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>