[Fwd: [PATCH] add sysfs class support for raw devices [06/10]]

[Jeff Garzik <jgarzik@xxxxxxxxx>]

Regarding the recent discussion on bonding/vlan/bridge/blah configuration...

--- Begin Message ---

To:	Andrew Morton <akpm@xxxxxxxx>
Subject:	[PATCH] add sysfs class support for raw devices [06/10]
From:	Greg KH <greg@xxxxxxxxx>
Date:	Thu, 15 Jan 2004 12:42:41 -0800
Cc:	linux-kernel@xxxxxxxxxxxxxxx, linux-hotplug-devel@xxxxxxxxxxxxxxxxxxxxx
Delivered-to:	garzik@gtf.org
Delivered-to:	jgarzik@pobox.com
In-reply-to:	<20040115204209.GF22199@kroah.com>
References:	<20040115204048.GA22199@kroah.com> <20040115204111.GB22199@kroah.com> <20040115204125.GC22199@kroah.com> <20040115204138.GD22199@kroah.com> <20040115204153.GE22199@kroah.com> <20040115204209.GF22199@kroah.com>
Sender:	linux-kernel-owner@xxxxxxxxxxxxxxx
User-agent:	Mutt/1.4.1i

This adds class/raw/ support for all raw devices.  It also provides a
symlink to the block device that the raw device is mapped to.  For
example:

$ tree /sys/class/raw/
/sys/class/raw/
|-- raw1
|   |-- dev
|   `-- device -> ../../../block/sda
|-- raw2
|   |-- dev
|   `-- device -> ../../../block/sda/sda2
`-- rawctl
    `-- dev


Note, in order to get that symlink, I had to export get_gendisk() so that
modules can use it.  I hope this is ok with everyone.

This is based on a patch originally written by 
Leann Ogasawara <ogasawara@xxxxxxxx>



diff -Nru a/drivers/block/genhd.c b/drivers/block/genhd.c
--- a/drivers/block/genhd.c     Thu Jan 15 11:05:57 2004
+++ b/drivers/block/genhd.c     Thu Jan 15 11:05:57 2004
@@ -224,6 +224,8 @@
        return  kobj ? to_disk(kobj) : NULL;
 }
 
+EXPORT_SYMBOL(get_gendisk);
+
 #ifdef CONFIG_PROC_FS
 /* iterator */
 static void *part_start(struct seq_file *part, loff_t *pos)
diff -Nru a/drivers/char/raw.c b/drivers/char/raw.c
--- a/drivers/char/raw.c        Thu Jan 15 11:05:47 2004
+++ b/drivers/char/raw.c        Thu Jan 15 11:05:47 2004
@@ -17,6 +17,8 @@
 #include <linux/raw.h>
 #include <linux/capability.h>
 #include <linux/uio.h>
+#include <linux/device.h>
+#include <linux/genhd.h>
 
 #include <asm/uaccess.h>
 
@@ -25,6 +27,7 @@
        int inuse;
 };
 
+static struct class_simple *raw_class;
 static struct raw_device_data raw_devices[MAX_RAW_MINORS];
 static DECLARE_MUTEX(raw_mutex);
 static struct file_operations raw_ctl_fops;         /* forward declaration */
@@ -119,6 +122,29 @@
        return ioctl_by_bdev(bdev, command, arg);
 }
 
+static void bind_device(struct raw_config_request rq)
+{
+       int part;
+       struct gendisk *gen;
+       struct class_device *dev;
+       struct kobject *target = NULL;
+
+       gen = get_gendisk(MKDEV(rq.block_major, rq.block_minor), &part);
+       if (gen) {
+               if (part && gen->part[part])
+                       target = &gen->part[part]->kobj;
+               else
+                       target = &gen->kobj;
+       }
+
+       class_simple_device_remove(MKDEV(RAW_MAJOR, rq.raw_minor));
+       dev = class_simple_device_add(raw_class, MKDEV(RAW_MAJOR, rq.raw_minor),
+                                     NULL, "raw%d", rq.raw_minor);
+       if (dev && target) {
+               sysfs_create_link(&dev->kobj, target, "device");
+       }
+}
+
 /*
  * Deal with ioctls against the raw-device control interface, to bind
  * and unbind other raw devices.
@@ -187,12 +213,15 @@
                        if (rq.block_major == 0 && rq.block_minor == 0) {
                                /* unbind */
                                rawdev->binding = NULL;
+                               class_simple_device_remove(MKDEV(RAW_MAJOR, 
rq.raw_minor));
                        } else {
                                rawdev->binding = bdget(dev);
                                if (rawdev->binding == NULL)
                                        err = -ENOMEM;
-                               else
+                               else {
                                        __module_get(THIS_MODULE);
+                                       bind_device(rq);
+                               }
                        }
                        up(&raw_mutex);
                } else {
@@ -262,6 +291,14 @@
        int i;
 
        register_chrdev(RAW_MAJOR, "raw", &raw_fops);
+
+       raw_class = class_simple_create(THIS_MODULE, "raw");
+       if (IS_ERR(raw_class)) {
+               printk (KERN_ERR "Error creating raw class.\n");
+               return PTR_ERR(raw_class);
+       }
+       class_simple_device_add(raw_class, MKDEV(RAW_MAJOR, 0), NULL, "rawctl");
+
        devfs_mk_cdev(MKDEV(RAW_MAJOR, 0),
                      S_IFCHR | S_IRUGO | S_IWUGO,
                      "raw/rawctl");
@@ -280,6 +317,8 @@
                devfs_remove("raw/raw%d", i);
        devfs_remove("raw/rawctl");
        devfs_remove("raw");
+       class_simple_device_remove(MKDEV(RAW_MAJOR, 0));
+       class_simple_destroy(raw_class);
        unregister_chrdev(RAW_MAJOR, "raw");
 }
 
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

--- End Message ---