[djwong-xfs:report-refcounts 363/363] ./usr/include/linux/fsrefcounts.h:68:19: error: unknown type name 'size_t'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git report-refcounts
head:   6784319c4da4ff33090c0679fec1f93fe3822852
commit: 6784319c4da4ff33090c0679fec1f93fe3822852 [363/363] xfs: export reference count information to userspace
config: x86_64-randconfig-a006-20210826 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/commit/?id=6784319c4da4ff33090c0679fec1f93fe3822852
        git remote add djwong-xfs https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git
        git fetch --no-tags djwong-xfs report-refcounts
        git checkout 6784319c4da4ff33090c0679fec1f93fe3822852
        # save the attached .config to linux build tree
        mkdir build_dir
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

   In file included from <command-line>:32:
>> ./usr/include/linux/fsrefcounts.h:68:19: error: unknown type name 'size_t'
      68 | static __inline__ size_t
         |                   ^~~~~~

---
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