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831978e37e
Patch series "Clean up and refinement for maple tree", v2. This patchset cleans up and refines some maple tree code. A few small changes make the code easier to understand and for better readability. This patch (of 7): These extra space and blank lines are unnecessary, so drop them. Link: https://lkml.kernel.org/r/20221221060058.609003-1-vernon2gm@gmail.com Link: https://lkml.kernel.org/r/20221221060058.609003-2-vernon2gm@gmail.com Signed-off-by: Vernon Yang <vernon2gm@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
7154 lines
177 KiB
C
7154 lines
177 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Maple Tree implementation
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* Copyright (c) 2018-2022 Oracle Corporation
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* Authors: Liam R. Howlett <Liam.Howlett@oracle.com>
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* Matthew Wilcox <willy@infradead.org>
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*/
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/*
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* DOC: Interesting implementation details of the Maple Tree
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*
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* Each node type has a number of slots for entries and a number of slots for
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* pivots. In the case of dense nodes, the pivots are implied by the position
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* and are simply the slot index + the minimum of the node.
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*
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* In regular B-Tree terms, pivots are called keys. The term pivot is used to
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* indicate that the tree is specifying ranges, Pivots may appear in the
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* subtree with an entry attached to the value where as keys are unique to a
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* specific position of a B-tree. Pivot values are inclusive of the slot with
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* the same index.
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*
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*
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* The following illustrates the layout of a range64 nodes slots and pivots.
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*
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*
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* Slots -> | 0 | 1 | 2 | ... | 12 | 13 | 14 | 15 |
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* ┬ ┬ ┬ ┬ ┬ ┬ ┬ ┬ ┬
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* │ │ │ │ │ │ │ │ └─ Implied maximum
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* │ │ │ │ │ │ │ └─ Pivot 14
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* │ │ │ │ │ │ └─ Pivot 13
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* │ │ │ │ │ └─ Pivot 12
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* │ │ │ │ └─ Pivot 11
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* │ │ │ └─ Pivot 2
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* │ │ └─ Pivot 1
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* │ └─ Pivot 0
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* └─ Implied minimum
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*
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* Slot contents:
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* Internal (non-leaf) nodes contain pointers to other nodes.
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* Leaf nodes contain entries.
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*
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* The location of interest is often referred to as an offset. All offsets have
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* a slot, but the last offset has an implied pivot from the node above (or
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* UINT_MAX for the root node.
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*
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* Ranges complicate certain write activities. When modifying any of
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* the B-tree variants, it is known that one entry will either be added or
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* deleted. When modifying the Maple Tree, one store operation may overwrite
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* the entire data set, or one half of the tree, or the middle half of the tree.
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*
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*/
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#include <linux/maple_tree.h>
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#include <linux/xarray.h>
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#include <linux/types.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/limits.h>
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#include <asm/barrier.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/maple_tree.h>
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#define MA_ROOT_PARENT 1
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/*
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* Maple state flags
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* * MA_STATE_BULK - Bulk insert mode
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* * MA_STATE_REBALANCE - Indicate a rebalance during bulk insert
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* * MA_STATE_PREALLOC - Preallocated nodes, WARN_ON allocation
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*/
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#define MA_STATE_BULK 1
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#define MA_STATE_REBALANCE 2
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#define MA_STATE_PREALLOC 4
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#define ma_parent_ptr(x) ((struct maple_pnode *)(x))
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#define ma_mnode_ptr(x) ((struct maple_node *)(x))
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#define ma_enode_ptr(x) ((struct maple_enode *)(x))
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static struct kmem_cache *maple_node_cache;
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#ifdef CONFIG_DEBUG_MAPLE_TREE
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static const unsigned long mt_max[] = {
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[maple_dense] = MAPLE_NODE_SLOTS,
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[maple_leaf_64] = ULONG_MAX,
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[maple_range_64] = ULONG_MAX,
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[maple_arange_64] = ULONG_MAX,
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};
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#define mt_node_max(x) mt_max[mte_node_type(x)]
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#endif
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static const unsigned char mt_slots[] = {
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[maple_dense] = MAPLE_NODE_SLOTS,
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[maple_leaf_64] = MAPLE_RANGE64_SLOTS,
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[maple_range_64] = MAPLE_RANGE64_SLOTS,
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[maple_arange_64] = MAPLE_ARANGE64_SLOTS,
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};
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#define mt_slot_count(x) mt_slots[mte_node_type(x)]
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static const unsigned char mt_pivots[] = {
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[maple_dense] = 0,
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[maple_leaf_64] = MAPLE_RANGE64_SLOTS - 1,
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[maple_range_64] = MAPLE_RANGE64_SLOTS - 1,
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[maple_arange_64] = MAPLE_ARANGE64_SLOTS - 1,
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};
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#define mt_pivot_count(x) mt_pivots[mte_node_type(x)]
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static const unsigned char mt_min_slots[] = {
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[maple_dense] = MAPLE_NODE_SLOTS / 2,
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[maple_leaf_64] = (MAPLE_RANGE64_SLOTS / 2) - 2,
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[maple_range_64] = (MAPLE_RANGE64_SLOTS / 2) - 2,
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[maple_arange_64] = (MAPLE_ARANGE64_SLOTS / 2) - 1,
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};
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#define mt_min_slot_count(x) mt_min_slots[mte_node_type(x)]
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#define MAPLE_BIG_NODE_SLOTS (MAPLE_RANGE64_SLOTS * 2 + 2)
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#define MAPLE_BIG_NODE_GAPS (MAPLE_ARANGE64_SLOTS * 2 + 1)
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struct maple_big_node {
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struct maple_pnode *parent;
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unsigned long pivot[MAPLE_BIG_NODE_SLOTS - 1];
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union {
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struct maple_enode *slot[MAPLE_BIG_NODE_SLOTS];
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struct {
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unsigned long padding[MAPLE_BIG_NODE_GAPS];
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unsigned long gap[MAPLE_BIG_NODE_GAPS];
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};
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};
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unsigned char b_end;
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enum maple_type type;
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};
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/*
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* The maple_subtree_state is used to build a tree to replace a segment of an
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* existing tree in a more atomic way. Any walkers of the older tree will hit a
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* dead node and restart on updates.
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*/
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struct maple_subtree_state {
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struct ma_state *orig_l; /* Original left side of subtree */
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struct ma_state *orig_r; /* Original right side of subtree */
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struct ma_state *l; /* New left side of subtree */
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struct ma_state *m; /* New middle of subtree (rare) */
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struct ma_state *r; /* New right side of subtree */
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struct ma_topiary *free; /* nodes to be freed */
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struct ma_topiary *destroy; /* Nodes to be destroyed (walked and freed) */
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struct maple_big_node *bn;
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};
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/* Functions */
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static inline struct maple_node *mt_alloc_one(gfp_t gfp)
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{
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return kmem_cache_alloc(maple_node_cache, gfp | __GFP_ZERO);
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}
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static inline int mt_alloc_bulk(gfp_t gfp, size_t size, void **nodes)
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{
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return kmem_cache_alloc_bulk(maple_node_cache, gfp | __GFP_ZERO, size,
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nodes);
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}
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static inline void mt_free_bulk(size_t size, void __rcu **nodes)
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{
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kmem_cache_free_bulk(maple_node_cache, size, (void **)nodes);
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}
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static void mt_free_rcu(struct rcu_head *head)
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{
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struct maple_node *node = container_of(head, struct maple_node, rcu);
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kmem_cache_free(maple_node_cache, node);
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}
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/*
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* ma_free_rcu() - Use rcu callback to free a maple node
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* @node: The node to free
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*
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* The maple tree uses the parent pointer to indicate this node is no longer in
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* use and will be freed.
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*/
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static void ma_free_rcu(struct maple_node *node)
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{
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node->parent = ma_parent_ptr(node);
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call_rcu(&node->rcu, mt_free_rcu);
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}
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static void mas_set_height(struct ma_state *mas)
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{
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unsigned int new_flags = mas->tree->ma_flags;
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new_flags &= ~MT_FLAGS_HEIGHT_MASK;
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BUG_ON(mas->depth > MAPLE_HEIGHT_MAX);
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new_flags |= mas->depth << MT_FLAGS_HEIGHT_OFFSET;
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mas->tree->ma_flags = new_flags;
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}
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static unsigned int mas_mt_height(struct ma_state *mas)
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{
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return mt_height(mas->tree);
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}
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static inline enum maple_type mte_node_type(const struct maple_enode *entry)
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{
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return ((unsigned long)entry >> MAPLE_NODE_TYPE_SHIFT) &
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MAPLE_NODE_TYPE_MASK;
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}
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static inline bool ma_is_dense(const enum maple_type type)
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{
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return type < maple_leaf_64;
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}
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static inline bool ma_is_leaf(const enum maple_type type)
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{
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return type < maple_range_64;
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}
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static inline bool mte_is_leaf(const struct maple_enode *entry)
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{
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return ma_is_leaf(mte_node_type(entry));
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}
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/*
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* We also reserve values with the bottom two bits set to '10' which are
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* below 4096
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*/
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static inline bool mt_is_reserved(const void *entry)
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{
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return ((unsigned long)entry < MAPLE_RESERVED_RANGE) &&
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xa_is_internal(entry);
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}
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static inline void mas_set_err(struct ma_state *mas, long err)
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{
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mas->node = MA_ERROR(err);
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}
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static inline bool mas_is_ptr(struct ma_state *mas)
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{
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return mas->node == MAS_ROOT;
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}
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static inline bool mas_is_start(struct ma_state *mas)
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{
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return mas->node == MAS_START;
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}
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bool mas_is_err(struct ma_state *mas)
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{
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return xa_is_err(mas->node);
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}
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static inline bool mas_searchable(struct ma_state *mas)
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{
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if (mas_is_none(mas))
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return false;
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if (mas_is_ptr(mas))
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return false;
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return true;
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}
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static inline struct maple_node *mte_to_node(const struct maple_enode *entry)
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{
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return (struct maple_node *)((unsigned long)entry & ~MAPLE_NODE_MASK);
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}
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/*
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* mte_to_mat() - Convert a maple encoded node to a maple topiary node.
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* @entry: The maple encoded node
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*
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* Return: a maple topiary pointer
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*/
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static inline struct maple_topiary *mte_to_mat(const struct maple_enode *entry)
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{
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return (struct maple_topiary *)
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((unsigned long)entry & ~MAPLE_NODE_MASK);
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}
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/*
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* mas_mn() - Get the maple state node.
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* @mas: The maple state
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*
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* Return: the maple node (not encoded - bare pointer).
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*/
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static inline struct maple_node *mas_mn(const struct ma_state *mas)
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{
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return mte_to_node(mas->node);
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}
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/*
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* mte_set_node_dead() - Set a maple encoded node as dead.
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* @mn: The maple encoded node.
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*/
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static inline void mte_set_node_dead(struct maple_enode *mn)
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{
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mte_to_node(mn)->parent = ma_parent_ptr(mte_to_node(mn));
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smp_wmb(); /* Needed for RCU */
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}
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/* Bit 1 indicates the root is a node */
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#define MAPLE_ROOT_NODE 0x02
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/* maple_type stored bit 3-6 */
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#define MAPLE_ENODE_TYPE_SHIFT 0x03
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/* Bit 2 means a NULL somewhere below */
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#define MAPLE_ENODE_NULL 0x04
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static inline struct maple_enode *mt_mk_node(const struct maple_node *node,
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enum maple_type type)
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{
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return (void *)((unsigned long)node |
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(type << MAPLE_ENODE_TYPE_SHIFT) | MAPLE_ENODE_NULL);
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}
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static inline void *mte_mk_root(const struct maple_enode *node)
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{
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return (void *)((unsigned long)node | MAPLE_ROOT_NODE);
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}
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static inline void *mte_safe_root(const struct maple_enode *node)
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{
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return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
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}
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static inline void *mte_set_full(const struct maple_enode *node)
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{
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return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
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}
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static inline void *mte_clear_full(const struct maple_enode *node)
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{
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return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
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}
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static inline bool mte_has_null(const struct maple_enode *node)
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{
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return (unsigned long)node & MAPLE_ENODE_NULL;
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}
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static inline bool ma_is_root(struct maple_node *node)
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{
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return ((unsigned long)node->parent & MA_ROOT_PARENT);
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}
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static inline bool mte_is_root(const struct maple_enode *node)
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{
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return ma_is_root(mte_to_node(node));
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}
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static inline bool mas_is_root_limits(const struct ma_state *mas)
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{
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return !mas->min && mas->max == ULONG_MAX;
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}
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static inline bool mt_is_alloc(struct maple_tree *mt)
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{
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return (mt->ma_flags & MT_FLAGS_ALLOC_RANGE);
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}
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/*
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* The Parent Pointer
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* Excluding root, the parent pointer is 256B aligned like all other tree nodes.
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* When storing a 32 or 64 bit values, the offset can fit into 5 bits. The 16
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* bit values need an extra bit to store the offset. This extra bit comes from
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* a reuse of the last bit in the node type. This is possible by using bit 1 to
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* indicate if bit 2 is part of the type or the slot.
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*
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* Note types:
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* 0x??1 = Root
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* 0x?00 = 16 bit nodes
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* 0x010 = 32 bit nodes
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* 0x110 = 64 bit nodes
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*
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* Slot size and alignment
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* 0b??1 : Root
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* 0b?00 : 16 bit values, type in 0-1, slot in 2-7
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* 0b010 : 32 bit values, type in 0-2, slot in 3-7
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* 0b110 : 64 bit values, type in 0-2, slot in 3-7
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*/
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#define MAPLE_PARENT_ROOT 0x01
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#define MAPLE_PARENT_SLOT_SHIFT 0x03
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#define MAPLE_PARENT_SLOT_MASK 0xF8
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#define MAPLE_PARENT_16B_SLOT_SHIFT 0x02
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#define MAPLE_PARENT_16B_SLOT_MASK 0xFC
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#define MAPLE_PARENT_RANGE64 0x06
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#define MAPLE_PARENT_RANGE32 0x04
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#define MAPLE_PARENT_NOT_RANGE16 0x02
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/*
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* mte_parent_shift() - Get the parent shift for the slot storage.
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* @parent: The parent pointer cast as an unsigned long
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* Return: The shift into that pointer to the star to of the slot
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*/
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static inline unsigned long mte_parent_shift(unsigned long parent)
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{
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/* Note bit 1 == 0 means 16B */
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if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
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return MAPLE_PARENT_SLOT_SHIFT;
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return MAPLE_PARENT_16B_SLOT_SHIFT;
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}
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/*
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* mte_parent_slot_mask() - Get the slot mask for the parent.
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* @parent: The parent pointer cast as an unsigned long.
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* Return: The slot mask for that parent.
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*/
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static inline unsigned long mte_parent_slot_mask(unsigned long parent)
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{
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/* Note bit 1 == 0 means 16B */
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if (likely(parent & MAPLE_PARENT_NOT_RANGE16))
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return MAPLE_PARENT_SLOT_MASK;
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return MAPLE_PARENT_16B_SLOT_MASK;
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}
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/*
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* mas_parent_enum() - Return the maple_type of the parent from the stored
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* parent type.
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* @mas: The maple state
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* @node: The maple_enode to extract the parent's enum
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* Return: The node->parent maple_type
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*/
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static inline
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enum maple_type mte_parent_enum(struct maple_enode *p_enode,
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struct maple_tree *mt)
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{
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unsigned long p_type;
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p_type = (unsigned long)p_enode;
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if (p_type & MAPLE_PARENT_ROOT)
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return 0; /* Validated in the caller. */
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p_type &= MAPLE_NODE_MASK;
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p_type = p_type & ~(MAPLE_PARENT_ROOT | mte_parent_slot_mask(p_type));
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switch (p_type) {
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case MAPLE_PARENT_RANGE64: /* or MAPLE_PARENT_ARANGE64 */
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if (mt_is_alloc(mt))
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return maple_arange_64;
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return maple_range_64;
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}
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return 0;
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}
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static inline
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enum maple_type mas_parent_enum(struct ma_state *mas, struct maple_enode *enode)
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{
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return mte_parent_enum(ma_enode_ptr(mte_to_node(enode)->parent), mas->tree);
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}
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/*
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* mte_set_parent() - Set the parent node and encode the slot
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* @enode: The encoded maple node.
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* @parent: The encoded maple node that is the parent of @enode.
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* @slot: The slot that @enode resides in @parent.
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*
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* Slot number is encoded in the enode->parent bit 3-6 or 2-6, depending on the
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* parent type.
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*/
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static inline
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void mte_set_parent(struct maple_enode *enode, const struct maple_enode *parent,
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unsigned char slot)
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{
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unsigned long val = (unsigned long)parent;
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unsigned long shift;
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unsigned long type;
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enum maple_type p_type = mte_node_type(parent);
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BUG_ON(p_type == maple_dense);
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BUG_ON(p_type == maple_leaf_64);
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switch (p_type) {
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case maple_range_64:
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case maple_arange_64:
|
|
shift = MAPLE_PARENT_SLOT_SHIFT;
|
|
type = MAPLE_PARENT_RANGE64;
|
|
break;
|
|
default:
|
|
case maple_dense:
|
|
case maple_leaf_64:
|
|
shift = type = 0;
|
|
break;
|
|
}
|
|
|
|
val &= ~MAPLE_NODE_MASK; /* Clear all node metadata in parent */
|
|
val |= (slot << shift) | type;
|
|
mte_to_node(enode)->parent = ma_parent_ptr(val);
|
|
}
|
|
|
|
/*
|
|
* mte_parent_slot() - get the parent slot of @enode.
|
|
* @enode: The encoded maple node.
|
|
*
|
|
* Return: The slot in the parent node where @enode resides.
|
|
*/
|
|
static inline unsigned int mte_parent_slot(const struct maple_enode *enode)
|
|
{
|
|
unsigned long val = (unsigned long)mte_to_node(enode)->parent;
|
|
|
|
/* Root. */
|
|
if (val & 1)
|
|
return 0;
|
|
|
|
/*
|
|
* Okay to use MAPLE_PARENT_16B_SLOT_MASK as the last bit will be lost
|
|
* by shift if the parent shift is MAPLE_PARENT_SLOT_SHIFT
|
|
*/
|
|
return (val & MAPLE_PARENT_16B_SLOT_MASK) >> mte_parent_shift(val);
|
|
}
|
|
|
|
/*
|
|
* mte_parent() - Get the parent of @node.
|
|
* @node: The encoded maple node.
|
|
*
|
|
* Return: The parent maple node.
|
|
*/
|
|
static inline struct maple_node *mte_parent(const struct maple_enode *enode)
|
|
{
|
|
return (void *)((unsigned long)
|
|
(mte_to_node(enode)->parent) & ~MAPLE_NODE_MASK);
|
|
}
|
|
|
|
/*
|
|
* ma_dead_node() - check if the @enode is dead.
|
|
* @enode: The encoded maple node
|
|
*
|
|
* Return: true if dead, false otherwise.
|
|
*/
|
|
static inline bool ma_dead_node(const struct maple_node *node)
|
|
{
|
|
struct maple_node *parent = (void *)((unsigned long)
|
|
node->parent & ~MAPLE_NODE_MASK);
|
|
|
|
return (parent == node);
|
|
}
|
|
/*
|
|
* mte_dead_node() - check if the @enode is dead.
|
|
* @enode: The encoded maple node
|
|
*
|
|
* Return: true if dead, false otherwise.
|
|
*/
|
|
static inline bool mte_dead_node(const struct maple_enode *enode)
|
|
{
|
|
struct maple_node *parent, *node;
|
|
|
|
node = mte_to_node(enode);
|
|
parent = mte_parent(enode);
|
|
return (parent == node);
|
|
}
|
|
|
|
/*
|
|
* mas_allocated() - Get the number of nodes allocated in a maple state.
|
|
* @mas: The maple state
|
|
*
|
|
* The ma_state alloc member is overloaded to hold a pointer to the first
|
|
* allocated node or to the number of requested nodes to allocate. If bit 0 is
|
|
* set, then the alloc contains the number of requested nodes. If there is an
|
|
* allocated node, then the total allocated nodes is in that node.
|
|
*
|
|
* Return: The total number of nodes allocated
|
|
*/
|
|
static inline unsigned long mas_allocated(const struct ma_state *mas)
|
|
{
|
|
if (!mas->alloc || ((unsigned long)mas->alloc & 0x1))
|
|
return 0;
|
|
|
|
return mas->alloc->total;
|
|
}
|
|
|
|
/*
|
|
* mas_set_alloc_req() - Set the requested number of allocations.
|
|
* @mas: the maple state
|
|
* @count: the number of allocations.
|
|
*
|
|
* The requested number of allocations is either in the first allocated node,
|
|
* located in @mas->alloc->request_count, or directly in @mas->alloc if there is
|
|
* no allocated node. Set the request either in the node or do the necessary
|
|
* encoding to store in @mas->alloc directly.
|
|
*/
|
|
static inline void mas_set_alloc_req(struct ma_state *mas, unsigned long count)
|
|
{
|
|
if (!mas->alloc || ((unsigned long)mas->alloc & 0x1)) {
|
|
if (!count)
|
|
mas->alloc = NULL;
|
|
else
|
|
mas->alloc = (struct maple_alloc *)(((count) << 1U) | 1U);
|
|
return;
|
|
}
|
|
|
|
mas->alloc->request_count = count;
|
|
}
|
|
|
|
/*
|
|
* mas_alloc_req() - get the requested number of allocations.
|
|
* @mas: The maple state
|
|
*
|
|
* The alloc count is either stored directly in @mas, or in
|
|
* @mas->alloc->request_count if there is at least one node allocated. Decode
|
|
* the request count if it's stored directly in @mas->alloc.
|
|
*
|
|
* Return: The allocation request count.
|
|
*/
|
|
static inline unsigned int mas_alloc_req(const struct ma_state *mas)
|
|
{
|
|
if ((unsigned long)mas->alloc & 0x1)
|
|
return (unsigned long)(mas->alloc) >> 1;
|
|
else if (mas->alloc)
|
|
return mas->alloc->request_count;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ma_pivots() - Get a pointer to the maple node pivots.
|
|
* @node - the maple node
|
|
* @type - the node type
|
|
*
|
|
* Return: A pointer to the maple node pivots
|
|
*/
|
|
static inline unsigned long *ma_pivots(struct maple_node *node,
|
|
enum maple_type type)
|
|
{
|
|
switch (type) {
|
|
case maple_arange_64:
|
|
return node->ma64.pivot;
|
|
case maple_range_64:
|
|
case maple_leaf_64:
|
|
return node->mr64.pivot;
|
|
case maple_dense:
|
|
return NULL;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* ma_gaps() - Get a pointer to the maple node gaps.
|
|
* @node - the maple node
|
|
* @type - the node type
|
|
*
|
|
* Return: A pointer to the maple node gaps
|
|
*/
|
|
static inline unsigned long *ma_gaps(struct maple_node *node,
|
|
enum maple_type type)
|
|
{
|
|
switch (type) {
|
|
case maple_arange_64:
|
|
return node->ma64.gap;
|
|
case maple_range_64:
|
|
case maple_leaf_64:
|
|
case maple_dense:
|
|
return NULL;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* mte_pivot() - Get the pivot at @piv of the maple encoded node.
|
|
* @mn: The maple encoded node.
|
|
* @piv: The pivot.
|
|
*
|
|
* Return: the pivot at @piv of @mn.
|
|
*/
|
|
static inline unsigned long mte_pivot(const struct maple_enode *mn,
|
|
unsigned char piv)
|
|
{
|
|
struct maple_node *node = mte_to_node(mn);
|
|
|
|
if (piv >= mt_pivots[piv]) {
|
|
WARN_ON(1);
|
|
return 0;
|
|
}
|
|
switch (mte_node_type(mn)) {
|
|
case maple_arange_64:
|
|
return node->ma64.pivot[piv];
|
|
case maple_range_64:
|
|
case maple_leaf_64:
|
|
return node->mr64.pivot[piv];
|
|
case maple_dense:
|
|
return 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* mas_safe_pivot() - get the pivot at @piv or mas->max.
|
|
* @mas: The maple state
|
|
* @pivots: The pointer to the maple node pivots
|
|
* @piv: The pivot to fetch
|
|
* @type: The maple node type
|
|
*
|
|
* Return: The pivot at @piv within the limit of the @pivots array, @mas->max
|
|
* otherwise.
|
|
*/
|
|
static inline unsigned long
|
|
mas_safe_pivot(const struct ma_state *mas, unsigned long *pivots,
|
|
unsigned char piv, enum maple_type type)
|
|
{
|
|
if (piv >= mt_pivots[type])
|
|
return mas->max;
|
|
|
|
return pivots[piv];
|
|
}
|
|
|
|
/*
|
|
* mas_safe_min() - Return the minimum for a given offset.
|
|
* @mas: The maple state
|
|
* @pivots: The pointer to the maple node pivots
|
|
* @offset: The offset into the pivot array
|
|
*
|
|
* Return: The minimum range value that is contained in @offset.
|
|
*/
|
|
static inline unsigned long
|
|
mas_safe_min(struct ma_state *mas, unsigned long *pivots, unsigned char offset)
|
|
{
|
|
if (likely(offset))
|
|
return pivots[offset - 1] + 1;
|
|
|
|
return mas->min;
|
|
}
|
|
|
|
/*
|
|
* mas_logical_pivot() - Get the logical pivot of a given offset.
|
|
* @mas: The maple state
|
|
* @pivots: The pointer to the maple node pivots
|
|
* @offset: The offset into the pivot array
|
|
* @type: The maple node type
|
|
*
|
|
* When there is no value at a pivot (beyond the end of the data), then the
|
|
* pivot is actually @mas->max.
|
|
*
|
|
* Return: the logical pivot of a given @offset.
|
|
*/
|
|
static inline unsigned long
|
|
mas_logical_pivot(struct ma_state *mas, unsigned long *pivots,
|
|
unsigned char offset, enum maple_type type)
|
|
{
|
|
unsigned long lpiv = mas_safe_pivot(mas, pivots, offset, type);
|
|
|
|
if (likely(lpiv))
|
|
return lpiv;
|
|
|
|
if (likely(offset))
|
|
return mas->max;
|
|
|
|
return lpiv;
|
|
}
|
|
|
|
/*
|
|
* mte_set_pivot() - Set a pivot to a value in an encoded maple node.
|
|
* @mn: The encoded maple node
|
|
* @piv: The pivot offset
|
|
* @val: The value of the pivot
|
|
*/
|
|
static inline void mte_set_pivot(struct maple_enode *mn, unsigned char piv,
|
|
unsigned long val)
|
|
{
|
|
struct maple_node *node = mte_to_node(mn);
|
|
enum maple_type type = mte_node_type(mn);
|
|
|
|
BUG_ON(piv >= mt_pivots[type]);
|
|
switch (type) {
|
|
default:
|
|
case maple_range_64:
|
|
case maple_leaf_64:
|
|
node->mr64.pivot[piv] = val;
|
|
break;
|
|
case maple_arange_64:
|
|
node->ma64.pivot[piv] = val;
|
|
break;
|
|
case maple_dense:
|
|
break;
|
|
}
|
|
|
|
}
|
|
|
|
/*
|
|
* ma_slots() - Get a pointer to the maple node slots.
|
|
* @mn: The maple node
|
|
* @mt: The maple node type
|
|
*
|
|
* Return: A pointer to the maple node slots
|
|
*/
|
|
static inline void __rcu **ma_slots(struct maple_node *mn, enum maple_type mt)
|
|
{
|
|
switch (mt) {
|
|
default:
|
|
case maple_arange_64:
|
|
return mn->ma64.slot;
|
|
case maple_range_64:
|
|
case maple_leaf_64:
|
|
return mn->mr64.slot;
|
|
case maple_dense:
|
|
return mn->slot;
|
|
}
|
|
}
|
|
|
|
static inline bool mt_locked(const struct maple_tree *mt)
|
|
{
|
|
return mt_external_lock(mt) ? mt_lock_is_held(mt) :
|
|
lockdep_is_held(&mt->ma_lock);
|
|
}
|
|
|
|
static inline void *mt_slot(const struct maple_tree *mt,
|
|
void __rcu **slots, unsigned char offset)
|
|
{
|
|
return rcu_dereference_check(slots[offset], mt_locked(mt));
|
|
}
|
|
|
|
/*
|
|
* mas_slot_locked() - Get the slot value when holding the maple tree lock.
|
|
* @mas: The maple state
|
|
* @slots: The pointer to the slots
|
|
* @offset: The offset into the slots array to fetch
|
|
*
|
|
* Return: The entry stored in @slots at the @offset.
|
|
*/
|
|
static inline void *mas_slot_locked(struct ma_state *mas, void __rcu **slots,
|
|
unsigned char offset)
|
|
{
|
|
return rcu_dereference_protected(slots[offset], mt_locked(mas->tree));
|
|
}
|
|
|
|
/*
|
|
* mas_slot() - Get the slot value when not holding the maple tree lock.
|
|
* @mas: The maple state
|
|
* @slots: The pointer to the slots
|
|
* @offset: The offset into the slots array to fetch
|
|
*
|
|
* Return: The entry stored in @slots at the @offset
|
|
*/
|
|
static inline void *mas_slot(struct ma_state *mas, void __rcu **slots,
|
|
unsigned char offset)
|
|
{
|
|
return mt_slot(mas->tree, slots, offset);
|
|
}
|
|
|
|
/*
|
|
* mas_root() - Get the maple tree root.
|
|
* @mas: The maple state.
|
|
*
|
|
* Return: The pointer to the root of the tree
|
|
*/
|
|
static inline void *mas_root(struct ma_state *mas)
|
|
{
|
|
return rcu_dereference_check(mas->tree->ma_root, mt_locked(mas->tree));
|
|
}
|
|
|
|
static inline void *mt_root_locked(struct maple_tree *mt)
|
|
{
|
|
return rcu_dereference_protected(mt->ma_root, mt_locked(mt));
|
|
}
|
|
|
|
/*
|
|
* mas_root_locked() - Get the maple tree root when holding the maple tree lock.
|
|
* @mas: The maple state.
|
|
*
|
|
* Return: The pointer to the root of the tree
|
|
*/
|
|
static inline void *mas_root_locked(struct ma_state *mas)
|
|
{
|
|
return mt_root_locked(mas->tree);
|
|
}
|
|
|
|
static inline struct maple_metadata *ma_meta(struct maple_node *mn,
|
|
enum maple_type mt)
|
|
{
|
|
switch (mt) {
|
|
case maple_arange_64:
|
|
return &mn->ma64.meta;
|
|
default:
|
|
return &mn->mr64.meta;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* ma_set_meta() - Set the metadata information of a node.
|
|
* @mn: The maple node
|
|
* @mt: The maple node type
|
|
* @offset: The offset of the highest sub-gap in this node.
|
|
* @end: The end of the data in this node.
|
|
*/
|
|
static inline void ma_set_meta(struct maple_node *mn, enum maple_type mt,
|
|
unsigned char offset, unsigned char end)
|
|
{
|
|
struct maple_metadata *meta = ma_meta(mn, mt);
|
|
|
|
meta->gap = offset;
|
|
meta->end = end;
|
|
}
|
|
|
|
/*
|
|
* ma_meta_end() - Get the data end of a node from the metadata
|
|
* @mn: The maple node
|
|
* @mt: The maple node type
|
|
*/
|
|
static inline unsigned char ma_meta_end(struct maple_node *mn,
|
|
enum maple_type mt)
|
|
{
|
|
struct maple_metadata *meta = ma_meta(mn, mt);
|
|
|
|
return meta->end;
|
|
}
|
|
|
|
/*
|
|
* ma_meta_gap() - Get the largest gap location of a node from the metadata
|
|
* @mn: The maple node
|
|
* @mt: The maple node type
|
|
*/
|
|
static inline unsigned char ma_meta_gap(struct maple_node *mn,
|
|
enum maple_type mt)
|
|
{
|
|
BUG_ON(mt != maple_arange_64);
|
|
|
|
return mn->ma64.meta.gap;
|
|
}
|
|
|
|
/*
|
|
* ma_set_meta_gap() - Set the largest gap location in a nodes metadata
|
|
* @mn: The maple node
|
|
* @mn: The maple node type
|
|
* @offset: The location of the largest gap.
