xarray: Add XArray load operation

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 commit is contained in:
Matthew Wilcox 2017-11-07 14:57:46 -05:00
parent 992a8e60e3
commit ad3d6c7263
14 changed files with 661 additions and 45 deletions

View file

@ -70,6 +70,7 @@
#define BUG_ON(cond) assert(!(cond))
#endif
#endif
#define BUG() BUG_ON(1)
#if __BYTE_ORDER == __BIG_ENDIAN
#define cpu_to_le16 bswap_16