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[SCSI] libiscsi: fix nop response/reply and session cleanup race

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If we are responding to a nop from the target by sending our nop,
and the session is getting torn down, then iscsi_start_session_recovery
could set the conn stop bits while the recv path is sending the nop
response and we will hit the bug ons in __iscsi_conn_send_pdu.

This has us check the state in __iscsi_conn_send_pdu and fail all
incoming mgmt IO if we are  not logged in and if the pdu is not login
related. It also changes the ordering of the setting of conn stop state
bits so they are set after the session state is set (both are set under
the session lock).

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This commit is contained in:
Mike Christie 2009-05-13 17:57:43 -05:00 committed by James Bottomley
parent edbc9aa058
commit 26013ad4c4
1 changed files with 8 additions and 3 deletions
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11
drivers/scsi/libiscsi.c
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@ -546,6 +546,9 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
*/
task = conn->login_task;
else {
if (session->state != ISCSI_STATE_LOGGED_IN)
return NULL;
BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
@ -2566,8 +2569,6 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
{
int old_stop_stage;
del_timer_sync(&conn->transport_timer);
mutex_lock(&session->eh_mutex);
spin_lock_bh(&session->lock);
if (conn->stop_stage == STOP_CONN_TERM) {
@ -2585,13 +2586,17 @@ static void iscsi_start_session_recovery(struct iscsi_session *session,
session->state = ISCSI_STATE_TERMINATE;
else if (conn->stop_stage != STOP_CONN_RECOVER)
session->state = ISCSI_STATE_IN_RECOVERY;
spin_unlock_bh(&session->lock);
del_timer_sync(&conn->transport_timer);
iscsi_suspend_tx(conn);
spin_lock_bh(&session->lock);
old_stop_stage = conn->stop_stage;
conn->stop_stage = flag;
conn->c_stage = ISCSI_CONN_STOPPED;
spin_unlock_bh(&session->lock);
iscsi_suspend_tx(conn);
/*
* for connection level recovery we should not calculate
* header digest. conn->hdr_size used for optimization