|
|
*/
|
|
static inline void ma_set_meta_gap(struct maple_node *mn, enum maple_type mt,
|
|
unsigned char offset)
|
|
{
|
|
|
|
struct maple_metadata *meta = ma_meta(mn, mt);
|
|
|
|
meta->gap = offset;
|
|
}
|
|
|
|
/*
|
|
* mat_add() - Add a @dead_enode to the ma_topiary of a list of dead nodes.
|
|
* @mat - the ma_topiary, a linked list of dead nodes.
|
|
* @dead_enode - the node to be marked as dead and added to the tail of the list
|
|
*
|
|
* Add the @dead_enode to the linked list in @mat.
|
|
*/
|
|
static inline void mat_add(struct ma_topiary *mat,
|
|
struct maple_enode *dead_enode)
|
|
{
|
|
mte_set_node_dead(dead_enode);
|
|
mte_to_mat(dead_enode)->next = NULL;
|
|
if (!mat->tail) {
|
|
mat->tail = mat->head = dead_enode;
|
|
return;
|
|
}
|
|
|
|
mte_to_mat(mat->tail)->next = dead_enode;
|
|
mat->tail = dead_enode;
|
|
}
|
|
|
|
static void mte_destroy_walk(struct maple_enode *, struct maple_tree *);
|
|
static inline void mas_free(struct ma_state *mas, struct maple_enode *used);
|
|
|
|
/*
|
|
* mas_mat_free() - Free all nodes in a dead list.
|
|
* @mas - the maple state
|
|
* @mat - the ma_topiary linked list of dead nodes to free.
|
|
*
|
|
* Free walk a dead list.
|
|
*/
|
|
static void mas_mat_free(struct ma_state *mas, struct ma_topiary *mat)
|
|
{
|
|
struct maple_enode *next;
|
|
|
|
while (mat->head) {
|
|
next = mte_to_mat(mat->head)->next;
|
|
mas_free(mas, mat->head);
|
|
mat->head = next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_mat_destroy() - Free all nodes and subtrees in a dead list.
|
|
* @mas - the maple state
|
|
* @mat - the ma_topiary linked list of dead nodes to free.
|
|
*
|
|
* Destroy walk a dead list.
|
|
*/
|
|
static void mas_mat_destroy(struct ma_state *mas, struct ma_topiary *mat)
|
|
{
|
|
struct maple_enode *next;
|
|
|
|
while (mat->head) {
|
|
next = mte_to_mat(mat->head)->next;
|
|
mte_destroy_walk(mat->head, mat->mtree);
|
|
mat->head = next;
|
|
}
|
|
}
|
|
/*
|
|
* mas_descend() - Descend into the slot stored in the ma_state.
|
|
* @mas - the maple state.
|
|
*
|
|
* Note: Not RCU safe, only use in write side or debug code.
|
|
*/
|
|
static inline void mas_descend(struct ma_state *mas)
|
|
{
|
|
enum maple_type type;
|
|
unsigned long *pivots;
|
|
struct maple_node *node;
|
|
void __rcu **slots;
|
|
|
|
node = mas_mn(mas);
|
|
type = mte_node_type(mas->node);
|
|
pivots = ma_pivots(node, type);
|
|
slots = ma_slots(node, type);
|
|
|
|
if (mas->offset)
|
|
mas->min = pivots[mas->offset - 1] + 1;
|
|
mas->max = mas_safe_pivot(mas, pivots, mas->offset, type);
|
|
mas->node = mas_slot(mas, slots, mas->offset);
|
|
}
|
|
|
|
/*
|
|
* mte_set_gap() - Set a maple node gap.
|
|
* @mn: The encoded maple node
|
|
* @gap: The offset of the gap to set
|
|
* @val: The gap value
|
|
*/
|
|
static inline void mte_set_gap(const struct maple_enode *mn,
|
|
unsigned char gap, unsigned long val)
|
|
{
|
|
switch (mte_node_type(mn)) {
|
|
default:
|
|
break;
|
|
case maple_arange_64:
|
|
mte_to_node(mn)->ma64.gap[gap] = val;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_ascend() - Walk up a level of the tree.
|
|
* @mas: The maple state
|
|
*
|
|
* Sets the @mas->max and @mas->min to the correct values when walking up. This
|
|
* may cause several levels of walking up to find the correct min and max.
|
|
* May find a dead node which will cause a premature return.
|
|
* Return: 1 on dead node, 0 otherwise
|
|
*/
|
|
static int mas_ascend(struct ma_state *mas)
|
|
{
|
|
struct maple_enode *p_enode; /* parent enode. */
|
|
struct maple_enode *a_enode; /* ancestor enode. */
|
|
struct maple_node *a_node; /* ancestor node. */
|
|
struct maple_node *p_node; /* parent node. */
|
|
unsigned char a_slot;
|
|
enum maple_type a_type;
|
|
unsigned long min, max;
|
|
unsigned long *pivots;
|
|
unsigned char offset;
|
|
bool set_max = false, set_min = false;
|
|
|
|
a_node = mas_mn(mas);
|
|
if (ma_is_root(a_node)) {
|
|
mas->offset = 0;
|
|
return 0;
|
|
}
|
|
|
|
p_node = mte_parent(mas->node);
|
|
if (unlikely(a_node == p_node))
|
|
return 1;
|
|
a_type = mas_parent_enum(mas, mas->node);
|
|
offset = mte_parent_slot(mas->node);
|
|
a_enode = mt_mk_node(p_node, a_type);
|
|
|
|
/* Check to make sure all parent information is still accurate */
|
|
if (p_node != mte_parent(mas->node))
|
|
return 1;
|
|
|
|
mas->node = a_enode;
|
|
mas->offset = offset;
|
|
|
|
if (mte_is_root(a_enode)) {
|
|
mas->max = ULONG_MAX;
|
|
mas->min = 0;
|
|
return 0;
|
|
}
|
|
|
|
min = 0;
|
|
max = ULONG_MAX;
|
|
do {
|
|
p_enode = a_enode;
|
|
a_type = mas_parent_enum(mas, p_enode);
|
|
a_node = mte_parent(p_enode);
|
|
a_slot = mte_parent_slot(p_enode);
|
|
pivots = ma_pivots(a_node, a_type);
|
|
a_enode = mt_mk_node(a_node, a_type);
|
|
|
|
if (!set_min && a_slot) {
|
|
set_min = true;
|
|
min = pivots[a_slot - 1] + 1;
|
|
}
|
|
|
|
if (!set_max && a_slot < mt_pivots[a_type]) {
|
|
set_max = true;
|
|
max = pivots[a_slot];
|
|
}
|
|
|
|
if (unlikely(ma_dead_node(a_node)))
|
|
return 1;
|
|
|
|
if (unlikely(ma_is_root(a_node)))
|
|
break;
|
|
|
|
} while (!set_min || !set_max);
|
|
|
|
mas->max = max;
|
|
mas->min = min;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* mas_pop_node() - Get a previously allocated maple node from the maple state.
|
|
* @mas: The maple state
|
|
*
|
|
* Return: A pointer to a maple node.
|
|
*/
|
|
static inline struct maple_node *mas_pop_node(struct ma_state *mas)
|
|
{
|
|
struct maple_alloc *ret, *node = mas->alloc;
|
|
unsigned long total = mas_allocated(mas);
|
|
|
|
/* nothing or a request pending. */
|
|
if (unlikely(!total))
|
|
return NULL;
|
|
|
|
if (total == 1) {
|
|
/* single allocation in this ma_state */
|
|
mas->alloc = NULL;
|
|
ret = node;
|
|
goto single_node;
|
|
}
|
|
|
|
if (!node->node_count) {
|
|
/* Single allocation in this node. */
|
|
mas->alloc = node->slot[0];
|
|
node->slot[0] = NULL;
|
|
mas->alloc->total = node->total - 1;
|
|
ret = node;
|
|
goto new_head;
|
|
}
|
|
|
|
node->total--;
|
|
ret = node->slot[node->node_count];
|
|
node->slot[node->node_count--] = NULL;
|
|
|
|
single_node:
|
|
new_head:
|
|
ret->total = 0;
|
|
ret->node_count = 0;
|
|
if (ret->request_count) {
|
|
mas_set_alloc_req(mas, ret->request_count + 1);
|
|
ret->request_count = 0;
|
|
}
|
|
return (struct maple_node *)ret;
|
|
}
|
|
|
|
/*
|
|
* mas_push_node() - Push a node back on the maple state allocation.
|
|
* @mas: The maple state
|
|
* @used: The used maple node
|
|
*
|
|
* Stores the maple node back into @mas->alloc for reuse. Updates allocated and
|
|
* requested node count as necessary.
|
|
*/
|
|
static inline void mas_push_node(struct ma_state *mas, struct maple_node *used)
|
|
{
|
|
struct maple_alloc *reuse = (struct maple_alloc *)used;
|
|
struct maple_alloc *head = mas->alloc;
|
|
unsigned long count;
|
|
unsigned int requested = mas_alloc_req(mas);
|
|
|
|
memset(reuse, 0, sizeof(*reuse));
|
|
count = mas_allocated(mas);
|
|
|
|
if (count && (head->node_count < MAPLE_ALLOC_SLOTS - 1)) {
|
|
if (head->slot[0])
|
|
head->node_count++;
|
|
head->slot[head->node_count] = reuse;
|
|
head->total++;
|
|
goto done;
|
|
}
|
|
|
|
reuse->total = 1;
|
|
if ((head) && !((unsigned long)head & 0x1)) {
|
|
head->request_count = 0;
|
|
reuse->slot[0] = head;
|
|
reuse->total += head->total;
|
|
}
|
|
|
|
mas->alloc = reuse;
|
|
done:
|
|
if (requested > 1)
|
|
mas_set_alloc_req(mas, requested - 1);
|
|
}
|
|
|
|
/*
|
|
* mas_alloc_nodes() - Allocate nodes into a maple state
|
|
* @mas: The maple state
|
|
* @gfp: The GFP Flags
|
|
*/
|
|
static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
|
|
{
|
|
struct maple_alloc *node;
|
|
unsigned long allocated = mas_allocated(mas);
|
|
unsigned long success = allocated;
|
|
unsigned int requested = mas_alloc_req(mas);
|
|
unsigned int count;
|
|
void **slots = NULL;
|
|
unsigned int max_req = 0;
|
|
|
|
if (!requested)
|
|
return;
|
|
|
|
mas_set_alloc_req(mas, 0);
|
|
if (mas->mas_flags & MA_STATE_PREALLOC) {
|
|
if (allocated)
|
|
return;
|
|
WARN_ON(!allocated);
|
|
}
|
|
|
|
if (!allocated || mas->alloc->node_count == MAPLE_ALLOC_SLOTS - 1) {
|
|
node = (struct maple_alloc *)mt_alloc_one(gfp);
|
|
if (!node)
|
|
goto nomem_one;
|
|
|
|
if (allocated)
|
|
node->slot[0] = mas->alloc;
|
|
|
|
success++;
|
|
mas->alloc = node;
|
|
requested--;
|
|
}
|
|
|
|
node = mas->alloc;
|
|
while (requested) {
|
|
max_req = MAPLE_ALLOC_SLOTS;
|
|
if (node->slot[0]) {
|
|
unsigned int offset = node->node_count + 1;
|
|
|
|
slots = (void **)&node->slot[offset];
|
|
max_req -= offset;
|
|
} else {
|
|
slots = (void **)&node->slot;
|
|
}
|
|
|
|
max_req = min(requested, max_req);
|
|
count = mt_alloc_bulk(gfp, max_req, slots);
|
|
if (!count)
|
|
goto nomem_bulk;
|
|
|
|
node->node_count += count;
|
|
/* zero indexed. */
|
|
if (slots == (void **)&node->slot)
|
|
node->node_count--;
|
|
|
|
success += count;
|
|
node = node->slot[0];
|
|
requested -= count;
|
|
}
|
|
mas->alloc->total = success;
|
|
return;
|
|
|
|
nomem_bulk:
|
|
/* Clean up potential freed allocations on bulk failure */
|
|
memset(slots, 0, max_req * sizeof(unsigned long));
|
|
nomem_one:
|
|
mas_set_alloc_req(mas, requested);
|
|
if (mas->alloc && !(((unsigned long)mas->alloc & 0x1)))
|
|
mas->alloc->total = success;
|
|
mas_set_err(mas, -ENOMEM);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* mas_free() - Free an encoded maple node
|
|
* @mas: The maple state
|
|
* @used: The encoded maple node to free.
|
|
*
|
|
* Uses rcu free if necessary, pushes @used back on the maple state allocations
|
|
* otherwise.
|
|
*/
|
|
static inline void mas_free(struct ma_state *mas, struct maple_enode *used)
|
|
{
|
|
struct maple_node *tmp = mte_to_node(used);
|
|
|
|
if (mt_in_rcu(mas->tree))
|
|
ma_free_rcu(tmp);
|
|
else
|
|
mas_push_node(mas, tmp);
|
|
}
|
|
|
|
/*
|
|
* mas_node_count() - Check if enough nodes are allocated and request more if
|
|
* there is not enough nodes.
|
|
* @mas: The maple state
|
|
* @count: The number of nodes needed
|
|
* @gfp: the gfp flags
|
|
*/
|
|
static void mas_node_count_gfp(struct ma_state *mas, int count, gfp_t gfp)
|
|
{
|
|
unsigned long allocated = mas_allocated(mas);
|
|
|
|
if (allocated < count) {
|
|
mas_set_alloc_req(mas, count - allocated);
|
|
mas_alloc_nodes(mas, gfp);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_node_count() - Check if enough nodes are allocated and request more if
|
|
* there is not enough nodes.
|
|
* @mas: The maple state
|
|
* @count: The number of nodes needed
|
|
*
|
|
* Note: Uses GFP_NOWAIT | __GFP_NOWARN for gfp flags.
|
|
*/
|
|
static void mas_node_count(struct ma_state *mas, int count)
|
|
{
|
|
return mas_node_count_gfp(mas, count, GFP_NOWAIT | __GFP_NOWARN);
|
|
}
|
|
|
|
/*
|
|
* mas_start() - Sets up maple state for operations.
|
|
* @mas: The maple state.
|
|
*
|
|
* If mas->node == MAS_START, then set the min, max, depth, and offset to
|
|
* defaults.
|
|
*
|
|
* Return:
|
|
* - If mas->node is an error or not MAS_START, return NULL.
|
|
* - If it's an empty tree: NULL & mas->node == MAS_NONE
|
|
* - If it's a single entry: The entry & mas->node == MAS_ROOT
|
|
* - If it's a tree: NULL & mas->node == safe root node.
|
|
*/
|
|
static inline struct maple_enode *mas_start(struct ma_state *mas)
|
|
{
|
|
if (likely(mas_is_start(mas))) {
|
|
struct maple_enode *root;
|
|
|
|
mas->node = MAS_NONE;
|
|
mas->min = 0;
|
|
mas->max = ULONG_MAX;
|
|
mas->depth = 0;
|
|
mas->offset = 0;
|
|
|
|
root = mas_root(mas);
|
|
/* Tree with nodes */
|
|
if (likely(xa_is_node(root))) {
|
|
mas->depth = 1;
|
|
mas->node = mte_safe_root(root);
|
|
return NULL;
|
|
}
|
|
|
|
/* empty tree */
|
|
if (unlikely(!root)) {
|
|
mas->offset = MAPLE_NODE_SLOTS;
|
|
return NULL;
|
|
}
|
|
|
|
/* Single entry tree */
|
|
mas->node = MAS_ROOT;
|
|
mas->offset = MAPLE_NODE_SLOTS;
|
|
|
|
/* Single entry tree. */
|
|
if (mas->index > 0)
|
|
return NULL;
|
|
|
|
return root;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* ma_data_end() - Find the end of the data in a node.
|
|
* @node: The maple node
|
|
* @type: The maple node type
|
|
* @pivots: The array of pivots in the node
|
|
* @max: The maximum value in the node
|
|
*
|
|
* Uses metadata to find the end of the data when possible.
|
|
* Return: The zero indexed last slot with data (may be null).
|
|
*/
|
|
static inline unsigned char ma_data_end(struct maple_node *node,
|
|
enum maple_type type,
|
|
unsigned long *pivots,
|
|
unsigned long max)
|
|
{
|
|
unsigned char offset;
|
|
|
|
if (type == maple_arange_64)
|
|
return ma_meta_end(node, type);
|
|
|
|
offset = mt_pivots[type] - 1;
|
|
if (likely(!pivots[offset]))
|
|
return ma_meta_end(node, type);
|
|
|
|
if (likely(pivots[offset] == max))
|
|
return offset;
|
|
|
|
return mt_pivots[type];
|
|
}
|
|
|
|
/*
|
|
* mas_data_end() - Find the end of the data (slot).
|
|
* @mas: the maple state
|
|
*
|
|
* This method is optimized to check the metadata of a node if the node type
|
|
* supports data end metadata.
|
|
*
|
|
* Return: The zero indexed last slot with data (may be null).
|
|
*/
|
|
static inline unsigned char mas_data_end(struct ma_state *mas)
|
|
{
|
|
enum maple_type type;
|
|
struct maple_node *node;
|
|
unsigned char offset;
|
|
unsigned long *pivots;
|
|
|
|
type = mte_node_type(mas->node);
|
|
node = mas_mn(mas);
|
|
if (type == maple_arange_64)
|
|
return ma_meta_end(node, type);
|
|
|
|
pivots = ma_pivots(node, type);
|
|
offset = mt_pivots[type] - 1;
|
|
if (likely(!pivots[offset]))
|
|
return ma_meta_end(node, type);
|
|
|
|
if (likely(pivots[offset] == mas->max))
|
|
return offset;
|
|
|
|
return mt_pivots[type];
|
|
}
|
|
|
|
/*
|
|
* mas_leaf_max_gap() - Returns the largest gap in a leaf node
|
|
* @mas - the maple state
|
|
*
|
|
* Return: The maximum gap in the leaf.
|
|
*/
|
|
static unsigned long mas_leaf_max_gap(struct ma_state *mas)
|
|
{
|
|
enum maple_type mt;
|
|
unsigned long pstart, gap, max_gap;
|
|
struct maple_node *mn;
|
|
unsigned long *pivots;
|
|
void __rcu **slots;
|
|
unsigned char i;
|
|
unsigned char max_piv;
|
|
|
|
mt = mte_node_type(mas->node);
|
|
mn = mas_mn(mas);
|
|
slots = ma_slots(mn, mt);
|
|
max_gap = 0;
|
|
if (unlikely(ma_is_dense(mt))) {
|
|
gap = 0;
|
|
for (i = 0; i < mt_slots[mt]; i++) {
|
|
if (slots[i]) {
|
|
if (gap > max_gap)
|
|
max_gap = gap;
|
|
gap = 0;
|
|
} else {
|
|
gap++;
|
|
}
|
|
}
|
|
if (gap > max_gap)
|
|
max_gap = gap;
|
|
return max_gap;
|
|
}
|
|
|
|
/*
|
|
* Check the first implied pivot optimizes the loop below and slot 1 may
|
|
* be skipped if there is a gap in slot 0.
|
|
*/
|
|
pivots = ma_pivots(mn, mt);
|
|
if (likely(!slots[0])) {
|
|
max_gap = pivots[0] - mas->min + 1;
|
|
i = 2;
|
|
} else {
|
|
i = 1;
|
|
}
|
|
|
|
/* reduce max_piv as the special case is checked before the loop */
|
|
max_piv = ma_data_end(mn, mt, pivots, mas->max) - 1;
|
|
/*
|
|
* Check end implied pivot which can only be a gap on the right most
|
|
* node.
|
|
*/
|
|
if (unlikely(mas->max == ULONG_MAX) && !slots[max_piv + 1]) {
|
|
gap = ULONG_MAX - pivots[max_piv];
|
|
if (gap > max_gap)
|
|
max_gap = gap;
|
|
}
|
|
|
|
for (; i <= max_piv; i++) {
|
|
/* data == no gap. */
|
|
if (likely(slots[i]))
|
|
continue;
|
|
|
|
pstart = pivots[i - 1];
|
|
gap = pivots[i] - pstart;
|
|
if (gap > max_gap)
|
|
max_gap = gap;
|
|
|
|
/* There cannot be two gaps in a row. */
|
|
i++;
|
|
}
|
|
return max_gap;
|
|
}
|
|
|
|
/*
|
|
* ma_max_gap() - Get the maximum gap in a maple node (non-leaf)
|
|
* @node: The maple node
|
|
* @gaps: The pointer to the gaps
|
|
* @mt: The maple node type
|
|
* @*off: Pointer to store the offset location of the gap.
|
|
*
|
|
* Uses the metadata data end to scan backwards across set gaps.
|
|
*
|
|
* Return: The maximum gap value
|
|
*/
|
|
static inline unsigned long
|
|
ma_max_gap(struct maple_node *node, unsigned long *gaps, enum maple_type mt,
|
|
unsigned char *off)
|
|
{
|
|
unsigned char offset, i;
|
|
unsigned long max_gap = 0;
|
|
|
|
i = offset = ma_meta_end(node, mt);
|
|
do {
|
|
if (gaps[i] > max_gap) {
|
|
max_gap = gaps[i];
|
|
offset = i;
|
|
}
|
|
} while (i--);
|
|
|
|
*off = offset;
|
|
return max_gap;
|
|
}
|
|
|
|
/*
|
|
* mas_max_gap() - find the largest gap in a non-leaf node and set the slot.
|
|
* @mas: The maple state.
|
|
*
|
|
* If the metadata gap is set to MAPLE_ARANGE64_META_MAX, there is no gap.
|
|
*
|
|
* Return: The gap value.
|
|
*/
|
|
static inline unsigned long mas_max_gap(struct ma_state *mas)
|
|
{
|
|
unsigned long *gaps;
|
|
unsigned char offset;
|
|
enum maple_type mt;
|
|
struct maple_node *node;
|
|
|
|
mt = mte_node_type(mas->node);
|
|
if (ma_is_leaf(mt))
|
|
return mas_leaf_max_gap(mas);
|
|
|
|
node = mas_mn(mas);
|
|
offset = ma_meta_gap(node, mt);
|
|
if (offset == MAPLE_ARANGE64_META_MAX)
|
|
return 0;
|
|
|
|
gaps = ma_gaps(node, mt);
|
|
return gaps[offset];
|
|
}
|
|
|
|
/*
|
|
* mas_parent_gap() - Set the parent gap and any gaps above, as needed
|
|
* @mas: The maple state
|
|
* @offset: The gap offset in the parent to set
|
|
* @new: The new gap value.
|
|
*
|
|
* Set the parent gap then continue to set the gap upwards, using the metadata
|
|
* of the parent to see if it is necessary to check the node above.
|
|
*/
|
|
static inline void mas_parent_gap(struct ma_state *mas, unsigned char offset,
|
|
unsigned long new)
|
|
{
|
|
unsigned long meta_gap = 0;
|
|
struct maple_node *pnode;
|
|
struct maple_enode *penode;
|
|
unsigned long *pgaps;
|
|
unsigned char meta_offset;
|
|
enum maple_type pmt;
|
|
|
|
pnode = mte_parent(mas->node);
|
|
pmt = mas_parent_enum(mas, mas->node);
|
|
penode = mt_mk_node(pnode, pmt);
|
|
pgaps = ma_gaps(pnode, pmt);
|
|
|
|
ascend:
|
|
meta_offset = ma_meta_gap(pnode, pmt);
|
|
if (meta_offset == MAPLE_ARANGE64_META_MAX)
|
|
meta_gap = 0;
|
|
else
|
|
meta_gap = pgaps[meta_offset];
|
|
|
|
pgaps[offset] = new;
|
|
|
|
if (meta_gap == new)
|
|
return;
|
|
|
|
if (offset != meta_offset) {
|
|
if (meta_gap > new)
|
|
return;
|
|
|
|
ma_set_meta_gap(pnode, pmt, offset);
|
|
} else if (new < meta_gap) {
|
|
meta_offset = 15;
|
|
new = ma_max_gap(pnode, pgaps, pmt, &meta_offset);
|
|
ma_set_meta_gap(pnode, pmt, meta_offset);
|
|
}
|
|
|
|
if (ma_is_root(pnode))
|
|
return;
|
|
|
|
/* Go to the parent node. */
|
|
pnode = mte_parent(penode);
|
|
pmt = mas_parent_enum(mas, penode);
|
|
pgaps = ma_gaps(pnode, pmt);
|
|
offset = mte_parent_slot(penode);
|
|
penode = mt_mk_node(pnode, pmt);
|
|
goto ascend;
|
|
}
|
|
|
|
/*
|
|
* mas_update_gap() - Update a nodes gaps and propagate up if necessary.
|
|
* @mas - the maple state.
|
|
*/
|
|
static inline void mas_update_gap(struct ma_state *mas)
|
|
{
|
|
unsigned char pslot;
|
|
unsigned long p_gap;
|
|
unsigned long max_gap;
|
|
|
|
if (!mt_is_alloc(mas->tree))
|
|
return;
|
|
|
|
if (mte_is_root(mas->node))
|
|
return;
|
|
|
|
max_gap = mas_max_gap(mas);
|
|
|
|
pslot = mte_parent_slot(mas->node);
|
|
p_gap = ma_gaps(mte_parent(mas->node),
|
|
mas_parent_enum(mas, mas->node))[pslot];
|
|
|
|
if (p_gap != max_gap)
|
|
mas_parent_gap(mas, pslot, max_gap);
|
|
}
|
|
|
|
/*
|
|
* mas_adopt_children() - Set the parent pointer of all nodes in @parent to
|
|
* @parent with the slot encoded.
|
|
* @mas - the maple state (for the tree)
|
|
* @parent - the maple encoded node containing the children.
|
|
*/
|
|
static inline void mas_adopt_children(struct ma_state *mas,
|
|
struct maple_enode *parent)
|
|
{
|
|
enum maple_type type = mte_node_type(parent);
|
|
struct maple_node *node = mas_mn(mas);
|
|
void __rcu **slots = ma_slots(node, type);
|
|
unsigned long *pivots = ma_pivots(node, type);
|
|
struct maple_enode *child;
|
|
unsigned char offset;
|
|
|
|
offset = ma_data_end(node, type, pivots, mas->max);
|
|
do {
|
|
child = mas_slot_locked(mas, slots, offset);
|
|
mte_set_parent(child, parent, offset);
|
|
} while (offset--);
|
|
}
|
|
|
|
/*
|
|
* mas_replace() - Replace a maple node in the tree with mas->node. Uses the
|
|
* parent encoding to locate the maple node in the tree.
|
|
* @mas - the ma_state to use for operations.
|
|
* @advanced - boolean to adopt the child nodes and free the old node (false) or
|
|
* leave the node (true) and handle the adoption and free elsewhere.
|
|
*/
|
|
static inline void mas_replace(struct ma_state *mas, bool advanced)
|
|
__must_hold(mas->tree->lock)
|
|
{
|
|
struct maple_node *mn = mas_mn(mas);
|
|
struct maple_enode *old_enode;
|
|
unsigned char offset = 0;
|
|
void __rcu **slots = NULL;
|
|
|
|
if (ma_is_root(mn)) {
|
|
old_enode = mas_root_locked(mas);
|
|
} else {
|
|
offset = mte_parent_slot(mas->node);
|
|
slots = ma_slots(mte_parent(mas->node),
|
|
mas_parent_enum(mas, mas->node));
|
|
old_enode = mas_slot_locked(mas, slots, offset);
|
|
}
|
|
|
|
if (!advanced && !mte_is_leaf(mas->node))
|
|
mas_adopt_children(mas, mas->node);
|
|
|
|
if (mte_is_root(mas->node)) {
|
|
mn->parent = ma_parent_ptr(
|
|
((unsigned long)mas->tree | MA_ROOT_PARENT));
|
|
rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
|
|
mas_set_height(mas);
|
|
} else {
|
|
rcu_assign_pointer(slots[offset], mas->node);
|
|
}
|
|
|
|
if (!advanced)
|
|
mas_free(mas, old_enode);
|
|
}
|
|
|
|
/*
|
|
* mas_new_child() - Find the new child of a node.
|
|
* @mas: the maple state
|
|
* @child: the maple state to store the child.
|
|
*/
|
|
static inline bool mas_new_child(struct ma_state *mas, struct ma_state *child)
|
|
__must_hold(mas->tree->lock)
|
|
{
|
|
enum maple_type mt;
|
|
unsigned char offset;
|
|
unsigned char end;
|
|
unsigned long *pivots;
|
|
struct maple_enode *entry;
|
|
struct maple_node *node;
|
|
void __rcu **slots;
|
|
|
|
mt = mte_node_type(mas->node);
|
|
node = mas_mn(mas);
|
|
slots = ma_slots(node, mt);
|
|
pivots = ma_pivots(node, mt);
|
|
end = ma_data_end(node, mt, pivots, mas->max);
|
|
for (offset = mas->offset; offset <= end; offset++) {
|
|
entry = mas_slot_locked(mas, slots, offset);
|
|
if (mte_parent(entry) == node) {
|
|
*child = *mas;
|
|
mas->offset = offset + 1;
|
|
child->offset = offset;
|
|
mas_descend(child);
|
|
child->offset = 0;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* mab_shift_right() - Shift the data in mab right. Note, does not clean out the
|
|
* old data or set b_node->b_end.
|
|
* @b_node: the maple_big_node
|
|
* @shift: the shift count
|
|
*/
|
|
static inline void mab_shift_right(struct maple_big_node *b_node,
|
|
unsigned char shift)
|
|
{
|
|
unsigned long size = b_node->b_end * sizeof(unsigned long);
|
|
|
|
memmove(b_node->pivot + shift, b_node->pivot, size);
|
|
memmove(b_node->slot + shift, b_node->slot, size);
|
|
if (b_node->type == maple_arange_64)
|
|
memmove(b_node->gap + shift, b_node->gap, size);
|
|
}
|
|
|
|
/*
|
|
* mab_middle_node() - Check if a middle node is needed (unlikely)
|
|
* @b_node: the maple_big_node that contains the data.
|
|
* @size: the amount of data in the b_node
|
|
* @split: the potential split location
|
|
* @slot_count: the size that can be stored in a single node being considered.
|
|
*
|
|
* Return: true if a middle node is required.
|
|
*/
|
|
static inline bool mab_middle_node(struct maple_big_node *b_node, int split,
|
|
unsigned char slot_count)
|
|
{
|
|
unsigned char size = b_node->b_end;
|
|
|
|
if (size >= 2 * slot_count)
|
|
return true;
|
|
|
|
if (!b_node->slot[split] && (size >= 2 * slot_count - 1))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* mab_no_null_split() - ensure the split doesn't fall on a NULL
|
|
* @b_node: the maple_big_node with the data
|
|
* @split: the suggested split location
|
|
* @slot_count: the number of slots in the node being considered.
|
|
*
|
|
* Return: the split location.
|
|
*/
|
|
static inline int mab_no_null_split(struct maple_big_node *b_node,
|
|
unsigned char split, unsigned char slot_count)
|
|
{
|
|
if (!b_node->slot[split]) {
|
|
/*
|
|
* If the split is less than the max slot && the right side will
|
|
* still be sufficient, then increment the split on NULL.
|
|
*/
|
|
if ((split < slot_count - 1) &&
|
|
(b_node->b_end - split) > (mt_min_slots[b_node->type]))
|
|
split++;
|
|
else
|
|
split--;
|
|
}
|
|
return split;
|
|
}
|
|
|
|
/*
|
|
* mab_calc_split() - Calculate the split location and if there needs to be two
|
|
* splits.
|
|
* @bn: The maple_big_node with the data
|
|
* @mid_split: The second split, if required. 0 otherwise.
|
|
*
|
|
* Return: The first split location. The middle split is set in @mid_split.
|
|
*/
|
|
static inline int mab_calc_split(struct ma_state *mas,
|
|
struct maple_big_node *bn, unsigned char *mid_split, unsigned long min)
|
|
{
|
|
unsigned char b_end = bn->b_end;
|
|
int split = b_end / 2; /* Assume equal split. */
|
|
unsigned char slot_min, slot_count = mt_slots[bn->type];
|
|
|
|
/*
|
|
* To support gap tracking, all NULL entries are kept together and a node cannot
|
|
* end on a NULL entry, with the exception of the left-most leaf. The
|
|
* limitation means that the split of a node must be checked for this condition
|
|
* and be able to put more data in one direction or the other.
