scsi: libsas: Use dynamic alloced work to avoid sas event lost

Now libsas hotplug work is static, every sas event type has its own
static work, LLDD driver queues the hotplug work into shost->work_q.  If
LLDD driver burst posts lots hotplug events to libsas, the hotplug
events may pending in the workqueue like

shost->work_q
new work[PORTE_BYTES_DMAED] --> |[PHYE_LOSS_OF_SIGNAL][PORTE_BYTES_DMAED] -> processing
                                |<-------wait worker to process-------->|

In this case, a new PORTE_BYTES_DMAED event coming, libsas try to queue
it to shost->work_q, but this work is already pending, so it would be
lost. Finally, libsas delete the related sas port and sas devices, but
LLDD driver expect libsas add the sas port and devices(last sas event).

This patch use dynamic allocated work to avoid this issue.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 11 insertions, 6 deletions

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 0f9cbf96c093..ee1b25299dd6 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -292,6 +292,7 @@ struct asd_sas_port {
 struct asd_sas_event {
         struct sas_work work;
         struct asd_sas_phy *phy;
+        int event;
 };
 
 static inline struct asd_sas_event *to_asd_sas_event(struct work_struct *work)
@@ -301,17 +302,21 @@ static inline struct asd_sas_event *to_asd_sas_event(struct work_struct *work)
         return ev;
 }
 
+static inline void INIT_SAS_EVENT(struct asd_sas_event *ev,
+                void (*fn)(struct work_struct *),
+                struct asd_sas_phy *phy, int event)
+{
+        INIT_SAS_WORK(&ev->work, fn);
+        ev->phy = phy;
+        ev->event = event;
+}
+
+
 /* The phy pretty much is controlled by the LLDD.
  * The class only reads those fields.
  */
 struct asd_sas_phy {
 /* private: */
-        struct asd_sas_event   port_events[PORT_NUM_EVENTS];
-        struct asd_sas_event   phy_events[PHY_NUM_EVENTS];
-
-        unsigned long port_events_pending;
-        unsigned long phy_events_pending;
-
         int error;
         int suspended;