Uniform max queue depth handling in iSCSI

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@1556 d57e44dd-8a1f-0410-8b47-8ef2f437770f

iscsi-scst/kernel/config.c

@@ -1004,6 +1004,7 @@ static int iscsi_register(void __user *arg)
 
 	memset(&reg, 0, sizeof(reg));
 	reg.max_data_seg_len = ISCSI_CONN_IOV_MAX << PAGE_SHIFT;
+	reg.max_queued_cmds = scst_get_max_lun_commands(NULL, NO_SUCH_LUN);
 
 	res = 0;
 

iscsi-scst/kernel/conn.c

@@ -473,7 +473,7 @@ static void conn_nop_in_delayed_work_fn(struct delayed_work *work)
 	}
 
 	if (conn->nop_in_interval > 0) {
-		TRACE_DBG("Reschedule NOP-In work for conn %p", conn);
+		TRACE_DBG("Reschedule Nop-In work for conn %p", conn);
 		schedule_delayed_work(&conn->nop_in_delayed_work,
 			conn->nop_in_interval + ISCSI_ADD_SCHED_TIME);
 	}
@@ -755,7 +755,7 @@ static int iscsi_conn_alloc(struct iscsi_session *session,
 	conn->rsp_timeout = session->tgt_params.rsp_timeout * HZ;
 	conn->nop_in_interval = session->tgt_params.nop_in_interval * HZ;
 	if (conn->nop_in_interval > 0) {
-		TRACE_DBG("Schedule NOP-In work for conn %p", conn);
+		TRACE_DBG("Schedule Nop-In work for conn %p", conn);
 		schedule_delayed_work(&conn->nop_in_delayed_work,
 			conn->nop_in_interval + ISCSI_ADD_SCHED_TIME);
 	}

iscsi-scst/kernel/iscsi.c

@@ -1558,7 +1558,7 @@ static int nop_out_start(struct iscsi_cmnd *cmnd)
 	iscsi_extracheck_is_rd_thread(conn);
 
 	if (!(req_hdr->flags & ISCSI_FLG_FINAL)) {
-		PRINT_ERROR("%s", "Initiator sent NOP-Out with not a single "
+		PRINT_ERROR("%s", "Initiator sent Nop-Out with not a single "
 			"PDU");
 		err = -ISCSI_REASON_PROTOCOL_ERROR;
 		goto out;
@@ -1567,7 +1567,7 @@ static int nop_out_start(struct iscsi_cmnd *cmnd)
 	if (cmnd_itt(cmnd) == cpu_to_be32(ISCSI_RESERVED_TAG)) {
 		if (unlikely(!(cmnd->pdu.bhs.opcode & ISCSI_OP_IMMEDIATE)))
 			PRINT_ERROR("%s", "Initiator sent RESERVED tag for "
-				"non-immediate NOP-Out command");
+				"non-immediate Nop-Out command");
 	}
 
 	spin_lock(&conn->session->sn_lock);
@@ -1588,7 +1588,7 @@ static int nop_out_start(struct iscsi_cmnd *cmnd)
 						&cmnd->sg_cnt);
 			if (sg == NULL) {
 				TRACE(TRACE_OUT_OF_MEM, "Allocating buffer for"
-				      " %d NOP-Out payload failed", size);
+				      " %d Nop-Out payload failed", size);
 				err = -ISCSI_REASON_OUT_OF_RESOURCES;
 				goto out;
 			}
@@ -2509,7 +2509,7 @@ static void nop_out_exec(struct iscsi_cmnd *req)
 		struct iscsi_cmnd *r;
 		struct iscsi_conn *conn = req->conn;
 
