From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch adds a new tcm_qla2xxx_clear_sess_lookup() call to clear session
specific s_id + loop_id entries used for se_node_acl pointer lookup ahead
of releasing se_session within the process context workqueue callback in
tcm_qla2xxx_free_session().
It makes the call in existing tcm_qla2xxx_clear_nacl_from_fcport_map()
code invoked from qlt_unreg_sess() in interrupt context w/ hardware_lock
held, ahead of the process context callback into qlt_free_session_done()
-> tcm_qla2xxx_free_session().
We are doing this to address a race between incoming ATIO or TMR packets
using stale se_node_acl pointer once session shutdown has been invoked via
qlt_unreg_sess() in qla_target.c LLD code, and when the entire tcm_qla2xxx
endpoint has not been forced into shutdown w/ echo 0 > ../$QLA2XXX_PORT/enable
Cc: Joern Engel <joern@xxxxxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Cc: Arun Easi <arun.easi@xxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/scsi/qla2xxx/tcm_qla2xxx.c | 48 +++++++++++++++++++++++------------
1 files changed, 31 insertions(+), 17 deletions(-)
diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index 5aa8372..470969e 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -821,6 +821,8 @@ static int tcm_qla2xxx_setup_nacl_from_rport(
return 0;
}
+static void tcm_qla2xxx_clear_sess_lookup(struct tcm_qla2xxx_lport *,
+ struct tcm_qla2xxx_nacl *, struct qla_tgt_sess *);
/*
* Expected to be called with struct qla_hw_data->hardware_lock held
*/
@@ -843,6 +845,16 @@ static void tcm_qla2xxx_clear_nacl_from_fcport_map(struct qla_tgt_sess *sess)
pr_debug("Removed from fcport_map: %p for WWNN: 0x%016LX,"
" port_id: 0x%06x\n", se_nacl, nacl->nport_wwnn,
nacl->nport_id);
+ /*
+ * Now clear the se_nacl and session pointers from our HW lport lookup
+ * table mapping for this initiator's fabric S_ID and LOOP_ID entries.
+ *
+ * This is done ahead of callbacks into tcm_qla2xxx_free_session() ->
+ * target_wait_for_sess_cmds() before the session waits for outstanding
+ * I/O to complete, to avoid a race between session shutdown execution
+ * and incoming ATIOs or TMRs picking up a stale se_node_act reference.
+ */
+ tcm_qla2xxx_clear_sess_lookup(lport, nacl, sess);
}
static void tcm_qla2xxx_release_session(struct kref *kref)
@@ -1420,6 +1432,25 @@ static void tcm_qla2xxx_set_sess_by_loop_id(
new_se_nacl->initiatorname);
}
+/*
+ * Should always be called with qla_hw_data->hardware_lock held.
+ */
+static void tcm_qla2xxx_clear_sess_lookup(struct tcm_qla2xxx_lport *lport,
+ struct tcm_qla2xxx_nacl *nacl, struct qla_tgt_sess *sess)
+{
+ struct se_session *se_sess = sess->se_sess;
+ unsigned char be_sid[3];
+
+ be_sid[0] = sess->s_id.b.domain;
+ be_sid[1] = sess->s_id.b.area;
+ be_sid[2] = sess->s_id.b.al_pa;
+
+ tcm_qla2xxx_set_sess_by_s_id(lport, NULL, nacl, se_sess,
+ sess, be_sid);
+ tcm_qla2xxx_set_sess_by_loop_id(lport, NULL, nacl, se_sess,
+ sess, sess->loop_id);
+}
+
static void tcm_qla2xxx_free_session(struct qla_tgt_sess *sess)
{
struct qla_tgt *tgt = sess->tgt;
@@ -1428,8 +1459,6 @@ static void tcm_qla2xxx_free_session(struct qla_tgt_sess *sess)
struct se_node_acl *se_nacl;
struct tcm_qla2xxx_lport *lport;
struct tcm_qla2xxx_nacl *nacl;
- unsigned char be_sid[3];
- unsigned long flags;
BUG_ON(in_interrupt());
@@ -1449,21 +1478,6 @@ static void tcm_qla2xxx_free_session(struct qla_tgt_sess *sess)
return;
}
target_wait_for_sess_cmds(se_sess, 0);
- /*
- * And now clear the se_nacl and session pointers from our HW lport
- * mappings for fabric S_ID and LOOP_ID.
- */
- memset(&be_sid, 0, 3);
- be_sid[0] = sess->s_id.b.domain;
- be_sid[1] = sess->s_id.b.area;
- be_sid[2] = sess->s_id.b.al_pa;
-
- spin_lock_irqsave(&ha->hardware_lock, flags);
- tcm_qla2xxx_set_sess_by_s_id(lport, NULL, nacl, se_sess,
- sess, be_sid);
- tcm_qla2xxx_set_sess_by_loop_id(lport, NULL, nacl, se_sess,
- sess, sess->loop_id);
- spin_unlock_irqrestore(&ha->hardware_lock, flags);
transport_deregister_session_configfs(sess->se_sess);
transport_deregister_session(sess->se_sess);
--
1.7.2.5
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