */
- radix_tree_for_each_slot(slot, &tree, &iter, 1) {
- int height = order[i] / RADIX_TREE_MAP_SHIFT;
- int shift = height * RADIX_TREE_MAP_SHIFT;
+ for (j = 0; j < 256; j++) {
+ for (i = 0; i < NUM_ENTRIES; i++)
+ if (j <= (index[i] | ((1 << order[i]) - 1)))
+ break;
- assert(iter.index == index[i]);
- assert(iter.shift == shift);
- i++;
- }
+ radix_tree_for_each_slot(slot, &tree, &iter, j) {
+ int height = order[i] / RADIX_TREE_MAP_SHIFT;
+ int shift = height * RADIX_TREE_MAP_SHIFT;
+ int mask = (1 << order[i]) - 1;
- /*
- * Now iterate through the tree starting at an elevated multi-order
- * entry, beginning at an index in the middle of the range.
- */
- i = 8;
- radix_tree_for_each_slot(slot, &tree, &iter, 70) {
- int height = order[i] / RADIX_TREE_MAP_SHIFT;
- int shift = height * RADIX_TREE_MAP_SHIFT;
-
- assert(iter.index == index[i]);
- assert(iter.shift == shift);
- i++;
+ assert(iter.index >= (index[i] &~ mask));
+ assert(iter.index <= (index[i] | mask));
+ assert(iter.shift == shift);
+ i++;
+ }
}
item_kill_tree(&tree);
@@ -249,7 +241,7 @@
struct radix_tree_iter iter;
void **slot;
unsigned long first = 0;
- int i;
+ int i, j;
printf("Multiorder tagged iteration test\n");
@@ -268,30 +260,49 @@
for (i = 0; i < TAG_ENTRIES; i++)
assert(radix_tree_tag_set(&tree, tag_index[i], 1));
- i = 0;
- /* start from index 1 to verify we find the multi-order entry at 0 */
- radix_tree_for_each_tagged(slot, &tree, &iter, 1, 1) {
- assert(iter.index == tag_index[i]);
- i++;
- }
+ for (j = 0; j < 256; j++) {
+ int mask, k;
- /*
- * Now iterate through the tree starting at an elevated multi-order
- * entry, beginning at an index in the middle of the range.
- */
- i = 4;
- radix_tree_for_each_slot(slot, &tree, &iter, 70) {
- assert(iter.index == tag_index[i]);
- i++;
+ for (i = 0; i < TAG_ENTRIES; i++) {
+ for (k = i; index[k] < tag_index[i]; k++)
+ ;
+ if (j <= (index[k] | ((1 << order[k]) - 1)))
+ break;
+ }
+
+ radix_tree_for_each_tagged(slot, &tree, &iter, j, 1) {
+ for (k = i; index[k] < tag_index[i]; k++)
+ ;
+ mask = (1 << order[k]) - 1;
+
+ assert(iter.index >= (tag_index[i] &~ mask));
+ assert(iter.index <= (tag_index[i] | mask));
+ i++;
+ }
}
radix_tree_range_tag_if_tagged(&tree, &first, ~0UL,
MT_NUM_ENTRIES, 1, 2);
- i = 0;
- radix_tree_for_each_tagged(slot, &tree, &iter, 1, 2) {
- assert(iter.index == tag_index[i]);
- i++;
+ for (j = 0; j < 256; j++) {
+ int mask, k;
+
+ for (i = 0; i < TAG_ENTRIES; i++) {
+ for (k = i; index[k] < tag_index[i]; k++)
+ ;
+ if (j <= (index[k] | ((1 << order[k]) - 1)))
+ break;
+ }
+
+ radix_tree_for_each_tagged(slot, &tree, &iter, j, 2) {
+ for (k = i; index[k] < tag_index[i]; k++)
+ ;
+ mask = (1 << order[k]) - 1;
+
+ assert(iter.index >= (tag_index[i] &~ mask));
+ assert(iter.index <= (tag_index[i] | mask));
+ i++;
+ }
}
first = 1;