This patch adds target reset support. If your driver was already setting
the sht->eh_target_reset_handler callout to iscsi_eh_target_reset you do
not have to make any code changes. The old
iscsi_eh_target_reset function was just dropping the session. Now it
will try a warm target reset. If that fails we will drop drop the
session and try ERL0 recovery.
Patch was made over the linux-2.6-iscsi iscsi branch. The last commit in
there is Hannes's tmf state fix up:
commit ca15aa0c02d03f1a8154073763d6ed7a13a53ef7
Author: Mike Christie <micha...@cs.wisc.edu>
Date: Thu Sep 10 12:11:22 2009 -0500
libiscsi: Check TMF state before sending PDU
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diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index e98dd1c..1671d80 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -298,17 +298,18 @@ static int iscsi_check_tmf_restrictions(struct iscsi_task
*task, int opcode)
hdr_lun = scsilun_to_int((struct scsi_lun *)tmf->lun);
if (hdr_lun != task->sc->device->lun)
return 0;
-
+ /* fall through */
+ case ISCSI_TM_FUNC_TARGET_WARM_RESET:
/*
* Fail all SCSI cmd PDUs
*/
if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
iscsi_conn_printk(KERN_INFO, conn,
"task [op %x/%x itt "
- "0x%x/0x%x lun %u] "
+ "0x%x/0x%x] "
"rejected.\n",
task->hdr->opcode, opcode,
- task->itt, task->hdr_itt, hdr_lun);
+ task->itt, task->hdr_itt);
return -EACCES;
}
/*
@@ -318,10 +319,9 @@ static int iscsi_check_tmf_restrictions(struct iscsi_task
*task, int opcode)
if (conn->session->fast_abort) {
iscsi_conn_printk(KERN_INFO, conn,
"task [op %x/%x itt "
- "0x%x/0x%x lun %u] "
- "fast abort.\n",
+ "0x%x/0x%x] fast abort.\n",
task->hdr->opcode, opcode,
- task->itt, task->hdr_itt, hdr_lun);
+ task->itt, task->hdr_itt);
return -EACCES;
}
break;
@@ -1754,72 +1754,6 @@ int iscsi_target_alloc(struct scsi_target *starget)
}
EXPORT_SYMBOL_GPL(iscsi_target_alloc);
-void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
-{
- struct iscsi_session *session = cls_session->dd_data;
-
- spin_lock_bh(&session->lock);
- if (session->state != ISCSI_STATE_LOGGED_IN) {
- session->state = ISCSI_STATE_RECOVERY_FAILED;
- if (session->leadconn)
- wake_up(&session->leadconn->ehwait);
- }
- spin_unlock_bh(&session->lock);
-}
-EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
-
-int iscsi_eh_target_reset(struct scsi_cmnd *sc)
-{
- struct iscsi_cls_session *cls_session;
- struct iscsi_session *session;
- struct iscsi_conn *conn;
-
- cls_session = starget_to_session(scsi_target(sc->device));
- session = cls_session->dd_data;
- conn = session->leadconn;
-
- mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
- if (session->state == ISCSI_STATE_TERMINATE) {
-failed:
- ISCSI_DBG_EH(session,
- "failing target reset: Could not log back into "
- "target [age %d]\n",
- session->age);
- spin_unlock_bh(&session->lock);
- mutex_unlock(&session->eh_mutex);
- return FAILED;
- }
-
- spin_unlock_bh(&session->lock);
- mutex_unlock(&session->eh_mutex);
- /*
- * we drop the lock here but the leadconn cannot be destoyed while
- * we are in the scsi eh
- */
- iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-
- ISCSI_DBG_EH(session, "wait for relogin\n");
- wait_event_interruptible(conn->ehwait,
- session->state == ISCSI_STATE_TERMINATE ||
- session->state == ISCSI_STATE_LOGGED_IN ||
- session->state == ISCSI_STATE_RECOVERY_FAILED);
- if (signal_pending(current))
- flush_signals(current);
-
- mutex_lock(&session->eh_mutex);
- spin_lock_bh(&session->lock);
- if (session->state == ISCSI_STATE_LOGGED_IN) {
- ISCSI_DBG_EH(session,
- "target reset succeeded\n");
- } else
- goto failed;
- spin_unlock_bh(&session->lock);
- mutex_unlock(&session->eh_mutex);
- return SUCCESS;
-}
-EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
-
static void iscsi_tmf_timedout(unsigned long data)
{
struct iscsi_conn *conn = (struct iscsi_conn *)data;
@@ -2326,6 +2260,174 @@ done:
}
EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
+void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
+{
+ struct iscsi_session *session = cls_session->dd_data;
+
+ spin_lock_bh(&session->lock);
+ if (session->state != ISCSI_STATE_LOGGED_IN) {
+ session->state = ISCSI_STATE_RECOVERY_FAILED;
+ if (session->leadconn)
+ wake_up(&session->leadconn->ehwait);
+ }
+ spin_unlock_bh(&session->lock);
+}
+EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
+
+/**
+ * iscsi_eh_session_reset - drop session and attempt relogin
+ * @sc: scsi command
+ *
+ * This function will wait for a relogin, session termination from
+ * userspace, or a recovery/replacement timeout.
