[Yaffs] Linux 4.9 support

Hi,
We recently jumped one of our products up to Linux 4.9, and found some
minor incompatibilities with YAFFS (head). I've attached a patch to fix it,
it isn't super controversial I don't think, although I didn't spend much
time working out which kernel version the changes should really kick in at
- I just assumed it was all for 4.9. Probably some of the changes should
kick in for earlier versions.

Regards,
Andre
diff --git a/yaffs_vfs_multi.c b/yaffs_vfs_multi.c
index d70d406..acb0c4a 100644
--- a/yaffs_vfs_multi.c
+++ b/yaffs_vfs_multi.c
@@ -241,6 +241,10 @@ MODULE_PARM(yaffs_gc_control, "i");
#define YAFFS_USE_DIR_ITERATE
#endif

+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0))
+#define YAFFS_USE_XATTR
+#endif
+
 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,12,0))
 #define YAFFS_NEW_PROCFS
 #include <linux/seq_file.h>
@@ -263,6 +267,13 @@ MODULE_PARM(yaffs_gc_control, "i");
             (dir)->i_ctime = (dir)->i_mtime = CURRENT_TIME; \
         } while (0)

+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 9, 0))
+static inline int setattr_prepare(struct dentry *dentry, struct iattr *attr)
+{
+    return inode_change_ok(dentry->d_inode, attr);
+}
+#endif
+
 static void yaffs_fill_inode_from_obj(struct inode *inode,
                       struct yaffs_obj *obj);

@@ -895,7 +906,7 @@ static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
#endif

     if (error == 0)
-        error = inode_change_ok(inode, attr);
+        error = setattr_prepare(dentry, attr);
     if (error == 0) {
         int result;
         if (!error) {
@@ -929,6 +940,7 @@ static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
     return error;
 }

+#ifdef YAFFS_USE_XATTR
 #if (YAFFS_NEW_XATTR > 0)
 static int yaffs_setxattr(struct dentry *dentry, struct inode *inode,
         const char *name, const void *value, size_t size, int flags)
@@ -1019,6 +1031,7 @@ static int yaffs_removexattr(struct dentry *dentry, const char *name)

     return error;
 }
+#endif

static ssize_t yaffs_listxattr(struct dentry * dentry, char *buff, size_t size)
{
@@ -1046,10 +1059,12 @@ static ssize_t yaffs_listxattr(struct dentry * dentry, char *buff, size_t size)

 static const struct inode_operations yaffs_file_inode_operations = {
     .setattr = yaffs_setattr,
+#ifdef YAFFS_USE_XATTR
     .setxattr = yaffs_setxattr,
     .getxattr = yaffs_getxattr,
-    .listxattr = yaffs_listxattr,
     .removexattr = yaffs_removexattr,
+#endif
+    .listxattr = yaffs_listxattr,
 };

@@ -1173,10 +1188,12 @@ static const struct inode_operations yaffs_symlink_inode_operations = {
     .put_link = yaffs_put_link,
 #endif
     .setattr = yaffs_setattr,
+#ifdef YAFFS_USE_XATTR
     .setxattr = yaffs_setxattr,
     .getxattr = yaffs_getxattr,
-    .listxattr = yaffs_listxattr,
     .removexattr = yaffs_removexattr,
+#endif
+    .listxattr = yaffs_listxattr,
 };

 #ifdef YAFFS_USE_OWN_IGET
@@ -1558,8 +1575,13 @@ static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
  *
  * NB: POSIX says you can rename an object over an old object of the same name
  */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0))
+static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
+            struct inode *new_dir, struct dentry *new_dentry, unsigned int unused)
+#else
 static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
             struct inode *new_dir, struct dentry *new_dentry)
+#endif
 {
     struct yaffs_dev *dev;
     int ret_val = YAFFS_FAIL;
@@ -1647,10 +1669,12 @@ static const struct inode_operations yaffs_dir_inode_operations = {
     .mknod = yaffs_mknod,
     .rename = yaffs_rename,
     .setattr = yaffs_setattr,
+    .listxattr = yaffs_listxattr,
+#ifdef YAFFS_USE_XATTR
     .setxattr = yaffs_setxattr,
     .getxattr = yaffs_getxattr,
-    .listxattr = yaffs_listxattr,
     .removexattr = yaffs_removexattr,
+#endif
 };

/*-----------------------------------------------------------------*/