Merge tag 'for-4.16/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - a stable DM multipath fix to restore ability to pass integrity data

 - two DM multipath fixes for a fix that was merged into 4.16-rc5

* tag 'for-4.16/dm-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm mpath: fix passing integrity data
  dm mpath: eliminate need to use scsi_device_from_queue
  dm mpath: fix uninitialized 'pg_init_wait' waitqueue_head NULL pointer

1 files changed, 21 insertions, 22 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 3fde9e9faddd..a05a560d3cba 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>
@@ -223,6 +222,16 @@ static int alloc_multipath_stage2(struct dm_target *ti, struct multipath *m)
 
         dm_table_set_type(ti->table, m->queue_mode);
 
+        /*
+         * Init fields that are only used when a scsi_dh is attached
+         * - must do this unconditionally (really doesn't hurt non-SCSI uses)
+         */
+        set_bit(MPATHF_QUEUE_IO, &m->flags);
+        atomic_set(&m->pg_init_in_progress, 0);
+        atomic_set(&m->pg_init_count, 0);
+        m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT;
+        init_waitqueue_head(&m->pg_init_wait);
+
         return 0;
 }
 
@@ -331,7 +340,6 @@ static void __switch_pg(struct multipath *m, struct priority_group *pg)
                 set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
                 set_bit(MPATHF_QUEUE_IO, &m->flags);
         } else {
-                /* FIXME: not needed if no scsi_dh is attached */
                 clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
                 clear_bit(MPATHF_QUEUE_IO, &m->flags);
         }
@@ -796,15 +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
@@ -823,16 +830,6 @@ retain:
                          */
                         kfree(m->hw_handler_name);
                         m->hw_handler_name = attached_handler_name;
-
-                        /*
-                         * Init fields that are only used when a scsi_dh is attached
-                         */
-                        if (!test_and_set_bit(MPATHF_QUEUE_IO, &m->flags)) {
-                                atomic_set(&m->pg_init_in_progress, 0);
-                                atomic_set(&m->pg_init_count, 0);
-                                m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT;
-                                init_waitqueue_head(&m->pg_init_wait);
-                        }
                 }
         }
 
@@ -868,7 +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) {
@@ -887,11 +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;
@@ -2022,8 +2020,9 @@ static int multipath_busy(struct dm_target *ti)
  *---------------------------------------------------------------*/
 static struct target_type multipath_target = {
         .name = "multipath",
-        .version = {1, 12, 0},
-        .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE,
+        .version = {1, 13, 0},
+        .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE |
+                    DM_TARGET_PASSES_INTEGRITY,
         .module = THIS_MODULE,
         .ctr = multipath_ctr,
         .dtr = multipath_dtr,