[PATCH 4.19 79/79] SUNRPC: use _bh spinlocking on ->transport_lock

Greg Kroah-Hartman
2022-09-13T15:16:58Z

From: "NeilBrown" <neilb@suse.de>

Prior to Linux 5.3, ->transport_lock in sunrpc required the _bh style
spinlocks (when not called from a bottom-half handler).

When upstream 3848e96edf4788f772d83990022fa7023a233d83 was backported to
stable kernels, the spin_lock/unlock calls should have been changed to
the _bh version, but this wasn't noted in the patch and didn't happen.

So convert these lock/unlock calls to the _bh versions.

This patch is required for any stable kernel prior to 5.3 to which the
above mentioned patch was backported. Namely 4.9.y, 4.14.y, 4.19.y.

Signed-off-by: NeilBrown <neilb@suse.de>
Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
---
net/sunrpc/xprt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1550,9 +1550,9 @@ static void xprt_destroy(struct rpc_xprt
* is cleared. We use ->transport_lock to ensure the mod_timer()
* can only run *before* del_time_sync(), never after.
*/
- spin_lock(&xprt->transport_lock);
+ spin_lock_bh(&xprt->transport_lock);
del_timer_sync(&xprt->timer);
- spin_unlock(&xprt->transport_lock);
+ spin_unlock_bh(&xprt->transport_lock);

/*
* Destroy sockets etc from the system workqueue so they can