|
|
*/
|
|
if (unlikely((mas->mas_flags & MA_STATE_BULK))) {
|
|
*mid_split = 0;
|
|
split = b_end - mt_min_slots[bn->type];
|
|
|
|
if (!ma_is_leaf(bn->type))
|
|
return split;
|
|
|
|
mas->mas_flags |= MA_STATE_REBALANCE;
|
|
if (!bn->slot[split])
|
|
split--;
|
|
return split;
|
|
}
|
|
|
|
/*
|
|
* Although extremely rare, it is possible to enter what is known as the 3-way
|
|
* split scenario. The 3-way split comes about by means of a store of a range
|
|
* that overwrites the end and beginning of two full nodes. The result is a set
|
|
* of entries that cannot be stored in 2 nodes. Sometimes, these two nodes can
|
|
* also be located in different parent nodes which are also full. This can
|
|
* carry upwards all the way to the root in the worst case.
|
|
*/
|
|
if (unlikely(mab_middle_node(bn, split, slot_count))) {
|
|
split = b_end / 3;
|
|
*mid_split = split * 2;
|
|
} else {
|
|
slot_min = mt_min_slots[bn->type];
|
|
|
|
*mid_split = 0;
|
|
/*
|
|
* Avoid having a range less than the slot count unless it
|
|
* causes one node to be deficient.
|
|
* NOTE: mt_min_slots is 1 based, b_end and split are zero.
|
|
*/
|
|
while (((bn->pivot[split] - min) < slot_count - 1) &&
|
|
(split < slot_count - 1) && (b_end - split > slot_min))
|
|
split++;
|
|
}
|
|
|
|
/* Avoid ending a node on a NULL entry */
|
|
split = mab_no_null_split(bn, split, slot_count);
|
|
if (!(*mid_split))
|
|
return split;
|
|
|
|
*mid_split = mab_no_null_split(bn, *mid_split, slot_count);
|
|
|
|
return split;
|
|
}
|
|
|
|
/*
|
|
* mas_mab_cp() - Copy data from a maple state inclusively to a maple_big_node
|
|
* and set @b_node->b_end to the next free slot.
|
|
* @mas: The maple state
|
|
* @mas_start: The starting slot to copy
|
|
* @mas_end: The end slot to copy (inclusively)
|
|
* @b_node: The maple_big_node to place the data
|
|
* @mab_start: The starting location in maple_big_node to store the data.
|
|
*/
|
|
static inline void mas_mab_cp(struct ma_state *mas, unsigned char mas_start,
|
|
unsigned char mas_end, struct maple_big_node *b_node,
|
|
unsigned char mab_start)
|
|
{
|
|
enum maple_type mt;
|
|
struct maple_node *node;
|
|
void __rcu **slots;
|
|
unsigned long *pivots, *gaps;
|
|
int i = mas_start, j = mab_start;
|
|
unsigned char piv_end;
|
|
|
|
node = mas_mn(mas);
|
|
mt = mte_node_type(mas->node);
|
|
pivots = ma_pivots(node, mt);
|
|
if (!i) {
|
|
b_node->pivot[j] = pivots[i++];
|
|
if (unlikely(i > mas_end))
|
|
goto complete;
|
|
j++;
|
|
}
|
|
|
|
piv_end = min(mas_end, mt_pivots[mt]);
|
|
for (; i < piv_end; i++, j++) {
|
|
b_node->pivot[j] = pivots[i];
|
|
if (unlikely(!b_node->pivot[j]))
|
|
break;
|
|
|
|
if (unlikely(mas->max == b_node->pivot[j]))
|
|
goto complete;
|
|
}
|
|
|
|
if (likely(i <= mas_end))
|
|
b_node->pivot[j] = mas_safe_pivot(mas, pivots, i, mt);
|
|
|
|
complete:
|
|
b_node->b_end = ++j;
|
|
j -= mab_start;
|
|
slots = ma_slots(node, mt);
|
|
memcpy(b_node->slot + mab_start, slots + mas_start, sizeof(void *) * j);
|
|
if (!ma_is_leaf(mt) && mt_is_alloc(mas->tree)) {
|
|
gaps = ma_gaps(node, mt);
|
|
memcpy(b_node->gap + mab_start, gaps + mas_start,
|
|
sizeof(unsigned long) * j);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_leaf_set_meta() - Set the metadata of a leaf if possible.
|
|
* @mas: The maple state
|
|
* @node: The maple node
|
|
* @pivots: pointer to the maple node pivots
|
|
* @mt: The maple type
|
|
* @end: The assumed end
|
|
*
|
|
* Note, end may be incremented within this function but not modified at the
|
|
* source. This is fine since the metadata is the last thing to be stored in a
|
|
* node during a write.
|
|
*/
|
|
static inline void mas_leaf_set_meta(struct ma_state *mas,
|
|
struct maple_node *node, unsigned long *pivots,
|
|
enum maple_type mt, unsigned char end)
|
|
{
|
|
/* There is no room for metadata already */
|
|
if (mt_pivots[mt] <= end)
|
|
return;
|
|
|
|
if (pivots[end] && pivots[end] < mas->max)
|
|
end++;
|
|
|
|
if (end < mt_slots[mt] - 1)
|
|
ma_set_meta(node, mt, 0, end);
|
|
}
|
|
|
|
/*
|
|
* mab_mas_cp() - Copy data from maple_big_node to a maple encoded node.
|
|
* @b_node: the maple_big_node that has the data
|
|
* @mab_start: the start location in @b_node.
|
|
* @mab_end: The end location in @b_node (inclusively)
|
|
* @mas: The maple state with the maple encoded node.
|
|
*/
|
|
static inline void mab_mas_cp(struct maple_big_node *b_node,
|
|
unsigned char mab_start, unsigned char mab_end,
|
|
struct ma_state *mas, bool new_max)
|
|
{
|
|
int i, j = 0;
|
|
enum maple_type mt = mte_node_type(mas->node);
|
|
struct maple_node *node = mte_to_node(mas->node);
|
|
void __rcu **slots = ma_slots(node, mt);
|
|
unsigned long *pivots = ma_pivots(node, mt);
|
|
unsigned long *gaps = NULL;
|
|
unsigned char end;
|
|
|
|
if (mab_end - mab_start > mt_pivots[mt])
|
|
mab_end--;
|
|
|
|
if (!pivots[mt_pivots[mt] - 1])
|
|
slots[mt_pivots[mt]] = NULL;
|
|
|
|
i = mab_start;
|
|
do {
|
|
pivots[j++] = b_node->pivot[i++];
|
|
} while (i <= mab_end && likely(b_node->pivot[i]));
|
|
|
|
memcpy(slots, b_node->slot + mab_start,
|
|
sizeof(void *) * (i - mab_start));
|
|
|
|
if (new_max)
|
|
mas->max = b_node->pivot[i - 1];
|
|
|
|
end = j - 1;
|
|
if (likely(!ma_is_leaf(mt) && mt_is_alloc(mas->tree))) {
|
|
unsigned long max_gap = 0;
|
|
unsigned char offset = 15;
|
|
|
|
gaps = ma_gaps(node, mt);
|
|
do {
|
|
gaps[--j] = b_node->gap[--i];
|
|
if (gaps[j] > max_gap) {
|
|
offset = j;
|
|
max_gap = gaps[j];
|
|
}
|
|
} while (j);
|
|
|
|
ma_set_meta(node, mt, offset, end);
|
|
} else {
|
|
mas_leaf_set_meta(mas, node, pivots, mt, end);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_descend_adopt() - Descend through a sub-tree and adopt children.
|
|
* @mas: the maple state with the maple encoded node of the sub-tree.
|
|
*
|
|
* Descend through a sub-tree and adopt children who do not have the correct
|
|
* parents set. Follow the parents which have the correct parents as they are
|
|
* the new entries which need to be followed to find other incorrectly set
|
|
* parents.
|
|
*/
|
|
static inline void mas_descend_adopt(struct ma_state *mas)
|
|
{
|
|
struct ma_state list[3], next[3];
|
|
int i, n;
|
|
|
|
/*
|
|
* At each level there may be up to 3 correct parent pointers which indicates
|
|
* the new nodes which need to be walked to find any new nodes at a lower level.
|
|
*/
|
|
|
|
for (i = 0; i < 3; i++) {
|
|
list[i] = *mas;
|
|
list[i].offset = 0;
|
|
next[i].offset = 0;
|
|
}
|
|
next[0] = *mas;
|
|
|
|
while (!mte_is_leaf(list[0].node)) {
|
|
n = 0;
|
|
for (i = 0; i < 3; i++) {
|
|
if (mas_is_none(&list[i]))
|
|
continue;
|
|
|
|
if (i && list[i-1].node == list[i].node)
|
|
continue;
|
|
|
|
while ((n < 3) && (mas_new_child(&list[i], &next[n])))
|
|
n++;
|
|
|
|
mas_adopt_children(&list[i], list[i].node);
|
|
}
|
|
|
|
while (n < 3)
|
|
next[n++].node = MAS_NONE;
|
|
|
|
/* descend by setting the list to the children */
|
|
for (i = 0; i < 3; i++)
|
|
list[i] = next[i];
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_bulk_rebalance() - Rebalance the end of a tree after a bulk insert.
|
|
* @mas: The maple state
|
|
* @end: The maple node end
|
|
* @mt: The maple node type
|
|
*/
|
|
static inline void mas_bulk_rebalance(struct ma_state *mas, unsigned char end,
|
|
enum maple_type mt)
|
|
{
|
|
if (!(mas->mas_flags & MA_STATE_BULK))
|
|
return;
|
|
|
|
if (mte_is_root(mas->node))
|
|
return;
|
|
|
|
if (end > mt_min_slots[mt]) {
|
|
mas->mas_flags &= ~MA_STATE_REBALANCE;
|
|
return;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_store_b_node() - Store an @entry into the b_node while also copying the
|
|
* data from a maple encoded node.
|
|
* @wr_mas: the maple write state
|
|
* @b_node: the maple_big_node to fill with data
|
|
* @offset_end: the offset to end copying
|
|
*
|
|
* Return: The actual end of the data stored in @b_node
|
|
*/
|
|
static inline void mas_store_b_node(struct ma_wr_state *wr_mas,
|
|
struct maple_big_node *b_node, unsigned char offset_end)
|
|
{
|
|
unsigned char slot;
|
|
unsigned char b_end;
|
|
/* Possible underflow of piv will wrap back to 0 before use. */
|
|
unsigned long piv;
|
|
struct ma_state *mas = wr_mas->mas;
|
|
|
|
b_node->type = wr_mas->type;
|
|
b_end = 0;
|
|
slot = mas->offset;
|
|
if (slot) {
|
|
/* Copy start data up to insert. */
|
|
mas_mab_cp(mas, 0, slot - 1, b_node, 0);
|
|
b_end = b_node->b_end;
|
|
piv = b_node->pivot[b_end - 1];
|
|
} else
|
|
piv = mas->min - 1;
|
|
|
|
if (piv + 1 < mas->index) {
|
|
/* Handle range starting after old range */
|
|
b_node->slot[b_end] = wr_mas->content;
|
|
if (!wr_mas->content)
|
|
b_node->gap[b_end] = mas->index - 1 - piv;
|
|
b_node->pivot[b_end++] = mas->index - 1;
|
|
}
|
|
|
|
/* Store the new entry. */
|
|
mas->offset = b_end;
|
|
b_node->slot[b_end] = wr_mas->entry;
|
|
b_node->pivot[b_end] = mas->last;
|
|
|
|
/* Appended. */
|
|
if (mas->last >= mas->max)
|
|
goto b_end;
|
|
|
|
/* Handle new range ending before old range ends */
|
|
piv = mas_logical_pivot(mas, wr_mas->pivots, offset_end, wr_mas->type);
|
|
if (piv > mas->last) {
|
|
if (piv == ULONG_MAX)
|
|
mas_bulk_rebalance(mas, b_node->b_end, wr_mas->type);
|
|
|
|
if (offset_end != slot)
|
|
wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
|
|
offset_end);
|
|
|
|
b_node->slot[++b_end] = wr_mas->content;
|
|
if (!wr_mas->content)
|
|
b_node->gap[b_end] = piv - mas->last + 1;
|
|
b_node->pivot[b_end] = piv;
|
|
}
|
|
|
|
slot = offset_end + 1;
|
|
if (slot > wr_mas->node_end)
|
|
goto b_end;
|
|
|
|
/* Copy end data to the end of the node. */
|
|
mas_mab_cp(mas, slot, wr_mas->node_end + 1, b_node, ++b_end);
|
|
b_node->b_end--;
|
|
return;
|
|
|
|
b_end:
|
|
b_node->b_end = b_end;
|
|
}
|
|
|
|
/*
|
|
* mas_prev_sibling() - Find the previous node with the same parent.
|
|
* @mas: the maple state
|
|
*
|
|
* Return: True if there is a previous sibling, false otherwise.
|
|
*/
|
|
static inline bool mas_prev_sibling(struct ma_state *mas)
|
|
{
|
|
unsigned int p_slot = mte_parent_slot(mas->node);
|
|
|
|
if (mte_is_root(mas->node))
|
|
return false;
|
|
|
|
if (!p_slot)
|
|
return false;
|
|
|
|
mas_ascend(mas);
|
|
mas->offset = p_slot - 1;
|
|
mas_descend(mas);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mas_next_sibling() - Find the next node with the same parent.
|
|
* @mas: the maple state
|
|
*
|
|
* Return: true if there is a next sibling, false otherwise.
|
|
*/
|
|
static inline bool mas_next_sibling(struct ma_state *mas)
|
|
{
|
|
MA_STATE(parent, mas->tree, mas->index, mas->last);
|
|
|
|
if (mte_is_root(mas->node))
|
|
return false;
|
|
|
|
parent = *mas;
|
|
mas_ascend(&parent);
|
|
parent.offset = mte_parent_slot(mas->node) + 1;
|
|
if (parent.offset > mas_data_end(&parent))
|
|
return false;
|
|
|
|
*mas = parent;
|
|
mas_descend(mas);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mte_node_or_node() - Return the encoded node or MAS_NONE.
|
|
* @enode: The encoded maple node.
|
|
*
|
|
* Shorthand to avoid setting %NULLs in the tree or maple_subtree_state.
|
|
*
|
|
* Return: @enode or MAS_NONE
|
|
*/
|
|
static inline struct maple_enode *mte_node_or_none(struct maple_enode *enode)
|
|
{
|
|
if (enode)
|
|
return enode;
|
|
|
|
return ma_enode_ptr(MAS_NONE);
|
|
}
|
|
|
|
/*
|
|
* mas_wr_node_walk() - Find the correct offset for the index in the @mas.
|
|
* @wr_mas: The maple write state
|
|
*
|
|
* Uses mas_slot_locked() and does not need to worry about dead nodes.
|
|
*/
|
|
static inline void mas_wr_node_walk(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct ma_state *mas = wr_mas->mas;
|
|
unsigned char count;
|
|
unsigned char offset;
|
|
unsigned long index, min, max;
|
|
|
|
if (unlikely(ma_is_dense(wr_mas->type))) {
|
|
wr_mas->r_max = wr_mas->r_min = mas->index;
|
|
mas->offset = mas->index = mas->min;
|
|
return;
|
|
}
|
|
|
|
wr_mas->node = mas_mn(wr_mas->mas);
|
|
wr_mas->pivots = ma_pivots(wr_mas->node, wr_mas->type);
|
|
count = wr_mas->node_end = ma_data_end(wr_mas->node, wr_mas->type,
|
|
wr_mas->pivots, mas->max);
|
|
offset = mas->offset;
|
|
min = mas_safe_min(mas, wr_mas->pivots, offset);
|
|
if (unlikely(offset == count))
|
|
goto max;
|
|
|
|
max = wr_mas->pivots[offset];
|
|
index = mas->index;
|
|
if (unlikely(index <= max))
|
|
goto done;
|
|
|
|
if (unlikely(!max && offset))
|
|
goto max;
|
|
|
|
min = max + 1;
|
|
while (++offset < count) {
|
|
max = wr_mas->pivots[offset];
|
|
if (index <= max)
|
|
goto done;
|
|
else if (unlikely(!max))
|
|
break;
|
|
|
|
min = max + 1;
|
|
}
|
|
|
|
max:
|
|
max = mas->max;
|
|
done:
|
|
wr_mas->r_max = max;
|
|
wr_mas->r_min = min;
|
|
wr_mas->offset_end = mas->offset = offset;
|
|
}
|
|
|
|
/*
|
|
* mas_topiary_range() - Add a range of slots to the topiary.
|
|
* @mas: The maple state
|
|
* @destroy: The topiary to add the slots (usually destroy)
|
|
* @start: The starting slot inclusively
|
|
* @end: The end slot inclusively
|
|
*/
|
|
static inline void mas_topiary_range(struct ma_state *mas,
|
|
struct ma_topiary *destroy, unsigned char start, unsigned char end)
|
|
{
|
|
void __rcu **slots;
|
|
unsigned char offset;
|
|
|
|
MT_BUG_ON(mas->tree, mte_is_leaf(mas->node));
|
|
slots = ma_slots(mas_mn(mas), mte_node_type(mas->node));
|
|
for (offset = start; offset <= end; offset++) {
|
|
struct maple_enode *enode = mas_slot_locked(mas, slots, offset);
|
|
|
|
if (mte_dead_node(enode))
|
|
continue;
|
|
|
|
mat_add(destroy, enode);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mast_topiary() - Add the portions of the tree to the removal list; either to
|
|
* be freed or discarded (destroy walk).
|
|
* @mast: The maple_subtree_state.
|
|
*/
|
|
static inline void mast_topiary(struct maple_subtree_state *mast)
|
|
{
|
|
MA_WR_STATE(wr_mas, mast->orig_l, NULL);
|
|
unsigned char r_start, r_end;
|
|
unsigned char l_start, l_end;
|
|
void __rcu **l_slots, **r_slots;
|
|
|
|
wr_mas.type = mte_node_type(mast->orig_l->node);
|
|
mast->orig_l->index = mast->orig_l->last;
|
|
mas_wr_node_walk(&wr_mas);
|
|
l_start = mast->orig_l->offset + 1;
|
|
l_end = mas_data_end(mast->orig_l);
|
|
r_start = 0;
|
|
r_end = mast->orig_r->offset;
|
|
|
|
if (r_end)
|
|
r_end--;
|
|
|
|
l_slots = ma_slots(mas_mn(mast->orig_l),
|
|
mte_node_type(mast->orig_l->node));
|
|
|
|
r_slots = ma_slots(mas_mn(mast->orig_r),
|
|
mte_node_type(mast->orig_r->node));
|
|
|
|
if ((l_start < l_end) &&
|
|
mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_start))) {
|
|
l_start++;
|
|
}
|
|
|
|
if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_end))) {
|
|
if (r_end)
|
|
r_end--;
|
|
}
|
|
|
|
if ((l_start > r_end) && (mast->orig_l->node == mast->orig_r->node))
|
|
return;
|
|
|
|
/* At the node where left and right sides meet, add the parts between */
|
|
if (mast->orig_l->node == mast->orig_r->node) {
|
|
return mas_topiary_range(mast->orig_l, mast->destroy,
|
|
l_start, r_end);
|
|
}
|
|
|
|
/* mast->orig_r is different and consumed. */
|
|
if (mte_is_leaf(mast->orig_r->node))
|
|
return;
|
|
|
|
if (mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_end)))
|
|
l_end--;
|
|
|
|
|
|
if (l_start <= l_end)
|
|
mas_topiary_range(mast->orig_l, mast->destroy, l_start, l_end);
|
|
|
|
if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_start)))
|
|
r_start++;
|
|
|
|
if (r_start <= r_end)
|
|
mas_topiary_range(mast->orig_r, mast->destroy, 0, r_end);
|
|
}
|
|
|
|
/*
|
|
* mast_rebalance_next() - Rebalance against the next node
|
|
* @mast: The maple subtree state
|
|
* @old_r: The encoded maple node to the right (next node).
|
|
*/
|
|
static inline void mast_rebalance_next(struct maple_subtree_state *mast)
|
|
{
|
|
unsigned char b_end = mast->bn->b_end;
|
|
|
|
mas_mab_cp(mast->orig_r, 0, mt_slot_count(mast->orig_r->node),
|
|
mast->bn, b_end);
|
|
mast->orig_r->last = mast->orig_r->max;
|
|
}
|
|
|
|
/*
|
|
* mast_rebalance_prev() - Rebalance against the previous node
|
|
* @mast: The maple subtree state
|
|
* @old_l: The encoded maple node to the left (previous node)
|
|
*/
|
|
static inline void mast_rebalance_prev(struct maple_subtree_state *mast)
|
|
{
|
|
unsigned char end = mas_data_end(mast->orig_l) + 1;
|
|
unsigned char b_end = mast->bn->b_end;
|
|
|
|
mab_shift_right(mast->bn, end);
|
|
mas_mab_cp(mast->orig_l, 0, end - 1, mast->bn, 0);
|
|
mast->l->min = mast->orig_l->min;
|
|
mast->orig_l->index = mast->orig_l->min;
|
|
mast->bn->b_end = end + b_end;
|
|
mast->l->offset += end;
|
|
}
|
|
|
|
/*
|
|
* mast_spanning_rebalance() - Rebalance nodes with nearest neighbour favouring
|
|
* the node to the right. Checking the nodes to the right then the left at each
|
|
* level upwards until root is reached. Free and destroy as needed.
|
|
* Data is copied into the @mast->bn.
|
|
* @mast: The maple_subtree_state.
|
|
*/
|
|
static inline
|
|
bool mast_spanning_rebalance(struct maple_subtree_state *mast)
|
|
{
|
|
struct ma_state r_tmp = *mast->orig_r;
|
|
struct ma_state l_tmp = *mast->orig_l;
|
|
struct maple_enode *ancestor = NULL;
|
|
unsigned char start, end;
|
|
unsigned char depth = 0;
|
|
|
|
r_tmp = *mast->orig_r;
|
|
l_tmp = *mast->orig_l;
|
|
do {
|
|
mas_ascend(mast->orig_r);
|
|
mas_ascend(mast->orig_l);
|
|
depth++;
|
|
if (!ancestor &&
|
|
(mast->orig_r->node == mast->orig_l->node)) {
|
|
ancestor = mast->orig_r->node;
|
|
end = mast->orig_r->offset - 1;
|
|
start = mast->orig_l->offset + 1;
|
|
}
|
|
|
|
if (mast->orig_r->offset < mas_data_end(mast->orig_r)) {
|
|
if (!ancestor) {
|
|
ancestor = mast->orig_r->node;
|
|
start = 0;
|
|
}
|
|
|
|
mast->orig_r->offset++;
|
|
do {
|
|
mas_descend(mast->orig_r);
|
|
mast->orig_r->offset = 0;
|
|
depth--;
|
|
} while (depth);
|
|
|
|
mast_rebalance_next(mast);
|
|
do {
|
|
unsigned char l_off = 0;
|
|
struct maple_enode *child = r_tmp.node;
|
|
|
|
mas_ascend(&r_tmp);
|
|
if (ancestor == r_tmp.node)
|
|
l_off = start;
|
|
|
|
if (r_tmp.offset)
|
|
r_tmp.offset--;
|
|
|
|
if (l_off < r_tmp.offset)
|
|
mas_topiary_range(&r_tmp, mast->destroy,
|
|
l_off, r_tmp.offset);
|
|
|
|
if (l_tmp.node != child)
|
|
mat_add(mast->free, child);
|
|
|
|
} while (r_tmp.node != ancestor);
|
|
|
|
*mast->orig_l = l_tmp;
|
|
return true;
|
|
|
|
} else if (mast->orig_l->offset != 0) {
|
|
if (!ancestor) {
|
|
ancestor = mast->orig_l->node;
|
|
end = mas_data_end(mast->orig_l);
|
|
}
|
|
|
|
mast->orig_l->offset--;
|
|
do {
|
|
mas_descend(mast->orig_l);
|
|
mast->orig_l->offset =
|
|
mas_data_end(mast->orig_l);
|
|
depth--;
|
|
} while (depth);
|
|
|
|
mast_rebalance_prev(mast);
|
|
do {
|
|
unsigned char r_off;
|
|
struct maple_enode *child = l_tmp.node;
|
|
|
|
mas_ascend(&l_tmp);
|
|
if (ancestor == l_tmp.node)
|
|
r_off = end;
|
|
else
|
|
r_off = mas_data_end(&l_tmp);
|
|
|
|
if (l_tmp.offset < r_off)
|
|
l_tmp.offset++;
|
|
|
|
if (l_tmp.offset < r_off)
|
|
mas_topiary_range(&l_tmp, mast->destroy,
|
|
l_tmp.offset, r_off);
|
|
|
|
if (r_tmp.node != child)
|
|
mat_add(mast->free, child);
|
|
|
|
} while (l_tmp.node != ancestor);
|
|
|
|
*mast->orig_r = r_tmp;
|
|
return true;
|
|
}
|
|
} while (!mte_is_root(mast->orig_r->node));
|
|
|
|
*mast->orig_r = r_tmp;
|
|
*mast->orig_l = l_tmp;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* mast_ascend_free() - Add current original maple state nodes to the free list
|
|
* and ascend.
|
|
* @mast: the maple subtree state.
|
|
*
|
|
* Ascend the original left and right sides and add the previous nodes to the
|
|
* free list. Set the slots to point to the correct location in the new nodes.
|
|
*/
|
|
static inline void
|
|
mast_ascend_free(struct maple_subtree_state *mast)
|
|
{
|
|
MA_WR_STATE(wr_mas, mast->orig_r, NULL);
|
|
struct maple_enode *left = mast->orig_l->node;
|
|
struct maple_enode *right = mast->orig_r->node;
|
|
|
|
mas_ascend(mast->orig_l);
|
|
mas_ascend(mast->orig_r);
|
|
mat_add(mast->free, left);
|
|
|
|
if (left != right)
|
|
mat_add(mast->free, right);
|
|
|
|
mast->orig_r->offset = 0;
|
|
mast->orig_r->index = mast->r->max;
|
|
/* last should be larger than or equal to index */
|
|
if (mast->orig_r->last < mast->orig_r->index)
|
|
mast->orig_r->last = mast->orig_r->index;
|
|
/*
|
|
* The node may not contain the value so set slot to ensure all
|
|
* of the nodes contents are freed or destroyed.
|
|
*/
|
|
wr_mas.type = mte_node_type(mast->orig_r->node);
|
|
mas_wr_node_walk(&wr_mas);
|
|
/* Set up the left side of things */
|
|
mast->orig_l->offset = 0;
|
|
mast->orig_l->index = mast->l->min;
|
|
wr_mas.mas = mast->orig_l;
|
|
wr_mas.type = mte_node_type(mast->orig_l->node);
|
|
mas_wr_node_walk(&wr_mas);
|
|
|
|
mast->bn->type = wr_mas.type;
|
|
}
|
|
|
|
/*
|
|
* mas_new_ma_node() - Create and return a new maple node. Helper function.
|
|
* @mas: the maple state with the allocations.
|
|
* @b_node: the maple_big_node with the type encoding.
|
|
*
|
|
* Use the node type from the maple_big_node to allocate a new node from the
|
|
* ma_state. This function exists mainly for code readability.
|
|
*
|
|
* Return: A new maple encoded node
|
|
*/
|
|
static inline struct maple_enode
|
|
*mas_new_ma_node(struct ma_state *mas, struct maple_big_node *b_node)
|
|
{
|
|
return mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)), b_node->type);
|
|
}
|
|
|
|
/*
|
|
* mas_mab_to_node() - Set up right and middle nodes
|
|
*
|
|
* @mas: the maple state that contains the allocations.
|
|
* @b_node: the node which contains the data.
|
|
* @left: The pointer which will have the left node
|
|
* @right: The pointer which may have the right node
|
|
* @middle: the pointer which may have the middle node (rare)
|
|
* @mid_split: the split location for the middle node
|
|
*
|
|
* Return: the split of left.
|
|
*/
|
|
static inline unsigned char mas_mab_to_node(struct ma_state *mas,
|
|
struct maple_big_node *b_node, struct maple_enode **left,
|
|
struct maple_enode **right, struct maple_enode **middle,
|
|
unsigned char *mid_split, unsigned long min)
|
|
{
|
|
unsigned char split = 0;
|
|
unsigned char slot_count = mt_slots[b_node->type];
|
|
|
|
*left = mas_new_ma_node(mas, b_node);
|
|
*right = NULL;
|
|
*middle = NULL;
|
|
*mid_split = 0;
|
|
|
|
if (b_node->b_end < slot_count) {
|
|
split = b_node->b_end;
|
|
} else {
|
|
split = mab_calc_split(mas, b_node, mid_split, min);
|
|
*right = mas_new_ma_node(mas, b_node);
|
|
}
|
|
|
|
if (*mid_split)
|
|
*middle = mas_new_ma_node(mas, b_node);
|
|
|
|
return split;
|
|
|
|
}
|
|
|
|
/*
|
|
* mab_set_b_end() - Add entry to b_node at b_node->b_end and increment the end
|
|
* pointer.
|
|
* @b_node - the big node to add the entry
|
|
* @mas - the maple state to get the pivot (mas->max)
|
|
* @entry - the entry to add, if NULL nothing happens.
|
|
*/
|
|
static inline void mab_set_b_end(struct maple_big_node *b_node,
|
|
struct ma_state *mas,
|
|
void *entry)
|
|
{
|
|
if (!entry)
|
|
return;
|
|
|
|
b_node->slot[b_node->b_end] = entry;
|
|
if (mt_is_alloc(mas->tree))
|
|
b_node->gap[b_node->b_end] = mas_max_gap(mas);
|
|
b_node->pivot[b_node->b_end++] = mas->max;
|
|
}
|
|
|
|
/*
|
|
* mas_set_split_parent() - combine_then_separate helper function. Sets the parent
|
|
* of @mas->node to either @left or @right, depending on @slot and @split
|
|
*
|
|
* @mas - the maple state with the node that needs a parent
|
|
* @left - possible parent 1
|
|
* @right - possible parent 2
|
|
* @slot - the slot the mas->node was placed
|
|
* @split - the split location between @left and @right
|
|
*/
|
|
static inline void mas_set_split_parent(struct ma_state *mas,
|
|
struct maple_enode *left,
|
|
struct maple_enode *right,
|
|
unsigned char *slot, unsigned char split)
|
|
{
|
|
if (mas_is_none(mas))
|
|
return;
|
|
|
|
if ((*slot) <= split)
|
|
mte_set_parent(mas->node, left, *slot);
|
|
else if (right)
|
|
mte_set_parent(mas->node, right, (*slot) - split - 1);
|
|
|
|
(*slot)++;
|
|
}
|
|
|
|
/*
|
|
* mte_mid_split_check() - Check if the next node passes the mid-split
|
|
* @**l: Pointer to left encoded maple node.
|
|
* @**m: Pointer to middle encoded maple node.
|
|
* @**r: Pointer to right encoded maple node.
|
|
* @slot: The offset
|
|
* @*split: The split location.
|
|
* @mid_split: The middle split.
|
|
*/
|
|
static inline void mte_mid_split_check(struct maple_enode **l,
|
|
struct maple_enode **r,
|
|
struct maple_enode *right,
|
|
unsigned char slot,
|
|
unsigned char *split,
|
|
unsigned char mid_split)
|
|
{
|
|
if (*r == right)
|
|
return;
|
|
|
|
if (slot < mid_split)
|
|
return;
|
|
|
|
*l = *r;
|
|
*r = right;
|
|
*split = mid_split;
|
|
}
|
|
|
|
/*
|
|
* mast_set_split_parents() - Helper function to set three nodes parents. Slot
|
|
* is taken from @mast->l.
|
|
* @mast - the maple subtree state
|
|
* @left - the left node
|
|
* @right - the right node
|
|
* @split - the split location.
