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radix-tree: rename INDIRECT_PTR to INTERNAL_NODE 

The name RADIX_TREE_INDIRECT_PTR doesn't really match the meaning.
RADIX_TREE_INTERNAL_NODE is a better name.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox 2016-05-20 17:03:22 -07:00 committed by Linus Torvalds
parent d0891265bb
commit 30ff46ccb3
2 changed files with 13 additions and 17 deletions
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28
include/linux/radix-tree.h
View File

@ -29,20 +29,16 @@
#include <linux/rcupdate.h>
/*
* An indirect pointer (root->rnode pointing to a radix_tree_node, rather
* than a data item) is signalled by the low bit set in the root->rnode
* pointer.
* Entries in the radix tree have the low bit set if they refer to a
* radix_tree_node. If the low bit is clear then the entry is user data.
*
* In this case root->height is > 0, but the indirect pointer tests are
* needed for RCU lookups (because root->height is unreliable). The only
* time callers need worry about this is when doing a lookup_slot under
* RCU.
*
* Indirect pointer in fact is also used to tag the last pointer of a node
* when it is shrunk, before we rcu free the node. See shrink code for
* details.
* We also use the low bit to indicate that the slot will be freed in the
* next RCU idle period, and users need to re-walk the tree to find the
* new slot for the index that they were looking for. See the comment in
* radix_tree_shrink() for details.
*/
#define RADIX_TREE_INDIRECT_PTR 1
#define RADIX_TREE_INTERNAL_NODE 1
/*
* A common use of the radix tree is to store pointers to struct pages;
* but shmem/tmpfs needs also to store swap entries in the same tree:
@ -63,7 +59,7 @@
static inline int radix_tree_is_indirect_ptr(void *ptr)
{
return (int)((unsigned long)ptr & RADIX_TREE_INDIRECT_PTR);
return (int)((unsigned long)ptr & RADIX_TREE_INTERNAL_NODE);
}
/*** radix-tree API starts here ***/
@ -228,7 +224,7 @@ static inline void *radix_tree_deref_slot_protected(void **pslot,
*/
static inline int radix_tree_deref_retry(void *arg)
{
return unlikely((unsigned long)arg & RADIX_TREE_INDIRECT_PTR);
return unlikely(radix_tree_is_indirect_ptr(arg));
}
/**
@ -250,7 +246,7 @@ static inline int radix_tree_exceptional_entry(void *arg)
static inline int radix_tree_exception(void *arg)
{
return unlikely((unsigned long)arg &
(RADIX_TREE_INDIRECT_PTR | RADIX_TREE_EXCEPTIONAL_ENTRY));
(RADIX_TREE_INTERNAL_NODE | RADIX_TREE_EXCEPTIONAL_ENTRY));
}
/**
@ -448,7 +444,7 @@ radix_tree_chunk_size(struct radix_tree_iter *iter)
static inline void *indirect_to_ptr(void *ptr)
{
return (void *)((unsigned long)ptr & ~RADIX_TREE_INDIRECT_PTR);
return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE);
}
/**

2
lib/radix-tree.c
View File

@ -68,7 +68,7 @@ static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
static inline void *ptr_to_indirect(void *ptr)
{
return (void *)((unsigned long)ptr | RADIX_TREE_INDIRECT_PTR);
return (void *)((unsigned long)ptr | RADIX_TREE_INTERNAL_NODE);
}
#define RADIX_TREE_RETRY ptr_to_indirect(NULL)