[Cluster-devel] [PATCHv2 dlm/next 4/5] fs: dlm: disallow buffer size below default

[Alexander Aring <aahringo@redhat.com>]

I observed that the upper layer will not send messages above this value.
As conclusion the application receive buffer should not below that
value, otherwise we are not capable to deliver the dlm message to the
upper layer. This patch forbids to set the receive buffer below the
maximum possible dlm message size.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
---
 fs/dlm/config.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index e03b409a4df01..a4bed304a8430 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -166,8 +166,14 @@ static bool dlm_check_zero(unsigned int x)
 	return !x;
 }
 
+#define DEFAULT_BUFFER_SIZE     4096
+static bool dlm_check_buffer_size(unsigned int x)
+{
+	return (x < DEFAULT_BUFFER_SIZE);
+}
+
 CLUSTER_ATTR(tcp_port, dlm_check_zero);
-CLUSTER_ATTR(buffer_size, dlm_check_zero);
+CLUSTER_ATTR(buffer_size, dlm_check_buffer_size);
 CLUSTER_ATTR(rsbtbl_size, dlm_check_zero);
 CLUSTER_ATTR(recover_timer, dlm_check_zero);
 CLUSTER_ATTR(toss_secs, dlm_check_zero);
@@ -901,7 +907,6 @@ int dlm_our_addr(struct sockaddr_storage *addr, int num)
 
 /* Config file defaults */
 #define DEFAULT_TCP_PORT       21064
-#define DEFAULT_BUFFER_SIZE     4096
 #define DEFAULT_RSBTBL_SIZE     1024
 #define DEFAULT_RECOVER_TIMER      5
 #define DEFAULT_TOSS_SECS         10
-- 
2.26.2