|
|
*/
|
|
static inline void mast_set_split_parents(struct maple_subtree_state *mast,
|
|
struct maple_enode *left,
|
|
struct maple_enode *middle,
|
|
struct maple_enode *right,
|
|
unsigned char split,
|
|
unsigned char mid_split)
|
|
{
|
|
unsigned char slot;
|
|
struct maple_enode *l = left;
|
|
struct maple_enode *r = right;
|
|
|
|
if (mas_is_none(mast->l))
|
|
return;
|
|
|
|
if (middle)
|
|
r = middle;
|
|
|
|
slot = mast->l->offset;
|
|
|
|
mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
|
|
mas_set_split_parent(mast->l, l, r, &slot, split);
|
|
|
|
mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
|
|
mas_set_split_parent(mast->m, l, r, &slot, split);
|
|
|
|
mte_mid_split_check(&l, &r, right, slot, &split, mid_split);
|
|
mas_set_split_parent(mast->r, l, r, &slot, split);
|
|
}
|
|
|
|
/*
|
|
* mas_wmb_replace() - Write memory barrier and replace
|
|
* @mas: The maple state
|
|
* @free: the maple topiary list of nodes to free
|
|
* @destroy: The maple topiary list of nodes to destroy (walk and free)
|
|
*
|
|
* Updates gap as necessary.
|
|
*/
|
|
static inline void mas_wmb_replace(struct ma_state *mas,
|
|
struct ma_topiary *free,
|
|
struct ma_topiary *destroy)
|
|
{
|
|
/* All nodes must see old data as dead prior to replacing that data */
|
|
smp_wmb(); /* Needed for RCU */
|
|
|
|
/* Insert the new data in the tree */
|
|
mas_replace(mas, true);
|
|
|
|
if (!mte_is_leaf(mas->node))
|
|
mas_descend_adopt(mas);
|
|
|
|
mas_mat_free(mas, free);
|
|
|
|
if (destroy)
|
|
mas_mat_destroy(mas, destroy);
|
|
|
|
if (mte_is_leaf(mas->node))
|
|
return;
|
|
|
|
mas_update_gap(mas);
|
|
}
|
|
|
|
/*
|
|
* mast_new_root() - Set a new tree root during subtree creation
|
|
* @mast: The maple subtree state
|
|
* @mas: The maple state
|
|
*/
|
|
static inline void mast_new_root(struct maple_subtree_state *mast,
|
|
struct ma_state *mas)
|
|
{
|
|
mas_mn(mast->l)->parent =
|
|
ma_parent_ptr(((unsigned long)mas->tree | MA_ROOT_PARENT));
|
|
if (!mte_dead_node(mast->orig_l->node) &&
|
|
!mte_is_root(mast->orig_l->node)) {
|
|
do {
|
|
mast_ascend_free(mast);
|
|
mast_topiary(mast);
|
|
} while (!mte_is_root(mast->orig_l->node));
|
|
}
|
|
if ((mast->orig_l->node != mas->node) &&
|
|
(mast->l->depth > mas_mt_height(mas))) {
|
|
mat_add(mast->free, mas->node);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mast_cp_to_nodes() - Copy data out to nodes.
|
|
* @mast: The maple subtree state
|
|
* @left: The left encoded maple node
|
|
* @middle: The middle encoded maple node
|
|
* @right: The right encoded maple node
|
|
* @split: The location to split between left and (middle ? middle : right)
|
|
* @mid_split: The location to split between middle and right.
|
|
*/
|
|
static inline void mast_cp_to_nodes(struct maple_subtree_state *mast,
|
|
struct maple_enode *left, struct maple_enode *middle,
|
|
struct maple_enode *right, unsigned char split, unsigned char mid_split)
|
|
{
|
|
bool new_lmax = true;
|
|
|
|
mast->l->node = mte_node_or_none(left);
|
|
mast->m->node = mte_node_or_none(middle);
|
|
mast->r->node = mte_node_or_none(right);
|
|
|
|
mast->l->min = mast->orig_l->min;
|
|
if (split == mast->bn->b_end) {
|
|
mast->l->max = mast->orig_r->max;
|
|
new_lmax = false;
|
|
}
|
|
|
|
mab_mas_cp(mast->bn, 0, split, mast->l, new_lmax);
|
|
|
|
if (middle) {
|
|
mab_mas_cp(mast->bn, 1 + split, mid_split, mast->m, true);
|
|
mast->m->min = mast->bn->pivot[split] + 1;
|
|
split = mid_split;
|
|
}
|
|
|
|
mast->r->max = mast->orig_r->max;
|
|
if (right) {
|
|
mab_mas_cp(mast->bn, 1 + split, mast->bn->b_end, mast->r, false);
|
|
mast->r->min = mast->bn->pivot[split] + 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mast_combine_cp_left - Copy in the original left side of the tree into the
|
|
* combined data set in the maple subtree state big node.
|
|
* @mast: The maple subtree state
|
|
*/
|
|
static inline void mast_combine_cp_left(struct maple_subtree_state *mast)
|
|
{
|
|
unsigned char l_slot = mast->orig_l->offset;
|
|
|
|
if (!l_slot)
|
|
return;
|
|
|
|
mas_mab_cp(mast->orig_l, 0, l_slot - 1, mast->bn, 0);
|
|
}
|
|
|
|
/*
|
|
* mast_combine_cp_right: Copy in the original right side of the tree into the
|
|
* combined data set in the maple subtree state big node.
|
|
* @mast: The maple subtree state
|
|
*/
|
|
static inline void mast_combine_cp_right(struct maple_subtree_state *mast)
|
|
{
|
|
if (mast->bn->pivot[mast->bn->b_end - 1] >= mast->orig_r->max)
|
|
return;
|
|
|
|
mas_mab_cp(mast->orig_r, mast->orig_r->offset + 1,
|
|
mt_slot_count(mast->orig_r->node), mast->bn,
|
|
mast->bn->b_end);
|
|
mast->orig_r->last = mast->orig_r->max;
|
|
}
|
|
|
|
/*
|
|
* mast_sufficient: Check if the maple subtree state has enough data in the big
|
|
* node to create at least one sufficient node
|
|
* @mast: the maple subtree state
|
|
*/
|
|
static inline bool mast_sufficient(struct maple_subtree_state *mast)
|
|
{
|
|
if (mast->bn->b_end > mt_min_slot_count(mast->orig_l->node))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* mast_overflow: Check if there is too much data in the subtree state for a
|
|
* single node.
|
|
* @mast: The maple subtree state
|
|
*/
|
|
static inline bool mast_overflow(struct maple_subtree_state *mast)
|
|
{
|
|
if (mast->bn->b_end >= mt_slot_count(mast->orig_l->node))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline void *mtree_range_walk(struct ma_state *mas)
|
|
{
|
|
unsigned long *pivots;
|
|
unsigned char offset;
|
|
struct maple_node *node;
|
|
struct maple_enode *next, *last;
|
|
enum maple_type type;
|
|
void __rcu **slots;
|
|
unsigned char end;
|
|
unsigned long max, min;
|
|
unsigned long prev_max, prev_min;
|
|
|
|
next = mas->node;
|
|
min = mas->min;
|
|
max = mas->max;
|
|
do {
|
|
offset = 0;
|
|
last = next;
|
|
node = mte_to_node(next);
|
|
type = mte_node_type(next);
|
|
pivots = ma_pivots(node, type);
|
|
end = ma_data_end(node, type, pivots, max);
|
|
if (unlikely(ma_dead_node(node)))
|
|
goto dead_node;
|
|
|
|
if (pivots[offset] >= mas->index) {
|
|
prev_max = max;
|
|
prev_min = min;
|
|
max = pivots[offset];
|
|
goto next;
|
|
}
|
|
|
|
do {
|
|
offset++;
|
|
} while ((offset < end) && (pivots[offset] < mas->index));
|
|
|
|
prev_min = min;
|
|
min = pivots[offset - 1] + 1;
|
|
prev_max = max;
|
|
if (likely(offset < end && pivots[offset]))
|
|
max = pivots[offset];
|
|
|
|
next:
|
|
slots = ma_slots(node, type);
|
|
next = mt_slot(mas->tree, slots, offset);
|
|
if (unlikely(ma_dead_node(node)))
|
|
goto dead_node;
|
|
} while (!ma_is_leaf(type));
|
|
|
|
mas->offset = offset;
|
|
mas->index = min;
|
|
mas->last = max;
|
|
mas->min = prev_min;
|
|
mas->max = prev_max;
|
|
mas->node = last;
|
|
return (void *)next;
|
|
|
|
dead_node:
|
|
mas_reset(mas);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* mas_spanning_rebalance() - Rebalance across two nodes which may not be peers.
|
|
* @mas: The starting maple state
|
|
* @mast: The maple_subtree_state, keeps track of 4 maple states.
|
|
* @count: The estimated count of iterations needed.
|
|
*
|
|
* Follow the tree upwards from @l_mas and @r_mas for @count, or until the root
|
|
* is hit. First @b_node is split into two entries which are inserted into the
|
|
* next iteration of the loop. @b_node is returned populated with the final
|
|
* iteration. @mas is used to obtain allocations. orig_l_mas keeps track of the
|
|
* nodes that will remain active by using orig_l_mas->index and orig_l_mas->last
|
|
* to account of what has been copied into the new sub-tree. The update of
|
|
* orig_l_mas->last is used in mas_consume to find the slots that will need to
|
|
* be either freed or destroyed. orig_l_mas->depth keeps track of the height of
|
|
* the new sub-tree in case the sub-tree becomes the full tree.
|
|
*
|
|
* Return: the number of elements in b_node during the last loop.
|
|
*/
|
|
static int mas_spanning_rebalance(struct ma_state *mas,
|
|
struct maple_subtree_state *mast, unsigned char count)
|
|
{
|
|
unsigned char split, mid_split;
|
|
unsigned char slot = 0;
|
|
struct maple_enode *left = NULL, *middle = NULL, *right = NULL;
|
|
|
|
MA_STATE(l_mas, mas->tree, mas->index, mas->index);
|
|
MA_STATE(r_mas, mas->tree, mas->index, mas->last);
|
|
MA_STATE(m_mas, mas->tree, mas->index, mas->index);
|
|
MA_TOPIARY(free, mas->tree);
|
|
MA_TOPIARY(destroy, mas->tree);
|
|
|
|
/*
|
|
* The tree needs to be rebalanced and leaves need to be kept at the same level.
|
|
* Rebalancing is done by use of the ``struct maple_topiary``.
|
|
*/
|
|
mast->l = &l_mas;
|
|
mast->m = &m_mas;
|
|
mast->r = &r_mas;
|
|
mast->free = &free;
|
|
mast->destroy = &destroy;
|
|
l_mas.node = r_mas.node = m_mas.node = MAS_NONE;
|
|
|
|
/* Check if this is not root and has sufficient data. */
|
|
if (((mast->orig_l->min != 0) || (mast->orig_r->max != ULONG_MAX)) &&
|
|
unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type]))
|
|
mast_spanning_rebalance(mast);
|
|
|
|
mast->orig_l->depth = 0;
|
|
|
|
/*
|
|
* Each level of the tree is examined and balanced, pushing data to the left or
|
|
* right, or rebalancing against left or right nodes is employed to avoid
|
|
* rippling up the tree to limit the amount of churn. Once a new sub-section of
|
|
* the tree is created, there may be a mix of new and old nodes. The old nodes
|
|
* will have the incorrect parent pointers and currently be in two trees: the
|
|
* original tree and the partially new tree. To remedy the parent pointers in
|
|
* the old tree, the new data is swapped into the active tree and a walk down
|
|
* the tree is performed and the parent pointers are updated.
|
|
* See mas_descend_adopt() for more information..
|
|
*/
|
|
while (count--) {
|
|
mast->bn->b_end--;
|
|
mast->bn->type = mte_node_type(mast->orig_l->node);
|
|
split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle,
|
|
&mid_split, mast->orig_l->min);
|
|
mast_set_split_parents(mast, left, middle, right, split,
|
|
mid_split);
|
|
mast_cp_to_nodes(mast, left, middle, right, split, mid_split);
|
|
|
|
/*
|
|
* Copy data from next level in the tree to mast->bn from next
|
|
* iteration
|
|
*/
|
|
memset(mast->bn, 0, sizeof(struct maple_big_node));
|
|
mast->bn->type = mte_node_type(left);
|
|
mast->orig_l->depth++;
|
|
|
|
/* Root already stored in l->node. */
|
|
if (mas_is_root_limits(mast->l))
|
|
goto new_root;
|
|
|
|
mast_ascend_free(mast);
|
|
mast_combine_cp_left(mast);
|
|
l_mas.offset = mast->bn->b_end;
|
|
mab_set_b_end(mast->bn, &l_mas, left);
|
|
mab_set_b_end(mast->bn, &m_mas, middle);
|
|
mab_set_b_end(mast->bn, &r_mas, right);
|
|
|
|
/* Copy anything necessary out of the right node. */
|
|
mast_combine_cp_right(mast);
|
|
mast_topiary(mast);
|
|
mast->orig_l->last = mast->orig_l->max;
|
|
|
|
if (mast_sufficient(mast))
|
|
continue;
|
|
|
|
if (mast_overflow(mast))
|
|
continue;
|
|
|
|
/* May be a new root stored in mast->bn */
|
|
if (mas_is_root_limits(mast->orig_l))
|
|
break;
|
|
|
|
mast_spanning_rebalance(mast);
|
|
|
|
/* rebalancing from other nodes may require another loop. */
|
|
if (!count)
|
|
count++;
|
|
}
|
|
|
|
l_mas.node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)),
|
|
mte_node_type(mast->orig_l->node));
|
|
mast->orig_l->depth++;
|
|
mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, &l_mas, true);
|
|
mte_set_parent(left, l_mas.node, slot);
|
|
if (middle)
|
|
mte_set_parent(middle, l_mas.node, ++slot);
|
|
|
|
if (right)
|
|
mte_set_parent(right, l_mas.node, ++slot);
|
|
|
|
if (mas_is_root_limits(mast->l)) {
|
|
new_root:
|
|
mast_new_root(mast, mas);
|
|
} else {
|
|
mas_mn(&l_mas)->parent = mas_mn(mast->orig_l)->parent;
|
|
}
|
|
|
|
if (!mte_dead_node(mast->orig_l->node))
|
|
mat_add(&free, mast->orig_l->node);
|
|
|
|
mas->depth = mast->orig_l->depth;
|
|
*mast->orig_l = l_mas;
|
|
mte_set_node_dead(mas->node);
|
|
|
|
/* Set up mas for insertion. */
|
|
mast->orig_l->depth = mas->depth;
|
|
mast->orig_l->alloc = mas->alloc;
|
|
*mas = *mast->orig_l;
|
|
mas_wmb_replace(mas, &free, &destroy);
|
|
mtree_range_walk(mas);
|
|
return mast->bn->b_end;
|
|
}
|
|
|
|
/*
|
|
* mas_rebalance() - Rebalance a given node.
|
|
* @mas: The maple state
|
|
* @b_node: The big maple node.
|
|
*
|
|
* Rebalance two nodes into a single node or two new nodes that are sufficient.
|
|
* Continue upwards until tree is sufficient.
|
|
*
|
|
* Return: the number of elements in b_node during the last loop.
|
|
*/
|
|
static inline int mas_rebalance(struct ma_state *mas,
|
|
struct maple_big_node *b_node)
|
|
{
|
|
char empty_count = mas_mt_height(mas);
|
|
struct maple_subtree_state mast;
|
|
unsigned char shift, b_end = ++b_node->b_end;
|
|
|
|
MA_STATE(l_mas, mas->tree, mas->index, mas->last);
|
|
MA_STATE(r_mas, mas->tree, mas->index, mas->last);
|
|
|
|
trace_ma_op(__func__, mas);
|
|
|
|
/*
|
|
* Rebalancing occurs if a node is insufficient. Data is rebalanced
|
|
* against the node to the right if it exists, otherwise the node to the
|
|
* left of this node is rebalanced against this node. If rebalancing
|
|
* causes just one node to be produced instead of two, then the parent
|
|
* is also examined and rebalanced if it is insufficient. Every level
|
|
* tries to combine the data in the same way. If one node contains the
|
|
* entire range of the tree, then that node is used as a new root node.
|
|
*/
|
|
mas_node_count(mas, 1 + empty_count * 3);
|
|
if (mas_is_err(mas))
|
|
return 0;
|
|
|
|
mast.orig_l = &l_mas;
|
|
mast.orig_r = &r_mas;
|
|
mast.bn = b_node;
|
|
mast.bn->type = mte_node_type(mas->node);
|
|
|
|
l_mas = r_mas = *mas;
|
|
|
|
if (mas_next_sibling(&r_mas)) {
|
|
mas_mab_cp(&r_mas, 0, mt_slot_count(r_mas.node), b_node, b_end);
|
|
r_mas.last = r_mas.index = r_mas.max;
|
|
} else {
|
|
mas_prev_sibling(&l_mas);
|
|
shift = mas_data_end(&l_mas) + 1;
|
|
mab_shift_right(b_node, shift);
|
|
mas->offset += shift;
|
|
mas_mab_cp(&l_mas, 0, shift - 1, b_node, 0);
|
|
b_node->b_end = shift + b_end;
|
|
l_mas.index = l_mas.last = l_mas.min;
|
|
}
|
|
|
|
return mas_spanning_rebalance(mas, &mast, empty_count);
|
|
}
|
|
|
|
/*
|
|
* mas_destroy_rebalance() - Rebalance left-most node while destroying the maple
|
|
* state.
|
|
* @mas: The maple state
|
|
* @end: The end of the left-most node.
|
|
*
|
|
* During a mass-insert event (such as forking), it may be necessary to
|
|
* rebalance the left-most node when it is not sufficient.
|
|
*/
|
|
static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end)
|
|
{
|
|
enum maple_type mt = mte_node_type(mas->node);
|
|
struct maple_node reuse, *newnode, *parent, *new_left, *left, *node;
|
|
struct maple_enode *eparent;
|
|
unsigned char offset, tmp, split = mt_slots[mt] / 2;
|
|
void __rcu **l_slots, **slots;
|
|
unsigned long *l_pivs, *pivs, gap;
|
|
bool in_rcu = mt_in_rcu(mas->tree);
|
|
|
|
MA_STATE(l_mas, mas->tree, mas->index, mas->last);
|
|
|
|
l_mas = *mas;
|
|
mas_prev_sibling(&l_mas);
|
|
|
|
/* set up node. */
|
|
if (in_rcu) {
|
|
/* Allocate for both left and right as well as parent. */
|
|
mas_node_count(mas, 3);
|
|
if (mas_is_err(mas))
|
|
return;
|
|
|
|
newnode = mas_pop_node(mas);
|
|
} else {
|
|
newnode = &reuse;
|
|
}
|
|
|
|
node = mas_mn(mas);
|
|
newnode->parent = node->parent;
|
|
slots = ma_slots(newnode, mt);
|
|
pivs = ma_pivots(newnode, mt);
|
|
left = mas_mn(&l_mas);
|
|
l_slots = ma_slots(left, mt);
|
|
l_pivs = ma_pivots(left, mt);
|
|
if (!l_slots[split])
|
|
split++;
|
|
tmp = mas_data_end(&l_mas) - split;
|
|
|
|
memcpy(slots, l_slots + split + 1, sizeof(void *) * tmp);
|
|
memcpy(pivs, l_pivs + split + 1, sizeof(unsigned long) * tmp);
|
|
pivs[tmp] = l_mas.max;
|
|
memcpy(slots + tmp, ma_slots(node, mt), sizeof(void *) * end);
|
|
memcpy(pivs + tmp, ma_pivots(node, mt), sizeof(unsigned long) * end);
|
|
|
|
l_mas.max = l_pivs[split];
|
|
mas->min = l_mas.max + 1;
|
|
eparent = mt_mk_node(mte_parent(l_mas.node),
|
|
mas_parent_enum(&l_mas, l_mas.node));
|
|
tmp += end;
|
|
if (!in_rcu) {
|
|
unsigned char max_p = mt_pivots[mt];
|
|
unsigned char max_s = mt_slots[mt];
|
|
|
|
if (tmp < max_p)
|
|
memset(pivs + tmp, 0,
|
|
sizeof(unsigned long *) * (max_p - tmp));
|
|
|
|
if (tmp < mt_slots[mt])
|
|
memset(slots + tmp, 0, sizeof(void *) * (max_s - tmp));
|
|
|
|
memcpy(node, newnode, sizeof(struct maple_node));
|
|
ma_set_meta(node, mt, 0, tmp - 1);
|
|
mte_set_pivot(eparent, mte_parent_slot(l_mas.node),
|
|
l_pivs[split]);
|
|
|
|
/* Remove data from l_pivs. */
|
|
tmp = split + 1;
|
|
memset(l_pivs + tmp, 0, sizeof(unsigned long) * (max_p - tmp));
|
|
memset(l_slots + tmp, 0, sizeof(void *) * (max_s - tmp));
|
|
ma_set_meta(left, mt, 0, split);
|
|
|
|
goto done;
|
|
}
|
|
|
|
/* RCU requires replacing both l_mas, mas, and parent. */
|
|
mas->node = mt_mk_node(newnode, mt);
|
|
ma_set_meta(newnode, mt, 0, tmp);
|
|
|
|
new_left = mas_pop_node(mas);
|
|
new_left->parent = left->parent;
|
|
mt = mte_node_type(l_mas.node);
|
|
slots = ma_slots(new_left, mt);
|
|
pivs = ma_pivots(new_left, mt);
|
|
memcpy(slots, l_slots, sizeof(void *) * split);
|
|
memcpy(pivs, l_pivs, sizeof(unsigned long) * split);
|
|
ma_set_meta(new_left, mt, 0, split);
|
|
l_mas.node = mt_mk_node(new_left, mt);
|
|
|
|
/* replace parent. */
|
|
offset = mte_parent_slot(mas->node);
|
|
mt = mas_parent_enum(&l_mas, l_mas.node);
|
|
parent = mas_pop_node(mas);
|
|
slots = ma_slots(parent, mt);
|
|
pivs = ma_pivots(parent, mt);
|
|
memcpy(parent, mte_to_node(eparent), sizeof(struct maple_node));
|
|
rcu_assign_pointer(slots[offset], mas->node);
|
|
rcu_assign_pointer(slots[offset - 1], l_mas.node);
|
|
pivs[offset - 1] = l_mas.max;
|
|
eparent = mt_mk_node(parent, mt);
|
|
done:
|
|
gap = mas_leaf_max_gap(mas);
|
|
mte_set_gap(eparent, mte_parent_slot(mas->node), gap);
|
|
gap = mas_leaf_max_gap(&l_mas);
|
|
mte_set_gap(eparent, mte_parent_slot(l_mas.node), gap);
|
|
mas_ascend(mas);
|
|
|
|
if (in_rcu)
|
|
mas_replace(mas, false);
|
|
|
|
mas_update_gap(mas);
|
|
}
|
|
|
|
/*
|
|
* mas_split_final_node() - Split the final node in a subtree operation.
|
|
* @mast: the maple subtree state
|
|
* @mas: The maple state
|
|
* @height: The height of the tree in case it's a new root.
|
|
*/
|
|
static inline bool mas_split_final_node(struct maple_subtree_state *mast,
|
|
struct ma_state *mas, int height)
|
|
{
|
|
struct maple_enode *ancestor;
|
|
|
|
if (mte_is_root(mas->node)) {
|
|
if (mt_is_alloc(mas->tree))
|
|
mast->bn->type = maple_arange_64;
|
|
else
|
|
mast->bn->type = maple_range_64;
|
|
mas->depth = height;
|
|
}
|
|
/*
|
|
* Only a single node is used here, could be root.
|
|
* The Big_node data should just fit in a single node.
|
|
*/
|
|
ancestor = mas_new_ma_node(mas, mast->bn);
|
|
mte_set_parent(mast->l->node, ancestor, mast->l->offset);
|
|
mte_set_parent(mast->r->node, ancestor, mast->r->offset);
|
|
mte_to_node(ancestor)->parent = mas_mn(mas)->parent;
|
|
|
|
mast->l->node = ancestor;
|
|
mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, mast->l, true);
|
|
mas->offset = mast->bn->b_end - 1;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mast_fill_bnode() - Copy data into the big node in the subtree state
|
|
* @mast: The maple subtree state
|
|
* @mas: the maple state
|
|
* @skip: The number of entries to skip for new nodes insertion.
|
|
*/
|
|
static inline void mast_fill_bnode(struct maple_subtree_state *mast,
|
|
struct ma_state *mas,
|
|
unsigned char skip)
|
|
{
|
|
bool cp = true;
|
|
struct maple_enode *old = mas->node;
|
|
unsigned char split;
|
|
|
|
memset(mast->bn->gap, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->gap));
|
|
memset(mast->bn->slot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->slot));
|
|
memset(mast->bn->pivot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->pivot));
|
|
mast->bn->b_end = 0;
|
|
|
|
if (mte_is_root(mas->node)) {
|
|
cp = false;
|
|
} else {
|
|
mas_ascend(mas);
|
|
mat_add(mast->free, old);
|
|
mas->offset = mte_parent_slot(mas->node);
|
|
}
|
|
|
|
if (cp && mast->l->offset)
|
|
mas_mab_cp(mas, 0, mast->l->offset - 1, mast->bn, 0);
|
|
|
|
split = mast->bn->b_end;
|
|
mab_set_b_end(mast->bn, mast->l, mast->l->node);
|
|
mast->r->offset = mast->bn->b_end;
|
|
mab_set_b_end(mast->bn, mast->r, mast->r->node);
|
|
if (mast->bn->pivot[mast->bn->b_end - 1] == mas->max)
|
|
cp = false;
|
|
|
|
if (cp)
|
|
mas_mab_cp(mas, split + skip, mt_slot_count(mas->node) - 1,
|
|
mast->bn, mast->bn->b_end);
|
|
|
|
mast->bn->b_end--;
|
|
mast->bn->type = mte_node_type(mas->node);
|
|
}
|
|
|
|
/*
|
|
* mast_split_data() - Split the data in the subtree state big node into regular
|
|
* nodes.
|
|
* @mast: The maple subtree state
|
|
* @mas: The maple state
|
|
* @split: The location to split the big node
|
|
*/
|
|
static inline void mast_split_data(struct maple_subtree_state *mast,
|
|
struct ma_state *mas, unsigned char split)
|
|
{
|
|
unsigned char p_slot;
|
|
|
|
mab_mas_cp(mast->bn, 0, split, mast->l, true);
|
|
mte_set_pivot(mast->r->node, 0, mast->r->max);
|
|
mab_mas_cp(mast->bn, split + 1, mast->bn->b_end, mast->r, false);
|
|
mast->l->offset = mte_parent_slot(mas->node);
|
|
mast->l->max = mast->bn->pivot[split];
|
|
mast->r->min = mast->l->max + 1;
|
|
if (mte_is_leaf(mas->node))
|
|
return;
|
|
|
|
p_slot = mast->orig_l->offset;
|
|
mas_set_split_parent(mast->orig_l, mast->l->node, mast->r->node,
|
|
&p_slot, split);
|
|
mas_set_split_parent(mast->orig_r, mast->l->node, mast->r->node,
|
|
&p_slot, split);
|
|
}
|
|
|
|
/*
|
|
* mas_push_data() - Instead of splitting a node, it is beneficial to push the
|
|
* data to the right or left node if there is room.
|
|
* @mas: The maple state
|
|
* @height: The current height of the maple state
|
|
* @mast: The maple subtree state
|
|
* @left: Push left or not.
|
|
*
|
|
* Keeping the height of the tree low means faster lookups.
|
|
*
|
|
* Return: True if pushed, false otherwise.
|
|
*/
|
|
static inline bool mas_push_data(struct ma_state *mas, int height,
|
|
struct maple_subtree_state *mast, bool left)
|
|
{
|
|
unsigned char slot_total = mast->bn->b_end;
|
|
unsigned char end, space, split;
|
|
|
|
MA_STATE(tmp_mas, mas->tree, mas->index, mas->last);
|
|
tmp_mas = *mas;
|
|
tmp_mas.depth = mast->l->depth;
|
|
|
|
if (left && !mas_prev_sibling(&tmp_mas))
|
|
return false;
|
|
else if (!left && !mas_next_sibling(&tmp_mas))
|
|
return false;
|
|
|
|
end = mas_data_end(&tmp_mas);
|
|
slot_total += end;
|
|
space = 2 * mt_slot_count(mas->node) - 2;
|
|
/* -2 instead of -1 to ensure there isn't a triple split */
|
|
if (ma_is_leaf(mast->bn->type))
|
|
space--;
|
|
|
|
if (mas->max == ULONG_MAX)
|
|
space--;
|
|
|
|
if (slot_total >= space)
|
|
return false;
|
|
|
|
/* Get the data; Fill mast->bn */
|
|
mast->bn->b_end++;
|
|
if (left) {
|
|
mab_shift_right(mast->bn, end + 1);
|
|
mas_mab_cp(&tmp_mas, 0, end, mast->bn, 0);
|
|
mast->bn->b_end = slot_total + 1;
|
|
} else {
|
|
mas_mab_cp(&tmp_mas, 0, end, mast->bn, mast->bn->b_end);
|
|
}
|
|
|
|
/* Configure mast for splitting of mast->bn */
|
|
split = mt_slots[mast->bn->type] - 2;
|
|
if (left) {
|
|
/* Switch mas to prev node */
|
|
mat_add(mast->free, mas->node);
|
|
*mas = tmp_mas;
|
|
/* Start using mast->l for the left side. */
|
|
tmp_mas.node = mast->l->node;
|
|
*mast->l = tmp_mas;
|
|
} else {
|
|
mat_add(mast->free, tmp_mas.node);
|
|
tmp_mas.node = mast->r->node;
|
|
*mast->r = tmp_mas;
|
|
split = slot_total - split;
|
|
}
|
|
split = mab_no_null_split(mast->bn, split, mt_slots[mast->bn->type]);
|
|
/* Update parent slot for split calculation. */
|
|
if (left)
|
|
mast->orig_l->offset += end + 1;
|
|
|
|
mast_split_data(mast, mas, split);
|
|
mast_fill_bnode(mast, mas, 2);
|
|
mas_split_final_node(mast, mas, height + 1);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mas_split() - Split data that is too big for one node into two.
|
|
* @mas: The maple state
|
|
* @b_node: The maple big node
|
|
* Return: 1 on success, 0 on failure.
|
|
*/
|
|
static int mas_split(struct ma_state *mas, struct maple_big_node *b_node)
|
|
{
|
|
struct maple_subtree_state mast;
|
|
int height = 0;
|
|
unsigned char mid_split, split = 0;
|
|
|
|
/*
|
|
* Splitting is handled differently from any other B-tree; the Maple
|
|
* Tree splits upwards. Splitting up means that the split operation
|
|
* occurs when the walk of the tree hits the leaves and not on the way
|
|
* down. The reason for splitting up is that it is impossible to know
|
|
* how much space will be needed until the leaf is (or leaves are)
|
|
* reached. Since overwriting data is allowed and a range could
|
|
* overwrite more than one range or result in changing one entry into 3
|
|
* entries, it is impossible to know if a split is required until the
|
|
* data is examined.
|
|
*
|
|
* Splitting is a balancing act between keeping allocations to a minimum
|
|
* and avoiding a 'jitter' event where a tree is expanded to make room
|
|
* for an entry followed by a contraction when the entry is removed. To
|
|
* accomplish the balance, there are empty slots remaining in both left
|
|
* and right nodes after a split.
|
|
*/
|
|
MA_STATE(l_mas, mas->tree, mas->index, mas->last);
|
|
MA_STATE(r_mas, mas->tree, mas->index, mas->last);
|
|
MA_STATE(prev_l_mas, mas->tree, mas->index, mas->last);
|
|
MA_STATE(prev_r_mas, mas->tree, mas->index, mas->last);
|
|
MA_TOPIARY(mat, mas->tree);
|
|
|
|
trace_ma_op(__func__, mas);
|
|
mas->depth = mas_mt_height(mas);
|
|
/* Allocation failures will happen early. */
|
|
mas_node_count(mas, 1 + mas->depth * 2);
|
|
if (mas_is_err(mas))
|
|
return 0;
|
|
|
|
mast.l = &l_mas;
|
|
mast.r = &r_mas;
|
|
mast.orig_l = &prev_l_mas;
|
|
mast.orig_r = &prev_r_mas;
|
|
mast.free = &mat;
|
|
mast.bn = b_node;
|
|
|
|
while (height++ <= mas->depth) {
|
|
if (mt_slots[b_node->type] > b_node->b_end) {
|
|
mas_split_final_node(&mast, mas, height);
|
|
break;
|
|
}
|
|
|
|
l_mas = r_mas = *mas;
|
|
l_mas.node = mas_new_ma_node(mas, b_node);
|
|
r_mas.node = mas_new_ma_node(mas, b_node);
|
|
/*
|
|
* Another way that 'jitter' is avoided is to terminate a split up early if the
|
|
* left or right node has space to spare. This is referred to as "pushing left"
|
|
* or "pushing right" and is similar to the B* tree, except the nodes left or
|
|
* right can rarely be reused due to RCU, but the ripple upwards is halted which
|
|
* is a significant savings.
