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-rw-r--r--lib/maple_tree.c236
1 files changed, 142 insertions, 94 deletions
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index d0bea23fa4bc..b4ee2d29d7a9 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -211,14 +211,14 @@ static void ma_free_rcu(struct maple_node *node)
call_rcu(&node->rcu, mt_free_rcu);
}
-static void mas_set_height(struct ma_state *mas)
+static void mt_set_height(struct maple_tree *mt, unsigned char height)
{
- unsigned int new_flags = mas->tree->ma_flags;
+ unsigned int new_flags = mt->ma_flags;
new_flags &= ~MT_FLAGS_HEIGHT_MASK;
- MAS_BUG_ON(mas, mas->depth > MAPLE_HEIGHT_MAX);
- new_flags |= mas->depth << MT_FLAGS_HEIGHT_OFFSET;
- mas->tree->ma_flags = new_flags;
+ MT_BUG_ON(mt, height > MAPLE_HEIGHT_MAX);
+ new_flags |= height << MT_FLAGS_HEIGHT_OFFSET;
+ mt->ma_flags = new_flags;
}
static unsigned int mas_mt_height(struct ma_state *mas)
@@ -1053,7 +1053,7 @@ static inline void mte_set_gap(const struct maple_enode *mn,
* 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
+ * Sets the @mas->max and @mas->min for the parent node of mas->node. 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
@@ -1098,6 +1098,12 @@ static int mas_ascend(struct ma_state *mas)
min = 0;
max = ULONG_MAX;
+
+ /*
+ * !mas->offset implies that parent node min == mas->min.
+ * mas->offset > 0 implies that we need to walk up to find the
+ * implied pivot min.
+ */
if (!mas->offset) {
min = mas->min;
set_min = true;
@@ -1371,7 +1377,7 @@ retry:
root = mas_root(mas);
/* Tree with nodes */
if (likely(xa_is_node(root))) {
- mas->depth = 1;
+ mas->depth = 0;
mas->status = ma_active;
mas->node = mte_safe_root(root);
mas->offset = 0;
@@ -1712,9 +1718,10 @@ static inline void mas_adopt_children(struct ma_state *mas,
* node as dead.
* @mas: the maple state with the new node
* @old_enode: The old maple encoded node to replace.
+ * @new_height: if we are inserting a root node, update the height of the tree
*/
static inline void mas_put_in_tree(struct ma_state *mas,
- struct maple_enode *old_enode)
+ struct maple_enode *old_enode, char new_height)
__must_hold(mas->tree->ma_lock)
{
unsigned char offset;
@@ -1723,7 +1730,7 @@ static inline void mas_put_in_tree(struct ma_state *mas,
if (mte_is_root(mas->node)) {
mas_mn(mas)->parent = ma_parent_ptr(mas_tree_parent(mas));
rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
- mas_set_height(mas);
+ mt_set_height(mas->tree, new_height);
} else {
offset = mte_parent_slot(mas->node);
@@ -1741,12 +1748,13 @@ static inline void mas_put_in_tree(struct ma_state *mas,
* the parent encoding to locate the maple node in the tree.
* @mas: the ma_state with @mas->node pointing to the new node.
* @old_enode: The old maple encoded node.
+ * @new_height: The new height of the tree as a result of the operation
*/
static inline void mas_replace_node(struct ma_state *mas,
- struct maple_enode *old_enode)
+ struct maple_enode *old_enode, unsigned char new_height)
__must_hold(mas->tree->ma_lock)
{
- mas_put_in_tree(mas, old_enode);
+ mas_put_in_tree(mas, old_enode, new_height);
mas_free(mas, old_enode);
}
@@ -2536,10 +2544,11 @@ static inline void mas_topiary_node(struct ma_state *mas,
*
* @mas: The maple state pointing at the new data
* @old_enode: The maple encoded node being replaced
+ * @new_height: The new height of the tree as a result of the operation
*
*/
static inline void mas_topiary_replace(struct ma_state *mas,
- struct maple_enode *old_enode)
+ struct maple_enode *old_enode, unsigned char new_height)
{
struct ma_state tmp[3], tmp_next[3];
MA_TOPIARY(subtrees, mas->tree);
@@ -2547,7 +2556,7 @@ static inline void mas_topiary_replace(struct ma_state *mas,
int i, n;
/* Place data in tree & then mark node as old */
- mas_put_in_tree(mas, old_enode);
+ mas_put_in_tree(mas, old_enode, new_height);
/* Update the parent pointers in the tree */
tmp[0] = *mas;
@@ -2631,14 +2640,15 @@ static inline void mas_topiary_replace(struct ma_state *mas,
* mas_wmb_replace() - Write memory barrier and replace
* @mas: The maple state
* @old_enode: The old maple encoded node that is being replaced.
