Commit 35534c86 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

radix tree: constify some pointers 



If we're just getting the value of a tag, or looking up an entry,
we won't modify the radix tree, so we can declare these functions as
taking a const pointer.  Mostly for documentation purposes, though it
might help code generation.

Signed-off-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
parent 15f2e88d

include/linux/radix-tree.h

+11 −11
Original line number Diff line number Diff line
@@ -125,7 +125,7 @@ do { \ 
	(root)->rnode = NULL;						\

} while (0)



static inline bool radix_tree_empty(struct radix_tree_root *root)

static inline bool radix_tree_empty(const struct radix_tree_root *root)

{

	return root->rnode == NULL;

}
@@ -294,10 +294,10 @@ static inline int radix_tree_insert(struct radix_tree_root *root, 
{

	return __radix_tree_insert(root, index, 0, entry);

}

void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index,

void *__radix_tree_lookup(const struct radix_tree_root *, unsigned long index,

			  struct radix_tree_node **nodep, void ***slotp);

void *radix_tree_lookup(struct radix_tree_root *, unsigned long);

void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long);

void *radix_tree_lookup(const struct radix_tree_root *, unsigned long);

void **radix_tree_lookup_slot(const struct radix_tree_root *, unsigned long);

typedef void (*radix_tree_update_node_t)(struct radix_tree_node *, void *);

void __radix_tree_replace(struct radix_tree_root *root,

			  struct radix_tree_node *node,
@@ -316,10 +316,10 @@ void *radix_tree_delete(struct radix_tree_root *, unsigned long); 
void radix_tree_clear_tags(struct radix_tree_root *root,

			   struct radix_tree_node *node,

			   void **slot);

unsigned int radix_tree_gang_lookup(struct radix_tree_root *root,

unsigned int radix_tree_gang_lookup(const struct radix_tree_root *,

			void **results, unsigned long first_index,

			unsigned int max_items);

unsigned int radix_tree_gang_lookup_slot(struct radix_tree_root *root,

unsigned int radix_tree_gang_lookup_slot(const struct radix_tree_root *,

			void ***results, unsigned long *indices,

			unsigned long first_index, unsigned int max_items);

int radix_tree_preload(gfp_t gfp_mask);
@@ -330,19 +330,19 @@ void *radix_tree_tag_set(struct radix_tree_root *root, 
			unsigned long index, unsigned int tag);

void *radix_tree_tag_clear(struct radix_tree_root *root,

			unsigned long index, unsigned int tag);

int radix_tree_tag_get(struct radix_tree_root *root,

int radix_tree_tag_get(const struct radix_tree_root *,

			unsigned long index, unsigned int tag);

void radix_tree_iter_tag_set(struct radix_tree_root *root,

		const struct radix_tree_iter *iter, unsigned int tag);

unsigned int

radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,

radix_tree_gang_lookup_tag(const struct radix_tree_root *, void **results,

		unsigned long first_index, unsigned int max_items,

		unsigned int tag);

unsigned int

radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,

radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *, void ***results,

		unsigned long first_index, unsigned int max_items,

		unsigned int tag);

int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag);

int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag);



static inline void radix_tree_preload_end(void)

{
@@ -395,7 +395,7 @@ radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start) 
 * Also it fills @iter with data about chunk: position in the tree (index),

 * its end (next_index), and constructs a bit mask for tagged iterating (tags).

 */

void **radix_tree_next_chunk(struct radix_tree_root *root,

void **radix_tree_next_chunk(const struct radix_tree_root *,

			     struct radix_tree_iter *iter, unsigned flags);



/**

lib/radix-tree.c

+31 −26
Original line number Diff line number Diff line
@@ -83,26 +83,28 @@ static inline void *node_to_entry(void *ptr) 


#ifdef CONFIG_RADIX_TREE_MULTIORDER

/* Sibling slots point directly to another slot in the same node */

static inline bool is_sibling_entry(struct radix_tree_node *parent, void *node)

static inline

bool is_sibling_entry(const struct radix_tree_node *parent, void *node)

{

	void **ptr = node;

	return (parent->slots <= ptr) &&

			(ptr < parent->slots + RADIX_TREE_MAP_SIZE);

}

#else

static inline bool is_sibling_entry(struct radix_tree_node *parent, void *node)

static inline

bool is_sibling_entry(const struct radix_tree_node *parent, void *node)

{

	return false;

}

#endif



static inline unsigned long get_slot_offset(struct radix_tree_node *parent,

						 void **slot)

static inline

unsigned long get_slot_offset(const struct radix_tree_node *parent, void **slot)

{

	return slot - parent->slots;

}



static unsigned int radix_tree_descend(struct radix_tree_node *parent,

static unsigned int radix_tree_descend(const struct radix_tree_node *parent,

			struct radix_tree_node **nodep, unsigned long index)

{

	unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK;
@@ -122,7 +124,7 @@ static unsigned int radix_tree_descend(struct radix_tree_node *parent, 
	return offset;

}



static inline gfp_t root_gfp_mask(struct radix_tree_root *root)

static inline gfp_t root_gfp_mask(const struct radix_tree_root *root)

{

	return root->gfp_mask & __GFP_BITS_MASK;

}
@@ -139,13 +141,13 @@ static inline void tag_clear(struct radix_tree_node *node, unsigned int tag, 
	__clear_bit(offset, node->tags[tag]);

}



static inline int tag_get(struct radix_tree_node *node, unsigned int tag,

static inline int tag_get(const struct radix_tree_node *node, unsigned int tag,

		int offset)

{

	return test_bit(offset, node->tags[tag]);

}



static inline void root_tag_set(struct radix_tree_root *root, unsigned int tag)

static inline void root_tag_set(struct radix_tree_root *root, unsigned tag)

{

	root->gfp_mask |= (__force gfp_t)(1 << (tag + __GFP_BITS_SHIFT));

}
@@ -160,12 +162,12 @@ static inline void root_tag_clear_all(struct radix_tree_root *root) 
	root->gfp_mask &= __GFP_BITS_MASK;

}



static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag)

static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag)

{

	return (__force int)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT));

}



static inline unsigned root_tags_get(struct radix_tree_root *root)

static inline unsigned root_tags_get(const struct radix_tree_root *root)

{

	return (__force unsigned)root->gfp_mask >> __GFP_BITS_SHIFT;

}
@@ -174,7 +176,8 @@ static inline unsigned root_tags_get(struct radix_tree_root *root) 
 * Returns 1 if any slot in the node has this tag set.