|
|
*/
|
|
/* Try to push left. */
|
|
if (mas_push_data(mas, height, &mast, true))
|
|
break;
|
|
|
|
/* Try to push right. */
|
|
if (mas_push_data(mas, height, &mast, false))
|
|
break;
|
|
|
|
split = mab_calc_split(mas, b_node, &mid_split, prev_l_mas.min);
|
|
mast_split_data(&mast, mas, split);
|
|
/*
|
|
* Usually correct, mab_mas_cp in the above call overwrites
|
|
* r->max.
|
|
*/
|
|
mast.r->max = mas->max;
|
|
mast_fill_bnode(&mast, mas, 1);
|
|
prev_l_mas = *mast.l;
|
|
prev_r_mas = *mast.r;
|
|
}
|
|
|
|
/* Set the original node as dead */
|
|
mat_add(mast.free, mas->node);
|
|
mas->node = l_mas.node;
|
|
mas_wmb_replace(mas, mast.free, NULL);
|
|
mtree_range_walk(mas);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* mas_reuse_node() - Reuse the node to store the data.
|
|
* @wr_mas: The maple write state
|
|
* @bn: The maple big node
|
|
* @end: The end of the data.
|
|
*
|
|
* Will always return false in RCU mode.
|
|
*
|
|
* Return: True if node was reused, false otherwise.
|
|
*/
|
|
static inline bool mas_reuse_node(struct ma_wr_state *wr_mas,
|
|
struct maple_big_node *bn, unsigned char end)
|
|
{
|
|
/* Need to be rcu safe. */
|
|
if (mt_in_rcu(wr_mas->mas->tree))
|
|
return false;
|
|
|
|
if (end > bn->b_end) {
|
|
int clear = mt_slots[wr_mas->type] - bn->b_end;
|
|
|
|
memset(wr_mas->slots + bn->b_end, 0, sizeof(void *) * clear--);
|
|
memset(wr_mas->pivots + bn->b_end, 0, sizeof(void *) * clear);
|
|
}
|
|
mab_mas_cp(bn, 0, bn->b_end, wr_mas->mas, false);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mas_commit_b_node() - Commit the big node into the tree.
|
|
* @wr_mas: The maple write state
|
|
* @b_node: The maple big node
|
|
* @end: The end of the data.
|
|
*/
|
|
static inline int mas_commit_b_node(struct ma_wr_state *wr_mas,
|
|
struct maple_big_node *b_node, unsigned char end)
|
|
{
|
|
struct maple_node *node;
|
|
unsigned char b_end = b_node->b_end;
|
|
enum maple_type b_type = b_node->type;
|
|
|
|
if ((b_end < mt_min_slots[b_type]) &&
|
|
(!mte_is_root(wr_mas->mas->node)) &&
|
|
(mas_mt_height(wr_mas->mas) > 1))
|
|
return mas_rebalance(wr_mas->mas, b_node);
|
|
|
|
if (b_end >= mt_slots[b_type])
|
|
return mas_split(wr_mas->mas, b_node);
|
|
|
|
if (mas_reuse_node(wr_mas, b_node, end))
|
|
goto reuse_node;
|
|
|
|
mas_node_count(wr_mas->mas, 1);
|
|
if (mas_is_err(wr_mas->mas))
|
|
return 0;
|
|
|
|
node = mas_pop_node(wr_mas->mas);
|
|
node->parent = mas_mn(wr_mas->mas)->parent;
|
|
wr_mas->mas->node = mt_mk_node(node, b_type);
|
|
mab_mas_cp(b_node, 0, b_end, wr_mas->mas, false);
|
|
mas_replace(wr_mas->mas, false);
|
|
reuse_node:
|
|
mas_update_gap(wr_mas->mas);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* mas_root_expand() - Expand a root to a node
|
|
* @mas: The maple state
|
|
* @entry: The entry to store into the tree
|
|
*/
|
|
static inline int mas_root_expand(struct ma_state *mas, void *entry)
|
|
{
|
|
void *contents = mas_root_locked(mas);
|
|
enum maple_type type = maple_leaf_64;
|
|
struct maple_node *node;
|
|
void __rcu **slots;
|
|
unsigned long *pivots;
|
|
int slot = 0;
|
|
|
|
mas_node_count(mas, 1);
|
|
if (unlikely(mas_is_err(mas)))
|
|
return 0;
|
|
|
|
node = mas_pop_node(mas);
|
|
pivots = ma_pivots(node, type);
|
|
slots = ma_slots(node, type);
|
|
node->parent = ma_parent_ptr(
|
|
((unsigned long)mas->tree | MA_ROOT_PARENT));
|
|
mas->node = mt_mk_node(node, type);
|
|
|
|
if (mas->index) {
|
|
if (contents) {
|
|
rcu_assign_pointer(slots[slot], contents);
|
|
if (likely(mas->index > 1))
|
|
slot++;
|
|
}
|
|
pivots[slot++] = mas->index - 1;
|
|
}
|
|
|
|
rcu_assign_pointer(slots[slot], entry);
|
|
mas->offset = slot;
|
|
pivots[slot] = mas->last;
|
|
if (mas->last != ULONG_MAX)
|
|
slot++;
|
|
mas->depth = 1;
|
|
mas_set_height(mas);
|
|
|
|
/* swap the new root into the tree */
|
|
rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
|
|
ma_set_meta(node, maple_leaf_64, 0, slot);
|
|
return slot;
|
|
}
|
|
|
|
static inline void mas_store_root(struct ma_state *mas, void *entry)
|
|
{
|
|
if (likely((mas->last != 0) || (mas->index != 0)))
|
|
mas_root_expand(mas, entry);
|
|
else if (((unsigned long) (entry) & 3) == 2)
|
|
mas_root_expand(mas, entry);
|
|
else {
|
|
rcu_assign_pointer(mas->tree->ma_root, entry);
|
|
mas->node = MAS_START;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_is_span_wr() - Check if the write needs to be treated as a write that
|
|
* spans the node.
|
|
* @mas: The maple state
|
|
* @piv: The pivot value being written
|
|
* @type: The maple node type
|
|
* @entry: The data to write
|
|
*
|
|
* Spanning writes are writes that start in one node and end in another OR if
|
|
* the write of a %NULL will cause the node to end with a %NULL.
|
|
*
|
|
* Return: True if this is a spanning write, false otherwise.
|
|
*/
|
|
static bool mas_is_span_wr(struct ma_wr_state *wr_mas)
|
|
{
|
|
unsigned long max;
|
|
unsigned long last = wr_mas->mas->last;
|
|
unsigned long piv = wr_mas->r_max;
|
|
enum maple_type type = wr_mas->type;
|
|
void *entry = wr_mas->entry;
|
|
|
|
/* Contained in this pivot */
|
|
if (piv > last)
|
|
return false;
|
|
|
|
max = wr_mas->mas->max;
|
|
if (unlikely(ma_is_leaf(type))) {
|
|
/* Fits in the node, but may span slots. */
|
|
if (last < max)
|
|
return false;
|
|
|
|
/* Writes to the end of the node but not null. */
|
|
if ((last == max) && entry)
|
|
return false;
|
|
|
|
/*
|
|
* Writing ULONG_MAX is not a spanning write regardless of the
|
|
* value being written as long as the range fits in the node.
|
|
*/
|
|
if ((last == ULONG_MAX) && (last == max))
|
|
return false;
|
|
} else if (piv == last) {
|
|
if (entry)
|
|
return false;
|
|
|
|
/* Detect spanning store wr walk */
|
|
if (last == ULONG_MAX)
|
|
return false;
|
|
}
|
|
|
|
trace_ma_write(__func__, wr_mas->mas, piv, entry);
|
|
|
|
return true;
|
|
}
|
|
|
|
static inline void mas_wr_walk_descend(struct ma_wr_state *wr_mas)
|
|
{
|
|
wr_mas->type = mte_node_type(wr_mas->mas->node);
|
|
mas_wr_node_walk(wr_mas);
|
|
wr_mas->slots = ma_slots(wr_mas->node, wr_mas->type);
|
|
}
|
|
|
|
static inline void mas_wr_walk_traverse(struct ma_wr_state *wr_mas)
|
|
{
|
|
wr_mas->mas->max = wr_mas->r_max;
|
|
wr_mas->mas->min = wr_mas->r_min;
|
|
wr_mas->mas->node = wr_mas->content;
|
|
wr_mas->mas->offset = 0;
|
|
wr_mas->mas->depth++;
|
|
}
|
|
/*
|
|
* mas_wr_walk() - Walk the tree for a write.
|
|
* @wr_mas: The maple write state
|
|
*
|
|
* Uses mas_slot_locked() and does not need to worry about dead nodes.
|
|
*
|
|
* Return: True if it's contained in a node, false on spanning write.
|
|
*/
|
|
static bool mas_wr_walk(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct ma_state *mas = wr_mas->mas;
|
|
|
|
while (true) {
|
|
mas_wr_walk_descend(wr_mas);
|
|
if (unlikely(mas_is_span_wr(wr_mas)))
|
|
return false;
|
|
|
|
wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
|
|
mas->offset);
|
|
if (ma_is_leaf(wr_mas->type))
|
|
return true;
|
|
|
|
mas_wr_walk_traverse(wr_mas);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool mas_wr_walk_index(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct ma_state *mas = wr_mas->mas;
|
|
|
|
while (true) {
|
|
mas_wr_walk_descend(wr_mas);
|
|
wr_mas->content = mas_slot_locked(mas, wr_mas->slots,
|
|
mas->offset);
|
|
if (ma_is_leaf(wr_mas->type))
|
|
return true;
|
|
mas_wr_walk_traverse(wr_mas);
|
|
|
|
}
|
|
return true;
|
|
}
|
|
/*
|
|
* mas_extend_spanning_null() - Extend a store of a %NULL to include surrounding %NULLs.
|
|
* @l_wr_mas: The left maple write state
|
|
* @r_wr_mas: The right maple write state
|
|
*/
|
|
static inline void mas_extend_spanning_null(struct ma_wr_state *l_wr_mas,
|
|
struct ma_wr_state *r_wr_mas)
|
|
{
|
|
struct ma_state *r_mas = r_wr_mas->mas;
|
|
struct ma_state *l_mas = l_wr_mas->mas;
|
|
unsigned char l_slot;
|
|
|
|
l_slot = l_mas->offset;
|
|
if (!l_wr_mas->content)
|
|
l_mas->index = l_wr_mas->r_min;
|
|
|
|
if ((l_mas->index == l_wr_mas->r_min) &&
|
|
(l_slot &&
|
|
!mas_slot_locked(l_mas, l_wr_mas->slots, l_slot - 1))) {
|
|
if (l_slot > 1)
|
|
l_mas->index = l_wr_mas->pivots[l_slot - 2] + 1;
|
|
else
|
|
l_mas->index = l_mas->min;
|
|
|
|
l_mas->offset = l_slot - 1;
|
|
}
|
|
|
|
if (!r_wr_mas->content) {
|
|
if (r_mas->last < r_wr_mas->r_max)
|
|
r_mas->last = r_wr_mas->r_max;
|
|
r_mas->offset++;
|
|
} else if ((r_mas->last == r_wr_mas->r_max) &&
|
|
(r_mas->last < r_mas->max) &&
|
|
!mas_slot_locked(r_mas, r_wr_mas->slots, r_mas->offset + 1)) {
|
|
r_mas->last = mas_safe_pivot(r_mas, r_wr_mas->pivots,
|
|
r_wr_mas->type, r_mas->offset + 1);
|
|
r_mas->offset++;
|
|
}
|
|
}
|
|
|
|
static inline void *mas_state_walk(struct ma_state *mas)
|
|
{
|
|
void *entry;
|
|
|
|
entry = mas_start(mas);
|
|
if (mas_is_none(mas))
|
|
return NULL;
|
|
|
|
if (mas_is_ptr(mas))
|
|
return entry;
|
|
|
|
return mtree_range_walk(mas);
|
|
}
|
|
|
|
/*
|
|
* mtree_lookup_walk() - Internal quick lookup that does not keep maple state up
|
|
* to date.
|
|
*
|
|
* @mas: The maple state.
|
|
*
|
|
* Note: Leaves mas in undesirable state.
|
|
* Return: The entry for @mas->index or %NULL on dead node.
|
|
*/
|
|
static inline void *mtree_lookup_walk(struct ma_state *mas)
|
|
{
|
|
unsigned long *pivots;
|
|
unsigned char offset;
|
|
struct maple_node *node;
|
|
struct maple_enode *next;
|
|
enum maple_type type;
|
|
void __rcu **slots;
|
|
unsigned char end;
|
|
unsigned long max;
|
|
|
|
next = mas->node;
|
|
max = ULONG_MAX;
|
|
do {
|
|
offset = 0;
|
|
node = mte_to_node(next);
|
|
type = mte_node_type(next);
|
|
pivots = ma_pivots(node, type);
|
|
end = ma_data_end(node, type, pivots, max);
|
|
if (unlikely(ma_dead_node(node)))
|
|
goto dead_node;
|
|
|
|
if (pivots[offset] >= mas->index)
|
|
goto next;
|
|
|
|
do {
|
|
offset++;
|
|
} while ((offset < end) && (pivots[offset] < mas->index));
|
|
|
|
if (likely(offset > end))
|
|
max = pivots[offset];
|
|
|
|
next:
|
|
slots = ma_slots(node, type);
|
|
next = mt_slot(mas->tree, slots, offset);
|
|
if (unlikely(ma_dead_node(node)))
|
|
goto dead_node;
|
|
} while (!ma_is_leaf(type));
|
|
|
|
return (void *)next;
|
|
|
|
dead_node:
|
|
mas_reset(mas);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* mas_new_root() - Create a new root node that only contains the entry passed
|
|
* in.
|
|
* @mas: The maple state
|
|
* @entry: The entry to store.
|
|
*
|
|
* Only valid when the index == 0 and the last == ULONG_MAX
|
|
*
|
|
* Return 0 on error, 1 on success.
|
|
*/
|
|
static inline int mas_new_root(struct ma_state *mas, void *entry)
|
|
{
|
|
struct maple_enode *root = mas_root_locked(mas);
|
|
enum maple_type type = maple_leaf_64;
|
|
struct maple_node *node;
|
|
void __rcu **slots;
|
|
unsigned long *pivots;
|
|
|
|
if (!entry && !mas->index && mas->last == ULONG_MAX) {
|
|
mas->depth = 0;
|
|
mas_set_height(mas);
|
|
rcu_assign_pointer(mas->tree->ma_root, entry);
|
|
mas->node = MAS_START;
|
|
goto done;
|
|
}
|
|
|
|
mas_node_count(mas, 1);
|
|
if (mas_is_err(mas))
|
|
return 0;
|
|
|
|
node = mas_pop_node(mas);
|
|
pivots = ma_pivots(node, type);
|
|
slots = ma_slots(node, type);
|
|
node->parent = ma_parent_ptr(
|
|
((unsigned long)mas->tree | MA_ROOT_PARENT));
|
|
mas->node = mt_mk_node(node, type);
|
|
rcu_assign_pointer(slots[0], entry);
|
|
pivots[0] = mas->last;
|
|
mas->depth = 1;
|
|
mas_set_height(mas);
|
|
rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
|
|
|
|
done:
|
|
if (xa_is_node(root))
|
|
mte_destroy_walk(root, mas->tree);
|
|
|
|
return 1;
|
|
}
|
|
/*
|
|
* mas_wr_spanning_store() - Create a subtree with the store operation completed
|
|
* and new nodes where necessary, then place the sub-tree in the actual tree.
|
|
* Note that mas is expected to point to the node which caused the store to
|
|
* span.
|
|
* @wr_mas: The maple write state
|
|
*
|
|
* Return: 0 on error, positive on success.
|
|
*/
|
|
static inline int mas_wr_spanning_store(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct maple_subtree_state mast;
|
|
struct maple_big_node b_node;
|
|
struct ma_state *mas;
|
|
unsigned char height;
|
|
|
|
/* Left and Right side of spanning store */
|
|
MA_STATE(l_mas, NULL, 0, 0);
|
|
MA_STATE(r_mas, NULL, 0, 0);
|
|
|
|
MA_WR_STATE(r_wr_mas, &r_mas, wr_mas->entry);
|
|
MA_WR_STATE(l_wr_mas, &l_mas, wr_mas->entry);
|
|
|
|
/*
|
|
* A store operation that spans multiple nodes is called a spanning
|
|
* store and is handled early in the store call stack by the function
|
|
* mas_is_span_wr(). When a spanning store is identified, the maple
|
|
* state is duplicated. The first maple state walks the left tree path
|
|
* to ``index``, the duplicate walks the right tree path to ``last``.
|
|
* The data in the two nodes are combined into a single node, two nodes,
|
|
* or possibly three nodes (see the 3-way split above). A ``NULL``
|
|
* written to the last entry of a node is considered a spanning store as
|
|
* a rebalance is required for the operation to complete and an overflow
|
|
* of data may happen.
|
|
*/
|
|
mas = wr_mas->mas;
|
|
trace_ma_op(__func__, mas);
|
|
|
|
if (unlikely(!mas->index && mas->last == ULONG_MAX))
|
|
return mas_new_root(mas, wr_mas->entry);
|
|
/*
|
|
* Node rebalancing may occur due to this store, so there may be three new
|
|
* entries per level plus a new root.
|
|
*/
|
|
height = mas_mt_height(mas);
|
|
mas_node_count(mas, 1 + height * 3);
|
|
if (mas_is_err(mas))
|
|
return 0;
|
|
|
|
/*
|
|
* Set up right side. Need to get to the next offset after the spanning
|
|
* store to ensure it's not NULL and to combine both the next node and
|
|
* the node with the start together.
|
|
*/
|
|
r_mas = *mas;
|
|
/* Avoid overflow, walk to next slot in the tree. */
|
|
if (r_mas.last + 1)
|
|
r_mas.last++;
|
|
|
|
r_mas.index = r_mas.last;
|
|
mas_wr_walk_index(&r_wr_mas);
|
|
r_mas.last = r_mas.index = mas->last;
|
|
|
|
/* Set up left side. */
|
|
l_mas = *mas;
|
|
mas_wr_walk_index(&l_wr_mas);
|
|
|
|
if (!wr_mas->entry) {
|
|
mas_extend_spanning_null(&l_wr_mas, &r_wr_mas);
|
|
mas->offset = l_mas.offset;
|
|
mas->index = l_mas.index;
|
|
mas->last = l_mas.last = r_mas.last;
|
|
}
|
|
|
|
/* expanding NULLs may make this cover the entire range */
|
|
if (!l_mas.index && r_mas.last == ULONG_MAX) {
|
|
mas_set_range(mas, 0, ULONG_MAX);
|
|
return mas_new_root(mas, wr_mas->entry);
|
|
}
|
|
|
|
memset(&b_node, 0, sizeof(struct maple_big_node));
|
|
/* Copy l_mas and store the value in b_node. */
|
|
mas_store_b_node(&l_wr_mas, &b_node, l_wr_mas.node_end);
|
|
/* Copy r_mas into b_node. */
|
|
if (r_mas.offset <= r_wr_mas.node_end)
|
|
mas_mab_cp(&r_mas, r_mas.offset, r_wr_mas.node_end,
|
|
&b_node, b_node.b_end + 1);
|
|
else
|
|
b_node.b_end++;
|
|
|
|
/* Stop spanning searches by searching for just index. */
|
|
l_mas.index = l_mas.last = mas->index;
|
|
|
|
mast.bn = &b_node;
|
|
mast.orig_l = &l_mas;
|
|
mast.orig_r = &r_mas;
|
|
/* Combine l_mas and r_mas and split them up evenly again. */
|
|
return mas_spanning_rebalance(mas, &mast, height + 1);
|
|
}
|
|
|
|
/*
|
|
* mas_wr_node_store() - Attempt to store the value in a node
|
|
* @wr_mas: The maple write state
|
|
*
|
|
* Attempts to reuse the node, but may allocate.
|
|
*
|
|
* Return: True if stored, false otherwise
|
|
*/
|
|
static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct ma_state *mas = wr_mas->mas;
|
|
void __rcu **dst_slots;
|
|
unsigned long *dst_pivots;
|
|
unsigned char dst_offset;
|
|
unsigned char new_end = wr_mas->node_end;
|
|
unsigned char offset;
|
|
unsigned char node_slots = mt_slots[wr_mas->type];
|
|
struct maple_node reuse, *newnode;
|
|
unsigned char copy_size, max_piv = mt_pivots[wr_mas->type];
|
|
bool in_rcu = mt_in_rcu(mas->tree);
|
|
|
|
offset = mas->offset;
|
|
if (mas->last == wr_mas->r_max) {
|
|
/* runs right to the end of the node */
|
|
if (mas->last == mas->max)
|
|
new_end = offset;
|
|
/* don't copy this offset */
|
|
wr_mas->offset_end++;
|
|
} else if (mas->last < wr_mas->r_max) {
|
|
/* new range ends in this range */
|
|
if (unlikely(wr_mas->r_max == ULONG_MAX))
|
|
mas_bulk_rebalance(mas, wr_mas->node_end, wr_mas->type);
|
|
|
|
new_end++;
|
|
} else {
|
|
if (wr_mas->end_piv == mas->last)
|
|
wr_mas->offset_end++;
|
|
|
|
new_end -= wr_mas->offset_end - offset - 1;
|
|
}
|
|
|
|
/* new range starts within a range */
|
|
if (wr_mas->r_min < mas->index)
|
|
new_end++;
|
|
|
|
/* Not enough room */
|
|
if (new_end >= node_slots)
|
|
return false;
|
|
|
|
/* Not enough data. */
|
|
if (!mte_is_root(mas->node) && (new_end <= mt_min_slots[wr_mas->type]) &&
|
|
!(mas->mas_flags & MA_STATE_BULK))
|
|
return false;
|
|
|
|
/* set up node. */
|
|
if (in_rcu) {
|
|
mas_node_count(mas, 1);
|
|
if (mas_is_err(mas))
|
|
return false;
|
|
|
|
newnode = mas_pop_node(mas);
|
|
} else {
|
|
memset(&reuse, 0, sizeof(struct maple_node));
|
|
newnode = &reuse;
|
|
}
|
|
|
|
newnode->parent = mas_mn(mas)->parent;
|
|
dst_pivots = ma_pivots(newnode, wr_mas->type);
|
|
dst_slots = ma_slots(newnode, wr_mas->type);
|
|
/* Copy from start to insert point */
|
|
memcpy(dst_pivots, wr_mas->pivots, sizeof(unsigned long) * (offset + 1));
|
|
memcpy(dst_slots, wr_mas->slots, sizeof(void *) * (offset + 1));
|
|
dst_offset = offset;
|
|
|
|
/* Handle insert of new range starting after old range */
|
|
if (wr_mas->r_min < mas->index) {
|
|
mas->offset++;
|
|
rcu_assign_pointer(dst_slots[dst_offset], wr_mas->content);
|
|
dst_pivots[dst_offset++] = mas->index - 1;
|
|
}
|
|
|
|
/* Store the new entry and range end. */
|
|
if (dst_offset < max_piv)
|
|
dst_pivots[dst_offset] = mas->last;
|
|
mas->offset = dst_offset;
|
|
rcu_assign_pointer(dst_slots[dst_offset], wr_mas->entry);
|
|
|
|
/*
|
|
* this range wrote to the end of the node or it overwrote the rest of
|
|
* the data
|
|
*/
|
|
if (wr_mas->offset_end > wr_mas->node_end || mas->last >= mas->max) {
|
|
new_end = dst_offset;
|
|
goto done;
|
|
}
|
|
|
|
dst_offset++;
|
|
/* Copy to the end of node if necessary. */
|
|
copy_size = wr_mas->node_end - wr_mas->offset_end + 1;
|
|
memcpy(dst_slots + dst_offset, wr_mas->slots + wr_mas->offset_end,
|
|
sizeof(void *) * copy_size);
|
|
if (dst_offset < max_piv) {
|
|
if (copy_size > max_piv - dst_offset)
|
|
copy_size = max_piv - dst_offset;
|
|
|
|
memcpy(dst_pivots + dst_offset,
|
|
wr_mas->pivots + wr_mas->offset_end,
|
|
sizeof(unsigned long) * copy_size);
|
|
}
|
|
|
|
if ((wr_mas->node_end == node_slots - 1) && (new_end < node_slots - 1))
|
|
dst_pivots[new_end] = mas->max;
|
|
|
|
done:
|
|
mas_leaf_set_meta(mas, newnode, dst_pivots, maple_leaf_64, new_end);
|
|
if (in_rcu) {
|
|
mas->node = mt_mk_node(newnode, wr_mas->type);
|
|
mas_replace(mas, false);
|
|
} else {
|
|
memcpy(wr_mas->node, newnode, sizeof(struct maple_node));
|
|
}
|
|
trace_ma_write(__func__, mas, 0, wr_mas->entry);
|
|
mas_update_gap(mas);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mas_wr_slot_store: Attempt to store a value in a slot.
|
|
* @wr_mas: the maple write state
|
|
*
|
|
* Return: True if stored, false otherwise
|
|
*/
|
|
static inline bool mas_wr_slot_store(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct ma_state *mas = wr_mas->mas;
|
|
unsigned long lmax; /* Logical max. */
|
|
unsigned char offset = mas->offset;
|
|
|
|
if ((wr_mas->r_max > mas->last) && ((wr_mas->r_min != mas->index) ||
|
|
(offset != wr_mas->node_end)))
|
|
return false;
|
|
|
|
if (offset == wr_mas->node_end - 1)
|
|
lmax = mas->max;
|
|
else
|
|
lmax = wr_mas->pivots[offset + 1];
|
|
|
|
/* going to overwrite too many slots. */
|
|
if (lmax < mas->last)
|
|
return false;
|
|
|
|
if (wr_mas->r_min == mas->index) {
|
|
/* overwriting two or more ranges with one. */
|
|
if (lmax == mas->last)
|
|
return false;
|
|
|
|
/* Overwriting all of offset and a portion of offset + 1. */
|
|
rcu_assign_pointer(wr_mas->slots[offset], wr_mas->entry);
|
|
wr_mas->pivots[offset] = mas->last;
|
|
goto done;
|
|
}
|
|
|
|
/* Doesn't end on the next range end. */
|
|
if (lmax != mas->last)
|
|
return false;
|
|
|
|
/* Overwriting a portion of offset and all of offset + 1 */
|
|
if ((offset + 1 < mt_pivots[wr_mas->type]) &&
|
|
(wr_mas->entry || wr_mas->pivots[offset + 1]))
|
|
wr_mas->pivots[offset + 1] = mas->last;
|
|
|
|
rcu_assign_pointer(wr_mas->slots[offset + 1], wr_mas->entry);
|
|
wr_mas->pivots[offset] = mas->index - 1;
|
|
mas->offset++; /* Keep mas accurate. */
|
|
|
|
done:
|
|
trace_ma_write(__func__, mas, 0, wr_mas->entry);
|
|
mas_update_gap(mas);
|
|
return true;
|
|
}
|
|
|
|
static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
|
|
{
|
|
while ((wr_mas->mas->last > wr_mas->end_piv) &&
|
|
(wr_mas->offset_end < wr_mas->node_end))
|
|
wr_mas->end_piv = wr_mas->pivots[++wr_mas->offset_end];
|
|
|
|
if (wr_mas->mas->last > wr_mas->end_piv)
|
|
wr_mas->end_piv = wr_mas->mas->max;
|
|
}
|
|
|
|
static inline void mas_wr_extend_null(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct ma_state *mas = wr_mas->mas;
|
|
|
|
if (mas->last < wr_mas->end_piv && !wr_mas->slots[wr_mas->offset_end])
|
|
mas->last = wr_mas->end_piv;
|
|
|
|
/* Check next slot(s) if we are overwriting the end */
|
|
if ((mas->last == wr_mas->end_piv) &&
|
|
(wr_mas->node_end != wr_mas->offset_end) &&
|
|
!wr_mas->slots[wr_mas->offset_end + 1]) {
|
|
wr_mas->offset_end++;
|
|
if (wr_mas->offset_end == wr_mas->node_end)
|
|
mas->last = mas->max;
|
|
else
|
|
mas->last = wr_mas->pivots[wr_mas->offset_end];
|
|
wr_mas->end_piv = mas->last;
|
|
}
|
|
|
|
if (!wr_mas->content) {
|
|
/* If this one is null, the next and prev are not */
|
|
mas->index = wr_mas->r_min;
|
|
} else {
|
|
/* Check prev slot if we are overwriting the start */
|
|
if (mas->index == wr_mas->r_min && mas->offset &&
|
|
!wr_mas->slots[mas->offset - 1]) {
|
|
mas->offset--;
|
|
wr_mas->r_min = mas->index =
|
|
mas_safe_min(mas, wr_mas->pivots, mas->offset);
|
|
wr_mas->r_max = wr_mas->pivots[mas->offset];
|
|
}
|
|
}
|
|
}
|
|
|
|
static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
|
|
{
|
|
unsigned char end = wr_mas->node_end;
|
|
unsigned char new_end = end + 1;
|
|
struct ma_state *mas = wr_mas->mas;
|
|
unsigned char node_pivots = mt_pivots[wr_mas->type];
|
|
|
|
if ((mas->index != wr_mas->r_min) && (mas->last == wr_mas->r_max)) {
|
|
if (new_end < node_pivots)
|
|
wr_mas->pivots[new_end] = wr_mas->pivots[end];
|
|
|
|
if (new_end < node_pivots)
|
|
ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
|
|
|
|
rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->entry);
|
|
mas->offset = new_end;
|
|
wr_mas->pivots[end] = mas->index - 1;
|
|
|
|
return true;
|
|
}
|
|
|
|
if ((mas->index == wr_mas->r_min) && (mas->last < wr_mas->r_max)) {
|
|
if (new_end < node_pivots)
|
|
wr_mas->pivots[new_end] = wr_mas->pivots[end];
|
|
|
|
rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->content);
|
|
if (new_end < node_pivots)
|
|
ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
|
|
|
|
wr_mas->pivots[end] = mas->last;
|
|
rcu_assign_pointer(wr_mas->slots[end], wr_mas->entry);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* mas_wr_bnode() - Slow path for a modification.
|
|
* @wr_mas: The write maple state
|
|
*
|
|
* This is where split, rebalance end up.
|
|
*/
|
|
static void mas_wr_bnode(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct maple_big_node b_node;
|
|
|
|
trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry);
|
|
memset(&b_node, 0, sizeof(struct maple_big_node));
|
|
mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end);
|
|
mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end);
|
|
}
|
|
|
|
static inline void mas_wr_modify(struct ma_wr_state *wr_mas)
|
|
{
|
|
unsigned char node_slots;
|
|
unsigned char node_size;
|
|
struct ma_state *mas = wr_mas->mas;
|
|
|
|
/* Direct replacement */
|
|
if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) {
|
|
rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
|
|
if (!!wr_mas->entry ^ !!wr_mas->content)
|
|
mas_update_gap(mas);
|
|
return;
|
|
}
|
|
|
|
/* Attempt to append */
|
|
node_slots = mt_slots[wr_mas->type];
|
|
node_size = wr_mas->node_end - wr_mas->offset_end + mas->offset + 2;
|
|
if (mas->max == ULONG_MAX)
|
|
node_size++;
|
|
|
|
/* slot and node store will not fit, go to the slow path */
|
|
if (unlikely(node_size >= node_slots))
|
|
goto slow_path;
|
|
|
|
if (wr_mas->entry && (wr_mas->node_end < node_slots - 1) &&
|
|
(mas->offset == wr_mas->node_end) && mas_wr_append(wr_mas)) {
|
|
if (!wr_mas->content || !wr_mas->entry)
|
|
mas_update_gap(mas);
|
|
return;
|
|
}
|
|
|
|
if ((wr_mas->offset_end - mas->offset <= 1) && mas_wr_slot_store(wr_mas))
|
|
return;
|
|
else if (mas_wr_node_store(wr_mas))
|
|
return;
|
|
|
|
if (mas_is_err(mas))
|
|
return;
|
|
|
|
slow_path:
|
|
mas_wr_bnode(wr_mas);
|
|
}
|
|
|
|
/*
|
|
* mas_wr_store_entry() - Internal call to store a value
|
|
* @mas: The maple state
|
|
* @entry: The entry to store.