- 		TRACE_DBG("Receive NOP-in response (ttt 0x%08x)",
+ 		TRACE_DBG("Receive Nop-In response (ttt 0x%08x)",
 			be32_to_cpu(cmnd_ttt(req)));
 
 		spin_lock_bh(&conn->nop_req_list_lock);
@@ -2526,8 +2526,8 @@ static void nop_out_exec(struct iscsi_cmnd *req)
 		if (found)
 			cmnd_put(r);
 		else
-			TRACE_MGMT_DBG("%s", "Got NOP-out response without "
-				"corresponding NOP-in request");
+			TRACE_MGMT_DBG("%s", "Got Nop-out response without "
+				"corresponding Nop-In request");
 	}
 
 	req_cmnd_release(req);
@@ -3489,13 +3489,13 @@ void iscsi_send_nop_in(struct iscsi_conn *conn)
 
 	req = cmnd_alloc(conn, NULL);
 	if (req == NULL) {
-		PRINT_ERROR("%s", "Unable to alloc fake NOP-IN request");
+		PRINT_ERROR("%s", "Unable to alloc fake Nop-In request");
 		goto out_err;
 	}
 
 	rsp = iscsi_alloc_main_rsp(req);
 	if (rsp == NULL) {
-		PRINT_ERROR("%s", "Unable to alloc NOP-IN rsp");
+		PRINT_ERROR("%s", "Unable to alloc Nop-In rsp");
 		goto out_err_free_req;
 	}
 
@@ -3512,7 +3512,7 @@ void iscsi_send_nop_in(struct iscsi_conn *conn)
 
 	/* Supposed that all other fields are zeroed */
 
-	TRACE_DBG("Sending NOP-in request (ttt 0x%08x)", rsp_hdr->ttt);
+	TRACE_DBG("Sending Nop-In request (ttt 0x%08x)", rsp_hdr->ttt);
 	spin_lock_bh(&conn->nop_req_list_lock);
 	list_add_tail(&rsp->nop_req_list_entry, &conn->nop_req_list);
 	spin_unlock_bh(&conn->nop_req_list_lock);

iscsi-scst/kernel/nthread.c

@@ -767,7 +767,7 @@ static int iscsi_rx_check_ddigest(struct iscsi_conn *conn)
 			cmnd_get(cmnd);
 		} else if (cmnd_opcode(cmnd) != ISCSI_OP_SCSI_DATA_OUT) {
 			/*
-			 * We could get here only for NOP-Out. ISCSI RFC
+			 * We could get here only for Nop-Out. ISCSI RFC
 			 * doesn't specify how to deal with digest errors in
 			 * this case. Is closing connection correct?
 			 */

iscsi-scst/kernel/param.c

@@ -22,12 +22,17 @@ do {										\
 		TRACE_DBG("%s: %u", #word, (iparams)[key_##word]);		\
 		if ((iparams)[key_##word] < (min) ||				\
 			(iparams)[key_##word] > (max)) {			\
-			PRINT_ERROR("%s: %u is out of range (%u %u)",		\
-				#word, (iparams)[key_##word], (min), (max));	\
-			if ((iparams)[key_##word] < (min))			\
+			if ((iparams)[key_##word] < (min)) {			\
 				(iparams)[key_##word] = (min);			\
-			else							\
+				PRINT_WARNING("%s: %u is too small, resetting "	\
+					"it to allowed min %u",			\
+					#word, (iparams)[key_##word], (min));	\
+			} else {						\
+				PRINT_WARNING("%s: %u is too big, resetting "	\
+					"it to allowed max %u",			\
+					#word, (iparams)[key_##word], (max));	\
 				(iparams)[key_##word] = (max);			\
+			}							\
 		}								\
 	}									\
 } while (0)
@@ -186,12 +191,14 @@ static void sess_params_get(struct iscsi_sess_params *params,
 }
 
 /* target_mutex supposed to be locked */
-static void tgt_params_check(struct iscsi_kern_params_info *info)
+static void tgt_params_check(struct iscsi_session *session,
+	struct iscsi_kern_params_info *info)
 {
 	int32_t *iparams = info->target_params;
 
 	CHECK_PARAM(info, iparams, queued_cmnds, MIN_NR_QUEUED_CMNDS,
-		    MAX_NR_QUEUED_CMNDS);
+		min_t(int, MAX_NR_QUEUED_CMNDS,
+		      scst_get_max_lun_commands(session->scst_sess, NO_SUCH_LUN)));
 	CHECK_PARAM(info, iparams, rsp_timeout, MIN_RSP_TIMEOUT,
 		MAX_RSP_TIMEOUT);
 	CHECK_PARAM(info, iparams, nop_in_interval, MIN_NOP_IN_INTERVAL,
@@ -209,14 +216,14 @@ static int iscsi_tgt_params_set(struct iscsi_session *session,
 	if (set) {
 		struct iscsi_conn *conn;
 
