CIFS: Introduce credit-based flow control
and send no more than credits value requests at once. For SMB/CIFS
it's trivial: increment this value by receiving any message and
decrement by sending one.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 703ef5c..c273c12 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -690,3 +690,22 @@
return false;
}
+
+void
+cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add)
+{
+ spin_lock(&server->req_lock);
+ server->credits += add;
+ server->in_flight--;
+ spin_unlock(&server->req_lock);
+ wake_up(&server->request_q);
+}
+
+void
+cifs_set_credits(struct TCP_Server_Info *server, const int val)
+{
+ spin_lock(&server->req_lock);
+ server->credits = val;
+ server->oplocks = val > 1 ? enable_oplocks : false;
+ spin_unlock(&server->req_lock);
+}