ksmbd: add smbd max io size parameter

Add 'smbd max io size' parameter to adjust smbd-direct max read/write
size.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/ksmbd_netlink.h

@@ -104,7 +104,8 @@ struct ksmbd_startup_request {
 					 */
 	__u32	sub_auth[3];		/* Subauth value for Security ID */
 	__u32	smb2_max_credits;	/* MAX credits */
-	__u32	reserved[128];		/* Reserved room */
+	__u32	smbd_max_io_size;	/* smbd read write size */
+	__u32	reserved[127];		/* Reserved room */
 	__u32	ifc_list_sz;		/* interfaces list size */
 	__s8	____payload[];
 };

fs/ksmbd/transport_ipc.c

@@ -26,6 +26,7 @@
 #include "mgmt/ksmbd_ida.h"
 #include "connection.h"
 #include "transport_tcp.h"
+#include "transport_rdma.h"
 
 #define IPC_WAIT_TIMEOUT	(2 * HZ)
 
@@ -303,6 +304,8 @@ static int ipc_server_config_on_startup(struct ksmbd_startup_request *req)
 		init_smb2_max_trans_size(req->smb2_max_trans);
 	if (req->smb2_max_credits)
 		init_smb2_max_credits(req->smb2_max_credits);
+	if (req->smbd_max_io_size)
+		init_smbd_max_io_size(req->smbd_max_io_size);
 
 	ret = ksmbd_set_netbios_name(req->netbios_name);
 	ret |= ksmbd_set_server_string(req->server_string);

fs/ksmbd/transport_rdma.c

@@ -80,7 +80,7 @@ static int smb_direct_max_fragmented_recv_size = 1024 * 1024;
 /*  The maximum single-message size which can be received */
 static int smb_direct_max_receive_size = 8192;
 
-static int smb_direct_max_read_write_size = 8 * 1024 * 1024;
+static int smb_direct_max_read_write_size = SMBD_DEFAULT_IOSIZE;
 
 static LIST_HEAD(smb_direct_device_list);
 static DEFINE_RWLOCK(smb_direct_device_lock);
@@ -214,6 +214,12 @@ struct smb_direct_rdma_rw_msg {
 	struct scatterlist	sg_list[];
 };
 
+void init_smbd_max_io_size(unsigned int sz)
+{
+	sz = clamp_val(sz, SMBD_MIN_IOSIZE, SMBD_MAX_IOSIZE);
+	smb_direct_max_read_write_size = sz;
+}
+
 static inline int get_buf_page_count(void *buf, int size)
 {
 	return DIV_ROUND_UP((uintptr_t)buf + size, PAGE_SIZE) -

fs/ksmbd/transport_rdma.h

@@ -7,6 +7,10 @@
 #ifndef __KSMBD_TRANSPORT_RDMA_H__
 #define __KSMBD_TRANSPORT_RDMA_H__
 
+#define SMBD_DEFAULT_IOSIZE (8 * 1024 * 1024)
+#define SMBD_MIN_IOSIZE (512 * 1024)
+#define SMBD_MAX_IOSIZE (16 * 1024 * 1024)
+
 /* SMB DIRECT negotiation request packet [MS-SMBD] 2.2.1 */
 struct smb_direct_negotiate_req {
 	__le16 min_version;
@@ -52,10 +56,12 @@ struct smb_direct_data_transfer {
 int ksmbd_rdma_init(void);
 void ksmbd_rdma_destroy(void);
 bool ksmbd_rdma_capable_netdev(struct net_device *netdev);
+void init_smbd_max_io_size(unsigned int sz);
 #else
 static inline int ksmbd_rdma_init(void) { return 0; }
 static inline int ksmbd_rdma_destroy(void) { return 0; }
 static inline bool ksmbd_rdma_capable_netdev(struct net_device *netdev) { return false; }
+static inline void init_smbd_max_io_size(unsigned int sz) { }
 #endif
 
 #endif /* __KSMBD_TRANSPORT_RDMA_H__ */