f2fs: fix a deadlock during init_acl procedure

The deadlock is found through the following scenario.

sys_mkdir()
 -> f2fs_add_link()
  -> __f2fs_add_link()
   -> init_inode_metadata()
     : lock_page(inode);
    -> f2fs_init_acl()
     -> f2fs_set_acl()
      -> f2fs_setxattr(..., NULL)
       : This NULL page incurs a deadlock at update_inode_page().

So, likewise f2fs_init_security(), this patch adds a parameter to transfer the
locked inode page to f2fs_setxattr().

Found by Linux File System Verification project (linuxtesting.org).

Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/acl.h b/fs/f2fs/acl.h
index 3839048..4963313 100644
--- a/fs/f2fs/acl.h
+++ b/fs/f2fs/acl.h
@@ -38,7 +38,7 @@
 
 extern struct posix_acl *f2fs_get_acl(struct inode *, int);
 extern int f2fs_acl_chmod(struct inode *);
-extern int f2fs_init_acl(struct inode *, struct inode *);
+extern int f2fs_init_acl(struct inode *, struct inode *, struct page *);
 #else
 #define f2fs_check_acl	NULL
 #define f2fs_get_acl	NULL
@@ -49,7 +49,8 @@
 	return 0;
 }
 
-static inline int f2fs_init_acl(struct inode *inode, struct inode *dir)
+static inline int f2fs_init_acl(struct inode *inode, struct inode *dir,
+							struct page *page)
 {
 	return 0;
 }