iscsi-target: Add MaxXmitDataSegmentLength connection recovery check

The iSCSI TMR TASK_REASSIGN completion logic in iscsi_tmr_task_reassign()
does an explict check for MRDSL across task reassignment, so go ahead and
add an explict MaxXmitDataSegmentLength check here as well to be safe.

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, 10 insertions, 1 deletions

diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index b26611aa5ff3..e6a830545c89 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -579,6 +579,7 @@ struct iscsi_conn_recovery {
         u16                     cid;
         u32                     cmd_count;
         u32                     maxrecvdatasegmentlength;
+        u32                     maxxmitdatasegmentlength;
         int                     ready_for_reallegiance;
         struct list_head        conn_recovery_cmd_list;
         spinlock_t              conn_recovery_cmd_lock;
diff --git a/drivers/target/iscsi/iscsi_target_erl2.c b/drivers/target/iscsi/iscsi_target_erl2.c
index 65aac14fd831..667c19cc3b28 100644
--- a/drivers/target/iscsi/iscsi_target_erl2.c
+++ b/drivers/target/iscsi/iscsi_target_erl2.c
@@ -421,6 +421,7 @@ int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn)
         cr->cid = conn->cid;
         cr->cmd_count = cmd_count;
         cr->maxrecvdatasegmentlength = conn->conn_ops->MaxRecvDataSegmentLength;
+        cr->maxxmitdatasegmentlength = conn->conn_ops->MaxXmitDataSegmentLength;
         cr->sess = conn->sess;
 
         iscsit_attach_inactive_connection_recovery_entry(conn->sess, cr);
diff --git a/drivers/target/iscsi/iscsi_target_tmr.c b/drivers/target/iscsi/iscsi_target_tmr.c
index f62fe123d902..05d2e6445ade 100644
--- a/drivers/target/iscsi/iscsi_target_tmr.c
+++ b/drivers/target/iscsi/iscsi_target_tmr.c
@@ -146,7 +146,7 @@ u8 iscsit_tmr_task_reassign(
         }
         /*
          * Temporary check to prevent connection recovery for
-         * connections with a differing MaxRecvDataSegmentLength.
+         * connections with a differing Max*DataSegmentLength.
          */
         if (cr->maxrecvdatasegmentlength !=
             conn->conn_ops->MaxRecvDataSegmentLength) {
@@ -155,6 +155,13 @@ u8 iscsit_tmr_task_reassign(
                         " TMR TASK_REASSIGN.\n");
                 return ISCSI_TMF_RSP_REJECTED;
         }
+        if (cr->maxxmitdatasegmentlength !=
+            conn->conn_ops->MaxXmitDataSegmentLength) {
+                pr_err("Unable to perform connection recovery for"
+                        " differing MaxXmitDataSegmentLength, rejecting"
+                        " TMR TASK_REASSIGN.\n");
+                return ISCSI_TMF_RSP_REJECTED;
+        }
 
         ref_lun = scsilun_to_int(&hdr->lun);
         if (ref_lun != ref_cmd->se_cmd.orig_fe_lun) {