When using multiple queues, there was a race with the kernel
in setting up the second channel. This regression is due to a kernel change
which does not allow accessing sysfs files for Hyper-V channels that are not
opened.
The fix is simple, just move the logic to detect not ready
sub channels earlier in the existing loop.
Fixes: 831dba47bd36 ("bus/vmbus: add Hyper-V virtual bus support")
Reported-by:Mohammed Gamal <mga...@redhat.com>
Signed-off-by: Stephen Hemminger <sthem...@microsoft.com>
---
drivers/bus/vmbus/linux/vmbus_uio.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/bus/vmbus/linux/vmbus_uio.c
b/drivers/bus/vmbus/linux/vmbus_uio.c
index 12e97e3a420a..38df4d724ed5 100644
--- a/drivers/bus/vmbus/linux/vmbus_uio.c
+++ b/drivers/bus/vmbus/linux/vmbus_uio.c
@@ -357,6 +357,12 @@ int vmbus_uio_get_subchan(struct vmbus_channel *primary,
continue;
}
+ if (!vmbus_isnew_subchannel(primary, relid))
+ continue; /* Already know about you */
+
+ if (!vmbus_uio_ring_present(dev, relid))
+ continue; /* Ring may not be ready yet */
+
snprintf(subchan_path, sizeof(subchan_path), "%s/%lu",
chan_path, relid);
err = vmbus_uio_sysfs_read(subchan_path, "subchannel_id",
@@ -370,12 +376,6 @@ int vmbus_uio_get_subchan(struct vmbus_channel *primary,
if (subid == 0)
continue; /* skip primary channel */
- if (!vmbus_isnew_subchannel(primary, relid))
- continue;
-
- if (!vmbus_uio_ring_present(dev, relid))
- continue; /* Ring may not be ready yet */
-
err = vmbus_uio_sysfs_read(subchan_path, "monitor_id",
&monid, UINT8_MAX);
if (err) {
--
2.19.2