+ * @new_height: The new height of the tree as a result of the operation
*
* Updates gap as necessary.
*/
static inline void mas_wmb_replace(struct ma_state *mas,
- struct maple_enode *old_enode)
+ struct maple_enode *old_enode, unsigned char new_height)
{
/* Insert the new data in the tree */
- mas_topiary_replace(mas, old_enode);
+ mas_topiary_replace(mas, old_enode, new_height);
if (mte_is_leaf(mas->node))
return;
@@ -2737,7 +2747,7 @@ static inline bool mast_sufficient(struct maple_subtree_state *mast)
*/
static inline bool mast_overflow(struct maple_subtree_state *mast)
{
- if (mast->bn->b_end >= mt_slot_count(mast->orig_l->node))
+ if (mast->bn->b_end > mt_slot_count(mast->orig_l->node))
return true;
return false;
@@ -2824,6 +2834,7 @@ static void mas_spanning_rebalance(struct ma_state *mas,
{
unsigned char split, mid_split;
unsigned char slot = 0;
+ unsigned char new_height = 0; /* used if node is a new root */
struct maple_enode *left = NULL, *middle = NULL, *right = NULL;
struct maple_enode *old_enode;
@@ -2845,8 +2856,6 @@ static void mas_spanning_rebalance(struct ma_state *mas,
unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type]))
mast_spanning_rebalance(mast);
- l_mas.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
@@ -2866,6 +2875,7 @@ static void mas_spanning_rebalance(struct ma_state *mas,
mast_set_split_parents(mast, left, middle, right, split,
mid_split);
mast_cp_to_nodes(mast, left, middle, right, split, mid_split);
+ new_height++;
/*
* Copy data from next level in the tree to mast->bn from next
@@ -2873,7 +2883,6 @@ static void mas_spanning_rebalance(struct ma_state *mas,
*/
memset(mast->bn, 0, sizeof(struct maple_big_node));
mast->bn->type = mte_node_type(left);
- l_mas.depth++;
/* Root already stored in l->node. */
if (mas_is_root_limits(mast->l))
@@ -2890,11 +2899,21 @@ static void mas_spanning_rebalance(struct ma_state *mas,
mast_combine_cp_right(mast);
mast->orig_l->last = mast->orig_l->max;
- if (mast_sufficient(mast))
- continue;
+ if (mast_sufficient(mast)) {
+ if (mast_overflow(mast))
+ continue;
+
+ if (mast->orig_l->node == mast->orig_r->node) {
+ /*
+ * The data in b_node should be stored in one
+ * node and in the tree
+ */
+ slot = mast->l->offset;
+ break;
+ }
- if (mast_overflow(mast))
continue;
+ }
/* May be a new root stored in mast->bn */
if (mas_is_root_limits(mast->orig_l))
@@ -2909,8 +2928,9 @@ static void mas_spanning_rebalance(struct ma_state *mas,
l_mas.node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)),
mte_node_type(mast->orig_l->node));
- l_mas.depth++;
+
mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, &l_mas, true);
+ new_height++;
mas_set_parent(mas, left, l_mas.node, slot);
if (middle)
mas_set_parent(mas, middle, l_mas.node, ++slot);
@@ -2933,7 +2953,7 @@ new_root:
mas->min = l_mas.min;
mas->max = l_mas.max;
mas->offset = l_mas.offset;
- mas_wmb_replace(mas, old_enode);
+ mas_wmb_replace(mas, old_enode, new_height);
mtree_range_walk(mas);
return;
}
@@ -3009,6 +3029,7 @@ static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end
void __rcu **l_slots, **slots;
unsigned long *l_pivs, *pivs, gap;
bool in_rcu = mt_in_rcu(mas->tree);
+ unsigned char new_height = mas_mt_height(mas);
MA_STATE(l_mas, mas->tree, mas->index, mas->last);
@@ -3103,7 +3124,7 @@ done:
mas_ascend(mas);
if (in_rcu) {
- mas_replace_node(mas, old_eparent);
+ mas_replace_node(mas, old_eparent, new_height);
mas_adopt_children(mas, mas->node);
}
@@ -3114,10 +3135,9 @@ done:
* 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 void mas_split_final_node(struct maple_subtree_state *mast,
- struct ma_state *mas, int height)
+ struct ma_state *mas)
{
struct maple_enode *ancestor;
@@ -3126,7 +3146,6 @@ static inline void mas_split_final_node(struct maple_subtree_state *mast,
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.
