ext4 crypto: get rid of ci_mode from struct ext4_crypt_info

The ci_mode field was superfluous, and getting rid of it gets rid of
an unused hole in the structure.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/crypto.c

@@ -137,14 +137,13 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
 
 	/* Allocate a new Crypto API context if we don't already have
 	 * one or if it isn't the right mode. */
-	BUG_ON(ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID);
-	if (ctx->tfm && (ctx->mode != ci->ci_mode)) {
+	if (ctx->tfm && (ctx->mode != ci->ci_data_mode)) {
 		crypto_free_tfm(ctx->tfm);
 		ctx->tfm = NULL;
 		ctx->mode = EXT4_ENCRYPTION_MODE_INVALID;
 	}
 	if (!ctx->tfm) {
-		switch (ci->ci_mode) {
+		switch (ci->ci_data_mode) {
 		case EXT4_ENCRYPTION_MODE_AES_256_XTS:
 			ctx->tfm = crypto_ablkcipher_tfm(
 				crypto_alloc_ablkcipher("xts(aes)", 0, 0));
@@ -162,9 +161,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
 			ctx->tfm = NULL;
 			goto out;
 		}
-		ctx->mode = ci->ci_mode;
+		ctx->mode = ci->ci_data_mode;
 	}
-	BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_mode));
+	BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_data_mode));
 
 	/* There shouldn't be a bounce page attached to the crypto
 	 * context at this point. */
@@ -321,7 +320,7 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
 	int res = 0;
 
 	BUG_ON(!ctx->tfm);
-	BUG_ON(ctx->mode != ei->i_crypt_info->ci_mode);
+	BUG_ON(ctx->mode != ei->i_crypt_info->ci_data_mode);
 
 	if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) {
 		printk_ratelimited(KERN_ERR

fs/ext4/crypto_fname.c

@@ -272,9 +272,9 @@ int ext4_setup_fname_crypto(struct inode *inode)
 	if (!ci || ci->ci_ctfm)
 		return 0;
 
-	if (ci->ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
+	if (ci->ci_filename_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
 		printk_once(KERN_WARNING "ext4: unsupported key mode %d\n",
-			    ci->ci_mode);
+			    ci->ci_filename_mode);
 		return -ENOKEY;
 	}
 

fs/ext4/crypto_key.c

@@ -152,14 +152,13 @@ int _ext4_get_encryption_info(struct inode *inode)
 	memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
 	       sizeof(crypt_info->ci_master_key));
 	if (S_ISREG(inode->i_mode))
-		crypt_info->ci_mode = ctx.contents_encryption_mode;
+		crypt_info->ci_size =
+			ext4_encryption_key_size(crypt_info->ci_data_mode);
 	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		crypt_info->ci_mode = ctx.filenames_encryption_mode;
-	else {
-		printk(KERN_ERR "ext4 crypto: Unsupported inode type.\n");
+		crypt_info->ci_size =
+			ext4_encryption_key_size(crypt_info->ci_filename_mode);
+	else
 		BUG();
-	}
-	crypt_info->ci_size = ext4_encryption_key_size(crypt_info->ci_mode);
 	BUG_ON(!crypt_info->ci_size);
 	if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
 		memset(crypt_info->ci_raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE);

fs/ext4/ext4_crypto.h

@@ -74,7 +74,6 @@ struct ext4_encryption_key {
 } __attribute__((__packed__));
 
 struct ext4_crypt_info {
-	unsigned char	ci_mode;
 	unsigned char	ci_size;
 	char		ci_data_mode;
 	char		ci_filename_mode;