[SCSI] iscsi: fix up iscsi eh

The current iscsi_tcp eh is not nicely setup for dm-multipath
and performs some extra task management functions when they
are not needed.

The attached patch:

- Fixes the TMF issues. If a session is rebuilt
then we do not send aborts.

- Fixes the problem where if the host reset fired, we would
return SUCCESS even though we had not really done anything
yet. This ends up causing problem with scsi_error.c's TUR.

- If someone has turned on the userspace nop daemon code to try
and detect network problems before the scsi command timeout
we can now drop and clean up the session before the scsi command
timesout and fires the eh speeding up the time it takes for a
command to go from one patch to another. For network problems
we fail the command with DID_BUS_BUSY so if failfast is set
scsi_decide_disposition fails the command up to dm for it to
try on another path.

- And we had to add some basic iscsi session block code. Previously
if we were trying to repair a session we would retrun a MLQUEUE code
in the queuecommand. This worked but it was not the most efficient
or pretty thing to do since it would take a while to relogin
to the target. For iscsi_tcp/open-iscsi a lot of the iscsi error handler
is in userspace the block code is pretty bare. We will be
adding to that for qla4xxx.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index ba26741ac154..12ef64179b4c 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -159,6 +159,7 @@ struct iscsi_conn {
         struct kfifo            *immqueue;      /* immediate xmit queue */
         struct kfifo            *mgmtqueue;     /* mgmt (control) xmit queue */
         struct kfifo            *xmitqueue;     /* data-path cmd queue */
+        struct list_head        run_list;       /* list of cmds in progress */
         struct work_struct      xmitwork;       /* per-conn. xmit workqueue */
         struct mutex            xmitmutex;      /* serializes connection xmit,
                                                  * access to kfifos:      *
@@ -228,6 +229,7 @@ struct iscsi_session {
                                                  * - mgmtpool,             *
                                                  * - r2tpool               */
         int                     state;          /* session state           */
+        int                     recovery_failed;
         struct list_head        item;
         void                    *auth_client;
         int                     conn_cnt;
@@ -310,6 +312,7 @@ struct iscsi_cmd_task {
         struct iscsi_conn       *conn;                  /* used connection    */
         struct iscsi_mgmt_task  *mtask;                 /* tmf mtask in progr */
 
+        struct list_head        running;                /* running cmd list */
         struct iscsi_r2t_info   *r2t;                   /* in progress R2T    */
         struct iscsi_queue      r2tpool;
         struct kfifo            *r2tqueue;