@@ -3214,7 +3233,6 @@ static inline void mast_split_data(struct maple_subtree_state *mast,
* 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.
*
@@ -3222,8 +3240,8 @@ static inline void mast_split_data(struct maple_subtree_state *mast,
*
* 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)
+static inline bool mas_push_data(struct ma_state *mas,
+ struct maple_subtree_state *mast, bool left)
{
unsigned char slot_total = mast->bn->b_end;
unsigned char end, space, split;
@@ -3280,7 +3298,7 @@ static inline bool mas_push_data(struct ma_state *mas, int height,
mast_split_data(mast, mas, split);
mast_fill_bnode(mast, mas, 2);
- mas_split_final_node(mast, mas, height + 1);
+ mas_split_final_node(mast, mas);
return true;
}
@@ -3293,6 +3311,7 @@ static void mas_split(struct ma_state *mas, struct maple_big_node *b_node)
{
struct maple_subtree_state mast;
int height = 0;
+ unsigned int orig_height = mas_mt_height(mas);
unsigned char mid_split, split = 0;
struct maple_enode *old;
@@ -3319,7 +3338,6 @@ static void mas_split(struct ma_state *mas, struct maple_big_node *b_node)
MA_STATE(prev_r_mas, mas->tree, mas->index, mas->last);
trace_ma_op(__func__, mas);
- mas->depth = mas_mt_height(mas);
mast.l = &l_mas;
mast.r = &r_mas;
@@ -3327,9 +3345,9 @@ static void mas_split(struct ma_state *mas, struct maple_big_node *b_node)
mast.orig_r = &prev_r_mas;
mast.bn = b_node;
- while (height++ <= mas->depth) {
+ while (height++ <= orig_height) {
if (mt_slots[b_node->type] > b_node->b_end) {
- mas_split_final_node(&mast, mas, height);
+ mas_split_final_node(&mast, mas);
break;
}
@@ -3344,11 +3362,15 @@ static void mas_split(struct ma_state *mas, struct maple_big_node *b_node)
* is a significant savings.
*/
/* Try to push left. */
- if (mas_push_data(mas, height, &mast, true))
+ if (mas_push_data(mas, &mast, true)) {
+ height++;
break;
+ }
/* Try to push right. */
- if (mas_push_data(mas, height, &mast, false))
+ if (mas_push_data(mas, &mast, false)) {
+ height++;
break;
+ }
split = mab_calc_split(mas, b_node, &mid_split);
mast_split_data(&mast, mas, split);
@@ -3365,7 +3387,7 @@ static void mas_split(struct ma_state *mas, struct maple_big_node *b_node)
/* Set the original node as dead */
old = mas->node;
mas->node = l_mas.node;
- mas_wmb_replace(mas, old);
+ mas_wmb_replace(mas, old, height);
mtree_range_walk(mas);
return;
}
@@ -3424,8 +3446,7 @@ static inline void mas_root_expand(struct ma_state *mas, void *entry)
if (mas->last != ULONG_MAX)
pivots[++slot] = ULONG_MAX;
- mas->depth = 1;
- mas_set_height(mas);
+ mt_set_height(mas->tree, 1);
ma_set_meta(node, maple_leaf_64, 0, slot);
/* swap the new root into the tree */
rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
@@ -3532,6 +3553,16 @@ static bool mas_wr_walk(struct ma_wr_state *wr_mas)
if (ma_is_leaf(wr_mas->type))
return true;
+ if (mas->end < mt_slots[wr_mas->type] - 1)
+ wr_mas->vacant_height = mas->depth + 1;
+
+ if (ma_is_root(mas_mn(mas))) {
+ /* root needs more than 2 entries to be sufficient + 1 */
+ if (mas->end > 2)
+ wr_mas->sufficient_height = 1;
+ } else if (mas->end > mt_min_slots[wr_mas->type] + 1)
+ wr_mas->sufficient_height = mas->depth + 1;
+
mas_wr_walk_traverse(wr_mas);
}
@@ -3669,8 +3700,7 @@ static inline void mas_new_root(struct ma_state *mas, void *entry)
WARN_ON_ONCE(mas->index || mas->last != ULONG_MAX);
if (!entry) {
- mas->depth = 0;
- mas_set_height(mas);
+ mt_set_height(mas->tree, 0);
rcu_assign_pointer(mas->tree->ma_root, entry);
mas->status = ma_start;
goto done;
@@ -3684,8 +3714,7 @@ static inline void mas_new_root(struct ma_state *mas, void *entry)
mas->status = ma_active;
rcu_assign_pointer(slots[0], entry);
