Re: patch: partition type f

Janet Walz (jwalz@Radix.Net)
Fri, 16 Jan 1998 16:10:26 -0500 (EST)

>James Mastros wrote:
>On Fri, 16 Jan 1998, Janet Walz wrote:
>> Checking the kernel source, the fields Linux uses work the exact same way for
>> types f and 5 (based on the one sample on hand). Thus, the following trivial
>> patch to the kernel (of apparently any recent version -- 2.0.30, 2.0.33, and
>> 2.1.76 have no differences in these areas.)

>Umm... 2.1.77 and up have this functionality (calling them
>WIN98_EXTENDED_PARTITIONs); it is implemented in almost exactly the same way
>(it goes between DOS_... and LINUX_...).

Oops. I was so amazed that no one had done it in over a year that I
didn't recheck whether someone done it in the last two weeks.

>> Also note that this is only a solution to half the problem. You can see
>> and access the existing partitions inside a type f, but until the Linux
>> fdisk knows how to deal with type f partitions, you still won't be able
>> to put Linux-type logical partitions inside a type f, and Windows 95
>> fdisk seemed to reject the idea of large type 5s.
>(Not a kernel problem (just mentioning, not flaming)).

Right. Just that the kernel patch alone won't solve people's problems.

>The patch to fdisk should be as trivial as this one.

No, because fdisk is written with lots of explicit references to type 5
(not even recognizing Linux's type 85), and the cylinder numbers related
to type f are in some but not all places what fdisk calls dos-compatible
(max possible value of 1023 vs. mod 1024). Irrelevant to Linux, but I
suspect Windows will be upset without duplicating that. Not exactly
difficult, but not adding two lines of code either.