diff --git a/Documentation/ABI/testing/sysfs-bus-rbd b/Documentation/ABI/testing/sysfs-bus-rbd
index 17b119c..501adc2 100644
--- a/Documentation/ABI/testing/sysfs-bus-rbd
+++ b/Documentation/ABI/testing/sysfs-bus-rbd
@@ -18,6 +18,28 @@
 
   $ echo <dev-id> > /sys/bus/rbd/remove
 
+What:		/sys/bus/rbd/add_single_major
+Date:		December 2013
+KernelVersion:	3.14
+Contact:	Sage Weil <sage@inktank.com>
+Description:	Available only if rbd module is inserted with single_major
+		parameter set to true.
+		Usage is the same as for /sys/bus/rbd/add.  If present,
+		should be used instead of the latter: any attempts to use
+		/sys/bus/rbd/add if /sys/bus/rbd/add_single_major is
+		available will fail for backwards compatibility reasons.
+
+What:		/sys/bus/rbd/remove_single_major
+Date:		December 2013
+KernelVersion:	3.14
+Contact:	Sage Weil <sage@inktank.com>
+Description:	Available only if rbd module is inserted with single_major
+		parameter set to true.
+		Usage is the same as for /sys/bus/rbd/remove.  If present,
+		should be used instead of the latter: any attempts to use
+		/sys/bus/rbd/remove if /sys/bus/rbd/remove_single_major is
+		available will fail for backwards compatibility reasons.
+
 Entries under /sys/bus/rbd/devices/<dev-id>/
 --------------------------------------------
 
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 3fa18b0..e5ddcb5 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -91,7 +91,7 @@
 
 #define RBD_DRV_NAME "rbd"
 
-#define RBD_MINORS_PER_MAJOR	256		/* max minors per blkdev */
+#define RBD_PART_SHIFT	8
 
 #define RBD_SNAP_DEV_NAME_PREFIX	"snap_"
 #define RBD_MAX_SNAP_NAME_LEN	\
@@ -387,8 +387,17 @@
 static struct kmem_cache	*rbd_obj_request_cache;
 static struct kmem_cache	*rbd_segment_name_cache;
 
+static int rbd_major;
 static DEFINE_IDA(rbd_dev_id_ida);
 
+/*
+ * Default to false for now, as single-major requires >= 0.75 version of
+ * userspace rbd utility.
+ */
+static bool single_major = false;
+module_param(single_major, bool, S_IRUGO);
+MODULE_PARM_DESC(single_major, "Use a single major number for all rbd devices (default: false)");
+
 static int rbd_img_request_submit(struct rbd_img_request *img_request);
 
 static void rbd_dev_device_release(struct device *dev);
@@ -397,21 +406,44 @@
 		       size_t count);
 static ssize_t rbd_remove(struct bus_type *bus, const char *buf,
 			  size_t count);
+static ssize_t rbd_add_single_major(struct bus_type *bus, const char *buf,
+				    size_t count);
+static ssize_t rbd_remove_single_major(struct bus_type *bus, const char *buf,
+				       size_t count);
 static int rbd_dev_image_probe(struct rbd_device *rbd_dev, bool mapping);
 static void rbd_spec_put(struct rbd_spec *spec);
 
+static int rbd_dev_id_to_minor(int dev_id)
+{
+	return dev_id << RBD_PART_SHIFT;
+}
+
+static int minor_to_rbd_dev_id(int minor)
+{
+	return minor >> RBD_PART_SHIFT;
+}
+
 static BUS_ATTR(add, S_IWUSR, NULL, rbd_add);
 static BUS_ATTR(remove, S_IWUSR, NULL, rbd_remove);
+static BUS_ATTR(add_single_major, S_IWUSR, NULL, rbd_add_single_major);
+static BUS_ATTR(remove_single_major, S_IWUSR, NULL, rbd_remove_single_major);
 
 static struct attribute *rbd_bus_attrs[] = {
 	&bus_attr_add.attr,
 	&bus_attr_remove.attr,
+	&bus_attr_add_single_major.attr,
+	&bus_attr_remove_single_major.attr,
 	NULL,
 };
 
 static umode_t rbd_bus_is_visible(struct kobject *kobj,
 				  struct attribute *attr, int index)
 {
+	if (!single_major &&
+	    (attr == &bus_attr_add_single_major.attr ||
+	     attr == &bus_attr_remove_single_major.attr))
+		return 0;
+
 	return attr->mode;
 }
 
@@ -3402,7 +3434,7 @@
 	u64 segment_size;
 
 	/* create gendisk info */
-	disk = alloc_disk(RBD_MINORS_PER_MAJOR);
+	disk = alloc_disk(1 << RBD_PART_SHIFT);
 	if (!disk)
 		return -ENOMEM;
 
@@ -4403,7 +4435,9 @@
 {
 	int new_dev_id;
 
-	new_dev_id = ida_simple_get(&rbd_dev_id_ida, 0, 0, GFP_KERNEL);
+	new_dev_id = ida_simple_get(&rbd_dev_id_ida,
+				    0, minor_to_rbd_dev_id(1 << MINORBITS),
+				    GFP_KERNEL);
 	if (new_dev_id < 0)
 		return new_dev_id;
 
