[[PATCH v1] 25/37] [CIFS] SMBD: Support SMBD idle connection timer

From: Long Li
Date: Wed Aug 02 2017 - 16:15:34 EST


From: Long Li <longli@xxxxxxxxxxxxx>

This is part of the keep alive protocol. Each peer maintains a timer, and will send a message to peer when it expires.

Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
---
fs/cifs/cifsrdma.c | 25 +++++++++++++++++++++++++
fs/cifs/cifsrdma.h | 6 ++++--
2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/cifsrdma.c b/fs/cifs/cifsrdma.c
index e275834..523c80f 100644
--- a/fs/cifs/cifsrdma.c
+++ b/fs/cifs/cifsrdma.c
@@ -89,6 +89,7 @@ static int send_credit_target = 512;
static int max_send_size = 8192;
static int max_fragmented_recv_size = 1024*1024;
static int max_receive_size = 8192;
+static int keep_alive_interval = 120;

// maximum number of SGEs in a RDMA I/O
static int max_send_sge = 16;
@@ -1200,6 +1201,25 @@ static void destroy_receive_buffers(struct cifs_rdma_info *info)
mempool_free(response, info->response_mempool);
}

+// Implement idle connection timer [MS-SMBD] 3.1.6.2
+static void idle_connection_timer(struct work_struct *work)
+{
+ struct cifs_rdma_info *info = container_of(
+ work, struct cifs_rdma_info,
+ idle_timer_work.work);
+
+ if (info->keep_alive_requested != KEEP_ALIVE_NONE)
+ log_keep_alive("error status info->keep_alive_requested=%d\n",
+ info->keep_alive_requested);
+
+ log_keep_alive("about to send an empty idle message\n");
+ cifs_rdma_post_send_empty(info);
+
+ // setup the next idle timeout work
+ schedule_delayed_work(&info->idle_timer_work,
+ info->keep_alive_interval*HZ);
+}
+
int cifs_reconnect_rdma_session(struct TCP_Server_Info *server)
{
log_rdma_event("reconnecting rdma session\n");
@@ -1262,6 +1282,7 @@ struct cifs_rdma_info* cifs_create_rdma_session(
info->max_send_size = max_send_size;
info->max_fragmented_recv_size = max_fragmented_recv_size;
info->max_receive_size = max_receive_size;
+ info->keep_alive_interval = keep_alive_interval;

max_send_sge = min_t(int, max_send_sge,
info->id->device->attrs.max_sge);
@@ -1348,6 +1369,10 @@ struct cifs_rdma_info* cifs_create_rdma_session(
init_waitqueue_head(&info->wait_send_queue);
init_waitqueue_head(&info->wait_reassembly_queue);

+ INIT_DELAYED_WORK(&info->idle_timer_work, idle_connection_timer);
+ schedule_delayed_work(&info->idle_timer_work,
+ info->keep_alive_interval*HZ);
+
init_waitqueue_head(&info->wait_send_pending);
atomic_set(&info->send_pending, 0);

diff --git a/fs/cifs/cifsrdma.h b/fs/cifs/cifsrdma.h
index 62d0bb8..dd497ce 100644
--- a/fs/cifs/cifsrdma.h
+++ b/fs/cifs/cifsrdma.h
@@ -73,6 +73,7 @@ struct cifs_rdma_info {
int max_fragmented_recv_size;
int max_fragmented_send_size;
int max_receive_size;
+ int keep_alive_interval;
int max_readwrite_size;
enum keep_alive_status keep_alive_requested;
int protocol;
@@ -101,12 +102,13 @@ struct cifs_rdma_info {

wait_queue_head_t wait_send_queue;

+ bool full_packet_received;
+ struct delayed_work idle_timer_work;;
+
// request pool for RDMA send
struct kmem_cache *request_cache;
mempool_t *request_mempool;

- bool full_packet_received;
-
// response pool for RDMA receive
struct kmem_cache *response_cache;
mempool_t *response_mempool;
--
2.7.4