SUNRPC: use _bh spinlocking on ->transport_lock

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>

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index e7d55d63d4f13744667b369a5d68a57459bb5bbe..7f9b94acf59757964cfd6df438a4c764c75f3bb4 100644 (file)
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1525,9 +1525,9 @@ static void xprt_destroy(struct rpc_xprt *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