Add myself as XArray and IDR maintainer.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
 S:     Maintained
 F:     arch/x86/entry/vdso/
 
+XARRAY
+M:     Matthew Wilcox <willy@infradead.org>
+L:     linux-fsdevel@vger.kernel.org
+S:     Supported
+F:     Documentation/core-api/xarray.rst
+F:     lib/idr.c
+F:     lib/xarray.c
+F:     include/linux/idr.h
+F:     include/linux/xarray.h
+F:     tools/testing/radix-tree
+
 XC2028/3028 TUNER DRIVER
 M:     Mauro Carvalho Chehab <mchehab@kernel.org>
 L:     linux-media@vger.kernel.org