From 0070e28d97e72aeac2a85f538d8a452400dfe1c7 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Thu, 17 Mar 2016 14:21:51 -0700 Subject: [PATCH] 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 Cc: Johannes Weiner Cc: Matthew Wilcox Cc: "Kirill A. Shutemov" Cc: Ross Zwisler Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/radix-tree.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/radix-tree.c b/lib/radix-tree.c index ff91792346f6..9bb440f317c9 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -415,10 +415,10 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, 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 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, } /* 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--; }