mm: Make default vm_ops provide ->page_mkwrite handler

Make default vm_ops provide ->page_mkwrite handler. Currently it only updates
file's modification times and gets locked page but later it will also handle
filesystem freezing.

BugLink: https://bugs.launchpad.net/bugs/897421
Tested-by: Kamal Mostafa <kamal@canonical.com>
Tested-by: Peter M. Petrakis <peter.petrakis@canonical.com>
Tested-by: Dann Frazier <dann.frazier@canonical.com>
Tested-by: Massimo Morana <massimo.morana@canonical.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index b36d08ce5c57..15987d8e1d59 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1411,6 +1411,7 @@ extern void truncate_inode_pages_range(struct address_space *,
 
 /* generic vm_area_ops exported for stackable file systems */
 extern int filemap_fault(struct vm_area_struct *, struct vm_fault *);
+extern int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
 
 /* mm/page-writeback.c */
 int write_one_page(struct page *page, int wait);