hugetlb: implement memfd sealing

Implements memfd sealing, similar to shmem:
 - WRITE: deny fallocate(PUNCH_HOLE). mmap() write is denied in
   memfd_add_seals(). write() doesn't exist for hugetlbfs.
 - SHRINK: added similar check as shmem_setattr()
 - GROW: added similar check as shmem_setattr() & shmem_fallocate()

Except write() operation that doesn't exist with hugetlbfs, that should
make sealing as close as it can be to shmem support.

Link: http://lkml.kernel.org/r/20171107122800.25517-5-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Marc-André Lureau
2018-01-31 16:19:25 -08:00
committed by Linus Torvalds
parent da14c1e524
commit ff62a34210
2 changed files with 28 additions and 2 deletions

View File

@@ -273,6 +273,7 @@ static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb)
struct hugetlbfs_inode_info {
struct shared_policy policy;
struct inode vfs_inode;
unsigned int seals;
};
static inline struct hugetlbfs_inode_info *HUGETLBFS_I(struct inode *inode)