|
|
*
|
|
* Return: The contents that was stored at the index.
|
|
*/
|
|
static inline void *mas_wr_store_entry(struct ma_wr_state *wr_mas)
|
|
{
|
|
struct ma_state *mas = wr_mas->mas;
|
|
|
|
wr_mas->content = mas_start(mas);
|
|
if (mas_is_none(mas) || mas_is_ptr(mas)) {
|
|
mas_store_root(mas, wr_mas->entry);
|
|
return wr_mas->content;
|
|
}
|
|
|
|
if (unlikely(!mas_wr_walk(wr_mas))) {
|
|
mas_wr_spanning_store(wr_mas);
|
|
return wr_mas->content;
|
|
}
|
|
|
|
/* At this point, we are at the leaf node that needs to be altered. */
|
|
wr_mas->end_piv = wr_mas->r_max;
|
|
mas_wr_end_piv(wr_mas);
|
|
|
|
if (!wr_mas->entry)
|
|
mas_wr_extend_null(wr_mas);
|
|
|
|
/* New root for a single pointer */
|
|
if (unlikely(!mas->index && mas->last == ULONG_MAX)) {
|
|
mas_new_root(mas, wr_mas->entry);
|
|
return wr_mas->content;
|
|
}
|
|
|
|
mas_wr_modify(wr_mas);
|
|
return wr_mas->content;
|
|
}
|
|
|
|
/**
|
|
* mas_insert() - Internal call to insert a value
|
|
* @mas: The maple state
|
|
* @entry: The entry to store
|
|
*
|
|
* Return: %NULL or the contents that already exists at the requested index
|
|
* otherwise. The maple state needs to be checked for error conditions.
|
|
*/
|
|
static inline void *mas_insert(struct ma_state *mas, void *entry)
|
|
{
|
|
MA_WR_STATE(wr_mas, mas, entry);
|
|
|
|
/*
|
|
* Inserting a new range inserts either 0, 1, or 2 pivots within the
|
|
* tree. If the insert fits exactly into an existing gap with a value
|
|
* of NULL, then the slot only needs to be written with the new value.
|
|
* If the range being inserted is adjacent to another range, then only a
|
|
* single pivot needs to be inserted (as well as writing the entry). If
|
|
* the new range is within a gap but does not touch any other ranges,
|
|
* then two pivots need to be inserted: the start - 1, and the end. As
|
|
* usual, the entry must be written. Most operations require a new node
|
|
* to be allocated and replace an existing node to ensure RCU safety,
|
|
* when in RCU mode. The exception to requiring a newly allocated node
|
|
* is when inserting at the end of a node (appending). When done
|
|
* carefully, appending can reuse the node in place.
|
|
*/
|
|
wr_mas.content = mas_start(mas);
|
|
if (wr_mas.content)
|
|
goto exists;
|
|
|
|
if (mas_is_none(mas) || mas_is_ptr(mas)) {
|
|
mas_store_root(mas, entry);
|
|
return NULL;
|
|
}
|
|
|
|
/* spanning writes always overwrite something */
|
|
if (!mas_wr_walk(&wr_mas))
|
|
goto exists;
|
|
|
|
/* At this point, we are at the leaf node that needs to be altered. */
|
|
wr_mas.offset_end = mas->offset;
|
|
wr_mas.end_piv = wr_mas.r_max;
|
|
|
|
if (wr_mas.content || (mas->last > wr_mas.r_max))
|
|
goto exists;
|
|
|
|
if (!entry)
|
|
return NULL;
|
|
|
|
mas_wr_modify(&wr_mas);
|
|
return wr_mas.content;
|
|
|
|
exists:
|
|
mas_set_err(mas, -EEXIST);
|
|
return wr_mas.content;
|
|
|
|
}
|
|
|
|
/*
|
|
* mas_prev_node() - Find the prev non-null entry at the same level in the
|
|
* tree. The prev value will be mas->node[mas->offset] or MAS_NONE.
|
|
* @mas: The maple state
|
|
* @min: The lower limit to search
|
|
*
|
|
* The prev node value will be mas->node[mas->offset] or MAS_NONE.
|
|
* Return: 1 if the node is dead, 0 otherwise.
|
|
*/
|
|
static inline int mas_prev_node(struct ma_state *mas, unsigned long min)
|
|
{
|
|
enum maple_type mt;
|
|
int offset, level;
|
|
void __rcu **slots;
|
|
struct maple_node *node;
|
|
struct maple_enode *enode;
|
|
unsigned long *pivots;
|
|
|
|
if (mas_is_none(mas))
|
|
return 0;
|
|
|
|
level = 0;
|
|
do {
|
|
node = mas_mn(mas);
|
|
if (ma_is_root(node))
|
|
goto no_entry;
|
|
|
|
/* Walk up. */
|
|
if (unlikely(mas_ascend(mas)))
|
|
return 1;
|
|
offset = mas->offset;
|
|
level++;
|
|
} while (!offset);
|
|
|
|
offset--;
|
|
mt = mte_node_type(mas->node);
|
|
node = mas_mn(mas);
|
|
slots = ma_slots(node, mt);
|
|
pivots = ma_pivots(node, mt);
|
|
mas->max = pivots[offset];
|
|
if (offset)
|
|
mas->min = pivots[offset - 1] + 1;
|
|
if (unlikely(ma_dead_node(node)))
|
|
return 1;
|
|
|
|
if (mas->max < min)
|
|
goto no_entry_min;
|
|
|
|
while (level > 1) {
|
|
level--;
|
|
enode = mas_slot(mas, slots, offset);
|
|
if (unlikely(ma_dead_node(node)))
|
|
return 1;
|
|
|
|
mas->node = enode;
|
|
mt = mte_node_type(mas->node);
|
|
node = mas_mn(mas);
|
|
slots = ma_slots(node, mt);
|
|
pivots = ma_pivots(node, mt);
|
|
offset = ma_data_end(node, mt, pivots, mas->max);
|
|
if (offset)
|
|
mas->min = pivots[offset - 1] + 1;
|
|
|
|
if (offset < mt_pivots[mt])
|
|
mas->max = pivots[offset];
|
|
|
|
if (mas->max < min)
|
|
goto no_entry;
|
|
}
|
|
|
|
mas->node = mas_slot(mas, slots, offset);
|
|
if (unlikely(ma_dead_node(node)))
|
|
return 1;
|
|
|
|
mas->offset = mas_data_end(mas);
|
|
if (unlikely(mte_dead_node(mas->node)))
|
|
return 1;
|
|
|
|
return 0;
|
|
|
|
no_entry_min:
|
|
mas->offset = offset;
|
|
if (offset)
|
|
mas->min = pivots[offset - 1] + 1;
|
|
no_entry:
|
|
if (unlikely(ma_dead_node(node)))
|
|
return 1;
|
|
|
|
mas->node = MAS_NONE;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* mas_next_node() - Get the next node at the same level in the tree.
|
|
* @mas: The maple state
|
|
* @max: The maximum pivot value to check.
|
|
*
|
|
* The next value will be mas->node[mas->offset] or MAS_NONE.
|
|
* Return: 1 on dead node, 0 otherwise.
|
|
*/
|
|
static inline int mas_next_node(struct ma_state *mas, struct maple_node *node,
|
|
unsigned long max)
|
|
{
|
|
unsigned long min, pivot;
|
|
unsigned long *pivots;
|
|
struct maple_enode *enode;
|
|
int level = 0;
|
|
unsigned char offset;
|
|
enum maple_type mt;
|
|
void __rcu **slots;
|
|
|
|
if (mas->max >= max)
|
|
goto no_entry;
|
|
|
|
level = 0;
|
|
do {
|
|
if (ma_is_root(node))
|
|
goto no_entry;
|
|
|
|
min = mas->max + 1;
|
|
if (min > max)
|
|
goto no_entry;
|
|
|
|
if (unlikely(mas_ascend(mas)))
|
|
return 1;
|
|
|
|
offset = mas->offset;
|
|
level++;
|
|
node = mas_mn(mas);
|
|
mt = mte_node_type(mas->node);
|
|
pivots = ma_pivots(node, mt);
|
|
} while (unlikely(offset == ma_data_end(node, mt, pivots, mas->max)));
|
|
|
|
slots = ma_slots(node, mt);
|
|
pivot = mas_safe_pivot(mas, pivots, ++offset, mt);
|
|
while (unlikely(level > 1)) {
|
|
/* Descend, if necessary */
|
|
enode = mas_slot(mas, slots, offset);
|
|
if (unlikely(ma_dead_node(node)))
|
|
return 1;
|
|
|
|
mas->node = enode;
|
|
level--;
|
|
node = mas_mn(mas);
|
|
mt = mte_node_type(mas->node);
|
|
slots = ma_slots(node, mt);
|
|
pivots = ma_pivots(node, mt);
|
|
offset = 0;
|
|
pivot = pivots[0];
|
|
}
|
|
|
|
enode = mas_slot(mas, slots, offset);
|
|
if (unlikely(ma_dead_node(node)))
|
|
return 1;
|
|
|
|
mas->node = enode;
|
|
mas->min = min;
|
|
mas->max = pivot;
|
|
return 0;
|
|
|
|
no_entry:
|
|
if (unlikely(ma_dead_node(node)))
|
|
return 1;
|
|
|
|
mas->node = MAS_NONE;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* mas_next_nentry() - Get the next node entry
|
|
* @mas: The maple state
|
|
* @max: The maximum value to check
|
|
* @*range_start: Pointer to store the start of the range.
|
|
*
|
|
* Sets @mas->offset to the offset of the next node entry, @mas->last to the
|
|
* pivot of the entry.
|
|
*
|
|
* Return: The next entry, %NULL otherwise
|
|
*/
|
|
static inline void *mas_next_nentry(struct ma_state *mas,
|
|
struct maple_node *node, unsigned long max, enum maple_type type)
|
|
{
|
|
unsigned char count;
|
|
unsigned long pivot;
|
|
unsigned long *pivots;
|
|
void __rcu **slots;
|
|
void *entry;
|
|
|
|
if (mas->last == mas->max) {
|
|
mas->index = mas->max;
|
|
return NULL;
|
|
}
|
|
|
|
pivots = ma_pivots(node, type);
|
|
slots = ma_slots(node, type);
|
|
mas->index = mas_safe_min(mas, pivots, mas->offset);
|
|
if (ma_dead_node(node))
|
|
return NULL;
|
|
|
|
if (mas->index > max)
|
|
return NULL;
|
|
|
|
count = ma_data_end(node, type, pivots, mas->max);
|
|
if (mas->offset > count)
|
|
return NULL;
|
|
|
|
while (mas->offset < count) {
|
|
pivot = pivots[mas->offset];
|
|
entry = mas_slot(mas, slots, mas->offset);
|
|
if (ma_dead_node(node))
|
|
return NULL;
|
|
|
|
if (entry)
|
|
goto found;
|
|
|
|
if (pivot >= max)
|
|
return NULL;
|
|
|
|
mas->index = pivot + 1;
|
|
mas->offset++;
|
|
}
|
|
|
|
if (mas->index > mas->max) {
|
|
mas->index = mas->last;
|
|
return NULL;
|
|
}
|
|
|
|
pivot = mas_safe_pivot(mas, pivots, mas->offset, type);
|
|
entry = mas_slot(mas, slots, mas->offset);
|
|
if (ma_dead_node(node))
|
|
return NULL;
|
|
|
|
if (!pivot)
|
|
return NULL;
|
|
|
|
if (!entry)
|
|
return NULL;
|
|
|
|
found:
|
|
mas->last = pivot;
|
|
return entry;
|
|
}
|
|
|
|
static inline void mas_rewalk(struct ma_state *mas, unsigned long index)
|
|
{
|
|
retry:
|
|
mas_set(mas, index);
|
|
mas_state_walk(mas);
|
|
if (mas_is_start(mas))
|
|
goto retry;
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* mas_next_entry() - Internal function to get the next entry.
|
|
* @mas: The maple state
|
|
* @limit: The maximum range start.
|
|
*
|
|
* Set the @mas->node to the next entry and the range_start to
|
|
* the beginning value for the entry. Does not check beyond @limit.
|
|
* Sets @mas->index and @mas->last to the limit if it is hit.
|
|
* Restarts on dead nodes.
|
|
*
|
|
* Return: the next entry or %NULL.
|
|
*/
|
|
static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit)
|
|
{
|
|
void *entry = NULL;
|
|
struct maple_enode *prev_node;
|
|
struct maple_node *node;
|
|
unsigned char offset;
|
|
unsigned long last;
|
|
enum maple_type mt;
|
|
|
|
last = mas->last;
|
|
retry:
|
|
offset = mas->offset;
|
|
prev_node = mas->node;
|
|
node = mas_mn(mas);
|
|
mt = mte_node_type(mas->node);
|
|
mas->offset++;
|
|
if (unlikely(mas->offset >= mt_slots[mt])) {
|
|
mas->offset = mt_slots[mt] - 1;
|
|
goto next_node;
|
|
}
|
|
|
|
while (!mas_is_none(mas)) {
|
|
entry = mas_next_nentry(mas, node, limit, mt);
|
|
if (unlikely(ma_dead_node(node))) {
|
|
mas_rewalk(mas, last);
|
|
goto retry;
|
|
}
|
|
|
|
if (likely(entry))
|
|
return entry;
|
|
|
|
if (unlikely((mas->index > limit)))
|
|
break;
|
|
|
|
next_node:
|
|
prev_node = mas->node;
|
|
offset = mas->offset;
|
|
if (unlikely(mas_next_node(mas, node, limit))) {
|
|
mas_rewalk(mas, last);
|
|
goto retry;
|
|
}
|
|
mas->offset = 0;
|
|
node = mas_mn(mas);
|
|
mt = mte_node_type(mas->node);
|
|
}
|
|
|
|
mas->index = mas->last = limit;
|
|
mas->offset = offset;
|
|
mas->node = prev_node;
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* mas_prev_nentry() - Get the previous node entry.
|
|
* @mas: The maple state.
|
|
* @limit: The lower limit to check for a value.
|
|
*
|
|
* Return: the entry, %NULL otherwise.
|
|
*/
|
|
static inline void *mas_prev_nentry(struct ma_state *mas, unsigned long limit,
|
|
unsigned long index)
|
|
{
|
|
unsigned long pivot, min;
|
|
unsigned char offset;
|
|
struct maple_node *mn;
|
|
enum maple_type mt;
|
|
unsigned long *pivots;
|
|
void __rcu **slots;
|
|
void *entry;
|
|
|
|
retry:
|
|
if (!mas->offset)
|
|
return NULL;
|
|
|
|
mn = mas_mn(mas);
|
|
mt = mte_node_type(mas->node);
|
|
offset = mas->offset - 1;
|
|
if (offset >= mt_slots[mt])
|
|
offset = mt_slots[mt] - 1;
|
|
|
|
slots = ma_slots(mn, mt);
|
|
pivots = ma_pivots(mn, mt);
|
|
if (offset == mt_pivots[mt])
|
|
pivot = mas->max;
|
|
else
|
|
pivot = pivots[offset];
|
|
|
|
if (unlikely(ma_dead_node(mn))) {
|
|
mas_rewalk(mas, index);
|
|
goto retry;
|
|
}
|
|
|
|
while (offset && ((!mas_slot(mas, slots, offset) && pivot >= limit) ||
|
|
!pivot))
|
|
pivot = pivots[--offset];
|
|
|
|
min = mas_safe_min(mas, pivots, offset);
|
|
entry = mas_slot(mas, slots, offset);
|
|
if (unlikely(ma_dead_node(mn))) {
|
|
mas_rewalk(mas, index);
|
|
goto retry;
|
|
}
|
|
|
|
if (likely(entry)) {
|
|
mas->offset = offset;
|
|
mas->last = pivot;
|
|
mas->index = min;
|
|
}
|
|
return entry;
|
|
}
|
|
|
|
static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min)
|
|
{
|
|
void *entry;
|
|
|
|
retry:
|
|
while (likely(!mas_is_none(mas))) {
|
|
entry = mas_prev_nentry(mas, min, mas->index);
|
|
if (unlikely(mas->last < min))
|
|
goto not_found;
|
|
|
|
if (likely(entry))
|
|
return entry;
|
|
|
|
if (unlikely(mas_prev_node(mas, min))) {
|
|
mas_rewalk(mas, mas->index);
|
|
goto retry;
|
|
}
|
|
|
|
mas->offset++;
|
|
}
|
|
|
|
mas->offset--;
|
|
not_found:
|
|
mas->index = mas->last = min;
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* mas_rev_awalk() - Internal function. Reverse allocation walk. Find the
|
|
* highest gap address of a given size in a given node and descend.
|
|
* @mas: The maple state
|
|
* @size: The needed size.
|
|
*
|
|
* Return: True if found in a leaf, false otherwise.
|
|
*
|
|
*/
|
|
static bool mas_rev_awalk(struct ma_state *mas, unsigned long size)
|
|
{
|
|
enum maple_type type = mte_node_type(mas->node);
|
|
struct maple_node *node = mas_mn(mas);
|
|
unsigned long *pivots, *gaps;
|
|
void __rcu **slots;
|
|
unsigned long gap = 0;
|
|
unsigned long max, min, index;
|
|
unsigned char offset;
|
|
|
|
if (unlikely(mas_is_err(mas)))
|
|
return true;
|
|
|
|
if (ma_is_dense(type)) {
|
|
/* dense nodes. */
|
|
mas->offset = (unsigned char)(mas->index - mas->min);
|
|
return true;
|
|
}
|
|
|
|
pivots = ma_pivots(node, type);
|
|
slots = ma_slots(node, type);
|
|
gaps = ma_gaps(node, type);
|
|
offset = mas->offset;
|
|
min = mas_safe_min(mas, pivots, offset);
|
|
/* Skip out of bounds. */
|
|
while (mas->last < min)
|
|
min = mas_safe_min(mas, pivots, --offset);
|
|
|
|
max = mas_safe_pivot(mas, pivots, offset, type);
|
|
index = mas->index;
|
|
while (index <= max) {
|
|
gap = 0;
|
|
if (gaps)
|
|
gap = gaps[offset];
|
|
else if (!mas_slot(mas, slots, offset))
|
|
gap = max - min + 1;
|
|
|
|
if (gap) {
|
|
if ((size <= gap) && (size <= mas->last - min + 1))
|
|
break;
|
|
|
|
if (!gaps) {
|
|
/* Skip the next slot, it cannot be a gap. */
|
|
if (offset < 2)
|
|
goto ascend;
|
|
|
|
offset -= 2;
|
|
max = pivots[offset];
|
|
min = mas_safe_min(mas, pivots, offset);
|
|
continue;
|
|
}
|
|
}
|
|
|
|
if (!offset)
|
|
goto ascend;
|
|
|
|
offset--;
|
|
max = min - 1;
|
|
min = mas_safe_min(mas, pivots, offset);
|
|
}
|
|
|
|
if (unlikely(index > max)) {
|
|
mas_set_err(mas, -EBUSY);
|
|
return false;
|
|
}
|
|
|
|
if (unlikely(ma_is_leaf(type))) {
|
|
mas->offset = offset;
|
|
mas->min = min;
|
|
mas->max = min + gap - 1;
|
|
return true;
|
|
}
|
|
|
|
/* descend, only happens under lock. */
|
|
mas->node = mas_slot(mas, slots, offset);
|
|
mas->min = min;
|
|
mas->max = max;
|
|
mas->offset = mas_data_end(mas);
|
|
return false;
|
|
|
|
ascend:
|
|
if (mte_is_root(mas->node))
|
|
mas_set_err(mas, -EBUSY);
|
|
|
|
return false;
|
|
}
|
|
|
|
static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size)
|
|
{
|
|
enum maple_type type = mte_node_type(mas->node);
|
|
unsigned long pivot, min, gap = 0;
|
|
unsigned char offset;
|
|
unsigned long *gaps;
|
|
unsigned long *pivots = ma_pivots(mas_mn(mas), type);
|
|
void __rcu **slots = ma_slots(mas_mn(mas), type);
|
|
bool found = false;
|
|
|
|
if (ma_is_dense(type)) {
|
|
mas->offset = (unsigned char)(mas->index - mas->min);
|
|
return true;
|
|
}
|
|
|
|
gaps = ma_gaps(mte_to_node(mas->node), type);
|
|
offset = mas->offset;
|
|
min = mas_safe_min(mas, pivots, offset);
|
|
for (; offset < mt_slots[type]; offset++) {
|
|
pivot = mas_safe_pivot(mas, pivots, offset, type);
|
|
if (offset && !pivot)
|
|
break;
|
|
|
|
/* Not within lower bounds */
|
|
if (mas->index > pivot)
|
|
goto next_slot;
|
|
|
|
if (gaps)
|
|
gap = gaps[offset];
|
|
else if (!mas_slot(mas, slots, offset))
|
|
gap = min(pivot, mas->last) - max(mas->index, min) + 1;
|
|
else
|
|
goto next_slot;
|
|
|
|
if (gap >= size) {
|
|
if (ma_is_leaf(type)) {
|
|
found = true;
|
|
goto done;
|
|
}
|
|
if (mas->index <= pivot) {
|
|
mas->node = mas_slot(mas, slots, offset);
|
|
mas->min = min;
|
|
mas->max = pivot;
|
|
offset = 0;
|
|
break;
|
|
}
|
|
}
|
|
next_slot:
|
|
min = pivot + 1;
|
|
if (mas->last <= pivot) {
|
|
mas_set_err(mas, -EBUSY);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
if (mte_is_root(mas->node))
|
|
found = true;
|
|
done:
|
|
mas->offset = offset;
|
|
return found;
|
|
}
|
|
|
|
/**
|
|
* mas_walk() - Search for @mas->index in the tree.
|
|
* @mas: The maple state.
|
|
*
|
|
* mas->index and mas->last will be set to the range if there is a value. If
|
|
* mas->node is MAS_NONE, reset to MAS_START.
|
|
*
|
|
* Return: the entry at the location or %NULL.
|
|
*/
|
|
void *mas_walk(struct ma_state *mas)
|
|
{
|
|
void *entry;
|
|
|
|
retry:
|
|
entry = mas_state_walk(mas);
|
|
if (mas_is_start(mas))
|
|
goto retry;
|
|
|
|
if (mas_is_ptr(mas)) {
|
|
if (!mas->index) {
|
|
mas->last = 0;
|
|
} else {
|
|
mas->index = 1;
|
|
mas->last = ULONG_MAX;
|
|
}
|
|
return entry;
|
|
}
|
|
|
|
if (mas_is_none(mas)) {
|
|
mas->index = 0;
|
|
mas->last = ULONG_MAX;
|
|
}
|
|
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_walk);
|
|
|
|
static inline bool mas_rewind_node(struct ma_state *mas)
|
|
{
|
|
unsigned char slot;
|
|
|
|
do {
|
|
if (mte_is_root(mas->node)) {
|
|
slot = mas->offset;
|
|
if (!slot)
|
|
return false;
|
|
} else {
|
|
mas_ascend(mas);
|
|
slot = mas->offset;
|
|
}
|
|
} while (!slot);
|
|
|
|
mas->offset = --slot;
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mas_skip_node() - Internal function. Skip over a node.
|
|
* @mas: The maple state.
|
|
*
|
|
* Return: true if there is another node, false otherwise.
|
|
*/
|
|
static inline bool mas_skip_node(struct ma_state *mas)
|
|
{
|
|
unsigned char slot, slot_count;
|
|
unsigned long *pivots;
|
|
enum maple_type mt;
|
|
|
|
mt = mte_node_type(mas->node);
|
|
slot_count = mt_slots[mt] - 1;
|
|
do {
|
|
if (mte_is_root(mas->node)) {
|
|
slot = mas->offset;
|
|
if (slot > slot_count) {
|
|
mas_set_err(mas, -EBUSY);
|
|
return false;
|
|
}
|
|
} else {
|
|
mas_ascend(mas);
|
|
slot = mas->offset;
|
|
mt = mte_node_type(mas->node);
|
|
slot_count = mt_slots[mt] - 1;
|
|
}
|
|
} while (slot > slot_count);
|
|
|
|
mas->offset = ++slot;
|
|
pivots = ma_pivots(mas_mn(mas), mt);
|
|
if (slot > 0)
|
|
mas->min = pivots[slot - 1] + 1;
|
|
|
|
if (slot <= slot_count)
|
|
mas->max = pivots[slot];
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* mas_awalk() - Allocation walk. Search from low address to high, for a gap of
|
|
* @size
|
|
* @mas: The maple state
|
|
* @size: The size of the gap required
|
|
*
|
|
* Search between @mas->index and @mas->last for a gap of @size.
|
|
*/
|
|
static inline void mas_awalk(struct ma_state *mas, unsigned long size)
|
|
{
|
|
struct maple_enode *last = NULL;
|
|
|
|
/*
|
|
* There are 4 options:
|
|
* go to child (descend)
|
|
* go back to parent (ascend)
|
|
* no gap found. (return, slot == MAPLE_NODE_SLOTS)
|
|
* found the gap. (return, slot != MAPLE_NODE_SLOTS)
|
|
*/
|
|
while (!mas_is_err(mas) && !mas_anode_descend(mas, size)) {
|
|
if (last == mas->node)
|
|
mas_skip_node(mas);
|
|
else
|
|
last = mas->node;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* mas_fill_gap() - Fill a located gap with @entry.
|
|
* @mas: The maple state
|
|
* @entry: The value to store
|
|
* @slot: The offset into the node to store the @entry
|
|
* @size: The size of the entry
|
|
* @index: The start location
|
|
*/
|
|
static inline void mas_fill_gap(struct ma_state *mas, void *entry,
|
|
unsigned char slot, unsigned long size, unsigned long *index)
|
|
{
|
|
MA_WR_STATE(wr_mas, mas, entry);
|
|
unsigned char pslot = mte_parent_slot(mas->node);
|
|
struct maple_enode *mn = mas->node;
|
|
unsigned long *pivots;
|
|
enum maple_type ptype;
|
|
/*
|
|
* mas->index is the start address for the search
|
|
* which may no longer be needed.
|
|
* mas->last is the end address for the search
|
|
*/
|
|
|
|
*index = mas->index;
|
|
mas->last = mas->index + size - 1;
|
|
|
|
/*
|
|
* It is possible that using mas->max and mas->min to correctly
|
|
* calculate the index and last will cause an issue in the gap
|
|
* calculation, so fix the ma_state here
|
|
*/
|
|
mas_ascend(mas);
|
|
ptype = mte_node_type(mas->node);
|
|
pivots = ma_pivots(mas_mn(mas), ptype);
|
|
mas->max = mas_safe_pivot(mas, pivots, pslot, ptype);
|
|
mas->min = mas_safe_min(mas, pivots, pslot);
|
|
mas->node = mn;
|
|
mas->offset = slot;
|
|
mas_wr_store_entry(&wr_mas);
|
|
}
|
|
|
|
/*
|
|
* mas_sparse_area() - Internal function. Return upper or lower limit when
|
|
* searching for a gap in an empty tree.
|
|
* @mas: The maple state
|
|
* @min: the minimum range
|
|
* @max: The maximum range
|
|
* @size: The size of the gap
|
|
* @fwd: Searching forward or back
|
|
*/
|
|
static inline void mas_sparse_area(struct ma_state *mas, unsigned long min,
|
|
unsigned long max, unsigned long size, bool fwd)
|
|
{
|
|
unsigned long start = 0;
|
|
|
|
if (!unlikely(mas_is_none(mas)))
|
|
start++;
|
|
/* mas_is_ptr */
|
|
|
|
if (start < min)
|
|
start = min;
|
|
|
|
if (fwd) {
|
|
mas->index = start;
|
|
mas->last = start + size - 1;
|
|
return;
|
|
}
|
|
|
|
mas->index = max;
|
|
}
|
|
|
|
/*
|
|
* mas_empty_area() - Get the lowest address within the range that is
|
|
* sufficient for the size requested.
|
|
* @mas: The maple state
|
|
* @min: The lowest value of the range
|
|
* @max: The highest value of the range
|
|
* @size: The size needed
|
|
*/
|
|
int mas_empty_area(struct ma_state *mas, unsigned long min,
|
|
unsigned long max, unsigned long size)
|
|
{
|
|
unsigned char offset;
|
|
unsigned long *pivots;
|
|
enum maple_type mt;
|
|
|
|
if (mas_is_start(mas))
|
|
mas_start(mas);
|
|
else if (mas->offset >= 2)
|
|
mas->offset -= 2;
|
|
else if (!mas_skip_node(mas))
|
|
return -EBUSY;
|
|
|
|
/* Empty set */
|
|
if (mas_is_none(mas) || mas_is_ptr(mas)) {
|
|
mas_sparse_area(mas, min, max, size, true);
|
|
return 0;
|
|
}
|
|
|
|
/* The start of the window can only be within these values */
|
|
mas->index = min;
|
|
mas->last = max;
|
|
mas_awalk(mas, size);
|
|
|
|
if (unlikely(mas_is_err(mas)))
|
|
return xa_err(mas->node);
|
|
|
|
offset = mas->offset;
|
|
if (unlikely(offset == MAPLE_NODE_SLOTS))
|
|
return -EBUSY;
|
|
|
|
mt = mte_node_type(mas->node);
|
|
pivots = ma_pivots(mas_mn(mas), mt);
|
|
if (offset)
|
|
mas->min = pivots[offset - 1] + 1;
|
|
|
|
if (offset < mt_pivots[mt])
|
|
mas->max = pivots[offset];
|
|
|
|
if (mas->index < mas->min)
|
|
mas->index = mas->min;
|
|
|
|
mas->last = mas->index + size - 1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_empty_area);
|
|
|
|
/*
|
|
* mas_empty_area_rev() - Get the highest address within the range that is
|
|
* sufficient for the size requested.
|
|
* @mas: The maple state
|
|
* @min: The lowest value of the range
|
|
* @max: The highest value of the range
|
|
* @size: The size needed
|
|
*/
|
|
int mas_empty_area_rev(struct ma_state *mas, unsigned long min,
|
|
unsigned long max, unsigned long size)
|
|
{
|
|
struct maple_enode *last = mas->node;
|
|
|
|
if (mas_is_start(mas)) {
|
|
mas_start(mas);
|
|
mas->offset = mas_data_end(mas);
|
|
} else if (mas->offset >= 2) {
|
|
mas->offset -= 2;
|
|
} else if (!mas_rewind_node(mas)) {
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* Empty set. */
|
|
if (mas_is_none(mas) || mas_is_ptr(mas)) {
|
|
mas_sparse_area(mas, min, max, size, false);
|
|
return 0;
|
|
}
|
|
|
|
/* The start of the window can only be within these values. */
|
|
mas->index = min;
|
|
mas->last = max;
|
|
|
|
while (!mas_rev_awalk(mas, size)) {
|
|
if (last == mas->node) {
|
|
if (!mas_rewind_node(mas))
|
|
return -EBUSY;
|
|
} else {
|
|
last = mas->node;
|
|
}
|
|
}
|
|
|
|
if (mas_is_err(mas))
|
|
return xa_err(mas->node);
|
|
|
|
if (unlikely(mas->offset == MAPLE_NODE_SLOTS))
|
|
return -EBUSY;
|
|
|
|
/*
|
|
* mas_rev_awalk() has set mas->min and mas->max to the gap values. If
|
|
* the maximum is outside the window we are searching, then use the last
|
|
* location in the search.
|
|
* mas->max and mas->min is the range of the gap.
|
|
* mas->index and mas->last are currently set to the search range.
