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authorQuinn Tran <quinn.tran@cavium.com>2017-03-15 19:48:47 +0300
committerNicholas Bellinger <nab@linux-iscsi.org>2017-03-19 03:28:08 +0300
commitf159b3c7cd45c550d0f73806451a10b6b6bc08ae (patch)
tree336f315eb431a87177eb963411e644587a3394d5
parent8f6fc8d4e7ae2347d6261d11a7eb2b247d2954d8 (diff)
downloadlinux-f159b3c7cd45c550d0f73806451a10b6b6bc08ae.tar.xz
qla2xxx: Fix sess_lock & hardware_lock lock order problem.
The main lock that needs to be held for CMD or TMR submission to upper layer is the sess_lock. The sess_lock is used to serialize cmd submission and session deletion. The addition of hardware_lock being held is not necessary. This patch removes hardware_lock dependency from CMD/TMR submission. Use hardware_lock only for error response in this case. Path1 CPU0 CPU1 ---- ---- lock(&(&ha->tgt.sess_lock)->rlock); lock(&(&ha->hardware_lock)->rlock); lock(&(&ha->tgt.sess_lock)->rlock); lock(&(&ha->hardware_lock)->rlock); Path2/deadlock *** DEADLOCK *** Call Trace: dump_stack+0x85/0xc2 print_circular_bug+0x1e3/0x250 __lock_acquire+0x1425/0x1620 lock_acquire+0xbf/0x210 _raw_spin_lock_irqsave+0x53/0x70 qlt_sess_work_fn+0x21d/0x480 [qla2xxx] process_one_work+0x1f4/0x6e0 Cc: <stable@vger.kernel.org> Cc: Bart Van Assche <Bart.VanAssche@sandisk.com> Reported-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Quinn Tran <quinn.tran@cavium.com> Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
-rw-r--r--drivers/scsi/qla2xxx/qla_target.c41
1 files changed, 18 insertions, 23 deletions
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index a78c3e9bcb57..989f931af156 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -5727,30 +5727,23 @@ static void qlt_abort_work(struct qla_tgt *tgt,
}
}
- spin_lock_irqsave(&ha->hardware_lock, flags);
-
- if (tgt->tgt_stop)
- goto out_term;
-
rc = __qlt_24xx_handle_abts(vha, &prm->abts, sess);
+ ha->tgt.tgt_ops->put_sess(sess);
+ spin_unlock_irqrestore(&ha->tgt.sess_lock, flags2);
+
if (rc != 0)
goto out_term;
- spin_unlock_irqrestore(&ha->hardware_lock, flags);
- if (sess)
- ha->tgt.tgt_ops->put_sess(sess);
- spin_unlock_irqrestore(&ha->tgt.sess_lock, flags2);
return;
out_term2:
- spin_lock_irqsave(&ha->hardware_lock, flags);
+ if (sess)
+ ha->tgt.tgt_ops->put_sess(sess);
+ spin_unlock_irqrestore(&ha->tgt.sess_lock, flags2);
out_term:
+ spin_lock_irqsave(&ha->hardware_lock, flags);
qlt_24xx_send_abts_resp(vha, &prm->abts, FCP_TMF_REJECTED, false);
spin_unlock_irqrestore(&ha->hardware_lock, flags);
-
- if (sess)
- ha->tgt.tgt_ops->put_sess(sess);
- spin_unlock_irqrestore(&ha->tgt.sess_lock, flags2);
}
static void qlt_tmr_work(struct qla_tgt *tgt,
@@ -5770,7 +5763,7 @@ static void qlt_tmr_work(struct qla_tgt *tgt,
spin_lock_irqsave(&ha->tgt.sess_lock, flags);
if (tgt->tgt_stop)
- goto out_term;
+ goto out_term2;
s_id = prm->tm_iocb2.u.isp24.fcp_hdr.s_id;
sess = ha->tgt.tgt_ops->find_sess_by_s_id(vha, s_id);
@@ -5782,11 +5775,11 @@ static void qlt_tmr_work(struct qla_tgt *tgt,
spin_lock_irqsave(&ha->tgt.sess_lock, flags);
if (!sess)
- goto out_term;
+ goto out_term2;
} else {
if (sess->deleted) {
sess = NULL;
- goto out_term;
+ goto out_term2;
}
if (!kref_get_unless_zero(&sess->sess_kref)) {
@@ -5794,7 +5787,7 @@ static void qlt_tmr_work(struct qla_tgt *tgt,
"%s: kref_get fail %8phC\n",
__func__, sess->port_name);
sess = NULL;
- goto out_term;
+ goto out_term2;
}
}
@@ -5804,17 +5797,19 @@ static void qlt_tmr_work(struct qla_tgt *tgt,
unpacked_lun = scsilun_to_int((struct scsi_lun *)&lun);
rc = qlt_issue_task_mgmt(sess, unpacked_lun, fn, iocb, 0);
- if (rc != 0)
- goto out_term;
-
ha->tgt.tgt_ops->put_sess(sess);
spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
+
+ if (rc != 0)
+ goto out_term;
return;
+out_term2:
+ if (sess)
+ ha->tgt.tgt_ops->put_sess(sess);
+ spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
out_term:
qlt_send_term_exchange(vha, NULL, &prm->tm_iocb2, 1, 0);
- ha->tgt.tgt_ops->put_sess(sess);
- spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
}
static void qlt_sess_work_fn(struct work_struct *work)