|
 |
aed176 |
From 25363eb99bc43443bec354abea1e40db61280b30 Mon Sep 17 00:00:00 2001
|
|
|
aed176 |
From: Stephen Hemminger <sthemmin@microsoft.com>
|
|
|
aed176 |
Date: Wed, 5 Dec 2018 14:11:56 -0800
|
|
|
aed176 |
Subject: [PATCH 1/3] bus/vmbus: fix race in subchannel creation
|
|
|
aed176 |
|
|
|
aed176 |
[ upstream commit 4970103e89f4f828669acf3b465e984fdc891e1e ]
|
|
|
aed176 |
|
|
|
aed176 |
When using multiple queues, there was a race with the kernel
|
|
|
aed176 |
in setting up the second channel. This regression is due to a kernel change
|
|
|
aed176 |
which does not allow accessing sysfs files for Hyper-V channels that are not opened.
|
|
|
aed176 |
|
|
|
aed176 |
The fix is simple, just move the logic to detect not ready
|
|
|
aed176 |
sub channels earlier in the existing loop.
|
|
|
aed176 |
|
|
|
aed176 |
Fixes: 831dba47bd36 ("bus/vmbus: add Hyper-V virtual bus support")
|
|
|
aed176 |
|
|
|
aed176 |
Reported-by: Mohammed Gamal <mgamal@redhat.com>
|
|
|
aed176 |
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
|
|
|
aed176 |
(cherry picked from commit ca17e6624251b05cf188997cffc3e1ab2e50561a)
|
|
|
aed176 |
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
|
|
|
aed176 |
---
|
|
|
aed176 |
drivers/bus/vmbus/linux/vmbus_uio.c | 12 ++++++------
|
|
|
aed176 |
1 file changed, 6 insertions(+), 6 deletions(-)
|
|
|
aed176 |
|
|
|
aed176 |
diff --git a/drivers/bus/vmbus/linux/vmbus_uio.c b/drivers/bus/vmbus/linux/vmbus_uio.c
|
|
|
aed176 |
index 12e97e3a4..38df4d724 100644
|
|
|
aed176 |
--- a/drivers/bus/vmbus/linux/vmbus_uio.c
|
|
|
aed176 |
+++ b/drivers/bus/vmbus/linux/vmbus_uio.c
|
|
|
aed176 |
@@ -357,6 +357,12 @@ int vmbus_uio_get_subchan(struct vmbus_channel *primary,
|
|
|
aed176 |
continue;
|
|
|
aed176 |
}
|
|
|
aed176 |
|
|
|
aed176 |
+ if (!vmbus_isnew_subchannel(primary, relid))
|
|
|
aed176 |
+ continue; /* Already know about you */
|
|
|
aed176 |
+
|
|
|
aed176 |
+ if (!vmbus_uio_ring_present(dev, relid))
|
|
|
aed176 |
+ continue; /* Ring may not be ready yet */
|
|
|
aed176 |
+
|
|
|
aed176 |
snprintf(subchan_path, sizeof(subchan_path), "%s/%lu",
|
|
|
aed176 |
chan_path, relid);
|
|
|
aed176 |
err = vmbus_uio_sysfs_read(subchan_path, "subchannel_id",
|
|
|
aed176 |
@@ -370,12 +376,6 @@ int vmbus_uio_get_subchan(struct vmbus_channel *primary,
|
|
|
aed176 |
if (subid == 0)
|
|
|
aed176 |
continue; /* skip primary channel */
|
|
|
aed176 |
|
|
|
aed176 |
- if (!vmbus_isnew_subchannel(primary, relid))
|
|
|
aed176 |
- continue;
|
|
|
aed176 |
-
|
|
|
aed176 |
- if (!vmbus_uio_ring_present(dev, relid))
|
|
|
aed176 |
- continue; /* Ring may not be ready yet */
|
|
|
aed176 |
-
|
|
|
aed176 |
err = vmbus_uio_sysfs_read(subchan_path, "monitor_id",
|
|
|
aed176 |
&monid, UINT8_MAX);
|
|
|
aed176 |
if (err) {
|
|
|
aed176 |
--
|
|
|
aed176 |
2.20.1
|
|
|
aed176 |
|