Commit 69b6c131 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

mm: Convert truncate to XArray 



This is essentially xa_cmpxchg() with the locking handled above us,
and it doesn't have to handle replacing a NULL entry.

Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
parent a97e7904

mm/truncate.c

+6 −9
Original line number Diff line number Diff line
@@ -33,15 +33,12 @@ 
static inline void __clear_shadow_entry(struct address_space *mapping,

				pgoff_t index, void *entry)

{

	struct radix_tree_node *node;

	void **slot;

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



	if (!__radix_tree_lookup(&mapping->i_pages, index, &node, &slot))

	xas_set_update(&xas, workingset_update_node);

	if (xas_load(&xas) != entry)

		return;

	if (*slot != entry)

		return;

	__radix_tree_replace(&mapping->i_pages, node, slot, NULL,

			     workingset_update_node);

	xas_store(&xas, NULL);

	mapping->nrexceptional--;

}
@@ -738,10 +735,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping, 
		index++;

	}

	/*

	 * For DAX we invalidate page tables after invalidating radix tree.  We

	 * For DAX we invalidate page tables after invalidating page cache.  We

	 * could invalidate page tables while invalidating each entry however

	 * that would be expensive. And doing range unmapping before doesn't

	 * work as we have no cheap way to find whether radix tree entry didn't

	 * work as we have no cheap way to find whether page cache entry didn't

	 * get remapped later.

	 */

	if (dax_mapping(mapping)) {