isofs: don't bother with ->d_op for normal case

we only need it for joliet and case-insensitive mounts
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/isofs/inode.c

@@ -29,13 +29,9 @@
 #define BEQUIET
 
 static int isofs_hashi(const struct dentry *parent, struct qstr *qstr);
-static int isofs_hash(const struct dentry *parent, struct qstr *qstr);
 static int isofs_dentry_cmpi(const struct dentry *parent,
 		const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name);
-static int isofs_dentry_cmp(const struct dentry *parent,
-		const struct dentry *dentry,
-		unsigned int len, const char *str, const struct qstr *name);
 
 #ifdef CONFIG_JOLIET
 static int isofs_hashi_ms(const struct dentry *parent, struct qstr *qstr);
@@ -134,10 +130,6 @@ static const struct super_operations isofs_sops = {
 
 
 static const struct dentry_operations isofs_dentry_ops[] = {
-	{
-		.d_hash		= isofs_hash,
-		.d_compare	= isofs_dentry_cmp,
-	},
 	{
 		.d_hash		= isofs_hashi,
 		.d_compare	= isofs_dentry_cmpi,
@@ -257,25 +249,12 @@ static int isofs_dentry_cmp_common(
 	return 1;
 }
 
-static int
-isofs_hash(const struct dentry *dentry, struct qstr *qstr)
-{
-	return isofs_hash_common(qstr, 0);
-}
-
 static int
 isofs_hashi(const struct dentry *dentry, struct qstr *qstr)
 {
 	return isofs_hashi_common(qstr, 0);
 }
 
-static int
-isofs_dentry_cmp(const struct dentry *parent, const struct dentry *dentry,
-		unsigned int len, const char *str, const struct qstr *name)
-{
-	return isofs_dentry_cmp_common(len, str, name, 0, 0);
-}
-
 static int
 isofs_dentry_cmpi(const struct dentry *parent, const struct dentry *dentry,
 		unsigned int len, const char *str, const struct qstr *name)
@@ -930,7 +909,8 @@ static int isofs_fill_super(struct super_block *s, void *data, int silent)
 	if (opt.check == 'r')
 		table++;
 
-	s->s_d_op = &isofs_dentry_ops[table];
+	if (table)
+		s->s_d_op = &isofs_dentry_ops[table - 1];
 
 	/* get the root dentry */
 	s->s_root = d_make_root(inode);

fs/isofs/namei.c

@@ -20,6 +20,8 @@ isofs_cmp(struct dentry *dentry, const char *compare, int dlen)
 	struct qstr qstr;
 	qstr.name = compare;
 	qstr.len = dlen;
+	if (likely(!dentry->d_op))
+		return dentry->d_name.len != dlen || memcmp(dentry->d_name.name, compare, dlen);
 	return dentry->d_op->d_compare(NULL, NULL, dentry->d_name.len, dentry->d_name.name, &qstr);
 }