shmem: unexport shmem_add_seals()/shmem_get_seals()

Patch series "memfd: add sealing to hugetlb-backed memory", v3.

Recently, Mike Kravetz added hugetlbfs support to memfd.  However, he
didn't add sealing support.  One of the reasons to use memfd is to have
shared memory sealing when doing IPC or sharing memory with another
process with some extra safety.  qemu uses shared memory & hugetables
with vhost-user (used by dpdk), so it is reasonable to use memfd now
instead for convenience and security reasons.

This patch (of 9):

The functions are called through shmem_fcntl() only.  And no danger in
removing the EXPORTs as the routines only work with shmem file structs.

Link: http://lkml.kernel.org/r/20171107122800.25517-2-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>

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 06b295bec00dd8bd3310290d147c97a3166bc706..e464815a7e4c28a77193f4ad7721ddc5c6dc102d 100644 (file)
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -112,8 +112,6 @@ extern void shmem_uncharge(struct inode *inode, long pages);
 
 #ifdef CONFIG_TMPFS
 
-extern int shmem_add_seals(struct file *file, unsigned int seals);
-extern int shmem_get_seals(struct file *file);
 extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg);
 
 #else

diff --git a/mm/shmem.c b/mm/shmem.c
index 7fbe67be86fa816b13d06603c098ccf10cca4fe2..975efd81621fe7fb62780fbfb21b4963ae3778d3 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2722,7 +2722,7 @@ continue_resched:
                     F_SEAL_GROW | \
                     F_SEAL_WRITE)
 
-int shmem_add_seals(struct file *file, unsigned int seals)
+static int shmem_add_seals(struct file *file, unsigned int seals)
 {
        struct inode *inode = file_inode(file);
        struct shmem_inode_info *info = SHMEM_I(inode);
@@ -2791,16 +2791,14 @@ unlock:
        inode_unlock(inode);
        return error;
 }
-EXPORT_SYMBOL_GPL(shmem_add_seals);
 
-int shmem_get_seals(struct file *file)
+static int shmem_get_seals(struct file *file)
 {
        if (file->f_op != &shmem_file_operations)
                return -EINVAL;
 
        return SHMEM_I(file_inode(file))->seals;
 }
-EXPORT_SYMBOL_GPL(shmem_get_seals);
 
 long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
 {