ksmbd: add support for smb2 max credit parameter

Add smb2 max credits parameter to adjust maximum credits value to limit
number of outstanding requests.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/connection.h

@@ -62,7 +62,6 @@ struct ksmbd_conn {
 	/* References which are made for this Server object*/
 	atomic_t			r_count;
 	unsigned short			total_credits;
-	unsigned short			max_credits;
 	spinlock_t			credits_lock;
 	wait_queue_head_t		req_running_q;
 	/* Lock to protect requests list*/

fs/ksmbd/ksmbd_netlink.h

@@ -103,6 +103,7 @@ struct ksmbd_startup_request {
 					 * we set the SPARSE_FILES bit (0x40).
 					 */
 	__u32	sub_auth[3];		/* Subauth value for Security ID */
+	__u32	smb2_max_credits;	/* MAX credits */
 	__u32	ifc_list_sz;		/* interfaces list size */
 	__s8	____payload[];
 };

fs/ksmbd/smb2misc.c

@@ -326,7 +326,7 @@ static int smb2_validate_credit_charge(struct ksmbd_conn *conn,
 		ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n",
 			    credit_charge, calc_credit_num);
 		return 1;
-	} else if (credit_charge > conn->max_credits) {
+	} else if (credit_charge > conn->vals->max_credits) {
 		ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge);
 		return 1;
 	}

fs/ksmbd/smb2ops.c

@@ -19,6 +19,7 @@ static struct smb_version_values smb21_server_values = {
 	.max_read_size = SMB21_DEFAULT_IOSIZE,
 	.max_write_size = SMB21_DEFAULT_IOSIZE,
 	.max_trans_size = SMB21_DEFAULT_IOSIZE,
+	.max_credits = SMB2_MAX_CREDITS,
 	.large_lock_type = 0,
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED,
@@ -44,6 +45,7 @@ static struct smb_version_values smb30_server_values = {
 	.max_read_size = SMB3_DEFAULT_IOSIZE,
 	.max_write_size = SMB3_DEFAULT_IOSIZE,
 	.max_trans_size = SMB3_DEFAULT_TRANS_SIZE,
+	.max_credits = SMB2_MAX_CREDITS,
 	.large_lock_type = 0,
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED,
@@ -70,6 +72,7 @@ static struct smb_version_values smb302_server_values = {
 	.max_read_size = SMB3_DEFAULT_IOSIZE,
 	.max_write_size = SMB3_DEFAULT_IOSIZE,
 	.max_trans_size = SMB3_DEFAULT_TRANS_SIZE,
+	.max_credits = SMB2_MAX_CREDITS,
 	.large_lock_type = 0,
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED,
@@ -96,6 +99,7 @@ static struct smb_version_values smb311_server_values = {
 	.max_read_size = SMB3_DEFAULT_IOSIZE,
 	.max_write_size = SMB3_DEFAULT_IOSIZE,
 	.max_trans_size = SMB3_DEFAULT_TRANS_SIZE,
+	.max_credits = SMB2_MAX_CREDITS,
 	.large_lock_type = 0,
 	.exclusive_lock_type = SMB2_LOCKFLAG_EXCLUSIVE,
 	.shared_lock_type = SMB2_LOCKFLAG_SHARED,
@@ -197,7 +201,6 @@ void init_smb2_1_server(struct ksmbd_conn *conn)
 	conn->ops = &smb2_0_server_ops;
 	conn->cmds = smb2_0_server_cmds;
 	conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
-	conn->max_credits = SMB2_MAX_CREDITS;
 	conn->signing_algorithm = SIGNING_ALG_HMAC_SHA256_LE;
 
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_LEASES)
@@ -215,7 +218,6 @@ void init_smb3_0_server(struct ksmbd_conn *conn)
 	conn->ops = &smb3_0_server_ops;
 	conn->cmds = smb2_0_server_cmds;
 	conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
-	conn->max_credits = SMB2_MAX_CREDITS;
 	conn->signing_algorithm = SIGNING_ALG_AES_CMAC_LE;
 
