[PATCH] fscrypt: shrink the size of struct fscrypt_inode_info slightly

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

Shrink the size of struct fscrypt_inode_info by 8 bytes by packing the
small fields into the 64 bits after ci_enc_key.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/crypto/fscrypt_private.h | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index 1892356cf924a..8371e4e1f596a 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -215,40 +215,46 @@ struct fscrypt_prepared_key {
  * When an encrypted file's key is made available, an instance of this struct is
  * allocated and stored in ->i_crypt_info.  Once created, it remains until the
  * inode is evicted.
  */
 struct fscrypt_inode_info {
 
 	/* The key in a form prepared for actual encryption/decryption */
 	struct fscrypt_prepared_key ci_enc_key;
 
 	/* True if ci_enc_key should be freed when this struct is freed */
-	bool ci_owns_key;
+	u8 ci_owns_key : 1;
 
 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
 	/*
 	 * True if this inode will use inline encryption (blk-crypto) instead of
 	 * the traditional filesystem-layer encryption.
 	 */
-	bool ci_inlinecrypt;
+	u8 ci_inlinecrypt : 1;
 #endif
 
+	/* True if ci_dirhash_key is initialized */
+	u8 ci_dirhash_key_initialized : 1;
+
 	/*
 	 * log2 of the data unit size (granularity of contents encryption) of
 	 * this file.  This is computable from ci_policy and ci_inode but is
 	 * cached here for efficiency.  Only used for regular files.
 	 */
 	u8 ci_data_unit_bits;
 
 	/* Cached value: log2 of number of data units per FS block */
 	u8 ci_data_units_per_block_bits;
 
+	/* Hashed inode number.  Only set for IV_INO_LBLK_32 */
+	u32 ci_hashed_ino;
+
 	/*
 	 * Encryption mode used for this inode.  It corresponds to either the
 	 * contents or filenames encryption mode, depending on the inode type.
 	 */
 	struct fscrypt_mode *ci_mode;
 
 	/* Back-pointer to the inode */
 	struct inode *ci_inode;
 
 	/*
@@ -269,30 +275,26 @@ struct fscrypt_inode_info {
 	 * and ci_enc_key will equal ci_direct_key->dk_key.
 	 */
 	struct fscrypt_direct_key *ci_direct_key;
 
 	/*
 	 * This inode's hash key for filenames.  This is a 128-bit SipHash-2-4
 	 * key.  This is only set for directories that use a keyed dirhash over
 	 * the plaintext filenames -- currently just casefolded directories.
 	 */
 	siphash_key_t ci_dirhash_key;
-	bool ci_dirhash_key_initialized;
 
 	/* The encryption policy used by this inode */
 	union fscrypt_policy ci_policy;
 
 	/* This inode's nonce, copied from the fscrypt_context */
 	u8 ci_nonce[FSCRYPT_FILE_NONCE_SIZE];
-
-	/* Hashed inode number.  Only set for IV_INO_LBLK_32 */
-	u32 ci_hashed_ino;
 };
 
 typedef enum {
 	FS_DECRYPT = 0,
 	FS_ENCRYPT,
 } fscrypt_direction_t;
 
 /* crypto.c */
 extern struct kmem_cache *fscrypt_inode_info_cachep;
 int fscrypt_initialize(struct super_block *sb);

base-commit: 2f944c66ae73eed4250607ccd3acdf2531afc194
-- 
2.43.2