 * Otherwise returns 0.

 */

static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag)

static inline int any_tag_set(const struct radix_tree_node *node,

							unsigned int tag)

{

	unsigned idx;

	for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
@@ -232,7 +235,7 @@ static inline unsigned long shift_maxindex(unsigned int shift) 
	return (RADIX_TREE_MAP_SIZE << shift) - 1;

}



static inline unsigned long node_maxindex(struct radix_tree_node *node)

static inline unsigned long node_maxindex(const struct radix_tree_node *node)

{

	return shift_maxindex(node->shift);

}
@@ -510,7 +513,7 @@ int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order) 
	return __radix_tree_preload(gfp_mask, nr_nodes);

}



static unsigned radix_tree_load_root(struct radix_tree_root *root,

static unsigned radix_tree_load_root(const struct radix_tree_root *root,

		struct radix_tree_node **nodep, unsigned long *maxindex)

{

	struct radix_tree_node *node = rcu_dereference_raw(root->rnode);
@@ -908,8 +911,9 @@ EXPORT_SYMBOL(__radix_tree_insert); 
 *	allocated and @root->rnode is used as a direct slot instead of

 *	pointing to a node, in which case *@nodep will be NULL.

 */

void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index,

			  struct radix_tree_node **nodep, void ***slotp)

void *__radix_tree_lookup(const struct radix_tree_root *root,

			  unsigned long index, struct radix_tree_node **nodep,

			  void ***slotp)

{

	struct radix_tree_node *node, *parent;

	unsigned long maxindex;
@@ -952,7 +956,8 @@ void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index, 
 *	exclusive from other writers. Any dereference of the slot must be done

 *	using radix_tree_deref_slot.

 */

void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index)

void **radix_tree_lookup_slot(const struct radix_tree_root *root,

				unsigned long index)

{

	void **slot;
@@ -974,7 +979,7 @@ EXPORT_SYMBOL(radix_tree_lookup_slot); 
 *	them safely). No RCU barriers are required to access or modify the

 *	returned item, however.

 */

void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index)

void *radix_tree_lookup(const struct radix_tree_root *root, unsigned long index)

{

	return __radix_tree_lookup(root, index, NULL, NULL);

}
@@ -1404,7 +1409,7 @@ EXPORT_SYMBOL(radix_tree_tag_clear); 
 * the RCU lock is held, unless tag modification and node deletion are excluded

 * from concurrency.

 */

int radix_tree_tag_get(struct radix_tree_root *root,

int radix_tree_tag_get(const struct radix_tree_root *root,

			unsigned long index, unsigned int tag)

{

	struct radix_tree_node *node, *parent;
@@ -1568,7 +1573,7 @@ EXPORT_SYMBOL(radix_tree_iter_resume); 
 * @flags:	RADIX_TREE_ITER_* flags and tag index

 * Returns:	pointer to chunk first slot, or NULL if iteration is over

 */

void **radix_tree_next_chunk(struct radix_tree_root *root,

void **radix_tree_next_chunk(const struct radix_tree_root *root,

			     struct radix_tree_iter *iter, unsigned flags)

{

	unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
@@ -1679,7 +1684,7 @@ EXPORT_SYMBOL(radix_tree_next_chunk); 
 *	stored in 'results'.

 */

unsigned int

radix_tree_gang_lookup(struct radix_tree_root *root, void **results,

radix_tree_gang_lookup(const struct radix_tree_root *root, void **results,

			unsigned long first_index, unsigned int max_items)

{

	struct radix_tree_iter iter;
@@ -1724,7 +1729,7 @@ EXPORT_SYMBOL(radix_tree_gang_lookup); 
 *	protection, radix_tree_deref_slot may fail requiring a retry.

 */

unsigned int

radix_tree_gang_lookup_slot(struct radix_tree_root *root,

radix_tree_gang_lookup_slot(const struct radix_tree_root *root,

			void ***results, unsigned long *indices,

			unsigned long first_index, unsigned int max_items)

{
@@ -1761,7 +1766,7 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_slot); 
 *	returns the number of items which were placed at *@results.

 */

unsigned int

radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,

radix_tree_gang_lookup_tag(const struct radix_tree_root *root, void **results,

		unsigned long first_index, unsigned int max_items,

		unsigned int tag)

{
@@ -1802,9 +1807,9 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_tag); 
 *	returns the number of slots which were placed at *@results.

 */

unsigned int

radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,

		unsigned long first_index, unsigned int max_items,

		unsigned int tag)

radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root,

		void ***results, unsigned long first_index,

		unsigned int max_items, unsigned int tag)

{

	struct radix_tree_iter iter;

	void **slot;
@@ -1921,7 +1926,7 @@ void radix_tree_clear_tags(struct radix_tree_root *root, 
 *	@root:		radix tree root

 *	@tag:		tag to test

 */

int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag)

int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag)

{

	return root_tag_get(root, tag);

}