[PATCH 10/13] scsi: alua: Add scsi_alua_prep_fn()

[John Garry]

Add a core version of alua_prep_fn() from scsi_dh_alua.c

Signed-off-by: John Garry <john.g.ga...@oracle.com>
---
 drivers/scsi/scsi_alua.c | 23 +++++++++++++++++++++++
 include/scsi/scsi_alua.h |  8 ++++++++
 2 files changed, 31 insertions(+)

diff --git a/drivers/scsi/scsi_alua.c b/drivers/scsi/scsi_alua.c
index d19d1845bc324..c269105dbae4a 100644
--- a/drivers/scsi/scsi_alua.c
+++ b/drivers/scsi/scsi_alua.c
@@ -608,6 +608,29 @@ void scsi_alua_sdev_exit(struct scsi_device *sdev)
        sdev->alua = NULL;
 }
 
+blk_status_t scsi_alua_prep_fn(struct scsi_device *sdev, struct request *req)
+{
+       struct alua_data *alua = sdev->alua;
+       unsigned long flags;
+       unsigned char state;
+
+       spin_lock_irqsave(&alua->lock, flags);
+       state = alua->state;
+       spin_unlock_irqrestore(&alua->lock, flags);
+
+       switch (state) {
+       case SCSI_ACCESS_STATE_OPTIMAL:
+       case SCSI_ACCESS_STATE_ACTIVE:
+       case SCSI_ACCESS_STATE_LBA:
+       case SCSI_ACCESS_STATE_TRANSITIONING:
+               return BLK_STS_OK;
+       default:
+               req->rq_flags |= RQF_QUIET;
+               return BLK_STS_IOERR;
+       }
+}
+EXPORT_SYMBOL_GPL(scsi_alua_prep_fn);
+
 int scsi_alua_init(void)
 {
        kalua_wq = alloc_workqueue("kalua", WQ_MEM_RECLAIM | WQ_PERCPU, 0);
diff --git a/include/scsi/scsi_alua.h b/include/scsi/scsi_alua.h
index 5b3a12861658f..c16d4adc915ec 100644
--- a/include/scsi/scsi_alua.h
+++ b/include/scsi/scsi_alua.h
@@ -8,6 +8,7 @@
 #ifndef _SCSI_ALUA_H
 #define _SCSI_ALUA_H
 
+#include <linux/blk-mq.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_device.h>
 
@@ -37,6 +38,8 @@ int scsi_alua_check_tpgs(struct scsi_device *sdev);
 int scsi_alua_rtpg_run(struct scsi_device *sdev);
 int scsi_alua_stpg_run(struct scsi_device *sdev, bool optimize);
 
+blk_status_t scsi_alua_prep_fn(struct scsi_device *sdev, struct request *req);
+
 int scsi_alua_init(void);
 void scsi_exit_alua(void);
 #else //CONFIG_SCSI_ALUA
@@ -56,6 +59,11 @@ static inline int scsi_alua_stpg_run(struct scsi_device 
*sdev, bool optimize)
 {
        return 0;
 }
+static inline
+blk_status_t scsi_alua_prep_fn(struct scsi_device *sdev, struct request *req)
+{
+       return BLK_STS_OK;
+}
 static inline int scsi_alua_sdev_init(struct scsi_device *sdev)
 {
        return 0;
-- 
2.43.5