[SCSI] libiscsi, iscsi_tcp: add device support

This patch adds logical unit reset support. This should work for ib_iser,
but I have not finished testing that driver so it is not hooked in yet.

This patch also temporarily reverts the iscsi_tcp r2t write out patch.
That code is completely rewritten in this patchset.

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

1 files changed, 281 insertions, 213 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 8b57af5baaec..176458f35316 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -86,7 +86,7 @@ iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
                  * xmit thread
                  */
                 if (!list_empty(&session->leadconn->xmitqueue) ||
-                    __kfifo_len(session->leadconn->mgmtqueue))
+                    !list_empty(&session->leadconn->mgmtqueue))
                         scsi_queue_work(session->host,
                                         &session->leadconn->xmitwork);
         }
@@ -318,15 +318,15 @@ static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
         conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
         conn->tmfrsp_pdus_cnt++;
 
-        if (conn->tmabort_state != TMABORT_INITIAL)
+        if (conn->tmf_state != TMF_QUEUED)
                 return;
 
         if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
-                conn->tmabort_state = TMABORT_SUCCESS;
+                conn->tmf_state = TMF_SUCCESS;
         else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
-                conn->tmabort_state = TMABORT_NOT_FOUND;
+                conn->tmf_state = TMF_NOT_FOUND;
         else
-                conn->tmabort_state = TMABORT_FAILED;
+                conn->tmf_state = TMF_FAILED;
         wake_up(&conn->ehwait);
 }
 
@@ -429,7 +429,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
                          */
                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
                                 rc = ISCSI_ERR_CONN_FAILED;
-                        list_del(&mtask->running);
+                        list_del_init(&mtask->running);
                         if (conn->login_mtask != mtask)
                                 __kfifo_put(session->mgmtpool.queue,
                                             (void*)&mtask, sizeof(void*));
@@ -451,10 +451,9 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 
                         if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
                                 rc = ISCSI_ERR_CONN_FAILED;
-                        list_del(&mtask->running);
-                        if (conn->login_mtask != mtask)
-                                __kfifo_put(session->mgmtpool.queue,
-                                            (void*)&mtask, sizeof(void*));
+                        list_del_init(&mtask->running);
+                        __kfifo_put(session->mgmtpool.queue,
+                                    (void*)&mtask, sizeof(void*));
                         break;
                 default:
                         rc = ISCSI_ERR_BAD_OPCODE;
@@ -609,7 +608,8 @@ static void iscsi_prep_mtask(struct iscsi_conn *conn,
                 session->tt->init_mgmt_task(conn, mtask);
 
         debug_scsi("mgmtpdu [op 0x%x hdr->itt 0x%x datalen %d]\n",
-                   hdr->opcode, hdr->itt, mtask->data_count);
+                   hdr->opcode & ISCSI_OPCODE_MASK, hdr->itt,
+                   mtask->data_count);
 }
 
 static int iscsi_xmit_mtask(struct iscsi_conn *conn)
@@ -658,21 +658,13 @@ static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
 static int iscsi_xmit_ctask(struct iscsi_conn *conn)
 {
         struct iscsi_cmd_task *ctask = conn->ctask;
-        int rc = 0;
-
-        /*
-         * serialize with TMF AbortTask
-         */
-        if (ctask->state == ISCSI_TASK_ABORTING)
-                goto done;
+        int rc;
 
         __iscsi_get_ctask(ctask);
         spin_unlock_bh(&conn->session->lock);
         rc = conn->session->tt->xmit_cmd_task(conn, ctask);
         spin_lock_bh(&conn->session->lock);
         __iscsi_put_ctask(ctask);
-
-done:
         if (!rc)
                 /* done with this ctask */
                 conn->ctask = NULL;
@@ -680,6 +672,22 @@ done:
 }
 
