Commit 62f945b6 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

shmem: Convert shmem_radix_tree_replace to XArray 



Rename shmem_radix_tree_replace() to shmem_replace_entry() and
convert it to use the XArray API.

Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
parent 10bbd235

mm/shmem.c

+8 −14
Original line number Diff line number Diff line
@@ -322,24 +322,20 @@ void shmem_uncharge(struct inode *inode, long pages) 
}



/*

 * Replace item expected in radix tree by a new item, while holding tree lock.

 * Replace item expected in xarray by a new item, while holding xa_lock.

 */

static int shmem_radix_tree_replace(struct address_space *mapping,

static int shmem_replace_entry(struct address_space *mapping,

			pgoff_t index, void *expected, void *replacement)

{

	struct radix_tree_node *node;

	void __rcu **pslot;

	XA_STATE(xas, &mapping->i_pages, index);

	void *item;



	VM_BUG_ON(!expected);

	VM_BUG_ON(!replacement);

	item = __radix_tree_lookup(&mapping->i_pages, index, &node, &pslot);

	if (!item)

		return -ENOENT;

	item = xas_load(&xas);

	if (item != expected)

		return -ENOENT;

	__radix_tree_replace(&mapping->i_pages, node, pslot,

			     replacement, NULL);

	xas_store(&xas, replacement);

	return 0;

}
@@ -624,8 +620,7 @@ static int shmem_add_to_page_cache(struct page *page, 
	} else if (!expected) {

		error = radix_tree_insert(&mapping->i_pages, index, page);

	} else {

		error = shmem_radix_tree_replace(mapping, index, expected,

								 page);

		error = shmem_replace_entry(mapping, index, expected, page);

	}



	if (!error) {
@@ -654,7 +649,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) 
	VM_BUG_ON_PAGE(PageCompound(page), page);



	xa_lock_irq(&mapping->i_pages);

	error = shmem_radix_tree_replace(mapping, page->index, page, radswap);

	error = shmem_replace_entry(mapping, page->index, page, radswap);

	page->mapping = NULL;

	mapping->nrpages--;

	__dec_node_page_state(page, NR_FILE_PAGES);
@@ -1578,8 +1573,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp, 
	 * a nice clean interface for us to replace oldpage by newpage there.

	 */

	xa_lock_irq(&swap_mapping->i_pages);

	error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage,

								   newpage);

	error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);

	if (!error) {

		__inc_node_page_state(newpage, NR_FILE_PAGES);

		__dec_node_page_state(oldpage, NR_FILE_PAGES);