From: Xiang Chen chenxiang66@hisilicon.com
mainline inclusion from mainline-v5.17-rc1 commit 307d9f49cce966c2ba969f58bd6227bc0092afaa category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4ZHSV CVE: NA
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/dr...
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Processing events such as PORTE_BROADCAST_RCVD may cause dependency issues for runtime power management support. Such a problem would be that handling a PORTE_BROADCAST_RCVD event requires that the host is resumed to send SMP commands. However, in resuming the host, the phyup events generated from re-enabling the phys are processed in the same workqueue as the original PORTE_BROADCAST_RCVD event. As such, the host will never finish resuming (as it waits for the phyup event processing), and then the PORTE_BROADCAST_RCVD event can't be processed as the SMP commands are blocked, and so we have a deadlock. Solve this problem by ensuring that libsas keeps the host active until completely finished phy or port events, such as PORTE_BYTES_DMAED. As such, we don't have to worry about resuming the host for processing individual SMP commands in this example.
Link: https://lore.kernel.org/r/1639999298-244569-15-git-send-email-chenxiang66@hi... Reviewed-by: John Garry john.garry@huawei.com Signed-off-by: Xiang Chen chenxiang66@hisilicon.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Fujai Ninifuijia1@hisilicon.com Reviewed-by: Jason Yan yanaijie@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/scsi/libsas/sas_event.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c index 626ef96b9348..3613b9b315bc 100644 --- a/drivers/scsi/libsas/sas_event.c +++ b/drivers/scsi/libsas/sas_event.c @@ -50,8 +50,10 @@ void sas_queue_deferred_work(struct sas_ha_struct *ha) list_for_each_entry_safe(sw, _sw, &ha->defer_q, drain_node) { list_del_init(&sw->drain_node); ret = sas_queue_work(ha, sw); - if (ret != 1) + if (ret != 1) { + pm_runtime_put(ha->dev); sas_free_event(to_asd_sas_event(&sw->work)); + } } spin_unlock_irq(&ha->lock); } @@ -126,16 +128,22 @@ void sas_enable_revalidation(struct sas_ha_struct *ha) static void sas_port_event_worker(struct work_struct *work) { struct asd_sas_event *ev = to_asd_sas_event(work); + struct asd_sas_phy *phy = ev->phy; + struct sas_ha_struct *ha = phy->ha;
sas_port_event_fns[ev->event](work); + pm_runtime_put(ha->dev); sas_free_event(ev); }
static void sas_phy_event_worker(struct work_struct *work) { struct asd_sas_event *ev = to_asd_sas_event(work); + struct asd_sas_phy *phy = ev->phy; + struct sas_ha_struct *ha = phy->ha;
sas_phy_event_fns[ev->event](work); + pm_runtime_put(ha->dev); sas_free_event(ev); }
@@ -170,14 +178,19 @@ int sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event, if (!ev) return -ENOMEM;
+ /* Call pm_runtime_put() with pairs in sas_port_event_worker() */ + pm_runtime_get_noresume(ha->dev); + INIT_SAS_EVENT(ev, sas_port_event_worker, phy, event);
if (sas_defer_event(phy, ev)) return 0;
ret = sas_queue_event(event, &ev->work, ha); - if (ret != 1) + if (ret != 1) { + pm_runtime_put(ha->dev); sas_free_event(ev); + }
return ret; } @@ -196,14 +209,19 @@ int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event, if (!ev) return -ENOMEM;
+ /* Call pm_runtime_put() with pairs in sas_phy_event_worker() */ + pm_runtime_get_noresume(ha->dev); + INIT_SAS_EVENT(ev, sas_phy_event_worker, phy, event);
if (sas_defer_event(phy, ev)) return 0;
ret = sas_queue_event(event, &ev->work, ha); - if (ret != 1) + if (ret != 1) { + pm_runtime_put(ha->dev); sas_free_event(ev); + }
return ret; }