 /**
+ * iscsi_requeue_ctask - requeue ctask to run from session workqueue
+ * @ctask: ctask to requeue
+ *
+ * LLDs that need to run a ctask from the session workqueue should call
+ * this. The session lock must be held.
+ */
+void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask)
+{
+        struct iscsi_conn *conn = ctask->conn;
+
+        list_move_tail(&ctask->running, &conn->requeue);
+        scsi_queue_work(conn->session->host, &conn->xmitwork);
+}
+EXPORT_SYMBOL_GPL(iscsi_requeue_ctask);
+
+/**
  * iscsi_data_xmit - xmit any command into the scheduled connection
  * @conn: iscsi connection
  *
@@ -717,36 +725,27 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
          * overflow us with nop-ins
          */
 check_mgmt:
-        while (__kfifo_get(conn->mgmtqueue, (void*)&conn->mtask,
-                           sizeof(void*))) {
+        while (!list_empty(&conn->mgmtqueue)) {
+                conn->mtask = list_entry(conn->mgmtqueue.next,
+                                         struct iscsi_mgmt_task, running);
                 iscsi_prep_mtask(conn, conn->mtask);
-                list_add_tail(&conn->mtask->running, &conn->mgmt_run_list);
+                list_move_tail(conn->mgmtqueue.next, &conn->mgmt_run_list);
                 rc = iscsi_xmit_mtask(conn);
                 if (rc)
                         goto again;
         }
 
-        /* process command queue */
+        /* process pending command queue */
         while (!list_empty(&conn->xmitqueue)) {
-                /*
-                 * iscsi tcp may readd the task to the xmitqueue to send
-                 * write data
-                 */
+                if (conn->tmf_state == TMF_QUEUED)
+                        break;
+
                 conn->ctask = list_entry(conn->xmitqueue.next,
                                          struct iscsi_cmd_task, running);
-                switch (conn->ctask->state) {
-                case ISCSI_TASK_ABORTING:
-                        break;
-                case ISCSI_TASK_PENDING:
-                        iscsi_prep_scsi_cmd_pdu(conn->ctask);
-                        conn->session->tt->init_cmd_task(conn->ctask);
-                        /* fall through */
-                default:
-                        conn->ctask->state = ISCSI_TASK_RUNNING;
-                        break;
-                }
+                iscsi_prep_scsi_cmd_pdu(conn->ctask);
+                conn->session->tt->init_cmd_task(conn->ctask);
+                conn->ctask->state = ISCSI_TASK_RUNNING;
                 list_move_tail(conn->xmitqueue.next, &conn->run_list);
-
                 rc = iscsi_xmit_ctask(conn);
                 if (rc)
                         goto again;
@@ -755,7 +754,22 @@ check_mgmt:
                  * we need to check the mgmt queue for nops that need to
                  * be sent to aviod starvation
                  */
-                if (__kfifo_len(conn->mgmtqueue))
+                if (!list_empty(&conn->mgmtqueue))
+                        goto check_mgmt;
+        }
+
+        while (!list_empty(&conn->requeue)) {
+                if (conn->session->fast_abort && conn->tmf_state != TMF_INITIAL)
+                        break;
+
+                conn->ctask = list_entry(conn->requeue.next,
+                                         struct iscsi_cmd_task, running);
+                conn->ctask->state = ISCSI_TASK_RUNNING;
+                list_move_tail(conn->requeue.next, &conn->run_list);
+                rc = iscsi_xmit_ctask(conn);
+                if (rc)
+                        goto again;
+                if (!list_empty(&conn->mgmtqueue))
                         goto check_mgmt;
         }
         spin_unlock_bh(&conn->session->lock);
@@ -859,7 +873,6 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 
         atomic_set(&ctask->refcount, 1);
         ctask->state = ISCSI_TASK_PENDING;
-        ctask->mtask = NULL;
         ctask->conn = conn;
         ctask->sc = sc;
         INIT_LIST_HEAD(&ctask->running);
@@ -929,9 +942,9 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
         } else
                 mtask->data_count = 0;
 