|
|
*/
|
|
|
|
/* Trim the upper limit to the max. */
|
|
if (mas->max <= mas->last)
|
|
mas->last = mas->max;
|
|
|
|
mas->index = mas->last - size + 1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_empty_area_rev);
|
|
|
|
static inline int mas_alloc(struct ma_state *mas, void *entry,
|
|
unsigned long size, unsigned long *index)
|
|
{
|
|
unsigned long min;
|
|
|
|
mas_start(mas);
|
|
if (mas_is_none(mas) || mas_is_ptr(mas)) {
|
|
mas_root_expand(mas, entry);
|
|
if (mas_is_err(mas))
|
|
return xa_err(mas->node);
|
|
|
|
if (!mas->index)
|
|
return mte_pivot(mas->node, 0);
|
|
return mte_pivot(mas->node, 1);
|
|
}
|
|
|
|
/* Must be walking a tree. */
|
|
mas_awalk(mas, size);
|
|
if (mas_is_err(mas))
|
|
return xa_err(mas->node);
|
|
|
|
if (mas->offset == MAPLE_NODE_SLOTS)
|
|
goto no_gap;
|
|
|
|
/*
|
|
* At this point, mas->node points to the right node and we have an
|
|
* offset that has a sufficient gap.
|
|
*/
|
|
min = mas->min;
|
|
if (mas->offset)
|
|
min = mte_pivot(mas->node, mas->offset - 1) + 1;
|
|
|
|
if (mas->index < min)
|
|
mas->index = min;
|
|
|
|
mas_fill_gap(mas, entry, mas->offset, size, index);
|
|
return 0;
|
|
|
|
no_gap:
|
|
return -EBUSY;
|
|
}
|
|
|
|
static inline int mas_rev_alloc(struct ma_state *mas, unsigned long min,
|
|
unsigned long max, void *entry,
|
|
unsigned long size, unsigned long *index)
|
|
{
|
|
int ret = 0;
|
|
|
|
ret = mas_empty_area_rev(mas, min, max, size);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (mas_is_err(mas))
|
|
return xa_err(mas->node);
|
|
|
|
if (mas->offset == MAPLE_NODE_SLOTS)
|
|
goto no_gap;
|
|
|
|
mas_fill_gap(mas, entry, mas->offset, size, index);
|
|
return 0;
|
|
|
|
no_gap:
|
|
return -EBUSY;
|
|
}
|
|
|
|
/*
|
|
* mas_dead_leaves() - Mark all leaves of a node as dead.
|
|
* @mas: The maple state
|
|
* @slots: Pointer to the slot array
|
|
*
|
|
* Must hold the write lock.
|
|
*
|
|
* Return: The number of leaves marked as dead.
|
|
*/
|
|
static inline
|
|
unsigned char mas_dead_leaves(struct ma_state *mas, void __rcu **slots)
|
|
{
|
|
struct maple_node *node;
|
|
enum maple_type type;
|
|
void *entry;
|
|
int offset;
|
|
|
|
for (offset = 0; offset < mt_slot_count(mas->node); offset++) {
|
|
entry = mas_slot_locked(mas, slots, offset);
|
|
type = mte_node_type(entry);
|
|
node = mte_to_node(entry);
|
|
/* Use both node and type to catch LE & BE metadata */
|
|
if (!node || !type)
|
|
break;
|
|
|
|
mte_set_node_dead(entry);
|
|
smp_wmb(); /* Needed for RCU */
|
|
node->type = type;
|
|
rcu_assign_pointer(slots[offset], node);
|
|
}
|
|
|
|
return offset;
|
|
}
|
|
|
|
static void __rcu **mas_dead_walk(struct ma_state *mas, unsigned char offset)
|
|
{
|
|
struct maple_node *node, *next;
|
|
void __rcu **slots = NULL;
|
|
|
|
next = mas_mn(mas);
|
|
do {
|
|
mas->node = ma_enode_ptr(next);
|
|
node = mas_mn(mas);
|
|
slots = ma_slots(node, node->type);
|
|
next = mas_slot_locked(mas, slots, offset);
|
|
offset = 0;
|
|
} while (!ma_is_leaf(next->type));
|
|
|
|
return slots;
|
|
}
|
|
|
|
static void mt_free_walk(struct rcu_head *head)
|
|
{
|
|
void __rcu **slots;
|
|
struct maple_node *node, *start;
|
|
struct maple_tree mt;
|
|
unsigned char offset;
|
|
enum maple_type type;
|
|
MA_STATE(mas, &mt, 0, 0);
|
|
|
|
node = container_of(head, struct maple_node, rcu);
|
|
|
|
if (ma_is_leaf(node->type))
|
|
goto free_leaf;
|
|
|
|
mt_init_flags(&mt, node->ma_flags);
|
|
mas_lock(&mas);
|
|
start = node;
|
|
mas.node = mt_mk_node(node, node->type);
|
|
slots = mas_dead_walk(&mas, 0);
|
|
node = mas_mn(&mas);
|
|
do {
|
|
mt_free_bulk(node->slot_len, slots);
|
|
offset = node->parent_slot + 1;
|
|
mas.node = node->piv_parent;
|
|
if (mas_mn(&mas) == node)
|
|
goto start_slots_free;
|
|
|
|
type = mte_node_type(mas.node);
|
|
slots = ma_slots(mte_to_node(mas.node), type);
|
|
if ((offset < mt_slots[type]) && (slots[offset]))
|
|
slots = mas_dead_walk(&mas, offset);
|
|
|
|
node = mas_mn(&mas);
|
|
} while ((node != start) || (node->slot_len < offset));
|
|
|
|
slots = ma_slots(node, node->type);
|
|
mt_free_bulk(node->slot_len, slots);
|
|
|
|
start_slots_free:
|
|
mas_unlock(&mas);
|
|
free_leaf:
|
|
mt_free_rcu(&node->rcu);
|
|
}
|
|
|
|
static inline void __rcu **mas_destroy_descend(struct ma_state *mas,
|
|
struct maple_enode *prev, unsigned char offset)
|
|
{
|
|
struct maple_node *node;
|
|
struct maple_enode *next = mas->node;
|
|
void __rcu **slots = NULL;
|
|
|
|
do {
|
|
mas->node = next;
|
|
node = mas_mn(mas);
|
|
slots = ma_slots(node, mte_node_type(mas->node));
|
|
next = mas_slot_locked(mas, slots, 0);
|
|
if ((mte_dead_node(next)))
|
|
next = mas_slot_locked(mas, slots, 1);
|
|
|
|
mte_set_node_dead(mas->node);
|
|
node->type = mte_node_type(mas->node);
|
|
node->piv_parent = prev;
|
|
node->parent_slot = offset;
|
|
offset = 0;
|
|
prev = mas->node;
|
|
} while (!mte_is_leaf(next));
|
|
|
|
return slots;
|
|
}
|
|
|
|
static void mt_destroy_walk(struct maple_enode *enode, unsigned char ma_flags,
|
|
bool free)
|
|
{
|
|
void __rcu **slots;
|
|
struct maple_node *node = mte_to_node(enode);
|
|
struct maple_enode *start;
|
|
struct maple_tree mt;
|
|
|
|
MA_STATE(mas, &mt, 0, 0);
|
|
|
|
if (mte_is_leaf(enode))
|
|
goto free_leaf;
|
|
|
|
mt_init_flags(&mt, ma_flags);
|
|
mas_lock(&mas);
|
|
|
|
mas.node = start = enode;
|
|
slots = mas_destroy_descend(&mas, start, 0);
|
|
node = mas_mn(&mas);
|
|
do {
|
|
enum maple_type type;
|
|
unsigned char offset;
|
|
struct maple_enode *parent, *tmp;
|
|
|
|
node->slot_len = mas_dead_leaves(&mas, slots);
|
|
if (free)
|
|
mt_free_bulk(node->slot_len, slots);
|
|
offset = node->parent_slot + 1;
|
|
mas.node = node->piv_parent;
|
|
if (mas_mn(&mas) == node)
|
|
goto start_slots_free;
|
|
|
|
type = mte_node_type(mas.node);
|
|
slots = ma_slots(mte_to_node(mas.node), type);
|
|
if (offset >= mt_slots[type])
|
|
goto next;
|
|
|
|
tmp = mas_slot_locked(&mas, slots, offset);
|
|
if (mte_node_type(tmp) && mte_to_node(tmp)) {
|
|
parent = mas.node;
|
|
mas.node = tmp;
|
|
slots = mas_destroy_descend(&mas, parent, offset);
|
|
}
|
|
next:
|
|
node = mas_mn(&mas);
|
|
} while (start != mas.node);
|
|
|
|
node = mas_mn(&mas);
|
|
node->slot_len = mas_dead_leaves(&mas, slots);
|
|
if (free)
|
|
mt_free_bulk(node->slot_len, slots);
|
|
|
|
start_slots_free:
|
|
mas_unlock(&mas);
|
|
|
|
free_leaf:
|
|
if (free)
|
|
mt_free_rcu(&node->rcu);
|
|
}
|
|
|
|
/*
|
|
* mte_destroy_walk() - Free a tree or sub-tree.
|
|
* @enode - the encoded maple node (maple_enode) to start
|
|
* @mn - the tree to free - needed for node types.
|
|
*
|
|
* Must hold the write lock.
|
|
*/
|
|
static inline void mte_destroy_walk(struct maple_enode *enode,
|
|
struct maple_tree *mt)
|
|
{
|
|
struct maple_node *node = mte_to_node(enode);
|
|
|
|
if (mt_in_rcu(mt)) {
|
|
mt_destroy_walk(enode, mt->ma_flags, false);
|
|
call_rcu(&node->rcu, mt_free_walk);
|
|
} else {
|
|
mt_destroy_walk(enode, mt->ma_flags, true);
|
|
}
|
|
}
|
|
|
|
static void mas_wr_store_setup(struct ma_wr_state *wr_mas)
|
|
{
|
|
if (!mas_is_start(wr_mas->mas)) {
|
|
if (mas_is_none(wr_mas->mas)) {
|
|
mas_reset(wr_mas->mas);
|
|
} else {
|
|
wr_mas->r_max = wr_mas->mas->max;
|
|
wr_mas->type = mte_node_type(wr_mas->mas->node);
|
|
if (mas_is_span_wr(wr_mas))
|
|
mas_reset(wr_mas->mas);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Interface */
|
|
|
|
/**
|
|
* mas_store() - Store an @entry.
|
|
* @mas: The maple state.
|
|
* @entry: The entry to store.
|
|
*
|
|
* The @mas->index and @mas->last is used to set the range for the @entry.
|
|
* Note: The @mas should have pre-allocated entries to ensure there is memory to
|
|
* store the entry. Please see mas_expected_entries()/mas_destroy() for more details.
|
|
*
|
|
* Return: the first entry between mas->index and mas->last or %NULL.
|
|
*/
|
|
void *mas_store(struct ma_state *mas, void *entry)
|
|
{
|
|
MA_WR_STATE(wr_mas, mas, entry);
|
|
|
|
trace_ma_write(__func__, mas, 0, entry);
|
|
#ifdef CONFIG_DEBUG_MAPLE_TREE
|
|
if (mas->index > mas->last)
|
|
pr_err("Error %lu > %lu %p\n", mas->index, mas->last, entry);
|
|
MT_BUG_ON(mas->tree, mas->index > mas->last);
|
|
if (mas->index > mas->last) {
|
|
mas_set_err(mas, -EINVAL);
|
|
return NULL;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
* Storing is the same operation as insert with the added caveat that it
|
|
* can overwrite entries. Although this seems simple enough, one may
|
|
* want to examine what happens if a single store operation was to
|
|
* overwrite multiple entries within a self-balancing B-Tree.
|
|
*/
|
|
mas_wr_store_setup(&wr_mas);
|
|
mas_wr_store_entry(&wr_mas);
|
|
return wr_mas.content;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_store);
|
|
|
|
/**
|
|
* mas_store_gfp() - Store a value into the tree.
|
|
* @mas: The maple state
|
|
* @entry: The entry to store
|
|
* @gfp: The GFP_FLAGS to use for allocations if necessary.
|
|
*
|
|
* Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
|
|
* be allocated.
|
|
*/
|
|
int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp)
|
|
{
|
|
MA_WR_STATE(wr_mas, mas, entry);
|
|
|
|
mas_wr_store_setup(&wr_mas);
|
|
trace_ma_write(__func__, mas, 0, entry);
|
|
retry:
|
|
mas_wr_store_entry(&wr_mas);
|
|
if (unlikely(mas_nomem(mas, gfp)))
|
|
goto retry;
|
|
|
|
if (unlikely(mas_is_err(mas)))
|
|
return xa_err(mas->node);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_store_gfp);
|
|
|
|
/**
|
|
* mas_store_prealloc() - Store a value into the tree using memory
|
|
* preallocated in the maple state.
|
|
* @mas: The maple state
|
|
* @entry: The entry to store.
|
|
*/
|
|
void mas_store_prealloc(struct ma_state *mas, void *entry)
|
|
{
|
|
MA_WR_STATE(wr_mas, mas, entry);
|
|
|
|
mas_wr_store_setup(&wr_mas);
|
|
trace_ma_write(__func__, mas, 0, entry);
|
|
mas_wr_store_entry(&wr_mas);
|
|
BUG_ON(mas_is_err(mas));
|
|
mas_destroy(mas);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_store_prealloc);
|
|
|
|
/**
|
|
* mas_preallocate() - Preallocate enough nodes for a store operation
|
|
* @mas: The maple state
|
|
* @entry: The entry that will be stored
|
|
* @gfp: The GFP_FLAGS to use for allocations.
|
|
*
|
|
* Return: 0 on success, -ENOMEM if memory could not be allocated.
|
|
*/
|
|
int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp)
|
|
{
|
|
int ret;
|
|
|
|
mas_node_count_gfp(mas, 1 + mas_mt_height(mas) * 3, gfp);
|
|
mas->mas_flags |= MA_STATE_PREALLOC;
|
|
if (likely(!mas_is_err(mas)))
|
|
return 0;
|
|
|
|
mas_set_alloc_req(mas, 0);
|
|
ret = xa_err(mas->node);
|
|
mas_reset(mas);
|
|
mas_destroy(mas);
|
|
mas_reset(mas);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* mas_destroy() - destroy a maple state.
|
|
* @mas: The maple state
|
|
*
|
|
* Upon completion, check the left-most node and rebalance against the node to
|
|
* the right if necessary. Frees any allocated nodes associated with this maple
|
|
* state.
|
|
*/
|
|
void mas_destroy(struct ma_state *mas)
|
|
{
|
|
struct maple_alloc *node;
|
|
|
|
/*
|
|
* When using mas_for_each() to insert an expected number of elements,
|
|
* it is possible that the number inserted is less than the expected
|
|
* number. To fix an invalid final node, a check is performed here to
|
|
* rebalance the previous node with the final node.
|
|
*/
|
|
if (mas->mas_flags & MA_STATE_REBALANCE) {
|
|
unsigned char end;
|
|
|
|
if (mas_is_start(mas))
|
|
mas_start(mas);
|
|
|
|
mtree_range_walk(mas);
|
|
end = mas_data_end(mas) + 1;
|
|
if (end < mt_min_slot_count(mas->node) - 1)
|
|
mas_destroy_rebalance(mas, end);
|
|
|
|
mas->mas_flags &= ~MA_STATE_REBALANCE;
|
|
}
|
|
mas->mas_flags &= ~(MA_STATE_BULK|MA_STATE_PREALLOC);
|
|
|
|
while (mas->alloc && !((unsigned long)mas->alloc & 0x1)) {
|
|
node = mas->alloc;
|
|
mas->alloc = node->slot[0];
|
|
if (node->node_count > 0)
|
|
mt_free_bulk(node->node_count,
|
|
(void __rcu **)&node->slot[1]);
|
|
kmem_cache_free(maple_node_cache, node);
|
|
}
|
|
mas->alloc = NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_destroy);
|
|
|
|
/*
|
|
* mas_expected_entries() - Set the expected number of entries that will be inserted.
|
|
* @mas: The maple state
|
|
* @nr_entries: The number of expected entries.
|
|
*
|
|
* This will attempt to pre-allocate enough nodes to store the expected number
|
|
* of entries. The allocations will occur using the bulk allocator interface
|
|
* for speed. Please call mas_destroy() on the @mas after inserting the entries
|
|
* to ensure any unused nodes are freed.
|
|
*
|
|
* Return: 0 on success, -ENOMEM if memory could not be allocated.
|
|
*/
|
|
int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries)
|
|
{
|
|
int nonleaf_cap = MAPLE_ARANGE64_SLOTS - 2;
|
|
struct maple_enode *enode = mas->node;
|
|
int nr_nodes;
|
|
int ret;
|
|
|
|
/*
|
|
* Sometimes it is necessary to duplicate a tree to a new tree, such as
|
|
* forking a process and duplicating the VMAs from one tree to a new
|
|
* tree. When such a situation arises, it is known that the new tree is
|
|
* not going to be used until the entire tree is populated. For
|
|
* performance reasons, it is best to use a bulk load with RCU disabled.
|
|
* This allows for optimistic splitting that favours the left and reuse
|
|
* of nodes during the operation.
|
|
*/
|
|
|
|
/* Optimize splitting for bulk insert in-order */
|
|
mas->mas_flags |= MA_STATE_BULK;
|
|
|
|
/*
|
|
* Avoid overflow, assume a gap between each entry and a trailing null.
|
|
* If this is wrong, it just means allocation can happen during
|
|
* insertion of entries.
|
|
*/
|
|
nr_nodes = max(nr_entries, nr_entries * 2 + 1);
|
|
if (!mt_is_alloc(mas->tree))
|
|
nonleaf_cap = MAPLE_RANGE64_SLOTS - 2;
|
|
|
|
/* Leaves; reduce slots to keep space for expansion */
|
|
nr_nodes = DIV_ROUND_UP(nr_nodes, MAPLE_RANGE64_SLOTS - 2);
|
|
/* Internal nodes */
|
|
nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap);
|
|
/* Add working room for split (2 nodes) + new parents */
|
|
mas_node_count(mas, nr_nodes + 3);
|
|
|
|
/* Detect if allocations run out */
|
|
mas->mas_flags |= MA_STATE_PREALLOC;
|
|
|
|
if (!mas_is_err(mas))
|
|
return 0;
|
|
|
|
ret = xa_err(mas->node);
|
|
mas->node = enode;
|
|
mas_destroy(mas);
|
|
return ret;
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_expected_entries);
|
|
|
|
/**
|
|
* mas_next() - Get the next entry.
|
|
* @mas: The maple state
|
|
* @max: The maximum index to check.
|
|
*
|
|
* Returns the next entry after @mas->index.
|
|
* Must hold rcu_read_lock or the write lock.
|
|
* Can return the zero entry.
|
|
*
|
|
* Return: The next entry or %NULL
|
|
*/
|
|
void *mas_next(struct ma_state *mas, unsigned long max)
|
|
{
|
|
if (mas_is_none(mas) || mas_is_paused(mas))
|
|
mas->node = MAS_START;
|
|
|
|
if (mas_is_start(mas))
|
|
mas_walk(mas); /* Retries on dead nodes handled by mas_walk */
|
|
|
|
if (mas_is_ptr(mas)) {
|
|
if (!mas->index) {
|
|
mas->index = 1;
|
|
mas->last = ULONG_MAX;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
if (mas->last == ULONG_MAX)
|
|
return NULL;
|
|
|
|
/* Retries on dead nodes handled by mas_next_entry */
|
|
return mas_next_entry(mas, max);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_next);
|
|
|
|
/**
|
|
* mt_next() - get the next value in the maple tree
|
|
* @mt: The maple tree
|
|
* @index: The start index
|
|
* @max: The maximum index to check
|
|
*
|
|
* Return: The entry at @index or higher, or %NULL if nothing is found.
|
|
*/
|
|
void *mt_next(struct maple_tree *mt, unsigned long index, unsigned long max)
|
|
{
|
|
void *entry = NULL;
|
|
MA_STATE(mas, mt, index, index);
|
|
|
|
rcu_read_lock();
|
|
entry = mas_next(&mas, max);
|
|
rcu_read_unlock();
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mt_next);
|
|
|
|
/**
|
|
* mas_prev() - Get the previous entry
|
|
* @mas: The maple state
|
|
* @min: The minimum value to check.
|
|
*
|
|
* Must hold rcu_read_lock or the write lock.
|
|
* Will reset mas to MAS_START if the node is MAS_NONE. Will stop on not
|
|
* searchable nodes.
|
|
*
|
|
* Return: the previous value or %NULL.
|
|
*/
|
|
void *mas_prev(struct ma_state *mas, unsigned long min)
|
|
{
|
|
if (!mas->index) {
|
|
/* Nothing comes before 0 */
|
|
mas->last = 0;
|
|
return NULL;
|
|
}
|
|
|
|
if (unlikely(mas_is_ptr(mas)))
|
|
return NULL;
|
|
|
|
if (mas_is_none(mas) || mas_is_paused(mas))
|
|
mas->node = MAS_START;
|
|
|
|
if (mas_is_start(mas)) {
|
|
mas_walk(mas);
|
|
if (!mas->index)
|
|
return NULL;
|
|
}
|
|
|
|
if (mas_is_ptr(mas)) {
|
|
if (!mas->index) {
|
|
mas->last = 0;
|
|
return NULL;
|
|
}
|
|
|
|
mas->index = mas->last = 0;
|
|
return mas_root_locked(mas);
|
|
}
|
|
return mas_prev_entry(mas, min);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_prev);
|
|
|
|
/**
|
|
* mt_prev() - get the previous value in the maple tree
|
|
* @mt: The maple tree
|
|
* @index: The start index
|
|
* @min: The minimum index to check
|
|
*
|
|
* Return: The entry at @index or lower, or %NULL if nothing is found.
|
|
*/
|
|
void *mt_prev(struct maple_tree *mt, unsigned long index, unsigned long min)
|
|
{
|
|
void *entry = NULL;
|
|
MA_STATE(mas, mt, index, index);
|
|
|
|
rcu_read_lock();
|
|
entry = mas_prev(&mas, min);
|
|
rcu_read_unlock();
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mt_prev);
|
|
|
|
/**
|
|
* mas_pause() - Pause a mas_find/mas_for_each to drop the lock.
|
|
* @mas: The maple state to pause
|
|
*
|
|
* Some users need to pause a walk and drop the lock they're holding in
|
|
* order to yield to a higher priority thread or carry out an operation
|
|
* on an entry. Those users should call this function before they drop
|
|
* the lock. It resets the @mas to be suitable for the next iteration
|
|
* of the loop after the user has reacquired the lock. If most entries
|
|
* found during a walk require you to call mas_pause(), the mt_for_each()
|
|
* iterator may be more appropriate.
|
|
*
|
|
*/
|
|
void mas_pause(struct ma_state *mas)
|
|
{
|
|
mas->node = MAS_PAUSE;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_pause);
|
|
|
|
/**
|
|
* mas_find() - On the first call, find the entry at or after mas->index up to
|
|
* %max. Otherwise, find the entry after mas->index.
|
|
* @mas: The maple state
|
|
* @max: The maximum value to check.
|
|
*
|
|
* Must hold rcu_read_lock or the write lock.
|
|
* If an entry exists, last and index are updated accordingly.
|
|
* May set @mas->node to MAS_NONE.
|
|
*
|
|
* Return: The entry or %NULL.
|
|
*/
|
|
void *mas_find(struct ma_state *mas, unsigned long max)
|
|
{
|
|
if (unlikely(mas_is_paused(mas))) {
|
|
if (unlikely(mas->last == ULONG_MAX)) {
|
|
mas->node = MAS_NONE;
|
|
return NULL;
|
|
}
|
|
mas->node = MAS_START;
|
|
mas->index = ++mas->last;
|
|
}
|
|
|
|
if (unlikely(mas_is_start(mas))) {
|
|
/* First run or continue */
|
|
void *entry;
|
|
|
|
if (mas->index > max)
|
|
return NULL;
|
|
|
|
entry = mas_walk(mas);
|
|
if (entry)
|
|
return entry;
|
|
}
|
|
|
|
if (unlikely(!mas_searchable(mas)))
|
|
return NULL;
|
|
|
|
/* Retries on dead nodes handled by mas_next_entry */
|
|
return mas_next_entry(mas, max);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_find);
|
|
|
|
/**
|
|
* mas_find_rev: On the first call, find the first non-null entry at or below
|
|
* mas->index down to %min. Otherwise find the first non-null entry below
|
|
* mas->index down to %min.
|
|
* @mas: The maple state
|
|
* @min: The minimum value to check.
|
|
*
|
|
* Must hold rcu_read_lock or the write lock.
|
|
* If an entry exists, last and index are updated accordingly.
|
|
* May set @mas->node to MAS_NONE.
|
|
*
|
|
* Return: The entry or %NULL.
|
|
*/
|
|
void *mas_find_rev(struct ma_state *mas, unsigned long min)
|
|
{
|
|
if (unlikely(mas_is_paused(mas))) {
|
|
if (unlikely(mas->last == ULONG_MAX)) {
|
|
mas->node = MAS_NONE;
|
|
return NULL;
|
|
}
|
|
mas->node = MAS_START;
|
|
mas->last = --mas->index;
|
|
}
|
|
|
|
if (unlikely(mas_is_start(mas))) {
|
|
/* First run or continue */
|
|
void *entry;
|
|
|
|
if (mas->index < min)
|
|
return NULL;
|
|
|
|
entry = mas_walk(mas);
|
|
if (entry)
|
|
return entry;
|
|
}
|
|
|
|
if (unlikely(!mas_searchable(mas)))
|
|
return NULL;
|
|
|
|
if (mas->index < min)
|
|
return NULL;
|
|
|
|
/* Retries on dead nodes handled by mas_prev_entry */
|
|
return mas_prev_entry(mas, min);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_find_rev);
|
|
|
|
/**
|
|
* mas_erase() - Find the range in which index resides and erase the entire
|
|
* range.
|
|
* @mas: The maple state
|
|
*
|
|
* Must hold the write lock.
|
|
* Searches for @mas->index, sets @mas->index and @mas->last to the range and
|
|
* erases that range.
|
|
*
|
|
* Return: the entry that was erased or %NULL, @mas->index and @mas->last are updated.
|
|
*/
|
|
void *mas_erase(struct ma_state *mas)
|
|
{
|
|
void *entry;
|
|
MA_WR_STATE(wr_mas, mas, NULL);
|
|
|
|
if (mas_is_none(mas) || mas_is_paused(mas))
|
|
mas->node = MAS_START;
|
|
|
|
/* Retry unnecessary when holding the write lock. */
|
|
entry = mas_state_walk(mas);
|
|
if (!entry)
|
|
return NULL;
|
|
|
|
write_retry:
|
|
/* Must reset to ensure spanning writes of last slot are detected */
|
|
mas_reset(mas);
|
|
mas_wr_store_setup(&wr_mas);
|
|
mas_wr_store_entry(&wr_mas);
|
|
if (mas_nomem(mas, GFP_KERNEL))
|
|
goto write_retry;
|
|
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL_GPL(mas_erase);
|
|
|
|
/**
|
|
* mas_nomem() - Check if there was an error allocating and do the allocation
|
|
* if necessary If there are allocations, then free them.
|
|
* @mas: The maple state
|
|
* @gfp: The GFP_FLAGS to use for allocations
|
|
* Return: true on allocation, false otherwise.
|
|
*/
|
|
bool mas_nomem(struct ma_state *mas, gfp_t gfp)
|
|
__must_hold(mas->tree->lock)
|
|
{
|
|
if (likely(mas->node != MA_ERROR(-ENOMEM))) {
|
|
mas_destroy(mas);
|
|
return false;
|
|
}
|
|
|
|
if (gfpflags_allow_blocking(gfp) && !mt_external_lock(mas->tree)) {
|
|
mtree_unlock(mas->tree);
|
|
mas_alloc_nodes(mas, gfp);
|
|
mtree_lock(mas->tree);
|
|
} else {
|
|
mas_alloc_nodes(mas, gfp);
|
|
}
|
|
|
|
if (!mas_allocated(mas))
|
|
return false;
|
|
|
|
mas->node = MAS_START;
|
|
return true;
|
|
}
|
|
|
|
void __init maple_tree_init(void)
|
|
{
|
|
maple_node_cache = kmem_cache_create("maple_node",
|
|
sizeof(struct maple_node), sizeof(struct maple_node),
|
|
SLAB_PANIC, NULL);
|
|
}
|
|
|
|
/**
|
|
* mtree_load() - Load a value stored in a maple tree
|
|
* @mt: The maple tree
|
|
* @index: The index to load
|
|
*
|
|
* Return: the entry or %NULL
|
|
*/
|
|
void *mtree_load(struct maple_tree *mt, unsigned long index)
|
|
{
|
|
MA_STATE(mas, mt, index, index);
|
|
void *entry;
|
|
|
|
trace_ma_read(__func__, &mas);
|
|
rcu_read_lock();
|
|
retry:
|
|
entry = mas_start(&mas);
|
|
if (unlikely(mas_is_none(&mas)))
|
|
goto unlock;
|
|
|
|
if (unlikely(mas_is_ptr(&mas))) {
|
|
if (index)
|
|
entry = NULL;
|
|
|
|
goto unlock;
|
|
}
|
|
|
|
entry = mtree_lookup_walk(&mas);
|
|
if (!entry && unlikely(mas_is_start(&mas)))
|
|
goto retry;
|
|
unlock:
|
|
rcu_read_unlock();
|
|
if (xa_is_zero(entry))
|
|
return NULL;
|
|
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL(mtree_load);
|
|
|
|
/**
|
|
* mtree_store_range() - Store an entry at a given range.
|
|
* @mt: The maple tree
|
|
* @index: The start of the range
|
|
* @last: The end of the range
|
|
* @entry: The entry to store
|
|
* @gfp: The GFP_FLAGS to use for allocations
|
|
*
|
|
* Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
|
|
* be allocated.
|
|
*/
|
|
int mtree_store_range(struct maple_tree *mt, unsigned long index,
|
|
unsigned long last, void *entry, gfp_t gfp)
|
|
{
|
|
MA_STATE(mas, mt, index, last);
|
|
MA_WR_STATE(wr_mas, &mas, entry);
|
|
|
|
trace_ma_write(__func__, &mas, 0, entry);
|
|
if (WARN_ON_ONCE(xa_is_advanced(entry)))
|
|
return -EINVAL;
|
|
|
|
if (index > last)
|
|
return -EINVAL;
|
|
|
|
mtree_lock(mt);
|
|
retry:
|
|
mas_wr_store_entry(&wr_mas);
|
|
if (mas_nomem(&mas, gfp))
|
|
goto retry;
|
|
|
|
mtree_unlock(mt);
|
|
if (mas_is_err(&mas))
|
|
return xa_err(mas.node);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(mtree_store_range);
|
|
|
|
/**
|
|
* mtree_store() - Store an entry at a given index.
|
|
* @mt: The maple tree
|
|
* @index: The index to store the value
|
|
* @entry: The entry to store
|
|
* @gfp: The GFP_FLAGS to use for allocations
|
|
*
|
|
* Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not
|
|
* be allocated.
|
|
*/
|
|
int mtree_store(struct maple_tree *mt, unsigned long index, void *entry,
|
|
gfp_t gfp)
|
|
{
|
|
return mtree_store_range(mt, index, index, entry, gfp);
|
|
}
|
|
EXPORT_SYMBOL(mtree_store);
|
|
|
|
/**
|
|
* mtree_insert_range() - Insert an entry at a give range if there is no value.
|
|
* @mt: The maple tree
|
|
* @first: The start of the range
|
|
* @last: The end of the range
|
|
* @entry: The entry to store
|
|
* @gfp: The GFP_FLAGS to use for allocations.
|
|
*
|
|
* Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
|
|
* request, -ENOMEM if memory could not be allocated.
|
|
*/
|
|
int mtree_insert_range(struct maple_tree *mt, unsigned long first,
|
|
unsigned long last, void *entry, gfp_t gfp)
|
|
{
|
|
MA_STATE(ms, mt, first, last);
|
|
|
|
if (WARN_ON_ONCE(xa_is_advanced(entry)))
|
|
return -EINVAL;
|
|
|
|
if (first > last)
|
|
return -EINVAL;
|
|
|
|
mtree_lock(mt);
|
|
retry:
|
|
mas_insert(&ms, entry);
|
|
if (mas_nomem(&ms, gfp))
|
|
goto retry;
|
|
|
|
mtree_unlock(mt);
|
|
if (mas_is_err(&ms))
|
|
return xa_err(ms.node);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(mtree_insert_range);
|
|
|
|
/**
|
|
* mtree_insert() - Insert an entry at a give index if there is no value.
