1 files changed, 7 insertions, 0 deletions

diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index 9b907f408b8d..29123b5604f2 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -70,6 +70,13 @@ extern void nfs_callback_down(void);
 #define nfs_callback_down()     do {} while(0)
 #endif
 
+/*
+ * nfs41: Callbacks are expected to not cause substantial latency,
+ * so we limit their concurrency to 1 by setting up the maximum number
+ * of slots for the backchannel.
+ */
+#define NFS41_BC_MIN_CALLBACKS 1
+
 extern unsigned int nfs_callback_set_tcpport;
 extern unsigned short nfs_callback_tcpport;
 extern unsigned short nfs_callback_tcpport6;