-        INIT_LIST_HEAD(&mtask->running);
         memcpy(mtask->hdr, hdr, sizeof(struct iscsi_hdr));
-        __kfifo_put(conn->mgmtqueue, (void*)&mtask, sizeof(void*));
+        INIT_LIST_HEAD(&mtask->running);
+        list_add_tail(&mtask->running, &conn->mgmtqueue);
         return mtask;
 }
 
@@ -954,13 +967,12 @@ EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 {
         struct iscsi_session *session = class_to_transport_session(cls_session);
-        struct iscsi_conn *conn = session->leadconn;
 
         spin_lock_bh(&session->lock);
         if (session->state != ISCSI_STATE_LOGGED_IN) {
                 session->state = ISCSI_STATE_RECOVERY_FAILED;
-                if (conn)
-                        wake_up(&conn->ehwait);
+                if (session->leadconn)
+                        wake_up(&session->leadconn->ehwait);
         }
         spin_unlock_bh(&session->lock);
 }
@@ -971,7 +983,6 @@ int iscsi_eh_host_reset(struct scsi_cmnd *sc)
         struct Scsi_Host *host = sc->device->host;
         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
         struct iscsi_conn *conn = session->leadconn;
-        int fail_session = 0;
 
         spin_lock_bh(&session->lock);
         if (session->state == ISCSI_STATE_TERMINATE) {
@@ -982,19 +993,13 @@ failed:
                 return FAILED;
         }
 
-        if (sc->SCp.phase == session->age) {
-                debug_scsi("failing connection CID %d due to SCSI host reset\n",
-                           conn->id);
-                fail_session = 1;
-        }
         spin_unlock_bh(&session->lock);
 
         /*
          * we drop the lock here but the leadconn cannot be destoyed while
          * we are in the scsi eh
          */
-        if (fail_session)
-                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+        iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 
         debug_scsi("iscsi_eh_host_reset wait for relogin\n");
         wait_event_interruptible(conn->ehwait,
@@ -1015,62 +1020,43 @@ failed:
 }
 EXPORT_SYMBOL_GPL(iscsi_eh_host_reset);
 
-static void iscsi_tmabort_timedout(unsigned long data)
+static void iscsi_tmf_timedout(unsigned long data)
 {
-        struct iscsi_cmd_task *ctask = (struct iscsi_cmd_task *)data;
-        struct iscsi_conn *conn = ctask->conn;
+        struct iscsi_conn *conn = (struct iscsi_conn *)data;
         struct iscsi_session *session = conn->session;
 
         spin_lock(&session->lock);
-        if (conn->tmabort_state == TMABORT_INITIAL) {
-                conn->tmabort_state = TMABORT_TIMEDOUT;
-                debug_scsi("tmabort timedout [sc %p itt 0x%x]\n",
-                        ctask->sc, ctask->itt);
+        if (conn->tmf_state == TMF_QUEUED) {
+                conn->tmf_state = TMF_TIMEDOUT;
+                debug_scsi("tmf timedout\n");
                 /* unblock eh_abort() */
                 wake_up(&conn->ehwait);
         }
         spin_unlock(&session->lock);
 }
 
-static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
-                                 struct iscsi_cmd_task *ctask)
+static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
+                                   struct iscsi_tm *hdr, int age)
 {
-        struct iscsi_conn *conn = ctask->conn;
         struct iscsi_session *session = conn->session;
-        struct iscsi_tm *hdr = &conn->tmhdr;
-
-        /*
-         * ctask timed out but session is OK requests must be serialized.
-         */
-        memset(hdr, 0, sizeof(struct iscsi_tm));
-        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
-        hdr->flags = ISCSI_TM_FUNC_ABORT_TASK;
-        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
-        memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
-        hdr->rtt = ctask->hdr->itt;
-        hdr->refcmdsn = ctask->hdr->cmdsn;
+        struct iscsi_mgmt_task *mtask;
 
