From: Michael Kelley <mhklinux@outlook.com>

Patch 1 fixes util_probe() to not force the error return value to
ENODEV when the util_init function fails -- just return the error
code from util_init so the real error code is displayed in messages.

Patch 2 fixes a more serious race condition between initialization
of the VMBus channel and initial operations of the user space
daemons for KVP and VSS. The fix reorders the initialization in
util_probe() so the race condition can't happen.

The two fixes are functionally independent, but Patch 2 introduces
the util_init_transport function that parallels the existing code
for the util_init function. Doing Patch 1 first avoids an
inconsistency in the error handling in similar code for these two
parts of util_probe().

This series is v2 of a single patch first posted by Dexuan Cui
to fix the race condition.[1] I've taken over the patch per
discussion with Dexuan.

[1] https://lore.kernel.org/linux-hyperv/20240909164719.41000-1-decui@microsoft.com/

Michael Kelley (2):
  Drivers: hv: util: Don't force error code to ENODEV in util_probe()
  Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet

 drivers/hv/hv_kvp.c       |  6 ++++++
 drivers/hv/hv_snapshot.c  |  6 ++++++
 drivers/hv/hv_util.c      | 13 ++++++++++---
 drivers/hv/hyperv_vmbus.h |  2 ++
 include/linux/hyperv.h    |  1 +
 5 files changed, 25 insertions(+), 3 deletions(-)

-- 
2.25.1

On Wed, Nov 06, 2024 at 07:42:45AM -0800, mhkelley58@gmail.com wrote:
> From: Michael Kelley <mhklinux@outlook.com>
> 
> Patch 1 fixes util_probe() to not force the error return value to
> ENODEV when the util_init function fails -- just return the error
> code from util_init so the real error code is displayed in messages.
> 
> Patch 2 fixes a more serious race condition between initialization
> of the VMBus channel and initial operations of the user space
> daemons for KVP and VSS. The fix reorders the initialization in
> util_probe() so the race condition can't happen.
> 
> The two fixes are functionally independent, but Patch 2 introduces
> the util_init_transport function that parallels the existing code
> for the util_init function. Doing Patch 1 first avoids an
> inconsistency in the error handling in similar code for these two
> parts of util_probe().
> 
> This series is v2 of a single patch first posted by Dexuan Cui
> to fix the race condition.[1] I've taken over the patch per
> discussion with Dexuan.
> 
> [1] https://lore.kernel.org/linux-hyperv/20240909164719.41000-1-decui@microsoft.com/
> 
> Michael Kelley (2):
>   Drivers: hv: util: Don't force error code to ENODEV in util_probe()
>   Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet

Acked-by: Wei Liu <wei.liu@kernel.org>

On Sat, Dec 07, 2024 at 07:02:55AM +0000, Wei Liu wrote:
> On Wed, Nov 06, 2024 at 07:42:45AM -0800, mhkelley58@gmail.com wrote:
> > From: Michael Kelley <mhklinux@outlook.com>
> > 
> > Patch 1 fixes util_probe() to not force the error return value to
> > ENODEV when the util_init function fails -- just return the error
> > code from util_init so the real error code is displayed in messages.
> > 
> > Patch 2 fixes a more serious race condition between initialization
> > of the VMBus channel and initial operations of the user space
> > daemons for KVP and VSS. The fix reorders the initialization in
> > util_probe() so the race condition can't happen.
> > 
> > The two fixes are functionally independent, but Patch 2 introduces
> > the util_init_transport function that parallels the existing code
> > for the util_init function. Doing Patch 1 first avoids an
> > inconsistency in the error handling in similar code for these two
> > parts of util_probe().
> > 
> > This series is v2 of a single patch first posted by Dexuan Cui
> > to fix the race condition.[1] I've taken over the patch per
> > discussion with Dexuan.
> > 
> > [1] https://lore.kernel.org/linux-hyperv/20240909164719.41000-1-decui@microsoft.com/
> > 
> > Michael Kelley (2):
> >   Drivers: hv: util: Don't force error code to ENODEV in util_probe()
> >   Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet
> 
> Acked-by: Wei Liu <wei.liu@kernel.org>

Applied to hyperv-fixes, thanks.