iscsi-target: Enable MaxXmitDataSegmentLength operation in login path

This patch activates MaxXmitDataSegmentLength usage that performs the
following sequence of events:

- Once the incoming initiator's MAXRECVDATASEGMENTLENGTH key is detected
  within iscsi_check_acceptor_state(), save the requested MRDSL into
  conn->conn_ops->MaxRecvDataSegmentLength

- Next change the outgoing target's MaxRecvDataSegmenthLength key=value
  based upon the local TPG's MaxXmitDataSegmentLength attribute value.

- Change iscsi_set_connection_parameters() to skip the assignment of
  conn->conn_ops->MaxRecvDataSegmentLength, now setup within
  iscsi_check_acceptor_state()

Also update iscsi_decode_text_input() -> iscsi_check_acceptor_state()
code-path to accept struct iscsi_conn *.

Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Andy Grover <agrover@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 44 insertions, 12 deletions

diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index a9a73ac88fd0..d08373fa8caf 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -550,7 +550,7 @@ static int iscsi_target_handle_csg_zero(
                         SENDER_INITIATOR|SENDER_RECEIVER,
                         login->req_buf,
                         payload_length,
-                        conn->param_list);
+                        conn);
         if (ret < 0)
                 return -1;
 
@@ -627,7 +627,7 @@ static int iscsi_target_handle_csg_one(struct iscsi_conn *conn, struct iscsi_log
                         SENDER_INITIATOR|SENDER_RECEIVER,
                         login->req_buf,
                         payload_length,
-                        conn->param_list);
+                        conn);
         if (ret < 0)
                 return -1;
 
diff --git a/drivers/target/iscsi/iscsi_target_parameters.c b/drivers/target/iscsi/iscsi_target_parameters.c
index 40864ee70302..3678ff2139de 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -1065,7 +1065,8 @@ out:
         return proposer_values;
 }
 
-static int iscsi_check_acceptor_state(struct iscsi_param *param, char *value)
+static int iscsi_check_acceptor_state(struct iscsi_param *param, char *value,
+                                struct iscsi_conn *conn)
 {
         u8 acceptor_boolean_value = 0, proposer_boolean_value = 0;
         char *negoitated_value = NULL;
@@ -1140,8 +1141,35 @@ static int iscsi_check_acceptor_state(struct iscsi_param *param, char *value)
                                 return -1;
                 }
 
-                if (!strcmp(param->name, MAXRECVDATASEGMENTLENGTH))
-                        SET_PSTATE_REPLY_OPTIONAL(param);
+                if (!strcmp(param->name, MAXRECVDATASEGMENTLENGTH)) {
+                        struct iscsi_param *param_mxdsl;
+                        unsigned long long tmp;
+                        int rc;
+
+                        rc = strict_strtoull(param->value, 0, &tmp);
+                        if (rc < 0)
+                                return -1;
+
+                        conn->conn_ops->MaxRecvDataSegmentLength = tmp;
+                        pr_debug("Saving op->MaxRecvDataSegmentLength from"
+                                " original initiator received value: %u\n",
+                                conn->conn_ops->MaxRecvDataSegmentLength);
+
+                        param_mxdsl = iscsi_find_param_from_key(
+                                                MAXXMITDATASEGMENTLENGTH,
+                                                conn->param_list);
+                        if (!param_mxdsl)
+                                return -1;
+
+                        rc = iscsi_update_param_value(param,
+                                                param_mxdsl->value);
+                        if (rc < 0)
+                                return -1;
+
+                        pr_debug("Updated %s to target MXDSL value: %s\n",
+                                        param->name, param->value);
+                }
+
         } else if (IS_TYPE_NUMBER_RANGE(param)) {
                 negoitated_value = iscsi_get_value_from_number_range(
                                         param, value);
@@ -1535,8 +1563,9 @@ int iscsi_decode_text_input(
         u8 sender,
         char *textbuf,
         u32 length,
-        struct iscsi_param_list *param_list)
+        struct iscsi_conn *conn)
 {
+        struct iscsi_param_list *param_list = conn->param_list;
         char *tmpbuf, *start = NULL, *end = NULL;
 
         tmpbuf = kzalloc(length + 1, GFP_KERNEL);
@@ -1594,7 +1623,7 @@ int iscsi_decode_text_input(
                         }
                         SET_PSTATE_RESPONSE_GOT(param);
                 } else {
-                        if (iscsi_check_acceptor_state(param, value) < 0) {
+                        if (iscsi_check_acceptor_state(param, value, conn) < 0) {
                                 kfree(tmpbuf);
                                 return -1;
                         }
@@ -1755,10 +1784,13 @@ void iscsi_set_connection_parameters(
                         pr_debug("DataDigest:                   %s\n",
                                 param->value);
                 } else if (!strcmp(param->name, MAXRECVDATASEGMENTLENGTH)) {
-                        ops->MaxRecvDataSegmentLength =
-                                simple_strtoul(param->value, &tmpptr, 0);
-                        pr_debug("MaxRecvDataSegmentLength:     %s\n",
-                                param->value);
+                        /*
+                         * At this point iscsi_check_acceptor_state() will have
+                         * set ops->MaxRecvDataSegmentLength from the original
+                         * initiator provided value.
+                         */
+                        pr_debug("MaxRecvDataSegmentLength:     %u\n",
+                                ops->MaxRecvDataSegmentLength);
                 } else if (!strcmp(param->name, OFMARKER)) {
                         ops->OFMarker = !strcmp(param->value, YES);
                         pr_debug("OFMarker:                     %s\n",
diff --git a/drivers/target/iscsi/iscsi_target_parameters.h b/drivers/target/iscsi/iscsi_target_parameters.h
index 77a28b589d56..1e1b7504a76b 100644
--- a/drivers/target/iscsi/iscsi_target_parameters.h
+++ b/drivers/target/iscsi/iscsi_target_parameters.h
@@ -36,7 +36,7 @@ extern void iscsi_release_param_list(struct iscsi_param_list *);
 extern struct iscsi_param *iscsi_find_param_from_key(char *, struct iscsi_param_list *);
 extern int iscsi_extract_key_value(char *, char **, char **);
 extern int iscsi_update_param_value(struct iscsi_param *, char *);
-extern int iscsi_decode_text_input(u8, u8, char *, u32, struct iscsi_param_list *);
+extern int iscsi_decode_text_input(u8, u8, char *, u32, struct iscsi_conn *);
 extern int iscsi_encode_text_output(u8, u8, char *, u32 *,
                         struct iscsi_param_list *);
 extern int iscsi_check_negotiated_keys(struct iscsi_param_list *);