From: Shradha Gupta <shradhagupta@xxxxxxxxxxxxx>
> Sent: Friday, May 13, 2022 3:21 AM
> To: linux-kernel@xxxxxxxxxxxxxxx; linux-hyperv@xxxxxxxxxxxxxxx
> Subject: [PATCH] hv_balloon: Fix balloon_probe() and balloon_remove() error handling
>
> <haiyangz@xxxxxxxxxxxxx>, Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>,
> Wei Liu <wei.liu@xxxxxxxxxx>, Dexuan Cui <decui@xxxxxxxxxxxxx>
>
> Add missing cleanup in balloon_probe() if the call to
> balloon_connect_vsp() fails. Also correctly handle cleanup in
> balloon_remove() when dm_state is DM_INIT_ERROR because
> balloon_resume() failed.
>
> Signed-off-by: Shradha Gupta <shradhagupta@xxxxxxxxxxxxx>
> ---
> drivers/hv/hv_balloon.c | 21 ++++++++++++++++-----
> 1 file changed, 16 insertions(+), 5 deletions(-)
>
I think these changes look good now, but there are some
formatting and process problems with this patch email. Let me
get with you offline on the details.
Michael
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index eee7402cfc02..98fcfb516bbc 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -1842,7 +1842,7 @@ static int balloon_probe(struct hv_device *dev,
>
> ret = balloon_connect_vsp(dev);
> if (ret != 0)
> - return ret;
> + goto connect_error;
>
> enable_page_reporting();
> dm_device.state = DM_INITIALIZED;
> @@ -1861,6 +1861,7 @@ static int balloon_probe(struct hv_device *dev,
> dm_device.thread = NULL;
> disable_page_reporting();
> vmbus_close(dev->channel);
> +connect_error:
> #ifdef CONFIG_MEMORY_HOTPLUG
> unregister_memory_notifier(&hv_memory_nb);
> restore_online_page_callback(&hv_online_page);
> @@ -1882,12 +1883,21 @@ static int balloon_remove(struct hv_device *dev)
> cancel_work_sync(&dm->ha_wrk.wrk);
>
> kthread_stop(dm->thread);
> - disable_page_reporting();
> - vmbus_close(dev->channel);
> +
> + /*
> + * This is to handle the case when balloon_resume()
> + * call has failed and some cleanup has been done as
> + * a part of the error handling.
> + */
> + if (dm_device.state != DM_INIT_ERROR) {
> + disable_page_reporting();
> + vmbus_close(dev->channel);
> #ifdef CONFIG_MEMORY_HOTPLUG
> - unregister_memory_notifier(&hv_memory_nb);
> - restore_online_page_callback(&hv_online_page);
> + unregister_memory_notifier(&hv_memory_nb);
> + restore_online_page_callback(&hv_online_page);
> #endif
> + }
> +
> spin_lock_irqsave(&dm_device.ha_lock, flags);
> list_for_each_entry_safe(has, tmp, &dm->ha_region_list, list) {
> list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) {
> @@ -1948,6 +1958,7 @@ static int balloon_resume(struct hv_device *dev)
> vmbus_close(dev->channel);
> out:
> dm_device.state = DM_INIT_ERROR;
> + disable_page_reporting();
> #ifdef CONFIG_MEMORY_HOTPLUG
> unregister_memory_notifier(&hv_memory_nb);
> restore_online_page_callback(&hv_online_page);
> --
> 2.17.1