-		tgt_params_check(info);
+		tgt_params_check(session, info);
 
 		SET_PARAM(params, info, iparams, queued_cmnds);
 		SET_PARAM(params, info, iparams, rsp_timeout);
 		SET_PARAM(params, info, iparams, nop_in_interval);
 
 		PRINT_INFO("Target parameters set for session %llx: "
-			"QueuedCommands %d, Response timeout %d, NOP-in "
+			"QueuedCommands %d, Response timeout %d, Nop-In "
 			"interval %d", session->sid, params->queued_cmnds,
 			params->rsp_timeout, params->nop_in_interval);
 
@@ -226,7 +233,7 @@ static int iscsi_tgt_params_set(struct iscsi_session *session,
 			conn->nop_in_interval = session->tgt_params.nop_in_interval * HZ;
 			spin_lock_bh(&iscsi_rd_lock);
 			if (!conn->closing && (conn->nop_in_interval > 0)) {
-				TRACE_DBG("Schedule NOP-In work for conn %p", conn);
+				TRACE_DBG("Schedule Nop-In work for conn %p", conn);
 				schedule_delayed_work(&conn->nop_in_delayed_work,
 					conn->nop_in_interval + ISCSI_ADD_SCHED_TIME);
 			}

iscsi-scst/usr/ctldev.c

@@ -29,7 +29,7 @@
 
 #define CTL_DEVICE	"/dev/iscsi-scst-ctl"
 
-int kernel_open(int *max_data_seg_len)
+int kernel_open(void)
 {
 	FILE *f;
 	char devname[256];
@@ -91,8 +91,10 @@ int kernel_open(int *max_data_seg_len)
 			"kernel module?\n", strerror(errno));
 		goto out_close;
 	} else {
-		log_debug(0, "MAX_DATA_SEG_LEN %d", err);
-		*max_data_seg_len = reg.max_data_seg_len;
+		log_debug(0, "max_data_seg_len %d, max_queued_cmds %d, ",
+			reg.max_data_seg_len, reg.max_queued_cmds);
+		iscsi_init_params.max_data_seg_len = reg.max_data_seg_len;
+		iscsi_init_params.max_queued_cmds = reg.max_queued_cmds;
 	}
 
 out:

iscsi-scst/usr/iscsi_scstd.c

@@ -62,6 +62,8 @@ static int incoming_cnt;
 int ctrl_fd, ipc_fd, nl_fd;
 int conn_blocked;
 
+struct iscsi_init_params iscsi_init_params;
+
 static char program_name[] = "iscsi-scstd";
 
 static struct option const long_options[] =
@@ -566,7 +568,7 @@ static void event_loop(void)
 	}
 }
 
-static void init_max_data_seg_len(int max_data_seg_len)
+static void init_max_params(void)
 {
 	if ((session_keys[key_max_recv_data_length].local_def != -1) ||
 	    (session_keys[key_max_recv_data_length].max != -1) ||
@@ -580,21 +582,29 @@ static void init_max_data_seg_len(int max_data_seg_len)
 		exit(-1);
 	}
 
+	/* QueuedCommands */
+	target_keys[key_queued_cmnds].local_def = min(target_keys[key_queued_cmnds].local_def,
+						      iscsi_init_params.max_queued_cmds);
+	target_keys[key_queued_cmnds].max = min(target_keys[key_queued_cmnds].max,
+						iscsi_init_params.max_queued_cmds);
+	target_keys[key_queued_cmnds].min = min(target_keys[key_queued_cmnds].min,
+						iscsi_init_params.max_queued_cmds);
+
 	/* MaxRecvDataSegmentLength */
-	session_keys[key_max_recv_data_length].local_def = max_data_seg_len;
-	session_keys[key_max_recv_data_length].max = max_data_seg_len;
+	session_keys[key_max_recv_data_length].local_def = iscsi_init_params.max_data_seg_len;
+	session_keys[key_max_recv_data_length].max = iscsi_init_params.max_data_seg_len;
 
 	/* MaxXmitDataSegmentLength */
-	session_keys[key_max_xmit_data_length].local_def = max_data_seg_len;
-	session_keys[key_max_xmit_data_length].max = max_data_seg_len;
+	session_keys[key_max_xmit_data_length].local_def = iscsi_init_params.max_data_seg_len;
+	session_keys[key_max_xmit_data_length].max = iscsi_init_params.max_data_seg_len;
 