-        ctask->mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
-                                            NULL, 0);
-        if (!ctask->mtask) {
+        mtask = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
+                                      NULL, 0);
+        if (!mtask) {
                 spin_unlock_bh(&session->lock);
                 iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-                spin_lock_bh(&session->lock)
-                debug_scsi("abort sent failure [itt 0x%x]\n", ctask->itt);
+                spin_lock_bh(&session->lock);
+                debug_scsi("tmf exec failure\n");
                 return -EPERM;
         }
-        ctask->state = ISCSI_TASK_ABORTING;
-
-        debug_scsi("abort sent [itt 0x%x]\n", ctask->itt);
+        conn->tmfcmd_pdus_cnt++;
+        conn->tmf_timer.expires = 30 * HZ + jiffies;
+        conn->tmf_timer.function = iscsi_tmf_timedout;
+        conn->tmf_timer.data = (unsigned long)conn;
+        add_timer(&conn->tmf_timer);
+        debug_scsi("tmf set timeout\n");
 
-        if (conn->tmabort_state == TMABORT_INITIAL) {
-                conn->tmfcmd_pdus_cnt++;
-                conn->tmabort_timer.expires = 20*HZ + jiffies;
-                conn->tmabort_timer.function = iscsi_tmabort_timedout;
-                conn->tmabort_timer.data = (unsigned long)ctask;
-                add_timer(&conn->tmabort_timer);
-                debug_scsi("abort set timeout [itt 0x%x]\n", ctask->itt);
-        }
         spin_unlock_bh(&session->lock);
         mutex_unlock(&session->eh_mutex);
         scsi_queue_work(session->host, &conn->xmitwork);
@@ -1078,61 +1064,30 @@ static int iscsi_exec_abort_task(struct scsi_cmnd *sc,
         /*
          * block eh thread until:
          *
-         * 1) abort response
-         * 2) abort timeout
+         * 1) tmf response
+         * 2) tmf timeout
          * 3) session is terminated or restarted or userspace has
          * given up on recovery
          */
-        wait_event_interruptible(conn->ehwait,
-                                 sc->SCp.phase != session->age ||
+        wait_event_interruptible(conn->ehwait, age != session->age ||
                                  session->state != ISCSI_STATE_LOGGED_IN ||
-                                 conn->tmabort_state != TMABORT_INITIAL);
+                                 conn->tmf_state != TMF_QUEUED);
         if (signal_pending(current))
                 flush_signals(current);
-        del_timer_sync(&conn->tmabort_timer);
+        del_timer_sync(&conn->tmf_timer);
+
         mutex_lock(&session->eh_mutex);
         spin_lock_bh(&session->lock);
-        return 0;
-}
-
-/*
- * session lock must be held
- */
-static struct iscsi_mgmt_task *
-iscsi_remove_mgmt_task(struct kfifo *fifo, uint32_t itt)
-{
-        int i, nr_tasks = __kfifo_len(fifo) / sizeof(void*);
-        struct iscsi_mgmt_task *task;
-
-        debug_scsi("searching %d tasks\n", nr_tasks);
-
-        for (i = 0; i < nr_tasks; i++) {
-                __kfifo_get(fifo, (void*)&task, sizeof(void*));
-                debug_scsi("check task %u\n", task->itt);
-
-                if (task->itt == itt) {
-                        debug_scsi("matched task\n");
-                        return task;
-                }
+        /* if the session drops it will clean up the mtask */
+        if (age != session->age ||
+            session->state != ISCSI_STATE_LOGGED_IN)
+                return -ENOTCONN;
 
-                __kfifo_put(fifo, (void*)&task, sizeof(void*));
+        if (!list_empty(&mtask->running)) {
+                list_del_init(&mtask->running);
+                __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
+                            sizeof(void*));
         }
-        return NULL;
-}
-
-static int iscsi_ctask_mtask_cleanup(struct iscsi_cmd_task *ctask)
-{
-        struct iscsi_conn *conn = ctask->conn;
-        struct iscsi_session *session = conn->session;
-
-        if (!ctask->mtask)
-                return -EINVAL;
-
-        if (!iscsi_remove_mgmt_task(conn->mgmtqueue, ctask->mtask->itt))
-                list_del(&ctask->mtask->running);
-        __kfifo_put(session->mgmtpool.queue, (void*)&ctask->mtask,
-                    sizeof(void*));
-        ctask->mtask = NULL;
         return 0;
 }
 
