diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/radix-tree.c | 109 |
1 files changed, 83 insertions, 26 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 9bb440f317c9..d907dca302d5 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -333,7 +333,8 @@ static inline unsigned long radix_tree_maxindex(unsigned int height) /* * Extend a radix tree so it can store key @index. */ -static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) +static int radix_tree_extend(struct radix_tree_root *root, + unsigned long index, unsigned order) { struct radix_tree_node *node; struct radix_tree_node *slot; @@ -345,7 +346,7 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index) while (index > radix_tree_maxindex(height)) height++; - if (root->rnode == NULL) { + if ((root->rnode == NULL) && (order == 0)) { root->height = height; goto out; } @@ -386,6 +387,7 @@ out: * __radix_tree_create - create a slot in a radix tree * @root: radix tree root * @index: index key + * @order: index occupies 2^order aligned slots * @nodep: returns node * @slotp: returns slot * @@ -399,26 +401,29 @@ out: * Returns -ENOMEM, or 0 for success. */ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, - struct radix_tree_node **nodep, void ***slotp) + unsigned order, struct radix_tree_node **nodep, + void ***slotp) { struct radix_tree_node *node = NULL, *slot; unsigned int height, shift, offset; int error; + BUG_ON((0 < order) && (order < RADIX_TREE_MAP_SHIFT)); + /* Make sure the tree is high enough. */ if (index > radix_tree_maxindex(root->height)) { - error = radix_tree_extend(root, index); + error = radix_tree_extend(root, index, order); if (error) return error; } - slot = indirect_to_ptr(root->rnode); + slot = root->rnode; height = root->height; shift = height * RADIX_TREE_MAP_SHIFT; offset = 0; /* uninitialised var warning */ - while (shift > 0) { + while (shift > order) { if (slot == NULL) { /* Have to add a child node. */ if (!(slot = radix_tree_node_alloc(root))) @@ -433,15 +438,31 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, } else rcu_assign_pointer(root->rnode, ptr_to_indirect(slot)); - } + } else if (!radix_tree_is_indirect_ptr(slot)) + break; /* Go a level down */ + height--; shift -= RADIX_TREE_MAP_SHIFT; offset = (index >> shift) & RADIX_TREE_MAP_MASK; - node = slot; + node = indirect_to_ptr(slot); slot = node->slots[offset]; - slot = indirect_to_ptr(slot); - height--; + } + + /* Insert pointers to the canonical entry */ + if ((shift - order) > 0) { + int i, n = 1 << (shift - order); + offset = offset & ~(n - 1); + slot = ptr_to_indirect(&node->slots[offset]); + for (i = 0; i < n; i++) { + if (node->slots[offset + i]) + return -EEXIST; + } + + for (i = 1; i < n; i++) { + rcu_assign_pointer(node->slots[offset + i], slot); + node->count++; + } } if (nodep) @@ -452,15 +473,16 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index, } /** - * radix_tree_insert - insert into a radix tree + * __radix_tree_insert - insert into a radix tree * @root: radix tree root * @index: index key + * @order: key covers the 2^order indices around index * @item: item to insert * * Insert an item into the radix tree at position @index. */ -int radix_tree_insert(struct radix_tree_root *root, - unsigned long index, void *item) +int __radix_tree_insert(struct radix_tree_root *root, unsigned long index, + unsigned order, void *item) { struct radix_tree_node *node; void **slot; @@ -468,7 +490,7 @@ int radix_tree_insert(struct radix_tree_root *root, BUG_ON(radix_tree_is_indirect_ptr(item)); - error = __radix_tree_create(root, index, &node, &slot); + error = __radix_tree_create(root, index, order, &node, &slot); if (error) return error; if (*slot != NULL) @@ -486,7 +508,7 @@ int radix_tree_insert(struct radix_tree_root *root, return 0; } -EXPORT_SYMBOL(radix_tree_insert); +EXPORT_SYMBOL(__radix_tree_insert); /** * __radix_tree_lookup - lookup an item in a radix tree @@ -537,6 +559,8 @@ void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index, node = rcu_dereference_raw(*slot); if (node == NULL) return NULL; + if (!radix_tree_is_indirect_ptr(node)) + break; node = indirect_to_ptr(node); shift -= RADIX_TREE_MAP_SHIFT; @@ -624,6 +648,8 @@ void *radix_tree_tag_set(struct radix_tree_root *root, tag_set(slot, tag, offset); slot = slot->slots[offset]; BUG_ON(slot == NULL); + if (!radix_tree_is_indirect_ptr(slot)) + break; slot = indirect_to_ptr(slot); shift -= RADIX_TREE_MAP_SHIFT; height--; @@ -669,6 +695,8 @@ void *radix_tree_tag_clear(struct radix_tree_root *root, while (shift) { if (slot == NULL) goto out; + if (!radix_tree_is_indirect_ptr(slot)) + break; slot = indirect_to_ptr(slot); shift -= RADIX_TREE_MAP_SHIFT; @@ -753,6 +781,8 @@ int radix_tree_tag_get(struct radix_tree_root *root, if (height == 1) return 1; node = rcu_dereference_raw(node->slots[offset]); + if (!radix_tree_is_indirect_ptr(node)) + return 1; shift -= RADIX_TREE_MAP_SHIFT; height--; } @@ -813,6 +843,7 @@ restart: node = rnode; while (1) { + struct radix_tree_node *slot; if ((flags & RADIX_TREE_ITER_TAGGED) ? !test_bit(offset, node->tags[tag]) : !node->slots[offset]) { @@ -843,10 +874,12 @@ restart: if (!shift) break; - node = rcu_dereference_raw(node->slots[offset]); - if (node == NULL) + slot = rcu_dereference_raw(node->slots[offset]); + if (slot == NULL) goto restart; - node = indirect_to_ptr(node); + if (!radix_tree_is_indirect_ptr(slot)) + break; + node = indirect_to_ptr(slot); shift -= RADIX_TREE_MAP_SHIFT; offset = (index >> shift) & RADIX_TREE_MAP_MASK; } @@ -944,16 +977,20 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, if (!tag_get(slot, iftag, offset)) goto next; if (shift) { - /* Go down one level */ - shift -= RADIX_TREE_MAP_SHIFT; node = slot; slot = slot->slots[offset]; - slot = indirect_to_ptr(slot); - continue; + if (radix_tree_is_indirect_ptr(slot)) { + slot = indirect_to_ptr(slot); + shift -= RADIX_TREE_MAP_SHIFT; + continue; + } else { + slot = node; + node = node->parent; + } } /* tag the leaf */ - tagged++; + tagged += 1 << shift; tag_set(slot, settag, offset); /* walk back up the path tagging interior nodes */ @@ -1201,11 +1238,20 @@ static unsigned long __locate(struct radix_tree_node *slot, void *item, goto out; } - shift -= RADIX_TREE_MAP_SHIFT; slot = rcu_dereference_raw(slot->slots[i]); if (slot == NULL) goto out; + if (!radix_tree_is_indirect_ptr(slot)) { + if (slot == item) { + *found_index = index + i; + index = 0; + } else { + index += shift; + } + goto out; + } slot = indirect_to_ptr(slot); + shift -= RADIX_TREE_MAP_SHIFT; } /* Bottom level: check items */ @@ -1285,7 +1331,8 @@ static inline void radix_tree_shrink(struct radix_tree_root *root) /* * The candidate node has more than one child, or its child - * is not at the leftmost slot, we cannot shrink. + * is not at the leftmost slot, or it is a multiorder entry, + * we cannot shrink. */ if (to_free->count != 1) break; @@ -1301,6 +1348,9 @@ static inline void radix_tree_shrink(struct radix_tree_root *root) * one (root->rnode) as far as dependent read barriers go. */ if (root->height > 1) { + if (!radix_tree_is_indirect_ptr(slot)) + break; + slot = indirect_to_ptr(slot); slot->parent = NULL; slot = ptr_to_indirect(slot); @@ -1399,7 +1449,7 @@ void *radix_tree_delete_item(struct radix_tree_root *root, unsigned long index, void *item) { struct radix_tree_node *node; - unsigned int offset; + unsigned int offset, i; void **slot; void *entry; int tag; @@ -1428,6 +1478,13 @@ void *radix_tree_delete_item(struct radix_tree_root *root, radix_tree_tag_clear(root, index, tag); } + /* Delete any sibling slots pointing to this slot */ + for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) { + if (node->slots[offset + i] != ptr_to_indirect(slot)) + break; + node->slots[offset + i] = NULL; + node->count--; + } node->slots[offset] = NULL; node->count--; |