radix-tree: delete radix_tree_locate_item()

This rather complicated function can be better implemented as an
iterator.  It has only one caller, so move the functionality to the only
place that needs it.  Update the test suite to follow the same pattern.

Link: http://lkml.kernel.org/r/1480369871-5271-56-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.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
2016-12-14 15:08:52 -08:00
committed by Linus Torvalds
parent 148deab223
commit 478922e2b0
6 changed files with 53 additions and 105 deletions
-99
View File
@@ -1579,105 +1579,6 @@ radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
}
EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);
#if defined(CONFIG_SHMEM) && defined(CONFIG_SWAP)
#include <linux/sched.h> /* for cond_resched() */
struct locate_info {
unsigned long found_index;
bool stop;
};
/*
* This linear search is at present only useful to shmem_unuse_inode().
*/
static unsigned long __locate(struct radix_tree_node *slot, void *item,
unsigned long index, struct locate_info *info)
{
unsigned long i;
do {
unsigned int shift = slot->shift;
for (i = (index >> shift) & RADIX_TREE_MAP_MASK;
i < RADIX_TREE_MAP_SIZE;
i++, index += (1UL << shift)) {
struct radix_tree_node *node =
rcu_dereference_raw(slot->slots[i]);
if (node == RADIX_TREE_RETRY)
goto out;
if (!radix_tree_is_internal_node(node)) {
if (node == item) {
info->found_index = index;
info->stop = true;
goto out;
}
continue;
}
node = entry_to_node(node);
if (is_sibling_entry(slot, node))
continue;
slot = node;
break;
}
} while (i < RADIX_TREE_MAP_SIZE);
out:
if ((index == 0) && (i == RADIX_TREE_MAP_SIZE))
info->stop = true;
return index;
}
/**
* radix_tree_locate_item - search through radix tree for item
* @root: radix tree root
* @item: item to be found
*
* Returns index where item was found, or -1 if not found.
* Caller must hold no lock (since this time-consuming function needs
* to be preemptible), and must check afterwards if item is still there.
*/
unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item)
{
struct radix_tree_node *node;
unsigned long max_index;
unsigned long cur_index = 0;
struct locate_info info = {
.found_index = -1,
.stop = false,
};
do {
rcu_read_lock();
node = rcu_dereference_raw(root->rnode);
if (!radix_tree_is_internal_node(node)) {
rcu_read_unlock();
if (node == item)
info.found_index = 0;
break;
}
node = entry_to_node(node);
max_index = node_maxindex(node);
if (cur_index > max_index) {
rcu_read_unlock();
break;
}
cur_index = __locate(node, item, cur_index, &info);
rcu_read_unlock();
cond_resched();
} while (!info.stop && cur_index <= max_index);
return info.found_index;
}
#else
unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item)
{
return -1;
}
#endif /* CONFIG_SHMEM && CONFIG_SWAP */
/**
* __radix_tree_delete_node - try to free node after clearing a slot
* @root: radix tree root