@@ -1156,7 +1111,6 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
                 conn->session->queued_cmdsn--;
         else
                 conn->session->tt->cleanup_cmd_task(conn, ctask);
-        iscsi_ctask_mtask_cleanup(ctask);
 
         sc->result = err;
         scsi_set_resid(sc, scsi_bufflen(sc));
@@ -1166,6 +1120,44 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
         __iscsi_put_ctask(ctask);
 }
 
+/*
+ * Fail commands. session lock held and recv side suspended and xmit
+ * thread flushed
+ */
+static void fail_all_commands(struct iscsi_conn *conn, unsigned lun)
+{
+        struct iscsi_cmd_task *ctask, *tmp;
+
+        if (conn->ctask && (conn->ctask->sc->device->lun == lun || lun == -1))
+                conn->ctask = NULL;
+
+        /* flush pending */
+        list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
+                if (lun == ctask->sc->device->lun || lun == -1) {
+                        debug_scsi("failing pending sc %p itt 0x%x\n",
+                                   ctask->sc, ctask->itt);
+                        fail_command(conn, ctask, DID_BUS_BUSY << 16);
+                }
+        }
+
+        list_for_each_entry_safe(ctask, tmp, &conn->requeue, running) {
+                if (lun == ctask->sc->device->lun || lun == -1) {
+                        debug_scsi("failing requeued sc %p itt 0x%x\n",
+                                   ctask->sc, ctask->itt);
+                        fail_command(conn, ctask, DID_BUS_BUSY << 16);
+                }
+        }
+
+        /* fail all other running */
+        list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
+                if (lun == ctask->sc->device->lun || lun == -1) {
+                        debug_scsi("failing in progress sc %p itt 0x%x\n",
+                                   ctask->sc, ctask->itt);
+                        fail_command(conn, ctask, DID_BUS_BUSY << 16);
+                }
+        }
+}
+
 static void iscsi_suspend_tx(struct iscsi_conn *conn)
 {
         set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
@@ -1178,13 +1170,26 @@ static void iscsi_start_tx(struct iscsi_conn *conn)
         scsi_queue_work(conn->session->host, &conn->xmitwork);
 }
 
+static void iscsi_prep_abort_task_pdu(struct iscsi_cmd_task *ctask,
+                                      struct iscsi_tm *hdr)
+{
+        memset(hdr, 0, sizeof(*hdr));
+        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
+        hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
+        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+        memcpy(hdr->lun, ctask->hdr->lun, sizeof(hdr->lun));
+        hdr->rtt = ctask->hdr->itt;
+        hdr->refcmdsn = ctask->hdr->cmdsn;
+}
+
 int iscsi_eh_abort(struct scsi_cmnd *sc)
 {
         struct Scsi_Host *host = sc->device->host;
         struct iscsi_session *session = iscsi_hostdata(host->hostdata);
-        struct iscsi_cmd_task *ctask;
         struct iscsi_conn *conn;
-        int rc;
+        struct iscsi_cmd_task *ctask;
+        struct iscsi_tm *hdr;
+        int rc, age;
 
         mutex_lock(&session->eh_mutex);
         spin_lock_bh(&session->lock);
@@ -1199,19 +1204,23 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
                 return SUCCESS;
         }
 
