This is a note to let you know that I've just added the patch titled
scsi: target: qla2xxx: Wait for stop_phase1 at WWN removal
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-target-qla2xxx-wait-for-stop_phase1-at-wwn-remo.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 923f9d608717fd6c472788ae9106a56c83d64c1d
Author: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx>
Date: Thu Apr 15 23:35:54 2021 +0300
scsi: target: qla2xxx: Wait for stop_phase1 at WWN removal
[ 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>
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);
