[SCSI] iscsi class, libiscsi: add iscsi sysfs session state file
This adds a iscsi session state file which exports the session
state for both software and hardware iscsi. It also hooks libiscsi
in.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index e794262..c8c00e1 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -996,6 +996,7 @@
FAILURE_SESSION_IN_RECOVERY,
FAILURE_SESSION_RECOVERY_TIMEOUT,
FAILURE_SESSION_LOGGING_OUT,
+ FAILURE_SESSION_NOT_READY,
};
int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
@@ -1016,6 +1017,12 @@
session = iscsi_hostdata(host->hostdata);
spin_lock(&session->lock);
+ reason = iscsi_session_chkready(session_to_cls(session));
+ if (reason) {
+ sc->result = reason;
+ goto fault;
+ }
+
/*
* ISCSI_STATE_FAILED is a temp. state. The recovery
* code will decide what is best to do with command queued
@@ -1032,18 +1039,23 @@
switch (session->state) {
case ISCSI_STATE_IN_RECOVERY:
reason = FAILURE_SESSION_IN_RECOVERY;
- goto reject;
+ sc->result = DID_IMM_RETRY << 16;
+ break;
case ISCSI_STATE_LOGGING_OUT:
reason = FAILURE_SESSION_LOGGING_OUT;
- goto reject;
+ sc->result = DID_IMM_RETRY << 16;
+ break;
case ISCSI_STATE_RECOVERY_FAILED:
reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
+ sc->result = DID_NO_CONNECT << 16;
break;
case ISCSI_STATE_TERMINATE:
reason = FAILURE_SESSION_TERMINATE;
+ sc->result = DID_NO_CONNECT << 16;
break;
default:
reason = FAILURE_SESSION_FREED;
+ sc->result = DID_NO_CONNECT << 16;
}
goto fault;
}
@@ -1051,6 +1063,7 @@
conn = session->leadconn;
if (!conn) {
reason = FAILURE_SESSION_FREED;
+ sc->result = DID_NO_CONNECT << 16;
goto fault;
}
@@ -1090,9 +1103,7 @@
fault:
spin_unlock(&session->lock);
- printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
- sc->cmnd[0], reason);
- sc->result = (DID_NO_CONNECT << 16);
+ debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);
scsi_set_resid(sc, scsi_bufflen(sc));
sc->scsi_done(sc);
spin_lock(host->host_lock);
@@ -1238,7 +1249,8 @@
* Fail commands. session lock held and recv side suspended and xmit
* thread flushed
*/
-static void fail_all_commands(struct iscsi_conn *conn, unsigned lun)
+static void fail_all_commands(struct iscsi_conn *conn, unsigned lun,
+ int error)
{
struct iscsi_cmd_task *ctask, *tmp;
@@ -1250,7 +1262,7 @@
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);
+ fail_command(conn, ctask, error << 16);
}
}
@@ -1258,7 +1270,7 @@
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_command(conn, ctask, error << 16);
}
}
@@ -1572,7 +1584,7 @@
/* 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);
+ fail_all_commands(conn, sc->device->lun, DID_ERROR);
conn->tmf_state = TMF_INITIAL;
spin_unlock(&session->lock);
write_unlock_bh(conn->recv_lock);
@@ -2018,11 +2030,7 @@
conn->stop_stage = 0;
conn->tmf_state = TMF_INITIAL;
session->age++;
- spin_unlock_bh(&session->lock);
-
- iscsi_unblock_session(session_to_cls(session));
- wake_up(&conn->ehwait);
- return 0;
+ break;
case STOP_CONN_TERM:
conn->stop_stage = 0;
break;
@@ -2031,6 +2039,8 @@
}
spin_unlock_bh(&session->lock);
+ iscsi_unblock_session(session_to_cls(session));
+ wake_up(&conn->ehwait);
return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_start);
@@ -2122,7 +2132,8 @@
* flush queues.
*/
spin_lock_bh(&session->lock);
- fail_all_commands(conn, -1);
+ fail_all_commands(conn, -1,
+ STOP_CONN_RECOVER ? DID_BUS_BUSY : DID_ERROR);
flush_control_queues(session, conn);
spin_unlock_bh(&session->lock);
mutex_unlock(&session->eh_mutex);
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 0d7b4e7..f876b0a 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -30,7 +30,7 @@
#include <scsi/scsi_transport_iscsi.h>
#include <scsi/iscsi_if.h>
-#define ISCSI_SESSION_ATTRS 18
+#define ISCSI_SESSION_ATTRS 19
#define ISCSI_CONN_ATTRS 11
#define ISCSI_HOST_ATTRS 4
#define ISCSI_TRANSPORT_VERSION "2.0-867"
@@ -221,6 +221,54 @@
* The following functions can be used by LLDs that allocate
* their own scsi_hosts or by software iscsi LLDs
*/
+static struct {
+ int value;
+ char *name;
+} iscsi_session_state_names[] = {
+ { ISCSI_SESSION_LOGGED_IN, "LOGGED_IN" },
+ { ISCSI_SESSION_FAILED, "FAILED" },
+ { ISCSI_SESSION_FREE, "FREE" },
+};
+
+const char *iscsi_session_state_name(int state)
+{
+ int i;
+ char *name = NULL;
+
+ for (i = 0; i < ARRAY_SIZE(iscsi_session_state_names); i++) {
+ if (iscsi_session_state_names[i].value == state) {
+ name = iscsi_session_state_names[i].name;
+ break;
+ }
+ }
+ return name;
+}
+
+int iscsi_session_chkready(struct iscsi_cls_session *session)
+{
+ unsigned long flags;
+ int err;
+
