diff mbox

[11/12] qla2xxx: Fix race between switch cmd completion and timeout

Message ID 20180607051926.27940-12-himanshu.madhani@cavium.com (mailing list archive)
State Accepted
Headers show

Commit Message

Madhani, Himanshu June 7, 2018, 5:19 a.m. UTC 
From: Quinn Tran <quinn.tran@cavium.com>

Fix race condition between switch cmd completion and timeout
timer. Timer has popped triggers command free. On IOCB completion,
stale sp point was reused. Instead, an abort will be sent to FW
to nudge the command out of FW, where the normal completion
will take place.

RIP: 0010:qla2x00_chk_ms_status+0xf3/0x1b0 [qla2xxx]
Call Trace:
<IRQ>
qla24xx_els_ct_entry.isra.15+0x1d4/0x2b0 [qla2xxx]
 qla24xx_msix_rsp_q+0x39/0xf0 [qla2xxx]
qla24xx_process_response_queue+0xbc/0x2b0 [qla2xxx]
qla24xx_msix_rsp_q+0x8a/0xf0 [qla2xxx]
__handle_irq_event_percpu+0xa0/0x1f0

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
---
 drivers/scsi/qla2xxx/qla_def.h  |  1 +
 drivers/scsi/qla2xxx/qla_gbl.h  |  2 +-
 drivers/scsi/qla2xxx/qla_init.c | 75 ++++++++++++++++++++++++++++++-----------
 3 files changed, 58 insertions(+), 20 deletions(-)
diff mbox

Patch

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 9a98f1c73f5e..416b5ac29666 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -313,6 +313,7 @@  struct srb_cmd {
 #define SRB_CRC_CTX_DMA_VALID		BIT_2	/* DIF: context DMA valid */
 #define SRB_CRC_PROT_DMA_VALID		BIT_4	/* DIF: prot DMA valid */
 #define SRB_CRC_CTX_DSD_VALID		BIT_5	/* DIF: dsd_list valid */
+#define SRB_WAKEUP_ON_COMP		BIT_6
 
 /* To identify if a srb is of T10-CRC type. @sp => srb_t pointer */
 #define IS_PROT_IO(sp)	(sp->flags & SRB_CRC_CTX_DSD_VALID)
diff --git a/drivers/scsi/qla2xxx/qla_gbl.h b/drivers/scsi/qla2xxx/qla_gbl.h
index 00fbd49a9a7a..6f2a37220a55 100644
--- a/drivers/scsi/qla2xxx/qla_gbl.h
+++ b/drivers/scsi/qla2xxx/qla_gbl.h
@@ -213,7 +213,7 @@  extern int qla24xx_post_upd_fcport_work(struct scsi_qla_host *, fc_port_t *);
 void qla2x00_handle_login_done_event(struct scsi_qla_host *, fc_port_t *,
 	uint16_t *);
 int qla24xx_post_gnl_work(struct scsi_qla_host *, fc_port_t *);
-int qla24xx_async_abort_cmd(srb_t *);
+int qla24xx_async_abort_cmd(srb_t *, bool);
 int qla24xx_post_relogin_work(struct scsi_qla_host *vha);
 
 /*
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index addfc53a7bb5..f6211bd7c86e 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -50,16 +50,15 @@  qla2x00_sp_timeout(struct timer_list *t)
 {
 	srb_t *sp = from_timer(sp, t, u.iocb_cmd.timer);
 	struct srb_iocb *iocb;
-	scsi_qla_host_t *vha = sp->vha;
 	struct req_que *req;
 	unsigned long flags;
 
-	spin_lock_irqsave(&vha->hw->hardware_lock, flags);
-	req = vha->hw->req_q_map[0];
+	spin_lock_irqsave(sp->qpair->qp_lock_ptr, flags);
+	req = sp->qpair->req;
 	req->outstanding_cmds[sp->handle] = NULL;
 	iocb = &sp->u.iocb_cmd;
+	spin_unlock_irqrestore(sp->qpair->qp_lock_ptr, flags);
 	iocb->timeout(sp);
-	spin_unlock_irqrestore(&vha->hw->hardware_lock, flags);
 }
 
 void
@@ -100,6 +99,8 @@  qla2x00_async_iocb_timeout(void *data)
 	srb_t *sp = data;
 	fc_port_t *fcport = sp->fcport;
 	struct srb_iocb *lio = &sp->u.iocb_cmd;
+	int rc, h;
+	unsigned long flags;
 
 	if (fcport) {
 		ql_dbg(ql_dbg_disc, fcport->vha, 0x2071,
@@ -114,11 +115,26 @@  qla2x00_async_iocb_timeout(void *data)
 
