[SCSI] iscsi: fix command requeues during iscsi recovery

Do not flush queues then block session. This will cause commands
to needlessly swing around on us and remove goofy
recovery_failed field and replace with state value.

And do not start recovery from within the host reset function.
This causeis too many problems becuase open-iscsi was desinged to
call out to userspace then have userpscae decide if we should
go into recovery or kill the session.

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

3 files changed, 50 insertions, 42 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 580c0505603c..d810acae45f7 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -487,6 +487,11 @@ void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
         unsigned long flags;
 
         spin_lock_irqsave(&session->lock, flags);
+        if (session->state == ISCSI_STATE_FAILED) {
+                spin_unlock_irqrestore(&session->lock, flags);
+                return;
+        }
+
         if (session->conn_cnt == 1 || session->leadconn == conn)
                 session->state = ISCSI_STATE_FAILED;
         spin_unlock_irqrestore(&session->lock, flags);
@@ -612,6 +617,7 @@ enum {
         FAILURE_SESSION_FREED,
         FAILURE_WINDOW_CLOSED,
         FAILURE_SESSION_TERMINATE,
+        FAILURE_SESSION_IN_RECOVERY,
         FAILURE_SESSION_RECOVERY_TIMEOUT,
 };
 
@@ -631,18 +637,30 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 
         spin_lock(&session->lock);
 
-        if (session->state != ISCSI_STATE_LOGGED_IN) {
-                if (session->recovery_failed) {
-                        reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
-                        goto fault;
-                } else if (session->state == ISCSI_STATE_FAILED) {
-                        reason = FAILURE_SESSION_FAILED;
-                        goto reject;
-                } else if (session->state == ISCSI_STATE_TERMINATE) {
-                        reason = FAILURE_SESSION_TERMINATE;
+        /*
+         * ISCSI_STATE_FAILED is a temp. state. The recovery
+         * code will decide what is best to do with command queued
+         * during this time
+         */
+        if (session->state != ISCSI_STATE_LOGGED_IN &&
+            session->state != ISCSI_STATE_FAILED) {
+                /*
+                 * to handle the race between when we set the recovery state
+                 * and block the session we requeue here (commands could
+                 * be entering our queuecommand while a block is starting
+                 * up because the block code is not locked)
+                 */
+                if (session->state == ISCSI_STATE_IN_RECOVERY) {
+                        reason = FAILURE_SESSION_IN_RECOVERY;
                         goto fault;
                 }
-                reason = FAILURE_SESSION_FREED;
+
+                if (session->state == ISCSI_STATE_RECOVERY_FAILED)
+                        reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
+                else if (session->state == ISCSI_STATE_TERMINATE)
+                        reason = FAILURE_SESSION_TERMINATE;
+                else
+                        reason = FAILURE_SESSION_FREED;
                 goto fault;
         }
 
@@ -728,8 +746,8 @@ iscsi_conn_send_generic(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
                  */
                 mtask = conn->login_mtask;
         else {
-                BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
-                BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
+                BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
+                BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
 
                 nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
                 if (!__kfifo_get(session->mgmtpool.queue,
@@ -803,7 +821,7 @@ void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 
         spin_lock_bh(&session->lock);
         if (session->state != ISCSI_STATE_LOGGED_IN) {
-                session->recovery_failed = 1;
+                session->state = ISCSI_STATE_RECOVERY_FAILED;
                 if (conn)
                         wake_up(&conn->ehwait);
         }
@@ -838,20 +856,14 @@ failed:
          * we drop the lock here but the leadconn cannot be destoyed while
          * we are in the scsi eh
          */
-        if (fail_session) {
+        if (fail_session)
                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-                /*
-                 * if userspace cannot respond then we must kick this off
-                 * here for it
-                 */
-                iscsi_start_session_recovery(session, conn, STOP_CONN_RECOVER);
-        }
 
         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
         wait_event_interruptible(conn->ehwait,
                                  session->state == ISCSI_STATE_TERMINATE ||
                                  session->state == ISCSI_STATE_LOGGED_IN ||
-                                 session->recovery_failed);
+                                 session->state == ISCSI_STATE_RECOVERY_FAILED);
         if (signal_pending(current))
                 flush_signals(current);
 