-        ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
-        conn = ctask->conn;
-
-        conn->eh_abort_cnt++;
-        debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
-
         /*
          * If we are not logged in or we have started a new session
          * then let the host reset code handle this
          */
-        if (session->state != ISCSI_STATE_LOGGED_IN ||
-            sc->SCp.phase != session->age)
-                goto failed;
+        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
+            sc->SCp.phase != session->age) {
+                spin_unlock_bh(&session->lock);
+                mutex_unlock(&session->eh_mutex);
+                return FAILED;
+        }
+
+        conn = session->leadconn;
+        conn->eh_abort_cnt++;
+        age = session->age;
+
+        ctask = (struct iscsi_cmd_task *)sc->SCp.ptr;
+        debug_scsi("aborting [sc %p itt 0x%x]\n", sc, ctask->itt);
 
         /* ctask completed before time out */
         if (!ctask->sc) {
@@ -1219,27 +1228,26 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
                 goto success;
         }
 
-        /* what should we do here ? */
-        if (conn->ctask == ctask) {
-                printk(KERN_INFO "iscsi: sc %p itt 0x%x partially sent. "
-                       "Failing abort\n", sc, ctask->itt);
-                goto failed;
-        }
-
         if (ctask->state == ISCSI_TASK_PENDING) {
                 fail_command(conn, ctask, DID_ABORT << 16);
                 goto success;
         }
 
-        conn->tmabort_state = TMABORT_INITIAL;
-        rc = iscsi_exec_abort_task(sc, ctask);
-        if (rc || sc->SCp.phase != session->age ||
-            session->state != ISCSI_STATE_LOGGED_IN)
+        /* only have one tmf outstanding at a time */
+        if (conn->tmf_state != TMF_INITIAL)
                 goto failed;
-        iscsi_ctask_mtask_cleanup(ctask);
+        conn->tmf_state = TMF_QUEUED;
 
-        switch (conn->tmabort_state) {
-        case TMABORT_SUCCESS:
+        hdr = &conn->tmhdr;
+        iscsi_prep_abort_task_pdu(ctask, hdr);
+
+        if (iscsi_exec_task_mgmt_fn(conn, hdr, age)) {
+                rc = FAILED;
+                goto failed;
+        }
+
+        switch (conn->tmf_state) {
+        case TMF_SUCCESS:
                 spin_unlock_bh(&session->lock);
                 iscsi_suspend_tx(conn);
                 /*
@@ -1248,22 +1256,26 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
                 write_lock_bh(conn->recv_lock);
                 spin_lock(&session->lock);
                 fail_command(conn, ctask, DID_ABORT << 16);
+                conn->tmf_state = TMF_INITIAL;
                 spin_unlock(&session->lock);
                 write_unlock_bh(conn->recv_lock);
                 iscsi_start_tx(conn);
                 goto success_unlocked;
-        case TMABORT_NOT_FOUND:
-                if (!ctask->sc) {
+        case TMF_TIMEDOUT:
+                spin_unlock_bh(&session->lock);
+                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+                goto failed_unlocked;
+        case TMF_NOT_FOUND:
+                if (!sc->SCp.ptr) {
+                        conn->tmf_state = TMF_INITIAL;
                         /* ctask completed before tmf abort response */
                         debug_scsi("sc completed while abort in progress\n");
                         goto success;
                 }
                 /* fall through */
         default:
-                /* timedout or failed */
-                spin_unlock_bh(&session->lock);
-                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-                goto failed_unlocked;
+                conn->tmf_state = TMF_INITIAL;
+                goto failed;
         }
 
 success:
@@ -1276,12 +1288,93 @@ success_unlocked:
 failed:
         spin_unlock_bh(&session->lock);
 failed_unlocked:
-        debug_scsi("abort failed [sc %lx itt 0x%x]\n", (long)sc, ctask->itt);
+        debug_scsi("abort failed [sc %p itt 0x%x]\n", sc,
+                    ctask ? ctask->itt : 0);
         mutex_unlock(&session->eh_mutex);
         return FAILED;
 }
 EXPORT_SYMBOL_GPL(iscsi_eh_abort);
 
