With the addition of memfd hugetlbfs support, we now have the situation where memfd depends on TMPFS -or- HUGETLBFS. Previously, memfd was only supported on tmpfs, so it made sense that the code resides in shmem.c.
This patch series moves the memfd code to separate files (memfd.c and memfd.h). It creates a new config option MEMFD_CREATE that is defined if either TMPFS or HUGETLBFS is defined. In the current code, memfd is only functional if TMPFS is defined. If HUGETLFS is defined and TMPFS is not defined, then memfd functionality will not be available for hugetlbfs. This does not cause BUGs, just a potential lack of desired functionality. Another way to approach this issue would be to simply make HUGETLBFS depend on TMPFS. This patch series is built on top of the Marc-André Lureau v3 series "memfd: add sealing to hugetlb-backed memory": http://lkml.kernel.org/r/20171107122800.25517-1-marcandre.lur...@redhat.com Mike Kravetz (3): mm: hugetlbfs: move HUGETLBFS_I outside #ifdef CONFIG_HUGETLBFS mm: memfd: split out memfd for use by multiple filesystems mm: memfd: remove memfd code from shmem files and use new memfd files fs/Kconfig | 3 + fs/fcntl.c | 2 +- include/linux/hugetlb.h | 27 ++-- include/linux/memfd.h | 16 +++ include/linux/shmem_fs.h | 13 -- mm/Makefile | 1 + mm/memfd.c | 341 +++++++++++++++++++++++++++++++++++++++++++++++ mm/shmem.c | 323 -------------------------------------------- 8 files changed, 378 insertions(+), 348 deletions(-) create mode 100644 include/linux/memfd.h create mode 100644 mm/memfd.c -- 2.13.6