@@ -940,8 +952,7 @@ static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
         wait_event_interruptible(conn->ehwait,
                                  sc->SCp.phase != session->age ||
                                  session->state != ISCSI_STATE_LOGGED_IN ||
-                                 conn->tmabort_state != TMABORT_INITIAL ||
-                                 session->recovery_failed);
+                                 conn->tmabort_state != TMABORT_INITIAL);
         if (signal_pending(current))
                 flush_signals(current);
         del_timer_sync(&conn->tmabort_timer);
@@ -1491,7 +1502,6 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
                 conn->stop_stage = 0;
                 conn->tmabort_state = TMABORT_INITIAL;
                 session->age++;
-                session->recovery_failed = 0;
                 spin_unlock_bh(&session->lock);
 
                 iscsi_unblock_session(session_to_cls(session));
@@ -1566,8 +1576,8 @@ static void fail_all_commands(struct iscsi_conn *conn)
         conn->ctask = NULL;
 }
 
-void iscsi_start_session_recovery(struct iscsi_session *session,
-                                  struct iscsi_conn *conn, int flag)
+static void iscsi_start_session_recovery(struct iscsi_session *session,
+                                         struct iscsi_conn *conn, int flag)
 {
         int old_stop_stage;
 
@@ -1597,19 +1607,10 @@ void iscsi_start_session_recovery(struct iscsi_session *session,
         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
 
         if (session->conn_cnt == 0 || session->leadconn == conn)
-                session->state = ISCSI_STATE_FAILED;
+                session->state = ISCSI_STATE_IN_RECOVERY;
 
         spin_unlock_bh(&session->lock);
 
-        session->tt->terminate_conn(conn);
-        /*
-         * flush queues.
-         */
-        spin_lock_bh(&session->lock);
-        fail_all_commands(conn);
-        flush_control_queues(session, conn);
-        spin_unlock_bh(&session->lock);
-
         /*
          * for connection level recovery we should not calculate
          * header digest. conn->hdr_size used for optimization
@@ -1619,18 +1620,26 @@ void iscsi_start_session_recovery(struct iscsi_session *session,
         if (flag == STOP_CONN_RECOVER) {
                 conn->hdrdgst_en = 0;
                 conn->datadgst_en = 0;
-
                 /*
                  * if this is called from the eh and and from userspace
                  * then we only need to block once.
                  */
-                if (session->state == ISCSI_STATE_FAILED &&
+                if (session->state == ISCSI_STATE_IN_RECOVERY &&
                     old_stop_stage != STOP_CONN_RECOVER)
                         iscsi_block_session(session_to_cls(session));
         }
+
+        session->tt->terminate_conn(conn);
+        /*
+         * flush queues.
+         */
+        spin_lock_bh(&session->lock);
+        fail_all_commands(conn);
+        flush_control_queues(session, conn);
+        spin_unlock_bh(&session->lock);
+
         mutex_unlock(&conn->xmitmutex);
 }
-EXPORT_SYMBOL_GPL(iscsi_start_session_recovery);
 
 void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
 {
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 2dba929a2a05..17b28f08b692 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -210,7 +210,6 @@ struct iscsi_session {
                                                  * - mgmtpool,             *
                                                  * - r2tpool               */
         int                     state;          /* session state           */
-        int                     recovery_failed;
         struct list_head        item;
         int                     conn_cnt;
         int                     age;            /* counts session re-opens */
@@ -241,8 +240,6 @@ iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
                     int, int, uint32_t, uint32_t *);
 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
-extern void iscsi_start_session_recovery(struct iscsi_session *,
-                                        struct iscsi_conn *, int);
 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
 
 #define session_to_cls(_sess) \
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index c9e9475c6dff..92129b97d31e 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -173,6 +173,8 @@ struct iscsi_cls_conn {
 #define ISCSI_STATE_LOGGED_IN           2
 #define ISCSI_STATE_FAILED              3
 #define ISCSI_STATE_TERMINATE           4
+#define ISCSI_STATE_IN_RECOVERY         5
+#define ISCSI_STATE_RECOVERY_FAILED     6
 
 struct iscsi_cls_session {
         struct list_head sess_list;             /* item in session_list */