[PATCH V2 07/12] Drivers: hv: vmbus: do sanity check of channel state in vmbus_close_internal()

From: K. Y. Srinivasan
Date: Wed Nov 11 2015 - 19:55:04 EST


From: Dexuan Cui <decui@xxxxxxxxxxxxx>

This fixes an incorrect assumption of channel state in the function.

Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/channel.c | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index f7f3d5c..00e1be7 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -512,6 +512,18 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
tasklet = hv_context.event_dpc[channel->target_cpu];
tasklet_disable(tasklet);

+ /*
+ * In case a device driver's probe() fails (e.g.,
+ * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
+ * rescinded later (e.g., we dynamically disble an Integrated Service
+ * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
+ * here we should skip most of the below cleanup work.
+ */
+ if (channel->state != CHANNEL_OPENED_STATE) {
+ ret = -EINVAL;
+ goto out;
+ }
+
channel->state = CHANNEL_OPEN_STATE;
channel->sc_creation_callback = NULL;
/* Stop callback and cancel the timer asap */
--
1.7.4.1

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