xen/scsiback: correct frontend counting

When adding a new frontend to xen-scsiback don't decrement the number
of active frontends in case of no error. Doing so results in a failure
when trying to remove the xen-pvscsi nexus even if no domain is using
it.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index ad4eb1024d1f..51387d75c7bf 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -939,12 +939,12 @@ out:
         spin_unlock_irqrestore(&info->v2p_lock, flags);
 
 out_free:
-        mutex_lock(&tpg->tv_tpg_mutex);
-        tpg->tv_tpg_fe_count--;
-        mutex_unlock(&tpg->tv_tpg_mutex);
-
-        if (err)
+        if (err) {
+                mutex_lock(&tpg->tv_tpg_mutex);
+                tpg->tv_tpg_fe_count--;
+                mutex_unlock(&tpg->tv_tpg_mutex);
                 kfree(new);
+        }
 
         return err;
 }