[patch 084/119] shmem: unexport shmem_add_seals()/shmem_get_seals()

[patch 084/119] shmem: unexport shmem_add_seals()/shmem_get_seals()

[akpm]

From: Marc-André Lureau <marcandre.lureau@redhat.com>
Subject: 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>
---

 include/linux/shmem_fs.h |    2 --
 mm/shmem.c               |    6 ++----
 2 files changed, 2 insertions(+), 6 deletions(-)

diff -puN include/linux/shmem_fs.h~shmem-unexport-shmem_add_seals-shmem_get_seals include/linux/shmem_fs.h
--- a/include/linux/shmem_fs.h~shmem-unexport-shmem_add_seals-shmem_get_seals
+++ a/include/linux/shmem_fs.h
@@ -112,8 +112,6 @@ extern void shmem_uncharge(struct inode
 
 #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 -puN mm/shmem.c~shmem-unexport-shmem_add_seals-shmem_get_seals mm/shmem.c
--- a/mm/shmem.c~shmem-unexport-shmem_add_seals-shmem_get_seals
+++ a/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)
 {
_