[PATCH 3/3] eCryptfs: Set inode key only once per crypto operation

Michael Halcrow
2007-11-02T18:55:52Z

There is no need to keep re-setting the same key for any given
eCryptfs inode. This patch optimizes the use of the crypto API and
helps performance a bit.

Signed-off-by: Trevor Highland <trevor.highland@gmail.com>
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
---
fs/ecryptfs/crypto.c | 7 +++++--
fs/ecryptfs/ecryptfs_kernel.h | 1 +
2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 4f14d4c..a0f53aa 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -337,8 +337,11 @@ static int encrypt_scatterlist(struct ecryptfs_crypt_stat *crypt_stat,
}
/* Consider doing this once, when the file is opened */
mutex_lock(&crypt_stat->cs_tfm_mutex);
- rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
- crypt_stat->key_size);
+ if (!(crypt_stat->flags & ECRYPTFS_KEY_SET)) {
+ rc = crypto_blkcipher_setkey(crypt_stat->tfm, crypt_stat->key,
+ crypt_stat->key_size);
+ crypt_stat->flags |= ECRYPTFS_KEY_SET;
+ }
if (rc) {
ecryptfs_printk(KERN_ERR, "Error setting key; rc = [%d]\n",
rc);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 78b7916..114cb86 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -234,6 +234,7 @@ struct ecryptfs_crypt_stat {
#define ECRYPTFS_KEY_VALID 0x00000080
#define ECRYPTFS_METADATA_IN_XATTR 0x00000100
#define ECRYPTFS_VIEW_AS_ENCRYPTED 0x00000200
+#define ECRYPTFS_KEY_SET 0x00000400
u32 flags;
unsigned int file_version;
size_t iv_bytes;
--
1.5.0.6