1 files changed, 6 insertions, 21 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index eff7bdd7731d..5a67671a3973 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -159,12 +159,9 @@ static struct priority_group *alloc_priority_group(void)
 static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
 {
         struct pgpath *pgpath, *tmp;
-        struct multipath *m = ti->private;
 
         list_for_each_entry_safe(pgpath, tmp, pgpaths, list) {
                 list_del(&pgpath->list);
-                if (m->hw_handler_name)
-                        scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev));
                 dm_put_device(ti, pgpath->path.dev);
                 free_pgpath(pgpath);
         }
@@ -580,6 +577,7 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
                 q = bdev_get_queue(p->path.dev->bdev);
 
         if (m->retain_attached_hw_handler) {
+retain:
                 attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
                 if (attached_handler_name) {
                         /*
@@ -599,20 +597,14 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
         }
 
         if (m->hw_handler_name) {
-                /*
-                 * Increments scsi_dh reference, even when using an
-                 * already-attached handler.
-                 */
                 r = scsi_dh_attach(q, m->hw_handler_name);
                 if (r == -EBUSY) {
-                        /*
-                         * Already attached to different hw_handler:
-                         * try to reattach with correct one.
-                         */
-                        scsi_dh_detach(q);
-                        r = scsi_dh_attach(q, m->hw_handler_name);
-                }
+                        char b[BDEVNAME_SIZE];
 
+                        printk(KERN_INFO "dm-mpath: retaining handler on device %s\n",
+                                bdevname(p->path.dev->bdev, b));
+                        goto retain;
+                }
                 if (r < 0) {
                         ti->error = "error attaching hardware handler";
                         dm_put_device(ti, p->path.dev);
@@ -624,7 +616,6 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps
                         if (r < 0) {
                                 ti->error = "unable to set hardware "
                                                         "handler parameters";
-                                scsi_dh_detach(q);
                                 dm_put_device(ti, p->path.dev);
                                 goto bad;
                         }
@@ -734,12 +725,6 @@ static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
                 return 0;
 
         m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL);
-        if (!try_then_request_module(scsi_dh_handler_exist(m->hw_handler_name),
-                                     "scsi_dh_%s", m->hw_handler_name)) {
-                ti->error = "unknown hardware handler type";
-                ret = -EINVAL;
-                goto fail;
-        }
 
         if (hw_argc > 1) {
                 char *p;