From: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx> [ 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@xxxxxxxxx Reviewed-by: Roman Bolshakov <r.bolshakov@xxxxxxxxx> Signed-off-by: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 1d9f19e5e0f8..0a8a5841e1b8 100644 --- a/drivers/scsi/qla2xxx/qla_target.c +++ b/drivers/scsi/qla2xxx/qla_target.c @@ -1042,6 +1042,7 @@ void qlt_stop_phase2(struct qla_tgt *tgt) "Waiting for %d IRQ commands to complete (tgt %p)", tgt->irq_cmd_count, tgt); + mutex_lock(&tgt->ha->optrom_mutex); mutex_lock(&vha->vha_tgt.tgt_mutex); spin_lock_irqsave(&ha->hardware_lock, flags); while (tgt->irq_cmd_count != 0) { @@ -1053,6 +1054,7 @@ void qlt_stop_phase2(struct qla_tgt *tgt) tgt->tgt_stopped = 1; spin_unlock_irqrestore(&ha->hardware_lock, flags); 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", tgt); -- 2.30.2
