RE: [PATCH v2 1/2] Drivers: hv: vmbus: Refactor chan->state if statement

From: Michael Kelley
Date: Sun Feb 24 2019 - 11:54:10 EST


From: Kimberly Brown <kimbrownkd@xxxxxxxxx> Sent: Thursday, February 21, 2019 7:47 PM
>
> The chan->state "if statement" was introduced in commit 6712cc9c2211
> ("vmbus: don't return values for uninitalized channels"). That commit
> states that the purpose of the chan->state "if statement" is to prevent
> returning garbage or causing a kernel OOPS when the channel ring buffer
> is not initialized. The changes in this patch provide the same
> protection.
>
> Refactor the chan->state âif statementâ in vmbus_chan_attr_show():
> - Instead of checking the channel state in the "if statement", check
> whether the channel ring buffer pointer is NULL. Checking the
> ring buffer pointer makes this code consistent with
> hv_ringbuffer_get_debuginfo().
>
> - Move the "if statement" to the four "_show" functions that access a
> channel ring buffer. Only four of the channel-level "_show" functions
> access a ring buffer. The ring buffer pointer does not need to be
> checked before calling the other "_show" functions, and moving the
> ring buffer pointer "if statement" to the "_show" functions that
> access a ring buffer makes the purpose of the "if statement" clear.
>
> Signed-off-by: Kimberly Brown <kimbrownkd@xxxxxxxxx>

Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>