[PATCH] fscrypt: Remove FSCRYPT_MODE_MAX

[PATCH] fscrypt: Remove FSCRYPT_MODE_MAX

[Eric Biggers]

Now that the arrays of per-mode keys in struct fscrypt_master_key have
been replaced by a linked list, the definition of FSCRYPT_MODE_MAX
doesn't do anything useful.  (Previously it was used to size these
arrays.)  Remove it.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 fs/crypto/fscrypt_private.h        | 3 ---
 fs/crypto/keysetup.c               | 5 -----
 include/uapi/linux/fscrypt.h       | 1 -
 tools/include/uapi/linux/fscrypt.h | 1 -
 4 files changed, 10 deletions(-)

diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 0053b5c45412..45307f7fa540 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -64,13 +64,10 @@
 	 CRYPTO_ALG_KERN_DRIVER_ONLY)
 
 #define FSCRYPT_CONTEXT_V1	1
 #define FSCRYPT_CONTEXT_V2	2
 
-/* Keep this in sync with include/uapi/linux/fscrypt.h */
-#define FSCRYPT_MODE_MAX	FSCRYPT_MODE_AES_256_HCTR2
-
 struct fscrypt_context_v1 {
 	u8 version; /* FSCRYPT_CONTEXT_V1 */
 	u8 contents_encryption_mode;
 	u8 filenames_encryption_mode;
 	u8 flags;
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index 281b5a8b0bcd..cfd348e2252e 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -81,12 +81,10 @@ static DEFINE_MUTEX(fscrypt_mode_key_setup_mutex);
 
 static struct fscrypt_mode *
 select_encryption_mode(const union fscrypt_policy *policy,
 		       const struct inode *inode)
 {
-	BUILD_BUG_ON(ARRAY_SIZE(fscrypt_modes) != FSCRYPT_MODE_MAX + 1);
-
 	if (S_ISREG(inode->i_mode))
 		return &fscrypt_modes[fscrypt_policy_contents_mode(policy)];
 
 	if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
 		return &fscrypt_modes[fscrypt_policy_fnames_mode(policy)];
@@ -227,13 +225,10 @@ static int setup_per_mode_enc_key(struct fscrypt_inode_info *ci,
 	u8 hkdf_info[sizeof(mode_num) + sizeof(sb->s_uuid)];
 	unsigned int hkdf_infolen = 0;
 	bool use_hw_wrapped_key = false;
 	int err;
 
-	if (WARN_ON_ONCE(mode_num > FSCRYPT_MODE_MAX))
-		return -EINVAL;
-
 	if (mk->mk_secret.is_hw_wrapped && S_ISREG(inode->i_mode)) {
 		/* Using a hardware-wrapped key for file contents encryption */
 		if (!fscrypt_using_inline_encryption(ci)) {
 			if (sb->s_flags & SB_INLINECRYPT)
 				fscrypt_warn(ci->ci_inode,
diff --git a/include/uapi/linux/fscrypt.h b/include/uapi/linux/fscrypt.h
index 3aff99f2696a..84507280b3ea 100644
--- a/include/uapi/linux/fscrypt.h
+++ b/include/uapi/linux/fscrypt.h
@@ -28,11 +28,10 @@
 #define FSCRYPT_MODE_AES_128_CTS		6
 #define FSCRYPT_MODE_SM4_XTS			7
 #define FSCRYPT_MODE_SM4_CTS			8
 #define FSCRYPT_MODE_ADIANTUM			9
 #define FSCRYPT_MODE_AES_256_HCTR2		10
-/* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */
 
 /*
  * Legacy policy version; ad-hoc KDF and no key verification.
  * For new encrypted directories, use fscrypt_policy_v2 instead.
  *
diff --git a/tools/include/uapi/linux/fscrypt.h b/tools/include/uapi/linux/fscrypt.h
index 3aff99f2696a..84507280b3ea 100644
--- a/tools/include/uapi/linux/fscrypt.h
+++ b/tools/include/uapi/linux/fscrypt.h
@@ -28,11 +28,10 @@
 #define FSCRYPT_MODE_AES_128_CTS		6
 #define FSCRYPT_MODE_SM4_XTS			7
 #define FSCRYPT_MODE_SM4_CTS			8
 #define FSCRYPT_MODE_ADIANTUM			9
 #define FSCRYPT_MODE_AES_256_HCTR2		10
-/* If adding a mode number > 10, update FSCRYPT_MODE_MAX in fscrypt_private.h */
 
 /*
  * Legacy policy version; ad-hoc KDF and no key verification.
  * For new encrypted directories, use fscrypt_policy_v2 instead.
  *

base-commit: 83f1454877cc292b88baf13c829c16ce6937d120
prerequisite-patch-id: 319d2891e88c7df1ebb5ebf434d18b68f770399f
prerequisite-patch-id: 5330c9e4b65644baae81bd177a46be6223d2b494
prerequisite-patch-id: f6157c86deab0ff5ec953ae3ed6b0e84f37741bf
-- 
2.54.0