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scsi: qla2xxx: Reduce holding sess_lock to prevent CPU lock-up
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- Reduce sess_lock holding to prevent CPU Lock up. sess_lock was held across
  fc_port registration and deletion.  These calls can be blocked by upper
  layer. Sess_lock is also being accessed by interrupt thread.

- Reduce number of loops in processing work_list to prevent kernel complaint
  of CPU lockup or holding sess_lock.

Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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@martinkpetersen
Quinn Tran authored and martinkpetersen committed Sep 12, 2018
1 parent 6a62946 commit 0aca778
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Showing 5 changed files with 33 additions and 25 deletions.
2 changes: 1 addition & 1 deletion drivers/scsi/qla2xxx/qla_def.h
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Original file line number Diff line number Diff line change
Expand Up @@ -262,8 +262,8 @@ struct name_list_extended {
struct get_name_list_extended *l;
dma_addr_t ldma;
struct list_head fcports;
spinlock_t fcports_lock;
u32 size;
u8 sent;
};
/*
* Timeout timer counts in seconds
Expand Down
18 changes: 12 additions & 6 deletions drivers/scsi/qla2xxx/qla_gs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -3946,11 +3946,10 @@ void qla24xx_async_gnnft_done(scsi_qla_host_t *vha, srb_t *sp)
if ((qla_dual_mode_enabled(vha) ||
qla_ini_mode_enabled(vha)) &&
atomic_read(&fcport->state) == FCS_ONLINE) {
qla2x00_mark_device_lost(vha, fcport,
ql2xplogiabsentdevice, 0);
if (fcport->loop_id != FC_NO_LOOP_ID) {
if (fcport->flags & FCF_FCP2_DEVICE)
fcport->logout_on_delete = 0;

if (fcport->loop_id != FC_NO_LOOP_ID &&
(fcport->flags & FCF_FCP2_DEVICE) == 0) {
ql_dbg(ql_dbg_disc, vha, 0x20f0,
"%s %d %8phC post del sess\n",
__func__, __LINE__,
Expand Down Expand Up @@ -4188,12 +4187,13 @@ static void qla2x00_async_gpnft_gnnft_sp_done(void *s, int res)

sp->rc = res;
rc = qla2x00_post_nvme_gpnft_done_work(vha, sp, QLA_EVT_GPNFT);
if (!rc) {
if (rc) {
qla24xx_sp_unmap(vha, sp);
set_bit(LOCAL_LOOP_UPDATE, &vha->dpc_flags);
set_bit(LOOP_RESYNC_NEEDED, &vha->dpc_flags);
return;
}
return;
}

if (cmd == GPN_FT_CMD) {
Expand Down Expand Up @@ -4243,6 +4243,8 @@ static int qla24xx_async_gnnft(scsi_qla_host_t *vha, struct srb *sp,
vha->scan.scan_flags &= ~SF_SCANNING;
spin_unlock_irqrestore(&vha->work_lock, flags);
WARN_ON(1);
set_bit(LOCAL_LOOP_UPDATE, &vha->dpc_flags);
set_bit(LOOP_RESYNC_NEEDED, &vha->dpc_flags);
goto done_free_sp;
}

Expand Down Expand Up @@ -4276,8 +4278,12 @@ static int qla24xx_async_gnnft(scsi_qla_host_t *vha, struct srb *sp,
sp->done = qla2x00_async_gpnft_gnnft_sp_done;

rval = qla2x00_start_sp(sp);
if (rval != QLA_SUCCESS)
if (rval != QLA_SUCCESS) {
spin_lock_irqsave(&vha->work_lock, flags);
vha->scan.scan_flags &= ~SF_SCANNING;
spin_unlock_irqrestore(&vha->work_lock, flags);
goto done_free_sp;
}

ql_dbg(ql_dbg_disc, vha, 0xffff,
"Async-%s hdl=%x FC4Type %x.\n", sp->name,
Expand Down
33 changes: 17 additions & 16 deletions drivers/scsi/qla2xxx/qla_init.c
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Original file line number Diff line number Diff line change
Expand Up @@ -790,6 +790,7 @@ qla24xx_async_gnl_sp_done(void *s, int res)
sp->name, res, sp->u.iocb_cmd.u.mbx.in_mb[1],
sp->u.iocb_cmd.u.mbx.in_mb[2]);

sp->fcport->flags &= ~(FCF_ASYNC_SENT|FCF_ASYNC_ACTIVE);
memset(&ea, 0, sizeof(ea));
ea.sp = sp;
ea.rc = res;
Expand Down Expand Up @@ -817,25 +818,24 @@ qla24xx_async_gnl_sp_done(void *s, int res)
(loop_id & 0x7fff));
}

spin_lock_irqsave(&vha->gnl.fcports_lock, flags);
spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);

