4.19-stable review patch. If anyone has any objections, please let me know.
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From: Naman Jain namjain@linux.microsoft.com
commit 6fd28941447bf2c8ca0f26fda612a1cabc41663f upstream.
Rescind offer handling relies on rescind callbacks for some of the resources cleanup, if they are registered. It does not unregister vmbus device for the primary channel closure, when callback is registered. Without it, next onoffer does not come, rescind flag remains set and device goes to unusable state.
Add logic to unregister vmbus for the primary channel in rescind callback to ensure channel removal and relid release, and to ensure that next onoffer can be received and handled properly.
Cc: stable@vger.kernel.org Fixes: ca3cda6fcf1e ("uio_hv_generic: add rescind support") Signed-off-by: Naman Jain namjain@linux.microsoft.com Reviewed-by: Saurabh Sengar ssengar@linux.microsoft.com Link: https://lore.kernel.org/r/20240829071312.1595-3-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hv/vmbus_drv.c | 1 + drivers/uio/uio_hv_generic.c | 8 ++++++++ 2 files changed, 9 insertions(+)
--- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1973,6 +1973,7 @@ acpi_walk_err: vmbus_acpi_remove(device); return ret_val; } +EXPORT_SYMBOL_GPL(vmbus_device_unregister);
static const struct acpi_device_id vmbus_acpi_device_ids[] = { {"VMBUS", 0}, --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -119,6 +119,14 @@ static void hv_uio_rescind(struct vmbus_
/* Wake up reader */ uio_event_notify(&pdata->info); + + /* + * With rescind callback registered, rescind path will not unregister the device + * from vmbus when the primary channel is rescinded. + * Without it, rescind handling is incomplete and next onoffer msg does not come. + * Unregister the device from vmbus here. + */ + vmbus_device_unregister(channel->device_obj); }
/* Sysfs API to allow mmap of the ring buffers