pivots[0] = mas->last;
- mas->depth = 1;
- mas_set_height(mas);
+ mt_set_height(mas->tree, 1);
rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node));
done:
@@ -3804,6 +3833,7 @@ static inline void mas_wr_node_store(struct ma_wr_state *wr_mas,
struct maple_node reuse, *newnode;
unsigned char copy_size, node_pivots = mt_pivots[wr_mas->type];
bool in_rcu = mt_in_rcu(mas->tree);
+ unsigned char height = mas_mt_height(mas);
if (mas->last == wr_mas->end_piv)
offset_end++; /* don't copy this offset */
@@ -3860,7 +3890,7 @@ done:
struct maple_enode *old_enode = mas->node;
mas->node = mt_mk_node(newnode, wr_mas->type);
- mas_replace_node(mas, old_enode);
+ mas_replace_node(mas, old_enode, height);
} else {
memcpy(wr_mas->node, newnode, sizeof(struct maple_node));
}
@@ -4059,15 +4089,6 @@ static inline void mas_wr_store_entry(struct ma_wr_state *wr_mas)
unsigned char new_end = mas_wr_new_end(wr_mas);
switch (mas->store_type) {
- case wr_invalid:
- MT_BUG_ON(mas->tree, 1);
- return;
- case wr_new_root:
- mas_new_root(mas, wr_mas->entry);
- break;
- case wr_store_root:
- mas_store_root(mas, wr_mas->entry);
- break;
case wr_exact_fit:
rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry);
if (!!wr_mas->entry ^ !!wr_mas->content)
@@ -4089,6 +4110,14 @@ static inline void mas_wr_store_entry(struct ma_wr_state *wr_mas)
case wr_rebalance:
mas_wr_bnode(wr_mas);
break;
+ case wr_new_root:
+ mas_new_root(mas, wr_mas->entry);
+ break;
+ case wr_store_root:
+ mas_store_root(mas, wr_mas->entry);
+ break;
+ case wr_invalid:
+ MT_BUG_ON(mas->tree, 1);
}
return;
@@ -4140,18 +4169,41 @@ set_content:
/**
* mas_prealloc_calc() - Calculate number of nodes needed for a
* given store oepration
- * @mas: The maple state
+ * @wr_mas: The maple write state
* @entry: The entry to store into the tree
*
* Return: Number of nodes required for preallocation.
*/
-static inline int mas_prealloc_calc(struct ma_state *mas, void *entry)
+static inline int mas_prealloc_calc(struct ma_wr_state *wr_mas, void *entry)
{
- int ret = mas_mt_height(mas) * 3 + 1;
+ struct ma_state *mas = wr_mas->mas;
+ unsigned char height = mas_mt_height(mas);
+ int ret = height * 3 + 1;
+ unsigned char delta = height - wr_mas->vacant_height;
switch (mas->store_type) {
- case wr_invalid:
- WARN_ON_ONCE(1);
+ case wr_exact_fit:
+ case wr_append:
+ case wr_slot_store:
+ ret = 0;
+ break;
+ case wr_spanning_store:
+ if (wr_mas->sufficient_height < wr_mas->vacant_height)
+ ret = (height - wr_mas->sufficient_height) * 3 + 1;
+ else
+ ret = delta * 3 + 1;
+ break;
+ case wr_split_store:
+ ret = delta * 2 + 1;
+ break;
+ case wr_rebalance:
+ if (wr_mas->sufficient_height < wr_mas->vacant_height)
+ ret = (height - wr_mas->sufficient_height) * 2 + 1;
+ else
+ ret = delta * 2 + 1;
+ break;
+ case wr_node_store:
+ ret = mt_in_rcu(mas->tree) ? 1 : 0;
break;
case wr_new_root:
ret = 1;
@@ -4164,22 +4216,8 @@ static inline int mas_prealloc_calc(struct ma_state *mas, void *entry)
else
ret = 0;
break;
- case wr_spanning_store:
- ret = mas_mt_height(mas) * 3 + 1;
- break;
- case wr_split_store:
- ret = mas_mt_height(mas) * 2 + 1;
- break;
- case wr_rebalance:
- ret = mas_mt_height(mas) * 2 - 1;
- break;
- case wr_node_store:
- ret = mt_in_rcu(mas->tree) ? 1 : 0;
- break;
- case wr_append:
- case wr_exact_fit:
- case wr_slot_store:
- ret = 0;
+ case wr_invalid:
+ WARN_ON_ONCE(1);
}
return ret;
@@ -4243,16 +4281,15 @@ static inline enum store_type mas_wr_store_type(struct ma_wr_state *wr_mas)
*/
static inline void mas_wr_preallocate(struct ma_wr_state *wr_mas, void *entry)
{
- struct ma_state *mas = wr_mas->mas;
int request;
