Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull second round of SCSI updates from James Bottomley:
 "There's one late arriving patch here (added today), fixing a build
  issue which the scsi_dh patch set in here uncovered.  Other than that,
  everything has been incubated in -next and the checkers for a week.

  The major pieces of this patch are a set patches facilitating better
  integration between scsi and scsi_dh (the device handling layer used
  by multi-path; all the dm parts are acked by Mike Snitzer).

  This also includes driver updates for mp3sas, scsi_debug and an
  assortment of bug fixes"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (50 commits)
  scsi_dh: fix randconfig build error
  scsi: fix scsi_error_handler vs. scsi_host_dev_release race
  fcoe: Convert use of __constant_htons to htons
  mpt2sas: setpci reset kernel oops fix
  pm80xx: Don't override ts->stat on IO_OPEN_CNX_ERROR_HW_RESOURCE_BUSY
  lpfc: Fix possible use-after-free and double free in lpfc_mbx_cmpl_rdp_page_a2()
  bfa: Fix incorrect de-reference of pointer
  bfa: Fix indentation
  scsi_transport_sas: Remove check for SAS expander when querying bay/enclosure IDs.
  scsi_debug: resp_request: remove unused variable
  scsi_debug: fix REPORT LUNS Well Known LU
  scsi_debug: schedule_resp fix input variable check
  scsi_debug: make dump_sector static
  scsi_debug: vfree is null safe so drop the check
  scsi_debug: use SCSI_W_LUN_REPORT_LUNS instead of SAM2_WLUN_REPORT_LUNS;
  scsi_debug: define pr_fmt() for consistent logging
  mpt2sas: Refcount fw_events and fix unsafe list usage
  mpt2sas: Refcount sas_device objects and fix unsafe list usage
  scsi_dh: return SCSI_DH_NOTCONN in scsi_dh_activate()
  scsi_dh: don't allow to detach device handlers at runtime
  ...

2 files changed, 7 insertions, 22 deletions

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index d5415eedba86..3e01e6fb3424 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -393,7 +393,7 @@ config DM_MULTIPATH
 	# of SCSI_DH if the latter isn't defined but if
 	# it is, DM_MULTIPATH must depend on it.  We get a build
 	# error if SCSI_DH=m and DM_MULTIPATH=y
-	depends on SCSI_DH || !SCSI_DH
+	depends on !SCSI_DH || SCSI
 	---help---
 	  Allow volume managers to support multipath hardware.
 
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;