Re: [PATCH] Smack: Restore the smackfsdef mount option

From: Casey Schaufler
Date: Tue May 28 2019 - 16:00:44 EST


On 5/28/2019 11:54 AM, David Howells wrote:
> Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
>
>>> Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
>>>
>>>>> Also, should all of these be prefixed with "smack"? So:
>>>>>
>>>>> fsparam_string("smackfsdef", Opt_fsdefault),
>>>>> fsparam_string("smackfsfloor", Opt_fsfloor),
>>>>> fsparam_string("smackfshat", Opt_fshat),
>>>> No. smack_fs_parameters takes care of that.
>>> It does? *Blink*.
>> Well, something does. I can't say that I 100% understand all
>> of how the new mount code handles the mount options. Y'all made
>> sweeping changes, and the code works the way it used to except
>> for the awkward change from smackfsdef to smackfsdefault. It
>> took no small amount of head scratching and experimentation to
>> convince myself that the fix I proposed was correct.
> Ah... I suspect the issue is that smack_sb_eat_lsm_opts() strips the prefix
> for an unconverted filesystem, but smack_fs_context_parse_param() doesn't
> (which it shouldn't).
>
> Can you try grabbing my mount-api-viro branch from:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git
>
> and testing setting smack options on a tmpfs filesystem?

My fedora system won't boot because smackfsdef isn't recognized. :(
I will put in my fix and retry.

>
> You might need to try modifying samples/vfs/test-fsmount.c to make it mount a
> trmpfs filesystem through the new mount UAPI.
>
> David