diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 3fd27e14ebdd6..371e8f01d1c8e 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -402,6 +402,28 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
 }
 EXPORT_SYMBOL(fscrypt_setup_filename);
 
+/**
+ * fscrypt_fname_siphash() - Calculate the siphash for a file name
+ * @dir: the parent directory
+ * @name: the name of the file to get the siphash of
+ *
+ * Given a user-provided filename @name, this function calculates the siphash of
+ * that name using the directory's hash key.
+ *
+ * This assumes the directory uses a v2 policy, and the key is available.
+ *
+ * Return: the siphash of @name using the hash key of @dir
+ */
+u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name)
+{
+	struct fscrypt_info *ci = dir->i_crypt_info;
+
+	WARN_ON(!ci->ci_hash_key_initialized);
+
+	return siphash(name->name, name->len, &ci->ci_hash_key);
+}
+EXPORT_SYMBOL(fscrypt_fname_siphash);
+
 /*
  * Validate dentries in encrypted directories to make sure we aren't potentially
  * caching stale dentries after a key has been added.
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index b22e8decebedd..8b37a5eebb574 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -12,6 +12,7 @@
 #define _FSCRYPT_PRIVATE_H
 
 #include <linux/fscrypt.h>
+#include <linux/siphash.h>
 #include <crypto/hash.h>
 
 #define CONST_STRLEN(str)	(sizeof(str) - 1)
@@ -188,6 +189,13 @@ struct fscrypt_info {
 	 */
 	struct fscrypt_direct_key *ci_direct_key;
 
+	/*
+	 * With v2 policies, this can be used with siphash
+	 * When the key has been set, ci_hash_key_initialized is set to true
+	 */
+	siphash_key_t ci_hash_key;
+	bool ci_hash_key_initialized;
+
 	/* The encryption policy used by this inode */
 	union fscrypt_policy ci_policy;
 
@@ -262,6 +270,7 @@ extern int fscrypt_init_hkdf(struct fscrypt_hkdf *hkdf, const u8 *master_key,
 #define HKDF_CONTEXT_PER_FILE_KEY	2
 #define HKDF_CONTEXT_DIRECT_KEY		3
 #define HKDF_CONTEXT_IV_INO_LBLK_64_KEY	4
+#define HKDF_CONTEXT_FNAME_HASH_KEY     5
 
 extern int fscrypt_hkdf_expand(const struct fscrypt_hkdf *hkdf, u8 context,
 			       const u8 *info, unsigned int infolen,
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 96074054bdbc8..7445ab76e0b32 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -189,7 +189,7 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
 		 * This ensures that the master key is consistently used only
 		 * for HKDF, avoiding key reuse issues.
 		 */
-		return setup_per_mode_key(ci, mk, mk->mk_direct_tfms,
+		err = setup_per_mode_key(ci, mk, mk->mk_direct_tfms,
 					  HKDF_CONTEXT_DIRECT_KEY, false);
 	} else if (ci->ci_policy.v2.flags &
 		   FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) {
@@ -199,21 +199,36 @@ static int fscrypt_setup_v2_file_key(struct fscrypt_info *ci,
 		 * the IVs.  This format is optimized for use with inline
 		 * encryption hardware compliant with the UFS or eMMC standards.
 		 */
-		return setup_per_mode_key(ci, mk, mk->mk_iv_ino_lblk_64_tfms,
+		err = setup_per_mode_key(ci, mk, mk->mk_iv_ino_lblk_64_tfms,
 					  HKDF_CONTEXT_IV_INO_LBLK_64_KEY,
 					  true);
+	} else {
+		err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
+					  HKDF_CONTEXT_PER_FILE_KEY,
+					  ci->ci_nonce,
+					  FS_KEY_DERIVATION_NONCE_SIZE,
+					  derived_key, ci->ci_mode->keysize);
+		if (err)
+			return err;
+
+		err = fscrypt_set_derived_key(ci, derived_key);
+		memzero_explicit(derived_key, ci->ci_mode->keysize);
 	}
-
-	err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
-				  HKDF_CONTEXT_PER_FILE_KEY,
-				  ci->ci_nonce, FS_KEY_DERIVATION_NONCE_SIZE,
-				  derived_key, ci->ci_mode->keysize);
 	if (err)
 		return err;
 
-	err = fscrypt_set_derived_key(ci, derived_key);
-	memzero_explicit(derived_key, ci->ci_mode->keysize);
-	return err;
+	if (S_ISDIR(ci->ci_inode->i_mode)) {
+		err = fscrypt_hkdf_expand(&mk->mk_secret.hkdf,
+					  HKDF_CONTEXT_FNAME_HASH_KEY,
+					  ci->ci_nonce,
+					  FS_KEY_DERIVATION_NONCE_SIZE,
+					  (u8 *)&ci->ci_hash_key,
+					  sizeof(ci->ci_hash_key));
+		if (err)
+			return err;
+		ci->ci_hash_key_initialized = true;
+	}
+	return 0;
 }
 
 /*
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 6fe8d0f96a4ac..1dfbed855beeb 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -172,6 +172,8 @@ extern int fscrypt_fname_disk_to_usr(const struct inode *inode,
 				     u32 hash, u32 minor_hash,
 				     const struct fscrypt_str *iname,
 				     struct fscrypt_str *oname);
+extern u64 fscrypt_fname_siphash(const struct inode *dir,
+				 const struct qstr *name);
 
 #define FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE	32
 
@@ -468,6 +470,13 @@ static inline int fscrypt_fname_disk_to_usr(const struct inode *inode,
 	return -EOPNOTSUPP;
 }
 
+static inline u64 fscrypt_fname_siphash(const struct inode *dir,
+					const struct qstr *name)
+{
+	WARN_ON_ONCE(1);
+	return 0;
+}
+
 static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
 				      const u8 *de_name, u32 de_name_len)
 {
