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-rw-r--r--lib/radix-tree.c182
1 files changed, 148 insertions, 34 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 6b79e9026..1624c4117 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -173,6 +173,41 @@ radix_tree_find_next_bit(const unsigned long *addr,
return size;
}
+#if 0
+static void dump_node(void *slot, int height, int offset)
+{
+ struct radix_tree_node *node;
+ int i;
+
+ if (!slot)
+ return;
+
+ if (height == 0) {
+ pr_debug("radix entry %p offset %d\n", slot, offset);
+ return;
+ }
+
+ node = indirect_to_ptr(slot);
+ pr_debug("radix node: %p offset %d tags %lx %lx %lx path %x count %d parent %p\n",
+ slot, offset, node->tags[0][0], node->tags[1][0],
+ node->tags[2][0], node->path, node->count, node->parent);
+
+ for (i = 0; i < RADIX_TREE_MAP_SIZE; i++)
+ dump_node(node->slots[i], height - 1, i);
+}
+
+/* For debug */
+static void radix_tree_dump(struct radix_tree_root *root)
+{
+ pr_debug("radix root: %p height %d rnode %p tags %x\n",
+ root, root->height, root->rnode,
+ root->gfp_mask >> __GFP_BITS_SHIFT);
+ if (!radix_tree_is_indirect_ptr(root->rnode))
+ return;
+ dump_node(root->rnode, root->height, 0);
+}
+#endif
+
/*
* This assumes that the caller has performed appropriate preallocation, and
* that the caller has pinned this thread of control to the current CPU.
@@ -192,6 +227,15 @@ radix_tree_node_alloc(struct radix_tree_root *root)
struct radix_tree_preload *rtp;
/*
+ * Even if the caller has preloaded, try to allocate from the
+ * cache first for the new node to get accounted.
+ */
+ ret = kmem_cache_alloc(radix_tree_node_cachep,
+ gfp_mask | __GFP_ACCOUNT | __GFP_NOWARN);
+ if (ret)
+ goto out;
+
+ /*
* Provided the caller has preloaded here, we will always
* succeed in getting a node here (and never reach
* kmem_cache_alloc)
@@ -208,10 +252,11 @@ radix_tree_node_alloc(struct radix_tree_root *root)
* for debugging.
*/
kmemleak_update_trace(ret);
+ goto out;
}
- if (ret == NULL)
- ret = kmem_cache_alloc(radix_tree_node_cachep, gfp_mask);
-
+ ret = kmem_cache_alloc(radix_tree_node_cachep,
+ gfp_mask | __GFP_ACCOUNT);
+out:
BUG_ON(radix_tree_is_indirect_ptr(ret));
return ret;
}
@@ -323,7 +368,8 @@ 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;
@@ -335,7 +381,7 @@ 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;
}
@@ -358,9 +404,10 @@ static int radix_tree_extend(struct radix_tree_root *root, unsigned long index)
node->count = 1;
node->parent = NULL;
slot = root->rnode;
- if (newheight > 1) {
+ if (radix_tree_is_indirect_ptr(slot) && newheight > 1) {
slot = indirect_to_ptr(slot);
slot->parent = node;
+ slot = ptr_to_indirect(slot);
}
node->slots[0] = slot;
node = ptr_to_indirect(node);
@@ -375,6 +422,7 @@ 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
*
@@ -388,26 +436,29 @@ 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-1) * RADIX_TREE_MAP_SHIFT;
+ shift = height * RADIX_TREE_MAP_SHIFT;
offset = 0; /* uninitialised var warning */
- while (height > 0) {
+ while (shift > order) {
if (slot == NULL) {
/* Have to add a child node. */
if (!(slot = radix_tree_node_alloc(root)))
@@ -415,19 +466,38 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
slot->path = height;
slot->parent = node;
if (node) {
- rcu_assign_pointer(node->slots[offset], slot);
+ rcu_assign_pointer(node->slots[offset],
+ ptr_to_indirect(slot));
node->count++;
slot->path |= offset << RADIX_TREE_HEIGHT_SHIFT;
} else
- rcu_assign_pointer(root->rnode, ptr_to_indirect(slot));
- }
+ 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];
- shift -= RADIX_TREE_MAP_SHIFT;
- 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)
@@ -438,15 +508,16 @@ 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;
@@ -454,7 +525,7 @@ 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)
@@ -472,7 +543,7 @@ 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
@@ -523,6 +594,9 @@ 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;
height--;
@@ -609,6 +683,9 @@ 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--;
}
@@ -648,11 +725,14 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
goto out;
shift = height * RADIX_TREE_MAP_SHIFT;
- slot = indirect_to_ptr(root->rnode);
+ slot = root->rnode;
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;
offset = (index >> shift) & RADIX_TREE_MAP_MASK;
@@ -728,6 +808,7 @@ int radix_tree_tag_get(struct radix_tree_root *root,
if (node == NULL)
return 0;
+ node = indirect_to_ptr(node);
offset = (index >> shift) & RADIX_TREE_MAP_MASK;
if (!tag_get(node, tag, offset))
@@ -735,6 +816,8 @@ 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--;
}
@@ -795,6 +878,7 @@ 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]) {
@@ -825,9 +909,12 @@ 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;
+ 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;
}
@@ -925,15 +1012,20 @@ 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];
- 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 */
@@ -1181,10 +1273,20 @@ 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 */
@@ -1264,11 +1366,13 @@ 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;
- if (!to_free->slots[0])
+ slot = to_free->slots[0];
+ if (!slot)
break;
/*
@@ -1278,8 +1382,11 @@ static inline void radix_tree_shrink(struct radix_tree_root *root)
* (to_free->slots[0]), it will be safe to dereference the new
* one (root->rnode) as far as dependent read barriers go.
*/
- slot = to_free->slots[0];
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);
}
@@ -1377,7 +1484,7 @@ 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;
@@ -1406,6 +1513,13 @@ 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--;