+ */
+static int iscsi_eh_session_reset(struct scsi_cmnd *sc)
+{
+ struct iscsi_cls_session *cls_session;
+ struct iscsi_session *session;
+ struct iscsi_conn *conn;
+
+ cls_session = starget_to_session(scsi_target(sc->device));
+ session = cls_session->dd_data;
+ conn = session->leadconn;
+
+ mutex_lock(&session->eh_mutex);
+ spin_lock_bh(&session->lock);
+ if (session->state == ISCSI_STATE_TERMINATE) {
+failed:
+ ISCSI_DBG_EH(session,
+ "failing session reset: Could not log back into "
+ "%s, %s [age %d]\n", session->targetname,
+ conn->persistent_address, session->age);
+ spin_unlock_bh(&session->lock);
+ mutex_unlock(&session->eh_mutex);
+ return FAILED;
+ }
+
+ spin_unlock_bh(&session->lock);
+ mutex_unlock(&session->eh_mutex);
+ /*
+ * we drop the lock here but the leadconn cannot be destoyed while
+ * we are in the scsi eh
+ */
+ iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+
+ ISCSI_DBG_EH(session, "wait for relogin\n");
+ wait_event_interruptible(conn->ehwait,
+ session->state == ISCSI_STATE_TERMINATE ||
+ session->state == ISCSI_STATE_LOGGED_IN ||
+ session->state == ISCSI_STATE_RECOVERY_FAILED);
+ if (signal_pending(current))
+ flush_signals(current);
+
+ mutex_lock(&session->eh_mutex);
+ spin_lock_bh(&session->lock);
+ if (session->state == ISCSI_STATE_LOGGED_IN) {
+ ISCSI_DBG_EH(session,
+ "session reset succeeded for %s,%s\n",
+ session->targetname, conn->persistent_address);
+ } else
+ goto failed;
+ spin_unlock_bh(&session->lock);
+ mutex_unlock(&session->eh_mutex);
+ return SUCCESS;
+}
+
+static void iscsi_prep_tgt_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_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
+ hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+ hdr->rtt = RESERVED_ITT;
+}
+
+/**
+ * iscsi_eh_target_reset - reset target
+ * @sc: scsi command
+ *
+ * This will attempt to send a warm target reset. If that fails
+ * then we will drop the session and attempt ERL0 recovery.
+ */
+int iscsi_eh_target_reset(struct scsi_cmnd *sc)
+{
+ struct iscsi_cls_session *cls_session;
+ struct iscsi_session *session;
+ struct iscsi_conn *conn;
+ struct iscsi_tm *hdr;
+ int rc = FAILED;
+
+ cls_session = starget_to_session(scsi_target(sc->device));
+ session = cls_session->dd_data;
+
+ ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
+ session->targetname);
+
+ 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_tgt_reset_pdu(sc, hdr);
+
+ /*
+ * TODO: make tgt reset timeout configurable
+ */
+ if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age, 60)) {
+ 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);
+
+ spin_lock_bh(&session->lock);
+ memset(hdr, 0, sizeof(*hdr));
+ fail_scsi_tasks(conn, -1, DID_ERROR);
+ conn->tmf_state = TMF_INITIAL;
+ spin_unlock_bh(&session->lock);
+
+ iscsi_start_tx(conn);
+ goto done;
+
+unlock:
+ spin_unlock_bh(&session->lock);
+done:
+ ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
+ rc == SUCCESS ? "SUCCESS" : "FAILED");
+ mutex_unlock(&session->eh_mutex);
+
+ if (rc == FAILED)
+ rc = iscsi_eh_session_reset(sc);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
+
/*
* Pre-allocate a pool of @max items of @item_size. By default, the pool
* should be accessed via kfifo_{get,put} on q->queue.