+static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
+{
+        memset(hdr, 0, sizeof(*hdr));
+        hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
+        hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
+        hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+        int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
+        hdr->rtt = ISCSI_RESERVED_TAG;
+}
+
+int iscsi_eh_device_reset(struct scsi_cmnd *sc)
+{
+        struct Scsi_Host *host = sc->device->host;
+        struct iscsi_session *session = iscsi_hostdata(host->hostdata);
+        struct iscsi_conn *conn;
+        struct iscsi_tm *hdr;
+        int rc = FAILED;
+
+        debug_scsi("LU Reset [sc %p lun %u]\n", sc, sc->device->lun);
+
+        mutex_lock(&session->eh_mutex);
+        spin_lock_bh(&session->lock);
+        /*
+         * Just check if we are not logged in. We cannot check for
+         * the phase because the reset could come from a ioctl.
+         */
+        if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
+                goto unlock;
+        conn = session->leadconn;
+
+        /* only have one tmf outstanding at a time */
+        if (conn->tmf_state != TMF_INITIAL)
+                goto unlock;
+        conn->tmf_state = TMF_QUEUED;
+
+        hdr = &conn->tmhdr;
+        iscsi_prep_lun_reset_pdu(sc, hdr);
+
+        if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age)) {
+                rc = FAILED;
+                goto unlock;
+        }
+
+        switch (conn->tmf_state) {
+        case TMF_SUCCESS:
+                break;
+        case TMF_TIMEDOUT:
+                spin_unlock_bh(&session->lock);
+                iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+                goto done;
+        default:
+                conn->tmf_state = TMF_INITIAL;
+                goto unlock;
+        }
+
+        rc = SUCCESS;
+        spin_unlock_bh(&session->lock);
+
+        iscsi_suspend_tx(conn);
+        /* need to grab the recv lock then session lock */
+        write_lock_bh(conn->recv_lock);
+        spin_lock(&session->lock);
+        fail_all_commands(conn, sc->device->lun);
+        conn->tmf_state = TMF_INITIAL;
+        spin_unlock(&session->lock);
+        write_unlock_bh(conn->recv_lock);
+
+        iscsi_start_tx(conn);
+        goto done;
+
+unlock:
+        spin_unlock_bh(&session->lock);
+done:
+        debug_scsi("iscsi_eh_device_reset %s\n",
+                  rc == SUCCESS ? "SUCCESS" : "FAILED");
+        mutex_unlock(&session->eh_mutex);
+        return rc;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
+
 int
 iscsi_pool_init(struct iscsi_queue *q, int max, void ***items, int item_size)
 {
@@ -1546,17 +1639,12 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
         conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
         conn->id = conn_idx;
         conn->exp_statsn = 0;
-        conn->tmabort_state = TMABORT_INITIAL;
+        conn->tmf_state = TMF_INITIAL;
         INIT_LIST_HEAD(&conn->run_list);
         INIT_LIST_HEAD(&conn->mgmt_run_list);
+        INIT_LIST_HEAD(&conn->mgmtqueue);
         INIT_LIST_HEAD(&conn->xmitqueue);
-
-        /* initialize general immediate & non-immediate PDU commands queue */
-        conn->mgmtqueue = kfifo_alloc(session->mgmtpool_max * sizeof(void*),
-                                        GFP_KERNEL, NULL);
-        if (conn->mgmtqueue == ERR_PTR(-ENOMEM))
-                goto mgmtqueue_alloc_fail;
-
+        INIT_LIST_HEAD(&conn->requeue);
         INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
 
         /* allocate login_mtask used for the login/text sequences */
@@ -1574,7 +1662,7 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
                 goto login_mtask_data_alloc_fail;
         conn->login_mtask->data = conn->data = data;
 
