This is a note to let you know that I've just added the patch titled
9p/xen: fix init sequence
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
9p-xen-fix-init-sequence.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e8713c8526c33b9b5e7945a20fa2ff10dd4d7ab8
Author: Alex Zenla <alex@xxxxxxxxx>
Date: Tue Nov 19 21:16:33 2024 +0000
9p/xen: fix init sequence
[ Upstream commit 7ef3ae82a6ebbf4750967d1ce43bcdb7e44ff74b ]
Large amount of mount hangs observed during hotplugging of 9pfs devices. The
9pfs Xen driver attempts to initialize itself more than once, causing the
frontend and backend to disagree: the backend listens on a channel that the
frontend does not send on, resulting in stalled processing.
Only allow initialization of 9p frontend once.
Fixes: c15fe55d14b3b ("9p/xen: fix connection sequence")
Signed-off-by: Alex Zenla <alex@xxxxxxxxx>
Signed-off-by: Alexander Merritt <alexander@xxxxxxxxx>
Signed-off-by: Ariadne Conill <ariadne@ariadne.space>
Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Message-ID: <20241119211633.38321-1-alexander@xxxxxxxxx>
Signed-off-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c
index 4a16c5dd1576d..f5b8f009b8a95 100644
--- a/net/9p/trans_xen.c
+++ b/net/9p/trans_xen.c
@@ -480,6 +480,7 @@ static int xen_9pfs_front_init(struct xenbus_device *dev)
goto error;
}
+ xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
error_xenbus:
@@ -527,8 +528,10 @@ static void xen_9pfs_front_changed(struct xenbus_device *dev,
break;
case XenbusStateInitWait:
- if (!xen_9pfs_front_init(dev))
- xenbus_switch_state(dev, XenbusStateInitialised);
+ if (dev->state != XenbusStateInitialising)
+ break;
+
+ xen_9pfs_front_init(dev);
break;
case XenbusStateConnected:
