dm: allow autoloading of dm mod

Add devname:mapper/control and MAPPER_CTRL_MINOR module alias
to support dm-mod module autoloading.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/Documentation/devices.txt b/Documentation/devices.txt
index f2da781..d0d1df6 100644 (file)
--- a/Documentation/devices.txt
+++ b/Documentation/devices.txt
@@ -445,6 +445,7 @@ Your cooperation is appreciated.
                233 = /dev/kmview       View-OS A process with a view
                234 = /dev/btrfs-control        Btrfs control device
                235 = /dev/autofs       Autofs control device
+               236 = /dev/mapper/control       Device-Mapper control device
                240-254                 Reserved for local use
                255                     Reserved for MISC_DYNAMIC_MINOR
 

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 4d4ced8..3e39193 100644 (file)
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1599,12 +1599,15 @@ static const struct file_operations _ctl_fops = {
 };
 
 static struct miscdevice _dm_misc = {
-       .minor          = MISC_DYNAMIC_MINOR,
+       .minor          = MAPPER_CTRL_MINOR,
        .name           = DM_NAME,
-       .nodename       = "mapper/control",
+       .nodename       = DM_DIR "/" DM_CONTROL_NODE,
        .fops           = &_ctl_fops
 };
 
+MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
+MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
+
 /*
  * Create misc character device and link to DM_DIR/control.
  */

diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index 43b2de1..49eab36 100644 (file)
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -11,6 +11,7 @@
 #include <linux/types.h>
 
 #define DM_DIR "mapper"                /* Slashes not supported */
+#define DM_CONTROL_NODE "control"
 #define DM_MAX_TYPE_NAME 16
 #define DM_NAME_LEN 128
 #define DM_UUID_LEN 129

diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h
index f6c9b7d..bafffc7 100644 (file)
--- a/include/linux/miscdevice.h
+++ b/include/linux/miscdevice.h
@@ -38,6 +38,7 @@
 #define KVM_MINOR              232
 #define BTRFS_MINOR            234
 #define AUTOFS_MINOR           235
+#define MAPPER_CTRL_MINOR      236
 #define MISC_DYNAMIC_MINOR     255
 
 struct device;