mas_wr_prealloc_setup(wr_mas);
- mas->store_type = mas_wr_store_type(wr_mas);
- request = mas_prealloc_calc(mas, entry);
+ wr_mas->mas->store_type = mas_wr_store_type(wr_mas);
+ request = mas_prealloc_calc(wr_mas, entry);
if (!request)
return;
- mas_node_count(mas, request);
+ mas_node_count(wr_mas->mas, request);
}
/**
@@ -4529,15 +4566,12 @@ again:
if (unlikely(mas_rewalk_if_dead(mas, node, save_point)))
goto retry;
-
if (likely(entry))
return entry;
if (!empty) {
- if (mas->index <= min) {
- mas->status = ma_underflow;
- return NULL;
- }
+ if (mas->index <= min)
+ goto underflow;
goto again;
}
@@ -4899,7 +4933,7 @@ void *mas_walk(struct ma_state *mas)
{
void *entry;
- if (!mas_is_active(mas) || !mas_is_start(mas))
+ if (!mas_is_active(mas) && !mas_is_start(mas))
mas->status = ma_start;
retry:
entry = mas_state_walk(mas);
@@ -5288,6 +5322,7 @@ static void mt_destroy_walk(struct maple_enode *enode, struct maple_tree *mt,
struct maple_enode *start;
if (mte_is_leaf(enode)) {
+ mte_set_node_dead(enode);
node->type = mte_node_type(enode);
goto free_leaf;
}
@@ -5397,7 +5432,7 @@ void *mas_store(struct ma_state *mas, void *entry)
return wr_mas.content;
}
- request = mas_prealloc_calc(mas, entry);
+ request = mas_prealloc_calc(&wr_mas, entry);
if (!request)
goto store;
@@ -5494,10 +5529,11 @@ int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp)
mas_wr_prealloc_setup(&wr_mas);
mas->store_type = mas_wr_store_type(&wr_mas);
- request = mas_prealloc_calc(mas, entry);
+ request = mas_prealloc_calc(&wr_mas, entry);
if (!request)
- return ret;
+ goto set_flag;
+ mas->mas_flags &= ~MA_STATE_PREALLOC;
mas_node_count_gfp(mas, request, gfp);
if (mas_is_err(mas)) {
mas_set_alloc_req(mas, 0);
@@ -5507,6 +5543,7 @@ int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp)
return ret;
}
+set_flag:
mas->mas_flags |= MA_STATE_PREALLOC;
return ret;
}
@@ -5625,6 +5662,17 @@ int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries)
}
EXPORT_SYMBOL_GPL(mas_expected_entries);
+static void mas_may_activate(struct ma_state *mas)
+{
+ if (!mas->node) {
+ mas->status = ma_start;
+ } else if (mas->index > mas->max || mas->index < mas->min) {
+ mas->status = ma_start;
+ } else {
+ mas->status = ma_active;
+ }
+}
+
static bool mas_next_setup(struct ma_state *mas, unsigned long max,
void **entry)
{
@@ -5648,11 +5696,11 @@ static bool mas_next_setup(struct ma_state *mas, unsigned long max,
break;
case ma_overflow:
/* Overflowed before, but the max changed */
- mas->status = ma_active;
+ mas_may_activate(mas);
break;
case ma_underflow:
/* The user expects the mas to be one before where it is */
- mas->status = ma_active;
+ mas_may_activate(mas);
*entry = mas_walk(mas);
if (*entry)
return true;
@@ -5773,11 +5821,11 @@ static bool mas_prev_setup(struct ma_state *mas, unsigned long min, void **entry
break;
case ma_underflow:
/* underflowed before but the min changed */
- mas->status = ma_active;
+ mas_may_activate(mas);
break;
case ma_overflow:
/* User expects mas to be one after where it is */
- mas->status = ma_active;
+ mas_may_activate(mas);
*entry = mas_walk(mas);
if (*entry)
return true;
@@ -5942,7 +5990,7 @@ static __always_inline bool mas_find_setup(struct ma_state *mas, unsigned long m
return true;
}
- mas->status = ma_active;
+ mas_may_activate(mas);
*entry = mas_walk(mas);
if (*entry)
return true;
@@ -5951,7 +5999,7 @@ static __always_inline bool mas_find_setup(struct ma_state *mas, unsigned long m
if (unlikely(mas->last >= max))
return true;
- mas->status = ma_active;
+ mas_may_activate(mas);
*entry = mas_walk(mas);
if (*entry)
return true;
generated by cgit (git 2.34.1) at 2025-08-05 14:23:40 +0000