eCryptfs: comments for some structs
Andrew Morton wrote:
> > +struct ecryptfs_global_auth_tok {
> > +#define ECRYPTFS_AUTH_TOK_INVALID 0x00000001
> > + u32 flags;
> > + struct list_head mount_crypt_stat_list;
> > + struct key *global_auth_tok_key;
> > + struct ecryptfs_auth_tok *global_auth_tok;
> > + unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
> > +};
> > +
> > +struct ecryptfs_key_tfm {
> > + struct crypto_blkcipher *key_tfm;
> > + size_t key_size;
> > + struct mutex key_tfm_mutex;
> > + struct list_head key_tfm_list;
> > + unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
> > +};
>
> Please consider commenting your struct fields carefully: it's a
> great way to help other to understand your code.
Add some comments to the ecryptfs_global_auth_tok and ecryptfs_key_tfm
structs to make their functions more easily ascertained.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 69f6a22..fd6dd58 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -273,20 +273,36 @@
struct ecryptfs_crypt_stat *crypt_stat;
};
+/**
+ * ecryptfs_global_auth_tok structs refer to authentication token keys
+ * in the user keyring that apply to newly created files. A list of
+ * these objects hangs off of the mount_crypt_stat struct for any
+ * given eCryptfs mount. This struct maintains a reference to both the
+ * key contents and the key itself so that the key can be put on
+ * unmount.
+ */
struct ecryptfs_global_auth_tok {
#define ECRYPTFS_AUTH_TOK_INVALID 0x00000001
u32 flags;
- struct list_head mount_crypt_stat_list;
- struct key *global_auth_tok_key;
- struct ecryptfs_auth_tok *global_auth_tok;
- unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
+ struct list_head mount_crypt_stat_list; /* Default auth_tok list for
+ * the mount_crypt_stat */
+ struct key *global_auth_tok_key; /* The key from the user's keyring for
+ * the sig */
+ struct ecryptfs_auth_tok *global_auth_tok; /* The key contents */
+ unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1]; /* The key identifier */
};
+/**
+ * Typically, eCryptfs will use the same ciphers repeatedly throughout
+ * the course of its operations. In order to avoid unnecessarily
+ * destroying and initializing the same cipher repeatedly, eCryptfs
+ * keeps a list of crypto API contexts around to use when needed.
+ */
struct ecryptfs_key_tfm {
struct crypto_blkcipher *key_tfm;
size_t key_size;
struct mutex key_tfm_mutex;
- struct list_head key_tfm_list;
+ struct list_head key_tfm_list; /* The module's tfm list */
unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
};