switch 9p

here we actually *want* ->d_op for root; setting it allows to get rid
of kludge in v9fs_kill_super() since now we have proper ->d_release()
for root and don't need to call it manually.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/9p/v9fs_vfs.h

@@ -59,7 +59,6 @@ void v9fs_stat2inode_dotl(struct p9_stat_dotl *, struct inode *);
 int v9fs_dir_release(struct inode *inode, struct file *filp);
 int v9fs_file_open(struct inode *inode, struct file *file);
 void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
-void v9fs_dentry_release(struct dentry *);
 int v9fs_uflags2omode(int uflags, int extended);
 
 ssize_t v9fs_file_readn(struct file *, char *, char __user *, u32, u64);

fs/9p/vfs_dentry.c

@@ -86,7 +86,7 @@ static int v9fs_cached_dentry_delete(const struct dentry *dentry)
  *
  */
 
-void v9fs_dentry_release(struct dentry *dentry)
+static void v9fs_dentry_release(struct dentry *dentry)
 {
 	struct v9fs_dentry *dent;
 	struct p9_fid *temp, *current_fid;

fs/9p/vfs_inode.c

@@ -699,11 +699,6 @@ struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 		goto error_iput;
 
 inst_out:
-	if (v9ses->cache)
-		d_set_d_op(dentry, &v9fs_cached_dentry_operations);
-	else
-		d_set_d_op(dentry, &v9fs_dentry_operations);
-
 	d_add(dentry, inode);
 	return NULL;
 

fs/9p/vfs_super.c

@@ -141,6 +141,11 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
 	}
 	v9fs_fill_super(sb, v9ses, flags, data);
 
+	if (v9ses->cache)
+		sb->s_d_op = &v9fs_cached_dentry_operations;
+	else
+		sb->s_d_op = &v9fs_dentry_operations;
+
 	inode = v9fs_get_inode(sb, S_IFDIR | mode);
 	if (IS_ERR(inode)) {
 		retval = PTR_ERR(inode);
@@ -217,9 +222,6 @@ static void v9fs_kill_super(struct super_block *s)
 
 	P9_DPRINTK(P9_DEBUG_VFS, " %p\n", s);
 
-	if (s->s_root)
-		v9fs_dentry_release(s->s_root);	/* clunk root */
-
 	kill_anon_super(s);
 
 	v9fs_session_cancel(v9ses);