Add a core version of alua_check_tpgs() from scsi_sh_alua.c
Signed-off-by: John Garry <john.g.garry@oracle.com>
---
drivers/scsi/scsi_alua.c | 53 ++++++++++++++++++++++++++++++++++++++++
include/scsi/scsi_alua.h | 6 +++++
2 files changed, 59 insertions(+)
diff --git a/drivers/scsi/scsi_alua.c b/drivers/scsi/scsi_alua.c
index 4e20a537a4ad6..9c317e60d031e 100644
--- a/drivers/scsi/scsi_alua.c
+++ b/drivers/scsi/scsi_alua.c
@@ -128,6 +128,59 @@ static int submit_stpg(struct scsi_device *sdev,
ALUA_FAILOVER_RETRIES, &exec_args);
}
+/*
+ * scsi_alua_check_tpgs - Evaluate TPGS setting
+ * @sdev: device to be checked
+ *
+ * Examine the TPGS setting of the sdev to find out if ALUA
+ * is supported.
+ */
+int scsi_alua_check_tpgs(struct scsi_device *sdev)
+{
+ int tpgs = TPGS_MODE_NONE;
+
+ /*
+ * ALUA support for non-disk devices is fraught with
+ * difficulties, so disable it for now.
+ */
+ if (sdev->type != TYPE_DISK) {
+ sdev_printk(KERN_INFO, sdev,
+ "%s: disable for non-disk devices\n",
+ DRV_NAME);
+ return tpgs;
+ }
+
+ tpgs = scsi_device_tpgs(sdev);
+ switch (tpgs) {
+ case TPGS_MODE_EXPLICIT|TPGS_MODE_IMPLICIT:
+ sdev_printk(KERN_INFO, sdev,
+ "%s: supports implicit and explicit TPGS\n",
+ DRV_NAME);
+ break;
+ case TPGS_MODE_EXPLICIT:
+ sdev_printk(KERN_INFO, sdev, "%s: supports explicit TPGS\n",
+ DRV_NAME);
+ break;
+ case TPGS_MODE_IMPLICIT:
+ sdev_printk(KERN_INFO, sdev, "%s: supports implicit TPGS\n",
+ DRV_NAME);
+ break;
+ case TPGS_MODE_NONE:
+ sdev_printk(KERN_INFO, sdev, "%s: not supported\n",
+ DRV_NAME);
+ break;
+ default:
+ sdev_printk(KERN_INFO, sdev,
+ "%s: unsupported TPGS setting %d\n",
+ DRV_NAME, tpgs);
+ tpgs = TPGS_MODE_NONE;
+ break;
+ }
+
+ return tpgs;
+}
+EXPORT_SYMBOL_GPL(scsi_alua_check_tpgs);
+
static char print_alua_state(unsigned char state)
{
switch (state) {
diff --git a/include/scsi/scsi_alua.h b/include/scsi/scsi_alua.h
index 6e4f262bbfbc0..2e664f20d9681 100644
--- a/include/scsi/scsi_alua.h
+++ b/include/scsi/scsi_alua.h
@@ -30,6 +30,8 @@ struct alua_data {
int scsi_alua_sdev_init(struct scsi_device *sdev);
void scsi_alua_sdev_exit(struct scsi_device *sdev);
+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);
@@ -37,6 +39,10 @@ int scsi_alua_init(void);
void scsi_exit_alua(void);
#else //CONFIG_SCSI_ALUA
+static inline int scsi_alua_check_tpgs(struct scsi_device *sdev)
+{
+ return 0;
+}
static inline int scsi_alua_rtpg_run(struct scsi_device *sdev)
{
return 0;
--
2.43.5