|
|
* @mt: The maple tree
|
|
* @index : The index to store the value
|
|
* @entry: The entry to store
|
|
* @gfp: The FGP_FLAGS to use for allocations.
|
|
*
|
|
* Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid
|
|
* request, -ENOMEM if memory could not be allocated.
|
|
*/
|
|
int mtree_insert(struct maple_tree *mt, unsigned long index, void *entry,
|
|
gfp_t gfp)
|
|
{
|
|
return mtree_insert_range(mt, index, index, entry, gfp);
|
|
}
|
|
EXPORT_SYMBOL(mtree_insert);
|
|
|
|
int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
|
|
void *entry, unsigned long size, unsigned long min,
|
|
unsigned long max, gfp_t gfp)
|
|
{
|
|
int ret = 0;
|
|
|
|
MA_STATE(mas, mt, min, max - size);
|
|
if (!mt_is_alloc(mt))
|
|
return -EINVAL;
|
|
|
|
if (WARN_ON_ONCE(mt_is_reserved(entry)))
|
|
return -EINVAL;
|
|
|
|
if (min > max)
|
|
return -EINVAL;
|
|
|
|
if (max < size)
|
|
return -EINVAL;
|
|
|
|
if (!size)
|
|
return -EINVAL;
|
|
|
|
mtree_lock(mt);
|
|
retry:
|
|
mas.offset = 0;
|
|
mas.index = min;
|
|
mas.last = max - size;
|
|
ret = mas_alloc(&mas, entry, size, startp);
|
|
if (mas_nomem(&mas, gfp))
|
|
goto retry;
|
|
|
|
mtree_unlock(mt);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(mtree_alloc_range);
|
|
|
|
int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
|
|
void *entry, unsigned long size, unsigned long min,
|
|
unsigned long max, gfp_t gfp)
|
|
{
|
|
int ret = 0;
|
|
|
|
MA_STATE(mas, mt, min, max - size);
|
|
if (!mt_is_alloc(mt))
|
|
return -EINVAL;
|
|
|
|
if (WARN_ON_ONCE(mt_is_reserved(entry)))
|
|
return -EINVAL;
|
|
|
|
if (min >= max)
|
|
return -EINVAL;
|
|
|
|
if (max < size - 1)
|
|
return -EINVAL;
|
|
|
|
if (!size)
|
|
return -EINVAL;
|
|
|
|
mtree_lock(mt);
|
|
retry:
|
|
ret = mas_rev_alloc(&mas, min, max, entry, size, startp);
|
|
if (mas_nomem(&mas, gfp))
|
|
goto retry;
|
|
|
|
mtree_unlock(mt);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(mtree_alloc_rrange);
|
|
|
|
/**
|
|
* mtree_erase() - Find an index and erase the entire range.
|
|
* @mt: The maple tree
|
|
* @index: The index to erase
|
|
*
|
|
* Erasing is the same as a walk to an entry then a store of a NULL to that
|
|
* ENTIRE range. In fact, it is implemented as such using the advanced API.
|
|
*
|
|
* Return: The entry stored at the @index or %NULL
|
|
*/
|
|
void *mtree_erase(struct maple_tree *mt, unsigned long index)
|
|
{
|
|
void *entry = NULL;
|
|
|
|
MA_STATE(mas, mt, index, index);
|
|
trace_ma_op(__func__, &mas);
|
|
|
|
mtree_lock(mt);
|
|
entry = mas_erase(&mas);
|
|
mtree_unlock(mt);
|
|
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL(mtree_erase);
|
|
|
|
/**
|
|
* __mt_destroy() - Walk and free all nodes of a locked maple tree.
|
|
* @mt: The maple tree
|
|
*
|
|
* Note: Does not handle locking.
|
|
*/
|
|
void __mt_destroy(struct maple_tree *mt)
|
|
{
|
|
void *root = mt_root_locked(mt);
|
|
|
|
rcu_assign_pointer(mt->ma_root, NULL);
|
|
if (xa_is_node(root))
|
|
mte_destroy_walk(root, mt);
|
|
|
|
mt->ma_flags = 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__mt_destroy);
|
|
|
|
/**
|
|
* mtree_destroy() - Destroy a maple tree
|
|
* @mt: The maple tree
|
|
*
|
|
* Frees all resources used by the tree. Handles locking.
|
|
*/
|
|
void mtree_destroy(struct maple_tree *mt)
|
|
{
|
|
mtree_lock(mt);
|
|
__mt_destroy(mt);
|
|
mtree_unlock(mt);
|
|
}
|
|
EXPORT_SYMBOL(mtree_destroy);
|
|
|
|
/**
|
|
* mt_find() - Search from the start up until an entry is found.
|
|
* @mt: The maple tree
|
|
* @index: Pointer which contains the start location of the search
|
|
* @max: The maximum value to check
|
|
*
|
|
* Handles locking. @index will be incremented to one beyond the range.
|
|
*
|
|
* Return: The entry at or after the @index or %NULL
|
|
*/
|
|
void *mt_find(struct maple_tree *mt, unsigned long *index, unsigned long max)
|
|
{
|
|
MA_STATE(mas, mt, *index, *index);
|
|
void *entry;
|
|
#ifdef CONFIG_DEBUG_MAPLE_TREE
|
|
unsigned long copy = *index;
|
|
#endif
|
|
|
|
trace_ma_read(__func__, &mas);
|
|
|
|
if ((*index) > max)
|
|
return NULL;
|
|
|
|
rcu_read_lock();
|
|
retry:
|
|
entry = mas_state_walk(&mas);
|
|
if (mas_is_start(&mas))
|
|
goto retry;
|
|
|
|
if (unlikely(xa_is_zero(entry)))
|
|
entry = NULL;
|
|
|
|
if (entry)
|
|
goto unlock;
|
|
|
|
while (mas_searchable(&mas) && (mas.index < max)) {
|
|
entry = mas_next_entry(&mas, max);
|
|
if (likely(entry && !xa_is_zero(entry)))
|
|
break;
|
|
}
|
|
|
|
if (unlikely(xa_is_zero(entry)))
|
|
entry = NULL;
|
|
unlock:
|
|
rcu_read_unlock();
|
|
if (likely(entry)) {
|
|
*index = mas.last + 1;
|
|
#ifdef CONFIG_DEBUG_MAPLE_TREE
|
|
if ((*index) && (*index) <= copy)
|
|
pr_err("index not increased! %lx <= %lx\n",
|
|
*index, copy);
|
|
MT_BUG_ON(mt, (*index) && ((*index) <= copy));
|
|
#endif
|
|
}
|
|
|
|
return entry;
|
|
}
|
|
EXPORT_SYMBOL(mt_find);
|
|
|
|
/**
|
|
* mt_find_after() - Search from the start up until an entry is found.
|
|
* @mt: The maple tree
|
|
* @index: Pointer which contains the start location of the search
|
|
* @max: The maximum value to check
|
|
*
|
|
* Handles locking, detects wrapping on index == 0
|
|
*
|
|
* Return: The entry at or after the @index or %NULL
|
|
*/
|
|
void *mt_find_after(struct maple_tree *mt, unsigned long *index,
|
|
unsigned long max)
|
|
{
|
|
if (!(*index))
|
|
return NULL;
|
|
|
|
return mt_find(mt, index, max);
|
|
}
|
|
EXPORT_SYMBOL(mt_find_after);
|
|
|
|
#ifdef CONFIG_DEBUG_MAPLE_TREE
|
|
atomic_t maple_tree_tests_run;
|
|
EXPORT_SYMBOL_GPL(maple_tree_tests_run);
|
|
atomic_t maple_tree_tests_passed;
|
|
EXPORT_SYMBOL_GPL(maple_tree_tests_passed);
|
|
|
|
#ifndef __KERNEL__
|
|
extern void kmem_cache_set_non_kernel(struct kmem_cache *, unsigned int);
|
|
void mt_set_non_kernel(unsigned int val)
|
|
{
|
|
kmem_cache_set_non_kernel(maple_node_cache, val);
|
|
}
|
|
|
|
extern unsigned long kmem_cache_get_alloc(struct kmem_cache *);
|
|
unsigned long mt_get_alloc_size(void)
|
|
{
|
|
return kmem_cache_get_alloc(maple_node_cache);
|
|
}
|
|
|
|
extern void kmem_cache_zero_nr_tallocated(struct kmem_cache *);
|
|
void mt_zero_nr_tallocated(void)
|
|
{
|
|
kmem_cache_zero_nr_tallocated(maple_node_cache);
|
|
}
|
|
|
|
extern unsigned int kmem_cache_nr_tallocated(struct kmem_cache *);
|
|
unsigned int mt_nr_tallocated(void)
|
|
{
|
|
return kmem_cache_nr_tallocated(maple_node_cache);
|
|
}
|
|
|
|
extern unsigned int kmem_cache_nr_allocated(struct kmem_cache *);
|
|
unsigned int mt_nr_allocated(void)
|
|
{
|
|
return kmem_cache_nr_allocated(maple_node_cache);
|
|
}
|
|
|
|
/*
|
|
* mas_dead_node() - Check if the maple state is pointing to a dead node.
|
|
* @mas: The maple state
|
|
* @index: The index to restore in @mas.
|
|
*
|
|
* Used in test code.
|
|
* Return: 1 if @mas has been reset to MAS_START, 0 otherwise.
|
|
*/
|
|
static inline int mas_dead_node(struct ma_state *mas, unsigned long index)
|
|
{
|
|
if (unlikely(!mas_searchable(mas) || mas_is_start(mas)))
|
|
return 0;
|
|
|
|
if (likely(!mte_dead_node(mas->node)))
|
|
return 0;
|
|
|
|
mas_rewalk(mas, index);
|
|
return 1;
|
|
}
|
|
|
|
void mt_cache_shrink(void)
|
|
{
|
|
}
|
|
#else
|
|
/*
|
|
* mt_cache_shrink() - For testing, don't use this.
|
|
*
|
|
* Certain testcases can trigger an OOM when combined with other memory
|
|
* debugging configuration options. This function is used to reduce the
|
|
* possibility of an out of memory even due to kmem_cache objects remaining
|
|
* around for longer than usual.
|
|
*/
|
|
void mt_cache_shrink(void)
|
|
{
|
|
kmem_cache_shrink(maple_node_cache);
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(mt_cache_shrink);
|
|
|
|
#endif /* not defined __KERNEL__ */
|
|
/*
|
|
* mas_get_slot() - Get the entry in the maple state node stored at @offset.
|
|
* @mas: The maple state
|
|
* @offset: The offset into the slot array to fetch.
|
|
*
|
|
* Return: The entry stored at @offset.
|
|
*/
|
|
static inline struct maple_enode *mas_get_slot(struct ma_state *mas,
|
|
unsigned char offset)
|
|
{
|
|
return mas_slot(mas, ma_slots(mas_mn(mas), mte_node_type(mas->node)),
|
|
offset);
|
|
}
|
|
|
|
|
|
/*
|
|
* mas_first_entry() - Go the first leaf and find the first entry.
|
|
* @mas: the maple state.
|
|
* @limit: the maximum index to check.
|
|
* @*r_start: Pointer to set to the range start.
|
|
*
|
|
* Sets mas->offset to the offset of the entry, r_start to the range minimum.
|
|
*
|
|
* Return: The first entry or MAS_NONE.
|
|
*/
|
|
static inline void *mas_first_entry(struct ma_state *mas, struct maple_node *mn,
|
|
unsigned long limit, enum maple_type mt)
|
|
|
|
{
|
|
unsigned long max;
|
|
unsigned long *pivots;
|
|
void __rcu **slots;
|
|
void *entry = NULL;
|
|
|
|
mas->index = mas->min;
|
|
if (mas->index > limit)
|
|
goto none;
|
|
|
|
max = mas->max;
|
|
mas->offset = 0;
|
|
while (likely(!ma_is_leaf(mt))) {
|
|
MT_BUG_ON(mas->tree, mte_dead_node(mas->node));
|
|
slots = ma_slots(mn, mt);
|
|
pivots = ma_pivots(mn, mt);
|
|
max = pivots[0];
|
|
entry = mas_slot(mas, slots, 0);
|
|
if (unlikely(ma_dead_node(mn)))
|
|
return NULL;
|
|
mas->node = entry;
|
|
mn = mas_mn(mas);
|
|
mt = mte_node_type(mas->node);
|
|
}
|
|
MT_BUG_ON(mas->tree, mte_dead_node(mas->node));
|
|
|
|
mas->max = max;
|
|
slots = ma_slots(mn, mt);
|
|
entry = mas_slot(mas, slots, 0);
|
|
if (unlikely(ma_dead_node(mn)))
|
|
return NULL;
|
|
|
|
/* Slot 0 or 1 must be set */
|
|
if (mas->index > limit)
|
|
goto none;
|
|
|
|
if (likely(entry))
|
|
return entry;
|
|
|
|
pivots = ma_pivots(mn, mt);
|
|
mas->index = pivots[0] + 1;
|
|
mas->offset = 1;
|
|
entry = mas_slot(mas, slots, 1);
|
|
if (unlikely(ma_dead_node(mn)))
|
|
return NULL;
|
|
|
|
if (mas->index > limit)
|
|
goto none;
|
|
|
|
if (likely(entry))
|
|
return entry;
|
|
|
|
none:
|
|
if (likely(!ma_dead_node(mn)))
|
|
mas->node = MAS_NONE;
|
|
return NULL;
|
|
}
|
|
|
|
/* Depth first search, post-order */
|
|
static void mas_dfs_postorder(struct ma_state *mas, unsigned long max)
|
|
{
|
|
|
|
struct maple_enode *p = MAS_NONE, *mn = mas->node;
|
|
unsigned long p_min, p_max;
|
|
|
|
mas_next_node(mas, mas_mn(mas), max);
|
|
if (!mas_is_none(mas))
|
|
return;
|
|
|
|
if (mte_is_root(mn))
|
|
return;
|
|
|
|
mas->node = mn;
|
|
mas_ascend(mas);
|
|
while (mas->node != MAS_NONE) {
|
|
p = mas->node;
|
|
p_min = mas->min;
|
|
p_max = mas->max;
|
|
mas_prev_node(mas, 0);
|
|
}
|
|
|
|
if (p == MAS_NONE)
|
|
return;
|
|
|
|
mas->node = p;
|
|
mas->max = p_max;
|
|
mas->min = p_min;
|
|
}
|
|
|
|
/* Tree validations */
|
|
static void mt_dump_node(const struct maple_tree *mt, void *entry,
|
|
unsigned long min, unsigned long max, unsigned int depth);
|
|
static void mt_dump_range(unsigned long min, unsigned long max,
|
|
unsigned int depth)
|
|
{
|
|
static const char spaces[] = " ";
|
|
|
|
if (min == max)
|
|
pr_info("%.*s%lu: ", depth * 2, spaces, min);
|
|
else
|
|
pr_info("%.*s%lu-%lu: ", depth * 2, spaces, min, max);
|
|
}
|
|
|
|
static void mt_dump_entry(void *entry, unsigned long min, unsigned long max,
|
|
unsigned int depth)
|
|
{
|
|
mt_dump_range(min, max, depth);
|
|
|
|
if (xa_is_value(entry))
|
|
pr_cont("value %ld (0x%lx) [%p]\n", xa_to_value(entry),
|
|
xa_to_value(entry), entry);
|
|
else if (xa_is_zero(entry))
|
|
pr_cont("zero (%ld)\n", xa_to_internal(entry));
|
|
else if (mt_is_reserved(entry))
|
|
pr_cont("UNKNOWN ENTRY (%p)\n", entry);
|
|
else
|
|
pr_cont("%p\n", entry);
|
|
}
|
|
|
|
static void mt_dump_range64(const struct maple_tree *mt, void *entry,
|
|
unsigned long min, unsigned long max, unsigned int depth)
|
|
{
|
|
struct maple_range_64 *node = &mte_to_node(entry)->mr64;
|
|
bool leaf = mte_is_leaf(entry);
|
|
unsigned long first = min;
|
|
int i;
|
|
|
|
pr_cont(" contents: ");
|
|
for (i = 0; i < MAPLE_RANGE64_SLOTS - 1; i++)
|
|
pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
|
|
pr_cont("%p\n", node->slot[i]);
|
|
for (i = 0; i < MAPLE_RANGE64_SLOTS; i++) {
|
|
unsigned long last = max;
|
|
|
|
if (i < (MAPLE_RANGE64_SLOTS - 1))
|
|
last = node->pivot[i];
|
|
else if (!node->slot[i] && max != mt_max[mte_node_type(entry)])
|
|
break;
|
|
if (last == 0 && i > 0)
|
|
break;
|
|
if (leaf)
|
|
mt_dump_entry(mt_slot(mt, node->slot, i),
|
|
first, last, depth + 1);
|
|
else if (node->slot[i])
|
|
mt_dump_node(mt, mt_slot(mt, node->slot, i),
|
|
first, last, depth + 1);
|
|
|
|
if (last == max)
|
|
break;
|
|
if (last > max) {
|
|
pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
|
|
node, last, max, i);
|
|
break;
|
|
}
|
|
first = last + 1;
|
|
}
|
|
}
|
|
|
|
static void mt_dump_arange64(const struct maple_tree *mt, void *entry,
|
|
unsigned long min, unsigned long max, unsigned int depth)
|
|
{
|
|
struct maple_arange_64 *node = &mte_to_node(entry)->ma64;
|
|
bool leaf = mte_is_leaf(entry);
|
|
unsigned long first = min;
|
|
int i;
|
|
|
|
pr_cont(" contents: ");
|
|
for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++)
|
|
pr_cont("%lu ", node->gap[i]);
|
|
pr_cont("| %02X %02X| ", node->meta.end, node->meta.gap);
|
|
for (i = 0; i < MAPLE_ARANGE64_SLOTS - 1; i++)
|
|
pr_cont("%p %lu ", node->slot[i], node->pivot[i]);
|
|
pr_cont("%p\n", node->slot[i]);
|
|
for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++) {
|
|
unsigned long last = max;
|
|
|
|
if (i < (MAPLE_ARANGE64_SLOTS - 1))
|
|
last = node->pivot[i];
|
|
else if (!node->slot[i])
|
|
break;
|
|
if (last == 0 && i > 0)
|
|
break;
|
|
if (leaf)
|
|
mt_dump_entry(mt_slot(mt, node->slot, i),
|
|
first, last, depth + 1);
|
|
else if (node->slot[i])
|
|
mt_dump_node(mt, mt_slot(mt, node->slot, i),
|
|
first, last, depth + 1);
|
|
|
|
if (last == max)
|
|
break;
|
|
if (last > max) {
|
|
pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n",
|
|
node, last, max, i);
|
|
break;
|
|
}
|
|
first = last + 1;
|
|
}
|
|
}
|
|
|
|
static void mt_dump_node(const struct maple_tree *mt, void *entry,
|
|
unsigned long min, unsigned long max, unsigned int depth)
|
|
{
|
|
struct maple_node *node = mte_to_node(entry);
|
|
unsigned int type = mte_node_type(entry);
|
|
unsigned int i;
|
|
|
|
mt_dump_range(min, max, depth);
|
|
|
|
pr_cont("node %p depth %d type %d parent %p", node, depth, type,
|
|
node ? node->parent : NULL);
|
|
switch (type) {
|
|
case maple_dense:
|
|
pr_cont("\n");
|
|
for (i = 0; i < MAPLE_NODE_SLOTS; i++) {
|
|
if (min + i > max)
|
|
pr_cont("OUT OF RANGE: ");
|
|
mt_dump_entry(mt_slot(mt, node->slot, i),
|
|
min + i, min + i, depth);
|
|
}
|
|
break;
|
|
case maple_leaf_64:
|
|
case maple_range_64:
|
|
mt_dump_range64(mt, entry, min, max, depth);
|
|
break;
|
|
case maple_arange_64:
|
|
mt_dump_arange64(mt, entry, min, max, depth);
|
|
break;
|
|
|
|
default:
|
|
pr_cont(" UNKNOWN TYPE\n");
|
|
}
|
|
}
|
|
|
|
void mt_dump(const struct maple_tree *mt)
|
|
{
|
|
void *entry = rcu_dereference_check(mt->ma_root, mt_locked(mt));
|
|
|
|
pr_info("maple_tree(%p) flags %X, height %u root %p\n",
|
|
mt, mt->ma_flags, mt_height(mt), entry);
|
|
if (!xa_is_node(entry))
|
|
mt_dump_entry(entry, 0, 0, 0);
|
|
else if (entry)
|
|
mt_dump_node(mt, entry, 0, mt_max[mte_node_type(entry)], 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(mt_dump);
|
|
|
|
/*
|
|
* Calculate the maximum gap in a node and check if that's what is reported in
|
|
* the parent (unless root).
|
|
*/
|
|
static void mas_validate_gaps(struct ma_state *mas)
|
|
{
|
|
struct maple_enode *mte = mas->node;
|
|
struct maple_node *p_mn;
|
|
unsigned long gap = 0, max_gap = 0;
|
|
unsigned long p_end, p_start = mas->min;
|
|
unsigned char p_slot;
|
|
unsigned long *gaps = NULL;
|
|
unsigned long *pivots = ma_pivots(mte_to_node(mte), mte_node_type(mte));
|
|
int i;
|
|
|
|
if (ma_is_dense(mte_node_type(mte))) {
|
|
for (i = 0; i < mt_slot_count(mte); i++) {
|
|
if (mas_get_slot(mas, i)) {
|
|
if (gap > max_gap)
|
|
max_gap = gap;
|
|
gap = 0;
|
|
continue;
|
|
}
|
|
gap++;
|
|
}
|
|
goto counted;
|
|
}
|
|
|
|
gaps = ma_gaps(mte_to_node(mte), mte_node_type(mte));
|
|
for (i = 0; i < mt_slot_count(mte); i++) {
|
|
p_end = mas_logical_pivot(mas, pivots, i, mte_node_type(mte));
|
|
|
|
if (!gaps) {
|
|
if (mas_get_slot(mas, i)) {
|
|
gap = 0;
|
|
goto not_empty;
|
|
}
|
|
|
|
gap += p_end - p_start + 1;
|
|
} else {
|
|
void *entry = mas_get_slot(mas, i);
|
|
|
|
gap = gaps[i];
|
|
if (!entry) {
|
|
if (gap != p_end - p_start + 1) {
|
|
pr_err("%p[%u] -> %p %lu != %lu - %lu + 1\n",
|
|
mas_mn(mas), i,
|
|
mas_get_slot(mas, i), gap,
|
|
p_end, p_start);
|
|
mt_dump(mas->tree);
|
|
|
|
MT_BUG_ON(mas->tree,
|
|
gap != p_end - p_start + 1);
|
|
}
|
|
} else {
|
|
if (gap > p_end - p_start + 1) {
|
|
pr_err("%p[%u] %lu >= %lu - %lu + 1 (%lu)\n",
|
|
mas_mn(mas), i, gap, p_end, p_start,
|
|
p_end - p_start + 1);
|
|
MT_BUG_ON(mas->tree,
|
|
gap > p_end - p_start + 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (gap > max_gap)
|
|
max_gap = gap;
|
|
not_empty:
|
|
p_start = p_end + 1;
|
|
if (p_end >= mas->max)
|
|
break;
|
|
}
|
|
|
|
counted:
|
|
if (mte_is_root(mte))
|
|
return;
|
|
|
|
p_slot = mte_parent_slot(mas->node);
|
|
p_mn = mte_parent(mte);
|
|
MT_BUG_ON(mas->tree, max_gap > mas->max);
|
|
if (ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap) {
|
|
pr_err("gap %p[%u] != %lu\n", p_mn, p_slot, max_gap);
|
|
mt_dump(mas->tree);
|
|
}
|
|
|
|
MT_BUG_ON(mas->tree,
|
|
ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap);
|
|
}
|
|
|
|
static void mas_validate_parent_slot(struct ma_state *mas)
|
|
{
|
|
struct maple_node *parent;
|
|
struct maple_enode *node;
|
|
enum maple_type p_type = mas_parent_enum(mas, mas->node);
|
|
unsigned char p_slot = mte_parent_slot(mas->node);
|
|
void __rcu **slots;
|
|
int i;
|
|
|
|
if (mte_is_root(mas->node))
|
|
return;
|
|
|
|
parent = mte_parent(mas->node);
|
|
slots = ma_slots(parent, p_type);
|
|
MT_BUG_ON(mas->tree, mas_mn(mas) == parent);
|
|
|
|
/* Check prev/next parent slot for duplicate node entry */
|
|
|
|
for (i = 0; i < mt_slots[p_type]; i++) {
|
|
node = mas_slot(mas, slots, i);
|
|
if (i == p_slot) {
|
|
if (node != mas->node)
|
|
pr_err("parent %p[%u] does not have %p\n",
|
|
parent, i, mas_mn(mas));
|
|
MT_BUG_ON(mas->tree, node != mas->node);
|
|
} else if (node == mas->node) {
|
|
pr_err("Invalid child %p at parent %p[%u] p_slot %u\n",
|
|
mas_mn(mas), parent, i, p_slot);
|
|
MT_BUG_ON(mas->tree, node == mas->node);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void mas_validate_child_slot(struct ma_state *mas)
|
|
{
|
|
enum maple_type type = mte_node_type(mas->node);
|
|
void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
|
|
unsigned long *pivots = ma_pivots(mte_to_node(mas->node), type);
|
|
struct maple_enode *child;
|
|
unsigned char i;
|
|
|
|
if (mte_is_leaf(mas->node))
|
|
return;
|
|
|
|
for (i = 0; i < mt_slots[type]; i++) {
|
|
child = mas_slot(mas, slots, i);
|
|
if (!pivots[i] || pivots[i] == mas->max)
|
|
break;
|
|
|
|
if (!child)
|
|
break;
|
|
|
|
if (mte_parent_slot(child) != i) {
|
|
pr_err("Slot error at %p[%u]: child %p has pslot %u\n",
|
|
mas_mn(mas), i, mte_to_node(child),
|
|
mte_parent_slot(child));
|
|
MT_BUG_ON(mas->tree, 1);
|
|
}
|
|
|
|
if (mte_parent(child) != mte_to_node(mas->node)) {
|
|
pr_err("child %p has parent %p not %p\n",
|
|
mte_to_node(child), mte_parent(child),
|
|
mte_to_node(mas->node));
|
|
MT_BUG_ON(mas->tree, 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Validate all pivots are within mas->min and mas->max.
|
|
*/
|
|
static void mas_validate_limits(struct ma_state *mas)
|
|
{
|
|
int i;
|
|
unsigned long prev_piv = 0;
|
|
enum maple_type type = mte_node_type(mas->node);
|
|
void __rcu **slots = ma_slots(mte_to_node(mas->node), type);
|
|
unsigned long *pivots = ma_pivots(mas_mn(mas), type);
|
|
|
|
/* all limits are fine here. */
|
|
if (mte_is_root(mas->node))
|
|
return;
|
|
|
|
for (i = 0; i < mt_slots[type]; i++) {
|
|
unsigned long piv;
|
|
|
|
piv = mas_safe_pivot(mas, pivots, i, type);
|
|
|
|
if (!piv && (i != 0))
|
|
break;
|
|
|
|
if (!mte_is_leaf(mas->node)) {
|
|
void *entry = mas_slot(mas, slots, i);
|
|
|
|
if (!entry)
|
|
pr_err("%p[%u] cannot be null\n",
|
|
mas_mn(mas), i);
|
|
|
|
MT_BUG_ON(mas->tree, !entry);
|
|
}
|
|
|
|
if (prev_piv > piv) {
|
|
pr_err("%p[%u] piv %lu < prev_piv %lu\n",
|
|
mas_mn(mas), i, piv, prev_piv);
|
|
MT_BUG_ON(mas->tree, piv < prev_piv);
|
|
}
|
|
|
|
if (piv < mas->min) {
|
|
pr_err("%p[%u] %lu < %lu\n", mas_mn(mas), i,
|
|
piv, mas->min);
|
|
MT_BUG_ON(mas->tree, piv < mas->min);
|
|
}
|
|
if (piv > mas->max) {
|
|
pr_err("%p[%u] %lu > %lu\n", mas_mn(mas), i,
|
|
piv, mas->max);
|
|
MT_BUG_ON(mas->tree, piv > mas->max);
|
|
}
|
|
prev_piv = piv;
|
|
if (piv == mas->max)
|
|
break;
|
|
}
|
|
for (i += 1; i < mt_slots[type]; i++) {
|
|
void *entry = mas_slot(mas, slots, i);
|
|
|
|
if (entry && (i != mt_slots[type] - 1)) {
|
|
pr_err("%p[%u] should not have entry %p\n", mas_mn(mas),
|
|
i, entry);
|
|
MT_BUG_ON(mas->tree, entry != NULL);
|
|
}
|
|
|
|
if (i < mt_pivots[type]) {
|
|
unsigned long piv = pivots[i];
|
|
|
|
if (!piv)
|
|
continue;
|
|
|
|
pr_err("%p[%u] should not have piv %lu\n",
|
|
mas_mn(mas), i, piv);
|
|
MT_BUG_ON(mas->tree, i < mt_pivots[type] - 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void mt_validate_nulls(struct maple_tree *mt)
|
|
{
|
|
void *entry, *last = (void *)1;
|
|
unsigned char offset = 0;
|
|
void __rcu **slots;
|
|
MA_STATE(mas, mt, 0, 0);
|
|
|
|
mas_start(&mas);
|
|
if (mas_is_none(&mas) || (mas.node == MAS_ROOT))
|
|
return;
|
|
|
|
while (!mte_is_leaf(mas.node))
|
|
mas_descend(&mas);
|
|
|
|
slots = ma_slots(mte_to_node(mas.node), mte_node_type(mas.node));
|
|
do {
|
|
entry = mas_slot(&mas, slots, offset);
|
|
if (!last && !entry) {
|
|
pr_err("Sequential nulls end at %p[%u]\n",
|
|
mas_mn(&mas), offset);
|
|
}
|
|
MT_BUG_ON(mt, !last && !entry);
|
|
last = entry;
|
|
if (offset == mas_data_end(&mas)) {
|
|
mas_next_node(&mas, mas_mn(&mas), ULONG_MAX);
|
|
if (mas_is_none(&mas))
|
|
return;
|
|
offset = 0;
|
|
slots = ma_slots(mte_to_node(mas.node),
|
|
mte_node_type(mas.node));
|
|
} else {
|
|
offset++;
|
|
}
|
|
|
|
} while (!mas_is_none(&mas));
|
|
}
|
|
|
|
/*
|
|
* validate a maple tree by checking:
|
|
* 1. The limits (pivots are within mas->min to mas->max)
|
|
* 2. The gap is correctly set in the parents
|
|
*/
|
|
void mt_validate(struct maple_tree *mt)
|
|
{
|
|
unsigned char end;
|
|
|
|
MA_STATE(mas, mt, 0, 0);
|
|
rcu_read_lock();
|
|
mas_start(&mas);
|
|
if (!mas_searchable(&mas))
|
|
goto done;
|
|
|
|
mas_first_entry(&mas, mas_mn(&mas), ULONG_MAX, mte_node_type(mas.node));
|
|
while (!mas_is_none(&mas)) {
|
|
MT_BUG_ON(mas.tree, mte_dead_node(mas.node));
|
|
if (!mte_is_root(mas.node)) {
|
|
end = mas_data_end(&mas);
|
|
if ((end < mt_min_slot_count(mas.node)) &&
|
|
(mas.max != ULONG_MAX)) {
|
|
pr_err("Invalid size %u of %p\n", end,
|
|
mas_mn(&mas));
|
|
MT_BUG_ON(mas.tree, 1);
|
|
}
|
|
|
|
}
|
|
mas_validate_parent_slot(&mas);
|
|
mas_validate_child_slot(&mas);
|
|
mas_validate_limits(&mas);
|
|
if (mt_is_alloc(mt))
|
|
mas_validate_gaps(&mas);
|
|
mas_dfs_postorder(&mas, ULONG_MAX);
|
|
}
|
|
mt_validate_nulls(mt);
|
|
done:
|
|
rcu_read_unlock();
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(mt_validate);
|
|
|
|
#endif /* CONFIG_DEBUG_MAPLE_TREE */
|