libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops

In preparation to get case-insensitive dentry operations from sb->s_d_op
again, use the same structure with and without fscrypt.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-6-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>

Author: krisman

fs/libfs.c

@@ -1772,19 +1772,14 @@ static int generic_ci_d_hash(const struct dentry *dentry, struct qstr *str)
 static const struct dentry_operations generic_ci_dentry_ops = {
 	.d_hash = generic_ci_d_hash,
 	.d_compare = generic_ci_d_compare,
-};
-#endif
-
 #ifdef CONFIG_FS_ENCRYPTION
-static const struct dentry_operations generic_encrypted_dentry_ops = {
 	.d_revalidate = fscrypt_d_revalidate,
+#endif
 };
 #endif
 
-#if defined(CONFIG_FS_ENCRYPTION) && IS_ENABLED(CONFIG_UNICODE)
-static const struct dentry_operations generic_encrypted_ci_dentry_ops = {
-	.d_hash = generic_ci_d_hash,
-	.d_compare = generic_ci_d_compare,
+#ifdef CONFIG_FS_ENCRYPTION
+static const struct dentry_operations generic_encrypted_dentry_ops = {
 	.d_revalidate = fscrypt_d_revalidate,
 };
 #endif
@@ -1805,38 +1800,21 @@ static const struct dentry_operations generic_encrypted_ci_dentry_ops = {
  * Encryption works differently in that the only dentry operation it needs is
  * d_revalidate, which it only needs on dentries that have the no-key name flag.
  * The no-key flag can't be set "later", so we don't have to worry about that.
- *
- * Finally, to maximize compatibility with overlayfs (which isn't compatible
- * with certain dentry operations) and to avoid taking an unnecessary
- * performance hit, we use custom dentry_operations for each possible
- * combination rather than always installing all operations.
  */
 void generic_set_encrypted_ci_d_ops(struct dentry *dentry)
 {
-#ifdef CONFIG_FS_ENCRYPTION
-	bool needs_encrypt_ops = dentry->d_flags & DCACHE_NOKEY_NAME;
-#endif
 #if IS_ENABLED(CONFIG_UNICODE)
-	bool needs_ci_ops = dentry->d_sb->s_encoding;
-#endif
-#if defined(CONFIG_FS_ENCRYPTION) && IS_ENABLED(CONFIG_UNICODE)
-	if (needs_encrypt_ops && needs_ci_ops) {
-		d_set_d_op(dentry, &generic_encrypted_ci_dentry_ops);
+	if (dentry->d_sb->s_encoding) {
+		d_set_d_op(dentry, &generic_ci_dentry_ops);
 		return;
 	}
 #endif
 #ifdef CONFIG_FS_ENCRYPTION
-	if (needs_encrypt_ops) {
+	if (dentry->d_flags & DCACHE_NOKEY_NAME) {
 		d_set_d_op(dentry, &generic_encrypted_dentry_ops);
 		return;
 	}
 #endif
-#if IS_ENABLED(CONFIG_UNICODE)
-	if (needs_ci_ops) {
-		d_set_d_op(dentry, &generic_ci_dentry_ops);
-		return;
-	}
-#endif
 }
 EXPORT_SYMBOL(generic_set_encrypted_ci_d_ops);