From: Dmitry Bogdanov d.bogdanov@yadro.com
[ Upstream commit 2ef7665dfd88830f15415ba007c7c9a46be7acd8 ]
Target de-configuration panics at high CPU load because TPGT and WWPN can be removed on separate threads.
TPGT removal requests a reset HBA on a separate thread and waits for reset complete (phase1). Due to high CPU load that HBA reset can be delayed for some time.
WWPN removal does qlt_stop_phase2(). There it is believed that phase1 has already completed and thus tgt.tgt_ops is subsequently cleared. However, tgt.tgt_ops is needed to process incoming traffic and therefore this will cause one of the following panics:
NIP qlt_reset+0x7c/0x220 [qla2xxx] LR qlt_reset+0x68/0x220 [qla2xxx] Call Trace: 0xc000003ffff63a78 (unreliable) qlt_handle_imm_notify+0x800/0x10c0 [qla2xxx] qlt_24xx_atio_pkt+0x208/0x590 [qla2xxx] qlt_24xx_process_atio_queue+0x33c/0x7a0 [qla2xxx] qla83xx_msix_atio_q+0x54/0x90 [qla2xxx]
or
NIP qlt_24xx_handle_abts+0xd0/0x2a0 [qla2xxx] LR qlt_24xx_handle_abts+0xb4/0x2a0 [qla2xxx] Call Trace: qlt_24xx_handle_abts+0x90/0x2a0 [qla2xxx] (unreliable) qlt_24xx_process_atio_queue+0x500/0x7a0 [qla2xxx] qla83xx_msix_atio_q+0x54/0x90 [qla2xxx]
or
NIP qlt_create_sess+0x90/0x4e0 [qla2xxx] LR qla24xx_do_nack_work+0xa8/0x180 [qla2xxx] Call Trace: 0xc0000000348fba30 (unreliable) qla24xx_do_nack_work+0xa8/0x180 [qla2xxx] qla2x00_do_work+0x674/0xbf0 [qla2xxx] qla2x00_iocb_work_fn
The patch fixes the issue by serializing qlt_stop_phase1() and qlt_stop_phase2() functions to make WWPN removal wait for phase1 completion.
Link: https://lore.kernel.org/r/20210415203554.27890-1-d.bogdanov@yadro.com Reviewed-by: Roman Bolshakov r.bolshakov@yadro.com Signed-off-by: Dmitry Bogdanov d.bogdanov@yadro.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/qla2xxx/qla_target.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c index 21011c5fddeb..bd8f9b03386a 100644 --- a/drivers/scsi/qla2xxx/qla_target.c +++ b/drivers/scsi/qla2xxx/qla_target.c @@ -1517,10 +1517,12 @@ void qlt_stop_phase2(struct qla_tgt *tgt) return; }
+ mutex_lock(&tgt->ha->optrom_mutex); mutex_lock(&vha->vha_tgt.tgt_mutex); tgt->tgt_stop = 0; tgt->tgt_stopped = 1; mutex_unlock(&vha->vha_tgt.tgt_mutex); + mutex_unlock(&tgt->ha->optrom_mutex);
ql_dbg(ql_dbg_tgt_mgt, vha, 0xf00c, "Stop of tgt %p finished\n", tgt);