XArray marks are like the radix tree tags, only slightly more strongly
typed. They are renamed in order to distinguish them from tagged
pointers. This commit adds the basic get/set/clear operations.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
The xa_load function brings with it a lot of infrastructure; xa_empty(),
xa_is_err(), and large chunks of the XArray advanced API that are used
to implement xa_load.
As the test-suite demonstrates, it is possible to use the XArray functions
on a radix tree. The radix tree functions depend on the GFP flags being
stored in the root of the tree, so it's not possible to use the radix
tree functions on an XArray.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
This is a direct replacement for struct radix_tree_root. Some of the
struct members have changed name; convert those, and use a #define so
that radix_tree users continue to work without change.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Matthew Wilcox