Re: [PATCH v4 15/16] block: sed-opal: don't repeat opal_discovery0 in each steps array

From: David Kozub
Date: Sun Feb 10 2019 - 12:46:57 EST

On Fri, 8 Feb 2019, Derrick, Jonathan wrote:

On Mon, 2019-02-04 at 23:44 +0100, David Kozub wrote:
On Mon, 4 Feb 2019, Christoph Hellwig wrote:

+ /* first do a discovery0 */
+ error = opal_discovery0_step(dev);

+ for (state = 0; !error && state < n_steps; state++)
+ error = execute_step(dev, &steps[state], state);
+ /*
+ * For each OPAL command the first step in steps starts some sort of
+ * session. If an error occurred in the initial discovery0 or if an
+ * error occurred in the first step (and thus stopping the loop with
+ * state == 1) then there was an error before or during the attempt to
+ * start a session. Therefore we shouldn't attempt to terminate a
+ * session, as one has not yet been created.
+ */
+ if (error && state > 1)
+ end_opal_session_error(dev);

return error;

The flow here is a little too condensed for my taste. Why not the
plain obvoious, if a little longer:

error = error = opal_discovery0_step(dev);
if (error)
return error;

for (state = 0; state < n_steps; state++) {
error = execute_step(dev, &steps[state], state);
if (error)
goto out_error;

return 0;

if (state > 1)
return error;

No problem, I can use this version. But I think there is a minor issue -
the same one I hit in my original change, just from the other direction:

If the loop succeds for the 0-th element of steps, and then fails for the
1st element, then state equals 1 yet the session has been started, so we
should close it.

I think the condition in out_error should be if (state > 0).

Best regards,
Looks good with Christoph's suggestion (for 14/16) and your state check fix

Reviewed-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>

Hi Jon,

What suggestion by Christoph you have in mind? I don't see any for 14/16. Currently, in my git repo, for this patch, I applied Christoph suggestion for this (15/16) patch + the "state > 0" fix. Is this what you mean?

Best regards,