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_LEASES)
@@ -240,7 +242,6 @@ void init_smb3_02_server(struct ksmbd_conn *conn)
 	conn->ops = &smb3_0_server_ops;
 	conn->cmds = smb2_0_server_cmds;
 	conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
-	conn->max_credits = SMB2_MAX_CREDITS;
 	conn->signing_algorithm = SIGNING_ALG_AES_CMAC_LE;
 
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_LEASES)
@@ -265,7 +266,6 @@ int init_smb3_11_server(struct ksmbd_conn *conn)
 	conn->ops = &smb3_11_server_ops;
 	conn->cmds = smb2_0_server_cmds;
 	conn->max_cmds = ARRAY_SIZE(smb2_0_server_cmds);
-	conn->max_credits = SMB2_MAX_CREDITS;
 	conn->signing_algorithm = SIGNING_ALG_AES_CMAC_LE;
 
 	if (server_conf.flags & KSMBD_GLOBAL_FLAG_SMB2_LEASES)
@@ -304,3 +304,11 @@ void init_smb2_max_trans_size(unsigned int sz)
 	smb302_server_values.max_trans_size = sz;
 	smb311_server_values.max_trans_size = sz;
 }
+
+void init_smb2_max_credits(unsigned int sz)
+{
+	smb21_server_values.max_credits = sz;
+	smb30_server_values.max_credits = sz;
+	smb302_server_values.max_credits = sz;
+	smb311_server_values.max_credits = sz;
+}

fs/ksmbd/smb2pdu.c

@@ -308,7 +308,7 @@ int smb2_set_rsp_credits(struct ksmbd_work *work)
 
 	hdr->CreditCharge = req_hdr->CreditCharge;
 
-	if (conn->total_credits > conn->max_credits) {
+	if (conn->total_credits > conn->vals->max_credits) {
 		hdr->CreditRequest = 0;
 		pr_err("Total credits overflow: %d\n", conn->total_credits);
 		return -EINVAL;
@@ -329,12 +329,12 @@ int smb2_set_rsp_credits(struct ksmbd_work *work)
 	if (hdr->Command == SMB2_NEGOTIATE)
 		aux_max = 0;
 	else
-		aux_max = conn->max_credits - credit_charge;
+		aux_max = conn->vals->max_credits - credit_charge;
 	aux_credits = min_t(unsigned short, aux_credits, aux_max);
 	credits_granted = credit_charge + aux_credits;
 
-	if (conn->max_credits - conn->total_credits < credits_granted)
-		credits_granted = conn->max_credits -
+	if (conn->vals->max_credits - conn->total_credits < credits_granted)
+		credits_granted = conn->vals->max_credits -
 			conn->total_credits;
 
 	conn->total_credits += credits_granted;

fs/ksmbd/smb2pdu.h

@@ -980,6 +980,7 @@ int init_smb3_11_server(struct ksmbd_conn *conn);
 void init_smb2_max_read_size(unsigned int sz);
 void init_smb2_max_write_size(unsigned int sz);
 void init_smb2_max_trans_size(unsigned int sz);
+void init_smb2_max_credits(unsigned int sz);
 
 bool is_smb2_neg_cmd(struct ksmbd_work *work);
 bool is_smb2_rsp(struct ksmbd_work *work);

fs/ksmbd/smb_common.h

@@ -365,6 +365,7 @@ struct smb_version_values {
 	__u32		max_read_size;
 	__u32		max_write_size;
 	__u32		max_trans_size;
+	__u32		max_credits;
 	__u32		large_lock_type;
 	__u32		exclusive_lock_type;
 	__u32		shared_lock_type;

fs/ksmbd/transport_ipc.c

@@ -301,6 +301,8 @@ static int ipc_server_config_on_startup(struct ksmbd_startup_request *req)
 		init_smb2_max_write_size(req->smb2_max_write);
 	if (req->smb2_max_trans)
 		init_smb2_max_trans_size(req->smb2_max_trans);
+	if (req->smb2_max_credits)
+		init_smb2_max_credits(req->smb2_max_credits);
 
 	ret = ksmbd_set_netbios_name(req->netbios_name);
 	ret |= ksmbd_set_server_string(req->server_string);