+ spin_lock_irqsave(&session->lock, flags);
+ switch (session->state) {
+ case ISCSI_SESSION_LOGGED_IN:
+ err = 0;
+ break;
+ case ISCSI_SESSION_FAILED:
+ err = DID_IMM_RETRY << 16;
+ break;
+ case ISCSI_SESSION_FREE:
+ err = DID_NO_CONNECT << 16;
+ break;
+ default:
+ err = DID_NO_CONNECT << 16;
+ break;
+ }
+ spin_unlock_irqrestore(&session->lock, flags);
+ return err;
+}
+EXPORT_SYMBOL_GPL(iscsi_session_chkready);
+
static void iscsi_session_release(struct device *dev)
{
struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
@@ -259,26 +307,57 @@
struct iscsi_cls_session *session =
container_of(work, struct iscsi_cls_session,
recovery_work.work);
+ unsigned long flags;
dev_printk(KERN_INFO, &session->dev, "iscsi: session recovery timed "
"out after %d secs\n", session->recovery_tmo);
+ spin_lock_irqsave(&session->lock, flags);
+ switch (session->state) {
+ case ISCSI_SESSION_FAILED:
+ session->state = ISCSI_SESSION_FREE;
+ break;
+ case ISCSI_SESSION_LOGGED_IN:
+ case ISCSI_SESSION_FREE:
+ /* we raced with the unblock's flush */
+ spin_unlock_irqrestore(&session->lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&session->lock, flags);
+
if (session->transport->session_recovery_timedout)
session->transport->session_recovery_timedout(session);
scsi_target_unblock(&session->dev);
}
-void iscsi_unblock_session(struct iscsi_cls_session *session)
+void __iscsi_unblock_session(struct iscsi_cls_session *session)
{
if (!cancel_delayed_work(&session->recovery_work))
flush_workqueue(iscsi_eh_timer_workq);
scsi_target_unblock(&session->dev);
}
+
+void iscsi_unblock_session(struct iscsi_cls_session *session)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&session->lock, flags);
+ session->state = ISCSI_SESSION_LOGGED_IN;
+ spin_unlock_irqrestore(&session->lock, flags);
+
+ __iscsi_unblock_session(session);
+}
EXPORT_SYMBOL_GPL(iscsi_unblock_session);
void iscsi_block_session(struct iscsi_cls_session *session)
{
+ unsigned long flags;
+
+ spin_lock_irqsave(&session->lock, flags);
+ session->state = ISCSI_SESSION_FAILED;
+ spin_unlock_irqrestore(&session->lock, flags);
+
scsi_target_block(&session->dev);
queue_delayed_work(iscsi_eh_timer_workq, &session->recovery_work,
session->recovery_tmo * HZ);
@@ -327,10 +406,12 @@
session->transport = transport;
session->recovery_tmo = 120;
+ session->state = ISCSI_SESSION_FREE;
INIT_DELAYED_WORK(&session->recovery_work, session_recovery_timedout);
INIT_LIST_HEAD(&session->host_list);
INIT_LIST_HEAD(&session->sess_list);
INIT_WORK(&session->unbind_work, __iscsi_unbind_session);
+ spin_lock_init(&session->lock);
/* this is released in the dev's release function */
scsi_host_get(shost);
@@ -444,7 +525,10 @@
* If we are blocked let commands flow again. The lld or iscsi
* layer should set up the queuecommand to fail commands.
*/
- iscsi_unblock_session(session);
+ spin_lock_irqsave(&session->lock, flags);
+ session->state = ISCSI_SESSION_FREE;
+ spin_unlock_irqrestore(&session->lock, flags);
+ __iscsi_unblock_session(session);
iscsi_unbind_session(session);
/*
* If the session dropped while removing devices then we need to make
@@ -661,16 +745,23 @@
void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error)
{
+ struct iscsi_cls_session *session = iscsi_conn_to_session(conn);
struct nlmsghdr *nlh;
struct sk_buff *skb;
struct iscsi_uevent *ev;
struct iscsi_internal *priv;
int len = NLMSG_SPACE(sizeof(*ev));
+ unsigned long flags;
priv = iscsi_if_transport_lookup(conn->transport);
if (!priv)
return;
+ spin_lock_irqsave(&session->lock, flags);
+ if (session->state == ISCSI_SESSION_LOGGED_IN)
+ session->state = ISCSI_SESSION_FAILED;
+ spin_unlock_irqrestore(&session->lock, flags);
+
skb = alloc_skb(len, GFP_ATOMIC);
if (!skb) {
dev_printk(KERN_ERR, &conn->dev, "iscsi: gracefully ignored "
@@ -1246,6 +1337,15 @@
iscsi_session_attr(abort_tmo, ISCSI_PARAM_ABORT_TMO, 0);
iscsi_session_attr(lu_reset_tmo, ISCSI_PARAM_LU_RESET_TMO, 0);
+static ssize_t
+show_priv_session_state(struct class_device *cdev, char *buf)
+{
+ struct iscsi_cls_session *session = iscsi_cdev_to_session(cdev);
+ return sprintf(buf, "%s\n", iscsi_session_state_name(session->state));
+}
+static ISCSI_CLASS_ATTR(priv_sess, state, S_IRUGO, show_priv_session_state,
+ NULL);
+
#define iscsi_priv_session_attr_show(field, format) \
static ssize_t \
show_priv_session_##field(struct class_device *cdev, char *buf) \
@@ -1472,6 +1572,7 @@
SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
SETUP_PRIV_SESSION_RD_ATTR(recovery_tmo);
+ SETUP_PRIV_SESSION_RD_ATTR(state);
BUG_ON(count > ISCSI_SESSION_ATTRS);
priv->session_attrs[count] = NULL;