dm: add 'use_blk_mq' module param and expose in per-device ro sysfs attr

[firefly-linux-kernel-4.4.55.git] / drivers / md / dm-sysfs.c

diff --git a/drivers/md/dm-sysfs.c b/drivers/md/dm-sysfs.c
index f5bb3944f75e19a542c8e5678d56cc187213b91d..7e818f5f1dc4e048344b08a7b1ddf8e32304b2ac 100644 (file)
--- a/drivers/md/dm-sysfs.c
+++ b/drivers/md/dm-sysfs.c
@@ -89,15 +89,24 @@ static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
        return strlen(buf);
 }
 
+static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf)
+{
+       sprintf(buf, "%d\n", dm_use_blk_mq(md));
+
+       return strlen(buf);
+}
+
 static DM_ATTR_RO(name);
 static DM_ATTR_RO(uuid);
 static DM_ATTR_RO(suspended);
+static DM_ATTR_RO(use_blk_mq);
 static DM_ATTR_RW(rq_based_seq_io_merge_deadline);
 
 static struct attribute *dm_attrs[] = {
        &dm_attr_name.attr,
        &dm_attr_uuid.attr,
        &dm_attr_suspended.attr,
+       &dm_attr_use_blk_mq.attr,
        &dm_attr_rq_based_seq_io_merge_deadline.attr,
        NULL,
 };