Patch "dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
dm-table-an-all_blk_mq-table-must-be-loaded-for-a-blk-mq-dm-device.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Bart Van Assche <[email protected]>
Date: Wed, 7 Dec 2016 16:56:06 -0800
Subject: dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device

From: Bart Van Assche <[email protected]>

commit 301fc3f5efb98633115bd887655b19f42c6dfaa8 upstream.

When dm_table_set_type() is used by a target to establish a DM table's type (e.g. DM_TYPE_MQ_REQUEST_BASED in the case of DM multipath) the DM core must go on to verify that the devices in the table are compatible with the established type.

---
 drivers/md/dm-table.c |    5 +++++
 1 file changed, 5 insertions(+)

@@ -981,6 +981,11 @@ verify_rq_based:
 		t->all_blk_mq = true;
 	}
 
+	if (t->type == DM_TYPE_MQ_REQUEST_BASED && !t->all_blk_mq) {
+		DMERR("table load rejected: all devices are not blk-mq request-stackable");
+		return -EINVAL;
+	}
+
 	return 0;
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/dm-rq-fix-a-race-condition-in-rq_completed.patch queue-4.9/blk-mq-do-not-invoke-.queue_rq-for-a-stopped-queue.patch queue-4.9/dm-table-fix-all_blk_mq-inconsistency-when-an-empty-table-is-loaded.patch queue-4.9/dm-table-an-all_blk_mq-table-must-be-loaded-for-a-blk-mq-dm-device.patch