[PATCH 1/1] Create megaraid ioctl device node

[PATCH 1/1] Create megaraid ioctl device node

[Patrick Monnerat]

From: Patrick Monnerat <pm@datasphere.ch>

  Create ioctl device node for megaraid_sas driver. Let this node be
managed by udev. Fix a typo.

Reported-by: pm@datasphere.ch
To: Neela Syam Kolli <megaraidlinux@lsi.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Patrick Monnerat <pm@datasphere.ch>
---
diff -uprN
linux-3.8.11-200.1pm.fc18.x86_64.orig/drivers/scsi/megaraid/megaraid_sas
_base.c
linux-3.8.11-200.1pm.fc18.x86_64.new/drivers/scsi/megaraid/megaraid_sas_
base.c
---
linux-3.8.11-200.1pm.fc18.x86_64.orig/drivers/scsi/megaraid/megaraid_sas
_base.c	2013-02-19 00:58:34.000000000 +0100
+++
linux-3.8.11-200.1pm.fc18.x86_64.new/drivers/scsi/megaraid/megaraid_sas_
base.c	2013-05-06 13:39:27.903234426 +0200
@@ -49,6 +49,7 @@
 #include <linux/blkdev.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
+#include <linux/device.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -127,6 +128,8 @@ static struct pci_device_id megasas_pci_
 
 MODULE_DEVICE_TABLE(pci, megasas_pci_table);
 
+static struct class *megasas_mgmt_class;
+static struct device *megasas_mgmt_device;
 static int megasas_mgmt_majorno;
 static struct megasas_mgmt_info megasas_mgmt_info;
 static struct fasync_struct *megasas_async_queue;
@@ -5450,7 +5453,7 @@ static int __init megasas_init(void)
 	rval = pci_register_driver(&megasas_pci_driver);
 
 	if (rval) {
-		printk(KERN_DEBUG "megasas: PCI hotplug regisration
failed \n");
+		printk(KERN_DEBUG "megasas: PCI hotplug registration
failed\n");
 		goto err_pcidrv;
 	}
 
@@ -5477,8 +5480,28 @@ static int __init megasas_init(void)
 	if (rval)
 		goto err_dcf_support_device_change;
 
-	return rval;
+	/*
+	 * Register as an udev-controlled device.
+	 */
+	megasas_mgmt_class = class_create(THIS_MODULE, "megaraid");
+	rval = PTR_ERR(megasas_mgmt_class);
+	if (IS_ERR(megasas_mgmt_class))
+		goto err_class;
+
+	megasas_mgmt_device = device_create(megasas_mgmt_class, NULL,
+					    MKDEV(megasas_mgmt_majorno,
0),
+					    NULL, "megaraid_sas_ioctl");
+	rval = PTR_ERR(megasas_mgmt_device);
+	if (IS_ERR(megasas_mgmt_device))
+		goto err_create_device;
 
+	return 0;
+
+err_create_device:
+	class_destroy(megasas_mgmt_class);
+err_class:
+	driver_remove_file(&megasas_pci_driver.driver,
+			   &driver_attr_support_device_change);
 err_dcf_support_device_change:
 	driver_remove_file(&megasas_pci_driver.driver,
 			   &driver_attr_dbg_lvl);
@@ -5504,6 +5527,9 @@ err_pcidrv:
  */
 static void __exit megasas_exit(void)
 {
+	device_destroy(megasas_mgmt_class, MKDEV(megasas_mgmt_majorno,
0));
+	class_destroy(megasas_mgmt_class);
+
 	driver_remove_file(&megasas_pci_driver.driver,
 			   &driver_attr_dbg_lvl);
 	driver_remove_file(&megasas_pci_driver.driver,

Re: [PATCH 1/1] Create megaraid ioctl device node

[Bjørn Mork]

"Patrick Monnerat" <Patrick.Monnerat@datasphere.ch> writes:

> From: Patrick Monnerat <pm@datasphere.ch>
>
>   Create ioctl device node for megaraid_sas driver. Let this node be
> managed by udev. Fix a typo.

Or maybe just simplify it all and use a misc device instead?  See how
this is done in e.g. drivers/scsi/mpt3sas/mpt3sas_ctl.c or
drivers/message/fusion/mptctl.c



Bjørn

Re: [PATCH 1/1] Create megaraid ioctl device node

[Patrick Monnerat]

On 05/06/2013 04:23 PM, Bjørn Mork wrote:
> "Patrick Monnerat" <Patrick.Monnerat@datasphere.ch> writes:
>>    Create ioctl device node for megaraid_sas driver. Let this node be
>> managed by udev. Fix a typo.
>
> Or maybe just simplify it all and use a misc device instead?  See how
> this is done in e.g. drivers/scsi/mpt3sas/mpt3sas_ctl.c or
> drivers/message/fusion/mptctl.c

Yes, could be done that way, But I want to retain compatibility with 
existing shell scripts doing things like:

DEVICE=/dev/megaraid_sas_ioctl_node
DEVICENAME=megaraid_sas_ioctl
DEVICEPERM=400
MAJOR=`grep "$DEVICENAME" /proc/devices | awk '{print $1}'`

if [ -n "$MAJOR" -a ! -e "$DEVICE" ]; then
     mknod "$DEVICE" c "$MAJOR" 0
     chmod "$DEVICEPERM" "$DEVICE"
fi

Snippets like this one appear both in open-source projects and Dell scripts.

Patrick

Re: [PATCH 1/1] Create megaraid ioctl device node

[Patrick Monnerat]

On 05/06/2013 04:23 PM, Bjørn Mork wrote:
> "Patrick Monnerat" <Patrick.Monnerat@datasphere.ch> writes:
>>    Create ioctl device node for megaraid_sas driver. Let this node be
>> managed by udev. Fix a typo.
>
> Or maybe just simplify it all and use a misc device instead?  See how
> this is done in e.g. drivers/scsi/mpt3sas/mpt3sas_ctl.c or
> drivers/message/fusion/mptctl.c

Yes, could be done that way, but I want to retain compatibility with 
existing shell scripts doing things like:


DEVICE=/dev/megaraid_sas_ioctl_node
DEVICENAME=megaraid_sas_ioctl
DEVICEPERM=400
MAJOR=`grep "$DEVICENAME" /proc/devices | awk '{print $1}'`

if [ -n "$MAJOR" -a ! -e "$DEVICE" ]; then
     mknod "$DEVICE" c "$MAJOR" 0
     chmod "$DEVICEPERM" "$DEVICE"
fi