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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>
This commit is contained in:
Liam R. Howlett 2023-05-18 10:55:37 -04:00 committed by Andrew Morton
parent fff4a58cc0
commit 6169b55319
2 changed files with 144 additions and 71 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/linux/maple_tree.h
View File

@ -455,6 +455,7 @@ void *mas_erase(struct ma_state *mas);
int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp);
void mas_store_prealloc(struct ma_state *mas, void *entry);
void *mas_find(struct ma_state *mas, unsigned long max);
void *mas_find_range(struct ma_state *mas, unsigned long max);
void *mas_find_rev(struct ma_state *mas, unsigned long min);
int mas_preallocate(struct ma_state *mas, gfp_t gfp);
bool mas_is_err(struct ma_state *mas);
@ -467,6 +468,7 @@ int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries);
void *mas_prev(struct ma_state *mas, unsigned long min);
void *mas_next(struct ma_state *mas, unsigned long max);
void *mas_next_range(struct ma_state *mas, unsigned long max);
int mas_empty_area(struct ma_state *mas, unsigned long min, unsigned long max,
unsigned long size);
@ -528,7 +530,6 @@ static inline void mas_reset(struct ma_state *mas)
#define mas_for_each(__mas, __entry, __max) \
while (((__entry) = mas_find((__mas), (__max))) != NULL)
/**
* mas_set_range() - Set up Maple Tree operation state for a different index.
* @mas: Maple Tree operation state.

212
lib/maple_tree.c
View File

@ -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);
}
/*
@ -5880,6 +5877,34 @@ int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries)
}
EXPORT_SYMBOL_GPL(mas_expected_entries);
static inline bool mas_next_setup(struct ma_state *mas, unsigned long max,
void **entry)
{
bool was_none = mas_is_none(mas);
if (mas_is_none(mas) || mas_is_paused(mas))
mas->node = MAS_START;
if (mas_is_start(mas))
*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 true;
}
mas->index = 1;
mas->last = ULONG_MAX;
mas->node = MAS_NONE;
return true;
}
if (mas_is_none(mas))
return true;
return false;
}
/**
* mas_next() - Get the next entry.
* @mas: The maple state
@ -5893,30 +5918,39 @@ EXPORT_SYMBOL_GPL(mas_expected_entries);
*/
void *mas_next(struct ma_state *mas, unsigned long max)
{
bool was_none = mas_is_none(mas);
void *entry = NULL;
if (mas_is_none(mas) || mas_is_paused(mas))
mas->node = MAS_START;
if (mas_next_setup(mas, max, &entry))
return entry;
if (mas_is_start(mas))
mas_walk(mas); /* Retries on dead nodes handled by mas_walk */
if (mas_is_ptr(mas)) {
if (was_none && mas->index == 0) {
mas->index = mas->last = 0;
return mas_root(mas);
}
mas->index = 1;
mas->last = ULONG_MAX;
mas->node = MAS_NONE;
return NULL;
}
/* Retries on dead nodes handled by mas_next_entry */
return mas_next_entry(mas, max);
/* 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
@ -6025,6 +6059,64 @@ void mas_pause(struct ma_state *mas)
}
EXPORT_SYMBOL_GPL(mas_pause);
/**
* mas_find_setup() - Internal function to set up mas_find*().
* @mas: The maple state
* @max: The maximum index
* @entry: Pointer to the entry
*
* Returns: True if entry is the answer, false otherwise.
*/
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 true;
mas->index = mas->last;
mas->node = MAS_START;
} else if (unlikely(mas_is_paused(mas))) {
if (unlikely(mas->last >= max))
return true;
mas->node = MAS_START;
mas->index = ++mas->last;
} else if (unlikely(mas_is_ptr(mas)))
goto ptr_out_of_range;
if (unlikely(mas_is_start(mas))) {
/* First run or continue */
if (mas->index > max)
return true;
*entry = mas_walk(mas);
if (*entry)
return true;
}
if (unlikely(!mas_searchable(mas))) {
if (unlikely(mas_is_ptr(mas)))
goto ptr_out_of_range;
return true;
}
if (mas->index == max)
return true;
return false;
ptr_out_of_range:
mas->node = MAS_NONE;
mas->index = 1;
mas->last = ULONG_MAX;
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.
@ -6039,60 +6131,40 @@ EXPORT_SYMBOL_GPL(mas_pause);
*/
void *mas_find(struct ma_state *mas, unsigned long max)
{
if (unlikely(mas_is_none(mas))) {
if (unlikely(mas->last >= max))
return NULL;
void *entry = NULL;
mas->index = mas->last;
mas->node = MAS_START;
}
if (unlikely(mas_is_paused(mas))) {
if (unlikely(mas->last >= max))
return NULL;
mas->node = MAS_START;
mas->index = ++mas->last;
}
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;
entry = mas_walk(mas);
if (entry)
return entry;
}
if (unlikely(!mas_searchable(mas))) {
if (unlikely(mas_is_ptr(mas)))
goto ptr_out_of_range;
return NULL;
}
if (mas->index == max)
return 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);
ptr_out_of_range:
mas->node = MAS_NONE;
mas->index = 1;
mas->last = ULONG_MAX;
return NULL;
}
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