radix_tree: loop based on shift count, not height
When we introduce entries that can cover multiple indices, we will need
to stop in __radix_tree_create based on the shift, not the height.
Split out for ease of bisect.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Hugh Dickins <hughd@google.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 ff91792..9bb440f 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -415,10 +415,10 @@
slot = indirect_to_ptr(root->rnode);
height = root->height;
- shift = (height-1) * RADIX_TREE_MAP_SHIFT;
+ shift = height * RADIX_TREE_MAP_SHIFT;
offset = 0; /* uninitialised var warning */
- while (height > 0) {
+ while (shift > 0) {
if (slot == NULL) {
/* Have to add a child node. */
if (!(slot = radix_tree_node_alloc(root)))
@@ -436,11 +436,11 @@
}
/* Go a level down */
+ shift -= RADIX_TREE_MAP_SHIFT;
offset = (index >> shift) & RADIX_TREE_MAP_MASK;
node = slot;
slot = node->slots[offset];
slot = indirect_to_ptr(slot);
- shift -= RADIX_TREE_MAP_SHIFT;
height--;
}