INIT_LIST_HEAD(&h);
fcport = tf = NULL;
if (!list_empty(&vha->gnl.fcports))
list_splice_init(&vha->gnl.fcports, &h);
spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);

list_for_each_entry_safe(fcport, tf, &h, gnl_entry) {
list_del_init(&fcport->gnl_entry);
spin_lock(&vha->hw->tgt.sess_lock);
spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
fcport->flags &= ~(FCF_ASYNC_SENT | FCF_ASYNC_ACTIVE);
spin_unlock(&vha->hw->tgt.sess_lock);
spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
ea.fcport = fcport;

qla2x00_fcport_event_handler(vha, &ea);
}
spin_unlock_irqrestore(&vha->gnl.fcports_lock, flags);

spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
/* create new fcport if fw has knowledge of new sessions */
for (i = 0; i < n; i++) {
port_id_t id;
Expand Down Expand Up @@ -868,6 +868,8 @@ qla24xx_async_gnl_sp_done(void *s, int res)
}
}

spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
vha->gnl.sent = 0;
spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);

sp->free(sp);
Expand All @@ -887,27 +889,24 @@ int qla24xx_async_gnl(struct scsi_qla_host *vha, fc_port_t *fcport)
ql_dbg(ql_dbg_disc, vha, 0x20d9,
"Async-gnlist WWPN %8phC \n", fcport->port_name);

spin_lock_irqsave(&vha->gnl.fcports_lock, flags);
if (!list_empty(&fcport->gnl_entry)) {
spin_unlock_irqrestore(&vha->gnl.fcports_lock, flags);
rval = QLA_SUCCESS;
goto done;
}

spin_lock(&vha->hw->tgt.sess_lock);
spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
fcport->flags |= FCF_ASYNC_SENT;
fcport->disc_state = DSC_GNL;
fcport->last_rscn_gen = fcport->rscn_gen;
fcport->last_login_gen = fcport->login_gen;
spin_unlock(&vha->hw->tgt.sess_lock);

list_add_tail(&fcport->gnl_entry, &vha->gnl.fcports);
spin_unlock_irqrestore(&vha->gnl.fcports_lock, flags);
if (vha->gnl.sent) {
spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
return QLA_SUCCESS;
}
vha->gnl.sent = 1;
spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);

sp = qla2x00_get_sp(vha, fcport, GFP_KERNEL);
if (!sp)
goto done;

fcport->flags |= FCF_ASYNC_SENT;
sp->type = SRB_MB_IOCB;
sp->name = "gnlist";
sp->gen1 = fcport->rscn_gen;
Expand Down Expand Up @@ -1185,7 +1184,9 @@ void __qla24xx_handle_gpdb_event(scsi_qla_host_t *vha, struct event_arg *ea)
vha->fcport_count++;
ea->fcport->login_succ = 1;

spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
qla24xx_sched_upd_fcport(ea->fcport);
spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
} else if (ea->fcport->login_succ) {
/*
* We have an existing session. A late RSCN delivery
Expand Down
3 changes: 1 addition & 2 deletions drivers/scsi/qla2xxx/qla_os.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2730,7 +2730,7 @@ static void qla2x00_iocb_work_fn(struct work_struct *work)
struct scsi_qla_host, iocb_work);
struct qla_hw_data *ha = vha->hw;
struct scsi_qla_host *base_vha = pci_get_drvdata(ha->pdev);
int i = 20;
int i = 2;
unsigned long flags;

if (test_bit(UNLOADING, &base_vha->dpc_flags))
Expand Down Expand Up @@ -4603,7 +4603,6 @@ struct scsi_qla_host *qla2x00_create_host(struct scsi_host_template *sht,

spin_lock_init(&vha->work_lock);
spin_lock_init(&vha->cmd_list_lock);
spin_lock_init(&vha->gnl.fcports_lock);
init_waitqueue_head(&vha->fcport_waitQ);
init_waitqueue_head(&vha->vref_waitq);

Expand Down
2 changes: 2 additions & 0 deletions drivers/scsi/qla2xxx/qla_target.c
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Original file line number Diff line number Diff line change
Expand Up @@ -601,7 +601,9 @@ void qla2x00_async_nack_sp_done(void *s, int res)
sp->fcport->login_succ = 1;

vha->fcport_count++;
spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags);
qla24xx_sched_upd_fcport(sp->fcport);
spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags);
} else {
sp->fcport->login_retry = 0;
sp->fcport->disc_state = DSC_LOGIN_COMPLETE;
Expand Down

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