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authorLiam R. Howlett <Liam.Howlett@oracle.com>2023-05-18 17:55:37 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-06-10 02:25:34 +0300
commit6169b553195a193c52a675e45a9578f595fe194f (patch)
tree444b3def2be5736f030dbaea59f74524115523d6 /lib/maple_tree.c
parentfff4a58cc00b3baef860c82d6e5e149f71c79d44 (diff)
downloadlinux-6169b553195a193c52a675e45a9578f595fe194f.tar.xz
maple_tree: add mas_next_range() and mas_find_range() interfaces
Some users of the maple tree may want to move to the next range in the tree, even if it stores a NULL. This family of function provides that functionality by advancing one slot at a time and returning the result, while mas_contiguous() will iterate over the range and stop on encountering the first NULL. Link: https://lkml.kernel.org/r/20230518145544.1722059-29-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: David Binderman <dcb314@hotmail.com> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Vernon Yang <vernon2gm@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/maple_tree.c')
-rw-r--r--lib/maple_tree.c172
1 files changed, 122 insertions, 50 deletions
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 205664f46e58..41c152718000 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4793,13 +4793,10 @@ again:
*/
static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit)
{
- void *entry = NULL;
-
if (mas->last >= limit)
return NULL;
- entry = mas_next_slot(mas, limit, false);
- return entry;
+ return mas_next_slot(mas, limit, false);
}
/*
@@ -5880,18 +5877,8 @@ int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries)
}
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)
+static inline bool mas_next_setup(struct ma_state *mas, unsigned long max,
+ void **entry)
{
bool was_none = mas_is_none(mas);
@@ -5899,25 +5886,72 @@ void *mas_next(struct ma_state *mas, unsigned long max)
mas->node = MAS_START;
if (mas_is_start(mas))
- mas_walk(mas); /* Retries on dead nodes handled by mas_walk */
+ *entry = mas_walk(mas); /* Retries on dead nodes handled by mas_walk */
if (mas_is_ptr(mas)) {
+ *entry = NULL;
if (was_none && mas->index == 0) {
mas->index = mas->last = 0;
- return mas_root(mas);
+ return true;
}
mas->index = 1;
mas->last = ULONG_MAX;
mas->node = MAS_NONE;
- return NULL;
+ return true;
}
- /* Retries on dead nodes handled by mas_next_entry */
- return mas_next_entry(mas, max);
+ if (mas_is_none(mas))
+ return true;
+ return false;
+}
+
+/**
+ * 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)
+{
+ void *entry = NULL;
+
+ if (mas_next_setup(mas, max, &entry))
+ return entry;
+
+ /* Retries on dead nodes handled by mas_next_slot */
+ return mas_next_slot(mas, max, false);
}
EXPORT_SYMBOL_GPL(mas_next);
/**
+ * mas_next_range() - Advance the maple state to the next range
+ * @mas: The maple state
+ * @max: The maximum index to check.
+ *
+ * Sets @mas->index and @mas->last to the range.
+ * Must hold rcu_read_lock or the write lock.
+ * Can return the zero entry.
+ *
+ * Return: The next entry or %NULL
+ */
+void *mas_next_range(struct ma_state *mas, unsigned long max)
+{
+ void *entry = NULL;
+
+ if (mas_next_setup(mas, max, &entry))
+ return entry;
+
+ /* Retries on dead nodes handled by mas_next_slot */
+ return mas_next_slot(mas, max, true);
+}
+EXPORT_SYMBOL_GPL(mas_next_range);
+
+/**
* mt_next() - get the next value in the maple tree
* @mt: The maple tree
* @index: The start index
@@ -6026,49 +6060,41 @@ void mas_pause(struct ma_state *mas)
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_find_setup() - Internal function to set up mas_find*().
* @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.
+ * @max: The maximum index
+ * @entry: Pointer to the entry
*
- * Return: The entry or %NULL.
+ * Returns: True if entry is the answer, false otherwise.
*/
-void *mas_find(struct ma_state *mas, unsigned long max)
+static inline bool mas_find_setup(struct ma_state *mas, unsigned long max,
+ void **entry)
{
+ *entry = NULL;
+
if (unlikely(mas_is_none(mas))) {
if (unlikely(mas->last >= max))
- return NULL;
+ return true;
mas->index = mas->last;
mas->node = MAS_START;
- }
-
- if (unlikely(mas_is_paused(mas))) {
+ } else if (unlikely(mas_is_paused(mas))) {
if (unlikely(mas->last >= max))
- return NULL;
+ return true;
mas->node = MAS_START;
mas->index = ++mas->last;
- }
-
-
- if (unlikely(mas_is_ptr(mas)))
+ } else if (unlikely(mas_is_ptr(mas)))
goto ptr_out_of_range;
if (unlikely(mas_is_start(mas))) {
/* First run or continue */
- void *entry;
-
if (mas->index > max)
- return NULL;
+ return true;
- entry = mas_walk(mas);
- if (entry)
- return entry;
+ *entry = mas_walk(mas);
+ if (*entry)
+ return true;
}
@@ -6076,24 +6102,70 @@ void *mas_find(struct ma_state *mas, unsigned long max)
if (unlikely(mas_is_ptr(mas)))
goto ptr_out_of_range;
- return NULL;
+ return true;
}
if (mas->index == max)
- return NULL;
+ return true;
- /* Retries on dead nodes handled by mas_next_slot */
- return mas_next_slot(mas, max, false);
+ return false;
ptr_out_of_range:
mas->node = MAS_NONE;
mas->index = 1;
mas->last = ULONG_MAX;
- return NULL;
+ return true;
+}
+
+/**
+ * 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)
+{
+ void *entry = NULL;
+
+ if (mas_find_setup(mas, max, &entry))
+ return entry;
+
+ /* Retries on dead nodes handled by mas_next_slot */
+ return mas_next_slot(mas, max, false);
}
EXPORT_SYMBOL_GPL(mas_find);
/**
+ * mas_find_range() - On the first call, find the entry at or after
+ * mas->index up to %max. Otherwise, advance to the next slot 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_range(struct ma_state *mas, unsigned long max)
+{
+ void *entry;
+
+ if (mas_find_setup(mas, max, &entry))
+ return entry;
+
+ /* Retries on dead nodes handled by mas_next_slot */
+ return mas_next_slot(mas, max, true);
+}
+EXPORT_SYMBOL_GPL(mas_find_range);
+
+/**
* 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.