dm mpath: eliminate need to use scsi_device_from_queue

Instead of scsi_device_from_queue(), use scsi_dh_attached_handler_name()
-- whose implementation uses scsi_device_from_queue() to avoid trying to
access SCSI-specific resources from non-SCSI devices.

Fixes buildbot reported issue when CONFIG_SCSI isn't set:
 ERROR: "scsi_device_from_queue" [drivers/md/dm-multipath.ko] undefined!

Fixes: 8d47e65948dd ("dm mpath: remove unnecessary NVMe branching in favor of scsi_dh checks")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 87c404eebe9f..2481c4794ed6 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -22,7 +22,6 @@
 #include <linux/time.h>
 #include <linux/workqueue.h>
 #include <linux/delay.h>
-#include <scsi/scsi_device.h>
 #include <scsi/scsi_dh.h>
 #include <linux/atomic.h>
 #include <linux/blk-mq.h>
@@ -805,15 +804,14 @@ static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg,
         return 0;
 }
 
-static int setup_scsi_dh(struct block_device *bdev, struct multipath *m, char **error)
+static int setup_scsi_dh(struct block_device *bdev, struct multipath *m,
+                         const char *attached_handler_name, char **error)
 {
         struct request_queue *q = bdev_get_queue(bdev);
-        const char *attached_handler_name;
         int r;
 
         if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) {
 retain:
-                attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
                 if (attached_handler_name) {
                         /*
                          * Clear any hw_handler_params associated with a
@@ -867,7 +865,8 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
         int r;
         struct pgpath *p;
         struct multipath *m = ti->private;
-        struct scsi_device *sdev;
+        struct request_queue *q;
+        const char *attached_handler_name;
 
         /* we need at least a path arg */
         if (as->argc < 1) {
@@ -886,11 +885,11 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
                 goto bad;
         }
 
-        sdev = scsi_device_from_queue(bdev_get_queue(p->path.dev->bdev));
-        if (sdev) {
-                put_device(&sdev->sdev_gendev);
+        q = bdev_get_queue(p->path.dev->bdev);
+        attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
+        if (attached_handler_name) {
                 INIT_DELAYED_WORK(&p->activate_path, activate_path_work);
-                r = setup_scsi_dh(p->path.dev->bdev, m, &ti->error);
+                r = setup_scsi_dh(p->path.dev->bdev, m, attached_handler_name, &ti->error);
                 if (r) {
                         dm_put_device(ti, p->path.dev);
                         goto bad;