[PATCH v4 18/28] scsi-multipath: revalidate paths upon device unblock

[John Garry]

From: John Garry <john.garry@xxxxxxxxx>

When a scsi_device is unblocked, we need revalidate paths which means that
we clear paths and requeue any queued bios.

Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
 drivers/scsi/scsi_lib.c       | 2 ++
 drivers/scsi/scsi_multipath.c | 8 ++++++++
 include/scsi/scsi_multipath.h | 5 +++++
 3 files changed, 15 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index dafa781288046..1e13aefdb6d64 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -3100,6 +3100,8 @@ static int scsi_internal_device_unblock(struct scsi_device *sdev,
 
 	mutex_lock(&sdev->state_mutex);
 	ret = scsi_internal_device_unblock_nowait(sdev, new_state);
+	if ((ret == 0) && sdev->scsi_mpath_dev)
+		scsi_mpath_revalidate_paths(sdev->scsi_mpath_dev);
 	mutex_unlock(&sdev->state_mutex);
 
 	return ret;
diff --git a/drivers/scsi/scsi_multipath.c b/drivers/scsi/scsi_multipath.c
index 6a2b06c148c1a..b896d28a7dd9a 100644
--- a/drivers/scsi/scsi_multipath.c
+++ b/drivers/scsi/scsi_multipath.c
@@ -230,6 +230,14 @@ static int scsi_multipath_sdev_init(struct scsi_device *sdev)
 	return 0;
 }
 
+void scsi_mpath_revalidate_paths(struct scsi_mpath_device *scsi_mpath_dev)
+{
+       struct scsi_mpath_head *scsi_mpath_head = scsi_mpath_dev->scsi_mpath_head;
+       struct mpath_head *mpath_head = &scsi_mpath_head->mpath_head;
+
+       mpath_revalidate_paths(mpath_head);
+}
+
 void scsi_mpath_dev_clear_path(struct scsi_mpath_device *scsi_mpath_dev)
 {
        struct mpath_device *mpath_device = &scsi_mpath_dev->mpath_device;
diff --git a/include/scsi/scsi_multipath.h b/include/scsi/scsi_multipath.h
index 8f58c44d96a77..cc77e63c43da3 100644
--- a/include/scsi/scsi_multipath.h
+++ b/include/scsi/scsi_multipath.h
@@ -55,6 +55,7 @@ void scsi_mpath_remove_sysfs_link(struct scsi_device *sdev);
 int scsi_mpath_get_head(struct scsi_mpath_head *scsi_mpath_head);
 void scsi_mpath_put_head(struct scsi_mpath_head *scsi_mpath_head);
 void scsi_mpath_dev_clear_path(struct scsi_mpath_device *scsi_mpath_dev);
+void scsi_mpath_revalidate_paths(struct scsi_mpath_device *scsi_mpath_dev);
 #else /* CONFIG_SCSI_MULTIPATH */
 
 struct scsi_mpath_head {
@@ -93,6 +94,10 @@ static inline
 void scsi_mpath_dev_clear_path(struct scsi_mpath_device *scsi_mpath_dev)
 {
 }
+static inline
+void scsi_mpath_revalidate_paths(struct scsi_mpath_device *scsi_mpath_dev)
+{
+}
 static inline void scsi_mpath_add_sysfs_link(struct scsi_device *sdev)
 {
 }
-- 
2.43.7