If a device needs to be rescanned the device_handler might need
to be rechecked, too.
So add a 'rescan' callback to the device handler and call it
upon scsi_rescan_device().
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/scsi/device_handler/scsi_dh_alua.c | 53 +++++++++++++++++++++++-------
drivers/scsi/scsi_lib.c | 1 +
drivers/scsi/scsi_scan.c | 8 ++++-
include/scsi/scsi_dh.h | 1 +
4 files changed, 51 insertions(+), 12 deletions(-)
diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index e4cabc8..5b52017 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -262,7 +262,8 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
int group_id = -1;
char device_id_str[256], *device_id = NULL;
int device_id_size, device_id_type = 0;
- struct alua_port_group *tmp_pg, *pg = NULL;
+ struct alua_port_group *tmp_pg, *pg = NULL, *old_pg = NULL;
+ bool pg_found = false;
rcu_read_lock();
if (!rcu_dereference(sdev->vpd_pg83)) {
@@ -407,17 +408,25 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
if (memcmp(tmp_pg->device_id, device_id,
device_id_size))
continue;
- kref_get(&tmp_pg->kref);
spin_lock(&h->pg_lock);
- rcu_assign_pointer(h->pg, tmp_pg);
+ pg = rcu_dereference(h->pg);
+ if (pg) {
+ /*
+ * This can happen if the VPD information changed
+ */
+ if (tmp_pg != pg) {
+ old_pg = pg;
+ kref_get(&tmp_pg->kref);
+ rcu_assign_pointer(h->pg, tmp_pg);
+ }
+ pg_found = true;
+ }
spin_unlock(&h->pg_lock);
break;
}
spin_unlock(&port_group_lock);
- if (h->pg) {
- synchronize_rcu();
- return SCSI_DH_OK;
- }
+ if (pg_found)
+ goto out;
pg = kzalloc(sizeof(struct alua_port_group), GFP_KERNEL);
if (!pg) {
@@ -466,12 +475,17 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
if (memcmp(tmp_pg->device_id, pg->device_id,
device_id_size))
continue;
- kref_get(&tmp_pg->kref);
spin_lock(&h->pg_lock);
- rcu_assign_pointer(h->pg, tmp_pg);
+ pg = rcu_dereference(h->pg);
+ if (pg) {
+ if (tmp_pg != pg) {
+ old_pg = pg;
+ kref_get(&tmp_pg->kref);
+ rcu_assign_pointer(h->pg, tmp_pg);
+ }
+ pg = NULL;
+ }
spin_unlock(&h->pg_lock);
- kfree(pg);
- pg = NULL;
break;
}
if (pg) {
@@ -481,6 +495,13 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h)
spin_unlock(&h->pg_lock);
}
spin_unlock(&port_group_lock);
+out:
+ if (old_pg) {
+ synchronize_rcu();
+ if (old_pg->rtpg_sdev)
+ flush_workqueue(old_pg->work_q);
+ kref_put(&pg->kref, release_port_group);
+ }
return SCSI_DH_OK;
}
@@ -1011,6 +1032,8 @@ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
kref_get(&pg->kref);
rcu_read_unlock();
}
+ } else {
+ WARN_ON(rcu_dereference(h->pg));
}
complete(&h->init_complete);
if (pg) {
@@ -1195,6 +1218,13 @@ static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
}
+static void alua_rescan(struct scsi_device *sdev)
+{
+ struct alua_dh_data *h = sdev->handler_data;
+
+ alua_initialize(sdev, h);
+}
+
/*
* alua_bus_attach - Attach device handler
* @sdev: device to be attached to
@@ -1256,6 +1286,7 @@ static struct scsi_device_handler alua_dh = {
.prep_fn = alua_prep_fn,
.check_sense = alua_check_sense,
.activate = alua_activate,
+ .rescan = alua_rescan,
.set_params = alua_set_params,
};
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 18ab4ad..991b9e1 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2704,6 +2704,7 @@ static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
envp[idx++] = "SDEV_MEDIA_CHANGE=1";
break;
case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
+ scsi_rescan_device(&sdev->sdev_gendev);
envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
break;
case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 190d743..5d3e2ae 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -43,6 +43,7 @@
#include <scsi/scsi_devinfo.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>
+#include <scsi/scsi_dh.h>
#include <scsi/scsi_eh.h>
#include "scsi_priv.h"
@@ -1516,9 +1517,14 @@ EXPORT_SYMBOL(scsi_add_device);
void scsi_rescan_device(struct device *dev)
{
+ struct scsi_device *sdev = to_scsi_device(dev);
+
device_lock(dev);
- scsi_attach_vpd(to_scsi_device(dev));
+ scsi_attach_vpd(sdev);
+
+ if (sdev->handler && sdev->handler->rescan)
+ sdev->handler->rescan(sdev);
if (dev->driver && try_module_get(dev->driver->owner)) {
struct scsi_driver *drv = to_scsi_driver(dev->driver);
diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h
index 85d7317..5c73062 100644
--- a/include/scsi/scsi_dh.h
+++ b/include/scsi/scsi_dh.h
@@ -70,6 +70,7 @@ struct scsi_device_handler {
int (*activate)(struct scsi_device *, activate_complete, void *);
int (*prep_fn)(struct scsi_device *, struct request *);
int (*set_params)(struct scsi_device *, const char *);
+ void (*rescan)(struct scsi_device *);
};
#ifdef CONFIG_SCSI_DH
--
1.8.5.2
--
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