[vbox-dev] Removing code only used by no longer supported hosts (was Opportunity to significantly shrink the vboxsf Linux driver)

[Hans de Goede]

Hi,

On 25-08-17 10:29, Michael Thayer wrote:
> Hello Hans,
> 
> 21.08.2017 14:49, Hans de Goede wrote:
> [...]
>>> First of all thank you for the answers to the above questions (see
>>> archives).
>>>
>>> I've just found one more piece of code where I wonder if that should
>>> be kept. VbglR0SfMapFolder first tries SHFL_FN_MAP_FOLDER and if thar
>>> fails falls back to SHFL_FN_MAP_FOLDER_OLD. Are hosts only supporting
>>> SHFL_FN_MAP_FOLDER_OLD still supported, or can the fallback path
>>> be dropped ?
>>
>> Ping? Getting an answer to this would be goold.
>>
>> Likewise vfsmod.c has this:
>>
>>          if (info->nullchar != '\0'
>>              || info->signature[0] != VBSF_MOUNT_SIGNATURE_BYTE_0
>>              || info->signature[1] != VBSF_MOUNT_SIGNATURE_BYTE_1
>>              || info->signature[2] != VBSF_MOUNT_SIGNATURE_BYTE_2) {
>>                  /*
>>                   * An old version of mount.vboxsf made the syscall.
>>                   * Translate the old parameters to the new structure.
>>                   */
>>                  struct vbsf_mount_info_old *info_old = (void *)info;
>>                  static struct vbsf_mount_info_new info_compat;
>>
>> Is this support for older mount.vboxsf binaries still necessary ?
> [...]
> Back from holiday and trying to catch up on unread e-mail.  From reading
> the code, I would say that both of those can be removed.  Did you test
> it?  Regarding supporting old versions of mount.vboxsf (which I would
> have got rid of long ago anyway if I had found time: the module could
> just as well do the parsing without a user-space helper), the only
> reason for that I can think of is if one is downgrading the Additions,
> presumably for testing purposes, and does not want to reboot to reload
> the old kernel modules.  Not really an argument for keeping that code
> any more.

Ok, thank you for the feedback.

I've removed support for both old interfaces and things still work fine:

https://github.com/jwrdegoede/vboxsf/commit/e89091819397785f687185413919023aacf2253f

Regards,

Hans