 	/* MaxBurstLength */
-	session_keys[key_max_burst_length].local_def = max_data_seg_len;
-	session_keys[key_max_burst_length].max = max_data_seg_len;
+	session_keys[key_max_burst_length].local_def = iscsi_init_params.max_data_seg_len;
+	session_keys[key_max_burst_length].max = iscsi_init_params.max_data_seg_len;
 
 	/* FirstBurstLength */
-	session_keys[key_first_burst_length].local_def = max_data_seg_len;
-	session_keys[key_first_burst_length].max = max_data_seg_len;
+	session_keys[key_first_burst_length].local_def = iscsi_init_params.max_data_seg_len;
+	session_keys[key_first_burst_length].max = iscsi_init_params.max_data_seg_len;
 
 	return;
 }
@@ -605,7 +615,6 @@ int main(int argc, char **argv)
 	char *config = NULL;
 	uid_t uid = 0;
 	gid_t gid = 0;
-	int max_data_seg_len = -1;
 	int err;
 
 #ifdef CONFIG_SCST_PROC
@@ -668,10 +677,10 @@ int main(int argc, char **argv)
 		exit(-1);
 	};
 
-	if ((ctrl_fd = kernel_open(&max_data_seg_len)) < 0)
+	if ((ctrl_fd = kernel_open()) < 0)
 		exit(-1);
 
-	init_max_data_seg_len(max_data_seg_len);
+	init_max_params();
 
 #ifndef CONFIG_SCST_PROC
 	err = kernel_attr_add(NULL, ISCSI_ISNS_SERVER_PARAM_NAME,

iscsi-scst/usr/iscsid.h

@@ -30,6 +30,11 @@
 #define sBUG() assert(0)
 #define sBUG_ON(p) assert(!(p))
 
+struct iscsi_init_params {
+	int max_data_seg_len;
+	int max_queued_cmds;
+};
+
 struct buf_segment {
 	struct __qelem entry;
 
@@ -199,6 +204,7 @@ extern void conn_free_rsp_buf_list(struct connection *conn);
 
 /* iscsi_scstd.c */
 extern uint16_t server_port;
+extern struct iscsi_init_params iscsi_init_params;
 extern void isns_set_fd(int isns, int scn_listen, int scn);
 
 /* iscsid.c */
@@ -253,7 +259,7 @@ extern int iscsi_adm_request_listen(void);
 extern int iscsi_adm_request_handle(int accept_fd);
 
 /* ctldev.c */
-extern int kernel_open(int *max_data_seg_len);
+extern int kernel_open(void);
 extern int kernel_params_get(u32 tid, u64 sid, int type, struct iscsi_param *params);
 extern int kernel_params_set(u32 tid, u64 sid, int type, u32 partial,
 	const struct iscsi_param *params);

scst/include/scst.h

@@ -3638,6 +3638,18 @@ int scst_tape_generic_dev_done(struct scst_cmd *cmd,
  */
 int scst_obtain_device_parameters(struct scst_device *dev);
 
+/*
+ * Returns maximum commands count which can be queued to this LUN in this
+ * session.
+ *
+ * If lun is NO_SUCH_LUN, returns minimum of maximum commands count which
+ * can be queued to any LUN in this session.
+ *
+ * If sess is NULL, returns minimum of maximum commands count which can be
+ * queued to any SCST device.
+ */
+int scst_get_max_lun_commands(struct scst_session *sess, uint64_t lun);
+
 /*
  * Has to be put here open coded, because Linux doesn't have equivalent, which
  * allows exclusive wake ups of threads in LIFO order. We need it to let (yet)

scst/src/scst_lib.c

@@ -5826,6 +5826,12 @@ out:
 	return;
 }
 
+int scst_get_max_lun_commands(struct scst_session *sess, uint64_t lun)
+{
+	return SCST_MAX_TGT_DEV_COMMANDS;
+}
+EXPORT_SYMBOL(scst_get_max_lun_commands);
+
 char *scst_get_next_lexem(char **token_str)
 {
 	char *p = *token_str;