From c36c826ad3e64c20ff1486774d54a753ac51daa6 Mon Sep 17 00:00:00 2001 From: Naman Jain Date: Thu, 29 Aug 2024 12:43:12 +0530 Subject: [PATCH] Drivers: hv: vmbus: Fix rescind handling in uio_hv_generic 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 Reviewed-by: Saurabh Sengar Link: https://lore.kernel.org/r/20240829071312.1595-3-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman --- drivers/hv/vmbus_drv.c | 1 + drivers/uio/uio_hv_generic.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 115835bd562c..02aeb192e367 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -2008,6 +2008,7 @@ static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj, return attr->mode; } +EXPORT_SYMBOL_GPL(vmbus_device_unregister); static struct attribute_group vmbus_chan_group = { .attrs = vmbus_chan_attrs, diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index bbc512ecce39..56bf01182764 100644 --- 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_channel *channel) /* 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rescind callback registered, rescind path will not unregister the device + * from vmbus when the primary channel is rescinded.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