 	switch (sp->type) {
 	case SRB_LOGIN_CMD:
-		/* Retry as needed. */
-		lio->u.logio.data[0] = MBS_COMMAND_ERROR;
-		lio->u.logio.data[1] = lio->u.logio.flags & SRB_LOGIN_RETRIED ?
-			QLA_LOGIO_LOGIN_RETRIED : 0;
-		sp->done(sp, QLA_FUNCTION_TIMEOUT);
+		rc = qla24xx_async_abort_cmd(sp, false);
+		if (rc) {
+			/* Retry as needed. */
+			lio->u.logio.data[0] = MBS_COMMAND_ERROR;
+			lio->u.logio.data[1] =
+				lio->u.logio.flags & SRB_LOGIN_RETRIED ?
+				QLA_LOGIO_LOGIN_RETRIED : 0;
+			spin_lock_irqsave(sp->qpair->qp_lock_ptr, flags);
+			for (h = 1; h < sp->qpair->req->num_outstanding_cmds;
+			    h++) {
+				if (sp->qpair->req->outstanding_cmds[h] ==
+				    sp) {
+					sp->qpair->req->outstanding_cmds[h] =
+					    NULL;
+					break;
+				}
+			}
+			spin_unlock_irqrestore(sp->qpair->qp_lock_ptr, flags);
+			sp->done(sp, QLA_FUNCTION_TIMEOUT);
+		}
 		break;
 	case SRB_LOGOUT_CMD:
 	case SRB_CT_PTHRU_CMD:
@@ -127,7 +143,21 @@  qla2x00_async_iocb_timeout(void *data)
 	case SRB_NACK_PRLI:
 	case SRB_NACK_LOGO:
 	case SRB_CTRL_VP:
-		sp->done(sp, QLA_FUNCTION_TIMEOUT);
+		rc = qla24xx_async_abort_cmd(sp, false);
+		if (rc) {
+			spin_lock_irqsave(sp->qpair->qp_lock_ptr, flags);
+			for (h = 1; h < sp->qpair->req->num_outstanding_cmds;
+			    h++) {
+				if (sp->qpair->req->outstanding_cmds[h] ==
+				    sp) {
+					sp->qpair->req->outstanding_cmds[h] =
+					    NULL;
+					break;
+				}
+			}
+			spin_unlock_irqrestore(sp->qpair->qp_lock_ptr, flags);
+			sp->done(sp, QLA_FUNCTION_TIMEOUT);
+		}
 		break;
 	}
 }
@@ -1596,7 +1626,7 @@  qla24xx_abort_iocb_timeout(void *data)
 	struct srb_iocb *abt = &sp->u.iocb_cmd;
 
 	abt->u.abt.comp_status = CS_TIMEOUT;
-	complete(&abt->u.abt.comp);
+	sp->done(sp, QLA_FUNCTION_TIMEOUT);
 }
 
 static void
@@ -1605,12 +1635,16 @@  qla24xx_abort_sp_done(void *ptr, int res)
 	srb_t *sp = ptr;
 	struct srb_iocb *abt = &sp->u.iocb_cmd;
 
-	if (del_timer(&sp->u.iocb_cmd.timer))
-		complete(&abt->u.abt.comp);
+	if (del_timer(&sp->u.iocb_cmd.timer)) {
+		if (sp->flags & SRB_WAKEUP_ON_COMP)
+			complete(&abt->u.abt.comp);
+		else
+			sp->free(sp);
+	}
 }
 
 int
-qla24xx_async_abort_cmd(srb_t *cmd_sp)
+qla24xx_async_abort_cmd(srb_t *cmd_sp, bool wait)
 {
 	scsi_qla_host_t *vha = cmd_sp->vha;
 	fc_port_t *fcport = cmd_sp->fcport;
@@ -1625,6 +1659,8 @@  qla24xx_async_abort_cmd(srb_t *cmd_sp)
 	abt_iocb = &sp->u.iocb_cmd;
 	sp->type = SRB_ABT_CMD;
 	sp->name = "abort";
+	if (wait)
+		sp->flags = SRB_WAKEUP_ON_COMP;
 
 	abt_iocb->timeout = qla24xx_abort_iocb_timeout;
 	init_completion(&abt_iocb->u.abt.comp);
@@ -1648,10 +1684,11 @@  qla24xx_async_abort_cmd(srb_t *cmd_sp)
 	    "Abort command issued - hdl=%x, target_id=%x\n",
 	    cmd_sp->handle, fcport->tgt_id);
 
-	wait_for_completion(&abt_iocb->u.abt.comp);
-
-	rval = abt_iocb->u.abt.comp_status == CS_COMPLETE ?
-	    QLA_SUCCESS : QLA_FUNCTION_FAILED;
+	if (wait) {
+		wait_for_completion(&abt_iocb->u.abt.comp);
+		rval = abt_iocb->u.abt.comp_status == CS_COMPLETE ?
+			QLA_SUCCESS : QLA_FUNCTION_FAILED;
+	}
 
 done_free_sp:
 	sp->free(sp);
@@ -1687,7 +1724,7 @@  qla24xx_async_abort_command(srb_t *sp)
 		return qlafx00_fx_disc(vha, &vha->hw->mr.fcport,
 		    FXDISC_ABORT_IOCTL);
 
-	return qla24xx_async_abort_cmd(sp);
+	return qla24xx_async_abort_cmd(sp, true);
 }
 
 static void