On Fri, Feb 08, 2019 at 12:44:14AM +0000, Derrick, Jonathan wrote:

On Thu, 2019-02-07 at 23:56 +0100, David Kozub wrote:

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On Mon, 4 Feb 2019, Christoph Hellwig wrote:

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 static int opal_enable_disable_shadow_mbr(struct opal_dev *dev,
 					  struct opal_mbr_data *opal_mbr)
 {
+	u8 token = opal_mbr->enable_disable == OPAL_MBR_ENABLE
+		? OPAL_TRUE : OPAL_FALSE;
 	const struct opal_step mbr_steps[] = {
 		{ opal_discovery0, },
 		{ start_admin1LSP_opal_session, &opal_mbr->key },
-		{ set_mbr_done, &opal_mbr->enable_disable },
+		{ set_mbr_done, &token },

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Am I missing something here? This seems wrong to me. And I think this 
patch actually changes it by introducing:

+    u8 token = opal_mbr->enable_disable == OPAL_MBR_ENABLE
+            ? OPAL_TRUE : OPAL_FALSE;

which is essentially a negation (map 0 to 1 and 1 to 0).

Agreed the original code did the opposite of what the user wanted, looks like
when I authored it I messed up that enum which set everything off.

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With regard to the new IOC_OPAL_MBR_STATUS: I find the usage of 
OPAL_MBR_ENABLE/DISABLE for this confusing: what should passing 
OPAL_MBR_ENABLE do? Should it enable the shadow MBR? Or should it 
enable the MBR-done flag? I think the implementation in this patch 
interprets OPAL_MBR_ENABLE as 'set the "done" flag to true', thus hiding 
the shadow MBR. But this is not obvious looking at the IOCTL name.

For the new ioctl I think we should just add a new enum with the correct
nomenclature.  So OPAL_MBR_DONE, OPAL_MBR_NOT_DONE.

In order to keep the userspace interface consistent, I'll ACK your
change in this patch, unless Scott can fill me in on why this looks
wrong but is actually right.

I think it is just wrong. 

We have 7 bytes in the opal_mbr_data struct we could use for DONE/NOT
DONE. I'm not sure how to go about keeping it consistent with old uapi,
although arguably opal_enable_disable_shadow_mbr is already doing the
wrong thing with DONE and ENABLE so it's low impact.

Can we keep the old mbr struct the same and just add a new struct with new enums
for the new done ioctl? I think this will keep the new ioctl cleaner instead
of trying to apply older, some what incorrectly named, enums.

Lastly someone will need to backport his

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+       u8 token = opal_mbr->enable_disable == OPAL_MBR_ENABLE
+               ? OPAL_TRUE : OPAL_FALSE;

to stable so we can fix up my broken coding in older kernels.


I can do that or, if David wants to do that that's fine... just want to coordinate.