-        init_timer(&conn->tmabort_timer);
+        init_timer(&conn->tmf_timer);
         init_waitqueue_head(&conn->ehwait);
 
         return cls_conn;
@@ -1583,8 +1671,6 @@ login_mtask_data_alloc_fail:
         __kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
                     sizeof(void*));
 login_mtask_alloc_fail:
-        kfifo_free(conn->mgmtqueue);
-mgmtqueue_alloc_fail:
         iscsi_destroy_conn(cls_conn);
         return NULL;
 }
@@ -1604,7 +1690,6 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
         unsigned long flags;
 
         spin_lock_bh(&session->lock);
-        set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
         conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
         if (session->leadconn == conn) {
                 /*
@@ -1637,7 +1722,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
         }
 
         /* flush queued up work because we free the connection below */
-        scsi_flush_work(session->host);
+        iscsi_suspend_tx(conn);
 
         spin_lock_bh(&session->lock);
         kfree(conn->data);
@@ -1648,8 +1733,6 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
                 session->leadconn = NULL;
         spin_unlock_bh(&session->lock);
 
-        kfifo_free(conn->mgmtqueue);
-
         iscsi_destroy_conn(cls_conn);
 }
 EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
@@ -1684,7 +1767,7 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
                  * commands after successful recovery
                  */
                 conn->stop_stage = 0;
-                conn->tmabort_state = TMABORT_INITIAL;
+                conn->tmf_state = TMF_INITIAL;
                 session->age++;
                 spin_unlock_bh(&session->lock);
 
@@ -1709,10 +1792,11 @@ flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
         struct iscsi_mgmt_task *mtask, *tmp;
 
         /* handle pending */
-        while (__kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
+        list_for_each_entry_safe(mtask, tmp, &conn->mgmtqueue, running) {
+                debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
+                list_del_init(&mtask->running);
                 if (mtask == conn->login_mtask)
                         continue;
-                debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
                 __kfifo_put(session->mgmtpool.queue, (void*)&mtask,
                             sizeof(void*));
         }
@@ -1720,7 +1804,7 @@ flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
         /* handle running */
         list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
                 debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
-                list_del(&mtask->running);
+                list_del_init(&mtask->running);
 
                 if (mtask == conn->login_mtask)
                         continue;
@@ -1731,28 +1815,6 @@ flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
         conn->mtask = NULL;
 }
 
-/* Fail commands. Mutex and session lock held and recv side suspended */
-static void fail_all_commands(struct iscsi_conn *conn)
-{
-        struct iscsi_cmd_task *ctask, *tmp;
-
-        /* flush pending */
-        list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
-                debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
-                           ctask->itt);
-                fail_command(conn, ctask, DID_BUS_BUSY << 16);
-        }
-
-        /* fail all other running */
-        list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
-                debug_scsi("failing in progress sc %p itt 0x%x\n",
-                           ctask->sc, ctask->itt);
-                fail_command(conn, ctask, DID_BUS_BUSY << 16);
-        }
-
-        conn->ctask = NULL;
-}
-
 static void iscsi_start_session_recovery(struct iscsi_session *session,
                                          struct iscsi_conn *conn, int flag)
 {
@@ -1818,7 +1880,7 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
          * flush queues.
          */
         spin_lock_bh(&session->lock);
-        fail_all_commands(conn);
+        fail_all_commands(conn, -1);
         flush_control_queues(session, conn);
         spin_unlock_bh(&session->lock);
         mutex_unlock(&session->eh_mutex);
@@ -1869,6 +1931,9 @@ int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
         uint32_t value;
 
         switch(param) {
+        case ISCSI_PARAM_FAST_ABORT:
+                sscanf(buf, "%d", &session->fast_abort);
+                break;
         case ISCSI_PARAM_MAX_RECV_DLENGTH:
                 sscanf(buf, "%d", &conn->max_recv_dlength);
                 break;
@@ -1983,6 +2048,9 @@ int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
         int len;
 
         switch(param) {
+        case ISCSI_PARAM_FAST_ABORT:
+                len = sprintf(buf, "%d\n", session->fast_abort);
+                break;
         case ISCSI_PARAM_INITIAL_R2T_EN:
                 len = sprintf(buf, "%d\n", session->initial_r2t_en);
                 break;