Re: [PATCH] fscrypto: make filename crypto functions return 0 on success

[Eric Biggers <ebiggers@google.com>]

On Wed, Sep 14, 2016 at 05:10:21PM -0700, Jaegeuk Kim wrote:
> Hi Eric,
> 
> On Wed, Sep 14, 2016 at 04:00:45PM -0700, Eric Biggers wrote:
> > Several filename crypto functions: fname_decrypt(),
> > fscrypt_fname_disk_to_usr(), and fscrypt_fname_usr_to_disk(), returned
> > the output length on success or -errno on failure.  However, the output
> > length was redundant with the value written to 'oname->len'.  It is also
> > potentially error-prone to make callers have to check for '< 0' instead
> > of '!= 0'.
> 
> At a glance, you missed some places like
> - fscrypt_fname_usr_to_disk() in ext4_symlink() and f2fs_symlink()
> - fscrypt_fname_disk_to_usr() in dx_show_leaf() and f2fs_fill_dentries()
> 

Those callers don't have to be updated because they only check for an error
value --- they don't use the return value as a length.  I did check all the
callers of fscrypt_fname_{usr_to_disk,disk_to_usr()}, and only the three I
update in the patch used the return value as a length.

Eric