@@ -4863,13 +4897,19 @@
 			< sizeof (RBD_DRV_NAME) + MAX_INT_FORMAT_WIDTH);
 	sprintf(rbd_dev->name, "%s%d", RBD_DRV_NAME, rbd_dev->dev_id);
 
-	/* Get our block major device number. */
+	/* Record our major and minor device numbers. */
 
-	ret = register_blkdev(0, rbd_dev->name);
-	if (ret < 0)
-		goto err_out_id;
-	rbd_dev->major = ret;
-	rbd_dev->minor = 0;
+	if (!single_major) {
+		ret = register_blkdev(0, rbd_dev->name);
+		if (ret < 0)
+			goto err_out_id;
+
+		rbd_dev->major = ret;
+		rbd_dev->minor = 0;
+	} else {
+		rbd_dev->major = rbd_major;
+		rbd_dev->minor = rbd_dev_id_to_minor(rbd_dev->dev_id);
+	}
 
 	/* Set up the blkdev mapping. */
 
@@ -4901,7 +4941,8 @@
 err_out_disk:
 	rbd_free_disk(rbd_dev);
 err_out_blkdev:
-	unregister_blkdev(rbd_dev->major, rbd_dev->name);
+	if (!single_major)
+		unregister_blkdev(rbd_dev->major, rbd_dev->name);
 err_out_id:
 	rbd_dev_id_put(rbd_dev);
 	rbd_dev_mapping_clear(rbd_dev);
@@ -5022,9 +5063,9 @@
 	return ret;
 }
 
-static ssize_t rbd_add(struct bus_type *bus,
-		       const char *buf,
-		       size_t count)
+static ssize_t do_rbd_add(struct bus_type *bus,
+			  const char *buf,
+			  size_t count)
 {
 	struct rbd_device *rbd_dev = NULL;
 	struct ceph_options *ceph_opts = NULL;
@@ -5106,6 +5147,23 @@
 	return (ssize_t)rc;
 }
 
+static ssize_t rbd_add(struct bus_type *bus,
+		       const char *buf,
+		       size_t count)
+{
+	if (single_major)
+		return -EINVAL;
+
+	return do_rbd_add(bus, buf, count);
+}
+
+static ssize_t rbd_add_single_major(struct bus_type *bus,
+				    const char *buf,
+				    size_t count)
+{
+	return do_rbd_add(bus, buf, count);
+}
+
 static void rbd_dev_device_release(struct device *dev)
 {
 	struct rbd_device *rbd_dev = dev_to_rbd_dev(dev);
@@ -5113,8 +5171,8 @@
 	rbd_free_disk(rbd_dev);
 	clear_bit(RBD_DEV_FLAG_EXISTS, &rbd_dev->flags);
 	rbd_dev_mapping_clear(rbd_dev);
-	unregister_blkdev(rbd_dev->major, rbd_dev->name);
-	rbd_dev->major = 0;
+	if (!single_major)
+		unregister_blkdev(rbd_dev->major, rbd_dev->name);
 	rbd_dev_id_put(rbd_dev);
 	rbd_dev_mapping_clear(rbd_dev);
 }
@@ -5145,9 +5203,9 @@
 	}
 }
 
-static ssize_t rbd_remove(struct bus_type *bus,
-			  const char *buf,
-			  size_t count)
+static ssize_t do_rbd_remove(struct bus_type *bus,
+			     const char *buf,
+			     size_t count)
 {
 	struct rbd_device *rbd_dev = NULL;
 	struct list_head *tmp;
@@ -5210,6 +5268,23 @@
 	return count;
 }
 
+static ssize_t rbd_remove(struct bus_type *bus,
+			  const char *buf,
+			  size_t count)
+{
+	if (single_major)
+		return -EINVAL;
+
+	return do_rbd_remove(bus, buf, count);
+}
+
+static ssize_t rbd_remove_single_major(struct bus_type *bus,
+				       const char *buf,
+				       size_t count)
+{
+	return do_rbd_remove(bus, buf, count);
+}
+
 /*
  * create control files in sysfs
  * /sys/bus/rbd/...
@@ -5298,13 +5373,28 @@
 	if (rc)
 		return rc;
 
+	if (single_major) {
+		rbd_major = register_blkdev(0, RBD_DRV_NAME);
+		if (rbd_major < 0) {
+			rc = rbd_major;
+			goto err_out_slab;
+		}
+	}
+
 	rc = rbd_sysfs_init();
 	if (rc)
-		goto err_out_slab;
+		goto err_out_blkdev;
 
-	pr_info("loaded\n");
+	if (single_major)
+		pr_info("loaded (major %d)\n", rbd_major);
+	else
+		pr_info("loaded\n");
+
 	return 0;
 
+err_out_blkdev:
+	if (single_major)
+		unregister_blkdev(rbd_major, RBD_DRV_NAME);
 err_out_slab:
 	rbd_slab_exit();
 	return rc;
@@ -5313,6 +5403,8 @@
 static void __exit rbd_exit(void)
 {
 	rbd_sysfs_cleanup();
+	if (single_major)
+		unregister_blkdev(rbd_major, RBD_DRV_NAME);
 	rbd_slab_exit();
 }